* config/rs6000/aix61.h (PROCESSOR_DEFAULT): Change to
[official-gcc.git] / gcc / function.c
blob3f721fb1a2f2fe7ade1230391c9633c2e91155fc
1 /* Expands front end tree to back end RTL for GCC.
2 Copyright (C) 1987, 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
4 2010 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 /* This file handles the generation of rtl code from tree structure
23 at the level of the function as a whole.
24 It creates the rtl expressions for parameters and auto variables
25 and has full responsibility for allocating stack slots.
27 `expand_function_start' is called at the beginning of a function,
28 before the function body is parsed, and `expand_function_end' is
29 called after parsing the body.
31 Call `assign_stack_local' to allocate a stack slot for a local variable.
32 This is usually done during the RTL generation for the function body,
33 but it can also be done in the reload pass when a pseudo-register does
34 not get a hard register. */
36 #include "config.h"
37 #include "system.h"
38 #include "coretypes.h"
39 #include "tm.h"
40 #include "rtl-error.h"
41 #include "tree.h"
42 #include "flags.h"
43 #include "except.h"
44 #include "function.h"
45 #include "expr.h"
46 #include "optabs.h"
47 #include "libfuncs.h"
48 #include "regs.h"
49 #include "hard-reg-set.h"
50 #include "insn-config.h"
51 #include "recog.h"
52 #include "output.h"
53 #include "basic-block.h"
54 #include "hashtab.h"
55 #include "ggc.h"
56 #include "tm_p.h"
57 #include "integrate.h"
58 #include "langhooks.h"
59 #include "target.h"
60 #include "cfglayout.h"
61 #include "gimple.h"
62 #include "tree-pass.h"
63 #include "predict.h"
64 #include "df.h"
65 #include "timevar.h"
66 #include "vecprim.h"
68 /* So we can assign to cfun in this file. */
69 #undef cfun
71 #ifndef STACK_ALIGNMENT_NEEDED
72 #define STACK_ALIGNMENT_NEEDED 1
73 #endif
75 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
77 /* Some systems use __main in a way incompatible with its use in gcc, in these
78 cases use the macros NAME__MAIN to give a quoted symbol and SYMBOL__MAIN to
79 give the same symbol without quotes for an alternative entry point. You
80 must define both, or neither. */
81 #ifndef NAME__MAIN
82 #define NAME__MAIN "__main"
83 #endif
85 /* Round a value to the lowest integer less than it that is a multiple of
86 the required alignment. Avoid using division in case the value is
87 negative. Assume the alignment is a power of two. */
88 #define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1))
90 /* Similar, but round to the next highest integer that meets the
91 alignment. */
92 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
94 /* Nonzero if function being compiled doesn't contain any calls
95 (ignoring the prologue and epilogue). This is set prior to
96 local register allocation and is valid for the remaining
97 compiler passes. */
98 int current_function_is_leaf;
100 /* Nonzero if function being compiled doesn't modify the stack pointer
101 (ignoring the prologue and epilogue). This is only valid after
102 pass_stack_ptr_mod has run. */
103 int current_function_sp_is_unchanging;
105 /* Nonzero if the function being compiled is a leaf function which only
106 uses leaf registers. This is valid after reload (specifically after
107 sched2) and is useful only if the port defines LEAF_REGISTERS. */
108 int current_function_uses_only_leaf_regs;
110 /* Nonzero once virtual register instantiation has been done.
111 assign_stack_local uses frame_pointer_rtx when this is nonzero.
112 calls.c:emit_library_call_value_1 uses it to set up
113 post-instantiation libcalls. */
114 int virtuals_instantiated;
116 /* Assign unique numbers to labels generated for profiling, debugging, etc. */
117 static GTY(()) int funcdef_no;
119 /* These variables hold pointers to functions to create and destroy
120 target specific, per-function data structures. */
121 struct machine_function * (*init_machine_status) (void);
123 /* The currently compiled function. */
124 struct function *cfun = 0;
126 /* These hashes record the prologue and epilogue insns. */
127 static GTY((if_marked ("ggc_marked_p"), param_is (struct rtx_def)))
128 htab_t prologue_insn_hash;
129 static GTY((if_marked ("ggc_marked_p"), param_is (struct rtx_def)))
130 htab_t epilogue_insn_hash;
133 htab_t types_used_by_vars_hash = NULL;
134 VEC(tree,gc) *types_used_by_cur_var_decl;
136 /* Forward declarations. */
138 static struct temp_slot *find_temp_slot_from_address (rtx);
139 static void pad_to_arg_alignment (struct args_size *, int, struct args_size *);
140 static void pad_below (struct args_size *, enum machine_mode, tree);
141 static void reorder_blocks_1 (rtx, tree, VEC(tree,heap) **);
142 static int all_blocks (tree, tree *);
143 static tree *get_block_vector (tree, int *);
144 extern tree debug_find_var_in_block_tree (tree, tree);
145 /* We always define `record_insns' even if it's not used so that we
146 can always export `prologue_epilogue_contains'. */
147 static void record_insns (rtx, rtx, htab_t *) ATTRIBUTE_UNUSED;
148 static bool contains (const_rtx, htab_t);
149 #ifdef HAVE_return
150 static void emit_return_into_block (basic_block);
151 #endif
152 static void prepare_function_start (void);
153 static void do_clobber_return_reg (rtx, void *);
154 static void do_use_return_reg (rtx, void *);
155 static void set_insn_locators (rtx, int) ATTRIBUTE_UNUSED;
157 /* Stack of nested functions. */
158 /* Keep track of the cfun stack. */
160 typedef struct function *function_p;
162 DEF_VEC_P(function_p);
163 DEF_VEC_ALLOC_P(function_p,heap);
164 static VEC(function_p,heap) *function_context_stack;
166 /* Save the current context for compilation of a nested function.
167 This is called from language-specific code. */
169 void
170 push_function_context (void)
172 if (cfun == 0)
173 allocate_struct_function (NULL, false);
175 VEC_safe_push (function_p, heap, function_context_stack, cfun);
176 set_cfun (NULL);
179 /* Restore the last saved context, at the end of a nested function.
180 This function is called from language-specific code. */
182 void
183 pop_function_context (void)
185 struct function *p = VEC_pop (function_p, function_context_stack);
186 set_cfun (p);
187 current_function_decl = p->decl;
189 /* Reset variables that have known state during rtx generation. */
190 virtuals_instantiated = 0;
191 generating_concat_p = 1;
194 /* Clear out all parts of the state in F that can safely be discarded
195 after the function has been parsed, but not compiled, to let
196 garbage collection reclaim the memory. */
198 void
199 free_after_parsing (struct function *f)
201 f->language = 0;
204 /* Clear out all parts of the state in F that can safely be discarded
205 after the function has been compiled, to let garbage collection
206 reclaim the memory. */
208 void
209 free_after_compilation (struct function *f)
211 prologue_insn_hash = NULL;
212 epilogue_insn_hash = NULL;
214 if (crtl->emit.regno_pointer_align)
215 free (crtl->emit.regno_pointer_align);
217 memset (crtl, 0, sizeof (struct rtl_data));
218 f->eh = NULL;
219 f->machine = NULL;
220 f->cfg = NULL;
222 regno_reg_rtx = NULL;
223 insn_locators_free ();
226 /* Return size needed for stack frame based on slots so far allocated.
227 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
228 the caller may have to do that. */
230 HOST_WIDE_INT
231 get_frame_size (void)
233 if (FRAME_GROWS_DOWNWARD)
234 return -frame_offset;
235 else
236 return frame_offset;
239 /* Issue an error message and return TRUE if frame OFFSET overflows in
240 the signed target pointer arithmetics for function FUNC. Otherwise
241 return FALSE. */
243 bool
244 frame_offset_overflow (HOST_WIDE_INT offset, tree func)
246 unsigned HOST_WIDE_INT size = FRAME_GROWS_DOWNWARD ? -offset : offset;
248 if (size > ((unsigned HOST_WIDE_INT) 1 << (GET_MODE_BITSIZE (Pmode) - 1))
249 /* Leave room for the fixed part of the frame. */
250 - 64 * UNITS_PER_WORD)
252 error_at (DECL_SOURCE_LOCATION (func),
253 "total size of local objects too large");
254 return TRUE;
257 return FALSE;
260 /* Return stack slot alignment in bits for TYPE and MODE. */
262 static unsigned int
263 get_stack_local_alignment (tree type, enum machine_mode mode)
265 unsigned int alignment;
267 if (mode == BLKmode)
268 alignment = BIGGEST_ALIGNMENT;
269 else
270 alignment = GET_MODE_ALIGNMENT (mode);
272 /* Allow the frond-end to (possibly) increase the alignment of this
273 stack slot. */
274 if (! type)
275 type = lang_hooks.types.type_for_mode (mode, 0);
277 return STACK_SLOT_ALIGNMENT (type, mode, alignment);
280 /* Determine whether it is possible to fit a stack slot of size SIZE and
281 alignment ALIGNMENT into an area in the stack frame that starts at
282 frame offset START and has a length of LENGTH. If so, store the frame
283 offset to be used for the stack slot in *POFFSET and return true;
284 return false otherwise. This function will extend the frame size when
285 given a start/length pair that lies at the end of the frame. */
287 static bool
288 try_fit_stack_local (HOST_WIDE_INT start, HOST_WIDE_INT length,
289 HOST_WIDE_INT size, unsigned int alignment,
290 HOST_WIDE_INT *poffset)
292 HOST_WIDE_INT this_frame_offset;
293 int frame_off, frame_alignment, frame_phase;
295 /* Calculate how many bytes the start of local variables is off from
296 stack alignment. */
297 frame_alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
298 frame_off = STARTING_FRAME_OFFSET % frame_alignment;
299 frame_phase = frame_off ? frame_alignment - frame_off : 0;
301 /* Round the frame offset to the specified alignment. */
303 /* We must be careful here, since FRAME_OFFSET might be negative and
304 division with a negative dividend isn't as well defined as we might
305 like. So we instead assume that ALIGNMENT is a power of two and
306 use logical operations which are unambiguous. */
307 if (FRAME_GROWS_DOWNWARD)
308 this_frame_offset
309 = (FLOOR_ROUND (start + length - size - frame_phase,
310 (unsigned HOST_WIDE_INT) alignment)
311 + frame_phase);
312 else
313 this_frame_offset
314 = (CEIL_ROUND (start - frame_phase,
315 (unsigned HOST_WIDE_INT) alignment)
316 + frame_phase);
318 /* See if it fits. If this space is at the edge of the frame,
319 consider extending the frame to make it fit. Our caller relies on
320 this when allocating a new slot. */
321 if (frame_offset == start && this_frame_offset < frame_offset)
322 frame_offset = this_frame_offset;
323 else if (this_frame_offset < start)
324 return false;
325 else if (start + length == frame_offset
326 && this_frame_offset + size > start + length)
327 frame_offset = this_frame_offset + size;
328 else if (this_frame_offset + size > start + length)
329 return false;
331 *poffset = this_frame_offset;
332 return true;
335 /* Create a new frame_space structure describing free space in the stack
336 frame beginning at START and ending at END, and chain it into the
337 function's frame_space_list. */
339 static void
340 add_frame_space (HOST_WIDE_INT start, HOST_WIDE_INT end)
342 struct frame_space *space = ggc_alloc_frame_space ();
343 space->next = crtl->frame_space_list;
344 crtl->frame_space_list = space;
345 space->start = start;
346 space->length = end - start;
349 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
350 with machine mode MODE.
352 ALIGN controls the amount of alignment for the address of the slot:
353 0 means according to MODE,
354 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
355 -2 means use BITS_PER_UNIT,
356 positive specifies alignment boundary in bits.
358 If REDUCE_ALIGNMENT_OK is true, it is OK to reduce alignment.
360 We do not round to stack_boundary here. */
363 assign_stack_local_1 (enum machine_mode mode, HOST_WIDE_INT size,
364 int align,
365 bool reduce_alignment_ok ATTRIBUTE_UNUSED)
367 rtx x, addr;
368 int bigend_correction = 0;
369 HOST_WIDE_INT slot_offset = 0, old_frame_offset;
370 unsigned int alignment, alignment_in_bits;
372 if (align == 0)
374 alignment = get_stack_local_alignment (NULL, mode);
375 alignment /= BITS_PER_UNIT;
377 else if (align == -1)
379 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
380 size = CEIL_ROUND (size, alignment);
382 else if (align == -2)
383 alignment = 1; /* BITS_PER_UNIT / BITS_PER_UNIT */
384 else
385 alignment = align / BITS_PER_UNIT;
387 alignment_in_bits = alignment * BITS_PER_UNIT;
389 /* Ignore alignment if it exceeds MAX_SUPPORTED_STACK_ALIGNMENT. */
390 if (alignment_in_bits > MAX_SUPPORTED_STACK_ALIGNMENT)
392 alignment_in_bits = MAX_SUPPORTED_STACK_ALIGNMENT;
393 alignment = alignment_in_bits / BITS_PER_UNIT;
396 if (SUPPORTS_STACK_ALIGNMENT)
398 if (crtl->stack_alignment_estimated < alignment_in_bits)
400 if (!crtl->stack_realign_processed)
401 crtl->stack_alignment_estimated = alignment_in_bits;
402 else
404 /* If stack is realigned and stack alignment value
405 hasn't been finalized, it is OK not to increase
406 stack_alignment_estimated. The bigger alignment
407 requirement is recorded in stack_alignment_needed
408 below. */
409 gcc_assert (!crtl->stack_realign_finalized);
410 if (!crtl->stack_realign_needed)
412 /* It is OK to reduce the alignment as long as the
413 requested size is 0 or the estimated stack
414 alignment >= mode alignment. */
415 gcc_assert (reduce_alignment_ok
416 || size == 0
417 || (crtl->stack_alignment_estimated
418 >= GET_MODE_ALIGNMENT (mode)));
419 alignment_in_bits = crtl->stack_alignment_estimated;
420 alignment = alignment_in_bits / BITS_PER_UNIT;
426 if (crtl->stack_alignment_needed < alignment_in_bits)
427 crtl->stack_alignment_needed = alignment_in_bits;
428 if (crtl->max_used_stack_slot_alignment < alignment_in_bits)
429 crtl->max_used_stack_slot_alignment = alignment_in_bits;
431 if (mode != BLKmode || size != 0)
433 struct frame_space **psp;
435 for (psp = &crtl->frame_space_list; *psp; psp = &(*psp)->next)
437 struct frame_space *space = *psp;
438 if (!try_fit_stack_local (space->start, space->length, size,
439 alignment, &slot_offset))
440 continue;
441 *psp = space->next;
442 if (slot_offset > space->start)
443 add_frame_space (space->start, slot_offset);
444 if (slot_offset + size < space->start + space->length)
445 add_frame_space (slot_offset + size,
446 space->start + space->length);
447 goto found_space;
450 else if (!STACK_ALIGNMENT_NEEDED)
452 slot_offset = frame_offset;
453 goto found_space;
456 old_frame_offset = frame_offset;
458 if (FRAME_GROWS_DOWNWARD)
460 frame_offset -= size;
461 try_fit_stack_local (frame_offset, size, size, alignment, &slot_offset);
463 if (slot_offset > frame_offset)
464 add_frame_space (frame_offset, slot_offset);
465 if (slot_offset + size < old_frame_offset)
466 add_frame_space (slot_offset + size, old_frame_offset);
468 else
470 frame_offset += size;
471 try_fit_stack_local (old_frame_offset, size, size, alignment, &slot_offset);
473 if (slot_offset > old_frame_offset)
474 add_frame_space (old_frame_offset, slot_offset);
475 if (slot_offset + size < frame_offset)
476 add_frame_space (slot_offset + size, frame_offset);
479 found_space:
480 /* On a big-endian machine, if we are allocating more space than we will use,
481 use the least significant bytes of those that are allocated. */
482 if (BYTES_BIG_ENDIAN && mode != BLKmode && GET_MODE_SIZE (mode) < size)
483 bigend_correction = size - GET_MODE_SIZE (mode);
485 /* If we have already instantiated virtual registers, return the actual
486 address relative to the frame pointer. */
487 if (virtuals_instantiated)
488 addr = plus_constant (frame_pointer_rtx,
489 trunc_int_for_mode
490 (slot_offset + bigend_correction
491 + STARTING_FRAME_OFFSET, Pmode));
492 else
493 addr = plus_constant (virtual_stack_vars_rtx,
494 trunc_int_for_mode
495 (slot_offset + bigend_correction,
496 Pmode));
498 x = gen_rtx_MEM (mode, addr);
499 set_mem_align (x, alignment_in_bits);
500 MEM_NOTRAP_P (x) = 1;
502 stack_slot_list
503 = gen_rtx_EXPR_LIST (VOIDmode, x, stack_slot_list);
505 if (frame_offset_overflow (frame_offset, current_function_decl))
506 frame_offset = 0;
508 return x;
511 /* Wrap up assign_stack_local_1 with last parameter as false. */
514 assign_stack_local (enum machine_mode mode, HOST_WIDE_INT size, int align)
516 return assign_stack_local_1 (mode, size, align, false);
520 /* In order to evaluate some expressions, such as function calls returning
521 structures in memory, we need to temporarily allocate stack locations.
522 We record each allocated temporary in the following structure.
524 Associated with each temporary slot is a nesting level. When we pop up
525 one level, all temporaries associated with the previous level are freed.
526 Normally, all temporaries are freed after the execution of the statement
527 in which they were created. However, if we are inside a ({...}) grouping,
528 the result may be in a temporary and hence must be preserved. If the
529 result could be in a temporary, we preserve it if we can determine which
530 one it is in. If we cannot determine which temporary may contain the
531 result, all temporaries are preserved. A temporary is preserved by
532 pretending it was allocated at the previous nesting level.
534 Automatic variables are also assigned temporary slots, at the nesting
535 level where they are defined. They are marked a "kept" so that
536 free_temp_slots will not free them. */
538 struct GTY(()) temp_slot {
539 /* Points to next temporary slot. */
540 struct temp_slot *next;
541 /* Points to previous temporary slot. */
542 struct temp_slot *prev;
543 /* The rtx to used to reference the slot. */
544 rtx slot;
545 /* The size, in units, of the slot. */
546 HOST_WIDE_INT size;
547 /* The type of the object in the slot, or zero if it doesn't correspond
548 to a type. We use this to determine whether a slot can be reused.
549 It can be reused if objects of the type of the new slot will always
550 conflict with objects of the type of the old slot. */
551 tree type;
552 /* The alignment (in bits) of the slot. */
553 unsigned int align;
554 /* Nonzero if this temporary is currently in use. */
555 char in_use;
556 /* Nonzero if this temporary has its address taken. */
557 char addr_taken;
558 /* Nesting level at which this slot is being used. */
559 int level;
560 /* Nonzero if this should survive a call to free_temp_slots. */
561 int keep;
562 /* The offset of the slot from the frame_pointer, including extra space
563 for alignment. This info is for combine_temp_slots. */
564 HOST_WIDE_INT base_offset;
565 /* The size of the slot, including extra space for alignment. This
566 info is for combine_temp_slots. */
567 HOST_WIDE_INT full_size;
570 /* A table of addresses that represent a stack slot. The table is a mapping
571 from address RTXen to a temp slot. */
572 static GTY((param_is(struct temp_slot_address_entry))) htab_t temp_slot_address_table;
574 /* Entry for the above hash table. */
575 struct GTY(()) temp_slot_address_entry {
576 hashval_t hash;
577 rtx address;
578 struct temp_slot *temp_slot;
581 /* Removes temporary slot TEMP from LIST. */
583 static void
584 cut_slot_from_list (struct temp_slot *temp, struct temp_slot **list)
586 if (temp->next)
587 temp->next->prev = temp->prev;
588 if (temp->prev)
589 temp->prev->next = temp->next;
590 else
591 *list = temp->next;
593 temp->prev = temp->next = NULL;
596 /* Inserts temporary slot TEMP to LIST. */
598 static void
599 insert_slot_to_list (struct temp_slot *temp, struct temp_slot **list)
601 temp->next = *list;
602 if (*list)
603 (*list)->prev = temp;
604 temp->prev = NULL;
605 *list = temp;
608 /* Returns the list of used temp slots at LEVEL. */
610 static struct temp_slot **
611 temp_slots_at_level (int level)
613 if (level >= (int) VEC_length (temp_slot_p, used_temp_slots))
614 VEC_safe_grow_cleared (temp_slot_p, gc, used_temp_slots, level + 1);
616 return &(VEC_address (temp_slot_p, used_temp_slots)[level]);
619 /* Returns the maximal temporary slot level. */
621 static int
622 max_slot_level (void)
624 if (!used_temp_slots)
625 return -1;
627 return VEC_length (temp_slot_p, used_temp_slots) - 1;
630 /* Moves temporary slot TEMP to LEVEL. */
632 static void
633 move_slot_to_level (struct temp_slot *temp, int level)
635 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
636 insert_slot_to_list (temp, temp_slots_at_level (level));
637 temp->level = level;
640 /* Make temporary slot TEMP available. */
642 static void
643 make_slot_available (struct temp_slot *temp)
645 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
646 insert_slot_to_list (temp, &avail_temp_slots);
647 temp->in_use = 0;
648 temp->level = -1;
651 /* Compute the hash value for an address -> temp slot mapping.
652 The value is cached on the mapping entry. */
653 static hashval_t
654 temp_slot_address_compute_hash (struct temp_slot_address_entry *t)
656 int do_not_record = 0;
657 return hash_rtx (t->address, GET_MODE (t->address),
658 &do_not_record, NULL, false);
661 /* Return the hash value for an address -> temp slot mapping. */
662 static hashval_t
663 temp_slot_address_hash (const void *p)
665 const struct temp_slot_address_entry *t;
666 t = (const struct temp_slot_address_entry *) p;
667 return t->hash;
670 /* Compare two address -> temp slot mapping entries. */
671 static int
672 temp_slot_address_eq (const void *p1, const void *p2)
674 const struct temp_slot_address_entry *t1, *t2;
675 t1 = (const struct temp_slot_address_entry *) p1;
676 t2 = (const struct temp_slot_address_entry *) p2;
677 return exp_equiv_p (t1->address, t2->address, 0, true);
680 /* Add ADDRESS as an alias of TEMP_SLOT to the addess -> temp slot mapping. */
681 static void
682 insert_temp_slot_address (rtx address, struct temp_slot *temp_slot)
684 void **slot;
685 struct temp_slot_address_entry *t = ggc_alloc_temp_slot_address_entry ();
686 t->address = address;
687 t->temp_slot = temp_slot;
688 t->hash = temp_slot_address_compute_hash (t);
689 slot = htab_find_slot_with_hash (temp_slot_address_table, t, t->hash, INSERT);
690 *slot = t;
693 /* Remove an address -> temp slot mapping entry if the temp slot is
694 not in use anymore. Callback for remove_unused_temp_slot_addresses. */
695 static int
696 remove_unused_temp_slot_addresses_1 (void **slot, void *data ATTRIBUTE_UNUSED)
698 const struct temp_slot_address_entry *t;
699 t = (const struct temp_slot_address_entry *) *slot;
700 if (! t->temp_slot->in_use)
701 *slot = NULL;
702 return 1;
705 /* Remove all mappings of addresses to unused temp slots. */
706 static void
707 remove_unused_temp_slot_addresses (void)
709 htab_traverse (temp_slot_address_table,
710 remove_unused_temp_slot_addresses_1,
711 NULL);
714 /* Find the temp slot corresponding to the object at address X. */
716 static struct temp_slot *
717 find_temp_slot_from_address (rtx x)
719 struct temp_slot *p;
720 struct temp_slot_address_entry tmp, *t;
722 /* First try the easy way:
723 See if X exists in the address -> temp slot mapping. */
724 tmp.address = x;
725 tmp.temp_slot = NULL;
726 tmp.hash = temp_slot_address_compute_hash (&tmp);
727 t = (struct temp_slot_address_entry *)
728 htab_find_with_hash (temp_slot_address_table, &tmp, tmp.hash);
729 if (t)
730 return t->temp_slot;
732 /* If we have a sum involving a register, see if it points to a temp
733 slot. */
734 if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 0))
735 && (p = find_temp_slot_from_address (XEXP (x, 0))) != 0)
736 return p;
737 else if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 1))
738 && (p = find_temp_slot_from_address (XEXP (x, 1))) != 0)
739 return p;
741 /* Last resort: Address is a virtual stack var address. */
742 if (GET_CODE (x) == PLUS
743 && XEXP (x, 0) == virtual_stack_vars_rtx
744 && CONST_INT_P (XEXP (x, 1)))
746 int i;
747 for (i = max_slot_level (); i >= 0; i--)
748 for (p = *temp_slots_at_level (i); p; p = p->next)
750 if (INTVAL (XEXP (x, 1)) >= p->base_offset
751 && INTVAL (XEXP (x, 1)) < p->base_offset + p->full_size)
752 return p;
756 return NULL;
759 /* Allocate a temporary stack slot and record it for possible later
760 reuse.
762 MODE is the machine mode to be given to the returned rtx.
764 SIZE is the size in units of the space required. We do no rounding here
765 since assign_stack_local will do any required rounding.
767 KEEP is 1 if this slot is to be retained after a call to
768 free_temp_slots. Automatic variables for a block are allocated
769 with this flag. KEEP values of 2 or 3 were needed respectively
770 for variables whose lifetime is controlled by CLEANUP_POINT_EXPRs
771 or for SAVE_EXPRs, but they are now unused.
