1 /* Convert function calls to rtl insns, for GNU C compiler.
2 Copyright (C) 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
24 #include "coretypes.h"
40 #include "langhooks.h"
45 #include "tree-flow.h"
47 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
48 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
50 /* Data structure and subroutines used within expand_call. */
54 /* Tree node for this argument. */
56 /* Mode for value; TYPE_MODE unless promoted. */
57 enum machine_mode mode;
58 /* Current RTL value for argument, or 0 if it isn't precomputed. */
60 /* Initially-compute RTL value for argument; only for const functions. */
62 /* Register to pass this argument in, 0 if passed on stack, or an
63 PARALLEL if the arg is to be copied into multiple non-contiguous
66 /* Register to pass this argument in when generating tail call sequence.
67 This is not the same register as for normal calls on machines with
70 /* If REG is a PARALLEL, this is a copy of VALUE pulled into the correct
71 form for emit_group_move. */
73 /* If REG was promoted from the actual mode of the argument expression,
74 indicates whether the promotion is sign- or zero-extended. */
76 /* Number of bytes to put in registers. 0 means put the whole arg
77 in registers. Also 0 if not passed in registers. */
79 /* Nonzero if argument must be passed on stack.
80 Note that some arguments may be passed on the stack
81 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
82 pass_on_stack identifies arguments that *cannot* go in registers. */
84 /* Some fields packaged up for locate_and_pad_parm. */
85 struct locate_and_pad_arg_data locate;
86 /* Location on the stack at which parameter should be stored. The store
87 has already been done if STACK == VALUE. */
89 /* Location on the stack of the start of this argument slot. This can
90 differ from STACK if this arg pads downward. This location is known
91 to be aligned to FUNCTION_ARG_BOUNDARY. */
93 /* Place that this stack area has been saved, if needed. */
95 /* If an argument's alignment does not permit direct copying into registers,
96 copy in smaller-sized pieces into pseudos. These are stored in a
97 block pointed to by this field. The next field says how many
98 word-sized pseudos we made. */
103 /* A vector of one char per byte of stack space. A byte if nonzero if
104 the corresponding stack location has been used.
105 This vector is used to prevent a function call within an argument from
106 clobbering any stack already set up. */
107 static char *stack_usage_map;
109 /* Size of STACK_USAGE_MAP. */
110 static int highest_outgoing_arg_in_use;
112 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
113 stack location's tail call argument has been already stored into the stack.
114 This bitmap is used to prevent sibling call optimization if function tries
115 to use parent's incoming argument slots when they have been already
116 overwritten with tail call arguments. */
117 static sbitmap stored_args_map;
119 /* stack_arg_under_construction is nonzero when an argument may be
120 initialized with a constructor call (including a C function that
121 returns a BLKmode struct) and expand_call must take special action
122 to make sure the object being constructed does not overlap the
123 argument list for the constructor call. */
124 static int stack_arg_under_construction;
126 static void emit_call_1 (rtx, tree, tree, tree, HOST_WIDE_INT, HOST_WIDE_INT,
127 HOST_WIDE_INT, rtx, rtx, int, rtx, int,
129 static void precompute_register_parameters (int, struct arg_data *, int *);
130 static int store_one_arg (struct arg_data *, rtx, int, int, int);
131 static void store_unaligned_arguments_into_pseudos (struct arg_data *, int);
132 static int finalize_must_preallocate (int, int, struct arg_data *,
134 static void precompute_arguments (int, struct arg_data *);
135 static int compute_argument_block_size (int, struct args_size *, tree, int);
136 static void initialize_argument_information (int, struct arg_data *,
137 struct args_size *, int,
139 tree, CUMULATIVE_ARGS *, int,
140 rtx *, int *, int *, int *,
142 static void compute_argument_addresses (struct arg_data *, rtx, int);
143 static rtx rtx_for_function_call (tree, tree);
144 static void load_register_parameters (struct arg_data *, int, rtx *, int,
146 static rtx emit_library_call_value_1 (int, rtx, rtx, enum libcall_type,
147 enum machine_mode, int, va_list);
148 static int special_function_p (const_tree, int);
149 static int check_sibcall_argument_overlap_1 (rtx);
150 static int check_sibcall_argument_overlap (rtx, struct arg_data *, int);
152 static int combine_pending_stack_adjustment_and_call (int, struct args_size *,
154 static tree split_complex_types (tree);
156 #ifdef REG_PARM_STACK_SPACE
157 static rtx save_fixed_argument_area (int, rtx, int *, int *);
158 static void restore_fixed_argument_area (rtx, rtx, int, int);
161 /* Force FUNEXP into a form suitable for the address of a CALL,
162 and return that as an rtx. Also load the static chain register
163 if FNDECL is a nested function.
165 CALL_FUSAGE points to a variable holding the prospective
166 CALL_INSN_FUNCTION_USAGE information. */
169 prepare_call_address (rtx funexp, rtx static_chain_value,
170 rtx *call_fusage, int reg_parm_seen, int sibcallp)
172 /* Make a valid memory address and copy constants through pseudo-regs,
173 but not for a constant address if -fno-function-cse. */
174 if (GET_CODE (funexp) != SYMBOL_REF)
175 /* If we are using registers for parameters, force the
176 function address into a register now. */
177 funexp = ((SMALL_REGISTER_CLASSES && reg_parm_seen)
178 ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
179 : memory_address (FUNCTION_MODE, funexp));
182 #ifndef NO_FUNCTION_CSE
183 if (optimize && ! flag_no_function_cse)
184 funexp = force_reg (Pmode, funexp);
188 if (static_chain_value != 0)
190 static_chain_value = convert_memory_address (Pmode, static_chain_value);
191 emit_move_insn (static_chain_rtx, static_chain_value);
193 if (REG_P (static_chain_rtx))
194 use_reg (call_fusage, static_chain_rtx);
200 /* Generate instructions to call function FUNEXP,
201 and optionally pop the results.
202 The CALL_INSN is the first insn generated.
204 FNDECL is the declaration node of the function. This is given to the
205 macro RETURN_POPS_ARGS to determine whether this function pops its own args.
207 FUNTYPE is the data type of the function. This is given to the macro
208 RETURN_POPS_ARGS to determine whether this function pops its own args.
209 We used to allow an identifier for library functions, but that doesn't
210 work when the return type is an aggregate type and the calling convention
211 says that the pointer to this aggregate is to be popped by the callee.
213 STACK_SIZE is the number of bytes of arguments on the stack,
214 ROUNDED_STACK_SIZE is that number rounded up to
215 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
216 both to put into the call insn and to generate explicit popping
219 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
220 It is zero if this call doesn't want a structure value.
222 NEXT_ARG_REG is the rtx that results from executing
223 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
224 just after all the args have had their registers assigned.
225 This could be whatever you like, but normally it is the first
226 arg-register beyond those used for args in this call,
227 or 0 if all the arg-registers are used in this call.
228 It is passed on to `gen_call' so you can put this info in the call insn.
230 VALREG is a hard register in which a value is returned,
231 or 0 if the call does not return a value.
233 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
234 the args to this call were processed.
235 We restore `inhibit_defer_pop' to that value.
237 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
238 denote registers used by the called function. */
241 emit_call_1 (rtx funexp, tree fntree, tree fndecl ATTRIBUTE_UNUSED,
242 tree funtype ATTRIBUTE_UNUSED,
243 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED,
244 HOST_WIDE_INT rounded_stack_size,
245 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED,
246 rtx next_arg_reg ATTRIBUTE_UNUSED, rtx valreg,
247 int old_inhibit_defer_pop, rtx call_fusage, int ecf_flags,
248 CUMULATIVE_ARGS *args_so_far ATTRIBUTE_UNUSED)
250 rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
252 int already_popped = 0;
253 HOST_WIDE_INT n_popped = RETURN_POPS_ARGS (fndecl, funtype, stack_size);
254 #if defined (HAVE_call) && defined (HAVE_call_value)
255 rtx struct_value_size_rtx;
256 struct_value_size_rtx = GEN_INT (struct_value_size);
259 #ifdef CALL_POPS_ARGS
260 n_popped += CALL_POPS_ARGS (* args_so_far);
263 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
264 and we don't want to load it into a register as an optimization,
265 because prepare_call_address already did it if it should be done. */
266 if (GET_CODE (funexp) != SYMBOL_REF)
267 funexp = memory_address (FUNCTION_MODE, funexp);
269 #if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
270 if ((ecf_flags & ECF_SIBCALL)
271 && HAVE_sibcall_pop && HAVE_sibcall_value_pop
272 && (n_popped > 0 || stack_size == 0))
274 rtx n_pop = GEN_INT (n_popped);
277 /* If this subroutine pops its own args, record that in the call insn
278 if possible, for the sake of frame pointer elimination. */
281 pat = GEN_SIBCALL_VALUE_POP (valreg,
282 gen_rtx_MEM (FUNCTION_MODE, funexp),
283 rounded_stack_size_rtx, next_arg_reg,
286 pat = GEN_SIBCALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
287 rounded_stack_size_rtx, next_arg_reg, n_pop);
289 emit_call_insn (pat);
295 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
296 /* If the target has "call" or "call_value" insns, then prefer them
297 if no arguments are actually popped. If the target does not have
298 "call" or "call_value" insns, then we must use the popping versions
299 even if the call has no arguments to pop. */
300 #if defined (HAVE_call) && defined (HAVE_call_value)
301 if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop
304 if (HAVE_call_pop && HAVE_call_value_pop)
307 rtx n_pop = GEN_INT (n_popped);
310 /* If this subroutine pops its own args, record that in the call insn
311 if possible, for the sake of frame pointer elimination. */
314 pat = GEN_CALL_VALUE_POP (valreg,
315 gen_rtx_MEM (FUNCTION_MODE, funexp),
316 rounded_stack_size_rtx, next_arg_reg, n_pop);
318 pat = GEN_CALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
319 rounded_stack_size_rtx, next_arg_reg, n_pop);
321 emit_call_insn (pat);
327 #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
328 if ((ecf_flags & ECF_SIBCALL)
329 && HAVE_sibcall && HAVE_sibcall_value)
332 emit_call_insn (GEN_SIBCALL_VALUE (valreg,
333 gen_rtx_MEM (FUNCTION_MODE, funexp),
334 rounded_stack_size_rtx,
335 next_arg_reg, NULL_RTX));
337 emit_call_insn (GEN_SIBCALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
338 rounded_stack_size_rtx, next_arg_reg,
339 struct_value_size_rtx));
344 #if defined (HAVE_call) && defined (HAVE_call_value)
345 if (HAVE_call && HAVE_call_value)
348 emit_call_insn (GEN_CALL_VALUE (valreg,
349 gen_rtx_MEM (FUNCTION_MODE, funexp),
350 rounded_stack_size_rtx, next_arg_reg,
353 emit_call_insn (GEN_CALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
354 rounded_stack_size_rtx, next_arg_reg,
355 struct_value_size_rtx));
361 /* Find the call we just emitted. */
362 call_insn = last_call_insn ();
364 /* Put the register usage information there. */
365 add_function_usage_to (call_insn, call_fusage);
367 /* If this is a const call, then set the insn's unchanging bit. */
368 if (ecf_flags & ECF_CONST)
369 RTL_CONST_CALL_P (call_insn) = 1;
371 /* If this is a pure call, then set the insn's unchanging bit. */
372 if (ecf_flags & ECF_PURE)
373 RTL_PURE_CALL_P (call_insn) = 1;
375 /* If this is a const call, then set the insn's unchanging bit. */
376 if (ecf_flags & ECF_LOOPING_CONST_OR_PURE)
377 RTL_LOOPING_CONST_OR_PURE_CALL_P (call_insn) = 1;
379 /* If this call can't throw, attach a REG_EH_REGION reg note to that
381 if (ecf_flags & ECF_NOTHROW)
382 add_reg_note (call_insn, REG_EH_REGION, const0_rtx);
385 int rn = lookup_expr_eh_region (fntree);
387 /* If rn < 0, then either (1) tree-ssa not used or (2) doesn't
388 throw, which we already took care of. */
390 add_reg_note (call_insn, REG_EH_REGION, GEN_INT (rn));
393 if (ecf_flags & ECF_NORETURN)
394 add_reg_note (call_insn, REG_NORETURN, const0_rtx);
396 if (ecf_flags & ECF_RETURNS_TWICE)
398 add_reg_note (call_insn, REG_SETJMP, const0_rtx);
399 cfun->calls_setjmp = 1;
402 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
404 /* Restore this now, so that we do defer pops for this call's args
405 if the context of the call as a whole permits. */
406 inhibit_defer_pop = old_inhibit_defer_pop;
411 CALL_INSN_FUNCTION_USAGE (call_insn)
412 = gen_rtx_EXPR_LIST (VOIDmode,
413 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
414 CALL_INSN_FUNCTION_USAGE (call_insn));
415 rounded_stack_size -= n_popped;
416 rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
417 stack_pointer_delta -= n_popped;
419 /* If popup is needed, stack realign must use DRAP */
420 if (SUPPORTS_STACK_ALIGNMENT)
421 crtl->need_drap = true;
424 if (!ACCUMULATE_OUTGOING_ARGS)
426 /* If returning from the subroutine does not automatically pop the args,
427 we need an instruction to pop them sooner or later.
428 Perhaps do it now; perhaps just record how much space to pop later.
430 If returning from the subroutine does pop the args, indicate that the
431 stack pointer will be changed. */
433 if (rounded_stack_size != 0)
435 if (ecf_flags & ECF_NORETURN)
436 /* Just pretend we did the pop. */
437 stack_pointer_delta -= rounded_stack_size;
438 else if (flag_defer_pop && inhibit_defer_pop == 0
439 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
440 pending_stack_adjust += rounded_stack_size;
442 adjust_stack (rounded_stack_size_rtx);
445 /* When we accumulate outgoing args, we must avoid any stack manipulations.
446 Restore the stack pointer to its original value now. Usually
447 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
448 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
449 popping variants of functions exist as well.
451 ??? We may optimize similar to defer_pop above, but it is
452 probably not worthwhile.
454 ??? It will be worthwhile to enable combine_stack_adjustments even for
457 anti_adjust_stack (GEN_INT (n_popped));
460 /* Determine if the function identified by NAME and FNDECL is one with
461 special properties we wish to know about.
463 For example, if the function might return more than one time (setjmp), then
464 set RETURNS_TWICE to a nonzero value.
