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, 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,
941 tree fndecl, tree fntype,
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
1123 ? TREE_TYPE (fndecl)
1125 mode = promote_mode (type, mode, &unsignedp, 1);
1127 args[i].unsignedp = unsignedp;
1128 args[i].mode = mode;
1130 args[i].reg = FUNCTION_ARG (*args_so_far, mode, type,
1131 argpos < n_named_args);
1132 #ifdef FUNCTION_INCOMING_ARG
1133 /* If this is a sibling call and the machine has register windows, the
1134 register window has to be unwinded before calling the routine, so
1135 arguments have to go into the incoming registers. */
1136 args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type,
1137 argpos < n_named_args);
1139 args[i].tail_call_reg = args[i].reg;
1144 = targetm.calls.arg_partial_bytes (args_so_far, mode, type,
1145 argpos < n_named_args);
1147 args[i].pass_on_stack = targetm.calls.must_pass_in_stack (mode, type);
1149 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1150 it means that we are to pass this arg in the register(s) designated
1151 by the PARALLEL, but also to pass it in the stack. */
1152 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1153 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1154 args[i].pass_on_stack = 1;
1156 /* If this is an addressable type, we must preallocate the stack
1157 since we must evaluate the object into its final location.
1159 If this is to be passed in both registers and the stack, it is simpler
1161 if (TREE_ADDRESSABLE (type)
1162 || (args[i].pass_on_stack && args[i].reg != 0))
1163 *must_preallocate = 1;
1165 /* Compute the stack-size of this argument. */
1166 if (args[i].reg == 0 || args[i].partial != 0
1167 || reg_parm_stack_space > 0
1168 || args[i].pass_on_stack)
1169 locate_and_pad_parm (mode, type,
1170 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1175 args[i].pass_on_stack ? 0 : args[i].partial,
1176 fndecl, args_size, &args[i].locate);
1177 #ifdef BLOCK_REG_PADDING
1179 /* The argument is passed entirely in registers. See at which
1180 end it should be padded. */
1181 args[i].locate.where_pad =
1182 BLOCK_REG_PADDING (mode, type,
1183 int_size_in_bytes (type) <= UNITS_PER_WORD);
1186 /* Update ARGS_SIZE, the total stack space for args so far. */
1188 args_size->constant += args[i].locate.size.constant;
1189 if (args[i].locate.size.var)
1190 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
1192 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1193 have been used, etc. */
1195 FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type,
1196 argpos < n_named_args);
1200 /* Update ARGS_SIZE to contain the total size for the argument block.
1201 Return the original constant component of the argument block's size.
1203 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1204 for arguments passed in registers. */
1207 compute_argument_block_size (int reg_parm_stack_space,
1208 struct args_size *args_size,
1209 tree fndecl ATTRIBUTE_UNUSED,
1210 tree fntype ATTRIBUTE_UNUSED,
1211 int preferred_stack_boundary ATTRIBUTE_UNUSED)
1213 int unadjusted_args_size = args_size->constant;
1215 /* For accumulate outgoing args mode we don't need to align, since the frame
1216 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1217 backends from generating misaligned frame sizes. */
1218 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1219 preferred_stack_boundary = STACK_BOUNDARY;
1221 /* Compute the actual size of the argument block required. The variable
1222 and constant sizes must be combined, the size may have to be rounded,
1223 and there may be a minimum required size. */
1227 args_size->var = ARGS_SIZE_TREE (*args_size);
1228 args_size->constant = 0;
1230 preferred_stack_boundary /= BITS_PER_UNIT;
1231 if (preferred_stack_boundary > 1)
1233 /* We don't handle this case yet. To handle it correctly we have
1234 to add the delta, round and subtract the delta.
1235 Currently no machine description requires this support. */
1236 gcc_assert (!(stack_pointer_delta & (preferred_stack_boundary - 1)));
1237 args_size->var = round_up (args_size->var, preferred_stack_boundary);
1240 if (reg_parm_stack_space > 0)
1243 = size_binop (MAX_EXPR, args_size->var,
1244 ssize_int (reg_parm_stack_space));
1246 /* The area corresponding to register parameters is not to count in
1247 the size of the block we need. So make the adjustment. */
1248 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
1250 = size_binop (MINUS_EXPR, args_size->var,
1251 ssize_int (reg_parm_stack_space));
1256 preferred_stack_boundary /= BITS_PER_UNIT;
1257 if (preferred_stack_boundary < 1)
1258 preferred_stack_boundary = 1;
1259 args_size->constant = (((args_size->constant
1260 + stack_pointer_delta
1261 + preferred_stack_boundary - 1)
1262 / preferred_stack_boundary
1263 * preferred_stack_boundary)
1264 - stack_pointer_delta);
1266 args_size->constant = MAX (args_size->constant,
1267 reg_parm_stack_space);
1269 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
1270 args_size->constant -= reg_parm_stack_space;
1272 return unadjusted_args_size;
1275 /* Precompute parameters as needed for a function call.
1277 FLAGS is mask of ECF_* constants.
1279 NUM_ACTUALS is the number of arguments.
1281 ARGS is an array containing information for each argument; this
1282 routine fills in the INITIAL_VALUE and VALUE fields for each
1283 precomputed argument. */
1286 precompute_arguments (int num_actuals, struct arg_data *args)
1290 /* If this is a libcall, then precompute all arguments so that we do not
1291 get extraneous instructions emitted as part of the libcall sequence. */
1293 /* If we preallocated the stack space, and some arguments must be passed
1294 on the stack, then we must precompute any parameter which contains a
1295 function call which will store arguments on the stack.
1296 Otherwise, evaluating the parameter may clobber previous parameters
1297 which have already been stored into the stack. (we have code to avoid
1298 such case by saving the outgoing stack arguments, but it results in
1300 if (!ACCUMULATE_OUTGOING_ARGS)
1303 for (i = 0; i < num_actuals; i++)
1305 enum machine_mode mode;
1307 if (TREE_CODE (args[i].tree_value) != CALL_EXPR)
1310 /* If this is an addressable type, we cannot pre-evaluate it. */
1311 gcc_assert (!TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)));
1313 args[i].initial_value = args[i].value
1314 = expand_normal (args[i].tree_value);
1316 mode = TYPE_MODE (TREE_TYPE (args[i].tree_value));
1317 if (mode != args[i].mode)
1320 = convert_modes (args[i].mode, mode,
1321 args[i].value, args[i].unsignedp);
1322 #if defined(PROMOTE_FUNCTION_MODE) && !defined(PROMOTE_MODE)
1323 /* CSE will replace this only if it contains args[i].value
1324 pseudo, so convert it down to the declared mode using
1326 if (REG_P (args[i].value)
1327 && GET_MODE_CLASS (args[i].mode) == MODE_INT)
1329 args[i].initial_value
1330 = gen_lowpart_SUBREG (mode, args[i].value);
1331 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1332 SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value,
1340 /* Given the current state of MUST_PREALLOCATE and information about
1341 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1342 compute and return the final value for MUST_PREALLOCATE. */
1345 finalize_must_preallocate (int must_preallocate, int num_actuals,
1346 struct arg_data *args, struct args_size *args_size)
1348 /* See if we have or want to preallocate stack space.
1350 If we would have to push a partially-in-regs parm
1351 before other stack parms, preallocate stack space instead.
1353 If the size of some parm is not a multiple of the required stack
1354 alignment, we must preallocate.
1356 If the total size of arguments that would otherwise create a copy in
1357 a temporary (such as a CALL) is more than half the total argument list
1358 size, preallocation is faster.
1360 Another reason to preallocate is if we have a machine (like the m88k)
1361 where stack alignment is required to be maintained between every
1362 pair of insns, not just when the call is made. However, we assume here
1363 that such machines either do not have push insns (and hence preallocation
1364 would occur anyway) or the problem is taken care of with
1367 if (! must_preallocate)
1369 int partial_seen = 0;
1370 int copy_to_evaluate_size = 0;
1373 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1375 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1377 else if (partial_seen && args[i].reg == 0)
1378 must_preallocate = 1;
1380 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1381 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1382 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1383 || TREE_CODE (args[i].tree_value) == COND_EXPR
1384 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1385 copy_to_evaluate_size
1386 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1389 if (copy_to_evaluate_size * 2 >= args_size->constant
1390 && args_size->constant > 0)
1391 must_preallocate = 1;
1393 return must_preallocate;
1396 /* If we preallocated stack space, compute the address of each argument
1397 and store it into the ARGS array.
1399 We need not ensure it is a valid memory address here; it will be
1400 validized when it is used.
1402 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1405 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
1409 rtx arg_reg = argblock;
1410 int i, arg_offset = 0;
1412 if (GET_CODE (argblock) == PLUS)
1413 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1415 for (i = 0; i < num_actuals; i++)
1417 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
1418 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
1420 unsigned int align, boundary;
1421 unsigned int units_on_stack = 0;
1422 enum machine_mode partial_mode = VOIDmode;
1424 /* Skip this parm if it will not be passed on the stack. */
1425 if (! args[i].pass_on_stack
1427 && args[i].partial == 0)
1430 if (GET_CODE (offset) == CONST_INT)
1431 addr = plus_constant (arg_reg, INTVAL (offset));
1433 addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1435 addr = plus_constant (addr, arg_offset);
1437 if (args[i].partial != 0)
1439 /* Only part of the parameter is being passed on the stack.
1440 Generate a simple memory reference of the correct size. */
1441 units_on_stack = args[i].locate.size.constant;
1442 partial_mode = mode_for_size (units_on_stack * BITS_PER_UNIT,
1444 args[i].stack = gen_rtx_MEM (partial_mode, addr);
1445 set_mem_size (args[i].stack, GEN_INT (units_on_stack));
1449 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1450 set_mem_attributes (args[i].stack,
1451 TREE_TYPE (args[i].tree_value), 1);
1453 align = BITS_PER_UNIT;
1454 boundary = args[i].locate.boundary;
1455 if (args[i].locate.where_pad != downward)
1457 else if (GET_CODE (offset) == CONST_INT)
1459 align = INTVAL (offset) * BITS_PER_UNIT | boundary;
1460 align = align & -align;
1462 set_mem_align (args[i].stack, align);
1464 if (GET_CODE (slot_offset) == CONST_INT)
1465 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1467 addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1469 addr = plus_constant (addr, arg_offset);
1471 if (args[i].partial != 0)
1473 /* Only part of the parameter is being passed on the stack.
1474 Generate a simple memory reference of the correct size.
1476 args[i].stack_slot = gen_rtx_MEM (partial_mode, addr);
1477 set_mem_size (args[i].stack_slot, GEN_INT (units_on_stack));
1481 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1482 set_mem_attributes (args[i].stack_slot,
1483 TREE_TYPE (args[i].tree_value), 1);
1485 set_mem_align (args[i].stack_slot, args[i].locate.boundary);
1487 /* Function incoming arguments may overlap with sibling call
1488 outgoing arguments and we cannot allow reordering of reads
1489 from function arguments with stores to outgoing arguments
1490 of sibling calls. */
1491 set_mem_alias_set (args[i].stack, 0);
1492 set_mem_alias_set (args[i].stack_slot, 0);
1497 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1498 in a call instruction.
