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, 2011, 2012 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
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. */
38 #include "coretypes.h"
40 #include "rtl-error.h"
49 #include "hard-reg-set.h"
50 #include "insn-config.h"
53 #include "basic-block.h"
57 #include "langhooks.h"
59 #include "common/common-target.h"
61 #include "tree-pass.h"
66 #include "bb-reorder.h"
68 /* So we can assign to cfun in this file. */
71 #ifndef STACK_ALIGNMENT_NEEDED
72 #define STACK_ALIGNMENT_NEEDED 1
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. */
82 #define NAME__MAIN "__main"
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
92 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
94 /* Nonzero once virtual register instantiation has been done.
95 assign_stack_local uses frame_pointer_rtx when this is nonzero.
96 calls.c:emit_library_call_value_1 uses it to set up
97 post-instantiation libcalls. */
98 int virtuals_instantiated
;
100 /* Assign unique numbers to labels generated for profiling, debugging, etc. */
101 static GTY(()) int funcdef_no
;
103 /* These variables hold pointers to functions to create and destroy
104 target specific, per-function data structures. */
105 struct machine_function
* (*init_machine_status
) (void);
107 /* The currently compiled function. */
108 struct function
*cfun
= 0;
110 /* These hashes record the prologue and epilogue insns. */
111 static GTY((if_marked ("ggc_marked_p"), param_is (struct rtx_def
)))
112 htab_t prologue_insn_hash
;
113 static GTY((if_marked ("ggc_marked_p"), param_is (struct rtx_def
)))
114 htab_t epilogue_insn_hash
;
117 htab_t types_used_by_vars_hash
= NULL
;
118 VEC(tree
,gc
) *types_used_by_cur_var_decl
;
120 /* Forward declarations. */
122 static struct temp_slot
*find_temp_slot_from_address (rtx
);
123 static void pad_to_arg_alignment (struct args_size
*, int, struct args_size
*);
124 static void pad_below (struct args_size
*, enum machine_mode
, tree
);
125 static void reorder_blocks_1 (rtx
, tree
, VEC(tree
,heap
) **);
126 static int all_blocks (tree
, tree
*);
127 static tree
*get_block_vector (tree
, int *);
128 extern tree
debug_find_var_in_block_tree (tree
, tree
);
129 /* We always define `record_insns' even if it's not used so that we
130 can always export `prologue_epilogue_contains'. */
131 static void record_insns (rtx
, rtx
, htab_t
*) ATTRIBUTE_UNUSED
;
132 static bool contains (const_rtx
, htab_t
);
133 static void prepare_function_start (void);
134 static void do_clobber_return_reg (rtx
, void *);
135 static void do_use_return_reg (rtx
, void *);
136 static void set_insn_locations (rtx
, int) ATTRIBUTE_UNUSED
;
138 /* Stack of nested functions. */
139 /* Keep track of the cfun stack. */
141 typedef struct function
*function_p
;
143 DEF_VEC_P(function_p
);
144 DEF_VEC_ALLOC_P(function_p
,heap
);
145 static VEC(function_p
,heap
) *function_context_stack
;
147 /* Save the current context for compilation of a nested function.
148 This is called from language-specific code. */
151 push_function_context (void)
154 allocate_struct_function (NULL
, false);
156 VEC_safe_push (function_p
, heap
, function_context_stack
, cfun
);
160 /* Restore the last saved context, at the end of a nested function.
161 This function is called from language-specific code. */
164 pop_function_context (void)
166 struct function
*p
= VEC_pop (function_p
, function_context_stack
);
168 current_function_decl
= p
->decl
;
170 /* Reset variables that have known state during rtx generation. */
171 virtuals_instantiated
= 0;
172 generating_concat_p
= 1;
175 /* Clear out all parts of the state in F that can safely be discarded
176 after the function has been parsed, but not compiled, to let
177 garbage collection reclaim the memory. */
180 free_after_parsing (struct function
*f
)
185 /* Clear out all parts of the state in F that can safely be discarded
186 after the function has been compiled, to let garbage collection
187 reclaim the memory. */
190 free_after_compilation (struct function
*f
)
192 prologue_insn_hash
= NULL
;
193 epilogue_insn_hash
= NULL
;
195 free (crtl
->emit
.regno_pointer_align
);
197 memset (crtl
, 0, sizeof (struct rtl_data
));
202 regno_reg_rtx
= NULL
;
205 /* Return size needed for stack frame based on slots so far allocated.
206 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
207 the caller may have to do that. */
210 get_frame_size (void)
212 if (FRAME_GROWS_DOWNWARD
)
213 return -frame_offset
;
218 /* Issue an error message and return TRUE if frame OFFSET overflows in
219 the signed target pointer arithmetics for function FUNC. Otherwise
223 frame_offset_overflow (HOST_WIDE_INT offset
, tree func
)
225 unsigned HOST_WIDE_INT size
= FRAME_GROWS_DOWNWARD
? -offset
: offset
;
227 if (size
> ((unsigned HOST_WIDE_INT
) 1 << (GET_MODE_BITSIZE (Pmode
) - 1))
228 /* Leave room for the fixed part of the frame. */
229 - 64 * UNITS_PER_WORD
)
231 error_at (DECL_SOURCE_LOCATION (func
),
232 "total size of local objects too large");
239 /* Return stack slot alignment in bits for TYPE and MODE. */
242 get_stack_local_alignment (tree type
, enum machine_mode mode
)
244 unsigned int alignment
;
247 alignment
= BIGGEST_ALIGNMENT
;
249 alignment
= GET_MODE_ALIGNMENT (mode
);
251 /* Allow the frond-end to (possibly) increase the alignment of this
254 type
= lang_hooks
.types
.type_for_mode (mode
, 0);
256 return STACK_SLOT_ALIGNMENT (type
, mode
, alignment
);
259 /* Determine whether it is possible to fit a stack slot of size SIZE and
260 alignment ALIGNMENT into an area in the stack frame that starts at
261 frame offset START and has a length of LENGTH. If so, store the frame
262 offset to be used for the stack slot in *POFFSET and return true;
263 return false otherwise. This function will extend the frame size when
264 given a start/length pair that lies at the end of the frame. */
267 try_fit_stack_local (HOST_WIDE_INT start
, HOST_WIDE_INT length
,
268 HOST_WIDE_INT size
, unsigned int alignment
,
269 HOST_WIDE_INT
*poffset
)
271 HOST_WIDE_INT this_frame_offset
;
272 int frame_off
, frame_alignment
, frame_phase
;
274 /* Calculate how many bytes the start of local variables is off from
276 frame_alignment
= PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
;
277 frame_off
= STARTING_FRAME_OFFSET
% frame_alignment
;
278 frame_phase
= frame_off
? frame_alignment
- frame_off
: 0;
280 /* Round the frame offset to the specified alignment. */
282 /* We must be careful here, since FRAME_OFFSET might be negative and
283 division with a negative dividend isn't as well defined as we might
284 like. So we instead assume that ALIGNMENT is a power of two and
285 use logical operations which are unambiguous. */
286 if (FRAME_GROWS_DOWNWARD
)
288 = (FLOOR_ROUND (start
+ length
- size
- frame_phase
,
289 (unsigned HOST_WIDE_INT
) alignment
)
293 = (CEIL_ROUND (start
- frame_phase
,
294 (unsigned HOST_WIDE_INT
) alignment
)
297 /* See if it fits. If this space is at the edge of the frame,
298 consider extending the frame to make it fit. Our caller relies on
299 this when allocating a new slot. */
300 if (frame_offset
== start
&& this_frame_offset
< frame_offset
)
301 frame_offset
= this_frame_offset
;
302 else if (this_frame_offset
< start
)
304 else if (start
+ length
== frame_offset
305 && this_frame_offset
+ size
> start
+ length
)
306 frame_offset
= this_frame_offset
+ size
;
307 else if (this_frame_offset
+ size
> start
+ length
)
310 *poffset
= this_frame_offset
;
314 /* Create a new frame_space structure describing free space in the stack
315 frame beginning at START and ending at END, and chain it into the
316 function's frame_space_list. */
319 add_frame_space (HOST_WIDE_INT start
, HOST_WIDE_INT end
)
321 struct frame_space
*space
= ggc_alloc_frame_space ();
322 space
->next
= crtl
->frame_space_list
;
323 crtl
->frame_space_list
= space
;
324 space
->start
= start
;
325 space
->length
= end
- start
;
328 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
329 with machine mode MODE.
331 ALIGN controls the amount of alignment for the address of the slot:
332 0 means according to MODE,
333 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
334 -2 means use BITS_PER_UNIT,
335 positive specifies alignment boundary in bits.
337 KIND has ASLK_REDUCE_ALIGN bit set if it is OK to reduce
338 alignment and ASLK_RECORD_PAD bit set if we should remember
339 extra space we allocated for alignment purposes. When we are
340 called from assign_stack_temp_for_type, it is not set so we don't
341 track the same stack slot in two independent lists.
343 We do not round to stack_boundary here. */
346 assign_stack_local_1 (enum machine_mode mode
, HOST_WIDE_INT size
,
350 int bigend_correction
= 0;
351 HOST_WIDE_INT slot_offset
= 0, old_frame_offset
;
352 unsigned int alignment
, alignment_in_bits
;
356 alignment
= get_stack_local_alignment (NULL
, mode
);
357 alignment
/= BITS_PER_UNIT
;
359 else if (align
== -1)
361 alignment
= BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
;
362 size
= CEIL_ROUND (size
, alignment
);
364 else if (align
== -2)
365 alignment
= 1; /* BITS_PER_UNIT / BITS_PER_UNIT */
367 alignment
= align
/ BITS_PER_UNIT
;
369 alignment_in_bits
= alignment
* BITS_PER_UNIT
;
371 /* Ignore alignment if it exceeds MAX_SUPPORTED_STACK_ALIGNMENT. */
372 if (alignment_in_bits
> MAX_SUPPORTED_STACK_ALIGNMENT
)
374 alignment_in_bits
= MAX_SUPPORTED_STACK_ALIGNMENT
;
375 alignment
= alignment_in_bits
/ BITS_PER_UNIT
;
378 if (SUPPORTS_STACK_ALIGNMENT
)
380 if (crtl
->stack_alignment_estimated
< alignment_in_bits
)
382 if (!crtl
->stack_realign_processed
)
383 crtl
->stack_alignment_estimated
= alignment_in_bits
;
386 /* If stack is realigned and stack alignment value
387 hasn't been finalized, it is OK not to increase
388 stack_alignment_estimated. The bigger alignment
389 requirement is recorded in stack_alignment_needed
391 gcc_assert (!crtl
->stack_realign_finalized
);
392 if (!crtl
->stack_realign_needed
)
394 /* It is OK to reduce the alignment as long as the
395 requested size is 0 or the estimated stack
396 alignment >= mode alignment. */
397 gcc_assert ((kind
& ASLK_REDUCE_ALIGN
)
399 || (crtl
->stack_alignment_estimated
400 >= GET_MODE_ALIGNMENT (mode
)));
401 alignment_in_bits
= crtl
->stack_alignment_estimated
;
402 alignment
= alignment_in_bits
/ BITS_PER_UNIT
;
408 if (crtl
->stack_alignment_needed
< alignment_in_bits
)
409 crtl
->stack_alignment_needed
= alignment_in_bits
;
410 if (crtl
->max_used_stack_slot_alignment
< alignment_in_bits
)
411 crtl
->max_used_stack_slot_alignment
= alignment_in_bits
;
413 if (mode
!= BLKmode
|| size
!= 0)
415 if (kind
& ASLK_RECORD_PAD
)
417 struct frame_space
**psp
;
419 for (psp
= &crtl
->frame_space_list
; *psp
; psp
= &(*psp
)->next
)
421 struct frame_space
*space
= *psp
;
422 if (!try_fit_stack_local (space
->start
, space
->length
, size
,
423 alignment
, &slot_offset
))
426 if (slot_offset
> space
->start
)
427 add_frame_space (space
->start
, slot_offset
);
428 if (slot_offset
+ size
< space
->start
+ space
->length
)
429 add_frame_space (slot_offset
+ size
,
430 space
->start
+ space
->length
);
435 else if (!STACK_ALIGNMENT_NEEDED
)
437 slot_offset
= frame_offset
;
441 old_frame_offset
= frame_offset
;
443 if (FRAME_GROWS_DOWNWARD
)
445 frame_offset
-= size
;
446 try_fit_stack_local (frame_offset
, size
, size
, alignment
, &slot_offset
);
448 if (kind
& ASLK_RECORD_PAD
)
450 if (slot_offset
> frame_offset
)
451 add_frame_space (frame_offset
, slot_offset
);
452 if (slot_offset
+ size
< old_frame_offset
)
453 add_frame_space (slot_offset
+ size
, old_frame_offset
);
458 frame_offset
+= size
;
459 try_fit_stack_local (old_frame_offset
, size
, size
, alignment
, &slot_offset
);
461 if (kind
& ASLK_RECORD_PAD
)
463 if (slot_offset
> old_frame_offset
)
464 add_frame_space (old_frame_offset
, slot_offset
);
465 if (slot_offset
+ size
< frame_offset
)
466 add_frame_space (slot_offset
+ size
, frame_offset
);
471 /* On a big-endian machine, if we are allocating more space than we will use,
472 use the least significant bytes of those that are allocated. */
473 if (BYTES_BIG_ENDIAN
&& mode
!= BLKmode
&& GET_MODE_SIZE (mode
) < size
)
474 bigend_correction
= size
- GET_MODE_SIZE (mode
);
476 /* If we have already instantiated virtual registers, return the actual
477 address relative to the frame pointer. */
478 if (virtuals_instantiated
)
479 addr
= plus_constant (Pmode
, frame_pointer_rtx
,
481 (slot_offset
+ bigend_correction
482 + STARTING_FRAME_OFFSET
, Pmode
));
484 addr
= plus_constant (Pmode
, virtual_stack_vars_rtx
,
486 (slot_offset
+ bigend_correction
,
489 x
= gen_rtx_MEM (mode
, addr
);
490 set_mem_align (x
, alignment_in_bits
);
491 MEM_NOTRAP_P (x
) = 1;
494 = gen_rtx_EXPR_LIST (VOIDmode
, x
, stack_slot_list
);
496 if (frame_offset_overflow (frame_offset
, current_function_decl
))
502 /* Wrap up assign_stack_local_1 with last parameter as false. */
505 assign_stack_local (enum machine_mode mode
, HOST_WIDE_INT size
, int align
)
507 return assign_stack_local_1 (mode
, size
, align
, ASLK_RECORD_PAD
);
510 /* In order to evaluate some expressions, such as function calls returning
511 structures in memory, we need to temporarily allocate stack locations.
512 We record each allocated temporary in the following structure.
514 Associated with each temporary slot is a nesting level. When we pop up
515 one level, all temporaries associated with the previous level are freed.
516 Normally, all temporaries are freed after the execution of the statement
517 in which they were created. However, if we are inside a ({...}) grouping,
518 the result may be in a temporary and hence must be preserved. If the
519 result could be in a temporary, we preserve it if we can determine which
520 one it is in. If we cannot determine which temporary may contain the
521 result, all temporaries are preserved. A temporary is preserved by
522 pretending it was allocated at the previous nesting level. */
524 struct GTY(()) temp_slot
{
525 /* Points to next temporary slot. */
526 struct temp_slot
*next
;
527 /* Points to previous temporary slot. */
528 struct temp_slot
*prev
;
529 /* The rtx to used to reference the slot. */
531 /* The size, in units, of the slot. */
533 /* The type of the object in the slot, or zero if it doesn't correspond
534 to a type. We use this to determine whether a slot can be reused.
535 It can be reused if objects of the type of the new slot will always
536 conflict with objects of the type of the old slot. */
538 /* The alignment (in bits) of the slot. */
540 /* Nonzero if this temporary is currently in use. */
542 /* Nesting level at which this slot is being used. */
544 /* The offset of the slot from the frame_pointer, including extra space
545 for alignment. This info is for combine_temp_slots. */
546 HOST_WIDE_INT base_offset
;
547 /* The size of the slot, including extra space for alignment. This
548 info is for combine_temp_slots. */
549 HOST_WIDE_INT full_size
;
552 /* A table of addresses that represent a stack slot. The table is a mapping
553 from address RTXen to a temp slot. */
554 static GTY((param_is(struct temp_slot_address_entry
))) htab_t temp_slot_address_table
;
555 static size_t n_temp_slots_in_use
;
557 /* Entry for the above hash table. */
558 struct GTY(()) temp_slot_address_entry
{
561 struct temp_slot
*temp_slot
;
564 /* Removes temporary slot TEMP from LIST. */
567 cut_slot_from_list (struct temp_slot
*temp
, struct temp_slot
**list
)
570 temp
->next
->prev
= temp
->prev
;
572 temp
->prev
->next
= temp
->next
;
576 temp
->prev
= temp
->next
= NULL
;
579 /* Inserts temporary slot TEMP to LIST. */
582 insert_slot_to_list (struct temp_slot
*temp
, struct temp_slot
**list
)
586 (*list
)->prev
= temp
;
591 /* Returns the list of used temp slots at LEVEL. */
593 static struct temp_slot
**
594 temp_slots_at_level (int level
)
596 if (level
>= (int) VEC_length (temp_slot_p
, used_temp_slots
))
597 VEC_safe_grow_cleared (temp_slot_p
, gc
, used_temp_slots
, level
+ 1);
599 return &(VEC_address (temp_slot_p
, used_temp_slots
)[level
]);
602 /* Returns the maximal temporary slot level. */
605 max_slot_level (void)
607 if (!used_temp_slots
)
610 return VEC_length (temp_slot_p
, used_temp_slots
) - 1;
613 /* Moves temporary slot TEMP to LEVEL. */
616 move_slot_to_level (struct temp_slot
*temp
, int level
)
618 cut_slot_from_list (temp
, temp_slots_at_level (temp
->level
));
619 insert_slot_to_list (temp
, temp_slots_at_level (level
));
623 /* Make temporary slot TEMP available. */
626 make_slot_available (struct temp_slot
*temp
)
628 cut_slot_from_list (temp
, temp_slots_at_level (temp
->level
));
629 insert_slot_to_list (temp
, &avail_temp_slots
);
632 n_temp_slots_in_use
--;
635 /* Compute the hash value for an address -> temp slot mapping.
636 The value is cached on the mapping entry. */
638 temp_slot_address_compute_hash (struct temp_slot_address_entry
*t
)
640 int do_not_record
= 0;
641 return hash_rtx (t
->address
, GET_MODE (t
->address
),
642 &do_not_record
, NULL
, false);
645 /* Return the hash value for an address -> temp slot mapping. */
647 temp_slot_address_hash (const void *p
)
649 const struct temp_slot_address_entry
*t
;
650 t
= (const struct temp_slot_address_entry
*) p
;
654 /* Compare two address -> temp slot mapping entries. */
656 temp_slot_address_eq (const void *p1
, const void *p2
)
658 const struct temp_slot_address_entry
*t1
, *t2
;
659 t1
= (const struct temp_slot_address_entry
*) p1
;
660 t2
= (const struct temp_slot_address_entry
*) p2
;
661 return exp_equiv_p (t1
->address
, t2
->address
, 0, true);
664 /* Add ADDRESS as an alias of TEMP_SLOT to the addess -> temp slot mapping. */
666 insert_temp_slot_address (rtx address
, struct temp_slot
*temp_slot
)
669 struct temp_slot_address_entry
*t
= ggc_alloc_temp_slot_address_entry ();
670 t
->address
= address
;
671 t
->temp_slot
= temp_slot
;
672 t
->hash
= temp_slot_address_compute_hash (t
);
673 slot
= htab_find_slot_with_hash (temp_slot_address_table
, t
, t
->hash
, INSERT
);
677 /* Remove an address -> temp slot mapping entry if the temp slot is
678 not in use anymore. Callback for remove_unused_temp_slot_addresses. */
680 remove_unused_temp_slot_addresses_1 (void **slot
, void *data ATTRIBUTE_UNUSED
)
682 const struct temp_slot_address_entry
*t
;
683 t
= (const struct temp_slot_address_entry
*) *slot
;
684 if (! t
->temp_slot
->in_use
)
685 htab_clear_slot (temp_slot_address_table
, slot
);
689 /* Remove all mappings of addresses to unused temp slots. */
691 remove_unused_temp_slot_addresses (void)
693 /* Use quicker clearing if there aren't any active temp slots. */
694 if (n_temp_slots_in_use
)
695 htab_traverse (temp_slot_address_table
,
696 remove_unused_temp_slot_addresses_1
,
699 htab_empty (temp_slot_address_table
);
702 /* Find the temp slot corresponding to the object at address X. */
704 static struct temp_slot
*
705 find_temp_slot_from_address (rtx x
)
708 struct temp_slot_address_entry tmp
, *t
;
710 /* First try the easy way:
711 See if X exists in the address -> temp slot mapping. */
713 tmp
.temp_slot
= NULL
;
714 tmp
.hash
= temp_slot_address_compute_hash (&tmp
);
715 t
= (struct temp_slot_address_entry
*)
716 htab_find_with_hash (temp_slot_address_table
, &tmp
, tmp
.hash
);
720 /* If we have a sum involving a register, see if it points to a temp
722 if (GET_CODE (x
) == PLUS
&& REG_P (XEXP (x
, 0))
723 && (p
= find_temp_slot_from_address (XEXP (x
, 0))) != 0)
725 else if (GET_CODE (x
) == PLUS
&& REG_P (XEXP (x
, 1))
726 && (p
= find_temp_slot_from_address (XEXP (x
, 1))) != 0)
729 /* Last resort: Address is a virtual stack var address. */
730 if (GET_CODE (x
) == PLUS
731 && XEXP (x
, 0) == virtual_stack_vars_rtx
732 && CONST_INT_P (XEXP (x
, 1)))
735 for (i
= max_slot_level (); i
>= 0; i
--)
736 for (p
= *temp_slots_at_level (i
); p
; p
= p
->next
)
738 if (INTVAL (XEXP (x
, 1)) >= p
->base_offset
739 && INTVAL (XEXP (x
, 1)) < p
->base_offset
+ p
->full_size
)
747 /* Allocate a temporary stack slot and record it for possible later
750 MODE is the machine mode to be given to the returned rtx.
752 SIZE is the size in units of the space required. We do no rounding here
753 since assign_stack_local will do any required rounding.
755 TYPE is the type that will be used for the stack slot. */
758 assign_stack_temp_for_type (enum machine_mode mode
, HOST_WIDE_INT size
,
762 struct temp_slot
*p
, *best_p
= 0, *selected
= NULL
, **pp
;
765 /* If SIZE is -1 it means that somebody tried to allocate a temporary
766 of a variable size. */
767 gcc_assert (size
!= -1);
769 align
= get_stack_local_alignment (type
, mode
);
771 /* Try to find an available, already-allocated temporary of the proper
772 mode which meets the size and alignment requirements. Choose the
773 smallest one with the closest alignment.
775 If assign_stack_temp is called outside of the tree->rtl expansion,
776 we cannot reuse the stack slots (that may still refer to
777 VIRTUAL_STACK_VARS_REGNUM). */
778 if (!virtuals_instantiated
)
780 for (p
= avail_temp_slots
; p
; p
= p
->next
)
782 if (p
->align
>= align
&& p
->size
>= size
783 && GET_MODE (p
->slot
) == mode
784 && objects_must_conflict_p (p
->type
, type
)
785 && (best_p
== 0 || best_p
->size
> p
->size
786 || (best_p
->size
== p
->size
&& best_p
->align
> p
->align
)))
788 if (p
->align
== align
&& p
->size
== size
)
791 cut_slot_from_list (selected
, &avail_temp_slots
);
800 /* Make our best, if any, the one to use. */
804 cut_slot_from_list (selected
, &avail_temp_slots
);
806 /* If there are enough aligned bytes left over, make them into a new
807 temp_slot so that the extra bytes don't get wasted. Do this only
808 for BLKmode slots, so that we can be sure of the alignment. */
809 if (GET_MODE (best_p
->slot
) == BLKmode
)
811 int alignment
= best_p
->align
/ BITS_PER_UNIT
;
812 HOST_WIDE_INT rounded_size
= CEIL_ROUND (size
, alignment
);
814 if (best_p
->size
- rounded_size
>= alignment
)
816 p
= ggc_alloc_temp_slot ();
818 p
->size
= best_p
->size
- rounded_size
;
819 p
->base_offset
= best_p
->base_offset
+ rounded_size
;
820 p
->full_size
= best_p
->full_size
- rounded_size
;
821 p
->slot
= adjust_address_nv (best_p
->slot
, BLKmode
, rounded_size
);
822 p
->align
= best_p
->align
;
823 p
->type
= best_p
->type
;
824 insert_slot_to_list (p
, &avail_temp_slots
);
826 stack_slot_list
= gen_rtx_EXPR_LIST (VOIDmode
, p
->slot
,
829 best_p
->size
= rounded_size
;
830 best_p
->full_size
= rounded_size
;
835 /* If we still didn't find one, make a new temporary. */
838 HOST_WIDE_INT frame_offset_old
= frame_offset
;
840 p
= ggc_alloc_temp_slot ();
842 /* We are passing an explicit alignment request to assign_stack_local.
843 One side effect of that is assign_stack_local will not round SIZE
844 to ensure the frame offset remains suitably aligned.
846 So for requests which depended on the rounding of SIZE, we go ahead
847 and round it now. We also make sure ALIGNMENT is at least
848 BIGGEST_ALIGNMENT. */
849 gcc_assert (mode
!= BLKmode
|| align
== BIGGEST_ALIGNMENT
);
850 p
->slot
= assign_stack_local_1 (mode
,
860 /* The following slot size computation is necessary because we don't
861 know the actual size of the temporary slot until assign_stack_local
862 has performed all the frame alignment and size rounding for the
863 requested temporary. Note that extra space added for alignment
864 can be either above or below this stack slot depending on which
865 way the frame grows. We include the extra space if and only if it
866 is above this slot. */
867 if (FRAME_GROWS_DOWNWARD
)
868 p
->size
= frame_offset_old
- frame_offset
;
872 /* Now define the fields used by combine_temp_slots. */
873 if (FRAME_GROWS_DOWNWARD
)
875 p
->base_offset
= frame_offset
;
876 p
->full_size
= frame_offset_old
- frame_offset
;
880 p
->base_offset
= frame_offset_old
;
881 p
->full_size
= frame_offset
- frame_offset_old
;
890 p
->level
= temp_slot_level
;
891 n_temp_slots_in_use
++;
893 pp
= temp_slots_at_level (p
->level
);
894 insert_slot_to_list (p
, pp
);
895 insert_temp_slot_address (XEXP (p
->slot
, 0), p
);
897 /* Create a new MEM rtx to avoid clobbering MEM flags of old slots. */
898 slot
= gen_rtx_MEM (mode
, XEXP (p
->slot
, 0));
899 stack_slot_list
= gen_rtx_EXPR_LIST (VOIDmode
, slot
, stack_slot_list
);
901 /* If we know the alias set for the memory that will be used, use
902 it. If there's no TYPE, then we don't know anything about the
903 alias set for the memory. */
904 set_mem_alias_set (slot
, type
? get_alias_set (type
) : 0);
905 set_mem_align (slot
, align
);
907 /* If a type is specified, set the relevant flags. */
909 MEM_VOLATILE_P (slot
) = TYPE_VOLATILE (type
);
910 MEM_NOTRAP_P (slot
) = 1;
915 /* Allocate a temporary stack slot and record it for possible later
916 reuse. First two arguments are same as in preceding function. */
919 assign_stack_temp (enum machine_mode mode
, HOST_WIDE_INT size
)
921 return assign_stack_temp_for_type (mode
, size
, NULL_TREE
);
924 /* Assign a temporary.
925 If TYPE_OR_DECL is a decl, then we are doing it on behalf of the decl
926 and so that should be used in error messages. In either case, we
927 allocate of the given type.
928 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
929 it is 0 if a register is OK.
930 DONT_PROMOTE is 1 if we should not promote values in register
934 assign_temp (tree type_or_decl
, int memory_required
,
935 int dont_promote ATTRIBUTE_UNUSED
)
938 enum machine_mode mode
;
943 if (DECL_P (type_or_decl
))
944 decl
= type_or_decl
, type
= TREE_TYPE (decl
);
946 decl
= NULL
, type
= type_or_decl
;
948 mode
= TYPE_MODE (type
);
950 unsignedp
= TYPE_UNSIGNED (type
);
953 if (mode
== BLKmode
|| memory_required
)
955 HOST_WIDE_INT size
= int_size_in_bytes (type
);
958 /* Zero sized arrays are GNU C extension. Set size to 1 to avoid
959 problems with allocating the stack space. */
963 /* Unfortunately, we don't yet know how to allocate variable-sized
964 temporaries. However, sometimes we can find a fixed upper limit on
965 the size, so try that instead. */
967 size
= max_int_size_in_bytes (type
);
969 /* The size of the temporary may be too large to fit into an integer. */
970 /* ??? Not sure this should happen except for user silliness, so limit
971 this to things that aren't compiler-generated temporaries. The
972 rest of the time we'll die in assign_stack_temp_for_type. */
973 if (decl
&& size
== -1
974 && TREE_CODE (TYPE_SIZE_UNIT (type
)) == INTEGER_CST
)
976 error ("size of variable %q+D is too large", decl
);
980 tmp
= assign_stack_temp_for_type (mode
, size
, type
);
986 mode
= promote_mode (type
, mode
, &unsignedp
);
989 return gen_reg_rtx (mode
);
992 /* Combine temporary stack slots which are adjacent on the stack.
