* gcc.dg/compat/struct-layout-1_generate.c (dg_options): New. Moved
[official-gcc.git] / gcc / calls.c
bloba3d35b3bf5c334e3abb4891e0ecb17228d72693d
1 /* Convert function calls to rtl insns, for GNU C compiler.
2 Copyright (C) 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
11 version.
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
16 for more details.
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/>. */
22 #include "config.h"
23 #include "system.h"
24 #include "coretypes.h"
25 #include "tm.h"
26 #include "rtl.h"
27 #include "tree.h"
28 #include "gimple.h"
29 #include "flags.h"
30 #include "expr.h"
31 #include "optabs.h"
32 #include "libfuncs.h"
33 #include "function.h"
34 #include "regs.h"
35 #include "toplev.h"
36 #include "output.h"
37 #include "tm_p.h"
38 #include "timevar.h"
39 #include "sbitmap.h"
40 #include "langhooks.h"
41 #include "target.h"
42 #include "cgraph.h"
43 #include "except.h"
44 #include "dbgcnt.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. */
52 struct arg_data
54 /* Tree node for this argument. */
55 tree tree_value;
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. */
59 rtx value;
60 /* Initially-compute RTL value for argument; only for const functions. */
61 rtx initial_value;
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
64 registers. */
65 rtx reg;
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
68 register windows. */
69 rtx tail_call_reg;
70 /* If REG is a PARALLEL, this is a copy of VALUE pulled into the correct
71 form for emit_group_move. */
72 rtx parallel_value;
73 /* If REG was promoted from the actual mode of the argument expression,
74 indicates whether the promotion is sign- or zero-extended. */
75 int unsignedp;
76 /* Number of bytes to put in registers. 0 means put the whole arg
77 in registers. Also 0 if not passed in registers. */
78 int partial;
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. */
83 int pass_on_stack;
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. */
88 rtx stack;
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. */
92 rtx stack_slot;
93 /* Place that this stack area has been saved, if needed. */
94 rtx save_area;
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. */
99 rtx *aligned_regs;
100 int n_aligned_regs;
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,
128 CUMULATIVE_ARGS *);
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 *,
133 struct args_size *);
134 static void precompute_arguments (int, struct arg_data *);
135 static int compute_argument_block_size (int, struct args_size *, tree, int);
136 static void initialize_argument_information (int, struct arg_data *,
137 struct args_size *, int,
138 tree, tree,
139 tree, CUMULATIVE_ARGS *, int,
140 rtx *, int *, int *, int *,
141 bool *, bool);
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,
145 int, 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 *,
153 unsigned int);
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);
159 #endif
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));
180 else if (! sibcallp)
182 #ifndef NO_FUNCTION_CSE
183 if (optimize && ! flag_no_function_cse)
184 funexp = force_reg (Pmode, funexp);
185 #endif
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);
197 return funexp;
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
217 code if necessary.
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. */
240 static void
241 emit_call_1 (rtx funexp, tree fntree, tree fndecl ATTRIBUTE_UNUSED,
242 tree funtype ATTRIBUTE_UNUSED,
243 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED,
244 HOST_WIDE_INT rounded_stack_size,
245 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED,
246 rtx next_arg_reg ATTRIBUTE_UNUSED, rtx valreg,
247 int old_inhibit_defer_pop, rtx call_fusage, int ecf_flags,
248 CUMULATIVE_ARGS *args_so_far ATTRIBUTE_UNUSED)
250 rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
251 rtx call_insn;
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);
257 #endif
259 #ifdef CALL_POPS_ARGS
260 n_popped += CALL_POPS_ARGS (* args_so_far);
261 #endif
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);
275 rtx pat;
277 /* If this subroutine pops its own args, record that in the call insn
278 if possible, for the sake of frame pointer elimination. */
280 if (valreg)
281 pat = GEN_SIBCALL_VALUE_POP (valreg,
282 gen_rtx_MEM (FUNCTION_MODE, funexp),
283 rounded_stack_size_rtx, next_arg_reg,
284 n_pop);
285 else
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);
290 already_popped = 1;
292 else
293 #endif
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
302 && n_popped > 0)
303 #else
304 if (HAVE_call_pop && HAVE_call_value_pop)
305 #endif
307 rtx n_pop = GEN_INT (n_popped);
308 rtx pat;
310 /* If this subroutine pops its own args, record that in the call insn
311 if possible, for the sake of frame pointer elimination. */
313 if (valreg)
314 pat = GEN_CALL_VALUE_POP (valreg,
315 gen_rtx_MEM (FUNCTION_MODE, funexp),
316 rounded_stack_size_rtx, next_arg_reg, n_pop);
317 else
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);
322 already_popped = 1;
324 else
325 #endif
327 #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
328 if ((ecf_flags & ECF_SIBCALL)
329 && HAVE_sibcall && HAVE_sibcall_value)
331 if (valreg)
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));
336 else
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));
341 else
342 #endif
344 #if defined (HAVE_call) && defined (HAVE_call_value)
345 if (HAVE_call && HAVE_call_value)
347 if (valreg)
348 emit_call_insn (GEN_CALL_VALUE (valreg,
349 gen_rtx_MEM (FUNCTION_MODE, funexp),
350 rounded_stack_size_rtx, next_arg_reg,
351 NULL_RTX));
352 else
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));
357 else
358 #endif
359 gcc_unreachable ();
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
380 effect. */
381 if (ecf_flags & ECF_NOTHROW)
382 add_reg_note (call_insn, REG_EH_REGION, const0_rtx);
383 else
385 int rn = lookup_expr_eh_region (fntree);
387 /* If rn < 0, then either (1) tree-ssa not used or (2) doesn't
388 throw, which we already took care of. */
389 if (rn > 0)
390 add_reg_note (call_insn, REG_EH_REGION, GEN_INT (rn));
393 if (ecf_flags & ECF_NORETURN)
394 add_reg_note (call_insn, REG_NORETURN, const0_rtx);
396 if (ecf_flags & ECF_RETURNS_TWICE)
398 add_reg_note (call_insn, REG_SETJMP, const0_rtx);
399 cfun->calls_setjmp = 1;
402 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
404 /* Restore this now, so that we do defer pops for this call's args
405 if the context of the call as a whole permits. */
406 inhibit_defer_pop = old_inhibit_defer_pop;
408 if (n_popped > 0)
410 if (!already_popped)
411 CALL_INSN_FUNCTION_USAGE (call_insn)
412 = gen_rtx_EXPR_LIST (VOIDmode,
413 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
414 CALL_INSN_FUNCTION_USAGE (call_insn));
415 rounded_stack_size -= n_popped;
416 rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
417 stack_pointer_delta -= n_popped;
419 /* If popup is needed, stack realign must use DRAP */
420 if (SUPPORTS_STACK_ALIGNMENT)
421 crtl->need_drap = true;
424 if (!ACCUMULATE_OUTGOING_ARGS)
426 /* If returning from the subroutine does not automatically pop the args,
427 we need an instruction to pop them sooner or later.
428 Perhaps do it now; perhaps just record how much space to pop later.
430 If returning from the subroutine does pop the args, indicate that the
431 stack pointer will be changed. */
433 if (rounded_stack_size != 0)
435 if (ecf_flags & ECF_NORETURN)
436 /* Just pretend we did the pop. */
437 stack_pointer_delta -= rounded_stack_size;
438 else if (flag_defer_pop && inhibit_defer_pop == 0
439 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
440 pending_stack_adjust += rounded_stack_size;
441 else
442 adjust_stack (rounded_stack_size_rtx);
445 /* When we accumulate outgoing args, we must avoid any stack manipulations.
446 Restore the stack pointer to its original value now. Usually
447 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
448 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
449 popping variants of functions exist as well.
451 ??? We may optimize similar to defer_pop above, but it is
452 probably not worthwhile.
454 ??? It will be worthwhile to enable combine_stack_adjustments even for
455 such machines. */
456 else if (n_popped)
457 anti_adjust_stack (GEN_INT (n_popped));
460 /* Determine if the function identified by NAME and FNDECL is one with
461 special properties we wish to know about.
463 For example, if the function might return more than one time (setjmp), then
464 set RETURNS_TWICE to a nonzero value.
466 Similarly set NORETURN if the function is in the longjmp family.
468 Set MAY_BE_ALLOCA for any memory allocation function that might allocate
469 space from the stack such as alloca. */
471 static int
472 special_function_p (const_tree fndecl, int flags)
474 if (fndecl && DECL_NAME (fndecl)
475 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
476 /* Exclude functions not at the file scope, or not `extern',
477 since they are not the magic functions we would otherwise
478 think they are.
479 FIXME: this should be handled with attributes, not with this
480 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
481 because you can declare fork() inside a function if you
482 wish. */
483 && (DECL_CONTEXT (fndecl) == NULL_TREE
484 || TREE_CODE (DECL_CONTEXT (fndecl)) == TRANSLATION_UNIT_DECL)
485 && TREE_PUBLIC (fndecl))
487 const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
488 const char *tname = name;
490 /* We assume that alloca will always be called by name. It
491 makes no sense to pass it as a pointer-to-function to
492 anything that does not understand its behavior. */
493 if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
494 && name[0] == 'a'
495 && ! strcmp (name, "alloca"))
496 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
497 && name[0] == '_'
498 && ! strcmp (name, "__builtin_alloca"))))
499 flags |= ECF_MAY_BE_ALLOCA;
501 /* Disregard prefix _, __ or __x. */
502 if (name[0] == '_')
504 if (name[1] == '_' && name[2] == 'x')
505 tname += 3;
506 else if (name[1] == '_')
507 tname += 2;
508 else
509 tname += 1;
512 if (tname[0] == 's')
514 if ((tname[1] == 'e'
515 && (! strcmp (tname, "setjmp")
516 || ! strcmp (tname, "setjmp_syscall")))
517 || (tname[1] == 'i'
518 && ! strcmp (tname, "sigsetjmp"))
519 || (tname[1] == 'a'
520 && ! strcmp (tname, "savectx")))
521 flags |= ECF_RETURNS_TWICE;
523 if (tname[1] == 'i'
524 && ! strcmp (tname, "siglongjmp"))
525 flags |= ECF_NORETURN;
527 else if ((tname[0] == 'q' && tname[1] == 's'
528 && ! strcmp (tname, "qsetjmp"))
529 || (tname[0] == 'v' && tname[1] == 'f'
530 && ! strcmp (tname, "vfork"))
531 || (tname[0] == 'g' && tname[1] == 'e'
532 && !strcmp (tname, "getcontext")))
533 flags |= ECF_RETURNS_TWICE;
535 else if (tname[0] == 'l' && tname[1] == 'o'
536 && ! strcmp (tname, "longjmp"))
537 flags |= ECF_NORETURN;
540 return flags;
543 /* Return nonzero when FNDECL represents a call to setjmp. */
546 setjmp_call_p (const_tree fndecl)
548 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
552 /* Return true if STMT is an alloca call. */
554 bool
555 gimple_alloca_call_p (const_gimple stmt)
557 tree fndecl;
559 if (!is_gimple_call (stmt))
560 return false;
562 fndecl = gimple_call_fndecl (stmt);
563 if (fndecl && (special_function_p (fndecl, 0) & ECF_MAY_BE_ALLOCA))
564 return true;
566 return false;
569 /* Return true when exp contains alloca call. */
571 bool
572 alloca_call_p (const_tree exp)
574 if (TREE_CODE (exp) == CALL_EXPR
575 && TREE_CODE (CALL_EXPR_FN (exp)) == ADDR_EXPR
576 && (TREE_CODE (TREE_OPERAND (CALL_EXPR_FN (exp), 0)) == FUNCTION_DECL)
577 && (special_function_p (TREE_OPERAND (CALL_EXPR_FN (exp), 0), 0)
578 & ECF_MAY_BE_ALLOCA))
579 return true;
580 return false;
583 /* Detect flags (function attributes) from the function decl or type node. */
586 flags_from_decl_or_type (const_tree exp)
588 int flags = 0;
589 const_tree type = exp;
591 if (DECL_P (exp))
593 type = TREE_TYPE (exp);
595 /* The function exp may have the `malloc' attribute. */
596 if (DECL_IS_MALLOC (exp))
597 flags |= ECF_MALLOC;
599 /* The function exp may have the `returns_twice' attribute. */
600 if (DECL_IS_RETURNS_TWICE (exp))
601 flags |= ECF_RETURNS_TWICE;
603 /* Process the pure and const attributes. */
604 if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
605 flags |= ECF_CONST;
606 if (DECL_PURE_P (exp))
607 flags |= ECF_PURE;
608 if (DECL_LOOPING_CONST_OR_PURE_P (exp))
609 flags |= ECF_LOOPING_CONST_OR_PURE;
611 if (DECL_IS_NOVOPS (exp))
612 flags |= ECF_NOVOPS;
614 if (TREE_NOTHROW (exp))
615 flags |= ECF_NOTHROW;
617 flags = special_function_p (exp, flags);
619 else if (TYPE_P (exp) && TYPE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
620 flags |= ECF_CONST;
622 if (TREE_THIS_VOLATILE (exp))
623 flags |= ECF_NORETURN;
625 return flags;
628 /* Detect flags from a CALL_EXPR. */
631 call_expr_flags (const_tree t)
633 int flags;
634 tree decl = get_callee_fndecl (t);
636 if (decl)
637 flags = flags_from_decl_or_type (decl);
638 else
640 t = TREE_TYPE (CALL_EXPR_FN (t));
641 if (t && TREE_CODE (t) == POINTER_TYPE)
642 flags = flags_from_decl_or_type (TREE_TYPE (t));
643 else
644 flags = 0;
647 return flags;
650 /* Precompute all register parameters as described by ARGS, storing values
651 into fields within the ARGS array.
653 NUM_ACTUALS indicates the total number elements in the ARGS array.
655 Set REG_PARM_SEEN if we encounter a register parameter. */
657 static void
658 precompute_register_parameters (int num_actuals, struct arg_data *args,
659 int *reg_parm_seen)
661 int i;
663 *reg_parm_seen = 0;
665 for (i = 0; i < num_actuals; i++)
666 if (args[i].reg != 0 && ! args[i].pass_on_stack)
668 *reg_parm_seen = 1;
670 if (args[i].value == 0)
672 push_temp_slots ();
673 args[i].value = expand_normal (args[i].tree_value);
674 preserve_temp_slots (args[i].value);
675 pop_temp_slots ();
678 /* If the value is a non-legitimate constant, force it into a
679 pseudo now. TLS symbols sometimes need a call to resolve. */
680 if (CONSTANT_P (args[i].value)
681 && !LEGITIMATE_CONSTANT_P (args[i].value))
682 args[i].value = force_reg (args[i].mode, args[i].value);
684 /* If we are to promote the function arg to a wider mode,
685 do it now. */
687 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
688 args[i].value
689 = convert_modes (args[i].mode,
690 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
691 args[i].value, args[i].unsignedp);
693 /* If we're going to have to load the value by parts, pull the
694 parts into pseudos. The part extraction process can involve
695 non-trivial computation. */
696 if (GET_CODE (args[i].reg) == PARALLEL)
698 tree type = TREE_TYPE (args[i].tree_value);
699 args[i].parallel_value
700 = emit_group_load_into_temps (args[i].reg, args[i].value,
701 type, int_size_in_bytes (type));
704 /* If the value is expensive, and we are inside an appropriately
705 short loop, put the value into a pseudo and then put the pseudo
706 into the hard reg.