1500 FNDECL is the tree node for the target function. For an indirect call
1501 FNDECL will be NULL_TREE.
1503 ADDR is the operand 0 of CALL_EXPR for this call. */
1506 rtx_for_function_call (tree fndecl, tree addr)
1510 /* Get the function to call, in the form of RTL. */
1513 /* If this is the first use of the function, see if we need to
1514 make an external definition for it. */
1515 if (!TREE_USED (fndecl) && fndecl != current_function_decl)
1517 assemble_external (fndecl);
1518 TREE_USED (fndecl) = 1;
1521 /* Get a SYMBOL_REF rtx for the function address. */
1522 funexp = XEXP (DECL_RTL (fndecl), 0);
1525 /* Generate an rtx (probably a pseudo-register) for the address. */
1528 funexp = expand_normal (addr);
1529 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1534 /* Return true if and only if SIZE storage units (usually bytes)
1535 starting from address ADDR overlap with already clobbered argument
1536 area. This function is used to determine if we should give up a
1540 mem_overlaps_already_clobbered_arg_p (rtx addr, unsigned HOST_WIDE_INT size)
1544 if (addr == crtl->args.internal_arg_pointer)
1546 else if (GET_CODE (addr) == PLUS
1547 && XEXP (addr, 0) == crtl->args.internal_arg_pointer
1548 && GET_CODE (XEXP (addr, 1)) == CONST_INT)
1549 i = INTVAL (XEXP (addr, 1));
1550 /* Return true for arg pointer based indexed addressing. */
1551 else if (GET_CODE (addr) == PLUS
1552 && (XEXP (addr, 0) == crtl->args.internal_arg_pointer
1553 || XEXP (addr, 1) == crtl->args.internal_arg_pointer))
1558 #ifdef ARGS_GROW_DOWNWARD
1563 unsigned HOST_WIDE_INT k;
1565 for (k = 0; k < size; k++)
1566 if (i + k < stored_args_map->n_bits
1567 && TEST_BIT (stored_args_map, i + k))
1574 /* Do the register loads required for any wholly-register parms or any
1575 parms which are passed both on the stack and in a register. Their
1576 expressions were already evaluated.
1578 Mark all register-parms as living through the call, putting these USE
1579 insns in the CALL_INSN_FUNCTION_USAGE field.
1581 When IS_SIBCALL, perform the check_sibcall_argument_overlap
1582 checking, setting *SIBCALL_FAILURE if appropriate. */
1585 load_register_parameters (struct arg_data *args, int num_actuals,
1586 rtx *call_fusage, int flags, int is_sibcall,
1587 int *sibcall_failure)
1591 for (i = 0; i < num_actuals; i++)
1593 rtx reg = ((flags & ECF_SIBCALL)
1594 ? args[i].tail_call_reg : args[i].reg);
1597 int partial = args[i].partial;
1600 rtx before_arg = get_last_insn ();
1601 /* Set non-negative if we must move a word at a time, even if
1602 just one word (e.g, partial == 4 && mode == DFmode). Set
1603 to -1 if we just use a normal move insn. This value can be
1604 zero if the argument is a zero size structure. */
1606 if (GET_CODE (reg) == PARALLEL)
1610 gcc_assert (partial % UNITS_PER_WORD == 0);
1611 nregs = partial / UNITS_PER_WORD;
1613 else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode)
1615 size = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1616 nregs = (size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
1619 size = GET_MODE_SIZE (args[i].mode);
1621 /* Handle calls that pass values in multiple non-contiguous
1622 locations. The Irix 6 ABI has examples of this. */
1624 if (GET_CODE (reg) == PARALLEL)
1625 emit_group_move (reg, args[i].parallel_value);
1627 /* If simple case, just do move. If normal partial, store_one_arg
1628 has already loaded the register for us. In all other cases,
1629 load the register(s) from memory. */
1631 else if (nregs == -1)
1633 emit_move_insn (reg, args[i].value);
1634 #ifdef BLOCK_REG_PADDING
1635 /* Handle case where we have a value that needs shifting
1636 up to the msb. eg. a QImode value and we're padding
1637 upward on a BYTES_BIG_ENDIAN machine. */
1638 if (size < UNITS_PER_WORD
1639 && (args[i].locate.where_pad
1640 == (BYTES_BIG_ENDIAN ? upward : downward)))
1643 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1645 /* Assigning REG here rather than a temp makes CALL_FUSAGE
1646 report the whole reg as used. Strictly speaking, the
1647 call only uses SIZE bytes at the msb end, but it doesn't
1648 seem worth generating rtl to say that. */
1649 reg = gen_rtx_REG (word_mode, REGNO (reg));
1650 x = expand_shift (LSHIFT_EXPR, word_mode, reg,
1651 build_int_cst (NULL_TREE, shift),
1654 emit_move_insn (reg, x);
1659 /* If we have pre-computed the values to put in the registers in
1660 the case of non-aligned structures, copy them in now. */
1662 else if (args[i].n_aligned_regs != 0)
1663 for (j = 0; j < args[i].n_aligned_regs; j++)
1664 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1665 args[i].aligned_regs[j]);
1667 else if (partial == 0 || args[i].pass_on_stack)
1669 rtx mem = validize_mem (args[i].value);
1671 /* Check for overlap with already clobbered argument area. */
1673 && mem_overlaps_already_clobbered_arg_p (XEXP (args[i].value, 0),
1675 *sibcall_failure = 1;
1677 /* Handle a BLKmode that needs shifting. */
1678 if (nregs == 1 && size < UNITS_PER_WORD
1679 #ifdef BLOCK_REG_PADDING
1680 && args[i].locate.where_pad == downward
1686 rtx tem = operand_subword_force (mem, 0, args[i].mode);
1687 rtx ri = gen_rtx_REG (word_mode, REGNO (reg));
1688 rtx x = gen_reg_rtx (word_mode);
1689 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1690 enum tree_code dir = BYTES_BIG_ENDIAN ? RSHIFT_EXPR
1693 emit_move_insn (x, tem);
1694 x = expand_shift (dir, word_mode, x,
1695 build_int_cst (NULL_TREE, shift),
1698 emit_move_insn (ri, x);
1701 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
1704 /* When a parameter is a block, and perhaps in other cases, it is
1705 possible that it did a load from an argument slot that was
1706 already clobbered. */
1708 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
1709 *sibcall_failure = 1;
1711 /* Handle calls that pass values in multiple non-contiguous
1712 locations. The Irix 6 ABI has examples of this. */
1713 if (GET_CODE (reg) == PARALLEL)
1714 use_group_regs (call_fusage, reg);
1715 else if (nregs == -1)
1716 use_reg (call_fusage, reg);
1718 use_regs (call_fusage, REGNO (reg), nregs);
1723 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1724 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1725 bytes, then we would need to push some additional bytes to pad the
1726 arguments. So, we compute an adjust to the stack pointer for an
1727 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1728 bytes. Then, when the arguments are pushed the stack will be perfectly
1729 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
1730 be popped after the call. Returns the adjustment. */
1733 combine_pending_stack_adjustment_and_call (int unadjusted_args_size,
1734 struct args_size *args_size,
1735 unsigned int preferred_unit_stack_boundary)
1737 /* The number of bytes to pop so that the stack will be
1738 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
1739 HOST_WIDE_INT adjustment;
1740 /* The alignment of the stack after the arguments are pushed, if we
1741 just pushed the arguments without adjust the stack here. */
1742 unsigned HOST_WIDE_INT unadjusted_alignment;
1744 unadjusted_alignment
1745 = ((stack_pointer_delta + unadjusted_args_size)
1746 % preferred_unit_stack_boundary);
1748 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1749 as possible -- leaving just enough left to cancel out the
1750 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
1751 PENDING_STACK_ADJUST is non-negative, and congruent to
1752 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
1754 /* Begin by trying to pop all the bytes. */
1755 unadjusted_alignment
1756 = (unadjusted_alignment
1757 - (pending_stack_adjust % preferred_unit_stack_boundary));
1758 adjustment = pending_stack_adjust;
1759 /* Push enough additional bytes that the stack will be aligned
1760 after the arguments are pushed. */
1761 if (preferred_unit_stack_boundary > 1)
1763 if (unadjusted_alignment > 0)
1764 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
1766 adjustment += unadjusted_alignment;
1769 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1770 bytes after the call. The right number is the entire
1771 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1772 by the arguments in the first place. */
1774 = pending_stack_adjust - adjustment + unadjusted_args_size;
1779 /* Scan X expression if it does not dereference any argument slots
1780 we already clobbered by tail call arguments (as noted in stored_args_map
1782 Return nonzero if X expression dereferences such argument slots,
1786 check_sibcall_argument_overlap_1 (rtx x)
1795 code = GET_CODE (x);
1798 return mem_overlaps_already_clobbered_arg_p (XEXP (x, 0),
1799 GET_MODE_SIZE (GET_MODE (x)));
1801 /* Scan all subexpressions. */
1802 fmt = GET_RTX_FORMAT (code);
1803 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
1807 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
1810 else if (*fmt == 'E')
1812 for (j = 0; j < XVECLEN (x, i); j++)
1813 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
1820 /* Scan sequence after INSN if it does not dereference any argument slots
1821 we already clobbered by tail call arguments (as noted in stored_args_map
1822 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
1823 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
1824 should be 0). Return nonzero if sequence after INSN dereferences such argument
1825 slots, zero otherwise. */
1828 check_sibcall_argument_overlap (rtx insn, struct arg_data *arg, int mark_stored_args_map)
1832 if (insn == NULL_RTX)
1833 insn = get_insns ();
1835 insn = NEXT_INSN (insn);
1837 for (; insn; insn = NEXT_INSN (insn))
1839 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
1842 if (mark_stored_args_map)
1844 #ifdef ARGS_GROW_DOWNWARD
1845 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
1847 low = arg->locate.slot_offset.constant;
1850 for (high = low + arg->locate.size.constant; low < high; low++)
1851 SET_BIT (stored_args_map, low);
1853 return insn != NULL_RTX;
1856 /* Given that a function returns a value of mode MODE at the most
1857 significant end of hard register VALUE, shift VALUE left or right
1858 as specified by LEFT_P. Return true if some action was needed. */
1861 shift_return_value (enum machine_mode mode, bool left_p, rtx value)
1863 HOST_WIDE_INT shift;
1865 gcc_assert (REG_P (value) && HARD_REGISTER_P (value));
1866 shift = GET_MODE_BITSIZE (GET_MODE (value)) - GET_MODE_BITSIZE (mode);
1870 /* Use ashr rather than lshr for right shifts. This is for the benefit
1871 of the MIPS port, which requires SImode values to be sign-extended
1872 when stored in 64-bit registers. */
1873 if (!force_expand_binop (GET_MODE (value), left_p ? ashl_optab : ashr_optab,
1874 value, GEN_INT (shift), value, 1, OPTAB_WIDEN))
1879 /* If X is a likely-spilled register value, copy it to a pseudo
1880 register and return that register. Return X otherwise. */
1883 avoid_likely_spilled_reg (rtx x)
1888 && HARD_REGISTER_P (x)
1889 && CLASS_LIKELY_SPILLED_P (REGNO_REG_CLASS (REGNO (x))))
1891 /* Make sure that we generate a REG rather than a CONCAT.
1892 Moves into CONCATs can need nontrivial instructions,
1893 and the whole point of this function is to avoid
1894 using the hard register directly in such a situation. */
1895 generating_concat_p = 0;
1896 new_rtx = gen_reg_rtx (GET_MODE (x));
1897 generating_concat_p = 1;
1898 emit_move_insn (new_rtx, x);
1904 /* Generate all the code for a CALL_EXPR exp
1905 and return an rtx for its value.
