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_locators (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
;
203 insn_locators_free ();
206 /* Return size needed for stack frame based on slots so far allocated.
207 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
208 the caller may have to do that. */
211 get_frame_size (void)
213 if (FRAME_GROWS_DOWNWARD
)
214 return -frame_offset
;
219 /* Issue an error message and return TRUE if frame OFFSET overflows in
220 the signed target pointer arithmetics for function FUNC. Otherwise
224 frame_offset_overflow (HOST_WIDE_INT offset
, tree func
)
226 unsigned HOST_WIDE_INT size
= FRAME_GROWS_DOWNWARD
? -offset
: offset
;
228 if (size
> ((unsigned HOST_WIDE_INT
) 1 << (GET_MODE_BITSIZE (Pmode
) - 1))
229 /* Leave room for the fixed part of the frame. */
230 - 64 * UNITS_PER_WORD
)
232 error_at (DECL_SOURCE_LOCATION (func
),
233 "total size of local objects too large");
240 /* Return stack slot alignment in bits for TYPE and MODE. */
243 get_stack_local_alignment (tree type
, enum machine_mode mode
)
245 unsigned int alignment
;
248 alignment
= BIGGEST_ALIGNMENT
;
250 alignment
= GET_MODE_ALIGNMENT (mode
);
252 /* Allow the frond-end to (possibly) increase the alignment of this
255 type
= lang_hooks
.types
.type_for_mode (mode
, 0);
257 return STACK_SLOT_ALIGNMENT (type
, mode
, alignment
);
260 /* Determine whether it is possible to fit a stack slot of size SIZE and
261 alignment ALIGNMENT into an area in the stack frame that starts at
262 frame offset START and has a length of LENGTH. If so, store the frame
263 offset to be used for the stack slot in *POFFSET and return true;
264 return false otherwise. This function will extend the frame size when
265 given a start/length pair that lies at the end of the frame. */
268 try_fit_stack_local (HOST_WIDE_INT start
, HOST_WIDE_INT length
,
269 HOST_WIDE_INT size
, unsigned int alignment
,
270 HOST_WIDE_INT
*poffset
)
272 HOST_WIDE_INT this_frame_offset
;
273 int frame_off
, frame_alignment
, frame_phase
;
275 /* Calculate how many bytes the start of local variables is off from
277 frame_alignment
= PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
;
278 frame_off
= STARTING_FRAME_OFFSET
% frame_alignment
;
279 frame_phase
= frame_off
? frame_alignment
- frame_off
: 0;
281 /* Round the frame offset to the specified alignment. */
283 /* We must be careful here, since FRAME_OFFSET might be negative and
284 division with a negative dividend isn't as well defined as we might
285 like. So we instead assume that ALIGNMENT is a power of two and
286 use logical operations which are unambiguous. */
287 if (FRAME_GROWS_DOWNWARD
)
289 = (FLOOR_ROUND (start
+ length
- size
- frame_phase
,
290 (unsigned HOST_WIDE_INT
) alignment
)
294 = (CEIL_ROUND (start
- frame_phase
,
295 (unsigned HOST_WIDE_INT
) alignment
)
298 /* See if it fits. If this space is at the edge of the frame,
299 consider extending the frame to make it fit. Our caller relies on
300 this when allocating a new slot. */
301 if (frame_offset
== start
&& this_frame_offset
< frame_offset
)
302 frame_offset
= this_frame_offset
;
303 else if (this_frame_offset
< start
)
305 else if (start
+ length
== frame_offset
306 && this_frame_offset
+ size
> start
+ length
)
307 frame_offset
= this_frame_offset
+ size
;
308 else if (this_frame_offset
+ size
> start
+ length
)
311 *poffset
= this_frame_offset
;
315 /* Create a new frame_space structure describing free space in the stack
316 frame beginning at START and ending at END, and chain it into the
317 function's frame_space_list. */
320 add_frame_space (HOST_WIDE_INT start
, HOST_WIDE_INT end
)
322 struct frame_space
*space
= ggc_alloc_frame_space ();
323 space
->next
= crtl
->frame_space_list
;
324 crtl
->frame_space_list
= space
;
325 space
->start
= start
;
326 space
->length
= end
- start
;
329 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
330 with machine mode MODE.
332 ALIGN controls the amount of alignment for the address of the slot:
333 0 means according to MODE,
334 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
335 -2 means use BITS_PER_UNIT,
336 positive specifies alignment boundary in bits.
338 KIND has ASLK_REDUCE_ALIGN bit set if it is OK to reduce
339 alignment and ASLK_RECORD_PAD bit set if we should remember
340 extra space we allocated for alignment purposes. When we are
341 called from assign_stack_temp_for_type, it is not set so we don't
342 track the same stack slot in two independent lists.
344 We do not round to stack_boundary here. */
347 assign_stack_local_1 (enum machine_mode mode
, HOST_WIDE_INT size
,
351 int bigend_correction
= 0;
352 HOST_WIDE_INT slot_offset
= 0, old_frame_offset
;
353 unsigned int alignment
, alignment_in_bits
;
357 alignment
= get_stack_local_alignment (NULL
, mode
);
358 alignment
/= BITS_PER_UNIT
;
360 else if (align
== -1)
362 alignment
= BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
;
363 size
= CEIL_ROUND (size
, alignment
);
365 else if (align
== -2)
366 alignment
= 1; /* BITS_PER_UNIT / BITS_PER_UNIT */
368 alignment
= align
/ BITS_PER_UNIT
;
370 alignment_in_bits
= alignment
* BITS_PER_UNIT
;
372 /* Ignore alignment if it exceeds MAX_SUPPORTED_STACK_ALIGNMENT. */
373 if (alignment_in_bits
> MAX_SUPPORTED_STACK_ALIGNMENT
)
375 alignment_in_bits
= MAX_SUPPORTED_STACK_ALIGNMENT
;
376 alignment
= alignment_in_bits
/ BITS_PER_UNIT
;
379 if (SUPPORTS_STACK_ALIGNMENT
)
381 if (crtl
->stack_alignment_estimated
< alignment_in_bits
)
383 if (!crtl
->stack_realign_processed
)
384 crtl
->stack_alignment_estimated
= alignment_in_bits
;
387 /* If stack is realigned and stack alignment value
388 hasn't been finalized, it is OK not to increase
389 stack_alignment_estimated. The bigger alignment
390 requirement is recorded in stack_alignment_needed
392 gcc_assert (!crtl
->stack_realign_finalized
);
393 if (!crtl
->stack_realign_needed
)
395 /* It is OK to reduce the alignment as long as the
396 requested size is 0 or the estimated stack
397 alignment >= mode alignment. */
398 gcc_assert ((kind
& ASLK_REDUCE_ALIGN
)
400 || (crtl
->stack_alignment_estimated
401 >= GET_MODE_ALIGNMENT (mode
)));
402 alignment_in_bits
= crtl
->stack_alignment_estimated
;
403 alignment
= alignment_in_bits
/ BITS_PER_UNIT
;
409 if (crtl
->stack_alignment_needed
< alignment_in_bits
)
410 crtl
->stack_alignment_needed
= alignment_in_bits
;
411 if (crtl
->max_used_stack_slot_alignment
< alignment_in_bits
)
412 crtl
->max_used_stack_slot_alignment
= alignment_in_bits
;
414 if (mode
!= BLKmode
|| size
!= 0)
416 if (kind
& ASLK_RECORD_PAD
)
418 struct frame_space
**psp
;
420 for (psp
= &crtl
->frame_space_list
; *psp
; psp
= &(*psp
)->next
)
422 struct frame_space
*space
= *psp
;
423 if (!try_fit_stack_local (space
->start
, space
->length
, size
,
424 alignment
, &slot_offset
))
427 if (slot_offset
> space
->start
)
428 add_frame_space (space
->start
, slot_offset
);
429 if (slot_offset
+ size
< space
->start
+ space
->length
)
430 add_frame_space (slot_offset
+ size
,
431 space
->start
+ space
->length
);
436 else if (!STACK_ALIGNMENT_NEEDED
)
438 slot_offset
= frame_offset
;
442 old_frame_offset
= frame_offset
;
444 if (FRAME_GROWS_DOWNWARD
)
446 frame_offset
-= size
;
447 try_fit_stack_local (frame_offset
, size
, size
, alignment
, &slot_offset
);
449 if (kind
& ASLK_RECORD_PAD
)
451 if (slot_offset
> frame_offset
)
452 add_frame_space (frame_offset
, slot_offset
);
453 if (slot_offset
+ size
< old_frame_offset
)
454 add_frame_space (slot_offset
+ size
, old_frame_offset
);
459 frame_offset
+= size
;
460 try_fit_stack_local (old_frame_offset
, size
, size
, alignment
, &slot_offset
);
462 if (kind
& ASLK_RECORD_PAD
)
464 if (slot_offset
> old_frame_offset
)
465 add_frame_space (old_frame_offset
, slot_offset
);
466 if (slot_offset
+ size
< frame_offset
)
467 add_frame_space (slot_offset
+ size
, frame_offset
);
472 /* On a big-endian machine, if we are allocating more space than we will use,
473 use the least significant bytes of those that are allocated. */
474 if (BYTES_BIG_ENDIAN
&& mode
!= BLKmode
&& GET_MODE_SIZE (mode
) < size
)
475 bigend_correction
= size
- GET_MODE_SIZE (mode
);
477 /* If we have already instantiated virtual registers, return the actual
478 address relative to the frame pointer. */
479 if (virtuals_instantiated
)
480 addr
= plus_constant (Pmode
, frame_pointer_rtx
,
482 (slot_offset
+ bigend_correction
483 + STARTING_FRAME_OFFSET
, Pmode
));
485 addr
= plus_constant (Pmode
, virtual_stack_vars_rtx
,
487 (slot_offset
+ bigend_correction
,
490 x
= gen_rtx_MEM (mode
, addr
);
491 set_mem_align (x
, alignment_in_bits
);
492 MEM_NOTRAP_P (x
) = 1;
495 = gen_rtx_EXPR_LIST (VOIDmode
, x
, stack_slot_list
);
497 if (frame_offset_overflow (frame_offset
, current_function_decl
))
503 /* Wrap up assign_stack_local_1 with last parameter as false. */
506 assign_stack_local (enum machine_mode mode
, HOST_WIDE_INT size
, int align
)
508 return assign_stack_local_1 (mode
, size
, align
, ASLK_RECORD_PAD
);
511 /* In order to evaluate some expressions, such as function calls returning
512 structures in memory, we need to temporarily allocate stack locations.
513 We record each allocated temporary in the following structure.
515 Associated with each temporary slot is a nesting level. When we pop up
516 one level, all temporaries associated with the previous level are freed.
517 Normally, all temporaries are freed after the execution of the statement
518 in which they were created. However, if we are inside a ({...}) grouping,
519 the result may be in a temporary and hence must be preserved. If the
520 result could be in a temporary, we preserve it if we can determine which
521 one it is in. If we cannot determine which temporary may contain the
522 result, all temporaries are preserved. A temporary is preserved by
523 pretending it was allocated at the previous nesting level. */
525 struct GTY(()) temp_slot
{
526 /* Points to next temporary slot. */
527 struct temp_slot
*next
;
528 /* Points to previous temporary slot. */
529 struct temp_slot
*prev
;
530 /* The rtx to used to reference the slot. */
532 /* The size, in units, of the slot. */
534 /* The type of the object in the slot, or zero if it doesn't correspond
535 to a type. We use this to determine whether a slot can be reused.
536 It can be reused if objects of the type of the new slot will always
537 conflict with objects of the type of the old slot. */
539 /* The alignment (in bits) of the slot. */
541 /* Nonzero if this temporary is currently in use. */
543 /* Nesting level at which this slot is being used. */
545 /* The offset of the slot from the frame_pointer, including extra space
546 for alignment. This info is for combine_temp_slots. */
547 HOST_WIDE_INT base_offset
;
548 /* The size of the slot, including extra space for alignment. This
549 info is for combine_temp_slots. */
550 HOST_WIDE_INT full_size
;
553 /* A table of addresses that represent a stack slot. The table is a mapping
554 from address RTXen to a temp slot. */
555 static GTY((param_is(struct temp_slot_address_entry
))) htab_t temp_slot_address_table
;
556 static size_t n_temp_slots_in_use
;
558 /* Entry for the above hash table. */
559 struct GTY(()) temp_slot_address_entry
{
562 struct temp_slot
*temp_slot
;
565 /* Removes temporary slot TEMP from LIST. */
568 cut_slot_from_list (struct temp_slot
*temp
, struct temp_slot
**list
)
571 temp
->next
->prev
= temp
->prev
;
573 temp
->prev
->next
= temp
->next
;
577 temp
->prev
= temp
->next
= NULL
;
580 /* Inserts temporary slot TEMP to LIST. */
583 insert_slot_to_list (struct temp_slot
*temp
, struct temp_slot
**list
)
587 (*list
)->prev
= temp
;
592 /* Returns the list of used temp slots at LEVEL. */
594 static struct temp_slot
**
595 temp_slots_at_level (int level
)
597 if (level
>= (int) VEC_length (temp_slot_p
, used_temp_slots
))
598 VEC_safe_grow_cleared (temp_slot_p
, gc
, used_temp_slots
, level
+ 1);
600 return &(VEC_address (temp_slot_p
, used_temp_slots
)[level
]);
603 /* Returns the maximal temporary slot level. */
606 max_slot_level (void)
608 if (!used_temp_slots
)
611 return VEC_length (temp_slot_p
, used_temp_slots
) - 1;
614 /* Moves temporary slot TEMP to LEVEL. */
617 move_slot_to_level (struct temp_slot
*temp
, int level
)
619 cut_slot_from_list (temp
, temp_slots_at_level (temp
->level
));
620 insert_slot_to_list (temp
, temp_slots_at_level (level
));
624 /* Make temporary slot TEMP available. */
627 make_slot_available (struct temp_slot
*temp
)
629 cut_slot_from_list (temp
, temp_slots_at_level (temp
->level
));
630 insert_slot_to_list (temp
, &avail_temp_slots
);
633 n_temp_slots_in_use
--;
636 /* Compute the hash value for an address -> temp slot mapping.
637 The value is cached on the mapping entry. */
639 temp_slot_address_compute_hash (struct temp_slot_address_entry
*t
)
641 int do_not_record
= 0;
642 return hash_rtx (t
->address
, GET_MODE (t
->address
),
643 &do_not_record
, NULL
, false);
646 /* Return the hash value for an address -> temp slot mapping. */
648 temp_slot_address_hash (const void *p
)
650 const struct temp_slot_address_entry
*t
;
651 t
= (const struct temp_slot_address_entry
*) p
;
655 /* Compare two address -> temp slot mapping entries. */
657 temp_slot_address_eq (const void *p1
, const void *p2
)
659 const struct temp_slot_address_entry
*t1
, *t2
;
660 t1
= (const struct temp_slot_address_entry
*) p1
;
661 t2
= (const struct temp_slot_address_entry
*) p2
;
662 return exp_equiv_p (t1
->address
, t2
->address
, 0, true);
665 /* Add ADDRESS as an alias of TEMP_SLOT to the addess -> temp slot mapping. */
667 insert_temp_slot_address (rtx address
, struct temp_slot
*temp_slot
)
670 struct temp_slot_address_entry
*t
= ggc_alloc_temp_slot_address_entry ();
671 t
->address
= address
;
672 t
->temp_slot
= temp_slot
;
673 t
->hash
= temp_slot_address_compute_hash (t
);
674 slot
= htab_find_slot_with_hash (temp_slot_address_table
, t
, t
->hash
, INSERT
);
678 /* Remove an address -> temp slot mapping entry if the temp slot is
679 not in use anymore. Callback for remove_unused_temp_slot_addresses. */
681 remove_unused_temp_slot_addresses_1 (void **slot
, void *data ATTRIBUTE_UNUSED
)
683 const struct temp_slot_address_entry
*t
;
684 t
= (const struct temp_slot_address_entry
*) *slot
;
685 if (! t
->temp_slot
->in_use
)
686 htab_clear_slot (temp_slot_address_table
, slot
);
690 /* Remove all mappings of addresses to unused temp slots. */
692 remove_unused_temp_slot_addresses (void)
694 /* Use quicker clearing if there aren't any active temp slots. */
695 if (n_temp_slots_in_use
)
696 htab_traverse (temp_slot_address_table
,
697 remove_unused_temp_slot_addresses_1
,
700 htab_empty (temp_slot_address_table
);
703 /* Find the temp slot corresponding to the object at address X. */
705 static struct temp_slot
*
706 find_temp_slot_from_address (rtx x
)
709 struct temp_slot_address_entry tmp
, *t
;
711 /* First try the easy way:
712 See if X exists in the address -> temp slot mapping. */
714 tmp
.temp_slot
= NULL
;
715 tmp
.hash
= temp_slot_address_compute_hash (&tmp
);
716 t
= (struct temp_slot_address_entry
*)
717 htab_find_with_hash (temp_slot_address_table
, &tmp
, tmp
.hash
);
721 /* If we have a sum involving a register, see if it points to a temp
723 if (GET_CODE (x
) == PLUS
&& REG_P (XEXP (x
, 0))
724 && (p
= find_temp_slot_from_address (XEXP (x
, 0))) != 0)
726 else if (GET_CODE (x
) == PLUS
&& REG_P (XEXP (x
, 1))
727 && (p
= find_temp_slot_from_address (XEXP (x
, 1))) != 0)
730 /* Last resort: Address is a virtual stack var address. */
731 if (GET_CODE (x
) == PLUS
732 && XEXP (x
, 0) == virtual_stack_vars_rtx
733 && CONST_INT_P (XEXP (x
, 1)))
736 for (i
= max_slot_level (); i
>= 0; i
--)
737 for (p
= *temp_slots_at_level (i
); p
; p
= p
->next
)
739 if (INTVAL (XEXP (x
, 1)) >= p
->base_offset
740 && INTVAL (XEXP (x
, 1)) < p
->base_offset
+ p
->full_size
)
748 /* Allocate a temporary stack slot and record it for possible later
751 MODE is the machine mode to be given to the returned rtx.
753 SIZE is the size in units of the space required. We do no rounding here
754 since assign_stack_local will do any required rounding.
756 TYPE is the type that will be used for the stack slot. */
759 assign_stack_temp_for_type (enum machine_mode mode
, HOST_WIDE_INT size
,
763 struct temp_slot
*p
, *best_p
= 0, *selected
= NULL
, **pp
;
766 /* If SIZE is -1 it means that somebody tried to allocate a temporary
767 of a variable size. */
768 gcc_assert (size
!= -1);
770 align
= get_stack_local_alignment (type
, mode
);
772 /* Try to find an available, already-allocated temporary of the proper
773 mode which meets the size and alignment requirements. Choose the
774 smallest one with the closest alignment.
776 If assign_stack_temp is called outside of the tree->rtl expansion,
777 we cannot reuse the stack slots (that may still refer to
778 VIRTUAL_STACK_VARS_REGNUM). */
779 if (!virtuals_instantiated
)
781 for (p
= avail_temp_slots
; p
; p
= p
->next
)
783 if (p
->align
>= align
&& p
->size
>= size
784 && GET_MODE (p
->slot
) == mode
785 && objects_must_conflict_p (p
->type
, type
)
786 && (best_p
== 0 || best_p
->size
> p
->size
787 || (best_p
->size
== p
->size
&& best_p
->align
> p
->align
)))
789 if (p
->align
== align
&& p
->size
== size
)
792 cut_slot_from_list (selected
, &avail_temp_slots
);
801 /* Make our best, if any, the one to use. */
805 cut_slot_from_list (selected
, &avail_temp_slots
);
807 /* If there are enough aligned bytes left over, make them into a new
808 temp_slot so that the extra bytes don't get wasted. Do this only
809 for BLKmode slots, so that we can be sure of the alignment. */
810 if (GET_MODE (best_p
->slot
) == BLKmode
)
812 int alignment
= best_p
->align
/ BITS_PER_UNIT
;
813 HOST_WIDE_INT rounded_size
= CEIL_ROUND (size
, alignment
);
815 if (best_p
->size
- rounded_size
>= alignment
)
817 p
= ggc_alloc_temp_slot ();
819 p
->size
= best_p
->size
- rounded_size
;
820 p
->base_offset
= best_p
->base_offset
+ rounded_size
;
821 p
->full_size
= best_p
->full_size
- rounded_size
;
822 p
->slot
= adjust_address_nv (best_p
->slot
, BLKmode
, rounded_size
);
823 p
->align
= best_p
->align
;
824 p
->type
= best_p
->type
;
825 insert_slot_to_list (p
, &avail_temp_slots
);
827 stack_slot_list
= gen_rtx_EXPR_LIST (VOIDmode
, p
->slot
,
830 best_p
->size
= rounded_size
;
831 best_p
->full_size
= rounded_size
;
836 /* If we still didn't find one, make a new temporary. */
839 HOST_WIDE_INT frame_offset_old
= frame_offset
;
841 p
= ggc_alloc_temp_slot ();
843 /* We are passing an explicit alignment request to assign_stack_local.
844 One side effect of that is assign_stack_local will not round SIZE
845 to ensure the frame offset remains suitably aligned.
847 So for requests which depended on the rounding of SIZE, we go ahead
848 and round it now. We also make sure ALIGNMENT is at least
849 BIGGEST_ALIGNMENT. */
850 gcc_assert (mode
!= BLKmode
|| align
== BIGGEST_ALIGNMENT
);
851 p
->slot
= assign_stack_local_1 (mode
,
861 /* The following slot size computation is necessary because we don't
862 know the actual size of the temporary slot until assign_stack_local
863 has performed all the frame alignment and size rounding for the
864 requested temporary. Note that extra space added for alignment
865 can be either above or below this stack slot depending on which
866 way the frame grows. We include the extra space if and only if it
867 is above this slot. */
868 if (FRAME_GROWS_DOWNWARD
)
869 p
->size
= frame_offset_old
- frame_offset
;
873 /* Now define the fields used by combine_temp_slots. */
874 if (FRAME_GROWS_DOWNWARD
)
876 p
->base_offset
= frame_offset
;
877 p
->full_size
= frame_offset_old
- frame_offset
;
881 p
->base_offset
= frame_offset_old
;
882 p
->full_size
= frame_offset
- frame_offset_old
;
891 p
->level
= temp_slot_level
;
892 n_temp_slots_in_use
++;
894 pp
= temp_slots_at_level (p
->level
);
895 insert_slot_to_list (p
, pp
);
896 insert_temp_slot_address (XEXP (p
->slot
, 0), p
);
898 /* Create a new MEM rtx to avoid clobbering MEM flags of old slots. */
899 slot
= gen_rtx_MEM (mode
, XEXP (p
->slot
, 0));
900 stack_slot_list
= gen_rtx_EXPR_LIST (VOIDmode
, slot
, stack_slot_list
);
902 /* If we know the alias set for the memory that will be used, use
903 it. If there's no TYPE, then we don't know anything about the
904 alias set for the memory. */
905 set_mem_alias_set (slot
, type
? get_alias_set (type
) : 0);
906 set_mem_align (slot
, align
);
908 /* If a type is specified, set the relevant flags. */
910 MEM_VOLATILE_P (slot
) = TYPE_VOLATILE (type
);
911 MEM_NOTRAP_P (slot
) = 1;
916 /* Allocate a temporary stack slot and record it for possible later
917 reuse. First two arguments are same as in preceding function. */
920 assign_stack_temp (enum machine_mode mode
, HOST_WIDE_INT size
)
922 return assign_stack_temp_for_type (mode
, size
, NULL_TREE
);
925 /* Assign a temporary.
926 If TYPE_OR_DECL is a decl, then we are doing it on behalf of the decl
927 and so that should be used in error messages. In either case, we
928 allocate of the given type.
929 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
930 it is 0 if a register is OK.
931 DONT_PROMOTE is 1 if we should not promote values in register
935 assign_temp (tree type_or_decl
, int memory_required
,
936 int dont_promote ATTRIBUTE_UNUSED
)
939 enum machine_mode mode
;
944 if (DECL_P (type_or_decl
))
945 decl
= type_or_decl
, type
= TREE_TYPE (decl
);
947 decl
= NULL
, type
= type_or_decl
;
949 mode
= TYPE_MODE (type
);
951 unsignedp
= TYPE_UNSIGNED (type
);
954 if (mode
== BLKmode
|| memory_required
)
956 HOST_WIDE_INT size
= int_size_in_bytes (type
);
959 /* Zero sized arrays are GNU C extension. Set size to 1 to avoid
960 problems with allocating the stack space. */
964 /* Unfortunately, we don't yet know how to allocate variable-sized
965 temporaries. However, sometimes we can find a fixed upper limit on
966 the size, so try that instead. */
968 size
= max_int_size_in_bytes (type
);
970 /* The size of the temporary may be too large to fit into an integer. */
971 /* ??? Not sure this should happen except for user silliness, so limit
972 this to things that aren't compiler-generated temporaries. The
973 rest of the time we'll die in assign_stack_temp_for_type. */
974 if (decl
&& size
== -1
975 && TREE_CODE (TYPE_SIZE_UNIT (type
)) == INTEGER_CST
)
977 error ("size of variable %q+D is too large", decl
);
981 tmp
= assign_stack_temp_for_type (mode
, size
, type
);
987 mode
= promote_mode (type
, mode
, &unsignedp
);
990 return gen_reg_rtx (mode
);
993 /* Combine temporary stack slots which are adjacent on the stack.
995 This allows for better use of already allocated stack space. This is only
996 done for BLKmode slots because we can be sure that we won't have alignment
997 problems in this case. */
1000 combine_temp_slots (void)
1002 struct temp_slot
*p
, *q
, *next
, *next_q
;
1005 /* We can't combine slots, because the information about which slot
1006 is in which alias set will be lost. */
1007 if (flag_strict_aliasing
)
1010 /* If there are a lot of temp slots, don't do anything unless
1011 high levels of optimization. */
1012 if (! flag_expensive_optimizations
)
1013 for (p
= avail_temp_slots
, num_slots
= 0; p
; p
= p
->next
, num_slots
++)
1014 if (num_slots
> 100 || (num_slots
> 10 && optimize
== 0))
1017 for (p
= avail_temp_slots
; p
; p
= next
)
1023 if (GET_MODE (p
->slot
) != BLKmode
)
1026 for (q
= p
->next
; q
; q
= next_q
)
1032 if (GET_MODE (q
->slot
) != BLKmode
)
1035 if (p
->base_offset
+ p
->full_size
== q
->base_offset
)
1037 /* Q comes after P; combine Q into P. */
1039 p
->full_size
+= q
->full_size
;
1042 else if (q
->base_offset
+ q
->full_size
== p
->base_offset
)
1044 /* P comes after Q; combine P into Q. */
1046 q
->full_size
+= p
->full_size
;
1051 cut_slot_from_list (q
, &avail_temp_slots
);
1054 /* Either delete P or advance past it. */
1056 cut_slot_from_list (p
, &avail_temp_slots
);
1060 /* Indicate that NEW_RTX is an alternate way of referring to the temp
1061 slot that previously was known by OLD_RTX. */
1064 update_temp_slot_address (rtx old_rtx
, rtx new_rtx
)
1066 struct temp_slot
*p
;
1068 if (rtx_equal_p (old_rtx
, new_rtx
))
1071 p
= find_temp_slot_from_address (old_rtx
);
1073 /* If we didn't find one, see if both OLD_RTX is a PLUS. If so, and
1074 NEW_RTX is a register, see if one operand of the PLUS is a
1075 temporary location. If so, NEW_RTX points into it. Otherwise,
1076 if both OLD_RTX and NEW_RTX are a PLUS and if there is a register
1077 in common between them. If so, try a recursive call on those
1081 if (GET_CODE (old_rtx
) != PLUS
)
1084 if (REG_P (new_rtx
))
1086 update_temp_slot_address (XEXP (old_rtx
, 0), new_rtx
);
1087 update_temp_slot_address (XEXP (old_rtx
, 1), new_rtx
);
1090 else if (GET_CODE (new_rtx
) != PLUS
)
1093 if (rtx_equal_p (XEXP (old_rtx
, 0), XEXP (new_rtx
, 0)))
1094 update_temp_slot_address (XEXP (old_rtx
, 1), XEXP (new_rtx
, 1));
1095 else if (rtx_equal_p (XEXP (old_rtx
, 1), XEXP (new_rtx
, 0)))
1096 update_temp_slot_address (XEXP (old_rtx
, 0), XEXP (new_rtx
, 1));
1097 else if (rtx_equal_p (XEXP (old_rtx
, 0), XEXP (new_rtx
, 1)))
1098 update_temp_slot_address (XEXP (old_rtx
, 1), XEXP (new_rtx
, 0));
1099 else if (rtx_equal_p (XEXP (old_rtx
, 1), XEXP (new_rtx
, 1)))
1100 update_temp_slot_address (XEXP (old_rtx
, 0), XEXP (new_rtx
, 0));
1105 /* Otherwise add an alias for the temp's address. */
1106 insert_temp_slot_address (new_rtx
, p
);
1109 /* If X could be a reference to a temporary slot, mark that slot as
1110 belonging to the to one level higher than the current level. If X
1111 matched one of our slots, just mark that one. Otherwise, we can't
1112 easily predict which it is, so upgrade all of them.
