1 /* Convert function calls to rtl insns, for GNU C compiler.
2 Copyright (C) 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
24 #include "coretypes.h"
40 #include "langhooks.h"
45 #include "tree-flow.h"
47 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
48 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
50 /* Data structure and subroutines used within expand_call. */
54 /* Tree node for this argument. */
56 /* Mode for value; TYPE_MODE unless promoted. */
57 enum machine_mode mode;
58 /* Current RTL value for argument, or 0 if it isn't precomputed. */
60 /* Initially-compute RTL value for argument; only for const functions. */
62 /* Register to pass this argument in, 0 if passed on stack, or an
63 PARALLEL if the arg is to be copied into multiple non-contiguous
66 /* Register to pass this argument in when generating tail call sequence.
67 This is not the same register as for normal calls on machines with
70 /* If REG is a PARALLEL, this is a copy of VALUE pulled into the correct
71 form for emit_group_move. */
73 /* If REG was promoted from the actual mode of the argument expression,
74 indicates whether the promotion is sign- or zero-extended. */
76 /* Number of bytes to put in registers. 0 means put the whole arg
77 in registers. Also 0 if not passed in registers. */
79 /* Nonzero if argument must be passed on stack.
80 Note that some arguments may be passed on the stack
81 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
82 pass_on_stack identifies arguments that *cannot* go in registers. */
84 /* Some fields packaged up for locate_and_pad_parm. */
85 struct locate_and_pad_arg_data locate;
86 /* Location on the stack at which parameter should be stored. The store
87 has already been done if STACK == VALUE. */
89 /* Location on the stack of the start of this argument slot. This can
90 differ from STACK if this arg pads downward. This location is known
91 to be aligned to FUNCTION_ARG_BOUNDARY. */
93 /* Place that this stack area has been saved, if needed. */
95 /* If an argument's alignment does not permit direct copying into registers,
96 copy in smaller-sized pieces into pseudos. These are stored in a
97 block pointed to by this field. The next field says how many
98 word-sized pseudos we made. */
103 /* A vector of one char per byte of stack space. A byte if nonzero if
104 the corresponding stack location has been used.
105 This vector is used to prevent a function call within an argument from
106 clobbering any stack already set up. */
107 static char *stack_usage_map;
109 /* Size of STACK_USAGE_MAP. */
110 static int highest_outgoing_arg_in_use;
112 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
113 stack location's tail call argument has been already stored into the stack.
114 This bitmap is used to prevent sibling call optimization if function tries
115 to use parent's incoming argument slots when they have been already
116 overwritten with tail call arguments. */
117 static sbitmap stored_args_map;
119 /* stack_arg_under_construction is nonzero when an argument may be
120 initialized with a constructor call (including a C function that
121 returns a BLKmode struct) and expand_call must take special action
122 to make sure the object being constructed does not overlap the
123 argument list for the constructor call. */
124 static int stack_arg_under_construction;
126 static void emit_call_1 (rtx, tree, tree, tree, HOST_WIDE_INT, HOST_WIDE_INT,
127 HOST_WIDE_INT, rtx, rtx, int, rtx, int,
129 static void precompute_register_parameters (int, struct arg_data *, int *);
130 static int store_one_arg (struct arg_data *, rtx, int, int, int);
131 static void store_unaligned_arguments_into_pseudos (struct arg_data *, int);
132 static int finalize_must_preallocate (int, int, struct arg_data *,
134 static void precompute_arguments (int, struct arg_data *);
135 static int compute_argument_block_size (int, struct args_size *, tree, tree, int);
136 static void initialize_argument_information (int, struct arg_data *,
137 struct args_size *, int,
139 tree, tree, CUMULATIVE_ARGS *, int,
140 rtx *, int *, int *, int *,
142 static void compute_argument_addresses (struct arg_data *, rtx, int);
143 static rtx rtx_for_function_call (tree, tree);
144 static void load_register_parameters (struct arg_data *, int, rtx *, int,
146 static rtx emit_library_call_value_1 (int, rtx, rtx, enum libcall_type,
147 enum machine_mode, int, va_list);
148 static int special_function_p (const_tree, int);
149 static int check_sibcall_argument_overlap_1 (rtx);
150 static int check_sibcall_argument_overlap (rtx, struct arg_data *, int);
152 static int combine_pending_stack_adjustment_and_call (int, struct args_size *,
154 static tree split_complex_types (tree);
156 #ifdef REG_PARM_STACK_SPACE
157 static rtx save_fixed_argument_area (int, rtx, int *, int *);
158 static void restore_fixed_argument_area (rtx, rtx, int, int);
161 /* Force FUNEXP into a form suitable for the address of a CALL,
162 and return that as an rtx. Also load the static chain register
163 if FNDECL is a nested function.
165 CALL_FUSAGE points to a variable holding the prospective
166 CALL_INSN_FUNCTION_USAGE information. */
169 prepare_call_address (rtx funexp, rtx static_chain_value,
170 rtx *call_fusage, int reg_parm_seen, int sibcallp)
172 /* Make a valid memory address and copy constants through pseudo-regs,
173 but not for a constant address if -fno-function-cse. */
174 if (GET_CODE (funexp) != SYMBOL_REF)
175 /* If we are using registers for parameters, force the
176 function address into a register now. */
177 funexp = ((SMALL_REGISTER_CLASSES && reg_parm_seen)
178 ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
179 : memory_address (FUNCTION_MODE, funexp));
182 #ifndef NO_FUNCTION_CSE
183 if (optimize && ! flag_no_function_cse)
184 funexp = force_reg (Pmode, funexp);
188 if (static_chain_value != 0)
190 static_chain_value = convert_memory_address (Pmode, static_chain_value);
191 emit_move_insn (static_chain_rtx, static_chain_value);
193 if (REG_P (static_chain_rtx))
194 use_reg (call_fusage, static_chain_rtx);
200 /* Generate instructions to call function FUNEXP,
201 and optionally pop the results.
202 The CALL_INSN is the first insn generated.
204 FNDECL is the declaration node of the function. This is given to the
205 macro RETURN_POPS_ARGS to determine whether this function pops its own args.
207 FUNTYPE is the data type of the function. This is given to the macro
208 RETURN_POPS_ARGS to determine whether this function pops its own args.
209 We used to allow an identifier for library functions, but that doesn't
210 work when the return type is an aggregate type and the calling convention
211 says that the pointer to this aggregate is to be popped by the callee.
213 STACK_SIZE is the number of bytes of arguments on the stack,
214 ROUNDED_STACK_SIZE is that number rounded up to
215 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
216 both to put into the call insn and to generate explicit popping
219 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
220 It is zero if this call doesn't want a structure value.
222 NEXT_ARG_REG is the rtx that results from executing
223 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
224 just after all the args have had their registers assigned.
225 This could be whatever you like, but normally it is the first
226 arg-register beyond those used for args in this call,
227 or 0 if all the arg-registers are used in this call.
228 It is passed on to `gen_call' so you can put this info in the call insn.
230 VALREG is a hard register in which a value is returned,
231 or 0 if the call does not return a value.
233 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
234 the args to this call were processed.
235 We restore `inhibit_defer_pop' to that value.
237 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
238 denote registers used by the called function. */
241 emit_call_1 (rtx funexp, tree fntree ATTRIBUTE_UNUSED, tree fndecl ATTRIBUTE_UNUSED,
242 tree funtype ATTRIBUTE_UNUSED,
243 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED,
244 HOST_WIDE_INT rounded_stack_size,
245 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED,
246 rtx next_arg_reg ATTRIBUTE_UNUSED, rtx valreg,
247 int old_inhibit_defer_pop, rtx call_fusage, int ecf_flags,
248 CUMULATIVE_ARGS *args_so_far ATTRIBUTE_UNUSED)
250 rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
252 int already_popped = 0;
253 HOST_WIDE_INT n_popped = RETURN_POPS_ARGS (fndecl, funtype, stack_size);
254 #if defined (HAVE_call) && defined (HAVE_call_value)
255 rtx struct_value_size_rtx;
256 struct_value_size_rtx = GEN_INT (struct_value_size);
259 #ifdef CALL_POPS_ARGS
260 n_popped += CALL_POPS_ARGS (* args_so_far);
263 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
264 and we don't want to load it into a register as an optimization,
265 because prepare_call_address already did it if it should be done. */
266 if (GET_CODE (funexp) != SYMBOL_REF)
267 funexp = memory_address (FUNCTION_MODE, funexp);
269 #if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
270 if ((ecf_flags & ECF_SIBCALL)
271 && HAVE_sibcall_pop && HAVE_sibcall_value_pop
272 && (n_popped > 0 || stack_size == 0))
274 rtx n_pop = GEN_INT (n_popped);
277 /* If this subroutine pops its own args, record that in the call insn
278 if possible, for the sake of frame pointer elimination. */
281 pat = GEN_SIBCALL_VALUE_POP (valreg,
282 gen_rtx_MEM (FUNCTION_MODE, funexp),
283 rounded_stack_size_rtx, next_arg_reg,
286 pat = GEN_SIBCALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
287 rounded_stack_size_rtx, next_arg_reg, n_pop);
289 emit_call_insn (pat);
295 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
296 /* If the target has "call" or "call_value" insns, then prefer them
297 if no arguments are actually popped. If the target does not have
298 "call" or "call_value" insns, then we must use the popping versions
299 even if the call has no arguments to pop. */
300 #if defined (HAVE_call) && defined (HAVE_call_value)
301 if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop
304 if (HAVE_call_pop && HAVE_call_value_pop)
307 rtx n_pop = GEN_INT (n_popped);
310 /* If this subroutine pops its own args, record that in the call insn
311 if possible, for the sake of frame pointer elimination. */
314 pat = GEN_CALL_VALUE_POP (valreg,
315 gen_rtx_MEM (FUNCTION_MODE, funexp),
316 rounded_stack_size_rtx, next_arg_reg, n_pop);
318 pat = GEN_CALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
319 rounded_stack_size_rtx, next_arg_reg, n_pop);
321 emit_call_insn (pat);
327 #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
328 if ((ecf_flags & ECF_SIBCALL)
329 && HAVE_sibcall && HAVE_sibcall_value)
332 emit_call_insn (GEN_SIBCALL_VALUE (valreg,
333 gen_rtx_MEM (FUNCTION_MODE, funexp),
334 rounded_stack_size_rtx,
335 next_arg_reg, NULL_RTX));
337 emit_call_insn (GEN_SIBCALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
338 rounded_stack_size_rtx, next_arg_reg,
339 struct_value_size_rtx));
344 #if defined (HAVE_call) && defined (HAVE_call_value)
345 if (HAVE_call && HAVE_call_value)
348 emit_call_insn (GEN_CALL_VALUE (valreg,
349 gen_rtx_MEM (FUNCTION_MODE, funexp),
350 rounded_stack_size_rtx, next_arg_reg,
353 emit_call_insn (GEN_CALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
354 rounded_stack_size_rtx, next_arg_reg,
355 struct_value_size_rtx));
361 /* Find the call we just emitted. */
362 call_insn = last_call_insn ();
364 /* Put the register usage information there. */
365 add_function_usage_to (call_insn, call_fusage);
367 /* If this is a const call, then set the insn's unchanging bit. */
368 if (ecf_flags & ECF_CONST)
369 RTL_CONST_CALL_P (call_insn) = 1;
371 /* If this is a pure call, then set the insn's unchanging bit. */
372 if (ecf_flags & ECF_PURE)
373 RTL_PURE_CALL_P (call_insn) = 1;
375 /* If this is a const call, then set the insn's unchanging bit. */
376 if (ecf_flags & ECF_LOOPING_CONST_OR_PURE)
377 RTL_LOOPING_CONST_OR_PURE_CALL_P (call_insn) = 1;
379 /* 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);
384 if (ecf_flags & ECF_NORETURN)
385 add_reg_note (call_insn, REG_NORETURN, const0_rtx);
387 if (ecf_flags & ECF_RETURNS_TWICE)
389 add_reg_note (call_insn, REG_SETJMP, const0_rtx);
390 cfun->calls_setjmp = 1;
393 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
395 /* Restore this now, so that we do defer pops for this call's args
396 if the context of the call as a whole permits. */
397 inhibit_defer_pop = old_inhibit_defer_pop;
402 CALL_INSN_FUNCTION_USAGE (call_insn)
403 = gen_rtx_EXPR_LIST (VOIDmode,
404 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
405 CALL_INSN_FUNCTION_USAGE (call_insn));
406 rounded_stack_size -= n_popped;
407 rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
408 stack_pointer_delta -= n_popped;
410 /* If popup is needed, stack realign must use DRAP */
411 if (SUPPORTS_STACK_ALIGNMENT)
412 crtl->need_drap = true;
415 if (!ACCUMULATE_OUTGOING_ARGS)
417 /* If returning from the subroutine does not automatically pop the args,
418 we need an instruction to pop them sooner or later.
419 Perhaps do it now; perhaps just record how much space to pop later.
421 If returning from the subroutine does pop the args, indicate that the
422 stack pointer will be changed. */
424 if (rounded_stack_size != 0)
426 if (ecf_flags & ECF_NORETURN)
427 /* Just pretend we did the pop. */
428 stack_pointer_delta -= rounded_stack_size;
429 else if (flag_defer_pop && inhibit_defer_pop == 0
430 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
431 pending_stack_adjust += rounded_stack_size;
433 adjust_stack (rounded_stack_size_rtx);
436 /* When we accumulate outgoing args, we must avoid any stack manipulations.
437 Restore the stack pointer to its original value now. Usually
438 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
439 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
440 popping variants of functions exist as well.
442 ??? We may optimize similar to defer_pop above, but it is
443 probably not worthwhile.
445 ??? It will be worthwhile to enable combine_stack_adjustments even for
448 anti_adjust_stack (GEN_INT (n_popped));
451 /* Determine if the function identified by NAME and FNDECL is one with
452 special properties we wish to know about.
454 For example, if the function might return more than one time (setjmp), then
455 set RETURNS_TWICE to a nonzero value.