994 This allows for better use of already allocated stack space. This is only
995 done for BLKmode slots because we can be sure that we won't have alignment
996 problems in this case. */
999 combine_temp_slots (void)
1001 struct temp_slot
*p
, *q
, *next
, *next_q
;
1004 /* We can't combine slots, because the information about which slot
1005 is in which alias set will be lost. */
1006 if (flag_strict_aliasing
)
1009 /* If there are a lot of temp slots, don't do anything unless
1010 high levels of optimization. */
1011 if (! flag_expensive_optimizations
)
1012 for (p
= avail_temp_slots
, num_slots
= 0; p
; p
= p
->next
, num_slots
++)
1013 if (num_slots
> 100 || (num_slots
> 10 && optimize
== 0))
1016 for (p
= avail_temp_slots
; p
; p
= next
)
1022 if (GET_MODE (p
->slot
) != BLKmode
)
1025 for (q
= p
->next
; q
; q
= next_q
)
1031 if (GET_MODE (q
->slot
) != BLKmode
)
1034 if (p
->base_offset
+ p
->full_size
== q
->base_offset
)
1036 /* Q comes after P; combine Q into P. */
1038 p
->full_size
+= q
->full_size
;
1041 else if (q
->base_offset
+ q
->full_size
== p
->base_offset
)
1043 /* P comes after Q; combine P into Q. */
1045 q
->full_size
+= p
->full_size
;
1050 cut_slot_from_list (q
, &avail_temp_slots
);
1053 /* Either delete P or advance past it. */
1055 cut_slot_from_list (p
, &avail_temp_slots
);
1059 /* Indicate that NEW_RTX is an alternate way of referring to the temp
1060 slot that previously was known by OLD_RTX. */
1063 update_temp_slot_address (rtx old_rtx
, rtx new_rtx
)
1065 struct temp_slot
*p
;
1067 if (rtx_equal_p (old_rtx
, new_rtx
))
1070 p
= find_temp_slot_from_address (old_rtx
);
1072 /* If we didn't find one, see if both OLD_RTX is a PLUS. If so, and
1073 NEW_RTX is a register, see if one operand of the PLUS is a
1074 temporary location. If so, NEW_RTX points into it. Otherwise,
1075 if both OLD_RTX and NEW_RTX are a PLUS and if there is a register
1076 in common between them. If so, try a recursive call on those
1080 if (GET_CODE (old_rtx
) != PLUS
)
1083 if (REG_P (new_rtx
))
1085 update_temp_slot_address (XEXP (old_rtx
, 0), new_rtx
);
1086 update_temp_slot_address (XEXP (old_rtx
, 1), new_rtx
);
1089 else if (GET_CODE (new_rtx
) != PLUS
)
1092 if (rtx_equal_p (XEXP (old_rtx
, 0), XEXP (new_rtx
, 0)))
1093 update_temp_slot_address (XEXP (old_rtx
, 1), XEXP (new_rtx
, 1));
1094 else if (rtx_equal_p (XEXP (old_rtx
, 1), XEXP (new_rtx
, 0)))
1095 update_temp_slot_address (XEXP (old_rtx
, 0), XEXP (new_rtx
, 1));
1096 else if (rtx_equal_p (XEXP (old_rtx
, 0), XEXP (new_rtx
, 1)))
1097 update_temp_slot_address (XEXP (old_rtx
, 1), XEXP (new_rtx
, 0));
1098 else if (rtx_equal_p (XEXP (old_rtx
, 1), XEXP (new_rtx
, 1)))
1099 update_temp_slot_address (XEXP (old_rtx
, 0), XEXP (new_rtx
, 0));
1104 /* Otherwise add an alias for the temp's address. */
1105 insert_temp_slot_address (new_rtx
, p
);
1108 /* If X could be a reference to a temporary slot, mark that slot as
1109 belonging to the to one level higher than the current level. If X
1110 matched one of our slots, just mark that one. Otherwise, we can't
1111 easily predict which it is, so upgrade all of them.
1113 This is called when an ({...}) construct occurs and a statement
1114 returns a value in memory. */
1117 preserve_temp_slots (rtx x
)
1119 struct temp_slot
*p
= 0, *next
;
1124 /* If X is a register that is being used as a pointer, see if we have
1125 a temporary slot we know it points to. */
1126 if (REG_P (x
) && REG_POINTER (x
))
1127 p
= find_temp_slot_from_address (x
);
1129 /* If X is not in memory or is at a constant address, it cannot be in
1130 a temporary slot. */
1131 if (p
== 0 && (!MEM_P (x
) || CONSTANT_P (XEXP (x
, 0))))
1134 /* First see if we can find a match. */
1136 p
= find_temp_slot_from_address (XEXP (x
, 0));
1140 if (p
->level
== temp_slot_level
)
1141 move_slot_to_level (p
, temp_slot_level
- 1);
1145 /* Otherwise, preserve all non-kept slots at this level. */
1146 for (p
= *temp_slots_at_level (temp_slot_level
); p
; p
= next
)
1149 move_slot_to_level (p
, temp_slot_level
- 1);
1153 /* Free all temporaries used so far. This is normally called at the
1154 end of generating code for a statement. */
1157 free_temp_slots (void)
1159 struct temp_slot
*p
, *next
;
1160 bool some_available
= false;
1162 for (p
= *temp_slots_at_level (temp_slot_level
); p
; p
= next
)
1165 make_slot_available (p
);
1166 some_available
= true;
1171 remove_unused_temp_slot_addresses ();
1172 combine_temp_slots ();
1176 /* Push deeper into the nesting level for stack temporaries. */
1179 push_temp_slots (void)
1184 /* Pop a temporary nesting level. All slots in use in the current level
1188 pop_temp_slots (void)
1194 /* Initialize temporary slots. */
1197 init_temp_slots (void)
1199 /* We have not allocated any temporaries yet. */
1200 avail_temp_slots
= 0;
1201 used_temp_slots
= 0;
1202 temp_slot_level
= 0;
1203 n_temp_slots_in_use
= 0;
1205 /* Set up the table to map addresses to temp slots. */
1206 if (! temp_slot_address_table
)
1207 temp_slot_address_table
= htab_create_ggc (32,
1208 temp_slot_address_hash
,
1209 temp_slot_address_eq
,
1212 htab_empty (temp_slot_address_table
);
1215 /* Functions and data structures to keep track of the values hard regs
1216 had at the start of the function. */
1218 /* Private type used by get_hard_reg_initial_reg, get_hard_reg_initial_val,
1219 and has_hard_reg_initial_val.. */
1220 typedef struct GTY(()) initial_value_pair
{
1223 } initial_value_pair
;
1224 /* ??? This could be a VEC but there is currently no way to define an
1225 opaque VEC type. This could be worked around by defining struct
1226 initial_value_pair in function.h. */
1227 typedef struct GTY(()) initial_value_struct
{
1230 initial_value_pair
* GTY ((length ("%h.num_entries"))) entries
;
1231 } initial_value_struct
;
1233 /* If a pseudo represents an initial hard reg (or expression), return
1234 it, else return NULL_RTX. */
1237 get_hard_reg_initial_reg (rtx reg
)
1239 struct initial_value_struct
*ivs
= crtl
->hard_reg_initial_vals
;
1245 for (i
= 0; i
< ivs
->num_entries
; i
++)
1246 if (rtx_equal_p (ivs
->entries
[i
].pseudo
, reg
))
1247 return ivs
->entries
[i
].hard_reg
;
1252 /* Make sure that there's a pseudo register of mode MODE that stores the
1253 initial value of hard register REGNO. Return an rtx for such a pseudo. */
1256 get_hard_reg_initial_val (enum machine_mode mode
, unsigned int regno
)
1258 struct initial_value_struct
*ivs
;
1261 rv
= has_hard_reg_initial_val (mode
, regno
);
1265 ivs
= crtl
->hard_reg_initial_vals
;
1268 ivs
= ggc_alloc_initial_value_struct ();
1269 ivs
->num_entries
= 0;
1270 ivs
->max_entries
= 5;
1271 ivs
->entries
= ggc_alloc_vec_initial_value_pair (5);
1272 crtl
->hard_reg_initial_vals
= ivs
;
1275 if (ivs
->num_entries
>= ivs
->max_entries
)
1277 ivs
->max_entries
+= 5;
1278 ivs
->entries
= GGC_RESIZEVEC (initial_value_pair
, ivs
->entries
,
1282 ivs
->entries
[ivs
->num_entries
].hard_reg
= gen_rtx_REG (mode
, regno
);
1283 ivs
->entries
[ivs
->num_entries
].pseudo
= gen_reg_rtx (mode
);
1285 return ivs
->entries
[ivs
->num_entries
++].pseudo
;
1288 /* See if get_hard_reg_initial_val has been used to create a pseudo
1289 for the initial value of hard register REGNO in mode MODE. Return
1290 the associated pseudo if so, otherwise return NULL. */
1293 has_hard_reg_initial_val (enum machine_mode mode
, unsigned int regno
)
1295 struct initial_value_struct
*ivs
;
1298 ivs
= crtl
->hard_reg_initial_vals
;
1300 for (i
= 0; i
< ivs
->num_entries
; i
++)
1301 if (GET_MODE (ivs
->entries
[i
].hard_reg
) == mode
1302 && REGNO (ivs
->entries
[i
].hard_reg
) == regno
)
1303 return ivs
->entries
[i
].pseudo
;
1309 emit_initial_value_sets (void)
1311 struct initial_value_struct
*ivs
= crtl
->hard_reg_initial_vals
;
1319 for (i
= 0; i
< ivs
->num_entries
; i
++)
1320 emit_move_insn (ivs
->entries
[i
].pseudo
, ivs
->entries
[i
].hard_reg
);
1324 emit_insn_at_entry (seq
);
1328 /* Return the hardreg-pseudoreg initial values pair entry I and
1329 TRUE if I is a valid entry, or FALSE if I is not a valid entry. */
1331 initial_value_entry (int i
, rtx
*hreg
, rtx
*preg
)
1333 struct initial_value_struct
*ivs
= crtl
->hard_reg_initial_vals
;
1334 if (!ivs
|| i
>= ivs
->num_entries
)
1337 *hreg
= ivs
->entries
[i
].hard_reg
;
1338 *preg
= ivs
->entries
[i
].pseudo
;
1342 /* These routines are responsible for converting virtual register references
1343 to the actual hard register references once RTL generation is complete.
1345 The following four variables are used for communication between the
1346 routines. They contain the offsets of the virtual registers from their
1347 respective hard registers. */
1349 static int in_arg_offset
;
1350 static int var_offset
;
1351 static int dynamic_offset
;
1352 static int out_arg_offset
;
1353 static int cfa_offset
;
1355 /* In most machines, the stack pointer register is equivalent to the bottom
1358 #ifndef STACK_POINTER_OFFSET
1359 #define STACK_POINTER_OFFSET 0
1362 /* If not defined, pick an appropriate default for the offset of dynamically
1363 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
1364 REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
1366 #ifndef STACK_DYNAMIC_OFFSET
1368 /* The bottom of the stack points to the actual arguments. If
1369 REG_PARM_STACK_SPACE is defined, this includes the space for the register
1370 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
1371 stack space for register parameters is not pushed by the caller, but
1372 rather part of the fixed stack areas and hence not included in
1373 `crtl->outgoing_args_size'. Nevertheless, we must allow
1374 for it when allocating stack dynamic objects. */
1376 #if defined(REG_PARM_STACK_SPACE)
1377 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1378 ((ACCUMULATE_OUTGOING_ARGS \
1379 ? (crtl->outgoing_args_size \
1380 + (OUTGOING_REG_PARM_STACK_SPACE ((!(FNDECL) ? NULL_TREE : TREE_TYPE (FNDECL))) ? 0 \
1381 : REG_PARM_STACK_SPACE (FNDECL))) \
1382 : 0) + (STACK_POINTER_OFFSET))
1384 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1385 ((ACCUMULATE_OUTGOING_ARGS ? crtl->outgoing_args_size : 0) \
1386 + (STACK_POINTER_OFFSET))
1391 /* Given a piece of RTX and a pointer to a HOST_WIDE_INT, if the RTX
1392 is a virtual register, return the equivalent hard register and set the
1393 offset indirectly through the pointer. Otherwise, return 0. */
1396 instantiate_new_reg (rtx x
, HOST_WIDE_INT
*poffset
)
1399 HOST_WIDE_INT offset
;
1401 if (x
== virtual_incoming_args_rtx
)
1403 if (stack_realign_drap
)
1405 /* Replace virtual_incoming_args_rtx with internal arg
1406 pointer if DRAP is used to realign stack. */
1407 new_rtx
= crtl
->args
.internal_arg_pointer
;
1411 new_rtx
= arg_pointer_rtx
, offset
= in_arg_offset
;
1413 else if (x
== virtual_stack_vars_rtx
)
1414 new_rtx
= frame_pointer_rtx
, offset
= var_offset
;
1415 else if (x
== virtual_stack_dynamic_rtx
)
1416 new_rtx
= stack_pointer_rtx
, offset
= dynamic_offset
;
1417 else if (x
== virtual_outgoing_args_rtx
)
1418 new_rtx
= stack_pointer_rtx
, offset
= out_arg_offset
;
1419 else if (x
== virtual_cfa_rtx
)
1421 #ifdef FRAME_POINTER_CFA_OFFSET
1422 new_rtx
= frame_pointer_rtx
;
1424 new_rtx
= arg_pointer_rtx
;
1426 offset
= cfa_offset
;
1428 else if (x
== virtual_preferred_stack_boundary_rtx
)
1430 new_rtx
= GEN_INT (crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
);
1440 /* A subroutine of instantiate_virtual_regs, called via for_each_rtx.
1441 Instantiate any virtual registers present inside of *LOC. The expression
1442 is simplified, as much as possible, but is not to be considered "valid"
1443 in any sense implied by the target. If any change is made, set CHANGED
1447 instantiate_virtual_regs_in_rtx (rtx
*loc
, void *data
)
1449 HOST_WIDE_INT offset
;
1450 bool *changed
= (bool *) data
;
1457 switch (GET_CODE (x
))
1460 new_rtx
= instantiate_new_reg (x
, &offset
);
1463 *loc
= plus_constant (GET_MODE (x
), new_rtx
, offset
);
1470 new_rtx
= instantiate_new_reg (XEXP (x
, 0), &offset
);
1473 new_rtx
= plus_constant (GET_MODE (x
), new_rtx
, offset
);
1474 *loc
= simplify_gen_binary (PLUS
, GET_MODE (x
), new_rtx
, XEXP (x
, 1));
1480 /* FIXME -- from old code */
1481 /* If we have (plus (subreg (virtual-reg)) (const_int)), we know
1482 we can commute the PLUS and SUBREG because pointers into the
1483 frame are well-behaved. */
1493 /* A subroutine of instantiate_virtual_regs_in_insn. Return true if X
1494 matches the predicate for insn CODE operand OPERAND. */
1497 safe_insn_predicate (int code
, int operand
, rtx x
)
1499 return code
< 0 || insn_operand_matches ((enum insn_code
) code
, operand
, x
);
1502 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1503 registers present inside of insn. The result will be a valid insn. */
1506 instantiate_virtual_regs_in_insn (rtx insn
)
1508 HOST_WIDE_INT offset
;
1510 bool any_change
= false;
1511 rtx set
, new_rtx
, x
, seq
;
1513 /* There are some special cases to be handled first. */
1514 set
= single_set (insn
);
1517 /* We're allowed to assign to a virtual register. This is interpreted
1518 to mean that the underlying register gets assigned the inverse
1519 transformation. This is used, for example, in the handling of
1521 new_rtx
= instantiate_new_reg (SET_DEST (set
), &offset
);
1526 for_each_rtx (&SET_SRC (set
), instantiate_virtual_regs_in_rtx
, NULL
);
1527 x
= simplify_gen_binary (PLUS
, GET_MODE (new_rtx
), SET_SRC (set
),
1529 x
= force_operand (x
, new_rtx
);
1531 emit_move_insn (new_rtx
, x
);
1536 emit_insn_before (seq
, insn
);
1541 /* Handle a straight copy from a virtual register by generating a
1542 new add insn. The difference between this and falling through
1543 to the generic case is avoiding a new pseudo and eliminating a
1544 move insn in the initial rtl stream. */
1545 new_rtx
= instantiate_new_reg (SET_SRC (set
), &offset
);
1546 if (new_rtx
&& offset
!= 0
1547 && REG_P (SET_DEST (set
))
1548 && REGNO (SET_DEST (set
)) > LAST_VIRTUAL_REGISTER
)
1552 x
= expand_simple_binop (GET_MODE (SET_DEST (set
)), PLUS
,
1553 new_rtx
, GEN_INT (offset
), SET_DEST (set
),
1554 1, OPTAB_LIB_WIDEN
);
1555 if (x
!= SET_DEST (set
))
1556 emit_move_insn (SET_DEST (set
), x
);
1561 emit_insn_before (seq
, insn
);
1566 extract_insn (insn
);
1567 insn_code
= INSN_CODE (insn
);
1569 /* Handle a plus involving a virtual register by determining if the
1570 operands remain valid if they're modified in place. */
1571 if (GET_CODE (SET_SRC (set
)) == PLUS
1572 && recog_data
.n_operands
>= 3
1573 && recog_data
.operand_loc
[1] == &XEXP (SET_SRC (set
), 0)
1574 && recog_data
.operand_loc
[2] == &XEXP (SET_SRC (set
), 1)
1575 && CONST_INT_P (recog_data
.operand
[2])
1576 && (new_rtx
= instantiate_new_reg (recog_data
.operand
[1], &offset
)))
1578 offset
+= INTVAL (recog_data
.operand
[2]);
1580 /* If the sum is zero, then replace with a plain move. */
1582 && REG_P (SET_DEST (set
))
1583 && REGNO (SET_DEST (set
)) > LAST_VIRTUAL_REGISTER
)
1586 emit_move_insn (SET_DEST (set
), new_rtx
);
1590 emit_insn_before (seq
, insn
);
1595 x
= gen_int_mode (offset
, recog_data
.operand_mode
[2]);
1597 /* Using validate_change and apply_change_group here leaves
1598 recog_data in an invalid state. Since we know exactly what
1599 we want to check, do those two by hand. */
1600 if (safe_insn_predicate (insn_code
, 1, new_rtx
)
1601 && safe_insn_predicate (insn_code
, 2, x
))
1603 *recog_data
.operand_loc
[1] = recog_data
.operand
[1] = new_rtx
;
1604 *recog_data
.operand_loc
[2] = recog_data
.operand
[2] = x
;
1607 /* Fall through into the regular operand fixup loop in
1608 order to take care of operands other than 1 and 2. */
1614 extract_insn (insn
);
1615 insn_code
= INSN_CODE (insn
);
1618 /* In the general case, we expect virtual registers to appear only in
1619 operands, and then only as either bare registers or inside memories. */
1620 for (i
= 0; i
< recog_data
.n_operands
; ++i
)
1622 x
= recog_data
.operand
[i
];
1623 switch (GET_CODE (x
))
1627 rtx addr
= XEXP (x
, 0);
1628 bool changed
= false;
1630 for_each_rtx (&addr
, instantiate_virtual_regs_in_rtx
, &changed
);
1635 x
= replace_equiv_address (x
, addr
);
1636 /* It may happen that the address with the virtual reg
1637 was valid (e.g. based on the virtual stack reg, which might
1638 be acceptable to the predicates with all offsets), whereas
1639 the address now isn't anymore, for instance when the address
1640 is still offsetted, but the base reg isn't virtual-stack-reg
1641 anymore. Below we would do a force_reg on the whole operand,
1642 but this insn might actually only accept memory. Hence,
1643 before doing that last resort, try to reload the address into
1644 a register, so this operand stays a MEM. */
1645 if (!safe_insn_predicate (insn_code
, i
, x
))
1647 addr
= force_reg (GET_MODE (addr
), addr
);
1648 x
= replace_equiv_address (x
, addr
);
1653 emit_insn_before (seq
, insn
);
1658 new_rtx
= instantiate_new_reg (x
, &offset
);
1659 if (new_rtx
== NULL
)
1667 /* Careful, special mode predicates may have stuff in
1668 insn_data[insn_code].operand[i].mode that isn't useful
1669 to us for computing a new value. */
1670 /* ??? Recognize address_operand and/or "p" constraints
1671 to see if (plus new offset) is a valid before we put
1672 this through expand_simple_binop. */
1673 x
= expand_simple_binop (GET_MODE (x
), PLUS
, new_rtx
,
1674 GEN_INT (offset
), NULL_RTX
,
1675 1, OPTAB_LIB_WIDEN
);
1678 emit_insn_before (seq
, insn
);
1683 new_rtx
= instantiate_new_reg (SUBREG_REG (x
), &offset
);
1684 if (new_rtx
== NULL
)
1689 new_rtx
= expand_simple_binop (GET_MODE (new_rtx
), PLUS
, new_rtx
,
1690 GEN_INT (offset
), NULL_RTX
,
1691 1, OPTAB_LIB_WIDEN
);
1694 emit_insn_before (seq
, insn
);
1696 x
= simplify_gen_subreg (recog_data
.operand_mode
[i
], new_rtx
,
1697 GET_MODE (new_rtx
), SUBREG_BYTE (x
));
1705 /* At this point, X contains the new value for the operand.
1706 Validate the new value vs the insn predicate. Note that
1707 asm insns will have insn_code -1 here. */
1708 if (!safe_insn_predicate (insn_code
, i
, x
))
1713 gcc_assert (REGNO (x
) <= LAST_VIRTUAL_REGISTER
);
1714 x
= copy_to_reg (x
);
1717 x
= force_reg (insn_data
[insn_code
].operand
[i
].mode
, x
);
1721 emit_insn_before (seq
, insn
);
1724 *recog_data
.operand_loc
[i
] = recog_data
.operand
[i
] = x
;
1730 /* Propagate operand changes into the duplicates. */
1731 for (i
= 0; i
< recog_data
.n_dups
; ++i
)
1732 *recog_data
.dup_loc
[i
]
1733 = copy_rtx (recog_data
.operand
[(unsigned)recog_data
.dup_num
[i
]]);
1735 /* Force re-recognition of the instruction for validation. */
1736 INSN_CODE (insn
) = -1;
1739 if (asm_noperands (PATTERN (insn
)) >= 0)
1741 if (!check_asm_operands (PATTERN (insn
)))
1743 error_for_asm (insn
, "impossible constraint in %<asm%>");
1744 delete_insn_and_edges (insn
);
1749 if (recog_memoized (insn
) < 0)
1750 fatal_insn_not_found (insn
);
1754 /* Subroutine of instantiate_decls. Given RTL representing a decl,
1755 do any instantiation required. */
1758 instantiate_decl_rtl (rtx x
)
1765 /* If this is a CONCAT, recurse for the pieces. */
1766 if (GET_CODE (x
) == CONCAT
)
1768 instantiate_decl_rtl (XEXP (x
, 0));
1769 instantiate_decl_rtl (XEXP (x
, 1));
1773 /* If this is not a MEM, no need to do anything. Similarly if the
1774 address is a constant or a register that is not a virtual register. */
1779 if (CONSTANT_P (addr
)
1781 && (REGNO (addr
) < FIRST_VIRTUAL_REGISTER
1782 || REGNO (addr
) > LAST_VIRTUAL_REGISTER
)))
1785 for_each_rtx (&XEXP (x
, 0), instantiate_virtual_regs_in_rtx
, NULL
);
1788 /* Helper for instantiate_decls called via walk_tree: Process all decls
1789 in the given DECL_VALUE_EXPR. */
1792 instantiate_expr (tree
*tp
, int *walk_subtrees
, void *data ATTRIBUTE_UNUSED
)
1800 if (DECL_RTL_SET_P (t
))
1801 instantiate_decl_rtl (DECL_RTL (t
));
1802 if (TREE_CODE (t
) == PARM_DECL
&& DECL_NAMELESS (t
)
1803 && DECL_INCOMING_RTL (t
))
1804 instantiate_decl_rtl (DECL_INCOMING_RTL (t
));
1805 if ((TREE_CODE (t
) == VAR_DECL
1806 || TREE_CODE (t
) == RESULT_DECL
)
1807 && DECL_HAS_VALUE_EXPR_P (t
))
1809 tree v
= DECL_VALUE_EXPR (t
);
1810 walk_tree (&v
, instantiate_expr
, NULL
, NULL
);
1817 /* Subroutine of instantiate_decls: Process all decls in the given
1818 BLOCK node and all its subblocks. */
1821 instantiate_decls_1 (tree let
)
1825 for (t
= BLOCK_VARS (let
); t
; t
= DECL_CHAIN (t
))
1827 if (DECL_RTL_SET_P (t
))
1828 instantiate_decl_rtl (DECL_RTL (t
));
1829 if (TREE_CODE (t
) == VAR_DECL
&& DECL_HAS_VALUE_EXPR_P (t
))
1831 tree v
= DECL_VALUE_EXPR (t
);
1832 walk_tree (&v
, instantiate_expr
, NULL
, NULL
);
1836 /* Process all subblocks. */
1837 for (t
= BLOCK_SUBBLOCKS (let
); t
; t
= BLOCK_CHAIN (t
))
1838 instantiate_decls_1 (t
);
1841 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
1842 all virtual registers in their DECL_RTL's. */
1845 instantiate_decls (tree fndecl
)
1850 /* Process all parameters of the function. */
1851 for (decl
= DECL_ARGUMENTS (fndecl
); decl
; decl
= DECL_CHAIN (decl
))
1853 instantiate_decl_rtl (DECL_RTL (decl
));
1854 instantiate_decl_rtl (DECL_INCOMING_RTL (decl
));
1855 if (DECL_HAS_VALUE_EXPR_P (decl
))
1857 tree v
= DECL_VALUE_EXPR (decl
);
1858 walk_tree (&v
, instantiate_expr
, NULL
, NULL
);
1862 if ((decl
= DECL_RESULT (fndecl
))
1863 && TREE_CODE (decl
) == RESULT_DECL
)
1865 if (DECL_RTL_SET_P (decl
))
1866 instantiate_decl_rtl (DECL_RTL (decl
));
1867 if (DECL_HAS_VALUE_EXPR_P (decl
))
1869 tree v
= DECL_VALUE_EXPR (decl
);
1870 walk_tree (&v
, instantiate_expr
, NULL
, NULL
);
1874 /* Now process all variables defined in the function or its subblocks. */
1875 instantiate_decls_1 (DECL_INITIAL (fndecl
));
1877 FOR_EACH_LOCAL_DECL (cfun
, ix
, decl
)
1878 if (DECL_RTL_SET_P (decl
))
1879 instantiate_decl_rtl (DECL_RTL (decl
));
1880 VEC_free (tree
, gc
, cfun
->local_decls
);
1883 /* Pass through the INSNS of function FNDECL and convert virtual register
1884 references to hard register references. */
1887 instantiate_virtual_regs (void)
1891 /* Compute the offsets to use for this function. */
1892 in_arg_offset
= FIRST_PARM_OFFSET (current_function_decl
);
1893 var_offset
= STARTING_FRAME_OFFSET
;
1894 dynamic_offset
= STACK_DYNAMIC_OFFSET (current_function_decl
);
1895 out_arg_offset
= STACK_POINTER_OFFSET
;
1896 #ifdef FRAME_POINTER_CFA_OFFSET
1897 cfa_offset
= FRAME_POINTER_CFA_OFFSET (current_function_decl
);
1899 cfa_offset
= ARG_POINTER_CFA_OFFSET (current_function_decl
);
1902 /* Initialize recognition, indicating that volatile is OK. */
1905 /* Scan through all the insns, instantiating every virtual register still
1907 for (insn
= get_insns (); insn
; insn
= NEXT_INSN (insn
))
1910 /* These patterns in the instruction stream can never be recognized.
