1 /* Convert function calls to rtl insns, for GNU C compiler.
2 Copyright (C) 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
24 #include "coretypes.h"
40 #include "langhooks.h"
45 #include "tree-flow.h"
47 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
48 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
50 /* Data structure and subroutines used within expand_call. */
54 /* Tree node for this argument. */
56 /* Mode for value; TYPE_MODE unless promoted. */
57 enum machine_mode mode;
58 /* Current RTL value for argument, or 0 if it isn't precomputed. */
60 /* Initially-compute RTL value for argument; only for const functions. */
62 /* Register to pass this argument in, 0 if passed on stack, or an
63 PARALLEL if the arg is to be copied into multiple non-contiguous
66 /* Register to pass this argument in when generating tail call sequence.
67 This is not the same register as for normal calls on machines with
70 /* If REG is a PARALLEL, this is a copy of VALUE pulled into the correct
71 form for emit_group_move. */
73 /* If REG was promoted from the actual mode of the argument expression,
74 indicates whether the promotion is sign- or zero-extended. */
76 /* Number of bytes to put in registers. 0 means put the whole arg
77 in registers. Also 0 if not passed in registers. */
79 /* Nonzero if argument must be passed on stack.
80 Note that some arguments may be passed on the stack
81 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
82 pass_on_stack identifies arguments that *cannot* go in registers. */
84 /* Some fields packaged up for locate_and_pad_parm. */
85 struct locate_and_pad_arg_data locate;
86 /* Location on the stack at which parameter should be stored. The store
87 has already been done if STACK == VALUE. */
89 /* Location on the stack of the start of this argument slot. This can
90 differ from STACK if this arg pads downward. This location is known
91 to be aligned to FUNCTION_ARG_BOUNDARY. */
93 /* Place that this stack area has been saved, if needed. */
95 /* If an argument's alignment does not permit direct copying into registers,
96 copy in smaller-sized pieces into pseudos. These are stored in a
97 block pointed to by this field. The next field says how many
98 word-sized pseudos we made. */
103 /* A vector of one char per byte of stack space. A byte if nonzero if
104 the corresponding stack location has been used.
105 This vector is used to prevent a function call within an argument from
106 clobbering any stack already set up. */
107 static char *stack_usage_map;
109 /* Size of STACK_USAGE_MAP. */
110 static int highest_outgoing_arg_in_use;
112 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
113 stack location's tail call argument has been already stored into the stack.
114 This bitmap is used to prevent sibling call optimization if function tries
115 to use parent's incoming argument slots when they have been already
116 overwritten with tail call arguments. */
117 static sbitmap stored_args_map;
119 /* stack_arg_under_construction is nonzero when an argument may be
120 initialized with a constructor call (including a C function that
121 returns a BLKmode struct) and expand_call must take special action
122 to make sure the object being constructed does not overlap the
123 argument list for the constructor call. */
124 static int stack_arg_under_construction;
126 static void emit_call_1 (rtx, tree, tree, tree, HOST_WIDE_INT, HOST_WIDE_INT,
127 HOST_WIDE_INT, rtx, rtx, int, rtx, int,
129 static void precompute_register_parameters (int, struct arg_data *, int *);
130 static int store_one_arg (struct arg_data *, rtx, int, int, int);
131 static void store_unaligned_arguments_into_pseudos (struct arg_data *, int);
132 static int finalize_must_preallocate (int, int, struct arg_data *,
134 static void precompute_arguments (int, struct arg_data *);
135 static int compute_argument_block_size (int, struct args_size *, tree, tree, int);
136 static void initialize_argument_information (int, struct arg_data *,
137 struct args_size *, int,
139 tree, CUMULATIVE_ARGS *, int,
140 rtx *, int *, int *, int *,
142 static void compute_argument_addresses (struct arg_data *, rtx, int);
143 static rtx rtx_for_function_call (tree, tree);
144 static void load_register_parameters (struct arg_data *, int, rtx *, int,
146 static rtx emit_library_call_value_1 (int, rtx, rtx, enum libcall_type,
147 enum machine_mode, int, va_list);
148 static int special_function_p (const_tree, int);
149 static int check_sibcall_argument_overlap_1 (rtx);
150 static int check_sibcall_argument_overlap (rtx, struct arg_data *, int);
152 static int combine_pending_stack_adjustment_and_call (int, struct args_size *,
154 static tree split_complex_types (tree);
156 #ifdef REG_PARM_STACK_SPACE
157 static rtx save_fixed_argument_area (int, rtx, int *, int *);
158 static void restore_fixed_argument_area (rtx, rtx, int, int);
161 /* Force FUNEXP into a form suitable for the address of a CALL,
162 and return that as an rtx. Also load the static chain register
163 if FNDECL is a nested function.
165 CALL_FUSAGE points to a variable holding the prospective
166 CALL_INSN_FUNCTION_USAGE information. */
169 prepare_call_address (rtx funexp, rtx static_chain_value,
170 rtx *call_fusage, int reg_parm_seen, int sibcallp)
172 /* Make a valid memory address and copy constants through pseudo-regs,
173 but not for a constant address if -fno-function-cse. */
174 if (GET_CODE (funexp) != SYMBOL_REF)
175 /* If we are using registers for parameters, force the
176 function address into a register now. */
177 funexp = ((SMALL_REGISTER_CLASSES && reg_parm_seen)
178 ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
179 : memory_address (FUNCTION_MODE, funexp));
182 #ifndef NO_FUNCTION_CSE
183 if (optimize && ! flag_no_function_cse)
184 funexp = force_reg (Pmode, funexp);
188 if (static_chain_value != 0)
190 static_chain_value = convert_memory_address (Pmode, static_chain_value);
191 emit_move_insn (static_chain_rtx, static_chain_value);
193 if (REG_P (static_chain_rtx))
194 use_reg (call_fusage, static_chain_rtx);
200 /* Generate instructions to call function FUNEXP,
201 and optionally pop the results.
202 The CALL_INSN is the first insn generated.
204 FNDECL is the declaration node of the function. This is given to the
205 macro RETURN_POPS_ARGS to determine whether this function pops its own args.
207 FUNTYPE is the data type of the function. This is given to the macro
208 RETURN_POPS_ARGS to determine whether this function pops its own args.
209 We used to allow an identifier for library functions, but that doesn't
210 work when the return type is an aggregate type and the calling convention
211 says that the pointer to this aggregate is to be popped by the callee.
213 STACK_SIZE is the number of bytes of arguments on the stack,
214 ROUNDED_STACK_SIZE is that number rounded up to
215 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
216 both to put into the call insn and to generate explicit popping
219 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
220 It is zero if this call doesn't want a structure value.
222 NEXT_ARG_REG is the rtx that results from executing
223 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
224 just after all the args have had their registers assigned.
225 This could be whatever you like, but normally it is the first
226 arg-register beyond those used for args in this call,
227 or 0 if all the arg-registers are used in this call.
228 It is passed on to `gen_call' so you can put this info in the call insn.
230 VALREG is a hard register in which a value is returned,
231 or 0 if the call does not return a value.
233 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
234 the args to this call were processed.
235 We restore `inhibit_defer_pop' to that value.
237 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
238 denote registers used by the called function. */
241 emit_call_1 (rtx funexp, tree fntree, tree fndecl ATTRIBUTE_UNUSED,
242 tree funtype ATTRIBUTE_UNUSED,
243 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED,
244 HOST_WIDE_INT rounded_stack_size,
245 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED,
246 rtx next_arg_reg ATTRIBUTE_UNUSED, rtx valreg,
247 int old_inhibit_defer_pop, rtx call_fusage, int ecf_flags,
248 CUMULATIVE_ARGS *args_so_far ATTRIBUTE_UNUSED)
250 rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
252 int already_popped = 0;
253 HOST_WIDE_INT n_popped = RETURN_POPS_ARGS (fndecl, funtype, stack_size);
254 #if defined (HAVE_call) && defined (HAVE_call_value)
255 rtx struct_value_size_rtx;
256 struct_value_size_rtx = GEN_INT (struct_value_size);
259 #ifdef CALL_POPS_ARGS
260 n_popped += CALL_POPS_ARGS (* args_so_far);
263 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
264 and we don't want to load it into a register as an optimization,
265 because prepare_call_address already did it if it should be done. */
266 if (GET_CODE (funexp) != SYMBOL_REF)
267 funexp = memory_address (FUNCTION_MODE, funexp);
269 #if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
270 if ((ecf_flags & ECF_SIBCALL)
271 && HAVE_sibcall_pop && HAVE_sibcall_value_pop
272 && (n_popped > 0 || stack_size == 0))
274 rtx n_pop = GEN_INT (n_popped);
277 /* If this subroutine pops its own args, record that in the call insn
278 if possible, for the sake of frame pointer elimination. */
281 pat = GEN_SIBCALL_VALUE_POP (valreg,
282 gen_rtx_MEM (FUNCTION_MODE, funexp),
283 rounded_stack_size_rtx, next_arg_reg,
286 pat = GEN_SIBCALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
287 rounded_stack_size_rtx, next_arg_reg, n_pop);
289 emit_call_insn (pat);
295 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
296 /* If the target has "call" or "call_value" insns, then prefer them
297 if no arguments are actually popped. If the target does not have
298 "call" or "call_value" insns, then we must use the popping versions
299 even if the call has no arguments to pop. */
300 #if defined (HAVE_call) && defined (HAVE_call_value)
301 if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop
304 if (HAVE_call_pop && HAVE_call_value_pop)
307 rtx n_pop = GEN_INT (n_popped);
310 /* If this subroutine pops its own args, record that in the call insn
311 if possible, for the sake of frame pointer elimination. */
314 pat = GEN_CALL_VALUE_POP (valreg,
315 gen_rtx_MEM (FUNCTION_MODE, funexp),
316 rounded_stack_size_rtx, next_arg_reg, n_pop);
318 pat = GEN_CALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
319 rounded_stack_size_rtx, next_arg_reg, n_pop);
321 emit_call_insn (pat);
327 #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
328 if ((ecf_flags & ECF_SIBCALL)
329 && HAVE_sibcall && HAVE_sibcall_value)
332 emit_call_insn (GEN_SIBCALL_VALUE (valreg,
333 gen_rtx_MEM (FUNCTION_MODE, funexp),
334 rounded_stack_size_rtx,
335 next_arg_reg, NULL_RTX));
337 emit_call_insn (GEN_SIBCALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
338 rounded_stack_size_rtx, next_arg_reg,
339 struct_value_size_rtx));
344 #if defined (HAVE_call) && defined (HAVE_call_value)
345 if (HAVE_call && HAVE_call_value)
348 emit_call_insn (GEN_CALL_VALUE (valreg,
349 gen_rtx_MEM (FUNCTION_MODE, funexp),
350 rounded_stack_size_rtx, next_arg_reg,
353 emit_call_insn (GEN_CALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
354 rounded_stack_size_rtx, next_arg_reg,
355 struct_value_size_rtx));
361 /* Find the call we just emitted. */
362 call_insn = last_call_insn ();
364 /* Put the register usage information there. */
365 add_function_usage_to (call_insn, call_fusage);
367 /* If this is a const call, then set the insn's unchanging bit. */
368 if (ecf_flags & ECF_CONST)
369 RTL_CONST_CALL_P (call_insn) = 1;
371 /* If this is a pure call, then set the insn's unchanging bit. */
372 if (ecf_flags & ECF_PURE)
373 RTL_PURE_CALL_P (call_insn) = 1;
375 /* If this is a const call, then set the insn's unchanging bit. */
376 if (ecf_flags & ECF_LOOPING_CONST_OR_PURE)
377 RTL_LOOPING_CONST_OR_PURE_CALL_P (call_insn) = 1;
379 /* If this call can't throw, attach a REG_EH_REGION reg note to that
381 if (ecf_flags & ECF_NOTHROW)
382 add_reg_note (call_insn, REG_EH_REGION, const0_rtx);
385 int rn = lookup_expr_eh_region (fntree);
387 /* If rn < 0, then either (1) tree-ssa not used or (2) doesn't
388 throw, which we already took care of. */
390 add_reg_note (call_insn, REG_EH_REGION, GEN_INT (rn));
393 if (ecf_flags & ECF_NORETURN)
394 add_reg_note (call_insn, REG_NORETURN, const0_rtx);
396 if (ecf_flags & ECF_RETURNS_TWICE)
398 add_reg_note (call_insn, REG_SETJMP, const0_rtx);
399 cfun->calls_setjmp = 1;
402 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
404 /* Restore this now, so that we do defer pops for this call's args
405 if the context of the call as a whole permits. */
406 inhibit_defer_pop = old_inhibit_defer_pop;
411 CALL_INSN_FUNCTION_USAGE (call_insn)
412 = gen_rtx_EXPR_LIST (VOIDmode,
413 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
414 CALL_INSN_FUNCTION_USAGE (call_insn));
415 rounded_stack_size -= n_popped;
416 rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
417 stack_pointer_delta -= n_popped;
419 /* If popup is needed, stack realign must use DRAP */
420 if (SUPPORTS_STACK_ALIGNMENT)
421 crtl->need_drap = true;
424 if (!ACCUMULATE_OUTGOING_ARGS)
426 /* If returning from the subroutine does not automatically pop the args,
427 we need an instruction to pop them sooner or later.
428 Perhaps do it now; perhaps just record how much space to pop later.
430 If returning from the subroutine does pop the args, indicate that the
431 stack pointer will be changed. */
433 if (rounded_stack_size != 0)
435 if (ecf_flags & ECF_NORETURN)
436 /* Just pretend we did the pop. */
437 stack_pointer_delta -= rounded_stack_size;
438 else if (flag_defer_pop && inhibit_defer_pop == 0
439 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
440 pending_stack_adjust += rounded_stack_size;
442 adjust_stack (rounded_stack_size_rtx);
445 /* When we accumulate outgoing args, we must avoid any stack manipulations.
446 Restore the stack pointer to its original value now. Usually
447 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
448 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
449 popping variants of functions exist as well.
451 ??? We may optimize similar to defer_pop above, but it is
452 probably not worthwhile.
454 ??? It will be worthwhile to enable combine_stack_adjustments even for
457 anti_adjust_stack (GEN_INT (n_popped));
460 /* Determine if the function identified by NAME and FNDECL is one with
461 special properties we wish to know about.
463 For example, if the function might return more than one time (setjmp), then
464 set RETURNS_TWICE to a nonzero value.