457 Similarly set NORETURN if the function is in the longjmp family.
459 Set MAY_BE_ALLOCA for any memory allocation function that might allocate
460 space from the stack such as alloca. */
463 special_function_p (const_tree fndecl, int flags)
465 if (fndecl && DECL_NAME (fndecl)
466 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
467 /* Exclude functions not at the file scope, or not `extern',
468 since they are not the magic functions we would otherwise
470 FIXME: this should be handled with attributes, not with this
471 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
472 because you can declare fork() inside a function if you
474 && (DECL_CONTEXT (fndecl) == NULL_TREE
475 || TREE_CODE (DECL_CONTEXT (fndecl)) == TRANSLATION_UNIT_DECL)
476 && TREE_PUBLIC (fndecl))
478 const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
479 const char *tname = name;
481 /* We assume that alloca will always be called by name. It
482 makes no sense to pass it as a pointer-to-function to
483 anything that does not understand its behavior. */
484 if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
486 && ! strcmp (name, "alloca"))
487 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
489 && ! strcmp (name, "__builtin_alloca"))))
490 flags |= ECF_MAY_BE_ALLOCA;
492 /* Disregard prefix _, __, __x or __builtin_. */
497 && !strncmp (name + 3, "uiltin_", 7))
499 else if (name[1] == '_' && name[2] == 'x')
501 else if (name[1] == '_')
510 && (! strcmp (tname, "setjmp")
511 || ! strcmp (tname, "setjmp_syscall")))
513 && ! strcmp (tname, "sigsetjmp"))
515 && ! strcmp (tname, "savectx")))
516 flags |= ECF_RETURNS_TWICE;
519 && ! strcmp (tname, "siglongjmp"))
520 flags |= ECF_NORETURN;
522 else if ((tname[0] == 'q' && tname[1] == 's'
523 && ! strcmp (tname, "qsetjmp"))
524 || (tname[0] == 'v' && tname[1] == 'f'
525 && ! strcmp (tname, "vfork"))
526 || (tname[0] == 'g' && tname[1] == 'e'
527 && !strcmp (tname, "getcontext")))
528 flags |= ECF_RETURNS_TWICE;
530 else if (tname[0] == 'l' && tname[1] == 'o'
531 && ! strcmp (tname, "longjmp"))
532 flags |= ECF_NORETURN;
538 /* Return nonzero when FNDECL represents a call to setjmp. */
541 setjmp_call_p (const_tree fndecl)
543 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
547 /* Return true if STMT is an alloca call. */
550 gimple_alloca_call_p (const_gimple stmt)
554 if (!is_gimple_call (stmt))
557 fndecl = gimple_call_fndecl (stmt);
558 if (fndecl && (special_function_p (fndecl, 0) & ECF_MAY_BE_ALLOCA))
564 /* Return true when exp contains alloca call. */
567 alloca_call_p (const_tree exp)
569 if (TREE_CODE (exp) == CALL_EXPR
570 && TREE_CODE (CALL_EXPR_FN (exp)) == ADDR_EXPR
571 && (TREE_CODE (TREE_OPERAND (CALL_EXPR_FN (exp), 0)) == FUNCTION_DECL)
572 && (special_function_p (TREE_OPERAND (CALL_EXPR_FN (exp), 0), 0)
573 & ECF_MAY_BE_ALLOCA))
578 /* Detect flags (function attributes) from the function decl or type node. */
581 flags_from_decl_or_type (const_tree exp)
584 const_tree type = exp;
588 type = TREE_TYPE (exp);
590 /* The function exp may have the `malloc' attribute. */
591 if (DECL_IS_MALLOC (exp))
594 /* The function exp may have the `returns_twice' attribute. */
595 if (DECL_IS_RETURNS_TWICE (exp))
596 flags |= ECF_RETURNS_TWICE;
598 /* Process the pure and const attributes. */
599 if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
601 if (DECL_PURE_P (exp))
603 if (DECL_LOOPING_CONST_OR_PURE_P (exp))
604 flags |= ECF_LOOPING_CONST_OR_PURE;
606 if (DECL_IS_NOVOPS (exp))
609 if (TREE_NOTHROW (exp))
610 flags |= ECF_NOTHROW;
612 flags = special_function_p (exp, flags);
614 else if (TYPE_P (exp) && TYPE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
617 if (TREE_THIS_VOLATILE (exp))
618 flags |= ECF_NORETURN;
623 /* Detect flags from a CALL_EXPR. */
626 call_expr_flags (const_tree t)
629 tree decl = get_callee_fndecl (t);
632 flags = flags_from_decl_or_type (decl);
635 t = TREE_TYPE (CALL_EXPR_FN (t));
636 if (t && TREE_CODE (t) == POINTER_TYPE)
637 flags = flags_from_decl_or_type (TREE_TYPE (t));
645 /* Precompute all register parameters as described by ARGS, storing values
646 into fields within the ARGS array.
648 NUM_ACTUALS indicates the total number elements in the ARGS array.
650 Set REG_PARM_SEEN if we encounter a register parameter. */
653 precompute_register_parameters (int num_actuals, struct arg_data *args,
660 for (i = 0; i < num_actuals; i++)
661 if (args[i].reg != 0 && ! args[i].pass_on_stack)
665 if (args[i].value == 0)
668 args[i].value = expand_normal (args[i].tree_value);
669 preserve_temp_slots (args[i].value);
673 /* If the value is a non-legitimate constant, force it into a
674 pseudo now. TLS symbols sometimes need a call to resolve. */
675 if (CONSTANT_P (args[i].value)
676 && !LEGITIMATE_CONSTANT_P (args[i].value))
677 args[i].value = force_reg (args[i].mode, args[i].value);
679 /* If we are to promote the function arg to a wider mode,
682 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
684 = convert_modes (args[i].mode,
685 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
686 args[i].value, args[i].unsignedp);
688 /* If we're going to have to load the value by parts, pull the
689 parts into pseudos. The part extraction process can involve
690 non-trivial computation. */
691 if (GET_CODE (args[i].reg) == PARALLEL)
693 tree type = TREE_TYPE (args[i].tree_value);
694 args[i].parallel_value
695 = emit_group_load_into_temps (args[i].reg, args[i].value,
696 type, int_size_in_bytes (type));
699 /* If the value is expensive, and we are inside an appropriately
700 short loop, put the value into a pseudo and then put the pseudo
703 For small register classes, also do this if this call uses
704 register parameters. This is to avoid reload conflicts while
705 loading the parameters registers. */
707 else if ((! (REG_P (args[i].value)
708 || (GET_CODE (args[i].value) == SUBREG
709 && REG_P (SUBREG_REG (args[i].value)))))
710 && args[i].mode != BLKmode
711 && rtx_cost (args[i].value, SET, optimize_insn_for_speed_p ())
713 && ((SMALL_REGISTER_CLASSES && *reg_parm_seen)
715 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
719 #ifdef REG_PARM_STACK_SPACE
721 /* The argument list is the property of the called routine and it
722 may clobber it. If the fixed area has been used for previous
723 parameters, we must save and restore it. */
726 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
731 /* Compute the boundary of the area that needs to be saved, if any. */
732 high = reg_parm_stack_space;
733 #ifdef ARGS_GROW_DOWNWARD
736 if (high > highest_outgoing_arg_in_use)
737 high = highest_outgoing_arg_in_use;
739 for (low = 0; low < high; low++)
740 if (stack_usage_map[low] != 0)
743 enum machine_mode save_mode;
748 while (stack_usage_map[--high] == 0)
752 *high_to_save = high;
754 num_to_save = high - low + 1;
755 save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
757 /* If we don't have the required alignment, must do this
759 if ((low & (MIN (GET_MODE_SIZE (save_mode),
760 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
763 #ifdef ARGS_GROW_DOWNWARD
768 stack_area = gen_rtx_MEM (save_mode,
769 memory_address (save_mode,
770 plus_constant (argblock,
773 set_mem_align (stack_area, PARM_BOUNDARY);
774 if (save_mode == BLKmode)
776 save_area = assign_stack_temp (BLKmode, num_to_save, 0);
777 emit_block_move (validize_mem (save_area), stack_area,
778 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
782 save_area = gen_reg_rtx (save_mode);
783 emit_move_insn (save_area, stack_area);
793 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
795 enum machine_mode save_mode = GET_MODE (save_area);
799 #ifdef ARGS_GROW_DOWNWARD
800 delta = -high_to_save;
804 stack_area = gen_rtx_MEM (save_mode,
805 memory_address (save_mode,
806 plus_constant (argblock, delta)));
807 set_mem_align (stack_area, PARM_BOUNDARY);
809 if (save_mode != BLKmode)
810 emit_move_insn (stack_area, save_area);
812 emit_block_move (stack_area, validize_mem (save_area),
813 GEN_INT (high_to_save - low_to_save + 1),
816 #endif /* REG_PARM_STACK_SPACE */
818 /* If any elements in ARGS refer to parameters that are to be passed in
819 registers, but not in memory, and whose alignment does not permit a
820 direct copy into registers. Copy the values into a group of pseudos
821 which we will later copy into the appropriate hard registers.
823 Pseudos for each unaligned argument will be stored into the array
824 args[argnum].aligned_regs. The caller is responsible for deallocating
825 the aligned_regs array if it is nonzero. */
828 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
832 for (i = 0; i < num_actuals; i++)
833 if (args[i].reg != 0 && ! args[i].pass_on_stack
834 && args[i].mode == BLKmode
835 && MEM_P (args[i].value)
836 && (MEM_ALIGN (args[i].value)
837 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
839 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
840 int endian_correction = 0;
844 gcc_assert (args[i].partial % UNITS_PER_WORD == 0);
845 args[i].n_aligned_regs = args[i].partial / UNITS_PER_WORD;
849 args[i].n_aligned_regs
850 = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
853 args[i].aligned_regs = XNEWVEC (rtx, args[i].n_aligned_regs);
855 /* Structures smaller than a word are normally aligned to the
856 least significant byte. On a BYTES_BIG_ENDIAN machine,
857 this means we must skip the empty high order bytes when
858 calculating the bit offset. */
859 if (bytes < UNITS_PER_WORD
860 #ifdef BLOCK_REG_PADDING
861 && (BLOCK_REG_PADDING (args[i].mode,
862 TREE_TYPE (args[i].tree_value), 1)
868 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
870 for (j = 0; j < args[i].n_aligned_regs; j++)
872 rtx reg = gen_reg_rtx (word_mode);
873 rtx word = operand_subword_force (args[i].value, j, BLKmode);
874 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
876 args[i].aligned_regs[j] = reg;
877 word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
878 word_mode, word_mode);
880 /* There is no need to restrict this code to loading items
881 in TYPE_ALIGN sized hunks. The bitfield instructions can
882 load up entire word sized registers efficiently.
884 ??? This may not be needed anymore.
885 We use to emit a clobber here but that doesn't let later
886 passes optimize the instructions we emit. By storing 0 into
887 the register later passes know the first AND to zero out the
888 bitfield being set in the register is unnecessary. The store
889 of 0 will be deleted as will at least the first AND. */
891 emit_move_insn (reg, const0_rtx);
893 bytes -= bitsize / BITS_PER_UNIT;
894 store_bit_field (reg, bitsize, endian_correction, word_mode,
900 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
903 NUM_ACTUALS is the total number of parameters.
905 N_NAMED_ARGS is the total number of named arguments.
907 STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
910 FNDECL is the tree code for the target of this call (if known)
912 ARGS_SO_FAR holds state needed by the target to know where to place
915 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
916 for arguments which are passed in registers.
918 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
919 and may be modified by this routine.
921 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
922 flags which may may be modified by this routine.
924 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
925 that requires allocation of stack space.
927 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
928 the thunked-to function. */
931 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
932 struct arg_data *args,
933 struct args_size *args_size,
934 int n_named_args ATTRIBUTE_UNUSED,
935 tree exp, tree struct_value_addr_value,
936 tree fndecl, tree fntype,
937 CUMULATIVE_ARGS *args_so_far,
938 int reg_parm_stack_space,
939 rtx *old_stack_level, int *old_pending_adj,
940 int *must_preallocate, int *ecf_flags,
941 bool *may_tailcall, bool call_from_thunk_p)
943 location_t loc = EXPR_LOCATION (exp);
944 /* 1 if scanning parms front to back, -1 if scanning back to front. */
947 /* Count arg position in order args appear. */
952 args_size->constant = 0;
955 /* In this loop, we consider args in the order they are written.
956 We fill up ARGS from the front or from the back if necessary
957 so that in any case the first arg to be pushed ends up at the front. */
959 if (PUSH_ARGS_REVERSED)
961 i = num_actuals - 1, inc = -1;
962 /* In this case, must reverse order of args
963 so that we compute and push the last arg first. */
970 /* First fill in the actual arguments in the ARGS array, splitting
971 complex arguments if necessary. */
974 call_expr_arg_iterator iter;
977 if (struct_value_addr_value)
979 args[j].tree_value = struct_value_addr_value;
982 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
984 tree argtype = TREE_TYPE (arg);
985 if (targetm.calls.split_complex_arg
987 && TREE_CODE (argtype) == COMPLEX_TYPE
988 && targetm.calls.split_complex_arg (argtype))
990 tree subtype = TREE_TYPE (argtype);
991 args[j].tree_value = build1 (REALPART_EXPR, subtype, arg);
993 args[j].tree_value = build1 (IMAGPART_EXPR, subtype, arg);
996 args[j].tree_value = arg;
1001 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1002 for (argpos = 0; argpos < num_actuals; i += inc, argpos++)
1004 tree type = TREE_TYPE (args[i].tree_value);
1006 enum machine_mode mode;
1008 /* Replace erroneous argument with constant zero. */
1009 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1010 args[i].tree_value = integer_zero_node, type = integer_type_node;
1012 /* If TYPE is a transparent union, pass things the way we would
1013 pass the first field of the union. We have already verified that
1014 the modes are the same. */
1015 if (TREE_CODE (type) == UNION_TYPE && TYPE_TRANSPARENT_UNION (type))
1016 type = TREE_TYPE (TYPE_FIELDS (type));
1018 /* Decide where to pass this arg.
1020 args[i].reg is nonzero if all or part is passed in registers.
1022 args[i].partial is nonzero if part but not all is passed in registers,
1023 and the exact value says how many bytes are passed in registers.
1025 args[i].pass_on_stack is nonzero if the argument must at least be
1026 computed on the stack. It may then be loaded back into registers
1027 if args[i].reg is nonzero.