773 TYPE is the type that will be used for the stack slot. */
776 assign_stack_temp_for_type (enum machine_mode mode, HOST_WIDE_INT size,
777 int keep, tree type)
779 unsigned int align;
780 struct temp_slot *p, *best_p = 0, *selected = NULL, **pp;
781 rtx slot;
783 /* If SIZE is -1 it means that somebody tried to allocate a temporary
784 of a variable size. */
785 gcc_assert (size != -1);
787 /* These are now unused. */
788 gcc_assert (keep <= 1);
790 align = get_stack_local_alignment (type, mode);
792 /* Try to find an available, already-allocated temporary of the proper
793 mode which meets the size and alignment requirements. Choose the
794 smallest one with the closest alignment.
796 If assign_stack_temp is called outside of the tree->rtl expansion,
797 we cannot reuse the stack slots (that may still refer to
798 VIRTUAL_STACK_VARS_REGNUM). */
799 if (!virtuals_instantiated)
801 for (p = avail_temp_slots; p; p = p->next)
803 if (p->align >= align && p->size >= size
804 && GET_MODE (p->slot) == mode
805 && objects_must_conflict_p (p->type, type)
806 && (best_p == 0 || best_p->size > p->size
807 || (best_p->size == p->size && best_p->align > p->align)))
809 if (p->align == align && p->size == size)
811 selected = p;
812 cut_slot_from_list (selected, &avail_temp_slots);
813 best_p = 0;
814 break;
816 best_p = p;
821 /* Make our best, if any, the one to use. */
822 if (best_p)
824 selected = best_p;
825 cut_slot_from_list (selected, &avail_temp_slots);
827 /* If there are enough aligned bytes left over, make them into a new
828 temp_slot so that the extra bytes don't get wasted. Do this only
829 for BLKmode slots, so that we can be sure of the alignment. */
830 if (GET_MODE (best_p->slot) == BLKmode)
832 int alignment = best_p->align / BITS_PER_UNIT;
833 HOST_WIDE_INT rounded_size = CEIL_ROUND (size, alignment);
835 if (best_p->size - rounded_size >= alignment)
837 p = ggc_alloc_temp_slot ();
838 p->in_use = p->addr_taken = 0;
839 p->size = best_p->size - rounded_size;
840 p->base_offset = best_p->base_offset + rounded_size;
841 p->full_size = best_p->full_size - rounded_size;
842 p->slot = adjust_address_nv (best_p->slot, BLKmode, rounded_size);
843 p->align = best_p->align;
844 p->type = best_p->type;
845 insert_slot_to_list (p, &avail_temp_slots);
847 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, p->slot,
848 stack_slot_list);
850 best_p->size = rounded_size;
851 best_p->full_size = rounded_size;
856 /* If we still didn't find one, make a new temporary. */
857 if (selected == 0)
859 HOST_WIDE_INT frame_offset_old = frame_offset;
861 p = ggc_alloc_temp_slot ();
863 /* We are passing an explicit alignment request to assign_stack_local.
864 One side effect of that is assign_stack_local will not round SIZE
865 to ensure the frame offset remains suitably aligned.
867 So for requests which depended on the rounding of SIZE, we go ahead
868 and round it now. We also make sure ALIGNMENT is at least
869 BIGGEST_ALIGNMENT. */
870 gcc_assert (mode != BLKmode || align == BIGGEST_ALIGNMENT);
871 p->slot = assign_stack_local (mode,
872 (mode == BLKmode
873 ? CEIL_ROUND (size, (int) align / BITS_PER_UNIT)
874 : size),
875 align);
877 p->align = align;
879 /* The following slot size computation is necessary because we don't
880 know the actual size of the temporary slot until assign_stack_local
881 has performed all the frame alignment and size rounding for the
882 requested temporary. Note that extra space added for alignment
883 can be either above or below this stack slot depending on which
884 way the frame grows. We include the extra space if and only if it
885 is above this slot. */
886 if (FRAME_GROWS_DOWNWARD)
887 p->size = frame_offset_old - frame_offset;
888 else
889 p->size = size;
891 /* Now define the fields used by combine_temp_slots. */
892 if (FRAME_GROWS_DOWNWARD)
894 p->base_offset = frame_offset;
895 p->full_size = frame_offset_old - frame_offset;
897 else
899 p->base_offset = frame_offset_old;
900 p->full_size = frame_offset - frame_offset_old;
903 selected = p;
906 p = selected;
907 p->in_use = 1;
908 p->addr_taken = 0;
909 p->type = type;
910 p->level = temp_slot_level;
911 p->keep = keep;
913 pp = temp_slots_at_level (p->level);
914 insert_slot_to_list (p, pp);
915 insert_temp_slot_address (XEXP (p->slot, 0), p);
917 /* Create a new MEM rtx to avoid clobbering MEM flags of old slots. */
918 slot = gen_rtx_MEM (mode, XEXP (p->slot, 0));
919 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, slot, stack_slot_list);
921 /* If we know the alias set for the memory that will be used, use
922 it. If there's no TYPE, then we don't know anything about the
923 alias set for the memory. */
924 set_mem_alias_set (slot, type ? get_alias_set (type) : 0);
925 set_mem_align (slot, align);
927 /* If a type is specified, set the relevant flags. */
928 if (type != 0)
930 MEM_VOLATILE_P (slot) = TYPE_VOLATILE (type);
931 MEM_SET_IN_STRUCT_P (slot, (AGGREGATE_TYPE_P (type)
932 || TREE_CODE (type) == COMPLEX_TYPE));
934 MEM_NOTRAP_P (slot) = 1;
936 return slot;
939 /* Allocate a temporary stack slot and record it for possible later
940 reuse. First three arguments are same as in preceding function. */
943 assign_stack_temp (enum machine_mode mode, HOST_WIDE_INT size, int keep)
945 return assign_stack_temp_for_type (mode, size, keep, NULL_TREE);
948 /* Assign a temporary.
949 If TYPE_OR_DECL is a decl, then we are doing it on behalf of the decl
950 and so that should be used in error messages. In either case, we
951 allocate of the given type.
952 KEEP is as for assign_stack_temp.
953 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
954 it is 0 if a register is OK.
955 DONT_PROMOTE is 1 if we should not promote values in register
956 to wider modes. */
959 assign_temp (tree type_or_decl, int keep, int memory_required,
960 int dont_promote ATTRIBUTE_UNUSED)
962 tree type, decl;
963 enum machine_mode mode;
964 #ifdef PROMOTE_MODE
965 int unsignedp;
966 #endif
968 if (DECL_P (type_or_decl))
969 decl = type_or_decl, type = TREE_TYPE (decl);
970 else
971 decl = NULL, type = type_or_decl;
973 mode = TYPE_MODE (type);
974 #ifdef PROMOTE_MODE
975 unsignedp = TYPE_UNSIGNED (type);
976 #endif
978 if (mode == BLKmode || memory_required)
980 HOST_WIDE_INT size = int_size_in_bytes (type);
981 rtx tmp;
983 /* Zero sized arrays are GNU C extension. Set size to 1 to avoid
984 problems with allocating the stack space. */
985 if (size == 0)
986 size = 1;
988 /* Unfortunately, we don't yet know how to allocate variable-sized
989 temporaries. However, sometimes we can find a fixed upper limit on
990 the size, so try that instead. */
991 else if (size == -1)
992 size = max_int_size_in_bytes (type);
994 /* The size of the temporary may be too large to fit into an integer. */
995 /* ??? Not sure this should happen except for user silliness, so limit
996 this to things that aren't compiler-generated temporaries. The
997 rest of the time we'll die in assign_stack_temp_for_type. */
998 if (decl && size == -1
999 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST)
1001 error ("size of variable %q+D is too large", decl);
1002 size = 1;
1005 tmp = assign_stack_temp_for_type (mode, size, keep, type);
1006 return tmp;
1009 #ifdef PROMOTE_MODE
1010 if (! dont_promote)
1011 mode = promote_mode (type, mode, &unsignedp);
1012 #endif
1014 return gen_reg_rtx (mode);
1017 /* Combine temporary stack slots which are adjacent on the stack.
1019 This allows for better use of already allocated stack space. This is only
1020 done for BLKmode slots because we can be sure that we won't have alignment
1021 problems in this case. */
1023 static void
1024 combine_temp_slots (void)
1026 struct temp_slot *p, *q, *next, *next_q;
1027 int num_slots;
1029 /* We can't combine slots, because the information about which slot
1030 is in which alias set will be lost. */
1031 if (flag_strict_aliasing)
1032 return;
1034 /* If there are a lot of temp slots, don't do anything unless
1035 high levels of optimization. */
1036 if (! flag_expensive_optimizations)
1037 for (p = avail_temp_slots, num_slots = 0; p; p = p->next, num_slots++)
1038 if (num_slots > 100 || (num_slots > 10 && optimize == 0))
1039 return;
1041 for (p = avail_temp_slots; p; p = next)
1043 int delete_p = 0;
1045 next = p->next;
1047 if (GET_MODE (p->slot) != BLKmode)
1048 continue;
1050 for (q = p->next; q; q = next_q)
1052 int delete_q = 0;
1054 next_q = q->next;
1056 if (GET_MODE (q->slot) != BLKmode)
1057 continue;
1059 if (p->base_offset + p->full_size == q->base_offset)
1061 /* Q comes after P; combine Q into P. */
1062 p->size += q->size;
1063 p->full_size += q->full_size;
1064 delete_q = 1;
1066 else if (q->base_offset + q->full_size == p->base_offset)
1068 /* P comes after Q; combine P into Q. */
1069 q->size += p->size;
1070 q->full_size += p->full_size;
1071 delete_p = 1;
1072 break;
1074 if (delete_q)
1075 cut_slot_from_list (q, &avail_temp_slots);
1078 /* Either delete P or advance past it. */
1079 if (delete_p)
1080 cut_slot_from_list (p, &avail_temp_slots);
1084 /* Indicate that NEW_RTX is an alternate way of referring to the temp
1085 slot that previously was known by OLD_RTX. */
1087 void
1088 update_temp_slot_address (rtx old_rtx, rtx new_rtx)
1090 struct temp_slot *p;
1092 if (rtx_equal_p (old_rtx, new_rtx))
1093 return;
1095 p = find_temp_slot_from_address (old_rtx);
1097 /* If we didn't find one, see if both OLD_RTX is a PLUS. If so, and
1098 NEW_RTX is a register, see if one operand of the PLUS is a
1099 temporary location. If so, NEW_RTX points into it. Otherwise,
1100 if both OLD_RTX and NEW_RTX are a PLUS and if there is a register
1101 in common between them. If so, try a recursive call on those
1102 values. */
1103 if (p == 0)
1105 if (GET_CODE (old_rtx) != PLUS)
1106 return;
1108 if (REG_P (new_rtx))
1110 update_temp_slot_address (XEXP (old_rtx, 0), new_rtx);
1111 update_temp_slot_address (XEXP (old_rtx, 1), new_rtx);
1112 return;
1114 else if (GET_CODE (new_rtx) != PLUS)
1115 return;
1117 if (rtx_equal_p (XEXP (old_rtx, 0), XEXP (new_rtx, 0)))
1118 update_temp_slot_address (XEXP (old_rtx, 1), XEXP (new_rtx, 1));
1119 else if (rtx_equal_p (XEXP (old_rtx, 1), XEXP (new_rtx, 0)))
1120 update_temp_slot_address (XEXP (old_rtx, 0), XEXP (new_rtx, 1));
1121 else if (rtx_equal_p (XEXP (old_rtx, 0), XEXP (new_rtx, 1)))
1122 update_temp_slot_address (XEXP (old_rtx, 1), XEXP (new_rtx, 0));
1123 else if (rtx_equal_p (XEXP (old_rtx, 1), XEXP (new_rtx, 1)))
1124 update_temp_slot_address (XEXP (old_rtx, 0), XEXP (new_rtx, 0));
1126 return;
1129 /* Otherwise add an alias for the temp's address. */
1130 insert_temp_slot_address (new_rtx, p);
1133 /* If X could be a reference to a temporary slot, mark the fact that its
1134 address was taken. */
1136 void
1137 mark_temp_addr_taken (rtx x)
1139 struct temp_slot *p;
1141 if (x == 0)
1142 return;
1144 /* If X is not in memory or is at a constant address, it cannot be in
1145 a temporary slot. */
1146 if (!MEM_P (x) || CONSTANT_P (XEXP (x, 0)))
1147 return;
1149 p = find_temp_slot_from_address (XEXP (x, 0));
1150 if (p != 0)
1151 p->addr_taken = 1;
1154 /* If X could be a reference to a temporary slot, mark that slot as
1155 belonging to the to one level higher than the current level. If X
1156 matched one of our slots, just mark that one. Otherwise, we can't
1157 easily predict which it is, so upgrade all of them. Kept slots
1158 need not be touched.
1160 This is called when an ({...}) construct occurs and a statement
1161 returns a value in memory. */
1163 void
1164 preserve_temp_slots (rtx x)
1166 struct temp_slot *p = 0, *next;
1168 /* If there is no result, we still might have some objects whose address
1169 were taken, so we need to make sure they stay around. */
1170 if (x == 0)
1172 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1174 next = p->next;
1176 if (p->addr_taken)
1177 move_slot_to_level (p, temp_slot_level - 1);
1180 return;
1183 /* If X is a register that is being used as a pointer, see if we have
1184 a temporary slot we know it points to. To be consistent with
1185 the code below, we really should preserve all non-kept slots
1186 if we can't find a match, but that seems to be much too costly. */
1187 if (REG_P (x) && REG_POINTER (x))
1188 p = find_temp_slot_from_address (x);
1190 /* If X is not in memory or is at a constant address, it cannot be in
1191 a temporary slot, but it can contain something whose address was
1192 taken. */
1193 if (p == 0 && (!MEM_P (x) || CONSTANT_P (XEXP (x, 0))))
1195 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1197 next = p->next;
1199 if (p->addr_taken)
1200 move_slot_to_level (p, temp_slot_level - 1);
1203 return;
1206 /* First see if we can find a match. */
1207 if (p == 0)
1208 p = find_temp_slot_from_address (XEXP (x, 0));
1210 if (p != 0)
1212 /* Move everything at our level whose address was taken to our new
1213 level in case we used its address. */
1214 struct temp_slot *q;
1216 if (p->level == temp_slot_level)
1218 for (q = *temp_slots_at_level (temp_slot_level); q; q = next)
1220 next = q->next;
1222 if (p != q && q->addr_taken)
1223 move_slot_to_level (q, temp_slot_level - 1);
1226 move_slot_to_level (p, temp_slot_level - 1);
1227 p->addr_taken = 0;
1229 return;
1232 /* Otherwise, preserve all non-kept slots at this level. */
1233 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1235 next = p->next;
1237 if (!p->keep)
1238 move_slot_to_level (p, temp_slot_level - 1);
1242 /* Free all temporaries used so far. This is normally called at the
1243 end of generating code for a statement. */
1245 void
1246 free_temp_slots (void)
1248 struct temp_slot *p, *next;
1249 bool some_available = false;
1251 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1253 next = p->next;
1255 if (!p->keep)
1257 make_slot_available (p);
1258 some_available = true;
1262 if (some_available)
1264 remove_unused_temp_slot_addresses ();
1265 combine_temp_slots ();
1269 /* Push deeper into the nesting level for stack temporaries. */
1271 void
1272 push_temp_slots (void)
1274 temp_slot_level++;
1277 /* Pop a temporary nesting level. All slots in use in the current level
1278 are freed. */
1280 void
1281 pop_temp_slots (void)
1283 struct temp_slot *p, *next;
1284 bool some_available = false;
1286 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1288 next = p->next;
1289 make_slot_available (p);
1290 some_available = true;
1293 if (some_available)
1295 remove_unused_temp_slot_addresses ();
1296 combine_temp_slots ();
1299 temp_slot_level--;
1302 /* Initialize temporary slots. */
1304 void
1305 init_temp_slots (void)
1307 /* We have not allocated any temporaries yet. */
1308 avail_temp_slots = 0;
1309 used_temp_slots = 0;
1310 temp_slot_level = 0;
1312 /* Set up the table to map addresses to temp slots. */
1313 if (! temp_slot_address_table)
1314 temp_slot_address_table = htab_create_ggc (32,
1315 temp_slot_address_hash,
1316 temp_slot_address_eq,
1317 NULL);
1318 else
1319 htab_empty (temp_slot_address_table);
1322 /* These routines are responsible for converting virtual register references
1323 to the actual hard register references once RTL generation is complete.
1325 The following four variables are used for communication between the
1326 routines. They contain the offsets of the virtual registers from their
1327 respective hard registers. */
1329 static int in_arg_offset;
1330 static int var_offset;
1331 static int dynamic_offset;
1332 static int out_arg_offset;
1333 static int cfa_offset;
1335 /* In most machines, the stack pointer register is equivalent to the bottom
1336 of the stack. */
1338 #ifndef STACK_POINTER_OFFSET
1339 #define STACK_POINTER_OFFSET 0
1340 #endif
1342 /* If not defined, pick an appropriate default for the offset of dynamically
1343 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
1344 REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
1346 #ifndef STACK_DYNAMIC_OFFSET
1348 /* The bottom of the stack points to the actual arguments. If
1349 REG_PARM_STACK_SPACE is defined, this includes the space for the register
1350 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
1351 stack space for register parameters is not pushed by the caller, but
1352 rather part of the fixed stack areas and hence not included in
1353 `crtl->outgoing_args_size'. Nevertheless, we must allow
1354 for it when allocating stack dynamic objects. */
1356 #if defined(REG_PARM_STACK_SPACE)
1357 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1358 ((ACCUMULATE_OUTGOING_ARGS \
1359 ? (crtl->outgoing_args_size \
1360 + (OUTGOING_REG_PARM_STACK_SPACE ((!(FNDECL) ? NULL_TREE : TREE_TYPE (FNDECL))) ? 0 \
1361 : REG_PARM_STACK_SPACE (FNDECL))) \
1362 : 0) + (STACK_POINTER_OFFSET))
1363 #else
1364 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1365 ((ACCUMULATE_OUTGOING_ARGS ? crtl->outgoing_args_size : 0) \
1366 + (STACK_POINTER_OFFSET))
1367 #endif
1368 #endif
1371 /* Given a piece of RTX and a pointer to a HOST_WIDE_INT, if the RTX
1372 is a virtual register, return the equivalent hard register and set the
1373 offset indirectly through the pointer. Otherwise, return 0. */
1375 static rtx
1376 instantiate_new_reg (rtx x, HOST_WIDE_INT *poffset)
1378 rtx new_rtx;
1379 HOST_WIDE_INT offset;
1381 if (x == virtual_incoming_args_rtx)
1383 if (stack_realign_drap)
1385 /* Replace virtual_incoming_args_rtx with internal arg
1386 pointer if DRAP is used to realign stack. */
1387 new_rtx = crtl->args.internal_arg_pointer;
1388 offset = 0;
1390 else
1391 new_rtx = arg_pointer_rtx, offset = in_arg_offset;
1393 else if (x == virtual_stack_vars_rtx)
1394 new_rtx = frame_pointer_rtx, offset = var_offset;
1395 else if (x == virtual_stack_dynamic_rtx)
1396 new_rtx = stack_pointer_rtx, offset = dynamic_offset;
1397 else if (x == virtual_outgoing_args_rtx)
1398 new_rtx = stack_pointer_rtx, offset = out_arg_offset;
1399 else if (x == virtual_cfa_rtx)
1401 #ifdef FRAME_POINTER_CFA_OFFSET
1402 new_rtx = frame_pointer_rtx;
1403 #else
1404 new_rtx = arg_pointer_rtx;
1405 #endif
1406 offset = cfa_offset;
1408 else if (x == virtual_preferred_stack_boundary_rtx)
1410 new_rtx = GEN_INT (crtl->preferred_stack_boundary / BITS_PER_UNIT);
1411 offset = 0;
1413 else
1414 return NULL_RTX;
1416 *poffset = offset;
1417 return new_rtx;
1420 /* A subroutine of instantiate_virtual_regs, called via for_each_rtx.
1421 Instantiate any virtual registers present inside of *LOC. The expression
1422 is simplified, as much as possible, but is not to be considered "valid"
1423 in any sense implied by the target. If any change is made, set CHANGED
1424 to true. */
1426 static int
1427 instantiate_virtual_regs_in_rtx (rtx *loc, void *data)
1429 HOST_WIDE_INT offset;
1430 bool *changed = (bool *) data;
1431 rtx x, new_rtx;
1433 x = *loc;
1434 if (x == 0)
1435 return 0;
1437 switch (GET_CODE (x))
1439 case REG:
1440 new_rtx = instantiate_new_reg (x, &offset);
1441 if (new_rtx)
1443 *loc = plus_constant (new_rtx, offset);
1444 if (changed)
1445 *changed = true;
1447 return -1;
1449 case PLUS:
1450 new_rtx = instantiate_new_reg (XEXP (x, 0), &offset);
1451 if (new_rtx)
1453 new_rtx = plus_constant (new_rtx, offset);
1454 *loc = simplify_gen_binary (PLUS, GET_MODE (x), new_rtx, XEXP (x, 1));
1455 if (changed)
1456 *changed = true;
1457 return -1;
1460 /* FIXME -- from old code */
1461 /* If we have (plus (subreg (virtual-reg)) (const_int)), we know
1462 we can commute the PLUS and SUBREG because pointers into the
1463 frame are well-behaved. */
1464 break;
1466 default:
1467 break;
1470 return 0;
1473 /* A subroutine of instantiate_virtual_regs_in_insn. Return true if X
1474 matches the predicate for insn CODE operand OPERAND. */
1476 static int
1477 safe_insn_predicate (int code, int operand, rtx x)
1479 const struct insn_operand_data *op_data;
1481 if (code < 0)
1482 return true;
1484 op_data = &insn_data[code].operand[operand];
1485 if (op_data->predicate == NULL)
1486 return true;
1488 return op_data->predicate (x, op_data->mode);
1491 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1492 registers present inside of insn. The result will be a valid insn. */
1494 static void
1495 instantiate_virtual_regs_in_insn (rtx insn)
1497 HOST_WIDE_INT offset;
1498 int insn_code, i;
1499 bool any_change = false;
1500 rtx set, new_rtx, x, seq;
1502 /* There are some special cases to be handled first. */
1503 set = single_set (insn);
1504 if (set)
1506 /* We're allowed to assign to a virtual register. This is interpreted
1507 to mean that the underlying register gets assigned the inverse
1508 transformation. This is used, for example, in the handling of
1509 non-local gotos. */
1510 new_rtx = instantiate_new_reg (SET_DEST (set), &offset);
1511 if (new_rtx)
1513 start_sequence ();
1515 for_each_rtx (&SET_SRC (set), instantiate_virtual_regs_in_rtx, NULL);
1516 x = simplify_gen_binary (PLUS, GET_MODE (new_rtx), SET_SRC (set),
1517 GEN_INT (-offset));
1518 x = force_operand (x, new_rtx);
1519 if (x != new_rtx)
1520 emit_move_insn (new_rtx, x);
1522 seq = get_insns ();
1523 end_sequence ();
1525 emit_insn_before (seq, insn);
1526 delete_insn (insn);
1527 return;
1530 /* Handle a straight copy from a virtual register by generating a
1531 new add insn. The difference between this and falling through
1532 to the generic case is avoiding a new pseudo and eliminating a
1533 move insn in the initial rtl stream. */
1534 new_rtx = instantiate_new_reg (SET_SRC (set), &offset);
1535 if (new_rtx && offset != 0
1536 && REG_P (SET_DEST (set))
1537 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1539 start_sequence ();
1541 x = expand_simple_binop (GET_MODE (SET_DEST (set)), PLUS,
1542 new_rtx, GEN_INT (offset), SET_DEST (set),
1543 1, OPTAB_LIB_WIDEN);
1544 if (x != SET_DEST (set))
1545 emit_move_insn (SET_DEST (set), x);
1547 seq = get_insns ();
1548 end_sequence ();
1550 emit_insn_before (seq, insn);
1551 delete_insn (insn);
1552 return;
1555 extract_insn (insn);
1556 insn_code = INSN_CODE (insn);
1558 /* Handle a plus involving a virtual register by determining if the
1559 operands remain valid if they're modified in place. */
1560 if (GET_CODE (SET_SRC (set)) == PLUS
1561 && recog_data.n_operands >= 3
1562 && recog_data.operand_loc[1] == &XEXP (SET_SRC (set), 0)
1563 && recog_data.operand_loc[2] == &XEXP (SET_SRC (set), 1)
1564 && CONST_INT_P (recog_data.operand[2])
1565 && (new_rtx = instantiate_new_reg (recog_data.operand[1], &offset)))
1567 offset += INTVAL (recog_data.operand[2]);
1569 /* If the sum is zero, then replace with a plain move. */
1570 if (offset == 0
1571 && REG_P (SET_DEST (set))
1572 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1574 start_sequence ();
1575 emit_move_insn (SET_DEST (set), new_rtx);
1576 seq = get_insns ();
1577 end_sequence ();
1579 emit_insn_before (seq, insn);
1580 delete_insn (insn);
1581 return;
1584 x = gen_int_mode (offset, recog_data.operand_mode[2]);
1586 /* Using validate_change and apply_change_group here leaves
1587 recog_data in an invalid state. Since we know exactly what
1588 we want to check, do those two by hand. */
1589 if (safe_insn_predicate (insn_code, 1, new_rtx)
1590 && safe_insn_predicate (insn_code, 2, x))
1592 *recog_data.operand_loc[1] = recog_data.operand[1] = new_rtx;
1593 *recog_data.operand_loc[2] = recog_data.operand[2] = x;
1594 any_change = true;
1596 /* Fall through into the regular operand fixup loop in
1597 order to take care of operands other than 1 and 2. */
1601 else
1603 extract_insn (insn);
1604 insn_code = INSN_CODE (insn);
1607 /* In the general case, we expect virtual registers to appear only in
1608 operands, and then only as either bare registers or inside memories. */
1609 for (i = 0; i < recog_data.n_operands; ++i)
1611 x = recog_data.operand[i];
1612 switch (GET_CODE (x))
1614 case MEM:
1616 rtx addr = XEXP (x, 0);
1617 bool changed = false;
1619 for_each_rtx (&addr, instantiate_virtual_regs_in_rtx, &changed);
1620 if (!changed)
1621 continue;
1623 start_sequence ();
1624 x = replace_equiv_address (x, addr);
1625 /* It may happen that the address with the virtual reg
1626 was valid (e.g. based on the virtual stack reg, which might
1627 be acceptable to the predicates with all offsets), whereas
1628 the address now isn't anymore, for instance when the address
1629 is still offsetted, but the base reg isn't virtual-stack-reg
1630 anymore. Below we would do a force_reg on the whole operand,
1631 but this insn might actually only accept memory. Hence,
1632 before doing that last resort, try to reload the address into
1633 a register, so this operand stays a MEM. */
1634 if (!safe_insn_predicate (insn_code, i, x))
1636 addr = force_reg (GET_MODE (addr), addr);
1637 x = replace_equiv_address (x, addr);
1639 seq = get_insns ();
1640 end_sequence ();
1641 if (seq)
1642 emit_insn_before (seq, insn);
1644 break;
1646 case REG:
1647 new_rtx = instantiate_new_reg (x, &offset);
1648 if (new_rtx == NULL)
1649 continue;
1650 if (offset == 0)
1651 x = new_rtx;
1652 else
1654 start_sequence ();
1656 /* Careful, special mode predicates may have stuff in
1657 insn_data[insn_code].operand[i].mode that isn't useful
1658 to us for computing a new value. */
1659 /* ??? Recognize address_operand and/or "p" constraints
1660 to see if (plus new offset) is a valid before we put
1661 this through expand_simple_binop. */
1662 x = expand_simple_binop (GET_MODE (x), PLUS, new_rtx,
1663 GEN_INT (offset), NULL_RTX,
1664 1, OPTAB_LIB_WIDEN);
1665 seq = get_insns ();
1666 end_sequence ();
1667 emit_insn_before (seq, insn);
1669 break;
1671 case SUBREG:
1672 new_rtx = instantiate_new_reg (SUBREG_REG (x), &offset);
1673 if (new_rtx == NULL)
1674 continue;
1675 if (offset != 0)
1677 start_sequence ();
1678 new_rtx = expand_simple_binop (GET_MODE (new_rtx), PLUS, new_rtx,
1679 GEN_INT (offset), NULL_RTX,
1680 1, OPTAB_LIB_WIDEN);
1681 seq = get_insns ();
1682 end_sequence ();
1683 emit_insn_before (seq, insn);
1685 x = simplify_gen_subreg (recog_data.operand_mode[i], new_rtx,
1686 GET_MODE (new_rtx), SUBREG_BYTE (x));
1687 gcc_assert (x);
1688 break;
1690 default:
1691 continue;
1694 /* At this point, X contains the new value for the operand.