1911 Fortunately, they shouldn't contain virtual registers either. */
1912 if (GET_CODE (PATTERN (insn
)) == USE
1913 || GET_CODE (PATTERN (insn
)) == CLOBBER
1914 || GET_CODE (PATTERN (insn
)) == ADDR_VEC
1915 || GET_CODE (PATTERN (insn
)) == ADDR_DIFF_VEC
1916 || GET_CODE (PATTERN (insn
)) == ASM_INPUT
)
1918 else if (DEBUG_INSN_P (insn
))
1919 for_each_rtx (&INSN_VAR_LOCATION (insn
),
1920 instantiate_virtual_regs_in_rtx
, NULL
);
1922 instantiate_virtual_regs_in_insn (insn
);
1924 if (INSN_DELETED_P (insn
))
1927 for_each_rtx (®_NOTES (insn
), instantiate_virtual_regs_in_rtx
, NULL
);
1929 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
1931 for_each_rtx (&CALL_INSN_FUNCTION_USAGE (insn
),
1932 instantiate_virtual_regs_in_rtx
, NULL
);
1935 /* Instantiate the virtual registers in the DECLs for debugging purposes. */
1936 instantiate_decls (current_function_decl
);
1938 targetm
.instantiate_decls ();
1940 /* Indicate that, from now on, assign_stack_local should use
1941 frame_pointer_rtx. */
1942 virtuals_instantiated
= 1;
1947 struct rtl_opt_pass pass_instantiate_virtual_regs
=
1952 OPTGROUP_NONE
, /* optinfo_flags */
1954 instantiate_virtual_regs
, /* execute */
1957 0, /* static_pass_number */
1958 TV_NONE
, /* tv_id */
1959 0, /* properties_required */
1960 0, /* properties_provided */
1961 0, /* properties_destroyed */
1962 0, /* todo_flags_start */
1963 0 /* todo_flags_finish */
1968 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
1969 This means a type for which function calls must pass an address to the
1970 function or get an address back from the function.
1971 EXP may be a type node or an expression (whose type is tested). */
1974 aggregate_value_p (const_tree exp
, const_tree fntype
)
1976 const_tree type
= (TYPE_P (exp
)) ? exp
: TREE_TYPE (exp
);
1977 int i
, regno
, nregs
;
1981 switch (TREE_CODE (fntype
))
1985 tree fndecl
= get_callee_fndecl (fntype
);
1987 ? TREE_TYPE (fndecl
)
1988 : TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (fntype
))));
1992 fntype
= TREE_TYPE (fntype
);
1997 case IDENTIFIER_NODE
:
2001 /* We don't expect other tree types here. */
2005 if (VOID_TYPE_P (type
))
2008 /* If a record should be passed the same as its first (and only) member
2009 don't pass it as an aggregate. */
2010 if (TREE_CODE (type
) == RECORD_TYPE
&& TYPE_TRANSPARENT_AGGR (type
))
2011 return aggregate_value_p (first_field (type
), fntype
);
2013 /* If the front end has decided that this needs to be passed by
2014 reference, do so. */
2015 if ((TREE_CODE (exp
) == PARM_DECL
|| TREE_CODE (exp
) == RESULT_DECL
)
2016 && DECL_BY_REFERENCE (exp
))
2019 /* Function types that are TREE_ADDRESSABLE force return in memory. */
2020 if (fntype
&& TREE_ADDRESSABLE (fntype
))
2023 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
2024 and thus can't be returned in registers. */
2025 if (TREE_ADDRESSABLE (type
))
2028 if (flag_pcc_struct_return
&& AGGREGATE_TYPE_P (type
))
2031 if (targetm
.calls
.return_in_memory (type
, fntype
))
2034 /* Make sure we have suitable call-clobbered regs to return
2035 the value in; if not, we must return it in memory. */
2036 reg
= hard_function_value (type
, 0, fntype
, 0);
2038 /* If we have something other than a REG (e.g. a PARALLEL), then assume
2043 regno
= REGNO (reg
);
2044 nregs
= hard_regno_nregs
[regno
][TYPE_MODE (type
)];
2045 for (i
= 0; i
< nregs
; i
++)
2046 if (! call_used_regs
[regno
+ i
])
2052 /* Return true if we should assign DECL a pseudo register; false if it
2053 should live on the local stack. */
2056 use_register_for_decl (const_tree decl
)
2058 if (!targetm
.calls
.allocate_stack_slots_for_args())
2061 /* Honor volatile. */
2062 if (TREE_SIDE_EFFECTS (decl
))
2065 /* Honor addressability. */
2066 if (TREE_ADDRESSABLE (decl
))
2069 /* Only register-like things go in registers. */
2070 if (DECL_MODE (decl
) == BLKmode
)
2073 /* If -ffloat-store specified, don't put explicit float variables
2075 /* ??? This should be checked after DECL_ARTIFICIAL, but tree-ssa
2076 propagates values across these stores, and it probably shouldn't. */
2077 if (flag_float_store
&& FLOAT_TYPE_P (TREE_TYPE (decl
)))
2080 /* If we're not interested in tracking debugging information for
2081 this decl, then we can certainly put it in a register. */
2082 if (DECL_IGNORED_P (decl
))
2088 if (!DECL_REGISTER (decl
))
2091 switch (TREE_CODE (TREE_TYPE (decl
)))
2095 case QUAL_UNION_TYPE
:
2096 /* When not optimizing, disregard register keyword for variables with
2097 types containing methods, otherwise the methods won't be callable
2098 from the debugger. */
2099 if (TYPE_METHODS (TREE_TYPE (decl
)))
2109 /* Return true if TYPE should be passed by invisible reference. */
2112 pass_by_reference (CUMULATIVE_ARGS
*ca
, enum machine_mode mode
,
2113 tree type
, bool named_arg
)
2117 /* If this type contains non-trivial constructors, then it is
2118 forbidden for the middle-end to create any new copies. */
2119 if (TREE_ADDRESSABLE (type
))
2122 /* GCC post 3.4 passes *all* variable sized types by reference. */
2123 if (!TYPE_SIZE (type
) || TREE_CODE (TYPE_SIZE (type
)) != INTEGER_CST
)
2126 /* If a record type should be passed the same as its first (and only)
2127 member, use the type and mode of that member. */
2128 if (TREE_CODE (type
) == RECORD_TYPE
&& TYPE_TRANSPARENT_AGGR (type
))
2130 type
= TREE_TYPE (first_field (type
));
2131 mode
= TYPE_MODE (type
);
2135 return targetm
.calls
.pass_by_reference (pack_cumulative_args (ca
), mode
,
2139 /* Return true if TYPE, which is passed by reference, should be callee
2140 copied instead of caller copied. */
2143 reference_callee_copied (CUMULATIVE_ARGS
*ca
, enum machine_mode mode
,
2144 tree type
, bool named_arg
)
2146 if (type
&& TREE_ADDRESSABLE (type
))
2148 return targetm
.calls
.callee_copies (pack_cumulative_args (ca
), mode
, type
,
2152 /* Structures to communicate between the subroutines of assign_parms.
2153 The first holds data persistent across all parameters, the second
2154 is cleared out for each parameter. */
2156 struct assign_parm_data_all
2158 /* When INIT_CUMULATIVE_ARGS gets revamped, allocating CUMULATIVE_ARGS
2159 should become a job of the target or otherwise encapsulated. */
2160 CUMULATIVE_ARGS args_so_far_v
;
2161 cumulative_args_t args_so_far
;
2162 struct args_size stack_args_size
;
2163 tree function_result_decl
;
2165 rtx first_conversion_insn
;
2166 rtx last_conversion_insn
;
2167 HOST_WIDE_INT pretend_args_size
;
2168 HOST_WIDE_INT extra_pretend_bytes
;
2169 int reg_parm_stack_space
;
2172 struct assign_parm_data_one
2178 enum machine_mode nominal_mode
;
2179 enum machine_mode passed_mode
;
2180 enum machine_mode promoted_mode
;
2181 struct locate_and_pad_arg_data locate
;
2183 BOOL_BITFIELD named_arg
: 1;
2184 BOOL_BITFIELD passed_pointer
: 1;
2185 BOOL_BITFIELD on_stack
: 1;
2186 BOOL_BITFIELD loaded_in_reg
: 1;
2189 /* A subroutine of assign_parms. Initialize ALL. */
2192 assign_parms_initialize_all (struct assign_parm_data_all
*all
)
2194 tree fntype ATTRIBUTE_UNUSED
;
2196 memset (all
, 0, sizeof (*all
));
2198 fntype
= TREE_TYPE (current_function_decl
);
2200 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
2201 INIT_CUMULATIVE_INCOMING_ARGS (all
->args_so_far_v
, fntype
, NULL_RTX
);
2203 INIT_CUMULATIVE_ARGS (all
->args_so_far_v
, fntype
, NULL_RTX
,
2204 current_function_decl
, -1);
2206 all
->args_so_far
= pack_cumulative_args (&all
->args_so_far_v
);
2208 #ifdef REG_PARM_STACK_SPACE
2209 all
->reg_parm_stack_space
= REG_PARM_STACK_SPACE (current_function_decl
);
2213 /* If ARGS contains entries with complex types, split the entry into two
2214 entries of the component type. Return a new list of substitutions are
2215 needed, else the old list. */
2218 split_complex_args (VEC(tree
, heap
) **args
)
2223 FOR_EACH_VEC_ELT (tree
, *args
, i
, p
)
2225 tree type
= TREE_TYPE (p
);
2226 if (TREE_CODE (type
) == COMPLEX_TYPE
2227 && targetm
.calls
.split_complex_arg (type
))
2230 tree subtype
= TREE_TYPE (type
);
2231 bool addressable
= TREE_ADDRESSABLE (p
);
2233 /* Rewrite the PARM_DECL's type with its component. */
2235 TREE_TYPE (p
) = subtype
;
2236 DECL_ARG_TYPE (p
) = TREE_TYPE (DECL_ARG_TYPE (p
));
2237 DECL_MODE (p
) = VOIDmode
;
2238 DECL_SIZE (p
) = NULL
;
2239 DECL_SIZE_UNIT (p
) = NULL
;
2240 /* If this arg must go in memory, put it in a pseudo here.
2241 We can't allow it to go in memory as per normal parms,
2242 because the usual place might not have the imag part
2243 adjacent to the real part. */
2244 DECL_ARTIFICIAL (p
) = addressable
;
2245 DECL_IGNORED_P (p
) = addressable
;
2246 TREE_ADDRESSABLE (p
) = 0;
2248 VEC_replace (tree
, *args
, i
, p
);
2250 /* Build a second synthetic decl. */
2251 decl
= build_decl (EXPR_LOCATION (p
),
2252 PARM_DECL
, NULL_TREE
, subtype
);
2253 DECL_ARG_TYPE (decl
) = DECL_ARG_TYPE (p
);
2254 DECL_ARTIFICIAL (decl
) = addressable
;
2255 DECL_IGNORED_P (decl
) = addressable
;
2256 layout_decl (decl
, 0);
2257 VEC_safe_insert (tree
, heap
, *args
, ++i
, decl
);
2262 /* A subroutine of assign_parms. Adjust the parameter list to incorporate
2263 the hidden struct return argument, and (abi willing) complex args.
2264 Return the new parameter list. */
2266 static VEC(tree
, heap
) *
2267 assign_parms_augmented_arg_list (struct assign_parm_data_all
*all
)
2269 tree fndecl
= current_function_decl
;
2270 tree fntype
= TREE_TYPE (fndecl
);
2271 VEC(tree
, heap
) *fnargs
= NULL
;
2274 for (arg
= DECL_ARGUMENTS (fndecl
); arg
; arg
= DECL_CHAIN (arg
))
2275 VEC_safe_push (tree
, heap
, fnargs
, arg
);
2277 all
->orig_fnargs
= DECL_ARGUMENTS (fndecl
);
2279 /* If struct value address is treated as the first argument, make it so. */
2280 if (aggregate_value_p (DECL_RESULT (fndecl
), fndecl
)
2281 && ! cfun
->returns_pcc_struct
2282 && targetm
.calls
.struct_value_rtx (TREE_TYPE (fndecl
), 1) == 0)
2284 tree type
= build_pointer_type (TREE_TYPE (fntype
));
2287 decl
= build_decl (DECL_SOURCE_LOCATION (fndecl
),
2288 PARM_DECL
, get_identifier (".result_ptr"), type
);
2289 DECL_ARG_TYPE (decl
) = type
;
2290 DECL_ARTIFICIAL (decl
) = 1;
2291 DECL_NAMELESS (decl
) = 1;
2292 TREE_CONSTANT (decl
) = 1;
2294 DECL_CHAIN (decl
) = all
->orig_fnargs
;
2295 all
->orig_fnargs
= decl
;
2296 VEC_safe_insert (tree
, heap
, fnargs
, 0, decl
);
2298 all
->function_result_decl
= decl
;
2301 /* If the target wants to split complex arguments into scalars, do so. */
2302 if (targetm
.calls
.split_complex_arg
)
2303 split_complex_args (&fnargs
);
2308 /* A subroutine of assign_parms. Examine PARM and pull out type and mode
2309 data for the parameter. Incorporate ABI specifics such as pass-by-
2310 reference and type promotion. */
2313 assign_parm_find_data_types (struct assign_parm_data_all
*all
, tree parm
,
2314 struct assign_parm_data_one
*data
)
2316 tree nominal_type
, passed_type
;
2317 enum machine_mode nominal_mode
, passed_mode
, promoted_mode
;
2320 memset (data
, 0, sizeof (*data
));
2322 /* NAMED_ARG is a misnomer. We really mean 'non-variadic'. */
2324 data
->named_arg
= 1; /* No variadic parms. */
2325 else if (DECL_CHAIN (parm
))
2326 data
->named_arg
= 1; /* Not the last non-variadic parm. */
2327 else if (targetm
.calls
.strict_argument_naming (all
->args_so_far
))
2328 data
->named_arg
= 1; /* Only variadic ones are unnamed. */
2330 data
->named_arg
= 0; /* Treat as variadic. */
2332 nominal_type
= TREE_TYPE (parm
);
2333 passed_type
= DECL_ARG_TYPE (parm
);
2335 /* Look out for errors propagating this far. Also, if the parameter's
2336 type is void then its value doesn't matter. */
2337 if (TREE_TYPE (parm
) == error_mark_node
2338 /* This can happen after weird syntax errors
2339 or if an enum type is defined among the parms. */
2340 || TREE_CODE (parm
) != PARM_DECL
2341 || passed_type
== NULL
2342 || VOID_TYPE_P (nominal_type
))
2344 nominal_type
= passed_type
= void_type_node
;
2345 nominal_mode
= passed_mode
= promoted_mode
= VOIDmode
;
2349 /* Find mode of arg as it is passed, and mode of arg as it should be
2350 during execution of this function. */
2351 passed_mode
= TYPE_MODE (passed_type
);
2352 nominal_mode
= TYPE_MODE (nominal_type
);
2354 /* If the parm is to be passed as a transparent union or record, use the
2355 type of the first field for the tests below. We have already verified
2356 that the modes are the same. */
2357 if ((TREE_CODE (passed_type
) == UNION_TYPE
2358 || TREE_CODE (passed_type
) == RECORD_TYPE
)
2359 && TYPE_TRANSPARENT_AGGR (passed_type
))
2360 passed_type
= TREE_TYPE (first_field (passed_type
));
2362 /* See if this arg was passed by invisible reference. */
2363 if (pass_by_reference (&all
->args_so_far_v
, passed_mode
,
2364 passed_type
, data
->named_arg
))
2366 passed_type
= nominal_type
= build_pointer_type (passed_type
);
2367 data
->passed_pointer
= true;
2368 passed_mode
= nominal_mode
= Pmode
;
2371 /* Find mode as it is passed by the ABI. */
2372 unsignedp
= TYPE_UNSIGNED (passed_type
);
2373 promoted_mode
= promote_function_mode (passed_type
, passed_mode
, &unsignedp
,
2374 TREE_TYPE (current_function_decl
), 0);
2377 data
->nominal_type
= nominal_type
;
2378 data
->passed_type
= passed_type
;
2379 data
->nominal_mode
= nominal_mode
;
2380 data
->passed_mode
= passed_mode
;
2381 data
->promoted_mode
= promoted_mode
;
2384 /* A subroutine of assign_parms. Invoke setup_incoming_varargs. */
2387 assign_parms_setup_varargs (struct assign_parm_data_all
*all
,
2388 struct assign_parm_data_one
*data
, bool no_rtl
)
2390 int varargs_pretend_bytes
= 0;
2392 targetm
.calls
.setup_incoming_varargs (all
->args_so_far
,
2393 data
->promoted_mode
,
2395 &varargs_pretend_bytes
, no_rtl
);
2397 /* If the back-end has requested extra stack space, record how much is
2398 needed. Do not change pretend_args_size otherwise since it may be
2399 nonzero from an earlier partial argument. */
2400 if (varargs_pretend_bytes
> 0)
2401 all
->pretend_args_size
= varargs_pretend_bytes
;
2404 /* A subroutine of assign_parms. Set DATA->ENTRY_PARM corresponding to
2405 the incoming location of the current parameter. */
2408 assign_parm_find_entry_rtl (struct assign_parm_data_all
*all
,
2409 struct assign_parm_data_one
*data
)
2411 HOST_WIDE_INT pretend_bytes
= 0;
2415 if (data
->promoted_mode
== VOIDmode
)
2417 data
->entry_parm
= data
->stack_parm
= const0_rtx
;
2421 entry_parm
= targetm
.calls
.function_incoming_arg (all
->args_so_far
,
2422 data
->promoted_mode
,
2426 if (entry_parm
== 0)
2427 data
->promoted_mode
= data
->passed_mode
;
2429 /* Determine parm's home in the stack, in case it arrives in the stack
2430 or we should pretend it did. Compute the stack position and rtx where
2431 the argument arrives and its size.
2433 There is one complexity here: If this was a parameter that would
2434 have been passed in registers, but wasn't only because it is
2435 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
2436 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
2437 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of 0
2438 as it was the previous time. */
2439 in_regs
= entry_parm
!= 0;
2440 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2443 if (!in_regs
&& !data
->named_arg
)
2445 if (targetm
.calls
.pretend_outgoing_varargs_named (all
->args_so_far
))
2448 tem
= targetm
.calls
.function_incoming_arg (all
->args_so_far
,
2449 data
->promoted_mode
,
2450 data
->passed_type
, true);
2451 in_regs
= tem
!= NULL
;
2455 /* If this parameter was passed both in registers and in the stack, use
2456 the copy on the stack. */
2457 if (targetm
.calls
.must_pass_in_stack (data
->promoted_mode
,
2465 partial
= targetm
.calls
.arg_partial_bytes (all
->args_so_far
,
2466 data
->promoted_mode
,
2469 data
->partial
= partial
;
2471 /* The caller might already have allocated stack space for the
2472 register parameters. */
2473 if (partial
!= 0 && all
->reg_parm_stack_space
== 0)
2475 /* Part of this argument is passed in registers and part
2476 is passed on the stack. Ask the prologue code to extend
2477 the stack part so that we can recreate the full value.
2479 PRETEND_BYTES is the size of the registers we need to store.
2480 CURRENT_FUNCTION_PRETEND_ARGS_SIZE is the amount of extra
2481 stack space that the prologue should allocate.
2483 Internally, gcc assumes that the argument pointer is aligned
2484 to STACK_BOUNDARY bits. This is used both for alignment
2485 optimizations (see init_emit) and to locate arguments that are
2486 aligned to more than PARM_BOUNDARY bits. We must preserve this
2487 invariant by rounding CURRENT_FUNCTION_PRETEND_ARGS_SIZE up to
2488 a stack boundary. */
2490 /* We assume at most one partial arg, and it must be the first
2491 argument on the stack. */
2492 gcc_assert (!all
->extra_pretend_bytes
&& !all
->pretend_args_size
);
2494 pretend_bytes
= partial
;
2495 all
->pretend_args_size
= CEIL_ROUND (pretend_bytes
, STACK_BYTES
);
2497 /* We want to align relative to the actual stack pointer, so
2498 don't include this in the stack size until later. */
2499 all
->extra_pretend_bytes
= all
->pretend_args_size
;
2503 locate_and_pad_parm (data
->promoted_mode
, data
->passed_type
, in_regs
,
2504 entry_parm
? data
->partial
: 0, current_function_decl
,
2505 &all
->stack_args_size
, &data
->locate
);
2507 /* Update parm_stack_boundary if this parameter is passed in the
2509 if (!in_regs
&& crtl
->parm_stack_boundary
< data
->locate
.boundary
)
2510 crtl
->parm_stack_boundary
= data
->locate
.boundary
;
2512 /* Adjust offsets to include the pretend args. */
2513 pretend_bytes
= all
->extra_pretend_bytes
- pretend_bytes
;
2514 data
->locate
.slot_offset
.constant
+= pretend_bytes
;
2515 data
->locate
.offset
.constant
+= pretend_bytes
;
2517 data
->entry_parm
= entry_parm
;
2520 /* A subroutine of assign_parms. If there is actually space on the stack
2521 for this parm, count it in stack_args_size and return true. */
2524 assign_parm_is_stack_parm (struct assign_parm_data_all
*all
,
2525 struct assign_parm_data_one
*data
)
2527 /* Trivially true if we've no incoming register. */
2528 if (data
->entry_parm
== NULL
)
2530 /* Also true if we're partially in registers and partially not,
2531 since we've arranged to drop the entire argument on the stack. */
2532 else if (data
->partial
!= 0)
2534 /* Also true if the target says that it's passed in both registers
2535 and on the stack. */
2536 else if (GET_CODE (data
->entry_parm
) == PARALLEL
2537 && XEXP (XVECEXP (data
->entry_parm
, 0, 0), 0) == NULL_RTX
)
2539 /* Also true if the target says that there's stack allocated for
2540 all register parameters. */
2541 else if (all
->reg_parm_stack_space
> 0)
2543 /* Otherwise, no, this parameter has no ABI defined stack slot. */
2547 all
->stack_args_size
.constant
+= data
->locate
.size
.constant
;
2548 if (data
->locate
.size
.var
)
2549 ADD_PARM_SIZE (all
->stack_args_size
, data
->locate
.size
.var
);
2554 /* A subroutine of assign_parms. Given that this parameter is allocated
2555 stack space by the ABI, find it. */
2558 assign_parm_find_stack_rtl (tree parm
, struct assign_parm_data_one
*data
)
2560 rtx offset_rtx
, stack_parm
;
2561 unsigned int align
, boundary
;
2563 /* If we're passing this arg using a reg, make its stack home the
2564 aligned stack slot. */
2565 if (data
->entry_parm
)
2566 offset_rtx
= ARGS_SIZE_RTX (data
->locate
.slot_offset
);
2568 offset_rtx
= ARGS_SIZE_RTX (data
->locate
.offset
);
2570 stack_parm
= crtl
->args
.internal_arg_pointer
;
2571 if (offset_rtx
!= const0_rtx
)
2572 stack_parm
= gen_rtx_PLUS (Pmode
, stack_parm
, offset_rtx
);
2573 stack_parm
= gen_rtx_MEM (data
->promoted_mode
, stack_parm
);
2575 if (!data
->passed_pointer
)
2577 set_mem_attributes (stack_parm
, parm
, 1);
2578 /* set_mem_attributes could set MEM_SIZE to the passed mode's size,
2579 while promoted mode's size is needed. */
2580 if (data
->promoted_mode
!= BLKmode
2581 && data
->promoted_mode
!= DECL_MODE (parm
))
2583 set_mem_size (stack_parm
, GET_MODE_SIZE (data
->promoted_mode
));
2584 if (MEM_EXPR (stack_parm
) && MEM_OFFSET_KNOWN_P (stack_parm
))
2586 int offset
= subreg_lowpart_offset (DECL_MODE (parm
),
2587 data
->promoted_mode
);
2589 set_mem_offset (stack_parm
, MEM_OFFSET (stack_parm
) - offset
);
2594 boundary
= data
->locate
.boundary
;
2595 align
= BITS_PER_UNIT
;
2597 /* If we're padding upward, we know that the alignment of the slot
2598 is TARGET_FUNCTION_ARG_BOUNDARY. If we're using slot_offset, we're
2599 intentionally forcing upward padding. Otherwise we have to come
2600 up with a guess at the alignment based on OFFSET_RTX. */
2601 if (data
->locate
.where_pad
!= downward
|| data
->entry_parm
)
2603 else if (CONST_INT_P (offset_rtx
))
2605 align
= INTVAL (offset_rtx
) * BITS_PER_UNIT
| boundary
;
2606 align
= align
& -align
;
2608 set_mem_align (stack_parm
, align
);
2610 if (data
->entry_parm
)
2611 set_reg_attrs_for_parm (data
->entry_parm
, stack_parm
);
2613 data
->stack_parm
= stack_parm
;
2616 /* A subroutine of assign_parms. Adjust DATA->ENTRY_RTL such that it's
2617 always valid and contiguous. */
2620 assign_parm_adjust_entry_rtl (struct assign_parm_data_one
*data
)
2622 rtx entry_parm
= data
->entry_parm
;
2623 rtx stack_parm
= data
->stack_parm
;
2625 /* If this parm was passed part in regs and part in memory, pretend it
2626 arrived entirely in memory by pushing the register-part onto the stack.
2627 In the special case of a DImode or DFmode that is split, we could put
2628 it together in a pseudoreg directly, but for now that's not worth
2630 if (data
->partial
!= 0)
2632 /* Handle calls that pass values in multiple non-contiguous
2633 locations. The Irix 6 ABI has examples of this. */
2634 if (GET_CODE (entry_parm
) == PARALLEL
)
2635 emit_group_store (validize_mem (stack_parm
), entry_parm
,
2637 int_size_in_bytes (data
->passed_type
));
2640 gcc_assert (data
->partial
% UNITS_PER_WORD
== 0);
2641 move_block_from_reg (REGNO (entry_parm
), validize_mem (stack_parm
),
2642 data
->partial
/ UNITS_PER_WORD
);
2645 entry_parm
= stack_parm
;
2648 /* If we didn't decide this parm came in a register, by default it came
2650 else if (entry_parm
== NULL
)
2651 entry_parm
= stack_parm
;
2653 /* When an argument is passed in multiple locations, we can't make use
2654 of this information, but we can save some copying if the whole argument
2655 is passed in a single register. */
2656 else if (GET_CODE (entry_parm
) == PARALLEL
2657 && data
->nominal_mode
!= BLKmode
2658 && data
->passed_mode
!= BLKmode
)
2660 size_t i
, len
= XVECLEN (entry_parm
, 0);
2662 for (i
= 0; i
< len
; i
++)
2663 if (XEXP (XVECEXP (entry_parm
, 0, i
), 0) != NULL_RTX
2664 && REG_P (XEXP (XVECEXP (entry_parm
, 0, i
), 0))
2665 && (GET_MODE (XEXP (XVECEXP (entry_parm
, 0, i
), 0))
2666 == data
->passed_mode
)
2667 && INTVAL (XEXP (XVECEXP (entry_parm
, 0, i
), 1)) == 0)
2669 entry_parm
= XEXP (XVECEXP (entry_parm
, 0, i
), 0);
2674 data
->entry_parm
= entry_parm
;
2677 /* A subroutine of assign_parms. Reconstitute any values which were
2678 passed in multiple registers and would fit in a single register. */
2681 assign_parm_remove_parallels (struct assign_parm_data_one
*data
)
2683 rtx entry_parm
= data
->entry_parm
;
2685 /* Convert the PARALLEL to a REG of the same mode as the parallel.
2686 This can be done with register operations rather than on the
2687 stack, even if we will store the reconstituted parameter on the
2689 if (GET_CODE (entry_parm
) == PARALLEL
&& GET_MODE (entry_parm
) != BLKmode
)
2691 rtx parmreg
= gen_reg_rtx (GET_MODE (entry_parm
));
2692 emit_group_store (parmreg
, entry_parm
, data
->passed_type
,
2693 GET_MODE_SIZE (GET_MODE (entry_parm
)));
2694 entry_parm
= parmreg
;
2697 data
->entry_parm
= entry_parm
;
2700 /* A subroutine of assign_parms. Adjust DATA->STACK_RTL such that it's
2701 always valid and properly aligned. */
2704 assign_parm_adjust_stack_rtl (struct assign_parm_data_one
*data
)
2706 rtx stack_parm
= data
->stack_parm
;
2708 /* If we can't trust the parm stack slot to be aligned enough for its
2709 ultimate type, don't use that slot after entry. We'll make another
2710 stack slot, if we need one. */
2712 && ((STRICT_ALIGNMENT
2713 && GET_MODE_ALIGNMENT (data
->nominal_mode
) > MEM_ALIGN (stack_parm
))
2714 || (data
->nominal_type
2715 && TYPE_ALIGN (data
->nominal_type
) > MEM_ALIGN (stack_parm
)
2716 && MEM_ALIGN (stack_parm
) < PREFERRED_STACK_BOUNDARY
)))
2719 /* If parm was passed in memory, and we need to convert it on entry,
2720 don't store it back in that same slot. */
2721 else if (data
->entry_parm
== stack_parm
2722 && data
->nominal_mode
!= BLKmode
2723 && data
->nominal_mode
!= data
->passed_mode
)
2726 /* If stack protection is in effect for this function, don't leave any
2727 pointers in their passed stack slots. */
2728 else if (crtl
->stack_protect_guard
2729 && (flag_stack_protect
== 2
2730 || data
->passed_pointer
2731 || POINTER_TYPE_P (data
->nominal_type
)))
2734 data
->stack_parm
= stack_parm
;
2737 /* A subroutine of assign_parms. Return true if the current parameter
2738 should be stored as a BLKmode in the current frame. */
2741 assign_parm_setup_block_p (struct assign_parm_data_one
*data
)
2743 if (data
->nominal_mode
== BLKmode
)
2745 if (GET_MODE (data
->entry_parm
) == BLKmode
)
2748 #ifdef BLOCK_REG_PADDING
2749 /* Only assign_parm_setup_block knows how to deal with register arguments
2750 that are padded at the least significant end. */
2751 if (REG_P (data
->entry_parm
)
2752 && GET_MODE_SIZE (data
->promoted_mode
) < UNITS_PER_WORD
2753 && (BLOCK_REG_PADDING (data
->passed_mode
, data
->passed_type
, 1)
2754 == (BYTES_BIG_ENDIAN
? upward
: downward
)))
2761 /* A subroutine of assign_parms. Arrange for the parameter to be
2762 present and valid in DATA->STACK_RTL. */
2765 assign_parm_setup_block (struct assign_parm_data_all
*all
,
2766 tree parm
, struct assign_parm_data_one
*data
)
2768 rtx entry_parm
= data
->entry_parm
;
2769 rtx stack_parm
= data
->stack_parm
;
2771 HOST_WIDE_INT size_stored
;
2773 if (GET_CODE (entry_parm
) == PARALLEL
)
2774 entry_parm
= emit_group_move_into_temps (entry_parm
);
2776 size
= int_size_in_bytes (data
->passed_type
);
2777 size_stored
= CEIL_ROUND (size
, UNITS_PER_WORD
);
2778 if (stack_parm
== 0)
2780 DECL_ALIGN (parm
) = MAX (DECL_ALIGN (parm
), BITS_PER_WORD
);
2781 stack_parm
= assign_stack_local (BLKmode
, size_stored
,
2783 if (GET_MODE_SIZE (GET_MODE (entry_parm
)) == size
)
2784 PUT_MODE (stack_parm
, GET_MODE (entry_parm
));
2785 set_mem_attributes (stack_parm
, parm
, 1);
2788 /* If a BLKmode arrives in registers, copy it to a stack slot. Handle
2789 calls that pass values in multiple non-contiguous locations. */
2790 if (REG_P (entry_parm
) || GET_CODE (entry_parm
) == PARALLEL
)
2794 /* Note that we will be storing an integral number of words.