466 Similarly set NORETURN if the function is in the longjmp family.
468 Set MAY_BE_ALLOCA for any memory allocation function that might allocate
469 space from the stack such as alloca. */
472 special_function_p (const_tree fndecl, int flags)
474 if (fndecl && DECL_NAME (fndecl)
475 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
476 /* Exclude functions not at the file scope, or not `extern',
477 since they are not the magic functions we would otherwise
479 FIXME: this should be handled with attributes, not with this
480 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
481 because you can declare fork() inside a function if you
483 && (DECL_CONTEXT (fndecl) == NULL_TREE
484 || TREE_CODE (DECL_CONTEXT (fndecl)) == TRANSLATION_UNIT_DECL)
485 && TREE_PUBLIC (fndecl))
487 const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
488 const char *tname = name;
490 /* We assume that alloca will always be called by name. It
491 makes no sense to pass it as a pointer-to-function to
492 anything that does not understand its behavior. */
493 if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
495 && ! strcmp (name, "alloca"))
496 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
498 && ! strcmp (name, "__builtin_alloca"))))
499 flags |= ECF_MAY_BE_ALLOCA;
501 /* Disregard prefix _, __ or __x. */
504 if (name[1] == '_' && name[2] == 'x')
506 else if (name[1] == '_')
515 && (! strcmp (tname, "setjmp")
516 || ! strcmp (tname, "setjmp_syscall")))
518 && ! strcmp (tname, "sigsetjmp"))
520 && ! strcmp (tname, "savectx")))
521 flags |= ECF_RETURNS_TWICE;
524 && ! strcmp (tname, "siglongjmp"))
525 flags |= ECF_NORETURN;
527 else if ((tname[0] == 'q' && tname[1] == 's'
528 && ! strcmp (tname, "qsetjmp"))
529 || (tname[0] == 'v' && tname[1] == 'f'
530 && ! strcmp (tname, "vfork"))
531 || (tname[0] == 'g' && tname[1] == 'e'
532 && !strcmp (tname, "getcontext")))
533 flags |= ECF_RETURNS_TWICE;
535 else if (tname[0] == 'l' && tname[1] == 'o'
536 && ! strcmp (tname, "longjmp"))
537 flags |= ECF_NORETURN;
543 /* Return nonzero when FNDECL represents a call to setjmp. */
546 setjmp_call_p (const_tree fndecl)
548 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
552 /* Return true if STMT is an alloca call. */
555 gimple_alloca_call_p (const_gimple stmt)
559 if (!is_gimple_call (stmt))
562 fndecl = gimple_call_fndecl (stmt);
563 if (fndecl && (special_function_p (fndecl, 0) & ECF_MAY_BE_ALLOCA))
569 /* Return true when exp contains alloca call. */
572 alloca_call_p (const_tree exp)
574 if (TREE_CODE (exp) == CALL_EXPR
575 && TREE_CODE (CALL_EXPR_FN (exp)) == ADDR_EXPR
576 && (TREE_CODE (TREE_OPERAND (CALL_EXPR_FN (exp), 0)) == FUNCTION_DECL)
577 && (special_function_p (TREE_OPERAND (CALL_EXPR_FN (exp), 0), 0)
578 & ECF_MAY_BE_ALLOCA))
583 /* Detect flags (function attributes) from the function decl or type node. */
586 flags_from_decl_or_type (const_tree exp)
589 const_tree type = exp;
593 type = TREE_TYPE (exp);
595 /* The function exp may have the `malloc' attribute. */
596 if (DECL_IS_MALLOC (exp))
599 /* The function exp may have the `returns_twice' attribute. */
600 if (DECL_IS_RETURNS_TWICE (exp))
601 flags |= ECF_RETURNS_TWICE;
603 /* Process the pure and const attributes. */
604 if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
606 if (DECL_PURE_P (exp))
608 if (DECL_LOOPING_CONST_OR_PURE_P (exp))
609 flags |= ECF_LOOPING_CONST_OR_PURE;
611 if (DECL_IS_NOVOPS (exp))
614 if (TREE_NOTHROW (exp))
615 flags |= ECF_NOTHROW;
617 flags = special_function_p (exp, flags);
619 else if (TYPE_P (exp) && TYPE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
622 if (TREE_THIS_VOLATILE (exp))
623 flags |= ECF_NORETURN;
628 /* Detect flags from a CALL_EXPR. */
631 call_expr_flags (const_tree t)
634 tree decl = get_callee_fndecl (t);
637 flags = flags_from_decl_or_type (decl);
640 t = TREE_TYPE (CALL_EXPR_FN (t));
641 if (t && TREE_CODE (t) == POINTER_TYPE)
642 flags = flags_from_decl_or_type (TREE_TYPE (t));
650 /* Precompute all register parameters as described by ARGS, storing values
651 into fields within the ARGS array.
653 NUM_ACTUALS indicates the total number elements in the ARGS array.
655 Set REG_PARM_SEEN if we encounter a register parameter. */
658 precompute_register_parameters (int num_actuals, struct arg_data *args,
665 for (i = 0; i < num_actuals; i++)
666 if (args[i].reg != 0 && ! args[i].pass_on_stack)
670 if (args[i].value == 0)
673 args[i].value = expand_normal (args[i].tree_value);
674 preserve_temp_slots (args[i].value);
678 /* If the value is a non-legitimate constant, force it into a
679 pseudo now. TLS symbols sometimes need a call to resolve. */
680 if (CONSTANT_P (args[i].value)
681 && !LEGITIMATE_CONSTANT_P (args[i].value))
682 args[i].value = force_reg (args[i].mode, args[i].value);
684 /* If we are to promote the function arg to a wider mode,
687 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
689 = convert_modes (args[i].mode,
690 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
691 args[i].value, args[i].unsignedp);
693 /* If we're going to have to load the value by parts, pull the
694 parts into pseudos. The part extraction process can involve
695 non-trivial computation. */
696 if (GET_CODE (args[i].reg) == PARALLEL)
698 tree type = TREE_TYPE (args[i].tree_value);
699 args[i].parallel_value
700 = emit_group_load_into_temps (args[i].reg, args[i].value,
701 type, int_size_in_bytes (type));
704 /* If the value is expensive, and we are inside an appropriately
705 short loop, put the value into a pseudo and then put the pseudo
708 For small register classes, also do this if this call uses
709 register parameters. This is to avoid reload conflicts while
710 loading the parameters registers. */
712 else if ((! (REG_P (args[i].value)
713 || (GET_CODE (args[i].value) == SUBREG
714 && REG_P (SUBREG_REG (args[i].value)))))
715 && args[i].mode != BLKmode
716 && rtx_cost (args[i].value, SET, optimize_insn_for_speed_p ())
718 && ((SMALL_REGISTER_CLASSES && *reg_parm_seen)
720 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
724 #ifdef REG_PARM_STACK_SPACE
726 /* The argument list is the property of the called routine and it
727 may clobber it. If the fixed area has been used for previous
728 parameters, we must save and restore it. */
731 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
736 /* Compute the boundary of the area that needs to be saved, if any. */
737 high = reg_parm_stack_space;
738 #ifdef ARGS_GROW_DOWNWARD
741 if (high > highest_outgoing_arg_in_use)
742 high = highest_outgoing_arg_in_use;
744 for (low = 0; low < high; low++)
745 if (stack_usage_map[low] != 0)
748 enum machine_mode save_mode;
753 while (stack_usage_map[--high] == 0)
757 *high_to_save = high;
759 num_to_save = high - low + 1;
760 save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
762 /* If we don't have the required alignment, must do this
764 if ((low & (MIN (GET_MODE_SIZE (save_mode),
765 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
768 #ifdef ARGS_GROW_DOWNWARD
773 stack_area = gen_rtx_MEM (save_mode,
774 memory_address (save_mode,
775 plus_constant (argblock,
778 set_mem_align (stack_area, PARM_BOUNDARY);
779 if (save_mode == BLKmode)
781 save_area = assign_stack_temp (BLKmode, num_to_save, 0);
782 emit_block_move (validize_mem (save_area), stack_area,
783 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
787 save_area = gen_reg_rtx (save_mode);
788 emit_move_insn (save_area, stack_area);
798 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
800 enum machine_mode save_mode = GET_MODE (save_area);
804 #ifdef ARGS_GROW_DOWNWARD
805 delta = -high_to_save;
809 stack_area = gen_rtx_MEM (save_mode,
810 memory_address (save_mode,
811 plus_constant (argblock, delta)));
812 set_mem_align (stack_area, PARM_BOUNDARY);
814 if (save_mode != BLKmode)
815 emit_move_insn (stack_area, save_area);
817 emit_block_move (stack_area, validize_mem (save_area),
818 GEN_INT (high_to_save - low_to_save + 1),
821 #endif /* REG_PARM_STACK_SPACE */
823 /* If any elements in ARGS refer to parameters that are to be passed in
824 registers, but not in memory, and whose alignment does not permit a
825 direct copy into registers. Copy the values into a group of pseudos
826 which we will later copy into the appropriate hard registers.
828 Pseudos for each unaligned argument will be stored into the array
829 args[argnum].aligned_regs. The caller is responsible for deallocating
830 the aligned_regs array if it is nonzero. */
833 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
837 for (i = 0; i < num_actuals; i++)
838 if (args[i].reg != 0 && ! args[i].pass_on_stack
839 && args[i].mode == BLKmode
840 && MEM_P (args[i].value)
841 && (MEM_ALIGN (args[i].value)
842 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
844 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
845 int endian_correction = 0;
849 gcc_assert (args[i].partial % UNITS_PER_WORD == 0);
850 args[i].n_aligned_regs = args[i].partial / UNITS_PER_WORD;
854 args[i].n_aligned_regs
855 = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
858 args[i].aligned_regs = XNEWVEC (rtx, args[i].n_aligned_regs);
860 /* Structures smaller than a word are normally aligned to the
861 least significant byte. On a BYTES_BIG_ENDIAN machine,
862 this means we must skip the empty high order bytes when
863 calculating the bit offset. */
864 if (bytes < UNITS_PER_WORD
865 #ifdef BLOCK_REG_PADDING
866 && (BLOCK_REG_PADDING (args[i].mode,
867 TREE_TYPE (args[i].tree_value), 1)
873 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
875 for (j = 0; j < args[i].n_aligned_regs; j++)
877 rtx reg = gen_reg_rtx (word_mode);
878 rtx word = operand_subword_force (args[i].value, j, BLKmode);
879 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
881 args[i].aligned_regs[j] = reg;
882 word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
883 word_mode, word_mode);
885 /* There is no need to restrict this code to loading items
886 in TYPE_ALIGN sized hunks. The bitfield instructions can
887 load up entire word sized registers efficiently.
889 ??? This may not be needed anymore.
890 We use to emit a clobber here but that doesn't let later
891 passes optimize the instructions we emit. By storing 0 into
892 the register later passes know the first AND to zero out the
893 bitfield being set in the register is unnecessary. The store
894 of 0 will be deleted as will at least the first AND. */
896 emit_move_insn (reg, const0_rtx);
898 bytes -= bitsize / BITS_PER_UNIT;
899 store_bit_field (reg, bitsize, endian_correction, word_mode,
905 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
908 NUM_ACTUALS is the total number of parameters.
910 N_NAMED_ARGS is the total number of named arguments.
912 STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
915 FNDECL is the tree code for the target of this call (if known)
917 ARGS_SO_FAR holds state needed by the target to know where to place
920 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
921 for arguments which are passed in registers.
923 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
924 and may be modified by this routine.
926 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
927 flags which may may be modified by this routine.
929 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
930 that requires allocation of stack space.
932 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
933 the thunked-to function. */
936 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
937 struct arg_data *args,
938 struct args_size *args_size,
939 int n_named_args ATTRIBUTE_UNUSED,
940 tree exp, tree struct_value_addr_value,
942 CUMULATIVE_ARGS *args_so_far,
943 int reg_parm_stack_space,
944 rtx *old_stack_level, int *old_pending_adj,
945 int *must_preallocate, int *ecf_flags,
946 bool *may_tailcall, bool call_from_thunk_p)
948 /* 1 if scanning parms front to back, -1 if scanning back to front. */
951 /* Count arg position in order args appear. */
956 args_size->constant = 0;
959 /* In this loop, we consider args in the order they are written.
960 We fill up ARGS from the front or from the back if necessary
961 so that in any case the first arg to be pushed ends up at the front. */
963 if (PUSH_ARGS_REVERSED)
965 i = num_actuals - 1, inc = -1;
966 /* In this case, must reverse order of args
967 so that we compute and push the last arg first. */
974 /* First fill in the actual arguments in the ARGS array, splitting
975 complex arguments if necessary. */
978 call_expr_arg_iterator iter;
981 if (struct_value_addr_value)
983 args[j].tree_value = struct_value_addr_value;
986 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
988 tree argtype = TREE_TYPE (arg);
989 if (targetm.calls.split_complex_arg
991 && TREE_CODE (argtype) == COMPLEX_TYPE
992 && targetm.calls.split_complex_arg (argtype))
994 tree subtype = TREE_TYPE (argtype);
995 arg = save_expr (arg);
996 args[j].tree_value = build1 (REALPART_EXPR, subtype, arg);
998 args[j].tree_value = build1 (IMAGPART_EXPR, subtype, arg);
1001 args[j].tree_value = arg;
1006 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1007 for (argpos = 0; argpos < num_actuals; i += inc, argpos++)
1009 tree type = TREE_TYPE (args[i].tree_value);
1011 enum machine_mode mode;
1013 /* Replace erroneous argument with constant zero. */
1014 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1015 args[i].tree_value = integer_zero_node, type = integer_type_node;
1017 /* If TYPE is a transparent union, pass things the way we would
1018 pass the first field of the union. We have already verified that
1019 the modes are the same. */
1020 if (TREE_CODE (type) == UNION_TYPE && TYPE_TRANSPARENT_UNION (type))
1021 type = TREE_TYPE (TYPE_FIELDS (type));
1023 /* Decide where to pass this arg.
1025 args[i].reg is nonzero if all or part is passed in registers.
1027 args[i].partial is nonzero if part but not all is passed in registers,
1028 and the exact value says how many bytes are passed in registers.
1030 args[i].pass_on_stack is nonzero if the argument must at least be
1031 computed on the stack. It may then be loaded back into registers
1032 if args[i].reg is nonzero.
1034 These decisions are driven by the FUNCTION_... macros and must agree
1035 with those made by function.c. */
1037 /* See if this argument should be passed by invisible reference. */
1038 if (pass_by_reference (args_so_far, TYPE_MODE (type),
1039 type, argpos < n_named_args))
1045 = reference_callee_copied (args_so_far, TYPE_MODE (type),
1046 type, argpos < n_named_args);
1048 /* If we're compiling a thunk, pass through invisible references
1049 instead of making a copy. */
1050 if (call_from_thunk_p
1052 && !TREE_ADDRESSABLE (type)
1053 && (base = get_base_address (args[i].tree_value))
1054 && (!DECL_P (base) || MEM_P (DECL_RTL (base)))))
1056 /* We can't use sibcalls if a callee-copied argument is
1057 stored in the current function's frame. */
1058 if (!call_from_thunk_p && DECL_P (base) && !TREE_STATIC (base))
1059 *may_tailcall = false;
1061 args[i].tree_value = build_fold_addr_expr (args[i].tree_value);
1062 type = TREE_TYPE (args[i].tree_value);
1064 if (*ecf_flags & ECF_CONST)
1065 *ecf_flags &= ~(ECF_CONST | ECF_LOOPING_CONST_OR_PURE);
1069 /* We make a copy of the object and pass the address to the
1070 function being called. */
1073 if (!COMPLETE_TYPE_P (type)
1074 || TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST
1075 || (flag_stack_check == GENERIC_STACK_CHECK
1076 && compare_tree_int (TYPE_SIZE_UNIT (type),
1077 STACK_CHECK_MAX_VAR_SIZE) > 0))
1079 /* This is a variable-sized object. Make space on the stack
1081 rtx size_rtx = expr_size (args[i].tree_value);
1083 if (*old_stack_level == 0)
1085 emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX);
1086 *old_pending_adj = pending_stack_adjust;
1087 pending_stack_adjust = 0;
1090 copy = gen_rtx_MEM (BLKmode,
1091 allocate_dynamic_stack_space
1092 (size_rtx, NULL_RTX, TYPE_ALIGN (type)));
1093 set_mem_attributes (copy, type, 1);
1096 copy = assign_temp (type, 0, 1, 0);
1098 store_expr (args[i].tree_value, copy, 0, false);
1100 /* Just change the const function to pure and then let
1101 the next test clear the pure based on
1103 if (*ecf_flags & ECF_CONST)
1105 *ecf_flags &= ~ECF_CONST;
1106 *ecf_flags |= ECF_PURE;
1109 if (!callee_copies && *ecf_flags & ECF_PURE)
1110 *ecf_flags &= ~(ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
1113 = build_fold_addr_expr (make_tree (type, copy));
1114 type = TREE_TYPE (args[i].tree_value);
1115 *may_tailcall = false;
1119 mode = TYPE_MODE (type);
1120 unsignedp = TYPE_UNSIGNED (type);
1122 if (targetm.calls.promote_function_args (fndecl ? TREE_TYPE (fndecl) : 0))
1123 mode = promote_mode (type, mode, &unsignedp, 1);
1125 args[i].unsignedp = unsignedp;
1126 args[i].mode = mode;
1128 args[i].reg = FUNCTION_ARG (*args_so_far, mode, type,
1129 argpos < n_named_args);
1130 #ifdef FUNCTION_INCOMING_ARG
1131 /* If this is a sibling call and the machine has register windows, the
1132 register window has to be unwinded before calling the routine, so
1133 arguments have to go into the incoming registers. */
1134 args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type,
1135 argpos < n_named_args);
1137 args[i].tail_call_reg = args[i].reg;
1142 = targetm.calls.arg_partial_bytes (args_so_far, mode, type,
1143 argpos < n_named_args);
1145 args[i].pass_on_stack = targetm.calls.must_pass_in_stack (mode, type);
1147 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1148 it means that we are to pass this arg in the register(s) designated
1149 by the PARALLEL, but also to pass it in the stack. */
1150 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1151 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1152 args[i].pass_on_stack = 1;
1154 /* If this is an addressable type, we must preallocate the stack
1155 since we must evaluate the object into its final location.