1695 Validate the new value vs the insn predicate. Note that
1696 asm insns will have insn_code -1 here. */
1697 if (!safe_insn_predicate (insn_code, i, x))
1699 start_sequence ();
1700 if (REG_P (x))
1702 gcc_assert (REGNO (x) <= LAST_VIRTUAL_REGISTER);
1703 x = copy_to_reg (x);
1705 else
1706 x = force_reg (insn_data[insn_code].operand[i].mode, x);
1707 seq = get_insns ();
1708 end_sequence ();
1709 if (seq)
1710 emit_insn_before (seq, insn);
1713 *recog_data.operand_loc[i] = recog_data.operand[i] = x;
1714 any_change = true;
1717 if (any_change)
1719 /* Propagate operand changes into the duplicates. */
1720 for (i = 0; i < recog_data.n_dups; ++i)
1721 *recog_data.dup_loc[i]
1722 = copy_rtx (recog_data.operand[(unsigned)recog_data.dup_num[i]]);
1724 /* Force re-recognition of the instruction for validation. */
1725 INSN_CODE (insn) = -1;
1728 if (asm_noperands (PATTERN (insn)) >= 0)
1730 if (!check_asm_operands (PATTERN (insn)))
1732 error_for_asm (insn, "impossible constraint in %<asm%>");
1733 delete_insn (insn);
1736 else
1738 if (recog_memoized (insn) < 0)
1739 fatal_insn_not_found (insn);
1743 /* Subroutine of instantiate_decls. Given RTL representing a decl,
1744 do any instantiation required. */
1746 void
1747 instantiate_decl_rtl (rtx x)
1749 rtx addr;
1751 if (x == 0)
1752 return;
1754 /* If this is a CONCAT, recurse for the pieces. */
1755 if (GET_CODE (x) == CONCAT)
1757 instantiate_decl_rtl (XEXP (x, 0));
1758 instantiate_decl_rtl (XEXP (x, 1));
1759 return;
1762 /* If this is not a MEM, no need to do anything. Similarly if the
1763 address is a constant or a register that is not a virtual register. */
1764 if (!MEM_P (x))
1765 return;
1767 addr = XEXP (x, 0);
1768 if (CONSTANT_P (addr)
1769 || (REG_P (addr)
1770 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
1771 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
1772 return;
1774 for_each_rtx (&XEXP (x, 0), instantiate_virtual_regs_in_rtx, NULL);
1777 /* Helper for instantiate_decls called via walk_tree: Process all decls
1778 in the given DECL_VALUE_EXPR. */
1780 static tree
1781 instantiate_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1783 tree t = *tp;
1784 if (! EXPR_P (t))
1786 *walk_subtrees = 0;
1787 if (DECL_P (t))
1789 if (DECL_RTL_SET_P (t))
1790 instantiate_decl_rtl (DECL_RTL (t));
1791 if (TREE_CODE (t) == PARM_DECL && DECL_NAMELESS (t)
1792 && DECL_INCOMING_RTL (t))
1793 instantiate_decl_rtl (DECL_INCOMING_RTL (t));
1794 if ((TREE_CODE (t) == VAR_DECL
1795 || TREE_CODE (t) == RESULT_DECL)
1796 && DECL_HAS_VALUE_EXPR_P (t))
1798 tree v = DECL_VALUE_EXPR (t);
1799 walk_tree (&v, instantiate_expr, NULL, NULL);
1803 return NULL;
1806 /* Subroutine of instantiate_decls: Process all decls in the given
1807 BLOCK node and all its subblocks. */
1809 static void
1810 instantiate_decls_1 (tree let)
1812 tree t;
1814 for (t = BLOCK_VARS (let); t; t = DECL_CHAIN (t))
1816 if (DECL_RTL_SET_P (t))
1817 instantiate_decl_rtl (DECL_RTL (t));
1818 if (TREE_CODE (t) == VAR_DECL && DECL_HAS_VALUE_EXPR_P (t))
1820 tree v = DECL_VALUE_EXPR (t);
1821 walk_tree (&v, instantiate_expr, NULL, NULL);
1825 /* Process all subblocks. */
1826 for (t = BLOCK_SUBBLOCKS (let); t; t = BLOCK_CHAIN (t))
1827 instantiate_decls_1 (t);
1830 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
1831 all virtual registers in their DECL_RTL's. */
1833 static void
1834 instantiate_decls (tree fndecl)
1836 tree decl;
1837 unsigned ix;
1839 /* Process all parameters of the function. */
1840 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = DECL_CHAIN (decl))
1842 instantiate_decl_rtl (DECL_RTL (decl));
1843 instantiate_decl_rtl (DECL_INCOMING_RTL (decl));
1844 if (DECL_HAS_VALUE_EXPR_P (decl))
1846 tree v = DECL_VALUE_EXPR (decl);
1847 walk_tree (&v, instantiate_expr, NULL, NULL);
1851 if ((decl = DECL_RESULT (fndecl))
1852 && TREE_CODE (decl) == RESULT_DECL)
1854 if (DECL_RTL_SET_P (decl))
1855 instantiate_decl_rtl (DECL_RTL (decl));
1856 if (DECL_HAS_VALUE_EXPR_P (decl))
1858 tree v = DECL_VALUE_EXPR (decl);
1859 walk_tree (&v, instantiate_expr, NULL, NULL);
1863 /* Now process all variables defined in the function or its subblocks. */
1864 instantiate_decls_1 (DECL_INITIAL (fndecl));
1866 FOR_EACH_LOCAL_DECL (cfun, ix, decl)
1867 if (DECL_RTL_SET_P (decl))
1868 instantiate_decl_rtl (DECL_RTL (decl));
1869 VEC_free (tree, gc, cfun->local_decls);
1872 /* Pass through the INSNS of function FNDECL and convert virtual register
1873 references to hard register references. */
1875 static unsigned int
1876 instantiate_virtual_regs (void)
1878 rtx insn;
1880 /* Compute the offsets to use for this function. */
1881 in_arg_offset = FIRST_PARM_OFFSET (current_function_decl);
1882 var_offset = STARTING_FRAME_OFFSET;
1883 dynamic_offset = STACK_DYNAMIC_OFFSET (current_function_decl);
1884 out_arg_offset = STACK_POINTER_OFFSET;
1885 #ifdef FRAME_POINTER_CFA_OFFSET
1886 cfa_offset = FRAME_POINTER_CFA_OFFSET (current_function_decl);
1887 #else
1888 cfa_offset = ARG_POINTER_CFA_OFFSET (current_function_decl);
1889 #endif
1891 /* Initialize recognition, indicating that volatile is OK. */
1892 init_recog ();
1894 /* Scan through all the insns, instantiating every virtual register still
1895 present. */
1896 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
1897 if (INSN_P (insn))
1899 /* These patterns in the instruction stream can never be recognized.
1900 Fortunately, they shouldn't contain virtual registers either. */
1901 if (GET_CODE (PATTERN (insn)) == USE
1902 || GET_CODE (PATTERN (insn)) == CLOBBER
1903 || GET_CODE (PATTERN (insn)) == ADDR_VEC
1904 || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC
1905 || GET_CODE (PATTERN (insn)) == ASM_INPUT)
1906 continue;
1907 else if (DEBUG_INSN_P (insn))
1908 for_each_rtx (&INSN_VAR_LOCATION (insn),
1909 instantiate_virtual_regs_in_rtx, NULL);
1910 else
1911 instantiate_virtual_regs_in_insn (insn);
1913 if (INSN_DELETED_P (insn))
1914 continue;
1916 for_each_rtx (&REG_NOTES (insn), instantiate_virtual_regs_in_rtx, NULL);
1918 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
1919 if (CALL_P (insn))
1920 for_each_rtx (&CALL_INSN_FUNCTION_USAGE (insn),
1921 instantiate_virtual_regs_in_rtx, NULL);
1924 /* Instantiate the virtual registers in the DECLs for debugging purposes. */
1925 instantiate_decls (current_function_decl);
1927 targetm.instantiate_decls ();
1929 /* Indicate that, from now on, assign_stack_local should use
1930 frame_pointer_rtx. */
1931 virtuals_instantiated = 1;
1933 /* See allocate_dynamic_stack_space for the rationale. */
1934 #ifdef SETJMP_VIA_SAVE_AREA
1935 if (flag_stack_usage && cfun->calls_setjmp)
1937 int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
1938 dynamic_offset = (dynamic_offset + align - 1) / align * align;
1939 current_function_dynamic_stack_size
1940 += current_function_dynamic_alloc_count * dynamic_offset;
1942 #endif
1944 return 0;
1947 struct rtl_opt_pass pass_instantiate_virtual_regs =
1950 RTL_PASS,
1951 "vregs", /* name */
1952 NULL, /* gate */
1953 instantiate_virtual_regs, /* execute */
1954 NULL, /* sub */
1955 NULL, /* next */
1956 0, /* static_pass_number */
1957 TV_NONE, /* tv_id */
1958 0, /* properties_required */
1959 0, /* properties_provided */
1960 0, /* properties_destroyed */
1961 0, /* todo_flags_start */
1962 TODO_dump_func /* todo_flags_finish */
1967 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
1968 This means a type for which function calls must pass an address to the
1969 function or get an address back from the function.
1970 EXP may be a type node or an expression (whose type is tested). */
1973 aggregate_value_p (const_tree exp, const_tree fntype)
1975 const_tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
1976 int i, regno, nregs;
1977 rtx reg;
1979 if (fntype)
1980 switch (TREE_CODE (fntype))
1982 case CALL_EXPR:
1984 tree fndecl = get_callee_fndecl (fntype);
1985 fntype = (fndecl
1986 ? TREE_TYPE (fndecl)
1987 : TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (fntype))));
1989 break;
1990 case FUNCTION_DECL:
1991 fntype = TREE_TYPE (fntype);
1992 break;
1993 case FUNCTION_TYPE:
1994 case METHOD_TYPE:
1995 break;
1996 case IDENTIFIER_NODE:
1997 fntype = NULL_TREE;
1998 break;
1999 default:
2000 /* We don't expect other tree types here. */
2001 gcc_unreachable ();
2004 if (VOID_TYPE_P (type))
2005 return 0;
2007 /* If a record should be passed the same as its first (and only) member
2008 don't pass it as an aggregate. */
2009 if (TREE_CODE (type) == RECORD_TYPE && TYPE_TRANSPARENT_AGGR (type))
2010 return aggregate_value_p (first_field (type), fntype);
2012 /* If the front end has decided that this needs to be passed by
2013 reference, do so. */
2014 if ((TREE_CODE (exp) == PARM_DECL || TREE_CODE (exp) == RESULT_DECL)
2015 && DECL_BY_REFERENCE (exp))
2016 return 1;
2018 /* Function types that are TREE_ADDRESSABLE force return in memory. */
2019 if (fntype && TREE_ADDRESSABLE (fntype))
2020 return 1;
2022 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
2023 and thus can't be returned in registers. */
2024 if (TREE_ADDRESSABLE (type))
2025 return 1;
2027 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
2028 return 1;
2030 if (targetm.calls.return_in_memory (type, fntype))
2031 return 1;
2033 /* Make sure we have suitable call-clobbered regs to return
2034 the value in; if not, we must return it in memory. */
2035 reg = hard_function_value (type, 0, fntype, 0);
2037 /* If we have something other than a REG (e.g. a PARALLEL), then assume
2038 it is OK. */
2039 if (!REG_P (reg))
2040 return 0;
2042 regno = REGNO (reg);
2043 nregs = hard_regno_nregs[regno][TYPE_MODE (type)];
2044 for (i = 0; i < nregs; i++)
2045 if (! call_used_regs[regno + i])
2046 return 1;
2048 return 0;
2051 /* Return true if we should assign DECL a pseudo register; false if it
2052 should live on the local stack. */
2054 bool
2055 use_register_for_decl (const_tree decl)
2057 if (!targetm.calls.allocate_stack_slots_for_args())
2058 return true;
2060 /* Honor volatile. */
2061 if (TREE_SIDE_EFFECTS (decl))
2062 return false;
2064 /* Honor addressability. */
2065 if (TREE_ADDRESSABLE (decl))
2066 return false;
2068 /* Only register-like things go in registers. */
2069 if (DECL_MODE (decl) == BLKmode)
2070 return false;
2072 /* If -ffloat-store specified, don't put explicit float variables
2073 into registers. */
2074 /* ??? This should be checked after DECL_ARTIFICIAL, but tree-ssa
2075 propagates values across these stores, and it probably shouldn't. */
2076 if (flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)))
2077 return false;
2079 /* If we're not interested in tracking debugging information for
2080 this decl, then we can certainly put it in a register. */
2081 if (DECL_IGNORED_P (decl))
2082 return true;
2084 if (optimize)
2085 return true;
2087 if (!DECL_REGISTER (decl))
2088 return false;
2090 switch (TREE_CODE (TREE_TYPE (decl)))
2092 case RECORD_TYPE:
2093 case UNION_TYPE:
2094 case QUAL_UNION_TYPE:
2095 /* When not optimizing, disregard register keyword for variables with
2096 types containing methods, otherwise the methods won't be callable
2097 from the debugger. */
2098 if (TYPE_METHODS (TREE_TYPE (decl)))
2099 return false;
2100 break;
2101 default:
2102 break;
2105 return true;
2108 /* Return true if TYPE should be passed by invisible reference. */
2110 bool
2111 pass_by_reference (CUMULATIVE_ARGS *ca, enum machine_mode mode,
2112 tree type, bool named_arg)
2114 if (type)
2116 /* If this type contains non-trivial constructors, then it is
2117 forbidden for the middle-end to create any new copies. */
2118 if (TREE_ADDRESSABLE (type))
2119 return true;
2121 /* GCC post 3.4 passes *all* variable sized types by reference. */
2122 if (!TYPE_SIZE (type) || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
2123 return true;
2125 /* If a record type should be passed the same as its first (and only)
2126 member, use the type and mode of that member. */
2127 if (TREE_CODE (type) == RECORD_TYPE && TYPE_TRANSPARENT_AGGR (type))
2129 type = TREE_TYPE (first_field (type));
2130 mode = TYPE_MODE (type);
2134 return targetm.calls.pass_by_reference (ca, mode, type, named_arg);
2137 /* Return true if TYPE, which is passed by reference, should be callee
2138 copied instead of caller copied. */
2140 bool
2141 reference_callee_copied (CUMULATIVE_ARGS *ca, enum machine_mode mode,
2142 tree type, bool named_arg)
2144 if (type && TREE_ADDRESSABLE (type))
2145 return false;
2146 return targetm.calls.callee_copies (ca, mode, type, named_arg);
2149 /* Structures to communicate between the subroutines of assign_parms.
2150 The first holds data persistent across all parameters, the second
2151 is cleared out for each parameter. */
2153 struct assign_parm_data_all
2155 CUMULATIVE_ARGS args_so_far;
2156 struct args_size stack_args_size;
2157 tree function_result_decl;
2158 tree orig_fnargs;
2159 rtx first_conversion_insn;
2160 rtx last_conversion_insn;
2161 HOST_WIDE_INT pretend_args_size;
2162 HOST_WIDE_INT extra_pretend_bytes;
2163 int reg_parm_stack_space;
2166 struct assign_parm_data_one
2168 tree nominal_type;
2169 tree passed_type;
2170 rtx entry_parm;
2171 rtx stack_parm;
2172 enum machine_mode nominal_mode;
2173 enum machine_mode passed_mode;
2174 enum machine_mode promoted_mode;
2175 struct locate_and_pad_arg_data locate;
2176 int partial;
2177 BOOL_BITFIELD named_arg : 1;
2178 BOOL_BITFIELD passed_pointer : 1;
2179 BOOL_BITFIELD on_stack : 1;
2180 BOOL_BITFIELD loaded_in_reg : 1;
2183 /* A subroutine of assign_parms. Initialize ALL. */
2185 static void
2186 assign_parms_initialize_all (struct assign_parm_data_all *all)
2188 tree fntype ATTRIBUTE_UNUSED;
2190 memset (all, 0, sizeof (*all));
2192 fntype = TREE_TYPE (current_function_decl);
2194 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
2195 INIT_CUMULATIVE_INCOMING_ARGS (all->args_so_far, fntype, NULL_RTX);
2196 #else
2197 INIT_CUMULATIVE_ARGS (all->args_so_far, fntype, NULL_RTX,
2198 current_function_decl, -1);
2199 #endif
2201 #ifdef REG_PARM_STACK_SPACE
2202 all->reg_parm_stack_space = REG_PARM_STACK_SPACE (current_function_decl);
2203 #endif
2206 /* If ARGS contains entries with complex types, split the entry into two
2207 entries of the component type. Return a new list of substitutions are
2208 needed, else the old list. */
2210 static void
2211 split_complex_args (VEC(tree, heap) **args)
2213 unsigned i;
2214 tree p;
2216 FOR_EACH_VEC_ELT (tree, *args, i, p)
2218 tree type = TREE_TYPE (p);
2219 if (TREE_CODE (type) == COMPLEX_TYPE
2220 && targetm.calls.split_complex_arg (type))
2222 tree decl;
2223 tree subtype = TREE_TYPE (type);
2224 bool addressable = TREE_ADDRESSABLE (p);
2226 /* Rewrite the PARM_DECL's type with its component. */
2227 p = copy_node (p);
2228 TREE_TYPE (p) = subtype;
2229 DECL_ARG_TYPE (p) = TREE_TYPE (DECL_ARG_TYPE (p));
2230 DECL_MODE (p) = VOIDmode;
2231 DECL_SIZE (p) = NULL;
2232 DECL_SIZE_UNIT (p) = NULL;
2233 /* If this arg must go in memory, put it in a pseudo here.
2234 We can't allow it to go in memory as per normal parms,
2235 because the usual place might not have the imag part
2236 adjacent to the real part. */
2237 DECL_ARTIFICIAL (p) = addressable;
2238 DECL_IGNORED_P (p) = addressable;
2239 TREE_ADDRESSABLE (p) = 0;
2240 layout_decl (p, 0);
2241 VEC_replace (tree, *args, i, p);
2243 /* Build a second synthetic decl. */
2244 decl = build_decl (EXPR_LOCATION (p),
2245 PARM_DECL, NULL_TREE, subtype);
2246 DECL_ARG_TYPE (decl) = DECL_ARG_TYPE (p);
2247 DECL_ARTIFICIAL (decl) = addressable;
2248 DECL_IGNORED_P (decl) = addressable;
2249 layout_decl (decl, 0);
2250 VEC_safe_insert (tree, heap, *args, ++i, decl);
2255 /* A subroutine of assign_parms. Adjust the parameter list to incorporate
2256 the hidden struct return argument, and (abi willing) complex args.
2257 Return the new parameter list. */
2259 static VEC(tree, heap) *
2260 assign_parms_augmented_arg_list (struct assign_parm_data_all *all)
2262 tree fndecl = current_function_decl;
2263 tree fntype = TREE_TYPE (fndecl);
2264 VEC(tree, heap) *fnargs = NULL;
2265 tree arg;
2267 for (arg = DECL_ARGUMENTS (fndecl); arg; arg = DECL_CHAIN (arg))
2268 VEC_safe_push (tree, heap, fnargs, arg);
2270 all->orig_fnargs = DECL_ARGUMENTS (fndecl);
2272 /* If struct value address is treated as the first argument, make it so. */
2273 if (aggregate_value_p (DECL_RESULT (fndecl), fndecl)
2274 && ! cfun->returns_pcc_struct
2275 && targetm.calls.struct_value_rtx (TREE_TYPE (fndecl), 1) == 0)
2277 tree type = build_pointer_type (TREE_TYPE (fntype));
2278 tree decl;
2280 decl = build_decl (DECL_SOURCE_LOCATION (fndecl),
2281 PARM_DECL, get_identifier (".result_ptr"), type);
2282 DECL_ARG_TYPE (decl) = type;
2283 DECL_ARTIFICIAL (decl) = 1;
2284 DECL_NAMELESS (decl) = 1;
2285 TREE_CONSTANT (decl) = 1;
2287 DECL_CHAIN (decl) = all->orig_fnargs;
2288 all->orig_fnargs = decl;
2289 VEC_safe_insert (tree, heap, fnargs, 0, decl);
2291 all->function_result_decl = decl;
2294 /* If the target wants to split complex arguments into scalars, do so. */
2295 if (targetm.calls.split_complex_arg)
2296 split_complex_args (&fnargs);
2298 return fnargs;
2301 /* A subroutine of assign_parms. Examine PARM and pull out type and mode
2302 data for the parameter. Incorporate ABI specifics such as pass-by-
2303 reference and type promotion. */
2305 static void
2306 assign_parm_find_data_types (struct assign_parm_data_all *all, tree parm,
2307 struct assign_parm_data_one *data)
2309 tree nominal_type, passed_type;
2310 enum machine_mode nominal_mode, passed_mode, promoted_mode;
2311 int unsignedp;
2313 memset (data, 0, sizeof (*data));
2315 /* NAMED_ARG is a misnomer. We really mean 'non-variadic'. */
2316 if (!cfun->stdarg)
2317 data->named_arg = 1; /* No variadic parms. */
2318 else if (DECL_CHAIN (parm))
2319 data->named_arg = 1; /* Not the last non-variadic parm. */
2320 else if (targetm.calls.strict_argument_naming (&all->args_so_far))
2321 data->named_arg = 1; /* Only variadic ones are unnamed. */
2322 else
2323 data->named_arg = 0; /* Treat as variadic. */
2325 nominal_type = TREE_TYPE (parm);
2326 passed_type = DECL_ARG_TYPE (parm);
2328 /* Look out for errors propagating this far. Also, if the parameter's
2329 type is void then its value doesn't matter. */
2330 if (TREE_TYPE (parm) == error_mark_node
2331 /* This can happen after weird syntax errors
2332 or if an enum type is defined among the parms. */
2333 || TREE_CODE (parm) != PARM_DECL
2334 || passed_type == NULL
2335 || VOID_TYPE_P (nominal_type))
2337 nominal_type = passed_type = void_type_node;
2338 nominal_mode = passed_mode = promoted_mode = VOIDmode;
2339 goto egress;
2342 /* Find mode of arg as it is passed, and mode of arg as it should be
2343 during execution of this function. */
2344 passed_mode = TYPE_MODE (passed_type);
2345 nominal_mode = TYPE_MODE (nominal_type);
2347 /* If the parm is to be passed as a transparent union or record, use the
2348 type of the first field for the tests below. We have already verified
2349 that the modes are the same. */
2350 if ((TREE_CODE (passed_type) == UNION_TYPE
2351 || TREE_CODE (passed_type) == RECORD_TYPE)
2352 && TYPE_TRANSPARENT_AGGR (passed_type))
2353 passed_type = TREE_TYPE (first_field (passed_type));
2355 /* See if this arg was passed by invisible reference. */
2356 if (pass_by_reference (&all->args_so_far, passed_mode,
2357 passed_type, data->named_arg))
2359 passed_type = nominal_type = build_pointer_type (passed_type);
2360 data->passed_pointer = true;
2361 passed_mode = nominal_mode = Pmode;
2364 /* Find mode as it is passed by the ABI. */
2365 unsignedp = TYPE_UNSIGNED (passed_type);
2366 promoted_mode = promote_function_mode (passed_type, passed_mode, &unsignedp,
2367 TREE_TYPE (current_function_decl), 0);
2369 egress:
2370 data->nominal_type = nominal_type;
2371 data->passed_type = passed_type;
2372 data->nominal_mode = nominal_mode;
2373 data->passed_mode = passed_mode;
2374 data->promoted_mode = promoted_mode;
2377 /* A subroutine of assign_parms. Invoke setup_incoming_varargs. */
2379 static void
2380 assign_parms_setup_varargs (struct assign_parm_data_all *all,
2381 struct assign_parm_data_one *data, bool no_rtl)
2383 int varargs_pretend_bytes = 0;
2385 targetm.calls.setup_incoming_varargs (&all->args_so_far,
2386 data->promoted_mode,
2387 data->passed_type,
2388 &varargs_pretend_bytes, no_rtl);
2390 /* If the back-end has requested extra stack space, record how much is
2391 needed. Do not change pretend_args_size otherwise since it may be
2392 nonzero from an earlier partial argument. */
2393 if (varargs_pretend_bytes > 0)
2394 all->pretend_args_size = varargs_pretend_bytes;
2397 /* A subroutine of assign_parms. Set DATA->ENTRY_PARM corresponding to
2398 the incoming location of the current parameter. */
2400 static void
2401 assign_parm_find_entry_rtl (struct assign_parm_data_all *all,
2402 struct assign_parm_data_one *data)
2404 HOST_WIDE_INT pretend_bytes = 0;
2405 rtx entry_parm;
2406 bool in_regs;
2408 if (data->promoted_mode == VOIDmode)
2410 data->entry_parm = data->stack_parm = const0_rtx;
2411 return;
2414 entry_parm = targetm.calls.function_incoming_arg (&all->args_so_far,
2415 data->promoted_mode,
2416 data->passed_type,
2417 data->named_arg);
2419 if (entry_parm == 0)
2420 data->promoted_mode = data->passed_mode;
2422 /* Determine parm's home in the stack, in case it arrives in the stack
2423 or we should pretend it did. Compute the stack position and rtx where
2424 the argument arrives and its size.