708 For small register classes, also do this if this call uses
709 register parameters. This is to avoid reload conflicts while
710 loading the parameters registers. */
712 else if ((! (REG_P (args[i].value)
713 || (GET_CODE (args[i].value) == SUBREG
714 && REG_P (SUBREG_REG (args[i].value)))))
715 && args[i].mode != BLKmode
716 && rtx_cost (args[i].value, SET, optimize_insn_for_speed_p ())
717 > COSTS_N_INSNS (1)
718 && ((SMALL_REGISTER_CLASSES && *reg_parm_seen)
719 || optimize))
720 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
724 #ifdef REG_PARM_STACK_SPACE
726 /* The argument list is the property of the called routine and it
727 may clobber it. If the fixed area has been used for previous
728 parameters, we must save and restore it. */
730 static rtx
731 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
733 int low;
734 int high;
736 /* Compute the boundary of the area that needs to be saved, if any. */
737 high = reg_parm_stack_space;
738 #ifdef ARGS_GROW_DOWNWARD
739 high += 1;
740 #endif
741 if (high > highest_outgoing_arg_in_use)
742 high = highest_outgoing_arg_in_use;
744 for (low = 0; low < high; low++)
745 if (stack_usage_map[low] != 0)
747 int num_to_save;
748 enum machine_mode save_mode;
749 int delta;
750 rtx stack_area;
751 rtx save_area;
753 while (stack_usage_map[--high] == 0)
756 *low_to_save = low;
757 *high_to_save = high;
759 num_to_save = high - low + 1;
760 save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
762 /* If we don't have the required alignment, must do this
763 in BLKmode. */
764 if ((low & (MIN (GET_MODE_SIZE (save_mode),
765 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
766 save_mode = BLKmode;
768 #ifdef ARGS_GROW_DOWNWARD
769 delta = -high;
770 #else
771 delta = low;
772 #endif
773 stack_area = gen_rtx_MEM (save_mode,
774 memory_address (save_mode,
775 plus_constant (argblock,
776 delta)));
778 set_mem_align (stack_area, PARM_BOUNDARY);
779 if (save_mode == BLKmode)
781 save_area = assign_stack_temp (BLKmode, num_to_save, 0);
782 emit_block_move (validize_mem (save_area), stack_area,
783 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
785 else
787 save_area = gen_reg_rtx (save_mode);
788 emit_move_insn (save_area, stack_area);
791 return save_area;
794 return NULL_RTX;
797 static void
798 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
800 enum machine_mode save_mode = GET_MODE (save_area);
801 int delta;
802 rtx stack_area;
804 #ifdef ARGS_GROW_DOWNWARD
805 delta = -high_to_save;
806 #else
807 delta = low_to_save;
808 #endif
809 stack_area = gen_rtx_MEM (save_mode,
810 memory_address (save_mode,
811 plus_constant (argblock, delta)));
812 set_mem_align (stack_area, PARM_BOUNDARY);
814 if (save_mode != BLKmode)
815 emit_move_insn (stack_area, save_area);
816 else
817 emit_block_move (stack_area, validize_mem (save_area),
818 GEN_INT (high_to_save - low_to_save + 1),
819 BLOCK_OP_CALL_PARM);
821 #endif /* REG_PARM_STACK_SPACE */
823 /* If any elements in ARGS refer to parameters that are to be passed in
824 registers, but not in memory, and whose alignment does not permit a
825 direct copy into registers. Copy the values into a group of pseudos
826 which we will later copy into the appropriate hard registers.
828 Pseudos for each unaligned argument will be stored into the array
829 args[argnum].aligned_regs. The caller is responsible for deallocating
830 the aligned_regs array if it is nonzero. */
832 static void
833 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
835 int i, j;
837 for (i = 0; i < num_actuals; i++)
838 if (args[i].reg != 0 && ! args[i].pass_on_stack
839 && args[i].mode == BLKmode
840 && (TYPE_ALIGN (TREE_TYPE (args[i].tree_value))
841 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
843 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
844 int endian_correction = 0;
846 if (args[i].partial)
848 gcc_assert (args[i].partial % UNITS_PER_WORD == 0);
849 args[i].n_aligned_regs = args[i].partial / UNITS_PER_WORD;
851 else
853 args[i].n_aligned_regs
854 = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
857 args[i].aligned_regs = XNEWVEC (rtx, args[i].n_aligned_regs);
859 /* Structures smaller than a word are normally aligned to the
860 least significant byte. On a BYTES_BIG_ENDIAN machine,
861 this means we must skip the empty high order bytes when
862 calculating the bit offset. */
863 if (bytes < UNITS_PER_WORD
864 #ifdef BLOCK_REG_PADDING
865 && (BLOCK_REG_PADDING (args[i].mode,
866 TREE_TYPE (args[i].tree_value), 1)
867 == downward)
868 #else
869 && BYTES_BIG_ENDIAN
870 #endif
872 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
874 for (j = 0; j < args[i].n_aligned_regs; j++)
876 rtx reg = gen_reg_rtx (word_mode);
877 rtx word = operand_subword_force (args[i].value, j, BLKmode);
878 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
880 args[i].aligned_regs[j] = reg;
881 word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
882 word_mode, word_mode);
884 /* There is no need to restrict this code to loading items
885 in TYPE_ALIGN sized hunks. The bitfield instructions can
886 load up entire word sized registers efficiently.
888 ??? This may not be needed anymore.
889 We use to emit a clobber here but that doesn't let later
890 passes optimize the instructions we emit. By storing 0 into
891 the register later passes know the first AND to zero out the
892 bitfield being set in the register is unnecessary. The store
893 of 0 will be deleted as will at least the first AND. */
895 emit_move_insn (reg, const0_rtx);
897 bytes -= bitsize / BITS_PER_UNIT;
898 store_bit_field (reg, bitsize, endian_correction, word_mode,
899 word);
904 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
905 CALL_EXPR EXP.
907 NUM_ACTUALS is the total number of parameters.
909 N_NAMED_ARGS is the total number of named arguments.
911 STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
912 value, or null.
914 FNDECL is the tree code for the target of this call (if known)
916 ARGS_SO_FAR holds state needed by the target to know where to place
917 the next argument.
919 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
920 for arguments which are passed in registers.
922 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
923 and may be modified by this routine.
925 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
926 flags which may may be modified by this routine.
928 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
929 that requires allocation of stack space.
931 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
932 the thunked-to function. */
934 static void
935 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
936 struct arg_data *args,
937 struct args_size *args_size,
938 int n_named_args ATTRIBUTE_UNUSED,
939 tree exp, tree struct_value_addr_value,
940 tree fndecl,
941 CUMULATIVE_ARGS *args_so_far,
942 int reg_parm_stack_space,
943 rtx *old_stack_level, int *old_pending_adj,
944 int *must_preallocate, int *ecf_flags,
945 bool *may_tailcall, bool call_from_thunk_p)
947 /* 1 if scanning parms front to back, -1 if scanning back to front. */
948 int inc;
950 /* Count arg position in order args appear. */
951 int argpos;
953 int i;
955 args_size->constant = 0;
956 args_size->var = 0;
958 /* In this loop, we consider args in the order they are written.
959 We fill up ARGS from the front or from the back if necessary
960 so that in any case the first arg to be pushed ends up at the front. */
962 if (PUSH_ARGS_REVERSED)
964 i = num_actuals - 1, inc = -1;
965 /* In this case, must reverse order of args
966 so that we compute and push the last arg first. */
968 else
970 i = 0, inc = 1;
973 /* First fill in the actual arguments in the ARGS array, splitting
974 complex arguments if necessary. */
976 int j = i;
977 call_expr_arg_iterator iter;
978 tree arg;
980 if (struct_value_addr_value)
982 args[j].tree_value = struct_value_addr_value;
983 j += inc;
985 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
987 tree argtype = TREE_TYPE (arg);
988 if (targetm.calls.split_complex_arg
989 && argtype
990 && TREE_CODE (argtype) == COMPLEX_TYPE
991 && targetm.calls.split_complex_arg (argtype))
993 tree subtype = TREE_TYPE (argtype);
994 arg = save_expr (arg);
995 args[j].tree_value = build1 (REALPART_EXPR, subtype, arg);
996 j += inc;
997 args[j].tree_value = build1 (IMAGPART_EXPR, subtype, arg);
999 else
1000 args[j].tree_value = arg;
1001 j += inc;
1005 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1006 for (argpos = 0; argpos < num_actuals; i += inc, argpos++)
1008 tree type = TREE_TYPE (args[i].tree_value);
1009 int unsignedp;
1010 enum machine_mode mode;
1012 /* Replace erroneous argument with constant zero. */
1013 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1014 args[i].tree_value = integer_zero_node, type = integer_type_node;
1016 /* If TYPE is a transparent union, pass things the way we would
1017 pass the first field of the union. We have already verified that
1018 the modes are the same. */
1019 if (TREE_CODE (type) == UNION_TYPE && TYPE_TRANSPARENT_UNION (type))
1020 type = TREE_TYPE (TYPE_FIELDS (type));
1022 /* Decide where to pass this arg.
1024 args[i].reg is nonzero if all or part is passed in registers.
1026 args[i].partial is nonzero if part but not all is passed in registers,
1027 and the exact value says how many bytes are passed in registers.
1029 args[i].pass_on_stack is nonzero if the argument must at least be
1030 computed on the stack. It may then be loaded back into registers
1031 if args[i].reg is nonzero.
1033 These decisions are driven by the FUNCTION_... macros and must agree
1034 with those made by function.c. */
1036 /* See if this argument should be passed by invisible reference. */
1037 if (pass_by_reference (args_so_far, TYPE_MODE (type),
1038 type, argpos < n_named_args))
1040 bool callee_copies;
1041 tree base;
1043 callee_copies
1044 = reference_callee_copied (args_so_far, TYPE_MODE (type),
1045 type, argpos < n_named_args);
1047 /* If we're compiling a thunk, pass through invisible references
1048 instead of making a copy. */
1049 if (call_from_thunk_p
1050 || (callee_copies
1051 && !TREE_ADDRESSABLE (type)
1052 && (base = get_base_address (args[i].tree_value))
1053 && (!DECL_P (base) || MEM_P (DECL_RTL (base)))))
1055 /* We can't use sibcalls if a callee-copied argument is
1056 stored in the current function's frame. */
1057 if (!call_from_thunk_p && DECL_P (base) && !TREE_STATIC (base))
1058 *may_tailcall = false;
1060 args[i].tree_value = build_fold_addr_expr (args[i].tree_value);
1061 type = TREE_TYPE (args[i].tree_value);
1063 if (*ecf_flags & ECF_CONST)
1064 *ecf_flags &= ~(ECF_CONST | ECF_LOOPING_CONST_OR_PURE);
1066 else
1068 /* We make a copy of the object and pass the address to the
1069 function being called. */
1070 rtx copy;
1072 if (!COMPLETE_TYPE_P (type)
1073 || TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST
1074 || (flag_stack_check == GENERIC_STACK_CHECK
1075 && compare_tree_int (TYPE_SIZE_UNIT (type),
1076 STACK_CHECK_MAX_VAR_SIZE) > 0))
1078 /* This is a variable-sized object. Make space on the stack
1079 for it. */
1080 rtx size_rtx = expr_size (args[i].tree_value);
1082 if (*old_stack_level == 0)
1084 emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX);
1085 *old_pending_adj = pending_stack_adjust;
1086 pending_stack_adjust = 0;
1089 copy = gen_rtx_MEM (BLKmode,
1090 allocate_dynamic_stack_space
1091 (size_rtx, NULL_RTX, TYPE_ALIGN (type)));
1092 set_mem_attributes (copy, type, 1);
1094 else
1095 copy = assign_temp (type, 0, 1, 0);
1097 store_expr (args[i].tree_value, copy, 0, false);
1099 /* Just change the const function to pure and then let
1100 the next test clear the pure based on
1101 callee_copies. */
1102 if (*ecf_flags & ECF_CONST)
1104 *ecf_flags &= ~ECF_CONST;
1105 *ecf_flags |= ECF_PURE;
1108 if (!callee_copies && *ecf_flags & ECF_PURE)
1109 *ecf_flags &= ~(ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
1111 args[i].tree_value
1112 = build_fold_addr_expr (make_tree (type, copy));
1113 type = TREE_TYPE (args[i].tree_value);
1114 *may_tailcall = false;
1118 mode = TYPE_MODE (type);
1119 unsignedp = TYPE_UNSIGNED (type);
1121 if (targetm.calls.promote_function_args (fndecl ? TREE_TYPE (fndecl) : 0))
1122 mode = promote_mode (type, mode, &unsignedp, 1);
1124 args[i].unsignedp = unsignedp;
1125 args[i].mode = mode;
1127 args[i].reg = FUNCTION_ARG (*args_so_far, mode, type,
1128 argpos < n_named_args);
1129 #ifdef FUNCTION_INCOMING_ARG
1130 /* If this is a sibling call and the machine has register windows, the
1131 register window has to be unwinded before calling the routine, so
1132 arguments have to go into the incoming registers. */
1133 args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type,
1134 argpos < n_named_args);
1135 #else
1136 args[i].tail_call_reg = args[i].reg;
1137 #endif
1139 if (args[i].reg)
1140 args[i].partial
1141 = targetm.calls.arg_partial_bytes (args_so_far, mode, type,
1142 argpos < n_named_args);
1144 args[i].pass_on_stack = targetm.calls.must_pass_in_stack (mode, type);
1146 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1147 it means that we are to pass this arg in the register(s) designated
1148 by the PARALLEL, but also to pass it in the stack. */
1149 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1150 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1151 args[i].pass_on_stack = 1;
1153 /* If this is an addressable type, we must preallocate the stack
1154 since we must evaluate the object into its final location.