1157 If this is to be passed in both registers and the stack, it is simpler
1159 if (TREE_ADDRESSABLE (type)
1160 || (args[i].pass_on_stack && args[i].reg != 0))
1161 *must_preallocate = 1;
1163 /* Compute the stack-size of this argument. */
1164 if (args[i].reg == 0 || args[i].partial != 0
1165 || reg_parm_stack_space > 0
1166 || args[i].pass_on_stack)
1167 locate_and_pad_parm (mode, type,
1168 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1173 args[i].pass_on_stack ? 0 : args[i].partial,
1174 fndecl, args_size, &args[i].locate);
1175 #ifdef BLOCK_REG_PADDING
1177 /* The argument is passed entirely in registers. See at which
1178 end it should be padded. */
1179 args[i].locate.where_pad =
1180 BLOCK_REG_PADDING (mode, type,
1181 int_size_in_bytes (type) <= UNITS_PER_WORD);
1184 /* Update ARGS_SIZE, the total stack space for args so far. */
1186 args_size->constant += args[i].locate.size.constant;
1187 if (args[i].locate.size.var)
1188 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
1190 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1191 have been used, etc. */
1193 FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type,
1194 argpos < n_named_args);
1198 /* Update ARGS_SIZE to contain the total size for the argument block.
1199 Return the original constant component of the argument block's size.
1201 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1202 for arguments passed in registers. */
1205 compute_argument_block_size (int reg_parm_stack_space,
1206 struct args_size *args_size,
1207 tree fndecl ATTRIBUTE_UNUSED,
1208 tree fntype ATTRIBUTE_UNUSED,
1209 int preferred_stack_boundary ATTRIBUTE_UNUSED)
1211 int unadjusted_args_size = args_size->constant;
1213 /* For accumulate outgoing args mode we don't need to align, since the frame
1214 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1215 backends from generating misaligned frame sizes. */
1216 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1217 preferred_stack_boundary = STACK_BOUNDARY;
1219 /* Compute the actual size of the argument block required. The variable
1220 and constant sizes must be combined, the size may have to be rounded,
1221 and there may be a minimum required size. */
1225 args_size->var = ARGS_SIZE_TREE (*args_size);
1226 args_size->constant = 0;
1228 preferred_stack_boundary /= BITS_PER_UNIT;
1229 if (preferred_stack_boundary > 1)
1231 /* We don't handle this case yet. To handle it correctly we have
1232 to add the delta, round and subtract the delta.
1233 Currently no machine description requires this support. */
1234 gcc_assert (!(stack_pointer_delta & (preferred_stack_boundary - 1)));
1235 args_size->var = round_up (args_size->var, preferred_stack_boundary);
1238 if (reg_parm_stack_space > 0)
1241 = size_binop (MAX_EXPR, args_size->var,
1242 ssize_int (reg_parm_stack_space));
1244 /* The area corresponding to register parameters is not to count in
1245 the size of the block we need. So make the adjustment. */
1246 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
1248 = size_binop (MINUS_EXPR, args_size->var,
1249 ssize_int (reg_parm_stack_space));
1254 preferred_stack_boundary /= BITS_PER_UNIT;
1255 if (preferred_stack_boundary < 1)
1256 preferred_stack_boundary = 1;
1257 args_size->constant = (((args_size->constant
1258 + stack_pointer_delta
1259 + preferred_stack_boundary - 1)
1260 / preferred_stack_boundary
1261 * preferred_stack_boundary)
1262 - stack_pointer_delta);
1264 args_size->constant = MAX (args_size->constant,
1265 reg_parm_stack_space);
1267 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
1268 args_size->constant -= reg_parm_stack_space;
1270 return unadjusted_args_size;
1273 /* Precompute parameters as needed for a function call.
1275 FLAGS is mask of ECF_* constants.
1277 NUM_ACTUALS is the number of arguments.
1279 ARGS is an array containing information for each argument; this
1280 routine fills in the INITIAL_VALUE and VALUE fields for each
1281 precomputed argument. */
1284 precompute_arguments (int num_actuals, struct arg_data *args)
1288 /* If this is a libcall, then precompute all arguments so that we do not
1289 get extraneous instructions emitted as part of the libcall sequence. */
1291 /* If we preallocated the stack space, and some arguments must be passed
1292 on the stack, then we must precompute any parameter which contains a
1293 function call which will store arguments on the stack.
1294 Otherwise, evaluating the parameter may clobber previous parameters
1295 which have already been stored into the stack. (we have code to avoid
1296 such case by saving the outgoing stack arguments, but it results in
1298 if (!ACCUMULATE_OUTGOING_ARGS)
1301 for (i = 0; i < num_actuals; i++)
1303 enum machine_mode mode;
1305 if (TREE_CODE (args[i].tree_value) != CALL_EXPR)
1308 /* If this is an addressable type, we cannot pre-evaluate it. */
1309 gcc_assert (!TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)));
1311 args[i].initial_value = args[i].value
1312 = expand_normal (args[i].tree_value);
1314 mode = TYPE_MODE (TREE_TYPE (args[i].tree_value));
1315 if (mode != args[i].mode)
1318 = convert_modes (args[i].mode, mode,
1319 args[i].value, args[i].unsignedp);
1320 #if defined(PROMOTE_FUNCTION_MODE) && !defined(PROMOTE_MODE)
1321 /* CSE will replace this only if it contains args[i].value
1322 pseudo, so convert it down to the declared mode using
1324 if (REG_P (args[i].value)
1325 && GET_MODE_CLASS (args[i].mode) == MODE_INT)
1327 args[i].initial_value
1328 = gen_lowpart_SUBREG (mode, args[i].value);
1329 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1330 SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value,
1338 /* Given the current state of MUST_PREALLOCATE and information about
1339 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1340 compute and return the final value for MUST_PREALLOCATE. */
1343 finalize_must_preallocate (int must_preallocate, int num_actuals,
1344 struct arg_data *args, struct args_size *args_size)
1346 /* See if we have or want to preallocate stack space.
1348 If we would have to push a partially-in-regs parm
1349 before other stack parms, preallocate stack space instead.
1351 If the size of some parm is not a multiple of the required stack
1352 alignment, we must preallocate.
1354 If the total size of arguments that would otherwise create a copy in
1355 a temporary (such as a CALL) is more than half the total argument list
1356 size, preallocation is faster.
1358 Another reason to preallocate is if we have a machine (like the m88k)
1359 where stack alignment is required to be maintained between every
1360 pair of insns, not just when the call is made. However, we assume here
1361 that such machines either do not have push insns (and hence preallocation
1362 would occur anyway) or the problem is taken care of with
1365 if (! must_preallocate)
1367 int partial_seen = 0;
1368 int copy_to_evaluate_size = 0;
1371 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1373 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1375 else if (partial_seen && args[i].reg == 0)
1376 must_preallocate = 1;
1378 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1379 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1380 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1381 || TREE_CODE (args[i].tree_value) == COND_EXPR
1382 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1383 copy_to_evaluate_size
1384 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1387 if (copy_to_evaluate_size * 2 >= args_size->constant
1388 && args_size->constant > 0)
1389 must_preallocate = 1;
1391 return must_preallocate;
1394 /* If we preallocated stack space, compute the address of each argument
1395 and store it into the ARGS array.
1397 We need not ensure it is a valid memory address here; it will be
1398 validized when it is used.
1400 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1403 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
1407 rtx arg_reg = argblock;
1408 int i, arg_offset = 0;
1410 if (GET_CODE (argblock) == PLUS)
1411 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1413 for (i = 0; i < num_actuals; i++)
1415 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
1416 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
1418 unsigned int align, boundary;
1419 unsigned int units_on_stack = 0;
1420 enum machine_mode partial_mode = VOIDmode;
1422 /* Skip this parm if it will not be passed on the stack. */
1423 if (! args[i].pass_on_stack
1425 && args[i].partial == 0)
1428 if (GET_CODE (offset) == CONST_INT)
1429 addr = plus_constant (arg_reg, INTVAL (offset));
1431 addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1433 addr = plus_constant (addr, arg_offset);
1435 if (args[i].partial != 0)
1437 /* Only part of the parameter is being passed on the stack.
1438 Generate a simple memory reference of the correct size. */
1439 units_on_stack = args[i].locate.size.constant;
1440 partial_mode = mode_for_size (units_on_stack * BITS_PER_UNIT,
1442 args[i].stack = gen_rtx_MEM (partial_mode, addr);
1443 set_mem_size (args[i].stack, GEN_INT (units_on_stack));
1447 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1448 set_mem_attributes (args[i].stack,
1449 TREE_TYPE (args[i].tree_value), 1);
1451 align = BITS_PER_UNIT;
1452 boundary = args[i].locate.boundary;
1453 if (args[i].locate.where_pad != downward)
1455 else if (GET_CODE (offset) == CONST_INT)
1457 align = INTVAL (offset) * BITS_PER_UNIT | boundary;
1458 align = align & -align;
1460 set_mem_align (args[i].stack, align);
1462 if (GET_CODE (slot_offset) == CONST_INT)
1463 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1465 addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1467 addr = plus_constant (addr, arg_offset);
1469 if (args[i].partial != 0)
1471 /* Only part of the parameter is being passed on the stack.
1472 Generate a simple memory reference of the correct size.
1474 args[i].stack_slot = gen_rtx_MEM (partial_mode, addr);
1475 set_mem_size (args[i].stack_slot, GEN_INT (units_on_stack));
1479 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1480 set_mem_attributes (args[i].stack_slot,
1481 TREE_TYPE (args[i].tree_value), 1);
1483 set_mem_align (args[i].stack_slot, args[i].locate.boundary);
1485 /* Function incoming arguments may overlap with sibling call
1486 outgoing arguments and we cannot allow reordering of reads
1487 from function arguments with stores to outgoing arguments
1488 of sibling calls. */
1489 set_mem_alias_set (args[i].stack, 0);
1490 set_mem_alias_set (args[i].stack_slot, 0);
1495 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1496 in a call instruction.
1498 FNDECL is the tree node for the target function. For an indirect call
1499 FNDECL will be NULL_TREE.
1501 ADDR is the operand 0 of CALL_EXPR for this call. */
1504 rtx_for_function_call (tree fndecl, tree addr)
1508 /* Get the function to call, in the form of RTL. */
1511 /* If this is the first use of the function, see if we need to
1512 make an external definition for it. */
1513 if (!TREE_USED (fndecl) && fndecl != current_function_decl)
1515 assemble_external (fndecl);
1516 TREE_USED (fndecl) = 1;
1519 /* Get a SYMBOL_REF rtx for the function address. */
1520 funexp = XEXP (DECL_RTL (fndecl), 0);
1523 /* Generate an rtx (probably a pseudo-register) for the address. */
1526 funexp = expand_normal (addr);
1527 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1532 /* Return true if and only if SIZE storage units (usually bytes)
1533 starting from address ADDR overlap with already clobbered argument
1534 area. This function is used to determine if we should give up a
1538 mem_overlaps_already_clobbered_arg_p (rtx addr, unsigned HOST_WIDE_INT size)
1542 if (addr == crtl->args.internal_arg_pointer)
1544 else if (GET_CODE (addr) == PLUS
1545 && XEXP (addr, 0) == crtl->args.internal_arg_pointer
1546 && GET_CODE (XEXP (addr, 1)) == CONST_INT)
1547 i = INTVAL (XEXP (addr, 1));
1548 /* Return true for arg pointer based indexed addressing. */
1549 else if (GET_CODE (addr) == PLUS
1550 && (XEXP (addr, 0) == crtl->args.internal_arg_pointer
1551 || XEXP (addr, 1) == crtl->args.internal_arg_pointer))
1556 #ifdef ARGS_GROW_DOWNWARD
1561 unsigned HOST_WIDE_INT k;
1563 for (k = 0; k < size; k++)
1564 if (i + k < stored_args_map->n_bits
1565 && TEST_BIT (stored_args_map, i + k))
1572 /* Do the register loads required for any wholly-register parms or any
1573 parms which are passed both on the stack and in a register. Their
1574 expressions were already evaluated.
1576 Mark all register-parms as living through the call, putting these USE
1577 insns in the CALL_INSN_FUNCTION_USAGE field.