2426 There is one complexity here: If this was a parameter that would
2427 have been passed in registers, but wasn't only because it is
2428 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
2429 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
2430 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of 0
2431 as it was the previous time. */
2432 in_regs = entry_parm != 0;
2433 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2434 in_regs = true;
2435 #endif
2436 if (!in_regs && !data->named_arg)
2438 if (targetm.calls.pretend_outgoing_varargs_named (&all->args_so_far))
2440 rtx tem;
2441 tem = targetm.calls.function_incoming_arg (&all->args_so_far,
2442 data->promoted_mode,
2443 data->passed_type, true);
2444 in_regs = tem != NULL;
2448 /* If this parameter was passed both in registers and in the stack, use
2449 the copy on the stack. */
2450 if (targetm.calls.must_pass_in_stack (data->promoted_mode,
2451 data->passed_type))
2452 entry_parm = 0;
2454 if (entry_parm)
2456 int partial;
2458 partial = targetm.calls.arg_partial_bytes (&all->args_so_far,
2459 data->promoted_mode,
2460 data->passed_type,
2461 data->named_arg);
2462 data->partial = partial;
2464 /* The caller might already have allocated stack space for the
2465 register parameters. */
2466 if (partial != 0 && all->reg_parm_stack_space == 0)
2468 /* Part of this argument is passed in registers and part
2469 is passed on the stack. Ask the prologue code to extend
2470 the stack part so that we can recreate the full value.
2472 PRETEND_BYTES is the size of the registers we need to store.
2473 CURRENT_FUNCTION_PRETEND_ARGS_SIZE is the amount of extra
2474 stack space that the prologue should allocate.
2476 Internally, gcc assumes that the argument pointer is aligned
2477 to STACK_BOUNDARY bits. This is used both for alignment
2478 optimizations (see init_emit) and to locate arguments that are
2479 aligned to more than PARM_BOUNDARY bits. We must preserve this
2480 invariant by rounding CURRENT_FUNCTION_PRETEND_ARGS_SIZE up to
2481 a stack boundary. */
2483 /* We assume at most one partial arg, and it must be the first
2484 argument on the stack. */
2485 gcc_assert (!all->extra_pretend_bytes && !all->pretend_args_size);
2487 pretend_bytes = partial;
2488 all->pretend_args_size = CEIL_ROUND (pretend_bytes, STACK_BYTES);
2490 /* We want to align relative to the actual stack pointer, so
2491 don't include this in the stack size until later. */
2492 all->extra_pretend_bytes = all->pretend_args_size;
2496 locate_and_pad_parm (data->promoted_mode, data->passed_type, in_regs,
2497 entry_parm ? data->partial : 0, current_function_decl,
2498 &all->stack_args_size, &data->locate);
2500 /* Update parm_stack_boundary if this parameter is passed in the
2501 stack. */
2502 if (!in_regs && crtl->parm_stack_boundary < data->locate.boundary)
2503 crtl->parm_stack_boundary = data->locate.boundary;
2505 /* Adjust offsets to include the pretend args. */
2506 pretend_bytes = all->extra_pretend_bytes - pretend_bytes;
2507 data->locate.slot_offset.constant += pretend_bytes;
2508 data->locate.offset.constant += pretend_bytes;
2510 data->entry_parm = entry_parm;
2513 /* A subroutine of assign_parms. If there is actually space on the stack
2514 for this parm, count it in stack_args_size and return true. */
2516 static bool
2517 assign_parm_is_stack_parm (struct assign_parm_data_all *all,
2518 struct assign_parm_data_one *data)
2520 /* Trivially true if we've no incoming register. */
2521 if (data->entry_parm == NULL)
2523 /* Also true if we're partially in registers and partially not,
2524 since we've arranged to drop the entire argument on the stack. */
2525 else if (data->partial != 0)
2527 /* Also true if the target says that it's passed in both registers
2528 and on the stack. */
2529 else if (GET_CODE (data->entry_parm) == PARALLEL
2530 && XEXP (XVECEXP (data->entry_parm, 0, 0), 0) == NULL_RTX)
2532 /* Also true if the target says that there's stack allocated for
2533 all register parameters. */
2534 else if (all->reg_parm_stack_space > 0)
2536 /* Otherwise, no, this parameter has no ABI defined stack slot. */
2537 else
2538 return false;
2540 all->stack_args_size.constant += data->locate.size.constant;
2541 if (data->locate.size.var)
2542 ADD_PARM_SIZE (all->stack_args_size, data->locate.size.var);
2544 return true;
2547 /* A subroutine of assign_parms. Given that this parameter is allocated
2548 stack space by the ABI, find it. */
2550 static void
2551 assign_parm_find_stack_rtl (tree parm, struct assign_parm_data_one *data)
2553 rtx offset_rtx, stack_parm;
2554 unsigned int align, boundary;
2556 /* If we're passing this arg using a reg, make its stack home the
2557 aligned stack slot. */
2558 if (data->entry_parm)
2559 offset_rtx = ARGS_SIZE_RTX (data->locate.slot_offset);
2560 else
2561 offset_rtx = ARGS_SIZE_RTX (data->locate.offset);
2563 stack_parm = crtl->args.internal_arg_pointer;
2564 if (offset_rtx != const0_rtx)
2565 stack_parm = gen_rtx_PLUS (Pmode, stack_parm, offset_rtx);
2566 stack_parm = gen_rtx_MEM (data->promoted_mode, stack_parm);
2568 if (!data->passed_pointer)
2570 set_mem_attributes (stack_parm, parm, 1);
2571 /* set_mem_attributes could set MEM_SIZE to the passed mode's size,
2572 while promoted mode's size is needed. */
2573 if (data->promoted_mode != BLKmode
2574 && data->promoted_mode != DECL_MODE (parm))
2576 set_mem_size (stack_parm,
2577 GEN_INT (GET_MODE_SIZE (data->promoted_mode)));
2578 if (MEM_EXPR (stack_parm) && MEM_OFFSET (stack_parm))
2580 int offset = subreg_lowpart_offset (DECL_MODE (parm),
2581 data->promoted_mode);
2582 if (offset)
2583 set_mem_offset (stack_parm,
2584 plus_constant (MEM_OFFSET (stack_parm),
2585 -offset));
2590 boundary = data->locate.boundary;
2591 align = BITS_PER_UNIT;
2593 /* If we're padding upward, we know that the alignment of the slot
2594 is TARGET_FUNCTION_ARG_BOUNDARY. If we're using slot_offset, we're
2595 intentionally forcing upward padding. Otherwise we have to come
2596 up with a guess at the alignment based on OFFSET_RTX. */
2597 if (data->locate.where_pad != downward || data->entry_parm)
2598 align = boundary;
2599 else if (CONST_INT_P (offset_rtx))
2601 align = INTVAL (offset_rtx) * BITS_PER_UNIT | boundary;
2602 align = align & -align;
2604 set_mem_align (stack_parm, align);
2606 if (data->entry_parm)
2607 set_reg_attrs_for_parm (data->entry_parm, stack_parm);
2609 data->stack_parm = stack_parm;
2612 /* A subroutine of assign_parms. Adjust DATA->ENTRY_RTL such that it's
2613 always valid and contiguous. */
2615 static void
2616 assign_parm_adjust_entry_rtl (struct assign_parm_data_one *data)
2618 rtx entry_parm = data->entry_parm;
2619 rtx stack_parm = data->stack_parm;
2621 /* If this parm was passed part in regs and part in memory, pretend it
2622 arrived entirely in memory by pushing the register-part onto the stack.
2623 In the special case of a DImode or DFmode that is split, we could put
2624 it together in a pseudoreg directly, but for now that's not worth
2625 bothering with. */
2626 if (data->partial != 0)
2628 /* Handle calls that pass values in multiple non-contiguous
2629 locations. The Irix 6 ABI has examples of this. */
2630 if (GET_CODE (entry_parm) == PARALLEL)
2631 emit_group_store (validize_mem (stack_parm), entry_parm,
2632 data->passed_type,
2633 int_size_in_bytes (data->passed_type));
2634 else
2636 gcc_assert (data->partial % UNITS_PER_WORD == 0);
2637 move_block_from_reg (REGNO (entry_parm), validize_mem (stack_parm),
2638 data->partial / UNITS_PER_WORD);
2641 entry_parm = stack_parm;
2644 /* If we didn't decide this parm came in a register, by default it came
2645 on the stack. */
2646 else if (entry_parm == NULL)
2647 entry_parm = stack_parm;
2649 /* When an argument is passed in multiple locations, we can't make use
2650 of this information, but we can save some copying if the whole argument
2651 is passed in a single register. */
2652 else if (GET_CODE (entry_parm) == PARALLEL
2653 && data->nominal_mode != BLKmode
2654 && data->passed_mode != BLKmode)
2656 size_t i, len = XVECLEN (entry_parm, 0);
2658 for (i = 0; i < len; i++)
2659 if (XEXP (XVECEXP (entry_parm, 0, i), 0) != NULL_RTX
2660 && REG_P (XEXP (XVECEXP (entry_parm, 0, i), 0))
2661 && (GET_MODE (XEXP (XVECEXP (entry_parm, 0, i), 0))
2662 == data->passed_mode)
2663 && INTVAL (XEXP (XVECEXP (entry_parm, 0, i), 1)) == 0)
2665 entry_parm = XEXP (XVECEXP (entry_parm, 0, i), 0);
2666 break;
2670 data->entry_parm = entry_parm;
2673 /* A subroutine of assign_parms. Reconstitute any values which were
2674 passed in multiple registers and would fit in a single register. */
2676 static void
2677 assign_parm_remove_parallels (struct assign_parm_data_one *data)
2679 rtx entry_parm = data->entry_parm;
2681 /* Convert the PARALLEL to a REG of the same mode as the parallel.
2682 This can be done with register operations rather than on the
2683 stack, even if we will store the reconstituted parameter on the
2684 stack later. */
2685 if (GET_CODE (entry_parm) == PARALLEL && GET_MODE (entry_parm) != BLKmode)
2687 rtx parmreg = gen_reg_rtx (GET_MODE (entry_parm));
2688 emit_group_store (parmreg, entry_parm, data->passed_type,
2689 GET_MODE_SIZE (GET_MODE (entry_parm)));
2690 entry_parm = parmreg;
2693 data->entry_parm = entry_parm;
2696 /* A subroutine of assign_parms. Adjust DATA->STACK_RTL such that it's
2697 always valid and properly aligned. */
2699 static void
2700 assign_parm_adjust_stack_rtl (struct assign_parm_data_one *data)
2702 rtx stack_parm = data->stack_parm;
2704 /* If we can't trust the parm stack slot to be aligned enough for its
2705 ultimate type, don't use that slot after entry. We'll make another
2706 stack slot, if we need one. */
2707 if (stack_parm
2708 && ((STRICT_ALIGNMENT
2709 && GET_MODE_ALIGNMENT (data->nominal_mode) > MEM_ALIGN (stack_parm))
2710 || (data->nominal_type
2711 && TYPE_ALIGN (data->nominal_type) > MEM_ALIGN (stack_parm)
2712 && MEM_ALIGN (stack_parm) < PREFERRED_STACK_BOUNDARY)))
2713 stack_parm = NULL;
2715 /* If parm was passed in memory, and we need to convert it on entry,
2716 don't store it back in that same slot. */
2717 else if (data->entry_parm == stack_parm
2718 && data->nominal_mode != BLKmode
2719 && data->nominal_mode != data->passed_mode)
2720 stack_parm = NULL;
2722 /* If stack protection is in effect for this function, don't leave any
2723 pointers in their passed stack slots. */
2724 else if (crtl->stack_protect_guard
2725 && (flag_stack_protect == 2
2726 || data->passed_pointer
2727 || POINTER_TYPE_P (data->nominal_type)))
2728 stack_parm = NULL;
2730 data->stack_parm = stack_parm;
2733 /* A subroutine of assign_parms. Return true if the current parameter
2734 should be stored as a BLKmode in the current frame. */
2736 static bool
2737 assign_parm_setup_block_p (struct assign_parm_data_one *data)
2739 if (data->nominal_mode == BLKmode)
2740 return true;
2741 if (GET_MODE (data->entry_parm) == BLKmode)
2742 return true;
2744 #ifdef BLOCK_REG_PADDING
2745 /* Only assign_parm_setup_block knows how to deal with register arguments
2746 that are padded at the least significant end. */
2747 if (REG_P (data->entry_parm)
2748 && GET_MODE_SIZE (data->promoted_mode) < UNITS_PER_WORD
2749 && (BLOCK_REG_PADDING (data->passed_mode, data->passed_type, 1)
2750 == (BYTES_BIG_ENDIAN ? upward : downward)))
2751 return true;
2752 #endif
2754 return false;
2757 /* A subroutine of assign_parms. Arrange for the parameter to be
2758 present and valid in DATA->STACK_RTL. */
2760 static void
2761 assign_parm_setup_block (struct assign_parm_data_all *all,
2762 tree parm, struct assign_parm_data_one *data)
2764 rtx entry_parm = data->entry_parm;
2765 rtx stack_parm = data->stack_parm;
2766 HOST_WIDE_INT size;
2767 HOST_WIDE_INT size_stored;
2769 if (GET_CODE (entry_parm) == PARALLEL)
2770 entry_parm = emit_group_move_into_temps (entry_parm);
2772 size = int_size_in_bytes (data->passed_type);
2773 size_stored = CEIL_ROUND (size, UNITS_PER_WORD);
2774 if (stack_parm == 0)
2776 DECL_ALIGN (parm) = MAX (DECL_ALIGN (parm), BITS_PER_WORD);
2777 stack_parm = assign_stack_local (BLKmode, size_stored,
2778 DECL_ALIGN (parm));
2779 if (GET_MODE_SIZE (GET_MODE (entry_parm)) == size)
2780 PUT_MODE (stack_parm, GET_MODE (entry_parm));
2781 set_mem_attributes (stack_parm, parm, 1);
2784 /* If a BLKmode arrives in registers, copy it to a stack slot. Handle
2785 calls that pass values in multiple non-contiguous locations. */
2786 if (REG_P (entry_parm) || GET_CODE (entry_parm) == PARALLEL)
2788 rtx mem;
2790 /* Note that we will be storing an integral number of words.
2791 So we have to be careful to ensure that we allocate an
2792 integral number of words. We do this above when we call
2793 assign_stack_local if space was not allocated in the argument
2794 list. If it was, this will not work if PARM_BOUNDARY is not
2795 a multiple of BITS_PER_WORD. It isn't clear how to fix this
2796 if it becomes a problem. Exception is when BLKmode arrives
2797 with arguments not conforming to word_mode. */
2799 if (data->stack_parm == 0)
2801 else if (GET_CODE (entry_parm) == PARALLEL)
2803 else
2804 gcc_assert (!size || !(PARM_BOUNDARY % BITS_PER_WORD));
2806 mem = validize_mem (stack_parm);
2808 /* Handle values in multiple non-contiguous locations. */
2809 if (GET_CODE (entry_parm) == PARALLEL)
2811 push_to_sequence2 (all->first_conversion_insn,
2812 all->last_conversion_insn);
2813 emit_group_store (mem, entry_parm, data->passed_type, size);
2814 all->first_conversion_insn = get_insns ();
2815 all->last_conversion_insn = get_last_insn ();
2816 end_sequence ();
2819 else if (size == 0)
2822 /* If SIZE is that of a mode no bigger than a word, just use
2823 that mode's store operation. */
2824 else if (size <= UNITS_PER_WORD)
2826 enum machine_mode mode
2827 = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
2829 if (mode != BLKmode
2830 #ifdef BLOCK_REG_PADDING
2831 && (size == UNITS_PER_WORD
2832 || (BLOCK_REG_PADDING (mode, data->passed_type, 1)
2833 != (BYTES_BIG_ENDIAN ? upward : downward)))
2834 #endif
2837 rtx reg;
2839 /* We are really truncating a word_mode value containing
2840 SIZE bytes into a value of mode MODE. If such an
2841 operation requires no actual instructions, we can refer
2842 to the value directly in mode MODE, otherwise we must
2843 start with the register in word_mode and explicitly
2844 convert it. */
2845 if (TRULY_NOOP_TRUNCATION (size * BITS_PER_UNIT, BITS_PER_WORD))
2846 reg = gen_rtx_REG (mode, REGNO (entry_parm));
2847 else
2849 reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
2850 reg = convert_to_mode (mode, copy_to_reg (reg), 1);
2852 emit_move_insn (change_address (mem, mode, 0), reg);
2855 /* Blocks smaller than a word on a BYTES_BIG_ENDIAN
2856 machine must be aligned to the left before storing
2857 to memory. Note that the previous test doesn't
2858 handle all cases (e.g. SIZE == 3). */
2859 else if (size != UNITS_PER_WORD
2860 #ifdef BLOCK_REG_PADDING
2861 && (BLOCK_REG_PADDING (mode, data->passed_type, 1)
2862 == downward)
2863 #else
2864 && BYTES_BIG_ENDIAN
2865 #endif
2868 rtx tem, x;
2869 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
2870 rtx reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
2872 x = expand_shift (LSHIFT_EXPR, word_mode, reg,
2873 build_int_cst (NULL_TREE, by),
2874 NULL_RTX, 1);
2875 tem = change_address (mem, word_mode, 0);
2876 emit_move_insn (tem, x);
2878 else
2879 move_block_from_reg (REGNO (entry_parm), mem,
2880 size_stored / UNITS_PER_WORD);
2882 else
2883 move_block_from_reg (REGNO (entry_parm), mem,
2884 size_stored / UNITS_PER_WORD);
2886 else if (data->stack_parm == 0)
2888 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
2889 emit_block_move (stack_parm, data->entry_parm, GEN_INT (size),
2890 BLOCK_OP_NORMAL);
2891 all->first_conversion_insn = get_insns ();
2892 all->last_conversion_insn = get_last_insn ();
2893 end_sequence ();
2896 data->stack_parm = stack_parm;
2897 SET_DECL_RTL (parm, stack_parm);
2900 /* A subroutine of assign_parm_setup_reg, called through note_stores.
2901 This collects sets and clobbers of hard registers in a HARD_REG_SET,
2902 which is pointed to by DATA. */
2903 static void
2904 record_hard_reg_sets (rtx x, const_rtx pat ATTRIBUTE_UNUSED, void *data)
2906 HARD_REG_SET *pset = (HARD_REG_SET *)data;
2907 if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER)
2909 int nregs = hard_regno_nregs[REGNO (x)][GET_MODE (x)];
2910 while (nregs-- > 0)
2911 SET_HARD_REG_BIT (*pset, REGNO (x) + nregs);
2915 /* A subroutine of assign_parms. Allocate a pseudo to hold the current
2916 parameter. Get it there. Perform all ABI specified conversions. */
2918 static void
2919 assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm,
2920 struct assign_parm_data_one *data)
2922 rtx parmreg, validated_mem;
2923 rtx equiv_stack_parm;
2924 enum machine_mode promoted_nominal_mode;
2925 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (parm));
2926 bool did_conversion = false;
2927 bool need_conversion, moved;
2929 /* Store the parm in a pseudoregister during the function, but we may
2930 need to do it in a wider mode. Using 2 here makes the result
2931 consistent with promote_decl_mode and thus expand_expr_real_1. */
2932 promoted_nominal_mode
2933 = promote_function_mode (data->nominal_type, data->nominal_mode, &unsignedp,
2934 TREE_TYPE (current_function_decl), 2);
2936 parmreg = gen_reg_rtx (promoted_nominal_mode);
2938 if (!DECL_ARTIFICIAL (parm))
2939 mark_user_reg (parmreg);
2941 /* If this was an item that we received a pointer to,
2942 set DECL_RTL appropriately. */
2943 if (data->passed_pointer)
2945 rtx x = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data->passed_type)), parmreg);
2946 set_mem_attributes (x, parm, 1);
2947 SET_DECL_RTL (parm, x);
2949 else
2950 SET_DECL_RTL (parm, parmreg);
2952 assign_parm_remove_parallels (data);
2954 /* Copy the value into the register, thus bridging between
2955 assign_parm_find_data_types and expand_expr_real_1. */
2957 equiv_stack_parm = data->stack_parm;
2958 validated_mem = validize_mem (data->entry_parm);
2960 need_conversion = (data->nominal_mode != data->passed_mode
2961 || promoted_nominal_mode != data->promoted_mode);
2962 moved = false;
2964 if (need_conversion
2965 && GET_MODE_CLASS (data->nominal_mode) == MODE_INT
2966 && data->nominal_mode == data->passed_mode
2967 && data->nominal_mode == GET_MODE (data->entry_parm))
2969 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
2970 mode, by the caller. We now have to convert it to
2971 NOMINAL_MODE, if different. However, PARMREG may be in
2972 a different mode than NOMINAL_MODE if it is being stored
2973 promoted.
2975 If ENTRY_PARM is a hard register, it might be in a register
2976 not valid for operating in its mode (e.g., an odd-numbered
2977 register for a DFmode). In that case, moves are the only
2978 thing valid, so we can't do a convert from there. This
2979 occurs when the calling sequence allow such misaligned
2980 usages.
2982 In addition, the conversion may involve a call, which could
2983 clobber parameters which haven't been copied to pseudo
2984 registers yet.