1114 This is called when an ({...}) construct occurs and a statement
1115 returns a value in memory. */
1118 preserve_temp_slots (rtx x
)
1120 struct temp_slot
*p
= 0, *next
;
1125 /* If X is a register that is being used as a pointer, see if we have
1126 a temporary slot we know it points to. */
1127 if (REG_P (x
) && REG_POINTER (x
))
1128 p
= find_temp_slot_from_address (x
);
1130 /* If X is not in memory or is at a constant address, it cannot be in
1131 a temporary slot. */
1132 if (p
== 0 && (!MEM_P (x
) || CONSTANT_P (XEXP (x
, 0))))
1135 /* First see if we can find a match. */
1137 p
= find_temp_slot_from_address (XEXP (x
, 0));
1141 if (p
->level
== temp_slot_level
)
1142 move_slot_to_level (p
, temp_slot_level
- 1);
1146 /* Otherwise, preserve all non-kept slots at this level. */
1147 for (p
= *temp_slots_at_level (temp_slot_level
); p
; p
= next
)
1150 move_slot_to_level (p
, temp_slot_level
- 1);
1154 /* Free all temporaries used so far. This is normally called at the
1155 end of generating code for a statement. */
1158 free_temp_slots (void)
1160 struct temp_slot
*p
, *next
;
1161 bool some_available
= false;
1163 for (p
= *temp_slots_at_level (temp_slot_level
); p
; p
= next
)
1166 make_slot_available (p
);
1167 some_available
= true;
1172 remove_unused_temp_slot_addresses ();
1173 combine_temp_slots ();
1177 /* Push deeper into the nesting level for stack temporaries. */
1180 push_temp_slots (void)
1185 /* Pop a temporary nesting level. All slots in use in the current level
1189 pop_temp_slots (void)
1195 /* Initialize temporary slots. */
1198 init_temp_slots (void)
1200 /* We have not allocated any temporaries yet. */
1201 avail_temp_slots
= 0;
1202 used_temp_slots
= 0;
1203 temp_slot_level
= 0;
1204 n_temp_slots_in_use
= 0;
1206 /* Set up the table to map addresses to temp slots. */
1207 if (! temp_slot_address_table
)
1208 temp_slot_address_table
= htab_create_ggc (32,
1209 temp_slot_address_hash
,
1210 temp_slot_address_eq
,
1213 htab_empty (temp_slot_address_table
);
1216 /* Functions and data structures to keep track of the values hard regs
1217 had at the start of the function. */
1219 /* Private type used by get_hard_reg_initial_reg, get_hard_reg_initial_val,
1220 and has_hard_reg_initial_val.. */
1221 typedef struct GTY(()) initial_value_pair
{
1224 } initial_value_pair
;
1225 /* ??? This could be a VEC but there is currently no way to define an
1226 opaque VEC type. This could be worked around by defining struct
1227 initial_value_pair in function.h. */
1228 typedef struct GTY(()) initial_value_struct
{
1231 initial_value_pair
* GTY ((length ("%h.num_entries"))) entries
;
1232 } initial_value_struct
;
1234 /* If a pseudo represents an initial hard reg (or expression), return
1235 it, else return NULL_RTX. */
1238 get_hard_reg_initial_reg (rtx reg
)
1240 struct initial_value_struct
*ivs
= crtl
->hard_reg_initial_vals
;
1246 for (i
= 0; i
< ivs
->num_entries
; i
++)
1247 if (rtx_equal_p (ivs
->entries
[i
].pseudo
, reg
))
1248 return ivs
->entries
[i
].hard_reg
;
1253 /* Make sure that there's a pseudo register of mode MODE that stores the
1254 initial value of hard register REGNO. Return an rtx for such a pseudo. */
1257 get_hard_reg_initial_val (enum machine_mode mode
, unsigned int regno
)
1259 struct initial_value_struct
*ivs
;
1262 rv
= has_hard_reg_initial_val (mode
, regno
);
1266 ivs
= crtl
->hard_reg_initial_vals
;
1269 ivs
= ggc_alloc_initial_value_struct ();
1270 ivs
->num_entries
= 0;
1271 ivs
->max_entries
= 5;
1272 ivs
->entries
= ggc_alloc_vec_initial_value_pair (5);
1273 crtl
->hard_reg_initial_vals
= ivs
;
1276 if (ivs
->num_entries
>= ivs
->max_entries
)
1278 ivs
->max_entries
+= 5;
1279 ivs
->entries
= GGC_RESIZEVEC (initial_value_pair
, ivs
->entries
,
1283 ivs
->entries
[ivs
->num_entries
].hard_reg
= gen_rtx_REG (mode
, regno
);
1284 ivs
->entries
[ivs
->num_entries
].pseudo
= gen_reg_rtx (mode
);
1286 return ivs
->entries
[ivs
->num_entries
++].pseudo
;
1289 /* See if get_hard_reg_initial_val has been used to create a pseudo
1290 for the initial value of hard register REGNO in mode MODE. Return
1291 the associated pseudo if so, otherwise return NULL. */
1294 has_hard_reg_initial_val (enum machine_mode mode
, unsigned int regno
)
1296 struct initial_value_struct
*ivs
;
1299 ivs
= crtl
->hard_reg_initial_vals
;
1301 for (i
= 0; i
< ivs
->num_entries
; i
++)
1302 if (GET_MODE (ivs
->entries
[i
].hard_reg
) == mode
1303 && REGNO (ivs
->entries
[i
].hard_reg
) == regno
)
1304 return ivs
->entries
[i
].pseudo
;
1310 emit_initial_value_sets (void)
1312 struct initial_value_struct
*ivs
= crtl
->hard_reg_initial_vals
;
1320 for (i
= 0; i
< ivs
->num_entries
; i
++)
1321 emit_move_insn (ivs
->entries
[i
].pseudo
, ivs
->entries
[i
].hard_reg
);
1325 emit_insn_at_entry (seq
);
1329 /* Return the hardreg-pseudoreg initial values pair entry I and
1330 TRUE if I is a valid entry, or FALSE if I is not a valid entry. */
1332 initial_value_entry (int i
, rtx
*hreg
, rtx
*preg
)
1334 struct initial_value_struct
*ivs
= crtl
->hard_reg_initial_vals
;
1335 if (!ivs
|| i
>= ivs
->num_entries
)
1338 *hreg
= ivs
->entries
[i
].hard_reg
;
1339 *preg
= ivs
->entries
[i
].pseudo
;
1343 /* These routines are responsible for converting virtual register references
1344 to the actual hard register references once RTL generation is complete.
1346 The following four variables are used for communication between the
1347 routines. They contain the offsets of the virtual registers from their
1348 respective hard registers. */
1350 static int in_arg_offset
;
1351 static int var_offset
;
1352 static int dynamic_offset
;
1353 static int out_arg_offset
;
1354 static int cfa_offset
;
1356 /* In most machines, the stack pointer register is equivalent to the bottom
1359 #ifndef STACK_POINTER_OFFSET
1360 #define STACK_POINTER_OFFSET 0
1363 /* If not defined, pick an appropriate default for the offset of dynamically
1364 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
1365 REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
1367 #ifndef STACK_DYNAMIC_OFFSET
1369 /* The bottom of the stack points to the actual arguments. If
1370 REG_PARM_STACK_SPACE is defined, this includes the space for the register
1371 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
1372 stack space for register parameters is not pushed by the caller, but
1373 rather part of the fixed stack areas and hence not included in
1374 `crtl->outgoing_args_size'. Nevertheless, we must allow
1375 for it when allocating stack dynamic objects. */
1377 #if defined(REG_PARM_STACK_SPACE)
1378 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1379 ((ACCUMULATE_OUTGOING_ARGS \
1380 ? (crtl->outgoing_args_size \
1381 + (OUTGOING_REG_PARM_STACK_SPACE ((!(FNDECL) ? NULL_TREE : TREE_TYPE (FNDECL))) ? 0 \
1382 : REG_PARM_STACK_SPACE (FNDECL))) \
1383 : 0) + (STACK_POINTER_OFFSET))
1385 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1386 ((ACCUMULATE_OUTGOING_ARGS ? crtl->outgoing_args_size : 0) \
1387 + (STACK_POINTER_OFFSET))
1392 /* Given a piece of RTX and a pointer to a HOST_WIDE_INT, if the RTX
1393 is a virtual register, return the equivalent hard register and set the
1394 offset indirectly through the pointer. Otherwise, return 0. */
1397 instantiate_new_reg (rtx x
, HOST_WIDE_INT
*poffset
)
1400 HOST_WIDE_INT offset
;
1402 if (x
== virtual_incoming_args_rtx
)
1404 if (stack_realign_drap
)
1406 /* Replace virtual_incoming_args_rtx with internal arg
1407 pointer if DRAP is used to realign stack. */
1408 new_rtx
= crtl
->args
.internal_arg_pointer
;
1412 new_rtx
= arg_pointer_rtx
, offset
= in_arg_offset
;
1414 else if (x
== virtual_stack_vars_rtx
)
1415 new_rtx
= frame_pointer_rtx
, offset
= var_offset
;
1416 else if (x
== virtual_stack_dynamic_rtx
)
1417 new_rtx
= stack_pointer_rtx
, offset
= dynamic_offset
;
1418 else if (x
== virtual_outgoing_args_rtx
)
1419 new_rtx
= stack_pointer_rtx
, offset
= out_arg_offset
;
1420 else if (x
== virtual_cfa_rtx
)
1422 #ifdef FRAME_POINTER_CFA_OFFSET
1423 new_rtx
= frame_pointer_rtx
;
1425 new_rtx
= arg_pointer_rtx
;
1427 offset
= cfa_offset
;
1429 else if (x
== virtual_preferred_stack_boundary_rtx
)
1431 new_rtx
= GEN_INT (crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
);
1441 /* A subroutine of instantiate_virtual_regs, called via for_each_rtx.
1442 Instantiate any virtual registers present inside of *LOC. The expression
1443 is simplified, as much as possible, but is not to be considered "valid"
1444 in any sense implied by the target. If any change is made, set CHANGED
1448 instantiate_virtual_regs_in_rtx (rtx
*loc
, void *data
)
1450 HOST_WIDE_INT offset
;
1451 bool *changed
= (bool *) data
;
1458 switch (GET_CODE (x
))
1461 new_rtx
= instantiate_new_reg (x
, &offset
);
1464 *loc
= plus_constant (GET_MODE (x
), new_rtx
, offset
);
1471 new_rtx
= instantiate_new_reg (XEXP (x
, 0), &offset
);
1474 new_rtx
= plus_constant (GET_MODE (x
), new_rtx
, offset
);
1475 *loc
= simplify_gen_binary (PLUS
, GET_MODE (x
), new_rtx
, XEXP (x
, 1));
1481 /* FIXME -- from old code */
1482 /* If we have (plus (subreg (virtual-reg)) (const_int)), we know
1483 we can commute the PLUS and SUBREG because pointers into the
1484 frame are well-behaved. */
1494 /* A subroutine of instantiate_virtual_regs_in_insn. Return true if X
1495 matches the predicate for insn CODE operand OPERAND. */
1498 safe_insn_predicate (int code
, int operand
, rtx x
)
1500 return code
< 0 || insn_operand_matches ((enum insn_code
) code
, operand
, x
);
1503 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1504 registers present inside of insn. The result will be a valid insn. */
1507 instantiate_virtual_regs_in_insn (rtx insn
)
1509 HOST_WIDE_INT offset
;
1511 bool any_change
= false;
1512 rtx set
, new_rtx
, x
, seq
;
1514 /* There are some special cases to be handled first. */
1515 set
= single_set (insn
);
1518 /* We're allowed to assign to a virtual register. This is interpreted
1519 to mean that the underlying register gets assigned the inverse
1520 transformation. This is used, for example, in the handling of
1522 new_rtx
= instantiate_new_reg (SET_DEST (set
), &offset
);
1527 for_each_rtx (&SET_SRC (set
), instantiate_virtual_regs_in_rtx
, NULL
);
1528 x
= simplify_gen_binary (PLUS
, GET_MODE (new_rtx
), SET_SRC (set
),
1530 x
= force_operand (x
, new_rtx
);
1532 emit_move_insn (new_rtx
, x
);
1537 emit_insn_before (seq
, insn
);
1542 /* Handle a straight copy from a virtual register by generating a
1543 new add insn. The difference between this and falling through
1544 to the generic case is avoiding a new pseudo and eliminating a
1545 move insn in the initial rtl stream. */
1546 new_rtx
= instantiate_new_reg (SET_SRC (set
), &offset
);
1547 if (new_rtx
&& offset
!= 0
1548 && REG_P (SET_DEST (set
))
1549 && REGNO (SET_DEST (set
)) > LAST_VIRTUAL_REGISTER
)
1553 x
= expand_simple_binop (GET_MODE (SET_DEST (set
)), PLUS
,
1554 new_rtx
, GEN_INT (offset
), SET_DEST (set
),
1555 1, OPTAB_LIB_WIDEN
);
1556 if (x
!= SET_DEST (set
))
1557 emit_move_insn (SET_DEST (set
), x
);
1562 emit_insn_before (seq
, insn
);
1567 extract_insn (insn
);
1568 insn_code
= INSN_CODE (insn
);
1570 /* Handle a plus involving a virtual register by determining if the
1571 operands remain valid if they're modified in place. */
1572 if (GET_CODE (SET_SRC (set
)) == PLUS
1573 && recog_data
.n_operands
>= 3
1574 && recog_data
.operand_loc
[1] == &XEXP (SET_SRC (set
), 0)
1575 && recog_data
.operand_loc
[2] == &XEXP (SET_SRC (set
), 1)
1576 && CONST_INT_P (recog_data
.operand
[2])
1577 && (new_rtx
= instantiate_new_reg (recog_data
.operand
[1], &offset
)))
1579 offset
+= INTVAL (recog_data
.operand
[2]);
1581 /* If the sum is zero, then replace with a plain move. */
1583 && REG_P (SET_DEST (set
))
1584 && REGNO (SET_DEST (set
)) > LAST_VIRTUAL_REGISTER
)
1587 emit_move_insn (SET_DEST (set
), new_rtx
);
1591 emit_insn_before (seq
, insn
);
1596 x
= gen_int_mode (offset
, recog_data
.operand_mode
[2]);
1598 /* Using validate_change and apply_change_group here leaves
1599 recog_data in an invalid state. Since we know exactly what
1600 we want to check, do those two by hand. */
1601 if (safe_insn_predicate (insn_code
, 1, new_rtx
)
1602 && safe_insn_predicate (insn_code
, 2, x
))
1604 *recog_data
.operand_loc
[1] = recog_data
.operand
[1] = new_rtx
;
1605 *recog_data
.operand_loc
[2] = recog_data
.operand
[2] = x
;
1608 /* Fall through into the regular operand fixup loop in
1609 order to take care of operands other than 1 and 2. */
1615 extract_insn (insn
);
1616 insn_code
= INSN_CODE (insn
);
1619 /* In the general case, we expect virtual registers to appear only in
1620 operands, and then only as either bare registers or inside memories. */
1621 for (i
= 0; i
< recog_data
.n_operands
; ++i
)
1623 x
= recog_data
.operand
[i
];
1624 switch (GET_CODE (x
))
1628 rtx addr
= XEXP (x
, 0);
1629 bool changed
= false;
1631 for_each_rtx (&addr
, instantiate_virtual_regs_in_rtx
, &changed
);
1636 x
= replace_equiv_address (x
, addr
);
1637 /* It may happen that the address with the virtual reg
1638 was valid (e.g. based on the virtual stack reg, which might
1639 be acceptable to the predicates with all offsets), whereas
1640 the address now isn't anymore, for instance when the address
1641 is still offsetted, but the base reg isn't virtual-stack-reg
1642 anymore. Below we would do a force_reg on the whole operand,
1643 but this insn might actually only accept memory. Hence,
1644 before doing that last resort, try to reload the address into
1645 a register, so this operand stays a MEM. */
1646 if (!safe_insn_predicate (insn_code
, i
, x
))
1648 addr
= force_reg (GET_MODE (addr
), addr
);
1649 x
= replace_equiv_address (x
, addr
);
1654 emit_insn_before (seq
, insn
);
1659 new_rtx
= instantiate_new_reg (x
, &offset
);
1660 if (new_rtx
== NULL
)
1668 /* Careful, special mode predicates may have stuff in
1669 insn_data[insn_code].operand[i].mode that isn't useful
1670 to us for computing a new value. */
1671 /* ??? Recognize address_operand and/or "p" constraints
1672 to see if (plus new offset) is a valid before we put
1673 this through expand_simple_binop. */
1674 x
= expand_simple_binop (GET_MODE (x
), PLUS
, new_rtx
,
1675 GEN_INT (offset
), NULL_RTX
,
1676 1, OPTAB_LIB_WIDEN
);
1679 emit_insn_before (seq
, insn
);
1684 new_rtx
= instantiate_new_reg (SUBREG_REG (x
), &offset
);
1685 if (new_rtx
== NULL
)
1690 new_rtx
= expand_simple_binop (GET_MODE (new_rtx
), PLUS
, new_rtx
,
1691 GEN_INT (offset
), NULL_RTX
,
1692 1, OPTAB_LIB_WIDEN
);
1695 emit_insn_before (seq
, insn
);
1697 x
= simplify_gen_subreg (recog_data
.operand_mode
[i
], new_rtx
,
1698 GET_MODE (new_rtx
), SUBREG_BYTE (x
));
1706 /* At this point, X contains the new value for the operand.
1707 Validate the new value vs the insn predicate. Note that
1708 asm insns will have insn_code -1 here. */
1709 if (!safe_insn_predicate (insn_code
, i
, x
))
1714 gcc_assert (REGNO (x
) <= LAST_VIRTUAL_REGISTER
);
1715 x
= copy_to_reg (x
);
1718 x
= force_reg (insn_data
[insn_code
].operand
[i
].mode
, x
);
1722 emit_insn_before (seq
, insn
);
1725 *recog_data
.operand_loc
[i
] = recog_data
.operand
[i
] = x
;
1731 /* Propagate operand changes into the duplicates. */
1732 for (i
= 0; i
< recog_data
.n_dups
; ++i
)
1733 *recog_data
.dup_loc
[i
]
1734 = copy_rtx (recog_data
.operand
[(unsigned)recog_data
.dup_num
[i
]]);
1736 /* Force re-recognition of the instruction for validation. */
1737 INSN_CODE (insn
) = -1;
1740 if (asm_noperands (PATTERN (insn
)) >= 0)
1742 if (!check_asm_operands (PATTERN (insn
)))
1744 error_for_asm (insn
, "impossible constraint in %<asm%>");
1745 delete_insn_and_edges (insn
);
1750 if (recog_memoized (insn
) < 0)
1751 fatal_insn_not_found (insn
);
1755 /* Subroutine of instantiate_decls. Given RTL representing a decl,
1756 do any instantiation required. */
1759 instantiate_decl_rtl (rtx x
)
1766 /* If this is a CONCAT, recurse for the pieces. */
1767 if (GET_CODE (x
) == CONCAT
)
1769 instantiate_decl_rtl (XEXP (x
, 0));
1770 instantiate_decl_rtl (XEXP (x
, 1));
1774 /* If this is not a MEM, no need to do anything. Similarly if the
1775 address is a constant or a register that is not a virtual register. */
1780 if (CONSTANT_P (addr
)
1782 && (REGNO (addr
) < FIRST_VIRTUAL_REGISTER
1783 || REGNO (addr
) > LAST_VIRTUAL_REGISTER
)))
1786 for_each_rtx (&XEXP (x
, 0), instantiate_virtual_regs_in_rtx
, NULL
);
1789 /* Helper for instantiate_decls called via walk_tree: Process all decls
1790 in the given DECL_VALUE_EXPR. */
1793 instantiate_expr (tree
*tp
, int *walk_subtrees
, void *data ATTRIBUTE_UNUSED
)
1801 if (DECL_RTL_SET_P (t
))
1802 instantiate_decl_rtl (DECL_RTL (t
));
1803 if (TREE_CODE (t
) == PARM_DECL
&& DECL_NAMELESS (t
)
1804 && DECL_INCOMING_RTL (t
))
1805 instantiate_decl_rtl (DECL_INCOMING_RTL (t
));
1806 if ((TREE_CODE (t
) == VAR_DECL
1807 || TREE_CODE (t
) == RESULT_DECL
)
1808 && DECL_HAS_VALUE_EXPR_P (t
))
1810 tree v
= DECL_VALUE_EXPR (t
);
1811 walk_tree (&v
, instantiate_expr
, NULL
, NULL
);
1818 /* Subroutine of instantiate_decls: Process all decls in the given
1819 BLOCK node and all its subblocks. */
1822 instantiate_decls_1 (tree let
)
1826 for (t
= BLOCK_VARS (let
); t
; t
= DECL_CHAIN (t
))
1828 if (DECL_RTL_SET_P (t
))
1829 instantiate_decl_rtl (DECL_RTL (t
));
1830 if (TREE_CODE (t
) == VAR_DECL
&& DECL_HAS_VALUE_EXPR_P (t
))
1832 tree v
= DECL_VALUE_EXPR (t
);
1833 walk_tree (&v
, instantiate_expr
, NULL
, NULL
);
1837 /* Process all subblocks. */
1838 for (t
= BLOCK_SUBBLOCKS (let
); t
; t
= BLOCK_CHAIN (t
))
1839 instantiate_decls_1 (t
);
1842 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
1843 all virtual registers in their DECL_RTL's. */
1846 instantiate_decls (tree fndecl
)
1851 /* Process all parameters of the function. */
1852 for (decl
= DECL_ARGUMENTS (fndecl
); decl
; decl
= DECL_CHAIN (decl
))
1854 instantiate_decl_rtl (DECL_RTL (decl
));
1855 instantiate_decl_rtl (DECL_INCOMING_RTL (decl
));
1856 if (DECL_HAS_VALUE_EXPR_P (decl
))
1858 tree v
= DECL_VALUE_EXPR (decl
);
1859 walk_tree (&v
, instantiate_expr
, NULL
, NULL
);
1863 if ((decl
= DECL_RESULT (fndecl
))
1864 && TREE_CODE (decl
) == RESULT_DECL
)
1866 if (DECL_RTL_SET_P (decl
))
1867 instantiate_decl_rtl (DECL_RTL (decl
));
1868 if (DECL_HAS_VALUE_EXPR_P (decl
))
1870 tree v
= DECL_VALUE_EXPR (decl
);
1871 walk_tree (&v
, instantiate_expr
, NULL
, NULL
);
1875 /* Now process all variables defined in the function or its subblocks. */
1876 instantiate_decls_1 (DECL_INITIAL (fndecl
));
1878 FOR_EACH_LOCAL_DECL (cfun
, ix
, decl
)
1879 if (DECL_RTL_SET_P (decl
))
1880 instantiate_decl_rtl (DECL_RTL (decl
));
1881 VEC_free (tree
, gc
, cfun
->local_decls
);
1884 /* Pass through the INSNS of function FNDECL and convert virtual register
1885 references to hard register references. */
1888 instantiate_virtual_regs (void)
1892 /* Compute the offsets to use for this function. */
1893 in_arg_offset
= FIRST_PARM_OFFSET (current_function_decl
);
1894 var_offset
= STARTING_FRAME_OFFSET
;
1896 dynamic_offset
= STACK_DYNAMIC_OFFSET (current_function_decl
);
1897 if (crtl
->max_dynamic_stack_alignment
)
1899 int align
= crtl
->max_dynamic_stack_alignment
/ BITS_PER_UNIT
;
1900 dynamic_offset
= (dynamic_offset
+ align
- 1) & -align
;
1903 out_arg_offset
= STACK_POINTER_OFFSET
;
1904 #ifdef FRAME_POINTER_CFA_OFFSET
1905 cfa_offset
= FRAME_POINTER_CFA_OFFSET (current_function_decl
);
1907 cfa_offset
= ARG_POINTER_CFA_OFFSET (current_function_decl
);
1910 /* Initialize recognition, indicating that volatile is OK. */
1913 /* Scan through all the insns, instantiating every virtual register still
1915 for (insn
= get_insns (); insn
; insn
= NEXT_INSN (insn
))
1918 /* These patterns in the instruction stream can never be recognized.
1919 Fortunately, they shouldn't contain virtual registers either. */
1920 if (GET_CODE (PATTERN (insn
)) == USE
1921 || GET_CODE (PATTERN (insn
)) == CLOBBER
1922 || GET_CODE (PATTERN (insn
)) == ADDR_VEC
1923 || GET_CODE (PATTERN (insn
)) == ADDR_DIFF_VEC
1924 || GET_CODE (PATTERN (insn
)) == ASM_INPUT
)
1926 else if (DEBUG_INSN_P (insn
))
1927 for_each_rtx (&INSN_VAR_LOCATION (insn
),
1928 instantiate_virtual_regs_in_rtx
, NULL
);
1930 instantiate_virtual_regs_in_insn (insn
);
1932 if (INSN_DELETED_P (insn
))
1935 for_each_rtx (®_NOTES (insn
), instantiate_virtual_regs_in_rtx
, NULL
);
1937 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
1939 for_each_rtx (&CALL_INSN_FUNCTION_USAGE (insn
),
1940 instantiate_virtual_regs_in_rtx
, NULL
);
1943 /* Instantiate the virtual registers in the DECLs for debugging purposes. */
1944 instantiate_decls (current_function_decl
);
1946 targetm
.instantiate_decls ();
1948 /* Indicate that, from now on, assign_stack_local should use
1949 frame_pointer_rtx. */
1950 virtuals_instantiated
= 1;
1955 struct rtl_opt_pass pass_instantiate_virtual_regs
=
1961 instantiate_virtual_regs
, /* execute */
1964 0, /* static_pass_number */
1965 TV_NONE
, /* tv_id */
1966 0, /* properties_required */
1967 0, /* properties_provided */
1968 0, /* properties_destroyed */
1969 0, /* todo_flags_start */
1970 0 /* todo_flags_finish */
1975 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
1976 This means a type for which function calls must pass an address to the
1977 function or get an address back from the function.