466 Similarly set NORETURN if the function is in the longjmp family.
468 Set MAY_BE_ALLOCA for any memory allocation function that might allocate
469 space from the stack such as alloca. */
472 special_function_p (const_tree fndecl, int flags)
474 if (fndecl && DECL_NAME (fndecl)
475 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
476 /* Exclude functions not at the file scope, or not `extern',
477 since they are not the magic functions we would otherwise
479 FIXME: this should be handled with attributes, not with this
480 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
481 because you can declare fork() inside a function if you
483 && (DECL_CONTEXT (fndecl) == NULL_TREE
484 || TREE_CODE (DECL_CONTEXT (fndecl)) == TRANSLATION_UNIT_DECL)
485 && TREE_PUBLIC (fndecl))
487 const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
488 const char *tname = name;
490 /* We assume that alloca will always be called by name. It
491 makes no sense to pass it as a pointer-to-function to
492 anything that does not understand its behavior. */
493 if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
495 && ! strcmp (name, "alloca"))
496 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
498 && ! strcmp (name, "__builtin_alloca"))))
499 flags |= ECF_MAY_BE_ALLOCA;
501 /* Disregard prefix _, __ or __x. */
504 if (name[1] == '_' && name[2] == 'x')
506 else if (name[1] == '_')
515 && (! strcmp (tname, "setjmp")
516 || ! strcmp (tname, "setjmp_syscall")))
518 && ! strcmp (tname, "sigsetjmp"))
520 && ! strcmp (tname, "savectx")))
521 flags |= ECF_RETURNS_TWICE;
524 && ! strcmp (tname, "siglongjmp"))
525 flags |= ECF_NORETURN;
527 else if ((tname[0] == 'q' && tname[1] == 's'
528 && ! strcmp (tname, "qsetjmp"))
529 || (tname[0] == 'v' && tname[1] == 'f'
530 && ! strcmp (tname, "vfork"))
531 || (tname[0] == 'g' && tname[1] == 'e'
532 && !strcmp (tname, "getcontext")))
533 flags |= ECF_RETURNS_TWICE;
535 else if (tname[0] == 'l' && tname[1] == 'o'
536 && ! strcmp (tname, "longjmp"))
537 flags |= ECF_NORETURN;
543 /* Return nonzero when FNDECL represents a call to setjmp. */
546 setjmp_call_p (const_tree fndecl)
548 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
552 /* Return true if STMT is an alloca call. */
555 gimple_alloca_call_p (const_gimple stmt)
559 if (!is_gimple_call (stmt))
562 fndecl = gimple_call_fndecl (stmt);
563 if (fndecl && (special_function_p (fndecl, 0) & ECF_MAY_BE_ALLOCA))
569 /* Return true when exp contains alloca call. */
572 alloca_call_p (const_tree exp)
574 if (TREE_CODE (exp) == CALL_EXPR
575 && TREE_CODE (CALL_EXPR_FN (exp)) == ADDR_EXPR
576 && (TREE_CODE (TREE_OPERAND (CALL_EXPR_FN (exp), 0)) == FUNCTION_DECL)
577 && (special_function_p (TREE_OPERAND (CALL_EXPR_FN (exp), 0), 0)
578 & ECF_MAY_BE_ALLOCA))
583 /* Detect flags (function attributes) from the function decl or type node. */
586 flags_from_decl_or_type (const_tree exp)
589 const_tree type = exp;
593 type = TREE_TYPE (exp);
595 /* The function exp may have the `malloc' attribute. */
596 if (DECL_IS_MALLOC (exp))
599 /* The function exp may have the `returns_twice' attribute. */
600 if (DECL_IS_RETURNS_TWICE (exp))
601 flags |= ECF_RETURNS_TWICE;
603 /* Process the pure and const attributes. */
604 if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
606 if (DECL_PURE_P (exp))
608 if (DECL_LOOPING_CONST_OR_PURE_P (exp))
609 flags |= ECF_LOOPING_CONST_OR_PURE;
611 if (DECL_IS_NOVOPS (exp))
614 if (TREE_NOTHROW (exp))
615 flags |= ECF_NOTHROW;
617 flags = special_function_p (exp, flags);
619 else if (TYPE_P (exp) && TYPE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
622 if (TREE_THIS_VOLATILE (exp))
623 flags |= ECF_NORETURN;
628 /* Detect flags from a CALL_EXPR. */
631 call_expr_flags (const_tree t)
634 tree decl = get_callee_fndecl (t);
637 flags = flags_from_decl_or_type (decl);
640 t = TREE_TYPE (CALL_EXPR_FN (t));
641 if (t && TREE_CODE (t) == POINTER_TYPE)
642 flags = flags_from_decl_or_type (TREE_TYPE (t));
650 /* Precompute all register parameters as described by ARGS, storing values
651 into fields within the ARGS array.
653 NUM_ACTUALS indicates the total number elements in the ARGS array.
655 Set REG_PARM_SEEN if we encounter a register parameter. */
658 precompute_register_parameters (int num_actuals, struct arg_data *args,
665 for (i = 0; i < num_actuals; i++)
666 if (args[i].reg != 0 && ! args[i].pass_on_stack)
670 if (args[i].value == 0)
673 args[i].value = expand_normal (args[i].tree_value);
674 preserve_temp_slots (args[i].value);
678 /* If the value is a non-legitimate constant, force it into a
679 pseudo now. TLS symbols sometimes need a call to resolve. */
680 if (CONSTANT_P (args[i].value)
681 && !LEGITIMATE_CONSTANT_P (args[i].value))
682 args[i].value = force_reg (args[i].mode, args[i].value);
684 /* If we are to promote the function arg to a wider mode,
687 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
689 = convert_modes (args[i].mode,
690 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
691 args[i].value, args[i].unsignedp);
693 /* If we're going to have to load the value by parts, pull the
694 parts into pseudos. The part extraction process can involve
695 non-trivial computation. */
696 if (GET_CODE (args[i].reg) == PARALLEL)
698 tree type = TREE_TYPE (args[i].tree_value);
699 args[i].parallel_value
700 = emit_group_load_into_temps (args[i].reg, args[i].value,
701 type, int_size_in_bytes (type));
704 /* If the value is expensive, and we are inside an appropriately
705 short loop, put the value into a pseudo and then put the pseudo
708 For small register classes, also do this if this call uses
709 register parameters. This is to avoid reload conflicts while
710 loading the parameters registers. */
712 else if ((! (REG_P (args[i].value)
713 || (GET_CODE (args[i].value) == SUBREG
714 && REG_P (SUBREG_REG (args[i].value)))))
715 && args[i].mode != BLKmode
716 && rtx_cost (args[i].value, SET, optimize_insn_for_speed_p ())
718 && ((SMALL_REGISTER_CLASSES && *reg_parm_seen)
720 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
724 #ifdef REG_PARM_STACK_SPACE
726 /* The argument list is the property of the called routine and it
727 may clobber it. If the fixed area has been used for previous
728 parameters, we must save and restore it. */
731 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
736 /* Compute the boundary of the area that needs to be saved, if any. */
737 high = reg_parm_stack_space;
738 #ifdef ARGS_GROW_DOWNWARD
741 if (high > highest_outgoing_arg_in_use)
742 high = highest_outgoing_arg_in_use;
744 for (low = 0; low < high; low++)
745 if (stack_usage_map[low] != 0)
748 enum machine_mode save_mode;
753 while (stack_usage_map[--high] == 0)
757 *high_to_save = high;
759 num_to_save = high - low + 1;
760 save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
762 /* If we don't have the required alignment, must do this
764 if ((low & (MIN (GET_MODE_SIZE (save_mode),
765 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
768 #ifdef ARGS_GROW_DOWNWARD
773 stack_area = gen_rtx_MEM (save_mode,
774 memory_address (save_mode,
775 plus_constant (argblock,
778 set_mem_align (stack_area, PARM_BOUNDARY);
779 if (save_mode == BLKmode)
781 save_area = assign_stack_temp (BLKmode, num_to_save, 0);
782 emit_block_move (validize_mem (save_area), stack_area,
783 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
787 save_area = gen_reg_rtx (save_mode);
788 emit_move_insn (save_area, stack_area);
798 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
800 enum machine_mode save_mode = GET_MODE (save_area);
804 #ifdef ARGS_GROW_DOWNWARD
805 delta = -high_to_save;
809 stack_area = gen_rtx_MEM (save_mode,
810 memory_address (save_mode,
811 plus_constant (argblock, delta)));
812 set_mem_align (stack_area, PARM_BOUNDARY);
814 if (save_mode != BLKmode)
815 emit_move_insn (stack_area, save_area);
817 emit_block_move (stack_area, validize_mem (save_area),
818 GEN_INT (high_to_save - low_to_save + 1),
821 #endif /* REG_PARM_STACK_SPACE */
823 /* If any elements in ARGS refer to parameters that are to be passed in
824 registers, but not in memory, and whose alignment does not permit a
825 direct copy into registers. Copy the values into a group of pseudos
826 which we will later copy into the appropriate hard registers.
828 Pseudos for each unaligned argument will be stored into the array
829 args[argnum].aligned_regs. The caller is responsible for deallocating
830 the aligned_regs array if it is nonzero. */
833 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
837 for (i = 0; i < num_actuals; i++)
838 if (args[i].reg != 0 && ! args[i].pass_on_stack
839 && args[i].mode == BLKmode
840 && MEM_P (args[i].value)
841 && (MEM_ALIGN (args[i].value)
842 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
844 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
845 int endian_correction = 0;
849 gcc_assert (args[i].partial % UNITS_PER_WORD == 0);
850 args[i].n_aligned_regs = args[i].partial / UNITS_PER_WORD;
854 args[i].n_aligned_regs
855 = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
858 args[i].aligned_regs = XNEWVEC (rtx, args[i].n_aligned_regs);
860 /* Structures smaller than a word are normally aligned to the
861 least significant byte. On a BYTES_BIG_ENDIAN machine,
862 this means we must skip the empty high order bytes when
863 calculating the bit offset. */
864 if (bytes < UNITS_PER_WORD
865 #ifdef BLOCK_REG_PADDING
866 && (BLOCK_REG_PADDING (args[i].mode,
867 TREE_TYPE (args[i].tree_value), 1)
873 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
875 for (j = 0; j < args[i].n_aligned_regs; j++)
877 rtx reg = gen_reg_rtx (word_mode);
878 rtx word = operand_subword_force (args[i].value, j, BLKmode);
879 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
881 args[i].aligned_regs[j] = reg;
882 word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
883 word_mode, word_mode);
885 /* There is no need to restrict this code to loading items
886 in TYPE_ALIGN sized hunks. The bitfield instructions can
887 load up entire word sized registers efficiently.
889 ??? This may not be needed anymore.
890 We use to emit a clobber here but that doesn't let later
891 passes optimize the instructions we emit. By storing 0 into
892 the register later passes know the first AND to zero out the
893 bitfield being set in the register is unnecessary. The store
894 of 0 will be deleted as will at least the first AND. */
896 emit_move_insn (reg, const0_rtx);
898 bytes -= bitsize / BITS_PER_UNIT;
899 store_bit_field (reg, bitsize, endian_correction, word_mode,
905 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
908 NUM_ACTUALS is the total number of parameters.
910 N_NAMED_ARGS is the total number of named arguments.
912 STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
915 FNDECL is the tree code for the target of this call (if known)
917 ARGS_SO_FAR holds state needed by the target to know where to place
920 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
921 for arguments which are passed in registers.
923 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
924 and may be modified by this routine.
926 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
927 flags which may may be modified by this routine.
929 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
930 that requires allocation of stack space.
932 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
933 the thunked-to function. */
936 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
937 struct arg_data *args,
938 struct args_size *args_size,
939 int n_named_args ATTRIBUTE_UNUSED,
940 tree exp, tree struct_value_addr_value,
942 CUMULATIVE_ARGS *args_so_far,
943 int reg_parm_stack_space,
944 rtx *old_stack_level, int *old_pending_adj,
945 int *must_preallocate, int *ecf_flags,
946 bool *may_tailcall, bool call_from_thunk_p)
948 /* 1 if scanning parms front to back, -1 if scanning back to front. */
951 /* Count arg position in order args appear. */
956 args_size->constant = 0;
959 /* In this loop, we consider args in the order they are written.
960 We fill up ARGS from the front or from the back if necessary
961 so that in any case the first arg to be pushed ends up at the front. */
963 if (PUSH_ARGS_REVERSED)
965 i = num_actuals - 1, inc = -1;
966 /* In this case, must reverse order of args
967 so that we compute and push the last arg first. */
974 /* First fill in the actual arguments in the ARGS array, splitting
975 complex arguments if necessary. */
978 call_expr_arg_iterator iter;
981 if (struct_value_addr_value)
983 args[j].tree_value = struct_value_addr_value;
986 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
988 tree argtype = TREE_TYPE (arg);
989 if (targetm.calls.split_complex_arg
991 && TREE_CODE (argtype) == COMPLEX_TYPE
992 && targetm.calls.split_complex_arg (argtype))
994 tree subtype = TREE_TYPE (argtype);
995 arg = save_expr (arg);
996 args[j].tree_value = build1 (REALPART_EXPR, subtype, arg);
998 args[j].tree_value = build1 (IMAGPART_EXPR, subtype, arg);
1001 args[j].tree_value = arg;
1006 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1007 for (argpos = 0; argpos < num_actuals; i += inc, argpos++)
1009 tree type = TREE_TYPE (args[i].tree_value);
1011 enum machine_mode mode;
1013 /* Replace erroneous argument with constant zero. */
1014 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1015 args[i].tree_value = integer_zero_node, type = integer_type_node;
1017 /* If TYPE is a transparent union, pass things the way we would
1018 pass the first field of the union. We have already verified that
1019 the modes are the same. */
1020 if (TREE_CODE (type) == UNION_TYPE && TYPE_TRANSPARENT_UNION (type))
1021 type = TREE_TYPE (TYPE_FIELDS (type));
1023 /* Decide where to pass this arg.
1025 args[i].reg is nonzero if all or part is passed in registers.
1027 args[i].partial is nonzero if part but not all is passed in registers,
1028 and the exact value says how many bytes are passed in registers.
1030 args[i].pass_on_stack is nonzero if the argument must at least be
1031 computed on the stack. It may then be loaded back into registers
1032 if args[i].reg is nonzero.
1034 These decisions are driven by the FUNCTION_... macros and must agree
1035 with those made by function.c. */
1037 /* See if this argument should be passed by invisible reference. */
1038 if (pass_by_reference (args_so_far, TYPE_MODE (type),
1039 type, argpos < n_named_args))
1045 = reference_callee_copied (args_so_far, TYPE_MODE (type),
1046 type, argpos < n_named_args);
1048 /* If we're compiling a thunk, pass through invisible references
1049 instead of making a copy. */
1050 if (call_from_thunk_p
1052 && !TREE_ADDRESSABLE (type)
1053 && (base = get_base_address (args[i].tree_value))
1054 && (!DECL_P (base) || MEM_P (DECL_RTL (base)))))
1056 /* We can't use sibcalls if a callee-copied argument is
1057 stored in the current function's frame. */
1058 if (!call_from_thunk_p && DECL_P (base) && !TREE_STATIC (base))
1059 *may_tailcall = false;
1061 args[i].tree_value = build_fold_addr_expr (args[i].tree_value);
1062 type = TREE_TYPE (args[i].tree_value);
1064 if (*ecf_flags & ECF_CONST)
1065 *ecf_flags &= ~(ECF_CONST | ECF_LOOPING_CONST_OR_PURE);
1069 /* We make a copy of the object and pass the address to the
1070 function being called. */
1073 if (!COMPLETE_TYPE_P (type)
1074 || TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST
1075 || (flag_stack_check == GENERIC_STACK_CHECK
1076 && compare_tree_int (TYPE_SIZE_UNIT (type),
1077 STACK_CHECK_MAX_VAR_SIZE) > 0))
1079 /* This is a variable-sized object. Make space on the stack
1081 rtx size_rtx = expr_size (args[i].tree_value);
1083 if (*old_stack_level == 0)
1085 emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX);
1086 *old_pending_adj = pending_stack_adjust;
1087 pending_stack_adjust = 0;
1090 copy = gen_rtx_MEM (BLKmode,
1091 allocate_dynamic_stack_space
1092 (size_rtx, NULL_RTX, TYPE_ALIGN (type)));
1093 set_mem_attributes (copy, type, 1);
1096 copy = assign_temp (type, 0, 1, 0);
1098 store_expr (args[i].tree_value, copy, 0, false);
1100 /* Just change the const function to pure and then let
1101 the next test clear the pure based on
1103 if (*ecf_flags & ECF_CONST)
1105 *ecf_flags &= ~ECF_CONST;
1106 *ecf_flags |= ECF_PURE;
1109 if (!callee_copies && *ecf_flags & ECF_PURE)
1110 *ecf_flags &= ~(ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
1113 = build_fold_addr_expr (make_tree (type, copy));
1114 type = TREE_TYPE (args[i].tree_value);
1115 *may_tailcall = false;
1119 mode = TYPE_MODE (type);
1120 unsignedp = TYPE_UNSIGNED (type);
1122 if (targetm.calls.promote_function_args (fndecl ? TREE_TYPE (fndecl) : 0))
1123 mode = promote_mode (type, mode, &unsignedp, 1);
1125 args[i].unsignedp = unsignedp;
1126 args[i].mode = mode;
1128 args[i].reg = FUNCTION_ARG (*args_so_far, mode, type,
1129 argpos < n_named_args);
1130 #ifdef FUNCTION_INCOMING_ARG
1131 /* If this is a sibling call and the machine has register windows, the
1132 register window has to be unwinded before calling the routine, so
1133 arguments have to go into the incoming registers. */
1134 args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type,
1135 argpos < n_named_args);
1137 args[i].tail_call_reg = args[i].reg;
1142 = targetm.calls.arg_partial_bytes (args_so_far, mode, type,
1143 argpos < n_named_args);
1145 args[i].pass_on_stack = targetm.calls.must_pass_in_stack (mode, type);
1147 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1148 it means that we are to pass this arg in the register(s) designated
1149 by the PARALLEL, but also to pass it in the stack. */
1150 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1151 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1152 args[i].pass_on_stack = 1;
1154 /* If this is an addressable type, we must preallocate the stack
1155 since we must evaluate the object into its final location.