2986 First, we try to emit an insn which performs the necessary
2987 conversion. We verify that this insn does not clobber any
2988 hard registers. */
2990 enum insn_code icode;
2991 rtx op0, op1;
2993 icode = can_extend_p (promoted_nominal_mode, data->passed_mode,
2994 unsignedp);
2996 op0 = parmreg;
2997 op1 = validated_mem;
2998 if (icode != CODE_FOR_nothing
2999 && insn_data[icode].operand[0].predicate (op0, promoted_nominal_mode)
3000 && insn_data[icode].operand[1].predicate (op1, data->passed_mode))
3002 enum rtx_code code = unsignedp ? ZERO_EXTEND : SIGN_EXTEND;
3003 rtx insn, insns;
3004 HARD_REG_SET hardregs;
3006 start_sequence ();
3007 insn = gen_extend_insn (op0, op1, promoted_nominal_mode,
3008 data->passed_mode, unsignedp);
3009 emit_insn (insn);
3010 insns = get_insns ();
3012 moved = true;
3013 CLEAR_HARD_REG_SET (hardregs);
3014 for (insn = insns; insn && moved; insn = NEXT_INSN (insn))
3016 if (INSN_P (insn))
3017 note_stores (PATTERN (insn), record_hard_reg_sets,
3018 &hardregs);
3019 if (!hard_reg_set_empty_p (hardregs))
3020 moved = false;
3023 end_sequence ();
3025 if (moved)
3027 emit_insn (insns);
3028 if (equiv_stack_parm != NULL_RTX)
3029 equiv_stack_parm = gen_rtx_fmt_e (code, GET_MODE (parmreg),
3030 equiv_stack_parm);
3035 if (moved)
3036 /* Nothing to do. */
3038 else if (need_conversion)
3040 /* We did not have an insn to convert directly, or the sequence
3041 generated appeared unsafe. We must first copy the parm to a
3042 pseudo reg, and save the conversion until after all
3043 parameters have been moved. */
3045 int save_tree_used;
3046 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
3048 emit_move_insn (tempreg, validated_mem);
3050 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3051 tempreg = convert_to_mode (data->nominal_mode, tempreg, unsignedp);
3053 if (GET_CODE (tempreg) == SUBREG
3054 && GET_MODE (tempreg) == data->nominal_mode
3055 && REG_P (SUBREG_REG (tempreg))
3056 && data->nominal_mode == data->passed_mode
3057 && GET_MODE (SUBREG_REG (tempreg)) == GET_MODE (data->entry_parm)
3058 && GET_MODE_SIZE (GET_MODE (tempreg))
3059 < GET_MODE_SIZE (GET_MODE (data->entry_parm)))
3061 /* The argument is already sign/zero extended, so note it
3062 into the subreg. */
3063 SUBREG_PROMOTED_VAR_P (tempreg) = 1;
3064 SUBREG_PROMOTED_UNSIGNED_SET (tempreg, unsignedp);
3067 /* TREE_USED gets set erroneously during expand_assignment. */
3068 save_tree_used = TREE_USED (parm);
3069 expand_assignment (parm, make_tree (data->nominal_type, tempreg), false);
3070 TREE_USED (parm) = save_tree_used;
3071 all->first_conversion_insn = get_insns ();
3072 all->last_conversion_insn = get_last_insn ();
3073 end_sequence ();
3075 did_conversion = true;
3077 else
3078 emit_move_insn (parmreg, validated_mem);
3080 /* If we were passed a pointer but the actual value can safely live
3081 in a register, put it in one. */
3082 if (data->passed_pointer
3083 && TYPE_MODE (TREE_TYPE (parm)) != BLKmode
3084 /* If by-reference argument was promoted, demote it. */
3085 && (TYPE_MODE (TREE_TYPE (parm)) != GET_MODE (DECL_RTL (parm))
3086 || use_register_for_decl (parm)))
3088 /* We can't use nominal_mode, because it will have been set to
3089 Pmode above. We must use the actual mode of the parm. */
3090 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
3091 mark_user_reg (parmreg);
3093 if (GET_MODE (parmreg) != GET_MODE (DECL_RTL (parm)))
3095 rtx tempreg = gen_reg_rtx (GET_MODE (DECL_RTL (parm)));
3096 int unsigned_p = TYPE_UNSIGNED (TREE_TYPE (parm));
3098 push_to_sequence2 (all->first_conversion_insn,
3099 all->last_conversion_insn);
3100 emit_move_insn (tempreg, DECL_RTL (parm));
3101 tempreg = convert_to_mode (GET_MODE (parmreg), tempreg, unsigned_p);
3102 emit_move_insn (parmreg, tempreg);
3103 all->first_conversion_insn = get_insns ();
3104 all->last_conversion_insn = get_last_insn ();
3105 end_sequence ();
3107 did_conversion = true;
3109 else
3110 emit_move_insn (parmreg, DECL_RTL (parm));
3112 SET_DECL_RTL (parm, parmreg);
3114 /* STACK_PARM is the pointer, not the parm, and PARMREG is
3115 now the parm. */
3116 data->stack_parm = NULL;
3119 /* Mark the register as eliminable if we did no conversion and it was
3120 copied from memory at a fixed offset, and the arg pointer was not
3121 copied to a pseudo-reg. If the arg pointer is a pseudo reg or the
3122 offset formed an invalid address, such memory-equivalences as we
3123 make here would screw up life analysis for it. */
3124 if (data->nominal_mode == data->passed_mode
3125 && !did_conversion
3126 && data->stack_parm != 0
3127 && MEM_P (data->stack_parm)
3128 && data->locate.offset.var == 0
3129 && reg_mentioned_p (virtual_incoming_args_rtx,
3130 XEXP (data->stack_parm, 0)))
3132 rtx linsn = get_last_insn ();
3133 rtx sinsn, set;
3135 /* Mark complex types separately. */
3136 if (GET_CODE (parmreg) == CONCAT)
3138 enum machine_mode submode
3139 = GET_MODE_INNER (GET_MODE (parmreg));
3140 int regnor = REGNO (XEXP (parmreg, 0));
3141 int regnoi = REGNO (XEXP (parmreg, 1));
3142 rtx stackr = adjust_address_nv (data->stack_parm, submode, 0);
3143 rtx stacki = adjust_address_nv (data->stack_parm, submode,
3144 GET_MODE_SIZE (submode));
3146 /* Scan backwards for the set of the real and
3147 imaginary parts. */
3148 for (sinsn = linsn; sinsn != 0;
3149 sinsn = prev_nonnote_insn (sinsn))
3151 set = single_set (sinsn);
3152 if (set == 0)
3153 continue;
3155 if (SET_DEST (set) == regno_reg_rtx [regnoi])
3156 set_unique_reg_note (sinsn, REG_EQUIV, stacki);
3157 else if (SET_DEST (set) == regno_reg_rtx [regnor])
3158 set_unique_reg_note (sinsn, REG_EQUIV, stackr);
3161 else if ((set = single_set (linsn)) != 0
3162 && SET_DEST (set) == parmreg)
3163 set_unique_reg_note (linsn, REG_EQUIV, equiv_stack_parm);
3166 /* For pointer data type, suggest pointer register. */
3167 if (POINTER_TYPE_P (TREE_TYPE (parm)))
3168 mark_reg_pointer (parmreg,
3169 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
3172 /* A subroutine of assign_parms. Allocate stack space to hold the current
3173 parameter. Get it there. Perform all ABI specified conversions. */
3175 static void
3176 assign_parm_setup_stack (struct assign_parm_data_all *all, tree parm,
3177 struct assign_parm_data_one *data)
3179 /* Value must be stored in the stack slot STACK_PARM during function
3180 execution. */
3181 bool to_conversion = false;
3183 assign_parm_remove_parallels (data);
3185 if (data->promoted_mode != data->nominal_mode)
3187 /* Conversion is required. */
3188 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
3190 emit_move_insn (tempreg, validize_mem (data->entry_parm));
3192 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3193 to_conversion = true;
3195 data->entry_parm = convert_to_mode (data->nominal_mode, tempreg,
3196 TYPE_UNSIGNED (TREE_TYPE (parm)));
3198 if (data->stack_parm)
3200 int offset = subreg_lowpart_offset (data->nominal_mode,
3201 GET_MODE (data->stack_parm));
3202 /* ??? This may need a big-endian conversion on sparc64. */
3203 data->stack_parm
3204 = adjust_address (data->stack_parm, data->nominal_mode, 0);
3205 if (offset && MEM_OFFSET (data->stack_parm))
3206 set_mem_offset (data->stack_parm,
3207 plus_constant (MEM_OFFSET (data->stack_parm),
3208 offset));
3212 if (data->entry_parm != data->stack_parm)
3214 rtx src, dest;
3216 if (data->stack_parm == 0)
3218 int align = STACK_SLOT_ALIGNMENT (data->passed_type,
3219 GET_MODE (data->entry_parm),
3220 TYPE_ALIGN (data->passed_type));
3221 data->stack_parm
3222 = assign_stack_local (GET_MODE (data->entry_parm),
3223 GET_MODE_SIZE (GET_MODE (data->entry_parm)),
3224 align);
3225 set_mem_attributes (data->stack_parm, parm, 1);
3228 dest = validize_mem (data->stack_parm);
3229 src = validize_mem (data->entry_parm);
3231 if (MEM_P (src))
3233 /* Use a block move to handle potentially misaligned entry_parm. */
3234 if (!to_conversion)
3235 push_to_sequence2 (all->first_conversion_insn,
3236 all->last_conversion_insn);
3237 to_conversion = true;
3239 emit_block_move (dest, src,
3240 GEN_INT (int_size_in_bytes (data->passed_type)),
3241 BLOCK_OP_NORMAL);
3243 else
3244 emit_move_insn (dest, src);
3247 if (to_conversion)
3249 all->first_conversion_insn = get_insns ();
3250 all->last_conversion_insn = get_last_insn ();
3251 end_sequence ();
3254 SET_DECL_RTL (parm, data->stack_parm);
3257 /* A subroutine of assign_parms. If the ABI splits complex arguments, then
3258 undo the frobbing that we did in assign_parms_augmented_arg_list. */
3260 static void
3261 assign_parms_unsplit_complex (struct assign_parm_data_all *all,
3262 VEC(tree, heap) *fnargs)
3264 tree parm;
3265 tree orig_fnargs = all->orig_fnargs;
3266 unsigned i = 0;
3268 for (parm = orig_fnargs; parm; parm = TREE_CHAIN (parm), ++i)
3270 if (TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE
3271 && targetm.calls.split_complex_arg (TREE_TYPE (parm)))
3273 rtx tmp, real, imag;
3274 enum machine_mode inner = GET_MODE_INNER (DECL_MODE (parm));
3276 real = DECL_RTL (VEC_index (tree, fnargs, i));
3277 imag = DECL_RTL (VEC_index (tree, fnargs, i + 1));
3278 if (inner != GET_MODE (real))
3280 real = gen_lowpart_SUBREG (inner, real);
3281 imag = gen_lowpart_SUBREG (inner, imag);
3284 if (TREE_ADDRESSABLE (parm))
3286 rtx rmem, imem;
3287 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (parm));
3288 int align = STACK_SLOT_ALIGNMENT (TREE_TYPE (parm),
3289 DECL_MODE (parm),
3290 TYPE_ALIGN (TREE_TYPE (parm)));
3292 /* split_complex_arg put the real and imag parts in
3293 pseudos. Move them to memory. */
3294 tmp = assign_stack_local (DECL_MODE (parm), size, align);
3295 set_mem_attributes (tmp, parm, 1);
3296 rmem = adjust_address_nv (tmp, inner, 0);
3297 imem = adjust_address_nv (tmp, inner, GET_MODE_SIZE (inner));
3298 push_to_sequence2 (all->first_conversion_insn,
3299 all->last_conversion_insn);
3300 emit_move_insn (rmem, real);
3301 emit_move_insn (imem, imag);
3302 all->first_conversion_insn = get_insns ();
3303 all->last_conversion_insn = get_last_insn ();
3304 end_sequence ();
3306 else
3307 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
3308 SET_DECL_RTL (parm, tmp);
3310 real = DECL_INCOMING_RTL (VEC_index (tree, fnargs, i));
3311 imag = DECL_INCOMING_RTL (VEC_index (tree, fnargs, i + 1));
3312 if (inner != GET_MODE (real))
3314 real = gen_lowpart_SUBREG (inner, real);
3315 imag = gen_lowpart_SUBREG (inner, imag);
3317 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
3318 set_decl_incoming_rtl (parm, tmp, false);
3319 i++;
3324 /* Assign RTL expressions to the function's parameters. This may involve
3325 copying them into registers and using those registers as the DECL_RTL. */
3327 static void
3328 assign_parms (tree fndecl)
3330 struct assign_parm_data_all all;
3331 tree parm;
3332 VEC(tree, heap) *fnargs;
3333 unsigned i;
3335 crtl->args.internal_arg_pointer
3336 = targetm.calls.internal_arg_pointer ();
3338 assign_parms_initialize_all (&all);
3339 fnargs = assign_parms_augmented_arg_list (&all);
3341 FOR_EACH_VEC_ELT (tree, fnargs, i, parm)
3343 struct assign_parm_data_one data;
3345 /* Extract the type of PARM; adjust it according to ABI. */
3346 assign_parm_find_data_types (&all, parm, &data);
3348 /* Early out for errors and void parameters. */
3349 if (data.passed_mode == VOIDmode)
3351 SET_DECL_RTL (parm, const0_rtx);
3352 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
3353 continue;
3356 /* Estimate stack alignment from parameter alignment. */
3357 if (SUPPORTS_STACK_ALIGNMENT)
3359 unsigned int align
3360 = targetm.calls.function_arg_boundary (data.promoted_mode,
3361 data.passed_type);
3362 align = MINIMUM_ALIGNMENT (data.passed_type, data.promoted_mode,
3363 align);
3364 if (TYPE_ALIGN (data.nominal_type) > align)
3365 align = MINIMUM_ALIGNMENT (data.nominal_type,
3366 TYPE_MODE (data.nominal_type),
3367 TYPE_ALIGN (data.nominal_type));
3368 if (crtl->stack_alignment_estimated < align)
3370 gcc_assert (!crtl->stack_realign_processed);
3371 crtl->stack_alignment_estimated = align;
3375 if (cfun->stdarg && !DECL_CHAIN (parm))
3376 assign_parms_setup_varargs (&all, &data, false);
3378 /* Find out where the parameter arrives in this function. */
3379 assign_parm_find_entry_rtl (&all, &data);
3381 /* Find out where stack space for this parameter might be. */
3382 if (assign_parm_is_stack_parm (&all, &data))
3384 assign_parm_find_stack_rtl (parm, &data);
3385 assign_parm_adjust_entry_rtl (&data);
3388 /* Record permanently how this parm was passed. */
3389 set_decl_incoming_rtl (parm, data.entry_parm, data.passed_pointer);
3391 /* Update info on where next arg arrives in registers. */
3392 targetm.calls.function_arg_advance (&all.args_so_far, data.promoted_mode,
3393 data.passed_type, data.named_arg);
3395 assign_parm_adjust_stack_rtl (&data);
3397 if (assign_parm_setup_block_p (&data))
3398 assign_parm_setup_block (&all, parm, &data);
3399 else if (data.passed_pointer || use_register_for_decl (parm))
3400 assign_parm_setup_reg (&all, parm, &data);
3401 else
3402 assign_parm_setup_stack (&all, parm, &data);
3405 if (targetm.calls.split_complex_arg)
3406 assign_parms_unsplit_complex (&all, fnargs);
3408 VEC_free (tree, heap, fnargs);
3410 /* Output all parameter conversion instructions (possibly including calls)
3411 now that all parameters have been copied out of hard registers. */
3412 emit_insn (all.first_conversion_insn);
3414 /* Estimate reload stack alignment from scalar return mode. */
3415 if (SUPPORTS_STACK_ALIGNMENT)
3417 if (DECL_RESULT (fndecl))
3419 tree type = TREE_TYPE (DECL_RESULT (fndecl));
3420 enum machine_mode mode = TYPE_MODE (type);
3422 if (mode != BLKmode
3423 && mode != VOIDmode
3424 && !AGGREGATE_TYPE_P (type))
3426 unsigned int align = GET_MODE_ALIGNMENT (mode);
3427 if (crtl->stack_alignment_estimated < align)
3429 gcc_assert (!crtl->stack_realign_processed);
3430 crtl->stack_alignment_estimated = align;
3436 /* If we are receiving a struct value address as the first argument, set up
3437 the RTL for the function result. As this might require code to convert
3438 the transmitted address to Pmode, we do this here to ensure that possible
3439 preliminary conversions of the address have been emitted already. */
3440 if (all.function_result_decl)
3442 tree result = DECL_RESULT (current_function_decl);
3443 rtx addr = DECL_RTL (all.function_result_decl);
3444 rtx x;
3446 if (DECL_BY_REFERENCE (result))
3448 SET_DECL_VALUE_EXPR (result, all.function_result_decl);
3449 x = addr;
3451 else
3453 SET_DECL_VALUE_EXPR (result,
3454 build1 (INDIRECT_REF, TREE_TYPE (result),
3455 all.function_result_decl));
3456 addr = convert_memory_address (Pmode, addr);
3457 x = gen_rtx_MEM (DECL_MODE (result), addr);
3458 set_mem_attributes (x, result, 1);
3461 DECL_HAS_VALUE_EXPR_P (result) = 1;
3463 SET_DECL_RTL (result, x);
3466 /* We have aligned all the args, so add space for the pretend args. */
3467 crtl->args.pretend_args_size = all.pretend_args_size;
3468 all.stack_args_size.constant += all.extra_pretend_bytes;
3469 crtl->args.size = all.stack_args_size.constant;
3471 /* Adjust function incoming argument size for alignment and
3472 minimum length. */
3474 #ifdef REG_PARM_STACK_SPACE
3475 crtl->args.size = MAX (crtl->args.size,
3476 REG_PARM_STACK_SPACE (fndecl));
3477 #endif
3479 crtl->args.size = CEIL_ROUND (crtl->args.size,
3480 PARM_BOUNDARY / BITS_PER_UNIT);
3482 #ifdef ARGS_GROW_DOWNWARD
3483 crtl->args.arg_offset_rtx
3484 = (all.stack_args_size.var == 0 ? GEN_INT (-all.stack_args_size.constant)
3485 : expand_expr (size_diffop (all.stack_args_size.var,
3486 size_int (-all.stack_args_size.constant)),
3487 NULL_RTX, VOIDmode, EXPAND_NORMAL));
3488 #else
3489 crtl->args.arg_offset_rtx = ARGS_SIZE_RTX (all.stack_args_size);
3490 #endif
3492 /* See how many bytes, if any, of its args a function should try to pop
3493 on return. */
3495 crtl->args.pops_args = targetm.calls.return_pops_args (fndecl,
3496 TREE_TYPE (fndecl),
3497 crtl->args.size);
3499 /* For stdarg.h function, save info about
3500 regs and stack space used by the named args. */
3502 crtl->args.info = all.args_so_far;
3504 /* Set the rtx used for the function return value. Put this in its
3505 own variable so any optimizers that need this information don't have
3506 to include tree.h. Do this here so it gets done when an inlined
3507 function gets output. */
3509 crtl->return_rtx
3510 = (DECL_RTL_SET_P (DECL_RESULT (fndecl))
3511 ? DECL_RTL (DECL_RESULT (fndecl)) : NULL_RTX);
3513 /* If scalar return value was computed in a pseudo-reg, or was a named
3514 return value that got dumped to the stack, copy that to the hard
3515 return register. */
3516 if (DECL_RTL_SET_P (DECL_RESULT (fndecl)))
3518 tree decl_result = DECL_RESULT (fndecl);
3519 rtx decl_rtl = DECL_RTL (decl_result);
3521 if (REG_P (decl_rtl)
3522 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
3523 : DECL_REGISTER (decl_result))
3525 rtx real_decl_rtl;
3527 real_decl_rtl = targetm.calls.function_value (TREE_TYPE (decl_result),
3528 fndecl, true);
3529 REG_FUNCTION_VALUE_P (real_decl_rtl) = 1;
3530 /* The delay slot scheduler assumes that crtl->return_rtx
3531 holds the hard register containing the return value, not a
3532 temporary pseudo. */
3533 crtl->return_rtx = real_decl_rtl;
3538 /* A subroutine of gimplify_parameters, invoked via walk_tree.
3539 For all seen types, gimplify their sizes. */
3541 static tree
3542 gimplify_parm_type (tree *tp, int *walk_subtrees, void *data)
3544 tree t = *tp;
3546 *walk_subtrees = 0;
3547 if (TYPE_P (t))
3549 if (POINTER_TYPE_P (t))
3550 *walk_subtrees = 1;
3551 else if (TYPE_SIZE (t) && !TREE_CONSTANT (TYPE_SIZE (t))
3552 && !TYPE_SIZES_GIMPLIFIED (t))
3554 gimplify_type_sizes (t, (gimple_seq *) data);
3555 *walk_subtrees = 1;
3559 return NULL;
3562 /* Gimplify the parameter list for current_function_decl. This involves
3563 evaluating SAVE_EXPRs of variable sized parameters and generating code
3564 to implement callee-copies reference parameters. Returns a sequence of
3565 statements to add to the beginning of the function. */
3567 gimple_seq
3568 gimplify_parameters (void)
3570 struct assign_parm_data_all all;
3571 tree parm;
3572 gimple_seq stmts = NULL;
3573 VEC(tree, heap) *fnargs;
3574 unsigned i;
3576 assign_parms_initialize_all (&all);
3577 fnargs = assign_parms_augmented_arg_list (&all);
3579 FOR_EACH_VEC_ELT (tree, fnargs, i, parm)
3581 struct assign_parm_data_one data;
3583 /* Extract the type of PARM; adjust it according to ABI. */
3584 assign_parm_find_data_types (&all, parm, &data);
3586 /* Early out for errors and void parameters. */
3587 if (data.passed_mode == VOIDmode || DECL_SIZE (parm) == NULL)
3588 continue;
3590 /* Update info on where next arg arrives in registers. */
3591 targetm.calls.function_arg_advance (&all.args_so_far, data.promoted_mode,
3592 data.passed_type, data.named_arg);
3594 /* ??? Once upon a time variable_size stuffed parameter list
3595 SAVE_EXPRs (amongst others) onto a pending sizes list. This
3596 turned out to be less than manageable in the gimple world.
3597 Now we have to hunt them down ourselves. */
3598 walk_tree_without_duplicates (&data.passed_type,
3599 gimplify_parm_type, &stmts);
3601 if (TREE_CODE (DECL_SIZE_UNIT (parm)) != INTEGER_CST)
3603 gimplify_one_sizepos (&DECL_SIZE (parm), &stmts);
3604 gimplify_one_sizepos (&DECL_SIZE_UNIT (parm), &stmts);
3607 if (data.passed_pointer)
3609 tree type = TREE_TYPE (data.passed_type);
3610 if (reference_callee_copied (&all.args_so_far, TYPE_MODE (type),
3611 type, data.named_arg))
3613 tree local, t;
3615 /* For constant-sized objects, this is trivial; for
3616 variable-sized objects, we have to play games. */
3617 if (TREE_CODE (DECL_SIZE_UNIT (parm)) == INTEGER_CST
3618 && !(flag_stack_check == GENERIC_STACK_CHECK
3619 && compare_tree_int (DECL_SIZE_UNIT (parm),
3620 STACK_CHECK_MAX_VAR_SIZE) > 0))
3622 local = create_tmp_reg (type, get_name (parm));
3623 DECL_IGNORED_P (local) = 0;
3624 /* If PARM was addressable, move that flag over
3625 to the local copy, as its address will be taken,
3626 not the PARMs. Keep the parms address taken
3627 as we'll query that flag during gimplification. */
3628 if (TREE_ADDRESSABLE (parm))
3629 TREE_ADDRESSABLE (local) = 1;
3631 else
3633 tree ptr_type, addr;
3635 ptr_type = build_pointer_type (type);
3636 addr = create_tmp_reg (ptr_type, get_name (parm));
3637 DECL_IGNORED_P (addr) = 0;
3638 local = build_fold_indirect_ref (addr);
3640 t = built_in_decls[BUILT_IN_ALLOCA];
3641 t = build_call_expr (t, 1, DECL_SIZE_UNIT (parm));
3642 /* The call has been built for a variable-sized object. */
3643 ALLOCA_FOR_VAR_P (t) = 1;
3644 t = fold_convert (ptr_type, t);
3645 t = build2 (MODIFY_EXPR, TREE_TYPE (addr), addr, t);
3646 gimplify_and_add (t, &stmts);
3649 gimplify_assign (local, parm, &stmts);
3651 SET_DECL_VALUE_EXPR (parm, local);
3652 DECL_HAS_VALUE_EXPR_P (parm) = 1;
3657 VEC_free (tree, heap, fnargs);
3659 return stmts;
3662 /* Compute the size and offset from the start of the stacked arguments for a
3663 parm passed in mode PASSED_MODE and with type TYPE.
3665 INITIAL_OFFSET_PTR points to the current offset into the stacked
3666 arguments.
3668 The starting offset and size for this parm are returned in
3669 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
3670 nonzero, the offset is that of stack slot, which is returned in
3671 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
3672 padding required from the initial offset ptr to the stack slot.
3674 IN_REGS is nonzero if the argument will be passed in registers. It will
3675 never be set if REG_PARM_STACK_SPACE is not defined.
3677 FNDECL is the function in which the argument was defined.
3679 There are two types of rounding that are done. The first, controlled by
3680 TARGET_FUNCTION_ARG_BOUNDARY, forces the offset from the start of the
3681 argument list to be aligned to the specific boundary (in bits). This
3682 rounding affects the initial and starting offsets, but not the argument
3683 size.