1978 EXP may be a type node or an expression (whose type is tested). */
1981 aggregate_value_p (const_tree exp
, const_tree fntype
)
1983 const_tree type
= (TYPE_P (exp
)) ? exp
: TREE_TYPE (exp
);
1984 int i
, regno
, nregs
;
1988 switch (TREE_CODE (fntype
))
1992 tree fndecl
= get_callee_fndecl (fntype
);
1994 ? TREE_TYPE (fndecl
)
1995 : TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (fntype
))));
1999 fntype
= TREE_TYPE (fntype
);
2004 case IDENTIFIER_NODE
:
2008 /* We don't expect other tree types here. */
2012 if (VOID_TYPE_P (type
))
2015 /* If a record should be passed the same as its first (and only) member
2016 don't pass it as an aggregate. */
2017 if (TREE_CODE (type
) == RECORD_TYPE
&& TYPE_TRANSPARENT_AGGR (type
))
2018 return aggregate_value_p (first_field (type
), fntype
);
2020 /* If the front end has decided that this needs to be passed by
2021 reference, do so. */
2022 if ((TREE_CODE (exp
) == PARM_DECL
|| TREE_CODE (exp
) == RESULT_DECL
)
2023 && DECL_BY_REFERENCE (exp
))
2026 /* Function types that are TREE_ADDRESSABLE force return in memory. */
2027 if (fntype
&& TREE_ADDRESSABLE (fntype
))
2030 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
2031 and thus can't be returned in registers. */
2032 if (TREE_ADDRESSABLE (type
))
2035 if (flag_pcc_struct_return
&& AGGREGATE_TYPE_P (type
))
2038 if (targetm
.calls
.return_in_memory (type
, fntype
))
2041 /* Make sure we have suitable call-clobbered regs to return
2042 the value in; if not, we must return it in memory. */
2043 reg
= hard_function_value (type
, 0, fntype
, 0);
2045 /* If we have something other than a REG (e.g. a PARALLEL), then assume
2050 regno
= REGNO (reg
);
2051 nregs
= hard_regno_nregs
[regno
][TYPE_MODE (type
)];
2052 for (i
= 0; i
< nregs
; i
++)
2053 if (! call_used_regs
[regno
+ i
])
2059 /* Return true if we should assign DECL a pseudo register; false if it
2060 should live on the local stack. */
2063 use_register_for_decl (const_tree decl
)
2065 if (!targetm
.calls
.allocate_stack_slots_for_args())
2068 /* Honor volatile. */
2069 if (TREE_SIDE_EFFECTS (decl
))
2072 /* Honor addressability. */
2073 if (TREE_ADDRESSABLE (decl
))
2076 /* Only register-like things go in registers. */
2077 if (DECL_MODE (decl
) == BLKmode
)
2080 /* If -ffloat-store specified, don't put explicit float variables
2082 /* ??? This should be checked after DECL_ARTIFICIAL, but tree-ssa
2083 propagates values across these stores, and it probably shouldn't. */
2084 if (flag_float_store
&& FLOAT_TYPE_P (TREE_TYPE (decl
)))
2087 /* If we're not interested in tracking debugging information for
2088 this decl, then we can certainly put it in a register. */
2089 if (DECL_IGNORED_P (decl
))
2095 if (!DECL_REGISTER (decl
))
2098 switch (TREE_CODE (TREE_TYPE (decl
)))
2102 case QUAL_UNION_TYPE
:
2103 /* When not optimizing, disregard register keyword for variables with
2104 types containing methods, otherwise the methods won't be callable
2105 from the debugger. */
2106 if (TYPE_METHODS (TREE_TYPE (decl
)))
2116 /* Return true if TYPE should be passed by invisible reference. */
2119 pass_by_reference (CUMULATIVE_ARGS
*ca
, enum machine_mode mode
,
2120 tree type
, bool named_arg
)
2124 /* If this type contains non-trivial constructors, then it is
2125 forbidden for the middle-end to create any new copies. */
2126 if (TREE_ADDRESSABLE (type
))
2129 /* GCC post 3.4 passes *all* variable sized types by reference. */
2130 if (!TYPE_SIZE (type
) || TREE_CODE (TYPE_SIZE (type
)) != INTEGER_CST
)
2133 /* If a record type should be passed the same as its first (and only)
2134 member, use the type and mode of that member. */
2135 if (TREE_CODE (type
) == RECORD_TYPE
&& TYPE_TRANSPARENT_AGGR (type
))
2137 type
= TREE_TYPE (first_field (type
));
2138 mode
= TYPE_MODE (type
);
2142 return targetm
.calls
.pass_by_reference (pack_cumulative_args (ca
), mode
,
2146 /* Return true if TYPE, which is passed by reference, should be callee
2147 copied instead of caller copied. */
2150 reference_callee_copied (CUMULATIVE_ARGS
*ca
, enum machine_mode mode
,
2151 tree type
, bool named_arg
)
2153 if (type
&& TREE_ADDRESSABLE (type
))
2155 return targetm
.calls
.callee_copies (pack_cumulative_args (ca
), mode
, type
,
2159 /* Structures to communicate between the subroutines of assign_parms.
2160 The first holds data persistent across all parameters, the second
2161 is cleared out for each parameter. */
2163 struct assign_parm_data_all
2165 /* When INIT_CUMULATIVE_ARGS gets revamped, allocating CUMULATIVE_ARGS
2166 should become a job of the target or otherwise encapsulated. */
2167 CUMULATIVE_ARGS args_so_far_v
;
2168 cumulative_args_t args_so_far
;
2169 struct args_size stack_args_size
;
2170 tree function_result_decl
;
2172 rtx first_conversion_insn
;
2173 rtx last_conversion_insn
;
2174 HOST_WIDE_INT pretend_args_size
;
2175 HOST_WIDE_INT extra_pretend_bytes
;
2176 int reg_parm_stack_space
;
2179 struct assign_parm_data_one
2185 enum machine_mode nominal_mode
;
2186 enum machine_mode passed_mode
;
2187 enum machine_mode promoted_mode
;
2188 struct locate_and_pad_arg_data locate
;
2190 BOOL_BITFIELD named_arg
: 1;
2191 BOOL_BITFIELD passed_pointer
: 1;
2192 BOOL_BITFIELD on_stack
: 1;
2193 BOOL_BITFIELD loaded_in_reg
: 1;
2196 /* A subroutine of assign_parms. Initialize ALL. */
2199 assign_parms_initialize_all (struct assign_parm_data_all
*all
)
2201 tree fntype ATTRIBUTE_UNUSED
;
2203 memset (all
, 0, sizeof (*all
));
2205 fntype
= TREE_TYPE (current_function_decl
);
2207 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
2208 INIT_CUMULATIVE_INCOMING_ARGS (all
->args_so_far_v
, fntype
, NULL_RTX
);
2210 INIT_CUMULATIVE_ARGS (all
->args_so_far_v
, fntype
, NULL_RTX
,
2211 current_function_decl
, -1);
2213 all
->args_so_far
= pack_cumulative_args (&all
->args_so_far_v
);
2215 #ifdef REG_PARM_STACK_SPACE
2216 all
->reg_parm_stack_space
= REG_PARM_STACK_SPACE (current_function_decl
);
2220 /* If ARGS contains entries with complex types, split the entry into two
2221 entries of the component type. Return a new list of substitutions are
2222 needed, else the old list. */
2225 split_complex_args (VEC(tree
, heap
) **args
)
2230 FOR_EACH_VEC_ELT (tree
, *args
, i
, p
)
2232 tree type
= TREE_TYPE (p
);
2233 if (TREE_CODE (type
) == COMPLEX_TYPE
2234 && targetm
.calls
.split_complex_arg (type
))
2237 tree subtype
= TREE_TYPE (type
);
2238 bool addressable
= TREE_ADDRESSABLE (p
);
2240 /* Rewrite the PARM_DECL's type with its component. */
2242 TREE_TYPE (p
) = subtype
;
2243 DECL_ARG_TYPE (p
) = TREE_TYPE (DECL_ARG_TYPE (p
));
2244 DECL_MODE (p
) = VOIDmode
;
2245 DECL_SIZE (p
) = NULL
;
2246 DECL_SIZE_UNIT (p
) = NULL
;
2247 /* If this arg must go in memory, put it in a pseudo here.
2248 We can't allow it to go in memory as per normal parms,
2249 because the usual place might not have the imag part
2250 adjacent to the real part. */
2251 DECL_ARTIFICIAL (p
) = addressable
;
2252 DECL_IGNORED_P (p
) = addressable
;
2253 TREE_ADDRESSABLE (p
) = 0;
2255 VEC_replace (tree
, *args
, i
, p
);
2257 /* Build a second synthetic decl. */
2258 decl
= build_decl (EXPR_LOCATION (p
),
2259 PARM_DECL
, NULL_TREE
, subtype
);
2260 DECL_ARG_TYPE (decl
) = DECL_ARG_TYPE (p
);
2261 DECL_ARTIFICIAL (decl
) = addressable
;
2262 DECL_IGNORED_P (decl
) = addressable
;
2263 layout_decl (decl
, 0);
2264 VEC_safe_insert (tree
, heap
, *args
, ++i
, decl
);
2269 /* A subroutine of assign_parms. Adjust the parameter list to incorporate
2270 the hidden struct return argument, and (abi willing) complex args.
2271 Return the new parameter list. */
2273 static VEC(tree
, heap
) *
2274 assign_parms_augmented_arg_list (struct assign_parm_data_all
*all
)
2276 tree fndecl
= current_function_decl
;
2277 tree fntype
= TREE_TYPE (fndecl
);
2278 VEC(tree
, heap
) *fnargs
= NULL
;
2281 for (arg
= DECL_ARGUMENTS (fndecl
); arg
; arg
= DECL_CHAIN (arg
))
2282 VEC_safe_push (tree
, heap
, fnargs
, arg
);
2284 all
->orig_fnargs
= DECL_ARGUMENTS (fndecl
);
2286 /* If struct value address is treated as the first argument, make it so. */
2287 if (aggregate_value_p (DECL_RESULT (fndecl
), fndecl
)
2288 && ! cfun
->returns_pcc_struct
2289 && targetm
.calls
.struct_value_rtx (TREE_TYPE (fndecl
), 1) == 0)
2291 tree type
= build_pointer_type (TREE_TYPE (fntype
));
2294 decl
= build_decl (DECL_SOURCE_LOCATION (fndecl
),
2295 PARM_DECL
, get_identifier (".result_ptr"), type
);
2296 DECL_ARG_TYPE (decl
) = type
;
2297 DECL_ARTIFICIAL (decl
) = 1;
2298 DECL_NAMELESS (decl
) = 1;
2299 TREE_CONSTANT (decl
) = 1;
2301 DECL_CHAIN (decl
) = all
->orig_fnargs
;
2302 all
->orig_fnargs
= decl
;
2303 VEC_safe_insert (tree
, heap
, fnargs
, 0, decl
);
2305 all
->function_result_decl
= decl
;
2308 /* If the target wants to split complex arguments into scalars, do so. */
2309 if (targetm
.calls
.split_complex_arg
)
2310 split_complex_args (&fnargs
);
2315 /* A subroutine of assign_parms. Examine PARM and pull out type and mode
2316 data for the parameter. Incorporate ABI specifics such as pass-by-
2317 reference and type promotion. */
2320 assign_parm_find_data_types (struct assign_parm_data_all
*all
, tree parm
,
2321 struct assign_parm_data_one
*data
)
2323 tree nominal_type
, passed_type
;
2324 enum machine_mode nominal_mode
, passed_mode
, promoted_mode
;
2327 memset (data
, 0, sizeof (*data
));
2329 /* NAMED_ARG is a misnomer. We really mean 'non-variadic'. */
2331 data
->named_arg
= 1; /* No variadic parms. */
2332 else if (DECL_CHAIN (parm
))
2333 data
->named_arg
= 1; /* Not the last non-variadic parm. */
2334 else if (targetm
.calls
.strict_argument_naming (all
->args_so_far
))
2335 data
->named_arg
= 1; /* Only variadic ones are unnamed. */
2337 data
->named_arg
= 0; /* Treat as variadic. */
2339 nominal_type
= TREE_TYPE (parm
);
2340 passed_type
= DECL_ARG_TYPE (parm
);
2342 /* Look out for errors propagating this far. Also, if the parameter's
2343 type is void then its value doesn't matter. */
2344 if (TREE_TYPE (parm
) == error_mark_node
2345 /* This can happen after weird syntax errors
2346 or if an enum type is defined among the parms. */
2347 || TREE_CODE (parm
) != PARM_DECL
2348 || passed_type
== NULL
2349 || VOID_TYPE_P (nominal_type
))
2351 nominal_type
= passed_type
= void_type_node
;
2352 nominal_mode
= passed_mode
= promoted_mode
= VOIDmode
;
2356 /* Find mode of arg as it is passed, and mode of arg as it should be
2357 during execution of this function. */
2358 passed_mode
= TYPE_MODE (passed_type
);
2359 nominal_mode
= TYPE_MODE (nominal_type
);
2361 /* If the parm is to be passed as a transparent union or record, use the
2362 type of the first field for the tests below. We have already verified
2363 that the modes are the same. */
2364 if ((TREE_CODE (passed_type
) == UNION_TYPE
2365 || TREE_CODE (passed_type
) == RECORD_TYPE
)
2366 && TYPE_TRANSPARENT_AGGR (passed_type
))
2367 passed_type
= TREE_TYPE (first_field (passed_type
));
2369 /* See if this arg was passed by invisible reference. */
2370 if (pass_by_reference (&all
->args_so_far_v
, passed_mode
,
2371 passed_type
, data
->named_arg
))
2373 passed_type
= nominal_type
= build_pointer_type (passed_type
);
2374 data
->passed_pointer
= true;
2375 passed_mode
= nominal_mode
= Pmode
;
2378 /* Find mode as it is passed by the ABI. */
2379 unsignedp
= TYPE_UNSIGNED (passed_type
);
2380 promoted_mode
= promote_function_mode (passed_type
, passed_mode
, &unsignedp
,
2381 TREE_TYPE (current_function_decl
), 0);
2384 data
->nominal_type
= nominal_type
;
2385 data
->passed_type
= passed_type
;
2386 data
->nominal_mode
= nominal_mode
;
2387 data
->passed_mode
= passed_mode
;
2388 data
->promoted_mode
= promoted_mode
;
2391 /* A subroutine of assign_parms. Invoke setup_incoming_varargs. */
2394 assign_parms_setup_varargs (struct assign_parm_data_all
*all
,
2395 struct assign_parm_data_one
*data
, bool no_rtl
)
2397 int varargs_pretend_bytes
= 0;
2399 targetm
.calls
.setup_incoming_varargs (all
->args_so_far
,
2400 data
->promoted_mode
,
2402 &varargs_pretend_bytes
, no_rtl
);
2404 /* If the back-end has requested extra stack space, record how much is
2405 needed. Do not change pretend_args_size otherwise since it may be
2406 nonzero from an earlier partial argument. */
2407 if (varargs_pretend_bytes
> 0)
2408 all
->pretend_args_size
= varargs_pretend_bytes
;
2411 /* A subroutine of assign_parms. Set DATA->ENTRY_PARM corresponding to
2412 the incoming location of the current parameter. */
2415 assign_parm_find_entry_rtl (struct assign_parm_data_all
*all
,
2416 struct assign_parm_data_one
*data
)
2418 HOST_WIDE_INT pretend_bytes
= 0;
2422 if (data
->promoted_mode
== VOIDmode
)
2424 data
->entry_parm
= data
->stack_parm
= const0_rtx
;
2428 entry_parm
= targetm
.calls
.function_incoming_arg (all
->args_so_far
,
2429 data
->promoted_mode
,
2433 if (entry_parm
== 0)
2434 data
->promoted_mode
= data
->passed_mode
;
2436 /* Determine parm's home in the stack, in case it arrives in the stack
2437 or we should pretend it did. Compute the stack position and rtx where
2438 the argument arrives and its size.
2440 There is one complexity here: If this was a parameter that would
2441 have been passed in registers, but wasn't only because it is
2442 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
2443 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
2444 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of 0
2445 as it was the previous time. */
2446 in_regs
= entry_parm
!= 0;
2447 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2450 if (!in_regs
&& !data
->named_arg
)
2452 if (targetm
.calls
.pretend_outgoing_varargs_named (all
->args_so_far
))
2455 tem
= targetm
.calls
.function_incoming_arg (all
->args_so_far
,
2456 data
->promoted_mode
,
2457 data
->passed_type
, true);
2458 in_regs
= tem
!= NULL
;
2462 /* If this parameter was passed both in registers and in the stack, use
2463 the copy on the stack. */
2464 if (targetm
.calls
.must_pass_in_stack (data
->promoted_mode
,
2472 partial
= targetm
.calls
.arg_partial_bytes (all
->args_so_far
,
2473 data
->promoted_mode
,
2476 data
->partial
= partial
;
2478 /* The caller might already have allocated stack space for the
2479 register parameters. */
2480 if (partial
!= 0 && all
->reg_parm_stack_space
== 0)
2482 /* Part of this argument is passed in registers and part
2483 is passed on the stack. Ask the prologue code to extend
2484 the stack part so that we can recreate the full value.
2486 PRETEND_BYTES is the size of the registers we need to store.
2487 CURRENT_FUNCTION_PRETEND_ARGS_SIZE is the amount of extra
2488 stack space that the prologue should allocate.
2490 Internally, gcc assumes that the argument pointer is aligned
2491 to STACK_BOUNDARY bits. This is used both for alignment
2492 optimizations (see init_emit) and to locate arguments that are
2493 aligned to more than PARM_BOUNDARY bits. We must preserve this
2494 invariant by rounding CURRENT_FUNCTION_PRETEND_ARGS_SIZE up to
2495 a stack boundary. */
2497 /* We assume at most one partial arg, and it must be the first
2498 argument on the stack. */
2499 gcc_assert (!all
->extra_pretend_bytes
&& !all
->pretend_args_size
);
2501 pretend_bytes
= partial
;
2502 all
->pretend_args_size
= CEIL_ROUND (pretend_bytes
, STACK_BYTES
);
2504 /* We want to align relative to the actual stack pointer, so
2505 don't include this in the stack size until later. */
2506 all
->extra_pretend_bytes
= all
->pretend_args_size
;
2510 locate_and_pad_parm (data
->promoted_mode
, data
->passed_type
, in_regs
,
2511 entry_parm
? data
->partial
: 0, current_function_decl
,
2512 &all
->stack_args_size
, &data
->locate
);
2514 /* Update parm_stack_boundary if this parameter is passed in the
2516 if (!in_regs
&& crtl
->parm_stack_boundary
< data
->locate
.boundary
)
2517 crtl
->parm_stack_boundary
= data
->locate
.boundary
;
2519 /* Adjust offsets to include the pretend args. */
2520 pretend_bytes
= all
->extra_pretend_bytes
- pretend_bytes
;
2521 data
->locate
.slot_offset
.constant
+= pretend_bytes
;
2522 data
->locate
.offset
.constant
+= pretend_bytes
;
2524 data
->entry_parm
= entry_parm
;
2527 /* A subroutine of assign_parms. If there is actually space on the stack
2528 for this parm, count it in stack_args_size and return true. */
2531 assign_parm_is_stack_parm (struct assign_parm_data_all
*all
,
2532 struct assign_parm_data_one
*data
)
2534 /* Trivially true if we've no incoming register. */
2535 if (data
->entry_parm
== NULL
)
2537 /* Also true if we're partially in registers and partially not,
2538 since we've arranged to drop the entire argument on the stack. */
2539 else if (data
->partial
!= 0)
2541 /* Also true if the target says that it's passed in both registers
2542 and on the stack. */
2543 else if (GET_CODE (data
->entry_parm
) == PARALLEL
2544 && XEXP (XVECEXP (data
->entry_parm
, 0, 0), 0) == NULL_RTX
)
2546 /* Also true if the target says that there's stack allocated for
2547 all register parameters. */
2548 else if (all
->reg_parm_stack_space
> 0)
2550 /* Otherwise, no, this parameter has no ABI defined stack slot. */
2554 all
->stack_args_size
.constant
+= data
->locate
.size
.constant
;
2555 if (data
->locate
.size
.var
)
2556 ADD_PARM_SIZE (all
->stack_args_size
, data
->locate
.size
.var
);
2561 /* A subroutine of assign_parms. Given that this parameter is allocated
2562 stack space by the ABI, find it. */
2565 assign_parm_find_stack_rtl (tree parm
, struct assign_parm_data_one
*data
)
2567 rtx offset_rtx
, stack_parm
;
2568 unsigned int align
, boundary
;
2570 /* If we're passing this arg using a reg, make its stack home the
2571 aligned stack slot. */
2572 if (data
->entry_parm
)
2573 offset_rtx
= ARGS_SIZE_RTX (data
->locate
.slot_offset
);
2575 offset_rtx
= ARGS_SIZE_RTX (data
->locate
.offset
);
2577 stack_parm
= crtl
->args
.internal_arg_pointer
;
2578 if (offset_rtx
!= const0_rtx
)
2579 stack_parm
= gen_rtx_PLUS (Pmode
, stack_parm
, offset_rtx
);
2580 stack_parm
= gen_rtx_MEM (data
->promoted_mode
, stack_parm
);
2582 if (!data
->passed_pointer
)
2584 set_mem_attributes (stack_parm
, parm
, 1);
2585 /* set_mem_attributes could set MEM_SIZE to the passed mode's size,
2586 while promoted mode's size is needed. */
2587 if (data
->promoted_mode
!= BLKmode
2588 && data
->promoted_mode
!= DECL_MODE (parm
))
2590 set_mem_size (stack_parm
, GET_MODE_SIZE (data
->promoted_mode
));
2591 if (MEM_EXPR (stack_parm
) && MEM_OFFSET_KNOWN_P (stack_parm
))
2593 int offset
= subreg_lowpart_offset (DECL_MODE (parm
),
2594 data
->promoted_mode
);
2596 set_mem_offset (stack_parm
, MEM_OFFSET (stack_parm
) - offset
);
2601 boundary
= data
->locate
.boundary
;
2602 align
= BITS_PER_UNIT
;
2604 /* If we're padding upward, we know that the alignment of the slot
2605 is TARGET_FUNCTION_ARG_BOUNDARY. If we're using slot_offset, we're
2606 intentionally forcing upward padding. Otherwise we have to come
2607 up with a guess at the alignment based on OFFSET_RTX. */
2608 if (data
->locate
.where_pad
!= downward
|| data
->entry_parm
)
2610 else if (CONST_INT_P (offset_rtx
))
2612 align
= INTVAL (offset_rtx
) * BITS_PER_UNIT
| boundary
;
2613 align
= align
& -align
;
2615 set_mem_align (stack_parm
, align
);
2617 if (data
->entry_parm
)
2618 set_reg_attrs_for_parm (data
->entry_parm
, stack_parm
);
2620 data
->stack_parm
= stack_parm
;
2623 /* A subroutine of assign_parms. Adjust DATA->ENTRY_RTL such that it's
2624 always valid and contiguous. */
2627 assign_parm_adjust_entry_rtl (struct assign_parm_data_one
*data
)
2629 rtx entry_parm
= data
->entry_parm
;
2630 rtx stack_parm
= data
->stack_parm
;
2632 /* If this parm was passed part in regs and part in memory, pretend it
2633 arrived entirely in memory by pushing the register-part onto the stack.
2634 In the special case of a DImode or DFmode that is split, we could put
2635 it together in a pseudoreg directly, but for now that's not worth
2637 if (data
->partial
!= 0)
2639 /* Handle calls that pass values in multiple non-contiguous
2640 locations. The Irix 6 ABI has examples of this. */
2641 if (GET_CODE (entry_parm
) == PARALLEL
)
2642 emit_group_store (validize_mem (stack_parm
), entry_parm
,
2644 int_size_in_bytes (data
->passed_type
));
2647 gcc_assert (data
->partial
% UNITS_PER_WORD
== 0);
2648 move_block_from_reg (REGNO (entry_parm
), validize_mem (stack_parm
),
2649 data
->partial
/ UNITS_PER_WORD
);
2652 entry_parm
= stack_parm
;
2655 /* If we didn't decide this parm came in a register, by default it came
2657 else if (entry_parm
== NULL
)
2658 entry_parm
= stack_parm
;
2660 /* When an argument is passed in multiple locations, we can't make use
2661 of this information, but we can save some copying if the whole argument
2662 is passed in a single register. */
2663 else if (GET_CODE (entry_parm
) == PARALLEL
2664 && data
->nominal_mode
!= BLKmode
2665 && data
->passed_mode
!= BLKmode
)
2667 size_t i
, len
= XVECLEN (entry_parm
, 0);
2669 for (i
= 0; i
< len
; i
++)
2670 if (XEXP (XVECEXP (entry_parm
, 0, i
), 0) != NULL_RTX
2671 && REG_P (XEXP (XVECEXP (entry_parm
, 0, i
), 0))
2672 && (GET_MODE (XEXP (XVECEXP (entry_parm
, 0, i
), 0))
2673 == data
->passed_mode
)
2674 && INTVAL (XEXP (XVECEXP (entry_parm
, 0, i
), 1)) == 0)
2676 entry_parm
= XEXP (XVECEXP (entry_parm
, 0, i
), 0);
2681 data
->entry_parm
= entry_parm
;
2684 /* A subroutine of assign_parms. Reconstitute any values which were
2685 passed in multiple registers and would fit in a single register. */
2688 assign_parm_remove_parallels (struct assign_parm_data_one
*data
)
2690 rtx entry_parm
= data
->entry_parm
;
2692 /* Convert the PARALLEL to a REG of the same mode as the parallel.
2693 This can be done with register operations rather than on the
2694 stack, even if we will store the reconstituted parameter on the
2696 if (GET_CODE (entry_parm
) == PARALLEL
&& GET_MODE (entry_parm
) != BLKmode
)
2698 rtx parmreg
= gen_reg_rtx (GET_MODE (entry_parm
));
2699 emit_group_store (parmreg
, entry_parm
, data
->passed_type
,
2700 GET_MODE_SIZE (GET_MODE (entry_parm
)));
2701 entry_parm
= parmreg
;
2704 data
->entry_parm
= entry_parm
;
2707 /* A subroutine of assign_parms. Adjust DATA->STACK_RTL such that it's
2708 always valid and properly aligned. */
2711 assign_parm_adjust_stack_rtl (struct assign_parm_data_one
*data
)
2713 rtx stack_parm
= data
->stack_parm
;
2715 /* If we can't trust the parm stack slot to be aligned enough for its
2716 ultimate type, don't use that slot after entry. We'll make another
2717 stack slot, if we need one. */
2719 && ((STRICT_ALIGNMENT
2720 && GET_MODE_ALIGNMENT (data
->nominal_mode
) > MEM_ALIGN (stack_parm
))
2721 || (data
->nominal_type
2722 && TYPE_ALIGN (data
->nominal_type
) > MEM_ALIGN (stack_parm
)
2723 && MEM_ALIGN (stack_parm
) < PREFERRED_STACK_BOUNDARY
)))
2726 /* If parm was passed in memory, and we need to convert it on entry,
2727 don't store it back in that same slot. */
2728 else if (data
->entry_parm
== stack_parm
2729 && data
->nominal_mode
!= BLKmode
2730 && data
->nominal_mode
!= data
->passed_mode
)
2733 /* If stack protection is in effect for this function, don't leave any
2734 pointers in their passed stack slots. */
2735 else if (crtl
->stack_protect_guard
2736 && (flag_stack_protect
== 2
2737 || data
->passed_pointer
2738 || POINTER_TYPE_P (data
->nominal_type
)))
2741 data
->stack_parm
= stack_parm
;
2744 /* A subroutine of assign_parms. Return true if the current parameter
2745 should be stored as a BLKmode in the current frame. */
2748 assign_parm_setup_block_p (struct assign_parm_data_one
*data
)
2750 if (data
->nominal_mode
== BLKmode
)
2752 if (GET_MODE (data
->entry_parm
) == BLKmode
)
2755 #ifdef BLOCK_REG_PADDING
2756 /* Only assign_parm_setup_block knows how to deal with register arguments
2757 that are padded at the least significant end. */
2758 if (REG_P (data
->entry_parm
)
2759 && GET_MODE_SIZE (data
->promoted_mode
) < UNITS_PER_WORD
2760 && (BLOCK_REG_PADDING (data
->passed_mode
, data
->passed_type
, 1)
2761 == (BYTES_BIG_ENDIAN
? upward
: downward
)))
2768 /* A subroutine of assign_parms. Arrange for the parameter to be
2769 present and valid in DATA->STACK_RTL. */
2772 assign_parm_setup_block (struct assign_parm_data_all
*all
,
2773 tree parm
, struct assign_parm_data_one
*data
)
2775 rtx entry_parm
= data
->entry_parm
;
2776 rtx stack_parm
= data
->stack_parm
;
2778 HOST_WIDE_INT size_stored
;
2780 if (GET_CODE (entry_parm
) == PARALLEL
)
2781 entry_parm
= emit_group_move_into_temps (entry_parm
);
2783 size
= int_size_in_bytes (data
->passed_type
);
2784 size_stored
= CEIL_ROUND (size
, UNITS_PER_WORD
);
2785 if (stack_parm
== 0)
2787 DECL_ALIGN (parm
) = MAX (DECL_ALIGN (parm
), BITS_PER_WORD
);
2788 stack_parm
= assign_stack_local (BLKmode
, size_stored
,
2790 if (GET_MODE_SIZE (GET_MODE (entry_parm
)) == size
)
2791 PUT_MODE (stack_parm
, GET_MODE (entry_parm
));
2792 set_mem_attributes (stack_parm
, parm
, 1);
2795 /* If a BLKmode arrives in registers, copy it to a stack slot. Handle
2796 calls that pass values in multiple non-contiguous locations. */
2797 if (REG_P (entry_parm
) || GET_CODE (entry_parm
) == PARALLEL
)
2801 /* Note that we will be storing an integral number of words.