1156 If this is to be passed in both registers and the stack, it is simpler
1157 to preallocate. */
1158 if (TREE_ADDRESSABLE (type)
1159 || (args[i].pass_on_stack && args[i].reg != 0))
1160 *must_preallocate = 1;
1162 /* Compute the stack-size of this argument. */
1163 if (args[i].reg == 0 || args[i].partial != 0
1164 || reg_parm_stack_space > 0
1165 || args[i].pass_on_stack)
1166 locate_and_pad_parm (mode, type,
1167 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1169 #else
1170 args[i].reg != 0,
1171 #endif
1172 args[i].pass_on_stack ? 0 : args[i].partial,
1173 fndecl, args_size, &args[i].locate);
1174 #ifdef BLOCK_REG_PADDING
1175 else
1176 /* The argument is passed entirely in registers. See at which
1177 end it should be padded. */
1178 args[i].locate.where_pad =
1179 BLOCK_REG_PADDING (mode, type,
1180 int_size_in_bytes (type) <= UNITS_PER_WORD);
1181 #endif
1183 /* Update ARGS_SIZE, the total stack space for args so far. */
1185 args_size->constant += args[i].locate.size.constant;
1186 if (args[i].locate.size.var)
1187 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
1189 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1190 have been used, etc. */
1192 FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type,
1193 argpos < n_named_args);
1197 /* Update ARGS_SIZE to contain the total size for the argument block.
1198 Return the original constant component of the argument block's size.
1200 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1201 for arguments passed in registers. */
1203 static int
1204 compute_argument_block_size (int reg_parm_stack_space,
1205 struct args_size *args_size,
1206 tree fndecl ATTRIBUTE_UNUSED,
1207 int preferred_stack_boundary ATTRIBUTE_UNUSED)
1209 int unadjusted_args_size = args_size->constant;
1211 /* For accumulate outgoing args mode we don't need to align, since the frame
1212 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1213 backends from generating misaligned frame sizes. */
1214 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1215 preferred_stack_boundary = STACK_BOUNDARY;
1217 /* Compute the actual size of the argument block required. The variable
1218 and constant sizes must be combined, the size may have to be rounded,
1219 and there may be a minimum required size. */
1221 if (args_size->var)
1223 args_size->var = ARGS_SIZE_TREE (*args_size);
1224 args_size->constant = 0;
1226 preferred_stack_boundary /= BITS_PER_UNIT;
1227 if (preferred_stack_boundary > 1)
1229 /* We don't handle this case yet. To handle it correctly we have
1230 to add the delta, round and subtract the delta.
1231 Currently no machine description requires this support. */
1232 gcc_assert (!(stack_pointer_delta & (preferred_stack_boundary - 1)));
1233 args_size->var = round_up (args_size->var, preferred_stack_boundary);
1236 if (reg_parm_stack_space > 0)
1238 args_size->var
1239 = size_binop (MAX_EXPR, args_size->var,
1240 ssize_int (reg_parm_stack_space));
1242 /* The area corresponding to register parameters is not to count in
1243 the size of the block we need. So make the adjustment. */
1244 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL_TREE : TREE_TYPE (fndecl))))
1245 args_size->var
1246 = size_binop (MINUS_EXPR, args_size->var,
1247 ssize_int (reg_parm_stack_space));
1250 else
1252 preferred_stack_boundary /= BITS_PER_UNIT;
1253 if (preferred_stack_boundary < 1)
1254 preferred_stack_boundary = 1;
1255 args_size->constant = (((args_size->constant
1256 + stack_pointer_delta
1257 + preferred_stack_boundary - 1)
1258 / preferred_stack_boundary
1259 * preferred_stack_boundary)
1260 - stack_pointer_delta);
1262 args_size->constant = MAX (args_size->constant,
1263 reg_parm_stack_space);
1265 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL_TREE : TREE_TYPE (fndecl))))
1266 args_size->constant -= reg_parm_stack_space;
1268 return unadjusted_args_size;
1271 /* Precompute parameters as needed for a function call.
1273 FLAGS is mask of ECF_* constants.
1275 NUM_ACTUALS is the number of arguments.
1277 ARGS is an array containing information for each argument; this
1278 routine fills in the INITIAL_VALUE and VALUE fields for each
1279 precomputed argument. */
1281 static void
1282 precompute_arguments (int num_actuals, struct arg_data *args)
1284 int i;
1286 /* If this is a libcall, then precompute all arguments so that we do not
1287 get extraneous instructions emitted as part of the libcall sequence. */
1289 /* If we preallocated the stack space, and some arguments must be passed
1290 on the stack, then we must precompute any parameter which contains a
1291 function call which will store arguments on the stack.
1292 Otherwise, evaluating the parameter may clobber previous parameters
1293 which have already been stored into the stack. (we have code to avoid
1294 such case by saving the outgoing stack arguments, but it results in
1295 worse code) */
1296 if (!ACCUMULATE_OUTGOING_ARGS)
1297 return;
1299 for (i = 0; i < num_actuals; i++)
1301 enum machine_mode mode;
1303 if (TREE_CODE (args[i].tree_value) != CALL_EXPR)
1304 continue;
1306 /* If this is an addressable type, we cannot pre-evaluate it. */
1307 gcc_assert (!TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)));
1309 args[i].initial_value = args[i].value
1310 = expand_normal (args[i].tree_value);
1312 mode = TYPE_MODE (TREE_TYPE (args[i].tree_value));
1313 if (mode != args[i].mode)
1315 args[i].value
1316 = convert_modes (args[i].mode, mode,
1317 args[i].value, args[i].unsignedp);
1318 #if defined(PROMOTE_FUNCTION_MODE) && !defined(PROMOTE_MODE)
1319 /* CSE will replace this only if it contains args[i].value
1320 pseudo, so convert it down to the declared mode using
1321 a SUBREG. */
1322 if (REG_P (args[i].value)
1323 && GET_MODE_CLASS (args[i].mode) == MODE_INT)
1325 args[i].initial_value
1326 = gen_lowpart_SUBREG (mode, args[i].value);
1327 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1328 SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value,
1329 args[i].unsignedp);
1331 #endif
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. */
1340 static int
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
1361 PUSH_ROUNDING. */
1363 if (! must_preallocate)
1365 int partial_seen = 0;
1366 int copy_to_evaluate_size = 0;
1367 int i;
1369 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1371 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1372 partial_seen = 1;
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. */
1400 static void
1401 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
1403 if (argblock)
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);
1415 rtx addr;
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
1422 && args[i].reg != 0
1423 && args[i].partial == 0)
1424 continue;
1426 if (GET_CODE (offset) == CONST_INT)
1427 addr = plus_constant (arg_reg, INTVAL (offset));
1428 else
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,
1439 MODE_INT, 1);
1440 args[i].stack = gen_rtx_MEM (partial_mode, addr);
1441 set_mem_size (args[i].stack, GEN_INT (units_on_stack));
1443 else
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)
1452 align = boundary;
1453 else if (GET_CODE (offset) == CONST_INT)
1455 align = INTVAL (offset) * BITS_PER_UNIT | boundary;
1456 align = align & -align;
1458 set_mem_align (args[i].stack, align);
1460 if (GET_CODE (slot_offset) == CONST_INT)
1461 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1462 else
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));
1475 else
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. */
1501 static rtx
1502 rtx_for_function_call (tree fndecl, tree addr)
1504 rtx funexp;
1506 /* Get the function to call, in the form of RTL. */
1507 if (fndecl)
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);
1520 else
1521 /* Generate an rtx (probably a pseudo-register) for the address. */
1523 push_temp_slots ();
1524 funexp = expand_normal (addr);
1525 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1527 return funexp;
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
1533 sibcall. */
1535 static bool
1536 mem_overlaps_already_clobbered_arg_p (rtx addr, unsigned HOST_WIDE_INT size)
1538 HOST_WIDE_INT i;
1540 if (addr == crtl->args.internal_arg_pointer)
1541 i = 0;
1542 else if (GET_CODE (addr) == PLUS
1543 && XEXP (addr, 0) == crtl->args.internal_arg_pointer
1544 && GET_CODE (XEXP (addr, 1)) == CONST_INT)
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))
1550 return true;
1551 else
1552 return false;
1554 #ifdef ARGS_GROW_DOWNWARD
1555 i = -i - size;
1556 #endif
1557 if (size > 0)
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))
1564 return true;
1567 return false;
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. */
1580 static void
1581 load_register_parameters (struct arg_data *args, int num_actuals,
1582 rtx *call_fusage, int flags, int is_sibcall,
1583 int *sibcall_failure)
1585 int i, j;
1587 for (i = 0; i < num_actuals; i++)
1589 rtx reg = ((flags & ECF_SIBCALL)
1590 ? args[i].tail_call_reg : args[i].reg);
1591 if (reg)
1593 int partial = args[i].partial;
1594 int nregs;
1595 int size = 0;
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. */
1601 nregs = -1;
1602 if (GET_CODE (reg) == PARALLEL)
1604 else if (partial)
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;
1614 else
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)))
1638 rtx x;
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),
1648 reg, 1);
1649 if (x != reg)
1650 emit_move_insn (reg, x);
1652 #endif
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. */
1668 if (is_sibcall
1669 && mem_overlaps_already_clobbered_arg_p (XEXP (args[i].value, 0),
1670 size))
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
1677 #else
1678 && BYTES_BIG_ENDIAN
1679 #endif
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
1687 : LSHIFT_EXPR;
1689 emit_move_insn (x, tem);
1690 x = expand_shift (dir, word_mode, x,
1691 build_int_cst (NULL_TREE, shift),
1692 ri, 1);
1693 if (x != ri)
1694 emit_move_insn (ri, x);
1696 else
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. */
1703 if (is_sibcall
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);
1713 else if (nregs > 0)
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. */
1728 static int
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;
1761 else
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. */
1769 args_size->constant
1770 = pending_stack_adjust - adjustment + unadjusted_args_size;
1772 return adjustment;
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
1777 bitmap).
1778 Return nonzero if X expression dereferences such argument slots,
1779 zero otherwise. */
1781 static int
1782 check_sibcall_argument_overlap_1 (rtx x)
1784 RTX_CODE code;
1785 int i, j;
1786 const char *fmt;
1788 if (x == NULL_RTX)
1789 return 0;
1791 code = GET_CODE (x);
1793 if (code == MEM)
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++)
1801 if (*fmt == 'e')
1803 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
1804 return 1;
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)))
1810 return 1;
1813 return 0;
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. */
1823 static int
1824 check_sibcall_argument_overlap (rtx insn, struct arg_data *arg, int mark_stored_args_map)
1826 int low, high;
1828 if (insn == NULL_RTX)
1829 insn = get_insns ();
1830 else
1831 insn = NEXT_INSN (insn);
1833 for (; insn; insn = NEXT_INSN (insn))
1834 if (INSN_P (insn)
1835 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
1836 break;
1838 if (mark_stored_args_map)
1840 #ifdef ARGS_GROW_DOWNWARD
1841 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
1842 #else
1843 low = arg->locate.slot_offset.constant;
1844 #endif
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. */
1856 bool
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);
1863 if (shift == 0)
1864 return false;
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))
1871 gcc_unreachable ();
1872 return true;
1875 /* If X is a likely-spilled register value, copy it to a pseudo
1876 register and return that register. Return X otherwise. */
1878 static rtx
1879 avoid_likely_spilled_reg (rtx x)
1881 rtx new_rtx;
1883 if (REG_P (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);
1895 return new_rtx;
1897 return 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. */
1913 rtx funexp;
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. */
1919 tree funtype;
1920 tree type_arg_types;
1921 /* Declaration of the function being called,
1922 or 0 if the function is computed (not known by name). */
1923 tree fndecl = 0;
1924 /* The type of the function being called. */
1925 tree fntype;
1926 bool try_tail_call = CALL_EXPR_TAILCALL (exp);
1927 int pass;
1929 /* Register in which non-BLKmode value will be returned,
1930 or 0 if no value or if value is BLKmode. */
1931 rtx valreg;
1932 /* Address where we should return a BLKmode value;
1933 0 if value not BLKmode. */
1934 rtx structure_value_addr = 0;
1935 /* Nonzero if that address is being passed by treating it as
1936 an extra, implicit first parameter. Otherwise,
1937 it is passed by being copied directly into struct_value_rtx. */
1938 int structure_value_addr_parm = 0;
1939 /* Holds the value of implicit argument for the struct value. */
1940 tree structure_value_addr_value = NULL_TREE;
1941 /* Size of aggregate value wanted, or zero if none wanted
1942 or if we are using the non-reentrant PCC calling convention
1943 or expecting the value in registers. */
1944 HOST_WIDE_INT struct_value_size = 0;
1945 /* Nonzero if called function returns an aggregate in memory PCC style,
1946 by returning the address of where to find it. */
1947 int pcc_struct_value = 0;
1948 rtx struct_value = 0;
1950 /* Number of actual parameters in this call, including struct value addr. */
1951 int num_actuals;
1952 /* Number of named args. Args after this are anonymous ones
1953 and they must all go on the stack. */
1954 int n_named_args;
1955 /* Number of complex actual arguments that need to be split. */
1956 int num_complex_actuals = 0;
1958 /* Vector of information about each argument.
1959 Arguments are numbered in the order they will be pushed,
1960 not the order they are written. */
1961 struct arg_data *args;
1963 /* Total size in bytes of all the stack-parms scanned so far. */
1964 struct args_size args_size;
1965 struct args_size adjusted_args_size;
1966 /* Size of arguments before any adjustments (such as rounding). */
1967 int unadjusted_args_size;
1968 /* Data on reg parms scanned so far. */
1969 CUMULATIVE_ARGS args_so_far;
1970 /* Nonzero if a reg parm has been scanned. */
1971 int reg_parm_seen;
1972 /* Nonzero if this is an indirect function call. */
1974 /* Nonzero if we must avoid push-insns in the args for this call.
1975 If stack space is allocated for register parameters, but not by the
1976 caller, then it is preallocated in the fixed part of the stack frame.