1157 If this is to be passed in both registers and the stack, it is simpler
1159 if (TREE_ADDRESSABLE (type)
1160 || (args[i].pass_on_stack && args[i].reg != 0))
1161 *must_preallocate = 1;
1163 /* Compute the stack-size of this argument. */
1164 if (args[i].reg == 0 || args[i].partial != 0
1165 || reg_parm_stack_space > 0
1166 || args[i].pass_on_stack)
1167 locate_and_pad_parm (mode, type,
1168 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1173 args[i].pass_on_stack ? 0 : args[i].partial,
1174 fndecl, args_size, &args[i].locate);
1175 #ifdef BLOCK_REG_PADDING
1177 /* The argument is passed entirely in registers. See at which
1178 end it should be padded. */
1179 args[i].locate.where_pad =
1180 BLOCK_REG_PADDING (mode, type,
1181 int_size_in_bytes (type) <= UNITS_PER_WORD);
1184 /* Update ARGS_SIZE, the total stack space for args so far. */
1186 args_size->constant += args[i].locate.size.constant;
1187 if (args[i].locate.size.var)
1188 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
1190 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1191 have been used, etc. */
1193 FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type,
1194 argpos < n_named_args);
1198 /* Update ARGS_SIZE to contain the total size for the argument block.
1199 Return the original constant component of the argument block's size.
1201 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1202 for arguments passed in registers. */
1205 compute_argument_block_size (int reg_parm_stack_space,
1206 struct args_size *args_size,
1207 tree fndecl ATTRIBUTE_UNUSED,
1208 int preferred_stack_boundary ATTRIBUTE_UNUSED)
1210 int unadjusted_args_size = args_size->constant;
1212 /* For accumulate outgoing args mode we don't need to align, since the frame
1213 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1214 backends from generating misaligned frame sizes. */
1215 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1216 preferred_stack_boundary = STACK_BOUNDARY;
1218 /* Compute the actual size of the argument block required. The variable
1219 and constant sizes must be combined, the size may have to be rounded,
1220 and there may be a minimum required size. */
1224 args_size->var = ARGS_SIZE_TREE (*args_size);
1225 args_size->constant = 0;
1227 preferred_stack_boundary /= BITS_PER_UNIT;
1228 if (preferred_stack_boundary > 1)
1230 /* We don't handle this case yet. To handle it correctly we have
1231 to add the delta, round and subtract the delta.
1232 Currently no machine description requires this support. */
1233 gcc_assert (!(stack_pointer_delta & (preferred_stack_boundary - 1)));
1234 args_size->var = round_up (args_size->var, preferred_stack_boundary);
1237 if (reg_parm_stack_space > 0)
1240 = size_binop (MAX_EXPR, args_size->var,
1241 ssize_int (reg_parm_stack_space));
1243 /* The area corresponding to register parameters is not to count in
1244 the size of the block we need. So make the adjustment. */
1245 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL_TREE : TREE_TYPE (fndecl))))
1247 = size_binop (MINUS_EXPR, args_size->var,
1248 ssize_int (reg_parm_stack_space));
1253 preferred_stack_boundary /= BITS_PER_UNIT;
1254 if (preferred_stack_boundary < 1)
1255 preferred_stack_boundary = 1;
1256 args_size->constant = (((args_size->constant
1257 + stack_pointer_delta
1258 + preferred_stack_boundary - 1)
1259 / preferred_stack_boundary
1260 * preferred_stack_boundary)
1261 - stack_pointer_delta);
1263 args_size->constant = MAX (args_size->constant,
1264 reg_parm_stack_space);
1266 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL_TREE : TREE_TYPE (fndecl))))
1267 args_size->constant -= reg_parm_stack_space;
1269 return unadjusted_args_size;
1272 /* Precompute parameters as needed for a function call.
1274 FLAGS is mask of ECF_* constants.
1276 NUM_ACTUALS is the number of arguments.
1278 ARGS is an array containing information for each argument; this
1279 routine fills in the INITIAL_VALUE and VALUE fields for each
1280 precomputed argument. */
1283 precompute_arguments (int num_actuals, struct arg_data *args)
1287 /* If this is a libcall, then precompute all arguments so that we do not
1288 get extraneous instructions emitted as part of the libcall sequence. */
1290 /* If we preallocated the stack space, and some arguments must be passed
1291 on the stack, then we must precompute any parameter which contains a
1292 function call which will store arguments on the stack.
1293 Otherwise, evaluating the parameter may clobber previous parameters
1294 which have already been stored into the stack. (we have code to avoid
1295 such case by saving the outgoing stack arguments, but it results in
1297 if (!ACCUMULATE_OUTGOING_ARGS)
1300 for (i = 0; i < num_actuals; i++)
1302 enum machine_mode mode;
1304 if (TREE_CODE (args[i].tree_value) != CALL_EXPR)
1307 /* If this is an addressable type, we cannot pre-evaluate it. */
1308 gcc_assert (!TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)));
1310 args[i].initial_value = args[i].value
1311 = expand_normal (args[i].tree_value);
1313 mode = TYPE_MODE (TREE_TYPE (args[i].tree_value));
1314 if (mode != args[i].mode)
1317 = convert_modes (args[i].mode, mode,
1318 args[i].value, args[i].unsignedp);
1319 #if defined(PROMOTE_FUNCTION_MODE) && !defined(PROMOTE_MODE)
1320 /* CSE will replace this only if it contains args[i].value
1321 pseudo, so convert it down to the declared mode using
1323 if (REG_P (args[i].value)
1324 && GET_MODE_CLASS (args[i].mode) == MODE_INT)
1326 args[i].initial_value
1327 = gen_lowpart_SUBREG (mode, args[i].value);
1328 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1329 SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value,
1337 /* Given the current state of MUST_PREALLOCATE and information about
1338 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1339 compute and return the final value for MUST_PREALLOCATE. */
1342 finalize_must_preallocate (int must_preallocate, int num_actuals,
1343 struct arg_data *args, struct args_size *args_size)
1345 /* See if we have or want to preallocate stack space.
1347 If we would have to push a partially-in-regs parm
1348 before other stack parms, preallocate stack space instead.
1350 If the size of some parm is not a multiple of the required stack
1351 alignment, we must preallocate.
1353 If the total size of arguments that would otherwise create a copy in
1354 a temporary (such as a CALL) is more than half the total argument list
1355 size, preallocation is faster.
1357 Another reason to preallocate is if we have a machine (like the m88k)
1358 where stack alignment is required to be maintained between every
1359 pair of insns, not just when the call is made. However, we assume here
1360 that such machines either do not have push insns (and hence preallocation
1361 would occur anyway) or the problem is taken care of with
1364 if (! must_preallocate)
1366 int partial_seen = 0;
1367 int copy_to_evaluate_size = 0;
1370 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1372 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1374 else if (partial_seen && args[i].reg == 0)
1375 must_preallocate = 1;
1377 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1378 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1379 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1380 || TREE_CODE (args[i].tree_value) == COND_EXPR
1381 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1382 copy_to_evaluate_size
1383 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1386 if (copy_to_evaluate_size * 2 >= args_size->constant
1387 && args_size->constant > 0)
1388 must_preallocate = 1;
1390 return must_preallocate;
1393 /* If we preallocated stack space, compute the address of each argument
1394 and store it into the ARGS array.
1396 We need not ensure it is a valid memory address here; it will be
1397 validized when it is used.
1399 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1402 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
1406 rtx arg_reg = argblock;
1407 int i, arg_offset = 0;
1409 if (GET_CODE (argblock) == PLUS)
1410 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1412 for (i = 0; i < num_actuals; i++)
1414 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
1415 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
1417 unsigned int align, boundary;
1418 unsigned int units_on_stack = 0;
1419 enum machine_mode partial_mode = VOIDmode;
1421 /* Skip this parm if it will not be passed on the stack. */
1422 if (! args[i].pass_on_stack
1424 && args[i].partial == 0)
1427 if (GET_CODE (offset) == CONST_INT)
1428 addr = plus_constant (arg_reg, INTVAL (offset));
1430 addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1432 addr = plus_constant (addr, arg_offset);
1434 if (args[i].partial != 0)
1436 /* Only part of the parameter is being passed on the stack.
1437 Generate a simple memory reference of the correct size. */
1438 units_on_stack = args[i].locate.size.constant;
1439 partial_mode = mode_for_size (units_on_stack * BITS_PER_UNIT,
1441 args[i].stack = gen_rtx_MEM (partial_mode, addr);
1442 set_mem_size (args[i].stack, GEN_INT (units_on_stack));
1446 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1447 set_mem_attributes (args[i].stack,
1448 TREE_TYPE (args[i].tree_value), 1);
1450 align = BITS_PER_UNIT;
1451 boundary = args[i].locate.boundary;
1452 if (args[i].locate.where_pad != downward)
1454 else if (GET_CODE (offset) == CONST_INT)
1456 align = INTVAL (offset) * BITS_PER_UNIT | boundary;
1457 align = align & -align;
1459 set_mem_align (args[i].stack, align);
1461 if (GET_CODE (slot_offset) == CONST_INT)
1462 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1464 addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1466 addr = plus_constant (addr, arg_offset);
1468 if (args[i].partial != 0)
1470 /* Only part of the parameter is being passed on the stack.
1471 Generate a simple memory reference of the correct size.
1473 args[i].stack_slot = gen_rtx_MEM (partial_mode, addr);
1474 set_mem_size (args[i].stack_slot, GEN_INT (units_on_stack));
1478 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1479 set_mem_attributes (args[i].stack_slot,
1480 TREE_TYPE (args[i].tree_value), 1);
1482 set_mem_align (args[i].stack_slot, args[i].locate.boundary);
1484 /* Function incoming arguments may overlap with sibling call
1485 outgoing arguments and we cannot allow reordering of reads
1486 from function arguments with stores to outgoing arguments
1487 of sibling calls. */
1488 set_mem_alias_set (args[i].stack, 0);
1489 set_mem_alias_set (args[i].stack_slot, 0);
1494 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1495 in a call instruction.
1497 FNDECL is the tree node for the target function. For an indirect call
1498 FNDECL will be NULL_TREE.
1500 ADDR is the operand 0 of CALL_EXPR for this call. */
1503 rtx_for_function_call (tree fndecl, tree addr)
1507 /* Get the function to call, in the form of RTL. */
1510 /* If this is the first use of the function, see if we need to
1511 make an external definition for it. */
1512 if (!TREE_USED (fndecl) && fndecl != current_function_decl)
1514 assemble_external (fndecl);
1515 TREE_USED (fndecl) = 1;
1518 /* Get a SYMBOL_REF rtx for the function address. */
1519 funexp = XEXP (DECL_RTL (fndecl), 0);
1522 /* Generate an rtx (probably a pseudo-register) for the address. */
1525 funexp = expand_normal (addr);
1526 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1531 /* Return true if and only if SIZE storage units (usually bytes)
1532 starting from address ADDR overlap with already clobbered argument
1533 area. This function is used to determine if we should give up a
1537 mem_overlaps_already_clobbered_arg_p (rtx addr, unsigned HOST_WIDE_INT size)
1541 if (addr == crtl->args.internal_arg_pointer)
1543 else if (GET_CODE (addr) == PLUS
1544 && XEXP (addr, 0) == crtl->args.internal_arg_pointer
1545 && GET_CODE (XEXP (addr, 1)) == CONST_INT)
1546 i = INTVAL (XEXP (addr, 1));
1547 /* Return true for arg pointer based indexed addressing. */
1548 else if (GET_CODE (addr) == PLUS
1549 && (XEXP (addr, 0) == crtl->args.internal_arg_pointer
1550 || XEXP (addr, 1) == crtl->args.internal_arg_pointer))
1555 #ifdef ARGS_GROW_DOWNWARD
1560 unsigned HOST_WIDE_INT k;
1562 for (k = 0; k < size; k++)
1563 if (i + k < stored_args_map->n_bits
1564 && TEST_BIT (stored_args_map, i + k))
1571 /* Do the register loads required for any wholly-register parms or any
1572 parms which are passed both on the stack and in a register. Their
1573 expressions were already evaluated.
1575 Mark all register-parms as living through the call, putting these USE
1576 insns in the CALL_INSN_FUNCTION_USAGE field.