2802 So we have to be careful to ensure that we allocate an
2803 integral number of words. We do this above when we call
2804 assign_stack_local if space was not allocated in the argument
2805 list. If it was, this will not work if PARM_BOUNDARY is not
2806 a multiple of BITS_PER_WORD. It isn't clear how to fix this
2807 if it becomes a problem. Exception is when BLKmode arrives
2808 with arguments not conforming to word_mode. */
2810 if (data
->stack_parm
== 0)
2812 else if (GET_CODE (entry_parm
) == PARALLEL
)
2815 gcc_assert (!size
|| !(PARM_BOUNDARY
% BITS_PER_WORD
));
2817 mem
= validize_mem (stack_parm
);
2819 /* Handle values in multiple non-contiguous locations. */
2820 if (GET_CODE (entry_parm
) == PARALLEL
)
2822 push_to_sequence2 (all
->first_conversion_insn
,
2823 all
->last_conversion_insn
);
2824 emit_group_store (mem
, entry_parm
, data
->passed_type
, size
);
2825 all
->first_conversion_insn
= get_insns ();
2826 all
->last_conversion_insn
= get_last_insn ();
2833 /* If SIZE is that of a mode no bigger than a word, just use
2834 that mode's store operation. */
2835 else if (size
<= UNITS_PER_WORD
)
2837 enum machine_mode mode
2838 = mode_for_size (size
* BITS_PER_UNIT
, MODE_INT
, 0);
2841 #ifdef BLOCK_REG_PADDING
2842 && (size
== UNITS_PER_WORD
2843 || (BLOCK_REG_PADDING (mode
, data
->passed_type
, 1)
2844 != (BYTES_BIG_ENDIAN
? upward
: downward
)))
2850 /* We are really truncating a word_mode value containing
2851 SIZE bytes into a value of mode MODE. If such an
2852 operation requires no actual instructions, we can refer
2853 to the value directly in mode MODE, otherwise we must
2854 start with the register in word_mode and explicitly
2856 if (TRULY_NOOP_TRUNCATION (size
* BITS_PER_UNIT
, BITS_PER_WORD
))
2857 reg
= gen_rtx_REG (mode
, REGNO (entry_parm
));
2860 reg
= gen_rtx_REG (word_mode
, REGNO (entry_parm
));
2861 reg
= convert_to_mode (mode
, copy_to_reg (reg
), 1);
2863 emit_move_insn (change_address (mem
, mode
, 0), reg
);
2866 /* Blocks smaller than a word on a BYTES_BIG_ENDIAN
2867 machine must be aligned to the left before storing
2868 to memory. Note that the previous test doesn't
2869 handle all cases (e.g. SIZE == 3). */
2870 else if (size
!= UNITS_PER_WORD
2871 #ifdef BLOCK_REG_PADDING
2872 && (BLOCK_REG_PADDING (mode
, data
->passed_type
, 1)
2880 int by
= (UNITS_PER_WORD
- size
) * BITS_PER_UNIT
;
2881 rtx reg
= gen_rtx_REG (word_mode
, REGNO (entry_parm
));
2883 x
= expand_shift (LSHIFT_EXPR
, word_mode
, reg
, by
, NULL_RTX
, 1);
2884 tem
= change_address (mem
, word_mode
, 0);
2885 emit_move_insn (tem
, x
);
2888 move_block_from_reg (REGNO (entry_parm
), mem
,
2889 size_stored
/ UNITS_PER_WORD
);
2892 move_block_from_reg (REGNO (entry_parm
), mem
,
2893 size_stored
/ UNITS_PER_WORD
);
2895 else if (data
->stack_parm
== 0)
2897 push_to_sequence2 (all
->first_conversion_insn
, all
->last_conversion_insn
);
2898 emit_block_move (stack_parm
, data
->entry_parm
, GEN_INT (size
),
2900 all
->first_conversion_insn
= get_insns ();
2901 all
->last_conversion_insn
= get_last_insn ();
2905 data
->stack_parm
= stack_parm
;
2906 SET_DECL_RTL (parm
, stack_parm
);
2909 /* A subroutine of assign_parms. Allocate a pseudo to hold the current
2910 parameter. Get it there. Perform all ABI specified conversions. */
2913 assign_parm_setup_reg (struct assign_parm_data_all
*all
, tree parm
,
2914 struct assign_parm_data_one
*data
)
2916 rtx parmreg
, validated_mem
;
2917 rtx equiv_stack_parm
;
2918 enum machine_mode promoted_nominal_mode
;
2919 int unsignedp
= TYPE_UNSIGNED (TREE_TYPE (parm
));
2920 bool did_conversion
= false;
2921 bool need_conversion
, moved
;
2923 /* Store the parm in a pseudoregister during the function, but we may
2924 need to do it in a wider mode. Using 2 here makes the result
2925 consistent with promote_decl_mode and thus expand_expr_real_1. */
2926 promoted_nominal_mode
2927 = promote_function_mode (data
->nominal_type
, data
->nominal_mode
, &unsignedp
,
2928 TREE_TYPE (current_function_decl
), 2);
2930 parmreg
= gen_reg_rtx (promoted_nominal_mode
);
2932 if (!DECL_ARTIFICIAL (parm
))
2933 mark_user_reg (parmreg
);
2935 /* If this was an item that we received a pointer to,
2936 set DECL_RTL appropriately. */
2937 if (data
->passed_pointer
)
2939 rtx x
= gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data
->passed_type
)), parmreg
);
2940 set_mem_attributes (x
, parm
, 1);
2941 SET_DECL_RTL (parm
, x
);
2944 SET_DECL_RTL (parm
, parmreg
);
2946 assign_parm_remove_parallels (data
);
2948 /* Copy the value into the register, thus bridging between
2949 assign_parm_find_data_types and expand_expr_real_1. */
2951 equiv_stack_parm
= data
->stack_parm
;
2952 validated_mem
= validize_mem (data
->entry_parm
);
2954 need_conversion
= (data
->nominal_mode
!= data
->passed_mode
2955 || promoted_nominal_mode
!= data
->promoted_mode
);
2959 && GET_MODE_CLASS (data
->nominal_mode
) == MODE_INT
2960 && data
->nominal_mode
== data
->passed_mode
2961 && data
->nominal_mode
== GET_MODE (data
->entry_parm
))
2963 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
2964 mode, by the caller. We now have to convert it to
2965 NOMINAL_MODE, if different. However, PARMREG may be in
2966 a different mode than NOMINAL_MODE if it is being stored
2969 If ENTRY_PARM is a hard register, it might be in a register
2970 not valid for operating in its mode (e.g., an odd-numbered
2971 register for a DFmode). In that case, moves are the only
2972 thing valid, so we can't do a convert from there. This
2973 occurs when the calling sequence allow such misaligned
2976 In addition, the conversion may involve a call, which could
2977 clobber parameters which haven't been copied to pseudo
2980 First, we try to emit an insn which performs the necessary
2981 conversion. We verify that this insn does not clobber any
2984 enum insn_code icode
;
2987 icode
= can_extend_p (promoted_nominal_mode
, data
->passed_mode
,
2991 op1
= validated_mem
;
2992 if (icode
!= CODE_FOR_nothing
2993 && insn_operand_matches (icode
, 0, op0
)
2994 && insn_operand_matches (icode
, 1, op1
))
2996 enum rtx_code code
= unsignedp
? ZERO_EXTEND
: SIGN_EXTEND
;
2997 rtx insn
, insns
, t
= op1
;
2998 HARD_REG_SET hardregs
;
3001 /* If op1 is a hard register that is likely spilled, first
3002 force it into a pseudo, otherwise combiner might extend
3003 its lifetime too much. */
3004 if (GET_CODE (t
) == SUBREG
)
3007 && HARD_REGISTER_P (t
)
3008 && ! TEST_HARD_REG_BIT (fixed_reg_set
, REGNO (t
))
3009 && targetm
.class_likely_spilled_p (REGNO_REG_CLASS (REGNO (t
))))
3011 t
= gen_reg_rtx (GET_MODE (op1
));
3012 emit_move_insn (t
, op1
);
3016 insn
= gen_extend_insn (op0
, t
, promoted_nominal_mode
,
3017 data
->passed_mode
, unsignedp
);
3019 insns
= get_insns ();
3022 CLEAR_HARD_REG_SET (hardregs
);
3023 for (insn
= insns
; insn
&& moved
; insn
= NEXT_INSN (insn
))
3026 note_stores (PATTERN (insn
), record_hard_reg_sets
,
3028 if (!hard_reg_set_empty_p (hardregs
))
3037 if (equiv_stack_parm
!= NULL_RTX
)
3038 equiv_stack_parm
= gen_rtx_fmt_e (code
, GET_MODE (parmreg
),
3045 /* Nothing to do. */
3047 else if (need_conversion
)
3049 /* We did not have an insn to convert directly, or the sequence
3050 generated appeared unsafe. We must first copy the parm to a
3051 pseudo reg, and save the conversion until after all
3052 parameters have been moved. */
3055 rtx tempreg
= gen_reg_rtx (GET_MODE (data
->entry_parm
));
3057 emit_move_insn (tempreg
, validated_mem
);
3059 push_to_sequence2 (all
->first_conversion_insn
, all
->last_conversion_insn
);
3060 tempreg
= convert_to_mode (data
->nominal_mode
, tempreg
, unsignedp
);
3062 if (GET_CODE (tempreg
) == SUBREG
3063 && GET_MODE (tempreg
) == data
->nominal_mode
3064 && REG_P (SUBREG_REG (tempreg
))
3065 && data
->nominal_mode
== data
->passed_mode
3066 && GET_MODE (SUBREG_REG (tempreg
)) == GET_MODE (data
->entry_parm
)
3067 && GET_MODE_SIZE (GET_MODE (tempreg
))
3068 < GET_MODE_SIZE (GET_MODE (data
->entry_parm
)))
3070 /* The argument is already sign/zero extended, so note it
3072 SUBREG_PROMOTED_VAR_P (tempreg
) = 1;
3073 SUBREG_PROMOTED_UNSIGNED_SET (tempreg
, unsignedp
);
3076 /* TREE_USED gets set erroneously during expand_assignment. */
3077 save_tree_used
= TREE_USED (parm
);
3078 expand_assignment (parm
, make_tree (data
->nominal_type
, tempreg
), false);
3079 TREE_USED (parm
) = save_tree_used
;
3080 all
->first_conversion_insn
= get_insns ();
3081 all
->last_conversion_insn
= get_last_insn ();
3084 did_conversion
= true;
3087 emit_move_insn (parmreg
, validated_mem
);
3089 /* If we were passed a pointer but the actual value can safely live
3090 in a register, put it in one. */
3091 if (data
->passed_pointer
3092 && TYPE_MODE (TREE_TYPE (parm
)) != BLKmode
3093 /* If by-reference argument was promoted, demote it. */
3094 && (TYPE_MODE (TREE_TYPE (parm
)) != GET_MODE (DECL_RTL (parm
))
3095 || use_register_for_decl (parm
)))
3097 /* We can't use nominal_mode, because it will have been set to
3098 Pmode above. We must use the actual mode of the parm. */
3099 parmreg
= gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm
)));
3100 mark_user_reg (parmreg
);
3102 if (GET_MODE (parmreg
) != GET_MODE (DECL_RTL (parm
)))
3104 rtx tempreg
= gen_reg_rtx (GET_MODE (DECL_RTL (parm
)));
3105 int unsigned_p
= TYPE_UNSIGNED (TREE_TYPE (parm
));
3107 push_to_sequence2 (all
->first_conversion_insn
,
3108 all
->last_conversion_insn
);
3109 emit_move_insn (tempreg
, DECL_RTL (parm
));
3110 tempreg
= convert_to_mode (GET_MODE (parmreg
), tempreg
, unsigned_p
);
3111 emit_move_insn (parmreg
, tempreg
);
3112 all
->first_conversion_insn
= get_insns ();
3113 all
->last_conversion_insn
= get_last_insn ();
3116 did_conversion
= true;
3119 emit_move_insn (parmreg
, DECL_RTL (parm
));
3121 SET_DECL_RTL (parm
, parmreg
);
3123 /* STACK_PARM is the pointer, not the parm, and PARMREG is
3125 data
->stack_parm
= NULL
;
3128 /* Mark the register as eliminable if we did no conversion and it was
3129 copied from memory at a fixed offset, and the arg pointer was not
3130 copied to a pseudo-reg. If the arg pointer is a pseudo reg or the
3131 offset formed an invalid address, such memory-equivalences as we
3132 make here would screw up life analysis for it. */
3133 if (data
->nominal_mode
== data
->passed_mode
3135 && data
->stack_parm
!= 0
3136 && MEM_P (data
->stack_parm
)
3137 && data
->locate
.offset
.var
== 0
3138 && reg_mentioned_p (virtual_incoming_args_rtx
,
3139 XEXP (data
->stack_parm
, 0)))
3141 rtx linsn
= get_last_insn ();
3144 /* Mark complex types separately. */
3145 if (GET_CODE (parmreg
) == CONCAT
)
3147 enum machine_mode submode
3148 = GET_MODE_INNER (GET_MODE (parmreg
));
3149 int regnor
= REGNO (XEXP (parmreg
, 0));
3150 int regnoi
= REGNO (XEXP (parmreg
, 1));
3151 rtx stackr
= adjust_address_nv (data
->stack_parm
, submode
, 0);
3152 rtx stacki
= adjust_address_nv (data
->stack_parm
, submode
,
3153 GET_MODE_SIZE (submode
));
3155 /* Scan backwards for the set of the real and
3157 for (sinsn
= linsn
; sinsn
!= 0;
3158 sinsn
= prev_nonnote_insn (sinsn
))
3160 set
= single_set (sinsn
);
3164 if (SET_DEST (set
) == regno_reg_rtx
[regnoi
])
3165 set_unique_reg_note (sinsn
, REG_EQUIV
, stacki
);
3166 else if (SET_DEST (set
) == regno_reg_rtx
[regnor
])
3167 set_unique_reg_note (sinsn
, REG_EQUIV
, stackr
);
3171 set_dst_reg_note (linsn
, REG_EQUIV
, equiv_stack_parm
, parmreg
);
3174 /* For pointer data type, suggest pointer register. */
3175 if (POINTER_TYPE_P (TREE_TYPE (parm
)))
3176 mark_reg_pointer (parmreg
,
3177 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm
))));
3180 /* A subroutine of assign_parms. Allocate stack space to hold the current
3181 parameter. Get it there. Perform all ABI specified conversions. */
3184 assign_parm_setup_stack (struct assign_parm_data_all
*all
, tree parm
,
3185 struct assign_parm_data_one
*data
)
3187 /* Value must be stored in the stack slot STACK_PARM during function
3189 bool to_conversion
= false;
3191 assign_parm_remove_parallels (data
);
3193 if (data
->promoted_mode
!= data
->nominal_mode
)
3195 /* Conversion is required. */
3196 rtx tempreg
= gen_reg_rtx (GET_MODE (data
->entry_parm
));
3198 emit_move_insn (tempreg
, validize_mem (data
->entry_parm
));
3200 push_to_sequence2 (all
->first_conversion_insn
, all
->last_conversion_insn
);
3201 to_conversion
= true;
3203 data
->entry_parm
= convert_to_mode (data
->nominal_mode
, tempreg
,
3204 TYPE_UNSIGNED (TREE_TYPE (parm
)));
3206 if (data
->stack_parm
)
3208 int offset
= subreg_lowpart_offset (data
->nominal_mode
,
3209 GET_MODE (data
->stack_parm
));
3210 /* ??? This may need a big-endian conversion on sparc64. */
3212 = adjust_address (data
->stack_parm
, data
->nominal_mode
, 0);
3213 if (offset
&& MEM_OFFSET_KNOWN_P (data
->stack_parm
))
3214 set_mem_offset (data
->stack_parm
,
3215 MEM_OFFSET (data
->stack_parm
) + offset
);
3219 if (data
->entry_parm
!= data
->stack_parm
)
3223 if (data
->stack_parm
== 0)
3225 int align
= STACK_SLOT_ALIGNMENT (data
->passed_type
,
3226 GET_MODE (data
->entry_parm
),
3227 TYPE_ALIGN (data
->passed_type
));
3229 = assign_stack_local (GET_MODE (data
->entry_parm
),
3230 GET_MODE_SIZE (GET_MODE (data
->entry_parm
)),
3232 set_mem_attributes (data
->stack_parm
, parm
, 1);
3235 dest
= validize_mem (data
->stack_parm
);
3236 src
= validize_mem (data
->entry_parm
);
3240 /* Use a block move to handle potentially misaligned entry_parm. */
3242 push_to_sequence2 (all
->first_conversion_insn
,
3243 all
->last_conversion_insn
);
3244 to_conversion
= true;
3246 emit_block_move (dest
, src
,
3247 GEN_INT (int_size_in_bytes (data
->passed_type
)),
3251 emit_move_insn (dest
, src
);
3256 all
->first_conversion_insn
= get_insns ();
3257 all
->last_conversion_insn
= get_last_insn ();
3261 SET_DECL_RTL (parm
, data
->stack_parm
);
3264 /* A subroutine of assign_parms. If the ABI splits complex arguments, then
3265 undo the frobbing that we did in assign_parms_augmented_arg_list. */
3268 assign_parms_unsplit_complex (struct assign_parm_data_all
*all
,
3269 VEC(tree
, heap
) *fnargs
)
3272 tree orig_fnargs
= all
->orig_fnargs
;
3275 for (parm
= orig_fnargs
; parm
; parm
= TREE_CHAIN (parm
), ++i
)
3277 if (TREE_CODE (TREE_TYPE (parm
)) == COMPLEX_TYPE
3278 && targetm
.calls
.split_complex_arg (TREE_TYPE (parm
)))
3280 rtx tmp
, real
, imag
;
3281 enum machine_mode inner
= GET_MODE_INNER (DECL_MODE (parm
));
3283 real
= DECL_RTL (VEC_index (tree
, fnargs
, i
));
3284 imag
= DECL_RTL (VEC_index (tree
, fnargs
, i
+ 1));
3285 if (inner
!= GET_MODE (real
))
3287 real
= gen_lowpart_SUBREG (inner
, real
);
3288 imag
= gen_lowpart_SUBREG (inner
, imag
);
3291 if (TREE_ADDRESSABLE (parm
))
3294 HOST_WIDE_INT size
= int_size_in_bytes (TREE_TYPE (parm
));
3295 int align
= STACK_SLOT_ALIGNMENT (TREE_TYPE (parm
),
3297 TYPE_ALIGN (TREE_TYPE (parm
)));
3299 /* split_complex_arg put the real and imag parts in
3300 pseudos. Move them to memory. */
3301 tmp
= assign_stack_local (DECL_MODE (parm
), size
, align
);
3302 set_mem_attributes (tmp
, parm
, 1);
3303 rmem
= adjust_address_nv (tmp
, inner
, 0);
3304 imem
= adjust_address_nv (tmp
, inner
, GET_MODE_SIZE (inner
));
3305 push_to_sequence2 (all
->first_conversion_insn
,
3306 all
->last_conversion_insn
);
3307 emit_move_insn (rmem
, real
);
3308 emit_move_insn (imem
, imag
);
3309 all
->first_conversion_insn
= get_insns ();
3310 all
->last_conversion_insn
= get_last_insn ();
3314 tmp
= gen_rtx_CONCAT (DECL_MODE (parm
), real
, imag
);
3315 SET_DECL_RTL (parm
, tmp
);
3317 real
= DECL_INCOMING_RTL (VEC_index (tree
, fnargs
, i
));
3318 imag
= DECL_INCOMING_RTL (VEC_index (tree
, fnargs
, i
+ 1));
3319 if (inner
!= GET_MODE (real
))
3321 real
= gen_lowpart_SUBREG (inner
, real
);
3322 imag
= gen_lowpart_SUBREG (inner
, imag
);
3324 tmp
= gen_rtx_CONCAT (DECL_MODE (parm
), real
, imag
);
3325 set_decl_incoming_rtl (parm
, tmp
, false);
3331 /* Assign RTL expressions to the function's parameters. This may involve
3332 copying them into registers and using those registers as the DECL_RTL. */
3335 assign_parms (tree fndecl
)
3337 struct assign_parm_data_all all
;
3339 VEC(tree
, heap
) *fnargs
;
3342 crtl
->args
.internal_arg_pointer
3343 = targetm
.calls
.internal_arg_pointer ();
3345 assign_parms_initialize_all (&all
);
3346 fnargs
= assign_parms_augmented_arg_list (&all
);
3348 FOR_EACH_VEC_ELT (tree
, fnargs
, i
, parm
)
3350 struct assign_parm_data_one data
;
3352 /* Extract the type of PARM; adjust it according to ABI. */
3353 assign_parm_find_data_types (&all
, parm
, &data
);
3355 /* Early out for errors and void parameters. */
3356 if (data
.passed_mode
== VOIDmode
)
3358 SET_DECL_RTL (parm
, const0_rtx
);
3359 DECL_INCOMING_RTL (parm
) = DECL_RTL (parm
);
3363 /* Estimate stack alignment from parameter alignment. */
3364 if (SUPPORTS_STACK_ALIGNMENT
)
3367 = targetm
.calls
.function_arg_boundary (data
.promoted_mode
,
3369 align
= MINIMUM_ALIGNMENT (data
.passed_type
, data
.promoted_mode
,
3371 if (TYPE_ALIGN (data
.nominal_type
) > align
)
3372 align
= MINIMUM_ALIGNMENT (data
.nominal_type
,
3373 TYPE_MODE (data
.nominal_type
),
3374 TYPE_ALIGN (data
.nominal_type
));
3375 if (crtl
->stack_alignment_estimated
< align
)
3377 gcc_assert (!crtl
->stack_realign_processed
);
3378 crtl
->stack_alignment_estimated
= align
;
3382 if (cfun
->stdarg
&& !DECL_CHAIN (parm
))
3383 assign_parms_setup_varargs (&all
, &data
, false);
3385 /* Find out where the parameter arrives in this function. */
3386 assign_parm_find_entry_rtl (&all
, &data
);
3388 /* Find out where stack space for this parameter might be. */
3389 if (assign_parm_is_stack_parm (&all
, &data
))
3391 assign_parm_find_stack_rtl (parm
, &data
);
3392 assign_parm_adjust_entry_rtl (&data
);
3395 /* Record permanently how this parm was passed. */
3396 if (data
.passed_pointer
)
3399 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data
.passed_type
)),
3401 set_decl_incoming_rtl (parm
, incoming_rtl
, true);
3404 set_decl_incoming_rtl (parm
, data
.entry_parm
, false);
3406 /* Update info on where next arg arrives in registers. */
3407 targetm
.calls
.function_arg_advance (all
.args_so_far
, data
.promoted_mode
,
3408 data
.passed_type
, data
.named_arg
);
3410 assign_parm_adjust_stack_rtl (&data
);
3412 if (assign_parm_setup_block_p (&data
))
3413 assign_parm_setup_block (&all
, parm
, &data
);
3414 else if (data
.passed_pointer
|| use_register_for_decl (parm
))
3415 assign_parm_setup_reg (&all
, parm
, &data
);
3417 assign_parm_setup_stack (&all
, parm
, &data
);
3420 if (targetm
.calls
.split_complex_arg
)
3421 assign_parms_unsplit_complex (&all
, fnargs
);
3423 VEC_free (tree
, heap
, fnargs
);
3425 /* Output all parameter conversion instructions (possibly including calls)
3426 now that all parameters have been copied out of hard registers. */
3427 emit_insn (all
.first_conversion_insn
);
3429 /* Estimate reload stack alignment from scalar return mode. */
3430 if (SUPPORTS_STACK_ALIGNMENT
)
3432 if (DECL_RESULT (fndecl
))
3434 tree type
= TREE_TYPE (DECL_RESULT (fndecl
));
3435 enum machine_mode mode
= TYPE_MODE (type
);
3439 && !AGGREGATE_TYPE_P (type
))
3441 unsigned int align
= GET_MODE_ALIGNMENT (mode
);
3442 if (crtl
->stack_alignment_estimated
< align
)
3444 gcc_assert (!crtl
->stack_realign_processed
);
3445 crtl
->stack_alignment_estimated
= align
;
3451 /* If we are receiving a struct value address as the first argument, set up
3452 the RTL for the function result. As this might require code to convert
3453 the transmitted address to Pmode, we do this here to ensure that possible
3454 preliminary conversions of the address have been emitted already. */
3455 if (all
.function_result_decl
)
3457 tree result
= DECL_RESULT (current_function_decl
);
3458 rtx addr
= DECL_RTL (all
.function_result_decl
);
3461 if (DECL_BY_REFERENCE (result
))
3463 SET_DECL_VALUE_EXPR (result
, all
.function_result_decl
);
3468 SET_DECL_VALUE_EXPR (result
,
3469 build1 (INDIRECT_REF
, TREE_TYPE (result
),
3470 all
.function_result_decl
));
3471 addr
= convert_memory_address (Pmode
, addr
);
3472 x
= gen_rtx_MEM (DECL_MODE (result
), addr
);
3473 set_mem_attributes (x
, result
, 1);
3476 DECL_HAS_VALUE_EXPR_P (result
) = 1;
3478 SET_DECL_RTL (result
, x
);
3481 /* We have aligned all the args, so add space for the pretend args. */
3482 crtl
->args
.pretend_args_size
= all
.pretend_args_size
;
3483 all
.stack_args_size
.constant
+= all
.extra_pretend_bytes
;
3484 crtl
->args
.size
= all
.stack_args_size
.constant
;
3486 /* Adjust function incoming argument size for alignment and
3489 #ifdef REG_PARM_STACK_SPACE
3490 crtl
->args
.size
= MAX (crtl
->args
.size
,
3491 REG_PARM_STACK_SPACE (fndecl
));
3494 crtl
->args
.size
= CEIL_ROUND (crtl
->args
.size
,
3495 PARM_BOUNDARY
/ BITS_PER_UNIT
);
3497 #ifdef ARGS_GROW_DOWNWARD
3498 crtl
->args
.arg_offset_rtx
3499 = (all
.stack_args_size
.var
== 0 ? GEN_INT (-all
.stack_args_size
.constant
)
3500 : expand_expr (size_diffop (all
.stack_args_size
.var
,
3501 size_int (-all
.stack_args_size
.constant
)),
3502 NULL_RTX
, VOIDmode
, EXPAND_NORMAL
));
3504 crtl
->args
.arg_offset_rtx
= ARGS_SIZE_RTX (all
.stack_args_size
);
3507 /* See how many bytes, if any, of its args a function should try to pop
3510 crtl
->args
.pops_args
= targetm
.calls
.return_pops_args (fndecl
,
3514 /* For stdarg.h function, save info about
3515 regs and stack space used by the named args. */
3517 crtl
->args
.info
= all
.args_so_far_v
;
3519 /* Set the rtx used for the function return value. Put this in its
3520 own variable so any optimizers that need this information don't have
3521 to include tree.h. Do this here so it gets done when an inlined
3522 function gets output. */
3525 = (DECL_RTL_SET_P (DECL_RESULT (fndecl
))
3526 ? DECL_RTL (DECL_RESULT (fndecl
)) : NULL_RTX
);
3528 /* If scalar return value was computed in a pseudo-reg, or was a named
3529 return value that got dumped to the stack, copy that to the hard
3531 if (DECL_RTL_SET_P (DECL_RESULT (fndecl
)))
3533 tree decl_result
= DECL_RESULT (fndecl
);
3534 rtx decl_rtl
= DECL_RTL (decl_result
);
3536 if (REG_P (decl_rtl
)
3537 ? REGNO (decl_rtl
) >= FIRST_PSEUDO_REGISTER
3538 : DECL_REGISTER (decl_result
))
3542 real_decl_rtl
= targetm
.calls
.function_value (TREE_TYPE (decl_result
),
3544 REG_FUNCTION_VALUE_P (real_decl_rtl
) = 1;
3545 /* The delay slot scheduler assumes that crtl->return_rtx
3546 holds the hard register containing the return value, not a
3547 temporary pseudo. */
3548 crtl
->return_rtx
= real_decl_rtl
;
3553 /* A subroutine of gimplify_parameters, invoked via walk_tree.