2795 So we have to be careful to ensure that we allocate an
2796 integral number of words. We do this above when we call
2797 assign_stack_local if space was not allocated in the argument
2798 list. If it was, this will not work if PARM_BOUNDARY is not
2799 a multiple of BITS_PER_WORD. It isn't clear how to fix this
2800 if it becomes a problem. Exception is when BLKmode arrives
2801 with arguments not conforming to word_mode. */
2803 if (data
->stack_parm
== 0)
2805 else if (GET_CODE (entry_parm
) == PARALLEL
)
2808 gcc_assert (!size
|| !(PARM_BOUNDARY
% BITS_PER_WORD
));
2810 mem
= validize_mem (stack_parm
);
2812 /* Handle values in multiple non-contiguous locations. */
2813 if (GET_CODE (entry_parm
) == PARALLEL
)
2815 push_to_sequence2 (all
->first_conversion_insn
,
2816 all
->last_conversion_insn
);
2817 emit_group_store (mem
, entry_parm
, data
->passed_type
, size
);
2818 all
->first_conversion_insn
= get_insns ();
2819 all
->last_conversion_insn
= get_last_insn ();
2826 /* If SIZE is that of a mode no bigger than a word, just use
2827 that mode's store operation. */
2828 else if (size
<= UNITS_PER_WORD
)
2830 enum machine_mode mode
2831 = mode_for_size (size
* BITS_PER_UNIT
, MODE_INT
, 0);
2834 #ifdef BLOCK_REG_PADDING
2835 && (size
== UNITS_PER_WORD
2836 || (BLOCK_REG_PADDING (mode
, data
->passed_type
, 1)
2837 != (BYTES_BIG_ENDIAN
? upward
: downward
)))
2843 /* We are really truncating a word_mode value containing
2844 SIZE bytes into a value of mode MODE. If such an
2845 operation requires no actual instructions, we can refer
2846 to the value directly in mode MODE, otherwise we must
2847 start with the register in word_mode and explicitly
2849 if (TRULY_NOOP_TRUNCATION (size
* BITS_PER_UNIT
, BITS_PER_WORD
))
2850 reg
= gen_rtx_REG (mode
, REGNO (entry_parm
));
2853 reg
= gen_rtx_REG (word_mode
, REGNO (entry_parm
));
2854 reg
= convert_to_mode (mode
, copy_to_reg (reg
), 1);
2856 emit_move_insn (change_address (mem
, mode
, 0), reg
);
2859 /* Blocks smaller than a word on a BYTES_BIG_ENDIAN
2860 machine must be aligned to the left before storing
2861 to memory. Note that the previous test doesn't
2862 handle all cases (e.g. SIZE == 3). */
2863 else if (size
!= UNITS_PER_WORD
2864 #ifdef BLOCK_REG_PADDING
2865 && (BLOCK_REG_PADDING (mode
, data
->passed_type
, 1)
2873 int by
= (UNITS_PER_WORD
- size
) * BITS_PER_UNIT
;
2874 rtx reg
= gen_rtx_REG (word_mode
, REGNO (entry_parm
));
2876 x
= expand_shift (LSHIFT_EXPR
, word_mode
, reg
, by
, NULL_RTX
, 1);
2877 tem
= change_address (mem
, word_mode
, 0);
2878 emit_move_insn (tem
, x
);
2881 move_block_from_reg (REGNO (entry_parm
), mem
,
2882 size_stored
/ UNITS_PER_WORD
);
2885 move_block_from_reg (REGNO (entry_parm
), mem
,
2886 size_stored
/ UNITS_PER_WORD
);
2888 else if (data
->stack_parm
== 0)
2890 push_to_sequence2 (all
->first_conversion_insn
, all
->last_conversion_insn
);
2891 emit_block_move (stack_parm
, data
->entry_parm
, GEN_INT (size
),
2893 all
->first_conversion_insn
= get_insns ();
2894 all
->last_conversion_insn
= get_last_insn ();
2898 data
->stack_parm
= stack_parm
;
2899 SET_DECL_RTL (parm
, stack_parm
);
2902 /* A subroutine of assign_parms. Allocate a pseudo to hold the current
2903 parameter. Get it there. Perform all ABI specified conversions. */
2906 assign_parm_setup_reg (struct assign_parm_data_all
*all
, tree parm
,
2907 struct assign_parm_data_one
*data
)
2909 rtx parmreg
, validated_mem
;
2910 rtx equiv_stack_parm
;
2911 enum machine_mode promoted_nominal_mode
;
2912 int unsignedp
= TYPE_UNSIGNED (TREE_TYPE (parm
));
2913 bool did_conversion
= false;
2914 bool need_conversion
, moved
;
2916 /* Store the parm in a pseudoregister during the function, but we may
2917 need to do it in a wider mode. Using 2 here makes the result
2918 consistent with promote_decl_mode and thus expand_expr_real_1. */
2919 promoted_nominal_mode
2920 = promote_function_mode (data
->nominal_type
, data
->nominal_mode
, &unsignedp
,
2921 TREE_TYPE (current_function_decl
), 2);
2923 parmreg
= gen_reg_rtx (promoted_nominal_mode
);
2925 if (!DECL_ARTIFICIAL (parm
))
2926 mark_user_reg (parmreg
);
2928 /* If this was an item that we received a pointer to,
2929 set DECL_RTL appropriately. */
2930 if (data
->passed_pointer
)
2932 rtx x
= gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data
->passed_type
)), parmreg
);
2933 set_mem_attributes (x
, parm
, 1);
2934 SET_DECL_RTL (parm
, x
);
2937 SET_DECL_RTL (parm
, parmreg
);
2939 assign_parm_remove_parallels (data
);
2941 /* Copy the value into the register, thus bridging between
2942 assign_parm_find_data_types and expand_expr_real_1. */
2944 equiv_stack_parm
= data
->stack_parm
;
2945 validated_mem
= validize_mem (data
->entry_parm
);
2947 need_conversion
= (data
->nominal_mode
!= data
->passed_mode
2948 || promoted_nominal_mode
!= data
->promoted_mode
);
2952 && GET_MODE_CLASS (data
->nominal_mode
) == MODE_INT
2953 && data
->nominal_mode
== data
->passed_mode
2954 && data
->nominal_mode
== GET_MODE (data
->entry_parm
))
2956 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
2957 mode, by the caller. We now have to convert it to
2958 NOMINAL_MODE, if different. However, PARMREG may be in
2959 a different mode than NOMINAL_MODE if it is being stored
2962 If ENTRY_PARM is a hard register, it might be in a register
2963 not valid for operating in its mode (e.g., an odd-numbered
2964 register for a DFmode). In that case, moves are the only
2965 thing valid, so we can't do a convert from there. This
2966 occurs when the calling sequence allow such misaligned
2969 In addition, the conversion may involve a call, which could
2970 clobber parameters which haven't been copied to pseudo
2973 First, we try to emit an insn which performs the necessary
2974 conversion. We verify that this insn does not clobber any
2977 enum insn_code icode
;
2980 icode
= can_extend_p (promoted_nominal_mode
, data
->passed_mode
,
2984 op1
= validated_mem
;
2985 if (icode
!= CODE_FOR_nothing
2986 && insn_operand_matches (icode
, 0, op0
)
2987 && insn_operand_matches (icode
, 1, op1
))
2989 enum rtx_code code
= unsignedp
? ZERO_EXTEND
: SIGN_EXTEND
;
2990 rtx insn
, insns
, t
= op1
;
2991 HARD_REG_SET hardregs
;
2994 /* If op1 is a hard register that is likely spilled, first
2995 force it into a pseudo, otherwise combiner might extend
2996 its lifetime too much. */
2997 if (GET_CODE (t
) == SUBREG
)
3000 && HARD_REGISTER_P (t
)
3001 && ! TEST_HARD_REG_BIT (fixed_reg_set
, REGNO (t
))
3002 && targetm
.class_likely_spilled_p (REGNO_REG_CLASS (REGNO (t
))))
3004 t
= gen_reg_rtx (GET_MODE (op1
));
3005 emit_move_insn (t
, op1
);
3009 insn
= gen_extend_insn (op0
, t
, promoted_nominal_mode
,
3010 data
->passed_mode
, unsignedp
);
3012 insns
= get_insns ();
3015 CLEAR_HARD_REG_SET (hardregs
);
3016 for (insn
= insns
; insn
&& moved
; insn
= NEXT_INSN (insn
))
3019 note_stores (PATTERN (insn
), record_hard_reg_sets
,
3021 if (!hard_reg_set_empty_p (hardregs
))
3030 if (equiv_stack_parm
!= NULL_RTX
)
3031 equiv_stack_parm
= gen_rtx_fmt_e (code
, GET_MODE (parmreg
),
3038 /* Nothing to do. */
3040 else if (need_conversion
)
3042 /* We did not have an insn to convert directly, or the sequence
3043 generated appeared unsafe. We must first copy the parm to a
3044 pseudo reg, and save the conversion until after all
3045 parameters have been moved. */
3048 rtx tempreg
= gen_reg_rtx (GET_MODE (data
->entry_parm
));
3050 emit_move_insn (tempreg
, validated_mem
);
3052 push_to_sequence2 (all
->first_conversion_insn
, all
->last_conversion_insn
);
3053 tempreg
= convert_to_mode (data
->nominal_mode
, tempreg
, unsignedp
);
3055 if (GET_CODE (tempreg
) == SUBREG
3056 && GET_MODE (tempreg
) == data
->nominal_mode
3057 && REG_P (SUBREG_REG (tempreg
))
3058 && data
->nominal_mode
== data
->passed_mode
3059 && GET_MODE (SUBREG_REG (tempreg
)) == GET_MODE (data
->entry_parm
)
3060 && GET_MODE_SIZE (GET_MODE (tempreg
))
3061 < GET_MODE_SIZE (GET_MODE (data
->entry_parm
)))
3063 /* The argument is already sign/zero extended, so note it
3065 SUBREG_PROMOTED_VAR_P (tempreg
) = 1;
3066 SUBREG_PROMOTED_UNSIGNED_SET (tempreg
, unsignedp
);
3069 /* TREE_USED gets set erroneously during expand_assignment. */
3070 save_tree_used
= TREE_USED (parm
);
3071 expand_assignment (parm
, make_tree (data
->nominal_type
, tempreg
), false);
3072 TREE_USED (parm
) = save_tree_used
;
3073 all
->first_conversion_insn
= get_insns ();
3074 all
->last_conversion_insn
= get_last_insn ();
3077 did_conversion
= true;
3080 emit_move_insn (parmreg
, validated_mem
);
3082 /* If we were passed a pointer but the actual value can safely live
3083 in a register, put it in one. */
3084 if (data
->passed_pointer
3085 && TYPE_MODE (TREE_TYPE (parm
)) != BLKmode
3086 /* If by-reference argument was promoted, demote it. */
3087 && (TYPE_MODE (TREE_TYPE (parm
)) != GET_MODE (DECL_RTL (parm
))
3088 || use_register_for_decl (parm
)))
3090 /* We can't use nominal_mode, because it will have been set to
3091 Pmode above. We must use the actual mode of the parm. */
3092 parmreg
= gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm
)));
3093 mark_user_reg (parmreg
);
3095 if (GET_MODE (parmreg
) != GET_MODE (DECL_RTL (parm
)))
3097 rtx tempreg
= gen_reg_rtx (GET_MODE (DECL_RTL (parm
)));
3098 int unsigned_p
= TYPE_UNSIGNED (TREE_TYPE (parm
));
3100 push_to_sequence2 (all
->first_conversion_insn
,
3101 all
->last_conversion_insn
);
3102 emit_move_insn (tempreg
, DECL_RTL (parm
));
3103 tempreg
= convert_to_mode (GET_MODE (parmreg
), tempreg
, unsigned_p
);
3104 emit_move_insn (parmreg
, tempreg
);
3105 all
->first_conversion_insn
= get_insns ();
3106 all
->last_conversion_insn
= get_last_insn ();
3109 did_conversion
= true;
3112 emit_move_insn (parmreg
, DECL_RTL (parm
));
3114 SET_DECL_RTL (parm
, parmreg
);
3116 /* STACK_PARM is the pointer, not the parm, and PARMREG is
3118 data
->stack_parm
= NULL
;
3121 /* Mark the register as eliminable if we did no conversion and it was
3122 copied from memory at a fixed offset, and the arg pointer was not
3123 copied to a pseudo-reg. If the arg pointer is a pseudo reg or the
3124 offset formed an invalid address, such memory-equivalences as we
3125 make here would screw up life analysis for it. */
3126 if (data
->nominal_mode
== data
->passed_mode
3128 && data
->stack_parm
!= 0
3129 && MEM_P (data
->stack_parm
)
3130 && data
->locate
.offset
.var
== 0
3131 && reg_mentioned_p (virtual_incoming_args_rtx
,
3132 XEXP (data
->stack_parm
, 0)))
3134 rtx linsn
= get_last_insn ();
3137 /* Mark complex types separately. */
3138 if (GET_CODE (parmreg
) == CONCAT
)
3140 enum machine_mode submode
3141 = GET_MODE_INNER (GET_MODE (parmreg
));
3142 int regnor
= REGNO (XEXP (parmreg
, 0));
3143 int regnoi
= REGNO (XEXP (parmreg
, 1));
3144 rtx stackr
= adjust_address_nv (data
->stack_parm
, submode
, 0);
3145 rtx stacki
= adjust_address_nv (data
->stack_parm
, submode
,
3146 GET_MODE_SIZE (submode
));
3148 /* Scan backwards for the set of the real and
3150 for (sinsn
= linsn
; sinsn
!= 0;
3151 sinsn
= prev_nonnote_insn (sinsn
))
3153 set
= single_set (sinsn
);
3157 if (SET_DEST (set
) == regno_reg_rtx
[regnoi
])
3158 set_unique_reg_note (sinsn
, REG_EQUIV
, stacki
);
3159 else if (SET_DEST (set
) == regno_reg_rtx
[regnor
])
3160 set_unique_reg_note (sinsn
, REG_EQUIV
, stackr
);
3164 set_dst_reg_note (linsn
, REG_EQUIV
, equiv_stack_parm
, parmreg
);
3167 /* For pointer data type, suggest pointer register. */
3168 if (POINTER_TYPE_P (TREE_TYPE (parm
)))
3169 mark_reg_pointer (parmreg
,
3170 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm
))));
3173 /* A subroutine of assign_parms. Allocate stack space to hold the current
3174 parameter. Get it there. Perform all ABI specified conversions. */
3177 assign_parm_setup_stack (struct assign_parm_data_all
*all
, tree parm
,
3178 struct assign_parm_data_one
*data
)
3180 /* Value must be stored in the stack slot STACK_PARM during function
3182 bool to_conversion
= false;
3184 assign_parm_remove_parallels (data
);
3186 if (data
->promoted_mode
!= data
->nominal_mode
)
3188 /* Conversion is required. */
3189 rtx tempreg
= gen_reg_rtx (GET_MODE (data
->entry_parm
));
3191 emit_move_insn (tempreg
, validize_mem (data
->entry_parm
));
3193 push_to_sequence2 (all
->first_conversion_insn
, all
->last_conversion_insn
);
3194 to_conversion
= true;
3196 data
->entry_parm
= convert_to_mode (data
->nominal_mode
, tempreg
,
3197 TYPE_UNSIGNED (TREE_TYPE (parm
)));
3199 if (data
->stack_parm
)
3201 int offset
= subreg_lowpart_offset (data
->nominal_mode
,
3202 GET_MODE (data
->stack_parm
));
3203 /* ??? This may need a big-endian conversion on sparc64. */
3205 = adjust_address (data
->stack_parm
, data
->nominal_mode
, 0);
3206 if (offset
&& MEM_OFFSET_KNOWN_P (data
->stack_parm
))
3207 set_mem_offset (data
->stack_parm
,
3208 MEM_OFFSET (data
->stack_parm
) + offset
);
3212 if (data
->entry_parm
!= data
->stack_parm
)
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
));
3222 = assign_stack_local (GET_MODE (data
->entry_parm
),
3223 GET_MODE_SIZE (GET_MODE (data
->entry_parm
)),
3225 set_mem_attributes (data
->stack_parm
, parm
, 1);
3228 dest
= validize_mem (data
->stack_parm
);
3229 src
= validize_mem (data
->entry_parm
);
3233 /* Use a block move to handle potentially misaligned entry_parm. */
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
)),
3244 emit_move_insn (dest
, src
);
3249 all
->first_conversion_insn
= get_insns ();
3250 all
->last_conversion_insn
= get_last_insn ();
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. */
3261 assign_parms_unsplit_complex (struct assign_parm_data_all
*all
,
3262 VEC(tree
, heap
) *fnargs
)
3265 tree orig_fnargs
= all
->orig_fnargs
;
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
))
3287 HOST_WIDE_INT size
= int_size_in_bytes (TREE_TYPE (parm
));
3288 int align
= STACK_SLOT_ALIGNMENT (TREE_TYPE (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 ();
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);
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. */
3328 assign_parms (tree fndecl
)
3330 struct assign_parm_data_all all
;
3332 VEC(tree
, heap
) *fnargs
;
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
);
3356 /* Estimate stack alignment from parameter alignment. */
3357 if (SUPPORTS_STACK_ALIGNMENT
)
3360 = targetm
.calls
.function_arg_boundary (data
.promoted_mode
,
3362 align
= MINIMUM_ALIGNMENT (data
.passed_type
, data
.promoted_mode
,
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 if (data
.passed_pointer
)
3392 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data
.passed_type
)),
3394 set_decl_incoming_rtl (parm
, incoming_rtl
, true);
3397 set_decl_incoming_rtl (parm
, data
.entry_parm
, false);
3399 /* Update info on where next arg arrives in registers. */
3400 targetm
.calls
.function_arg_advance (all
.args_so_far
, data
.promoted_mode
,
3401 data
.passed_type
, data
.named_arg
);
3403 assign_parm_adjust_stack_rtl (&data
);
3405 if (assign_parm_setup_block_p (&data
))
3406 assign_parm_setup_block (&all
, parm
, &data
);
3407 else if (data
.passed_pointer
|| use_register_for_decl (parm
))
3408 assign_parm_setup_reg (&all
, parm
, &data
);
3410 assign_parm_setup_stack (&all
, parm
, &data
);
3413 if (targetm
.calls
.split_complex_arg
)
3414 assign_parms_unsplit_complex (&all
, fnargs
);
3416 VEC_free (tree
, heap
, fnargs
);
3418 /* Output all parameter conversion instructions (possibly including calls)
3419 now that all parameters have been copied out of hard registers. */
3420 emit_insn (all
.first_conversion_insn
);
3422 /* Estimate reload stack alignment from scalar return mode. */
3423 if (SUPPORTS_STACK_ALIGNMENT
)
3425 if (DECL_RESULT (fndecl
))
3427 tree type
= TREE_TYPE (DECL_RESULT (fndecl
));
3428 enum machine_mode mode
= TYPE_MODE (type
);
3432 && !AGGREGATE_TYPE_P (type
))
3434 unsigned int align
= GET_MODE_ALIGNMENT (mode
);
3435 if (crtl
->stack_alignment_estimated
< align
)
3437 gcc_assert (!crtl
->stack_realign_processed
);
3438 crtl
->stack_alignment_estimated
= align
;
3444 /* If we are receiving a struct value address as the first argument, set up
3445 the RTL for the function result. As this might require code to convert
3446 the transmitted address to Pmode, we do this here to ensure that possible
3447 preliminary conversions of the address have been emitted already. */
3448 if (all
.function_result_decl
)
3450 tree result
= DECL_RESULT (current_function_decl
);
3451 rtx addr
= DECL_RTL (all
.function_result_decl
);
3454 if (DECL_BY_REFERENCE (result
))
3456 SET_DECL_VALUE_EXPR (result
, all
.function_result_decl
);
3461 SET_DECL_VALUE_EXPR (result
,
3462 build1 (INDIRECT_REF
, TREE_TYPE (result
),
3463 all
.function_result_decl
));
3464 addr
= convert_memory_address (Pmode
, addr
);
3465 x
= gen_rtx_MEM (DECL_MODE (result
), addr
);
3466 set_mem_attributes (x
, result
, 1);
3469 DECL_HAS_VALUE_EXPR_P (result
) = 1;
3471 SET_DECL_RTL (result
, x
);
3474 /* We have aligned all the args, so add space for the pretend args. */
3475 crtl
->args
.pretend_args_size
= all
.pretend_args_size
;
3476 all
.stack_args_size
.constant
+= all
.extra_pretend_bytes
;
3477 crtl
->args
.size
= all
.stack_args_size
.constant
;
3479 /* Adjust function incoming argument size for alignment and
3482 #ifdef REG_PARM_STACK_SPACE
3483 crtl
->args
.size
= MAX (crtl
->args
.size
,
3484 REG_PARM_STACK_SPACE (fndecl
));
3487 crtl
->args
.size
= CEIL_ROUND (crtl
->args
.size
,
3488 PARM_BOUNDARY
/ BITS_PER_UNIT
);
3490 #ifdef ARGS_GROW_DOWNWARD
3491 crtl
->args
.arg_offset_rtx
3492 = (all
.stack_args_size
.var
== 0 ? GEN_INT (-all
.stack_args_size
.constant
)
3493 : expand_expr (size_diffop (all
.stack_args_size
.var
,
3494 size_int (-all
.stack_args_size
.constant
)),
3495 NULL_RTX
, VOIDmode
, EXPAND_NORMAL
));
3497 crtl
->args
.arg_offset_rtx
= ARGS_SIZE_RTX (all
.stack_args_size
);
3500 /* See how many bytes, if any, of its args a function should try to pop
3503 crtl
->args
.pops_args
= targetm
.calls
.return_pops_args (fndecl
,
3507 /* For stdarg.h function, save info about
3508 regs and stack space used by the named args. */
3510 crtl
->args
.info
= all
.args_so_far_v
;
3512 /* Set the rtx used for the function return value. Put this in its
3513 own variable so any optimizers that need this information don't have
3514 to include tree.h. Do this here so it gets done when an inlined
3515 function gets output. */
3518 = (DECL_RTL_SET_P (DECL_RESULT (fndecl
))
3519 ? DECL_RTL (DECL_RESULT (fndecl
)) : NULL_RTX
);
3521 /* If scalar return value was computed in a pseudo-reg, or was a named
3522 return value that got dumped to the stack, copy that to the hard
3524 if (DECL_RTL_SET_P (DECL_RESULT (fndecl
)))
3526 tree decl_result
= DECL_RESULT (fndecl
);
3527 rtx decl_rtl
= DECL_RTL (decl_result
);
3529 if (REG_P (decl_rtl
)
3530 ? REGNO (decl_rtl
) >= FIRST_PSEUDO_REGISTER
3531 : DECL_REGISTER (decl_result
))
3535 real_decl_rtl
= targetm
.calls
.function_value (TREE_TYPE (decl_result
),
3537 REG_FUNCTION_VALUE_P (real_decl_rtl
) = 1;
3538 /* The delay slot scheduler assumes that crtl->return_rtx
3539 holds the hard register containing the return value, not a
3540 temporary pseudo. */
3541 crtl
->return_rtx
= real_decl_rtl
;
3546 /* A subroutine of gimplify_parameters, invoked via walk_tree.
3547 For all seen types, gimplify their sizes. */
3550 gimplify_parm_type (tree
*tp
, int *walk_subtrees
, void *data
)
3557 if (POINTER_TYPE_P (t
))
3559 else if (TYPE_SIZE (t
) && !TREE_CONSTANT (TYPE_SIZE (t
))
3560 && !TYPE_SIZES_GIMPLIFIED (t
))
3562 gimplify_type_sizes (t
, (gimple_seq
*) data
);
3570 /* Gimplify the parameter list for current_function_decl. This involves
3571 evaluating SAVE_EXPRs of variable sized parameters and generating code
3572 to implement callee-copies reference parameters. Returns a sequence of
3573 statements to add to the beginning of the function. */
3576 gimplify_parameters (void)
3578 struct assign_parm_data_all all
;
3580 gimple_seq stmts
= NULL
;
3581 VEC(tree
, heap
) *fnargs
;
3584 assign_parms_initialize_all (&all
);
3585 fnargs
= assign_parms_augmented_arg_list (&all
);
3587 FOR_EACH_VEC_ELT (tree
, fnargs
, i
, parm
)
3589 struct assign_parm_data_one data
;
3591 /* Extract the type of PARM; adjust it according to ABI. */
3592 assign_parm_find_data_types (&all
, parm
, &data
);
3594 /* Early out for errors and void parameters. */
3595 if (data
.passed_mode
== VOIDmode
|| DECL_SIZE (parm
) == NULL
)
3598 /* Update info on where next arg arrives in registers. */
3599 targetm
.calls
.function_arg_advance (all
.args_so_far
, data
.promoted_mode
,
3600 data
.passed_type
, data
.named_arg
);
3602 /* ??? Once upon a time variable_size stuffed parameter list
3603 SAVE_EXPRs (amongst others) onto a pending sizes list. This
3604 turned out to be less than manageable in the gimple world.
3605 Now we have to hunt them down ourselves. */
3606 walk_tree_without_duplicates (&data
.passed_type
,
3607 gimplify_parm_type
, &stmts
);
3609 if (TREE_CODE (DECL_SIZE_UNIT (parm
)) != INTEGER_CST
)
3611 gimplify_one_sizepos (&DECL_SIZE (parm
), &stmts
);
3612 gimplify_one_sizepos (&DECL_SIZE_UNIT (parm
), &stmts
);
3615 if (data
.passed_pointer
)
3617 tree type
= TREE_TYPE (data
.passed_type
);
3618 if (reference_callee_copied (&all
.args_so_far_v
, TYPE_MODE (type
),
3619 type
, data
.named_arg
))
3623 /* For constant-sized objects, this is trivial; for
3624 variable-sized objects, we have to play games. */
3625 if (TREE_CODE (DECL_SIZE_UNIT (parm
)) == INTEGER_CST
3626 && !(flag_stack_check
== GENERIC_STACK_CHECK
3627 && compare_tree_int (DECL_SIZE_UNIT (parm
),
3628 STACK_CHECK_MAX_VAR_SIZE
) > 0))
3630 local
= create_tmp_var (type
, get_name (parm
));
3631 DECL_IGNORED_P (local
) = 0;
3632 /* If PARM was addressable, move that flag over
3633 to the local copy, as its address will be taken,
3634 not the PARMs. Keep the parms address taken
3635 as we'll query that flag during gimplification. */
3636 if (TREE_ADDRESSABLE (parm
))
3637 TREE_ADDRESSABLE (local
) = 1;
3638 else if (TREE_CODE (type
) == COMPLEX_TYPE
3639 || TREE_CODE (type
) == VECTOR_TYPE
)
3640 DECL_GIMPLE_REG_P (local
) = 1;
3644 tree ptr_type
, addr
;
3646 ptr_type
= build_pointer_type (type
);
3647 addr
= create_tmp_reg (ptr_type
, get_name (parm
));
3648 DECL_IGNORED_P (addr
) = 0;
3649 local
= build_fold_indirect_ref (addr
);
3651 t
= builtin_decl_explicit (BUILT_IN_ALLOCA_WITH_ALIGN
);
3652 t
= build_call_expr (t
, 2, DECL_SIZE_UNIT (parm
),
3653 size_int (DECL_ALIGN (parm
)));
3655 /* The call has been built for a variable-sized object. */
3656 CALL_ALLOCA_FOR_VAR_P (t
) = 1;
3657 t
= fold_convert (ptr_type
, t
);
3658 t
= build2 (MODIFY_EXPR
, TREE_TYPE (addr
), addr
, t
);
3659 gimplify_and_add (t
, &stmts
);
3662 gimplify_assign (local
, parm
, &stmts
);
3664 SET_DECL_VALUE_EXPR (parm
, local
);
3665 DECL_HAS_VALUE_EXPR_P (parm
) = 1;
3670 VEC_free (tree
, heap
, fnargs
);
3675 /* Compute the size and offset from the start of the stacked arguments for a
3676 parm passed in mode PASSED_MODE and with type TYPE.