1906 Store the value in TARGET (specified as an rtx) if convenient.
1907 If the value is stored in TARGET then TARGET is returned.
1908 If IGNORE is nonzero, then we ignore the value of the function call. */
1911 expand_call (tree exp, rtx target, int ignore)
1913 /* Nonzero if we are currently expanding a call. */
1914 static int currently_expanding_call = 0;
1916 /* RTX for the function to be called. */
1918 /* Sequence of insns to perform a normal "call". */
1919 rtx normal_call_insns = NULL_RTX;
1920 /* Sequence of insns to perform a tail "call". */
1921 rtx tail_call_insns = NULL_RTX;
1922 /* Data type of the function. */
1924 tree type_arg_types;
1925 /* Declaration of the function being called,
1926 or 0 if the function is computed (not known by name). */
1928 /* The type of the function being called. */
1930 bool try_tail_call = CALL_EXPR_TAILCALL (exp);
1933 /* Register in which non-BLKmode value will be returned,
1934 or 0 if no value or if value is BLKmode. */
1936 /* Address where we should return a BLKmode value;
1937 0 if value not BLKmode. */
1938 rtx structure_value_addr = 0;
1939 /* Nonzero if that address is being passed by treating it as
1940 an extra, implicit first parameter. Otherwise,
1941 it is passed by being copied directly into struct_value_rtx. */
1942 int structure_value_addr_parm = 0;
1943 /* Holds the value of implicit argument for the struct value. */
1944 tree structure_value_addr_value = NULL_TREE;
1945 /* Size of aggregate value wanted, or zero if none wanted
1946 or if we are using the non-reentrant PCC calling convention
1947 or expecting the value in registers. */
1948 HOST_WIDE_INT struct_value_size = 0;
1949 /* Nonzero if called function returns an aggregate in memory PCC style,
1950 by returning the address of where to find it. */
1951 int pcc_struct_value = 0;
1952 rtx struct_value = 0;
1954 /* Number of actual parameters in this call, including struct value addr. */
1956 /* Number of named args. Args after this are anonymous ones
1957 and they must all go on the stack. */
1959 /* Number of complex actual arguments that need to be split. */
1960 int num_complex_actuals = 0;
1962 /* Vector of information about each argument.
1963 Arguments are numbered in the order they will be pushed,
1964 not the order they are written. */
1965 struct arg_data *args;
1967 /* Total size in bytes of all the stack-parms scanned so far. */
1968 struct args_size args_size;
1969 struct args_size adjusted_args_size;
1970 /* Size of arguments before any adjustments (such as rounding). */
1971 int unadjusted_args_size;
1972 /* Data on reg parms scanned so far. */
1973 CUMULATIVE_ARGS args_so_far;
1974 /* Nonzero if a reg parm has been scanned. */
1976 /* Nonzero if this is an indirect function call. */
1978 /* Nonzero if we must avoid push-insns in the args for this call.
1979 If stack space is allocated for register parameters, but not by the
1980 caller, then it is preallocated in the fixed part of the stack frame.
1981 So the entire argument block must then be preallocated (i.e., we
1982 ignore PUSH_ROUNDING in that case). */
1984 int must_preallocate = !PUSH_ARGS;
1986 /* Size of the stack reserved for parameter registers. */
1987 int reg_parm_stack_space = 0;
1989 /* Address of space preallocated for stack parms
1990 (on machines that lack push insns), or 0 if space not preallocated. */
1993 /* Mask of ECF_ flags. */
1995 #ifdef REG_PARM_STACK_SPACE
1996 /* Define the boundary of the register parm stack space that needs to be
1998 int low_to_save, high_to_save;
1999 rtx save_area = 0; /* Place that it is saved */
2002 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
2003 char *initial_stack_usage_map = stack_usage_map;
2004 char *stack_usage_map_buf = NULL;
2006 int old_stack_allocated;
2008 /* State variables to track stack modifications. */
2009 rtx old_stack_level = 0;
2010 int old_stack_arg_under_construction = 0;
2011 int old_pending_adj = 0;
2012 int old_inhibit_defer_pop = inhibit_defer_pop;
2014 /* Some stack pointer alterations we make are performed via
2015 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
2016 which we then also need to save/restore along the way. */
2017 int old_stack_pointer_delta = 0;
2020 tree p = CALL_EXPR_FN (exp);
2021 tree addr = CALL_EXPR_FN (exp);
2023 /* The alignment of the stack, in bits. */
2024 unsigned HOST_WIDE_INT preferred_stack_boundary;
2025 /* The alignment of the stack, in bytes. */
2026 unsigned HOST_WIDE_INT preferred_unit_stack_boundary;
2027 /* The static chain value to use for this call. */
2028 rtx static_chain_value;
2029 /* See if this is "nothrow" function call. */
2030 if (TREE_NOTHROW (exp))
2031 flags |= ECF_NOTHROW;
2033 /* See if we can find a DECL-node for the actual function, and get the
2034 function attributes (flags) from the function decl or type node. */
2035 fndecl = get_callee_fndecl (exp);
2038 fntype = TREE_TYPE (fndecl);
2039 flags |= flags_from_decl_or_type (fndecl);
2043 fntype = TREE_TYPE (TREE_TYPE (p));
2044 flags |= flags_from_decl_or_type (fntype);
2047 struct_value = targetm.calls.struct_value_rtx (fntype, 0);
2049 /* Warn if this value is an aggregate type,
2050 regardless of which calling convention we are using for it. */
2051 if (AGGREGATE_TYPE_P (TREE_TYPE (exp)))
2052 warning (OPT_Waggregate_return, "function call has aggregate value");
2054 /* If the result of a non looping pure or const function call is
2055 ignored (or void), and none of its arguments are volatile, we can
2056 avoid expanding the call and just evaluate the arguments for
2058 if ((flags & (ECF_CONST | ECF_PURE))
2059 && (!(flags & ECF_LOOPING_CONST_OR_PURE))
2060 && (ignore || target == const0_rtx
2061 || TYPE_MODE (TREE_TYPE (exp)) == VOIDmode))
2063 bool volatilep = false;
2065 call_expr_arg_iterator iter;
2067 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2068 if (TREE_THIS_VOLATILE (arg))
2076 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2077 expand_expr (arg, const0_rtx, VOIDmode, EXPAND_NORMAL);
2082 #ifdef REG_PARM_STACK_SPACE
2083 reg_parm_stack_space = REG_PARM_STACK_SPACE (!fndecl ? fntype : fndecl);
2086 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
2087 && reg_parm_stack_space > 0 && PUSH_ARGS)
2088 must_preallocate = 1;
2090 /* Set up a place to return a structure. */
2092 /* Cater to broken compilers. */
2093 if (aggregate_value_p (exp, (!fndecl ? fntype : fndecl)))
2095 /* This call returns a big structure. */
2096 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
2098 #ifdef PCC_STATIC_STRUCT_RETURN
2100 pcc_struct_value = 1;
2102 #else /* not PCC_STATIC_STRUCT_RETURN */
2104 struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
2106 if (target && MEM_P (target) && CALL_EXPR_RETURN_SLOT_OPT (exp))
2107 structure_value_addr = XEXP (target, 0);
2110 /* For variable-sized objects, we must be called with a target
2111 specified. If we were to allocate space on the stack here,
2112 we would have no way of knowing when to free it. */
2113 rtx d = assign_temp (TREE_TYPE (exp), 0, 1, 1);
2115 mark_temp_addr_taken (d);
2116 structure_value_addr = XEXP (d, 0);
2120 #endif /* not PCC_STATIC_STRUCT_RETURN */
2123 /* Figure out the amount to which the stack should be aligned. */
2124 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2127 struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl);
2128 /* Without automatic stack alignment, we can't increase preferred
2129 stack boundary. With automatic stack alignment, it is
2130 unnecessary since unless we can guarantee that all callers will
2131 align the outgoing stack properly, callee has to align its
2134 && i->preferred_incoming_stack_boundary
2135 && i->preferred_incoming_stack_boundary < preferred_stack_boundary)
2136 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
2139 /* Operand 0 is a pointer-to-function; get the type of the function. */
2140 funtype = TREE_TYPE (addr);
2141 gcc_assert (POINTER_TYPE_P (funtype));
2142 funtype = TREE_TYPE (funtype);
2144 /* Count whether there are actual complex arguments that need to be split
2145 into their real and imaginary parts. Munge the type_arg_types
2146 appropriately here as well. */
2147 if (targetm.calls.split_complex_arg)
2149 call_expr_arg_iterator iter;
2151 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2153 tree type = TREE_TYPE (arg);
2154 if (type && TREE_CODE (type) == COMPLEX_TYPE
2155 && targetm.calls.split_complex_arg (type))
2156 num_complex_actuals++;
2158 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
2161 type_arg_types = TYPE_ARG_TYPES (funtype);
2163 if (flags & ECF_MAY_BE_ALLOCA)
2164 cfun->calls_alloca = 1;
2166 /* If struct_value_rtx is 0, it means pass the address
2167 as if it were an extra parameter. Put the argument expression
2168 in structure_value_addr_value. */
2169 if (structure_value_addr && struct_value == 0)
2171 /* If structure_value_addr is a REG other than
2172 virtual_outgoing_args_rtx, we can use always use it. If it
2173 is not a REG, we must always copy it into a register.
2174 If it is virtual_outgoing_args_rtx, we must copy it to another
2175 register in some cases. */
2176 rtx temp = (!REG_P (structure_value_addr)
2177 || (ACCUMULATE_OUTGOING_ARGS
2178 && stack_arg_under_construction
2179 && structure_value_addr == virtual_outgoing_args_rtx)
2180 ? copy_addr_to_reg (convert_memory_address
2181 (Pmode, structure_value_addr))
2182 : structure_value_addr);
2184 structure_value_addr_value =
2185 make_tree (build_pointer_type (TREE_TYPE (funtype)), temp);
2186 structure_value_addr_parm = 1;
2189 /* Count the arguments and set NUM_ACTUALS. */
2191 call_expr_nargs (exp) + num_complex_actuals + structure_value_addr_parm;
2193 /* Compute number of named args.
2194 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
2196 if (type_arg_types != 0)
2198 = (list_length (type_arg_types)
2199 /* Count the struct value address, if it is passed as a parm. */
2200 + structure_value_addr_parm);
2202 /* If we know nothing, treat all args as named. */
2203 n_named_args = num_actuals;
2205 /* Start updating where the next arg would go.
2207 On some machines (such as the PA) indirect calls have a different
2208 calling convention than normal calls. The fourth argument in
2209 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2211 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, fndecl, n_named_args);
2213 /* Now possibly adjust the number of named args.
2214 Normally, don't include the last named arg if anonymous args follow.
2215 We do include the last named arg if
2216 targetm.calls.strict_argument_naming() returns nonzero.
2217 (If no anonymous args follow, the result of list_length is actually
2218 one too large. This is harmless.)
2220 If targetm.calls.pretend_outgoing_varargs_named() returns
2221 nonzero, and targetm.calls.strict_argument_naming() returns zero,
2222 this machine will be able to place unnamed args that were passed
2223 in registers into the stack. So treat all args as named. This
2224 allows the insns emitting for a specific argument list to be
2225 independent of the function declaration.
2227 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
2228 we do not have any reliable way to pass unnamed args in
2229 registers, so we must force them into memory. */
2231 if (type_arg_types != 0
2232 && targetm.calls.strict_argument_naming (&args_so_far))
2234 else if (type_arg_types != 0
2235 && ! targetm.calls.pretend_outgoing_varargs_named (&args_so_far))
2236 /* Don't include the last named arg. */
2239 /* Treat all args as named. */
2240 n_named_args = num_actuals;
2242 /* Make a vector to hold all the information about each arg. */
2243 args = XALLOCAVEC (struct arg_data, num_actuals);
2244 memset (args, 0, num_actuals * sizeof (struct arg_data));
2246 /* Build up entries in the ARGS array, compute the size of the
2247 arguments into ARGS_SIZE, etc. */
2248 initialize_argument_information (num_actuals, args, &args_size,
2250 structure_value_addr_value, fndecl, fntype,
2251 &args_so_far, reg_parm_stack_space,
2252 &old_stack_level, &old_pending_adj,
2253 &must_preallocate, &flags,
2254 &try_tail_call, CALL_FROM_THUNK_P (exp));
2257 must_preallocate = 1;
2259 /* Now make final decision about preallocating stack space. */
2260 must_preallocate = finalize_must_preallocate (must_preallocate,
2264 /* If the structure value address will reference the stack pointer, we
2265 must stabilize it. We don't need to do this if we know that we are
2266 not going to adjust the stack pointer in processing this call. */
2268 if (structure_value_addr
2269 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2270 || reg_mentioned_p (virtual_outgoing_args_rtx,
2271 structure_value_addr))
2273 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2274 structure_value_addr = copy_to_reg (structure_value_addr);
2276 /* Tail calls can make things harder to debug, and we've traditionally
2277 pushed these optimizations into -O2. Don't try if we're already
2278 expanding a call, as that means we're an argument. Don't try if
2279 there's cleanups, as we know there's code to follow the call. */
2281 if (currently_expanding_call++ != 0
2282 || !flag_optimize_sibling_calls
2284 || lookup_expr_eh_region (exp) >= 0
2285 || dbg_cnt (tail_call) == false)
2288 /* Rest of purposes for tail call optimizations to fail. */
2290 #ifdef HAVE_sibcall_epilogue
2291 !HAVE_sibcall_epilogue
2296 /* Doing sibling call optimization needs some work, since
2297 structure_value_addr can be allocated on the stack.