1029 These decisions are driven by the FUNCTION_... macros and must agree
1030 with those made by function.c. */
1032 /* See if this argument should be passed by invisible reference. */
1033 if (pass_by_reference (args_so_far, TYPE_MODE (type),
1034 type, argpos < n_named_args))
1040 = reference_callee_copied (args_so_far, TYPE_MODE (type),
1041 type, argpos < n_named_args);
1043 /* If we're compiling a thunk, pass through invisible references
1044 instead of making a copy. */
1045 if (call_from_thunk_p
1047 && !TREE_ADDRESSABLE (type)
1048 && (base = get_base_address (args[i].tree_value))
1049 && TREE_CODE (base) != SSA_NAME
1050 && (!DECL_P (base) || MEM_P (DECL_RTL (base)))))
1052 /* We can't use sibcalls if a callee-copied argument is
1053 stored in the current function's frame. */
1054 if (!call_from_thunk_p && DECL_P (base) && !TREE_STATIC (base))
1055 *may_tailcall = false;
1057 args[i].tree_value = build_fold_addr_expr_loc (loc,
1058 args[i].tree_value);
1059 type = TREE_TYPE (args[i].tree_value);
1061 if (*ecf_flags & ECF_CONST)
1062 *ecf_flags &= ~(ECF_CONST | ECF_LOOPING_CONST_OR_PURE);
1066 /* We make a copy of the object and pass the address to the
1067 function being called. */
1070 if (!COMPLETE_TYPE_P (type)
1071 || TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST
1072 || (flag_stack_check == GENERIC_STACK_CHECK
1073 && compare_tree_int (TYPE_SIZE_UNIT (type),
1074 STACK_CHECK_MAX_VAR_SIZE) > 0))
1076 /* This is a variable-sized object. Make space on the stack
1078 rtx size_rtx = expr_size (args[i].tree_value);
1080 if (*old_stack_level == 0)
1082 emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX);
1083 *old_pending_adj = pending_stack_adjust;
1084 pending_stack_adjust = 0;
1087 copy = gen_rtx_MEM (BLKmode,
1088 allocate_dynamic_stack_space
1089 (size_rtx, NULL_RTX, TYPE_ALIGN (type)));
1090 set_mem_attributes (copy, type, 1);
1093 copy = assign_temp (type, 0, 1, 0);
1095 store_expr (args[i].tree_value, copy, 0, false);
1097 /* Just change the const function to pure and then let
1098 the next test clear the pure based on
1100 if (*ecf_flags & ECF_CONST)
1102 *ecf_flags &= ~ECF_CONST;
1103 *ecf_flags |= ECF_PURE;
1106 if (!callee_copies && *ecf_flags & ECF_PURE)
1107 *ecf_flags &= ~(ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
1110 = build_fold_addr_expr_loc (loc, make_tree (type, copy));
1111 type = TREE_TYPE (args[i].tree_value);
1112 *may_tailcall = false;
1116 unsignedp = TYPE_UNSIGNED (type);
1117 mode = promote_function_mode (type, TYPE_MODE (type), &unsignedp,
1118 fndecl ? TREE_TYPE (fndecl) : fntype, 0);
1120 args[i].unsignedp = unsignedp;
1121 args[i].mode = mode;
1123 args[i].reg = FUNCTION_ARG (*args_so_far, mode, type,
1124 argpos < n_named_args);
1125 #ifdef FUNCTION_INCOMING_ARG
1126 /* If this is a sibling call and the machine has register windows, the
1127 register window has to be unwinded before calling the routine, so
1128 arguments have to go into the incoming registers. */
1129 args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type,
1130 argpos < n_named_args);
1132 args[i].tail_call_reg = args[i].reg;
1137 = targetm.calls.arg_partial_bytes (args_so_far, mode, type,
1138 argpos < n_named_args);
1140 args[i].pass_on_stack = targetm.calls.must_pass_in_stack (mode, type);
1142 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1143 it means that we are to pass this arg in the register(s) designated
1144 by the PARALLEL, but also to pass it in the stack. */
1145 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1146 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1147 args[i].pass_on_stack = 1;
1149 /* If this is an addressable type, we must preallocate the stack
1150 since we must evaluate the object into its final location.
1152 If this is to be passed in both registers and the stack, it is simpler
1154 if (TREE_ADDRESSABLE (type)
1155 || (args[i].pass_on_stack && args[i].reg != 0))
1156 *must_preallocate = 1;
1158 /* Compute the stack-size of this argument. */
1159 if (args[i].reg == 0 || args[i].partial != 0
1160 || reg_parm_stack_space > 0
1161 || args[i].pass_on_stack)
1162 locate_and_pad_parm (mode, type,
1163 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1168 args[i].pass_on_stack ? 0 : args[i].partial,
1169 fndecl, args_size, &args[i].locate);
1170 #ifdef BLOCK_REG_PADDING
1172 /* The argument is passed entirely in registers. See at which
1173 end it should be padded. */
1174 args[i].locate.where_pad =
1175 BLOCK_REG_PADDING (mode, type,
1176 int_size_in_bytes (type) <= UNITS_PER_WORD);
1179 /* Update ARGS_SIZE, the total stack space for args so far. */
1181 args_size->constant += args[i].locate.size.constant;
1182 if (args[i].locate.size.var)
1183 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
1185 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1186 have been used, etc. */
1188 FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type,
1189 argpos < n_named_args);
1193 /* Update ARGS_SIZE to contain the total size for the argument block.
1194 Return the original constant component of the argument block's size.
1196 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1197 for arguments passed in registers. */
1200 compute_argument_block_size (int reg_parm_stack_space,
1201 struct args_size *args_size,
1202 tree fndecl ATTRIBUTE_UNUSED,
1203 tree fntype ATTRIBUTE_UNUSED,
1204 int preferred_stack_boundary ATTRIBUTE_UNUSED)
1206 int unadjusted_args_size = args_size->constant;
1208 /* For accumulate outgoing args mode we don't need to align, since the frame
1209 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1210 backends from generating misaligned frame sizes. */
1211 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1212 preferred_stack_boundary = STACK_BOUNDARY;
1214 /* Compute the actual size of the argument block required. The variable
1215 and constant sizes must be combined, the size may have to be rounded,
1216 and there may be a minimum required size. */
1220 args_size->var = ARGS_SIZE_TREE (*args_size);
1221 args_size->constant = 0;
1223 preferred_stack_boundary /= BITS_PER_UNIT;
1224 if (preferred_stack_boundary > 1)
1226 /* We don't handle this case yet. To handle it correctly we have
1227 to add the delta, round and subtract the delta.
1228 Currently no machine description requires this support. */
1229 gcc_assert (!(stack_pointer_delta & (preferred_stack_boundary - 1)));
1230 args_size->var = round_up (args_size->var, preferred_stack_boundary);
1233 if (reg_parm_stack_space > 0)
1236 = size_binop (MAX_EXPR, args_size->var,
1237 ssize_int (reg_parm_stack_space));
1239 /* The area corresponding to register parameters is not to count in
1240 the size of the block we need. So make the adjustment. */
1241 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
1243 = size_binop (MINUS_EXPR, args_size->var,
1244 ssize_int (reg_parm_stack_space));
1249 preferred_stack_boundary /= BITS_PER_UNIT;
1250 if (preferred_stack_boundary < 1)
1251 preferred_stack_boundary = 1;
1252 args_size->constant = (((args_size->constant
1253 + stack_pointer_delta
1254 + preferred_stack_boundary - 1)
1255 / preferred_stack_boundary
1256 * preferred_stack_boundary)
1257 - stack_pointer_delta);
1259 args_size->constant = MAX (args_size->constant,
1260 reg_parm_stack_space);
1262 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
1263 args_size->constant -= reg_parm_stack_space;
1265 return unadjusted_args_size;
1268 /* Precompute parameters as needed for a function call.
1270 FLAGS is mask of ECF_* constants.
1272 NUM_ACTUALS is the number of arguments.
1274 ARGS is an array containing information for each argument; this
1275 routine fills in the INITIAL_VALUE and VALUE fields for each
1276 precomputed argument. */
1279 precompute_arguments (int num_actuals, struct arg_data *args)
1283 /* If this is a libcall, then precompute all arguments so that we do not
1284 get extraneous instructions emitted as part of the libcall sequence. */
1286 /* If we preallocated the stack space, and some arguments must be passed
1287 on the stack, then we must precompute any parameter which contains a
1288 function call which will store arguments on the stack.
1289 Otherwise, evaluating the parameter may clobber previous parameters
1290 which have already been stored into the stack. (we have code to avoid
1291 such case by saving the outgoing stack arguments, but it results in
1293 if (!ACCUMULATE_OUTGOING_ARGS)
1296 for (i = 0; i < num_actuals; i++)
1299 enum machine_mode mode;
1301 if (TREE_CODE (args[i].tree_value) != CALL_EXPR)
1304 /* If this is an addressable type, we cannot pre-evaluate it. */
1305 type = TREE_TYPE (args[i].tree_value);
1306 gcc_assert (!TREE_ADDRESSABLE (type));
1308 args[i].initial_value = args[i].value
1309 = expand_normal (args[i].tree_value);
1311 mode = TYPE_MODE (type);
1312 if (mode != args[i].mode)
1314 int unsignedp = args[i].unsignedp;
1316 = convert_modes (args[i].mode, mode,
1317 args[i].value, args[i].unsignedp);
1319 /* CSE will replace this only if it contains args[i].value
1320 pseudo, so convert it down to the declared mode using
1322 if (REG_P (args[i].value)
1323 && GET_MODE_CLASS (args[i].mode) == MODE_INT
1324 && promote_mode (type, mode, &unsignedp) != args[i].mode)
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,
1336 /* Given the current state of MUST_PREALLOCATE and information about
1337 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1338 compute and return the final value for MUST_PREALLOCATE. */
1341 finalize_must_preallocate (int must_preallocate, int num_actuals,
1342 struct arg_data *args, struct args_size *args_size)
1344 /* See if we have or want to preallocate stack space.
1346 If we would have to push a partially-in-regs parm
1347 before other stack parms, preallocate stack space instead.
1349 If the size of some parm is not a multiple of the required stack
1350 alignment, we must preallocate.
1352 If the total size of arguments that would otherwise create a copy in
1353 a temporary (such as a CALL) is more than half the total argument list
1354 size, preallocation is faster.
1356 Another reason to preallocate is if we have a machine (like the m88k)
1357 where stack alignment is required to be maintained between every
1358 pair of insns, not just when the call is made. However, we assume here
1359 that such machines either do not have push insns (and hence preallocation
1360 would occur anyway) or the problem is taken care of with
1363 if (! must_preallocate)
1365 int partial_seen = 0;
1366 int copy_to_evaluate_size = 0;
1369 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1371 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1373 else if (partial_seen && args[i].reg == 0)
1374 must_preallocate = 1;
1376 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1377 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1378 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1379 || TREE_CODE (args[i].tree_value) == COND_EXPR
1380 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1381 copy_to_evaluate_size
1382 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1385 if (copy_to_evaluate_size * 2 >= args_size->constant
1386 && args_size->constant > 0)
1387 must_preallocate = 1;
1389 return must_preallocate;
1392 /* If we preallocated stack space, compute the address of each argument
1393 and store it into the ARGS array.
1395 We need not ensure it is a valid memory address here; it will be
1396 validized when it is used.
1398 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1401 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
1405 rtx arg_reg = argblock;
1406 int i, arg_offset = 0;
1408 if (GET_CODE (argblock) == PLUS)
1409 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1411 for (i = 0; i < num_actuals; i++)
1413 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
1414 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
1416 unsigned int align, boundary;
1417 unsigned int units_on_stack = 0;
1418 enum machine_mode partial_mode = VOIDmode;
1420 /* Skip this parm if it will not be passed on the stack. */
1421 if (! args[i].pass_on_stack
1423 && args[i].partial == 0)
1426 if (CONST_INT_P (offset))
1427 addr = plus_constant (arg_reg, INTVAL (offset));
1429 addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1431 addr = plus_constant (addr, arg_offset);
1433 if (args[i].partial != 0)
1435 /* Only part of the parameter is being passed on the stack.
1436 Generate a simple memory reference of the correct size. */
1437 units_on_stack = args[i].locate.size.constant;
1438 partial_mode = mode_for_size (units_on_stack * BITS_PER_UNIT,
1440 args[i].stack = gen_rtx_MEM (partial_mode, addr);
1441 set_mem_size (args[i].stack, GEN_INT (units_on_stack));
1445 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1446 set_mem_attributes (args[i].stack,
1447 TREE_TYPE (args[i].tree_value), 1);
1449 align = BITS_PER_UNIT;
1450 boundary = args[i].locate.boundary;
1451 if (args[i].locate.where_pad != downward)
1453 else if (CONST_INT_P (offset))
1455 align = INTVAL (offset) * BITS_PER_UNIT | boundary;
1456 align = align & -align;
1458 set_mem_align (args[i].stack, align);
1460 if (CONST_INT_P (slot_offset))
1461 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1463 addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1465 addr = plus_constant (addr, arg_offset);
1467 if (args[i].partial != 0)
1469 /* Only part of the parameter is being passed on the stack.
1470 Generate a simple memory reference of the correct size.
1472 args[i].stack_slot = gen_rtx_MEM (partial_mode, addr);
1473 set_mem_size (args[i].stack_slot, GEN_INT (units_on_stack));
1477 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1478 set_mem_attributes (args[i].stack_slot,
1479 TREE_TYPE (args[i].tree_value), 1);
1481 set_mem_align (args[i].stack_slot, args[i].locate.boundary);
1483 /* Function incoming arguments may overlap with sibling call
1484 outgoing arguments and we cannot allow reordering of reads
1485 from function arguments with stores to outgoing arguments
1486 of sibling calls. */
1487 set_mem_alias_set (args[i].stack, 0);
1488 set_mem_alias_set (args[i].stack_slot, 0);
1493 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1494 in a call instruction.
1496 FNDECL is the tree node for the target function. For an indirect call
1497 FNDECL will be NULL_TREE.
1499 ADDR is the operand 0 of CALL_EXPR for this call. */
1502 rtx_for_function_call (tree fndecl, tree addr)
1506 /* Get the function to call, in the form of RTL. */
1509 /* If this is the first use of the function, see if we need to
1510 make an external definition for it. */
1511 if (!TREE_USED (fndecl) && fndecl != current_function_decl)
1513 assemble_external (fndecl);
1514 TREE_USED (fndecl) = 1;
1517 /* Get a SYMBOL_REF rtx for the function address. */
1518 funexp = XEXP (DECL_RTL (fndecl), 0);
1521 /* Generate an rtx (probably a pseudo-register) for the address. */
1524 funexp = expand_normal (addr);
1525 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1530 /* Return true if and only if SIZE storage units (usually bytes)
1531 starting from address ADDR overlap with already clobbered argument
1532 area. This function is used to determine if we should give up a
1536 mem_overlaps_already_clobbered_arg_p (rtx addr, unsigned HOST_WIDE_INT size)
1540 if (addr == crtl->args.internal_arg_pointer)
1542 else if (GET_CODE (addr) == PLUS
1543 && XEXP (addr, 0) == crtl->args.internal_arg_pointer
1544 && CONST_INT_P (XEXP (addr, 1)))
1545 i = INTVAL (XEXP (addr, 1));
1546 /* Return true for arg pointer based indexed addressing. */
1547 else if (GET_CODE (addr) == PLUS
1548 && (XEXP (addr, 0) == crtl->args.internal_arg_pointer
1549 || XEXP (addr, 1) == crtl->args.internal_arg_pointer))
1554 #ifdef ARGS_GROW_DOWNWARD
1559 unsigned HOST_WIDE_INT k;
1561 for (k = 0; k < size; k++)
1562 if (i + k < stored_args_map->n_bits
1563 && TEST_BIT (stored_args_map, i + k))
1570 /* Do the register loads required for any wholly-register parms or any
1571 parms which are passed both on the stack and in a register. Their
1572 expressions were already evaluated.