3685 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
3686 optionally rounds the size of the parm to PARM_BOUNDARY. The
3687 initial offset is not affected by this rounding, while the size always
3688 is and the starting offset may be. */
3690 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
3691 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
3692 callers pass in the total size of args so far as
3693 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
3695 void
3696 locate_and_pad_parm (enum machine_mode passed_mode, tree type, int in_regs,
3697 int partial, tree fndecl ATTRIBUTE_UNUSED,
3698 struct args_size *initial_offset_ptr,
3699 struct locate_and_pad_arg_data *locate)
3701 tree sizetree;
3702 enum direction where_pad;
3703 unsigned int boundary;
3704 int reg_parm_stack_space = 0;
3705 int part_size_in_regs;
3707 #ifdef REG_PARM_STACK_SPACE
3708 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
3710 /* If we have found a stack parm before we reach the end of the
3711 area reserved for registers, skip that area. */
3712 if (! in_regs)
3714 if (reg_parm_stack_space > 0)
3716 if (initial_offset_ptr->var)
3718 initial_offset_ptr->var
3719 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
3720 ssize_int (reg_parm_stack_space));
3721 initial_offset_ptr->constant = 0;
3723 else if (initial_offset_ptr->constant < reg_parm_stack_space)
3724 initial_offset_ptr->constant = reg_parm_stack_space;
3727 #endif /* REG_PARM_STACK_SPACE */
3729 part_size_in_regs = (reg_parm_stack_space == 0 ? partial : 0);
3731 sizetree
3732 = type ? size_in_bytes (type) : size_int (GET_MODE_SIZE (passed_mode));
3733 where_pad = FUNCTION_ARG_PADDING (passed_mode, type);
3734 boundary = targetm.calls.function_arg_boundary (passed_mode, type);
3735 locate->where_pad = where_pad;
3737 /* Alignment can't exceed MAX_SUPPORTED_STACK_ALIGNMENT. */
3738 if (boundary > MAX_SUPPORTED_STACK_ALIGNMENT)
3739 boundary = MAX_SUPPORTED_STACK_ALIGNMENT;
3741 locate->boundary = boundary;
3743 if (SUPPORTS_STACK_ALIGNMENT)
3745 /* stack_alignment_estimated can't change after stack has been
3746 realigned. */
3747 if (crtl->stack_alignment_estimated < boundary)
3749 if (!crtl->stack_realign_processed)
3750 crtl->stack_alignment_estimated = boundary;
3751 else
3753 /* If stack is realigned and stack alignment value
3754 hasn't been finalized, it is OK not to increase
3755 stack_alignment_estimated. The bigger alignment
3756 requirement is recorded in stack_alignment_needed
3757 below. */
3758 gcc_assert (!crtl->stack_realign_finalized
3759 && crtl->stack_realign_needed);
3764 /* Remember if the outgoing parameter requires extra alignment on the
3765 calling function side. */
3766 if (crtl->stack_alignment_needed < boundary)
3767 crtl->stack_alignment_needed = boundary;
3768 if (crtl->preferred_stack_boundary < boundary)
3769 crtl->preferred_stack_boundary = boundary;
3771 #ifdef ARGS_GROW_DOWNWARD
3772 locate->slot_offset.constant = -initial_offset_ptr->constant;
3773 if (initial_offset_ptr->var)
3774 locate->slot_offset.var = size_binop (MINUS_EXPR, ssize_int (0),
3775 initial_offset_ptr->var);
3778 tree s2 = sizetree;
3779 if (where_pad != none
3780 && (!host_integerp (sizetree, 1)
3781 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
3782 s2 = round_up (s2, PARM_BOUNDARY / BITS_PER_UNIT);
3783 SUB_PARM_SIZE (locate->slot_offset, s2);
3786 locate->slot_offset.constant += part_size_in_regs;
3788 if (!in_regs
3789 #ifdef REG_PARM_STACK_SPACE
3790 || REG_PARM_STACK_SPACE (fndecl) > 0
3791 #endif
3793 pad_to_arg_alignment (&locate->slot_offset, boundary,
3794 &locate->alignment_pad);
3796 locate->size.constant = (-initial_offset_ptr->constant
3797 - locate->slot_offset.constant);
3798 if (initial_offset_ptr->var)
3799 locate->size.var = size_binop (MINUS_EXPR,
3800 size_binop (MINUS_EXPR,
3801 ssize_int (0),
3802 initial_offset_ptr->var),
3803 locate->slot_offset.var);
3805 /* Pad_below needs the pre-rounded size to know how much to pad
3806 below. */
3807 locate->offset = locate->slot_offset;
3808 if (where_pad == downward)
3809 pad_below (&locate->offset, passed_mode, sizetree);
3811 #else /* !ARGS_GROW_DOWNWARD */
3812 if (!in_regs
3813 #ifdef REG_PARM_STACK_SPACE
3814 || REG_PARM_STACK_SPACE (fndecl) > 0
3815 #endif
3817 pad_to_arg_alignment (initial_offset_ptr, boundary,
3818 &locate->alignment_pad);
3819 locate->slot_offset = *initial_offset_ptr;
3821 #ifdef PUSH_ROUNDING
3822 if (passed_mode != BLKmode)
3823 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
3824 #endif
3826 /* Pad_below needs the pre-rounded size to know how much to pad below
3827 so this must be done before rounding up. */
3828 locate->offset = locate->slot_offset;
3829 if (where_pad == downward)
3830 pad_below (&locate->offset, passed_mode, sizetree);
3832 if (where_pad != none
3833 && (!host_integerp (sizetree, 1)
3834 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
3835 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3837 ADD_PARM_SIZE (locate->size, sizetree);
3839 locate->size.constant -= part_size_in_regs;
3840 #endif /* ARGS_GROW_DOWNWARD */
3842 #ifdef FUNCTION_ARG_OFFSET
3843 locate->offset.constant += FUNCTION_ARG_OFFSET (passed_mode, type);
3844 #endif
3847 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
3848 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
3850 static void
3851 pad_to_arg_alignment (struct args_size *offset_ptr, int boundary,
3852 struct args_size *alignment_pad)
3854 tree save_var = NULL_TREE;
3855 HOST_WIDE_INT save_constant = 0;
3856 int boundary_in_bytes = boundary / BITS_PER_UNIT;
3857 HOST_WIDE_INT sp_offset = STACK_POINTER_OFFSET;
3859 #ifdef SPARC_STACK_BOUNDARY_HACK
3860 /* ??? The SPARC port may claim a STACK_BOUNDARY higher than
3861 the real alignment of %sp. However, when it does this, the
3862 alignment of %sp+STACK_POINTER_OFFSET is STACK_BOUNDARY. */
3863 if (SPARC_STACK_BOUNDARY_HACK)
3864 sp_offset = 0;
3865 #endif
3867 if (boundary > PARM_BOUNDARY)
3869 save_var = offset_ptr->var;
3870 save_constant = offset_ptr->constant;
3873 alignment_pad->var = NULL_TREE;
3874 alignment_pad->constant = 0;
3876 if (boundary > BITS_PER_UNIT)
3878 if (offset_ptr->var)
3880 tree sp_offset_tree = ssize_int (sp_offset);
3881 tree offset = size_binop (PLUS_EXPR,
3882 ARGS_SIZE_TREE (*offset_ptr),
3883 sp_offset_tree);
3884 #ifdef ARGS_GROW_DOWNWARD
3885 tree rounded = round_down (offset, boundary / BITS_PER_UNIT);
3886 #else
3887 tree rounded = round_up (offset, boundary / BITS_PER_UNIT);
3888 #endif
3890 offset_ptr->var = size_binop (MINUS_EXPR, rounded, sp_offset_tree);
3891 /* ARGS_SIZE_TREE includes constant term. */
3892 offset_ptr->constant = 0;
3893 if (boundary > PARM_BOUNDARY)
3894 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
3895 save_var);
3897 else
3899 offset_ptr->constant = -sp_offset +
3900 #ifdef ARGS_GROW_DOWNWARD
3901 FLOOR_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
3902 #else
3903 CEIL_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
3904 #endif
3905 if (boundary > PARM_BOUNDARY)
3906 alignment_pad->constant = offset_ptr->constant - save_constant;
3911 static void
3912 pad_below (struct args_size *offset_ptr, enum machine_mode passed_mode, tree sizetree)
3914 if (passed_mode != BLKmode)
3916 if (GET_MODE_BITSIZE (passed_mode) % PARM_BOUNDARY)
3917 offset_ptr->constant
3918 += (((GET_MODE_BITSIZE (passed_mode) + PARM_BOUNDARY - 1)
3919 / PARM_BOUNDARY * PARM_BOUNDARY / BITS_PER_UNIT)
3920 - GET_MODE_SIZE (passed_mode));
3922 else
3924 if (TREE_CODE (sizetree) != INTEGER_CST
3925 || (TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)
3927 /* Round the size up to multiple of PARM_BOUNDARY bits. */
3928 tree s2 = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3929 /* Add it in. */
3930 ADD_PARM_SIZE (*offset_ptr, s2);
3931 SUB_PARM_SIZE (*offset_ptr, sizetree);
3937 /* True if register REGNO was alive at a place where `setjmp' was
3938 called and was set more than once or is an argument. Such regs may
3939 be clobbered by `longjmp'. */
3941 static bool
3942 regno_clobbered_at_setjmp (bitmap setjmp_crosses, int regno)
3944 /* There appear to be cases where some local vars never reach the
3945 backend but have bogus regnos. */
3946 if (regno >= max_reg_num ())
3947 return false;
3949 return ((REG_N_SETS (regno) > 1
3950 || REGNO_REG_SET_P (df_get_live_out (ENTRY_BLOCK_PTR), regno))
3951 && REGNO_REG_SET_P (setjmp_crosses, regno));
3954 /* Walk the tree of blocks describing the binding levels within a
3955 function and warn about variables the might be killed by setjmp or
3956 vfork. This is done after calling flow_analysis before register
3957 allocation since that will clobber the pseudo-regs to hard
3958 regs. */
3960 static void
3961 setjmp_vars_warning (bitmap setjmp_crosses, tree block)
3963 tree decl, sub;
3965 for (decl = BLOCK_VARS (block); decl; decl = DECL_CHAIN (decl))
3967 if (TREE_CODE (decl) == VAR_DECL
3968 && DECL_RTL_SET_P (decl)
3969 && REG_P (DECL_RTL (decl))
3970 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
3971 warning (OPT_Wclobbered, "variable %q+D might be clobbered by"
3972 " %<longjmp%> or %<vfork%>", decl);
3975 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = BLOCK_CHAIN (sub))
3976 setjmp_vars_warning (setjmp_crosses, sub);
3979 /* Do the appropriate part of setjmp_vars_warning
3980 but for arguments instead of local variables. */
3982 static void
3983 setjmp_args_warning (bitmap setjmp_crosses)
3985 tree decl;
3986 for (decl = DECL_ARGUMENTS (current_function_decl);
3987 decl; decl = DECL_CHAIN (decl))
3988 if (DECL_RTL (decl) != 0
3989 && REG_P (DECL_RTL (decl))
3990 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
3991 warning (OPT_Wclobbered,
3992 "argument %q+D might be clobbered by %<longjmp%> or %<vfork%>",
3993 decl);
3996 /* Generate warning messages for variables live across setjmp. */
3998 void
3999 generate_setjmp_warnings (void)
4001 bitmap setjmp_crosses = regstat_get_setjmp_crosses ();
4003 if (n_basic_blocks == NUM_FIXED_BLOCKS
4004 || bitmap_empty_p (setjmp_crosses))
4005 return;
4007 setjmp_vars_warning (setjmp_crosses, DECL_INITIAL (current_function_decl));
4008 setjmp_args_warning (setjmp_crosses);
4012 /* Reverse the order of elements in the fragment chain T of blocks,
4013 and return the new head of the chain (old last element). */
4015 static tree
4016 block_fragments_nreverse (tree t)
4018 tree prev = 0, block, next;
4019 for (block = t; block; block = next)
4021 next = BLOCK_FRAGMENT_CHAIN (block);
4022 BLOCK_FRAGMENT_CHAIN (block) = prev;
4023 prev = block;
4025 return prev;
4028 /* Reverse the order of elements in the chain T of blocks,
4029 and return the new head of the chain (old last element).
4030 Also do the same on subblocks and reverse the order of elements
4031 in BLOCK_FRAGMENT_CHAIN as well. */
4033 static tree
4034 blocks_nreverse_all (tree t)
4036 tree prev = 0, block, next;
4037 for (block = t; block; block = next)
4039 next = BLOCK_CHAIN (block);
4040 BLOCK_CHAIN (block) = prev;
4041 BLOCK_SUBBLOCKS (block) = blocks_nreverse_all (BLOCK_SUBBLOCKS (block));
4042 if (BLOCK_FRAGMENT_CHAIN (block)
4043 && BLOCK_FRAGMENT_ORIGIN (block) == NULL_TREE)
4044 BLOCK_FRAGMENT_CHAIN (block)
4045 = block_fragments_nreverse (BLOCK_FRAGMENT_CHAIN (block));
4046 prev = block;
4048 return prev;
4052 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
4053 and create duplicate blocks. */
4054 /* ??? Need an option to either create block fragments or to create
4055 abstract origin duplicates of a source block. It really depends
4056 on what optimization has been performed. */
4058 void
4059 reorder_blocks (void)
4061 tree block = DECL_INITIAL (current_function_decl);
4062 VEC(tree,heap) *block_stack;
4064 if (block == NULL_TREE)
4065 return;
4067 block_stack = VEC_alloc (tree, heap, 10);
4069 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
4070 clear_block_marks (block);
4072 /* Prune the old trees away, so that they don't get in the way. */
4073 BLOCK_SUBBLOCKS (block) = NULL_TREE;
4074 BLOCK_CHAIN (block) = NULL_TREE;
4076 /* Recreate the block tree from the note nesting. */
4077 reorder_blocks_1 (get_insns (), block, &block_stack);
4078 BLOCK_SUBBLOCKS (block) = blocks_nreverse_all (BLOCK_SUBBLOCKS (block));
4080 VEC_free (tree, heap, block_stack);
4083 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
4085 void
4086 clear_block_marks (tree block)
4088 while (block)
4090 TREE_ASM_WRITTEN (block) = 0;
4091 clear_block_marks (BLOCK_SUBBLOCKS (block));
4092 block = BLOCK_CHAIN (block);
4096 static void
4097 reorder_blocks_1 (rtx insns, tree current_block, VEC(tree,heap) **p_block_stack)
4099 rtx insn;
4101 for (insn = insns; insn; insn = NEXT_INSN (insn))
4103 if (NOTE_P (insn))
4105 if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_BEG)
4107 tree block = NOTE_BLOCK (insn);
4108 tree origin;
4110 gcc_assert (BLOCK_FRAGMENT_ORIGIN (block) == NULL_TREE);
4111 origin = block;
4113 /* If we have seen this block before, that means it now
4114 spans multiple address regions. Create a new fragment. */
4115 if (TREE_ASM_WRITTEN (block))
4117 tree new_block = copy_node (block);
4119 BLOCK_FRAGMENT_ORIGIN (new_block) = origin;
4120 BLOCK_FRAGMENT_CHAIN (new_block)
4121 = BLOCK_FRAGMENT_CHAIN (origin);
4122 BLOCK_FRAGMENT_CHAIN (origin) = new_block;
4124 NOTE_BLOCK (insn) = new_block;
4125 block = new_block;
4128 BLOCK_SUBBLOCKS (block) = 0;
4129 TREE_ASM_WRITTEN (block) = 1;
4130 /* When there's only one block for the entire function,
4131 current_block == block and we mustn't do this, it
4132 will cause infinite recursion. */
4133 if (block != current_block)
4135 if (block != origin)
4136 gcc_assert (BLOCK_SUPERCONTEXT (origin) == current_block);
4138 BLOCK_SUPERCONTEXT (block) = current_block;
4139 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
4140 BLOCK_SUBBLOCKS (current_block) = block;
4141 current_block = origin;
4143 VEC_safe_push (tree, heap, *p_block_stack, block);
4145 else if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_END)
4147 NOTE_BLOCK (insn) = VEC_pop (tree, *p_block_stack);
4148 current_block = BLOCK_SUPERCONTEXT (current_block);
4154 /* Reverse the order of elements in the chain T of blocks,
4155 and return the new head of the chain (old last element). */
4157 tree
4158 blocks_nreverse (tree t)
4160 tree prev = 0, block, next;
4161 for (block = t; block; block = next)
4163 next = BLOCK_CHAIN (block);
4164 BLOCK_CHAIN (block) = prev;
4165 prev = block;
4167 return prev;
4170 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
4171 non-NULL, list them all into VECTOR, in a depth-first preorder
4172 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
4173 blocks. */
4175 static int
4176 all_blocks (tree block, tree *vector)
4178 int n_blocks = 0;
4180 while (block)
4182 TREE_ASM_WRITTEN (block) = 0;
4184 /* Record this block. */
4185 if (vector)
4186 vector[n_blocks] = block;
4188 ++n_blocks;
4190 /* Record the subblocks, and their subblocks... */
4191 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
4192 vector ? vector + n_blocks : 0);
4193 block = BLOCK_CHAIN (block);
4196 return n_blocks;
4199 /* Return a vector containing all the blocks rooted at BLOCK. The
4200 number of elements in the vector is stored in N_BLOCKS_P. The
4201 vector is dynamically allocated; it is the caller's responsibility
4202 to call `free' on the pointer returned. */
4204 static tree *
4205 get_block_vector (tree block, int *n_blocks_p)
4207 tree *block_vector;
4209 *n_blocks_p = all_blocks (block, NULL);
4210 block_vector = XNEWVEC (tree, *n_blocks_p);
4211 all_blocks (block, block_vector);
4213 return block_vector;
4216 static GTY(()) int next_block_index = 2;
4218 /* Set BLOCK_NUMBER for all the blocks in FN. */
4220 void
4221 number_blocks (tree fn)
4223 int i;
4224 int n_blocks;
4225 tree *block_vector;
4227 /* For SDB and XCOFF debugging output, we start numbering the blocks
4228 from 1 within each function, rather than keeping a running
4229 count. */
4230 #if defined (SDB_DEBUGGING_INFO) || defined (XCOFF_DEBUGGING_INFO)
4231 if (write_symbols == SDB_DEBUG || write_symbols == XCOFF_DEBUG)
4232 next_block_index = 1;
4233 #endif
4235 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
4237 /* The top-level BLOCK isn't numbered at all. */
4238 for (i = 1; i < n_blocks; ++i)
4239 /* We number the blocks from two. */
4240 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
4242 free (block_vector);
4244 return;
4247 /* If VAR is present in a subblock of BLOCK, return the subblock. */
4249 DEBUG_FUNCTION tree
4250 debug_find_var_in_block_tree (tree var, tree block)
4252 tree t;
4254 for (t = BLOCK_VARS (block); t; t = TREE_CHAIN (t))
4255 if (t == var)
4256 return block;
4258 for (t = BLOCK_SUBBLOCKS (block); t; t = TREE_CHAIN (t))
4260 tree ret = debug_find_var_in_block_tree (var, t);
4261 if (ret)
4262 return ret;
4265 return NULL_TREE;
4268 /* Keep track of whether we're in a dummy function context. If we are,
4269 we don't want to invoke the set_current_function hook, because we'll
4270 get into trouble if the hook calls target_reinit () recursively or
4271 when the initial initialization is not yet complete. */
4273 static bool in_dummy_function;
4275 /* Invoke the target hook when setting cfun. Update the optimization options
4276 if the function uses different options than the default. */
4278 static void
4279 invoke_set_current_function_hook (tree fndecl)
4281 if (!in_dummy_function)
4283 tree opts = ((fndecl)
4284 ? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (fndecl)
4285 : optimization_default_node);
4287 if (!opts)
4288 opts = optimization_default_node;
4290 /* Change optimization options if needed. */
4291 if (optimization_current_node != opts)
4293 optimization_current_node = opts;
4294 cl_optimization_restore (&global_options, TREE_OPTIMIZATION (opts));
4297 targetm.set_current_function (fndecl);
4301 /* cfun should never be set directly; use this function. */
4303 void
4304 set_cfun (struct function *new_cfun)
4306 if (cfun != new_cfun)
4308 cfun = new_cfun;
4309 invoke_set_current_function_hook (new_cfun ? new_cfun->decl : NULL_TREE);
4313 /* Initialized with NOGC, making this poisonous to the garbage collector. */
4315 static VEC(function_p,heap) *cfun_stack;
4317 /* Push the current cfun onto the stack, and set cfun to new_cfun. */
4319 void
4320 push_cfun (struct function *new_cfun)
4322 VEC_safe_push (function_p, heap, cfun_stack, cfun);
4323 set_cfun (new_cfun);
4326 /* Pop cfun from the stack. */
4328 void
4329 pop_cfun (void)
4331 struct function *new_cfun = VEC_pop (function_p, cfun_stack);
4332 set_cfun (new_cfun);
4335 /* Return value of funcdef and increase it. */
4337 get_next_funcdef_no (void)
4339 return funcdef_no++;
4342 /* Allocate a function structure for FNDECL and set its contents
4343 to the defaults. Set cfun to the newly-allocated object.
4344 Some of the helper functions invoked during initialization assume
4345 that cfun has already been set. Therefore, assign the new object
4346 directly into cfun and invoke the back end hook explicitly at the
4347 very end, rather than initializing a temporary and calling set_cfun
4348 on it.
4350 ABSTRACT_P is true if this is a function that will never be seen by
4351 the middle-end. Such functions are front-end concepts (like C++
4352 function templates) that do not correspond directly to functions
4353 placed in object files. */
4355 void
4356 allocate_struct_function (tree fndecl, bool abstract_p)
4358 tree result;
4359 tree fntype = fndecl ? TREE_TYPE (fndecl) : NULL_TREE;
4361 cfun = ggc_alloc_cleared_function ();
4363 init_eh_for_function ();
4365 if (init_machine_status)
4366 cfun->machine = (*init_machine_status) ();
4368 #ifdef OVERRIDE_ABI_FORMAT
4369 OVERRIDE_ABI_FORMAT (fndecl);
4370 #endif
4372 invoke_set_current_function_hook (fndecl);
4374 if (fndecl != NULL_TREE)
4376 DECL_STRUCT_FUNCTION (fndecl) = cfun;
4377 cfun->decl = fndecl;
4378 current_function_funcdef_no = get_next_funcdef_no ();
4380 result = DECL_RESULT (fndecl);
4381 if (!abstract_p && aggregate_value_p (result, fndecl))
4383 #ifdef PCC_STATIC_STRUCT_RETURN
4384 cfun->returns_pcc_struct = 1;
4385 #endif
4386 cfun->returns_struct = 1;
4389 cfun->stdarg = stdarg_p (fntype);
4391 /* Assume all registers in stdarg functions need to be saved. */
4392 cfun->va_list_gpr_size = VA_LIST_MAX_GPR_SIZE;
4393 cfun->va_list_fpr_size = VA_LIST_MAX_FPR_SIZE;
4395 /* ??? This could be set on a per-function basis by the front-end
4396 but is this worth the hassle? */
4397 cfun->can_throw_non_call_exceptions = flag_non_call_exceptions;
4401 /* This is like allocate_struct_function, but pushes a new cfun for FNDECL
4402 instead of just setting it. */
4404 void
4405 push_struct_function (tree fndecl)
4407 VEC_safe_push (function_p, heap, cfun_stack, cfun);
4408 allocate_struct_function (fndecl, false);
4411 /* Reset crtl and other non-struct-function variables to defaults as
4412 appropriate for emitting rtl at the start of a function. */
4414 static void
4415 prepare_function_start (void)
4417 gcc_assert (!crtl->emit.x_last_insn);
4418 init_temp_slots ();
4419 init_emit ();
4420 init_varasm_status ();
4421 init_expr ();
4422 default_rtl_profile ();
4424 if (flag_stack_usage)
4426 cfun->su = ggc_alloc_cleared_stack_usage ();
4427 cfun->su->static_stack_size = -1;
4430 cse_not_expected = ! optimize;
4432 /* Caller save not needed yet. */
4433 caller_save_needed = 0;
4435 /* We haven't done register allocation yet. */
4436 reg_renumber = 0;
4438 /* Indicate that we have not instantiated virtual registers yet. */
4439 virtuals_instantiated = 0;
4441 /* Indicate that we want CONCATs now. */
4442 generating_concat_p = 1;
4444 /* Indicate we have no need of a frame pointer yet. */
4445 frame_pointer_needed = 0;
4448 /* Initialize the rtl expansion mechanism so that we can do simple things
4449 like generate sequences. This is used to provide a context during global
4450 initialization of some passes. You must call expand_dummy_function_end
4451 to exit this context. */
4453 void
4454 init_dummy_function_start (void)
4456 gcc_assert (!in_dummy_function);
4457 in_dummy_function = true;
4458 push_struct_function (NULL_TREE);
4459 prepare_function_start ();
4462 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
4463 and initialize static variables for generating RTL for the statements
4464 of the function. */
4466 void
4467 init_function_start (tree subr)
4469 if (subr && DECL_STRUCT_FUNCTION (subr))
4470 set_cfun (DECL_STRUCT_FUNCTION (subr));
4471 else
4472 allocate_struct_function (subr, false);
4473 prepare_function_start ();
4475 /* Warn if this value is an aggregate type,
4476 regardless of which calling convention we are using for it. */
4477 if (AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
4478 warning (OPT_Waggregate_return, "function returns an aggregate");
4481 /* Make sure all values used by the optimization passes have sane defaults. */
4482 unsigned int
4483 init_function_for_compilation (void)
4485 reg_renumber = 0;
4486 return 0;
4489 struct rtl_opt_pass pass_init_function =
4492 RTL_PASS,
4493 "*init_function", /* name */
4494 NULL, /* gate */
4495 init_function_for_compilation, /* execute */
4496 NULL, /* sub */
4497 NULL, /* next */
4498 0, /* static_pass_number */
4499 TV_NONE, /* tv_id */
4500 0, /* properties_required */
4501 0, /* properties_provided */
4502 0, /* properties_destroyed */
4503 0, /* todo_flags_start */
4504 0 /* todo_flags_finish */
4509 void
4510 expand_main_function (void)
4512 #if (defined(INVOKE__main) \
4513 || (!defined(HAS_INIT_SECTION) \
4514 && !defined(INIT_SECTION_ASM_OP) \
4515 && !defined(INIT_ARRAY_SECTION_ASM_OP)))
4516 emit_library_call (init_one_libfunc (NAME__MAIN), LCT_NORMAL, VOIDmode, 0);
4517 #endif
4520 /* Expand code to initialize the stack_protect_guard. This is invoked at
4521 the beginning of a function to be protected. */
4523 #ifndef HAVE_stack_protect_set
4524 # define HAVE_stack_protect_set 0
4525 # define gen_stack_protect_set(x,y) (gcc_unreachable (), NULL_RTX)
4526 #endif
4528 void
4529 stack_protect_prologue (void)
4531 tree guard_decl = targetm.stack_protect_guard ();
4532 rtx x, y;
4534 x = expand_normal (crtl->stack_protect_guard);
4535 y = expand_normal (guard_decl);
4537 /* Allow the target to copy from Y to X without leaking Y into a
4538 register. */
4539 if (HAVE_stack_protect_set)
4541 rtx insn = gen_stack_protect_set (x, y);
4542 if (insn)
4544 emit_insn (insn);
4545 return;
4549 /* Otherwise do a straight move. */
4550 emit_move_insn (x, y);
4553 /* Expand code to verify the stack_protect_guard. This is invoked at
4554 the end of a function to be protected. */
4556 #ifndef HAVE_stack_protect_test
4557 # define HAVE_stack_protect_test 0
4558 # define gen_stack_protect_test(x, y, z) (gcc_unreachable (), NULL_RTX)
4559 #endif
4561 void
4562 stack_protect_epilogue (void)
4564 tree guard_decl = targetm.stack_protect_guard ();
4565 rtx label = gen_label_rtx ();
4566 rtx x, y, tmp;
4568 x = expand_normal (crtl->stack_protect_guard);
4569 y = expand_normal (guard_decl);
4571 /* Allow the target to compare Y with X without leaking either into
4572 a register. */
4573 switch (HAVE_stack_protect_test != 0)
4575 case 1:
4576 tmp = gen_stack_protect_test (x, y, label);
4577 if (tmp)
4579 emit_insn (tmp);
4580 break;
4582 /* FALLTHRU */
4584 default:
4585 emit_cmp_and_jump_insns (x, y, EQ, NULL_RTX, ptr_mode, 1, label);
4586 break;
4589 /* The noreturn predictor has been moved to the tree level. The rtl-level
4590 predictors estimate this branch about 20%, which isn't enough to get
4591 things moved out of line. Since this is the only extant case of adding
4592 a noreturn function at the rtl level, it doesn't seem worth doing ought
4593 except adding the prediction by hand. */
4594 tmp = get_last_insn ();
4595 if (JUMP_P (tmp))
4596 predict_insn_def (tmp, PRED_NORETURN, TAKEN);
4598 expand_expr_stmt (targetm.stack_protect_fail ());
4599 emit_label (label);
4602 /* Start the RTL for a new function, and set variables used for
4603 emitting RTL.