2298 It does not seem worth the effort since few optimizable
2299 sibling calls will return a structure. */
2300 || structure_value_addr != NULL_RTX
2301 #ifdef REG_PARM_STACK_SPACE
2302 /* If outgoing reg parm stack space changes, we can not do sibcall. */
2303 || (OUTGOING_REG_PARM_STACK_SPACE (funtype)
2304 != OUTGOING_REG_PARM_STACK_SPACE (TREE_TYPE (current_function_decl)))
2305 || (reg_parm_stack_space != REG_PARM_STACK_SPACE (fndecl))
2307 /* Check whether the target is able to optimize the call
2309 || !targetm.function_ok_for_sibcall (fndecl, exp)
2310 /* Functions that do not return exactly once may not be sibcall
2312 || (flags & (ECF_RETURNS_TWICE | ECF_NORETURN))
2313 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr)))
2314 /* If the called function is nested in the current one, it might access
2315 some of the caller's arguments, but could clobber them beforehand if
2316 the argument areas are shared. */
2317 || (fndecl && decl_function_context (fndecl) == current_function_decl)
2318 /* If this function requires more stack slots than the current
2319 function, we cannot change it into a sibling call.
2320 crtl->args.pretend_args_size is not part of the
2321 stack allocated by our caller. */
2322 || args_size.constant > (crtl->args.size
2323 - crtl->args.pretend_args_size)
2324 /* If the callee pops its own arguments, then it must pop exactly
2325 the same number of arguments as the current function. */
2326 || (RETURN_POPS_ARGS (fndecl, funtype, args_size.constant)
2327 != RETURN_POPS_ARGS (current_function_decl,
2328 TREE_TYPE (current_function_decl),
2330 || !lang_hooks.decls.ok_for_sibcall (fndecl))
2333 /* Ensure current function's preferred stack boundary is at least
2334 what we need. Stack alignment may also increase preferred stack
2336 if (crtl->preferred_stack_boundary < preferred_stack_boundary)
2337 crtl->preferred_stack_boundary = preferred_stack_boundary;
2339 preferred_stack_boundary = crtl->preferred_stack_boundary;
2341 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2343 /* We want to make two insn chains; one for a sibling call, the other
2344 for a normal call. We will select one of the two chains after
2345 initial RTL generation is complete. */
2346 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
2348 int sibcall_failure = 0;
2349 /* We want to emit any pending stack adjustments before the tail
2350 recursion "call". That way we know any adjustment after the tail
2351 recursion call can be ignored if we indeed use the tail
2353 int save_pending_stack_adjust = 0;
2354 int save_stack_pointer_delta = 0;
2356 rtx before_call, next_arg_reg, after_args;
2360 /* State variables we need to save and restore between
2362 save_pending_stack_adjust = pending_stack_adjust;
2363 save_stack_pointer_delta = stack_pointer_delta;
2366 flags &= ~ECF_SIBCALL;
2368 flags |= ECF_SIBCALL;
2370 /* Other state variables that we must reinitialize each time
2371 through the loop (that are not initialized by the loop itself). */
2375 /* Start a new sequence for the normal call case.
2377 From this point on, if the sibling call fails, we want to set
2378 sibcall_failure instead of continuing the loop. */
2381 /* Don't let pending stack adjusts add up to too much.
2382 Also, do all pending adjustments now if there is any chance
2383 this might be a call to alloca or if we are expanding a sibling
2385 Also do the adjustments before a throwing call, otherwise
2386 exception handling can fail; PR 19225. */
2387 if (pending_stack_adjust >= 32
2388 || (pending_stack_adjust > 0
2389 && (flags & ECF_MAY_BE_ALLOCA))
2390 || (pending_stack_adjust > 0
2391 && flag_exceptions && !(flags & ECF_NOTHROW))
2393 do_pending_stack_adjust ();
2395 /* Precompute any arguments as needed. */
2397 precompute_arguments (num_actuals, args);
2399 /* Now we are about to start emitting insns that can be deleted
2400 if a libcall is deleted. */
2401 if (pass && (flags & ECF_MALLOC))
2404 if (pass == 0 && crtl->stack_protect_guard)
2405 stack_protect_epilogue ();
2407 adjusted_args_size = args_size;
2408 /* Compute the actual size of the argument block required. The variable
2409 and constant sizes must be combined, the size may have to be rounded,
2410 and there may be a minimum required size. When generating a sibcall
2411 pattern, do not round up, since we'll be re-using whatever space our
2413 unadjusted_args_size
2414 = compute_argument_block_size (reg_parm_stack_space,
2415 &adjusted_args_size,
2418 : preferred_stack_boundary));
2420 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2422 /* The argument block when performing a sibling call is the
2423 incoming argument block. */
2426 argblock = crtl->args.internal_arg_pointer;
2428 #ifdef STACK_GROWS_DOWNWARD
2429 = plus_constant (argblock, crtl->args.pretend_args_size);
2431 = plus_constant (argblock, -crtl->args.pretend_args_size);
2433 stored_args_map = sbitmap_alloc (args_size.constant);
2434 sbitmap_zero (stored_args_map);
2437 /* If we have no actual push instructions, or shouldn't use them,
2438 make space for all args right now. */
2439 else if (adjusted_args_size.var != 0)
2441 if (old_stack_level == 0)
2443 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2444 old_stack_pointer_delta = stack_pointer_delta;
2445 old_pending_adj = pending_stack_adjust;
2446 pending_stack_adjust = 0;
2447 /* stack_arg_under_construction says whether a stack arg is
2448 being constructed at the old stack level. Pushing the stack
2449 gets a clean outgoing argument block. */
2450 old_stack_arg_under_construction = stack_arg_under_construction;
2451 stack_arg_under_construction = 0;
2453 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2457 /* Note that we must go through the motions of allocating an argument
2458 block even if the size is zero because we may be storing args
2459 in the area reserved for register arguments, which may be part of
2462 int needed = adjusted_args_size.constant;
2464 /* Store the maximum argument space used. It will be pushed by
2465 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2468 if (needed > crtl->outgoing_args_size)
2469 crtl->outgoing_args_size = needed;
2471 if (must_preallocate)
2473 if (ACCUMULATE_OUTGOING_ARGS)
2475 /* Since the stack pointer will never be pushed, it is
2476 possible for the evaluation of a parm to clobber
2477 something we have already written to the stack.
2478 Since most function calls on RISC machines do not use
2479 the stack, this is uncommon, but must work correctly.
2481 Therefore, we save any area of the stack that was already
2482 written and that we are using. Here we set up to do this
2483 by making a new stack usage map from the old one. The
2484 actual save will be done by store_one_arg.
2486 Another approach might be to try to reorder the argument
2487 evaluations to avoid this conflicting stack usage. */
2489 /* Since we will be writing into the entire argument area,
2490 the map must be allocated for its entire size, not just
2491 the part that is the responsibility of the caller. */
2492 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
2493 needed += reg_parm_stack_space;
2495 #ifdef ARGS_GROW_DOWNWARD
2496 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2499 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2502 if (stack_usage_map_buf)
2503 free (stack_usage_map_buf);
2504 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
2505 stack_usage_map = stack_usage_map_buf;
2507 if (initial_highest_arg_in_use)
2508 memcpy (stack_usage_map, initial_stack_usage_map,
2509 initial_highest_arg_in_use);
2511 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2512 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2513 (highest_outgoing_arg_in_use
2514 - initial_highest_arg_in_use));
2517 /* The address of the outgoing argument list must not be
2518 copied to a register here, because argblock would be left
2519 pointing to the wrong place after the call to
2520 allocate_dynamic_stack_space below. */
2522 argblock = virtual_outgoing_args_rtx;
2526 if (inhibit_defer_pop == 0)
2528 /* Try to reuse some or all of the pending_stack_adjust
2529 to get this space. */
2531 = (combine_pending_stack_adjustment_and_call
2532 (unadjusted_args_size,
2533 &adjusted_args_size,
2534 preferred_unit_stack_boundary));
2536 /* combine_pending_stack_adjustment_and_call computes
2537 an adjustment before the arguments are allocated.
2538 Account for them and see whether or not the stack
2539 needs to go up or down. */
2540 needed = unadjusted_args_size - needed;
2544 /* We're releasing stack space. */
2545 /* ??? We can avoid any adjustment at all if we're
2546 already aligned. FIXME. */
2547 pending_stack_adjust = -needed;
2548 do_pending_stack_adjust ();
2552 /* We need to allocate space. We'll do that in
2553 push_block below. */
2554 pending_stack_adjust = 0;
2557 /* Special case this because overhead of `push_block' in
2558 this case is non-trivial. */
2560 argblock = virtual_outgoing_args_rtx;
2563 argblock = push_block (GEN_INT (needed), 0, 0);
2564 #ifdef ARGS_GROW_DOWNWARD
2565 argblock = plus_constant (argblock, needed);
2569 /* We only really need to call `copy_to_reg' in the case
2570 where push insns are going to be used to pass ARGBLOCK
2571 to a function call in ARGS. In that case, the stack
2572 pointer changes value from the allocation point to the
2573 call point, and hence the value of
2574 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2575 as well always do it. */
2576 argblock = copy_to_reg (argblock);
2581 if (ACCUMULATE_OUTGOING_ARGS)
2583 /* The save/restore code in store_one_arg handles all
2584 cases except one: a constructor call (including a C
2585 function returning a BLKmode struct) to initialize
2587 if (stack_arg_under_construction)
2590 = GEN_INT (adjusted_args_size.constant
2591 + (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype
2592 : TREE_TYPE (fndecl))) ? 0
2593 : reg_parm_stack_space));
2594 if (old_stack_level == 0)
2596 emit_stack_save (SAVE_BLOCK, &old_stack_level,
2598 old_stack_pointer_delta = stack_pointer_delta;
2599 old_pending_adj = pending_stack_adjust;
2600 pending_stack_adjust = 0;
2601 /* stack_arg_under_construction says whether a stack
2602 arg is being constructed at the old stack level.