1578 When IS_SIBCALL, perform the check_sibcall_argument_overlap
1579 checking, setting *SIBCALL_FAILURE if appropriate. */
1582 load_register_parameters (struct arg_data *args, int num_actuals,
1583 rtx *call_fusage, int flags, int is_sibcall,
1584 int *sibcall_failure)
1588 for (i = 0; i < num_actuals; i++)
1590 rtx reg = ((flags & ECF_SIBCALL)
1591 ? args[i].tail_call_reg : args[i].reg);
1594 int partial = args[i].partial;
1597 rtx before_arg = get_last_insn ();
1598 /* Set non-negative if we must move a word at a time, even if
1599 just one word (e.g, partial == 4 && mode == DFmode). Set
1600 to -1 if we just use a normal move insn. This value can be
1601 zero if the argument is a zero size structure. */
1603 if (GET_CODE (reg) == PARALLEL)
1607 gcc_assert (partial % UNITS_PER_WORD == 0);
1608 nregs = partial / UNITS_PER_WORD;
1610 else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode)
1612 size = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1613 nregs = (size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
1616 size = GET_MODE_SIZE (args[i].mode);
1618 /* Handle calls that pass values in multiple non-contiguous
1619 locations. The Irix 6 ABI has examples of this. */
1621 if (GET_CODE (reg) == PARALLEL)
1622 emit_group_move (reg, args[i].parallel_value);
1624 /* If simple case, just do move. If normal partial, store_one_arg
1625 has already loaded the register for us. In all other cases,
1626 load the register(s) from memory. */
1628 else if (nregs == -1)
1630 emit_move_insn (reg, args[i].value);
1631 #ifdef BLOCK_REG_PADDING
1632 /* Handle case where we have a value that needs shifting
1633 up to the msb. eg. a QImode value and we're padding
1634 upward on a BYTES_BIG_ENDIAN machine. */
1635 if (size < UNITS_PER_WORD
1636 && (args[i].locate.where_pad
1637 == (BYTES_BIG_ENDIAN ? upward : downward)))
1640 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1642 /* Assigning REG here rather than a temp makes CALL_FUSAGE
1643 report the whole reg as used. Strictly speaking, the
1644 call only uses SIZE bytes at the msb end, but it doesn't
1645 seem worth generating rtl to say that. */
1646 reg = gen_rtx_REG (word_mode, REGNO (reg));
1647 x = expand_shift (LSHIFT_EXPR, word_mode, reg,
1648 build_int_cst (NULL_TREE, shift),
1651 emit_move_insn (reg, x);
1656 /* If we have pre-computed the values to put in the registers in
1657 the case of non-aligned structures, copy them in now. */
1659 else if (args[i].n_aligned_regs != 0)
1660 for (j = 0; j < args[i].n_aligned_regs; j++)
1661 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1662 args[i].aligned_regs[j]);
1664 else if (partial == 0 || args[i].pass_on_stack)
1666 rtx mem = validize_mem (args[i].value);
1668 /* Check for overlap with already clobbered argument area. */
1670 && mem_overlaps_already_clobbered_arg_p (XEXP (args[i].value, 0),
1672 *sibcall_failure = 1;
1674 /* Handle a BLKmode that needs shifting. */
1675 if (nregs == 1 && size < UNITS_PER_WORD
1676 #ifdef BLOCK_REG_PADDING
1677 && args[i].locate.where_pad == downward
1683 rtx tem = operand_subword_force (mem, 0, args[i].mode);
1684 rtx ri = gen_rtx_REG (word_mode, REGNO (reg));
1685 rtx x = gen_reg_rtx (word_mode);
1686 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1687 enum tree_code dir = BYTES_BIG_ENDIAN ? RSHIFT_EXPR
1690 emit_move_insn (x, tem);
1691 x = expand_shift (dir, word_mode, x,
1692 build_int_cst (NULL_TREE, shift),
1695 emit_move_insn (ri, x);
1698 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
1701 /* When a parameter is a block, and perhaps in other cases, it is
1702 possible that it did a load from an argument slot that was
1703 already clobbered. */
1705 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
1706 *sibcall_failure = 1;
1708 /* Handle calls that pass values in multiple non-contiguous
1709 locations. The Irix 6 ABI has examples of this. */
1710 if (GET_CODE (reg) == PARALLEL)
1711 use_group_regs (call_fusage, reg);
1712 else if (nregs == -1)
1713 use_reg (call_fusage, reg);
1715 use_regs (call_fusage, REGNO (reg), nregs);
1720 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1721 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1722 bytes, then we would need to push some additional bytes to pad the
1723 arguments. So, we compute an adjust to the stack pointer for an
1724 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1725 bytes. Then, when the arguments are pushed the stack will be perfectly
1726 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
1727 be popped after the call. Returns the adjustment. */
1730 combine_pending_stack_adjustment_and_call (int unadjusted_args_size,
1731 struct args_size *args_size,
1732 unsigned int preferred_unit_stack_boundary)
1734 /* The number of bytes to pop so that the stack will be
1735 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
1736 HOST_WIDE_INT adjustment;
1737 /* The alignment of the stack after the arguments are pushed, if we
1738 just pushed the arguments without adjust the stack here. */
1739 unsigned HOST_WIDE_INT unadjusted_alignment;
1741 unadjusted_alignment
1742 = ((stack_pointer_delta + unadjusted_args_size)
1743 % preferred_unit_stack_boundary);
1745 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1746 as possible -- leaving just enough left to cancel out the
1747 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
1748 PENDING_STACK_ADJUST is non-negative, and congruent to
1749 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
1751 /* Begin by trying to pop all the bytes. */
1752 unadjusted_alignment
1753 = (unadjusted_alignment
1754 - (pending_stack_adjust % preferred_unit_stack_boundary));
1755 adjustment = pending_stack_adjust;
1756 /* Push enough additional bytes that the stack will be aligned
1757 after the arguments are pushed. */
1758 if (preferred_unit_stack_boundary > 1)
1760 if (unadjusted_alignment > 0)
1761 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
1763 adjustment += unadjusted_alignment;
1766 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1767 bytes after the call. The right number is the entire
1768 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1769 by the arguments in the first place. */
1771 = pending_stack_adjust - adjustment + unadjusted_args_size;
1776 /* Scan X expression if it does not dereference any argument slots
1777 we already clobbered by tail call arguments (as noted in stored_args_map
1779 Return nonzero if X expression dereferences such argument slots,
1783 check_sibcall_argument_overlap_1 (rtx x)
1792 code = GET_CODE (x);
1795 return mem_overlaps_already_clobbered_arg_p (XEXP (x, 0),
1796 GET_MODE_SIZE (GET_MODE (x)));
1798 /* Scan all subexpressions. */
1799 fmt = GET_RTX_FORMAT (code);
1800 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
1804 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
1807 else if (*fmt == 'E')
1809 for (j = 0; j < XVECLEN (x, i); j++)
1810 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
1817 /* Scan sequence after INSN if it does not dereference any argument slots
1818 we already clobbered by tail call arguments (as noted in stored_args_map
1819 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
1820 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
1821 should be 0). Return nonzero if sequence after INSN dereferences such argument
1822 slots, zero otherwise. */
1825 check_sibcall_argument_overlap (rtx insn, struct arg_data *arg, int mark_stored_args_map)
1829 if (insn == NULL_RTX)
1830 insn = get_insns ();
1832 insn = NEXT_INSN (insn);
1834 for (; insn; insn = NEXT_INSN (insn))
1836 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
1839 if (mark_stored_args_map)
1841 #ifdef ARGS_GROW_DOWNWARD
1842 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
1844 low = arg->locate.slot_offset.constant;
1847 for (high = low + arg->locate.size.constant; low < high; low++)
1848 SET_BIT (stored_args_map, low);
1850 return insn != NULL_RTX;
1853 /* Given that a function returns a value of mode MODE at the most
1854 significant end of hard register VALUE, shift VALUE left or right
1855 as specified by LEFT_P. Return true if some action was needed. */
1858 shift_return_value (enum machine_mode mode, bool left_p, rtx value)
1860 HOST_WIDE_INT shift;
1862 gcc_assert (REG_P (value) && HARD_REGISTER_P (value));
1863 shift = GET_MODE_BITSIZE (GET_MODE (value)) - GET_MODE_BITSIZE (mode);
1867 /* Use ashr rather than lshr for right shifts. This is for the benefit
1868 of the MIPS port, which requires SImode values to be sign-extended
1869 when stored in 64-bit registers. */
1870 if (!force_expand_binop (GET_MODE (value), left_p ? ashl_optab : ashr_optab,
1871 value, GEN_INT (shift), value, 1, OPTAB_WIDEN))
1876 /* If X is a likely-spilled register value, copy it to a pseudo
1877 register and return that register. Return X otherwise. */
1880 avoid_likely_spilled_reg (rtx x)
1885 && HARD_REGISTER_P (x)
1886 && CLASS_LIKELY_SPILLED_P (REGNO_REG_CLASS (REGNO (x))))
1888 /* Make sure that we generate a REG rather than a CONCAT.
1889 Moves into CONCATs can need nontrivial instructions,
1890 and the whole point of this function is to avoid
1891 using the hard register directly in such a situation. */
1892 generating_concat_p = 0;
1893 new_rtx = gen_reg_rtx (GET_MODE (x));
1894 generating_concat_p = 1;
1895 emit_move_insn (new_rtx, x);
1901 /* Generate all the code for a CALL_EXPR exp
1902 and return an rtx for its value.
1903 Store the value in TARGET (specified as an rtx) if convenient.
1904 If the value is stored in TARGET then TARGET is returned.
1905 If IGNORE is nonzero, then we ignore the value of the function call. */
1908 expand_call (tree exp, rtx target, int ignore)
1910 /* Nonzero if we are currently expanding a call. */
1911 static int currently_expanding_call = 0;
1913 /* RTX for the function to be called. */
1915 /* Sequence of insns to perform a normal "call". */
1916 rtx normal_call_insns = NULL_RTX;
1917 /* Sequence of insns to perform a tail "call". */
1918 rtx tail_call_insns = NULL_RTX;
1919 /* Data type of the function. */
1921 tree type_arg_types;
1922 /* Declaration of the function being called,
1923 or 0 if the function is computed (not known by name). */
1925 /* The type of the function being called. */
1927 bool try_tail_call = CALL_EXPR_TAILCALL (exp);
1930 /* Register in which non-BLKmode value will be returned,
1931 or 0 if no value or if value is BLKmode. */
1933 /* Address where we should return a BLKmode value;
1934 0 if value not BLKmode. */
1935 rtx structure_value_addr = 0;
1936 /* Nonzero if that address is being passed by treating it as
1937 an extra, implicit first parameter. Otherwise,
1938 it is passed by being copied directly into struct_value_rtx. */
1939 int structure_value_addr_parm = 0;
1940 /* Holds the value of implicit argument for the struct value. */
1941 tree structure_value_addr_value = NULL_TREE;
1942 /* Size of aggregate value wanted, or zero if none wanted
1943 or if we are using the non-reentrant PCC calling convention
1944 or expecting the value in registers. */
1945 HOST_WIDE_INT struct_value_size = 0;
1946 /* Nonzero if called function returns an aggregate in memory PCC style,
1947 by returning the address of where to find it. */
1948 int pcc_struct_value = 0;
1949 rtx struct_value = 0;
1951 /* Number of actual parameters in this call, including struct value addr. */
1953 /* Number of named args. Args after this are anonymous ones
1954 and they must all go on the stack. */
1956 /* Number of complex actual arguments that need to be split. */
1957 int num_complex_actuals = 0;
1959 /* Vector of information about each argument.
1960 Arguments are numbered in the order they will be pushed,
1961 not the order they are written. */
1962 struct arg_data *args;
1964 /* Total size in bytes of all the stack-parms scanned so far. */
1965 struct args_size args_size;
1966 struct args_size adjusted_args_size;
1967 /* Size of arguments before any adjustments (such as rounding). */
1968 int unadjusted_args_size;
1969 /* Data on reg parms scanned so far. */
1970 CUMULATIVE_ARGS args_so_far;
1971 /* Nonzero if a reg parm has been scanned. */
1973 /* Nonzero if this is an indirect function call. */
1975 /* Nonzero if we must avoid push-insns in the args for this call.
1976 If stack space is allocated for register parameters, but not by the
1977 caller, then it is preallocated in the fixed part of the stack frame.
1978 So the entire argument block must then be preallocated (i.e., we
1979 ignore PUSH_ROUNDING in that case). */
1981 int must_preallocate = !PUSH_ARGS;
1983 /* Size of the stack reserved for parameter registers. */
1984 int reg_parm_stack_space = 0;
1986 /* Address of space preallocated for stack parms
1987 (on machines that lack push insns), or 0 if space not preallocated. */
1990 /* Mask of ECF_ flags. */
1992 #ifdef REG_PARM_STACK_SPACE
1993 /* Define the boundary of the register parm stack space that needs to be
1995 int low_to_save, high_to_save;
1996 rtx save_area = 0; /* Place that it is saved */
1999 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
2000 char *initial_stack_usage_map = stack_usage_map;
2001 char *stack_usage_map_buf = NULL;
2003 int old_stack_allocated;
2005 /* State variables to track stack modifications. */
2006 rtx old_stack_level = 0;
2007 int old_stack_arg_under_construction = 0;
2008 int old_pending_adj = 0;
2009 int old_inhibit_defer_pop = inhibit_defer_pop;
2011 /* Some stack pointer alterations we make are performed via
2012 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
2013 which we then also need to save/restore along the way. */
2014 int old_stack_pointer_delta = 0;
2017 tree p = CALL_EXPR_FN (exp);
2018 tree addr = CALL_EXPR_FN (exp);
2020 /* The alignment of the stack, in bits. */
2021 unsigned HOST_WIDE_INT preferred_stack_boundary;
2022 /* The alignment of the stack, in bytes. */
2023 unsigned HOST_WIDE_INT preferred_unit_stack_boundary;
2024 /* The static chain value to use for this call. */
2025 rtx static_chain_value;
2026 /* See if this is "nothrow" function call. */
2027 if (TREE_NOTHROW (exp))
2028 flags |= ECF_NOTHROW;
2030 /* See if we can find a DECL-node for the actual function, and get the
2031 function attributes (flags) from the function decl or type node. */
2032 fndecl = get_callee_fndecl (exp);
2035 fntype = TREE_TYPE (fndecl);
2036 flags |= flags_from_decl_or_type (fndecl);
2040 fntype = TREE_TYPE (TREE_TYPE (p));
2041 flags |= flags_from_decl_or_type (fntype);
2044 struct_value = targetm.calls.struct_value_rtx (fntype, 0);
2046 /* Warn if this value is an aggregate type,
2047 regardless of which calling convention we are using for it. */
2048 if (AGGREGATE_TYPE_P (TREE_TYPE (exp)))
2049 warning (OPT_Waggregate_return, "function call has aggregate value");
2051 /* If the result of a non looping pure or const function call is
2052 ignored (or void), and none of its arguments are volatile, we can
2053 avoid expanding the call and just evaluate the arguments for
2055 if ((flags & (ECF_CONST | ECF_PURE))
2056 && (!(flags & ECF_LOOPING_CONST_OR_PURE))
2057 && (ignore || target == const0_rtx
2058 || TYPE_MODE (TREE_TYPE (exp)) == VOIDmode))
2060 bool volatilep = false;
2062 call_expr_arg_iterator iter;
2064 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2065 if (TREE_THIS_VOLATILE (arg))
2073 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2074 expand_expr (arg, const0_rtx, VOIDmode, EXPAND_NORMAL);
2079 #ifdef REG_PARM_STACK_SPACE
2080 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
2083 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL_TREE : TREE_TYPE (fndecl)))
2084 && reg_parm_stack_space > 0 && PUSH_ARGS)
2085 must_preallocate = 1;
2087 /* Set up a place to return a structure. */
2089 /* Cater to broken compilers. */
2090 if (aggregate_value_p (exp, fndecl))
2092 /* This call returns a big structure. */
2093 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
2095 #ifdef PCC_STATIC_STRUCT_RETURN
2097 pcc_struct_value = 1;
2099 #else /* not PCC_STATIC_STRUCT_RETURN */
2101 struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
2103 if (target && MEM_P (target) && CALL_EXPR_RETURN_SLOT_OPT (exp))
2104 structure_value_addr = XEXP (target, 0);
2107 /* For variable-sized objects, we must be called with a target
2108 specified. If we were to allocate space on the stack here,
2109 we would have no way of knowing when to free it. */
2110 rtx d = assign_temp (TREE_TYPE (exp), 0, 1, 1);
2112 mark_temp_addr_taken (d);
2113 structure_value_addr = XEXP (d, 0);
2117 #endif /* not PCC_STATIC_STRUCT_RETURN */
2120 /* Figure out the amount to which the stack should be aligned. */
2121 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2124 struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl);
2125 /* Without automatic stack alignment, we can't increase preferred
2126 stack boundary. With automatic stack alignment, it is
2127 unnecessary since unless we can guarantee that all callers will
2128 align the outgoing stack properly, callee has to align its
2131 && i->preferred_incoming_stack_boundary
2132 && i->preferred_incoming_stack_boundary < preferred_stack_boundary)
2133 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
2136 /* Operand 0 is a pointer-to-function; get the type of the function. */
2137 funtype = TREE_TYPE (addr);
2138 gcc_assert (POINTER_TYPE_P (funtype));
2139 funtype = TREE_TYPE (funtype);
2141 /* Count whether there are actual complex arguments that need to be split
2142 into their real and imaginary parts. Munge the type_arg_types
2143 appropriately here as well. */
2144 if (targetm.calls.split_complex_arg)
2146 call_expr_arg_iterator iter;
2148 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2150 tree type = TREE_TYPE (arg);
2151 if (type && TREE_CODE (type) == COMPLEX_TYPE
2152 && targetm.calls.split_complex_arg (type))
2153 num_complex_actuals++;
2155 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
2158 type_arg_types = TYPE_ARG_TYPES (funtype);
2160 if (flags & ECF_MAY_BE_ALLOCA)
2161 cfun->calls_alloca = 1;
2163 /* If struct_value_rtx is 0, it means pass the address
2164 as if it were an extra parameter. Put the argument expression
2165 in structure_value_addr_value. */
2166 if (structure_value_addr && struct_value == 0)
2168 /* If structure_value_addr is a REG other than
2169 virtual_outgoing_args_rtx, we can use always use it. If it
2170 is not a REG, we must always copy it into a register.