4604 SUBR is the FUNCTION_DECL node.
4605 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
4606 the function's parameters, which must be run at any return statement. */
4608 void
4609 expand_function_start (tree subr)
4611 /* Make sure volatile mem refs aren't considered
4612 valid operands of arithmetic insns. */
4613 init_recog_no_volatile ();
4615 crtl->profile
4616 = (profile_flag
4617 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
4619 crtl->limit_stack
4620 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
4622 /* Make the label for return statements to jump to. Do not special
4623 case machines with special return instructions -- they will be
4624 handled later during jump, ifcvt, or epilogue creation. */
4625 return_label = gen_label_rtx ();
4627 /* Initialize rtx used to return the value. */
4628 /* Do this before assign_parms so that we copy the struct value address
4629 before any library calls that assign parms might generate. */
4631 /* Decide whether to return the value in memory or in a register. */
4632 if (aggregate_value_p (DECL_RESULT (subr), subr))
4634 /* Returning something that won't go in a register. */
4635 rtx value_address = 0;
4637 #ifdef PCC_STATIC_STRUCT_RETURN
4638 if (cfun->returns_pcc_struct)
4640 int size = int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr)));
4641 value_address = assemble_static_space (size);
4643 else
4644 #endif
4646 rtx sv = targetm.calls.struct_value_rtx (TREE_TYPE (subr), 2);
4647 /* Expect to be passed the address of a place to store the value.
4648 If it is passed as an argument, assign_parms will take care of
4649 it. */
4650 if (sv)
4652 value_address = gen_reg_rtx (Pmode);
4653 emit_move_insn (value_address, sv);
4656 if (value_address)
4658 rtx x = value_address;
4659 if (!DECL_BY_REFERENCE (DECL_RESULT (subr)))
4661 x = gen_rtx_MEM (DECL_MODE (DECL_RESULT (subr)), x);
4662 set_mem_attributes (x, DECL_RESULT (subr), 1);
4664 SET_DECL_RTL (DECL_RESULT (subr), x);
4667 else if (DECL_MODE (DECL_RESULT (subr)) == VOIDmode)
4668 /* If return mode is void, this decl rtl should not be used. */
4669 SET_DECL_RTL (DECL_RESULT (subr), NULL_RTX);
4670 else
4672 /* Compute the return values into a pseudo reg, which we will copy
4673 into the true return register after the cleanups are done. */
4674 tree return_type = TREE_TYPE (DECL_RESULT (subr));
4675 if (TYPE_MODE (return_type) != BLKmode
4676 && targetm.calls.return_in_msb (return_type))
4677 /* expand_function_end will insert the appropriate padding in
4678 this case. Use the return value's natural (unpadded) mode
4679 within the function proper. */
4680 SET_DECL_RTL (DECL_RESULT (subr),
4681 gen_reg_rtx (TYPE_MODE (return_type)));
4682 else
4684 /* In order to figure out what mode to use for the pseudo, we
4685 figure out what the mode of the eventual return register will
4686 actually be, and use that. */
4687 rtx hard_reg = hard_function_value (return_type, subr, 0, 1);
4689 /* Structures that are returned in registers are not
4690 aggregate_value_p, so we may see a PARALLEL or a REG. */
4691 if (REG_P (hard_reg))
4692 SET_DECL_RTL (DECL_RESULT (subr),
4693 gen_reg_rtx (GET_MODE (hard_reg)));
4694 else
4696 gcc_assert (GET_CODE (hard_reg) == PARALLEL);
4697 SET_DECL_RTL (DECL_RESULT (subr), gen_group_rtx (hard_reg));
4701 /* Set DECL_REGISTER flag so that expand_function_end will copy the
4702 result to the real return register(s). */
4703 DECL_REGISTER (DECL_RESULT (subr)) = 1;
4706 /* Initialize rtx for parameters and local variables.
4707 In some cases this requires emitting insns. */
4708 assign_parms (subr);
4710 /* If function gets a static chain arg, store it. */
4711 if (cfun->static_chain_decl)
4713 tree parm = cfun->static_chain_decl;
4714 rtx local, chain, insn;
4716 local = gen_reg_rtx (Pmode);
4717 chain = targetm.calls.static_chain (current_function_decl, true);
4719 set_decl_incoming_rtl (parm, chain, false);
4720 SET_DECL_RTL (parm, local);
4721 mark_reg_pointer (local, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
4723 insn = emit_move_insn (local, chain);
4725 /* Mark the register as eliminable, similar to parameters. */
4726 if (MEM_P (chain)
4727 && reg_mentioned_p (arg_pointer_rtx, XEXP (chain, 0)))
4728 set_unique_reg_note (insn, REG_EQUIV, chain);
4731 /* If the function receives a non-local goto, then store the
4732 bits we need to restore the frame pointer. */
4733 if (cfun->nonlocal_goto_save_area)
4735 tree t_save;
4736 rtx r_save;
4738 /* ??? We need to do this save early. Unfortunately here is
4739 before the frame variable gets declared. Help out... */
4740 tree var = TREE_OPERAND (cfun->nonlocal_goto_save_area, 0);
4741 if (!DECL_RTL_SET_P (var))
4742 expand_decl (var);
4744 t_save = build4 (ARRAY_REF, ptr_type_node,
4745 cfun->nonlocal_goto_save_area,
4746 integer_zero_node, NULL_TREE, NULL_TREE);
4747 r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
4748 r_save = convert_memory_address (Pmode, r_save);
4750 emit_move_insn (r_save, targetm.builtin_setjmp_frame_value ());
4751 update_nonlocal_goto_save_area ();
4754 /* The following was moved from init_function_start.
4755 The move is supposed to make sdb output more accurate. */
4756 /* Indicate the beginning of the function body,
4757 as opposed to parm setup. */
4758 emit_note (NOTE_INSN_FUNCTION_BEG);
4760 gcc_assert (NOTE_P (get_last_insn ()));
4762 parm_birth_insn = get_last_insn ();
4764 if (crtl->profile)
4766 #ifdef PROFILE_HOOK
4767 PROFILE_HOOK (current_function_funcdef_no);
4768 #endif
4771 /* After the display initializations is where the stack checking
4772 probe should go. */
4773 if(flag_stack_check)
4774 stack_check_probe_note = emit_note (NOTE_INSN_DELETED);
4776 /* Make sure there is a line number after the function entry setup code. */
4777 force_next_line_note ();
4780 /* Undo the effects of init_dummy_function_start. */
4781 void
4782 expand_dummy_function_end (void)
4784 gcc_assert (in_dummy_function);
4786 /* End any sequences that failed to be closed due to syntax errors. */
4787 while (in_sequence_p ())
4788 end_sequence ();
4790 /* Outside function body, can't compute type's actual size
4791 until next function's body starts. */
4793 free_after_parsing (cfun);
4794 free_after_compilation (cfun);
4795 pop_cfun ();
4796 in_dummy_function = false;
4799 /* Call DOIT for each hard register used as a return value from
4800 the current function. */
4802 void
4803 diddle_return_value (void (*doit) (rtx, void *), void *arg)
4805 rtx outgoing = crtl->return_rtx;
4807 if (! outgoing)
4808 return;
4810 if (REG_P (outgoing))
4811 (*doit) (outgoing, arg);
4812 else if (GET_CODE (outgoing) == PARALLEL)
4814 int i;
4816 for (i = 0; i < XVECLEN (outgoing, 0); i++)
4818 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
4820 if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER)
4821 (*doit) (x, arg);
4826 static void
4827 do_clobber_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
4829 emit_clobber (reg);
4832 void
4833 clobber_return_register (void)
4835 diddle_return_value (do_clobber_return_reg, NULL);
4837 /* In case we do use pseudo to return value, clobber it too. */
4838 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
4840 tree decl_result = DECL_RESULT (current_function_decl);
4841 rtx decl_rtl = DECL_RTL (decl_result);
4842 if (REG_P (decl_rtl) && REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER)
4844 do_clobber_return_reg (decl_rtl, NULL);
4849 static void
4850 do_use_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
4852 emit_use (reg);
4855 static void
4856 use_return_register (void)
4858 diddle_return_value (do_use_return_reg, NULL);
4861 /* Possibly warn about unused parameters. */
4862 void
4863 do_warn_unused_parameter (tree fn)
4865 tree decl;
4867 for (decl = DECL_ARGUMENTS (fn);
4868 decl; decl = DECL_CHAIN (decl))
4869 if (!TREE_USED (decl) && TREE_CODE (decl) == PARM_DECL
4870 && DECL_NAME (decl) && !DECL_ARTIFICIAL (decl)
4871 && !TREE_NO_WARNING (decl))
4872 warning (OPT_Wunused_parameter, "unused parameter %q+D", decl);
4875 static GTY(()) rtx initial_trampoline;
4877 /* Generate RTL for the end of the current function. */
4879 void
4880 expand_function_end (void)
4882 rtx clobber_after;
4884 /* If arg_pointer_save_area was referenced only from a nested
4885 function, we will not have initialized it yet. Do that now. */
4886 if (arg_pointer_save_area && ! crtl->arg_pointer_save_area_init)
4887 get_arg_pointer_save_area ();
4889 /* If we are doing generic stack checking and this function makes calls,
4890 do a stack probe at the start of the function to ensure we have enough
4891 space for another stack frame. */
4892 if (flag_stack_check == GENERIC_STACK_CHECK)
4894 rtx insn, seq;
4896 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
4897 if (CALL_P (insn))
4899 rtx max_frame_size = GEN_INT (STACK_CHECK_MAX_FRAME_SIZE);
4900 start_sequence ();
4901 if (STACK_CHECK_MOVING_SP)
4902 anti_adjust_stack_and_probe (max_frame_size, true);
4903 else
4904 probe_stack_range (STACK_OLD_CHECK_PROTECT, max_frame_size);
4905 seq = get_insns ();
4906 end_sequence ();
4907 set_insn_locators (seq, prologue_locator);
4908 emit_insn_before (seq, stack_check_probe_note);
4909 break;
4913 /* End any sequences that failed to be closed due to syntax errors. */
4914 while (in_sequence_p ())
4915 end_sequence ();
4917 clear_pending_stack_adjust ();
4918 do_pending_stack_adjust ();
4920 /* Output a linenumber for the end of the function.
4921 SDB depends on this. */
4922 force_next_line_note ();
4923 set_curr_insn_source_location (input_location);
4925 /* Before the return label (if any), clobber the return
4926 registers so that they are not propagated live to the rest of
4927 the function. This can only happen with functions that drop
4928 through; if there had been a return statement, there would
4929 have either been a return rtx, or a jump to the return label.
4931 We delay actual code generation after the current_function_value_rtx
4932 is computed. */
4933 clobber_after = get_last_insn ();
4935 /* Output the label for the actual return from the function. */
4936 emit_label (return_label);
4938 if (targetm.except_unwind_info (&global_options) == UI_SJLJ)
4940 /* Let except.c know where it should emit the call to unregister
4941 the function context for sjlj exceptions. */
4942 if (flag_exceptions)
4943 sjlj_emit_function_exit_after (get_last_insn ());
4945 else
4947 /* We want to ensure that instructions that may trap are not
4948 moved into the epilogue by scheduling, because we don't
4949 always emit unwind information for the epilogue. */
4950 if (cfun->can_throw_non_call_exceptions)
4951 emit_insn (gen_blockage ());
4954 /* If this is an implementation of throw, do what's necessary to
4955 communicate between __builtin_eh_return and the epilogue. */
4956 expand_eh_return ();
4958 /* If scalar return value was computed in a pseudo-reg, or was a named
4959 return value that got dumped to the stack, copy that to the hard
4960 return register. */
4961 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
4963 tree decl_result = DECL_RESULT (current_function_decl);
4964 rtx decl_rtl = DECL_RTL (decl_result);
4966 if (REG_P (decl_rtl)
4967 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
4968 : DECL_REGISTER (decl_result))
4970 rtx real_decl_rtl = crtl->return_rtx;
4972 /* This should be set in assign_parms. */
4973 gcc_assert (REG_FUNCTION_VALUE_P (real_decl_rtl));
4975 /* If this is a BLKmode structure being returned in registers,
4976 then use the mode computed in expand_return. Note that if
4977 decl_rtl is memory, then its mode may have been changed,
4978 but that crtl->return_rtx has not. */
4979 if (GET_MODE (real_decl_rtl) == BLKmode)
4980 PUT_MODE (real_decl_rtl, GET_MODE (decl_rtl));
4982 /* If a non-BLKmode return value should be padded at the least
4983 significant end of the register, shift it left by the appropriate
4984 amount. BLKmode results are handled using the group load/store
4985 machinery. */
4986 if (TYPE_MODE (TREE_TYPE (decl_result)) != BLKmode
4987 && targetm.calls.return_in_msb (TREE_TYPE (decl_result)))
4989 emit_move_insn (gen_rtx_REG (GET_MODE (decl_rtl),
4990 REGNO (real_decl_rtl)),
4991 decl_rtl);
4992 shift_return_value (GET_MODE (decl_rtl), true, real_decl_rtl);
4994 /* If a named return value dumped decl_return to memory, then
4995 we may need to re-do the PROMOTE_MODE signed/unsigned
4996 extension. */
4997 else if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
4999 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (decl_result));
5000 promote_function_mode (TREE_TYPE (decl_result),
5001 GET_MODE (decl_rtl), &unsignedp,
5002 TREE_TYPE (current_function_decl), 1);
5004 convert_move (real_decl_rtl, decl_rtl, unsignedp);
5006 else if (GET_CODE (real_decl_rtl) == PARALLEL)
5008 /* If expand_function_start has created a PARALLEL for decl_rtl,
5009 move the result to the real return registers. Otherwise, do
5010 a group load from decl_rtl for a named return. */
5011 if (GET_CODE (decl_rtl) == PARALLEL)
5012 emit_group_move (real_decl_rtl, decl_rtl);
5013 else
5014 emit_group_load (real_decl_rtl, decl_rtl,
5015 TREE_TYPE (decl_result),
5016 int_size_in_bytes (TREE_TYPE (decl_result)));
5018 /* In the case of complex integer modes smaller than a word, we'll
5019 need to generate some non-trivial bitfield insertions. Do that
5020 on a pseudo and not the hard register. */
5021 else if (GET_CODE (decl_rtl) == CONCAT
5022 && GET_MODE_CLASS (GET_MODE (decl_rtl)) == MODE_COMPLEX_INT
5023 && GET_MODE_BITSIZE (GET_MODE (decl_rtl)) <= BITS_PER_WORD)
5025 int old_generating_concat_p;
5026 rtx tmp;
5028 old_generating_concat_p = generating_concat_p;
5029 generating_concat_p = 0;
5030 tmp = gen_reg_rtx (GET_MODE (decl_rtl));
5031 generating_concat_p = old_generating_concat_p;
5033 emit_move_insn (tmp, decl_rtl);
5034 emit_move_insn (real_decl_rtl, tmp);
5036 else
5037 emit_move_insn (real_decl_rtl, decl_rtl);
5041 /* If returning a structure, arrange to return the address of the value
5042 in a place where debuggers expect to find it.
5044 If returning a structure PCC style,
5045 the caller also depends on this value.
5046 And cfun->returns_pcc_struct is not necessarily set. */
5047 if (cfun->returns_struct
5048 || cfun->returns_pcc_struct)
5050 rtx value_address = DECL_RTL (DECL_RESULT (current_function_decl));
5051 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
5052 rtx outgoing;
5054 if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)))
5055 type = TREE_TYPE (type);
5056 else
5057 value_address = XEXP (value_address, 0);
5059 outgoing = targetm.calls.function_value (build_pointer_type (type),
5060 current_function_decl, true);
5062 /* Mark this as a function return value so integrate will delete the
5063 assignment and USE below when inlining this function. */
5064 REG_FUNCTION_VALUE_P (outgoing) = 1;
5066 /* The address may be ptr_mode and OUTGOING may be Pmode. */
5067 value_address = convert_memory_address (GET_MODE (outgoing),
5068 value_address);
5070 emit_move_insn (outgoing, value_address);
5072 /* Show return register used to hold result (in this case the address
5073 of the result. */
5074 crtl->return_rtx = outgoing;
5077 /* Emit the actual code to clobber return register. */
5079 rtx seq;
5081 start_sequence ();
5082 clobber_return_register ();
5083 seq = get_insns ();
5084 end_sequence ();
5086 emit_insn_after (seq, clobber_after);
5089 /* Output the label for the naked return from the function. */
5090 if (naked_return_label)
5091 emit_label (naked_return_label);
5093 /* @@@ This is a kludge. We want to ensure that instructions that
5094 may trap are not moved into the epilogue by scheduling, because
5095 we don't always emit unwind information for the epilogue. */
5096 if (cfun->can_throw_non_call_exceptions
5097 && targetm.except_unwind_info (&global_options) != UI_SJLJ)
5098 emit_insn (gen_blockage ());
5100 /* If stack protection is enabled for this function, check the guard. */
5101 if (crtl->stack_protect_guard)
5102 stack_protect_epilogue ();
5104 /* If we had calls to alloca, and this machine needs
5105 an accurate stack pointer to exit the function,
5106 insert some code to save and restore the stack pointer. */
5107 if (! EXIT_IGNORE_STACK
5108 && cfun->calls_alloca)
5110 rtx tem = 0;
5112 emit_stack_save (SAVE_FUNCTION, &tem, parm_birth_insn);
5113 emit_stack_restore (SAVE_FUNCTION, tem, NULL_RTX);
5116 /* ??? This should no longer be necessary since stupid is no longer with
5117 us, but there are some parts of the compiler (eg reload_combine, and
5118 sh mach_dep_reorg) that still try and compute their own lifetime info
5119 instead of using the general framework. */
5120 use_return_register ();
5124 get_arg_pointer_save_area (void)
5126 rtx ret = arg_pointer_save_area;
5128 if (! ret)
5130 ret = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
5131 arg_pointer_save_area = ret;
5134 if (! crtl->arg_pointer_save_area_init)
5136 rtx seq;
5138 /* Save the arg pointer at the beginning of the function. The
5139 generated stack slot may not be a valid memory address, so we
5140 have to check it and fix it if necessary. */
5141 start_sequence ();
5142 emit_move_insn (validize_mem (ret),
5143 crtl->args.internal_arg_pointer);
5144 seq = get_insns ();
5145 end_sequence ();
5147 push_topmost_sequence ();
5148 emit_insn_after (seq, entry_of_function ());
5149 pop_topmost_sequence ();
5151 crtl->arg_pointer_save_area_init = true;
5154 return ret;
5157 /* Add a list of INSNS to the hash HASHP, possibly allocating HASHP
5158 for the first time. */
5160 static void
5161 record_insns (rtx insns, rtx end, htab_t *hashp)
5163 rtx tmp;
5164 htab_t hash = *hashp;
5166 if (hash == NULL)
5167 *hashp = hash
5168 = htab_create_ggc (17, htab_hash_pointer, htab_eq_pointer, NULL);
5170 for (tmp = insns; tmp != end; tmp = NEXT_INSN (tmp))
5172 void **slot = htab_find_slot (hash, tmp, INSERT);
5173 gcc_assert (*slot == NULL);
5174 *slot = tmp;
5178 /* INSN has been duplicated or replaced by as COPY, perhaps by duplicating a
5179 basic block, splitting or peepholes. If INSN is a prologue or epilogue
5180 insn, then record COPY as well. */
5182 void
5183 maybe_copy_prologue_epilogue_insn (rtx insn, rtx copy)
5185 htab_t hash;
5186 void **slot;
5188 hash = epilogue_insn_hash;
5189 if (!hash || !htab_find (hash, insn))
5191 hash = prologue_insn_hash;
5192 if (!hash || !htab_find (hash, insn))
5193 return;
5196 slot = htab_find_slot (hash, copy, INSERT);
5197 gcc_assert (*slot == NULL);
5198 *slot = copy;
5201 /* Set the locator of the insn chain starting at INSN to LOC. */
5202 static void
5203 set_insn_locators (rtx insn, int loc)
5205 while (insn != NULL_RTX)
5207 if (INSN_P (insn))
5208 INSN_LOCATOR (insn) = loc;
5209 insn = NEXT_INSN (insn);
5213 /* Determine if any INSNs in HASH are, or are part of, INSN. Because
5214 we can be running after reorg, SEQUENCE rtl is possible. */
5216 static bool
5217 contains (const_rtx insn, htab_t hash)
5219 if (hash == NULL)
5220 return false;
5222 if (NONJUMP_INSN_P (insn) && GET_CODE (PATTERN (insn)) == SEQUENCE)
5224 int i;
5225 for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
5226 if (htab_find (hash, XVECEXP (PATTERN (insn), 0, i)))
5227 return true;
5228 return false;
5231 return htab_find (hash, insn) != NULL;
5235 prologue_epilogue_contains (const_rtx insn)
5237 if (contains (insn, prologue_insn_hash))
5238 return 1;
5239 if (contains (insn, epilogue_insn_hash))
5240 return 1;
5241 return 0;
5244 #ifdef HAVE_return
5245 /* Insert gen_return at the end of block BB. This also means updating
5246 block_for_insn appropriately. */
5248 static void
5249 emit_return_into_block (basic_block bb)
5251 emit_jump_insn_after (gen_return (), BB_END (bb));
5253 #endif /* HAVE_return */
5255 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
5256 this into place with notes indicating where the prologue ends and where
5257 the epilogue begins. Update the basic block information when possible. */
5259 static void
5260 thread_prologue_and_epilogue_insns (void)
5262 bool inserted;
5263 rtx seq ATTRIBUTE_UNUSED, epilogue_end ATTRIBUTE_UNUSED;
5264 edge entry_edge ATTRIBUTE_UNUSED;
5265 edge e;
5266 edge_iterator ei;
5268 rtl_profile_for_bb (ENTRY_BLOCK_PTR);
5270 inserted = false;
5271 seq = NULL_RTX;
5272 epilogue_end = NULL_RTX;
5274 /* Can't deal with multiple successors of the entry block at the
5275 moment. Function should always have at least one entry
5276 point. */
5277 gcc_assert (single_succ_p (ENTRY_BLOCK_PTR));
5278 entry_edge = single_succ_edge (ENTRY_BLOCK_PTR);
5280 if (flag_split_stack
5281 && (lookup_attribute ("no_split_stack", DECL_ATTRIBUTES (cfun->decl))
5282 == NULL))
5284 #ifndef HAVE_split_stack_prologue
5285 gcc_unreachable ();
5286 #else
5287 gcc_assert (HAVE_split_stack_prologue);
5289 start_sequence ();
5290 emit_insn (gen_split_stack_prologue ());
5291 seq = get_insns ();
5292 end_sequence ();
5294 record_insns (seq, NULL, &prologue_insn_hash);
5295 set_insn_locators (seq, prologue_locator);
5297 /* This relies on the fact that committing the edge insertion
5298 will look for basic blocks within the inserted instructions,
5299 which in turn relies on the fact that we are not in CFG
5300 layout mode here. */
5301 insert_insn_on_edge (seq, entry_edge);
5302 inserted = true;
5303 #endif
5306 #ifdef HAVE_prologue
5307 if (HAVE_prologue)
5309 start_sequence ();
5310 seq = gen_prologue ();
5311 emit_insn (seq);
5313 /* Insert an explicit USE for the frame pointer
5314 if the profiling is on and the frame pointer is required. */
5315 if (crtl->profile && frame_pointer_needed)
5316 emit_use (hard_frame_pointer_rtx);
5318 /* Retain a map of the prologue insns. */
5319 record_insns (seq, NULL, &prologue_insn_hash);
5320 emit_note (NOTE_INSN_PROLOGUE_END);
5322 /* Ensure that instructions are not moved into the prologue when
5323 profiling is on. The call to the profiling routine can be
5324 emitted within the live range of a call-clobbered register. */
5325 if (!targetm.profile_before_prologue () && crtl->profile)
5326 emit_insn (gen_blockage ());
5328 seq = get_insns ();
5329 end_sequence ();
5330 set_insn_locators (seq, prologue_locator);
5332 insert_insn_on_edge (seq, entry_edge);
5333 inserted = true;
5335 #endif
5337 /* If the exit block has no non-fake predecessors, we don't need
5338 an epilogue. */
5339 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
5340 if ((e->flags & EDGE_FAKE) == 0)
5341 break;
5342 if (e == NULL)
5343 goto epilogue_done;
5345 rtl_profile_for_bb (EXIT_BLOCK_PTR);
5346 #ifdef HAVE_return
5347 if (optimize && HAVE_return)
5349 /* If we're allowed to generate a simple return instruction,
5350 then by definition we don't need a full epilogue. Examine
5351 the block that falls through to EXIT. If it does not
5352 contain any code, examine its predecessors and try to
5353 emit (conditional) return instructions. */
5355 basic_block last;
5356 rtx label;
5358 e = find_fallthru_edge (EXIT_BLOCK_PTR->preds);
5359 if (e == NULL)
5360 goto epilogue_done;
5361 last = e->src;
5363 /* Verify that there are no active instructions in the last block. */
5364 label = BB_END (last);
5365 while (label && !LABEL_P (label))
5367 if (active_insn_p (label))
5368 break;
5369 label = PREV_INSN (label);
5372 if (BB_HEAD (last) == label && LABEL_P (label))
5374 edge_iterator ei2;
5376 for (ei2 = ei_start (last->preds); (e = ei_safe_edge (ei2)); )
5378 basic_block bb = e->src;
5379 rtx jump;
5381 if (bb == ENTRY_BLOCK_PTR)
5383 ei_next (&ei2);
5384 continue;
5387 jump = BB_END (bb);
5388 if (!JUMP_P (jump) || JUMP_LABEL (jump) != label)
5390 ei_next (&ei2);
5391 continue;
5394 /* If we have an unconditional jump, we can replace that
5395 with a simple return instruction. */
5396 if (simplejump_p (jump))
5398 emit_return_into_block (bb);
5399 delete_insn (jump);
5402 /* If we have a conditional jump, we can try to replace
5403 that with a conditional return instruction. */
5404 else if (condjump_p (jump))
5406 if (! redirect_jump (jump, 0, 0))
5408 ei_next (&ei2);
5409 continue;
5412 /* If this block has only one successor, it both jumps
5413 and falls through to the fallthru block, so we can't
5414 delete the edge. */
5415 if (single_succ_p (bb))
5417 ei_next (&ei2);
5418 continue;
5421 else
5423 ei_next (&ei2);
5424 continue;
5427 /* Fix up the CFG for the successful change we just made. */
5428 redirect_edge_succ (e, EXIT_BLOCK_PTR);
5431 /* Emit a return insn for the exit fallthru block. Whether
5432 this is still reachable will be determined later. */
5434 emit_barrier_after (BB_END (last));
5435 emit_return_into_block (last);
5436 epilogue_end = BB_END (last);
5437 single_succ_edge (last)->flags &= ~EDGE_FALLTHRU;
5438 goto epilogue_done;
5441 #endif
5443 /* A small fib -- epilogue is not yet completed, but we wish to re-use
5444 this marker for the splits of EH_RETURN patterns, and nothing else
5445 uses the flag in the meantime. */
5446 epilogue_completed = 1;
5448 #ifdef HAVE_eh_return
5449 /* Find non-fallthru edges that end with EH_RETURN instructions. On
5450 some targets, these get split to a special version of the epilogue
5451 code. In order to be able to properly annotate these with unwind
5452 info, try to split them now. If we get a valid split, drop an
5453 EPILOGUE_BEG note and mark the insns as epilogue insns. */
5454 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
5456 rtx prev, last, trial;
5458 if (e->flags & EDGE_FALLTHRU)
5459 continue;
5460 last = BB_END (e->src);
5461 if (!eh_returnjump_p (last))
5462 continue;
5464 prev = PREV_INSN (last);
5465 trial = try_split (PATTERN (last), last, 1);
5466 if (trial == last)
5467 continue;
5469 record_insns (NEXT_INSN (prev), NEXT_INSN (trial), &epilogue_insn_hash);
5470 emit_note_after (NOTE_INSN_EPILOGUE_BEG, prev);
5472 #endif
5474 /* Find the edge that falls through to EXIT. Other edges may exist
5475 due to RETURN instructions, but those don't need epilogues.