3678 INITIAL_OFFSET_PTR points to the current offset into the stacked
3681 The starting offset and size for this parm are returned in
3682 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
3683 nonzero, the offset is that of stack slot, which is returned in
3684 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
3685 padding required from the initial offset ptr to the stack slot.
3687 IN_REGS is nonzero if the argument will be passed in registers. It will
3688 never be set if REG_PARM_STACK_SPACE is not defined.
3690 FNDECL is the function in which the argument was defined.
3692 There are two types of rounding that are done. The first, controlled by
3693 TARGET_FUNCTION_ARG_BOUNDARY, forces the offset from the start of the
3694 argument list to be aligned to the specific boundary (in bits). This
3695 rounding affects the initial and starting offsets, but not the argument
3698 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
3699 optionally rounds the size of the parm to PARM_BOUNDARY. The
3700 initial offset is not affected by this rounding, while the size always
3701 is and the starting offset may be. */
3703 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
3704 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
3705 callers pass in the total size of args so far as
3706 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
3709 locate_and_pad_parm (enum machine_mode passed_mode
, tree type
, int in_regs
,
3710 int partial
, tree fndecl ATTRIBUTE_UNUSED
,
3711 struct args_size
*initial_offset_ptr
,
3712 struct locate_and_pad_arg_data
*locate
)
3715 enum direction where_pad
;
3716 unsigned int boundary
, round_boundary
;
3717 int reg_parm_stack_space
= 0;
3718 int part_size_in_regs
;
3720 #ifdef REG_PARM_STACK_SPACE
3721 reg_parm_stack_space
= REG_PARM_STACK_SPACE (fndecl
);
3723 /* If we have found a stack parm before we reach the end of the
3724 area reserved for registers, skip that area. */
3727 if (reg_parm_stack_space
> 0)
3729 if (initial_offset_ptr
->var
)
3731 initial_offset_ptr
->var
3732 = size_binop (MAX_EXPR
, ARGS_SIZE_TREE (*initial_offset_ptr
),
3733 ssize_int (reg_parm_stack_space
));
3734 initial_offset_ptr
->constant
= 0;
3736 else if (initial_offset_ptr
->constant
< reg_parm_stack_space
)
3737 initial_offset_ptr
->constant
= reg_parm_stack_space
;
3740 #endif /* REG_PARM_STACK_SPACE */
3742 part_size_in_regs
= (reg_parm_stack_space
== 0 ? partial
: 0);
3745 = type
? size_in_bytes (type
) : size_int (GET_MODE_SIZE (passed_mode
));
3746 where_pad
= FUNCTION_ARG_PADDING (passed_mode
, type
);
3747 boundary
= targetm
.calls
.function_arg_boundary (passed_mode
, type
);
3748 round_boundary
= targetm
.calls
.function_arg_round_boundary (passed_mode
,
3750 locate
->where_pad
= where_pad
;
3752 /* Alignment can't exceed MAX_SUPPORTED_STACK_ALIGNMENT. */
3753 if (boundary
> MAX_SUPPORTED_STACK_ALIGNMENT
)
3754 boundary
= MAX_SUPPORTED_STACK_ALIGNMENT
;
3756 locate
->boundary
= boundary
;
3758 if (SUPPORTS_STACK_ALIGNMENT
)
3760 /* stack_alignment_estimated can't change after stack has been
3762 if (crtl
->stack_alignment_estimated
< boundary
)
3764 if (!crtl
->stack_realign_processed
)
3765 crtl
->stack_alignment_estimated
= boundary
;
3768 /* If stack is realigned and stack alignment value
3769 hasn't been finalized, it is OK not to increase
3770 stack_alignment_estimated. The bigger alignment
3771 requirement is recorded in stack_alignment_needed
3773 gcc_assert (!crtl
->stack_realign_finalized
3774 && crtl
->stack_realign_needed
);
3779 /* Remember if the outgoing parameter requires extra alignment on the
3780 calling function side. */
3781 if (crtl
->stack_alignment_needed
< boundary
)
3782 crtl
->stack_alignment_needed
= boundary
;
3783 if (crtl
->preferred_stack_boundary
< boundary
)
3784 crtl
->preferred_stack_boundary
= boundary
;
3786 #ifdef ARGS_GROW_DOWNWARD
3787 locate
->slot_offset
.constant
= -initial_offset_ptr
->constant
;
3788 if (initial_offset_ptr
->var
)
3789 locate
->slot_offset
.var
= size_binop (MINUS_EXPR
, ssize_int (0),
3790 initial_offset_ptr
->var
);
3794 if (where_pad
!= none
3795 && (!host_integerp (sizetree
, 1)
3796 || (tree_low_cst (sizetree
, 1) * BITS_PER_UNIT
) % round_boundary
))
3797 s2
= round_up (s2
, round_boundary
/ BITS_PER_UNIT
);
3798 SUB_PARM_SIZE (locate
->slot_offset
, s2
);
3801 locate
->slot_offset
.constant
+= part_size_in_regs
;
3804 #ifdef REG_PARM_STACK_SPACE
3805 || REG_PARM_STACK_SPACE (fndecl
) > 0
3808 pad_to_arg_alignment (&locate
->slot_offset
, boundary
,
3809 &locate
->alignment_pad
);
3811 locate
->size
.constant
= (-initial_offset_ptr
->constant
3812 - locate
->slot_offset
.constant
);
3813 if (initial_offset_ptr
->var
)
3814 locate
->size
.var
= size_binop (MINUS_EXPR
,
3815 size_binop (MINUS_EXPR
,
3817 initial_offset_ptr
->var
),
3818 locate
->slot_offset
.var
);
3820 /* Pad_below needs the pre-rounded size to know how much to pad
3822 locate
->offset
= locate
->slot_offset
;
3823 if (where_pad
== downward
)
3824 pad_below (&locate
->offset
, passed_mode
, sizetree
);
3826 #else /* !ARGS_GROW_DOWNWARD */
3828 #ifdef REG_PARM_STACK_SPACE
3829 || REG_PARM_STACK_SPACE (fndecl
) > 0
3832 pad_to_arg_alignment (initial_offset_ptr
, boundary
,
3833 &locate
->alignment_pad
);
3834 locate
->slot_offset
= *initial_offset_ptr
;
3836 #ifdef PUSH_ROUNDING
3837 if (passed_mode
!= BLKmode
)
3838 sizetree
= size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree
)));
3841 /* Pad_below needs the pre-rounded size to know how much to pad below
3842 so this must be done before rounding up. */
3843 locate
->offset
= locate
->slot_offset
;
3844 if (where_pad
== downward
)
3845 pad_below (&locate
->offset
, passed_mode
, sizetree
);
3847 if (where_pad
!= none
3848 && (!host_integerp (sizetree
, 1)
3849 || (tree_low_cst (sizetree
, 1) * BITS_PER_UNIT
) % round_boundary
))
3850 sizetree
= round_up (sizetree
, round_boundary
/ BITS_PER_UNIT
);
3852 ADD_PARM_SIZE (locate
->size
, sizetree
);
3854 locate
->size
.constant
-= part_size_in_regs
;
3855 #endif /* ARGS_GROW_DOWNWARD */
3857 #ifdef FUNCTION_ARG_OFFSET
3858 locate
->offset
.constant
+= FUNCTION_ARG_OFFSET (passed_mode
, type
);
3862 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
3863 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
3866 pad_to_arg_alignment (struct args_size
*offset_ptr
, int boundary
,
3867 struct args_size
*alignment_pad
)
3869 tree save_var
= NULL_TREE
;
3870 HOST_WIDE_INT save_constant
= 0;
3871 int boundary_in_bytes
= boundary
/ BITS_PER_UNIT
;
3872 HOST_WIDE_INT sp_offset
= STACK_POINTER_OFFSET
;
3874 #ifdef SPARC_STACK_BOUNDARY_HACK
3875 /* ??? The SPARC port may claim a STACK_BOUNDARY higher than
3876 the real alignment of %sp. However, when it does this, the
3877 alignment of %sp+STACK_POINTER_OFFSET is STACK_BOUNDARY. */
3878 if (SPARC_STACK_BOUNDARY_HACK
)
3882 if (boundary
> PARM_BOUNDARY
)
3884 save_var
= offset_ptr
->var
;
3885 save_constant
= offset_ptr
->constant
;
3888 alignment_pad
->var
= NULL_TREE
;
3889 alignment_pad
->constant
= 0;
3891 if (boundary
> BITS_PER_UNIT
)
3893 if (offset_ptr
->var
)
3895 tree sp_offset_tree
= ssize_int (sp_offset
);
3896 tree offset
= size_binop (PLUS_EXPR
,
3897 ARGS_SIZE_TREE (*offset_ptr
),
3899 #ifdef ARGS_GROW_DOWNWARD
3900 tree rounded
= round_down (offset
, boundary
/ BITS_PER_UNIT
);
3902 tree rounded
= round_up (offset
, boundary
/ BITS_PER_UNIT
);
3905 offset_ptr
->var
= size_binop (MINUS_EXPR
, rounded
, sp_offset_tree
);
3906 /* ARGS_SIZE_TREE includes constant term. */
3907 offset_ptr
->constant
= 0;
3908 if (boundary
> PARM_BOUNDARY
)
3909 alignment_pad
->var
= size_binop (MINUS_EXPR
, offset_ptr
->var
,
3914 offset_ptr
->constant
= -sp_offset
+
3915 #ifdef ARGS_GROW_DOWNWARD
3916 FLOOR_ROUND (offset_ptr
->constant
+ sp_offset
, boundary_in_bytes
);
3918 CEIL_ROUND (offset_ptr
->constant
+ sp_offset
, boundary_in_bytes
);
3920 if (boundary
> PARM_BOUNDARY
)
3921 alignment_pad
->constant
= offset_ptr
->constant
- save_constant
;
3927 pad_below (struct args_size
*offset_ptr
, enum machine_mode passed_mode
, tree sizetree
)
3929 if (passed_mode
!= BLKmode
)
3931 if (GET_MODE_BITSIZE (passed_mode
) % PARM_BOUNDARY
)
3932 offset_ptr
->constant
3933 += (((GET_MODE_BITSIZE (passed_mode
) + PARM_BOUNDARY
- 1)
3934 / PARM_BOUNDARY
* PARM_BOUNDARY
/ BITS_PER_UNIT
)
3935 - GET_MODE_SIZE (passed_mode
));
3939 if (TREE_CODE (sizetree
) != INTEGER_CST
3940 || (TREE_INT_CST_LOW (sizetree
) * BITS_PER_UNIT
) % PARM_BOUNDARY
)
3942 /* Round the size up to multiple of PARM_BOUNDARY bits. */
3943 tree s2
= round_up (sizetree
, PARM_BOUNDARY
/ BITS_PER_UNIT
);
3945 ADD_PARM_SIZE (*offset_ptr
, s2
);
3946 SUB_PARM_SIZE (*offset_ptr
, sizetree
);
3952 /* True if register REGNO was alive at a place where `setjmp' was
3953 called and was set more than once or is an argument. Such regs may
3954 be clobbered by `longjmp'. */
3957 regno_clobbered_at_setjmp (bitmap setjmp_crosses
, int regno
)
3959 /* There appear to be cases where some local vars never reach the
3960 backend but have bogus regnos. */
3961 if (regno
>= max_reg_num ())
3964 return ((REG_N_SETS (regno
) > 1
3965 || REGNO_REG_SET_P (df_get_live_out (ENTRY_BLOCK_PTR
), regno
))
3966 && REGNO_REG_SET_P (setjmp_crosses
, regno
));
3969 /* Walk the tree of blocks describing the binding levels within a
3970 function and warn about variables the might be killed by setjmp or
3971 vfork. This is done after calling flow_analysis before register
3972 allocation since that will clobber the pseudo-regs to hard
3976 setjmp_vars_warning (bitmap setjmp_crosses
, tree block
)
3980 for (decl
= BLOCK_VARS (block
); decl
; decl
= DECL_CHAIN (decl
))
3982 if (TREE_CODE (decl
) == VAR_DECL
3983 && DECL_RTL_SET_P (decl
)
3984 && REG_P (DECL_RTL (decl
))
3985 && regno_clobbered_at_setjmp (setjmp_crosses
, REGNO (DECL_RTL (decl
))))
3986 warning (OPT_Wclobbered
, "variable %q+D might be clobbered by"
3987 " %<longjmp%> or %<vfork%>", decl
);
3990 for (sub
= BLOCK_SUBBLOCKS (block
); sub
; sub
= BLOCK_CHAIN (sub
))
3991 setjmp_vars_warning (setjmp_crosses
, sub
);
3994 /* Do the appropriate part of setjmp_vars_warning
3995 but for arguments instead of local variables. */
3998 setjmp_args_warning (bitmap setjmp_crosses
)
4001 for (decl
= DECL_ARGUMENTS (current_function_decl
);
4002 decl
; decl
= DECL_CHAIN (decl
))
4003 if (DECL_RTL (decl
) != 0
4004 && REG_P (DECL_RTL (decl
))
4005 && regno_clobbered_at_setjmp (setjmp_crosses
, REGNO (DECL_RTL (decl
))))
4006 warning (OPT_Wclobbered
,
4007 "argument %q+D might be clobbered by %<longjmp%> or %<vfork%>",
4011 /* Generate warning messages for variables live across setjmp. */
4014 generate_setjmp_warnings (void)
4016 bitmap setjmp_crosses
= regstat_get_setjmp_crosses ();
4018 if (n_basic_blocks
== NUM_FIXED_BLOCKS
4019 || bitmap_empty_p (setjmp_crosses
))
4022 setjmp_vars_warning (setjmp_crosses
, DECL_INITIAL (current_function_decl
));
4023 setjmp_args_warning (setjmp_crosses
);
4027 /* Reverse the order of elements in the fragment chain T of blocks,
4028 and return the new head of the chain (old last element).
4029 In addition to that clear BLOCK_SAME_RANGE flags when needed
4030 and adjust BLOCK_SUPERCONTEXT from the super fragment to
4031 its super fragment origin. */
4034 block_fragments_nreverse (tree t
)
4036 tree prev
= 0, block
, next
, prev_super
= 0;
4037 tree super
= BLOCK_SUPERCONTEXT (t
);
4038 if (BLOCK_FRAGMENT_ORIGIN (super
))
4039 super
= BLOCK_FRAGMENT_ORIGIN (super
);
4040 for (block
= t
; block
; block
= next
)
4042 next
= BLOCK_FRAGMENT_CHAIN (block
);
4043 BLOCK_FRAGMENT_CHAIN (block
) = prev
;
4044 if ((prev
&& !BLOCK_SAME_RANGE (prev
))
4045 || (BLOCK_FRAGMENT_CHAIN (BLOCK_SUPERCONTEXT (block
))
4047 BLOCK_SAME_RANGE (block
) = 0;
4048 prev_super
= BLOCK_SUPERCONTEXT (block
);
4049 BLOCK_SUPERCONTEXT (block
) = super
;
4052 t
= BLOCK_FRAGMENT_ORIGIN (t
);
4053 if (BLOCK_FRAGMENT_CHAIN (BLOCK_SUPERCONTEXT (t
))
4055 BLOCK_SAME_RANGE (t
) = 0;
4056 BLOCK_SUPERCONTEXT (t
) = super
;
4060 /* Reverse the order of elements in the chain T of blocks,
4061 and return the new head of the chain (old last element).
4062 Also do the same on subblocks and reverse the order of elements
4063 in BLOCK_FRAGMENT_CHAIN as well. */
4066 blocks_nreverse_all (tree t
)
4068 tree prev
= 0, block
, next
;
4069 for (block
= t
; block
; block
= next
)
4071 next
= BLOCK_CHAIN (block
);
4072 BLOCK_CHAIN (block
) = prev
;
4073 if (BLOCK_FRAGMENT_CHAIN (block
)
4074 && BLOCK_FRAGMENT_ORIGIN (block
) == NULL_TREE
)
4076 BLOCK_FRAGMENT_CHAIN (block
)
4077 = block_fragments_nreverse (BLOCK_FRAGMENT_CHAIN (block
));
4078 if (!BLOCK_SAME_RANGE (BLOCK_FRAGMENT_CHAIN (block
)))
4079 BLOCK_SAME_RANGE (block
) = 0;
4081 BLOCK_SUBBLOCKS (block
) = blocks_nreverse_all (BLOCK_SUBBLOCKS (block
));
4088 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
4089 and create duplicate blocks. */
4090 /* ??? Need an option to either create block fragments or to create
4091 abstract origin duplicates of a source block. It really depends
4092 on what optimization has been performed. */
4095 reorder_blocks (void)
4097 tree block
= DECL_INITIAL (current_function_decl
);
4098 VEC(tree
,heap
) *block_stack
;
4100 if (block
== NULL_TREE
)
4103 block_stack
= VEC_alloc (tree
, heap
, 10);
4105 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
4106 clear_block_marks (block
);
4108 /* Prune the old trees away, so that they don't get in the way. */
4109 BLOCK_SUBBLOCKS (block
) = NULL_TREE
;
4110 BLOCK_CHAIN (block
) = NULL_TREE
;
4112 /* Recreate the block tree from the note nesting. */
4113 reorder_blocks_1 (get_insns (), block
, &block_stack
);
4114 BLOCK_SUBBLOCKS (block
) = blocks_nreverse_all (BLOCK_SUBBLOCKS (block
));
4116 VEC_free (tree
, heap
, block_stack
);
4119 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
4122 clear_block_marks (tree block
)
4126 TREE_ASM_WRITTEN (block
) = 0;
4127 clear_block_marks (BLOCK_SUBBLOCKS (block
));
4128 block
= BLOCK_CHAIN (block
);
4133 reorder_blocks_1 (rtx insns
, tree current_block
, VEC(tree
,heap
) **p_block_stack
)
4136 tree prev_beg
= NULL_TREE
, prev_end
= NULL_TREE
;
4138 for (insn
= insns
; insn
; insn
= NEXT_INSN (insn
))
4142 if (NOTE_KIND (insn
) == NOTE_INSN_BLOCK_BEG
)
4144 tree block
= NOTE_BLOCK (insn
);
4147 gcc_assert (BLOCK_FRAGMENT_ORIGIN (block
) == NULL_TREE
);
4151 BLOCK_SAME_RANGE (prev_end
) = 0;
4152 prev_end
= NULL_TREE
;
4154 /* If we have seen this block before, that means it now
4155 spans multiple address regions. Create a new fragment. */
4156 if (TREE_ASM_WRITTEN (block
))
4158 tree new_block
= copy_node (block
);
4160 BLOCK_SAME_RANGE (new_block
) = 0;
4161 BLOCK_FRAGMENT_ORIGIN (new_block
) = origin
;
4162 BLOCK_FRAGMENT_CHAIN (new_block
)
4163 = BLOCK_FRAGMENT_CHAIN (origin
);
4164 BLOCK_FRAGMENT_CHAIN (origin
) = new_block
;
4166 NOTE_BLOCK (insn
) = new_block
;
4170 if (prev_beg
== current_block
&& prev_beg
)
4171 BLOCK_SAME_RANGE (block
) = 1;
4175 BLOCK_SUBBLOCKS (block
) = 0;
4176 TREE_ASM_WRITTEN (block
) = 1;
4177 /* When there's only one block for the entire function,
4178 current_block == block and we mustn't do this, it
4179 will cause infinite recursion. */
4180 if (block
!= current_block
)
4183 if (block
!= origin
)
4184 gcc_assert (BLOCK_SUPERCONTEXT (origin
) == current_block
4185 || BLOCK_FRAGMENT_ORIGIN (BLOCK_SUPERCONTEXT
4188 if (VEC_empty (tree
, *p_block_stack
))
4189 super
= current_block
;
4192 super
= VEC_last (tree
, *p_block_stack
);
4193 gcc_assert (super
== current_block
4194 || BLOCK_FRAGMENT_ORIGIN (super
)
4197 BLOCK_SUPERCONTEXT (block
) = super
;
4198 BLOCK_CHAIN (block
) = BLOCK_SUBBLOCKS (current_block
);
4199 BLOCK_SUBBLOCKS (current_block
) = block
;
4200 current_block
= origin
;
4202 VEC_safe_push (tree
, heap
, *p_block_stack
, block
);
4204 else if (NOTE_KIND (insn
) == NOTE_INSN_BLOCK_END
)
4206 NOTE_BLOCK (insn
) = VEC_pop (tree
, *p_block_stack
);
4207 current_block
= BLOCK_SUPERCONTEXT (current_block
);
4208 if (BLOCK_FRAGMENT_ORIGIN (current_block
))
4209 current_block
= BLOCK_FRAGMENT_ORIGIN (current_block
);
4210 prev_beg
= NULL_TREE
;
4211 prev_end
= BLOCK_SAME_RANGE (NOTE_BLOCK (insn
))
4212 ? NOTE_BLOCK (insn
) : NULL_TREE
;
4217 prev_beg
= NULL_TREE
;
4219 BLOCK_SAME_RANGE (prev_end
) = 0;
4220 prev_end
= NULL_TREE
;
4225 /* Reverse the order of elements in the chain T of blocks,
4226 and return the new head of the chain (old last element). */
4229 blocks_nreverse (tree t
)
4231 tree prev
= 0, block
, next
;
4232 for (block
= t
; block
; block
= next
)
4234 next
= BLOCK_CHAIN (block
);
4235 BLOCK_CHAIN (block
) = prev
;
4241 /* Concatenate two chains of blocks (chained through BLOCK_CHAIN)
4242 by modifying the last node in chain 1 to point to chain 2. */
4245 block_chainon (tree op1
, tree op2
)
4254 for (t1
= op1
; BLOCK_CHAIN (t1
); t1
= BLOCK_CHAIN (t1
))
4256 BLOCK_CHAIN (t1
) = op2
;
4258 #ifdef ENABLE_TREE_CHECKING
4261 for (t2
= op2
; t2
; t2
= BLOCK_CHAIN (t2
))
4262 gcc_assert (t2
!= t1
);
4269 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
4270 non-NULL, list them all into VECTOR, in a depth-first preorder
4271 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
4275 all_blocks (tree block
, tree
*vector
)
4281 TREE_ASM_WRITTEN (block
) = 0;
4283 /* Record this block. */
4285 vector
[n_blocks
] = block
;
4289 /* Record the subblocks, and their subblocks... */
4290 n_blocks
+= all_blocks (BLOCK_SUBBLOCKS (block
),
4291 vector
? vector
+ n_blocks
: 0);
4292 block
= BLOCK_CHAIN (block
);
4298 /* Return a vector containing all the blocks rooted at BLOCK. The
4299 number of elements in the vector is stored in N_BLOCKS_P. The
4300 vector is dynamically allocated; it is the caller's responsibility
4301 to call `free' on the pointer returned. */
4304 get_block_vector (tree block
, int *n_blocks_p
)
4308 *n_blocks_p
= all_blocks (block
, NULL
);
4309 block_vector
= XNEWVEC (tree
, *n_blocks_p
);
4310 all_blocks (block
, block_vector
);
4312 return block_vector
;
4315 static GTY(()) int next_block_index
= 2;
4317 /* Set BLOCK_NUMBER for all the blocks in FN. */
4320 number_blocks (tree fn
)
4326 /* For SDB and XCOFF debugging output, we start numbering the blocks
4327 from 1 within each function, rather than keeping a running
4329 #if defined (SDB_DEBUGGING_INFO) || defined (XCOFF_DEBUGGING_INFO)
4330 if (write_symbols
== SDB_DEBUG
|| write_symbols
== XCOFF_DEBUG
)
4331 next_block_index
= 1;
4334 block_vector
= get_block_vector (DECL_INITIAL (fn
), &n_blocks
);
4336 /* The top-level BLOCK isn't numbered at all. */
4337 for (i
= 1; i
< n_blocks
; ++i
)
4338 /* We number the blocks from two. */
4339 BLOCK_NUMBER (block_vector
[i
]) = next_block_index
++;
4341 free (block_vector
);
4346 /* If VAR is present in a subblock of BLOCK, return the subblock. */
4349 debug_find_var_in_block_tree (tree var
, tree block
)
4353 for (t
= BLOCK_VARS (block
); t
; t
= TREE_CHAIN (t
))
4357 for (t
= BLOCK_SUBBLOCKS (block
); t
; t
= TREE_CHAIN (t
))
4359 tree ret
= debug_find_var_in_block_tree (var
, t
);
4367 /* Keep track of whether we're in a dummy function context. If we are,
4368 we don't want to invoke the set_current_function hook, because we'll
4369 get into trouble if the hook calls target_reinit () recursively or
4370 when the initial initialization is not yet complete. */
4372 static bool in_dummy_function
;
4374 /* Invoke the target hook when setting cfun. Update the optimization options
4375 if the function uses different options than the default. */
4378 invoke_set_current_function_hook (tree fndecl
)
4380 if (!in_dummy_function
)
4382 tree opts
= ((fndecl
)
4383 ? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (fndecl
)
4384 : optimization_default_node
);
4387 opts
= optimization_default_node
;
4389 /* Change optimization options if needed. */
4390 if (optimization_current_node
!= opts
)
4392 optimization_current_node
= opts
;
4393 cl_optimization_restore (&global_options
, TREE_OPTIMIZATION (opts
));
4396 targetm
.set_current_function (fndecl
);
4400 /* cfun should never be set directly; use this function. */
4403 set_cfun (struct function
*new_cfun
)
4405 if (cfun
!= new_cfun
)
4408 invoke_set_current_function_hook (new_cfun
? new_cfun
->decl
: NULL_TREE
);
4412 /* Initialized with NOGC, making this poisonous to the garbage collector. */
4414 static VEC(function_p
,heap
) *cfun_stack
;
4416 /* Push the current cfun onto the stack, and set cfun to new_cfun. Also set
4417 current_function_decl accordingly. */
4420 push_cfun (struct function
*new_cfun
)
4422 gcc_assert ((!cfun
&& !current_function_decl
)
4423 || (cfun
&& current_function_decl
== cfun
->decl
));
4424 VEC_safe_push (function_p
, heap
, cfun_stack
, cfun
);
4425 current_function_decl
= new_cfun
? new_cfun
->decl
: NULL_TREE
;
4426 set_cfun (new_cfun
);
4429 /* Pop cfun from the stack. Also set current_function_decl accordingly. */
4434 struct function
*new_cfun
= VEC_pop (function_p
, cfun_stack
);
4435 /* When in_dummy_function, we do have a cfun but current_function_decl is
4436 NULL. We also allow pushing NULL cfun and subsequently changing
4437 current_function_decl to something else and have both restored by
4439 gcc_checking_assert (in_dummy_function
4441 || current_function_decl
== cfun
->decl
);
4442 set_cfun (new_cfun
);
4443 current_function_decl
= new_cfun
? new_cfun
->decl
: NULL_TREE
;
4446 /* Return value of funcdef and increase it. */
4448 get_next_funcdef_no (void)
4450 return funcdef_no
++;
4453 /* Return value of funcdef. */
4455 get_last_funcdef_no (void)
4460 /* Allocate a function structure for FNDECL and set its contents
4461 to the defaults. Set cfun to the newly-allocated object.