1579 When IS_SIBCALL, perform the check_sibcall_argument_overlap
1580 checking, setting *SIBCALL_FAILURE if appropriate. */
1583 load_register_parameters (struct arg_data *args, int num_actuals,
1584 rtx *call_fusage, int flags, int is_sibcall,
1585 int *sibcall_failure)
1589 for (i = 0; i < num_actuals; i++)
1591 rtx reg = ((flags & ECF_SIBCALL)
1592 ? args[i].tail_call_reg : args[i].reg);
1595 int partial = args[i].partial;
1598 rtx before_arg = get_last_insn ();
1599 /* Set non-negative if we must move a word at a time, even if
1600 just one word (e.g, partial == 4 && mode == DFmode). Set
1601 to -1 if we just use a normal move insn. This value can be
1602 zero if the argument is a zero size structure. */
1604 if (GET_CODE (reg) == PARALLEL)
1608 gcc_assert (partial % UNITS_PER_WORD == 0);
1609 nregs = partial / UNITS_PER_WORD;
1611 else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode)
1613 size = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1614 nregs = (size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
1617 size = GET_MODE_SIZE (args[i].mode);
1619 /* Handle calls that pass values in multiple non-contiguous
1620 locations. The Irix 6 ABI has examples of this. */
1622 if (GET_CODE (reg) == PARALLEL)
1623 emit_group_move (reg, args[i].parallel_value);
1625 /* If simple case, just do move. If normal partial, store_one_arg
1626 has already loaded the register for us. In all other cases,
1627 load the register(s) from memory. */
1629 else if (nregs == -1)
1631 emit_move_insn (reg, args[i].value);
1632 #ifdef BLOCK_REG_PADDING
1633 /* Handle case where we have a value that needs shifting
1634 up to the msb. eg. a QImode value and we're padding
1635 upward on a BYTES_BIG_ENDIAN machine. */
1636 if (size < UNITS_PER_WORD
1637 && (args[i].locate.where_pad
1638 == (BYTES_BIG_ENDIAN ? upward : downward)))
1641 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1643 /* Assigning REG here rather than a temp makes CALL_FUSAGE
1644 report the whole reg as used. Strictly speaking, the
1645 call only uses SIZE bytes at the msb end, but it doesn't
1646 seem worth generating rtl to say that. */
1647 reg = gen_rtx_REG (word_mode, REGNO (reg));
1648 x = expand_shift (LSHIFT_EXPR, word_mode, reg,
1649 build_int_cst (NULL_TREE, shift),
1652 emit_move_insn (reg, x);
1657 /* If we have pre-computed the values to put in the registers in
1658 the case of non-aligned structures, copy them in now. */
1660 else if (args[i].n_aligned_regs != 0)
1661 for (j = 0; j < args[i].n_aligned_regs; j++)
1662 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1663 args[i].aligned_regs[j]);
1665 else if (partial == 0 || args[i].pass_on_stack)
1667 rtx mem = validize_mem (args[i].value);
1669 /* Check for overlap with already clobbered argument area. */
1671 && mem_overlaps_already_clobbered_arg_p (XEXP (args[i].value, 0),
1673 *sibcall_failure = 1;
1675 /* Handle a BLKmode that needs shifting. */
1676 if (nregs == 1 && size < UNITS_PER_WORD
1677 #ifdef BLOCK_REG_PADDING
1678 && args[i].locate.where_pad == downward
1684 rtx tem = operand_subword_force (mem, 0, args[i].mode);
1685 rtx ri = gen_rtx_REG (word_mode, REGNO (reg));
1686 rtx x = gen_reg_rtx (word_mode);
1687 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1688 enum tree_code dir = BYTES_BIG_ENDIAN ? RSHIFT_EXPR
1691 emit_move_insn (x, tem);
1692 x = expand_shift (dir, word_mode, x,
1693 build_int_cst (NULL_TREE, shift),
1696 emit_move_insn (ri, x);
1699 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
1702 /* When a parameter is a block, and perhaps in other cases, it is
1703 possible that it did a load from an argument slot that was
1704 already clobbered. */
1706 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
1707 *sibcall_failure = 1;
1709 /* Handle calls that pass values in multiple non-contiguous
1710 locations. The Irix 6 ABI has examples of this. */
1711 if (GET_CODE (reg) == PARALLEL)
1712 use_group_regs (call_fusage, reg);
1713 else if (nregs == -1)
1714 use_reg (call_fusage, reg);
1716 use_regs (call_fusage, REGNO (reg), nregs);
1721 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1722 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1723 bytes, then we would need to push some additional bytes to pad the
1724 arguments. So, we compute an adjust to the stack pointer for an
1725 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1726 bytes. Then, when the arguments are pushed the stack will be perfectly
1727 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
1728 be popped after the call. Returns the adjustment. */
1731 combine_pending_stack_adjustment_and_call (int unadjusted_args_size,
1732 struct args_size *args_size,
1733 unsigned int preferred_unit_stack_boundary)
1735 /* The number of bytes to pop so that the stack will be
1736 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
1737 HOST_WIDE_INT adjustment;
1738 /* The alignment of the stack after the arguments are pushed, if we
1739 just pushed the arguments without adjust the stack here. */
1740 unsigned HOST_WIDE_INT unadjusted_alignment;
1742 unadjusted_alignment
1743 = ((stack_pointer_delta + unadjusted_args_size)
1744 % preferred_unit_stack_boundary);
1746 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1747 as possible -- leaving just enough left to cancel out the
1748 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
1749 PENDING_STACK_ADJUST is non-negative, and congruent to
1750 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
1752 /* Begin by trying to pop all the bytes. */
1753 unadjusted_alignment
1754 = (unadjusted_alignment
1755 - (pending_stack_adjust % preferred_unit_stack_boundary));
1756 adjustment = pending_stack_adjust;
1757 /* Push enough additional bytes that the stack will be aligned
1758 after the arguments are pushed. */
1759 if (preferred_unit_stack_boundary > 1)
1761 if (unadjusted_alignment > 0)
1762 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
1764 adjustment += unadjusted_alignment;
1767 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1768 bytes after the call. The right number is the entire
1769 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1770 by the arguments in the first place. */
1772 = pending_stack_adjust - adjustment + unadjusted_args_size;
1777 /* Scan X expression if it does not dereference any argument slots
1778 we already clobbered by tail call arguments (as noted in stored_args_map
1780 Return nonzero if X expression dereferences such argument slots,
1784 check_sibcall_argument_overlap_1 (rtx x)
1793 code = GET_CODE (x);
1796 return mem_overlaps_already_clobbered_arg_p (XEXP (x, 0),
1797 GET_MODE_SIZE (GET_MODE (x)));
1799 /* Scan all subexpressions. */
1800 fmt = GET_RTX_FORMAT (code);
1801 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
1805 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
1808 else if (*fmt == 'E')
1810 for (j = 0; j < XVECLEN (x, i); j++)
1811 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
1818 /* Scan sequence after INSN if it does not dereference any argument slots
1819 we already clobbered by tail call arguments (as noted in stored_args_map
1820 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
1821 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
1822 should be 0). Return nonzero if sequence after INSN dereferences such argument
1823 slots, zero otherwise. */
1826 check_sibcall_argument_overlap (rtx insn, struct arg_data *arg, int mark_stored_args_map)
1830 if (insn == NULL_RTX)
1831 insn = get_insns ();
1833 insn = NEXT_INSN (insn);
1835 for (; insn; insn = NEXT_INSN (insn))
1837 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
1840 if (mark_stored_args_map)
1842 #ifdef ARGS_GROW_DOWNWARD
1843 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
1845 low = arg->locate.slot_offset.constant;
1848 for (high = low + arg->locate.size.constant; low < high; low++)
1849 SET_BIT (stored_args_map, low);
1851 return insn != NULL_RTX;
1854 /* Given that a function returns a value of mode MODE at the most
1855 significant end of hard register VALUE, shift VALUE left or right
1856 as specified by LEFT_P. Return true if some action was needed. */
1859 shift_return_value (enum machine_mode mode, bool left_p, rtx value)
1861 HOST_WIDE_INT shift;
1863 gcc_assert (REG_P (value) && HARD_REGISTER_P (value));
1864 shift = GET_MODE_BITSIZE (GET_MODE (value)) - GET_MODE_BITSIZE (mode);
1868 /* Use ashr rather than lshr for right shifts. This is for the benefit
1869 of the MIPS port, which requires SImode values to be sign-extended
1870 when stored in 64-bit registers. */
1871 if (!force_expand_binop (GET_MODE (value), left_p ? ashl_optab : ashr_optab,
1872 value, GEN_INT (shift), value, 1, OPTAB_WIDEN))
1877 /* If X is a likely-spilled register value, copy it to a pseudo
1878 register and return that register. Return X otherwise. */
1881 avoid_likely_spilled_reg (rtx x)
1886 && HARD_REGISTER_P (x)
1887 && CLASS_LIKELY_SPILLED_P (REGNO_REG_CLASS (REGNO (x))))
1889 /* Make sure that we generate a REG rather than a CONCAT.
1890 Moves into CONCATs can need nontrivial instructions,
1891 and the whole point of this function is to avoid
1892 using the hard register directly in such a situation. */
1893 generating_concat_p = 0;
1894 new_rtx = gen_reg_rtx (GET_MODE (x));
1895 generating_concat_p = 1;
1896 emit_move_insn (new_rtx, x);
1902 /* Generate all the code for a CALL_EXPR exp
1903 and return an rtx for its value.
1904 Store the value in TARGET (specified as an rtx) if convenient.
1905 If the value is stored in TARGET then TARGET is returned.
1906 If IGNORE is nonzero, then we ignore the value of the function call. */
1909 expand_call (tree exp, rtx target, int ignore)
1911 /* Nonzero if we are currently expanding a call. */
1912 static int currently_expanding_call = 0;
1914 /* RTX for the function to be called. */
1916 /* Sequence of insns to perform a normal "call". */
1917 rtx normal_call_insns = NULL_RTX;
1918 /* Sequence of insns to perform a tail "call". */
1919 rtx tail_call_insns = NULL_RTX;
1920 /* Data type of the function. */
1922 tree type_arg_types;
1923 /* Declaration of the function being called,
1924 or 0 if the function is computed (not known by name). */
1926 /* The type of the function being called. */
1928 bool try_tail_call = CALL_EXPR_TAILCALL (exp);
1931 /* Register in which non-BLKmode value will be returned,
1932 or 0 if no value or if value is BLKmode. */
1934 /* Address where we should return a BLKmode value;
1935 0 if value not BLKmode. */
1936 rtx structure_value_addr = 0;
1937 /* Nonzero if that address is being passed by treating it as
1938 an extra, implicit first parameter. Otherwise,
1939 it is passed by being copied directly into struct_value_rtx. */
1940 int structure_value_addr_parm = 0;
1941 /* Holds the value of implicit argument for the struct value. */
1942 tree structure_value_addr_value = NULL_TREE;
1943 /* Size of aggregate value wanted, or zero if none wanted
1944 or if we are using the non-reentrant PCC calling convention
1945 or expecting the value in registers. */
1946 HOST_WIDE_INT struct_value_size = 0;
1947 /* Nonzero if called function returns an aggregate in memory PCC style,
1948 by returning the address of where to find it. */
1949 int pcc_struct_value = 0;
1950 rtx struct_value = 0;
1952 /* Number of actual parameters in this call, including struct value addr. */
1954 /* Number of named args. Args after this are anonymous ones
1955 and they must all go on the stack. */
1957 /* Number of complex actual arguments that need to be split. */
1958 int num_complex_actuals = 0;
1960 /* Vector of information about each argument.
1961 Arguments are numbered in the order they will be pushed,
1962 not the order they are written. */
1963 struct arg_data *args;
1965 /* Total size in bytes of all the stack-parms scanned so far. */
1966 struct args_size args_size;
1967 struct args_size adjusted_args_size;
1968 /* Size of arguments before any adjustments (such as rounding). */
1969 int unadjusted_args_size;
1970 /* Data on reg parms scanned so far. */
1971 CUMULATIVE_ARGS args_so_far;
1972 /* Nonzero if a reg parm has been scanned. */
1974 /* Nonzero if this is an indirect function call. */
1976 /* Nonzero if we must avoid push-insns in the args for this call.
1977 If stack space is allocated for register parameters, but not by the
1978 caller, then it is preallocated in the fixed part of the stack frame.
1979 So the entire argument block must then be preallocated (i.e., we
1980 ignore PUSH_ROUNDING in that case). */
1982 int must_preallocate = !PUSH_ARGS;
1984 /* Size of the stack reserved for parameter registers. */
1985 int reg_parm_stack_space = 0;
1987 /* Address of space preallocated for stack parms
1988 (on machines that lack push insns), or 0 if space not preallocated. */
1991 /* Mask of ECF_ flags. */
1993 #ifdef REG_PARM_STACK_SPACE
1994 /* Define the boundary of the register parm stack space that needs to be
1996 int low_to_save, high_to_save;
1997 rtx save_area = 0; /* Place that it is saved */
2000 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
2001 char *initial_stack_usage_map = stack_usage_map;
2002 char *stack_usage_map_buf = NULL;
2004 int old_stack_allocated;
2006 /* State variables to track stack modifications. */
2007 rtx old_stack_level = 0;
2008 int old_stack_arg_under_construction = 0;
2009 int old_pending_adj = 0;
2010 int old_inhibit_defer_pop = inhibit_defer_pop;
2012 /* Some stack pointer alterations we make are performed via
2013 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
2014 which we then also need to save/restore along the way. */
2015 int old_stack_pointer_delta = 0;
2018 tree p = CALL_EXPR_FN (exp);
2019 tree addr = CALL_EXPR_FN (exp);
2021 /* The alignment of the stack, in bits. */
2022 unsigned HOST_WIDE_INT preferred_stack_boundary;
2023 /* The alignment of the stack, in bytes. */
2024 unsigned HOST_WIDE_INT preferred_unit_stack_boundary;
2025 /* The static chain value to use for this call. */
2026 rtx static_chain_value;
2027 /* See if this is "nothrow" function call. */
2028 if (TREE_NOTHROW (exp))
2029 flags |= ECF_NOTHROW;
2031 /* See if we can find a DECL-node for the actual function, and get the
2032 function attributes (flags) from the function decl or type node. */
2033 fndecl = get_callee_fndecl (exp);
2036 fntype = TREE_TYPE (fndecl);
2037 flags |= flags_from_decl_or_type (fndecl);
2041 fntype = TREE_TYPE (TREE_TYPE (p));
2042 flags |= flags_from_decl_or_type (fntype);
2045 struct_value = targetm.calls.struct_value_rtx (fntype, 0);
2047 /* Warn if this value is an aggregate type,
2048 regardless of which calling convention we are using for it. */
2049 if (AGGREGATE_TYPE_P (TREE_TYPE (exp)))
2050 warning (OPT_Waggregate_return, "function call has aggregate value");
2052 /* If the result of a non looping pure or const function call is
2053 ignored (or void), and none of its arguments are volatile, we can
2054 avoid expanding the call and just evaluate the arguments for
2056 if ((flags & (ECF_CONST | ECF_PURE))
2057 && (!(flags & ECF_LOOPING_CONST_OR_PURE))
2058 && (ignore || target == const0_rtx
2059 || TYPE_MODE (TREE_TYPE (exp)) == VOIDmode))
2061 bool volatilep = false;
2063 call_expr_arg_iterator iter;
2065 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2066 if (TREE_THIS_VOLATILE (arg))
2074 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2075 expand_expr (arg, const0_rtx, VOIDmode, EXPAND_NORMAL);
2080 #ifdef REG_PARM_STACK_SPACE
2081 reg_parm_stack_space = REG_PARM_STACK_SPACE (!fndecl ? fntype : fndecl);
2084 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
2085 && reg_parm_stack_space > 0 && PUSH_ARGS)
2086 must_preallocate = 1;
2088 /* Set up a place to return a structure. */
2090 /* Cater to broken compilers. */
2091 if (aggregate_value_p (exp, fndecl))
2093 /* This call returns a big structure. */
2094 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
2096 #ifdef PCC_STATIC_STRUCT_RETURN
2098 pcc_struct_value = 1;
2100 #else /* not PCC_STATIC_STRUCT_RETURN */
2102 struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
2104 if (target && MEM_P (target) && CALL_EXPR_RETURN_SLOT_OPT (exp))
2105 structure_value_addr = XEXP (target, 0);
2108 /* For variable-sized objects, we must be called with a target
2109 specified. If we were to allocate space on the stack here,
2110 we would have no way of knowing when to free it. */
2111 rtx d = assign_temp (TREE_TYPE (exp), 0, 1, 1);
2113 mark_temp_addr_taken (d);
2114 structure_value_addr = XEXP (d, 0);
2118 #endif /* not PCC_STATIC_STRUCT_RETURN */
2121 /* Figure out the amount to which the stack should be aligned. */
2122 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2125 struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl);
2126 /* Without automatic stack alignment, we can't increase preferred
2127 stack boundary. With automatic stack alignment, it is
2128 unnecessary since unless we can guarantee that all callers will
2129 align the outgoing stack properly, callee has to align its
2132 && i->preferred_incoming_stack_boundary
2133 && i->preferred_incoming_stack_boundary < preferred_stack_boundary)
2134 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
2137 /* Operand 0 is a pointer-to-function; get the type of the function. */
2138 funtype = TREE_TYPE (addr);
2139 gcc_assert (POINTER_TYPE_P (funtype));
2140 funtype = TREE_TYPE (funtype);
2142 /* Count whether there are actual complex arguments that need to be split
2143 into their real and imaginary parts. Munge the type_arg_types
2144 appropriately here as well. */
2145 if (targetm.calls.split_complex_arg)
2147 call_expr_arg_iterator iter;
2149 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2151 tree type = TREE_TYPE (arg);
2152 if (type && TREE_CODE (type) == COMPLEX_TYPE
2153 && targetm.calls.split_complex_arg (type))
2154 num_complex_actuals++;
2156 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
2159 type_arg_types = TYPE_ARG_TYPES (funtype);
2161 if (flags & ECF_MAY_BE_ALLOCA)
2162 cfun->calls_alloca = 1;
2164 /* If struct_value_rtx is 0, it means pass the address
2165 as if it were an extra parameter. Put the argument expression
2166 in structure_value_addr_value. */
2167 if (structure_value_addr && struct_value == 0)
2169 /* If structure_value_addr is a REG other than
2170 virtual_outgoing_args_rtx, we can use always use it. If it
2171 is not a REG, we must always copy it into a register.