3554 For all seen types, gimplify their sizes. */
3557 gimplify_parm_type (tree
*tp
, int *walk_subtrees
, void *data
)
3564 if (POINTER_TYPE_P (t
))
3566 else if (TYPE_SIZE (t
) && !TREE_CONSTANT (TYPE_SIZE (t
))
3567 && !TYPE_SIZES_GIMPLIFIED (t
))
3569 gimplify_type_sizes (t
, (gimple_seq
*) data
);
3577 /* Gimplify the parameter list for current_function_decl. This involves
3578 evaluating SAVE_EXPRs of variable sized parameters and generating code
3579 to implement callee-copies reference parameters. Returns a sequence of
3580 statements to add to the beginning of the function. */
3583 gimplify_parameters (void)
3585 struct assign_parm_data_all all
;
3587 gimple_seq stmts
= NULL
;
3588 VEC(tree
, heap
) *fnargs
;
3591 assign_parms_initialize_all (&all
);
3592 fnargs
= assign_parms_augmented_arg_list (&all
);
3594 FOR_EACH_VEC_ELT (tree
, fnargs
, i
, parm
)
3596 struct assign_parm_data_one data
;
3598 /* Extract the type of PARM; adjust it according to ABI. */
3599 assign_parm_find_data_types (&all
, parm
, &data
);
3601 /* Early out for errors and void parameters. */
3602 if (data
.passed_mode
== VOIDmode
|| DECL_SIZE (parm
) == NULL
)
3605 /* Update info on where next arg arrives in registers. */
3606 targetm
.calls
.function_arg_advance (all
.args_so_far
, data
.promoted_mode
,
3607 data
.passed_type
, data
.named_arg
);
3609 /* ??? Once upon a time variable_size stuffed parameter list
3610 SAVE_EXPRs (amongst others) onto a pending sizes list. This
3611 turned out to be less than manageable in the gimple world.
3612 Now we have to hunt them down ourselves. */
3613 walk_tree_without_duplicates (&data
.passed_type
,
3614 gimplify_parm_type
, &stmts
);
3616 if (TREE_CODE (DECL_SIZE_UNIT (parm
)) != INTEGER_CST
)
3618 gimplify_one_sizepos (&DECL_SIZE (parm
), &stmts
);
3619 gimplify_one_sizepos (&DECL_SIZE_UNIT (parm
), &stmts
);
3622 if (data
.passed_pointer
)
3624 tree type
= TREE_TYPE (data
.passed_type
);
3625 if (reference_callee_copied (&all
.args_so_far_v
, TYPE_MODE (type
),
3626 type
, data
.named_arg
))
3630 /* For constant-sized objects, this is trivial; for
3631 variable-sized objects, we have to play games. */
3632 if (TREE_CODE (DECL_SIZE_UNIT (parm
)) == INTEGER_CST
3633 && !(flag_stack_check
== GENERIC_STACK_CHECK
3634 && compare_tree_int (DECL_SIZE_UNIT (parm
),
3635 STACK_CHECK_MAX_VAR_SIZE
) > 0))
3637 local
= create_tmp_var (type
, get_name (parm
));
3638 DECL_IGNORED_P (local
) = 0;
3639 /* If PARM was addressable, move that flag over
3640 to the local copy, as its address will be taken,
3641 not the PARMs. Keep the parms address taken
3642 as we'll query that flag during gimplification. */
3643 if (TREE_ADDRESSABLE (parm
))
3644 TREE_ADDRESSABLE (local
) = 1;
3645 else if (TREE_CODE (type
) == COMPLEX_TYPE
3646 || TREE_CODE (type
) == VECTOR_TYPE
)
3647 DECL_GIMPLE_REG_P (local
) = 1;
3651 tree ptr_type
, addr
;
3653 ptr_type
= build_pointer_type (type
);
3654 addr
= create_tmp_reg (ptr_type
, get_name (parm
));
3655 DECL_IGNORED_P (addr
) = 0;
3656 local
= build_fold_indirect_ref (addr
);
3658 t
= builtin_decl_explicit (BUILT_IN_ALLOCA_WITH_ALIGN
);
3659 t
= build_call_expr (t
, 2, DECL_SIZE_UNIT (parm
),
3660 size_int (DECL_ALIGN (parm
)));
3662 /* The call has been built for a variable-sized object. */
3663 CALL_ALLOCA_FOR_VAR_P (t
) = 1;
3664 t
= fold_convert (ptr_type
, t
);
3665 t
= build2 (MODIFY_EXPR
, TREE_TYPE (addr
), addr
, t
);
3666 gimplify_and_add (t
, &stmts
);
3669 gimplify_assign (local
, parm
, &stmts
);
3671 SET_DECL_VALUE_EXPR (parm
, local
);
3672 DECL_HAS_VALUE_EXPR_P (parm
) = 1;
3677 VEC_free (tree
, heap
, fnargs
);
3682 /* Compute the size and offset from the start of the stacked arguments for a
3683 parm passed in mode PASSED_MODE and with type TYPE.
3685 INITIAL_OFFSET_PTR points to the current offset into the stacked
3688 The starting offset and size for this parm are returned in
3689 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
3690 nonzero, the offset is that of stack slot, which is returned in
3691 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
3692 padding required from the initial offset ptr to the stack slot.
3694 IN_REGS is nonzero if the argument will be passed in registers. It will
3695 never be set if REG_PARM_STACK_SPACE is not defined.
3697 FNDECL is the function in which the argument was defined.
3699 There are two types of rounding that are done. The first, controlled by
3700 TARGET_FUNCTION_ARG_BOUNDARY, forces the offset from the start of the
3701 argument list to be aligned to the specific boundary (in bits). This
3702 rounding affects the initial and starting offsets, but not the argument
3705 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
3706 optionally rounds the size of the parm to PARM_BOUNDARY. The
3707 initial offset is not affected by this rounding, while the size always
3708 is and the starting offset may be. */
3710 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
3711 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
3712 callers pass in the total size of args so far as
3713 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
3716 locate_and_pad_parm (enum machine_mode passed_mode
, tree type
, int in_regs
,
3717 int partial
, tree fndecl ATTRIBUTE_UNUSED
,
3718 struct args_size
*initial_offset_ptr
,
3719 struct locate_and_pad_arg_data
*locate
)
3722 enum direction where_pad
;
3723 unsigned int boundary
, round_boundary
;
3724 int reg_parm_stack_space
= 0;
3725 int part_size_in_regs
;
3727 #ifdef REG_PARM_STACK_SPACE
3728 reg_parm_stack_space
= REG_PARM_STACK_SPACE (fndecl
);
3730 /* If we have found a stack parm before we reach the end of the
3731 area reserved for registers, skip that area. */
3734 if (reg_parm_stack_space
> 0)
3736 if (initial_offset_ptr
->var
)
3738 initial_offset_ptr
->var
3739 = size_binop (MAX_EXPR
, ARGS_SIZE_TREE (*initial_offset_ptr
),
3740 ssize_int (reg_parm_stack_space
));
3741 initial_offset_ptr
->constant
= 0;
3743 else if (initial_offset_ptr
->constant
< reg_parm_stack_space
)
3744 initial_offset_ptr
->constant
= reg_parm_stack_space
;
3747 #endif /* REG_PARM_STACK_SPACE */
3749 part_size_in_regs
= (reg_parm_stack_space
== 0 ? partial
: 0);
3752 = type
? size_in_bytes (type
) : size_int (GET_MODE_SIZE (passed_mode
));
3753 where_pad
= FUNCTION_ARG_PADDING (passed_mode
, type
);
3754 boundary
= targetm
.calls
.function_arg_boundary (passed_mode
, type
);
3755 round_boundary
= targetm
.calls
.function_arg_round_boundary (passed_mode
,
3757 locate
->where_pad
= where_pad
;
3759 /* Alignment can't exceed MAX_SUPPORTED_STACK_ALIGNMENT. */
3760 if (boundary
> MAX_SUPPORTED_STACK_ALIGNMENT
)
3761 boundary
= MAX_SUPPORTED_STACK_ALIGNMENT
;
3763 locate
->boundary
= boundary
;
3765 if (SUPPORTS_STACK_ALIGNMENT
)
3767 /* stack_alignment_estimated can't change after stack has been
3769 if (crtl
->stack_alignment_estimated
< boundary
)
3771 if (!crtl
->stack_realign_processed
)
3772 crtl
->stack_alignment_estimated
= boundary
;
3775 /* If stack is realigned and stack alignment value
3776 hasn't been finalized, it is OK not to increase
3777 stack_alignment_estimated. The bigger alignment
3778 requirement is recorded in stack_alignment_needed
3780 gcc_assert (!crtl
->stack_realign_finalized
3781 && crtl
->stack_realign_needed
);
3786 /* Remember if the outgoing parameter requires extra alignment on the
3787 calling function side. */
3788 if (crtl
->stack_alignment_needed
< boundary
)
3789 crtl
->stack_alignment_needed
= boundary
;
3790 if (crtl
->preferred_stack_boundary
< boundary
)
3791 crtl
->preferred_stack_boundary
= boundary
;
3793 #ifdef ARGS_GROW_DOWNWARD
3794 locate
->slot_offset
.constant
= -initial_offset_ptr
->constant
;
3795 if (initial_offset_ptr
->var
)
3796 locate
->slot_offset
.var
= size_binop (MINUS_EXPR
, ssize_int (0),
3797 initial_offset_ptr
->var
);
3801 if (where_pad
!= none
3802 && (!host_integerp (sizetree
, 1)
3803 || (tree_low_cst (sizetree
, 1) * BITS_PER_UNIT
) % round_boundary
))
3804 s2
= round_up (s2
, round_boundary
/ BITS_PER_UNIT
);
3805 SUB_PARM_SIZE (locate
->slot_offset
, s2
);
3808 locate
->slot_offset
.constant
+= part_size_in_regs
;
3811 #ifdef REG_PARM_STACK_SPACE
3812 || REG_PARM_STACK_SPACE (fndecl
) > 0
3815 pad_to_arg_alignment (&locate
->slot_offset
, boundary
,
3816 &locate
->alignment_pad
);
3818 locate
->size
.constant
= (-initial_offset_ptr
->constant
3819 - locate
->slot_offset
.constant
);
3820 if (initial_offset_ptr
->var
)
3821 locate
->size
.var
= size_binop (MINUS_EXPR
,
3822 size_binop (MINUS_EXPR
,
3824 initial_offset_ptr
->var
),
3825 locate
->slot_offset
.var
);
3827 /* Pad_below needs the pre-rounded size to know how much to pad
3829 locate
->offset
= locate
->slot_offset
;
3830 if (where_pad
== downward
)
3831 pad_below (&locate
->offset
, passed_mode
, sizetree
);
3833 #else /* !ARGS_GROW_DOWNWARD */
3835 #ifdef REG_PARM_STACK_SPACE
3836 || REG_PARM_STACK_SPACE (fndecl
) > 0
3839 pad_to_arg_alignment (initial_offset_ptr
, boundary
,
3840 &locate
->alignment_pad
);
3841 locate
->slot_offset
= *initial_offset_ptr
;
3843 #ifdef PUSH_ROUNDING
3844 if (passed_mode
!= BLKmode
)
3845 sizetree
= size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree
)));
3848 /* Pad_below needs the pre-rounded size to know how much to pad below
3849 so this must be done before rounding up. */
3850 locate
->offset
= locate
->slot_offset
;
3851 if (where_pad
== downward
)
3852 pad_below (&locate
->offset
, passed_mode
, sizetree
);
3854 if (where_pad
!= none
3855 && (!host_integerp (sizetree
, 1)
3856 || (tree_low_cst (sizetree
, 1) * BITS_PER_UNIT
) % round_boundary
))
3857 sizetree
= round_up (sizetree
, round_boundary
/ BITS_PER_UNIT
);
3859 ADD_PARM_SIZE (locate
->size
, sizetree
);
3861 locate
->size
.constant
-= part_size_in_regs
;
3862 #endif /* ARGS_GROW_DOWNWARD */
3864 #ifdef FUNCTION_ARG_OFFSET
3865 locate
->offset
.constant
+= FUNCTION_ARG_OFFSET (passed_mode
, type
);
3869 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
3870 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
3873 pad_to_arg_alignment (struct args_size
*offset_ptr
, int boundary
,
3874 struct args_size
*alignment_pad
)
3876 tree save_var
= NULL_TREE
;
3877 HOST_WIDE_INT save_constant
= 0;
3878 int boundary_in_bytes
= boundary
/ BITS_PER_UNIT
;
3879 HOST_WIDE_INT sp_offset
= STACK_POINTER_OFFSET
;
3881 #ifdef SPARC_STACK_BOUNDARY_HACK
3882 /* ??? The SPARC port may claim a STACK_BOUNDARY higher than
3883 the real alignment of %sp. However, when it does this, the
3884 alignment of %sp+STACK_POINTER_OFFSET is STACK_BOUNDARY. */
3885 if (SPARC_STACK_BOUNDARY_HACK
)
3889 if (boundary
> PARM_BOUNDARY
)
3891 save_var
= offset_ptr
->var
;
3892 save_constant
= offset_ptr
->constant
;
3895 alignment_pad
->var
= NULL_TREE
;
3896 alignment_pad
->constant
= 0;
3898 if (boundary
> BITS_PER_UNIT
)
3900 if (offset_ptr
->var
)
3902 tree sp_offset_tree
= ssize_int (sp_offset
);
3903 tree offset
= size_binop (PLUS_EXPR
,
3904 ARGS_SIZE_TREE (*offset_ptr
),
3906 #ifdef ARGS_GROW_DOWNWARD
3907 tree rounded
= round_down (offset
, boundary
/ BITS_PER_UNIT
);
3909 tree rounded
= round_up (offset
, boundary
/ BITS_PER_UNIT
);
3912 offset_ptr
->var
= size_binop (MINUS_EXPR
, rounded
, sp_offset_tree
);
3913 /* ARGS_SIZE_TREE includes constant term. */
3914 offset_ptr
->constant
= 0;
3915 if (boundary
> PARM_BOUNDARY
)
3916 alignment_pad
->var
= size_binop (MINUS_EXPR
, offset_ptr
->var
,
3921 offset_ptr
->constant
= -sp_offset
+
3922 #ifdef ARGS_GROW_DOWNWARD
3923 FLOOR_ROUND (offset_ptr
->constant
+ sp_offset
, boundary_in_bytes
);
3925 CEIL_ROUND (offset_ptr
->constant
+ sp_offset
, boundary_in_bytes
);
3927 if (boundary
> PARM_BOUNDARY
)
3928 alignment_pad
->constant
= offset_ptr
->constant
- save_constant
;
3934 pad_below (struct args_size
*offset_ptr
, enum machine_mode passed_mode
, tree sizetree
)
3936 if (passed_mode
!= BLKmode
)
3938 if (GET_MODE_BITSIZE (passed_mode
) % PARM_BOUNDARY
)
3939 offset_ptr
->constant
3940 += (((GET_MODE_BITSIZE (passed_mode
) + PARM_BOUNDARY
- 1)
3941 / PARM_BOUNDARY
* PARM_BOUNDARY
/ BITS_PER_UNIT
)
3942 - GET_MODE_SIZE (passed_mode
));
3946 if (TREE_CODE (sizetree
) != INTEGER_CST
3947 || (TREE_INT_CST_LOW (sizetree
) * BITS_PER_UNIT
) % PARM_BOUNDARY
)
3949 /* Round the size up to multiple of PARM_BOUNDARY bits. */
3950 tree s2
= round_up (sizetree
, PARM_BOUNDARY
/ BITS_PER_UNIT
);
3952 ADD_PARM_SIZE (*offset_ptr
, s2
);
3953 SUB_PARM_SIZE (*offset_ptr
, sizetree
);
3959 /* True if register REGNO was alive at a place where `setjmp' was
3960 called and was set more than once or is an argument. Such regs may
3961 be clobbered by `longjmp'. */
3964 regno_clobbered_at_setjmp (bitmap setjmp_crosses
, int regno
)
3966 /* There appear to be cases where some local vars never reach the
3967 backend but have bogus regnos. */
3968 if (regno
>= max_reg_num ())
3971 return ((REG_N_SETS (regno
) > 1
3972 || REGNO_REG_SET_P (df_get_live_out (ENTRY_BLOCK_PTR
), regno
))
3973 && REGNO_REG_SET_P (setjmp_crosses
, regno
));
3976 /* Walk the tree of blocks describing the binding levels within a
3977 function and warn about variables the might be killed by setjmp or
3978 vfork. This is done after calling flow_analysis before register
3979 allocation since that will clobber the pseudo-regs to hard
3983 setjmp_vars_warning (bitmap setjmp_crosses
, tree block
)
3987 for (decl
= BLOCK_VARS (block
); decl
; decl
= DECL_CHAIN (decl
))
3989 if (TREE_CODE (decl
) == VAR_DECL
3990 && DECL_RTL_SET_P (decl
)
3991 && REG_P (DECL_RTL (decl
))
3992 && regno_clobbered_at_setjmp (setjmp_crosses
, REGNO (DECL_RTL (decl
))))
3993 warning (OPT_Wclobbered
, "variable %q+D might be clobbered by"
3994 " %<longjmp%> or %<vfork%>", decl
);
3997 for (sub
= BLOCK_SUBBLOCKS (block
); sub
; sub
= BLOCK_CHAIN (sub
))
3998 setjmp_vars_warning (setjmp_crosses
, sub
);
4001 /* Do the appropriate part of setjmp_vars_warning
4002 but for arguments instead of local variables. */
4005 setjmp_args_warning (bitmap setjmp_crosses
)
4008 for (decl
= DECL_ARGUMENTS (current_function_decl
);
4009 decl
; decl
= DECL_CHAIN (decl
))
4010 if (DECL_RTL (decl
) != 0
4011 && REG_P (DECL_RTL (decl
))
4012 && regno_clobbered_at_setjmp (setjmp_crosses
, REGNO (DECL_RTL (decl
))))
4013 warning (OPT_Wclobbered
,
4014 "argument %q+D might be clobbered by %<longjmp%> or %<vfork%>",
4018 /* Generate warning messages for variables live across setjmp. */
4021 generate_setjmp_warnings (void)
4023 bitmap setjmp_crosses
= regstat_get_setjmp_crosses ();
4025 if (n_basic_blocks
== NUM_FIXED_BLOCKS
4026 || bitmap_empty_p (setjmp_crosses
))
4029 setjmp_vars_warning (setjmp_crosses
, DECL_INITIAL (current_function_decl
));
4030 setjmp_args_warning (setjmp_crosses
);
4034 /* Reverse the order of elements in the fragment chain T of blocks,
4035 and return the new head of the chain (old last element).
4036 In addition to that clear BLOCK_SAME_RANGE flags when needed
4037 and adjust BLOCK_SUPERCONTEXT from the super fragment to
4038 its super fragment origin. */
4041 block_fragments_nreverse (tree t
)
4043 tree prev
= 0, block
, next
, prev_super
= 0;
4044 tree super
= BLOCK_SUPERCONTEXT (t
);
4045 if (BLOCK_FRAGMENT_ORIGIN (super
))
4046 super
= BLOCK_FRAGMENT_ORIGIN (super
);
4047 for (block
= t
; block
; block
= next
)
4049 next
= BLOCK_FRAGMENT_CHAIN (block
);
4050 BLOCK_FRAGMENT_CHAIN (block
) = prev
;
4051 if ((prev
&& !BLOCK_SAME_RANGE (prev
))
4052 || (BLOCK_FRAGMENT_CHAIN (BLOCK_SUPERCONTEXT (block
))
4054 BLOCK_SAME_RANGE (block
) = 0;
4055 prev_super
= BLOCK_SUPERCONTEXT (block
);
4056 BLOCK_SUPERCONTEXT (block
) = super
;
4059 t
= BLOCK_FRAGMENT_ORIGIN (t
);
4060 if (BLOCK_FRAGMENT_CHAIN (BLOCK_SUPERCONTEXT (t
))
4062 BLOCK_SAME_RANGE (t
) = 0;
4063 BLOCK_SUPERCONTEXT (t
) = super
;
4067 /* Reverse the order of elements in the chain T of blocks,
4068 and return the new head of the chain (old last element).
4069 Also do the same on subblocks and reverse the order of elements
4070 in BLOCK_FRAGMENT_CHAIN as well. */
4073 blocks_nreverse_all (tree t
)
4075 tree prev
= 0, block
, next
;
4076 for (block
= t
; block
; block
= next
)
4078 next
= BLOCK_CHAIN (block
);
4079 BLOCK_CHAIN (block
) = prev
;
4080 if (BLOCK_FRAGMENT_CHAIN (block
)
4081 && BLOCK_FRAGMENT_ORIGIN (block
) == NULL_TREE
)
4083 BLOCK_FRAGMENT_CHAIN (block
)
4084 = block_fragments_nreverse (BLOCK_FRAGMENT_CHAIN (block
));
4085 if (!BLOCK_SAME_RANGE (BLOCK_FRAGMENT_CHAIN (block
)))
4086 BLOCK_SAME_RANGE (block
) = 0;
4088 BLOCK_SUBBLOCKS (block
) = blocks_nreverse_all (BLOCK_SUBBLOCKS (block
));
4095 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
4096 and create duplicate blocks. */
4097 /* ??? Need an option to either create block fragments or to create
4098 abstract origin duplicates of a source block. It really depends
4099 on what optimization has been performed. */
4102 reorder_blocks (void)
4104 tree block
= DECL_INITIAL (current_function_decl
);
4105 VEC(tree
,heap
) *block_stack
;
4107 if (block
== NULL_TREE
)
4110 block_stack
= VEC_alloc (tree
, heap
, 10);
4112 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
4113 clear_block_marks (block
);
4115 /* Prune the old trees away, so that they don't get in the way. */
4116 BLOCK_SUBBLOCKS (block
) = NULL_TREE
;
4117 BLOCK_CHAIN (block
) = NULL_TREE
;
4119 /* Recreate the block tree from the note nesting. */
4120 reorder_blocks_1 (get_insns (), block
, &block_stack
);
4121 BLOCK_SUBBLOCKS (block
) = blocks_nreverse_all (BLOCK_SUBBLOCKS (block
));
4123 VEC_free (tree
, heap
, block_stack
);
4126 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
4129 clear_block_marks (tree block
)
4133 TREE_ASM_WRITTEN (block
) = 0;
4134 clear_block_marks (BLOCK_SUBBLOCKS (block
));
4135 block
= BLOCK_CHAIN (block
);
4140 reorder_blocks_1 (rtx insns
, tree current_block
, VEC(tree
,heap
) **p_block_stack
)
4143 tree prev_beg
= NULL_TREE
, prev_end
= NULL_TREE
;
4145 for (insn
= insns
; insn
; insn
= NEXT_INSN (insn
))
4149 if (NOTE_KIND (insn
) == NOTE_INSN_BLOCK_BEG
)
4151 tree block
= NOTE_BLOCK (insn
);
4154 gcc_assert (BLOCK_FRAGMENT_ORIGIN (block
) == NULL_TREE
);
4158 BLOCK_SAME_RANGE (prev_end
) = 0;
4159 prev_end
= NULL_TREE
;
4161 /* If we have seen this block before, that means it now
4162 spans multiple address regions. Create a new fragment. */
4163 if (TREE_ASM_WRITTEN (block
))
4165 tree new_block
= copy_node (block
);
4167 BLOCK_SAME_RANGE (new_block
) = 0;
4168 BLOCK_FRAGMENT_ORIGIN (new_block
) = origin
;
4169 BLOCK_FRAGMENT_CHAIN (new_block
)
4170 = BLOCK_FRAGMENT_CHAIN (origin
);
4171 BLOCK_FRAGMENT_CHAIN (origin
) = new_block
;
4173 NOTE_BLOCK (insn
) = new_block
;
4177 if (prev_beg
== current_block
&& prev_beg
)
4178 BLOCK_SAME_RANGE (block
) = 1;
4182 BLOCK_SUBBLOCKS (block
) = 0;
4183 TREE_ASM_WRITTEN (block
) = 1;
4184 /* When there's only one block for the entire function,
4185 current_block == block and we mustn't do this, it
4186 will cause infinite recursion. */
4187 if (block
!= current_block
)
4190 if (block
!= origin
)
4191 gcc_assert (BLOCK_SUPERCONTEXT (origin
) == current_block
4192 || BLOCK_FRAGMENT_ORIGIN (BLOCK_SUPERCONTEXT
4195 if (VEC_empty (tree
, *p_block_stack
))
4196 super
= current_block
;
4199 super
= VEC_last (tree
, *p_block_stack
);
4200 gcc_assert (super
== current_block
4201 || BLOCK_FRAGMENT_ORIGIN (super
)
4204 BLOCK_SUPERCONTEXT (block
) = super
;
4205 BLOCK_CHAIN (block
) = BLOCK_SUBBLOCKS (current_block
);
4206 BLOCK_SUBBLOCKS (current_block
) = block
;
4207 current_block
= origin
;
4209 VEC_safe_push (tree
, heap
, *p_block_stack
, block
);
4211 else if (NOTE_KIND (insn
) == NOTE_INSN_BLOCK_END
)
4213 NOTE_BLOCK (insn
) = VEC_pop (tree
, *p_block_stack
);
4214 current_block
= BLOCK_SUPERCONTEXT (current_block
);
4215 if (BLOCK_FRAGMENT_ORIGIN (current_block
))
4216 current_block
= BLOCK_FRAGMENT_ORIGIN (current_block
);
4217 prev_beg
= NULL_TREE
;
4218 prev_end
= BLOCK_SAME_RANGE (NOTE_BLOCK (insn
))
4219 ? NOTE_BLOCK (insn
) : NULL_TREE
;
4224 prev_beg
= NULL_TREE
;
4226 BLOCK_SAME_RANGE (prev_end
) = 0;
4227 prev_end
= NULL_TREE
;
4232 /* Reverse the order of elements in the chain T of blocks,
4233 and return the new head of the chain (old last element). */
4236 blocks_nreverse (tree t
)
4238 tree prev
= 0, block
, next
;
4239 for (block
= t
; block
; block
= next
)
4241 next
= BLOCK_CHAIN (block
);
4242 BLOCK_CHAIN (block
) = prev
;
4248 /* Concatenate two chains of blocks (chained through BLOCK_CHAIN)
4249 by modifying the last node in chain 1 to point to chain 2. */
4252 block_chainon (tree op1
, tree op2
)
4261 for (t1
= op1
; BLOCK_CHAIN (t1
); t1
= BLOCK_CHAIN (t1
))
4263 BLOCK_CHAIN (t1
) = op2
;
4265 #ifdef ENABLE_TREE_CHECKING
4268 for (t2
= op2
; t2
; t2
= BLOCK_CHAIN (t2
))
4269 gcc_assert (t2
!= t1
);
4276 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
4277 non-NULL, list them all into VECTOR, in a depth-first preorder
4278 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
4282 all_blocks (tree block
, tree
*vector
)
4288 TREE_ASM_WRITTEN (block
) = 0;
4290 /* Record this block. */
4292 vector
[n_blocks
] = block
;
4296 /* Record the subblocks, and their subblocks... */
4297 n_blocks
+= all_blocks (BLOCK_SUBBLOCKS (block
),
4298 vector
? vector
+ n_blocks
: 0);
4299 block
= BLOCK_CHAIN (block
);
4305 /* Return a vector containing all the blocks rooted at BLOCK. The
4306 number of elements in the vector is stored in N_BLOCKS_P. The
4307 vector is dynamically allocated; it is the caller's responsibility
4308 to call `free' on the pointer returned. */
4311 get_block_vector (tree block
, int *n_blocks_p
)
4315 *n_blocks_p
= all_blocks (block
, NULL
);
4316 block_vector
= XNEWVEC (tree
, *n_blocks_p
);
4317 all_blocks (block
, block_vector
);
4319 return block_vector
;
4322 static GTY(()) int next_block_index
= 2;
4324 /* Set BLOCK_NUMBER for all the blocks in FN. */
4327 number_blocks (tree fn
)
4333 /* For SDB and XCOFF debugging output, we start numbering the blocks
4334 from 1 within each function, rather than keeping a running
4336 #if defined (SDB_DEBUGGING_INFO) || defined (XCOFF_DEBUGGING_INFO)
4337 if (write_symbols
== SDB_DEBUG
|| write_symbols
== XCOFF_DEBUG
)
4338 next_block_index
= 1;
4341 block_vector
= get_block_vector (DECL_INITIAL (fn
), &n_blocks
);
4343 /* The top-level BLOCK isn't numbered at all. */
4344 for (i
= 1; i
< n_blocks
; ++i
)
4345 /* We number the blocks from two. */
4346 BLOCK_NUMBER (block_vector
[i
]) = next_block_index
++;
4348 free (block_vector
);
4353 /* If VAR is present in a subblock of BLOCK, return the subblock. */
4356 debug_find_var_in_block_tree (tree var
, tree block
)
4360 for (t
= BLOCK_VARS (block
); t
; t
= TREE_CHAIN (t
))
4364 for (t
= BLOCK_SUBBLOCKS (block
); t
; t
= TREE_CHAIN (t
))
4366 tree ret
= debug_find_var_in_block_tree (var
, t
);
4374 /* Keep track of whether we're in a dummy function context. If we are,
4375 we don't want to invoke the set_current_function hook, because we'll
4376 get into trouble if the hook calls target_reinit () recursively or
4377 when the initial initialization is not yet complete. */
4379 static bool in_dummy_function
;
4381 /* Invoke the target hook when setting cfun. Update the optimization options
4382 if the function uses different options than the default. */
4385 invoke_set_current_function_hook (tree fndecl
)
4387 if (!in_dummy_function
)
4389 tree opts
= ((fndecl
)
4390 ? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (fndecl
)
4391 : optimization_default_node
);
4394 opts
= optimization_default_node
;
4396 /* Change optimization options if needed. */
4397 if (optimization_current_node
!= opts
)
4399 optimization_current_node
= opts
;
4400 cl_optimization_restore (&global_options
, TREE_OPTIMIZATION (opts
));
4403 targetm
.set_current_function (fndecl
);
4407 /* cfun should never be set directly; use this function. */
4410 set_cfun (struct function
*new_cfun
)
4412 if (cfun
!= new_cfun
)
4415 invoke_set_current_function_hook (new_cfun
? new_cfun
->decl
: NULL_TREE
);
4419 /* Initialized with NOGC, making this poisonous to the garbage collector. */
4421 static VEC(function_p
,heap
) *cfun_stack
;
4423 /* Push the current cfun onto the stack, and set cfun to new_cfun. */
4426 push_cfun (struct function
*new_cfun
)
4428 VEC_safe_push (function_p
, heap
, cfun_stack
, cfun
);
4429 set_cfun (new_cfun
);
4432 /* Pop cfun from the stack. */
4437 struct function
*new_cfun
= VEC_pop (function_p
, cfun_stack
);
4438 set_cfun (new_cfun
);
4441 /* Return value of funcdef and increase it. */
4443 get_next_funcdef_no (void)
4445 return funcdef_no
++;
4448 /* Return value of funcdef. */
4450 get_last_funcdef_no (void)
4455 /* Allocate a function structure for FNDECL and set its contents
4456 to the defaults. Set cfun to the newly-allocated object.