4462 Some of the helper functions invoked during initialization assume
4463 that cfun has already been set. Therefore, assign the new object
4464 directly into cfun and invoke the back end hook explicitly at the
4465 very end, rather than initializing a temporary and calling set_cfun
4468 ABSTRACT_P is true if this is a function that will never be seen by
4469 the middle-end. Such functions are front-end concepts (like C++
4470 function templates) that do not correspond directly to functions
4471 placed in object files. */
4474 allocate_struct_function (tree fndecl
, bool abstract_p
)
4477 tree fntype
= fndecl
? TREE_TYPE (fndecl
) : NULL_TREE
;
4479 cfun
= ggc_alloc_cleared_function ();
4481 init_eh_for_function ();
4483 if (init_machine_status
)
4484 cfun
->machine
= (*init_machine_status
) ();
4486 #ifdef OVERRIDE_ABI_FORMAT
4487 OVERRIDE_ABI_FORMAT (fndecl
);
4490 if (fndecl
!= NULL_TREE
)
4492 DECL_STRUCT_FUNCTION (fndecl
) = cfun
;
4493 cfun
->decl
= fndecl
;
4494 current_function_funcdef_no
= get_next_funcdef_no ();
4496 result
= DECL_RESULT (fndecl
);
4497 if (!abstract_p
&& aggregate_value_p (result
, fndecl
))
4499 #ifdef PCC_STATIC_STRUCT_RETURN
4500 cfun
->returns_pcc_struct
= 1;
4502 cfun
->returns_struct
= 1;
4505 cfun
->stdarg
= stdarg_p (fntype
);
4507 /* Assume all registers in stdarg functions need to be saved. */
4508 cfun
->va_list_gpr_size
= VA_LIST_MAX_GPR_SIZE
;
4509 cfun
->va_list_fpr_size
= VA_LIST_MAX_FPR_SIZE
;
4511 /* ??? This could be set on a per-function basis by the front-end
4512 but is this worth the hassle? */
4513 cfun
->can_throw_non_call_exceptions
= flag_non_call_exceptions
;
4516 invoke_set_current_function_hook (fndecl
);
4519 /* This is like allocate_struct_function, but pushes a new cfun for FNDECL
4520 instead of just setting it. */
4523 push_struct_function (tree fndecl
)
4525 /* When in_dummy_function we might be in the middle of a pop_cfun and
4526 current_function_decl and cfun may not match. */
4527 gcc_assert (in_dummy_function
4528 || (!cfun
&& !current_function_decl
)
4529 || (cfun
&& current_function_decl
== cfun
->decl
));
4530 VEC_safe_push (function_p
, heap
, cfun_stack
, cfun
);
4531 current_function_decl
= fndecl
;
4532 allocate_struct_function (fndecl
, false);
4535 /* Reset crtl and other non-struct-function variables to defaults as
4536 appropriate for emitting rtl at the start of a function. */
4539 prepare_function_start (void)
4541 gcc_assert (!crtl
->emit
.x_last_insn
);
4544 init_varasm_status ();
4546 default_rtl_profile ();
4548 if (flag_stack_usage_info
)
4550 cfun
->su
= ggc_alloc_cleared_stack_usage ();
4551 cfun
->su
->static_stack_size
= -1;
4554 cse_not_expected
= ! optimize
;
4556 /* Caller save not needed yet. */
4557 caller_save_needed
= 0;
4559 /* We haven't done register allocation yet. */
4562 /* Indicate that we have not instantiated virtual registers yet. */
4563 virtuals_instantiated
= 0;
4565 /* Indicate that we want CONCATs now. */
4566 generating_concat_p
= 1;
4568 /* Indicate we have no need of a frame pointer yet. */
4569 frame_pointer_needed
= 0;
4572 /* Initialize the rtl expansion mechanism so that we can do simple things
4573 like generate sequences. This is used to provide a context during global
4574 initialization of some passes. You must call expand_dummy_function_end
4575 to exit this context. */
4578 init_dummy_function_start (void)
4580 gcc_assert (!in_dummy_function
);
4581 in_dummy_function
= true;
4582 push_struct_function (NULL_TREE
);
4583 prepare_function_start ();
4586 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
4587 and initialize static variables for generating RTL for the statements
4591 init_function_start (tree subr
)
4593 if (subr
&& DECL_STRUCT_FUNCTION (subr
))
4594 set_cfun (DECL_STRUCT_FUNCTION (subr
));
4596 allocate_struct_function (subr
, false);
4597 prepare_function_start ();
4598 decide_function_section (subr
);
4600 /* Warn if this value is an aggregate type,
4601 regardless of which calling convention we are using for it. */
4602 if (AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr
))))
4603 warning (OPT_Waggregate_return
, "function returns an aggregate");
4608 expand_main_function (void)
4610 #if (defined(INVOKE__main) \
4611 || (!defined(HAS_INIT_SECTION) \
4612 && !defined(INIT_SECTION_ASM_OP) \
4613 && !defined(INIT_ARRAY_SECTION_ASM_OP)))
4614 emit_library_call (init_one_libfunc (NAME__MAIN
), LCT_NORMAL
, VOIDmode
, 0);
4618 /* Expand code to initialize the stack_protect_guard. This is invoked at
4619 the beginning of a function to be protected. */
4621 #ifndef HAVE_stack_protect_set
4622 # define HAVE_stack_protect_set 0
4623 # define gen_stack_protect_set(x,y) (gcc_unreachable (), NULL_RTX)
4627 stack_protect_prologue (void)
4629 tree guard_decl
= targetm
.stack_protect_guard ();
4632 x
= expand_normal (crtl
->stack_protect_guard
);
4633 y
= expand_normal (guard_decl
);
4635 /* Allow the target to copy from Y to X without leaking Y into a
4637 if (HAVE_stack_protect_set
)
4639 rtx insn
= gen_stack_protect_set (x
, y
);
4647 /* Otherwise do a straight move. */
4648 emit_move_insn (x
, y
);
4651 /* Expand code to verify the stack_protect_guard. This is invoked at
4652 the end of a function to be protected. */
4654 #ifndef HAVE_stack_protect_test
4655 # define HAVE_stack_protect_test 0
4656 # define gen_stack_protect_test(x, y, z) (gcc_unreachable (), NULL_RTX)
4660 stack_protect_epilogue (void)
4662 tree guard_decl
= targetm
.stack_protect_guard ();
4663 rtx label
= gen_label_rtx ();
4666 x
= expand_normal (crtl
->stack_protect_guard
);
4667 y
= expand_normal (guard_decl
);
4669 /* Allow the target to compare Y with X without leaking either into
4671 switch (HAVE_stack_protect_test
!= 0)
4674 tmp
= gen_stack_protect_test (x
, y
, label
);
4683 emit_cmp_and_jump_insns (x
, y
, EQ
, NULL_RTX
, ptr_mode
, 1, label
);
4687 /* The noreturn predictor has been moved to the tree level. The rtl-level
4688 predictors estimate this branch about 20%, which isn't enough to get
4689 things moved out of line. Since this is the only extant case of adding
4690 a noreturn function at the rtl level, it doesn't seem worth doing ought
4691 except adding the prediction by hand. */
4692 tmp
= get_last_insn ();
4694 predict_insn_def (tmp
, PRED_NORETURN
, TAKEN
);
4696 expand_call (targetm
.stack_protect_fail (), NULL_RTX
, /*ignore=*/true);
4701 /* Start the RTL for a new function, and set variables used for
4703 SUBR is the FUNCTION_DECL node.
4704 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
4705 the function's parameters, which must be run at any return statement. */
4708 expand_function_start (tree subr
)
4710 /* Make sure volatile mem refs aren't considered
4711 valid operands of arithmetic insns. */
4712 init_recog_no_volatile ();
4716 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr
));
4719 = (stack_limit_rtx
!= NULL_RTX
&& ! DECL_NO_LIMIT_STACK (subr
));
4721 /* Make the label for return statements to jump to. Do not special
4722 case machines with special return instructions -- they will be
4723 handled later during jump, ifcvt, or epilogue creation. */
4724 return_label
= gen_label_rtx ();
4726 /* Initialize rtx used to return the value. */
4727 /* Do this before assign_parms so that we copy the struct value address
4728 before any library calls that assign parms might generate. */
4730 /* Decide whether to return the value in memory or in a register. */
4731 if (aggregate_value_p (DECL_RESULT (subr
), subr
))
4733 /* Returning something that won't go in a register. */
4734 rtx value_address
= 0;
4736 #ifdef PCC_STATIC_STRUCT_RETURN
4737 if (cfun
->returns_pcc_struct
)
4739 int size
= int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr
)));
4740 value_address
= assemble_static_space (size
);
4745 rtx sv
= targetm
.calls
.struct_value_rtx (TREE_TYPE (subr
), 2);
4746 /* Expect to be passed the address of a place to store the value.
4747 If it is passed as an argument, assign_parms will take care of
4751 value_address
= gen_reg_rtx (Pmode
);
4752 emit_move_insn (value_address
, sv
);
4757 rtx x
= value_address
;
4758 if (!DECL_BY_REFERENCE (DECL_RESULT (subr
)))
4760 x
= gen_rtx_MEM (DECL_MODE (DECL_RESULT (subr
)), x
);
4761 set_mem_attributes (x
, DECL_RESULT (subr
), 1);
4763 SET_DECL_RTL (DECL_RESULT (subr
), x
);
4766 else if (DECL_MODE (DECL_RESULT (subr
)) == VOIDmode
)
4767 /* If return mode is void, this decl rtl should not be used. */
4768 SET_DECL_RTL (DECL_RESULT (subr
), NULL_RTX
);
4771 /* Compute the return values into a pseudo reg, which we will copy
4772 into the true return register after the cleanups are done. */
4773 tree return_type
= TREE_TYPE (DECL_RESULT (subr
));
4774 if (TYPE_MODE (return_type
) != BLKmode
4775 && targetm
.calls
.return_in_msb (return_type
))
4776 /* expand_function_end will insert the appropriate padding in
4777 this case. Use the return value's natural (unpadded) mode
4778 within the function proper. */
4779 SET_DECL_RTL (DECL_RESULT (subr
),
4780 gen_reg_rtx (TYPE_MODE (return_type
)));
4783 /* In order to figure out what mode to use for the pseudo, we
4784 figure out what the mode of the eventual return register will
4785 actually be, and use that. */
4786 rtx hard_reg
= hard_function_value (return_type
, subr
, 0, 1);
4788 /* Structures that are returned in registers are not
4789 aggregate_value_p, so we may see a PARALLEL or a REG. */
4790 if (REG_P (hard_reg
))
4791 SET_DECL_RTL (DECL_RESULT (subr
),
4792 gen_reg_rtx (GET_MODE (hard_reg
)));
4795 gcc_assert (GET_CODE (hard_reg
) == PARALLEL
);
4796 SET_DECL_RTL (DECL_RESULT (subr
), gen_group_rtx (hard_reg
));
4800 /* Set DECL_REGISTER flag so that expand_function_end will copy the
4801 result to the real return register(s). */
4802 DECL_REGISTER (DECL_RESULT (subr
)) = 1;
4805 /* Initialize rtx for parameters and local variables.
4806 In some cases this requires emitting insns. */
4807 assign_parms (subr
);
4809 /* If function gets a static chain arg, store it. */
4810 if (cfun
->static_chain_decl
)
4812 tree parm
= cfun
->static_chain_decl
;
4813 rtx local
, chain
, insn
;
4815 local
= gen_reg_rtx (Pmode
);
4816 chain
= targetm
.calls
.static_chain (current_function_decl
, true);
4818 set_decl_incoming_rtl (parm
, chain
, false);
4819 SET_DECL_RTL (parm
, local
);
4820 mark_reg_pointer (local
, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm
))));
4822 insn
= emit_move_insn (local
, chain
);
4824 /* Mark the register as eliminable, similar to parameters. */
4826 && reg_mentioned_p (arg_pointer_rtx
, XEXP (chain
, 0)))
4827 set_dst_reg_note (insn
, REG_EQUIV
, chain
, local
);
4830 /* If the function receives a non-local goto, then store the
4831 bits we need to restore the frame pointer. */
4832 if (cfun
->nonlocal_goto_save_area
)
4837 tree var
= TREE_OPERAND (cfun
->nonlocal_goto_save_area
, 0);
4838 gcc_assert (DECL_RTL_SET_P (var
));
4840 t_save
= build4 (ARRAY_REF
,
4841 TREE_TYPE (TREE_TYPE (cfun
->nonlocal_goto_save_area
)),
4842 cfun
->nonlocal_goto_save_area
,
4843 integer_zero_node
, NULL_TREE
, NULL_TREE
);
4844 r_save
= expand_expr (t_save
, NULL_RTX
, VOIDmode
, EXPAND_WRITE
);
4845 gcc_assert (GET_MODE (r_save
) == Pmode
);
4847 emit_move_insn (r_save
, targetm
.builtin_setjmp_frame_value ());
4848 update_nonlocal_goto_save_area ();
4851 /* The following was moved from init_function_start.
4852 The move is supposed to make sdb output more accurate. */
4853 /* Indicate the beginning of the function body,
4854 as opposed to parm setup. */
4855 emit_note (NOTE_INSN_FUNCTION_BEG
);
4857 gcc_assert (NOTE_P (get_last_insn ()));
4859 parm_birth_insn
= get_last_insn ();
4864 PROFILE_HOOK (current_function_funcdef_no
);
4868 /* If we are doing generic stack checking, the probe should go here. */
4869 if (flag_stack_check
== GENERIC_STACK_CHECK
)
4870 stack_check_probe_note
= emit_note (NOTE_INSN_DELETED
);
4873 /* Undo the effects of init_dummy_function_start. */
4875 expand_dummy_function_end (void)
4877 gcc_assert (in_dummy_function
);
4879 /* End any sequences that failed to be closed due to syntax errors. */
4880 while (in_sequence_p ())
4883 /* Outside function body, can't compute type's actual size
4884 until next function's body starts. */
4886 free_after_parsing (cfun
);
4887 free_after_compilation (cfun
);
4889 in_dummy_function
= false;
4892 /* Call DOIT for each hard register used as a return value from
4893 the current function. */
4896 diddle_return_value (void (*doit
) (rtx
, void *), void *arg
)
4898 rtx outgoing
= crtl
->return_rtx
;
4903 if (REG_P (outgoing
))
4904 (*doit
) (outgoing
, arg
);
4905 else if (GET_CODE (outgoing
) == PARALLEL
)
4909 for (i
= 0; i
< XVECLEN (outgoing
, 0); i
++)
4911 rtx x
= XEXP (XVECEXP (outgoing
, 0, i
), 0);
4913 if (REG_P (x
) && REGNO (x
) < FIRST_PSEUDO_REGISTER
)
4920 do_clobber_return_reg (rtx reg
, void *arg ATTRIBUTE_UNUSED
)
4926 clobber_return_register (void)
4928 diddle_return_value (do_clobber_return_reg
, NULL
);
4930 /* In case we do use pseudo to return value, clobber it too. */
4931 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl
)))
4933 tree decl_result
= DECL_RESULT (current_function_decl
);
4934 rtx decl_rtl
= DECL_RTL (decl_result
);
4935 if (REG_P (decl_rtl
) && REGNO (decl_rtl
) >= FIRST_PSEUDO_REGISTER
)
4937 do_clobber_return_reg (decl_rtl
, NULL
);
4943 do_use_return_reg (rtx reg
, void *arg ATTRIBUTE_UNUSED
)
4949 use_return_register (void)
4951 diddle_return_value (do_use_return_reg
, NULL
);
4954 /* Possibly warn about unused parameters. */
4956 do_warn_unused_parameter (tree fn
)
4960 for (decl
= DECL_ARGUMENTS (fn
);
4961 decl
; decl
= DECL_CHAIN (decl
))
4962 if (!TREE_USED (decl
) && TREE_CODE (decl
) == PARM_DECL
4963 && DECL_NAME (decl
) && !DECL_ARTIFICIAL (decl
)
4964 && !TREE_NO_WARNING (decl
))
4965 warning (OPT_Wunused_parameter
, "unused parameter %q+D", decl
);
4968 static GTY(()) rtx initial_trampoline
;
4970 /* Generate RTL for the end of the current function. */
4973 expand_function_end (void)
4977 /* If arg_pointer_save_area was referenced only from a nested
4978 function, we will not have initialized it yet. Do that now. */
4979 if (arg_pointer_save_area
&& ! crtl
->arg_pointer_save_area_init
)
4980 get_arg_pointer_save_area ();
4982 /* If we are doing generic stack checking and this function makes calls,
4983 do a stack probe at the start of the function to ensure we have enough
4984 space for another stack frame. */
4985 if (flag_stack_check
== GENERIC_STACK_CHECK
)
4989 for (insn
= get_insns (); insn
; insn
= NEXT_INSN (insn
))
4992 rtx max_frame_size
= GEN_INT (STACK_CHECK_MAX_FRAME_SIZE
);
4994 if (STACK_CHECK_MOVING_SP
)
4995 anti_adjust_stack_and_probe (max_frame_size
, true);
4997 probe_stack_range (STACK_OLD_CHECK_PROTECT
, max_frame_size
);
5000 set_insn_locations (seq
, prologue_location
);
5001 emit_insn_before (seq
, stack_check_probe_note
);
5006 /* End any sequences that failed to be closed due to syntax errors. */
5007 while (in_sequence_p ())
5010 clear_pending_stack_adjust ();
5011 do_pending_stack_adjust ();
5013 /* Output a linenumber for the end of the function.
5014 SDB depends on this. */
5015 set_curr_insn_location (input_location
);
5017 /* Before the return label (if any), clobber the return
5018 registers so that they are not propagated live to the rest of
5019 the function. This can only happen with functions that drop
5020 through; if there had been a return statement, there would
5021 have either been a return rtx, or a jump to the return label.
5023 We delay actual code generation after the current_function_value_rtx
5025 clobber_after
= get_last_insn ();
5027 /* Output the label for the actual return from the function. */
5028 emit_label (return_label
);
5030 if (targetm_common
.except_unwind_info (&global_options
) == UI_SJLJ
)
5032 /* Let except.c know where it should emit the call to unregister
5033 the function context for sjlj exceptions. */
5034 if (flag_exceptions
)
5035 sjlj_emit_function_exit_after (get_last_insn ());
5039 /* We want to ensure that instructions that may trap are not
5040 moved into the epilogue by scheduling, because we don't
5041 always emit unwind information for the epilogue. */
5042 if (cfun
->can_throw_non_call_exceptions
)
5043 emit_insn (gen_blockage ());
5046 /* If this is an implementation of throw, do what's necessary to
5047 communicate between __builtin_eh_return and the epilogue. */
5048 expand_eh_return ();
5050 /* If scalar return value was computed in a pseudo-reg, or was a named
5051 return value that got dumped to the stack, copy that to the hard
5053 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl
)))
5055 tree decl_result
= DECL_RESULT (current_function_decl
);
5056 rtx decl_rtl
= DECL_RTL (decl_result
);
5058 if (REG_P (decl_rtl
)
5059 ? REGNO (decl_rtl
) >= FIRST_PSEUDO_REGISTER
5060 : DECL_REGISTER (decl_result
))
5062 rtx real_decl_rtl
= crtl
->return_rtx
;
5064 /* This should be set in assign_parms. */
5065 gcc_assert (REG_FUNCTION_VALUE_P (real_decl_rtl
));
5067 /* If this is a BLKmode structure being returned in registers,
5068 then use the mode computed in expand_return. Note that if
5069 decl_rtl is memory, then its mode may have been changed,
5070 but that crtl->return_rtx has not. */
5071 if (GET_MODE (real_decl_rtl
) == BLKmode
)
5072 PUT_MODE (real_decl_rtl
, GET_MODE (decl_rtl
));
5074 /* If a non-BLKmode return value should be padded at the least
5075 significant end of the register, shift it left by the appropriate
5076 amount. BLKmode results are handled using the group load/store
5078 if (TYPE_MODE (TREE_TYPE (decl_result
)) != BLKmode
5079 && targetm
.calls
.return_in_msb (TREE_TYPE (decl_result
)))
5081 emit_move_insn (gen_rtx_REG (GET_MODE (decl_rtl
),
5082 REGNO (real_decl_rtl
)),
5084 shift_return_value (GET_MODE (decl_rtl
), true, real_decl_rtl
);
5086 /* If a named return value dumped decl_return to memory, then
5087 we may need to re-do the PROMOTE_MODE signed/unsigned
5089 else if (GET_MODE (real_decl_rtl
) != GET_MODE (decl_rtl
))
5091 int unsignedp
= TYPE_UNSIGNED (TREE_TYPE (decl_result
));
5092 promote_function_mode (TREE_TYPE (decl_result
),
5093 GET_MODE (decl_rtl
), &unsignedp
,
5094 TREE_TYPE (current_function_decl
), 1);
5096 convert_move (real_decl_rtl
, decl_rtl
, unsignedp
);
5098 else if (GET_CODE (real_decl_rtl
) == PARALLEL
)
5100 /* If expand_function_start has created a PARALLEL for decl_rtl,
5101 move the result to the real return registers. Otherwise, do
5102 a group load from decl_rtl for a named return. */
5103 if (GET_CODE (decl_rtl
) == PARALLEL
)
5104 emit_group_move (real_decl_rtl
, decl_rtl
);
5106 emit_group_load (real_decl_rtl
, decl_rtl
,
5107 TREE_TYPE (decl_result
),
5108 int_size_in_bytes (TREE_TYPE (decl_result
)));
5110 /* In the case of complex integer modes smaller than a word, we'll
5111 need to generate some non-trivial bitfield insertions. Do that
5112 on a pseudo and not the hard register. */
5113 else if (GET_CODE (decl_rtl
) == CONCAT
5114 && GET_MODE_CLASS (GET_MODE (decl_rtl
)) == MODE_COMPLEX_INT
5115 && GET_MODE_BITSIZE (GET_MODE (decl_rtl
)) <= BITS_PER_WORD
)
5117 int old_generating_concat_p
;
5120 old_generating_concat_p
= generating_concat_p
;
5121 generating_concat_p
= 0;
5122 tmp
= gen_reg_rtx (GET_MODE (decl_rtl
));
5123 generating_concat_p
= old_generating_concat_p
;
5125 emit_move_insn (tmp
, decl_rtl
);
5126 emit_move_insn (real_decl_rtl
, tmp
);
5129 emit_move_insn (real_decl_rtl
, decl_rtl
);
5133 /* If returning a structure, arrange to return the address of the value
5134 in a place where debuggers expect to find it.
5136 If returning a structure PCC style,
5137 the caller also depends on this value.
5138 And cfun->returns_pcc_struct is not necessarily set. */
5139 if (cfun
->returns_struct
5140 || cfun
->returns_pcc_struct
)
5142 rtx value_address
= DECL_RTL (DECL_RESULT (current_function_decl
));
5143 tree type
= TREE_TYPE (DECL_RESULT (current_function_decl
));
5146 if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl
)))
5147 type
= TREE_TYPE (type
);
5149 value_address
= XEXP (value_address
, 0);
5151 outgoing
= targetm
.calls
.function_value (build_pointer_type (type
),
5152 current_function_decl
, true);
5154 /* Mark this as a function return value so integrate will delete the
5155 assignment and USE below when inlining this function. */
5156 REG_FUNCTION_VALUE_P (outgoing
) = 1;
5158 /* The address may be ptr_mode and OUTGOING may be Pmode. */
5159 value_address
= convert_memory_address (GET_MODE (outgoing
),
5162 emit_move_insn (outgoing
, value_address
);
5164 /* Show return register used to hold result (in this case the address
5166 crtl
->return_rtx
= outgoing
;
5169 /* Emit the actual code to clobber return register. */
5174 clobber_return_register ();
5178 emit_insn_after (seq
, clobber_after
);
5181 /* Output the label for the naked return from the function. */
5182 if (naked_return_label
)
5183 emit_label (naked_return_label
);
5185 /* @@@ This is a kludge. We want to ensure that instructions that
5186 may trap are not moved into the epilogue by scheduling, because
5187 we don't always emit unwind information for the epilogue. */
5188 if (cfun
->can_throw_non_call_exceptions
5189 && targetm_common
.except_unwind_info (&global_options
) != UI_SJLJ
)
5190 emit_insn (gen_blockage ());
5192 /* If stack protection is enabled for this function, check the guard. */
5193 if (crtl
->stack_protect_guard
)
5194 stack_protect_epilogue ();
5196 /* If we had calls to alloca, and this machine needs
5197 an accurate stack pointer to exit the function,
5198 insert some code to save and restore the stack pointer. */
5199 if (! EXIT_IGNORE_STACK
5200 && cfun
->calls_alloca
)
5205 emit_stack_save (SAVE_FUNCTION
, &tem
);
5208 emit_insn_before (seq
, parm_birth_insn
);
5210 emit_stack_restore (SAVE_FUNCTION
, tem
);
5213 /* ??? This should no longer be necessary since stupid is no longer with
5214 us, but there are some parts of the compiler (eg reload_combine, and
5215 sh mach_dep_reorg) that still try and compute their own lifetime info
5216 instead of using the general framework. */
5217 use_return_register ();
5221 get_arg_pointer_save_area (void)
5223 rtx ret
= arg_pointer_save_area
;
5227 ret
= assign_stack_local (Pmode
, GET_MODE_SIZE (Pmode
), 0);
5228 arg_pointer_save_area
= ret
;
5231 if (! crtl
->arg_pointer_save_area_init
)
5235 /* Save the arg pointer at the beginning of the function. The
5236 generated stack slot may not be a valid memory address, so we
5237 have to check it and fix it if necessary. */
5239 emit_move_insn (validize_mem (ret
),
5240 crtl
->args
.internal_arg_pointer
);
5244 push_topmost_sequence ();
5245 emit_insn_after (seq
, entry_of_function ());
5246 pop_topmost_sequence ();
5248 crtl
->arg_pointer_save_area_init
= true;
5254 /* Add a list of INSNS to the hash HASHP, possibly allocating HASHP
5255 for the first time. */
5258 record_insns (rtx insns
, rtx end
, htab_t
*hashp
)
5261 htab_t hash
= *hashp
;
5265 = htab_create_ggc (17, htab_hash_pointer
, htab_eq_pointer
, NULL
);
5267 for (tmp
= insns
; tmp
!= end
; tmp
= NEXT_INSN (tmp
))
5269 void **slot
= htab_find_slot (hash
, tmp
, INSERT
);
5270 gcc_assert (*slot
== NULL
);
5275 /* INSN has been duplicated or replaced by as COPY, perhaps by duplicating a
5276 basic block, splitting or peepholes. If INSN is a prologue or epilogue
5277 insn, then record COPY as well. */
5280 maybe_copy_prologue_epilogue_insn (rtx insn
, rtx copy
)
5285 hash
= epilogue_insn_hash
;
5286 if (!hash
|| !htab_find (hash
, insn
))
5288 hash
= prologue_insn_hash
;
5289 if (!hash
|| !htab_find (hash
, insn
))
5293 slot
= htab_find_slot (hash
, copy
, INSERT
);
5294 gcc_assert (*slot
== NULL
);
5298 /* Set the location of the insn chain starting at INSN to LOC. */
5300 set_insn_locations (rtx insn
, int loc
)
5302 while (insn
!= NULL_RTX
)
5305 INSN_LOCATION (insn
) = loc
;
5306 insn
= NEXT_INSN (insn
);
5310 /* Determine if any INSNs in HASH are, or are part of, INSN. Because
5311 we can be running after reorg, SEQUENCE rtl is possible. */
5314 contains (const_rtx insn
, htab_t hash
)
5319 if (NONJUMP_INSN_P (insn
) && GET_CODE (PATTERN (insn
)) == SEQUENCE
)
5322 for (i
= XVECLEN (PATTERN (insn
), 0) - 1; i
>= 0; i
--)
5323 if (htab_find (hash
, XVECEXP (PATTERN (insn
), 0, i
)))
5328 return htab_find (hash
, insn
) != NULL
;
5332 prologue_epilogue_contains (const_rtx insn
)
5334 if (contains (insn
, prologue_insn_hash
))
5336 if (contains (insn
, epilogue_insn_hash
))
5341 #ifdef HAVE_simple_return
5343 /* Return true if INSN requires the stack frame to be set up.
5344 PROLOGUE_USED contains the hard registers used in the function
5345 prologue. SET_UP_BY_PROLOGUE is the set of registers we expect the
5346 prologue to set up for the function. */
5348 requires_stack_frame_p (rtx insn
, HARD_REG_SET prologue_used
,
5349 HARD_REG_SET set_up_by_prologue
)
5352 HARD_REG_SET hardregs
;
5356 return !SIBLING_CALL_P (insn
);
5358 /* We need a frame to get the unique CFA expected by the unwinder. */
5359 if (cfun
->can_throw_non_call_exceptions
&& can_throw_internal (insn
))
5362 CLEAR_HARD_REG_SET (hardregs
);
5363 for (df_rec
= DF_INSN_DEFS (insn
); *df_rec
; df_rec
++)
5365 rtx dreg
= DF_REF_REG (*df_rec
);
5370 add_to_hard_reg_set (&hardregs
, GET_MODE (dreg
),
5373 if (hard_reg_set_intersect_p (hardregs
, prologue_used
))
5375 AND_COMPL_HARD_REG_SET (hardregs
, call_used_reg_set
);
5376 for (regno
= 0; regno
< FIRST_PSEUDO_REGISTER
; regno
++)
5377 if (TEST_HARD_REG_BIT (hardregs
, regno
)
5378 && df_regs_ever_live_p (regno
))
5381 for (df_rec
= DF_INSN_USES (insn
); *df_rec
; df_rec
++)
5383 rtx reg
= DF_REF_REG (*df_rec
);
5388 add_to_hard_reg_set (&hardregs
, GET_MODE (reg
),
5391 if (hard_reg_set_intersect_p (hardregs
, set_up_by_prologue
))
5397 /* See whether BB has a single successor that uses [REGNO, END_REGNO),
5398 and if BB is its only predecessor. Return that block if so,
5399 otherwise return null. */
5402 next_block_for_reg (basic_block bb
, int regno
, int end_regno
)
5410 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
5412 live
= df_get_live_in (e
->dest
);
5413 for (i
= regno
; i
< end_regno
; i
++)
5414 if (REGNO_REG_SET_P (live
, i
))
5416 if (live_edge
&& live_edge
!= e
)
5422 /* We can sometimes encounter dead code. Don't try to move it
5423 into the exit block. */
5424 if (!live_edge
|| live_edge
->dest
== EXIT_BLOCK_PTR
)
5427 /* Reject targets of abnormal edges. This is needed for correctness
5428 on ports like Alpha and MIPS, whose pic_offset_table_rtx can die on
5429 exception edges even though it is generally treated as call-saved
5430 for the majority of the compilation. Moving across abnormal edges
5431 isn't going to be interesting for shrink-wrap usage anyway. */
5432 if (live_edge
->flags
& EDGE_ABNORMAL
)
5435 if (EDGE_COUNT (live_edge
->dest
->preds
) > 1)
5438 return live_edge
->dest
;
5441 /* Try to move INSN from BB to a successor. Return true on success.