1977 So the entire argument block must then be preallocated (i.e., we
1978 ignore PUSH_ROUNDING in that case). */
1980 int must_preallocate = !PUSH_ARGS;
1982 /* Size of the stack reserved for parameter registers. */
1983 int reg_parm_stack_space = 0;
1985 /* Address of space preallocated for stack parms
1986 (on machines that lack push insns), or 0 if space not preallocated. */
1987 rtx argblock = 0;
1989 /* Mask of ECF_ flags. */
1990 int flags = 0;
1991 #ifdef REG_PARM_STACK_SPACE
1992 /* Define the boundary of the register parm stack space that needs to be
1993 saved, if any. */
1994 int low_to_save, high_to_save;
1995 rtx save_area = 0; /* Place that it is saved */
1996 #endif
1998 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
1999 char *initial_stack_usage_map = stack_usage_map;
2000 char *stack_usage_map_buf = NULL;
2002 int old_stack_allocated;
2004 /* State variables to track stack modifications. */
2005 rtx old_stack_level = 0;
2006 int old_stack_arg_under_construction = 0;
2007 int old_pending_adj = 0;
2008 int old_inhibit_defer_pop = inhibit_defer_pop;
2010 /* Some stack pointer alterations we make are performed via
2011 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
2012 which we then also need to save/restore along the way. */
2013 int old_stack_pointer_delta = 0;
2015 rtx call_fusage;
2016 tree p = CALL_EXPR_FN (exp);
2017 tree addr = CALL_EXPR_FN (exp);
2018 int i;
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);
2032 if (fndecl)
2034 fntype = TREE_TYPE (fndecl);
2035 flags |= flags_from_decl_or_type (fndecl);
2037 else
2039 fntype = TREE_TYPE (TREE_TYPE (p));
2040 flags |= flags_from_decl_or_type (fntype);
2043 struct_value = targetm.calls.struct_value_rtx (fntype, 0);
2045 /* Warn if this value is an aggregate type,
2046 regardless of which calling convention we are using for it. */
2047 if (AGGREGATE_TYPE_P (TREE_TYPE (exp)))
2048 warning (OPT_Waggregate_return, "function call has aggregate value");
2050 /* If the result of a non looping pure or const function call is
2051 ignored (or void), and none of its arguments are volatile, we can
2052 avoid expanding the call and just evaluate the arguments for
2053 side-effects. */
2054 if ((flags & (ECF_CONST | ECF_PURE))
2055 && (!(flags & ECF_LOOPING_CONST_OR_PURE))
2056 && (ignore || target == const0_rtx
2057 || TYPE_MODE (TREE_TYPE (exp)) == VOIDmode))
2059 bool volatilep = false;
2060 tree arg;
2061 call_expr_arg_iterator iter;
2063 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2064 if (TREE_THIS_VOLATILE (arg))
2066 volatilep = true;
2067 break;
2070 if (! volatilep)
2072 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2073 expand_expr (arg, const0_rtx, VOIDmode, EXPAND_NORMAL);
2074 return const0_rtx;
2078 #ifdef REG_PARM_STACK_SPACE
2079 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
2080 #endif
2082 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL_TREE : TREE_TYPE (fndecl)))
2083 && reg_parm_stack_space > 0 && PUSH_ARGS)
2084 must_preallocate = 1;
2086 /* Set up a place to return a structure. */
2088 /* Cater to broken compilers. */
2089 if (aggregate_value_p (exp, fndecl))
2091 /* This call returns a big structure. */
2092 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
2094 #ifdef PCC_STATIC_STRUCT_RETURN
2096 pcc_struct_value = 1;
2098 #else /* not PCC_STATIC_STRUCT_RETURN */
2100 struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
2102 if (target && MEM_P (target) && CALL_EXPR_RETURN_SLOT_OPT (exp))
2103 structure_value_addr = XEXP (target, 0);
2104 else
2106 /* For variable-sized objects, we must be called with a target
2107 specified. If we were to allocate space on the stack here,
2108 we would have no way of knowing when to free it. */
2109 rtx d = assign_temp (TREE_TYPE (exp), 0, 1, 1);
2111 mark_temp_addr_taken (d);
2112 structure_value_addr = XEXP (d, 0);
2113 target = 0;
2116 #endif /* not PCC_STATIC_STRUCT_RETURN */
2119 /* Figure out the amount to which the stack should be aligned. */
2120 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2121 if (fndecl)
2123 struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl);
2124 /* Without automatic stack alignment, we can't increase preferred
2125 stack boundary. With automatic stack alignment, it is
2126 unnecessary since unless we can guarantee that all callers will
2127 align the outgoing stack properly, callee has to align its
2128 stack anyway. */
2129 if (i
2130 && i->preferred_incoming_stack_boundary
2131 && i->preferred_incoming_stack_boundary < preferred_stack_boundary)
2132 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
2135 /* Operand 0 is a pointer-to-function; get the type of the function. */
2136 funtype = TREE_TYPE (addr);
2137 gcc_assert (POINTER_TYPE_P (funtype));
2138 funtype = TREE_TYPE (funtype);
2140 /* Count whether there are actual complex arguments that need to be split
2141 into their real and imaginary parts. Munge the type_arg_types
2142 appropriately here as well. */
2143 if (targetm.calls.split_complex_arg)
2145 call_expr_arg_iterator iter;
2146 tree arg;
2147 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2149 tree type = TREE_TYPE (arg);
2150 if (type && TREE_CODE (type) == COMPLEX_TYPE
2151 && targetm.calls.split_complex_arg (type))
2152 num_complex_actuals++;
2154 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
2156 else
2157 type_arg_types = TYPE_ARG_TYPES (funtype);
2159 if (flags & ECF_MAY_BE_ALLOCA)
2160 cfun->calls_alloca = 1;
2162 /* If struct_value_rtx is 0, it means pass the address
2163 as if it were an extra parameter. Put the argument expression
2164 in structure_value_addr_value. */
2165 if (structure_value_addr && struct_value == 0)
2167 /* If structure_value_addr is a REG other than
2168 virtual_outgoing_args_rtx, we can use always use it. If it
2169 is not a REG, we must always copy it into a register.
2170 If it is virtual_outgoing_args_rtx, we must copy it to another
2171 register in some cases. */
2172 rtx temp = (!REG_P (structure_value_addr)
2173 || (ACCUMULATE_OUTGOING_ARGS
2174 && stack_arg_under_construction
2175 && structure_value_addr == virtual_outgoing_args_rtx)
2176 ? copy_addr_to_reg (convert_memory_address
2177 (Pmode, structure_value_addr))
2178 : structure_value_addr);
2180 structure_value_addr_value =
2181 make_tree (build_pointer_type (TREE_TYPE (funtype)), temp);
2182 structure_value_addr_parm = 1;
2185 /* Count the arguments and set NUM_ACTUALS. */
2186 num_actuals =
2187 call_expr_nargs (exp) + num_complex_actuals + structure_value_addr_parm;
2189 /* Compute number of named args.
2190 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
2192 if (type_arg_types != 0)
2193 n_named_args
2194 = (list_length (type_arg_types)
2195 /* Count the struct value address, if it is passed as a parm. */
2196 + structure_value_addr_parm);
2197 else
2198 /* If we know nothing, treat all args as named. */
2199 n_named_args = num_actuals;
2201 /* Start updating where the next arg would go.
2203 On some machines (such as the PA) indirect calls have a different
2204 calling convention than normal calls. The fourth argument in
2205 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2206 or not. */
2207 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, fndecl, n_named_args);
2209 /* Now possibly adjust the number of named args.
2210 Normally, don't include the last named arg if anonymous args follow.
2211 We do include the last named arg if
2212 targetm.calls.strict_argument_naming() returns nonzero.
2213 (If no anonymous args follow, the result of list_length is actually
2214 one too large. This is harmless.)
2216 If targetm.calls.pretend_outgoing_varargs_named() returns
2217 nonzero, and targetm.calls.strict_argument_naming() returns zero,
2218 this machine will be able to place unnamed args that were passed
2219 in registers into the stack. So treat all args as named. This
2220 allows the insns emitting for a specific argument list to be
2221 independent of the function declaration.
2223 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
2224 we do not have any reliable way to pass unnamed args in
2225 registers, so we must force them into memory. */
2227 if (type_arg_types != 0
2228 && targetm.calls.strict_argument_naming (&args_so_far))
2230 else if (type_arg_types != 0
2231 && ! targetm.calls.pretend_outgoing_varargs_named (&args_so_far))
2232 /* Don't include the last named arg. */
2233 --n_named_args;
2234 else
2235 /* Treat all args as named. */
2236 n_named_args = num_actuals;
2238 /* Make a vector to hold all the information about each arg. */
2239 args = XALLOCAVEC (struct arg_data, num_actuals);
2240 memset (args, 0, num_actuals * sizeof (struct arg_data));
2242 /* Build up entries in the ARGS array, compute the size of the
2243 arguments into ARGS_SIZE, etc. */
2244 initialize_argument_information (num_actuals, args, &args_size,
2245 n_named_args, exp,
2246 structure_value_addr_value, fndecl,
2247 &args_so_far, reg_parm_stack_space,
2248 &old_stack_level, &old_pending_adj,
2249 &must_preallocate, &flags,
2250 &try_tail_call, CALL_FROM_THUNK_P (exp));
2252 if (args_size.var)
2253 must_preallocate = 1;
2255 /* Now make final decision about preallocating stack space. */
2256 must_preallocate = finalize_must_preallocate (must_preallocate,
2257 num_actuals, args,
2258 &args_size);
2260 /* If the structure value address will reference the stack pointer, we
2261 must stabilize it. We don't need to do this if we know that we are
2262 not going to adjust the stack pointer in processing this call. */
2264 if (structure_value_addr
2265 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2266 || reg_mentioned_p (virtual_outgoing_args_rtx,
2267 structure_value_addr))
2268 && (args_size.var
2269 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2270 structure_value_addr = copy_to_reg (structure_value_addr);
2272 /* Tail calls can make things harder to debug, and we've traditionally
2273 pushed these optimizations into -O2. Don't try if we're already
2274 expanding a call, as that means we're an argument. Don't try if
2275 there's cleanups, as we know there's code to follow the call. */
2277 if (currently_expanding_call++ != 0
2278 || !flag_optimize_sibling_calls
2279 || args_size.var
2280 || lookup_expr_eh_region (exp) >= 0
2281 || dbg_cnt (tail_call) == false)
2282 try_tail_call = 0;
2284 /* Rest of purposes for tail call optimizations to fail. */
2285 if (
2286 #ifdef HAVE_sibcall_epilogue
2287 !HAVE_sibcall_epilogue
2288 #else
2290 #endif
2291 || !try_tail_call
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 /* Check whether the target is able to optimize the call
2298 into a sibcall. */
2299 || !targetm.function_ok_for_sibcall (fndecl, exp)
2300 /* Functions that do not return exactly once may not be sibcall
2301 optimized. */
2302 || (flags & (ECF_RETURNS_TWICE | ECF_NORETURN))
2303 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr)))
2304 /* If the called function is nested in the current one, it might access
2305 some of the caller's arguments, but could clobber them beforehand if
2306 the argument areas are shared. */
2307 || (fndecl && decl_function_context (fndecl) == current_function_decl)
2308 /* If this function requires more stack slots than the current
2309 function, we cannot change it into a sibling call.
2310 crtl->args.pretend_args_size is not part of the
2311 stack allocated by our caller. */
2312 || args_size.constant > (crtl->args.size
2313 - crtl->args.pretend_args_size)
2314 /* If the callee pops its own arguments, then it must pop exactly
2315 the same number of arguments as the current function. */
2316 || (RETURN_POPS_ARGS (fndecl, funtype, args_size.constant)
2317 != RETURN_POPS_ARGS (current_function_decl,
2318 TREE_TYPE (current_function_decl),
2319 crtl->args.size))
2320 || !lang_hooks.decls.ok_for_sibcall (fndecl))
2321 try_tail_call = 0;
2323 /* Ensure current function's preferred stack boundary is at least
2324 what we need. Stack alignment may also increase preferred stack
2325 boundary. */
2326 if (crtl->preferred_stack_boundary < preferred_stack_boundary)
2327 crtl->preferred_stack_boundary = preferred_stack_boundary;
2328 else
2329 preferred_stack_boundary = crtl->preferred_stack_boundary;
2331 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2333 /* We want to make two insn chains; one for a sibling call, the other
2334 for a normal call. We will select one of the two chains after
2335 initial RTL generation is complete. */
2336 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
2338 int sibcall_failure = 0;
2339 /* We want to emit any pending stack adjustments before the tail
2340 recursion "call". That way we know any adjustment after the tail
2341 recursion call can be ignored if we indeed use the tail
2342 call expansion. */
2343 int save_pending_stack_adjust = 0;
2344 int save_stack_pointer_delta = 0;
2345 rtx insns;
2346 rtx before_call, next_arg_reg, after_args;
2348 if (pass == 0)
2350 /* State variables we need to save and restore between
2351 iterations. */
2352 save_pending_stack_adjust = pending_stack_adjust;
2353 save_stack_pointer_delta = stack_pointer_delta;
2355 if (pass)
2356 flags &= ~ECF_SIBCALL;
2357 else
2358 flags |= ECF_SIBCALL;
2360 /* Other state variables that we must reinitialize each time
2361 through the loop (that are not initialized by the loop itself). */
2362 argblock = 0;
2363 call_fusage = 0;
2365 /* Start a new sequence for the normal call case.
2367 From this point on, if the sibling call fails, we want to set
2368 sibcall_failure instead of continuing the loop. */
2369 start_sequence ();
2371 /* Don't let pending stack adjusts add up to too much.
2372 Also, do all pending adjustments now if there is any chance
2373 this might be a call to alloca or if we are expanding a sibling
2374 call sequence.
2375 Also do the adjustments before a throwing call, otherwise
2376 exception handling can fail; PR 19225. */
2377 if (pending_stack_adjust >= 32
2378 || (pending_stack_adjust > 0
2379 && (flags & ECF_MAY_BE_ALLOCA))
2380 || (pending_stack_adjust > 0
2381 && flag_exceptions && !(flags & ECF_NOTHROW))
2382 || pass == 0)
2383 do_pending_stack_adjust ();
2385 /* Precompute any arguments as needed. */
2386 if (pass)
2387 precompute_arguments (num_actuals, args);
2389 /* Now we are about to start emitting insns that can be deleted
2390 if a libcall is deleted. */
2391 if (pass && (flags & ECF_MALLOC))
2392 start_sequence ();
2394 if (pass == 0 && crtl->stack_protect_guard)
2395 stack_protect_epilogue ();
2397 adjusted_args_size = args_size;
2398 /* Compute the actual size of the argument block required. The variable
2399 and constant sizes must be combined, the size may have to be rounded,
2400 and there may be a minimum required size. When generating a sibcall
2401 pattern, do not round up, since we'll be re-using whatever space our
2402 caller provided. */
2403 unadjusted_args_size
2404 = compute_argument_block_size (reg_parm_stack_space,
2405 &adjusted_args_size,
2406 fndecl,
2407 (pass == 0 ? 0
2408 : preferred_stack_boundary));
2410 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2412 /* The argument block when performing a sibling call is the
2413 incoming argument block. */
2414 if (pass == 0)
2416 argblock = crtl->args.internal_arg_pointer;
2417 argblock
2418 #ifdef STACK_GROWS_DOWNWARD
2419 = plus_constant (argblock, crtl->args.pretend_args_size);
2420 #else
2421 = plus_constant (argblock, -crtl->args.pretend_args_size);
2422 #endif
2423 stored_args_map = sbitmap_alloc (args_size.constant);
2424 sbitmap_zero (stored_args_map);
2427 /* If we have no actual push instructions, or shouldn't use them,
2428 make space for all args right now. */
2429 else if (adjusted_args_size.var != 0)
2431 if (old_stack_level == 0)
2433 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2434 old_stack_pointer_delta = stack_pointer_delta;
2435 old_pending_adj = pending_stack_adjust;
2436 pending_stack_adjust = 0;
2437 /* stack_arg_under_construction says whether a stack arg is
2438 being constructed at the old stack level. Pushing the stack
2439 gets a clean outgoing argument block. */
2440 old_stack_arg_under_construction = stack_arg_under_construction;
2441 stack_arg_under_construction = 0;
2443 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2445 else
2447 /* Note that we must go through the motions of allocating an argument
2448 block even if the size is zero because we may be storing args
2449 in the area reserved for register arguments, which may be part of
2450 the stack frame. */
2452 int needed = adjusted_args_size.constant;
2454 /* Store the maximum argument space used. It will be pushed by
2455 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2456 checking). */
2458 if (needed > crtl->outgoing_args_size)
2459 crtl->outgoing_args_size = needed;
2461 if (must_preallocate)
2463 if (ACCUMULATE_OUTGOING_ARGS)
2465 /* Since the stack pointer will never be pushed, it is
2466 possible for the evaluation of a parm to clobber
2467 something we have already written to the stack.