2171 If it is virtual_outgoing_args_rtx, we must copy it to another
2172 register in some cases. */
2173 rtx temp = (!REG_P (structure_value_addr)
2174 || (ACCUMULATE_OUTGOING_ARGS
2175 && stack_arg_under_construction
2176 && structure_value_addr == virtual_outgoing_args_rtx)
2177 ? copy_addr_to_reg (convert_memory_address
2178 (Pmode, structure_value_addr))
2179 : structure_value_addr);
2181 structure_value_addr_value =
2182 make_tree (build_pointer_type (TREE_TYPE (funtype)), temp);
2183 structure_value_addr_parm = 1;
2186 /* Count the arguments and set NUM_ACTUALS. */
2188 call_expr_nargs (exp) + num_complex_actuals + structure_value_addr_parm;
2190 /* Compute number of named args.
2191 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
2193 if (type_arg_types != 0)
2195 = (list_length (type_arg_types)
2196 /* Count the struct value address, if it is passed as a parm. */
2197 + structure_value_addr_parm);
2199 /* If we know nothing, treat all args as named. */
2200 n_named_args = num_actuals;
2202 /* Start updating where the next arg would go.
2204 On some machines (such as the PA) indirect calls have a different
2205 calling convention than normal calls. The fourth argument in
2206 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2208 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, fndecl, n_named_args);
2210 /* Now possibly adjust the number of named args.
2211 Normally, don't include the last named arg if anonymous args follow.
2212 We do include the last named arg if
2213 targetm.calls.strict_argument_naming() returns nonzero.
2214 (If no anonymous args follow, the result of list_length is actually
2215 one too large. This is harmless.)
2217 If targetm.calls.pretend_outgoing_varargs_named() returns
2218 nonzero, and targetm.calls.strict_argument_naming() returns zero,
2219 this machine will be able to place unnamed args that were passed
2220 in registers into the stack. So treat all args as named. This
2221 allows the insns emitting for a specific argument list to be
2222 independent of the function declaration.
2224 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
2225 we do not have any reliable way to pass unnamed args in
2226 registers, so we must force them into memory. */
2228 if (type_arg_types != 0
2229 && targetm.calls.strict_argument_naming (&args_so_far))
2231 else if (type_arg_types != 0
2232 && ! targetm.calls.pretend_outgoing_varargs_named (&args_so_far))
2233 /* Don't include the last named arg. */
2236 /* Treat all args as named. */
2237 n_named_args = num_actuals;
2239 /* Make a vector to hold all the information about each arg. */
2240 args = XALLOCAVEC (struct arg_data, num_actuals);
2241 memset (args, 0, num_actuals * sizeof (struct arg_data));
2243 /* Build up entries in the ARGS array, compute the size of the
2244 arguments into ARGS_SIZE, etc. */
2245 initialize_argument_information (num_actuals, args, &args_size,
2247 structure_value_addr_value, fndecl,
2248 &args_so_far, reg_parm_stack_space,
2249 &old_stack_level, &old_pending_adj,
2250 &must_preallocate, &flags,
2251 &try_tail_call, CALL_FROM_THUNK_P (exp));
2254 must_preallocate = 1;
2256 /* Now make final decision about preallocating stack space. */
2257 must_preallocate = finalize_must_preallocate (must_preallocate,
2261 /* If the structure value address will reference the stack pointer, we
2262 must stabilize it. We don't need to do this if we know that we are
2263 not going to adjust the stack pointer in processing this call. */
2265 if (structure_value_addr
2266 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2267 || reg_mentioned_p (virtual_outgoing_args_rtx,
2268 structure_value_addr))
2270 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2271 structure_value_addr = copy_to_reg (structure_value_addr);
2273 /* Tail calls can make things harder to debug, and we've traditionally
2274 pushed these optimizations into -O2. Don't try if we're already
2275 expanding a call, as that means we're an argument. Don't try if
2276 there's cleanups, as we know there's code to follow the call. */
2278 if (currently_expanding_call++ != 0
2279 || !flag_optimize_sibling_calls
2281 || lookup_expr_eh_region (exp) >= 0
2282 || dbg_cnt (tail_call) == false)
2285 /* Rest of purposes for tail call optimizations to fail. */
2287 #ifdef HAVE_sibcall_epilogue
2288 !HAVE_sibcall_epilogue
2293 /* Doing sibling call optimization needs some work, since
2294 structure_value_addr can be allocated on the stack.
2295 It does not seem worth the effort since few optimizable
2296 sibling calls will return a structure. */
2297 || structure_value_addr != NULL_RTX
2298 /* Check whether the target is able to optimize the call
2300 || !targetm.function_ok_for_sibcall (fndecl, exp)
2301 /* Functions that do not return exactly once may not be sibcall
2303 || (flags & (ECF_RETURNS_TWICE | ECF_NORETURN))
2304 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr)))
2305 /* If the called function is nested in the current one, it might access
2306 some of the caller's arguments, but could clobber them beforehand if
2307 the argument areas are shared. */
2308 || (fndecl && decl_function_context (fndecl) == current_function_decl)
2309 /* If this function requires more stack slots than the current
2310 function, we cannot change it into a sibling call.
2311 crtl->args.pretend_args_size is not part of the
2312 stack allocated by our caller. */
2313 || args_size.constant > (crtl->args.size
2314 - crtl->args.pretend_args_size)
2315 /* If the callee pops its own arguments, then it must pop exactly
2316 the same number of arguments as the current function. */
2317 || (RETURN_POPS_ARGS (fndecl, funtype, args_size.constant)
2318 != RETURN_POPS_ARGS (current_function_decl,
2319 TREE_TYPE (current_function_decl),
2321 || !lang_hooks.decls.ok_for_sibcall (fndecl))
2324 /* Ensure current function's preferred stack boundary is at least
2325 what we need. Stack alignment may also increase preferred stack
2327 if (crtl->preferred_stack_boundary < preferred_stack_boundary)
2328 crtl->preferred_stack_boundary = preferred_stack_boundary;
2330 preferred_stack_boundary = crtl->preferred_stack_boundary;
2332 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2334 /* We want to make two insn chains; one for a sibling call, the other
2335 for a normal call. We will select one of the two chains after
2336 initial RTL generation is complete. */
2337 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
2339 int sibcall_failure = 0;
2340 /* We want to emit any pending stack adjustments before the tail
2341 recursion "call". That way we know any adjustment after the tail
2342 recursion call can be ignored if we indeed use the tail
2344 int save_pending_stack_adjust = 0;
2345 int save_stack_pointer_delta = 0;
2347 rtx before_call, next_arg_reg, after_args;
2351 /* State variables we need to save and restore between
2353 save_pending_stack_adjust = pending_stack_adjust;
2354 save_stack_pointer_delta = stack_pointer_delta;
2357 flags &= ~ECF_SIBCALL;
2359 flags |= ECF_SIBCALL;
2361 /* Other state variables that we must reinitialize each time
2362 through the loop (that are not initialized by the loop itself). */
2366 /* Start a new sequence for the normal call case.
2368 From this point on, if the sibling call fails, we want to set
2369 sibcall_failure instead of continuing the loop. */
2372 /* Don't let pending stack adjusts add up to too much.
2373 Also, do all pending adjustments now if there is any chance
2374 this might be a call to alloca or if we are expanding a sibling
2376 Also do the adjustments before a throwing call, otherwise
2377 exception handling can fail; PR 19225. */
2378 if (pending_stack_adjust >= 32
2379 || (pending_stack_adjust > 0
2380 && (flags & ECF_MAY_BE_ALLOCA))
2381 || (pending_stack_adjust > 0
2382 && flag_exceptions && !(flags & ECF_NOTHROW))
2384 do_pending_stack_adjust ();
2386 /* Precompute any arguments as needed. */
2388 precompute_arguments (num_actuals, args);
2390 /* Now we are about to start emitting insns that can be deleted
2391 if a libcall is deleted. */
2392 if (pass && (flags & ECF_MALLOC))
2395 if (pass == 0 && crtl->stack_protect_guard)
2396 stack_protect_epilogue ();
2398 adjusted_args_size = args_size;
2399 /* Compute the actual size of the argument block required. The variable
2400 and constant sizes must be combined, the size may have to be rounded,
2401 and there may be a minimum required size. When generating a sibcall
2402 pattern, do not round up, since we'll be re-using whatever space our
2404 unadjusted_args_size
2405 = compute_argument_block_size (reg_parm_stack_space,
2406 &adjusted_args_size,
2409 : preferred_stack_boundary));
2411 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2413 /* The argument block when performing a sibling call is the
2414 incoming argument block. */
2417 argblock = crtl->args.internal_arg_pointer;
2419 #ifdef STACK_GROWS_DOWNWARD
2420 = plus_constant (argblock, crtl->args.pretend_args_size);
2422 = plus_constant (argblock, -crtl->args.pretend_args_size);
2424 stored_args_map = sbitmap_alloc (args_size.constant);
2425 sbitmap_zero (stored_args_map);
2428 /* If we have no actual push instructions, or shouldn't use them,
2429 make space for all args right now. */
2430 else if (adjusted_args_size.var != 0)
2432 if (old_stack_level == 0)
2434 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2435 old_stack_pointer_delta = stack_pointer_delta;
2436 old_pending_adj = pending_stack_adjust;
2437 pending_stack_adjust = 0;
2438 /* stack_arg_under_construction says whether a stack arg is
2439 being constructed at the old stack level. Pushing the stack
2440 gets a clean outgoing argument block. */
2441 old_stack_arg_under_construction = stack_arg_under_construction;
2442 stack_arg_under_construction = 0;
2444 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2448 /* Note that we must go through the motions of allocating an argument
2449 block even if the size is zero because we may be storing args
2450 in the area reserved for register arguments, which may be part of
2453 int needed = adjusted_args_size.constant;
2455 /* Store the maximum argument space used. It will be pushed by
2456 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2459 if (needed > crtl->outgoing_args_size)
2460 crtl->outgoing_args_size = needed;
2462 if (must_preallocate)
2464 if (ACCUMULATE_OUTGOING_ARGS)
2466 /* Since the stack pointer will never be pushed, it is
2467 possible for the evaluation of a parm to clobber
2468 something we have already written to the stack.
2469 Since most function calls on RISC machines do not use
2470 the stack, this is uncommon, but must work correctly.
2472 Therefore, we save any area of the stack that was already
2473 written and that we are using. Here we set up to do this
2474 by making a new stack usage map from the old one. The
2475 actual save will be done by store_one_arg.
2477 Another approach might be to try to reorder the argument
2478 evaluations to avoid this conflicting stack usage. */
2480 /* Since we will be writing into the entire argument area,
2481 the map must be allocated for its entire size, not just
2482 the part that is the responsibility of the caller. */
2483 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL_TREE : TREE_TYPE (fndecl))))
2484 needed += reg_parm_stack_space;
2486 #ifdef ARGS_GROW_DOWNWARD
2487 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2490 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2493 if (stack_usage_map_buf)
2494 free (stack_usage_map_buf);
2495 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
2496 stack_usage_map = stack_usage_map_buf;
2498 if (initial_highest_arg_in_use)
2499 memcpy (stack_usage_map, initial_stack_usage_map,
2500 initial_highest_arg_in_use);
2502 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2503 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2504 (highest_outgoing_arg_in_use
2505 - initial_highest_arg_in_use));
2508 /* The address of the outgoing argument list must not be
2509 copied to a register here, because argblock would be left
2510 pointing to the wrong place after the call to
2511 allocate_dynamic_stack_space below. */
2513 argblock = virtual_outgoing_args_rtx;
2517 if (inhibit_defer_pop == 0)
2519 /* Try to reuse some or all of the pending_stack_adjust
2520 to get this space. */
2522 = (combine_pending_stack_adjustment_and_call
2523 (unadjusted_args_size,
2524 &adjusted_args_size,
2525 preferred_unit_stack_boundary));
2527 /* combine_pending_stack_adjustment_and_call computes
2528 an adjustment before the arguments are allocated.
2529 Account for them and see whether or not the stack
2530 needs to go up or down. */
2531 needed = unadjusted_args_size - needed;
2535 /* We're releasing stack space. */
2536 /* ??? We can avoid any adjustment at all if we're
2537 already aligned. FIXME. */
2538 pending_stack_adjust = -needed;
2539 do_pending_stack_adjust ();
2543 /* We need to allocate space. We'll do that in
2544 push_block below. */
2545 pending_stack_adjust = 0;
2548 /* Special case this because overhead of `push_block' in
2549 this case is non-trivial. */
2551 argblock = virtual_outgoing_args_rtx;
2554 argblock = push_block (GEN_INT (needed), 0, 0);
2555 #ifdef ARGS_GROW_DOWNWARD
2556 argblock = plus_constant (argblock, needed);
2560 /* We only really need to call `copy_to_reg' in the case
2561 where push insns are going to be used to pass ARGBLOCK
2562 to a function call in ARGS. In that case, the stack
2563 pointer changes value from the allocation point to the
2564 call point, and hence the value of
2565 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2566 as well always do it. */
2567 argblock = copy_to_reg (argblock);
2572 if (ACCUMULATE_OUTGOING_ARGS)
2574 /* The save/restore code in store_one_arg handles all
2575 cases except one: a constructor call (including a C
2576 function returning a BLKmode struct) to initialize
2578 if (stack_arg_under_construction)
2581 = GEN_INT (adjusted_args_size.constant
2582 + (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL
2583 : TREE_TYPE (fndecl))) ? 0
2584 : reg_parm_stack_space));
2585 if (old_stack_level == 0)
2587 emit_stack_save (SAVE_BLOCK, &old_stack_level,
2589 old_stack_pointer_delta = stack_pointer_delta;
2590 old_pending_adj = pending_stack_adjust;
2591 pending_stack_adjust = 0;
2592 /* stack_arg_under_construction says whether a stack
2593 arg is being constructed at the old stack level.