5442 USES and DEFS are the set of registers that are used and defined
5443 after INSN in BB. */
5446 move_insn_for_shrink_wrap (basic_block bb
, rtx insn
,
5447 const HARD_REG_SET uses
,
5448 const HARD_REG_SET defs
)
5451 bitmap live_out
, live_in
, bb_uses
, bb_defs
;
5452 unsigned int i
, dregno
, end_dregno
, sregno
, end_sregno
;
5453 basic_block next_block
;
5455 /* Look for a simple register copy. */
5456 set
= single_set (insn
);
5459 src
= SET_SRC (set
);
5460 dest
= SET_DEST (set
);
5461 if (!REG_P (dest
) || !REG_P (src
))
5464 /* Make sure that the source register isn't defined later in BB. */
5465 sregno
= REGNO (src
);
5466 end_sregno
= END_REGNO (src
);
5467 if (overlaps_hard_reg_set_p (defs
, GET_MODE (src
), sregno
))
5470 /* Make sure that the destination register isn't referenced later in BB. */
5471 dregno
= REGNO (dest
);
5472 end_dregno
= END_REGNO (dest
);
5473 if (overlaps_hard_reg_set_p (uses
, GET_MODE (dest
), dregno
)
5474 || overlaps_hard_reg_set_p (defs
, GET_MODE (dest
), dregno
))
5477 /* See whether there is a successor block to which we could move INSN. */
5478 next_block
= next_block_for_reg (bb
, dregno
, end_dregno
);
5482 /* At this point we are committed to moving INSN, but let's try to
5483 move it as far as we can. */
5486 live_out
= df_get_live_out (bb
);
5487 live_in
= df_get_live_in (next_block
);
5490 /* Check whether BB uses DEST or clobbers DEST. We need to add
5491 INSN to BB if so. Either way, DEST is no longer live on entry,
5492 except for any part that overlaps SRC (next loop). */
5493 bb_uses
= &DF_LR_BB_INFO (bb
)->use
;
5494 bb_defs
= &DF_LR_BB_INFO (bb
)->def
;
5495 for (i
= dregno
; i
< end_dregno
; i
++)
5497 if (REGNO_REG_SET_P (bb_uses
, i
) || REGNO_REG_SET_P (bb_defs
, i
))
5499 CLEAR_REGNO_REG_SET (live_out
, i
);
5500 CLEAR_REGNO_REG_SET (live_in
, i
);
5503 /* Check whether BB clobbers SRC. We need to add INSN to BB if so.
5504 Either way, SRC is now live on entry. */
5505 for (i
= sregno
; i
< end_sregno
; i
++)
5507 if (REGNO_REG_SET_P (bb_defs
, i
))
5509 SET_REGNO_REG_SET (live_out
, i
);
5510 SET_REGNO_REG_SET (live_in
, i
);
5513 /* If we don't need to add the move to BB, look for a single
5516 next_block
= next_block_for_reg (next_block
, dregno
, end_dregno
);
5520 /* BB now defines DEST. It only uses the parts of DEST that overlap SRC
5522 for (i
= dregno
; i
< end_dregno
; i
++)
5524 CLEAR_REGNO_REG_SET (bb_uses
, i
);
5525 SET_REGNO_REG_SET (bb_defs
, i
);
5528 /* BB now uses SRC. */
5529 for (i
= sregno
; i
< end_sregno
; i
++)
5530 SET_REGNO_REG_SET (bb_uses
, i
);
5532 emit_insn_after (PATTERN (insn
), bb_note (bb
));
5537 /* Look for register copies in the first block of the function, and move
5538 them down into successor blocks if the register is used only on one
5539 path. This exposes more opportunities for shrink-wrapping. These
5540 kinds of sets often occur when incoming argument registers are moved
5541 to call-saved registers because their values are live across one or
5542 more calls during the function. */
5545 prepare_shrink_wrap (basic_block entry_block
)
5548 HARD_REG_SET uses
, defs
;
5551 CLEAR_HARD_REG_SET (uses
);
5552 CLEAR_HARD_REG_SET (defs
);
5553 FOR_BB_INSNS_REVERSE_SAFE (entry_block
, insn
, curr
)
5554 if (NONDEBUG_INSN_P (insn
)
5555 && !move_insn_for_shrink_wrap (entry_block
, insn
, uses
, defs
))
5557 /* Add all defined registers to DEFs. */
5558 for (ref
= DF_INSN_DEFS (insn
); *ref
; ref
++)
5560 x
= DF_REF_REG (*ref
);
5561 if (REG_P (x
) && HARD_REGISTER_P (x
))
5562 SET_HARD_REG_BIT (defs
, REGNO (x
));
5565 /* Add all used registers to USESs. */
5566 for (ref
= DF_INSN_USES (insn
); *ref
; ref
++)
5568 x
= DF_REF_REG (*ref
);
5569 if (REG_P (x
) && HARD_REGISTER_P (x
))
5570 SET_HARD_REG_BIT (uses
, REGNO (x
));
5578 /* Insert use of return register before the end of BB. */
5581 emit_use_return_register_into_block (basic_block bb
)
5585 use_return_register ();
5588 emit_insn_before (seq
, BB_END (bb
));
5592 /* Create a return pattern, either simple_return or return, depending on
5596 gen_return_pattern (bool simple_p
)
5598 #ifdef HAVE_simple_return
5599 return simple_p
? gen_simple_return () : gen_return ();
5601 gcc_assert (!simple_p
);
5602 return gen_return ();
5606 /* Insert an appropriate return pattern at the end of block BB. This
5607 also means updating block_for_insn appropriately. SIMPLE_P is
5608 the same as in gen_return_pattern and passed to it. */
5611 emit_return_into_block (bool simple_p
, basic_block bb
)
5614 jump
= emit_jump_insn_after (gen_return_pattern (simple_p
), BB_END (bb
));
5615 pat
= PATTERN (jump
);
5616 if (GET_CODE (pat
) == PARALLEL
)
5617 pat
= XVECEXP (pat
, 0, 0);
5618 gcc_assert (ANY_RETURN_P (pat
));
5619 JUMP_LABEL (jump
) = pat
;
5623 /* Set JUMP_LABEL for a return insn. */
5626 set_return_jump_label (rtx returnjump
)
5628 rtx pat
= PATTERN (returnjump
);
5629 if (GET_CODE (pat
) == PARALLEL
)
5630 pat
= XVECEXP (pat
, 0, 0);
5631 if (ANY_RETURN_P (pat
))
5632 JUMP_LABEL (returnjump
) = pat
;
5634 JUMP_LABEL (returnjump
) = ret_rtx
;
5637 #ifdef HAVE_simple_return
5638 /* Create a copy of BB instructions and insert at BEFORE. Redirect
5639 preds of BB to COPY_BB if they don't appear in NEED_PROLOGUE. */
5641 dup_block_and_redirect (basic_block bb
, basic_block copy_bb
, rtx before
,
5642 bitmap_head
*need_prologue
)
5646 rtx insn
= BB_END (bb
);
5648 /* We know BB has a single successor, so there is no need to copy a
5649 simple jump at the end of BB. */
5650 if (simplejump_p (insn
))
5651 insn
= PREV_INSN (insn
);
5654 duplicate_insn_chain (BB_HEAD (bb
), insn
);
5658 for (insn
= get_insns (); insn
; insn
= NEXT_INSN (insn
))
5659 if (active_insn_p (insn
))
5661 fprintf (dump_file
, "Duplicating bb %d to bb %d, %u active insns.\n",
5662 bb
->index
, copy_bb
->index
, count
);
5664 insn
= get_insns ();
5666 emit_insn_before (insn
, before
);
5668 /* Redirect all the paths that need no prologue into copy_bb. */
5669 for (ei
= ei_start (bb
->preds
); (e
= ei_safe_edge (ei
)); )
5670 if (!bitmap_bit_p (need_prologue
, e
->src
->index
))
5672 int freq
= EDGE_FREQUENCY (e
);
5673 copy_bb
->count
+= e
->count
;
5674 copy_bb
->frequency
+= EDGE_FREQUENCY (e
);
5675 e
->dest
->count
-= e
->count
;
5676 if (e
->dest
->count
< 0)
5678 e
->dest
->frequency
-= freq
;
5679 if (e
->dest
->frequency
< 0)
5680 e
->dest
->frequency
= 0;
5681 redirect_edge_and_branch_force (e
, copy_bb
);
5689 #if defined (HAVE_return) || defined (HAVE_simple_return)
5690 /* Return true if there are any active insns between HEAD and TAIL. */
5692 active_insn_between (rtx head
, rtx tail
)
5696 if (active_insn_p (tail
))
5700 tail
= PREV_INSN (tail
);
5705 /* LAST_BB is a block that exits, and empty of active instructions.
5706 Examine its predecessors for jumps that can be converted to
5707 (conditional) returns. */
5708 static VEC (edge
, heap
) *
5709 convert_jumps_to_returns (basic_block last_bb
, bool simple_p
,
5710 VEC (edge
, heap
) *unconverted ATTRIBUTE_UNUSED
)
5717 VEC(basic_block
,heap
) *src_bbs
;
5719 src_bbs
= VEC_alloc (basic_block
, heap
, EDGE_COUNT (last_bb
->preds
));
5720 FOR_EACH_EDGE (e
, ei
, last_bb
->preds
)
5721 if (e
->src
!= ENTRY_BLOCK_PTR
)
5722 VEC_quick_push (basic_block
, src_bbs
, e
->src
);
5724 label
= BB_HEAD (last_bb
);
5726 FOR_EACH_VEC_ELT (basic_block
, src_bbs
, i
, bb
)
5728 rtx jump
= BB_END (bb
);
5730 if (!JUMP_P (jump
) || JUMP_LABEL (jump
) != label
)
5733 e
= find_edge (bb
, last_bb
);
5735 /* If we have an unconditional jump, we can replace that
5736 with a simple return instruction. */
5737 if (simplejump_p (jump
))
5739 /* The use of the return register might be present in the exit
5740 fallthru block. Either:
5741 - removing the use is safe, and we should remove the use in
5742 the exit fallthru block, or
5743 - removing the use is not safe, and we should add it here.
5744 For now, we conservatively choose the latter. Either of the
5745 2 helps in crossjumping. */
5746 emit_use_return_register_into_block (bb
);
5748 emit_return_into_block (simple_p
, bb
);
5752 /* If we have a conditional jump branching to the last
5753 block, we can try to replace that with a conditional
5754 return instruction. */
5755 else if (condjump_p (jump
))
5760 dest
= simple_return_rtx
;
5763 if (!redirect_jump (jump
, dest
, 0))
5765 #ifdef HAVE_simple_return
5770 "Failed to redirect bb %d branch.\n", bb
->index
);
5771 VEC_safe_push (edge
, heap
, unconverted
, e
);
5777 /* See comment in simplejump_p case above. */
5778 emit_use_return_register_into_block (bb
);
5780 /* If this block has only one successor, it both jumps
5781 and falls through to the fallthru block, so we can't
5783 if (single_succ_p (bb
))
5788 #ifdef HAVE_simple_return
5793 "Failed to redirect bb %d branch.\n", bb
->index
);
5794 VEC_safe_push (edge
, heap
, unconverted
, e
);
5800 /* Fix up the CFG for the successful change we just made. */
5801 redirect_edge_succ (e
, EXIT_BLOCK_PTR
);
5802 e
->flags
&= ~EDGE_CROSSING
;
5804 VEC_free (basic_block
, heap
, src_bbs
);
5808 /* Emit a return insn for the exit fallthru block. */
5810 emit_return_for_exit (edge exit_fallthru_edge
, bool simple_p
)
5812 basic_block last_bb
= exit_fallthru_edge
->src
;
5814 if (JUMP_P (BB_END (last_bb
)))
5816 last_bb
= split_edge (exit_fallthru_edge
);
5817 exit_fallthru_edge
= single_succ_edge (last_bb
);
5819 emit_barrier_after (BB_END (last_bb
));
5820 emit_return_into_block (simple_p
, last_bb
);
5821 exit_fallthru_edge
->flags
&= ~EDGE_FALLTHRU
;
5827 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
5828 this into place with notes indicating where the prologue ends and where
5829 the epilogue begins. Update the basic block information when possible.
5831 Notes on epilogue placement:
5832 There are several kinds of edges to the exit block:
5833 * a single fallthru edge from LAST_BB
5834 * possibly, edges from blocks containing sibcalls
5835 * possibly, fake edges from infinite loops
5837 The epilogue is always emitted on the fallthru edge from the last basic
5838 block in the function, LAST_BB, into the exit block.
5840 If LAST_BB is empty except for a label, it is the target of every
5841 other basic block in the function that ends in a return. If a
5842 target has a return or simple_return pattern (possibly with
5843 conditional variants), these basic blocks can be changed so that a
5844 return insn is emitted into them, and their target is adjusted to
5845 the real exit block.
5847 Notes on shrink wrapping: We implement a fairly conservative
5848 version of shrink-wrapping rather than the textbook one. We only
5849 generate a single prologue and a single epilogue. This is
5850 sufficient to catch a number of interesting cases involving early
5853 First, we identify the blocks that require the prologue to occur before
5854 them. These are the ones that modify a call-saved register, or reference
5855 any of the stack or frame pointer registers. To simplify things, we then
5856 mark everything reachable from these blocks as also requiring a prologue.
5857 This takes care of loops automatically, and avoids the need to examine
5858 whether MEMs reference the frame, since it is sufficient to check for
5859 occurrences of the stack or frame pointer.
5861 We then compute the set of blocks for which the need for a prologue
5862 is anticipatable (borrowing terminology from the shrink-wrapping
5863 description in Muchnick's book). These are the blocks which either
5864 require a prologue themselves, or those that have only successors
5865 where the prologue is anticipatable. The prologue needs to be
5866 inserted on all edges from BB1->BB2 where BB2 is in ANTIC and BB1
5867 is not. For the moment, we ensure that only one such edge exists.
5869 The epilogue is placed as described above, but we make a
5870 distinction between inserting return and simple_return patterns
5871 when modifying other blocks that end in a return. Blocks that end
5872 in a sibcall omit the sibcall_epilogue if the block is not in
5876 thread_prologue_and_epilogue_insns (void)
5879 #ifdef HAVE_simple_return
5880 VEC (edge
, heap
) *unconverted_simple_returns
= NULL
;
5881 bool nonempty_prologue
;
5882 bitmap_head bb_flags
;
5883 unsigned max_grow_size
;
5886 rtx seq ATTRIBUTE_UNUSED
, epilogue_end ATTRIBUTE_UNUSED
;
5887 rtx prologue_seq ATTRIBUTE_UNUSED
, split_prologue_seq ATTRIBUTE_UNUSED
;
5888 edge e
, entry_edge
, orig_entry_edge
, exit_fallthru_edge
;
5893 rtl_profile_for_bb (ENTRY_BLOCK_PTR
);
5897 epilogue_end
= NULL_RTX
;
5898 returnjump
= NULL_RTX
;
5900 /* Can't deal with multiple successors of the entry block at the
5901 moment. Function should always have at least one entry
5903 gcc_assert (single_succ_p (ENTRY_BLOCK_PTR
));
5904 entry_edge
= single_succ_edge (ENTRY_BLOCK_PTR
);
5905 orig_entry_edge
= entry_edge
;
5907 split_prologue_seq
= NULL_RTX
;
5908 if (flag_split_stack
5909 && (lookup_attribute ("no_split_stack", DECL_ATTRIBUTES (cfun
->decl
))
5912 #ifndef HAVE_split_stack_prologue
5915 gcc_assert (HAVE_split_stack_prologue
);
5918 emit_insn (gen_split_stack_prologue ());
5919 split_prologue_seq
= get_insns ();
5922 record_insns (split_prologue_seq
, NULL
, &prologue_insn_hash
);
5923 set_insn_locations (split_prologue_seq
, prologue_location
);
5927 prologue_seq
= NULL_RTX
;
5928 #ifdef HAVE_prologue
5932 seq
= gen_prologue ();
5935 /* Insert an explicit USE for the frame pointer
5936 if the profiling is on and the frame pointer is required. */
5937 if (crtl
->profile
&& frame_pointer_needed
)
5938 emit_use (hard_frame_pointer_rtx
);
5940 /* Retain a map of the prologue insns. */
5941 record_insns (seq
, NULL
, &prologue_insn_hash
);
5942 emit_note (NOTE_INSN_PROLOGUE_END
);
5944 /* Ensure that instructions are not moved into the prologue when
5945 profiling is on. The call to the profiling routine can be
5946 emitted within the live range of a call-clobbered register. */
5947 if (!targetm
.profile_before_prologue () && crtl
->profile
)
5948 emit_insn (gen_blockage ());
5950 prologue_seq
= get_insns ();
5952 set_insn_locations (prologue_seq
, prologue_location
);
5956 #ifdef HAVE_simple_return
5957 bitmap_initialize (&bb_flags
, &bitmap_default_obstack
);
5959 /* Try to perform a kind of shrink-wrapping, making sure the
5960 prologue/epilogue is emitted only around those parts of the
5961 function that require it. */
5963 nonempty_prologue
= false;
5964 for (seq
= prologue_seq
; seq
; seq
= NEXT_INSN (seq
))
5965 if (!NOTE_P (seq
) || NOTE_KIND (seq
) != NOTE_INSN_PROLOGUE_END
)
5967 nonempty_prologue
= true;
5971 if (flag_shrink_wrap
&& HAVE_simple_return
5972 && (targetm
.profile_before_prologue () || !crtl
->profile
)
5973 && nonempty_prologue
&& !crtl
->calls_eh_return
)
5975 HARD_REG_SET prologue_clobbered
, prologue_used
, live_on_edge
;
5976 struct hard_reg_set_container set_up_by_prologue
;
5978 VEC(basic_block
, heap
) *vec
;
5980 bitmap_head bb_antic_flags
;
5981 bitmap_head bb_on_list
;
5982 bitmap_head bb_tail
;
5985 fprintf (dump_file
, "Attempting shrink-wrapping optimization.\n");
5987 /* Compute the registers set and used in the prologue. */
5988 CLEAR_HARD_REG_SET (prologue_clobbered
);
5989 CLEAR_HARD_REG_SET (prologue_used
);
5990 for (p_insn
= prologue_seq
; p_insn
; p_insn
= NEXT_INSN (p_insn
))
5992 HARD_REG_SET this_used
;
5993 if (!NONDEBUG_INSN_P (p_insn
))
5996 CLEAR_HARD_REG_SET (this_used
);
5997 note_uses (&PATTERN (p_insn
), record_hard_reg_uses
,
5999 AND_COMPL_HARD_REG_SET (this_used
, prologue_clobbered
);
6000 IOR_HARD_REG_SET (prologue_used
, this_used
);
6001 note_stores (PATTERN (p_insn
), record_hard_reg_sets
,
6002 &prologue_clobbered
);
6005 prepare_shrink_wrap (entry_edge
->dest
);
6007 bitmap_initialize (&bb_antic_flags
, &bitmap_default_obstack
);
6008 bitmap_initialize (&bb_on_list
, &bitmap_default_obstack
);
6009 bitmap_initialize (&bb_tail
, &bitmap_default_obstack
);
6011 /* Find the set of basic blocks that require a stack frame,
6012 and blocks that are too big to be duplicated. */
6014 vec
= VEC_alloc (basic_block
, heap
, n_basic_blocks
);
6016 CLEAR_HARD_REG_SET (set_up_by_prologue
.set
);
6017 add_to_hard_reg_set (&set_up_by_prologue
.set
, Pmode
,
6018 STACK_POINTER_REGNUM
);
6019 add_to_hard_reg_set (&set_up_by_prologue
.set
, Pmode
, ARG_POINTER_REGNUM
);
6020 if (frame_pointer_needed
)
6021 add_to_hard_reg_set (&set_up_by_prologue
.set
, Pmode
,
6022 HARD_FRAME_POINTER_REGNUM
);
6023 if (pic_offset_table_rtx
)
6024 add_to_hard_reg_set (&set_up_by_prologue
.set
, Pmode
,
6025 PIC_OFFSET_TABLE_REGNUM
);
6026 if (stack_realign_drap
&& crtl
->drap_reg
)
6027 add_to_hard_reg_set (&set_up_by_prologue
.set
,
6028 GET_MODE (crtl
->drap_reg
),
6029 REGNO (crtl
->drap_reg
));
6030 if (targetm
.set_up_by_prologue
)
6031 targetm
.set_up_by_prologue (&set_up_by_prologue
);
6033 /* We don't use a different max size depending on
6034 optimize_bb_for_speed_p because increasing shrink-wrapping
6035 opportunities by duplicating tail blocks can actually result
6036 in an overall decrease in code size. */
6037 max_grow_size
= get_uncond_jump_length ();
6038 max_grow_size
*= PARAM_VALUE (PARAM_MAX_GROW_COPY_BB_INSNS
);
6045 FOR_BB_INSNS (bb
, insn
)
6046 if (NONDEBUG_INSN_P (insn
))
6048 if (requires_stack_frame_p (insn
, prologue_used
,
6049 set_up_by_prologue
.set
))
6051 if (bb
== entry_edge
->dest
)
6052 goto fail_shrinkwrap
;
6053 bitmap_set_bit (&bb_flags
, bb
->index
);
6054 VEC_quick_push (basic_block
, vec
, bb
);
6057 else if (size
<= max_grow_size
)
6059 size
+= get_attr_min_length (insn
);
6060 if (size
> max_grow_size
)
6061 bitmap_set_bit (&bb_on_list
, bb
->index
);
6066 /* Blocks that really need a prologue, or are too big for tails. */
6067 bitmap_ior_into (&bb_on_list
, &bb_flags
);
6069 /* For every basic block that needs a prologue, mark all blocks
6070 reachable from it, so as to ensure they are also seen as
6071 requiring a prologue. */
6072 while (!VEC_empty (basic_block
, vec
))
6074 basic_block tmp_bb
= VEC_pop (basic_block
, vec
);
6076 FOR_EACH_EDGE (e
, ei
, tmp_bb
->succs
)
6077 if (e
->dest
!= EXIT_BLOCK_PTR
6078 && bitmap_set_bit (&bb_flags
, e
->dest
->index
))
6079 VEC_quick_push (basic_block
, vec
, e
->dest
);
6082 /* Find the set of basic blocks that need no prologue, have a
6083 single successor, can be duplicated, meet a max size
6084 requirement, and go to the exit via like blocks. */
6085 VEC_quick_push (basic_block
, vec
, EXIT_BLOCK_PTR
);
6086 while (!VEC_empty (basic_block
, vec
))
6088 basic_block tmp_bb
= VEC_pop (basic_block
, vec
);
6090 FOR_EACH_EDGE (e
, ei
, tmp_bb
->preds
)
6091 if (single_succ_p (e
->src
)
6092 && !bitmap_bit_p (&bb_on_list
, e
->src
->index
)
6093 && can_duplicate_block_p (e
->src
))
6098 /* If there is predecessor of e->src which doesn't
6099 need prologue and the edge is complex,
6100 we might not be able to redirect the branch
6101 to a copy of e->src. */
6102 FOR_EACH_EDGE (pe
, pei
, e
->src
->preds
)
6103 if ((pe
->flags
& EDGE_COMPLEX
) != 0
6104 && !bitmap_bit_p (&bb_flags
, pe
->src
->index
))
6106 if (pe
== NULL
&& bitmap_set_bit (&bb_tail
, e
->src
->index
))
6107 VEC_quick_push (basic_block
, vec
, e
->src
);
6111 /* Now walk backwards from every block that is marked as needing
6112 a prologue to compute the bb_antic_flags bitmap. Exclude
6113 tail blocks; They can be duplicated to be used on paths not
6114 needing a prologue. */
6115 bitmap_clear (&bb_on_list
);
6116 bitmap_and_compl (&bb_antic_flags
, &bb_flags
, &bb_tail
);
6119 if (!bitmap_bit_p (&bb_antic_flags
, bb
->index
))
6121 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
6122 if (!bitmap_bit_p (&bb_antic_flags
, e
->src
->index
)
6123 && bitmap_set_bit (&bb_on_list
, e
->src
->index
))
6124 VEC_quick_push (basic_block
, vec
, e
->src
);
6126 while (!VEC_empty (basic_block
, vec
))
6128 basic_block tmp_bb
= VEC_pop (basic_block
, vec
);
6129 bool all_set
= true;
6131 bitmap_clear_bit (&bb_on_list
, tmp_bb
->index
);
6132 FOR_EACH_EDGE (e
, ei
, tmp_bb
->succs
)
6133 if (!bitmap_bit_p (&bb_antic_flags
, e
->dest
->index
))
6141 bitmap_set_bit (&bb_antic_flags
, tmp_bb
->index
);
6142 FOR_EACH_EDGE (e
, ei
, tmp_bb
->preds
)
6143 if (!bitmap_bit_p (&bb_antic_flags
, e
->src
->index
)
6144 && bitmap_set_bit (&bb_on_list
, e
->src
->index
))
6145 VEC_quick_push (basic_block
, vec
, e
->src
);
6148 /* Find exactly one edge that leads to a block in ANTIC from
6149 a block that isn't. */
6150 if (!bitmap_bit_p (&bb_antic_flags
, entry_edge
->dest
->index
))
6153 if (!bitmap_bit_p (&bb_antic_flags
, bb
->index
))
6155 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
6156 if (!bitmap_bit_p (&bb_antic_flags
, e
->src
->index
))
6158 if (entry_edge
!= orig_entry_edge
)
6160 entry_edge
= orig_entry_edge
;
6162 fprintf (dump_file
, "More than one candidate edge.\n");
6163 goto fail_shrinkwrap
;
6166 fprintf (dump_file
, "Found candidate edge for "
6167 "shrink-wrapping, %d->%d.\n", e
->src
->index
,
6173 if (entry_edge
!= orig_entry_edge
)
6175 /* Test whether the prologue is known to clobber any register
6176 (other than FP or SP) which are live on the edge. */
6177 CLEAR_HARD_REG_BIT (prologue_clobbered
, STACK_POINTER_REGNUM
);
6178 if (frame_pointer_needed
)
6179 CLEAR_HARD_REG_BIT (prologue_clobbered
, HARD_FRAME_POINTER_REGNUM
);
6180 REG_SET_TO_HARD_REG_SET (live_on_edge
,
6181 df_get_live_in (entry_edge
->dest
));
6182 if (hard_reg_set_intersect_p (live_on_edge
, prologue_clobbered
))
6184 entry_edge
= orig_entry_edge
;
6187 "Shrink-wrapping aborted due to clobber.\n");
6190 if (entry_edge
!= orig_entry_edge
)
6192 crtl
->shrink_wrapped
= true;
6194 fprintf (dump_file
, "Performing shrink-wrapping.\n");
6196 /* Find tail blocks reachable from both blocks needing a
6197 prologue and blocks not needing a prologue. */
6198 if (!bitmap_empty_p (&bb_tail
))
6201 bool some_pro
, some_no_pro
;
6202 if (!bitmap_bit_p (&bb_tail
, bb
->index
))
6204 some_pro
= some_no_pro
= false;
6205 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
6207 if (bitmap_bit_p (&bb_flags
, e
->src
->index
))
6212 if (some_pro
&& some_no_pro
)
6213 VEC_quick_push (basic_block
, vec
, bb
);
6215 bitmap_clear_bit (&bb_tail
, bb
->index
);
6217 /* Find the head of each tail. */
6218 while (!VEC_empty (basic_block
, vec
))
6220 basic_block tbb
= VEC_pop (basic_block
, vec
);
6222 if (!bitmap_bit_p (&bb_tail
, tbb
->index
))
6225 while (single_succ_p (tbb
))
6227 tbb
= single_succ (tbb
);
6228 bitmap_clear_bit (&bb_tail
, tbb
->index
);
6231 /* Now duplicate the tails. */
6232 if (!bitmap_empty_p (&bb_tail
))
6233 FOR_EACH_BB_REVERSE (bb
)
6235 basic_block copy_bb
, tbb
;
6239 if (!bitmap_clear_bit (&bb_tail
, bb
->index
))
6242 /* Create a copy of BB, instructions and all, for
6243 use on paths that don't need a prologue.