2603 Pushing the stack gets a clean outgoing argument
2605 old_stack_arg_under_construction
2606 = stack_arg_under_construction;
2607 stack_arg_under_construction = 0;
2608 /* Make a new map for the new argument list. */
2609 if (stack_usage_map_buf)
2610 free (stack_usage_map_buf);
2611 stack_usage_map_buf = XCNEWVEC (char, highest_outgoing_arg_in_use);
2612 stack_usage_map = stack_usage_map_buf;
2613 highest_outgoing_arg_in_use = 0;
2615 allocate_dynamic_stack_space (push_size, NULL_RTX,
2619 /* If argument evaluation might modify the stack pointer,
2620 copy the address of the argument list to a register. */
2621 for (i = 0; i < num_actuals; i++)
2622 if (args[i].pass_on_stack)
2624 argblock = copy_addr_to_reg (argblock);
2629 compute_argument_addresses (args, argblock, num_actuals);
2631 /* If we push args individually in reverse order, perform stack alignment
2632 before the first push (the last arg). */
2633 if (PUSH_ARGS_REVERSED && argblock == 0
2634 && adjusted_args_size.constant != unadjusted_args_size)
2636 /* When the stack adjustment is pending, we get better code
2637 by combining the adjustments. */
2638 if (pending_stack_adjust
2639 && ! inhibit_defer_pop)
2641 pending_stack_adjust
2642 = (combine_pending_stack_adjustment_and_call
2643 (unadjusted_args_size,
2644 &adjusted_args_size,
2645 preferred_unit_stack_boundary));
2646 do_pending_stack_adjust ();
2648 else if (argblock == 0)
2649 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2650 - unadjusted_args_size));
2652 /* Now that the stack is properly aligned, pops can't safely
2653 be deferred during the evaluation of the arguments. */
2656 funexp = rtx_for_function_call (fndecl, addr);
2658 /* Figure out the register where the value, if any, will come back. */
2660 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
2661 && ! structure_value_addr)
2663 if (pcc_struct_value)
2664 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
2665 fndecl, NULL, (pass == 0));
2667 valreg = hard_function_value (TREE_TYPE (exp), fndecl, fntype,
2670 /* If VALREG is a PARALLEL whose first member has a zero
2671 offset, use that. This is for targets such as m68k that
2672 return the same value in multiple places. */
2673 if (GET_CODE (valreg) == PARALLEL)
2675 rtx elem = XVECEXP (valreg, 0, 0);
2676 rtx where = XEXP (elem, 0);
2677 rtx offset = XEXP (elem, 1);
2678 if (offset == const0_rtx
2679 && GET_MODE (where) == GET_MODE (valreg))
2684 /* Precompute all register parameters. It isn't safe to compute anything
2685 once we have started filling any specific hard regs. */
2686 precompute_register_parameters (num_actuals, args, ®_parm_seen);
2688 if (CALL_EXPR_STATIC_CHAIN (exp))
2689 static_chain_value = expand_normal (CALL_EXPR_STATIC_CHAIN (exp));
2691 static_chain_value = 0;
2693 #ifdef REG_PARM_STACK_SPACE
2694 /* Save the fixed argument area if it's part of the caller's frame and
2695 is clobbered by argument setup for this call. */
2696 if (ACCUMULATE_OUTGOING_ARGS && pass)
2697 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
2698 &low_to_save, &high_to_save);
2701 /* Now store (and compute if necessary) all non-register parms.
2702 These come before register parms, since they can require block-moves,
2703 which could clobber the registers used for register parms.
2704 Parms which have partial registers are not stored here,
2705 but we do preallocate space here if they want that. */
2707 for (i = 0; i < num_actuals; i++)
2708 if (args[i].reg == 0 || args[i].pass_on_stack)
2710 rtx before_arg = get_last_insn ();
2712 if (store_one_arg (&args[i], argblock, flags,
2713 adjusted_args_size.var != 0,
2714 reg_parm_stack_space)
2716 && check_sibcall_argument_overlap (before_arg,
2718 sibcall_failure = 1;
2720 if (flags & ECF_CONST
2722 && args[i].value == args[i].stack)
2723 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
2724 gen_rtx_USE (VOIDmode,
2729 /* If we have a parm that is passed in registers but not in memory
2730 and whose alignment does not permit a direct copy into registers,
2731 make a group of pseudos that correspond to each register that we
2733 if (STRICT_ALIGNMENT)
2734 store_unaligned_arguments_into_pseudos (args, num_actuals);
2736 /* Now store any partially-in-registers parm.
2737 This is the last place a block-move can happen. */
2739 for (i = 0; i < num_actuals; i++)
2740 if (args[i].partial != 0 && ! args[i].pass_on_stack)
2742 rtx before_arg = get_last_insn ();
2744 if (store_one_arg (&args[i], argblock, flags,
2745 adjusted_args_size.var != 0,
2746 reg_parm_stack_space)
2748 && check_sibcall_argument_overlap (before_arg,
2750 sibcall_failure = 1;
2753 /* If we pushed args in forward order, perform stack alignment
2754 after pushing the last arg. */
2755 if (!PUSH_ARGS_REVERSED && argblock == 0)
2756 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2757 - unadjusted_args_size));
2759 /* If register arguments require space on the stack and stack space
2760 was not preallocated, allocate stack space here for arguments
2761 passed in registers. */
2762 if (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
2763 && !ACCUMULATE_OUTGOING_ARGS
2764 && must_preallocate == 0 && reg_parm_stack_space > 0)
2765 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
2767 /* Pass the function the address in which to return a
2769 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
2771 structure_value_addr
2772 = convert_memory_address (Pmode, structure_value_addr);
2773 emit_move_insn (struct_value,
2775 force_operand (structure_value_addr,
2778 if (REG_P (struct_value))
2779 use_reg (&call_fusage, struct_value);
2782 after_args = get_last_insn ();
2783 funexp = prepare_call_address (funexp, static_chain_value,
2784 &call_fusage, reg_parm_seen, pass == 0);
2786 load_register_parameters (args, num_actuals, &call_fusage, flags,
2787 pass == 0, &sibcall_failure);
2789 /* Save a pointer to the last insn before the call, so that we can
2790 later safely search backwards to find the CALL_INSN. */
2791 before_call = get_last_insn ();
2793 /* Set up next argument register. For sibling calls on machines
2794 with register windows this should be the incoming register. */
2795 #ifdef FUNCTION_INCOMING_ARG
2797 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
2801 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
2804 /* All arguments and registers used for the call must be set up by
2807 /* Stack must be properly aligned now. */
2809 || !(stack_pointer_delta % preferred_unit_stack_boundary));
2811 /* Generate the actual call instruction. */
2812 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size,
2813 adjusted_args_size.constant, struct_value_size,
2814 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
2815 flags, & args_so_far);
2817 /* If the call setup or the call itself overlaps with anything
2818 of the argument setup we probably clobbered our call address.
2819 In that case we can't do sibcalls. */
2821 && check_sibcall_argument_overlap (after_args, 0, 0))
2822 sibcall_failure = 1;
2824 /* If a non-BLKmode value is returned at the most significant end
2825 of a register, shift the register right by the appropriate amount
2826 and update VALREG accordingly. BLKmode values are handled by the
2827 group load/store machinery below. */
2828 if (!structure_value_addr
2829 && !pcc_struct_value
2830 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
2831 && targetm.calls.return_in_msb (TREE_TYPE (exp)))
2833 if (shift_return_value (TYPE_MODE (TREE_TYPE (exp)), false, valreg))
2834 sibcall_failure = 1;
2835 valreg = gen_rtx_REG (TYPE_MODE (TREE_TYPE (exp)), REGNO (valreg));
2838 if (pass && (flags & ECF_MALLOC))
2840 rtx temp = gen_reg_rtx (GET_MODE (valreg));
2843 /* The return value from a malloc-like function is a pointer. */
2844 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
2845 mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
2847 emit_move_insn (temp, valreg);
2849 /* The return value from a malloc-like function can not alias
2851 last = get_last_insn ();
2852 add_reg_note (last, REG_NOALIAS, temp);
2854 /* Write out the sequence. */
2855 insns = get_insns ();
2861 /* For calls to `setjmp', etc., inform
2862 function.c:setjmp_warnings that it should complain if
2863 nonvolatile values are live. For functions that cannot
2864 return, inform flow that control does not fall through. */
2866 if ((flags & ECF_NORETURN) || pass == 0)
2868 /* The barrier must be emitted
2869 immediately after the CALL_INSN. Some ports emit more
2870 than just a CALL_INSN above, so we must search for it here. */
2872 rtx last = get_last_insn ();
2873 while (!CALL_P (last))
2875 last = PREV_INSN (last);
2876 /* There was no CALL_INSN? */
2877 gcc_assert (last != before_call);
2880 emit_barrier_after (last);
2882 /* Stack adjustments after a noreturn call are dead code.
2883 However when NO_DEFER_POP is in effect, we must preserve
2884 stack_pointer_delta. */
2885 if (inhibit_defer_pop == 0)
2887 stack_pointer_delta = old_stack_allocated;
2888 pending_stack_adjust = 0;
2892 /* If value type not void, return an rtx for the value. */
2894 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
2896 target = const0_rtx;
2897 else if (structure_value_addr)
2899 if (target == 0 || !MEM_P (target))
2902 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
2903 memory_address (TYPE_MODE (TREE_TYPE (exp)),
2904 structure_value_addr));
2905 set_mem_attributes (target, exp, 1);
2908 else if (pcc_struct_value)
2910 /* This is the special C++ case where we need to
2911 know what the true target was. We take care to
2912 never use this value more than once in one expression. */
2913 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
2914 copy_to_reg (valreg));
2915 set_mem_attributes (target, exp, 1);
2917 /* Handle calls that return values in multiple non-contiguous locations.
2918 The Irix 6 ABI has examples of this. */
2919 else if (GET_CODE (valreg) == PARALLEL)
2923 /* This will only be assigned once, so it can be readonly. */
2924 tree nt = build_qualified_type (TREE_TYPE (exp),
2925 (TYPE_QUALS (TREE_TYPE (exp))
2926 | TYPE_QUAL_CONST));
2928 target = assign_temp (nt, 0, 1, 1);
2931 if (! rtx_equal_p (target, valreg))
2932 emit_group_store (target, valreg, TREE_TYPE (exp),
2933 int_size_in_bytes (TREE_TYPE (exp)));
2935 /* We can not support sibling calls for this case. */
2936 sibcall_failure = 1;
2939 && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
2940 && GET_MODE (target) == GET_MODE (valreg))
2942 bool may_overlap = false;
2944 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
2945 reg to a plain register. */
2946 if (!REG_P (target) || HARD_REGISTER_P (target))
2947 valreg = avoid_likely_spilled_reg (valreg);
2949 /* If TARGET is a MEM in the argument area, and we have
2950 saved part of the argument area, then we can't store
2951 directly into TARGET as it may get overwritten when we
2952 restore the argument save area below. Don't work too
2953 hard though and simply force TARGET to a register if it
2954 is a MEM; the optimizer is quite likely to sort it out. */
2955 if (ACCUMULATE_OUTGOING_ARGS && pass && MEM_P (target))
2956 for (i = 0; i < num_actuals; i++)
2957 if (args[i].save_area)
2964 target = copy_to_reg (valreg);
2967 /* TARGET and VALREG cannot be equal at this point
2968 because the latter would not have
2969 REG_FUNCTION_VALUE_P true, while the former would if
2970 it were referring to the same register.
2972 If they refer to the same register, this move will be
2973 a no-op, except when function inlining is being
2975 emit_move_insn (target, valreg);
2977 /* If we are setting a MEM, this code must be executed.
2978 Since it is emitted after the call insn, sibcall
2979 optimization cannot be performed in that case. */
2981 sibcall_failure = 1;
2984 else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode)
2986 target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp));
2988 /* We can not support sibling calls for this case. */
2989 sibcall_failure = 1;
2992 target = copy_to_reg (avoid_likely_spilled_reg (valreg));
2994 if (targetm.calls.promote_function_return(funtype))
2996 /* If we promoted this return value, make the proper SUBREG.