5476 There really shouldn't be a mixture -- either all should have
5477 been converted or none, however... */
5479 e = find_fallthru_edge (EXIT_BLOCK_PTR->preds);
5480 if (e == NULL)
5481 goto epilogue_done;
5483 #ifdef HAVE_epilogue
5484 if (HAVE_epilogue)
5486 start_sequence ();
5487 epilogue_end = emit_note (NOTE_INSN_EPILOGUE_BEG);
5488 seq = gen_epilogue ();
5489 if (seq)
5490 emit_jump_insn (seq);
5492 /* Retain a map of the epilogue insns. */
5493 record_insns (seq, NULL, &epilogue_insn_hash);
5494 set_insn_locators (seq, epilogue_locator);
5496 seq = get_insns ();
5497 end_sequence ();
5499 insert_insn_on_edge (seq, e);
5500 inserted = true;
5502 else
5503 #endif
5505 basic_block cur_bb;
5507 if (! next_active_insn (BB_END (e->src)))
5508 goto epilogue_done;
5509 /* We have a fall-through edge to the exit block, the source is not
5510 at the end of the function, and there will be an assembler epilogue
5511 at the end of the function.
5512 We can't use force_nonfallthru here, because that would try to
5513 use return. Inserting a jump 'by hand' is extremely messy, so
5514 we take advantage of cfg_layout_finalize using
5515 fixup_fallthru_exit_predecessor. */
5516 cfg_layout_initialize (0);
5517 FOR_EACH_BB (cur_bb)
5518 if (cur_bb->index >= NUM_FIXED_BLOCKS
5519 && cur_bb->next_bb->index >= NUM_FIXED_BLOCKS)
5520 cur_bb->aux = cur_bb->next_bb;
5521 cfg_layout_finalize ();
5523 epilogue_done:
5524 default_rtl_profile ();
5526 if (inserted)
5528 commit_edge_insertions ();
5530 /* The epilogue insns we inserted may cause the exit edge to no longer
5531 be fallthru. */
5532 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
5534 if (((e->flags & EDGE_FALLTHRU) != 0)
5535 && returnjump_p (BB_END (e->src)))
5536 e->flags &= ~EDGE_FALLTHRU;
5540 #ifdef HAVE_sibcall_epilogue
5541 /* Emit sibling epilogues before any sibling call sites. */
5542 for (ei = ei_start (EXIT_BLOCK_PTR->preds); (e = ei_safe_edge (ei)); )
5544 basic_block bb = e->src;
5545 rtx insn = BB_END (bb);
5547 if (!CALL_P (insn)
5548 || ! SIBLING_CALL_P (insn))
5550 ei_next (&ei);
5551 continue;
5554 start_sequence ();
5555 emit_note (NOTE_INSN_EPILOGUE_BEG);
5556 emit_insn (gen_sibcall_epilogue ());
5557 seq = get_insns ();
5558 end_sequence ();
5560 /* Retain a map of the epilogue insns. Used in life analysis to
5561 avoid getting rid of sibcall epilogue insns. Do this before we
5562 actually emit the sequence. */
5563 record_insns (seq, NULL, &epilogue_insn_hash);
5564 set_insn_locators (seq, epilogue_locator);
5566 emit_insn_before (seq, insn);
5567 ei_next (&ei);
5569 #endif
5571 #ifdef HAVE_epilogue
5572 if (epilogue_end)
5574 rtx insn, next;
5576 /* Similarly, move any line notes that appear after the epilogue.
5577 There is no need, however, to be quite so anal about the existence
5578 of such a note. Also possibly move
5579 NOTE_INSN_FUNCTION_BEG notes, as those can be relevant for debug
5580 info generation. */
5581 for (insn = epilogue_end; insn; insn = next)
5583 next = NEXT_INSN (insn);
5584 if (NOTE_P (insn)
5585 && (NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG))
5586 reorder_insns (insn, insn, PREV_INSN (epilogue_end));
5589 #endif
5591 /* Threading the prologue and epilogue changes the artificial refs
5592 in the entry and exit blocks. */
5593 epilogue_completed = 1;
5594 df_update_entry_exit_and_calls ();
5597 /* Reposition the prologue-end and epilogue-begin notes after
5598 instruction scheduling. */
5600 void
5601 reposition_prologue_and_epilogue_notes (void)
5603 #if defined (HAVE_prologue) || defined (HAVE_epilogue) \
5604 || defined (HAVE_sibcall_epilogue)
5605 /* Since the hash table is created on demand, the fact that it is
5606 non-null is a signal that it is non-empty. */
5607 if (prologue_insn_hash != NULL)
5609 size_t len = htab_elements (prologue_insn_hash);
5610 rtx insn, last = NULL, note = NULL;
5612 /* Scan from the beginning until we reach the last prologue insn. */
5613 /* ??? While we do have the CFG intact, there are two problems:
5614 (1) The prologue can contain loops (typically probing the stack),
5615 which means that the end of the prologue isn't in the first bb.
5616 (2) Sometimes the PROLOGUE_END note gets pushed into the next bb. */
5617 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
5619 if (NOTE_P (insn))
5621 if (NOTE_KIND (insn) == NOTE_INSN_PROLOGUE_END)
5622 note = insn;
5624 else if (contains (insn, prologue_insn_hash))
5626 last = insn;
5627 if (--len == 0)
5628 break;
5632 if (last)
5634 if (note == NULL)
5636 /* Scan forward looking for the PROLOGUE_END note. It should
5637 be right at the beginning of the block, possibly with other
5638 insn notes that got moved there. */
5639 for (note = NEXT_INSN (last); ; note = NEXT_INSN (note))
5641 if (NOTE_P (note)
5642 && NOTE_KIND (note) == NOTE_INSN_PROLOGUE_END)
5643 break;
5647 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
5648 if (LABEL_P (last))
5649 last = NEXT_INSN (last);
5650 reorder_insns (note, note, last);
5654 if (epilogue_insn_hash != NULL)
5656 edge_iterator ei;
5657 edge e;
5659 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
5661 rtx insn, first = NULL, note = NULL;
5662 basic_block bb = e->src;
5664 /* Scan from the beginning until we reach the first epilogue insn. */
5665 FOR_BB_INSNS (bb, insn)
5667 if (NOTE_P (insn))
5669 if (NOTE_KIND (insn) == NOTE_INSN_EPILOGUE_BEG)
5671 note = insn;
5672 if (first != NULL)
5673 break;
5676 else if (first == NULL && contains (insn, epilogue_insn_hash))
5678 first = insn;
5679 if (note != NULL)
5680 break;
5684 if (note)
5686 /* If the function has a single basic block, and no real
5687 epilogue insns (e.g. sibcall with no cleanup), the
5688 epilogue note can get scheduled before the prologue
5689 note. If we have frame related prologue insns, having
5690 them scanned during the epilogue will result in a crash.
5691 In this case re-order the epilogue note to just before
5692 the last insn in the block. */
5693 if (first == NULL)
5694 first = BB_END (bb);
5696 if (PREV_INSN (first) != note)
5697 reorder_insns (note, note, PREV_INSN (first));
5701 #endif /* HAVE_prologue or HAVE_epilogue */
5704 /* Returns the name of the current function. */
5705 const char *
5706 current_function_name (void)
5708 if (cfun == NULL)
5709 return "<none>";
5710 return lang_hooks.decl_printable_name (cfun->decl, 2);
5714 static unsigned int
5715 rest_of_handle_check_leaf_regs (void)
5717 #ifdef LEAF_REGISTERS
5718 current_function_uses_only_leaf_regs
5719 = optimize > 0 && only_leaf_regs_used () && leaf_function_p ();
5720 #endif
5721 return 0;
5724 /* Insert a TYPE into the used types hash table of CFUN. */
5726 static void
5727 used_types_insert_helper (tree type, struct function *func)
5729 if (type != NULL && func != NULL)
5731 void **slot;
5733 if (func->used_types_hash == NULL)
5734 func->used_types_hash = htab_create_ggc (37, htab_hash_pointer,
5735 htab_eq_pointer, NULL);
5736 slot = htab_find_slot (func->used_types_hash, type, INSERT);
5737 if (*slot == NULL)
5738 *slot = type;
5742 /* Given a type, insert it into the used hash table in cfun. */
5743 void
5744 used_types_insert (tree t)
5746 while (POINTER_TYPE_P (t) || TREE_CODE (t) == ARRAY_TYPE)
5747 if (TYPE_NAME (t))
5748 break;
5749 else
5750 t = TREE_TYPE (t);
5751 if (TREE_CODE (t) == ERROR_MARK)
5752 return;
5753 if (TYPE_NAME (t) == NULL_TREE
5754 || TYPE_NAME (t) == TYPE_NAME (TYPE_MAIN_VARIANT (t)))
5755 t = TYPE_MAIN_VARIANT (t);
5756 if (debug_info_level > DINFO_LEVEL_NONE)
5758 if (cfun)
5759 used_types_insert_helper (t, cfun);
5760 else
5761 /* So this might be a type referenced by a global variable.
5762 Record that type so that we can later decide to emit its debug
5763 information. */
5764 VEC_safe_push (tree, gc, types_used_by_cur_var_decl, t);
5768 /* Helper to Hash a struct types_used_by_vars_entry. */
5770 static hashval_t
5771 hash_types_used_by_vars_entry (const struct types_used_by_vars_entry *entry)
5773 gcc_assert (entry && entry->var_decl && entry->type);
5775 return iterative_hash_object (entry->type,
5776 iterative_hash_object (entry->var_decl, 0));
5779 /* Hash function of the types_used_by_vars_entry hash table. */
5781 hashval_t
5782 types_used_by_vars_do_hash (const void *x)
5784 const struct types_used_by_vars_entry *entry =
5785 (const struct types_used_by_vars_entry *) x;
5787 return hash_types_used_by_vars_entry (entry);
5790 /*Equality function of the types_used_by_vars_entry hash table. */
5793 types_used_by_vars_eq (const void *x1, const void *x2)
5795 const struct types_used_by_vars_entry *e1 =
5796 (const struct types_used_by_vars_entry *) x1;
5797 const struct types_used_by_vars_entry *e2 =
5798 (const struct types_used_by_vars_entry *)x2;
5800 return (e1->var_decl == e2->var_decl && e1->type == e2->type);
5803 /* Inserts an entry into the types_used_by_vars_hash hash table. */
5805 void
5806 types_used_by_var_decl_insert (tree type, tree var_decl)
5808 if (type != NULL && var_decl != NULL)
5810 void **slot;
5811 struct types_used_by_vars_entry e;
5812 e.var_decl = var_decl;
5813 e.type = type;
5814 if (types_used_by_vars_hash == NULL)
5815 types_used_by_vars_hash =
5816 htab_create_ggc (37, types_used_by_vars_do_hash,
5817 types_used_by_vars_eq, NULL);
5818 slot = htab_find_slot_with_hash (types_used_by_vars_hash, &e,
5819 hash_types_used_by_vars_entry (&e), INSERT);
5820 if (*slot == NULL)
5822 struct types_used_by_vars_entry *entry;
5823 entry = ggc_alloc_types_used_by_vars_entry ();
5824 entry->type = type;
5825 entry->var_decl = var_decl;
5826 *slot = entry;
5831 struct rtl_opt_pass pass_leaf_regs =
5834 RTL_PASS,
5835 "*leaf_regs", /* name */
5836 NULL, /* gate */
5837 rest_of_handle_check_leaf_regs, /* execute */
5838 NULL, /* sub */
5839 NULL, /* next */
5840 0, /* static_pass_number */
5841 TV_NONE, /* tv_id */
5842 0, /* properties_required */
5843 0, /* properties_provided */
5844 0, /* properties_destroyed */
5845 0, /* todo_flags_start */
5846 0 /* todo_flags_finish */
5850 static unsigned int
5851 rest_of_handle_thread_prologue_and_epilogue (void)
5853 if (optimize)
5854 cleanup_cfg (CLEANUP_EXPENSIVE);
5856 /* On some machines, the prologue and epilogue code, or parts thereof,
5857 can be represented as RTL. Doing so lets us schedule insns between
5858 it and the rest of the code and also allows delayed branch
5859 scheduling to operate in the epilogue. */
5860 thread_prologue_and_epilogue_insns ();
5862 /* The stack usage info is finalized during prologue expansion. */
5863 if (flag_stack_usage)
5864 output_stack_usage ();
5866 return 0;
5869 struct rtl_opt_pass pass_thread_prologue_and_epilogue =
5872 RTL_PASS,
5873 "pro_and_epilogue", /* name */
5874 NULL, /* gate */
5875 rest_of_handle_thread_prologue_and_epilogue, /* execute */
5876 NULL, /* sub */
5877 NULL, /* next */
5878 0, /* static_pass_number */
5879 TV_THREAD_PROLOGUE_AND_EPILOGUE, /* tv_id */
5880 0, /* properties_required */
5881 0, /* properties_provided */
5882 0, /* properties_destroyed */
5883 TODO_verify_flow, /* todo_flags_start */
5884 TODO_dump_func |
5885 TODO_df_verify |
5886 TODO_df_finish | TODO_verify_rtl_sharing |
5887 TODO_ggc_collect /* todo_flags_finish */
5892 /* This mini-pass fixes fall-out from SSA in asm statements that have
5893 in-out constraints. Say you start with
5895 orig = inout;
5896 asm ("": "+mr" (inout));
5897 use (orig);
5899 which is transformed very early to use explicit output and match operands:
5901 orig = inout;
5902 asm ("": "=mr" (inout) : "0" (inout));
5903 use (orig);
5905 Or, after SSA and copyprop,
5907 asm ("": "=mr" (inout_2) : "0" (inout_1));
5908 use (inout_1);
5910 Clearly inout_2 and inout_1 can't be coalesced easily anymore, as
5911 they represent two separate values, so they will get different pseudo
5912 registers during expansion. Then, since the two operands need to match
5913 per the constraints, but use different pseudo registers, reload can
5914 only register a reload for these operands. But reloads can only be
5915 satisfied by hardregs, not by memory, so we need a register for this
5916 reload, just because we are presented with non-matching operands.
5917 So, even though we allow memory for this operand, no memory can be
5918 used for it, just because the two operands don't match. This can
5919 cause reload failures on register-starved targets.
5921 So it's a symptom of reload not being able to use memory for reloads
5922 or, alternatively it's also a symptom of both operands not coming into
5923 reload as matching (in which case the pseudo could go to memory just
5924 fine, as the alternative allows it, and no reload would be necessary).
5925 We fix the latter problem here, by transforming
5927 asm ("": "=mr" (inout_2) : "0" (inout_1));
5929 back to
5931 inout_2 = inout_1;
5932 asm ("": "=mr" (inout_2) : "0" (inout_2)); */
5934 static void
5935 match_asm_constraints_1 (rtx insn, rtx *p_sets, int noutputs)
5937 int i;
5938 bool changed = false;
5939 rtx op = SET_SRC (p_sets[0]);
5940 int ninputs = ASM_OPERANDS_INPUT_LENGTH (op);
5941 rtvec inputs = ASM_OPERANDS_INPUT_VEC (op);
5942 bool *output_matched = XALLOCAVEC (bool, noutputs);
5944 memset (output_matched, 0, noutputs * sizeof (bool));
5945 for (i = 0; i < ninputs; i++)
5947 rtx input, output, insns;
5948 const char *constraint = ASM_OPERANDS_INPUT_CONSTRAINT (op, i);
5949 char *end;
5950 int match, j;
5952 if (*constraint == '%')
5953 constraint++;
5955 match = strtoul (constraint, &end, 10);
5956 if (end == constraint)
5957 continue;
5959 gcc_assert (match < noutputs);
5960 output = SET_DEST (p_sets[match]);
5961 input = RTVEC_ELT (inputs, i);
5962 /* Only do the transformation for pseudos. */
5963 if (! REG_P (output)
5964 || rtx_equal_p (output, input)
5965 || (GET_MODE (input) != VOIDmode
5966 && GET_MODE (input) != GET_MODE (output)))
5967 continue;
5969 /* We can't do anything if the output is also used as input,
5970 as we're going to overwrite it. */
5971 for (j = 0; j < ninputs; j++)
5972 if (reg_overlap_mentioned_p (output, RTVEC_ELT (inputs, j)))
5973 break;
5974 if (j != ninputs)
5975 continue;
5977 /* Avoid changing the same input several times. For
5978 asm ("" : "=mr" (out1), "=mr" (out2) : "0" (in), "1" (in));
5979 only change in once (to out1), rather than changing it
5980 first to out1 and afterwards to out2. */
5981 if (i > 0)
5983 for (j = 0; j < noutputs; j++)
5984 if (output_matched[j] && input == SET_DEST (p_sets[j]))
5985 break;
5986 if (j != noutputs)
5987 continue;
5989 output_matched[match] = true;
5991 start_sequence ();
5992 emit_move_insn (output, input);
5993 insns = get_insns ();
5994 end_sequence ();
5995 emit_insn_before (insns, insn);
5997 /* Now replace all mentions of the input with output. We can't
5998 just replace the occurrence in inputs[i], as the register might
5999 also be used in some other input (or even in an address of an
6000 output), which would mean possibly increasing the number of
6001 inputs by one (namely 'output' in addition), which might pose
6002 a too complicated problem for reload to solve. E.g. this situation:
6004 asm ("" : "=r" (output), "=m" (input) : "0" (input))
6006 Here 'input' is used in two occurrences as input (once for the
6007 input operand, once for the address in the second output operand).
6008 If we would replace only the occurrence of the input operand (to
6009 make the matching) we would be left with this:
6011 output = input
6012 asm ("" : "=r" (output), "=m" (input) : "0" (output))
6014 Now we suddenly have two different input values (containing the same
6015 value, but different pseudos) where we formerly had only one.
6016 With more complicated asms this might lead to reload failures
6017 which wouldn't have happen without this pass. So, iterate over
6018 all operands and replace all occurrences of the register used. */
6019 for (j = 0; j < noutputs; j++)
6020 if (!rtx_equal_p (SET_DEST (p_sets[j]), input)
6021 && reg_overlap_mentioned_p (input, SET_DEST (p_sets[j])))
6022 SET_DEST (p_sets[j]) = replace_rtx (SET_DEST (p_sets[j]),
6023 input, output);
6024 for (j = 0; j < ninputs; j++)
6025 if (reg_overlap_mentioned_p (input, RTVEC_ELT (inputs, j)))
6026 RTVEC_ELT (inputs, j) = replace_rtx (RTVEC_ELT (inputs, j),
6027 input, output);
6029 changed = true;
6032 if (changed)
6033 df_insn_rescan (insn);
6036 static unsigned
6037 rest_of_match_asm_constraints (void)
6039 basic_block bb;
6040 rtx insn, pat, *p_sets;
6041 int noutputs;
6043 if (!crtl->has_asm_statement)
6044 return 0;
6046 df_set_flags (DF_DEFER_INSN_RESCAN);
6047 FOR_EACH_BB (bb)
6049 FOR_BB_INSNS (bb, insn)
6051 if (!INSN_P (insn))
6052 continue;
6054 pat = PATTERN (insn);
6055 if (GET_CODE (pat) == PARALLEL)
6056 p_sets = &XVECEXP (pat, 0, 0), noutputs = XVECLEN (pat, 0);
6057 else if (GET_CODE (pat) == SET)
6058 p_sets = &PATTERN (insn), noutputs = 1;
6059 else
6060 continue;
6062 if (GET_CODE (*p_sets) == SET
6063 && GET_CODE (SET_SRC (*p_sets)) == ASM_OPERANDS)
6064 match_asm_constraints_1 (insn, p_sets, noutputs);
6068 return TODO_df_finish;
6071 struct rtl_opt_pass pass_match_asm_constraints =
6074 RTL_PASS,
6075 "asmcons", /* name */
6076 NULL, /* gate */
6077 rest_of_match_asm_constraints, /* execute */
6078 NULL, /* sub */
6079 NULL, /* next */
6080 0, /* static_pass_number */
6081 TV_NONE, /* tv_id */
6082 0, /* properties_required */
6083 0, /* properties_provided */
6084 0, /* properties_destroyed */
6085 0, /* todo_flags_start */
6086 TODO_dump_func /* todo_flags_finish */
6091 #include "gt-function.h"