2172 If it is virtual_outgoing_args_rtx, we must copy it to another
2173 register in some cases. */
2174 rtx temp = (!REG_P (structure_value_addr)
2175 || (ACCUMULATE_OUTGOING_ARGS
2176 && stack_arg_under_construction
2177 && structure_value_addr == virtual_outgoing_args_rtx)
2178 ? copy_addr_to_reg (convert_memory_address
2179 (Pmode, structure_value_addr))
2180 : structure_value_addr);
2182 structure_value_addr_value =
2183 make_tree (build_pointer_type (TREE_TYPE (funtype)), temp);
2184 structure_value_addr_parm = 1;
2187 /* Count the arguments and set NUM_ACTUALS. */
2189 call_expr_nargs (exp) + num_complex_actuals + structure_value_addr_parm;
2191 /* Compute number of named args.
2192 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
2194 if (type_arg_types != 0)
2196 = (list_length (type_arg_types)
2197 /* Count the struct value address, if it is passed as a parm. */
2198 + structure_value_addr_parm);
2200 /* If we know nothing, treat all args as named. */
2201 n_named_args = num_actuals;
2203 /* Start updating where the next arg would go.
2205 On some machines (such as the PA) indirect calls have a different
2206 calling convention than normal calls. The fourth argument in
2207 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2209 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, fndecl, n_named_args);
2211 /* Now possibly adjust the number of named args.
2212 Normally, don't include the last named arg if anonymous args follow.
2213 We do include the last named arg if
2214 targetm.calls.strict_argument_naming() returns nonzero.
2215 (If no anonymous args follow, the result of list_length is actually
2216 one too large. This is harmless.)
2218 If targetm.calls.pretend_outgoing_varargs_named() returns
2219 nonzero, and targetm.calls.strict_argument_naming() returns zero,
2220 this machine will be able to place unnamed args that were passed
2221 in registers into the stack. So treat all args as named. This
2222 allows the insns emitting for a specific argument list to be
2223 independent of the function declaration.
2225 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
2226 we do not have any reliable way to pass unnamed args in
2227 registers, so we must force them into memory. */
2229 if (type_arg_types != 0
2230 && targetm.calls.strict_argument_naming (&args_so_far))
2232 else if (type_arg_types != 0
2233 && ! targetm.calls.pretend_outgoing_varargs_named (&args_so_far))
2234 /* Don't include the last named arg. */
2237 /* Treat all args as named. */
2238 n_named_args = num_actuals;
2240 /* Make a vector to hold all the information about each arg. */
2241 args = XALLOCAVEC (struct arg_data, num_actuals);
2242 memset (args, 0, num_actuals * sizeof (struct arg_data));
2244 /* Build up entries in the ARGS array, compute the size of the
2245 arguments into ARGS_SIZE, etc. */
2246 initialize_argument_information (num_actuals, args, &args_size,
2248 structure_value_addr_value, fndecl,
2249 &args_so_far, reg_parm_stack_space,
2250 &old_stack_level, &old_pending_adj,
2251 &must_preallocate, &flags,
2252 &try_tail_call, CALL_FROM_THUNK_P (exp));
2255 must_preallocate = 1;
2257 /* Now make final decision about preallocating stack space. */
2258 must_preallocate = finalize_must_preallocate (must_preallocate,
2262 /* If the structure value address will reference the stack pointer, we
2263 must stabilize it. We don't need to do this if we know that we are
2264 not going to adjust the stack pointer in processing this call. */
2266 if (structure_value_addr
2267 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2268 || reg_mentioned_p (virtual_outgoing_args_rtx,
2269 structure_value_addr))
2271 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2272 structure_value_addr = copy_to_reg (structure_value_addr);
2274 /* Tail calls can make things harder to debug, and we've traditionally
2275 pushed these optimizations into -O2. Don't try if we're already
2276 expanding a call, as that means we're an argument. Don't try if
2277 there's cleanups, as we know there's code to follow the call. */
2279 if (currently_expanding_call++ != 0
2280 || !flag_optimize_sibling_calls
2282 || lookup_expr_eh_region (exp) >= 0
2283 || dbg_cnt (tail_call) == false)
2286 /* Rest of purposes for tail call optimizations to fail. */
2288 #ifdef HAVE_sibcall_epilogue
2289 !HAVE_sibcall_epilogue
2294 /* Doing sibling call optimization needs some work, since
2295 structure_value_addr can be allocated on the stack.
2296 It does not seem worth the effort since few optimizable
2297 sibling calls will return a structure. */
2298 || structure_value_addr != NULL_RTX
2299 /* Check whether the target is able to optimize the call
2301 || !targetm.function_ok_for_sibcall (fndecl, exp)
2302 /* Functions that do not return exactly once may not be sibcall
2304 || (flags & (ECF_RETURNS_TWICE | ECF_NORETURN))
2305 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr)))
2306 /* If the called function is nested in the current one, it might access
2307 some of the caller's arguments, but could clobber them beforehand if
2308 the argument areas are shared. */
2309 || (fndecl && decl_function_context (fndecl) == current_function_decl)
2310 /* If this function requires more stack slots than the current
2311 function, we cannot change it into a sibling call.
2312 crtl->args.pretend_args_size is not part of the
2313 stack allocated by our caller. */
2314 || args_size.constant > (crtl->args.size
2315 - crtl->args.pretend_args_size)
2316 /* If the callee pops its own arguments, then it must pop exactly
2317 the same number of arguments as the current function. */
2318 || (RETURN_POPS_ARGS (fndecl, funtype, args_size.constant)
2319 != RETURN_POPS_ARGS (current_function_decl,
2320 TREE_TYPE (current_function_decl),
2322 || !lang_hooks.decls.ok_for_sibcall (fndecl))
2325 /* Ensure current function's preferred stack boundary is at least
2326 what we need. Stack alignment may also increase preferred stack
2328 if (crtl->preferred_stack_boundary < preferred_stack_boundary)
2329 crtl->preferred_stack_boundary = preferred_stack_boundary;
2331 preferred_stack_boundary = crtl->preferred_stack_boundary;
2333 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2335 /* We want to make two insn chains; one for a sibling call, the other
2336 for a normal call. We will select one of the two chains after
2337 initial RTL generation is complete. */
2338 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
2340 int sibcall_failure = 0;
2341 /* We want to emit any pending stack adjustments before the tail
2342 recursion "call". That way we know any adjustment after the tail
2343 recursion call can be ignored if we indeed use the tail
2345 int save_pending_stack_adjust = 0;
2346 int save_stack_pointer_delta = 0;
2348 rtx before_call, next_arg_reg, after_args;
2352 /* State variables we need to save and restore between
2354 save_pending_stack_adjust = pending_stack_adjust;
2355 save_stack_pointer_delta = stack_pointer_delta;
2358 flags &= ~ECF_SIBCALL;
2360 flags |= ECF_SIBCALL;
2362 /* Other state variables that we must reinitialize each time
2363 through the loop (that are not initialized by the loop itself). */
2367 /* Start a new sequence for the normal call case.
2369 From this point on, if the sibling call fails, we want to set
2370 sibcall_failure instead of continuing the loop. */
2373 /* Don't let pending stack adjusts add up to too much.
2374 Also, do all pending adjustments now if there is any chance
2375 this might be a call to alloca or if we are expanding a sibling
2377 Also do the adjustments before a throwing call, otherwise
2378 exception handling can fail; PR 19225. */
2379 if (pending_stack_adjust >= 32
2380 || (pending_stack_adjust > 0
2381 && (flags & ECF_MAY_BE_ALLOCA))
2382 || (pending_stack_adjust > 0
2383 && flag_exceptions && !(flags & ECF_NOTHROW))
2385 do_pending_stack_adjust ();
2387 /* Precompute any arguments as needed. */
2389 precompute_arguments (num_actuals, args);
2391 /* Now we are about to start emitting insns that can be deleted
2392 if a libcall is deleted. */
2393 if (pass && (flags & ECF_MALLOC))
2396 if (pass == 0 && crtl->stack_protect_guard)
2397 stack_protect_epilogue ();
2399 adjusted_args_size = args_size;
2400 /* Compute the actual size of the argument block required. The variable
2401 and constant sizes must be combined, the size may have to be rounded,
2402 and there may be a minimum required size. When generating a sibcall
2403 pattern, do not round up, since we'll be re-using whatever space our
2405 unadjusted_args_size
2406 = compute_argument_block_size (reg_parm_stack_space,
2407 &adjusted_args_size,
2410 : preferred_stack_boundary));
2412 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2414 /* The argument block when performing a sibling call is the
2415 incoming argument block. */
2418 argblock = crtl->args.internal_arg_pointer;
2420 #ifdef STACK_GROWS_DOWNWARD
2421 = plus_constant (argblock, crtl->args.pretend_args_size);
2423 = plus_constant (argblock, -crtl->args.pretend_args_size);
2425 stored_args_map = sbitmap_alloc (args_size.constant);
2426 sbitmap_zero (stored_args_map);
2429 /* If we have no actual push instructions, or shouldn't use them,
2430 make space for all args right now. */
2431 else if (adjusted_args_size.var != 0)
2433 if (old_stack_level == 0)
2435 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2436 old_stack_pointer_delta = stack_pointer_delta;
2437 old_pending_adj = pending_stack_adjust;
2438 pending_stack_adjust = 0;
2439 /* stack_arg_under_construction says whether a stack arg is
2440 being constructed at the old stack level. Pushing the stack
2441 gets a clean outgoing argument block. */
2442 old_stack_arg_under_construction = stack_arg_under_construction;
2443 stack_arg_under_construction = 0;
2445 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2449 /* Note that we must go through the motions of allocating an argument
2450 block even if the size is zero because we may be storing args
2451 in the area reserved for register arguments, which may be part of
2454 int needed = adjusted_args_size.constant;
2456 /* Store the maximum argument space used. It will be pushed by
2457 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2460 if (needed > crtl->outgoing_args_size)
2461 crtl->outgoing_args_size = needed;
2463 if (must_preallocate)
2465 if (ACCUMULATE_OUTGOING_ARGS)
2467 /* Since the stack pointer will never be pushed, it is
2468 possible for the evaluation of a parm to clobber
2469 something we have already written to the stack.
2470 Since most function calls on RISC machines do not use
2471 the stack, this is uncommon, but must work correctly.
2473 Therefore, we save any area of the stack that was already
2474 written and that we are using. Here we set up to do this
2475 by making a new stack usage map from the old one. The
2476 actual save will be done by store_one_arg.
2478 Another approach might be to try to reorder the argument
2479 evaluations to avoid this conflicting stack usage. */
2481 /* Since we will be writing into the entire argument area,
2482 the map must be allocated for its entire size, not just
2483 the part that is the responsibility of the caller. */
2484 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
2485 needed += reg_parm_stack_space;
2487 #ifdef ARGS_GROW_DOWNWARD
2488 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2491 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2494 if (stack_usage_map_buf)
2495 free (stack_usage_map_buf);
2496 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
2497 stack_usage_map = stack_usage_map_buf;
2499 if (initial_highest_arg_in_use)
2500 memcpy (stack_usage_map, initial_stack_usage_map,
2501 initial_highest_arg_in_use);
2503 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2504 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2505 (highest_outgoing_arg_in_use
2506 - initial_highest_arg_in_use));
2509 /* The address of the outgoing argument list must not be
2510 copied to a register here, because argblock would be left
2511 pointing to the wrong place after the call to
2512 allocate_dynamic_stack_space below. */
2514 argblock = virtual_outgoing_args_rtx;
2518 if (inhibit_defer_pop == 0)
2520 /* Try to reuse some or all of the pending_stack_adjust
2521 to get this space. */
2523 = (combine_pending_stack_adjustment_and_call
2524 (unadjusted_args_size,
2525 &adjusted_args_size,
2526 preferred_unit_stack_boundary));
2528 /* combine_pending_stack_adjustment_and_call computes
2529 an adjustment before the arguments are allocated.
2530 Account for them and see whether or not the stack
2531 needs to go up or down. */
2532 needed = unadjusted_args_size - needed;
2536 /* We're releasing stack space. */
2537 /* ??? We can avoid any adjustment at all if we're
2538 already aligned. FIXME. */
2539 pending_stack_adjust = -needed;
2540 do_pending_stack_adjust ();
2544 /* We need to allocate space. We'll do that in
2545 push_block below. */
2546 pending_stack_adjust = 0;
2549 /* Special case this because overhead of `push_block' in
2550 this case is non-trivial. */
2552 argblock = virtual_outgoing_args_rtx;
2555 argblock = push_block (GEN_INT (needed), 0, 0);
2556 #ifdef ARGS_GROW_DOWNWARD
2557 argblock = plus_constant (argblock, needed);
2561 /* We only really need to call `copy_to_reg' in the case
2562 where push insns are going to be used to pass ARGBLOCK
2563 to a function call in ARGS. In that case, the stack
2564 pointer changes value from the allocation point to the
2565 call point, and hence the value of
2566 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2567 as well always do it. */
2568 argblock = copy_to_reg (argblock);
2573 if (ACCUMULATE_OUTGOING_ARGS)
2575 /* The save/restore code in store_one_arg handles all
2576 cases except one: a constructor call (including a C
2577 function returning a BLKmode struct) to initialize
2579 if (stack_arg_under_construction)
2582 = GEN_INT (adjusted_args_size.constant
2583 + (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype
2584 : TREE_TYPE (fndecl))) ? 0
2585 : reg_parm_stack_space));
2586 if (old_stack_level == 0)
2588 emit_stack_save (SAVE_BLOCK, &old_stack_level,
2590 old_stack_pointer_delta = stack_pointer_delta;
2591 old_pending_adj = pending_stack_adjust;
2592 pending_stack_adjust = 0;
2593 /* stack_arg_under_construction says whether a stack
2594 arg is being constructed at the old stack level.