2468 Since most function calls on RISC machines do not use
2469 the stack, this is uncommon, but must work correctly.
2471 Therefore, we save any area of the stack that was already
2472 written and that we are using. Here we set up to do this
2473 by making a new stack usage map from the old one. The
2474 actual save will be done by store_one_arg.
2476 Another approach might be to try to reorder the argument
2477 evaluations to avoid this conflicting stack usage. */
2479 /* Since we will be writing into the entire argument area,
2480 the map must be allocated for its entire size, not just
2481 the part that is the responsibility of the caller. */
2482 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL_TREE : TREE_TYPE (fndecl))))
2483 needed += reg_parm_stack_space;
2485 #ifdef ARGS_GROW_DOWNWARD
2486 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2487 needed + 1);
2488 #else
2489 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2490 needed);
2491 #endif
2492 if (stack_usage_map_buf)
2493 free (stack_usage_map_buf);
2494 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
2495 stack_usage_map = stack_usage_map_buf;
2497 if (initial_highest_arg_in_use)
2498 memcpy (stack_usage_map, initial_stack_usage_map,
2499 initial_highest_arg_in_use);
2501 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2502 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2503 (highest_outgoing_arg_in_use
2504 - initial_highest_arg_in_use));
2505 needed = 0;
2507 /* The address of the outgoing argument list must not be
2508 copied to a register here, because argblock would be left
2509 pointing to the wrong place after the call to
2510 allocate_dynamic_stack_space below. */
2512 argblock = virtual_outgoing_args_rtx;
2514 else
2516 if (inhibit_defer_pop == 0)
2518 /* Try to reuse some or all of the pending_stack_adjust
2519 to get this space. */
2520 needed
2521 = (combine_pending_stack_adjustment_and_call
2522 (unadjusted_args_size,
2523 &adjusted_args_size,
2524 preferred_unit_stack_boundary));
2526 /* combine_pending_stack_adjustment_and_call computes
2527 an adjustment before the arguments are allocated.
2528 Account for them and see whether or not the stack
2529 needs to go up or down. */
2530 needed = unadjusted_args_size - needed;
2532 if (needed < 0)
2534 /* We're releasing stack space. */
2535 /* ??? We can avoid any adjustment at all if we're
2536 already aligned. FIXME. */
2537 pending_stack_adjust = -needed;
2538 do_pending_stack_adjust ();
2539 needed = 0;
2541 else
2542 /* We need to allocate space. We'll do that in
2543 push_block below. */
2544 pending_stack_adjust = 0;
2547 /* Special case this because overhead of `push_block' in
2548 this case is non-trivial. */
2549 if (needed == 0)
2550 argblock = virtual_outgoing_args_rtx;
2551 else
2553 argblock = push_block (GEN_INT (needed), 0, 0);
2554 #ifdef ARGS_GROW_DOWNWARD
2555 argblock = plus_constant (argblock, needed);
2556 #endif
2559 /* We only really need to call `copy_to_reg' in the case
2560 where push insns are going to be used to pass ARGBLOCK
2561 to a function call in ARGS. In that case, the stack
2562 pointer changes value from the allocation point to the
2563 call point, and hence the value of
2564 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2565 as well always do it. */
2566 argblock = copy_to_reg (argblock);
2571 if (ACCUMULATE_OUTGOING_ARGS)
2573 /* The save/restore code in store_one_arg handles all
2574 cases except one: a constructor call (including a C
2575 function returning a BLKmode struct) to initialize
2576 an argument. */
2577 if (stack_arg_under_construction)
2579 rtx push_size
2580 = GEN_INT (adjusted_args_size.constant
2581 + (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL
2582 : TREE_TYPE (fndecl))) ? 0
2583 : reg_parm_stack_space));
2584 if (old_stack_level == 0)
2586 emit_stack_save (SAVE_BLOCK, &old_stack_level,
2587 NULL_RTX);
2588 old_stack_pointer_delta = stack_pointer_delta;
2589 old_pending_adj = pending_stack_adjust;
2590 pending_stack_adjust = 0;
2591 /* stack_arg_under_construction says whether a stack
2592 arg is being constructed at the old stack level.
2593 Pushing the stack gets a clean outgoing argument
2594 block. */
2595 old_stack_arg_under_construction
2596 = stack_arg_under_construction;
2597 stack_arg_under_construction = 0;
2598 /* Make a new map for the new argument list. */
2599 if (stack_usage_map_buf)
2600 free (stack_usage_map_buf);
2601 stack_usage_map_buf = XCNEWVEC (char, highest_outgoing_arg_in_use);
2602 stack_usage_map = stack_usage_map_buf;
2603 highest_outgoing_arg_in_use = 0;
2605 allocate_dynamic_stack_space (push_size, NULL_RTX,
2606 BITS_PER_UNIT);
2609 /* If argument evaluation might modify the stack pointer,
2610 copy the address of the argument list to a register. */
2611 for (i = 0; i < num_actuals; i++)
2612 if (args[i].pass_on_stack)
2614 argblock = copy_addr_to_reg (argblock);
2615 break;
2619 compute_argument_addresses (args, argblock, num_actuals);
2621 /* If we push args individually in reverse order, perform stack alignment
2622 before the first push (the last arg). */
2623 if (PUSH_ARGS_REVERSED && argblock == 0
2624 && adjusted_args_size.constant != unadjusted_args_size)
2626 /* When the stack adjustment is pending, we get better code
2627 by combining the adjustments. */
2628 if (pending_stack_adjust
2629 && ! inhibit_defer_pop)
2631 pending_stack_adjust
2632 = (combine_pending_stack_adjustment_and_call
2633 (unadjusted_args_size,
2634 &adjusted_args_size,
2635 preferred_unit_stack_boundary));
2636 do_pending_stack_adjust ();
2638 else if (argblock == 0)
2639 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2640 - unadjusted_args_size));
2642 /* Now that the stack is properly aligned, pops can't safely
2643 be deferred during the evaluation of the arguments. */
2644 NO_DEFER_POP;
2646 funexp = rtx_for_function_call (fndecl, addr);
2648 /* Figure out the register where the value, if any, will come back. */
2649 valreg = 0;
2650 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
2651 && ! structure_value_addr)
2653 if (pcc_struct_value)
2654 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
2655 fndecl, NULL, (pass == 0));
2656 else
2657 valreg = hard_function_value (TREE_TYPE (exp), fndecl, fntype,
2658 (pass == 0));
2660 /* If VALREG is a PARALLEL whose first member has a zero
2661 offset, use that. This is for targets such as m68k that
2662 return the same value in multiple places. */
2663 if (GET_CODE (valreg) == PARALLEL)
2665 rtx elem = XVECEXP (valreg, 0, 0);
2666 rtx where = XEXP (elem, 0);
2667 rtx offset = XEXP (elem, 1);
2668 if (offset == const0_rtx
2669 && GET_MODE (where) == GET_MODE (valreg))
2670 valreg = where;
2674 /* Precompute all register parameters. It isn't safe to compute anything
2675 once we have started filling any specific hard regs. */
2676 precompute_register_parameters (num_actuals, args, &reg_parm_seen);
2678 if (CALL_EXPR_STATIC_CHAIN (exp))
2679 static_chain_value = expand_normal (CALL_EXPR_STATIC_CHAIN (exp));
2680 else
2681 static_chain_value = 0;
2683 #ifdef REG_PARM_STACK_SPACE
2684 /* Save the fixed argument area if it's part of the caller's frame and
2685 is clobbered by argument setup for this call. */
2686 if (ACCUMULATE_OUTGOING_ARGS && pass)
2687 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
2688 &low_to_save, &high_to_save);
2689 #endif
2691 /* Now store (and compute if necessary) all non-register parms.
2692 These come before register parms, since they can require block-moves,
2693 which could clobber the registers used for register parms.
2694 Parms which have partial registers are not stored here,
2695 but we do preallocate space here if they want that. */
2697 for (i = 0; i < num_actuals; i++)
2698 if (args[i].reg == 0 || args[i].pass_on_stack)
2700 rtx before_arg = get_last_insn ();
2702 if (store_one_arg (&args[i], argblock, flags,
2703 adjusted_args_size.var != 0,
2704 reg_parm_stack_space)
2705 || (pass == 0
2706 && check_sibcall_argument_overlap (before_arg,
2707 &args[i], 1)))
2708 sibcall_failure = 1;
2710 if (flags & ECF_CONST
2711 && args[i].stack
2712 && args[i].value == args[i].stack)
2713 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
2714 gen_rtx_USE (VOIDmode,
2715 args[i].value),
2716 call_fusage);
2719 /* If we have a parm that is passed in registers but not in memory
2720 and whose alignment does not permit a direct copy into registers,
2721 make a group of pseudos that correspond to each register that we
2722 will later fill. */
2723 if (STRICT_ALIGNMENT)
2724 store_unaligned_arguments_into_pseudos (args, num_actuals);
2726 /* Now store any partially-in-registers parm.
2727 This is the last place a block-move can happen. */
2728 if (reg_parm_seen)
2729 for (i = 0; i < num_actuals; i++)
2730 if (args[i].partial != 0 && ! args[i].pass_on_stack)
2732 rtx before_arg = get_last_insn ();
2734 if (store_one_arg (&args[i], argblock, flags,
2735 adjusted_args_size.var != 0,
2736 reg_parm_stack_space)
2737 || (pass == 0
2738 && check_sibcall_argument_overlap (before_arg,
2739 &args[i], 1)))
2740 sibcall_failure = 1;
2743 /* If we pushed args in forward order, perform stack alignment
2744 after pushing the last arg. */
2745 if (!PUSH_ARGS_REVERSED && argblock == 0)
2746 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2747 - unadjusted_args_size));
2749 /* If register arguments require space on the stack and stack space
2750 was not preallocated, allocate stack space here for arguments
2751 passed in registers. */
2752 if (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL_TREE : TREE_TYPE (fndecl)))
2753 && !ACCUMULATE_OUTGOING_ARGS
2754 && must_preallocate == 0 && reg_parm_stack_space > 0)
2755 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
2757 /* Pass the function the address in which to return a
2758 structure value. */
2759 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
2761 structure_value_addr
2762 = convert_memory_address (Pmode, structure_value_addr);
2763 emit_move_insn (struct_value,
2764 force_reg (Pmode,
2765 force_operand (structure_value_addr,
2766 NULL_RTX)));
2768 if (REG_P (struct_value))
2769 use_reg (&call_fusage, struct_value);
2772 after_args = get_last_insn ();
2773 funexp = prepare_call_address (funexp, static_chain_value,
2774 &call_fusage, reg_parm_seen, pass == 0);
2776 load_register_parameters (args, num_actuals, &call_fusage, flags,
2777 pass == 0, &sibcall_failure);
2779 /* Save a pointer to the last insn before the call, so that we can
2780 later safely search backwards to find the CALL_INSN. */
2781 before_call = get_last_insn ();
2783 /* Set up next argument register. For sibling calls on machines
2784 with register windows this should be the incoming register. */
2785 #ifdef FUNCTION_INCOMING_ARG
2786 if (pass == 0)
2787 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
2788 void_type_node, 1);
2789 else
2790 #endif
2791 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
2792 void_type_node, 1);
2794 /* All arguments and registers used for the call must be set up by
2795 now! */
2797 /* Stack must be properly aligned now. */
2798 gcc_assert (!pass
2799 || !(stack_pointer_delta % preferred_unit_stack_boundary));
2801 /* Generate the actual call instruction. */
2802 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size,
2803 adjusted_args_size.constant, struct_value_size,
2804 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
2805 flags, & args_so_far);
2807 /* If the call setup or the call itself overlaps with anything
2808 of the argument setup we probably clobbered our call address.
2809 In that case we can't do sibcalls. */
2810 if (pass == 0
2811 && check_sibcall_argument_overlap (after_args, 0, 0))
2812 sibcall_failure = 1;
2814 /* If a non-BLKmode value is returned at the most significant end
2815 of a register, shift the register right by the appropriate amount
2816 and update VALREG accordingly. BLKmode values are handled by the
2817 group load/store machinery below. */
2818 if (!structure_value_addr
2819 && !pcc_struct_value
2820 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
2821 && targetm.calls.return_in_msb (TREE_TYPE (exp)))
2823 if (shift_return_value (TYPE_MODE (TREE_TYPE (exp)), false, valreg))
2824 sibcall_failure = 1;
2825 valreg = gen_rtx_REG (TYPE_MODE (TREE_TYPE (exp)), REGNO (valreg));
2828 if (pass && (flags & ECF_MALLOC))
2830 rtx temp = gen_reg_rtx (GET_MODE (valreg));
2831 rtx last, insns;
2833 /* The return value from a malloc-like function is a pointer. */
2834 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
2835 mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
2837 emit_move_insn (temp, valreg);
2839 /* The return value from a malloc-like function can not alias
2840 anything else. */
2841 last = get_last_insn ();
2842 add_reg_note (last, REG_NOALIAS, temp);
2844 /* Write out the sequence. */
2845 insns = get_insns ();
2846 end_sequence ();
2847 emit_insn (insns);
2848 valreg = temp;
2851 /* For calls to `setjmp', etc., inform
2852 function.c:setjmp_warnings that it should complain if
2853 nonvolatile values are live. For functions that cannot
2854 return, inform flow that control does not fall through. */
2856 if ((flags & ECF_NORETURN) || pass == 0)
2858 /* The barrier must be emitted
2859 immediately after the CALL_INSN. Some ports emit more
2860 than just a CALL_INSN above, so we must search for it here. */
2862 rtx last = get_last_insn ();
2863 while (!CALL_P (last))
2865 last = PREV_INSN (last);
2866 /* There was no CALL_INSN? */
2867 gcc_assert (last != before_call);
2870 emit_barrier_after (last);
2872 /* Stack adjustments after a noreturn call are dead code.