1574 Mark all register-parms as living through the call, putting these USE
1575 insns in the CALL_INSN_FUNCTION_USAGE field.
1577 When IS_SIBCALL, perform the check_sibcall_argument_overlap
1578 checking, setting *SIBCALL_FAILURE if appropriate. */
1581 load_register_parameters (struct arg_data *args, int num_actuals,
1582 rtx *call_fusage, int flags, int is_sibcall,
1583 int *sibcall_failure)
1587 for (i = 0; i < num_actuals; i++)
1589 rtx reg = ((flags & ECF_SIBCALL)
1590 ? args[i].tail_call_reg : args[i].reg);
1593 int partial = args[i].partial;
1596 rtx before_arg = get_last_insn ();
1597 /* Set non-negative if we must move a word at a time, even if
1598 just one word (e.g, partial == 4 && mode == DFmode). Set
1599 to -1 if we just use a normal move insn. This value can be
1600 zero if the argument is a zero size structure. */
1602 if (GET_CODE (reg) == PARALLEL)
1606 gcc_assert (partial % UNITS_PER_WORD == 0);
1607 nregs = partial / UNITS_PER_WORD;
1609 else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode)
1611 size = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1612 nregs = (size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
1615 size = GET_MODE_SIZE (args[i].mode);
1617 /* Handle calls that pass values in multiple non-contiguous
1618 locations. The Irix 6 ABI has examples of this. */
1620 if (GET_CODE (reg) == PARALLEL)
1621 emit_group_move (reg, args[i].parallel_value);
1623 /* If simple case, just do move. If normal partial, store_one_arg
1624 has already loaded the register for us. In all other cases,
1625 load the register(s) from memory. */
1627 else if (nregs == -1)
1629 emit_move_insn (reg, args[i].value);
1630 #ifdef BLOCK_REG_PADDING
1631 /* Handle case where we have a value that needs shifting
1632 up to the msb. eg. a QImode value and we're padding
1633 upward on a BYTES_BIG_ENDIAN machine. */
1634 if (size < UNITS_PER_WORD
1635 && (args[i].locate.where_pad
1636 == (BYTES_BIG_ENDIAN ? upward : downward)))
1639 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1641 /* Assigning REG here rather than a temp makes CALL_FUSAGE
1642 report the whole reg as used. Strictly speaking, the
1643 call only uses SIZE bytes at the msb end, but it doesn't
1644 seem worth generating rtl to say that. */
1645 reg = gen_rtx_REG (word_mode, REGNO (reg));
1646 x = expand_shift (LSHIFT_EXPR, word_mode, reg,
1647 build_int_cst (NULL_TREE, shift),
1650 emit_move_insn (reg, x);
1655 /* If we have pre-computed the values to put in the registers in
1656 the case of non-aligned structures, copy them in now. */
1658 else if (args[i].n_aligned_regs != 0)
1659 for (j = 0; j < args[i].n_aligned_regs; j++)
1660 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1661 args[i].aligned_regs[j]);
1663 else if (partial == 0 || args[i].pass_on_stack)
1665 rtx mem = validize_mem (args[i].value);
1667 /* Check for overlap with already clobbered argument area. */
1669 && mem_overlaps_already_clobbered_arg_p (XEXP (args[i].value, 0),
1671 *sibcall_failure = 1;
1673 /* Handle a BLKmode that needs shifting. */
1674 if (nregs == 1 && size < UNITS_PER_WORD
1675 #ifdef BLOCK_REG_PADDING
1676 && args[i].locate.where_pad == downward
1682 rtx tem = operand_subword_force (mem, 0, args[i].mode);
1683 rtx ri = gen_rtx_REG (word_mode, REGNO (reg));
1684 rtx x = gen_reg_rtx (word_mode);
1685 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1686 enum tree_code dir = BYTES_BIG_ENDIAN ? RSHIFT_EXPR
1689 emit_move_insn (x, tem);
1690 x = expand_shift (dir, word_mode, x,
1691 build_int_cst (NULL_TREE, shift),
1694 emit_move_insn (ri, x);
1697 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
1700 /* When a parameter is a block, and perhaps in other cases, it is
1701 possible that it did a load from an argument slot that was
1702 already clobbered. */
1704 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
1705 *sibcall_failure = 1;
1707 /* Handle calls that pass values in multiple non-contiguous
1708 locations. The Irix 6 ABI has examples of this. */
1709 if (GET_CODE (reg) == PARALLEL)
1710 use_group_regs (call_fusage, reg);
1711 else if (nregs == -1)
1712 use_reg (call_fusage, reg);
1714 use_regs (call_fusage, REGNO (reg), nregs);
1719 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1720 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1721 bytes, then we would need to push some additional bytes to pad the
1722 arguments. So, we compute an adjust to the stack pointer for an
1723 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1724 bytes. Then, when the arguments are pushed the stack will be perfectly
1725 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
1726 be popped after the call. Returns the adjustment. */
1729 combine_pending_stack_adjustment_and_call (int unadjusted_args_size,
1730 struct args_size *args_size,
1731 unsigned int preferred_unit_stack_boundary)
1733 /* The number of bytes to pop so that the stack will be
1734 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
1735 HOST_WIDE_INT adjustment;
1736 /* The alignment of the stack after the arguments are pushed, if we
1737 just pushed the arguments without adjust the stack here. */
1738 unsigned HOST_WIDE_INT unadjusted_alignment;
1740 unadjusted_alignment
1741 = ((stack_pointer_delta + unadjusted_args_size)
1742 % preferred_unit_stack_boundary);
1744 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1745 as possible -- leaving just enough left to cancel out the
1746 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
1747 PENDING_STACK_ADJUST is non-negative, and congruent to
1748 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
1750 /* Begin by trying to pop all the bytes. */
1751 unadjusted_alignment
1752 = (unadjusted_alignment
1753 - (pending_stack_adjust % preferred_unit_stack_boundary));
1754 adjustment = pending_stack_adjust;
1755 /* Push enough additional bytes that the stack will be aligned
1756 after the arguments are pushed. */
1757 if (preferred_unit_stack_boundary > 1)
1759 if (unadjusted_alignment > 0)
1760 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
1762 adjustment += unadjusted_alignment;
1765 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1766 bytes after the call. The right number is the entire
1767 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1768 by the arguments in the first place. */
1770 = pending_stack_adjust - adjustment + unadjusted_args_size;
1775 /* Scan X expression if it does not dereference any argument slots
1776 we already clobbered by tail call arguments (as noted in stored_args_map
1778 Return nonzero if X expression dereferences such argument slots,
1782 check_sibcall_argument_overlap_1 (rtx x)
1791 code = GET_CODE (x);
1794 return mem_overlaps_already_clobbered_arg_p (XEXP (x, 0),
1795 GET_MODE_SIZE (GET_MODE (x)));
1797 /* Scan all subexpressions. */
1798 fmt = GET_RTX_FORMAT (code);
1799 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
1803 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
1806 else if (*fmt == 'E')
1808 for (j = 0; j < XVECLEN (x, i); j++)
1809 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
1816 /* Scan sequence after INSN if it does not dereference any argument slots
1817 we already clobbered by tail call arguments (as noted in stored_args_map
1818 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
1819 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
1820 should be 0). Return nonzero if sequence after INSN dereferences such argument
1821 slots, zero otherwise. */
1824 check_sibcall_argument_overlap (rtx insn, struct arg_data *arg, int mark_stored_args_map)
1828 if (insn == NULL_RTX)
1829 insn = get_insns ();
1831 insn = NEXT_INSN (insn);
1833 for (; insn; insn = NEXT_INSN (insn))
1835 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
1838 if (mark_stored_args_map)
1840 #ifdef ARGS_GROW_DOWNWARD
1841 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
1843 low = arg->locate.slot_offset.constant;
1846 for (high = low + arg->locate.size.constant; low < high; low++)
1847 SET_BIT (stored_args_map, low);
1849 return insn != NULL_RTX;
1852 /* Given that a function returns a value of mode MODE at the most
1853 significant end of hard register VALUE, shift VALUE left or right
1854 as specified by LEFT_P. Return true if some action was needed. */
1857 shift_return_value (enum machine_mode mode, bool left_p, rtx value)
1859 HOST_WIDE_INT shift;
1861 gcc_assert (REG_P (value) && HARD_REGISTER_P (value));
1862 shift = GET_MODE_BITSIZE (GET_MODE (value)) - GET_MODE_BITSIZE (mode);
1866 /* Use ashr rather than lshr for right shifts. This is for the benefit
1867 of the MIPS port, which requires SImode values to be sign-extended
1868 when stored in 64-bit registers. */
1869 if (!force_expand_binop (GET_MODE (value), left_p ? ashl_optab : ashr_optab,
1870 value, GEN_INT (shift), value, 1, OPTAB_WIDEN))
1875 /* If X is a likely-spilled register value, copy it to a pseudo
1876 register and return that register. Return X otherwise. */
1879 avoid_likely_spilled_reg (rtx x)
1884 && HARD_REGISTER_P (x)
1885 && CLASS_LIKELY_SPILLED_P (REGNO_REG_CLASS (REGNO (x))))
1887 /* Make sure that we generate a REG rather than a CONCAT.
1888 Moves into CONCATs can need nontrivial instructions,
1889 and the whole point of this function is to avoid
1890 using the hard register directly in such a situation. */
1891 generating_concat_p = 0;
1892 new_rtx = gen_reg_rtx (GET_MODE (x));
1893 generating_concat_p = 1;
1894 emit_move_insn (new_rtx, x);
1900 /* Generate all the code for a CALL_EXPR exp
1901 and return an rtx for its value.
1902 Store the value in TARGET (specified as an rtx) if convenient.
1903 If the value is stored in TARGET then TARGET is returned.
1904 If IGNORE is nonzero, then we ignore the value of the function call. */
1907 expand_call (tree exp, rtx target, int ignore)
1909 /* Nonzero if we are currently expanding a call. */
1910 static int currently_expanding_call = 0;
1912 /* RTX for the function to be called. */
1914 /* Sequence of insns to perform a normal "call". */
1915 rtx normal_call_insns = NULL_RTX;
1916 /* Sequence of insns to perform a tail "call". */
1917 rtx tail_call_insns = NULL_RTX;
1918 /* Data type of the function. */
1920 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 addr = CALL_EXPR_FN (exp);
2019 /* The alignment of the stack, in bits. */
2020 unsigned HOST_WIDE_INT preferred_stack_boundary;
2021 /* The alignment of the stack, in bytes. */
2022 unsigned HOST_WIDE_INT preferred_unit_stack_boundary;
2023 /* The static chain value to use for this call. */
2024 rtx static_chain_value;
2025 /* See if this is "nothrow" function call. */
2026 if (TREE_NOTHROW (exp))
2027 flags |= ECF_NOTHROW;
2029 /* See if we can find a DECL-node for the actual function, and get the
2030 function attributes (flags) from the function decl or type node. */
2031 fndecl = get_callee_fndecl (exp);
2034 fntype = TREE_TYPE (fndecl);
2035 flags |= flags_from_decl_or_type (fndecl);
2039 fntype = TREE_TYPE (TREE_TYPE (addr));
2040 flags |= flags_from_decl_or_type (fntype);
2042 rettype = TREE_TYPE (exp);
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 (rettype))
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 (rettype) == 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 ? fntype : fndecl);
2083 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : 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 ? fntype : 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 (rettype);
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 (rettype, 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, fntype,
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 || dbg_cnt (tail_call) == false)
2284 /* Rest of purposes for tail call optimizations to fail. */
2286 #ifdef HAVE_sibcall_epilogue
2287 !HAVE_sibcall_epilogue
2292 /* Doing sibling call optimization needs some work, since
2293 structure_value_addr can be allocated on the stack.
2294 It does not seem worth the effort since few optimizable
2295 sibling calls will return a structure. */
2296 || structure_value_addr != NULL_RTX
2297 #ifdef REG_PARM_STACK_SPACE
2298 /* If outgoing reg parm stack space changes, we can not do sibcall. */
2299 || (OUTGOING_REG_PARM_STACK_SPACE (funtype)
2300 != OUTGOING_REG_PARM_STACK_SPACE (TREE_TYPE (current_function_decl)))
2301 || (reg_parm_stack_space != REG_PARM_STACK_SPACE (fndecl))
2303 /* Check whether the target is able to optimize the call
2305 || !targetm.function_ok_for_sibcall (fndecl, exp)
2306 /* Functions that do not return exactly once may not be sibcall
2308 || (flags & (ECF_RETURNS_TWICE | ECF_NORETURN))
2309 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr)))
2310 /* If the called function is nested in the current one, it might access
2311 some of the caller's arguments, but could clobber them beforehand if
2312 the argument areas are shared. */
2313 || (fndecl && decl_function_context (fndecl) == current_function_decl)
2314 /* If this function requires more stack slots than the current
2315 function, we cannot change it into a sibling call.