6244 Ideal placement of the copy is on a fall-thru edge
6245 or after a block that would jump to the copy. */
6246 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
6247 if (!bitmap_bit_p (&bb_flags
, e
->src
->index
)
6248 && single_succ_p (e
->src
))
6252 copy_bb
= create_basic_block (NEXT_INSN (BB_END (e
->src
)),
6254 BB_COPY_PARTITION (copy_bb
, e
->src
);
6258 /* Otherwise put the copy at the end of the function. */
6259 copy_bb
= create_basic_block (NULL_RTX
, NULL_RTX
,
6260 EXIT_BLOCK_PTR
->prev_bb
);
6261 BB_COPY_PARTITION (copy_bb
, bb
);
6264 insert_point
= emit_note_after (NOTE_INSN_DELETED
,
6266 emit_barrier_after (BB_END (copy_bb
));
6271 dup_block_and_redirect (tbb
, copy_bb
, insert_point
,
6273 tbb
= single_succ (tbb
);
6274 if (tbb
== EXIT_BLOCK_PTR
)
6276 e
= split_block (copy_bb
, PREV_INSN (insert_point
));
6280 /* Quiet verify_flow_info by (ab)using EDGE_FAKE.
6281 We have yet to add a simple_return to the tails,
6282 as we'd like to first convert_jumps_to_returns in
6283 case the block is no longer used after that. */
6285 if (CALL_P (PREV_INSN (insert_point
))
6286 && SIBLING_CALL_P (PREV_INSN (insert_point
)))
6287 eflags
= EDGE_SIBCALL
| EDGE_ABNORMAL
;
6288 make_single_succ_edge (copy_bb
, EXIT_BLOCK_PTR
, eflags
);
6290 /* verify_flow_info doesn't like a note after a
6292 delete_insn (insert_point
);
6293 if (bitmap_empty_p (&bb_tail
))
6299 bitmap_clear (&bb_tail
);
6300 bitmap_clear (&bb_antic_flags
);
6301 bitmap_clear (&bb_on_list
);
6302 VEC_free (basic_block
, heap
, vec
);
6306 if (split_prologue_seq
!= NULL_RTX
)
6308 insert_insn_on_edge (split_prologue_seq
, orig_entry_edge
);
6311 if (prologue_seq
!= NULL_RTX
)
6313 insert_insn_on_edge (prologue_seq
, entry_edge
);
6317 /* If the exit block has no non-fake predecessors, we don't need
6319 FOR_EACH_EDGE (e
, ei
, EXIT_BLOCK_PTR
->preds
)
6320 if ((e
->flags
& EDGE_FAKE
) == 0)
6325 rtl_profile_for_bb (EXIT_BLOCK_PTR
);
6327 exit_fallthru_edge
= find_fallthru_edge (EXIT_BLOCK_PTR
->preds
);
6329 /* If we're allowed to generate a simple return instruction, then by
6330 definition we don't need a full epilogue. If the last basic
6331 block before the exit block does not contain active instructions,
6332 examine its predecessors and try to emit (conditional) return
6334 #ifdef HAVE_simple_return
6335 if (entry_edge
!= orig_entry_edge
)
6341 /* convert_jumps_to_returns may add to EXIT_BLOCK_PTR->preds
6342 (but won't remove). Stop at end of current preds. */
6343 last
= EDGE_COUNT (EXIT_BLOCK_PTR
->preds
);
6344 for (i
= 0; i
< last
; i
++)
6346 e
= EDGE_I (EXIT_BLOCK_PTR
->preds
, i
);
6347 if (LABEL_P (BB_HEAD (e
->src
))
6348 && !bitmap_bit_p (&bb_flags
, e
->src
->index
)
6349 && !active_insn_between (BB_HEAD (e
->src
), BB_END (e
->src
)))
6350 unconverted_simple_returns
6351 = convert_jumps_to_returns (e
->src
, true,
6352 unconverted_simple_returns
);
6356 if (exit_fallthru_edge
!= NULL
6357 && EDGE_COUNT (exit_fallthru_edge
->src
->preds
) != 0
6358 && !bitmap_bit_p (&bb_flags
, exit_fallthru_edge
->src
->index
))
6360 basic_block last_bb
;
6362 last_bb
= emit_return_for_exit (exit_fallthru_edge
, true);
6363 returnjump
= BB_END (last_bb
);
6364 exit_fallthru_edge
= NULL
;
6371 if (exit_fallthru_edge
== NULL
)
6376 basic_block last_bb
= exit_fallthru_edge
->src
;
6378 if (LABEL_P (BB_HEAD (last_bb
))
6379 && !active_insn_between (BB_HEAD (last_bb
), BB_END (last_bb
)))
6380 convert_jumps_to_returns (last_bb
, false, NULL
);
6382 if (EDGE_COUNT (last_bb
->preds
) != 0
6383 && single_succ_p (last_bb
))
6385 last_bb
= emit_return_for_exit (exit_fallthru_edge
, false);
6386 epilogue_end
= returnjump
= BB_END (last_bb
);
6387 #ifdef HAVE_simple_return
6388 /* Emitting the return may add a basic block.
6389 Fix bb_flags for the added block. */
6390 if (last_bb
!= exit_fallthru_edge
->src
)
6391 bitmap_set_bit (&bb_flags
, last_bb
->index
);
6399 /* A small fib -- epilogue is not yet completed, but we wish to re-use
6400 this marker for the splits of EH_RETURN patterns, and nothing else
6401 uses the flag in the meantime. */
6402 epilogue_completed
= 1;
6404 #ifdef HAVE_eh_return
6405 /* Find non-fallthru edges that end with EH_RETURN instructions. On
6406 some targets, these get split to a special version of the epilogue
6407 code. In order to be able to properly annotate these with unwind
6408 info, try to split them now. If we get a valid split, drop an
6409 EPILOGUE_BEG note and mark the insns as epilogue insns. */
6410 FOR_EACH_EDGE (e
, ei
, EXIT_BLOCK_PTR
->preds
)
6412 rtx prev
, last
, trial
;
6414 if (e
->flags
& EDGE_FALLTHRU
)
6416 last
= BB_END (e
->src
);
6417 if (!eh_returnjump_p (last
))
6420 prev
= PREV_INSN (last
);
6421 trial
= try_split (PATTERN (last
), last
, 1);
6425 record_insns (NEXT_INSN (prev
), NEXT_INSN (trial
), &epilogue_insn_hash
);
6426 emit_note_after (NOTE_INSN_EPILOGUE_BEG
, prev
);
6430 /* If nothing falls through into the exit block, we don't need an
6433 if (exit_fallthru_edge
== NULL
)
6436 #ifdef HAVE_epilogue
6440 epilogue_end
= emit_note (NOTE_INSN_EPILOGUE_BEG
);
6441 seq
= gen_epilogue ();
6443 emit_jump_insn (seq
);
6445 /* Retain a map of the epilogue insns. */
6446 record_insns (seq
, NULL
, &epilogue_insn_hash
);
6447 set_insn_locations (seq
, epilogue_location
);
6450 returnjump
= get_last_insn ();
6453 insert_insn_on_edge (seq
, exit_fallthru_edge
);
6456 if (JUMP_P (returnjump
))
6457 set_return_jump_label (returnjump
);
6464 if (! next_active_insn (BB_END (exit_fallthru_edge
->src
)))
6466 /* We have a fall-through edge to the exit block, the source is not
6467 at the end of the function, and there will be an assembler epilogue
6468 at the end of the function.
6469 We can't use force_nonfallthru here, because that would try to
6470 use return. Inserting a jump 'by hand' is extremely messy, so
6471 we take advantage of cfg_layout_finalize using
6472 fixup_fallthru_exit_predecessor. */
6473 cfg_layout_initialize (0);
6474 FOR_EACH_BB (cur_bb
)
6475 if (cur_bb
->index
>= NUM_FIXED_BLOCKS
6476 && cur_bb
->next_bb
->index
>= NUM_FIXED_BLOCKS
)
6477 cur_bb
->aux
= cur_bb
->next_bb
;
6478 cfg_layout_finalize ();
6483 default_rtl_profile ();
6489 commit_edge_insertions ();
6491 /* Look for basic blocks within the prologue insns. */
6492 blocks
= sbitmap_alloc (last_basic_block
);
6493 bitmap_clear (blocks
);
6494 bitmap_set_bit (blocks
, entry_edge
->dest
->index
);
6495 bitmap_set_bit (blocks
, orig_entry_edge
->dest
->index
);
6496 find_many_sub_basic_blocks (blocks
);
6497 sbitmap_free (blocks
);
6499 /* The epilogue insns we inserted may cause the exit edge to no longer
6501 FOR_EACH_EDGE (e
, ei
, EXIT_BLOCK_PTR
->preds
)
6503 if (((e
->flags
& EDGE_FALLTHRU
) != 0)
6504 && returnjump_p (BB_END (e
->src
)))
6505 e
->flags
&= ~EDGE_FALLTHRU
;
6509 #ifdef HAVE_simple_return
6510 /* If there were branches to an empty LAST_BB which we tried to
6511 convert to conditional simple_returns, but couldn't for some
6512 reason, create a block to hold a simple_return insn and redirect
6513 those remaining edges. */
6514 if (!VEC_empty (edge
, unconverted_simple_returns
))
6516 basic_block simple_return_block_hot
= NULL
;
6517 basic_block simple_return_block_cold
= NULL
;
6518 edge pending_edge_hot
= NULL
;
6519 edge pending_edge_cold
= NULL
;
6520 basic_block exit_pred
= EXIT_BLOCK_PTR
->prev_bb
;
6523 gcc_assert (entry_edge
!= orig_entry_edge
);
6525 /* See if we can reuse the last insn that was emitted for the
6527 if (returnjump
!= NULL_RTX
6528 && JUMP_LABEL (returnjump
) == simple_return_rtx
)
6530 e
= split_block (BLOCK_FOR_INSN (returnjump
), PREV_INSN (returnjump
));
6531 if (BB_PARTITION (e
->src
) == BB_HOT_PARTITION
)
6532 simple_return_block_hot
= e
->dest
;
6534 simple_return_block_cold
= e
->dest
;
6537 /* Also check returns we might need to add to tail blocks. */
6538 FOR_EACH_EDGE (e
, ei
, EXIT_BLOCK_PTR
->preds
)
6539 if (EDGE_COUNT (e
->src
->preds
) != 0
6540 && (e
->flags
& EDGE_FAKE
) != 0
6541 && !bitmap_bit_p (&bb_flags
, e
->src
->index
))
6543 if (BB_PARTITION (e
->src
) == BB_HOT_PARTITION
)
6544 pending_edge_hot
= e
;
6546 pending_edge_cold
= e
;
6549 FOR_EACH_VEC_ELT (edge
, unconverted_simple_returns
, i
, e
)
6551 basic_block
*pdest_bb
;
6554 if (BB_PARTITION (e
->src
) == BB_HOT_PARTITION
)
6556 pdest_bb
= &simple_return_block_hot
;
6557 pending
= pending_edge_hot
;
6561 pdest_bb
= &simple_return_block_cold
;
6562 pending
= pending_edge_cold
;
6565 if (*pdest_bb
== NULL
&& pending
!= NULL
)
6567 emit_return_into_block (true, pending
->src
);
6568 pending
->flags
&= ~(EDGE_FALLTHRU
| EDGE_FAKE
);
6569 *pdest_bb
= pending
->src
;
6571 else if (*pdest_bb
== NULL
)
6576 bb
= create_basic_block (NULL
, NULL
, exit_pred
);
6577 BB_COPY_PARTITION (bb
, e
->src
);
6578 start
= emit_jump_insn_after (gen_simple_return (),
6580 JUMP_LABEL (start
) = simple_return_rtx
;
6581 emit_barrier_after (start
);
6584 make_edge (bb
, EXIT_BLOCK_PTR
, 0);
6586 redirect_edge_and_branch_force (e
, *pdest_bb
);
6588 VEC_free (edge
, heap
, unconverted_simple_returns
);
6591 if (entry_edge
!= orig_entry_edge
)
6593 FOR_EACH_EDGE (e
, ei
, EXIT_BLOCK_PTR
->preds
)
6594 if (EDGE_COUNT (e
->src
->preds
) != 0
6595 && (e
->flags
& EDGE_FAKE
) != 0
6596 && !bitmap_bit_p (&bb_flags
, e
->src
->index
))
6598 emit_return_into_block (true, e
->src
);
6599 e
->flags
&= ~(EDGE_FALLTHRU
| EDGE_FAKE
);
6604 #ifdef HAVE_sibcall_epilogue
6605 /* Emit sibling epilogues before any sibling call sites. */
6606 for (ei
= ei_start (EXIT_BLOCK_PTR
->preds
); (e
= ei_safe_edge (ei
)); )
6608 basic_block bb
= e
->src
;
6609 rtx insn
= BB_END (bb
);
6613 || ! SIBLING_CALL_P (insn
)
6614 #ifdef HAVE_simple_return
6615 || (entry_edge
!= orig_entry_edge
6616 && !bitmap_bit_p (&bb_flags
, bb
->index
))
6624 ep_seq
= gen_sibcall_epilogue ();
6628 emit_note (NOTE_INSN_EPILOGUE_BEG
);
6633 /* Retain a map of the epilogue insns. Used in life analysis to
6634 avoid getting rid of sibcall epilogue insns. Do this before we
6635 actually emit the sequence. */
6636 record_insns (seq
, NULL
, &epilogue_insn_hash
);
6637 set_insn_locations (seq
, epilogue_location
);
6639 emit_insn_before (seq
, insn
);
6645 #ifdef HAVE_epilogue
6650 /* Similarly, move any line notes that appear after the epilogue.
6651 There is no need, however, to be quite so anal about the existence
6652 of such a note. Also possibly move
6653 NOTE_INSN_FUNCTION_BEG notes, as those can be relevant for debug
6655 for (insn
= epilogue_end
; insn
; insn
= next
)
6657 next
= NEXT_INSN (insn
);
6659 && (NOTE_KIND (insn
) == NOTE_INSN_FUNCTION_BEG
))
6660 reorder_insns (insn
, insn
, PREV_INSN (epilogue_end
));
6665 #ifdef HAVE_simple_return
6666 bitmap_clear (&bb_flags
);
6669 /* Threading the prologue and epilogue changes the artificial refs
6670 in the entry and exit blocks. */
6671 epilogue_completed
= 1;
6672 df_update_entry_exit_and_calls ();
6675 /* Reposition the prologue-end and epilogue-begin notes after
6676 instruction scheduling. */
6679 reposition_prologue_and_epilogue_notes (void)
6681 #if defined (HAVE_prologue) || defined (HAVE_epilogue) \
6682 || defined (HAVE_sibcall_epilogue)
6683 /* Since the hash table is created on demand, the fact that it is
6684 non-null is a signal that it is non-empty. */
6685 if (prologue_insn_hash
!= NULL
)
6687 size_t len
= htab_elements (prologue_insn_hash
);
6688 rtx insn
, last
= NULL
, note
= NULL
;
6690 /* Scan from the beginning until we reach the last prologue insn. */
6691 /* ??? While we do have the CFG intact, there are two problems:
6692 (1) The prologue can contain loops (typically probing the stack),
6693 which means that the end of the prologue isn't in the first bb.
6694 (2) Sometimes the PROLOGUE_END note gets pushed into the next bb. */
6695 for (insn
= get_insns (); insn
; insn
= NEXT_INSN (insn
))
6699 if (NOTE_KIND (insn
) == NOTE_INSN_PROLOGUE_END
)
6702 else if (contains (insn
, prologue_insn_hash
))
6714 /* Scan forward looking for the PROLOGUE_END note. It should
6715 be right at the beginning of the block, possibly with other
6716 insn notes that got moved there. */
6717 for (note
= NEXT_INSN (last
); ; note
= NEXT_INSN (note
))
6720 && NOTE_KIND (note
) == NOTE_INSN_PROLOGUE_END
)
6725 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
6727 last
= NEXT_INSN (last
);
6728 reorder_insns (note
, note
, last
);
6732 if (epilogue_insn_hash
!= NULL
)
6737 FOR_EACH_EDGE (e
, ei
, EXIT_BLOCK_PTR
->preds
)
6739 rtx insn
, first
= NULL
, note
= NULL
;
6740 basic_block bb
= e
->src
;
6742 /* Scan from the beginning until we reach the first epilogue insn. */
6743 FOR_BB_INSNS (bb
, insn
)
6747 if (NOTE_KIND (insn
) == NOTE_INSN_EPILOGUE_BEG
)
6754 else if (first
== NULL
&& contains (insn
, epilogue_insn_hash
))
6764 /* If the function has a single basic block, and no real
6765 epilogue insns (e.g. sibcall with no cleanup), the
6766 epilogue note can get scheduled before the prologue
6767 note. If we have frame related prologue insns, having
6768 them scanned during the epilogue will result in a crash.
6769 In this case re-order the epilogue note to just before
6770 the last insn in the block. */
6772 first
= BB_END (bb
);
6774 if (PREV_INSN (first
) != note
)
6775 reorder_insns (note
, note
, PREV_INSN (first
));
6779 #endif /* HAVE_prologue or HAVE_epilogue */
6782 /* Returns the name of function declared by FNDECL. */
6784 fndecl_name (tree fndecl
)
6788 return lang_hooks
.decl_printable_name (fndecl
, 2);
6791 /* Returns the name of function FN. */
6793 function_name (struct function
*fn
)
6795 tree fndecl
= (fn
== NULL
) ? NULL
: fn
->decl
;
6796 return fndecl_name (fndecl
);
6799 /* Returns the name of the current function. */
6801 current_function_name (void)
6803 return function_name (cfun
);
6808 rest_of_handle_check_leaf_regs (void)
6810 #ifdef LEAF_REGISTERS
6811 crtl
->uses_only_leaf_regs
6812 = optimize
> 0 && only_leaf_regs_used () && leaf_function_p ();
6817 /* Insert a TYPE into the used types hash table of CFUN. */
6820 used_types_insert_helper (tree type
, struct function
*func
)
6822 if (type
!= NULL
&& func
!= NULL
)
6826 if (func
->used_types_hash
== NULL
)
6827 func
->used_types_hash
= htab_create_ggc (37, htab_hash_pointer
,
6828 htab_eq_pointer
, NULL
);
6829 slot
= htab_find_slot (func
->used_types_hash
, type
, INSERT
);
6835 /* Given a type, insert it into the used hash table in cfun. */
6837 used_types_insert (tree t
)
6839 while (POINTER_TYPE_P (t
) || TREE_CODE (t
) == ARRAY_TYPE
)
6844 if (TREE_CODE (t
) == ERROR_MARK
)
6846 if (TYPE_NAME (t
) == NULL_TREE
6847 || TYPE_NAME (t
) == TYPE_NAME (TYPE_MAIN_VARIANT (t
)))
6848 t
= TYPE_MAIN_VARIANT (t
);
6849 if (debug_info_level
> DINFO_LEVEL_NONE
)
6852 used_types_insert_helper (t
, cfun
);
6854 /* So this might be a type referenced by a global variable.
6855 Record that type so that we can later decide to emit its debug
6857 VEC_safe_push (tree
, gc
, types_used_by_cur_var_decl
, t
);
6861 /* Helper to Hash a struct types_used_by_vars_entry. */
6864 hash_types_used_by_vars_entry (const struct types_used_by_vars_entry
*entry
)
6866 gcc_assert (entry
&& entry
->var_decl
&& entry
->type
);
6868 return iterative_hash_object (entry
->type
,
6869 iterative_hash_object (entry
->var_decl
, 0));
6872 /* Hash function of the types_used_by_vars_entry hash table. */
6875 types_used_by_vars_do_hash (const void *x
)
6877 const struct types_used_by_vars_entry
*entry
=
6878 (const struct types_used_by_vars_entry
*) x
;
6880 return hash_types_used_by_vars_entry (entry
);
6883 /*Equality function of the types_used_by_vars_entry hash table. */
6886 types_used_by_vars_eq (const void *x1
, const void *x2
)
6888 const struct types_used_by_vars_entry
*e1
=
6889 (const struct types_used_by_vars_entry
*) x1
;
6890 const struct types_used_by_vars_entry
*e2
=
6891 (const struct types_used_by_vars_entry
*)x2
;
6893 return (e1
->var_decl
== e2
->var_decl
&& e1
->type
== e2
->type
);
6896 /* Inserts an entry into the types_used_by_vars_hash hash table. */
6899 types_used_by_var_decl_insert (tree type
, tree var_decl
)
6901 if (type
!= NULL
&& var_decl
!= NULL
)
6904 struct types_used_by_vars_entry e
;
6905 e
.var_decl
= var_decl
;
6907 if (types_used_by_vars_hash
== NULL
)
6908 types_used_by_vars_hash
=
6909 htab_create_ggc (37, types_used_by_vars_do_hash
,
6910 types_used_by_vars_eq
, NULL
);
6911 slot
= htab_find_slot_with_hash (types_used_by_vars_hash
, &e
,
6912 hash_types_used_by_vars_entry (&e
), INSERT
);
6915 struct types_used_by_vars_entry
*entry
;
6916 entry
= ggc_alloc_types_used_by_vars_entry ();
6918 entry
->var_decl
= var_decl
;
6924 struct rtl_opt_pass pass_leaf_regs
=
6928 "*leaf_regs", /* name */
6929 OPTGROUP_NONE
, /* optinfo_flags */
6931 rest_of_handle_check_leaf_regs
, /* execute */
6934 0, /* static_pass_number */
6935 TV_NONE
, /* tv_id */
6936 0, /* properties_required */
6937 0, /* properties_provided */
6938 0, /* properties_destroyed */
6939 0, /* todo_flags_start */
6940 0 /* todo_flags_finish */
6945 rest_of_handle_thread_prologue_and_epilogue (void)
6948 cleanup_cfg (CLEANUP_EXPENSIVE
);
6950 /* On some machines, the prologue and epilogue code, or parts thereof,
6951 can be represented as RTL. Doing so lets us schedule insns between
6952 it and the rest of the code and also allows delayed branch
6953 scheduling to operate in the epilogue. */
6954 thread_prologue_and_epilogue_insns ();
6956 /* The stack usage info is finalized during prologue expansion. */
6957 if (flag_stack_usage_info
)
6958 output_stack_usage ();
6963 struct rtl_opt_pass pass_thread_prologue_and_epilogue
=
6967 "pro_and_epilogue", /* name */
6968 OPTGROUP_NONE
, /* optinfo_flags */
6970 rest_of_handle_thread_prologue_and_epilogue
, /* execute */
6973 0, /* static_pass_number */
6974 TV_THREAD_PROLOGUE_AND_EPILOGUE
, /* tv_id */
6975 0, /* properties_required */
6976 0, /* properties_provided */
6977 0, /* properties_destroyed */
6978 TODO_verify_flow
, /* todo_flags_start */
6980 TODO_df_finish
| TODO_verify_rtl_sharing
|
6981 TODO_ggc_collect
/* todo_flags_finish */
6986 /* This mini-pass fixes fall-out from SSA in asm statements that have
6987 in-out constraints. Say you start with
6990 asm ("": "+mr" (inout));
6993 which is transformed very early to use explicit output and match operands:
6996 asm ("": "=mr" (inout) : "0" (inout));
6999 Or, after SSA and copyprop,
7001 asm ("": "=mr" (inout_2) : "0" (inout_1));
7004 Clearly inout_2 and inout_1 can't be coalesced easily anymore, as
7005 they represent two separate values, so they will get different pseudo
7006 registers during expansion. Then, since the two operands need to match
7007 per the constraints, but use different pseudo registers, reload can
7008 only register a reload for these operands. But reloads can only be
7009 satisfied by hardregs, not by memory, so we need a register for this
7010 reload, just because we are presented with non-matching operands.
7011 So, even though we allow memory for this operand, no memory can be
7012 used for it, just because the two operands don't match. This can
7013 cause reload failures on register-starved targets.
7015 So it's a symptom of reload not being able to use memory for reloads
7016 or, alternatively it's also a symptom of both operands not coming into
7017 reload as matching (in which case the pseudo could go to memory just
7018 fine, as the alternative allows it, and no reload would be necessary).
7019 We fix the latter problem here, by transforming
7021 asm ("": "=mr" (inout_2) : "0" (inout_1));
7026 asm ("": "=mr" (inout_2) : "0" (inout_2)); */
7029 match_asm_constraints_1 (rtx insn
, rtx
*p_sets
, int noutputs
)
7032 bool changed
= false;
7033 rtx op
= SET_SRC (p_sets
[0]);
7034 int ninputs
= ASM_OPERANDS_INPUT_LENGTH (op
);
7035 rtvec inputs
= ASM_OPERANDS_INPUT_VEC (op
);
7036 bool *output_matched
= XALLOCAVEC (bool, noutputs
);
7038 memset (output_matched
, 0, noutputs
* sizeof (bool));
7039 for (i
= 0; i
< ninputs
; i
++)
7041 rtx input
, output
, insns
;
7042 const char *constraint
= ASM_OPERANDS_INPUT_CONSTRAINT (op
, i
);
7046 if (*constraint
== '%')
7049 match
= strtoul (constraint
, &end
, 10);
7050 if (end
== constraint
)
7053 gcc_assert (match
< noutputs
);
7054 output
= SET_DEST (p_sets
[match
]);
7055 input
= RTVEC_ELT (inputs
, i
);
7056 /* Only do the transformation for pseudos. */
7057 if (! REG_P (output
)
7058 || rtx_equal_p (output
, input
)
7059 || (GET_MODE (input
) != VOIDmode
7060 && GET_MODE (input
) != GET_MODE (output
)))
7063 /* We can't do anything if the output is also used as input,
7064 as we're going to overwrite it. */
7065 for (j
= 0; j
< ninputs
; j
++)
7066 if (reg_overlap_mentioned_p (output
, RTVEC_ELT (inputs
, j
)))
7071 /* Avoid changing the same input several times. For
7072 asm ("" : "=mr" (out1), "=mr" (out2) : "0" (in), "1" (in));
7073 only change in once (to out1), rather than changing it
7074 first to out1 and afterwards to out2. */
7077 for (j
= 0; j
< noutputs
; j
++)
7078 if (output_matched
[j
] && input
== SET_DEST (p_sets
[j
]))
7083 output_matched
[match
] = true;
7086 emit_move_insn (output
, input
);
7087 insns
= get_insns ();
7089 emit_insn_before (insns
, insn
);
7091 /* Now replace all mentions of the input with output. We can't
7092 just replace the occurrence in inputs[i], as the register might
7093 also be used in some other input (or even in an address of an
7094 output), which would mean possibly increasing the number of
7095 inputs by one (namely 'output' in addition), which might pose
7096 a too complicated problem for reload to solve. E.g. this situation:
7098 asm ("" : "=r" (output), "=m" (input) : "0" (input))
7100 Here 'input' is used in two occurrences as input (once for the
7101 input operand, once for the address in the second output operand).
7102 If we would replace only the occurrence of the input operand (to
7103 make the matching) we would be left with this:
7106 asm ("" : "=r" (output), "=m" (input) : "0" (output))
7108 Now we suddenly have two different input values (containing the same
7109 value, but different pseudos) where we formerly had only one.
7110 With more complicated asms this might lead to reload failures
7111 which wouldn't have happen without this pass. So, iterate over
7112 all operands and replace all occurrences of the register used. */
7113 for (j
= 0; j
< noutputs
; j
++)
7114 if (!rtx_equal_p (SET_DEST (p_sets
[j
]), input
)
7115 && reg_overlap_mentioned_p (input
, SET_DEST (p_sets
[j
])))
7116 SET_DEST (p_sets
[j
]) = replace_rtx (SET_DEST (p_sets
[j
]),
7118 for (j
= 0; j
< ninputs
; j
++)
7119 if (reg_overlap_mentioned_p (input
, RTVEC_ELT (inputs
, j
)))
7120 RTVEC_ELT (inputs
, j
) = replace_rtx (RTVEC_ELT (inputs
, j
),
7127 df_insn_rescan (insn
);
7131 rest_of_match_asm_constraints (void)
7134 rtx insn
, pat
, *p_sets
;
7137 if (!crtl
->has_asm_statement
)
7140 df_set_flags (DF_DEFER_INSN_RESCAN
);
7143 FOR_BB_INSNS (bb
, insn
)
7148 pat
= PATTERN (insn
);
7149 if (GET_CODE (pat
) == PARALLEL
)
7150 p_sets
= &XVECEXP (pat
, 0, 0), noutputs
= XVECLEN (pat
, 0);
7151 else if (GET_CODE (pat
) == SET
)
7152 p_sets
= &PATTERN (insn
), noutputs
= 1;
7156 if (GET_CODE (*p_sets
) == SET
7157 && GET_CODE (SET_SRC (*p_sets
)) == ASM_OPERANDS
)
7158 match_asm_constraints_1 (insn
, p_sets
, noutputs
);
7162 return TODO_df_finish
;
7165 struct rtl_opt_pass pass_match_asm_constraints
=
7169 "asmcons", /* name */
7170 OPTGROUP_NONE
, /* optinfo_flags */
7172 rest_of_match_asm_constraints
, /* execute */
7175 0, /* static_pass_number */
7176 TV_NONE
, /* tv_id */
7177 0, /* properties_required */
7178 0, /* properties_provided */
7179 0, /* properties_destroyed */
7180 0, /* todo_flags_start */
7181 0 /* todo_flags_finish */
7186 #include "gt-function.h"