2873 However when NO_DEFER_POP is in effect, we must preserve
2874 stack_pointer_delta. */
2875 if (inhibit_defer_pop == 0)
2877 stack_pointer_delta = old_stack_allocated;
2878 pending_stack_adjust = 0;
2882 /* If value type not void, return an rtx for the value. */
2884 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
2885 || ignore)
2886 target = const0_rtx;
2887 else if (structure_value_addr)
2889 if (target == 0 || !MEM_P (target))
2891 target
2892 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
2893 memory_address (TYPE_MODE (TREE_TYPE (exp)),
2894 structure_value_addr));
2895 set_mem_attributes (target, exp, 1);
2898 else if (pcc_struct_value)
2900 /* This is the special C++ case where we need to
2901 know what the true target was. We take care to
2902 never use this value more than once in one expression. */
2903 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
2904 copy_to_reg (valreg));
2905 set_mem_attributes (target, exp, 1);
2907 /* Handle calls that return values in multiple non-contiguous locations.
2908 The Irix 6 ABI has examples of this. */
2909 else if (GET_CODE (valreg) == PARALLEL)
2911 if (target == 0)
2913 /* This will only be assigned once, so it can be readonly. */
2914 tree nt = build_qualified_type (TREE_TYPE (exp),
2915 (TYPE_QUALS (TREE_TYPE (exp))
2916 | TYPE_QUAL_CONST));
2918 target = assign_temp (nt, 0, 1, 1);
2921 if (! rtx_equal_p (target, valreg))
2922 emit_group_store (target, valreg, TREE_TYPE (exp),
2923 int_size_in_bytes (TREE_TYPE (exp)));
2925 /* We can not support sibling calls for this case. */
2926 sibcall_failure = 1;
2928 else if (target
2929 && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
2930 && GET_MODE (target) == GET_MODE (valreg))
2932 bool may_overlap = false;
2934 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
2935 reg to a plain register. */
2936 if (!REG_P (target) || HARD_REGISTER_P (target))
2937 valreg = avoid_likely_spilled_reg (valreg);
2939 /* If TARGET is a MEM in the argument area, and we have
2940 saved part of the argument area, then we can't store
2941 directly into TARGET as it may get overwritten when we
2942 restore the argument save area below. Don't work too
2943 hard though and simply force TARGET to a register if it
2944 is a MEM; the optimizer is quite likely to sort it out. */
2945 if (ACCUMULATE_OUTGOING_ARGS && pass && MEM_P (target))
2946 for (i = 0; i < num_actuals; i++)
2947 if (args[i].save_area)
2949 may_overlap = true;
2950 break;
2953 if (may_overlap)
2954 target = copy_to_reg (valreg);
2955 else
2957 /* TARGET and VALREG cannot be equal at this point
2958 because the latter would not have
2959 REG_FUNCTION_VALUE_P true, while the former would if
2960 it were referring to the same register.
2962 If they refer to the same register, this move will be
2963 a no-op, except when function inlining is being
2964 done. */
2965 emit_move_insn (target, valreg);
2967 /* If we are setting a MEM, this code must be executed.
2968 Since it is emitted after the call insn, sibcall
2969 optimization cannot be performed in that case. */
2970 if (MEM_P (target))
2971 sibcall_failure = 1;
2974 else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode)
2976 target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp));
2978 /* We can not support sibling calls for this case. */
2979 sibcall_failure = 1;
2981 else
2982 target = copy_to_reg (avoid_likely_spilled_reg (valreg));
2984 if (targetm.calls.promote_function_return(funtype))
2986 /* If we promoted this return value, make the proper SUBREG.
2987 TARGET might be const0_rtx here, so be careful. */
2988 if (REG_P (target)
2989 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
2990 && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
2992 tree type = TREE_TYPE (exp);
2993 int unsignedp = TYPE_UNSIGNED (type);
2994 int offset = 0;
2995 enum machine_mode pmode;
2997 pmode = promote_mode (type, TYPE_MODE (type), &unsignedp, 1);
2998 /* If we don't promote as expected, something is wrong. */
2999 gcc_assert (GET_MODE (target) == pmode);
3001 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
3002 && (GET_MODE_SIZE (GET_MODE (target))
3003 > GET_MODE_SIZE (TYPE_MODE (type))))
3005 offset = GET_MODE_SIZE (GET_MODE (target))
3006 - GET_MODE_SIZE (TYPE_MODE (type));
3007 if (! BYTES_BIG_ENDIAN)
3008 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
3009 else if (! WORDS_BIG_ENDIAN)
3010 offset %= UNITS_PER_WORD;
3012 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
3013 SUBREG_PROMOTED_VAR_P (target) = 1;
3014 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
3018 /* If size of args is variable or this was a constructor call for a stack
3019 argument, restore saved stack-pointer value. */
3021 if (old_stack_level)
3023 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
3024 stack_pointer_delta = old_stack_pointer_delta;
3025 pending_stack_adjust = old_pending_adj;
3026 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
3027 stack_arg_under_construction = old_stack_arg_under_construction;
3028 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3029 stack_usage_map = initial_stack_usage_map;
3030 sibcall_failure = 1;
3032 else if (ACCUMULATE_OUTGOING_ARGS && pass)
3034 #ifdef REG_PARM_STACK_SPACE
3035 if (save_area)
3036 restore_fixed_argument_area (save_area, argblock,
3037 high_to_save, low_to_save);
3038 #endif
3040 /* If we saved any argument areas, restore them. */
3041 for (i = 0; i < num_actuals; i++)
3042 if (args[i].save_area)
3044 enum machine_mode save_mode = GET_MODE (args[i].save_area);
3045 rtx stack_area
3046 = gen_rtx_MEM (save_mode,
3047 memory_address (save_mode,
3048 XEXP (args[i].stack_slot, 0)));
3050 if (save_mode != BLKmode)
3051 emit_move_insn (stack_area, args[i].save_area);
3052 else
3053 emit_block_move (stack_area, args[i].save_area,
3054 GEN_INT (args[i].locate.size.constant),
3055 BLOCK_OP_CALL_PARM);
3058 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3059 stack_usage_map = initial_stack_usage_map;
3062 /* If this was alloca, record the new stack level for nonlocal gotos.
3063 Check for the handler slots since we might not have a save area
3064 for non-local gotos. */
3066 if ((flags & ECF_MAY_BE_ALLOCA) && cfun->nonlocal_goto_save_area != 0)
3067 update_nonlocal_goto_save_area ();
3069 /* Free up storage we no longer need. */
3070 for (i = 0; i < num_actuals; ++i)
3071 if (args[i].aligned_regs)
3072 free (args[i].aligned_regs);
3074 insns = get_insns ();
3075 end_sequence ();
3077 if (pass == 0)
3079 tail_call_insns = insns;
3081 /* Restore the pending stack adjustment now that we have
3082 finished generating the sibling call sequence. */
3084 pending_stack_adjust = save_pending_stack_adjust;
3085 stack_pointer_delta = save_stack_pointer_delta;
3087 /* Prepare arg structure for next iteration. */
3088 for (i = 0; i < num_actuals; i++)
3090 args[i].value = 0;
3091 args[i].aligned_regs = 0;
3092 args[i].stack = 0;
3095 sbitmap_free (stored_args_map);
3097 else
3099 normal_call_insns = insns;
3101 /* Verify that we've deallocated all the stack we used. */
3102 gcc_assert ((flags & ECF_NORETURN)
3103 || (old_stack_allocated
3104 == stack_pointer_delta - pending_stack_adjust));
3107 /* If something prevents making this a sibling call,
3108 zero out the sequence. */
3109 if (sibcall_failure)
3110 tail_call_insns = NULL_RTX;
3111 else
3112 break;
3115 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
3116 arguments too, as argument area is now clobbered by the call. */
3117 if (tail_call_insns)
3119 emit_insn (tail_call_insns);
3120 crtl->tail_call_emit = true;
3122 else
3123 emit_insn (normal_call_insns);
3125 currently_expanding_call--;
3127 if (stack_usage_map_buf)
3128 free (stack_usage_map_buf);
3130 return target;
3133 /* A sibling call sequence invalidates any REG_EQUIV notes made for
3134 this function's incoming arguments.
3136 At the start of RTL generation we know the only REG_EQUIV notes
3137 in the rtl chain are those for incoming arguments, so we can look
3138 for REG_EQUIV notes between the start of the function and the
3139 NOTE_INSN_FUNCTION_BEG.
3141 This is (slight) overkill. We could keep track of the highest
3142 argument we clobber and be more selective in removing notes, but it
3143 does not seem to be worth the effort. */
3145 void
3146 fixup_tail_calls (void)
3148 rtx insn;
3150 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3152 rtx note;
3154 /* There are never REG_EQUIV notes for the incoming arguments
3155 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
3156 if (NOTE_P (insn)
3157 && NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG)
3158 break;
3160 note = find_reg_note (insn, REG_EQUIV, 0);
3161 if (note)
3162 remove_note (insn, note);
3163 note = find_reg_note (insn, REG_EQUIV, 0);
3164 gcc_assert (!note);
3168 /* Traverse a list of TYPES and expand all complex types into their
3169 components. */
3170 static tree
3171 split_complex_types (tree types)
3173 tree p;
3175 /* Before allocating memory, check for the common case of no complex. */
3176 for (p = types; p; p = TREE_CHAIN (p))
3178 tree type = TREE_VALUE (p);
3179 if (TREE_CODE (type) == COMPLEX_TYPE
3180 && targetm.calls.split_complex_arg (type))
3181 goto found;
3183 return types;
3185 found:
3186 types = copy_list (types);
3188 for (p = types; p; p = TREE_CHAIN (p))
3190 tree complex_type = TREE_VALUE (p);
3192 if (TREE_CODE (complex_type) == COMPLEX_TYPE
3193 && targetm.calls.split_complex_arg (complex_type))
3195 tree next, imag;
3197 /* Rewrite complex type with component type. */
3198 TREE_VALUE (p) = TREE_TYPE (complex_type);
3199 next = TREE_CHAIN (p);
3201 /* Add another component type for the imaginary part. */
3202 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
3203 TREE_CHAIN (p) = imag;
3204 TREE_CHAIN (imag) = next;
3206 /* Skip the newly created node. */
3207 p = TREE_CHAIN (p);
3211 return types;
3214 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3215 The RETVAL parameter specifies whether return value needs to be saved, other
3216 parameters are documented in the emit_library_call function below. */
3218 static rtx
3219 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
3220 enum libcall_type fn_type,
3221 enum machine_mode outmode, int nargs, va_list p)
3223 /* Total size in bytes of all the stack-parms scanned so far. */
3224 struct args_size args_size;
3225 /* Size of arguments before any adjustments (such as rounding). */
3226 struct args_size original_args_size;
3227 int argnum;
3228 rtx fun;
3229 /* Todo, choose the correct decl type of orgfun. Sadly this information
3230 isn't present here, so we default to native calling abi here. */
3231 tree fndecl ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
3232 int inc;
3233 int count;
3234 rtx argblock = 0;
3235 CUMULATIVE_ARGS args_so_far;
3236 struct arg
3238 rtx value;
3239 enum machine_mode mode;
3240 rtx reg;
3241 int partial;
3242 struct locate_and_pad_arg_data locate;
3243 rtx save_area;
3245 struct arg *argvec;
3246 int old_inhibit_defer_pop = inhibit_defer_pop;
3247 rtx call_fusage = 0;
3248 rtx mem_value = 0;
3249 rtx valreg;
3250 int pcc_struct_value = 0;
3251 int struct_value_size = 0;
3252 int flags;
3253 int reg_parm_stack_space = 0;
3254 int needed;
3255 rtx before_call;
3256 tree tfom; /* type_for_mode (outmode, 0) */
3258 #ifdef REG_PARM_STACK_SPACE
3259 /* Define the boundary of the register parm stack space that needs to be
3260 save, if any. */
3261 int low_to_save = 0, high_to_save = 0;
3262 rtx save_area = 0; /* Place that it is saved. */
3263 #endif
3265 /* Size of the stack reserved for parameter registers. */
3266 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3267 char *initial_stack_usage_map = stack_usage_map;
3268 char *stack_usage_map_buf = NULL;
3270 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
3272 #ifdef REG_PARM_STACK_SPACE
3273 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3274 #endif
3276 /* By default, library functions can not throw. */
3277 flags = ECF_NOTHROW;
3279 switch (fn_type)
3281 case LCT_NORMAL:
3282 break;
3283 case LCT_CONST:
3284 flags |= ECF_CONST;
3285 break;
3286 case LCT_PURE:
3287 flags |= ECF_PURE;
3288 break;
3289 case LCT_NORETURN:
3290 flags |= ECF_NORETURN;
3291 break;
3292 case LCT_THROW:
3293 flags = ECF_NORETURN;
3294 break;
3295 case LCT_RETURNS_TWICE:
3296 flags = ECF_RETURNS_TWICE;
3297 break;
3299 fun = orgfun;
3301 /* Ensure current function's preferred stack boundary is at least
3302 what we need. */
3303 if (crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3304 crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3306 /* If this kind of value comes back in memory,
3307 decide where in memory it should come back. */
3308 if (outmode != VOIDmode)
3310 tfom = lang_hooks.types.type_for_mode (outmode, 0);
3311 if (aggregate_value_p (tfom, 0))
3313 #ifdef PCC_STATIC_STRUCT_RETURN
3314 rtx pointer_reg
3315 = hard_function_value (build_pointer_type (tfom), 0, 0, 0);
3316 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3317 pcc_struct_value = 1;
3318 if (value == 0)
3319 value = gen_reg_rtx (outmode);
3320 #else /* not PCC_STATIC_STRUCT_RETURN */
3321 struct_value_size = GET_MODE_SIZE (outmode);
3322 if (value != 0 && MEM_P (value))
3323 mem_value = value;
3324 else
3325 mem_value = assign_temp (tfom, 0, 1, 1);
3326 #endif
3327 /* This call returns a big structure. */
3328 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
3331 else
3332 tfom = void_type_node;
3334 /* ??? Unfinished: must pass the memory address as an argument. */
3336 /* Copy all the libcall-arguments out of the varargs data
3337 and into a vector ARGVEC.