2997 TARGET might be const0_rtx here, so be careful. */
2999 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
3000 && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
3002 tree type = TREE_TYPE (exp);
3003 int unsignedp = TYPE_UNSIGNED (type);
3005 enum machine_mode pmode;
3007 pmode = promote_mode (type, TYPE_MODE (type), &unsignedp, 1);
3008 /* If we don't promote as expected, something is wrong. */
3009 gcc_assert (GET_MODE (target) == pmode);
3011 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
3012 && (GET_MODE_SIZE (GET_MODE (target))
3013 > GET_MODE_SIZE (TYPE_MODE (type))))
3015 offset = GET_MODE_SIZE (GET_MODE (target))
3016 - GET_MODE_SIZE (TYPE_MODE (type));
3017 if (! BYTES_BIG_ENDIAN)
3018 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
3019 else if (! WORDS_BIG_ENDIAN)
3020 offset %= UNITS_PER_WORD;
3022 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
3023 SUBREG_PROMOTED_VAR_P (target) = 1;
3024 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
3028 /* If size of args is variable or this was a constructor call for a stack
3029 argument, restore saved stack-pointer value. */
3031 if (old_stack_level)
3033 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
3034 stack_pointer_delta = old_stack_pointer_delta;
3035 pending_stack_adjust = old_pending_adj;
3036 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
3037 stack_arg_under_construction = old_stack_arg_under_construction;
3038 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3039 stack_usage_map = initial_stack_usage_map;
3040 sibcall_failure = 1;
3042 else if (ACCUMULATE_OUTGOING_ARGS && pass)
3044 #ifdef REG_PARM_STACK_SPACE
3046 restore_fixed_argument_area (save_area, argblock,
3047 high_to_save, low_to_save);
3050 /* If we saved any argument areas, restore them. */
3051 for (i = 0; i < num_actuals; i++)
3052 if (args[i].save_area)
3054 enum machine_mode save_mode = GET_MODE (args[i].save_area);
3056 = gen_rtx_MEM (save_mode,
3057 memory_address (save_mode,
3058 XEXP (args[i].stack_slot, 0)));
3060 if (save_mode != BLKmode)
3061 emit_move_insn (stack_area, args[i].save_area);
3063 emit_block_move (stack_area, args[i].save_area,
3064 GEN_INT (args[i].locate.size.constant),
3065 BLOCK_OP_CALL_PARM);
3068 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3069 stack_usage_map = initial_stack_usage_map;
3072 /* If this was alloca, record the new stack level for nonlocal gotos.
3073 Check for the handler slots since we might not have a save area
3074 for non-local gotos. */
3076 if ((flags & ECF_MAY_BE_ALLOCA) && cfun->nonlocal_goto_save_area != 0)
3077 update_nonlocal_goto_save_area ();
3079 /* Free up storage we no longer need. */
3080 for (i = 0; i < num_actuals; ++i)
3081 if (args[i].aligned_regs)
3082 free (args[i].aligned_regs);
3084 insns = get_insns ();
3089 tail_call_insns = insns;
3091 /* Restore the pending stack adjustment now that we have
3092 finished generating the sibling call sequence. */
3094 pending_stack_adjust = save_pending_stack_adjust;
3095 stack_pointer_delta = save_stack_pointer_delta;
3097 /* Prepare arg structure for next iteration. */
3098 for (i = 0; i < num_actuals; i++)
3101 args[i].aligned_regs = 0;
3105 sbitmap_free (stored_args_map);
3109 normal_call_insns = insns;
3111 /* Verify that we've deallocated all the stack we used. */
3112 gcc_assert ((flags & ECF_NORETURN)
3113 || (old_stack_allocated
3114 == stack_pointer_delta - pending_stack_adjust));
3117 /* If something prevents making this a sibling call,
3118 zero out the sequence. */
3119 if (sibcall_failure)
3120 tail_call_insns = NULL_RTX;
3125 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
3126 arguments too, as argument area is now clobbered by the call. */
3127 if (tail_call_insns)
3129 emit_insn (tail_call_insns);
3130 crtl->tail_call_emit = true;
3133 emit_insn (normal_call_insns);
3135 currently_expanding_call--;
3137 if (stack_usage_map_buf)
3138 free (stack_usage_map_buf);
3143 /* A sibling call sequence invalidates any REG_EQUIV notes made for
3144 this function's incoming arguments.
3146 At the start of RTL generation we know the only REG_EQUIV notes
3147 in the rtl chain are those for incoming arguments, so we can look
3148 for REG_EQUIV notes between the start of the function and the
3149 NOTE_INSN_FUNCTION_BEG.
3151 This is (slight) overkill. We could keep track of the highest
3152 argument we clobber and be more selective in removing notes, but it
3153 does not seem to be worth the effort. */
3156 fixup_tail_calls (void)
3160 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3164 /* There are never REG_EQUIV notes for the incoming arguments
3165 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
3167 && NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG)
3170 note = find_reg_note (insn, REG_EQUIV, 0);
3172 remove_note (insn, note);
3173 note = find_reg_note (insn, REG_EQUIV, 0);
3178 /* Traverse a list of TYPES and expand all complex types into their
3181 split_complex_types (tree types)
3185 /* Before allocating memory, check for the common case of no complex. */
3186 for (p = types; p; p = TREE_CHAIN (p))
3188 tree type = TREE_VALUE (p);
3189 if (TREE_CODE (type) == COMPLEX_TYPE
3190 && targetm.calls.split_complex_arg (type))
3196 types = copy_list (types);
3198 for (p = types; p; p = TREE_CHAIN (p))
3200 tree complex_type = TREE_VALUE (p);
3202 if (TREE_CODE (complex_type) == COMPLEX_TYPE
3203 && targetm.calls.split_complex_arg (complex_type))
3207 /* Rewrite complex type with component type. */
3208 TREE_VALUE (p) = TREE_TYPE (complex_type);
3209 next = TREE_CHAIN (p);
3211 /* Add another component type for the imaginary part. */
3212 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
3213 TREE_CHAIN (p) = imag;
3214 TREE_CHAIN (imag) = next;
3216 /* Skip the newly created node. */
3224 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3225 The RETVAL parameter specifies whether return value needs to be saved, other
3226 parameters are documented in the emit_library_call function below. */
3229 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
3230 enum libcall_type fn_type,
3231 enum machine_mode outmode, int nargs, va_list p)
3233 /* Total size in bytes of all the stack-parms scanned so far. */
3234 struct args_size args_size;
3235 /* Size of arguments before any adjustments (such as rounding). */
3236 struct args_size original_args_size;
3239 /* Todo, choose the correct decl type of orgfun. Sadly this information
3240 isn't present here, so we default to native calling abi here. */
3241 tree fndecl ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
3242 tree fntype ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
3246 CUMULATIVE_ARGS args_so_far;
3250 enum machine_mode mode;
3253 struct locate_and_pad_arg_data locate;
3257 int old_inhibit_defer_pop = inhibit_defer_pop;
3258 rtx call_fusage = 0;
3261 int pcc_struct_value = 0;
3262 int struct_value_size = 0;
3264 int reg_parm_stack_space = 0;
3267 tree tfom; /* type_for_mode (outmode, 0) */
3269 #ifdef REG_PARM_STACK_SPACE
3270 /* Define the boundary of the register parm stack space that needs to be
3272 int low_to_save = 0, high_to_save = 0;
3273 rtx save_area = 0; /* Place that it is saved. */
3276 /* Size of the stack reserved for parameter registers. */
3277 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3278 char *initial_stack_usage_map = stack_usage_map;
3279 char *stack_usage_map_buf = NULL;
3281 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
3283 #ifdef REG_PARM_STACK_SPACE
3284 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3287 /* By default, library functions can not throw. */
3288 flags = ECF_NOTHROW;
3301 flags |= ECF_NORETURN;
3304 flags = ECF_NORETURN;
3306 case LCT_RETURNS_TWICE:
3307 flags = ECF_RETURNS_TWICE;
3312 /* Ensure current function's preferred stack boundary is at least
3314 if (crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3315 crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3317 /* If this kind of value comes back in memory,
3318 decide where in memory it should come back. */
3319 if (outmode != VOIDmode)
3321 tfom = lang_hooks.types.type_for_mode (outmode, 0);
3322 if (aggregate_value_p (tfom, 0))
3324 #ifdef PCC_STATIC_STRUCT_RETURN
3326 = hard_function_value (build_pointer_type (tfom), 0, 0, 0);
3327 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3328 pcc_struct_value = 1;
3330 value = gen_reg_rtx (outmode);
3331 #else /* not PCC_STATIC_STRUCT_RETURN */
3332 struct_value_size = GET_MODE_SIZE (outmode);
3333 if (value != 0 && MEM_P (value))
3336 mem_value = assign_temp (tfom, 0, 1, 1);
3338 /* This call returns a big structure. */
3339 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
3343 tfom = void_type_node;
3345 /* ??? Unfinished: must pass the memory address as an argument. */
3347 /* Copy all the libcall-arguments out of the varargs data
3348 and into a vector ARGVEC.
3350 Compute how to pass each argument. We only support a very small subset
3351 of the full argument passing conventions to limit complexity here since
3352 library functions shouldn't have many args. */
3354 argvec = XALLOCAVEC (struct arg, nargs + 1);
3355 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
3357 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3358 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun);
3360 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0, nargs);
3363 args_size.constant = 0;
3370 /* If there's a structure value address to be passed,
3371 either pass it in the special place, or pass it as an extra argument. */
3372 if (mem_value && struct_value == 0 && ! pcc_struct_value)
3374 rtx addr = XEXP (mem_value, 0);
3378 /* Make sure it is a reasonable operand for a move or push insn. */
3379 if (!REG_P (addr) && !MEM_P (addr)
3380 && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr)))
3381 addr = force_operand (addr, NULL_RTX);
3383 argvec[count].value = addr;
3384 argvec[count].mode = Pmode;
3385 argvec[count].partial = 0;
3387 argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1);
3388 gcc_assert (targetm.calls.arg_partial_bytes (&args_so_far, Pmode,
3389 NULL_TREE, 1) == 0);
3391 locate_and_pad_parm (Pmode, NULL_TREE,
3392 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3395 argvec[count].reg != 0,
3397 0, NULL_TREE, &args_size, &argvec[count].locate);
3399 if (argvec[count].reg == 0 || argvec[count].partial != 0
3400 || reg_parm_stack_space > 0)
3401 args_size.constant += argvec[count].locate.size.constant;
3403 FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1);
3408 for (; count < nargs; count++)
3410 rtx val = va_arg (p, rtx);
3411 enum machine_mode mode = va_arg (p, enum machine_mode);
3413 /* We cannot convert the arg value to the mode the library wants here;
3414 must do it earlier where we know the signedness of the arg. */
3415 gcc_assert (mode != BLKmode
3416 && (GET_MODE (val) == mode || GET_MODE (val) == VOIDmode));
3418 /* Make sure it is a reasonable operand for a move or push insn. */
3419 if (!REG_P (val) && !MEM_P (val)
3420 && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val)))
3421 val = force_operand (val, NULL_RTX);
3423 if (pass_by_reference (&args_so_far, mode, NULL_TREE, 1))
3427 = !reference_callee_copied (&args_so_far, mode, NULL_TREE, 1);
3429 /* If this was a CONST function, it is now PURE since it now
3431 if (flags & ECF_CONST)
3433 flags &= ~ECF_CONST;
3437 if (MEM_P (val) && !must_copy)
3441 slot = assign_temp (lang_hooks.types.type_for_mode (mode, 0),
3443 emit_move_insn (slot, val);
3446 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3447 gen_rtx_USE (VOIDmode, slot),
3450 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3451 gen_rtx_CLOBBER (VOIDmode,
3456 val = force_operand (XEXP (slot, 0), NULL_RTX);
3459 argvec[count].value = val;
3460 argvec[count].mode = mode;
3462 argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1);
3464 argvec[count].partial
3465 = targetm.calls.arg_partial_bytes (&args_so_far, mode, NULL_TREE, 1);
3467 locate_and_pad_parm (mode, NULL_TREE,
3468 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3471 argvec[count].reg != 0,
3473 argvec[count].partial,
3474 NULL_TREE, &args_size, &argvec[count].locate);
3476 gcc_assert (!argvec[count].locate.size.var);
3478 if (argvec[count].reg == 0 || argvec[count].partial != 0
3479 || reg_parm_stack_space > 0)
3480 args_size.constant += argvec[count].locate.size.constant;
3482 FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1);
3485 /* If this machine requires an external definition for library
3486 functions, write one out. */
3487 assemble_external_libcall (fun);
3489 original_args_size = args_size;
3490 args_size.constant = (((args_size.constant
3491 + stack_pointer_delta
3495 - stack_pointer_delta);
3497 args_size.constant = MAX (args_size.constant,
3498 reg_parm_stack_space);
3500 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
3501 args_size.constant -= reg_parm_stack_space;
3503 if (args_size.constant > crtl->outgoing_args_size)
3504 crtl->outgoing_args_size = args_size.constant;
3506 if (ACCUMULATE_OUTGOING_ARGS)
3508 /* Since the stack pointer will never be pushed, it is possible for
3509 the evaluation of a parm to clobber something we have already
3510 written to the stack. Since most function calls on RISC machines
3511 do not use the stack, this is uncommon, but must work correctly.