4457 Some of the helper functions invoked during initialization assume
4458 that cfun has already been set. Therefore, assign the new object
4459 directly into cfun and invoke the back end hook explicitly at the
4460 very end, rather than initializing a temporary and calling set_cfun
4463 ABSTRACT_P is true if this is a function that will never be seen by
4464 the middle-end. Such functions are front-end concepts (like C++
4465 function templates) that do not correspond directly to functions
4466 placed in object files. */
4469 allocate_struct_function (tree fndecl
, bool abstract_p
)
4472 tree fntype
= fndecl
? TREE_TYPE (fndecl
) : NULL_TREE
;
4474 cfun
= ggc_alloc_cleared_function ();
4476 init_eh_for_function ();
4478 if (init_machine_status
)
4479 cfun
->machine
= (*init_machine_status
) ();
4481 #ifdef OVERRIDE_ABI_FORMAT
4482 OVERRIDE_ABI_FORMAT (fndecl
);
4485 invoke_set_current_function_hook (fndecl
);
4487 if (fndecl
!= NULL_TREE
)
4489 DECL_STRUCT_FUNCTION (fndecl
) = cfun
;
4490 cfun
->decl
= fndecl
;
4491 current_function_funcdef_no
= get_next_funcdef_no ();
4493 result
= DECL_RESULT (fndecl
);
4494 if (!abstract_p
&& aggregate_value_p (result
, fndecl
))
4496 #ifdef PCC_STATIC_STRUCT_RETURN
4497 cfun
->returns_pcc_struct
= 1;
4499 cfun
->returns_struct
= 1;
4502 cfun
->stdarg
= stdarg_p (fntype
);
4504 /* Assume all registers in stdarg functions need to be saved. */
4505 cfun
->va_list_gpr_size
= VA_LIST_MAX_GPR_SIZE
;
4506 cfun
->va_list_fpr_size
= VA_LIST_MAX_FPR_SIZE
;
4508 /* ??? This could be set on a per-function basis by the front-end
4509 but is this worth the hassle? */
4510 cfun
->can_throw_non_call_exceptions
= flag_non_call_exceptions
;
4514 /* This is like allocate_struct_function, but pushes a new cfun for FNDECL
4515 instead of just setting it. */
4518 push_struct_function (tree fndecl
)
4520 VEC_safe_push (function_p
, heap
, cfun_stack
, cfun
);
4521 allocate_struct_function (fndecl
, false);
4524 /* Reset crtl and other non-struct-function variables to defaults as
4525 appropriate for emitting rtl at the start of a function. */
4528 prepare_function_start (void)
4530 gcc_assert (!crtl
->emit
.x_last_insn
);
4533 init_varasm_status ();
4535 default_rtl_profile ();
4537 if (flag_stack_usage_info
)
4539 cfun
->su
= ggc_alloc_cleared_stack_usage ();
4540 cfun
->su
->static_stack_size
= -1;
4543 cse_not_expected
= ! optimize
;
4545 /* Caller save not needed yet. */
4546 caller_save_needed
= 0;
4548 /* We haven't done register allocation yet. */
4551 /* Indicate that we have not instantiated virtual registers yet. */
4552 virtuals_instantiated
= 0;
4554 /* Indicate that we want CONCATs now. */
4555 generating_concat_p
= 1;
4557 /* Indicate we have no need of a frame pointer yet. */
4558 frame_pointer_needed
= 0;
4561 /* Initialize the rtl expansion mechanism so that we can do simple things
4562 like generate sequences. This is used to provide a context during global
4563 initialization of some passes. You must call expand_dummy_function_end
4564 to exit this context. */
4567 init_dummy_function_start (void)
4569 gcc_assert (!in_dummy_function
);
4570 in_dummy_function
= true;
4571 push_struct_function (NULL_TREE
);
4572 prepare_function_start ();
4575 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
4576 and initialize static variables for generating RTL for the statements
4580 init_function_start (tree subr
)
4582 if (subr
&& DECL_STRUCT_FUNCTION (subr
))
4583 set_cfun (DECL_STRUCT_FUNCTION (subr
));
4585 allocate_struct_function (subr
, false);
4586 prepare_function_start ();
4587 decide_function_section (subr
);
4589 /* Warn if this value is an aggregate type,
4590 regardless of which calling convention we are using for it. */
4591 if (AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr
))))
4592 warning (OPT_Waggregate_return
, "function returns an aggregate");
4597 expand_main_function (void)
4599 #if (defined(INVOKE__main) \
4600 || (!defined(HAS_INIT_SECTION) \
4601 && !defined(INIT_SECTION_ASM_OP) \
4602 && !defined(INIT_ARRAY_SECTION_ASM_OP)))
4603 emit_library_call (init_one_libfunc (NAME__MAIN
), LCT_NORMAL
, VOIDmode
, 0);
4607 /* Expand code to initialize the stack_protect_guard. This is invoked at
4608 the beginning of a function to be protected. */
4610 #ifndef HAVE_stack_protect_set
4611 # define HAVE_stack_protect_set 0
4612 # define gen_stack_protect_set(x,y) (gcc_unreachable (), NULL_RTX)
4616 stack_protect_prologue (void)
4618 tree guard_decl
= targetm
.stack_protect_guard ();
4621 x
= expand_normal (crtl
->stack_protect_guard
);
4622 y
= expand_normal (guard_decl
);
4624 /* Allow the target to copy from Y to X without leaking Y into a
4626 if (HAVE_stack_protect_set
)
4628 rtx insn
= gen_stack_protect_set (x
, y
);
4636 /* Otherwise do a straight move. */
4637 emit_move_insn (x
, y
);
4640 /* Expand code to verify the stack_protect_guard. This is invoked at
4641 the end of a function to be protected. */
4643 #ifndef HAVE_stack_protect_test
4644 # define HAVE_stack_protect_test 0
4645 # define gen_stack_protect_test(x, y, z) (gcc_unreachable (), NULL_RTX)
4649 stack_protect_epilogue (void)
4651 tree guard_decl
= targetm
.stack_protect_guard ();
4652 rtx label
= gen_label_rtx ();
4655 x
= expand_normal (crtl
->stack_protect_guard
);
4656 y
= expand_normal (guard_decl
);
4658 /* Allow the target to compare Y with X without leaking either into
4660 switch (HAVE_stack_protect_test
!= 0)
4663 tmp
= gen_stack_protect_test (x
, y
, label
);
4672 emit_cmp_and_jump_insns (x
, y
, EQ
, NULL_RTX
, ptr_mode
, 1, label
);
4676 /* The noreturn predictor has been moved to the tree level. The rtl-level
4677 predictors estimate this branch about 20%, which isn't enough to get
4678 things moved out of line. Since this is the only extant case of adding
4679 a noreturn function at the rtl level, it doesn't seem worth doing ought
4680 except adding the prediction by hand. */
4681 tmp
= get_last_insn ();
4683 predict_insn_def (tmp
, PRED_NORETURN
, TAKEN
);
4685 expand_call (targetm
.stack_protect_fail (), NULL_RTX
, /*ignore=*/true);
4690 /* Start the RTL for a new function, and set variables used for
4692 SUBR is the FUNCTION_DECL node.
4693 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
4694 the function's parameters, which must be run at any return statement. */
4697 expand_function_start (tree subr
)
4699 /* Make sure volatile mem refs aren't considered
4700 valid operands of arithmetic insns. */
4701 init_recog_no_volatile ();
4705 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr
));
4708 = (stack_limit_rtx
!= NULL_RTX
&& ! DECL_NO_LIMIT_STACK (subr
));
4710 /* Make the label for return statements to jump to. Do not special
4711 case machines with special return instructions -- they will be
4712 handled later during jump, ifcvt, or epilogue creation. */
4713 return_label
= gen_label_rtx ();
4715 /* Initialize rtx used to return the value. */
4716 /* Do this before assign_parms so that we copy the struct value address
4717 before any library calls that assign parms might generate. */
4719 /* Decide whether to return the value in memory or in a register. */
4720 if (aggregate_value_p (DECL_RESULT (subr
), subr
))
4722 /* Returning something that won't go in a register. */
4723 rtx value_address
= 0;
4725 #ifdef PCC_STATIC_STRUCT_RETURN
4726 if (cfun
->returns_pcc_struct
)
4728 int size
= int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr
)));
4729 value_address
= assemble_static_space (size
);
4734 rtx sv
= targetm
.calls
.struct_value_rtx (TREE_TYPE (subr
), 2);
4735 /* Expect to be passed the address of a place to store the value.
4736 If it is passed as an argument, assign_parms will take care of
4740 value_address
= gen_reg_rtx (Pmode
);
4741 emit_move_insn (value_address
, sv
);
4746 rtx x
= value_address
;
4747 if (!DECL_BY_REFERENCE (DECL_RESULT (subr
)))
4749 x
= gen_rtx_MEM (DECL_MODE (DECL_RESULT (subr
)), x
);
4750 set_mem_attributes (x
, DECL_RESULT (subr
), 1);
4752 SET_DECL_RTL (DECL_RESULT (subr
), x
);
4755 else if (DECL_MODE (DECL_RESULT (subr
)) == VOIDmode
)
4756 /* If return mode is void, this decl rtl should not be used. */
4757 SET_DECL_RTL (DECL_RESULT (subr
), NULL_RTX
);
4760 /* Compute the return values into a pseudo reg, which we will copy
4761 into the true return register after the cleanups are done. */
4762 tree return_type
= TREE_TYPE (DECL_RESULT (subr
));
4763 if (TYPE_MODE (return_type
) != BLKmode
4764 && targetm
.calls
.return_in_msb (return_type
))
4765 /* expand_function_end will insert the appropriate padding in
4766 this case. Use the return value's natural (unpadded) mode
4767 within the function proper. */
4768 SET_DECL_RTL (DECL_RESULT (subr
),
4769 gen_reg_rtx (TYPE_MODE (return_type
)));
4772 /* In order to figure out what mode to use for the pseudo, we
4773 figure out what the mode of the eventual return register will
4774 actually be, and use that. */
4775 rtx hard_reg
= hard_function_value (return_type
, subr
, 0, 1);
4777 /* Structures that are returned in registers are not
4778 aggregate_value_p, so we may see a PARALLEL or a REG. */
4779 if (REG_P (hard_reg
))
4780 SET_DECL_RTL (DECL_RESULT (subr
),
4781 gen_reg_rtx (GET_MODE (hard_reg
)));
4784 gcc_assert (GET_CODE (hard_reg
) == PARALLEL
);
4785 SET_DECL_RTL (DECL_RESULT (subr
), gen_group_rtx (hard_reg
));
4789 /* Set DECL_REGISTER flag so that expand_function_end will copy the
4790 result to the real return register(s). */
4791 DECL_REGISTER (DECL_RESULT (subr
)) = 1;
4794 /* Initialize rtx for parameters and local variables.
4795 In some cases this requires emitting insns. */
4796 assign_parms (subr
);
4798 /* If function gets a static chain arg, store it. */
4799 if (cfun
->static_chain_decl
)
4801 tree parm
= cfun
->static_chain_decl
;
4802 rtx local
, chain
, insn
;
4804 local
= gen_reg_rtx (Pmode
);
4805 chain
= targetm
.calls
.static_chain (current_function_decl
, true);
4807 set_decl_incoming_rtl (parm
, chain
, false);
4808 SET_DECL_RTL (parm
, local
);
4809 mark_reg_pointer (local
, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm
))));
4811 insn
= emit_move_insn (local
, chain
);
4813 /* Mark the register as eliminable, similar to parameters. */
4815 && reg_mentioned_p (arg_pointer_rtx
, XEXP (chain
, 0)))
4816 set_dst_reg_note (insn
, REG_EQUIV
, chain
, local
);
4819 /* If the function receives a non-local goto, then store the
4820 bits we need to restore the frame pointer. */
4821 if (cfun
->nonlocal_goto_save_area
)
4826 tree var
= TREE_OPERAND (cfun
->nonlocal_goto_save_area
, 0);
4827 gcc_assert (DECL_RTL_SET_P (var
));
4829 t_save
= build4 (ARRAY_REF
,
4830 TREE_TYPE (TREE_TYPE (cfun
->nonlocal_goto_save_area
)),
4831 cfun
->nonlocal_goto_save_area
,
4832 integer_zero_node
, NULL_TREE
, NULL_TREE
);
4833 r_save
= expand_expr (t_save
, NULL_RTX
, VOIDmode
, EXPAND_WRITE
);
4834 gcc_assert (GET_MODE (r_save
) == Pmode
);
4836 emit_move_insn (r_save
, targetm
.builtin_setjmp_frame_value ());
4837 update_nonlocal_goto_save_area ();
4840 /* The following was moved from init_function_start.
4841 The move is supposed to make sdb output more accurate. */
4842 /* Indicate the beginning of the function body,
4843 as opposed to parm setup. */
4844 emit_note (NOTE_INSN_FUNCTION_BEG
);
4846 gcc_assert (NOTE_P (get_last_insn ()));
4848 parm_birth_insn
= get_last_insn ();
4853 PROFILE_HOOK (current_function_funcdef_no
);
4857 /* If we are doing generic stack checking, the probe should go here. */
4858 if (flag_stack_check
== GENERIC_STACK_CHECK
)
4859 stack_check_probe_note
= emit_note (NOTE_INSN_DELETED
);
4862 /* Undo the effects of init_dummy_function_start. */
4864 expand_dummy_function_end (void)
4866 gcc_assert (in_dummy_function
);
4868 /* End any sequences that failed to be closed due to syntax errors. */
4869 while (in_sequence_p ())
4872 /* Outside function body, can't compute type's actual size
4873 until next function's body starts. */
4875 free_after_parsing (cfun
);
4876 free_after_compilation (cfun
);
4878 in_dummy_function
= false;
4881 /* Call DOIT for each hard register used as a return value from
4882 the current function. */
4885 diddle_return_value (void (*doit
) (rtx
, void *), void *arg
)
4887 rtx outgoing
= crtl
->return_rtx
;
4892 if (REG_P (outgoing
))
4893 (*doit
) (outgoing
, arg
);
4894 else if (GET_CODE (outgoing
) == PARALLEL
)
4898 for (i
= 0; i
< XVECLEN (outgoing
, 0); i
++)
4900 rtx x
= XEXP (XVECEXP (outgoing
, 0, i
), 0);
4902 if (REG_P (x
) && REGNO (x
) < FIRST_PSEUDO_REGISTER
)
4909 do_clobber_return_reg (rtx reg
, void *arg ATTRIBUTE_UNUSED
)
4915 clobber_return_register (void)
4917 diddle_return_value (do_clobber_return_reg
, NULL
);
4919 /* In case we do use pseudo to return value, clobber it too. */
4920 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl
)))
4922 tree decl_result
= DECL_RESULT (current_function_decl
);
4923 rtx decl_rtl
= DECL_RTL (decl_result
);
4924 if (REG_P (decl_rtl
) && REGNO (decl_rtl
) >= FIRST_PSEUDO_REGISTER
)
4926 do_clobber_return_reg (decl_rtl
, NULL
);
4932 do_use_return_reg (rtx reg
, void *arg ATTRIBUTE_UNUSED
)
4938 use_return_register (void)
4940 diddle_return_value (do_use_return_reg
, NULL
);
4943 /* Possibly warn about unused parameters. */
4945 do_warn_unused_parameter (tree fn
)
4949 for (decl
= DECL_ARGUMENTS (fn
);
4950 decl
; decl
= DECL_CHAIN (decl
))
4951 if (!TREE_USED (decl
) && TREE_CODE (decl
) == PARM_DECL
4952 && DECL_NAME (decl
) && !DECL_ARTIFICIAL (decl
)
4953 && !TREE_NO_WARNING (decl
))
4954 warning (OPT_Wunused_parameter
, "unused parameter %q+D", decl
);
4957 static GTY(()) rtx initial_trampoline
;
4959 /* Generate RTL for the end of the current function. */
4962 expand_function_end (void)
4966 /* If arg_pointer_save_area was referenced only from a nested
4967 function, we will not have initialized it yet. Do that now. */
4968 if (arg_pointer_save_area
&& ! crtl
->arg_pointer_save_area_init
)
4969 get_arg_pointer_save_area ();
4971 /* If we are doing generic stack checking and this function makes calls,
4972 do a stack probe at the start of the function to ensure we have enough
4973 space for another stack frame. */
4974 if (flag_stack_check
== GENERIC_STACK_CHECK
)
4978 for (insn
= get_insns (); insn
; insn
= NEXT_INSN (insn
))
4981 rtx max_frame_size
= GEN_INT (STACK_CHECK_MAX_FRAME_SIZE
);
4983 if (STACK_CHECK_MOVING_SP
)
4984 anti_adjust_stack_and_probe (max_frame_size
, true);
4986 probe_stack_range (STACK_OLD_CHECK_PROTECT
, max_frame_size
);
4989 set_insn_locators (seq
, prologue_locator
);
4990 emit_insn_before (seq
, stack_check_probe_note
);
4995 /* End any sequences that failed to be closed due to syntax errors. */
4996 while (in_sequence_p ())
4999 clear_pending_stack_adjust ();
5000 do_pending_stack_adjust ();
5002 /* Output a linenumber for the end of the function.
5003 SDB depends on this. */
5004 set_curr_insn_source_location (input_location
);
5006 /* Before the return label (if any), clobber the return
5007 registers so that they are not propagated live to the rest of
5008 the function. This can only happen with functions that drop
5009 through; if there had been a return statement, there would
5010 have either been a return rtx, or a jump to the return label.
5012 We delay actual code generation after the current_function_value_rtx
5014 clobber_after
= get_last_insn ();
5016 /* Output the label for the actual return from the function. */
5017 emit_label (return_label
);
5019 if (targetm_common
.except_unwind_info (&global_options
) == UI_SJLJ
)
5021 /* Let except.c know where it should emit the call to unregister
5022 the function context for sjlj exceptions. */
5023 if (flag_exceptions
)
5024 sjlj_emit_function_exit_after (get_last_insn ());
5028 /* We want to ensure that instructions that may trap are not
5029 moved into the epilogue by scheduling, because we don't
5030 always emit unwind information for the epilogue. */
5031 if (cfun
->can_throw_non_call_exceptions
)
5032 emit_insn (gen_blockage ());
5035 /* If this is an implementation of throw, do what's necessary to
5036 communicate between __builtin_eh_return and the epilogue. */
5037 expand_eh_return ();
5039 /* If scalar return value was computed in a pseudo-reg, or was a named
5040 return value that got dumped to the stack, copy that to the hard
5042 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl
)))
5044 tree decl_result
= DECL_RESULT (current_function_decl
);
5045 rtx decl_rtl
= DECL_RTL (decl_result
);
5047 if (REG_P (decl_rtl
)
5048 ? REGNO (decl_rtl
) >= FIRST_PSEUDO_REGISTER
5049 : DECL_REGISTER (decl_result
))
5051 rtx real_decl_rtl
= crtl
->return_rtx
;
5053 /* This should be set in assign_parms. */
5054 gcc_assert (REG_FUNCTION_VALUE_P (real_decl_rtl
));
5056 /* If this is a BLKmode structure being returned in registers,
5057 then use the mode computed in expand_return. Note that if
5058 decl_rtl is memory, then its mode may have been changed,
5059 but that crtl->return_rtx has not. */
5060 if (GET_MODE (real_decl_rtl
) == BLKmode
)
5061 PUT_MODE (real_decl_rtl
, GET_MODE (decl_rtl
));
5063 /* If a non-BLKmode return value should be padded at the least
5064 significant end of the register, shift it left by the appropriate
5065 amount. BLKmode results are handled using the group load/store
5067 if (TYPE_MODE (TREE_TYPE (decl_result
)) != BLKmode
5068 && targetm
.calls
.return_in_msb (TREE_TYPE (decl_result
)))
5070 emit_move_insn (gen_rtx_REG (GET_MODE (decl_rtl
),
5071 REGNO (real_decl_rtl
)),
5073 shift_return_value (GET_MODE (decl_rtl
), true, real_decl_rtl
);
5075 /* If a named return value dumped decl_return to memory, then
5076 we may need to re-do the PROMOTE_MODE signed/unsigned
5078 else if (GET_MODE (real_decl_rtl
) != GET_MODE (decl_rtl
))
5080 int unsignedp
= TYPE_UNSIGNED (TREE_TYPE (decl_result
));
5081 promote_function_mode (TREE_TYPE (decl_result
),
5082 GET_MODE (decl_rtl
), &unsignedp
,
5083 TREE_TYPE (current_function_decl
), 1);
5085 convert_move (real_decl_rtl
, decl_rtl
, unsignedp
);
5087 else if (GET_CODE (real_decl_rtl
) == PARALLEL
)
5089 /* If expand_function_start has created a PARALLEL for decl_rtl,
5090 move the result to the real return registers. Otherwise, do
5091 a group load from decl_rtl for a named return. */
5092 if (GET_CODE (decl_rtl
) == PARALLEL
)
5093 emit_group_move (real_decl_rtl
, decl_rtl
);
5095 emit_group_load (real_decl_rtl
, decl_rtl
,
5096 TREE_TYPE (decl_result
),
5097 int_size_in_bytes (TREE_TYPE (decl_result
)));
5099 /* In the case of complex integer modes smaller than a word, we'll
5100 need to generate some non-trivial bitfield insertions. Do that
5101 on a pseudo and not the hard register. */
5102 else if (GET_CODE (decl_rtl
) == CONCAT
5103 && GET_MODE_CLASS (GET_MODE (decl_rtl
)) == MODE_COMPLEX_INT
5104 && GET_MODE_BITSIZE (GET_MODE (decl_rtl
)) <= BITS_PER_WORD
)
5106 int old_generating_concat_p
;
5109 old_generating_concat_p
= generating_concat_p
;
5110 generating_concat_p
= 0;
5111 tmp
= gen_reg_rtx (GET_MODE (decl_rtl
));
5112 generating_concat_p
= old_generating_concat_p
;
5114 emit_move_insn (tmp
, decl_rtl
);
5115 emit_move_insn (real_decl_rtl
, tmp
);
5118 emit_move_insn (real_decl_rtl
, decl_rtl
);
5122 /* If returning a structure, arrange to return the address of the value
5123 in a place where debuggers expect to find it.
5125 If returning a structure PCC style,
5126 the caller also depends on this value.