2594 Pushing the stack gets a clean outgoing argument
2596 old_stack_arg_under_construction
2597 = stack_arg_under_construction;
2598 stack_arg_under_construction = 0;
2599 /* Make a new map for the new argument list. */
2600 if (stack_usage_map_buf)
2601 free (stack_usage_map_buf);
2602 stack_usage_map_buf = XCNEWVEC (char, highest_outgoing_arg_in_use);
2603 stack_usage_map = stack_usage_map_buf;
2604 highest_outgoing_arg_in_use = 0;
2606 allocate_dynamic_stack_space (push_size, NULL_RTX,
2610 /* If argument evaluation might modify the stack pointer,
2611 copy the address of the argument list to a register. */
2612 for (i = 0; i < num_actuals; i++)
2613 if (args[i].pass_on_stack)
2615 argblock = copy_addr_to_reg (argblock);
2620 compute_argument_addresses (args, argblock, num_actuals);
2622 /* If we push args individually in reverse order, perform stack alignment
2623 before the first push (the last arg). */
2624 if (PUSH_ARGS_REVERSED && argblock == 0
2625 && adjusted_args_size.constant != unadjusted_args_size)
2627 /* When the stack adjustment is pending, we get better code
2628 by combining the adjustments. */
2629 if (pending_stack_adjust
2630 && ! inhibit_defer_pop)
2632 pending_stack_adjust
2633 = (combine_pending_stack_adjustment_and_call
2634 (unadjusted_args_size,
2635 &adjusted_args_size,
2636 preferred_unit_stack_boundary));
2637 do_pending_stack_adjust ();
2639 else if (argblock == 0)
2640 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2641 - unadjusted_args_size));
2643 /* Now that the stack is properly aligned, pops can't safely
2644 be deferred during the evaluation of the arguments. */
2647 funexp = rtx_for_function_call (fndecl, addr);
2649 /* Figure out the register where the value, if any, will come back. */
2651 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
2652 && ! structure_value_addr)
2654 if (pcc_struct_value)
2655 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
2656 fndecl, NULL, (pass == 0));
2658 valreg = hard_function_value (TREE_TYPE (exp), fndecl, fntype,
2661 /* If VALREG is a PARALLEL whose first member has a zero
2662 offset, use that. This is for targets such as m68k that
2663 return the same value in multiple places. */
2664 if (GET_CODE (valreg) == PARALLEL)
2666 rtx elem = XVECEXP (valreg, 0, 0);
2667 rtx where = XEXP (elem, 0);
2668 rtx offset = XEXP (elem, 1);
2669 if (offset == const0_rtx
2670 && GET_MODE (where) == GET_MODE (valreg))
2675 /* Precompute all register parameters. It isn't safe to compute anything
2676 once we have started filling any specific hard regs. */
2677 precompute_register_parameters (num_actuals, args, ®_parm_seen);
2679 if (CALL_EXPR_STATIC_CHAIN (exp))
2680 static_chain_value = expand_normal (CALL_EXPR_STATIC_CHAIN (exp));
2682 static_chain_value = 0;
2684 #ifdef REG_PARM_STACK_SPACE
2685 /* Save the fixed argument area if it's part of the caller's frame and
2686 is clobbered by argument setup for this call. */
2687 if (ACCUMULATE_OUTGOING_ARGS && pass)
2688 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
2689 &low_to_save, &high_to_save);
2692 /* Now store (and compute if necessary) all non-register parms.
2693 These come before register parms, since they can require block-moves,
2694 which could clobber the registers used for register parms.
2695 Parms which have partial registers are not stored here,
2696 but we do preallocate space here if they want that. */
2698 for (i = 0; i < num_actuals; i++)
2699 if (args[i].reg == 0 || args[i].pass_on_stack)
2701 rtx before_arg = get_last_insn ();
2703 if (store_one_arg (&args[i], argblock, flags,
2704 adjusted_args_size.var != 0,
2705 reg_parm_stack_space)
2707 && check_sibcall_argument_overlap (before_arg,
2709 sibcall_failure = 1;
2711 if (flags & ECF_CONST
2713 && args[i].value == args[i].stack)
2714 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
2715 gen_rtx_USE (VOIDmode,
2720 /* If we have a parm that is passed in registers but not in memory
2721 and whose alignment does not permit a direct copy into registers,
2722 make a group of pseudos that correspond to each register that we
2724 if (STRICT_ALIGNMENT)
2725 store_unaligned_arguments_into_pseudos (args, num_actuals);
2727 /* Now store any partially-in-registers parm.
2728 This is the last place a block-move can happen. */
2730 for (i = 0; i < num_actuals; i++)
2731 if (args[i].partial != 0 && ! args[i].pass_on_stack)
2733 rtx before_arg = get_last_insn ();
2735 if (store_one_arg (&args[i], argblock, flags,
2736 adjusted_args_size.var != 0,
2737 reg_parm_stack_space)
2739 && check_sibcall_argument_overlap (before_arg,
2741 sibcall_failure = 1;
2744 /* If we pushed args in forward order, perform stack alignment
2745 after pushing the last arg. */
2746 if (!PUSH_ARGS_REVERSED && argblock == 0)
2747 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2748 - unadjusted_args_size));
2750 /* If register arguments require space on the stack and stack space
2751 was not preallocated, allocate stack space here for arguments
2752 passed in registers. */
2753 if (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL_TREE : TREE_TYPE (fndecl)))
2754 && !ACCUMULATE_OUTGOING_ARGS
2755 && must_preallocate == 0 && reg_parm_stack_space > 0)
2756 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
2758 /* Pass the function the address in which to return a
2760 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
2762 structure_value_addr
2763 = convert_memory_address (Pmode, structure_value_addr);
2764 emit_move_insn (struct_value,
2766 force_operand (structure_value_addr,
2769 if (REG_P (struct_value))
2770 use_reg (&call_fusage, struct_value);
2773 after_args = get_last_insn ();
2774 funexp = prepare_call_address (funexp, static_chain_value,
2775 &call_fusage, reg_parm_seen, pass == 0);
2777 load_register_parameters (args, num_actuals, &call_fusage, flags,
2778 pass == 0, &sibcall_failure);
2780 /* Save a pointer to the last insn before the call, so that we can
2781 later safely search backwards to find the CALL_INSN. */
2782 before_call = get_last_insn ();
2784 /* Set up next argument register. For sibling calls on machines
2785 with register windows this should be the incoming register. */
2786 #ifdef FUNCTION_INCOMING_ARG
2788 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
2792 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
2795 /* All arguments and registers used for the call must be set up by
2798 /* Stack must be properly aligned now. */
2800 || !(stack_pointer_delta % preferred_unit_stack_boundary));
2802 /* Generate the actual call instruction. */
2803 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size,
2804 adjusted_args_size.constant, struct_value_size,
2805 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
2806 flags, & args_so_far);
2808 /* If the call setup or the call itself overlaps with anything
2809 of the argument setup we probably clobbered our call address.
2810 In that case we can't do sibcalls. */
2812 && check_sibcall_argument_overlap (after_args, 0, 0))
2813 sibcall_failure = 1;
2815 /* If a non-BLKmode value is returned at the most significant end
2816 of a register, shift the register right by the appropriate amount
2817 and update VALREG accordingly. BLKmode values are handled by the
2818 group load/store machinery below. */
2819 if (!structure_value_addr
2820 && !pcc_struct_value
2821 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
2822 && targetm.calls.return_in_msb (TREE_TYPE (exp)))
2824 if (shift_return_value (TYPE_MODE (TREE_TYPE (exp)), false, valreg))
2825 sibcall_failure = 1;
2826 valreg = gen_rtx_REG (TYPE_MODE (TREE_TYPE (exp)), REGNO (valreg));
2829 if (pass && (flags & ECF_MALLOC))
2831 rtx temp = gen_reg_rtx (GET_MODE (valreg));
2834 /* The return value from a malloc-like function is a pointer. */
2835 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
2836 mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
2838 emit_move_insn (temp, valreg);
2840 /* The return value from a malloc-like function can not alias
2842 last = get_last_insn ();
2843 add_reg_note (last, REG_NOALIAS, temp);
2845 /* Write out the sequence. */
2846 insns = get_insns ();
2852 /* For calls to `setjmp', etc., inform
2853 function.c:setjmp_warnings that it should complain if
2854 nonvolatile values are live. For functions that cannot
2855 return, inform flow that control does not fall through. */
2857 if ((flags & ECF_NORETURN) || pass == 0)
2859 /* The barrier must be emitted
2860 immediately after the CALL_INSN. Some ports emit more
2861 than just a CALL_INSN above, so we must search for it here. */
2863 rtx last = get_last_insn ();
2864 while (!CALL_P (last))
2866 last = PREV_INSN (last);
2867 /* There was no CALL_INSN? */
2868 gcc_assert (last != before_call);
2871 emit_barrier_after (last);
2873 /* Stack adjustments after a noreturn call are dead code.
2874 However when NO_DEFER_POP is in effect, we must preserve
2875 stack_pointer_delta. */
2876 if (inhibit_defer_pop == 0)
2878 stack_pointer_delta = old_stack_allocated;
2879 pending_stack_adjust = 0;
2883 /* If value type not void, return an rtx for the value. */
2885 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
2887 target = const0_rtx;
2888 else if (structure_value_addr)
2890 if (target == 0 || !MEM_P (target))
2893 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
2894 memory_address (TYPE_MODE (TREE_TYPE (exp)),
2895 structure_value_addr));
2896 set_mem_attributes (target, exp, 1);
2899 else if (pcc_struct_value)
2901 /* This is the special C++ case where we need to
2902 know what the true target was. We take care to
2903 never use this value more than once in one expression. */
2904 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
2905 copy_to_reg (valreg));
2906 set_mem_attributes (target, exp, 1);
2908 /* Handle calls that return values in multiple non-contiguous locations.
2909 The Irix 6 ABI has examples of this. */
2910 else if (GET_CODE (valreg) == PARALLEL)
2914 /* This will only be assigned once, so it can be readonly. */
2915 tree nt = build_qualified_type (TREE_TYPE (exp),
2916 (TYPE_QUALS (TREE_TYPE (exp))
2917 | TYPE_QUAL_CONST));
2919 target = assign_temp (nt, 0, 1, 1);
2922 if (! rtx_equal_p (target, valreg))
2923 emit_group_store (target, valreg, TREE_TYPE (exp),
2924 int_size_in_bytes (TREE_TYPE (exp)));
2926 /* We can not support sibling calls for this case. */
2927 sibcall_failure = 1;
2930 && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
2931 && GET_MODE (target) == GET_MODE (valreg))
2933 bool may_overlap = false;
2935 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
2936 reg to a plain register. */
2937 if (!REG_P (target) || HARD_REGISTER_P (target))
2938 valreg = avoid_likely_spilled_reg (valreg);
2940 /* If TARGET is a MEM in the argument area, and we have
2941 saved part of the argument area, then we can't store
2942 directly into TARGET as it may get overwritten when we
2943 restore the argument save area below. Don't work too
2944 hard though and simply force TARGET to a register if it
2945 is a MEM; the optimizer is quite likely to sort it out. */
2946 if (ACCUMULATE_OUTGOING_ARGS && pass && MEM_P (target))
2947 for (i = 0; i < num_actuals; i++)
2948 if (args[i].save_area)
2955 target = copy_to_reg (valreg);
2958 /* TARGET and VALREG cannot be equal at this point
2959 because the latter would not have
2960 REG_FUNCTION_VALUE_P true, while the former would if
2961 it were referring to the same register.
2963 If they refer to the same register, this move will be
2964 a no-op, except when function inlining is being
2966 emit_move_insn (target, valreg);
2968 /* If we are setting a MEM, this code must be executed.
2969 Since it is emitted after the call insn, sibcall
2970 optimization cannot be performed in that case. */
2972 sibcall_failure = 1;
2975 else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode)
2977 target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp));
2979 /* We can not support sibling calls for this case. */
2980 sibcall_failure = 1;
2983 target = copy_to_reg (avoid_likely_spilled_reg (valreg));
2985 if (targetm.calls.promote_function_return(funtype))
2987 /* If we promoted this return value, make the proper SUBREG.
2988 TARGET might be const0_rtx here, so be careful. */
2990 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
2991 && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
2993 tree type = TREE_TYPE (exp);
2994 int unsignedp = TYPE_UNSIGNED (type);
2996 enum machine_mode pmode;
2998 pmode = promote_mode (type, TYPE_MODE (type), &unsignedp, 1);
2999 /* If we don't promote as expected, something is wrong. */
3000 gcc_assert (GET_MODE (target) == pmode);
3002 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
3003 && (GET_MODE_SIZE (GET_MODE (target))
3004 > GET_MODE_SIZE (TYPE_MODE (type))))
3006 offset = GET_MODE_SIZE (GET_MODE (target))
3007 - GET_MODE_SIZE (TYPE_MODE (type));
3008 if (! BYTES_BIG_ENDIAN)
3009 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
3010 else if (! WORDS_BIG_ENDIAN)
3011 offset %= UNITS_PER_WORD;
3013 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
3014 SUBREG_PROMOTED_VAR_P (target) = 1;
3015 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
3019 /* If size of args is variable or this was a constructor call for a stack
3020 argument, restore saved stack-pointer value. */
3022 if (old_stack_level)
3024 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
3025 stack_pointer_delta = old_stack_pointer_delta;
3026 pending_stack_adjust = old_pending_adj;
3027 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
3028 stack_arg_under_construction = old_stack_arg_under_construction;
3029 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3030 stack_usage_map = initial_stack_usage_map;
3031 sibcall_failure = 1;
3033 else if (ACCUMULATE_OUTGOING_ARGS && pass)
3035 #ifdef REG_PARM_STACK_SPACE
3037 restore_fixed_argument_area (save_area, argblock,
3038 high_to_save, low_to_save);
3041 /* If we saved any argument areas, restore them. */
3042 for (i = 0; i < num_actuals; i++)
3043 if (args[i].save_area)
3045 enum machine_mode save_mode = GET_MODE (args[i].save_area);
3047 = gen_rtx_MEM (save_mode,
3048 memory_address (save_mode,
3049 XEXP (args[i].stack_slot, 0)));
3051 if (save_mode != BLKmode)
3052 emit_move_insn (stack_area, args[i].save_area);
3054 emit_block_move (stack_area, args[i].save_area,
3055 GEN_INT (args[i].locate.size.constant),
3056 BLOCK_OP_CALL_PARM);
3059 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3060 stack_usage_map = initial_stack_usage_map;
3063 /* If this was alloca, record the new stack level for nonlocal gotos.
3064 Check for the handler slots since we might not have a save area
3065 for non-local gotos. */
3067 if ((flags & ECF_MAY_BE_ALLOCA) && cfun->nonlocal_goto_save_area != 0)
3068 update_nonlocal_goto_save_area ();
3070 /* Free up storage we no longer need. */
3071 for (i = 0; i < num_actuals; ++i)
3072 if (args[i].aligned_regs)
3073 free (args[i].aligned_regs);
3075 insns = get_insns ();
3080 tail_call_insns = insns;
3082 /* Restore the pending stack adjustment now that we have
3083 finished generating the sibling call sequence. */
3085 pending_stack_adjust = save_pending_stack_adjust;
3086 stack_pointer_delta = save_stack_pointer_delta;
3088 /* Prepare arg structure for next iteration. */
3089 for (i = 0; i < num_actuals; i++)
3092 args[i].aligned_regs = 0;
3096 sbitmap_free (stored_args_map);
3100 normal_call_insns = insns;
3102 /* Verify that we've deallocated all the stack we used. */
3103 gcc_assert ((flags & ECF_NORETURN)
3104 || (old_stack_allocated
3105 == stack_pointer_delta - pending_stack_adjust));
3108 /* If something prevents making this a sibling call,
3109 zero out the sequence. */
3110 if (sibcall_failure)
3111 tail_call_insns = NULL_RTX;
3116 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
3117 arguments too, as argument area is now clobbered by the call. */
3118 if (tail_call_insns)
3120 emit_insn (tail_call_insns);
3121 crtl->tail_call_emit = true;
3124 emit_insn (normal_call_insns);
3126 currently_expanding_call--;
3128 if (stack_usage_map_buf)
3129 free (stack_usage_map_buf);
3134 /* A sibling call sequence invalidates any REG_EQUIV notes made for
3135 this function's incoming arguments.