3513 Therefore, we save any area of the stack that was already written
3514 and that we are using. Here we set up to do this by making a new
3515 stack usage map from the old one.
3517 Another approach might be to try to reorder the argument
3518 evaluations to avoid this conflicting stack usage. */
3520 needed = args_size.constant;
3522 /* Since we will be writing into the entire argument area, the
3523 map must be allocated for its entire size, not just the part that
3524 is the responsibility of the caller. */
3525 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
3526 needed += reg_parm_stack_space;
3528 #ifdef ARGS_GROW_DOWNWARD
3529 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3532 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3535 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
3536 stack_usage_map = stack_usage_map_buf;
3538 if (initial_highest_arg_in_use)
3539 memcpy (stack_usage_map, initial_stack_usage_map,
3540 initial_highest_arg_in_use);
3542 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3543 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3544 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3547 /* We must be careful to use virtual regs before they're instantiated,
3548 and real regs afterwards. Loop optimization, for example, can create
3549 new libcalls after we've instantiated the virtual regs, and if we
3550 use virtuals anyway, they won't match the rtl patterns. */
3552 if (virtuals_instantiated)
3553 argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET);
3555 argblock = virtual_outgoing_args_rtx;
3560 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3563 /* If we push args individually in reverse order, perform stack alignment
3564 before the first push (the last arg). */
3565 if (argblock == 0 && PUSH_ARGS_REVERSED)
3566 anti_adjust_stack (GEN_INT (args_size.constant
3567 - original_args_size.constant));
3569 if (PUSH_ARGS_REVERSED)
3580 #ifdef REG_PARM_STACK_SPACE
3581 if (ACCUMULATE_OUTGOING_ARGS)
3583 /* The argument list is the property of the called routine and it
3584 may clobber it. If the fixed area has been used for previous
3585 parameters, we must save and restore it. */
3586 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3587 &low_to_save, &high_to_save);
3591 /* Push the args that need to be pushed. */
3593 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3594 are to be pushed. */
3595 for (count = 0; count < nargs; count++, argnum += inc)
3597 enum machine_mode mode = argvec[argnum].mode;
3598 rtx val = argvec[argnum].value;
3599 rtx reg = argvec[argnum].reg;
3600 int partial = argvec[argnum].partial;
3601 int lower_bound = 0, upper_bound = 0, i;
3603 if (! (reg != 0 && partial == 0))
3605 if (ACCUMULATE_OUTGOING_ARGS)
3607 /* If this is being stored into a pre-allocated, fixed-size,
3608 stack area, save any previous data at that location. */
3610 #ifdef ARGS_GROW_DOWNWARD
3611 /* stack_slot is negative, but we want to index stack_usage_map
3612 with positive values. */
3613 upper_bound = -argvec[argnum].locate.offset.constant + 1;
3614 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
3616 lower_bound = argvec[argnum].locate.offset.constant;
3617 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
3621 /* Don't worry about things in the fixed argument area;
3622 it has already been saved. */
3623 if (i < reg_parm_stack_space)
3624 i = reg_parm_stack_space;
3625 while (i < upper_bound && stack_usage_map[i] == 0)
3628 if (i < upper_bound)
3630 /* We need to make a save area. */
3632 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
3633 enum machine_mode save_mode
3634 = mode_for_size (size, MODE_INT, 1);
3636 = plus_constant (argblock,
3637 argvec[argnum].locate.offset.constant);
3639 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
3641 if (save_mode == BLKmode)
3643 argvec[argnum].save_area
3644 = assign_stack_temp (BLKmode,
3645 argvec[argnum].locate.size.constant,
3648 emit_block_move (validize_mem (argvec[argnum].save_area),
3650 GEN_INT (argvec[argnum].locate.size.constant),
3651 BLOCK_OP_CALL_PARM);
3655 argvec[argnum].save_area = gen_reg_rtx (save_mode);
3657 emit_move_insn (argvec[argnum].save_area, stack_area);
3662 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, PARM_BOUNDARY,
3663 partial, reg, 0, argblock,
3664 GEN_INT (argvec[argnum].locate.offset.constant),
3665 reg_parm_stack_space,
3666 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad));
3668 /* Now mark the segment we just used. */
3669 if (ACCUMULATE_OUTGOING_ARGS)
3670 for (i = lower_bound; i < upper_bound; i++)
3671 stack_usage_map[i] = 1;
3675 if (flags & ECF_CONST)
3679 /* Indicate argument access so that alias.c knows that these
3682 use = plus_constant (argblock,
3683 argvec[argnum].locate.offset.constant);
3685 /* When arguments are pushed, trying to tell alias.c where
3686 exactly this argument is won't work, because the
3687 auto-increment causes confusion. So we merely indicate
3688 that we access something with a known mode somewhere on
3690 use = gen_rtx_PLUS (Pmode, virtual_outgoing_args_rtx,
3691 gen_rtx_SCRATCH (Pmode));
3692 use = gen_rtx_MEM (argvec[argnum].mode, use);
3693 use = gen_rtx_USE (VOIDmode, use);
3694 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, use, call_fusage);
3699 /* If we pushed args in forward order, perform stack alignment
3700 after pushing the last arg. */
3701 if (argblock == 0 && !PUSH_ARGS_REVERSED)
3702 anti_adjust_stack (GEN_INT (args_size.constant
3703 - original_args_size.constant));
3705 if (PUSH_ARGS_REVERSED)
3710 fun = prepare_call_address (fun, NULL, &call_fusage, 0, 0);
3712 /* Now load any reg parms into their regs. */
3714 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3715 are to be pushed. */
3716 for (count = 0; count < nargs; count++, argnum += inc)
3718 enum machine_mode mode = argvec[argnum].mode;
3719 rtx val = argvec[argnum].value;
3720 rtx reg = argvec[argnum].reg;
3721 int partial = argvec[argnum].partial;
3723 /* Handle calls that pass values in multiple non-contiguous
3724 locations. The PA64 has examples of this for library calls. */
3725 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3726 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode));
3727 else if (reg != 0 && partial == 0)
3728 emit_move_insn (reg, val);
3733 /* Any regs containing parms remain in use through the call. */
3734 for (count = 0; count < nargs; count++)
3736 rtx reg = argvec[count].reg;
3737 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3738 use_group_regs (&call_fusage, reg);
3741 int partial = argvec[count].partial;
3745 gcc_assert (partial % UNITS_PER_WORD == 0);
3746 nregs = partial / UNITS_PER_WORD;
3747 use_regs (&call_fusage, REGNO (reg), nregs);
3750 use_reg (&call_fusage, reg);
3754 /* Pass the function the address in which to return a structure value. */
3755 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
3757 emit_move_insn (struct_value,
3759 force_operand (XEXP (mem_value, 0),
3761 if (REG_P (struct_value))
3762 use_reg (&call_fusage, struct_value);
3765 /* Don't allow popping to be deferred, since then
3766 cse'ing of library calls could delete a call and leave the pop. */
3768 valreg = (mem_value == 0 && outmode != VOIDmode
3769 ? hard_libcall_value (outmode) : NULL_RTX);
3771 /* Stack must be properly aligned now. */
3772 gcc_assert (!(stack_pointer_delta
3773 & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1)));
3775 before_call = get_last_insn ();
3777 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
3778 will set inhibit_defer_pop to that value. */
3779 /* The return type is needed to decide how many bytes the function pops.
3780 Signedness plays no role in that, so for simplicity, we pretend it's
3781 always signed. We also assume that the list of arguments passed has
3782 no impact, so we pretend it is unknown. */
3784 emit_call_1 (fun, NULL,
3785 get_identifier (XSTR (orgfun, 0)),
3786 build_function_type (tfom, NULL_TREE),
3787 original_args_size.constant, args_size.constant,
3789 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
3791 old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far);
3793 /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
3794 that it should complain if nonvolatile values are live. For
3795 functions that cannot return, inform flow that control does not
3798 if (flags & ECF_NORETURN)
3800 /* The barrier note must be emitted
3801 immediately after the CALL_INSN. Some ports emit more than
3802 just a CALL_INSN above, so we must search for it here. */
3804 rtx last = get_last_insn ();
3805 while (!CALL_P (last))
3807 last = PREV_INSN (last);
3808 /* There was no CALL_INSN? */
3809 gcc_assert (last != before_call);
3812 emit_barrier_after (last);
3815 /* Now restore inhibit_defer_pop to its actual original value. */
3820 /* Copy the value to the right place. */
3821 if (outmode != VOIDmode && retval)
3827 if (value != mem_value)
3828 emit_move_insn (value, mem_value);
3830 else if (GET_CODE (valreg) == PARALLEL)
3833 value = gen_reg_rtx (outmode);
3834 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
3838 /* Convert to the proper mode if PROMOTE_MODE has been active. */
3839 if (GET_MODE (valreg) != outmode)
3841 int unsignedp = TYPE_UNSIGNED (tfom);
3843 gcc_assert (targetm.calls.promote_function_return (tfom));
3844 gcc_assert (promote_mode (tfom, outmode, &unsignedp, 0)
3845 == GET_MODE (valreg));
3847 valreg = convert_modes (outmode, GET_MODE (valreg), valreg, 0);
3851 emit_move_insn (value, valreg);
3857 if (ACCUMULATE_OUTGOING_ARGS)
3859 #ifdef REG_PARM_STACK_SPACE
3861 restore_fixed_argument_area (save_area, argblock,
3862 high_to_save, low_to_save);
3865 /* If we saved any argument areas, restore them. */
3866 for (count = 0; count < nargs; count++)
3867 if (argvec[count].save_area)
3869 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
3870 rtx adr = plus_constant (argblock,
3871 argvec[count].locate.offset.constant);
3872 rtx stack_area = gen_rtx_MEM (save_mode,
3873 memory_address (save_mode, adr));
3875 if (save_mode == BLKmode)
3876 emit_block_move (stack_area,
3877 validize_mem (argvec[count].save_area),
3878 GEN_INT (argvec[count].locate.size.constant),
3879 BLOCK_OP_CALL_PARM);
3881 emit_move_insn (stack_area, argvec[count].save_area);
3884 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3885 stack_usage_map = initial_stack_usage_map;
3888 if (stack_usage_map_buf)
3889 free (stack_usage_map_buf);
3895 /* Output a library call to function FUN (a SYMBOL_REF rtx)
3896 (emitting the queue unless NO_QUEUE is nonzero),
3897 for a value of mode OUTMODE,
3898 with NARGS different arguments, passed as alternating rtx values
3899 and machine_modes to convert them to.
3901 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for
3902 `const' calls, LCT_PURE for `pure' calls, or other LCT_ value for
3903 other types of library calls. */
3906 emit_library_call (rtx orgfun, enum libcall_type fn_type,
3907 enum machine_mode outmode, int nargs, ...)