2316 crtl->args.pretend_args_size is not part of the
2317 stack allocated by our caller. */
2318 || args_size.constant > (crtl->args.size
2319 - crtl->args.pretend_args_size)
2320 /* If the callee pops its own arguments, then it must pop exactly
2321 the same number of arguments as the current function. */
2322 || (RETURN_POPS_ARGS (fndecl, funtype, args_size.constant)
2323 != RETURN_POPS_ARGS (current_function_decl,
2324 TREE_TYPE (current_function_decl),
2326 || !lang_hooks.decls.ok_for_sibcall (fndecl))
2329 /* Check if caller and callee disagree in promotion of function
2333 enum machine_mode caller_mode, caller_promoted_mode;
2334 enum machine_mode callee_mode, callee_promoted_mode;
2335 int caller_unsignedp, callee_unsignedp;
2336 tree caller_res = DECL_RESULT (current_function_decl);
2338 caller_unsignedp = TYPE_UNSIGNED (TREE_TYPE (caller_res));
2339 caller_mode = DECL_MODE (caller_res);
2340 callee_unsignedp = TYPE_UNSIGNED (TREE_TYPE (funtype));
2341 callee_mode = TYPE_MODE (TREE_TYPE (funtype));
2342 caller_promoted_mode
2343 = promote_function_mode (TREE_TYPE (caller_res), caller_mode,
2345 TREE_TYPE (current_function_decl), 1);
2346 callee_promoted_mode
2347 = promote_function_mode (TREE_TYPE (funtype), callee_mode,
2350 if (caller_mode != VOIDmode
2351 && (caller_promoted_mode != callee_promoted_mode
2352 || ((caller_mode != caller_promoted_mode
2353 || callee_mode != callee_promoted_mode)
2354 && (caller_unsignedp != callee_unsignedp
2355 || GET_MODE_BITSIZE (caller_mode)
2356 < GET_MODE_BITSIZE (callee_mode)))))
2360 /* Ensure current function's preferred stack boundary is at least
2361 what we need. Stack alignment may also increase preferred stack
2363 if (crtl->preferred_stack_boundary < preferred_stack_boundary)
2364 crtl->preferred_stack_boundary = preferred_stack_boundary;
2366 preferred_stack_boundary = crtl->preferred_stack_boundary;
2368 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2370 /* We want to make two insn chains; one for a sibling call, the other
2371 for a normal call. We will select one of the two chains after
2372 initial RTL generation is complete. */
2373 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
2375 int sibcall_failure = 0;
2376 /* We want to emit any pending stack adjustments before the tail
2377 recursion "call". That way we know any adjustment after the tail
2378 recursion call can be ignored if we indeed use the tail
2380 int save_pending_stack_adjust = 0;
2381 int save_stack_pointer_delta = 0;
2383 rtx before_call, next_arg_reg, after_args;
2387 /* State variables we need to save and restore between
2389 save_pending_stack_adjust = pending_stack_adjust;
2390 save_stack_pointer_delta = stack_pointer_delta;
2393 flags &= ~ECF_SIBCALL;
2395 flags |= ECF_SIBCALL;
2397 /* Other state variables that we must reinitialize each time
2398 through the loop (that are not initialized by the loop itself). */
2402 /* Start a new sequence for the normal call case.
2404 From this point on, if the sibling call fails, we want to set
2405 sibcall_failure instead of continuing the loop. */
2408 /* Don't let pending stack adjusts add up to too much.
2409 Also, do all pending adjustments now if there is any chance
2410 this might be a call to alloca or if we are expanding a sibling
2412 Also do the adjustments before a throwing call, otherwise
2413 exception handling can fail; PR 19225. */
2414 if (pending_stack_adjust >= 32
2415 || (pending_stack_adjust > 0
2416 && (flags & ECF_MAY_BE_ALLOCA))
2417 || (pending_stack_adjust > 0
2418 && flag_exceptions && !(flags & ECF_NOTHROW))
2420 do_pending_stack_adjust ();
2422 /* Precompute any arguments as needed. */
2424 precompute_arguments (num_actuals, args);
2426 /* Now we are about to start emitting insns that can be deleted
2427 if a libcall is deleted. */
2428 if (pass && (flags & ECF_MALLOC))
2431 if (pass == 0 && crtl->stack_protect_guard)
2432 stack_protect_epilogue ();
2434 adjusted_args_size = args_size;
2435 /* Compute the actual size of the argument block required. The variable
2436 and constant sizes must be combined, the size may have to be rounded,
2437 and there may be a minimum required size. When generating a sibcall
2438 pattern, do not round up, since we'll be re-using whatever space our
2440 unadjusted_args_size
2441 = compute_argument_block_size (reg_parm_stack_space,
2442 &adjusted_args_size,
2445 : preferred_stack_boundary));
2447 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2449 /* The argument block when performing a sibling call is the
2450 incoming argument block. */
2453 argblock = crtl->args.internal_arg_pointer;
2455 #ifdef STACK_GROWS_DOWNWARD
2456 = plus_constant (argblock, crtl->args.pretend_args_size);
2458 = plus_constant (argblock, -crtl->args.pretend_args_size);
2460 stored_args_map = sbitmap_alloc (args_size.constant);
2461 sbitmap_zero (stored_args_map);
2464 /* If we have no actual push instructions, or shouldn't use them,
2465 make space for all args right now. */
2466 else if (adjusted_args_size.var != 0)
2468 if (old_stack_level == 0)
2470 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2471 old_stack_pointer_delta = stack_pointer_delta;
2472 old_pending_adj = pending_stack_adjust;
2473 pending_stack_adjust = 0;
2474 /* stack_arg_under_construction says whether a stack arg is
2475 being constructed at the old stack level. Pushing the stack
2476 gets a clean outgoing argument block. */
2477 old_stack_arg_under_construction = stack_arg_under_construction;
2478 stack_arg_under_construction = 0;
2480 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2484 /* Note that we must go through the motions of allocating an argument
2485 block even if the size is zero because we may be storing args
2486 in the area reserved for register arguments, which may be part of
2489 int needed = adjusted_args_size.constant;
2491 /* Store the maximum argument space used. It will be pushed by
2492 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2495 if (needed > crtl->outgoing_args_size)
2496 crtl->outgoing_args_size = needed;
2498 if (must_preallocate)
2500 if (ACCUMULATE_OUTGOING_ARGS)
2502 /* Since the stack pointer will never be pushed, it is
2503 possible for the evaluation of a parm to clobber
2504 something we have already written to the stack.
2505 Since most function calls on RISC machines do not use
2506 the stack, this is uncommon, but must work correctly.
2508 Therefore, we save any area of the stack that was already
2509 written and that we are using. Here we set up to do this
2510 by making a new stack usage map from the old one. The
2511 actual save will be done by store_one_arg.
2513 Another approach might be to try to reorder the argument
2514 evaluations to avoid this conflicting stack usage. */
2516 /* Since we will be writing into the entire argument area,
2517 the map must be allocated for its entire size, not just
2518 the part that is the responsibility of the caller. */
2519 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
2520 needed += reg_parm_stack_space;
2522 #ifdef ARGS_GROW_DOWNWARD
2523 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2526 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2529 if (stack_usage_map_buf)
2530 free (stack_usage_map_buf);
2531 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
2532 stack_usage_map = stack_usage_map_buf;
2534 if (initial_highest_arg_in_use)
2535 memcpy (stack_usage_map, initial_stack_usage_map,
2536 initial_highest_arg_in_use);
2538 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2539 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2540 (highest_outgoing_arg_in_use
2541 - initial_highest_arg_in_use));
2544 /* The address of the outgoing argument list must not be
2545 copied to a register here, because argblock would be left
2546 pointing to the wrong place after the call to
2547 allocate_dynamic_stack_space below. */
2549 argblock = virtual_outgoing_args_rtx;
2553 if (inhibit_defer_pop == 0)
2555 /* Try to reuse some or all of the pending_stack_adjust
2556 to get this space. */
2558 = (combine_pending_stack_adjustment_and_call
2559 (unadjusted_args_size,
2560 &adjusted_args_size,
2561 preferred_unit_stack_boundary));
2563 /* combine_pending_stack_adjustment_and_call computes
2564 an adjustment before the arguments are allocated.
2565 Account for them and see whether or not the stack
2566 needs to go up or down. */
2567 needed = unadjusted_args_size - needed;
2571 /* We're releasing stack space. */
2572 /* ??? We can avoid any adjustment at all if we're
2573 already aligned. FIXME. */
2574 pending_stack_adjust = -needed;
2575 do_pending_stack_adjust ();
2579 /* We need to allocate space. We'll do that in
2580 push_block below. */
2581 pending_stack_adjust = 0;
2584 /* Special case this because overhead of `push_block' in
2585 this case is non-trivial. */
2587 argblock = virtual_outgoing_args_rtx;
2590 argblock = push_block (GEN_INT (needed), 0, 0);
2591 #ifdef ARGS_GROW_DOWNWARD
2592 argblock = plus_constant (argblock, needed);
2596 /* We only really need to call `copy_to_reg' in the case
2597 where push insns are going to be used to pass ARGBLOCK
2598 to a function call in ARGS. In that case, the stack
2599 pointer changes value from the allocation point to the
2600 call point, and hence the value of
2601 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2602 as well always do it. */
2603 argblock = copy_to_reg (argblock);
2608 if (ACCUMULATE_OUTGOING_ARGS)
2610 /* The save/restore code in store_one_arg handles all
2611 cases except one: a constructor call (including a C
2612 function returning a BLKmode struct) to initialize
2614 if (stack_arg_under_construction)
2617 = GEN_INT (adjusted_args_size.constant
2618 + (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype
2619 : TREE_TYPE (fndecl))) ? 0
2620 : reg_parm_stack_space));
2621 if (old_stack_level == 0)
2623 emit_stack_save (SAVE_BLOCK, &old_stack_level,
2625 old_stack_pointer_delta = stack_pointer_delta;
2626 old_pending_adj = pending_stack_adjust;
2627 pending_stack_adjust = 0;
2628 /* stack_arg_under_construction says whether a stack
2629 arg is being constructed at the old stack level.
2630 Pushing the stack gets a clean outgoing argument
2632 old_stack_arg_under_construction
2633 = stack_arg_under_construction;
2634 stack_arg_under_construction = 0;
2635 /* Make a new map for the new argument list. */
2636 if (stack_usage_map_buf)
2637 free (stack_usage_map_buf);
2638 stack_usage_map_buf = XCNEWVEC (char, highest_outgoing_arg_in_use);
2639 stack_usage_map = stack_usage_map_buf;
2640 highest_outgoing_arg_in_use = 0;
2642 allocate_dynamic_stack_space (push_size, NULL_RTX,
2646 /* If argument evaluation might modify the stack pointer,
2647 copy the address of the argument list to a register. */
2648 for (i = 0; i < num_actuals; i++)
2649 if (args[i].pass_on_stack)
2651 argblock = copy_addr_to_reg (argblock);
2656 compute_argument_addresses (args, argblock, num_actuals);
2658 /* If we push args individually in reverse order, perform stack alignment
2659 before the first push (the last arg). */
2660 if (PUSH_ARGS_REVERSED && argblock == 0
2661 && adjusted_args_size.constant != unadjusted_args_size)
2663 /* When the stack adjustment is pending, we get better code
2664 by combining the adjustments. */
2665 if (pending_stack_adjust
2666 && ! inhibit_defer_pop)
2668 pending_stack_adjust
2669 = (combine_pending_stack_adjustment_and_call
2670 (unadjusted_args_size,
2671 &adjusted_args_size,
2672 preferred_unit_stack_boundary));
2673 do_pending_stack_adjust ();
2675 else if (argblock == 0)
2676 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2677 - unadjusted_args_size));
2679 /* Now that the stack is properly aligned, pops can't safely
2680 be deferred during the evaluation of the arguments. */
2683 funexp = rtx_for_function_call (fndecl, addr);
2685 /* Figure out the register where the value, if any, will come back. */
2687 if (TYPE_MODE (rettype) != VOIDmode
2688 && ! structure_value_addr)
2690 if (pcc_struct_value)
2691 valreg = hard_function_value (build_pointer_type (rettype),
2692 fndecl, NULL, (pass == 0));
2694 valreg = hard_function_value (rettype, fndecl, fntype,
2697 /* If VALREG is a PARALLEL whose first member has a zero
2698 offset, use that. This is for targets such as m68k that
2699 return the same value in multiple places. */
2700 if (GET_CODE (valreg) == PARALLEL)
2702 rtx elem = XVECEXP (valreg, 0, 0);
2703 rtx where = XEXP (elem, 0);
2704 rtx offset = XEXP (elem, 1);
2705 if (offset == const0_rtx
2706 && GET_MODE (where) == GET_MODE (valreg))
2711 /* Precompute all register parameters. It isn't safe to compute anything
2712 once we have started filling any specific hard regs. */
2713 precompute_register_parameters (num_actuals, args, ®_parm_seen);
2715 if (CALL_EXPR_STATIC_CHAIN (exp))
2716 static_chain_value = expand_normal (CALL_EXPR_STATIC_CHAIN (exp));
2718 static_chain_value = 0;
2720 #ifdef REG_PARM_STACK_SPACE
2721 /* Save the fixed argument area if it's part of the caller's frame and
2722 is clobbered by argument setup for this call. */
2723 if (ACCUMULATE_OUTGOING_ARGS && pass)
2724 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
2725 &low_to_save, &high_to_save);
2728 /* Now store (and compute if necessary) all non-register parms.
2729 These come before register parms, since they can require block-moves,
2730 which could clobber the registers used for register parms.
2731 Parms which have partial registers are not stored here,
2732 but we do preallocate space here if they want that. */
2734 for (i = 0; i < num_actuals; i++)
2736 if (args[i].reg == 0 || args[i].pass_on_stack)
2738 rtx before_arg = get_last_insn ();
2740 if (store_one_arg (&args[i], argblock, flags,
2741 adjusted_args_size.var != 0,
2742 reg_parm_stack_space)
2744 && check_sibcall_argument_overlap (before_arg,
2746 sibcall_failure = 1;
2749 if (((flags & ECF_CONST)
2750 || ((flags & ECF_PURE) && ACCUMULATE_OUTGOING_ARGS))
2752 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
2753 gen_rtx_USE (VOIDmode,
2758 /* If we have a parm that is passed in registers but not in memory
2759 and whose alignment does not permit a direct copy into registers,
2760 make a group of pseudos that correspond to each register that we
2762 if (STRICT_ALIGNMENT)
2763 store_unaligned_arguments_into_pseudos (args, num_actuals);
2765 /* Now store any partially-in-registers parm.