2595 Pushing the stack gets a clean outgoing argument
2597 old_stack_arg_under_construction
2598 = stack_arg_under_construction;
2599 stack_arg_under_construction = 0;
2600 /* Make a new map for the new argument list. */
2601 if (stack_usage_map_buf)
2602 free (stack_usage_map_buf);
2603 stack_usage_map_buf = XCNEWVEC (char, highest_outgoing_arg_in_use);
2604 stack_usage_map = stack_usage_map_buf;
2605 highest_outgoing_arg_in_use = 0;
2607 allocate_dynamic_stack_space (push_size, NULL_RTX,
2611 /* If argument evaluation might modify the stack pointer,
2612 copy the address of the argument list to a register. */
2613 for (i = 0; i < num_actuals; i++)
2614 if (args[i].pass_on_stack)
2616 argblock = copy_addr_to_reg (argblock);
2621 compute_argument_addresses (args, argblock, num_actuals);
2623 /* If we push args individually in reverse order, perform stack alignment
2624 before the first push (the last arg). */
2625 if (PUSH_ARGS_REVERSED && argblock == 0
2626 && adjusted_args_size.constant != unadjusted_args_size)
2628 /* When the stack adjustment is pending, we get better code
2629 by combining the adjustments. */
2630 if (pending_stack_adjust
2631 && ! inhibit_defer_pop)
2633 pending_stack_adjust
2634 = (combine_pending_stack_adjustment_and_call
2635 (unadjusted_args_size,
2636 &adjusted_args_size,
2637 preferred_unit_stack_boundary));
2638 do_pending_stack_adjust ();
2640 else if (argblock == 0)
2641 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2642 - unadjusted_args_size));
2644 /* Now that the stack is properly aligned, pops can't safely
2645 be deferred during the evaluation of the arguments. */
2648 funexp = rtx_for_function_call (fndecl, addr);
2650 /* Figure out the register where the value, if any, will come back. */
2652 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
2653 && ! structure_value_addr)
2655 if (pcc_struct_value)
2656 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
2657 fndecl, NULL, (pass == 0));
2659 valreg = hard_function_value (TREE_TYPE (exp), fndecl, fntype,
2662 /* If VALREG is a PARALLEL whose first member has a zero
2663 offset, use that. This is for targets such as m68k that
2664 return the same value in multiple places. */
2665 if (GET_CODE (valreg) == PARALLEL)
2667 rtx elem = XVECEXP (valreg, 0, 0);
2668 rtx where = XEXP (elem, 0);
2669 rtx offset = XEXP (elem, 1);
2670 if (offset == const0_rtx
2671 && GET_MODE (where) == GET_MODE (valreg))
2676 /* Precompute all register parameters. It isn't safe to compute anything
2677 once we have started filling any specific hard regs. */
2678 precompute_register_parameters (num_actuals, args, ®_parm_seen);
2680 if (CALL_EXPR_STATIC_CHAIN (exp))
2681 static_chain_value = expand_normal (CALL_EXPR_STATIC_CHAIN (exp));
2683 static_chain_value = 0;
2685 #ifdef REG_PARM_STACK_SPACE
2686 /* Save the fixed argument area if it's part of the caller's frame and
2687 is clobbered by argument setup for this call. */
2688 if (ACCUMULATE_OUTGOING_ARGS && pass)
2689 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
2690 &low_to_save, &high_to_save);
2693 /* Now store (and compute if necessary) all non-register parms.
2694 These come before register parms, since they can require block-moves,
2695 which could clobber the registers used for register parms.
2696 Parms which have partial registers are not stored here,
2697 but we do preallocate space here if they want that. */
2699 for (i = 0; i < num_actuals; i++)
2700 if (args[i].reg == 0 || args[i].pass_on_stack)
2702 rtx before_arg = get_last_insn ();
2704 if (store_one_arg (&args[i], argblock, flags,
2705 adjusted_args_size.var != 0,
2706 reg_parm_stack_space)
2708 && check_sibcall_argument_overlap (before_arg,
2710 sibcall_failure = 1;
2712 if (flags & ECF_CONST
2714 && args[i].value == args[i].stack)
2715 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
2716 gen_rtx_USE (VOIDmode,
2721 /* If we have a parm that is passed in registers but not in memory
2722 and whose alignment does not permit a direct copy into registers,
2723 make a group of pseudos that correspond to each register that we
2725 if (STRICT_ALIGNMENT)
2726 store_unaligned_arguments_into_pseudos (args, num_actuals);
2728 /* Now store any partially-in-registers parm.
2729 This is the last place a block-move can happen. */
2731 for (i = 0; i < num_actuals; i++)
2732 if (args[i].partial != 0 && ! args[i].pass_on_stack)
2734 rtx before_arg = get_last_insn ();
2736 if (store_one_arg (&args[i], argblock, flags,
2737 adjusted_args_size.var != 0,
2738 reg_parm_stack_space)
2740 && check_sibcall_argument_overlap (before_arg,
2742 sibcall_failure = 1;
2745 /* If we pushed args in forward order, perform stack alignment
2746 after pushing the last arg. */
2747 if (!PUSH_ARGS_REVERSED && argblock == 0)
2748 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2749 - unadjusted_args_size));
2751 /* If register arguments require space on the stack and stack space
2752 was not preallocated, allocate stack space here for arguments
2753 passed in registers. */
2754 if (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
2755 && !ACCUMULATE_OUTGOING_ARGS
2756 && must_preallocate == 0 && reg_parm_stack_space > 0)
2757 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
2759 /* Pass the function the address in which to return a
2761 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
2763 structure_value_addr
2764 = convert_memory_address (Pmode, structure_value_addr);
2765 emit_move_insn (struct_value,
2767 force_operand (structure_value_addr,
2770 if (REG_P (struct_value))
2771 use_reg (&call_fusage, struct_value);
2774 after_args = get_last_insn ();
2775 funexp = prepare_call_address (funexp, static_chain_value,
2776 &call_fusage, reg_parm_seen, pass == 0);
2778 load_register_parameters (args, num_actuals, &call_fusage, flags,
2779 pass == 0, &sibcall_failure);
2781 /* Save a pointer to the last insn before the call, so that we can
2782 later safely search backwards to find the CALL_INSN. */
2783 before_call = get_last_insn ();
2785 /* Set up next argument register. For sibling calls on machines
2786 with register windows this should be the incoming register. */
2787 #ifdef FUNCTION_INCOMING_ARG
2789 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
2793 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
2796 /* All arguments and registers used for the call must be set up by
2799 /* Stack must be properly aligned now. */
2801 || !(stack_pointer_delta % preferred_unit_stack_boundary));
2803 /* Generate the actual call instruction. */
2804 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size,
2805 adjusted_args_size.constant, struct_value_size,
2806 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
2807 flags, & args_so_far);
2809 /* If the call setup or the call itself overlaps with anything
2810 of the argument setup we probably clobbered our call address.
2811 In that case we can't do sibcalls. */
2813 && check_sibcall_argument_overlap (after_args, 0, 0))
2814 sibcall_failure = 1;
2816 /* If a non-BLKmode value is returned at the most significant end
2817 of a register, shift the register right by the appropriate amount
2818 and update VALREG accordingly. BLKmode values are handled by the
2819 group load/store machinery below. */
2820 if (!structure_value_addr
2821 && !pcc_struct_value
2822 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
2823 && targetm.calls.return_in_msb (TREE_TYPE (exp)))
2825 if (shift_return_value (TYPE_MODE (TREE_TYPE (exp)), false, valreg))
2826 sibcall_failure = 1;
2827 valreg = gen_rtx_REG (TYPE_MODE (TREE_TYPE (exp)), REGNO (valreg));
2830 if (pass && (flags & ECF_MALLOC))
2832 rtx temp = gen_reg_rtx (GET_MODE (valreg));
2835 /* The return value from a malloc-like function is a pointer. */
2836 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
2837 mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
2839 emit_move_insn (temp, valreg);
2841 /* The return value from a malloc-like function can not alias
2843 last = get_last_insn ();
2844 add_reg_note (last, REG_NOALIAS, temp);
2846 /* Write out the sequence. */
2847 insns = get_insns ();
2853 /* For calls to `setjmp', etc., inform
2854 function.c:setjmp_warnings that it should complain if
2855 nonvolatile values are live. For functions that cannot
2856 return, inform flow that control does not fall through. */
2858 if ((flags & ECF_NORETURN) || pass == 0)
2860 /* The barrier must be emitted
2861 immediately after the CALL_INSN. Some ports emit more
2862 than just a CALL_INSN above, so we must search for it here. */
2864 rtx last = get_last_insn ();
2865 while (!CALL_P (last))
2867 last = PREV_INSN (last);
2868 /* There was no CALL_INSN? */
2869 gcc_assert (last != before_call);
2872 emit_barrier_after (last);
2874 /* Stack adjustments after a noreturn call are dead code.
2875 However when NO_DEFER_POP is in effect, we must preserve
2876 stack_pointer_delta. */
2877 if (inhibit_defer_pop == 0)
2879 stack_pointer_delta = old_stack_allocated;
2880 pending_stack_adjust = 0;
2884 /* If value type not void, return an rtx for the value. */
2886 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
2888 target = const0_rtx;
2889 else if (structure_value_addr)
2891 if (target == 0 || !MEM_P (target))
2894 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
2895 memory_address (TYPE_MODE (TREE_TYPE (exp)),
2896 structure_value_addr));
2897 set_mem_attributes (target, exp, 1);
2900 else if (pcc_struct_value)
2902 /* This is the special C++ case where we need to
2903 know what the true target was. We take care to
2904 never use this value more than once in one expression. */
2905 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
2906 copy_to_reg (valreg));
2907 set_mem_attributes (target, exp, 1);
2909 /* Handle calls that return values in multiple non-contiguous locations.
2910 The Irix 6 ABI has examples of this. */
2911 else if (GET_CODE (valreg) == PARALLEL)
2915 /* This will only be assigned once, so it can be readonly. */
2916 tree nt = build_qualified_type (TREE_TYPE (exp),
2917 (TYPE_QUALS (TREE_TYPE (exp))
2918 | TYPE_QUAL_CONST));
2920 target = assign_temp (nt, 0, 1, 1);
2923 if (! rtx_equal_p (target, valreg))
2924 emit_group_store (target, valreg, TREE_TYPE (exp),
2925 int_size_in_bytes (TREE_TYPE (exp)));
2927 /* We can not support sibling calls for this case. */
2928 sibcall_failure = 1;
2931 && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
2932 && GET_MODE (target) == GET_MODE (valreg))
2934 bool may_overlap = false;
2936 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
2937 reg to a plain register. */
2938 if (!REG_P (target) || HARD_REGISTER_P (target))
2939 valreg = avoid_likely_spilled_reg (valreg);
2941 /* If TARGET is a MEM in the argument area, and we have
2942 saved part of the argument area, then we can't store
2943 directly into TARGET as it may get overwritten when we
2944 restore the argument save area below. Don't work too
2945 hard though and simply force TARGET to a register if it
2946 is a MEM; the optimizer is quite likely to sort it out. */
2947 if (ACCUMULATE_OUTGOING_ARGS && pass && MEM_P (target))
2948 for (i = 0; i < num_actuals; i++)
2949 if (args[i].save_area)
2956 target = copy_to_reg (valreg);
2959 /* TARGET and VALREG cannot be equal at this point
2960 because the latter would not have
2961 REG_FUNCTION_VALUE_P true, while the former would if
2962 it were referring to the same register.
2964 If they refer to the same register, this move will be
2965 a no-op, except when function inlining is being
2967 emit_move_insn (target, valreg);
2969 /* If we are setting a MEM, this code must be executed.
2970 Since it is emitted after the call insn, sibcall
2971 optimization cannot be performed in that case. */
2973 sibcall_failure = 1;
2976 else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode)
2978 target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp));
2980 /* We can not support sibling calls for this case. */
2981 sibcall_failure = 1;
2984 target = copy_to_reg (avoid_likely_spilled_reg (valreg));
2986 if (targetm.calls.promote_function_return(funtype))
2988 /* If we promoted this return value, make the proper SUBREG.
2989 TARGET might be const0_rtx here, so be careful. */
2991 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
2992 && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
2994 tree type = TREE_TYPE (exp);
2995 int unsignedp = TYPE_UNSIGNED (type);
2997 enum machine_mode pmode;
2999 pmode = promote_mode (type, TYPE_MODE (type), &unsignedp, 1);
3000 /* If we don't promote as expected, something is wrong. */
3001 gcc_assert (GET_MODE (target) == pmode);
3003 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
3004 && (GET_MODE_SIZE (GET_MODE (target))
3005 > GET_MODE_SIZE (TYPE_MODE (type))))
3007 offset = GET_MODE_SIZE (GET_MODE (target))
3008 - GET_MODE_SIZE (TYPE_MODE (type));
3009 if (! BYTES_BIG_ENDIAN)
3010 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
3011 else if (! WORDS_BIG_ENDIAN)
3012 offset %= UNITS_PER_WORD;
3014 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
3015 SUBREG_PROMOTED_VAR_P (target) = 1;
3016 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
3020 /* If size of args is variable or this was a constructor call for a stack
3021 argument, restore saved stack-pointer value. */
3023 if (old_stack_level)
3025 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
3026 stack_pointer_delta = old_stack_pointer_delta;
3027 pending_stack_adjust = old_pending_adj;
3028 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
3029 stack_arg_under_construction = old_stack_arg_under_construction;
3030 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3031 stack_usage_map = initial_stack_usage_map;
3032 sibcall_failure = 1;
3034 else if (ACCUMULATE_OUTGOING_ARGS && pass)
3036 #ifdef REG_PARM_STACK_SPACE
3038 restore_fixed_argument_area (save_area, argblock,
3039 high_to_save, low_to_save);
3042 /* If we saved any argument areas, restore them. */
3043 for (i = 0; i < num_actuals; i++)
3044 if (args[i].save_area)
3046 enum machine_mode save_mode = GET_MODE (args[i].save_area);
3048 = gen_rtx_MEM (save_mode,
3049 memory_address (save_mode,
3050 XEXP (args[i].stack_slot, 0)));
3052 if (save_mode != BLKmode)
3053 emit_move_insn (stack_area, args[i].save_area);
3055 emit_block_move (stack_area, args[i].save_area,
3056 GEN_INT (args[i].locate.size.constant),
3057 BLOCK_OP_CALL_PARM);
3060 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3061 stack_usage_map = initial_stack_usage_map;
3064 /* If this was alloca, record the new stack level for nonlocal gotos.
3065 Check for the handler slots since we might not have a save area
3066 for non-local gotos. */
3068 if ((flags & ECF_MAY_BE_ALLOCA) && cfun->nonlocal_goto_save_area != 0)
3069 update_nonlocal_goto_save_area ();
3071 /* Free up storage we no longer need. */
3072 for (i = 0; i < num_actuals; ++i)
3073 if (args[i].aligned_regs)
3074 free (args[i].aligned_regs);
3076 insns = get_insns ();
3081 tail_call_insns = insns;
3083 /* Restore the pending stack adjustment now that we have
3084 finished generating the sibling call sequence. */
3086 pending_stack_adjust = save_pending_stack_adjust;
3087 stack_pointer_delta = save_stack_pointer_delta;
3089 /* Prepare arg structure for next iteration. */
3090 for (i = 0; i < num_actuals; i++)
3093 args[i].aligned_regs = 0;
3097 sbitmap_free (stored_args_map);
3101 normal_call_insns = insns;
3103 /* Verify that we've deallocated all the stack we used. */
3104 gcc_assert ((flags & ECF_NORETURN)
3105 || (old_stack_allocated
3106 == stack_pointer_delta - pending_stack_adjust));
3109 /* If something prevents making this a sibling call,
3110 zero out the sequence. */
3111 if (sibcall_failure)
3112 tail_call_insns = NULL_RTX;
3117 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
3118 arguments too, as argument area is now clobbered by the call. */
3119 if (tail_call_insns)
3121 emit_insn (tail_call_insns);
3122 crtl->tail_call_emit = true;
3125 emit_insn (normal_call_insns);
3127 currently_expanding_call--;
3129 if (stack_usage_map_buf)
3130 free (stack_usage_map_buf);
3135 /* A sibling call sequence invalidates any REG_EQUIV notes made for
3136 this function's incoming arguments.