5127 And cfun->returns_pcc_struct is not necessarily set. */
5128 if (cfun
->returns_struct
5129 || cfun
->returns_pcc_struct
)
5131 rtx value_address
= DECL_RTL (DECL_RESULT (current_function_decl
));
5132 tree type
= TREE_TYPE (DECL_RESULT (current_function_decl
));
5135 if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl
)))
5136 type
= TREE_TYPE (type
);
5138 value_address
= XEXP (value_address
, 0);
5140 outgoing
= targetm
.calls
.function_value (build_pointer_type (type
),
5141 current_function_decl
, true);
5143 /* Mark this as a function return value so integrate will delete the
5144 assignment and USE below when inlining this function. */
5145 REG_FUNCTION_VALUE_P (outgoing
) = 1;
5147 /* The address may be ptr_mode and OUTGOING may be Pmode. */
5148 value_address
= convert_memory_address (GET_MODE (outgoing
),
5151 emit_move_insn (outgoing
, value_address
);
5153 /* Show return register used to hold result (in this case the address
5155 crtl
->return_rtx
= outgoing
;
5158 /* Emit the actual code to clobber return register. */
5163 clobber_return_register ();
5167 emit_insn_after (seq
, clobber_after
);
5170 /* Output the label for the naked return from the function. */
5171 if (naked_return_label
)
5172 emit_label (naked_return_label
);
5174 /* @@@ This is a kludge. We want to ensure that instructions that
5175 may trap are not moved into the epilogue by scheduling, because
5176 we don't always emit unwind information for the epilogue. */
5177 if (cfun
->can_throw_non_call_exceptions
5178 && targetm_common
.except_unwind_info (&global_options
) != UI_SJLJ
)
5179 emit_insn (gen_blockage ());
5181 /* If stack protection is enabled for this function, check the guard. */
5182 if (crtl
->stack_protect_guard
)
5183 stack_protect_epilogue ();
5185 /* If we had calls to alloca, and this machine needs
5186 an accurate stack pointer to exit the function,
5187 insert some code to save and restore the stack pointer. */
5188 if (! EXIT_IGNORE_STACK
5189 && cfun
->calls_alloca
)
5194 emit_stack_save (SAVE_FUNCTION
, &tem
);
5197 emit_insn_before (seq
, parm_birth_insn
);
5199 emit_stack_restore (SAVE_FUNCTION
, tem
);
5202 /* ??? This should no longer be necessary since stupid is no longer with
5203 us, but there are some parts of the compiler (eg reload_combine, and
5204 sh mach_dep_reorg) that still try and compute their own lifetime info
5205 instead of using the general framework. */
5206 use_return_register ();
5210 get_arg_pointer_save_area (void)
5212 rtx ret
= arg_pointer_save_area
;
5216 ret
= assign_stack_local (Pmode
, GET_MODE_SIZE (Pmode
), 0);
5217 arg_pointer_save_area
= ret
;
5220 if (! crtl
->arg_pointer_save_area_init
)
5224 /* Save the arg pointer at the beginning of the function. The
5225 generated stack slot may not be a valid memory address, so we
5226 have to check it and fix it if necessary. */
5228 emit_move_insn (validize_mem (ret
),
5229 crtl
->args
.internal_arg_pointer
);
5233 push_topmost_sequence ();
5234 emit_insn_after (seq
, entry_of_function ());
5235 pop_topmost_sequence ();
5237 crtl
->arg_pointer_save_area_init
= true;
5243 /* Add a list of INSNS to the hash HASHP, possibly allocating HASHP
5244 for the first time. */
5247 record_insns (rtx insns
, rtx end
, htab_t
*hashp
)
5250 htab_t hash
= *hashp
;
5254 = htab_create_ggc (17, htab_hash_pointer
, htab_eq_pointer
, NULL
);
5256 for (tmp
= insns
; tmp
!= end
; tmp
= NEXT_INSN (tmp
))
5258 void **slot
= htab_find_slot (hash
, tmp
, INSERT
);
5259 gcc_assert (*slot
== NULL
);
5264 /* INSN has been duplicated or replaced by as COPY, perhaps by duplicating a
5265 basic block, splitting or peepholes. If INSN is a prologue or epilogue
5266 insn, then record COPY as well. */
5269 maybe_copy_prologue_epilogue_insn (rtx insn
, rtx copy
)
5274 hash
= epilogue_insn_hash
;
5275 if (!hash
|| !htab_find (hash
, insn
))
5277 hash
= prologue_insn_hash
;
5278 if (!hash
|| !htab_find (hash
, insn
))
5282 slot
= htab_find_slot (hash
, copy
, INSERT
);
5283 gcc_assert (*slot
== NULL
);
5287 /* Set the locator of the insn chain starting at INSN to LOC. */
5289 set_insn_locators (rtx insn
, int loc
)
5291 while (insn
!= NULL_RTX
)
5294 INSN_LOCATOR (insn
) = loc
;
5295 insn
= NEXT_INSN (insn
);
5299 /* Determine if any INSNs in HASH are, or are part of, INSN. Because
5300 we can be running after reorg, SEQUENCE rtl is possible. */
5303 contains (const_rtx insn
, htab_t hash
)
5308 if (NONJUMP_INSN_P (insn
) && GET_CODE (PATTERN (insn
)) == SEQUENCE
)
5311 for (i
= XVECLEN (PATTERN (insn
), 0) - 1; i
>= 0; i
--)
5312 if (htab_find (hash
, XVECEXP (PATTERN (insn
), 0, i
)))
5317 return htab_find (hash
, insn
) != NULL
;
5321 prologue_epilogue_contains (const_rtx insn
)
5323 if (contains (insn
, prologue_insn_hash
))
5325 if (contains (insn
, epilogue_insn_hash
))
5330 #ifdef HAVE_simple_return
5332 /* Return true if INSN requires the stack frame to be set up.
5333 PROLOGUE_USED contains the hard registers used in the function
5334 prologue. SET_UP_BY_PROLOGUE is the set of registers we expect the
5335 prologue to set up for the function. */
5337 requires_stack_frame_p (rtx insn
, HARD_REG_SET prologue_used
,
5338 HARD_REG_SET set_up_by_prologue
)
5341 HARD_REG_SET hardregs
;
5345 return !SIBLING_CALL_P (insn
);
5347 /* We need a frame to get the unique CFA expected by the unwinder. */
5348 if (cfun
->can_throw_non_call_exceptions
&& can_throw_internal (insn
))
5351 CLEAR_HARD_REG_SET (hardregs
);
5352 for (df_rec
= DF_INSN_DEFS (insn
); *df_rec
; df_rec
++)
5354 rtx dreg
= DF_REF_REG (*df_rec
);
5359 add_to_hard_reg_set (&hardregs
, GET_MODE (dreg
),
5362 if (hard_reg_set_intersect_p (hardregs
, prologue_used
))
5364 AND_COMPL_HARD_REG_SET (hardregs
, call_used_reg_set
);
5365 for (regno
= 0; regno
< FIRST_PSEUDO_REGISTER
; regno
++)
5366 if (TEST_HARD_REG_BIT (hardregs
, regno
)
5367 && df_regs_ever_live_p (regno
))
5370 for (df_rec
= DF_INSN_USES (insn
); *df_rec
; df_rec
++)
5372 rtx reg
= DF_REF_REG (*df_rec
);
5377 add_to_hard_reg_set (&hardregs
, GET_MODE (reg
),
5380 if (hard_reg_set_intersect_p (hardregs
, set_up_by_prologue
))
5386 /* See whether BB has a single successor that uses [REGNO, END_REGNO),
5387 and if BB is its only predecessor. Return that block if so,
5388 otherwise return null. */
5391 next_block_for_reg (basic_block bb
, int regno
, int end_regno
)
5399 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
5401 live
= df_get_live_in (e
->dest
);
5402 for (i
= regno
; i
< end_regno
; i
++)
5403 if (REGNO_REG_SET_P (live
, i
))
5405 if (live_edge
&& live_edge
!= e
)
5411 /* We can sometimes encounter dead code. Don't try to move it
5412 into the exit block. */
5413 if (!live_edge
|| live_edge
->dest
== EXIT_BLOCK_PTR
)
5416 /* Reject targets of abnormal edges. This is needed for correctness
5417 on ports like Alpha and MIPS, whose pic_offset_table_rtx can die on
5418 exception edges even though it is generally treated as call-saved
5419 for the majority of the compilation. Moving across abnormal edges
5420 isn't going to be interesting for shrink-wrap usage anyway. */
5421 if (live_edge
->flags
& EDGE_ABNORMAL
)
5424 if (EDGE_COUNT (live_edge
->dest
->preds
) > 1)
5427 return live_edge
->dest
;
5430 /* Try to move INSN from BB to a successor. Return true on success.
5431 USES and DEFS are the set of registers that are used and defined
5432 after INSN in BB. */
5435 move_insn_for_shrink_wrap (basic_block bb
, rtx insn
,
5436 const HARD_REG_SET uses
,
5437 const HARD_REG_SET defs
)
5440 bitmap live_out
, live_in
, bb_uses
, bb_defs
;
5441 unsigned int i
, dregno
, end_dregno
, sregno
, end_sregno
;
5442 basic_block next_block
;
5444 /* Look for a simple register copy. */
5445 set
= single_set (insn
);
5448 src
= SET_SRC (set
);
5449 dest
= SET_DEST (set
);
5450 if (!REG_P (dest
) || !REG_P (src
))
5453 /* Make sure that the source register isn't defined later in BB. */
5454 sregno
= REGNO (src
);
5455 end_sregno
= END_REGNO (src
);
5456 if (overlaps_hard_reg_set_p (defs
, GET_MODE (src
), sregno
))
5459 /* Make sure that the destination register isn't referenced later in BB. */
5460 dregno
= REGNO (dest
);
5461 end_dregno
= END_REGNO (dest
);
5462 if (overlaps_hard_reg_set_p (uses
, GET_MODE (dest
), dregno
)
5463 || overlaps_hard_reg_set_p (defs
, GET_MODE (dest
), dregno
))
5466 /* See whether there is a successor block to which we could move INSN. */
5467 next_block
= next_block_for_reg (bb
, dregno
, end_dregno
);
5471 /* At this point we are committed to moving INSN, but let's try to
5472 move it as far as we can. */
5475 live_out
= df_get_live_out (bb
);
5476 live_in
= df_get_live_in (next_block
);
5479 /* Check whether BB uses DEST or clobbers DEST. We need to add
5480 INSN to BB if so. Either way, DEST is no longer live on entry,
5481 except for any part that overlaps SRC (next loop). */
5482 bb_uses
= &DF_LR_BB_INFO (bb
)->use
;
5483 bb_defs
= &DF_LR_BB_INFO (bb
)->def
;
5484 for (i
= dregno
; i
< end_dregno
; i
++)
5486 if (REGNO_REG_SET_P (bb_uses
, i
) || REGNO_REG_SET_P (bb_defs
, i
))
5488 CLEAR_REGNO_REG_SET (live_out
, i
);
5489 CLEAR_REGNO_REG_SET (live_in
, i
);
5492 /* Check whether BB clobbers SRC. We need to add INSN to BB if so.
5493 Either way, SRC is now live on entry. */
5494 for (i
= sregno
; i
< end_sregno
; i
++)
5496 if (REGNO_REG_SET_P (bb_defs
, i
))
5498 SET_REGNO_REG_SET (live_out
, i
);
5499 SET_REGNO_REG_SET (live_in
, i
);
5502 /* If we don't need to add the move to BB, look for a single
5505 next_block
= next_block_for_reg (next_block
, dregno
, end_dregno
);
5509 /* BB now defines DEST. It only uses the parts of DEST that overlap SRC
5511 for (i
= dregno
; i
< end_dregno
; i
++)
5513 CLEAR_REGNO_REG_SET (bb_uses
, i
);
5514 SET_REGNO_REG_SET (bb_defs
, i
);
5517 /* BB now uses SRC. */
5518 for (i
= sregno
; i
< end_sregno
; i
++)
5519 SET_REGNO_REG_SET (bb_uses
, i
);
5521 emit_insn_after (PATTERN (insn
), bb_note (bb
));
5526 /* Look for register copies in the first block of the function, and move
5527 them down into successor blocks if the register is used only on one
5528 path. This exposes more opportunities for shrink-wrapping. These
5529 kinds of sets often occur when incoming argument registers are moved
5530 to call-saved registers because their values are live across one or
5531 more calls during the function. */
5534 prepare_shrink_wrap (basic_block entry_block
)
5537 HARD_REG_SET uses
, defs
;
5540 CLEAR_HARD_REG_SET (uses
);
5541 CLEAR_HARD_REG_SET (defs
);
5542 FOR_BB_INSNS_REVERSE_SAFE (entry_block
, insn
, curr
)
5543 if (NONDEBUG_INSN_P (insn
)
5544 && !move_insn_for_shrink_wrap (entry_block
, insn
, uses
, defs
))
5546 /* Add all defined registers to DEFs. */
5547 for (ref
= DF_INSN_DEFS (insn
); *ref
; ref
++)
5549 x
= DF_REF_REG (*ref
);
5550 if (REG_P (x
) && HARD_REGISTER_P (x
))
5551 SET_HARD_REG_BIT (defs
, REGNO (x
));
5554 /* Add all used registers to USESs. */
5555 for (ref
= DF_INSN_USES (insn
); *ref
; ref
++)
5557 x
= DF_REF_REG (*ref
);
5558 if (REG_P (x
) && HARD_REGISTER_P (x
))
5559 SET_HARD_REG_BIT (uses
, REGNO (x
));
5567 /* Insert use of return register before the end of BB. */
5570 emit_use_return_register_into_block (basic_block bb
)
5574 use_return_register ();
5577 emit_insn_before (seq
, BB_END (bb
));
5581 /* Create a return pattern, either simple_return or return, depending on
5585 gen_return_pattern (bool simple_p
)
5587 #ifdef HAVE_simple_return
5588 return simple_p
? gen_simple_return () : gen_return ();
5590 gcc_assert (!simple_p
);
5591 return gen_return ();
5595 /* Insert an appropriate return pattern at the end of block BB. This
5596 also means updating block_for_insn appropriately. SIMPLE_P is
5597 the same as in gen_return_pattern and passed to it. */
5600 emit_return_into_block (bool simple_p
, basic_block bb
)
5603 jump
= emit_jump_insn_after (gen_return_pattern (simple_p
), BB_END (bb
));
5604 pat
= PATTERN (jump
);
5605 if (GET_CODE (pat
) == PARALLEL
)
5606 pat
= XVECEXP (pat
, 0, 0);
5607 gcc_assert (ANY_RETURN_P (pat
));
5608 JUMP_LABEL (jump
) = pat
;
5612 /* Set JUMP_LABEL for a return insn. */
5615 set_return_jump_label (rtx returnjump
)
5617 rtx pat
= PATTERN (returnjump
);
5618 if (GET_CODE (pat
) == PARALLEL
)
5619 pat
= XVECEXP (pat
, 0, 0);
5620 if (ANY_RETURN_P (pat
))
5621 JUMP_LABEL (returnjump
) = pat
;
5623 JUMP_LABEL (returnjump
) = ret_rtx
;
5626 #ifdef HAVE_simple_return
5627 /* Create a copy of BB instructions and insert at BEFORE. Redirect
5628 preds of BB to COPY_BB if they don't appear in NEED_PROLOGUE. */
5630 dup_block_and_redirect (basic_block bb
, basic_block copy_bb
, rtx before
,
5631 bitmap_head
*need_prologue
)
5635 rtx insn
= BB_END (bb
);
5637 /* We know BB has a single successor, so there is no need to copy a
5638 simple jump at the end of BB. */
5639 if (simplejump_p (insn
))
5640 insn
= PREV_INSN (insn
);
5643 duplicate_insn_chain (BB_HEAD (bb
), insn
);
5647 for (insn
= get_insns (); insn
; insn
= NEXT_INSN (insn
))
5648 if (active_insn_p (insn
))
5650 fprintf (dump_file
, "Duplicating bb %d to bb %d, %u active insns.\n",
5651 bb
->index
, copy_bb
->index
, count
);
5653 insn
= get_insns ();
5655 emit_insn_before (insn
, before
);
5657 /* Redirect all the paths that need no prologue into copy_bb. */
5658 for (ei
= ei_start (bb
->preds
); (e
= ei_safe_edge (ei
)); )
5659 if (!bitmap_bit_p (need_prologue
, e
->src
->index
))
5661 redirect_edge_and_branch_force (e
, copy_bb
);
5669 #if defined (HAVE_return) || defined (HAVE_simple_return)
5670 /* Return true if there are any active insns between HEAD and TAIL. */
5672 active_insn_between (rtx head
, rtx tail
)
5676 if (active_insn_p (tail
))
5680 tail
= PREV_INSN (tail
);
5685 /* LAST_BB is a block that exits, and empty of active instructions.
5686 Examine its predecessors for jumps that can be converted to
5687 (conditional) returns. */
5688 static VEC (edge
, heap
) *
5689 convert_jumps_to_returns (basic_block last_bb
, bool simple_p
,
5690 VEC (edge
, heap
) *unconverted ATTRIBUTE_UNUSED
)
5697 VEC(basic_block
,heap
) *src_bbs
;
5699 src_bbs
= VEC_alloc (basic_block
, heap
, EDGE_COUNT (last_bb
->preds
));
5700 FOR_EACH_EDGE (e
, ei
, last_bb
->preds
)
5701 if (e
->src
!= ENTRY_BLOCK_PTR
)
5702 VEC_quick_push (basic_block
, src_bbs
, e
->src
);
5704 label
= BB_HEAD (last_bb
);
5706 FOR_EACH_VEC_ELT (basic_block
, src_bbs
, i
, bb
)
5708 rtx jump
= BB_END (bb
);
5710 if (!JUMP_P (jump
) || JUMP_LABEL (jump
) != label
)
5713 e
= find_edge (bb
, last_bb
);
5715 /* If we have an unconditional jump, we can replace that
5716 with a simple return instruction. */
5717 if (simplejump_p (jump
))
5719 /* The use of the return register might be present in the exit
5720 fallthru block. Either:
5721 - removing the use is safe, and we should remove the use in
5722 the exit fallthru block, or
5723 - removing the use is not safe, and we should add it here.
5724 For now, we conservatively choose the latter. Either of the
5725 2 helps in crossjumping. */
5726 emit_use_return_register_into_block (bb
);
5728 emit_return_into_block (simple_p
, bb
);
5732 /* If we have a conditional jump branching to the last
5733 block, we can try to replace that with a conditional
5734 return instruction. */
5735 else if (condjump_p (jump
))
5740 dest
= simple_return_rtx
;
5743 if (!redirect_jump (jump
, dest
, 0))
5745 #ifdef HAVE_simple_return
5750 "Failed to redirect bb %d branch.\n", bb
->index
);
5751 VEC_safe_push (edge
, heap
, unconverted
, e
);
5757 /* See comment in simplejump_p case above. */
5758 emit_use_return_register_into_block (bb
);
5760 /* If this block has only one successor, it both jumps
5761 and falls through to the fallthru block, so we can't
5763 if (single_succ_p (bb
))
5768 #ifdef HAVE_simple_return
5773 "Failed to redirect bb %d branch.\n", bb
->index
);
5774 VEC_safe_push (edge
, heap
, unconverted
, e
);
5780 /* Fix up the CFG for the successful change we just made. */
5781 redirect_edge_succ (e
, EXIT_BLOCK_PTR
);
5782 e
->flags
&= ~EDGE_CROSSING
;
5784 VEC_free (basic_block
, heap
, src_bbs
);
5788 /* Emit a return insn for the exit fallthru block. */
5790 emit_return_for_exit (edge exit_fallthru_edge
, bool simple_p
)
5792 basic_block last_bb
= exit_fallthru_edge
->src
;
5794 if (JUMP_P (BB_END (last_bb
)))
5796 last_bb
= split_edge (exit_fallthru_edge
);
5797 exit_fallthru_edge
= single_succ_edge (last_bb
);
5799 emit_barrier_after (BB_END (last_bb
));
5800 emit_return_into_block (simple_p
, last_bb
);
5801 exit_fallthru_edge
->flags
&= ~EDGE_FALLTHRU
;
5807 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
5808 this into place with notes indicating where the prologue ends and where
5809 the epilogue begins. Update the basic block information when possible.
5811 Notes on epilogue placement:
5812 There are several kinds of edges to the exit block:
5813 * a single fallthru edge from LAST_BB
5814 * possibly, edges from blocks containing sibcalls
5815 * possibly, fake edges from infinite loops
5817 The epilogue is always emitted on the fallthru edge from the last basic
5818 block in the function, LAST_BB, into the exit block.
5820 If LAST_BB is empty except for a label, it is the target of every
5821 other basic block in the function that ends in a return. If a
5822 target has a return or simple_return pattern (possibly with
5823 conditional variants), these basic blocks can be changed so that a
5824 return insn is emitted into them, and their target is adjusted to
5825 the real exit block.
5827 Notes on shrink wrapping: We implement a fairly conservative
5828 version of shrink-wrapping rather than the textbook one. We only
5829 generate a single prologue and a single epilogue. This is
5830 sufficient to catch a number of interesting cases involving early
5833 First, we identify the blocks that require the prologue to occur before
5834 them. These are the ones that modify a call-saved register, or reference
5835 any of the stack or frame pointer registers. To simplify things, we then
5836 mark everything reachable from these blocks as also requiring a prologue.
5837 This takes care of loops automatically, and avoids the need to examine
5838 whether MEMs reference the frame, since it is sufficient to check for
5839 occurrences of the stack or frame pointer.
5841 We then compute the set of blocks for which the need for a prologue
5842 is anticipatable (borrowing terminology from the shrink-wrapping
5843 description in Muchnick's book). These are the blocks which either
5844 require a prologue themselves, or those that have only successors
5845 where the prologue is anticipatable. The prologue needs to be
5846 inserted on all edges from BB1->BB2 where BB2 is in ANTIC and BB1
5847 is not. For the moment, we ensure that only one such edge exists.