3339 Compute how to pass each argument. We only support a very small subset
3340 of the full argument passing conventions to limit complexity here since
3341 library functions shouldn't have many args. */
3343 argvec = XALLOCAVEC (struct arg, nargs + 1);
3344 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
3346 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3347 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun);
3348 #else
3349 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0, nargs);
3350 #endif
3352 args_size.constant = 0;
3353 args_size.var = 0;
3355 count = 0;
3357 push_temp_slots ();
3359 /* If there's a structure value address to be passed,
3360 either pass it in the special place, or pass it as an extra argument. */
3361 if (mem_value && struct_value == 0 && ! pcc_struct_value)
3363 rtx addr = XEXP (mem_value, 0);
3365 nargs++;
3367 /* Make sure it is a reasonable operand for a move or push insn. */
3368 if (!REG_P (addr) && !MEM_P (addr)
3369 && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr)))
3370 addr = force_operand (addr, NULL_RTX);
3372 argvec[count].value = addr;
3373 argvec[count].mode = Pmode;
3374 argvec[count].partial = 0;
3376 argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1);
3377 gcc_assert (targetm.calls.arg_partial_bytes (&args_so_far, Pmode,
3378 NULL_TREE, 1) == 0);
3380 locate_and_pad_parm (Pmode, NULL_TREE,
3381 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3383 #else
3384 argvec[count].reg != 0,
3385 #endif
3386 0, NULL_TREE, &args_size, &argvec[count].locate);
3388 if (argvec[count].reg == 0 || argvec[count].partial != 0
3389 || reg_parm_stack_space > 0)
3390 args_size.constant += argvec[count].locate.size.constant;
3392 FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1);
3394 count++;
3397 for (; count < nargs; count++)
3399 rtx val = va_arg (p, rtx);
3400 enum machine_mode mode = va_arg (p, enum machine_mode);
3402 /* We cannot convert the arg value to the mode the library wants here;
3403 must do it earlier where we know the signedness of the arg. */
3404 gcc_assert (mode != BLKmode
3405 && (GET_MODE (val) == mode || GET_MODE (val) == VOIDmode));
3407 /* Make sure it is a reasonable operand for a move or push insn. */
3408 if (!REG_P (val) && !MEM_P (val)
3409 && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val)))
3410 val = force_operand (val, NULL_RTX);
3412 if (pass_by_reference (&args_so_far, mode, NULL_TREE, 1))
3414 rtx slot;
3415 int must_copy
3416 = !reference_callee_copied (&args_so_far, mode, NULL_TREE, 1);
3418 /* If this was a CONST function, it is now PURE since it now
3419 reads memory. */
3420 if (flags & ECF_CONST)
3422 flags &= ~ECF_CONST;
3423 flags |= ECF_PURE;
3426 if (MEM_P (val) && !must_copy)
3427 slot = val;
3428 else
3430 slot = assign_temp (lang_hooks.types.type_for_mode (mode, 0),
3431 0, 1, 1);
3432 emit_move_insn (slot, val);
3435 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3436 gen_rtx_USE (VOIDmode, slot),
3437 call_fusage);
3438 if (must_copy)
3439 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3440 gen_rtx_CLOBBER (VOIDmode,
3441 slot),
3442 call_fusage);
3444 mode = Pmode;
3445 val = force_operand (XEXP (slot, 0), NULL_RTX);
3448 argvec[count].value = val;
3449 argvec[count].mode = mode;
3451 argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1);
3453 argvec[count].partial
3454 = targetm.calls.arg_partial_bytes (&args_so_far, mode, NULL_TREE, 1);
3456 locate_and_pad_parm (mode, NULL_TREE,
3457 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3459 #else
3460 argvec[count].reg != 0,
3461 #endif
3462 argvec[count].partial,
3463 NULL_TREE, &args_size, &argvec[count].locate);
3465 gcc_assert (!argvec[count].locate.size.var);
3467 if (argvec[count].reg == 0 || argvec[count].partial != 0
3468 || reg_parm_stack_space > 0)
3469 args_size.constant += argvec[count].locate.size.constant;
3471 FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1);
3474 /* If this machine requires an external definition for library
3475 functions, write one out. */
3476 assemble_external_libcall (fun);
3478 original_args_size = args_size;
3479 args_size.constant = (((args_size.constant
3480 + stack_pointer_delta
3481 + STACK_BYTES - 1)
3482 / STACK_BYTES
3483 * STACK_BYTES)
3484 - stack_pointer_delta);
3486 args_size.constant = MAX (args_size.constant,
3487 reg_parm_stack_space);
3489 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL_TREE : TREE_TYPE (fndecl))))
3490 args_size.constant -= reg_parm_stack_space;
3492 if (args_size.constant > crtl->outgoing_args_size)
3493 crtl->outgoing_args_size = args_size.constant;
3495 if (ACCUMULATE_OUTGOING_ARGS)
3497 /* Since the stack pointer will never be pushed, it is possible for
3498 the evaluation of a parm to clobber something we have already
3499 written to the stack. Since most function calls on RISC machines
3500 do not use the stack, this is uncommon, but must work correctly.
3502 Therefore, we save any area of the stack that was already written
3503 and that we are using. Here we set up to do this by making a new
3504 stack usage map from the old one.
3506 Another approach might be to try to reorder the argument
3507 evaluations to avoid this conflicting stack usage. */
3509 needed = args_size.constant;
3511 /* Since we will be writing into the entire argument area, the
3512 map must be allocated for its entire size, not just the part that
3513 is the responsibility of the caller. */
3514 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL_TREE : TREE_TYPE (fndecl))))
3515 needed += reg_parm_stack_space;
3517 #ifdef ARGS_GROW_DOWNWARD
3518 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3519 needed + 1);
3520 #else
3521 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3522 needed);
3523 #endif
3524 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
3525 stack_usage_map = stack_usage_map_buf;
3527 if (initial_highest_arg_in_use)
3528 memcpy (stack_usage_map, initial_stack_usage_map,
3529 initial_highest_arg_in_use);
3531 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3532 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3533 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3534 needed = 0;
3536 /* We must be careful to use virtual regs before they're instantiated,
3537 and real regs afterwards. Loop optimization, for example, can create
3538 new libcalls after we've instantiated the virtual regs, and if we
3539 use virtuals anyway, they won't match the rtl patterns. */
3541 if (virtuals_instantiated)
3542 argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET);
3543 else
3544 argblock = virtual_outgoing_args_rtx;
3546 else
3548 if (!PUSH_ARGS)
3549 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3552 /* If we push args individually in reverse order, perform stack alignment
3553 before the first push (the last arg). */
3554 if (argblock == 0 && PUSH_ARGS_REVERSED)
3555 anti_adjust_stack (GEN_INT (args_size.constant
3556 - original_args_size.constant));
3558 if (PUSH_ARGS_REVERSED)
3560 inc = -1;
3561 argnum = nargs - 1;
3563 else
3565 inc = 1;
3566 argnum = 0;
3569 #ifdef REG_PARM_STACK_SPACE
3570 if (ACCUMULATE_OUTGOING_ARGS)
3572 /* The argument list is the property of the called routine and it
3573 may clobber it. If the fixed area has been used for previous
3574 parameters, we must save and restore it. */
3575 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3576 &low_to_save, &high_to_save);
3578 #endif
3580 /* Push the args that need to be pushed. */
3582 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3583 are to be pushed. */
3584 for (count = 0; count < nargs; count++, argnum += inc)
3586 enum machine_mode mode = argvec[argnum].mode;
3587 rtx val = argvec[argnum].value;
3588 rtx reg = argvec[argnum].reg;
3589 int partial = argvec[argnum].partial;
3590 int lower_bound = 0, upper_bound = 0, i;
3592 if (! (reg != 0 && partial == 0))
3594 if (ACCUMULATE_OUTGOING_ARGS)
3596 /* If this is being stored into a pre-allocated, fixed-size,
3597 stack area, save any previous data at that location. */
3599 #ifdef ARGS_GROW_DOWNWARD
3600 /* stack_slot is negative, but we want to index stack_usage_map
3601 with positive values. */
3602 upper_bound = -argvec[argnum].locate.offset.constant + 1;
3603 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
3604 #else
3605 lower_bound = argvec[argnum].locate.offset.constant;
3606 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
3607 #endif
3609 i = lower_bound;
3610 /* Don't worry about things in the fixed argument area;
3611 it has already been saved. */
3612 if (i < reg_parm_stack_space)
3613 i = reg_parm_stack_space;
3614 while (i < upper_bound && stack_usage_map[i] == 0)
3615 i++;
3617 if (i < upper_bound)
3619 /* We need to make a save area. */
3620 unsigned int size
3621 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
3622 enum machine_mode save_mode
3623 = mode_for_size (size, MODE_INT, 1);
3624 rtx adr
3625 = plus_constant (argblock,
3626 argvec[argnum].locate.offset.constant);
3627 rtx stack_area
3628 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
3630 if (save_mode == BLKmode)
3632 argvec[argnum].save_area
3633 = assign_stack_temp (BLKmode,
3634 argvec[argnum].locate.size.constant,
3637 emit_block_move (validize_mem (argvec[argnum].save_area),
3638 stack_area,
3639 GEN_INT (argvec[argnum].locate.size.constant),
3640 BLOCK_OP_CALL_PARM);
3642 else
3644 argvec[argnum].save_area = gen_reg_rtx (save_mode);
3646 emit_move_insn (argvec[argnum].save_area, stack_area);
3651 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, PARM_BOUNDARY,
3652 partial, reg, 0, argblock,
3653 GEN_INT (argvec[argnum].locate.offset.constant),
3654 reg_parm_stack_space,
3655 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad));
3657 /* Now mark the segment we just used. */
3658 if (ACCUMULATE_OUTGOING_ARGS)
3659 for (i = lower_bound; i < upper_bound; i++)
3660 stack_usage_map[i] = 1;
3662 NO_DEFER_POP;
3664 if (flags & ECF_CONST)
3666 rtx use;
3668 /* Indicate argument access so that alias.c knows that these
3669 values are live. */
3670 if (argblock)
3671 use = plus_constant (argblock,
3672 argvec[argnum].locate.offset.constant);
3673 else
3674 /* When arguments are pushed, trying to tell alias.c where
3675 exactly this argument is won't work, because the
3676 auto-increment causes confusion. So we merely indicate
3677 that we access something with a known mode somewhere on
3678 the stack. */
3679 use = gen_rtx_PLUS (Pmode, virtual_outgoing_args_rtx,
3680 gen_rtx_SCRATCH (Pmode));
3681 use = gen_rtx_MEM (argvec[argnum].mode, use);
3682 use = gen_rtx_USE (VOIDmode, use);
3683 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, use, call_fusage);
3688 /* If we pushed args in forward order, perform stack alignment
3689 after pushing the last arg. */
3690 if (argblock == 0 && !PUSH_ARGS_REVERSED)
3691 anti_adjust_stack (GEN_INT (args_size.constant
3692 - original_args_size.constant));
3694 if (PUSH_ARGS_REVERSED)
3695 argnum = nargs - 1;
3696 else
3697 argnum = 0;
3699 fun = prepare_call_address (fun, NULL, &call_fusage, 0, 0);
3701 /* Now load any reg parms into their regs. */
3703 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3704 are to be pushed. */
3705 for (count = 0; count < nargs; count++, argnum += inc)
3707 enum machine_mode mode = argvec[argnum].mode;
3708 rtx val = argvec[argnum].value;
3709 rtx reg = argvec[argnum].reg;
3710 int partial = argvec[argnum].partial;
3712 /* Handle calls that pass values in multiple non-contiguous
3713 locations. The PA64 has examples of this for library calls. */
3714 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3715 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode));
3716 else if (reg != 0 && partial == 0)
3717 emit_move_insn (reg, val);
3719 NO_DEFER_POP;
3722 /* Any regs containing parms remain in use through the call. */
3723 for (count = 0; count < nargs; count++)
3725 rtx reg = argvec[count].reg;
3726 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3727 use_group_regs (&call_fusage, reg);
3728 else if (reg != 0)
3730 int partial = argvec[count].partial;
3731 if (partial)
3733 int nregs;
3734 gcc_assert (partial % UNITS_PER_WORD == 0);
3735 nregs = partial / UNITS_PER_WORD;
3736 use_regs (&call_fusage, REGNO (reg), nregs);
3738 else
3739 use_reg (&call_fusage, reg);
3743 /* Pass the function the address in which to return a structure value. */
3744 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
3746 emit_move_insn (struct_value,
3747 force_reg (Pmode,
3748 force_operand (XEXP (mem_value, 0),
3749 NULL_RTX)));
3750 if (REG_P (struct_value))
3751 use_reg (&call_fusage, struct_value);
3754 /* Don't allow popping to be deferred, since then
3755 cse'ing of library calls could delete a call and leave the pop. */
3756 NO_DEFER_POP;
3757 valreg = (mem_value == 0 && outmode != VOIDmode
3758 ? hard_libcall_value (outmode) : NULL_RTX);
3760 /* Stack must be properly aligned now. */
3761 gcc_assert (!(stack_pointer_delta
3762 & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1)));
3764 before_call = get_last_insn ();
3766 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
3767 will set inhibit_defer_pop to that value. */
3768 /* The return type is needed to decide how many bytes the function pops.
3769 Signedness plays no role in that, so for simplicity, we pretend it's
3770 always signed. We also assume that the list of arguments passed has
3771 no impact, so we pretend it is unknown. */
3773 emit_call_1 (fun, NULL,
3774 get_identifier (XSTR (orgfun, 0)),
3775 build_function_type (tfom, NULL_TREE),
3776 original_args_size.constant, args_size.constant,
3777 struct_value_size,
3778 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
3779 valreg,
3780 old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far);
3782 /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
3783 that it should complain if nonvolatile values are live. For
3784 functions that cannot return, inform flow that control does not
3785 fall through. */
3787 if (flags & ECF_NORETURN)
3789 /* The barrier note must be emitted
3790 immediately after the CALL_INSN. Some ports emit more than
3791 just a CALL_INSN above, so we must search for it here. */
3793 rtx last = get_last_insn ();
3794 while (!CALL_P (last))
3796 last = PREV_INSN (last);
3797 /* There was no CALL_INSN? */
3798 gcc_assert (last != before_call);
3801 emit_barrier_after (last);
3804 /* Now restore inhibit_defer_pop to its actual original value. */
3805 OK_DEFER_POP;
3807 pop_temp_slots ();
3809 /* Copy the value to the right place. */
3810 if (outmode != VOIDmode && retval)
3812 if (mem_value)
3814 if (value == 0)
3815 value = mem_value;
3816 if (value != mem_value)
3817 emit_move_insn (value, mem_value);
3819 else if (GET_CODE (valreg) == PARALLEL)
3821 if (value == 0)
3822 value = gen_reg_rtx (outmode);
3823 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
3825 else
3827 /* Convert to the proper mode if PROMOTE_MODE has been active. */
3828 if (GET_MODE (valreg) != outmode)
3830 int unsignedp = TYPE_UNSIGNED (tfom);
3832 gcc_assert (targetm.calls.promote_function_return (tfom));
3833 gcc_assert (promote_mode (tfom, outmode, &unsignedp, 0)
3834 == GET_MODE (valreg));
3836 valreg = convert_modes (outmode, GET_MODE (valreg), valreg, 0);
3839 if (value != 0)
3840 emit_move_insn (value, valreg);
3841 else
3842 value = valreg;
3846 if (ACCUMULATE_OUTGOING_ARGS)
3848 #ifdef REG_PARM_STACK_SPACE
3849 if (save_area)
3850 restore_fixed_argument_area (save_area, argblock,
3851 high_to_save, low_to_save);
3852 #endif
3854 /* If we saved any argument areas, restore them. */
3855 for (count = 0; count < nargs; count++)
3856 if (argvec[count].save_area)
3858 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
3859 rtx adr = plus_constant (argblock,
3860 argvec[count].locate.offset.constant);
3861 rtx stack_area = gen_rtx_MEM (save_mode,
3862 memory_address (save_mode, adr));
3864 if (save_mode == BLKmode)
3865 emit_block_move (stack_area,
3866 validize_mem (argvec[count].save_area),
3867 GEN_INT (argvec[count].locate.size.constant),
3868 BLOCK_OP_CALL_PARM);
3869 else
3870 emit_move_insn (stack_area, argvec[count].save_area);
3873 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3874 stack_usage_map = initial_stack_usage_map;
3877 if (stack_usage_map_buf)
3878 free (stack_usage_map_buf);
3880 return value;
3884 /* Output a library call to function FUN (a SYMBOL_REF rtx)
3885 (emitting the queue unless NO_QUEUE is nonzero),
3886 for a value of mode OUTMODE,
3887 with NARGS different arguments, passed as alternating rtx values
3888 and machine_modes to convert them to.