2766 This is the last place a block-move can happen. */
2768 for (i = 0; i < num_actuals; i++)
2769 if (args[i].partial != 0 && ! args[i].pass_on_stack)
2771 rtx before_arg = get_last_insn ();
2773 if (store_one_arg (&args[i], argblock, flags,
2774 adjusted_args_size.var != 0,
2775 reg_parm_stack_space)
2777 && check_sibcall_argument_overlap (before_arg,
2779 sibcall_failure = 1;
2782 /* If we pushed args in forward order, perform stack alignment
2783 after pushing the last arg. */
2784 if (!PUSH_ARGS_REVERSED && argblock == 0)
2785 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2786 - unadjusted_args_size));
2788 /* If register arguments require space on the stack and stack space
2789 was not preallocated, allocate stack space here for arguments
2790 passed in registers. */
2791 if (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
2792 && !ACCUMULATE_OUTGOING_ARGS
2793 && must_preallocate == 0 && reg_parm_stack_space > 0)
2794 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
2796 /* Pass the function the address in which to return a
2798 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
2800 structure_value_addr
2801 = convert_memory_address (Pmode, structure_value_addr);
2802 emit_move_insn (struct_value,
2804 force_operand (structure_value_addr,
2807 if (REG_P (struct_value))
2808 use_reg (&call_fusage, struct_value);
2811 after_args = get_last_insn ();
2812 funexp = prepare_call_address (funexp, static_chain_value,
2813 &call_fusage, reg_parm_seen, pass == 0);
2815 load_register_parameters (args, num_actuals, &call_fusage, flags,
2816 pass == 0, &sibcall_failure);
2818 /* Save a pointer to the last insn before the call, so that we can
2819 later safely search backwards to find the CALL_INSN. */
2820 before_call = get_last_insn ();
2822 /* Set up next argument register. For sibling calls on machines
2823 with register windows this should be the incoming register. */
2824 #ifdef FUNCTION_INCOMING_ARG
2826 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
2830 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
2833 /* All arguments and registers used for the call must be set up by
2836 /* Stack must be properly aligned now. */
2838 || !(stack_pointer_delta % preferred_unit_stack_boundary));
2840 /* Generate the actual call instruction. */
2841 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size,
2842 adjusted_args_size.constant, struct_value_size,
2843 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
2844 flags, & args_so_far);
2846 /* If the call setup or the call itself overlaps with anything
2847 of the argument setup we probably clobbered our call address.
2848 In that case we can't do sibcalls. */
2850 && check_sibcall_argument_overlap (after_args, 0, 0))
2851 sibcall_failure = 1;
2853 /* If a non-BLKmode value is returned at the most significant end
2854 of a register, shift the register right by the appropriate amount
2855 and update VALREG accordingly. BLKmode values are handled by the
2856 group load/store machinery below. */
2857 if (!structure_value_addr
2858 && !pcc_struct_value
2859 && TYPE_MODE (rettype) != BLKmode
2860 && targetm.calls.return_in_msb (rettype))
2862 if (shift_return_value (TYPE_MODE (rettype), false, valreg))
2863 sibcall_failure = 1;
2864 valreg = gen_rtx_REG (TYPE_MODE (rettype), REGNO (valreg));
2867 if (pass && (flags & ECF_MALLOC))
2869 rtx temp = gen_reg_rtx (GET_MODE (valreg));
2872 /* The return value from a malloc-like function is a pointer. */
2873 if (TREE_CODE (rettype) == POINTER_TYPE)
2874 mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
2876 emit_move_insn (temp, valreg);
2878 /* The return value from a malloc-like function can not alias
2880 last = get_last_insn ();
2881 add_reg_note (last, REG_NOALIAS, temp);
2883 /* Write out the sequence. */
2884 insns = get_insns ();
2890 /* For calls to `setjmp', etc., inform
2891 function.c:setjmp_warnings that it should complain if
2892 nonvolatile values are live. For functions that cannot
2893 return, inform flow that control does not fall through. */
2895 if ((flags & ECF_NORETURN) || pass == 0)
2897 /* The barrier must be emitted
2898 immediately after the CALL_INSN. Some ports emit more
2899 than just a CALL_INSN above, so we must search for it here. */
2901 rtx last = get_last_insn ();
2902 while (!CALL_P (last))
2904 last = PREV_INSN (last);
2905 /* There was no CALL_INSN? */
2906 gcc_assert (last != before_call);
2909 emit_barrier_after (last);
2911 /* Stack adjustments after a noreturn call are dead code.
2912 However when NO_DEFER_POP is in effect, we must preserve
2913 stack_pointer_delta. */
2914 if (inhibit_defer_pop == 0)
2916 stack_pointer_delta = old_stack_allocated;
2917 pending_stack_adjust = 0;
2921 /* If value type not void, return an rtx for the value. */
2923 if (TYPE_MODE (rettype) == VOIDmode
2925 target = const0_rtx;
2926 else if (structure_value_addr)
2928 if (target == 0 || !MEM_P (target))
2931 = gen_rtx_MEM (TYPE_MODE (rettype),
2932 memory_address (TYPE_MODE (rettype),
2933 structure_value_addr));
2934 set_mem_attributes (target, rettype, 1);
2937 else if (pcc_struct_value)
2939 /* This is the special C++ case where we need to
2940 know what the true target was. We take care to
2941 never use this value more than once in one expression. */
2942 target = gen_rtx_MEM (TYPE_MODE (rettype),
2943 copy_to_reg (valreg));
2944 set_mem_attributes (target, rettype, 1);
2946 /* Handle calls that return values in multiple non-contiguous locations.
2947 The Irix 6 ABI has examples of this. */
2948 else if (GET_CODE (valreg) == PARALLEL)
2952 /* This will only be assigned once, so it can be readonly. */
2953 tree nt = build_qualified_type (rettype,
2954 (TYPE_QUALS (rettype)
2955 | TYPE_QUAL_CONST));
2957 target = assign_temp (nt, 0, 1, 1);
2960 if (! rtx_equal_p (target, valreg))
2961 emit_group_store (target, valreg, rettype,
2962 int_size_in_bytes (rettype));
2964 /* We can not support sibling calls for this case. */
2965 sibcall_failure = 1;
2968 && GET_MODE (target) == TYPE_MODE (rettype)
2969 && GET_MODE (target) == GET_MODE (valreg))
2971 bool may_overlap = false;
2973 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
2974 reg to a plain register. */
2975 if (!REG_P (target) || HARD_REGISTER_P (target))
2976 valreg = avoid_likely_spilled_reg (valreg);
2978 /* If TARGET is a MEM in the argument area, and we have
2979 saved part of the argument area, then we can't store
2980 directly into TARGET as it may get overwritten when we
2981 restore the argument save area below. Don't work too
2982 hard though and simply force TARGET to a register if it
2983 is a MEM; the optimizer is quite likely to sort it out. */
2984 if (ACCUMULATE_OUTGOING_ARGS && pass && MEM_P (target))
2985 for (i = 0; i < num_actuals; i++)
2986 if (args[i].save_area)
2993 target = copy_to_reg (valreg);
2996 /* TARGET and VALREG cannot be equal at this point
2997 because the latter would not have
2998 REG_FUNCTION_VALUE_P true, while the former would if
2999 it were referring to the same register.
3001 If they refer to the same register, this move will be
3002 a no-op, except when function inlining is being
3004 emit_move_insn (target, valreg);
3006 /* If we are setting a MEM, this code must be executed.
3007 Since it is emitted after the call insn, sibcall
3008 optimization cannot be performed in that case. */
3010 sibcall_failure = 1;
3013 else if (TYPE_MODE (rettype) == BLKmode)
3015 target = copy_blkmode_from_reg (target, valreg, rettype);
3017 /* We can not support sibling calls for this case. */
3018 sibcall_failure = 1;
3021 target = copy_to_reg (avoid_likely_spilled_reg (valreg));
3023 /* If we promoted this return value, make the proper SUBREG.
3024 TARGET might be const0_rtx here, so be careful. */
3026 && TYPE_MODE (rettype) != BLKmode
3027 && GET_MODE (target) != TYPE_MODE (rettype))
3029 tree type = rettype;
3030 int unsignedp = TYPE_UNSIGNED (type);
3032 enum machine_mode pmode;
3034 /* Ensure we promote as expected, and get the new unsignedness. */
3035 pmode = promote_function_mode (type, TYPE_MODE (type), &unsignedp,
3037 gcc_assert (GET_MODE (target) == pmode);
3039 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
3040 && (GET_MODE_SIZE (GET_MODE (target))
3041 > GET_MODE_SIZE (TYPE_MODE (type))))
3043 offset = GET_MODE_SIZE (GET_MODE (target))
3044 - GET_MODE_SIZE (TYPE_MODE (type));
3045 if (! BYTES_BIG_ENDIAN)
3046 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
3047 else if (! WORDS_BIG_ENDIAN)
3048 offset %= UNITS_PER_WORD;
3051 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
3052 SUBREG_PROMOTED_VAR_P (target) = 1;
3053 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
3056 /* If size of args is variable or this was a constructor call for a stack
3057 argument, restore saved stack-pointer value. */
3059 if (old_stack_level)
3061 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
3062 stack_pointer_delta = old_stack_pointer_delta;
3063 pending_stack_adjust = old_pending_adj;
3064 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
3065 stack_arg_under_construction = old_stack_arg_under_construction;
3066 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3067 stack_usage_map = initial_stack_usage_map;
3068 sibcall_failure = 1;
3070 else if (ACCUMULATE_OUTGOING_ARGS && pass)
3072 #ifdef REG_PARM_STACK_SPACE
3074 restore_fixed_argument_area (save_area, argblock,
3075 high_to_save, low_to_save);
3078 /* If we saved any argument areas, restore them. */
3079 for (i = 0; i < num_actuals; i++)
3080 if (args[i].save_area)
3082 enum machine_mode save_mode = GET_MODE (args[i].save_area);
3084 = gen_rtx_MEM (save_mode,
3085 memory_address (save_mode,
3086 XEXP (args[i].stack_slot, 0)));
3088 if (save_mode != BLKmode)
3089 emit_move_insn (stack_area, args[i].save_area);
3091 emit_block_move (stack_area, args[i].save_area,
3092 GEN_INT (args[i].locate.size.constant),
3093 BLOCK_OP_CALL_PARM);
3096 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3097 stack_usage_map = initial_stack_usage_map;
3100 /* If this was alloca, record the new stack level for nonlocal gotos.
3101 Check for the handler slots since we might not have a save area
3102 for non-local gotos. */
3104 if ((flags & ECF_MAY_BE_ALLOCA) && cfun->nonlocal_goto_save_area != 0)
3105 update_nonlocal_goto_save_area ();
3107 /* Free up storage we no longer need. */
3108 for (i = 0; i < num_actuals; ++i)
3109 if (args[i].aligned_regs)
3110 free (args[i].aligned_regs);
3112 insns = get_insns ();
3117 tail_call_insns = insns;
3119 /* Restore the pending stack adjustment now that we have
3120 finished generating the sibling call sequence. */
3122 pending_stack_adjust = save_pending_stack_adjust;
3123 stack_pointer_delta = save_stack_pointer_delta;
3125 /* Prepare arg structure for next iteration. */
3126 for (i = 0; i < num_actuals; i++)
3129 args[i].aligned_regs = 0;
3133 sbitmap_free (stored_args_map);
3137 normal_call_insns = insns;
3139 /* Verify that we've deallocated all the stack we used. */
3140 gcc_assert ((flags & ECF_NORETURN)
3141 || (old_stack_allocated
3142 == stack_pointer_delta - pending_stack_adjust));
3145 /* If something prevents making this a sibling call,
3146 zero out the sequence. */
3147 if (sibcall_failure)
3148 tail_call_insns = NULL_RTX;
3153 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
3154 arguments too, as argument area is now clobbered by the call. */
3155 if (tail_call_insns)
3157 emit_insn (tail_call_insns);
3158 crtl->tail_call_emit = true;
3161 emit_insn (normal_call_insns);
3163 currently_expanding_call--;
3165 if (stack_usage_map_buf)
3166 free (stack_usage_map_buf);
3171 /* A sibling call sequence invalidates any REG_EQUIV notes made for
3172 this function's incoming arguments.
3174 At the start of RTL generation we know the only REG_EQUIV notes
3175 in the rtl chain are those for incoming arguments, so we can look
3176 for REG_EQUIV notes between the start of the function and the
3177 NOTE_INSN_FUNCTION_BEG.
3179 This is (slight) overkill. We could keep track of the highest
3180 argument we clobber and be more selective in removing notes, but it
3181 does not seem to be worth the effort. */
3184 fixup_tail_calls (void)
3188 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3192 /* There are never REG_EQUIV notes for the incoming arguments
3193 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
3195 && NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG)
3198 note = find_reg_note (insn, REG_EQUIV, 0);
3200 remove_note (insn, note);
3201 note = find_reg_note (insn, REG_EQUIV, 0);
3206 /* Traverse a list of TYPES and expand all complex types into their
3209 split_complex_types (tree types)
3213 /* Before allocating memory, check for the common case of no complex. */
3214 for (p = types; p; p = TREE_CHAIN (p))
3216 tree type = TREE_VALUE (p);
3217 if (TREE_CODE (type) == COMPLEX_TYPE
3218 && targetm.calls.split_complex_arg (type))
3224 types = copy_list (types);
3226 for (p = types; p; p = TREE_CHAIN (p))
3228 tree complex_type = TREE_VALUE (p);
3230 if (TREE_CODE (complex_type) == COMPLEX_TYPE
3231 && targetm.calls.split_complex_arg (complex_type))
3235 /* Rewrite complex type with component type. */
3236 TREE_VALUE (p) = TREE_TYPE (complex_type);
3237 next = TREE_CHAIN (p);
3239 /* Add another component type for the imaginary part. */
3240 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
3241 TREE_CHAIN (p) = imag;
3242 TREE_CHAIN (imag) = next;
3244 /* Skip the newly created node. */
3252 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3253 The RETVAL parameter specifies whether return value needs to be saved, other
3254 parameters are documented in the emit_library_call function below. */
3257 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
3258 enum libcall_type fn_type,
3259 enum machine_mode outmode, int nargs, va_list p)
3261 /* Total size in bytes of all the stack-parms scanned so far. */
3262 struct args_size args_size;
3263 /* Size of arguments before any adjustments (such as rounding). */
3264 struct args_size original_args_size;
3267 /* Todo, choose the correct decl type of orgfun. Sadly this information
3268 isn't present here, so we default to native calling abi here. */
3269 tree fndecl ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
3270 tree fntype ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
3274 CUMULATIVE_ARGS args_so_far;
3278 enum machine_mode mode;
3281 struct locate_and_pad_arg_data locate;
3285 int old_inhibit_defer_pop = inhibit_defer_pop;
3286 rtx call_fusage = 0;
3289 int pcc_struct_value = 0;
3290 int struct_value_size = 0;
3292 int reg_parm_stack_space = 0;
3295 tree tfom; /* type_for_mode (outmode, 0) */
3297 #ifdef REG_PARM_STACK_SPACE
3298 /* Define the boundary of the register parm stack space that needs to be
3300 int low_to_save = 0, high_to_save = 0;
3301 rtx save_area = 0; /* Place that it is saved. */
3304 /* Size of the stack reserved for parameter registers. */
3305 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3306 char *initial_stack_usage_map = stack_usage_map;
3307 char *stack_usage_map_buf = NULL;
3309 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
3311 #ifdef REG_PARM_STACK_SPACE
3312 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3315 /* By default, library functions can not throw. */
3316 flags = ECF_NOTHROW;
3329 flags |= ECF_NORETURN;
3332 flags = ECF_NORETURN;
3334 case LCT_RETURNS_TWICE:
3335 flags = ECF_RETURNS_TWICE;
3340 /* Ensure current function's preferred stack boundary is at least
3342 if (crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3343 crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3345 /* If this kind of value comes back in memory,
3346 decide where in memory it should come back. */
3347 if (outmode != VOIDmode)
3349 tfom = lang_hooks.types.type_for_mode (outmode, 0);
3350 if (aggregate_value_p (tfom, 0))
3352 #ifdef PCC_STATIC_STRUCT_RETURN
3354 = hard_function_value (build_pointer_type (tfom), 0, 0, 0);
3355 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3356 pcc_struct_value = 1;
3358 value = gen_reg_rtx (outmode);
3359 #else /* not PCC_STATIC_STRUCT_RETURN */
3360 struct_value_size = GET_MODE_SIZE (outmode);
3361 if (value != 0 && MEM_P (value))
3364 mem_value = assign_temp (tfom, 0, 1, 1);
3366 /* This call returns a big structure. */
3367 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
3371 tfom = void_type_node;
3373 /* ??? Unfinished: must pass the memory address as an argument. */
3375 /* Copy all the libcall-arguments out of the varargs data
3376 and into a vector ARGVEC.