3138 At the start of RTL generation we know the only REG_EQUIV notes
3139 in the rtl chain are those for incoming arguments, so we can look
3140 for REG_EQUIV notes between the start of the function and the
3141 NOTE_INSN_FUNCTION_BEG.
3143 This is (slight) overkill. We could keep track of the highest
3144 argument we clobber and be more selective in removing notes, but it
3145 does not seem to be worth the effort. */
3148 fixup_tail_calls (void)
3152 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3156 /* There are never REG_EQUIV notes for the incoming arguments
3157 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
3159 && NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG)
3162 note = find_reg_note (insn, REG_EQUIV, 0);
3164 remove_note (insn, note);
3165 note = find_reg_note (insn, REG_EQUIV, 0);
3170 /* Traverse a list of TYPES and expand all complex types into their
3173 split_complex_types (tree types)
3177 /* Before allocating memory, check for the common case of no complex. */
3178 for (p = types; p; p = TREE_CHAIN (p))
3180 tree type = TREE_VALUE (p);
3181 if (TREE_CODE (type) == COMPLEX_TYPE
3182 && targetm.calls.split_complex_arg (type))
3188 types = copy_list (types);
3190 for (p = types; p; p = TREE_CHAIN (p))
3192 tree complex_type = TREE_VALUE (p);
3194 if (TREE_CODE (complex_type) == COMPLEX_TYPE
3195 && targetm.calls.split_complex_arg (complex_type))
3199 /* Rewrite complex type with component type. */
3200 TREE_VALUE (p) = TREE_TYPE (complex_type);
3201 next = TREE_CHAIN (p);
3203 /* Add another component type for the imaginary part. */
3204 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
3205 TREE_CHAIN (p) = imag;
3206 TREE_CHAIN (imag) = next;
3208 /* Skip the newly created node. */
3216 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3217 The RETVAL parameter specifies whether return value needs to be saved, other
3218 parameters are documented in the emit_library_call function below. */
3221 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
3222 enum libcall_type fn_type,
3223 enum machine_mode outmode, int nargs, va_list p)
3225 /* Total size in bytes of all the stack-parms scanned so far. */
3226 struct args_size args_size;
3227 /* Size of arguments before any adjustments (such as rounding). */
3228 struct args_size original_args_size;
3231 /* Todo, choose the correct decl type of orgfun. Sadly this information
3232 isn't present here, so we default to native calling abi here. */
3233 tree fndecl ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
3234 tree fntype ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
3238 CUMULATIVE_ARGS args_so_far;
3242 enum machine_mode mode;
3245 struct locate_and_pad_arg_data locate;
3249 int old_inhibit_defer_pop = inhibit_defer_pop;
3250 rtx call_fusage = 0;
3253 int pcc_struct_value = 0;
3254 int struct_value_size = 0;
3256 int reg_parm_stack_space = 0;
3259 tree tfom; /* type_for_mode (outmode, 0) */
3261 #ifdef REG_PARM_STACK_SPACE
3262 /* Define the boundary of the register parm stack space that needs to be
3264 int low_to_save = 0, high_to_save = 0;
3265 rtx save_area = 0; /* Place that it is saved. */
3268 /* Size of the stack reserved for parameter registers. */
3269 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3270 char *initial_stack_usage_map = stack_usage_map;
3271 char *stack_usage_map_buf = NULL;
3273 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
3275 #ifdef REG_PARM_STACK_SPACE
3276 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3279 /* By default, library functions can not throw. */
3280 flags = ECF_NOTHROW;
3293 flags |= ECF_NORETURN;
3296 flags = ECF_NORETURN;
3298 case LCT_RETURNS_TWICE:
3299 flags = ECF_RETURNS_TWICE;
3304 /* Ensure current function's preferred stack boundary is at least
3306 if (crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3307 crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3309 /* If this kind of value comes back in memory,
3310 decide where in memory it should come back. */
3311 if (outmode != VOIDmode)
3313 tfom = lang_hooks.types.type_for_mode (outmode, 0);
3314 if (aggregate_value_p (tfom, 0))
3316 #ifdef PCC_STATIC_STRUCT_RETURN
3318 = hard_function_value (build_pointer_type (tfom), 0, 0, 0);
3319 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3320 pcc_struct_value = 1;
3322 value = gen_reg_rtx (outmode);
3323 #else /* not PCC_STATIC_STRUCT_RETURN */
3324 struct_value_size = GET_MODE_SIZE (outmode);
3325 if (value != 0 && MEM_P (value))
3328 mem_value = assign_temp (tfom, 0, 1, 1);
3330 /* This call returns a big structure. */
3331 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
3335 tfom = void_type_node;
3337 /* ??? Unfinished: must pass the memory address as an argument. */
3339 /* Copy all the libcall-arguments out of the varargs data
3340 and into a vector ARGVEC.
3342 Compute how to pass each argument. We only support a very small subset
3343 of the full argument passing conventions to limit complexity here since
3344 library functions shouldn't have many args. */
3346 argvec = XALLOCAVEC (struct arg, nargs + 1);
3347 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
3349 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3350 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun);
3352 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0, nargs);
3355 args_size.constant = 0;
3362 /* If there's a structure value address to be passed,
3363 either pass it in the special place, or pass it as an extra argument. */
3364 if (mem_value && struct_value == 0 && ! pcc_struct_value)
3366 rtx addr = XEXP (mem_value, 0);
3370 /* Make sure it is a reasonable operand for a move or push insn. */
3371 if (!REG_P (addr) && !MEM_P (addr)
3372 && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr)))
3373 addr = force_operand (addr, NULL_RTX);
3375 argvec[count].value = addr;
3376 argvec[count].mode = Pmode;
3377 argvec[count].partial = 0;
3379 argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1);
3380 gcc_assert (targetm.calls.arg_partial_bytes (&args_so_far, Pmode,
3381 NULL_TREE, 1) == 0);
3383 locate_and_pad_parm (Pmode, NULL_TREE,
3384 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3387 argvec[count].reg != 0,
3389 0, NULL_TREE, &args_size, &argvec[count].locate);
3391 if (argvec[count].reg == 0 || argvec[count].partial != 0
3392 || reg_parm_stack_space > 0)
3393 args_size.constant += argvec[count].locate.size.constant;
3395 FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1);
3400 for (; count < nargs; count++)
3402 rtx val = va_arg (p, rtx);
3403 enum machine_mode mode = va_arg (p, enum machine_mode);
3405 /* We cannot convert the arg value to the mode the library wants here;
3406 must do it earlier where we know the signedness of the arg. */
3407 gcc_assert (mode != BLKmode
3408 && (GET_MODE (val) == mode || GET_MODE (val) == VOIDmode));
3410 /* Make sure it is a reasonable operand for a move or push insn. */
3411 if (!REG_P (val) && !MEM_P (val)
3412 && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val)))
3413 val = force_operand (val, NULL_RTX);
3415 if (pass_by_reference (&args_so_far, mode, NULL_TREE, 1))
3419 = !reference_callee_copied (&args_so_far, mode, NULL_TREE, 1);
3421 /* If this was a CONST function, it is now PURE since it now
3423 if (flags & ECF_CONST)
3425 flags &= ~ECF_CONST;
3429 if (MEM_P (val) && !must_copy)
3433 slot = assign_temp (lang_hooks.types.type_for_mode (mode, 0),
3435 emit_move_insn (slot, val);
3438 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3439 gen_rtx_USE (VOIDmode, slot),
3442 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3443 gen_rtx_CLOBBER (VOIDmode,
3448 val = force_operand (XEXP (slot, 0), NULL_RTX);
3451 argvec[count].value = val;
3452 argvec[count].mode = mode;
3454 argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1);
3456 argvec[count].partial
3457 = targetm.calls.arg_partial_bytes (&args_so_far, mode, NULL_TREE, 1);
3459 locate_and_pad_parm (mode, NULL_TREE,
3460 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3463 argvec[count].reg != 0,
3465 argvec[count].partial,
3466 NULL_TREE, &args_size, &argvec[count].locate);
3468 gcc_assert (!argvec[count].locate.size.var);
3470 if (argvec[count].reg == 0 || argvec[count].partial != 0
3471 || reg_parm_stack_space > 0)
3472 args_size.constant += argvec[count].locate.size.constant;
3474 FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1);
3477 /* If this machine requires an external definition for library
3478 functions, write one out. */
3479 assemble_external_libcall (fun);
3481 original_args_size = args_size;
3482 args_size.constant = (((args_size.constant
3483 + stack_pointer_delta
3487 - stack_pointer_delta);
3489 args_size.constant = MAX (args_size.constant,
3490 reg_parm_stack_space);
3492 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
3493 args_size.constant -= reg_parm_stack_space;
3495 if (args_size.constant > crtl->outgoing_args_size)
3496 crtl->outgoing_args_size = args_size.constant;
3498 if (ACCUMULATE_OUTGOING_ARGS)
3500 /* Since the stack pointer will never be pushed, it is possible for
3501 the evaluation of a parm to clobber something we have already
3502 written to the stack. Since most function calls on RISC machines
3503 do not use the stack, this is uncommon, but must work correctly.
3505 Therefore, we save any area of the stack that was already written
3506 and that we are using. Here we set up to do this by making a new
3507 stack usage map from the old one.
3509 Another approach might be to try to reorder the argument
3510 evaluations to avoid this conflicting stack usage. */
3512 needed = args_size.constant;
3514 /* Since we will be writing into the entire argument area, the
3515 map must be allocated for its entire size, not just the part that
3516 is the responsibility of the caller. */
3517 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
3518 needed += reg_parm_stack_space;
3520 #ifdef ARGS_GROW_DOWNWARD
3521 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3524 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3527 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
3528 stack_usage_map = stack_usage_map_buf;
3530 if (initial_highest_arg_in_use)
3531 memcpy (stack_usage_map, initial_stack_usage_map,
3532 initial_highest_arg_in_use);
3534 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3535 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3536 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3539 /* We must be careful to use virtual regs before they're instantiated,
3540 and real regs afterwards. Loop optimization, for example, can create
3541 new libcalls after we've instantiated the virtual regs, and if we
3542 use virtuals anyway, they won't match the rtl patterns. */
3544 if (virtuals_instantiated)
3545 argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET);
3547 argblock = virtual_outgoing_args_rtx;
3552 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3555 /* If we push args individually in reverse order, perform stack alignment
3556 before the first push (the last arg). */
3557 if (argblock == 0 && PUSH_ARGS_REVERSED)
3558 anti_adjust_stack (GEN_INT (args_size.constant
3559 - original_args_size.constant));
3561 if (PUSH_ARGS_REVERSED)
3572 #ifdef REG_PARM_STACK_SPACE
3573 if (ACCUMULATE_OUTGOING_ARGS)
3575 /* The argument list is the property of the called routine and it
3576 may clobber it. If the fixed area has been used for previous
3577 parameters, we must save and restore it. */
3578 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3579 &low_to_save, &high_to_save);
3583 /* Push the args that need to be pushed. */
3585 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3586 are to be pushed. */
3587 for (count = 0; count < nargs; count++, argnum += inc)
3589 enum machine_mode mode = argvec[argnum].mode;
3590 rtx val = argvec[argnum].value;
3591 rtx reg = argvec[argnum].reg;
3592 int partial = argvec[argnum].partial;
3593 int lower_bound = 0, upper_bound = 0, i;
3595 if (! (reg != 0 && partial == 0))
3597 if (ACCUMULATE_OUTGOING_ARGS)
3599 /* If this is being stored into a pre-allocated, fixed-size,
3600 stack area, save any previous data at that location. */
3602 #ifdef ARGS_GROW_DOWNWARD
3603 /* stack_slot is negative, but we want to index stack_usage_map
3604 with positive values. */
3605 upper_bound = -argvec[argnum].locate.offset.constant + 1;
3606 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
3608 lower_bound = argvec[argnum].locate.offset.constant;
3609 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
3613 /* Don't worry about things in the fixed argument area;
3614 it has already been saved. */
3615 if (i < reg_parm_stack_space)
3616 i = reg_parm_stack_space;
3617 while (i < upper_bound && stack_usage_map[i] == 0)
3620 if (i < upper_bound)
3622 /* We need to make a save area. */
3624 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
3625 enum machine_mode save_mode
3626 = mode_for_size (size, MODE_INT, 1);
3628 = plus_constant (argblock,
3629 argvec[argnum].locate.offset.constant);
3631 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
3633 if (save_mode == BLKmode)
3635 argvec[argnum].save_area
3636 = assign_stack_temp (BLKmode,
3637 argvec[argnum].locate.size.constant,
3640 emit_block_move (validize_mem (argvec[argnum].save_area),
3642 GEN_INT (argvec[argnum].locate.size.constant),
3643 BLOCK_OP_CALL_PARM);
3647 argvec[argnum].save_area = gen_reg_rtx (save_mode);
3649 emit_move_insn (argvec[argnum].save_area, stack_area);
3654 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, PARM_BOUNDARY,
3655 partial, reg, 0, argblock,
3656 GEN_INT (argvec[argnum].locate.offset.constant),
3657 reg_parm_stack_space,
3658 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad));
3660 /* Now mark the segment we just used. */
3661 if (ACCUMULATE_OUTGOING_ARGS)
3662 for (i = lower_bound; i < upper_bound; i++)
3663 stack_usage_map[i] = 1;
3667 if (flags & ECF_CONST)
3671 /* Indicate argument access so that alias.c knows that these
3674 use = plus_constant (argblock,
3675 argvec[argnum].locate.offset.constant);
3677 /* When arguments are pushed, trying to tell alias.c where
3678 exactly this argument is won't work, because the
3679 auto-increment causes confusion. So we merely indicate
3680 that we access something with a known mode somewhere on
3682 use = gen_rtx_PLUS (Pmode, virtual_outgoing_args_rtx,
3683 gen_rtx_SCRATCH (Pmode));
3684 use = gen_rtx_MEM (argvec[argnum].mode, use);
3685 use = gen_rtx_USE (VOIDmode, use);
3686 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, use, call_fusage);
3691 /* If we pushed args in forward order, perform stack alignment
3692 after pushing the last arg. */
3693 if (argblock == 0 && !PUSH_ARGS_REVERSED)
3694 anti_adjust_stack (GEN_INT (args_size.constant
3695 - original_args_size.constant));
3697 if (PUSH_ARGS_REVERSED)
3702 fun = prepare_call_address (fun, NULL, &call_fusage, 0, 0);
3704 /* Now load any reg parms into their regs. */
3706 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3707 are to be pushed. */
3708 for (count = 0; count < nargs; count++, argnum += inc)
3710 enum machine_mode mode = argvec[argnum].mode;
3711 rtx val = argvec[argnum].value;
3712 rtx reg = argvec[argnum].reg;
3713 int partial = argvec[argnum].partial;
3715 /* Handle calls that pass values in multiple non-contiguous
3716 locations. The PA64 has examples of this for library calls. */
3717 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3718 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode));
3719 else if (reg != 0 && partial == 0)
3720 emit_move_insn (reg, val);
3725 /* Any regs containing parms remain in use through the call. */
3726 for (count = 0; count < nargs; count++)
3728 rtx reg = argvec[count].reg;
3729 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3730 use_group_regs (&call_fusage, reg);
3733 int partial = argvec[count].partial;
3737 gcc_assert (partial % UNITS_PER_WORD == 0);
3738 nregs = partial / UNITS_PER_WORD;
3739 use_regs (&call_fusage, REGNO (reg), nregs);
3742 use_reg (&call_fusage, reg);
3746 /* Pass the function the address in which to return a structure value. */
3747 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
3749 emit_move_insn (struct_value,
3751 force_operand (XEXP (mem_value, 0),
3753 if (REG_P (struct_value))
3754 use_reg (&call_fusage, struct_value);
3757 /* Don't allow popping to be deferred, since then
3758 cse'ing of library calls could delete a call and leave the pop. */
3760 valreg = (mem_value == 0 && outmode != VOIDmode
3761 ? hard_libcall_value (outmode) : NULL_RTX);
3763 /* Stack must be properly aligned now. */
3764 gcc_assert (!(stack_pointer_delta
3765 & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1)));
3767 before_call = get_last_insn ();
3769 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
3770 will set inhibit_defer_pop to that value. */
3771 /* The return type is needed to decide how many bytes the function pops.