3137 At the start of RTL generation we know the only REG_EQUIV notes
3138 in the rtl chain are those for incoming arguments, so we can look
3139 for REG_EQUIV notes between the start of the function and the
3140 NOTE_INSN_FUNCTION_BEG.
3142 This is (slight) overkill. We could keep track of the highest
3143 argument we clobber and be more selective in removing notes, but it
3144 does not seem to be worth the effort. */
3147 fixup_tail_calls (void)
3151 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3155 /* There are never REG_EQUIV notes for the incoming arguments
3156 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
3158 && NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG)
3161 note = find_reg_note (insn, REG_EQUIV, 0);
3163 remove_note (insn, note);
3164 note = find_reg_note (insn, REG_EQUIV, 0);
3169 /* Traverse a list of TYPES and expand all complex types into their
3172 split_complex_types (tree types)
3176 /* Before allocating memory, check for the common case of no complex. */
3177 for (p = types; p; p = TREE_CHAIN (p))
3179 tree type = TREE_VALUE (p);
3180 if (TREE_CODE (type) == COMPLEX_TYPE
3181 && targetm.calls.split_complex_arg (type))
3187 types = copy_list (types);
3189 for (p = types; p; p = TREE_CHAIN (p))
3191 tree complex_type = TREE_VALUE (p);
3193 if (TREE_CODE (complex_type) == COMPLEX_TYPE
3194 && targetm.calls.split_complex_arg (complex_type))
3198 /* Rewrite complex type with component type. */
3199 TREE_VALUE (p) = TREE_TYPE (complex_type);
3200 next = TREE_CHAIN (p);
3202 /* Add another component type for the imaginary part. */
3203 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
3204 TREE_CHAIN (p) = imag;
3205 TREE_CHAIN (imag) = next;
3207 /* Skip the newly created node. */
3215 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3216 The RETVAL parameter specifies whether return value needs to be saved, other
3217 parameters are documented in the emit_library_call function below. */
3220 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
3221 enum libcall_type fn_type,
3222 enum machine_mode outmode, int nargs, va_list p)
3224 /* Total size in bytes of all the stack-parms scanned so far. */
3225 struct args_size args_size;
3226 /* Size of arguments before any adjustments (such as rounding). */
3227 struct args_size original_args_size;
3230 /* Todo, choose the correct decl type of orgfun. Sadly this information
3231 isn't present here, so we default to native calling abi here. */
3232 tree fndecl ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
3236 CUMULATIVE_ARGS args_so_far;
3240 enum machine_mode mode;
3243 struct locate_and_pad_arg_data locate;
3247 int old_inhibit_defer_pop = inhibit_defer_pop;
3248 rtx call_fusage = 0;
3251 int pcc_struct_value = 0;
3252 int struct_value_size = 0;
3254 int reg_parm_stack_space = 0;
3257 tree tfom; /* type_for_mode (outmode, 0) */
3259 #ifdef REG_PARM_STACK_SPACE
3260 /* Define the boundary of the register parm stack space that needs to be
3262 int low_to_save = 0, high_to_save = 0;
3263 rtx save_area = 0; /* Place that it is saved. */
3266 /* Size of the stack reserved for parameter registers. */
3267 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3268 char *initial_stack_usage_map = stack_usage_map;
3269 char *stack_usage_map_buf = NULL;
3271 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
3273 #ifdef REG_PARM_STACK_SPACE
3274 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3277 /* By default, library functions can not throw. */
3278 flags = ECF_NOTHROW;
3291 flags |= ECF_NORETURN;
3294 flags = ECF_NORETURN;
3296 case LCT_RETURNS_TWICE:
3297 flags = ECF_RETURNS_TWICE;
3302 /* Ensure current function's preferred stack boundary is at least
3304 if (crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3305 crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3307 /* If this kind of value comes back in memory,
3308 decide where in memory it should come back. */
3309 if (outmode != VOIDmode)
3311 tfom = lang_hooks.types.type_for_mode (outmode, 0);
3312 if (aggregate_value_p (tfom, 0))
3314 #ifdef PCC_STATIC_STRUCT_RETURN
3316 = hard_function_value (build_pointer_type (tfom), 0, 0, 0);
3317 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3318 pcc_struct_value = 1;
3320 value = gen_reg_rtx (outmode);
3321 #else /* not PCC_STATIC_STRUCT_RETURN */
3322 struct_value_size = GET_MODE_SIZE (outmode);
3323 if (value != 0 && MEM_P (value))
3326 mem_value = assign_temp (tfom, 0, 1, 1);
3328 /* This call returns a big structure. */
3329 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
3333 tfom = void_type_node;
3335 /* ??? Unfinished: must pass the memory address as an argument. */
3337 /* Copy all the libcall-arguments out of the varargs data
3338 and into a vector ARGVEC.
3340 Compute how to pass each argument. We only support a very small subset
3341 of the full argument passing conventions to limit complexity here since
3342 library functions shouldn't have many args. */
3344 argvec = XALLOCAVEC (struct arg, nargs + 1);
3345 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
3347 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3348 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun);
3350 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0, nargs);
3353 args_size.constant = 0;
3360 /* If there's a structure value address to be passed,
3361 either pass it in the special place, or pass it as an extra argument. */
3362 if (mem_value && struct_value == 0 && ! pcc_struct_value)
3364 rtx addr = XEXP (mem_value, 0);
3368 /* Make sure it is a reasonable operand for a move or push insn. */
3369 if (!REG_P (addr) && !MEM_P (addr)
3370 && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr)))
3371 addr = force_operand (addr, NULL_RTX);
3373 argvec[count].value = addr;
3374 argvec[count].mode = Pmode;
3375 argvec[count].partial = 0;
3377 argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1);
3378 gcc_assert (targetm.calls.arg_partial_bytes (&args_so_far, Pmode,
3379 NULL_TREE, 1) == 0);
3381 locate_and_pad_parm (Pmode, NULL_TREE,
3382 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3385 argvec[count].reg != 0,
3387 0, NULL_TREE, &args_size, &argvec[count].locate);
3389 if (argvec[count].reg == 0 || argvec[count].partial != 0
3390 || reg_parm_stack_space > 0)
3391 args_size.constant += argvec[count].locate.size.constant;
3393 FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1);
3398 for (; count < nargs; count++)
3400 rtx val = va_arg (p, rtx);
3401 enum machine_mode mode = va_arg (p, enum machine_mode);
3403 /* We cannot convert the arg value to the mode the library wants here;
3404 must do it earlier where we know the signedness of the arg. */
3405 gcc_assert (mode != BLKmode
3406 && (GET_MODE (val) == mode || GET_MODE (val) == VOIDmode));
3408 /* Make sure it is a reasonable operand for a move or push insn. */
3409 if (!REG_P (val) && !MEM_P (val)
3410 && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val)))
3411 val = force_operand (val, NULL_RTX);
3413 if (pass_by_reference (&args_so_far, mode, NULL_TREE, 1))
3417 = !reference_callee_copied (&args_so_far, mode, NULL_TREE, 1);
3419 /* If this was a CONST function, it is now PURE since it now
3421 if (flags & ECF_CONST)
3423 flags &= ~ECF_CONST;
3427 if (MEM_P (val) && !must_copy)
3431 slot = assign_temp (lang_hooks.types.type_for_mode (mode, 0),
3433 emit_move_insn (slot, val);
3436 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3437 gen_rtx_USE (VOIDmode, slot),
3440 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3441 gen_rtx_CLOBBER (VOIDmode,
3446 val = force_operand (XEXP (slot, 0), NULL_RTX);
3449 argvec[count].value = val;
3450 argvec[count].mode = mode;
3452 argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1);
3454 argvec[count].partial
3455 = targetm.calls.arg_partial_bytes (&args_so_far, mode, NULL_TREE, 1);
3457 locate_and_pad_parm (mode, NULL_TREE,
3458 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3461 argvec[count].reg != 0,
3463 argvec[count].partial,
3464 NULL_TREE, &args_size, &argvec[count].locate);
3466 gcc_assert (!argvec[count].locate.size.var);
3468 if (argvec[count].reg == 0 || argvec[count].partial != 0
3469 || reg_parm_stack_space > 0)
3470 args_size.constant += argvec[count].locate.size.constant;
3472 FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1);
3475 /* If this machine requires an external definition for library
3476 functions, write one out. */
3477 assemble_external_libcall (fun);
3479 original_args_size = args_size;
3480 args_size.constant = (((args_size.constant
3481 + stack_pointer_delta
3485 - stack_pointer_delta);
3487 args_size.constant = MAX (args_size.constant,
3488 reg_parm_stack_space);
3490 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL_TREE : TREE_TYPE (fndecl))))
3491 args_size.constant -= reg_parm_stack_space;
3493 if (args_size.constant > crtl->outgoing_args_size)
3494 crtl->outgoing_args_size = args_size.constant;
3496 if (ACCUMULATE_OUTGOING_ARGS)
3498 /* Since the stack pointer will never be pushed, it is possible for
3499 the evaluation of a parm to clobber something we have already
3500 written to the stack. Since most function calls on RISC machines
3501 do not use the stack, this is uncommon, but must work correctly.
3503 Therefore, we save any area of the stack that was already written
3504 and that we are using. Here we set up to do this by making a new
3505 stack usage map from the old one.
3507 Another approach might be to try to reorder the argument
3508 evaluations to avoid this conflicting stack usage. */
3510 needed = args_size.constant;
3512 /* Since we will be writing into the entire argument area, the
3513 map must be allocated for its entire size, not just the part that
3514 is the responsibility of the caller. */
3515 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL_TREE : TREE_TYPE (fndecl))))
3516 needed += reg_parm_stack_space;
3518 #ifdef ARGS_GROW_DOWNWARD
3519 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3522 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3525 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
3526 stack_usage_map = stack_usage_map_buf;
3528 if (initial_highest_arg_in_use)
3529 memcpy (stack_usage_map, initial_stack_usage_map,
3530 initial_highest_arg_in_use);
3532 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3533 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3534 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3537 /* We must be careful to use virtual regs before they're instantiated,
3538 and real regs afterwards. Loop optimization, for example, can create
3539 new libcalls after we've instantiated the virtual regs, and if we
3540 use virtuals anyway, they won't match the rtl patterns. */
3542 if (virtuals_instantiated)
3543 argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET);
3545 argblock = virtual_outgoing_args_rtx;
3550 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3553 /* If we push args individually in reverse order, perform stack alignment
3554 before the first push (the last arg). */
3555 if (argblock == 0 && PUSH_ARGS_REVERSED)
3556 anti_adjust_stack (GEN_INT (args_size.constant
3557 - original_args_size.constant));
3559 if (PUSH_ARGS_REVERSED)
3570 #ifdef REG_PARM_STACK_SPACE
3571 if (ACCUMULATE_OUTGOING_ARGS)
3573 /* The argument list is the property of the called routine and it
3574 may clobber it. If the fixed area has been used for previous
3575 parameters, we must save and restore it. */
3576 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3577 &low_to_save, &high_to_save);
3581 /* Push the args that need to be pushed. */
3583 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3584 are to be pushed. */
3585 for (count = 0; count < nargs; count++, argnum += inc)
3587 enum machine_mode mode = argvec[argnum].mode;
3588 rtx val = argvec[argnum].value;
3589 rtx reg = argvec[argnum].reg;
3590 int partial = argvec[argnum].partial;
3591 int lower_bound = 0, upper_bound = 0, i;
3593 if (! (reg != 0 && partial == 0))
3595 if (ACCUMULATE_OUTGOING_ARGS)
3597 /* If this is being stored into a pre-allocated, fixed-size,
3598 stack area, save any previous data at that location. */
3600 #ifdef ARGS_GROW_DOWNWARD
3601 /* stack_slot is negative, but we want to index stack_usage_map
3602 with positive values. */
3603 upper_bound = -argvec[argnum].locate.offset.constant + 1;
3604 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
3606 lower_bound = argvec[argnum].locate.offset.constant;
3607 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
3611 /* Don't worry about things in the fixed argument area;
3612 it has already been saved. */
3613 if (i < reg_parm_stack_space)
3614 i = reg_parm_stack_space;
3615 while (i < upper_bound && stack_usage_map[i] == 0)
3618 if (i < upper_bound)
3620 /* We need to make a save area. */
3622 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
3623 enum machine_mode save_mode
3624 = mode_for_size (size, MODE_INT, 1);
3626 = plus_constant (argblock,
3627 argvec[argnum].locate.offset.constant);
3629 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
3631 if (save_mode == BLKmode)
3633 argvec[argnum].save_area
3634 = assign_stack_temp (BLKmode,
3635 argvec[argnum].locate.size.constant,
3638 emit_block_move (validize_mem (argvec[argnum].save_area),
3640 GEN_INT (argvec[argnum].locate.size.constant),
3641 BLOCK_OP_CALL_PARM);
3645 argvec[argnum].save_area = gen_reg_rtx (save_mode);
3647 emit_move_insn (argvec[argnum].save_area, stack_area);
3652 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, PARM_BOUNDARY,
3653 partial, reg, 0, argblock,
3654 GEN_INT (argvec[argnum].locate.offset.constant),
3655 reg_parm_stack_space,
3656 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad));
3658 /* Now mark the segment we just used. */
3659 if (ACCUMULATE_OUTGOING_ARGS)
3660 for (i = lower_bound; i < upper_bound; i++)
3661 stack_usage_map[i] = 1;
3665 if (flags & ECF_CONST)
3669 /* Indicate argument access so that alias.c knows that these
3672 use = plus_constant (argblock,
3673 argvec[argnum].locate.offset.constant);
3675 /* When arguments are pushed, trying to tell alias.c where
3676 exactly this argument is won't work, because the
3677 auto-increment causes confusion. So we merely indicate
3678 that we access something with a known mode somewhere on
3680 use = gen_rtx_PLUS (Pmode, virtual_outgoing_args_rtx,
3681 gen_rtx_SCRATCH (Pmode));
3682 use = gen_rtx_MEM (argvec[argnum].mode, use);
3683 use = gen_rtx_USE (VOIDmode, use);
3684 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, use, call_fusage);
3689 /* If we pushed args in forward order, perform stack alignment
3690 after pushing the last arg. */
3691 if (argblock == 0 && !PUSH_ARGS_REVERSED)
3692 anti_adjust_stack (GEN_INT (args_size.constant
3693 - original_args_size.constant));
3695 if (PUSH_ARGS_REVERSED)
3700 fun = prepare_call_address (fun, NULL, &call_fusage, 0, 0);
3702 /* Now load any reg parms into their regs. */
3704 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3705 are to be pushed. */
3706 for (count = 0; count < nargs; count++, argnum += inc)
3708 enum machine_mode mode = argvec[argnum].mode;
3709 rtx val = argvec[argnum].value;
3710 rtx reg = argvec[argnum].reg;
3711 int partial = argvec[argnum].partial;
3713 /* Handle calls that pass values in multiple non-contiguous
3714 locations. The PA64 has examples of this for library calls. */
3715 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3716 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode));
3717 else if (reg != 0 && partial == 0)
3718 emit_move_insn (reg, val);
3723 /* Any regs containing parms remain in use through the call. */
3724 for (count = 0; count < nargs; count++)
3726 rtx reg = argvec[count].reg;
3727 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3728 use_group_regs (&call_fusage, reg);
3731 int partial = argvec[count].partial;
3735 gcc_assert (partial % UNITS_PER_WORD == 0);
3736 nregs = partial / UNITS_PER_WORD;
3737 use_regs (&call_fusage, REGNO (reg), nregs);
3740 use_reg (&call_fusage, reg);
3744 /* Pass the function the address in which to return a structure value. */
3745 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
3747 emit_move_insn (struct_value,
3749 force_operand (XEXP (mem_value, 0),
3751 if (REG_P (struct_value))
3752 use_reg (&call_fusage, struct_value);
3755 /* Don't allow popping to be deferred, since then
3756 cse'ing of library calls could delete a call and leave the pop. */
3758 valreg = (mem_value == 0 && outmode != VOIDmode
3759 ? hard_libcall_value (outmode) : NULL_RTX);
3761 /* Stack must be properly aligned now. */
3762 gcc_assert (!(stack_pointer_delta
3763 & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1)));
3765 before_call = get_last_insn ();
3767 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
3768 will set inhibit_defer_pop to that value. */
3769 /* The return type is needed to decide how many bytes the function pops.