3378 Compute how to pass each argument. We only support a very small subset
3379 of the full argument passing conventions to limit complexity here since
3380 library functions shouldn't have many args. */
3382 argvec = XALLOCAVEC (struct arg, nargs + 1);
3383 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
3385 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3386 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun);
3388 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0, nargs);
3391 args_size.constant = 0;
3398 /* If there's a structure value address to be passed,
3399 either pass it in the special place, or pass it as an extra argument. */
3400 if (mem_value && struct_value == 0 && ! pcc_struct_value)
3402 rtx addr = XEXP (mem_value, 0);
3406 /* Make sure it is a reasonable operand for a move or push insn. */
3407 if (!REG_P (addr) && !MEM_P (addr)
3408 && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr)))
3409 addr = force_operand (addr, NULL_RTX);
3411 argvec[count].value = addr;
3412 argvec[count].mode = Pmode;
3413 argvec[count].partial = 0;
3415 argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1);
3416 gcc_assert (targetm.calls.arg_partial_bytes (&args_so_far, Pmode,
3417 NULL_TREE, 1) == 0);
3419 locate_and_pad_parm (Pmode, NULL_TREE,
3420 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3423 argvec[count].reg != 0,
3425 0, NULL_TREE, &args_size, &argvec[count].locate);
3427 if (argvec[count].reg == 0 || argvec[count].partial != 0
3428 || reg_parm_stack_space > 0)
3429 args_size.constant += argvec[count].locate.size.constant;
3431 FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1);
3436 for (; count < nargs; count++)
3438 rtx val = va_arg (p, rtx);
3439 enum machine_mode mode = (enum machine_mode) va_arg (p, int);
3441 /* We cannot convert the arg value to the mode the library wants here;
3442 must do it earlier where we know the signedness of the arg. */
3443 gcc_assert (mode != BLKmode
3444 && (GET_MODE (val) == mode || GET_MODE (val) == VOIDmode));
3446 /* Make sure it is a reasonable operand for a move or push insn. */
3447 if (!REG_P (val) && !MEM_P (val)
3448 && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val)))
3449 val = force_operand (val, NULL_RTX);
3451 if (pass_by_reference (&args_so_far, mode, NULL_TREE, 1))
3455 = !reference_callee_copied (&args_so_far, mode, NULL_TREE, 1);
3457 /* If this was a CONST function, it is now PURE since it now
3459 if (flags & ECF_CONST)
3461 flags &= ~ECF_CONST;
3465 if (MEM_P (val) && !must_copy)
3469 slot = assign_temp (lang_hooks.types.type_for_mode (mode, 0),
3471 emit_move_insn (slot, val);
3474 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3475 gen_rtx_USE (VOIDmode, slot),
3478 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3479 gen_rtx_CLOBBER (VOIDmode,
3484 val = force_operand (XEXP (slot, 0), NULL_RTX);
3487 argvec[count].value = val;
3488 argvec[count].mode = mode;
3490 argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1);
3492 argvec[count].partial
3493 = targetm.calls.arg_partial_bytes (&args_so_far, mode, NULL_TREE, 1);
3495 locate_and_pad_parm (mode, NULL_TREE,
3496 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3499 argvec[count].reg != 0,
3501 argvec[count].partial,
3502 NULL_TREE, &args_size, &argvec[count].locate);
3504 gcc_assert (!argvec[count].locate.size.var);
3506 if (argvec[count].reg == 0 || argvec[count].partial != 0
3507 || reg_parm_stack_space > 0)
3508 args_size.constant += argvec[count].locate.size.constant;
3510 FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1);
3513 /* If this machine requires an external definition for library
3514 functions, write one out. */
3515 assemble_external_libcall (fun);
3517 original_args_size = args_size;
3518 args_size.constant = (((args_size.constant
3519 + stack_pointer_delta
3523 - stack_pointer_delta);
3525 args_size.constant = MAX (args_size.constant,
3526 reg_parm_stack_space);
3528 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
3529 args_size.constant -= reg_parm_stack_space;
3531 if (args_size.constant > crtl->outgoing_args_size)
3532 crtl->outgoing_args_size = args_size.constant;
3534 if (ACCUMULATE_OUTGOING_ARGS)
3536 /* Since the stack pointer will never be pushed, it is possible for
3537 the evaluation of a parm to clobber something we have already
3538 written to the stack. Since most function calls on RISC machines
3539 do not use the stack, this is uncommon, but must work correctly.
3541 Therefore, we save any area of the stack that was already written
3542 and that we are using. Here we set up to do this by making a new
3543 stack usage map from the old one.
3545 Another approach might be to try to reorder the argument
3546 evaluations to avoid this conflicting stack usage. */
3548 needed = args_size.constant;
3550 /* Since we will be writing into the entire argument area, the
3551 map must be allocated for its entire size, not just the part that
3552 is the responsibility of the caller. */
3553 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
3554 needed += reg_parm_stack_space;
3556 #ifdef ARGS_GROW_DOWNWARD
3557 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3560 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3563 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
3564 stack_usage_map = stack_usage_map_buf;
3566 if (initial_highest_arg_in_use)
3567 memcpy (stack_usage_map, initial_stack_usage_map,
3568 initial_highest_arg_in_use);
3570 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3571 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3572 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3575 /* We must be careful to use virtual regs before they're instantiated,
3576 and real regs afterwards. Loop optimization, for example, can create
3577 new libcalls after we've instantiated the virtual regs, and if we
3578 use virtuals anyway, they won't match the rtl patterns. */
3580 if (virtuals_instantiated)
3581 argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET);
3583 argblock = virtual_outgoing_args_rtx;
3588 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3591 /* If we push args individually in reverse order, perform stack alignment
3592 before the first push (the last arg). */
3593 if (argblock == 0 && PUSH_ARGS_REVERSED)
3594 anti_adjust_stack (GEN_INT (args_size.constant
3595 - original_args_size.constant));
3597 if (PUSH_ARGS_REVERSED)
3608 #ifdef REG_PARM_STACK_SPACE
3609 if (ACCUMULATE_OUTGOING_ARGS)
3611 /* The argument list is the property of the called routine and it
3612 may clobber it. If the fixed area has been used for previous
3613 parameters, we must save and restore it. */
3614 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3615 &low_to_save, &high_to_save);
3619 /* Push the args that need to be pushed. */
3621 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3622 are to be pushed. */
3623 for (count = 0; count < nargs; count++, argnum += inc)
3625 enum machine_mode mode = argvec[argnum].mode;
3626 rtx val = argvec[argnum].value;
3627 rtx reg = argvec[argnum].reg;
3628 int partial = argvec[argnum].partial;
3629 unsigned int parm_align = argvec[argnum].locate.boundary;
3630 int lower_bound = 0, upper_bound = 0, i;
3632 if (! (reg != 0 && partial == 0))
3634 if (ACCUMULATE_OUTGOING_ARGS)
3636 /* If this is being stored into a pre-allocated, fixed-size,
3637 stack area, save any previous data at that location. */
3639 #ifdef ARGS_GROW_DOWNWARD
3640 /* stack_slot is negative, but we want to index stack_usage_map
3641 with positive values. */
3642 upper_bound = -argvec[argnum].locate.slot_offset.constant + 1;
3643 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
3645 lower_bound = argvec[argnum].locate.slot_offset.constant;
3646 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
3650 /* Don't worry about things in the fixed argument area;
3651 it has already been saved. */
3652 if (i < reg_parm_stack_space)
3653 i = reg_parm_stack_space;
3654 while (i < upper_bound && stack_usage_map[i] == 0)
3657 if (i < upper_bound)
3659 /* We need to make a save area. */
3661 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
3662 enum machine_mode save_mode
3663 = mode_for_size (size, MODE_INT, 1);
3665 = plus_constant (argblock,
3666 argvec[argnum].locate.offset.constant);
3668 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
3670 if (save_mode == BLKmode)
3672 argvec[argnum].save_area
3673 = assign_stack_temp (BLKmode,
3674 argvec[argnum].locate.size.constant,
3677 emit_block_move (validize_mem (argvec[argnum].save_area),
3679 GEN_INT (argvec[argnum].locate.size.constant),
3680 BLOCK_OP_CALL_PARM);
3684 argvec[argnum].save_area = gen_reg_rtx (save_mode);
3686 emit_move_insn (argvec[argnum].save_area, stack_area);
3691 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, parm_align,
3692 partial, reg, 0, argblock,
3693 GEN_INT (argvec[argnum].locate.offset.constant),
3694 reg_parm_stack_space,
3695 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad));
3697 /* Now mark the segment we just used. */
3698 if (ACCUMULATE_OUTGOING_ARGS)
3699 for (i = lower_bound; i < upper_bound; i++)
3700 stack_usage_map[i] = 1;
3704 if ((flags & ECF_CONST)
3705 || ((flags & ECF_PURE) && ACCUMULATE_OUTGOING_ARGS))
3709 /* Indicate argument access so that alias.c knows that these
3712 use = plus_constant (argblock,
3713 argvec[argnum].locate.offset.constant);
3715 /* When arguments are pushed, trying to tell alias.c where
3716 exactly this argument is won't work, because the
3717 auto-increment causes confusion. So we merely indicate
3718 that we access something with a known mode somewhere on
3720 use = gen_rtx_PLUS (Pmode, virtual_outgoing_args_rtx,
3721 gen_rtx_SCRATCH (Pmode));
3722 use = gen_rtx_MEM (argvec[argnum].mode, use);
3723 use = gen_rtx_USE (VOIDmode, use);
3724 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, use, call_fusage);
3729 /* If we pushed args in forward order, perform stack alignment
3730 after pushing the last arg. */
3731 if (argblock == 0 && !PUSH_ARGS_REVERSED)
3732 anti_adjust_stack (GEN_INT (args_size.constant
3733 - original_args_size.constant));
3735 if (PUSH_ARGS_REVERSED)
3740 fun = prepare_call_address (fun, NULL, &call_fusage, 0, 0);
3742 /* Now load any reg parms into their regs. */
3744 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3745 are to be pushed. */
3746 for (count = 0; count < nargs; count++, argnum += inc)
3748 enum machine_mode mode = argvec[argnum].mode;
3749 rtx val = argvec[argnum].value;
3750 rtx reg = argvec[argnum].reg;
3751 int partial = argvec[argnum].partial;
3753 /* Handle calls that pass values in multiple non-contiguous
3754 locations. The PA64 has examples of this for library calls. */
3755 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3756 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode));
3757 else if (reg != 0 && partial == 0)
3758 emit_move_insn (reg, val);
3763 /* Any regs containing parms remain in use through the call. */
3764 for (count = 0; count < nargs; count++)
3766 rtx reg = argvec[count].reg;
3767 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3768 use_group_regs (&call_fusage, reg);
3771 int partial = argvec[count].partial;
3775 gcc_assert (partial % UNITS_PER_WORD == 0);
3776 nregs = partial / UNITS_PER_WORD;
3777 use_regs (&call_fusage, REGNO (reg), nregs);
3780 use_reg (&call_fusage, reg);
3784 /* Pass the function the address in which to return a structure value. */
3785 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
3787 emit_move_insn (struct_value,
3789 force_operand (XEXP (mem_value, 0),
3791 if (REG_P (struct_value))
3792 use_reg (&call_fusage, struct_value);
3795 /* Don't allow popping to be deferred, since then
3796 cse'ing of library calls could delete a call and leave the pop. */
3798 valreg = (mem_value == 0 && outmode != VOIDmode
3799 ? hard_libcall_value (outmode, orgfun) : NULL_RTX);
3801 /* Stack must be properly aligned now. */
3802 gcc_assert (!(stack_pointer_delta
3803 & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1)));
3805 before_call = get_last_insn ();
3807 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
3808 will set inhibit_defer_pop to that value. */
3809 /* The return type is needed to decide how many bytes the function pops.