3772 Signedness plays no role in that, so for simplicity, we pretend it's
3773 always signed. We also assume that the list of arguments passed has
3774 no impact, so we pretend it is unknown. */
3776 emit_call_1 (fun, NULL,
3777 get_identifier (XSTR (orgfun, 0)),
3778 build_function_type (tfom, NULL_TREE),
3779 original_args_size.constant, args_size.constant,
3781 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
3783 old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far);
3785 /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
3786 that it should complain if nonvolatile values are live. For
3787 functions that cannot return, inform flow that control does not
3790 if (flags & ECF_NORETURN)
3792 /* The barrier note must be emitted
3793 immediately after the CALL_INSN. Some ports emit more than
3794 just a CALL_INSN above, so we must search for it here. */
3796 rtx last = get_last_insn ();
3797 while (!CALL_P (last))
3799 last = PREV_INSN (last);
3800 /* There was no CALL_INSN? */
3801 gcc_assert (last != before_call);
3804 emit_barrier_after (last);
3807 /* Now restore inhibit_defer_pop to its actual original value. */
3812 /* Copy the value to the right place. */
3813 if (outmode != VOIDmode && retval)
3819 if (value != mem_value)
3820 emit_move_insn (value, mem_value);
3822 else if (GET_CODE (valreg) == PARALLEL)
3825 value = gen_reg_rtx (outmode);
3826 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
3830 /* Convert to the proper mode if PROMOTE_MODE has been active. */
3831 if (GET_MODE (valreg) != outmode)
3833 int unsignedp = TYPE_UNSIGNED (tfom);
3835 gcc_assert (targetm.calls.promote_function_return (tfom));
3836 gcc_assert (promote_mode (tfom, outmode, &unsignedp, 0)
3837 == GET_MODE (valreg));
3839 valreg = convert_modes (outmode, GET_MODE (valreg), valreg, 0);
3843 emit_move_insn (value, valreg);
3849 if (ACCUMULATE_OUTGOING_ARGS)
3851 #ifdef REG_PARM_STACK_SPACE
3853 restore_fixed_argument_area (save_area, argblock,
3854 high_to_save, low_to_save);
3857 /* If we saved any argument areas, restore them. */
3858 for (count = 0; count < nargs; count++)
3859 if (argvec[count].save_area)
3861 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
3862 rtx adr = plus_constant (argblock,
3863 argvec[count].locate.offset.constant);
3864 rtx stack_area = gen_rtx_MEM (save_mode,
3865 memory_address (save_mode, adr));
3867 if (save_mode == BLKmode)
3868 emit_block_move (stack_area,
3869 validize_mem (argvec[count].save_area),
3870 GEN_INT (argvec[count].locate.size.constant),
3871 BLOCK_OP_CALL_PARM);
3873 emit_move_insn (stack_area, argvec[count].save_area);
3876 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3877 stack_usage_map = initial_stack_usage_map;
3880 if (stack_usage_map_buf)
3881 free (stack_usage_map_buf);
3887 /* Output a library call to function FUN (a SYMBOL_REF rtx)
3888 (emitting the queue unless NO_QUEUE is nonzero),
3889 for a value of mode OUTMODE,
3890 with NARGS different arguments, passed as alternating rtx values
3891 and machine_modes to convert them to.
3893 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for
3894 `const' calls, LCT_PURE for `pure' calls, or other LCT_ value for
3895 other types of library calls. */
3898 emit_library_call (rtx orgfun, enum libcall_type fn_type,
3899 enum machine_mode outmode, int nargs, ...)
3903 va_start (p, nargs);
3904 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
3908 /* Like emit_library_call except that an extra argument, VALUE,
3909 comes second and says where to store the result.
3910 (If VALUE is zero, this function chooses a convenient way
3911 to return the value.
3913 This function returns an rtx for where the value is to be found.
3914 If VALUE is nonzero, VALUE is returned. */
3917 emit_library_call_value (rtx orgfun, rtx value,
3918 enum libcall_type fn_type,
3919 enum machine_mode outmode, int nargs, ...)
3924 va_start (p, nargs);
3925 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
3932 /* Store a single argument for a function call
3933 into the register or memory area where it must be passed.
3934 *ARG describes the argument value and where to pass it.
3936 ARGBLOCK is the address of the stack-block for all the arguments,
3937 or 0 on a machine where arguments are pushed individually.
3939 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
3940 so must be careful about how the stack is used.
3942 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
3943 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
3944 that we need not worry about saving and restoring the stack.
3946 FNDECL is the declaration of the function we are calling.
3948 Return nonzero if this arg should cause sibcall failure,
3952 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
3953 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
3955 tree pval = arg->tree_value;
3959 int i, lower_bound = 0, upper_bound = 0;
3960 int sibcall_failure = 0;
3962 if (TREE_CODE (pval) == ERROR_MARK)
3965 /* Push a new temporary level for any temporaries we make for
3969 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
3971 /* If this is being stored into a pre-allocated, fixed-size, stack area,
3972 save any previous data at that location. */
3973 if (argblock && ! variable_size && arg->stack)
3975 #ifdef ARGS_GROW_DOWNWARD
3976 /* stack_slot is negative, but we want to index stack_usage_map
3977 with positive values. */
3978 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
3979 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
3983 lower_bound = upper_bound - arg->locate.size.constant;
3985 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
3986 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
3990 upper_bound = lower_bound + arg->locate.size.constant;
3994 /* Don't worry about things in the fixed argument area;
3995 it has already been saved. */
3996 if (i < reg_parm_stack_space)
3997 i = reg_parm_stack_space;
3998 while (i < upper_bound && stack_usage_map[i] == 0)
4001 if (i < upper_bound)
4003 /* We need to make a save area. */
4004 unsigned int size = arg->locate.size.constant * BITS_PER_UNIT;
4005 enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1);
4006 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
4007 rtx stack_area = gen_rtx_MEM (save_mode, adr);
4009 if (save_mode == BLKmode)
4011 tree ot = TREE_TYPE (arg->tree_value);
4012 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
4013 | TYPE_QUAL_CONST));
4015 arg->save_area = assign_temp (nt, 0, 1, 1);
4016 preserve_temp_slots (arg->save_area);
4017 emit_block_move (validize_mem (arg->save_area), stack_area,
4018 GEN_INT (arg->locate.size.constant),
4019 BLOCK_OP_CALL_PARM);
4023 arg->save_area = gen_reg_rtx (save_mode);
4024 emit_move_insn (arg->save_area, stack_area);
4030 /* If this isn't going to be placed on both the stack and in registers,
4031 set up the register and number of words. */
4032 if (! arg->pass_on_stack)
4034 if (flags & ECF_SIBCALL)
4035 reg = arg->tail_call_reg;
4038 partial = arg->partial;
4041 /* Being passed entirely in a register. We shouldn't be called in
4043 gcc_assert (reg == 0 || partial != 0);
4045 /* If this arg needs special alignment, don't load the registers
4047 if (arg->n_aligned_regs != 0)
4050 /* If this is being passed partially in a register, we can't evaluate
4051 it directly into its stack slot. Otherwise, we can. */
4052 if (arg->value == 0)
4054 /* stack_arg_under_construction is nonzero if a function argument is
4055 being evaluated directly into the outgoing argument list and
4056 expand_call must take special action to preserve the argument list
4057 if it is called recursively.
4059 For scalar function arguments stack_usage_map is sufficient to
4060 determine which stack slots must be saved and restored. Scalar
4061 arguments in general have pass_on_stack == 0.
4063 If this argument is initialized by a function which takes the
4064 address of the argument (a C++ constructor or a C function
4065 returning a BLKmode structure), then stack_usage_map is
4066 insufficient and expand_call must push the stack around the
4067 function call. Such arguments have pass_on_stack == 1.
4069 Note that it is always safe to set stack_arg_under_construction,
4070 but this generates suboptimal code if set when not needed. */
4072 if (arg->pass_on_stack)
4073 stack_arg_under_construction++;
4075 arg->value = expand_expr (pval,
4077 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4078 ? NULL_RTX : arg->stack,
4079 VOIDmode, EXPAND_STACK_PARM);
4081 /* If we are promoting object (or for any other reason) the mode
4082 doesn't agree, convert the mode. */
4084 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4085 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4086 arg->value, arg->unsignedp);
4088 if (arg->pass_on_stack)
4089 stack_arg_under_construction--;
4092 /* Check for overlap with already clobbered argument area. */
4093 if ((flags & ECF_SIBCALL)
4094 && MEM_P (arg->value)
4095 && mem_overlaps_already_clobbered_arg_p (XEXP (arg->value, 0),
4096 arg->locate.size.constant))
4097 sibcall_failure = 1;
4099 /* Don't allow anything left on stack from computation
4100 of argument to alloca. */
4101 if (flags & ECF_MAY_BE_ALLOCA)
4102 do_pending_stack_adjust ();
4104 if (arg->value == arg->stack)
4105 /* If the value is already in the stack slot, we are done. */
4107 else if (arg->mode != BLKmode)
4110 unsigned int parm_align;
4112 /* Argument is a scalar, not entirely passed in registers.
4113 (If part is passed in registers, arg->partial says how much
4114 and emit_push_insn will take care of putting it there.)
4116 Push it, and if its size is less than the
4117 amount of space allocated to it,
4118 also bump stack pointer by the additional space.
4119 Note that in C the default argument promotions
4120 will prevent such mismatches. */
4122 size = GET_MODE_SIZE (arg->mode);
4123 /* Compute how much space the push instruction will push.
4124 On many machines, pushing a byte will advance the stack
4125 pointer by a halfword. */
4126 #ifdef PUSH_ROUNDING
4127 size = PUSH_ROUNDING (size);
4131 /* Compute how much space the argument should get:
4132 round up to a multiple of the alignment for arguments. */
4133 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4134 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4135 / (PARM_BOUNDARY / BITS_PER_UNIT))
4136 * (PARM_BOUNDARY / BITS_PER_UNIT));
4138 /* Compute the alignment of the pushed argument. */
4139 parm_align = arg->locate.boundary;
4140 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4142 int pad = used - size;
4145 unsigned int pad_align = (pad & -pad) * BITS_PER_UNIT;
4146 parm_align = MIN (parm_align, pad_align);
4150 /* This isn't already where we want it on the stack, so put it there.
4151 This can either be done with push or copy insns. */
4152 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4153 parm_align, partial, reg, used - size, argblock,
4154 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4155 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4157 /* Unless this is a partially-in-register argument, the argument is now
4160 arg->value = arg->stack;
4164 /* BLKmode, at least partly to be pushed. */
4166 unsigned int parm_align;
4170 /* Pushing a nonscalar.
4171 If part is passed in registers, PARTIAL says how much
4172 and emit_push_insn will take care of putting it there. */
4174 /* Round its size up to a multiple
4175 of the allocation unit for arguments. */
4177 if (arg->locate.size.var != 0)
4180 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
4184 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
4185 for BLKmode is careful to avoid it. */
4186 excess = (arg->locate.size.constant
4187 - int_size_in_bytes (TREE_TYPE (pval))
4189 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4190 NULL_RTX, TYPE_MODE (sizetype), 0);
4193 parm_align = arg->locate.boundary;
4195 /* When an argument is padded down, the block is aligned to
4196 PARM_BOUNDARY, but the actual argument isn't. */
4197 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4199 if (arg->locate.size.var)
4200 parm_align = BITS_PER_UNIT;
4203 unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4204 parm_align = MIN (parm_align, excess_align);
4208 if ((flags & ECF_SIBCALL) && MEM_P (arg->value))
4210 /* emit_push_insn might not work properly if arg->value and
4211 argblock + arg->locate.offset areas overlap. */
4215 if (XEXP (x, 0) == crtl->args.internal_arg_pointer
4216 || (GET_CODE (XEXP (x, 0)) == PLUS
4217 && XEXP (XEXP (x, 0), 0) ==
4218 crtl->args.internal_arg_pointer
4219 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT))
4221 if (XEXP (x, 0) != crtl->args.internal_arg_pointer)
4222 i = INTVAL (XEXP (XEXP (x, 0), 1));
4224 /* expand_call should ensure this. */
4225 gcc_assert (!arg->locate.offset.var
4226 && arg->locate.size.var == 0
4227 && GET_CODE (size_rtx) == CONST_INT);
4229 if (arg->locate.offset.constant > i)
4231 if (arg->locate.offset.constant < i + INTVAL (size_rtx))
4232 sibcall_failure = 1;
4234 else if (arg->locate.offset.constant < i)
4236 /* Use arg->locate.size.constant instead of size_rtx
4237 because we only care about the part of the argument
4239 if (i < (arg->locate.offset.constant
4240 + arg->locate.size.constant))
4241 sibcall_failure = 1;
4245 /* Even though they appear to be at the same location,
4246 if part of the outgoing argument is in registers,
4247 they aren't really at the same location. Check for
4248 this by making sure that the incoming size is the
4249 same as the outgoing size. */
4250 if (arg->locate.size.constant != INTVAL (size_rtx))
4251 sibcall_failure = 1;
4256 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4257 parm_align, partial, reg, excess, argblock,
4258 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4259 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4261 /* Unless this is a partially-in-register argument, the argument is now
4264 ??? Unlike the case above, in which we want the actual
4265 address of the data, so that we can load it directly into a
4266 register, here we want the address of the stack slot, so that
4267 it's properly aligned for word-by-word copying or something
4268 like that. It's not clear that this is always correct. */
4270 arg->value = arg->stack_slot;
4273 if (arg->reg && GET_CODE (arg->reg) == PARALLEL)
4275 tree type = TREE_TYPE (arg->tree_value);
4277 = emit_group_load_into_temps (arg->reg, arg->value, type,
4278 int_size_in_bytes (type));
4281 /* Mark all slots this store used. */
4282 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
4283 && argblock && ! variable_size && arg->stack)
4284 for (i = lower_bound; i < upper_bound; i++)
4285 stack_usage_map[i] = 1;
4287 /* Once we have pushed something, pops can't safely
4288 be deferred during the rest of the arguments. */
4291 /* Free any temporary slots made in processing this argument. Show
4292 that we might have taken the address of something and pushed that
4294 preserve_temp_slots (NULL_RTX);
4298 return sibcall_failure;
4301 /* Nonzero if we do not know how to pass TYPE solely in registers. */
4304 must_pass_in_stack_var_size (enum machine_mode mode ATTRIBUTE_UNUSED,
4310 /* If the type has variable size... */
4311 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4314 /* If the type is marked as addressable (it is required
4315 to be constructed into the stack)... */
4316 if (TREE_ADDRESSABLE (type))
4322 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
4323 takes trailing padding of a structure into account. */
4324 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
4327 must_pass_in_stack_var_size_or_pad (enum machine_mode mode, const_tree type)
4332 /* If the type has variable size... */
4333 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4336 /* If the type is marked as addressable (it is required
4337 to be constructed into the stack)... */
4338 if (TREE_ADDRESSABLE (type))
4341 /* If the padding and mode of the type is such that a copy into
4342 a register would put it into the wrong part of the register. */
4344 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
4345 && (FUNCTION_ARG_PADDING (mode, type)
4346 == (BYTES_BIG_ENDIAN ? upward : downward)))