3911 va_start (p, nargs);
3912 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
3916 /* Like emit_library_call except that an extra argument, VALUE,
3917 comes second and says where to store the result.
3918 (If VALUE is zero, this function chooses a convenient way
3919 to return the value.
3921 This function returns an rtx for where the value is to be found.
3922 If VALUE is nonzero, VALUE is returned. */
3925 emit_library_call_value (rtx orgfun, rtx value,
3926 enum libcall_type fn_type,
3927 enum machine_mode outmode, int nargs, ...)
3932 va_start (p, nargs);
3933 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
3940 /* Store a single argument for a function call
3941 into the register or memory area where it must be passed.
3942 *ARG describes the argument value and where to pass it.
3944 ARGBLOCK is the address of the stack-block for all the arguments,
3945 or 0 on a machine where arguments are pushed individually.
3947 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
3948 so must be careful about how the stack is used.
3950 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
3951 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
3952 that we need not worry about saving and restoring the stack.
3954 FNDECL is the declaration of the function we are calling.
3956 Return nonzero if this arg should cause sibcall failure,
3960 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
3961 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
3963 tree pval = arg->tree_value;
3967 int i, lower_bound = 0, upper_bound = 0;
3968 int sibcall_failure = 0;
3970 if (TREE_CODE (pval) == ERROR_MARK)
3973 /* Push a new temporary level for any temporaries we make for
3977 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
3979 /* If this is being stored into a pre-allocated, fixed-size, stack area,
3980 save any previous data at that location. */
3981 if (argblock && ! variable_size && arg->stack)
3983 #ifdef ARGS_GROW_DOWNWARD
3984 /* stack_slot is negative, but we want to index stack_usage_map
3985 with positive values. */
3986 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
3987 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
3991 lower_bound = upper_bound - arg->locate.size.constant;
3993 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
3994 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
3998 upper_bound = lower_bound + arg->locate.size.constant;
4002 /* Don't worry about things in the fixed argument area;
4003 it has already been saved. */
4004 if (i < reg_parm_stack_space)
4005 i = reg_parm_stack_space;
4006 while (i < upper_bound && stack_usage_map[i] == 0)
4009 if (i < upper_bound)
4011 /* We need to make a save area. */
4012 unsigned int size = arg->locate.size.constant * BITS_PER_UNIT;
4013 enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1);
4014 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
4015 rtx stack_area = gen_rtx_MEM (save_mode, adr);
4017 if (save_mode == BLKmode)
4019 tree ot = TREE_TYPE (arg->tree_value);
4020 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
4021 | TYPE_QUAL_CONST));
4023 arg->save_area = assign_temp (nt, 0, 1, 1);
4024 preserve_temp_slots (arg->save_area);
4025 emit_block_move (validize_mem (arg->save_area), stack_area,
4026 GEN_INT (arg->locate.size.constant),
4027 BLOCK_OP_CALL_PARM);
4031 arg->save_area = gen_reg_rtx (save_mode);
4032 emit_move_insn (arg->save_area, stack_area);
4038 /* If this isn't going to be placed on both the stack and in registers,
4039 set up the register and number of words. */
4040 if (! arg->pass_on_stack)
4042 if (flags & ECF_SIBCALL)
4043 reg = arg->tail_call_reg;
4046 partial = arg->partial;
4049 /* Being passed entirely in a register. We shouldn't be called in
4051 gcc_assert (reg == 0 || partial != 0);
4053 /* If this arg needs special alignment, don't load the registers
4055 if (arg->n_aligned_regs != 0)
4058 /* If this is being passed partially in a register, we can't evaluate
4059 it directly into its stack slot. Otherwise, we can. */
4060 if (arg->value == 0)
4062 /* stack_arg_under_construction is nonzero if a function argument is
4063 being evaluated directly into the outgoing argument list and
4064 expand_call must take special action to preserve the argument list
4065 if it is called recursively.
4067 For scalar function arguments stack_usage_map is sufficient to
4068 determine which stack slots must be saved and restored. Scalar
4069 arguments in general have pass_on_stack == 0.
4071 If this argument is initialized by a function which takes the
4072 address of the argument (a C++ constructor or a C function
4073 returning a BLKmode structure), then stack_usage_map is
4074 insufficient and expand_call must push the stack around the
4075 function call. Such arguments have pass_on_stack == 1.
4077 Note that it is always safe to set stack_arg_under_construction,
4078 but this generates suboptimal code if set when not needed. */
4080 if (arg->pass_on_stack)
4081 stack_arg_under_construction++;
4083 arg->value = expand_expr (pval,
4085 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4086 ? NULL_RTX : arg->stack,
4087 VOIDmode, EXPAND_STACK_PARM);
4089 /* If we are promoting object (or for any other reason) the mode
4090 doesn't agree, convert the mode. */
4092 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4093 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4094 arg->value, arg->unsignedp);
4096 if (arg->pass_on_stack)
4097 stack_arg_under_construction--;
4100 /* Check for overlap with already clobbered argument area. */
4101 if ((flags & ECF_SIBCALL)
4102 && MEM_P (arg->value)
4103 && mem_overlaps_already_clobbered_arg_p (XEXP (arg->value, 0),
4104 arg->locate.size.constant))
4105 sibcall_failure = 1;
4107 /* Don't allow anything left on stack from computation
4108 of argument to alloca. */
4109 if (flags & ECF_MAY_BE_ALLOCA)
4110 do_pending_stack_adjust ();
4112 if (arg->value == arg->stack)
4113 /* If the value is already in the stack slot, we are done. */
4115 else if (arg->mode != BLKmode)
4118 unsigned int parm_align;
4120 /* Argument is a scalar, not entirely passed in registers.
4121 (If part is passed in registers, arg->partial says how much
4122 and emit_push_insn will take care of putting it there.)
4124 Push it, and if its size is less than the
4125 amount of space allocated to it,
4126 also bump stack pointer by the additional space.
4127 Note that in C the default argument promotions
4128 will prevent such mismatches. */
4130 size = GET_MODE_SIZE (arg->mode);
4131 /* Compute how much space the push instruction will push.
4132 On many machines, pushing a byte will advance the stack
4133 pointer by a halfword. */
4134 #ifdef PUSH_ROUNDING
4135 size = PUSH_ROUNDING (size);
4139 /* Compute how much space the argument should get:
4140 round up to a multiple of the alignment for arguments. */
4141 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4142 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4143 / (PARM_BOUNDARY / BITS_PER_UNIT))
4144 * (PARM_BOUNDARY / BITS_PER_UNIT));
4146 /* Compute the alignment of the pushed argument. */
4147 parm_align = arg->locate.boundary;
4148 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4150 int pad = used - size;
4153 unsigned int pad_align = (pad & -pad) * BITS_PER_UNIT;
4154 parm_align = MIN (parm_align, pad_align);
4158 /* This isn't already where we want it on the stack, so put it there.
4159 This can either be done with push or copy insns. */
4160 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4161 parm_align, partial, reg, used - size, argblock,
4162 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4163 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4165 /* Unless this is a partially-in-register argument, the argument is now
4168 arg->value = arg->stack;
4172 /* BLKmode, at least partly to be pushed. */
4174 unsigned int parm_align;
4178 /* Pushing a nonscalar.
4179 If part is passed in registers, PARTIAL says how much
4180 and emit_push_insn will take care of putting it there. */
4182 /* Round its size up to a multiple
4183 of the allocation unit for arguments. */
4185 if (arg->locate.size.var != 0)
4188 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
4192 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
4193 for BLKmode is careful to avoid it. */
4194 excess = (arg->locate.size.constant
4195 - int_size_in_bytes (TREE_TYPE (pval))
4197 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4198 NULL_RTX, TYPE_MODE (sizetype), 0);
4201 parm_align = arg->locate.boundary;
4203 /* When an argument is padded down, the block is aligned to
4204 PARM_BOUNDARY, but the actual argument isn't. */
4205 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4207 if (arg->locate.size.var)
4208 parm_align = BITS_PER_UNIT;
4211 unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4212 parm_align = MIN (parm_align, excess_align);
4216 if ((flags & ECF_SIBCALL) && MEM_P (arg->value))
4218 /* emit_push_insn might not work properly if arg->value and
4219 argblock + arg->locate.offset areas overlap. */
4223 if (XEXP (x, 0) == crtl->args.internal_arg_pointer
4224 || (GET_CODE (XEXP (x, 0)) == PLUS
4225 && XEXP (XEXP (x, 0), 0) ==
4226 crtl->args.internal_arg_pointer
4227 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT))
4229 if (XEXP (x, 0) != crtl->args.internal_arg_pointer)
4230 i = INTVAL (XEXP (XEXP (x, 0), 1));
4232 /* expand_call should ensure this. */
4233 gcc_assert (!arg->locate.offset.var
4234 && arg->locate.size.var == 0
4235 && GET_CODE (size_rtx) == CONST_INT);
4237 if (arg->locate.offset.constant > i)
4239 if (arg->locate.offset.constant < i + INTVAL (size_rtx))
4240 sibcall_failure = 1;
4242 else if (arg->locate.offset.constant < i)
4244 /* Use arg->locate.size.constant instead of size_rtx
4245 because we only care about the part of the argument
4247 if (i < (arg->locate.offset.constant
4248 + arg->locate.size.constant))
4249 sibcall_failure = 1;
4253 /* Even though they appear to be at the same location,
4254 if part of the outgoing argument is in registers,
4255 they aren't really at the same location. Check for
4256 this by making sure that the incoming size is the
4257 same as the outgoing size. */
4258 if (arg->locate.size.constant != INTVAL (size_rtx))
4259 sibcall_failure = 1;
4264 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4265 parm_align, partial, reg, excess, argblock,
4266 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4267 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4269 /* Unless this is a partially-in-register argument, the argument is now
4272 ??? Unlike the case above, in which we want the actual
4273 address of the data, so that we can load it directly into a
4274 register, here we want the address of the stack slot, so that
4275 it's properly aligned for word-by-word copying or something
4276 like that. It's not clear that this is always correct. */
4278 arg->value = arg->stack_slot;
4281 if (arg->reg && GET_CODE (arg->reg) == PARALLEL)
4283 tree type = TREE_TYPE (arg->tree_value);
4285 = emit_group_load_into_temps (arg->reg, arg->value, type,
4286 int_size_in_bytes (type));
4289 /* Mark all slots this store used. */
4290 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
4291 && argblock && ! variable_size && arg->stack)
4292 for (i = lower_bound; i < upper_bound; i++)
4293 stack_usage_map[i] = 1;
4295 /* Once we have pushed something, pops can't safely
4296 be deferred during the rest of the arguments. */
4299 /* Free any temporary slots made in processing this argument. Show
4300 that we might have taken the address of something and pushed that
4302 preserve_temp_slots (NULL_RTX);
4306 return sibcall_failure;
4309 /* Nonzero if we do not know how to pass TYPE solely in registers. */
4312 must_pass_in_stack_var_size (enum machine_mode mode ATTRIBUTE_UNUSED,
4318 /* If the type has variable size... */
4319 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4322 /* If the type is marked as addressable (it is required
4323 to be constructed into the stack)... */
4324 if (TREE_ADDRESSABLE (type))
4330 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
4331 takes trailing padding of a structure into account. */
4332 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
4335 must_pass_in_stack_var_size_or_pad (enum machine_mode mode, const_tree type)
4340 /* If the type has variable size... */
4341 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4344 /* If the type is marked as addressable (it is required
4345 to be constructed into the stack)... */
4346 if (TREE_ADDRESSABLE (type))
4349 /* If the padding and mode of the type is such that a copy into
4350 a register would put it into the wrong part of the register. */
4352 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
4353 && (FUNCTION_ARG_PADDING (mode, type)
4354 == (BYTES_BIG_ENDIAN ? upward : downward)))