3810 Signedness plays no role in that, so for simplicity, we pretend it's
3811 always signed. We also assume that the list of arguments passed has
3812 no impact, so we pretend it is unknown. */
3814 emit_call_1 (fun, NULL,
3815 get_identifier (XSTR (orgfun, 0)),
3816 build_function_type (tfom, NULL_TREE),
3817 original_args_size.constant, args_size.constant,
3819 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
3821 old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far);
3823 /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
3824 that it should complain if nonvolatile values are live. For
3825 functions that cannot return, inform flow that control does not
3828 if (flags & ECF_NORETURN)
3830 /* The barrier note must be emitted
3831 immediately after the CALL_INSN. Some ports emit more than
3832 just a CALL_INSN above, so we must search for it here. */
3834 rtx last = get_last_insn ();
3835 while (!CALL_P (last))
3837 last = PREV_INSN (last);
3838 /* There was no CALL_INSN? */
3839 gcc_assert (last != before_call);
3842 emit_barrier_after (last);
3845 /* Now restore inhibit_defer_pop to its actual original value. */
3850 /* Copy the value to the right place. */
3851 if (outmode != VOIDmode && retval)
3857 if (value != mem_value)
3858 emit_move_insn (value, mem_value);
3860 else if (GET_CODE (valreg) == PARALLEL)
3863 value = gen_reg_rtx (outmode);
3864 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
3868 /* Convert to the proper mode if a promotion has been active. */
3869 if (GET_MODE (valreg) != outmode)
3871 int unsignedp = TYPE_UNSIGNED (tfom);
3873 gcc_assert (promote_function_mode (tfom, outmode, &unsignedp,
3874 fndecl ? TREE_TYPE (fndecl) : fntype, 1)
3875 == GET_MODE (valreg));
3876 valreg = convert_modes (outmode, GET_MODE (valreg), valreg, 0);
3880 emit_move_insn (value, valreg);
3886 if (ACCUMULATE_OUTGOING_ARGS)
3888 #ifdef REG_PARM_STACK_SPACE
3890 restore_fixed_argument_area (save_area, argblock,
3891 high_to_save, low_to_save);
3894 /* If we saved any argument areas, restore them. */
3895 for (count = 0; count < nargs; count++)
3896 if (argvec[count].save_area)
3898 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
3899 rtx adr = plus_constant (argblock,
3900 argvec[count].locate.offset.constant);
3901 rtx stack_area = gen_rtx_MEM (save_mode,
3902 memory_address (save_mode, adr));
3904 if (save_mode == BLKmode)
3905 emit_block_move (stack_area,
3906 validize_mem (argvec[count].save_area),
3907 GEN_INT (argvec[count].locate.size.constant),
3908 BLOCK_OP_CALL_PARM);
3910 emit_move_insn (stack_area, argvec[count].save_area);
3913 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3914 stack_usage_map = initial_stack_usage_map;
3917 if (stack_usage_map_buf)
3918 free (stack_usage_map_buf);
3924 /* Output a library call to function FUN (a SYMBOL_REF rtx)
3925 (emitting the queue unless NO_QUEUE is nonzero),
3926 for a value of mode OUTMODE,
3927 with NARGS different arguments, passed as alternating rtx values
3928 and machine_modes to convert them to.
3930 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for
3931 `const' calls, LCT_PURE for `pure' calls, or other LCT_ value for
3932 other types of library calls. */
3935 emit_library_call (rtx orgfun, enum libcall_type fn_type,
3936 enum machine_mode outmode, int nargs, ...)
3940 va_start (p, nargs);
3941 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
3945 /* Like emit_library_call except that an extra argument, VALUE,
3946 comes second and says where to store the result.
3947 (If VALUE is zero, this function chooses a convenient way
3948 to return the value.
3950 This function returns an rtx for where the value is to be found.
3951 If VALUE is nonzero, VALUE is returned. */
3954 emit_library_call_value (rtx orgfun, rtx value,
3955 enum libcall_type fn_type,
3956 enum machine_mode outmode, int nargs, ...)
3961 va_start (p, nargs);
3962 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
3969 /* Store a single argument for a function call
3970 into the register or memory area where it must be passed.
3971 *ARG describes the argument value and where to pass it.
3973 ARGBLOCK is the address of the stack-block for all the arguments,
3974 or 0 on a machine where arguments are pushed individually.
3976 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
3977 so must be careful about how the stack is used.
3979 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
3980 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
3981 that we need not worry about saving and restoring the stack.
3983 FNDECL is the declaration of the function we are calling.
3985 Return nonzero if this arg should cause sibcall failure,
3989 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
3990 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
3992 tree pval = arg->tree_value;
3996 int i, lower_bound = 0, upper_bound = 0;
3997 int sibcall_failure = 0;
3999 if (TREE_CODE (pval) == ERROR_MARK)
4002 /* Push a new temporary level for any temporaries we make for
4006 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
4008 /* If this is being stored into a pre-allocated, fixed-size, stack area,
4009 save any previous data at that location. */
4010 if (argblock && ! variable_size && arg->stack)
4012 #ifdef ARGS_GROW_DOWNWARD
4013 /* stack_slot is negative, but we want to index stack_usage_map
4014 with positive values. */
4015 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4016 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
4020 lower_bound = upper_bound - arg->locate.size.constant;
4022 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4023 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
4027 upper_bound = lower_bound + arg->locate.size.constant;
4031 /* Don't worry about things in the fixed argument area;
4032 it has already been saved. */
4033 if (i < reg_parm_stack_space)
4034 i = reg_parm_stack_space;
4035 while (i < upper_bound && stack_usage_map[i] == 0)
4038 if (i < upper_bound)
4040 /* We need to make a save area. */
4041 unsigned int size = arg->locate.size.constant * BITS_PER_UNIT;
4042 enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1);
4043 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
4044 rtx stack_area = gen_rtx_MEM (save_mode, adr);
4046 if (save_mode == BLKmode)
4048 tree ot = TREE_TYPE (arg->tree_value);
4049 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
4050 | TYPE_QUAL_CONST));
4052 arg->save_area = assign_temp (nt, 0, 1, 1);
4053 preserve_temp_slots (arg->save_area);
4054 emit_block_move (validize_mem (arg->save_area), stack_area,
4055 GEN_INT (arg->locate.size.constant),
4056 BLOCK_OP_CALL_PARM);
4060 arg->save_area = gen_reg_rtx (save_mode);
4061 emit_move_insn (arg->save_area, stack_area);
4067 /* If this isn't going to be placed on both the stack and in registers,
4068 set up the register and number of words. */
4069 if (! arg->pass_on_stack)
4071 if (flags & ECF_SIBCALL)
4072 reg = arg->tail_call_reg;
4075 partial = arg->partial;
4078 /* Being passed entirely in a register. We shouldn't be called in
4080 gcc_assert (reg == 0 || partial != 0);
4082 /* If this arg needs special alignment, don't load the registers
4084 if (arg->n_aligned_regs != 0)
4087 /* If this is being passed partially in a register, we can't evaluate
4088 it directly into its stack slot. Otherwise, we can. */
4089 if (arg->value == 0)
4091 /* stack_arg_under_construction is nonzero if a function argument is
4092 being evaluated directly into the outgoing argument list and
4093 expand_call must take special action to preserve the argument list
4094 if it is called recursively.
4096 For scalar function arguments stack_usage_map is sufficient to
4097 determine which stack slots must be saved and restored. Scalar
4098 arguments in general have pass_on_stack == 0.
4100 If this argument is initialized by a function which takes the
4101 address of the argument (a C++ constructor or a C function
4102 returning a BLKmode structure), then stack_usage_map is
4103 insufficient and expand_call must push the stack around the
4104 function call. Such arguments have pass_on_stack == 1.
4106 Note that it is always safe to set stack_arg_under_construction,
4107 but this generates suboptimal code if set when not needed. */
4109 if (arg->pass_on_stack)
4110 stack_arg_under_construction++;
4112 arg->value = expand_expr (pval,
4114 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4115 ? NULL_RTX : arg->stack,
4116 VOIDmode, EXPAND_STACK_PARM);
4118 /* If we are promoting object (or for any other reason) the mode
4119 doesn't agree, convert the mode. */
4121 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4122 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4123 arg->value, arg->unsignedp);
4125 if (arg->pass_on_stack)
4126 stack_arg_under_construction--;
4129 /* Check for overlap with already clobbered argument area. */
4130 if ((flags & ECF_SIBCALL)
4131 && MEM_P (arg->value)
4132 && mem_overlaps_already_clobbered_arg_p (XEXP (arg->value, 0),
4133 arg->locate.size.constant))
4134 sibcall_failure = 1;
4136 /* Don't allow anything left on stack from computation
4137 of argument to alloca. */
4138 if (flags & ECF_MAY_BE_ALLOCA)
4139 do_pending_stack_adjust ();
4141 if (arg->value == arg->stack)
4142 /* If the value is already in the stack slot, we are done. */
4144 else if (arg->mode != BLKmode)
4147 unsigned int parm_align;
4149 /* Argument is a scalar, not entirely passed in registers.
4150 (If part is passed in registers, arg->partial says how much
4151 and emit_push_insn will take care of putting it there.)
4153 Push it, and if its size is less than the
4154 amount of space allocated to it,
4155 also bump stack pointer by the additional space.
4156 Note that in C the default argument promotions
4157 will prevent such mismatches. */
4159 size = GET_MODE_SIZE (arg->mode);
4160 /* Compute how much space the push instruction will push.
4161 On many machines, pushing a byte will advance the stack
4162 pointer by a halfword. */
4163 #ifdef PUSH_ROUNDING
4164 size = PUSH_ROUNDING (size);
4168 /* Compute how much space the argument should get:
4169 round up to a multiple of the alignment for arguments. */
4170 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4171 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4172 / (PARM_BOUNDARY / BITS_PER_UNIT))
4173 * (PARM_BOUNDARY / BITS_PER_UNIT));
4175 /* Compute the alignment of the pushed argument. */
4176 parm_align = arg->locate.boundary;
4177 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4179 int pad = used - size;
4182 unsigned int pad_align = (pad & -pad) * BITS_PER_UNIT;
4183 parm_align = MIN (parm_align, pad_align);
4187 /* This isn't already where we want it on the stack, so put it there.
4188 This can either be done with push or copy insns. */
4189 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4190 parm_align, partial, reg, used - size, argblock,
4191 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4192 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4194 /* Unless this is a partially-in-register argument, the argument is now
4197 arg->value = arg->stack;
4201 /* BLKmode, at least partly to be pushed. */
4203 unsigned int parm_align;
4207 /* Pushing a nonscalar.
4208 If part is passed in registers, PARTIAL says how much
4209 and emit_push_insn will take care of putting it there. */
4211 /* Round its size up to a multiple
4212 of the allocation unit for arguments. */
4214 if (arg->locate.size.var != 0)
4217 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
4221 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
4222 for BLKmode is careful to avoid it. */
4223 excess = (arg->locate.size.constant
4224 - int_size_in_bytes (TREE_TYPE (pval))
4226 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4227 NULL_RTX, TYPE_MODE (sizetype),
4231 parm_align = arg->locate.boundary;
4233 /* When an argument is padded down, the block is aligned to
4234 PARM_BOUNDARY, but the actual argument isn't. */
4235 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4237 if (arg->locate.size.var)
4238 parm_align = BITS_PER_UNIT;
4241 unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4242 parm_align = MIN (parm_align, excess_align);
4246 if ((flags & ECF_SIBCALL) && MEM_P (arg->value))
4248 /* emit_push_insn might not work properly if arg->value and
4249 argblock + arg->locate.offset areas overlap. */
4253 if (XEXP (x, 0) == crtl->args.internal_arg_pointer
4254 || (GET_CODE (XEXP (x, 0)) == PLUS
4255 && XEXP (XEXP (x, 0), 0) ==
4256 crtl->args.internal_arg_pointer
4257 && CONST_INT_P (XEXP (XEXP (x, 0), 1))))
4259 if (XEXP (x, 0) != crtl->args.internal_arg_pointer)
4260 i = INTVAL (XEXP (XEXP (x, 0), 1));
4262 /* expand_call should ensure this. */
4263 gcc_assert (!arg->locate.offset.var
4264 && arg->locate.size.var == 0
4265 && CONST_INT_P (size_rtx));
4267 if (arg->locate.offset.constant > i)
4269 if (arg->locate.offset.constant < i + INTVAL (size_rtx))
4270 sibcall_failure = 1;
4272 else if (arg->locate.offset.constant < i)
4274 /* Use arg->locate.size.constant instead of size_rtx
4275 because we only care about the part of the argument
4277 if (i < (arg->locate.offset.constant
4278 + arg->locate.size.constant))
4279 sibcall_failure = 1;
4283 /* Even though they appear to be at the same location,
4284 if part of the outgoing argument is in registers,
4285 they aren't really at the same location. Check for
4286 this by making sure that the incoming size is the
4287 same as the outgoing size. */
4288 if (arg->locate.size.constant != INTVAL (size_rtx))
4289 sibcall_failure = 1;
4294 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4295 parm_align, partial, reg, excess, argblock,
4296 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4297 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4299 /* Unless this is a partially-in-register argument, the argument is now
4302 ??? Unlike the case above, in which we want the actual
4303 address of the data, so that we can load it directly into a
4304 register, here we want the address of the stack slot, so that
4305 it's properly aligned for word-by-word copying or something
4306 like that. It's not clear that this is always correct. */
4308 arg->value = arg->stack_slot;
4311 if (arg->reg && GET_CODE (arg->reg) == PARALLEL)
4313 tree type = TREE_TYPE (arg->tree_value);
4315 = emit_group_load_into_temps (arg->reg, arg->value, type,
4316 int_size_in_bytes (type));
4319 /* Mark all slots this store used. */
4320 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
4321 && argblock && ! variable_size && arg->stack)
4322 for (i = lower_bound; i < upper_bound; i++)
4323 stack_usage_map[i] = 1;
4325 /* Once we have pushed something, pops can't safely
4326 be deferred during the rest of the arguments. */
4329 /* Free any temporary slots made in processing this argument. Show
4330 that we might have taken the address of something and pushed that
4332 preserve_temp_slots (NULL_RTX);
4336 return sibcall_failure;
4339 /* Nonzero if we do not know how to pass TYPE solely in registers. */
4342 must_pass_in_stack_var_size (enum machine_mode mode ATTRIBUTE_UNUSED,
4348 /* If the type has variable size... */
4349 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4352 /* If the type is marked as addressable (it is required
4353 to be constructed into the stack)... */
4354 if (TREE_ADDRESSABLE (type))
4360 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
4361 takes trailing padding of a structure into account. */
4362 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
4365 must_pass_in_stack_var_size_or_pad (enum machine_mode mode, const_tree type)
4370 /* If the type has variable size... */
4371 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4374 /* If the type is marked as addressable (it is required
4375 to be constructed into the stack)... */
4376 if (TREE_ADDRESSABLE (type))
4379 /* If the padding and mode of the type is such that a copy into
4380 a register would put it into the wrong part of the register. */
4382 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
4383 && (FUNCTION_ARG_PADDING (mode, type)
4384 == (BYTES_BIG_ENDIAN ? upward : downward)))