3770 Signedness plays no role in that, so for simplicity, we pretend it's
3771 always signed. We also assume that the list of arguments passed has
3772 no impact, so we pretend it is unknown. */
3774 emit_call_1 (fun, NULL,
3775 get_identifier (XSTR (orgfun, 0)),
3776 build_function_type (tfom, NULL_TREE),
3777 original_args_size.constant, args_size.constant,
3779 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
3781 old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far);
3783 /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
3784 that it should complain if nonvolatile values are live. For
3785 functions that cannot return, inform flow that control does not
3788 if (flags & ECF_NORETURN)
3790 /* The barrier note must be emitted
3791 immediately after the CALL_INSN. Some ports emit more than
3792 just a CALL_INSN above, so we must search for it here. */
3794 rtx last = get_last_insn ();
3795 while (!CALL_P (last))
3797 last = PREV_INSN (last);
3798 /* There was no CALL_INSN? */
3799 gcc_assert (last != before_call);
3802 emit_barrier_after (last);
3805 /* Now restore inhibit_defer_pop to its actual original value. */
3810 /* Copy the value to the right place. */
3811 if (outmode != VOIDmode && retval)
3817 if (value != mem_value)
3818 emit_move_insn (value, mem_value);
3820 else if (GET_CODE (valreg) == PARALLEL)
3823 value = gen_reg_rtx (outmode);
3824 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
3828 /* Convert to the proper mode if PROMOTE_MODE has been active. */
3829 if (GET_MODE (valreg) != outmode)
3831 int unsignedp = TYPE_UNSIGNED (tfom);
3833 gcc_assert (targetm.calls.promote_function_return (tfom));
3834 gcc_assert (promote_mode (tfom, outmode, &unsignedp, 0)
3835 == GET_MODE (valreg));
3837 valreg = convert_modes (outmode, GET_MODE (valreg), valreg, 0);
3841 emit_move_insn (value, valreg);
3847 if (ACCUMULATE_OUTGOING_ARGS)
3849 #ifdef REG_PARM_STACK_SPACE
3851 restore_fixed_argument_area (save_area, argblock,
3852 high_to_save, low_to_save);
3855 /* If we saved any argument areas, restore them. */
3856 for (count = 0; count < nargs; count++)
3857 if (argvec[count].save_area)
3859 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
3860 rtx adr = plus_constant (argblock,
3861 argvec[count].locate.offset.constant);
3862 rtx stack_area = gen_rtx_MEM (save_mode,
3863 memory_address (save_mode, adr));
3865 if (save_mode == BLKmode)
3866 emit_block_move (stack_area,
3867 validize_mem (argvec[count].save_area),
3868 GEN_INT (argvec[count].locate.size.constant),
3869 BLOCK_OP_CALL_PARM);
3871 emit_move_insn (stack_area, argvec[count].save_area);
3874 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3875 stack_usage_map = initial_stack_usage_map;
3878 if (stack_usage_map_buf)
3879 free (stack_usage_map_buf);
3885 /* Output a library call to function FUN (a SYMBOL_REF rtx)
3886 (emitting the queue unless NO_QUEUE is nonzero),
3887 for a value of mode OUTMODE,
3888 with NARGS different arguments, passed as alternating rtx values
3889 and machine_modes to convert them to.
3891 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for
3892 `const' calls, LCT_PURE for `pure' calls, or other LCT_ value for
3893 other types of library calls. */
3896 emit_library_call (rtx orgfun, enum libcall_type fn_type,
3897 enum machine_mode outmode, int nargs, ...)
3901 va_start (p, nargs);
3902 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
3906 /* Like emit_library_call except that an extra argument, VALUE,
3907 comes second and says where to store the result.
3908 (If VALUE is zero, this function chooses a convenient way
3909 to return the value.
3911 This function returns an rtx for where the value is to be found.
3912 If VALUE is nonzero, VALUE is returned. */
3915 emit_library_call_value (rtx orgfun, rtx value,
3916 enum libcall_type fn_type,
3917 enum machine_mode outmode, int nargs, ...)
3922 va_start (p, nargs);
3923 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
3930 /* Store a single argument for a function call
3931 into the register or memory area where it must be passed.
3932 *ARG describes the argument value and where to pass it.
3934 ARGBLOCK is the address of the stack-block for all the arguments,
3935 or 0 on a machine where arguments are pushed individually.
3937 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
3938 so must be careful about how the stack is used.
3940 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
3941 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
3942 that we need not worry about saving and restoring the stack.
3944 FNDECL is the declaration of the function we are calling.
3946 Return nonzero if this arg should cause sibcall failure,
3950 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
3951 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
3953 tree pval = arg->tree_value;
3957 int i, lower_bound = 0, upper_bound = 0;
3958 int sibcall_failure = 0;
3960 if (TREE_CODE (pval) == ERROR_MARK)
3963 /* Push a new temporary level for any temporaries we make for
3967 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
3969 /* If this is being stored into a pre-allocated, fixed-size, stack area,
3970 save any previous data at that location. */
3971 if (argblock && ! variable_size && arg->stack)
3973 #ifdef ARGS_GROW_DOWNWARD
3974 /* stack_slot is negative, but we want to index stack_usage_map
3975 with positive values. */
3976 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
3977 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
3981 lower_bound = upper_bound - arg->locate.size.constant;
3983 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
3984 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
3988 upper_bound = lower_bound + arg->locate.size.constant;
3992 /* Don't worry about things in the fixed argument area;
3993 it has already been saved. */
3994 if (i < reg_parm_stack_space)
3995 i = reg_parm_stack_space;
3996 while (i < upper_bound && stack_usage_map[i] == 0)
3999 if (i < upper_bound)
4001 /* We need to make a save area. */
4002 unsigned int size = arg->locate.size.constant * BITS_PER_UNIT;
4003 enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1);
4004 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
4005 rtx stack_area = gen_rtx_MEM (save_mode, adr);
4007 if (save_mode == BLKmode)
4009 tree ot = TREE_TYPE (arg->tree_value);
4010 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
4011 | TYPE_QUAL_CONST));
4013 arg->save_area = assign_temp (nt, 0, 1, 1);
4014 preserve_temp_slots (arg->save_area);
4015 emit_block_move (validize_mem (arg->save_area), stack_area,
4016 GEN_INT (arg->locate.size.constant),
4017 BLOCK_OP_CALL_PARM);
4021 arg->save_area = gen_reg_rtx (save_mode);
4022 emit_move_insn (arg->save_area, stack_area);
4028 /* If this isn't going to be placed on both the stack and in registers,
4029 set up the register and number of words. */
4030 if (! arg->pass_on_stack)
4032 if (flags & ECF_SIBCALL)
4033 reg = arg->tail_call_reg;
4036 partial = arg->partial;
4039 /* Being passed entirely in a register. We shouldn't be called in
4041 gcc_assert (reg == 0 || partial != 0);
4043 /* If this arg needs special alignment, don't load the registers
4045 if (arg->n_aligned_regs != 0)
4048 /* If this is being passed partially in a register, we can't evaluate
4049 it directly into its stack slot. Otherwise, we can. */
4050 if (arg->value == 0)
4052 /* stack_arg_under_construction is nonzero if a function argument is
4053 being evaluated directly into the outgoing argument list and
4054 expand_call must take special action to preserve the argument list
4055 if it is called recursively.
4057 For scalar function arguments stack_usage_map is sufficient to
4058 determine which stack slots must be saved and restored. Scalar
4059 arguments in general have pass_on_stack == 0.
4061 If this argument is initialized by a function which takes the
4062 address of the argument (a C++ constructor or a C function
4063 returning a BLKmode structure), then stack_usage_map is
4064 insufficient and expand_call must push the stack around the
4065 function call. Such arguments have pass_on_stack == 1.
4067 Note that it is always safe to set stack_arg_under_construction,
4068 but this generates suboptimal code if set when not needed. */
4070 if (arg->pass_on_stack)
4071 stack_arg_under_construction++;
4073 arg->value = expand_expr (pval,
4075 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4076 ? NULL_RTX : arg->stack,
4077 VOIDmode, EXPAND_STACK_PARM);
4079 /* If we are promoting object (or for any other reason) the mode
4080 doesn't agree, convert the mode. */
4082 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4083 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4084 arg->value, arg->unsignedp);
4086 if (arg->pass_on_stack)
4087 stack_arg_under_construction--;
4090 /* Check for overlap with already clobbered argument area. */
4091 if ((flags & ECF_SIBCALL)
4092 && MEM_P (arg->value)
4093 && mem_overlaps_already_clobbered_arg_p (XEXP (arg->value, 0),
4094 arg->locate.size.constant))
4095 sibcall_failure = 1;
4097 /* Don't allow anything left on stack from computation
4098 of argument to alloca. */
4099 if (flags & ECF_MAY_BE_ALLOCA)
4100 do_pending_stack_adjust ();
4102 if (arg->value == arg->stack)
4103 /* If the value is already in the stack slot, we are done. */
4105 else if (arg->mode != BLKmode)
4108 unsigned int parm_align;
4110 /* Argument is a scalar, not entirely passed in registers.
4111 (If part is passed in registers, arg->partial says how much
4112 and emit_push_insn will take care of putting it there.)
4114 Push it, and if its size is less than the
4115 amount of space allocated to it,
4116 also bump stack pointer by the additional space.
4117 Note that in C the default argument promotions
4118 will prevent such mismatches. */
4120 size = GET_MODE_SIZE (arg->mode);
4121 /* Compute how much space the push instruction will push.
4122 On many machines, pushing a byte will advance the stack
4123 pointer by a halfword. */
4124 #ifdef PUSH_ROUNDING
4125 size = PUSH_ROUNDING (size);
4129 /* Compute how much space the argument should get:
4130 round up to a multiple of the alignment for arguments. */
4131 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4132 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4133 / (PARM_BOUNDARY / BITS_PER_UNIT))
4134 * (PARM_BOUNDARY / BITS_PER_UNIT));
4136 /* Compute the alignment of the pushed argument. */
4137 parm_align = arg->locate.boundary;
4138 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4140 int pad = used - size;
4143 unsigned int pad_align = (pad & -pad) * BITS_PER_UNIT;
4144 parm_align = MIN (parm_align, pad_align);
4148 /* This isn't already where we want it on the stack, so put it there.
4149 This can either be done with push or copy insns. */
4150 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4151 parm_align, partial, reg, used - size, argblock,
4152 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4153 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4155 /* Unless this is a partially-in-register argument, the argument is now
4158 arg->value = arg->stack;
4162 /* BLKmode, at least partly to be pushed. */
4164 unsigned int parm_align;
4168 /* Pushing a nonscalar.
4169 If part is passed in registers, PARTIAL says how much
4170 and emit_push_insn will take care of putting it there. */
4172 /* Round its size up to a multiple
4173 of the allocation unit for arguments. */
4175 if (arg->locate.size.var != 0)
4178 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
4182 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
4183 for BLKmode is careful to avoid it. */
4184 excess = (arg->locate.size.constant
4185 - int_size_in_bytes (TREE_TYPE (pval))
4187 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4188 NULL_RTX, TYPE_MODE (sizetype), 0);
4191 parm_align = arg->locate.boundary;
4193 /* When an argument is padded down, the block is aligned to
4194 PARM_BOUNDARY, but the actual argument isn't. */
4195 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4197 if (arg->locate.size.var)
4198 parm_align = BITS_PER_UNIT;
4201 unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4202 parm_align = MIN (parm_align, excess_align);
4206 if ((flags & ECF_SIBCALL) && MEM_P (arg->value))
4208 /* emit_push_insn might not work properly if arg->value and
4209 argblock + arg->locate.offset areas overlap. */
4213 if (XEXP (x, 0) == crtl->args.internal_arg_pointer
4214 || (GET_CODE (XEXP (x, 0)) == PLUS
4215 && XEXP (XEXP (x, 0), 0) ==
4216 crtl->args.internal_arg_pointer
4217 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT))
4219 if (XEXP (x, 0) != crtl->args.internal_arg_pointer)
4220 i = INTVAL (XEXP (XEXP (x, 0), 1));
4222 /* expand_call should ensure this. */
4223 gcc_assert (!arg->locate.offset.var
4224 && arg->locate.size.var == 0
4225 && GET_CODE (size_rtx) == CONST_INT);
4227 if (arg->locate.offset.constant > i)
4229 if (arg->locate.offset.constant < i + INTVAL (size_rtx))
4230 sibcall_failure = 1;
4232 else if (arg->locate.offset.constant < i)
4234 /* Use arg->locate.size.constant instead of size_rtx
4235 because we only care about the part of the argument
4237 if (i < (arg->locate.offset.constant
4238 + arg->locate.size.constant))
4239 sibcall_failure = 1;
4243 /* Even though they appear to be at the same location,
4244 if part of the outgoing argument is in registers,
4245 they aren't really at the same location. Check for
4246 this by making sure that the incoming size is the
4247 same as the outgoing size. */
4248 if (arg->locate.size.constant != INTVAL (size_rtx))
4249 sibcall_failure = 1;
4254 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4255 parm_align, partial, reg, excess, argblock,
4256 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4257 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4259 /* Unless this is a partially-in-register argument, the argument is now
4262 ??? Unlike the case above, in which we want the actual
4263 address of the data, so that we can load it directly into a
4264 register, here we want the address of the stack slot, so that
4265 it's properly aligned for word-by-word copying or something
4266 like that. It's not clear that this is always correct. */
4268 arg->value = arg->stack_slot;
4271 if (arg->reg && GET_CODE (arg->reg) == PARALLEL)
4273 tree type = TREE_TYPE (arg->tree_value);
4275 = emit_group_load_into_temps (arg->reg, arg->value, type,
4276 int_size_in_bytes (type));
4279 /* Mark all slots this store used. */
4280 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
4281 && argblock && ! variable_size && arg->stack)
4282 for (i = lower_bound; i < upper_bound; i++)
4283 stack_usage_map[i] = 1;
4285 /* Once we have pushed something, pops can't safely
4286 be deferred during the rest of the arguments. */
4289 /* Free any temporary slots made in processing this argument. Show
4290 that we might have taken the address of something and pushed that
4292 preserve_temp_slots (NULL_RTX);
4296 return sibcall_failure;
4299 /* Nonzero if we do not know how to pass TYPE solely in registers. */
4302 must_pass_in_stack_var_size (enum machine_mode mode ATTRIBUTE_UNUSED,
4308 /* If the type has variable size... */
4309 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4312 /* If the type is marked as addressable (it is required
4313 to be constructed into the stack)... */
4314 if (TREE_ADDRESSABLE (type))
4320 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
4321 takes trailing padding of a structure into account. */
4322 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
4325 must_pass_in_stack_var_size_or_pad (enum machine_mode mode, const_tree type)
4330 /* If the type has variable size... */
4331 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4334 /* If the type is marked as addressable (it is required
4335 to be constructed into the stack)... */
4336 if (TREE_ADDRESSABLE (type))
4339 /* If the padding and mode of the type is such that a copy into
4340 a register would put it into the wrong part of the register. */
4342 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
4343 && (FUNCTION_ARG_PADDING (mode, type)
4344 == (BYTES_BIG_ENDIAN ? upward : downward)))