3890 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for
3891 `const' calls, LCT_PURE for `pure' calls, or other LCT_ value for
3892 other types of library calls. */
3894 void
3895 emit_library_call (rtx orgfun, enum libcall_type fn_type,
3896 enum machine_mode outmode, int nargs, ...)
3898 va_list p;
3900 va_start (p, nargs);
3901 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
3902 va_end (p);
3905 /* Like emit_library_call except that an extra argument, VALUE,
3906 comes second and says where to store the result.
3907 (If VALUE is zero, this function chooses a convenient way
3908 to return the value.
3910 This function returns an rtx for where the value is to be found.
3911 If VALUE is nonzero, VALUE is returned. */
3914 emit_library_call_value (rtx orgfun, rtx value,
3915 enum libcall_type fn_type,
3916 enum machine_mode outmode, int nargs, ...)
3918 rtx result;
3919 va_list p;
3921 va_start (p, nargs);
3922 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
3923 nargs, p);
3924 va_end (p);
3926 return result;
3929 /* Store a single argument for a function call
3930 into the register or memory area where it must be passed.
3931 *ARG describes the argument value and where to pass it.
3933 ARGBLOCK is the address of the stack-block for all the arguments,
3934 or 0 on a machine where arguments are pushed individually.
3936 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
3937 so must be careful about how the stack is used.
3939 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
3940 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
3941 that we need not worry about saving and restoring the stack.
3943 FNDECL is the declaration of the function we are calling.
3945 Return nonzero if this arg should cause sibcall failure,
3946 zero otherwise. */
3948 static int
3949 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
3950 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
3952 tree pval = arg->tree_value;
3953 rtx reg = 0;
3954 int partial = 0;
3955 int used = 0;
3956 int i, lower_bound = 0, upper_bound = 0;
3957 int sibcall_failure = 0;
3959 if (TREE_CODE (pval) == ERROR_MARK)
3960 return 1;
3962 /* Push a new temporary level for any temporaries we make for
3963 this argument. */
3964 push_temp_slots ();
3966 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
3968 /* If this is being stored into a pre-allocated, fixed-size, stack area,
3969 save any previous data at that location. */
3970 if (argblock && ! variable_size && arg->stack)
3972 #ifdef ARGS_GROW_DOWNWARD
3973 /* stack_slot is negative, but we want to index stack_usage_map
3974 with positive values. */
3975 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
3976 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
3977 else
3978 upper_bound = 0;
3980 lower_bound = upper_bound - arg->locate.size.constant;
3981 #else
3982 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
3983 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
3984 else
3985 lower_bound = 0;
3987 upper_bound = lower_bound + arg->locate.size.constant;
3988 #endif
3990 i = lower_bound;
3991 /* Don't worry about things in the fixed argument area;
3992 it has already been saved. */
3993 if (i < reg_parm_stack_space)
3994 i = reg_parm_stack_space;
3995 while (i < upper_bound && stack_usage_map[i] == 0)
3996 i++;
3998 if (i < upper_bound)
4000 /* We need to make a save area. */
4001 unsigned int size = arg->locate.size.constant * BITS_PER_UNIT;
4002 enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1);
4003 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
4004 rtx stack_area = gen_rtx_MEM (save_mode, adr);
4006 if (save_mode == BLKmode)
4008 tree ot = TREE_TYPE (arg->tree_value);
4009 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
4010 | TYPE_QUAL_CONST));
4012 arg->save_area = assign_temp (nt, 0, 1, 1);
4013 preserve_temp_slots (arg->save_area);
4014 emit_block_move (validize_mem (arg->save_area), stack_area,
4015 GEN_INT (arg->locate.size.constant),
4016 BLOCK_OP_CALL_PARM);
4018 else
4020 arg->save_area = gen_reg_rtx (save_mode);
4021 emit_move_insn (arg->save_area, stack_area);
4027 /* If this isn't going to be placed on both the stack and in registers,
4028 set up the register and number of words. */
4029 if (! arg->pass_on_stack)
4031 if (flags & ECF_SIBCALL)
4032 reg = arg->tail_call_reg;
4033 else
4034 reg = arg->reg;
4035 partial = arg->partial;
4038 /* Being passed entirely in a register. We shouldn't be called in
4039 this case. */
4040 gcc_assert (reg == 0 || partial != 0);
4042 /* If this arg needs special alignment, don't load the registers
4043 here. */
4044 if (arg->n_aligned_regs != 0)
4045 reg = 0;
4047 /* If this is being passed partially in a register, we can't evaluate
4048 it directly into its stack slot. Otherwise, we can. */
4049 if (arg->value == 0)
4051 /* stack_arg_under_construction is nonzero if a function argument is
4052 being evaluated directly into the outgoing argument list and
4053 expand_call must take special action to preserve the argument list
4054 if it is called recursively.
4056 For scalar function arguments stack_usage_map is sufficient to
4057 determine which stack slots must be saved and restored. Scalar
4058 arguments in general have pass_on_stack == 0.
4060 If this argument is initialized by a function which takes the
4061 address of the argument (a C++ constructor or a C function
4062 returning a BLKmode structure), then stack_usage_map is
4063 insufficient and expand_call must push the stack around the
4064 function call. Such arguments have pass_on_stack == 1.
4066 Note that it is always safe to set stack_arg_under_construction,
4067 but this generates suboptimal code if set when not needed. */
4069 if (arg->pass_on_stack)
4070 stack_arg_under_construction++;
4072 arg->value = expand_expr (pval,
4073 (partial
4074 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4075 ? NULL_RTX : arg->stack,
4076 VOIDmode, EXPAND_STACK_PARM);
4078 /* If we are promoting object (or for any other reason) the mode
4079 doesn't agree, convert the mode. */
4081 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4082 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4083 arg->value, arg->unsignedp);
4085 if (arg->pass_on_stack)
4086 stack_arg_under_construction--;
4089 /* Check for overlap with already clobbered argument area. */
4090 if ((flags & ECF_SIBCALL)
4091 && MEM_P (arg->value)
4092 && mem_overlaps_already_clobbered_arg_p (XEXP (arg->value, 0),
4093 arg->locate.size.constant))
4094 sibcall_failure = 1;
4096 /* Don't allow anything left on stack from computation
4097 of argument to alloca. */
4098 if (flags & ECF_MAY_BE_ALLOCA)
4099 do_pending_stack_adjust ();
4101 if (arg->value == arg->stack)
4102 /* If the value is already in the stack slot, we are done. */
4104 else if (arg->mode != BLKmode)
4106 int size;
4107 unsigned int parm_align;
4109 /* Argument is a scalar, not entirely passed in registers.
4110 (If part is passed in registers, arg->partial says how much
4111 and emit_push_insn will take care of putting it there.)
4113 Push it, and if its size is less than the
4114 amount of space allocated to it,
4115 also bump stack pointer by the additional space.
4116 Note that in C the default argument promotions
4117 will prevent such mismatches. */
4119 size = GET_MODE_SIZE (arg->mode);
4120 /* Compute how much space the push instruction will push.
4121 On many machines, pushing a byte will advance the stack
4122 pointer by a halfword. */
4123 #ifdef PUSH_ROUNDING
4124 size = PUSH_ROUNDING (size);
4125 #endif
4126 used = size;
4128 /* Compute how much space the argument should get:
4129 round up to a multiple of the alignment for arguments. */
4130 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4131 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4132 / (PARM_BOUNDARY / BITS_PER_UNIT))
4133 * (PARM_BOUNDARY / BITS_PER_UNIT));
4135 /* Compute the alignment of the pushed argument. */
4136 parm_align = arg->locate.boundary;
4137 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4139 int pad = used - size;
4140 if (pad)
4142 unsigned int pad_align = (pad & -pad) * BITS_PER_UNIT;
4143 parm_align = MIN (parm_align, pad_align);
4147 /* This isn't already where we want it on the stack, so put it there.
4148 This can either be done with push or copy insns. */
4149 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4150 parm_align, partial, reg, used - size, argblock,
4151 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4152 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4154 /* Unless this is a partially-in-register argument, the argument is now
4155 in the stack. */
4156 if (partial == 0)
4157 arg->value = arg->stack;
4159 else
4161 /* BLKmode, at least partly to be pushed. */
4163 unsigned int parm_align;
4164 int excess;
4165 rtx size_rtx;
4167 /* Pushing a nonscalar.
4168 If part is passed in registers, PARTIAL says how much
4169 and emit_push_insn will take care of putting it there. */
4171 /* Round its size up to a multiple
4172 of the allocation unit for arguments. */
4174 if (arg->locate.size.var != 0)
4176 excess = 0;
4177 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
4179 else
4181 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
4182 for BLKmode is careful to avoid it. */
4183 excess = (arg->locate.size.constant
4184 - int_size_in_bytes (TREE_TYPE (pval))
4185 + partial);
4186 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4187 NULL_RTX, TYPE_MODE (sizetype), 0);
4190 parm_align = arg->locate.boundary;
4192 /* When an argument is padded down, the block is aligned to
4193 PARM_BOUNDARY, but the actual argument isn't. */
4194 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4196 if (arg->locate.size.var)
4197 parm_align = BITS_PER_UNIT;
4198 else if (excess)
4200 unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4201 parm_align = MIN (parm_align, excess_align);
4205 if ((flags & ECF_SIBCALL) && MEM_P (arg->value))
4207 /* emit_push_insn might not work properly if arg->value and
4208 argblock + arg->locate.offset areas overlap. */
4209 rtx x = arg->value;
4210 int i = 0;
4212 if (XEXP (x, 0) == crtl->args.internal_arg_pointer
4213 || (GET_CODE (XEXP (x, 0)) == PLUS
4214 && XEXP (XEXP (x, 0), 0) ==
4215 crtl->args.internal_arg_pointer
4216 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT))
4218 if (XEXP (x, 0) != crtl->args.internal_arg_pointer)
4219 i = INTVAL (XEXP (XEXP (x, 0), 1));
4221 /* expand_call should ensure this. */
4222 gcc_assert (!arg->locate.offset.var
4223 && arg->locate.size.var == 0
4224 && GET_CODE (size_rtx) == CONST_INT);
4226 if (arg->locate.offset.constant > i)
4228 if (arg->locate.offset.constant < i + INTVAL (size_rtx))
4229 sibcall_failure = 1;
4231 else if (arg->locate.offset.constant < i)
4233 /* Use arg->locate.size.constant instead of size_rtx
4234 because we only care about the part of the argument
4235 on the stack. */
4236 if (i < (arg->locate.offset.constant
4237 + arg->locate.size.constant))
4238 sibcall_failure = 1;
4240 else
4242 /* Even though they appear to be at the same location,
4243 if part of the outgoing argument is in registers,
4244 they aren't really at the same location. Check for
4245 this by making sure that the incoming size is the
4246 same as the outgoing size. */
4247 if (arg->locate.size.constant != INTVAL (size_rtx))
4248 sibcall_failure = 1;
4253 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4254 parm_align, partial, reg, excess, argblock,
4255 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4256 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4258 /* Unless this is a partially-in-register argument, the argument is now
4259 in the stack.
4261 ??? Unlike the case above, in which we want the actual
4262 address of the data, so that we can load it directly into a
4263 register, here we want the address of the stack slot, so that
4264 it's properly aligned for word-by-word copying or something
4265 like that. It's not clear that this is always correct. */
4266 if (partial == 0)
4267 arg->value = arg->stack_slot;
4270 if (arg->reg && GET_CODE (arg->reg) == PARALLEL)
4272 tree type = TREE_TYPE (arg->tree_value);
4273 arg->parallel_value
4274 = emit_group_load_into_temps (arg->reg, arg->value, type,
4275 int_size_in_bytes (type));
4278 /* Mark all slots this store used. */
4279 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
4280 && argblock && ! variable_size && arg->stack)
4281 for (i = lower_bound; i < upper_bound; i++)
4282 stack_usage_map[i] = 1;
4284 /* Once we have pushed something, pops can't safely
4285 be deferred during the rest of the arguments. */
4286 NO_DEFER_POP;
4288 /* Free any temporary slots made in processing this argument. Show
4289 that we might have taken the address of something and pushed that
4290 as an operand. */
4291 preserve_temp_slots (NULL_RTX);
4292 free_temp_slots ();
4293 pop_temp_slots ();
4295 return sibcall_failure;
4298 /* Nonzero if we do not know how to pass TYPE solely in registers. */
4300 bool
4301 must_pass_in_stack_var_size (enum machine_mode mode ATTRIBUTE_UNUSED,
4302 const_tree type)
4304 if (!type)
4305 return false;
4307 /* If the type has variable size... */
4308 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4309 return true;
4311 /* If the type is marked as addressable (it is required
4312 to be constructed into the stack)... */
4313 if (TREE_ADDRESSABLE (type))
4314 return true;
4316 return false;
4319 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
4320 takes trailing padding of a structure into account. */
4321 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
4323 bool
4324 must_pass_in_stack_var_size_or_pad (enum machine_mode mode, const_tree type)
4326 if (!type)
4327 return false;
4329 /* If the type has variable size... */
4330 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4331 return true;
4333 /* If the type is marked as addressable (it is required
4334 to be constructed into the stack)... */
4335 if (TREE_ADDRESSABLE (type))
4336 return true;
4338 /* If the padding and mode of the type is such that a copy into
4339 a register would put it into the wrong part of the register. */
4340 if (mode == BLKmode
4341 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
4342 && (FUNCTION_ARG_PADDING (mode, type)
4343 == (BYTES_BIG_ENDIAN ? upward : downward)))
4344 return true;
4346 return false;