5849 The epilogue is placed as described above, but we make a
5850 distinction between inserting return and simple_return patterns
5851 when modifying other blocks that end in a return. Blocks that end
5852 in a sibcall omit the sibcall_epilogue if the block is not in
5856 thread_prologue_and_epilogue_insns (void)
5859 #ifdef HAVE_simple_return
5860 VEC (edge
, heap
) *unconverted_simple_returns
= NULL
;
5861 bool nonempty_prologue
;
5862 bitmap_head bb_flags
;
5863 unsigned max_grow_size
;
5866 rtx seq ATTRIBUTE_UNUSED
, epilogue_end ATTRIBUTE_UNUSED
;
5867 rtx prologue_seq ATTRIBUTE_UNUSED
, split_prologue_seq ATTRIBUTE_UNUSED
;
5868 edge e
, entry_edge
, orig_entry_edge
, exit_fallthru_edge
;
5873 rtl_profile_for_bb (ENTRY_BLOCK_PTR
);
5877 epilogue_end
= NULL_RTX
;
5878 returnjump
= NULL_RTX
;
5880 /* Can't deal with multiple successors of the entry block at the
5881 moment. Function should always have at least one entry
5883 gcc_assert (single_succ_p (ENTRY_BLOCK_PTR
));
5884 entry_edge
= single_succ_edge (ENTRY_BLOCK_PTR
);
5885 orig_entry_edge
= entry_edge
;
5887 split_prologue_seq
= NULL_RTX
;
5888 if (flag_split_stack
5889 && (lookup_attribute ("no_split_stack", DECL_ATTRIBUTES (cfun
->decl
))
5892 #ifndef HAVE_split_stack_prologue
5895 gcc_assert (HAVE_split_stack_prologue
);
5898 emit_insn (gen_split_stack_prologue ());
5899 split_prologue_seq
= get_insns ();
5902 record_insns (split_prologue_seq
, NULL
, &prologue_insn_hash
);
5903 set_insn_locators (split_prologue_seq
, prologue_locator
);
5907 prologue_seq
= NULL_RTX
;
5908 #ifdef HAVE_prologue
5912 seq
= gen_prologue ();
5915 /* Insert an explicit USE for the frame pointer
5916 if the profiling is on and the frame pointer is required. */
5917 if (crtl
->profile
&& frame_pointer_needed
)
5918 emit_use (hard_frame_pointer_rtx
);
5920 /* Retain a map of the prologue insns. */
5921 record_insns (seq
, NULL
, &prologue_insn_hash
);
5922 emit_note (NOTE_INSN_PROLOGUE_END
);
5924 /* Ensure that instructions are not moved into the prologue when
5925 profiling is on. The call to the profiling routine can be
5926 emitted within the live range of a call-clobbered register. */
5927 if (!targetm
.profile_before_prologue () && crtl
->profile
)
5928 emit_insn (gen_blockage ());
5930 prologue_seq
= get_insns ();
5932 set_insn_locators (prologue_seq
, prologue_locator
);
5936 #ifdef HAVE_simple_return
5937 bitmap_initialize (&bb_flags
, &bitmap_default_obstack
);
5939 /* Try to perform a kind of shrink-wrapping, making sure the
5940 prologue/epilogue is emitted only around those parts of the
5941 function that require it. */
5943 nonempty_prologue
= false;
5944 for (seq
= prologue_seq
; seq
; seq
= NEXT_INSN (seq
))
5945 if (!NOTE_P (seq
) || NOTE_KIND (seq
) != NOTE_INSN_PROLOGUE_END
)
5947 nonempty_prologue
= true;
5951 if (flag_shrink_wrap
&& HAVE_simple_return
5952 && (targetm
.profile_before_prologue () || !crtl
->profile
)
5953 && nonempty_prologue
&& !crtl
->calls_eh_return
)
5955 HARD_REG_SET prologue_clobbered
, prologue_used
, live_on_edge
;
5956 struct hard_reg_set_container set_up_by_prologue
;
5958 VEC(basic_block
, heap
) *vec
;
5960 bitmap_head bb_antic_flags
;
5961 bitmap_head bb_on_list
;
5962 bitmap_head bb_tail
;
5965 fprintf (dump_file
, "Attempting shrink-wrapping optimization.\n");
5967 /* Compute the registers set and used in the prologue. */
5968 CLEAR_HARD_REG_SET (prologue_clobbered
);
5969 CLEAR_HARD_REG_SET (prologue_used
);
5970 for (p_insn
= prologue_seq
; p_insn
; p_insn
= NEXT_INSN (p_insn
))
5972 HARD_REG_SET this_used
;
5973 if (!NONDEBUG_INSN_P (p_insn
))
5976 CLEAR_HARD_REG_SET (this_used
);
5977 note_uses (&PATTERN (p_insn
), record_hard_reg_uses
,
5979 AND_COMPL_HARD_REG_SET (this_used
, prologue_clobbered
);
5980 IOR_HARD_REG_SET (prologue_used
, this_used
);
5981 note_stores (PATTERN (p_insn
), record_hard_reg_sets
,
5982 &prologue_clobbered
);
5985 prepare_shrink_wrap (entry_edge
->dest
);
5987 bitmap_initialize (&bb_antic_flags
, &bitmap_default_obstack
);
5988 bitmap_initialize (&bb_on_list
, &bitmap_default_obstack
);
5989 bitmap_initialize (&bb_tail
, &bitmap_default_obstack
);
5991 /* Find the set of basic blocks that require a stack frame,
5992 and blocks that are too big to be duplicated. */
5994 vec
= VEC_alloc (basic_block
, heap
, n_basic_blocks
);
5996 CLEAR_HARD_REG_SET (set_up_by_prologue
.set
);
5997 add_to_hard_reg_set (&set_up_by_prologue
.set
, Pmode
,
5998 STACK_POINTER_REGNUM
);
5999 add_to_hard_reg_set (&set_up_by_prologue
.set
, Pmode
, ARG_POINTER_REGNUM
);
6000 if (frame_pointer_needed
)
6001 add_to_hard_reg_set (&set_up_by_prologue
.set
, Pmode
,
6002 HARD_FRAME_POINTER_REGNUM
);
6003 if (pic_offset_table_rtx
)
6004 add_to_hard_reg_set (&set_up_by_prologue
.set
, Pmode
,
6005 PIC_OFFSET_TABLE_REGNUM
);
6006 if (stack_realign_drap
&& crtl
->drap_reg
)
6007 add_to_hard_reg_set (&set_up_by_prologue
.set
,
6008 GET_MODE (crtl
->drap_reg
),
6009 REGNO (crtl
->drap_reg
));
6010 if (targetm
.set_up_by_prologue
)
6011 targetm
.set_up_by_prologue (&set_up_by_prologue
);
6013 /* We don't use a different max size depending on
6014 optimize_bb_for_speed_p because increasing shrink-wrapping
6015 opportunities by duplicating tail blocks can actually result
6016 in an overall decrease in code size. */
6017 max_grow_size
= get_uncond_jump_length ();
6018 max_grow_size
*= PARAM_VALUE (PARAM_MAX_GROW_COPY_BB_INSNS
);
6025 FOR_BB_INSNS (bb
, insn
)
6026 if (NONDEBUG_INSN_P (insn
))
6028 if (requires_stack_frame_p (insn
, prologue_used
,
6029 set_up_by_prologue
.set
))
6031 if (bb
== entry_edge
->dest
)
6032 goto fail_shrinkwrap
;
6033 bitmap_set_bit (&bb_flags
, bb
->index
);
6034 VEC_quick_push (basic_block
, vec
, bb
);
6037 else if (size
<= max_grow_size
)
6039 size
+= get_attr_min_length (insn
);
6040 if (size
> max_grow_size
)
6041 bitmap_set_bit (&bb_on_list
, bb
->index
);
6046 /* Blocks that really need a prologue, or are too big for tails. */
6047 bitmap_ior_into (&bb_on_list
, &bb_flags
);
6049 /* For every basic block that needs a prologue, mark all blocks
6050 reachable from it, so as to ensure they are also seen as
6051 requiring a prologue. */
6052 while (!VEC_empty (basic_block
, vec
))
6054 basic_block tmp_bb
= VEC_pop (basic_block
, vec
);
6056 FOR_EACH_EDGE (e
, ei
, tmp_bb
->succs
)
6057 if (e
->dest
!= EXIT_BLOCK_PTR
6058 && bitmap_set_bit (&bb_flags
, e
->dest
->index
))
6059 VEC_quick_push (basic_block
, vec
, e
->dest
);
6062 /* Find the set of basic blocks that need no prologue, have a
6063 single successor, can be duplicated, meet a max size
6064 requirement, and go to the exit via like blocks. */
6065 VEC_quick_push (basic_block
, vec
, EXIT_BLOCK_PTR
);
6066 while (!VEC_empty (basic_block
, vec
))
6068 basic_block tmp_bb
= VEC_pop (basic_block
, vec
);
6070 FOR_EACH_EDGE (e
, ei
, tmp_bb
->preds
)
6071 if (single_succ_p (e
->src
)
6072 && !bitmap_bit_p (&bb_on_list
, e
->src
->index
)
6073 && can_duplicate_block_p (e
->src
))
6078 /* If there is predecessor of e->src which doesn't
6079 need prologue and the edge is complex,
6080 we might not be able to redirect the branch
6081 to a copy of e->src. */
6082 FOR_EACH_EDGE (pe
, pei
, e
->src
->preds
)
6083 if ((pe
->flags
& EDGE_COMPLEX
) != 0
6084 && !bitmap_bit_p (&bb_flags
, pe
->src
->index
))
6086 if (pe
== NULL
&& bitmap_set_bit (&bb_tail
, e
->src
->index
))
6087 VEC_quick_push (basic_block
, vec
, e
->src
);
6091 /* Now walk backwards from every block that is marked as needing
6092 a prologue to compute the bb_antic_flags bitmap. Exclude
6093 tail blocks; They can be duplicated to be used on paths not
6094 needing a prologue. */
6095 bitmap_clear (&bb_on_list
);
6096 bitmap_and_compl (&bb_antic_flags
, &bb_flags
, &bb_tail
);
6099 if (!bitmap_bit_p (&bb_antic_flags
, bb
->index
))
6101 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
6102 if (!bitmap_bit_p (&bb_antic_flags
, e
->src
->index
)
6103 && bitmap_set_bit (&bb_on_list
, e
->src
->index
))
6104 VEC_quick_push (basic_block
, vec
, e
->src
);
6106 while (!VEC_empty (basic_block
, vec
))
6108 basic_block tmp_bb
= VEC_pop (basic_block
, vec
);
6109 bool all_set
= true;
6111 bitmap_clear_bit (&bb_on_list
, tmp_bb
->index
);
6112 FOR_EACH_EDGE (e
, ei
, tmp_bb
->succs
)
6113 if (!bitmap_bit_p (&bb_antic_flags
, e
->dest
->index
))
6121 bitmap_set_bit (&bb_antic_flags
, tmp_bb
->index
);
6122 FOR_EACH_EDGE (e
, ei
, tmp_bb
->preds
)
6123 if (!bitmap_bit_p (&bb_antic_flags
, e
->src
->index
)
6124 && bitmap_set_bit (&bb_on_list
, e
->src
->index
))
6125 VEC_quick_push (basic_block
, vec
, e
->src
);
6128 /* Find exactly one edge that leads to a block in ANTIC from
6129 a block that isn't. */
6130 if (!bitmap_bit_p (&bb_antic_flags
, entry_edge
->dest
->index
))
6133 if (!bitmap_bit_p (&bb_antic_flags
, bb
->index
))
6135 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
6136 if (!bitmap_bit_p (&bb_antic_flags
, e
->src
->index
))
6138 if (entry_edge
!= orig_entry_edge
)
6140 entry_edge
= orig_entry_edge
;
6142 fprintf (dump_file
, "More than one candidate edge.\n");
6143 goto fail_shrinkwrap
;
6146 fprintf (dump_file
, "Found candidate edge for "
6147 "shrink-wrapping, %d->%d.\n", e
->src
->index
,
6153 if (entry_edge
!= orig_entry_edge
)
6155 /* Test whether the prologue is known to clobber any register
6156 (other than FP or SP) which are live on the edge. */
6157 CLEAR_HARD_REG_BIT (prologue_clobbered
, STACK_POINTER_REGNUM
);
6158 if (frame_pointer_needed
)
6159 CLEAR_HARD_REG_BIT (prologue_clobbered
, HARD_FRAME_POINTER_REGNUM
);
6160 CLEAR_HARD_REG_SET (live_on_edge
);
6161 reg_set_to_hard_reg_set (&live_on_edge
,
6162 df_get_live_in (entry_edge
->dest
));
6163 if (hard_reg_set_intersect_p (live_on_edge
, prologue_clobbered
))
6165 entry_edge
= orig_entry_edge
;
6168 "Shrink-wrapping aborted due to clobber.\n");
6171 if (entry_edge
!= orig_entry_edge
)
6173 crtl
->shrink_wrapped
= true;
6175 fprintf (dump_file
, "Performing shrink-wrapping.\n");
6177 /* Find tail blocks reachable from both blocks needing a
6178 prologue and blocks not needing a prologue. */
6179 if (!bitmap_empty_p (&bb_tail
))
6182 bool some_pro
, some_no_pro
;
6183 if (!bitmap_bit_p (&bb_tail
, bb
->index
))
6185 some_pro
= some_no_pro
= false;
6186 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
6188 if (bitmap_bit_p (&bb_flags
, e
->src
->index
))
6193 if (some_pro
&& some_no_pro
)
6194 VEC_quick_push (basic_block
, vec
, bb
);
6196 bitmap_clear_bit (&bb_tail
, bb
->index
);
6198 /* Find the head of each tail. */
6199 while (!VEC_empty (basic_block
, vec
))
6201 basic_block tbb
= VEC_pop (basic_block
, vec
);
6203 if (!bitmap_bit_p (&bb_tail
, tbb
->index
))
6206 while (single_succ_p (tbb
))
6208 tbb
= single_succ (tbb
);
6209 bitmap_clear_bit (&bb_tail
, tbb
->index
);
6212 /* Now duplicate the tails. */
6213 if (!bitmap_empty_p (&bb_tail
))
6214 FOR_EACH_BB_REVERSE (bb
)
6216 basic_block copy_bb
, tbb
;
6220 if (!bitmap_clear_bit (&bb_tail
, bb
->index
))
6223 /* Create a copy of BB, instructions and all, for
6224 use on paths that don't need a prologue.
6225 Ideal placement of the copy is on a fall-thru edge
6226 or after a block that would jump to the copy. */
6227 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
6228 if (!bitmap_bit_p (&bb_flags
, e
->src
->index
)
6229 && single_succ_p (e
->src
))
6233 copy_bb
= create_basic_block (NEXT_INSN (BB_END (e
->src
)),
6235 BB_COPY_PARTITION (copy_bb
, e
->src
);
6239 /* Otherwise put the copy at the end of the function. */
6240 copy_bb
= create_basic_block (NULL_RTX
, NULL_RTX
,
6241 EXIT_BLOCK_PTR
->prev_bb
);
6242 BB_COPY_PARTITION (copy_bb
, bb
);
6245 insert_point
= emit_note_after (NOTE_INSN_DELETED
,
6247 emit_barrier_after (BB_END (copy_bb
));
6252 dup_block_and_redirect (tbb
, copy_bb
, insert_point
,
6254 tbb
= single_succ (tbb
);
6255 if (tbb
== EXIT_BLOCK_PTR
)
6257 e
= split_block (copy_bb
, PREV_INSN (insert_point
));
6261 /* Quiet verify_flow_info by (ab)using EDGE_FAKE.
6262 We have yet to add a simple_return to the tails,
6263 as we'd like to first convert_jumps_to_returns in
6264 case the block is no longer used after that. */
6266 if (CALL_P (PREV_INSN (insert_point
))
6267 && SIBLING_CALL_P (PREV_INSN (insert_point
)))
6268 eflags
= EDGE_SIBCALL
| EDGE_ABNORMAL
;
6269 make_single_succ_edge (copy_bb
, EXIT_BLOCK_PTR
, eflags
);
6271 /* verify_flow_info doesn't like a note after a
6273 delete_insn (insert_point
);
6274 if (bitmap_empty_p (&bb_tail
))
6280 bitmap_clear (&bb_tail
);
6281 bitmap_clear (&bb_antic_flags
);
6282 bitmap_clear (&bb_on_list
);
6283 VEC_free (basic_block
, heap
, vec
);
6287 if (split_prologue_seq
!= NULL_RTX
)
6289 insert_insn_on_edge (split_prologue_seq
, orig_entry_edge
);
6292 if (prologue_seq
!= NULL_RTX
)
6294 insert_insn_on_edge (prologue_seq
, entry_edge
);
6298 /* If the exit block has no non-fake predecessors, we don't need
6300 FOR_EACH_EDGE (e
, ei
, EXIT_BLOCK_PTR
->preds
)
6301 if ((e
->flags
& EDGE_FAKE
) == 0)
6306 rtl_profile_for_bb (EXIT_BLOCK_PTR
);
6308 exit_fallthru_edge
= find_fallthru_edge (EXIT_BLOCK_PTR
->preds
);
6310 /* If we're allowed to generate a simple return instruction, then by
6311 definition we don't need a full epilogue. If the last basic
6312 block before the exit block does not contain active instructions,
6313 examine its predecessors and try to emit (conditional) return
6315 #ifdef HAVE_simple_return
6316 if (entry_edge
!= orig_entry_edge
)
6322 /* convert_jumps_to_returns may add to EXIT_BLOCK_PTR->preds
6323 (but won't remove). Stop at end of current preds. */
6324 last
= EDGE_COUNT (EXIT_BLOCK_PTR
->preds
);
6325 for (i
= 0; i
< last
; i
++)
6327 e
= EDGE_I (EXIT_BLOCK_PTR
->preds
, i
);
6328 if (LABEL_P (BB_HEAD (e
->src
))
6329 && !bitmap_bit_p (&bb_flags
, e
->src
->index
)
6330 && !active_insn_between (BB_HEAD (e
->src
), BB_END (e
->src
)))
6331 unconverted_simple_returns
6332 = convert_jumps_to_returns (e
->src
, true,
6333 unconverted_simple_returns
);
6337 if (exit_fallthru_edge
!= NULL
6338 && EDGE_COUNT (exit_fallthru_edge
->src
->preds
) != 0
6339 && !bitmap_bit_p (&bb_flags
, exit_fallthru_edge
->src
->index
))
6341 basic_block last_bb
;
6343 last_bb
= emit_return_for_exit (exit_fallthru_edge
, true);
6344 returnjump
= BB_END (last_bb
);
6345 exit_fallthru_edge
= NULL
;
6352 if (exit_fallthru_edge
== NULL
)
6357 basic_block last_bb
= exit_fallthru_edge
->src
;
6359 if (LABEL_P (BB_HEAD (last_bb
))
6360 && !active_insn_between (BB_HEAD (last_bb
), BB_END (last_bb
)))
6361 convert_jumps_to_returns (last_bb
, false, NULL
);
6363 if (EDGE_COUNT (last_bb
->preds
) != 0
6364 && single_succ_p (last_bb
))
6366 last_bb
= emit_return_for_exit (exit_fallthru_edge
, false);
6367 epilogue_end
= returnjump
= BB_END (last_bb
);
6368 #ifdef HAVE_simple_return
6369 /* Emitting the return may add a basic block.
6370 Fix bb_flags for the added block. */
6371 if (last_bb
!= exit_fallthru_edge
->src
)
6372 bitmap_set_bit (&bb_flags
, last_bb
->index
);
6380 /* A small fib -- epilogue is not yet completed, but we wish to re-use
6381 this marker for the splits of EH_RETURN patterns, and nothing else
6382 uses the flag in the meantime. */
6383 epilogue_completed
= 1;
6385 #ifdef HAVE_eh_return
6386 /* Find non-fallthru edges that end with EH_RETURN instructions. On
6387 some targets, these get split to a special version of the epilogue
6388 code. In order to be able to properly annotate these with unwind
6389 info, try to split them now. If we get a valid split, drop an
6390 EPILOGUE_BEG note and mark the insns as epilogue insns. */
6391 FOR_EACH_EDGE (e
, ei
, EXIT_BLOCK_PTR
->preds
)
6393 rtx prev
, last
, trial
;
6395 if (e
->flags
& EDGE_FALLTHRU
)
6397 last
= BB_END (e
->src
);
6398 if (!eh_returnjump_p (last
))
6401 prev
= PREV_INSN (last
);
6402 trial
= try_split (PATTERN (last
), last
, 1);
6406 record_insns (NEXT_INSN (prev
), NEXT_INSN (trial
), &epilogue_insn_hash
);
6407 emit_note_after (NOTE_INSN_EPILOGUE_BEG
, prev
);
6411 /* If nothing falls through into the exit block, we don't need an
6414 if (exit_fallthru_edge
== NULL
)
6417 #ifdef HAVE_epilogue
6421 epilogue_end
= emit_note (NOTE_INSN_EPILOGUE_BEG
);
6422 seq
= gen_epilogue ();
6424 emit_jump_insn (seq
);
6426 /* Retain a map of the epilogue insns. */
6427 record_insns (seq
, NULL
, &epilogue_insn_hash
);
6428 set_insn_locators (seq
, epilogue_locator
);
6431 returnjump
= get_last_insn ();
6434 insert_insn_on_edge (seq
, exit_fallthru_edge
);
6437 if (JUMP_P (returnjump
))
6438 set_return_jump_label (returnjump
);
6445 if (! next_active_insn (BB_END (exit_fallthru_edge
->src
)))
6447 /* We have a fall-through edge to the exit block, the source is not
6448 at the end of the function, and there will be an assembler epilogue
6449 at the end of the function.
6450 We can't use force_nonfallthru here, because that would try to
6451 use return. Inserting a jump 'by hand' is extremely messy, so
6452 we take advantage of cfg_layout_finalize using
6453 fixup_fallthru_exit_predecessor. */
6454 cfg_layout_initialize (0);
6455 FOR_EACH_BB (cur_bb
)
6456 if (cur_bb
->index
>= NUM_FIXED_BLOCKS
6457 && cur_bb
->next_bb
->index
>= NUM_FIXED_BLOCKS
)
6458 cur_bb
->aux
= cur_bb
->next_bb
;
6459 cfg_layout_finalize ();
6464 default_rtl_profile ();
6470 commit_edge_insertions ();
6472 /* Look for basic blocks within the prologue insns. */
6473 blocks
= sbitmap_alloc (last_basic_block
);
6474 sbitmap_zero (blocks
);
6475 SET_BIT (blocks
, entry_edge
->dest
->index
);
6476 SET_BIT (blocks
, orig_entry_edge
->dest
->index
);
6477 find_many_sub_basic_blocks (blocks
);
6478 sbitmap_free (blocks
);
6480 /* The epilogue insns we inserted may cause the exit edge to no longer
6482 FOR_EACH_EDGE (e
, ei
, EXIT_BLOCK_PTR
->preds
)
6484 if (((e
->flags
& EDGE_FALLTHRU
) != 0)
6485 && returnjump_p (BB_END (e
->src
)))
6486 e
->flags
&= ~EDGE_FALLTHRU
;
6490 #ifdef HAVE_simple_return
6491 /* If there were branches to an empty LAST_BB which we tried to
6492 convert to conditional simple_returns, but couldn't for some
6493 reason, create a block to hold a simple_return insn and redirect
6494 those remaining edges. */
6495 if (!VEC_empty (edge
, unconverted_simple_returns
))
6497 basic_block simple_return_block_hot
= NULL
;
6498 basic_block simple_return_block_cold
= NULL
;
6499 edge pending_edge_hot
= NULL
;
6500 edge pending_edge_cold
= NULL
;
6501 basic_block exit_pred
= EXIT_BLOCK_PTR
->prev_bb
;
6504 gcc_assert (entry_edge
!= orig_entry_edge
);
6506 /* See if we can reuse the last insn that was emitted for the
6508 if (returnjump
!= NULL_RTX
6509 && JUMP_LABEL (returnjump
) == simple_return_rtx
)
6511 e
= split_block (BLOCK_FOR_INSN (returnjump
), PREV_INSN (returnjump
));
6512 if (BB_PARTITION (e
->src
) == BB_HOT_PARTITION
)
6513 simple_return_block_hot
= e
->dest
;
6515 simple_return_block_cold
= e
->dest
;
6518 /* Also check returns we might need to add to tail blocks. */
6519 FOR_EACH_EDGE (e
, ei
, EXIT_BLOCK_PTR
->preds
)
6520 if (EDGE_COUNT (e
->src
->preds
) != 0
6521 && (e
->flags
& EDGE_FAKE
) != 0
6522 && !bitmap_bit_p (&bb_flags
, e
->src
->index
))
6524 if (BB_PARTITION (e
->src
) == BB_HOT_PARTITION
)
6525 pending_edge_hot
= e
;
6527 pending_edge_cold
= e
;
6530 FOR_EACH_VEC_ELT (edge
, unconverted_simple_returns
, i
, e
)
6532 basic_block
*pdest_bb
;
6535 if (BB_PARTITION (e
->src
) == BB_HOT_PARTITION
)
6537 pdest_bb
= &simple_return_block_hot
;
6538 pending
= pending_edge_hot
;
6542 pdest_bb
= &simple_return_block_cold
;
6543 pending
= pending_edge_cold
;
6546 if (*pdest_bb
== NULL
&& pending
!= NULL
)
6548 emit_return_into_block (true, pending
->src
);
6549 pending
->flags
&= ~(EDGE_FALLTHRU
| EDGE_FAKE
);
6550 *pdest_bb
= pending
->src
;
6552 else if (*pdest_bb
== NULL
)
6557 bb
= create_basic_block (NULL
, NULL
, exit_pred
);
6558 BB_COPY_PARTITION (bb
, e
->src
);
6559 start
= emit_jump_insn_after (gen_simple_return (),
6561 JUMP_LABEL (start
) = simple_return_rtx
;
6562 emit_barrier_after (start
);
6565 make_edge (bb
, EXIT_BLOCK_PTR
, 0);
6567 redirect_edge_and_branch_force (e
, *pdest_bb
);
6569 VEC_free (edge
, heap
, unconverted_simple_returns
);
6572 if (entry_edge
!= orig_entry_edge
)
6574 FOR_EACH_EDGE (e
, ei
, EXIT_BLOCK_PTR
->preds
)
6575 if (EDGE_COUNT (e
->src
->preds
) != 0
6576 && (e
->flags
& EDGE_FAKE
) != 0
6577 && !bitmap_bit_p (&bb_flags
, e
->src
->index
))
6579 emit_return_into_block (true, e
->src
);
6580 e
->flags
&= ~(EDGE_FALLTHRU
| EDGE_FAKE
);
6585 #ifdef HAVE_sibcall_epilogue
6586 /* Emit sibling epilogues before any sibling call sites. */
6587 for (ei
= ei_start (EXIT_BLOCK_PTR
->preds
); (e
= ei_safe_edge (ei
)); )
6589 basic_block bb
= e
->src
;
6590 rtx insn
= BB_END (bb
);
6594 || ! SIBLING_CALL_P (insn
)
6595 #ifdef HAVE_simple_return
6596 || (entry_edge
!= orig_entry_edge
6597 && !bitmap_bit_p (&bb_flags
, bb
->index
))
6605 ep_seq
= gen_sibcall_epilogue ();
6609 emit_note (NOTE_INSN_EPILOGUE_BEG
);
6614 /* Retain a map of the epilogue insns. Used in life analysis to
6615 avoid getting rid of sibcall epilogue insns. Do this before we
6616 actually emit the sequence. */
6617 record_insns (seq
, NULL
, &epilogue_insn_hash
);
6618 set_insn_locators (seq
, epilogue_locator
);
6620 emit_insn_before (seq
, insn
);
6626 #ifdef HAVE_epilogue
6631 /* Similarly, move any line notes that appear after the epilogue.
6632 There is no need, however, to be quite so anal about the existence
6633 of such a note. Also possibly move
6634 NOTE_INSN_FUNCTION_BEG notes, as those can be relevant for debug
6636 for (insn
= epilogue_end
; insn
; insn
= next
)
6638 next
= NEXT_INSN (insn
);
6640 && (NOTE_KIND (insn
) == NOTE_INSN_FUNCTION_BEG
))
6641 reorder_insns (insn
, insn
, PREV_INSN (epilogue_end
));
6646 #ifdef HAVE_simple_return
6647 bitmap_clear (&bb_flags
);
6650 /* Threading the prologue and epilogue changes the artificial refs
6651 in the entry and exit blocks. */
6652 epilogue_completed
= 1;
6653 df_update_entry_exit_and_calls ();
6656 /* Reposition the prologue-end and epilogue-begin notes after
6657 instruction scheduling. */
6660 reposition_prologue_and_epilogue_notes (void)
6662 #if defined (HAVE_prologue) || defined (HAVE_epilogue) \
6663 || defined (HAVE_sibcall_epilogue)
6664 /* Since the hash table is created on demand, the fact that it is
6665 non-null is a signal that it is non-empty. */
6666 if (prologue_insn_hash
!= NULL
)
6668 size_t len
= htab_elements (prologue_insn_hash
);
6669 rtx insn
, last
= NULL
, note
= NULL
;
6671 /* Scan from the beginning until we reach the last prologue insn. */
6672 /* ??? While we do have the CFG intact, there are two problems:
6673 (1) The prologue can contain loops (typically probing the stack),
6674 which means that the end of the prologue isn't in the first bb.
6675 (2) Sometimes the PROLOGUE_END note gets pushed into the next bb. */
6676 for (insn
= get_insns (); insn
; insn
= NEXT_INSN (insn
))
6680 if (NOTE_KIND (insn
) == NOTE_INSN_PROLOGUE_END
)
6683 else if (contains (insn
, prologue_insn_hash
))
6695 /* Scan forward looking for the PROLOGUE_END note. It should
6696 be right at the beginning of the block, possibly with other
6697 insn notes that got moved there. */
6698 for (note
= NEXT_INSN (last
); ; note
= NEXT_INSN (note
))
6701 && NOTE_KIND (note
) == NOTE_INSN_PROLOGUE_END
)
6706 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
6708 last
= NEXT_INSN (last
);
6709 reorder_insns (note
, note
, last
);
6713 if (epilogue_insn_hash
!= NULL
)
6718 FOR_EACH_EDGE (e
, ei
, EXIT_BLOCK_PTR
->preds
)
6720 rtx insn
, first
= NULL
, note
= NULL
;
6721 basic_block bb
= e
->src
;
6723 /* Scan from the beginning until we reach the first epilogue insn. */
6724 FOR_BB_INSNS (bb
, insn
)
6728 if (NOTE_KIND (insn
) == NOTE_INSN_EPILOGUE_BEG
)
6735 else if (first
== NULL
&& contains (insn
, epilogue_insn_hash
))
6745 /* If the function has a single basic block, and no real
6746 epilogue insns (e.g. sibcall with no cleanup), the
6747 epilogue note can get scheduled before the prologue
6748 note. If we have frame related prologue insns, having
6749 them scanned during the epilogue will result in a crash.
6750 In this case re-order the epilogue note to just before
6751 the last insn in the block. */
6753 first
= BB_END (bb
);
6755 if (PREV_INSN (first
) != note
)
6756 reorder_insns (note
, note
, PREV_INSN (first
));
6760 #endif /* HAVE_prologue or HAVE_epilogue */
6763 /* Returns the name of function FN. */
6765 function_name (struct function
*fn
)
6769 return lang_hooks
.decl_printable_name (fn
->decl
, 2);
6772 /* Returns the name of the current function. */
6774 current_function_name (void)
6776 return function_name (cfun
);
6781 rest_of_handle_check_leaf_regs (void)
6783 #ifdef LEAF_REGISTERS
6784 crtl
->uses_only_leaf_regs
6785 = optimize
> 0 && only_leaf_regs_used () && leaf_function_p ();
6790 /* Insert a TYPE into the used types hash table of CFUN. */
6793 used_types_insert_helper (tree type
, struct function
*func
)
6795 if (type
!= NULL
&& func
!= NULL
)
6799 if (func
->used_types_hash
== NULL
)
6800 func
->used_types_hash
= htab_create_ggc (37, htab_hash_pointer
,
6801 htab_eq_pointer
, NULL
);
6802 slot
= htab_find_slot (func
->used_types_hash
, type
, INSERT
);
6808 /* Given a type, insert it into the used hash table in cfun. */
6810 used_types_insert (tree t
)
6812 while (POINTER_TYPE_P (t
) || TREE_CODE (t
) == ARRAY_TYPE
)
6817 if (TREE_CODE (t
) == ERROR_MARK
)
6819 if (TYPE_NAME (t
) == NULL_TREE
6820 || TYPE_NAME (t
) == TYPE_NAME (TYPE_MAIN_VARIANT (t
)))
6821 t
= TYPE_MAIN_VARIANT (t
);
6822 if (debug_info_level
> DINFO_LEVEL_NONE
)
6825 used_types_insert_helper (t
, cfun
);
6827 /* So this might be a type referenced by a global variable.
6828 Record that type so that we can later decide to emit its debug
6830 VEC_safe_push (tree
, gc
, types_used_by_cur_var_decl
, t
);
6834 /* Helper to Hash a struct types_used_by_vars_entry. */
6837 hash_types_used_by_vars_entry (const struct types_used_by_vars_entry
*entry
)
6839 gcc_assert (entry
&& entry
->var_decl
&& entry
->type
);
6841 return iterative_hash_object (entry
->type
,
6842 iterative_hash_object (entry
->var_decl
, 0));
6845 /* Hash function of the types_used_by_vars_entry hash table. */
6848 types_used_by_vars_do_hash (const void *x
)
6850 const struct types_used_by_vars_entry
*entry
=
6851 (const struct types_used_by_vars_entry
*) x
;
6853 return hash_types_used_by_vars_entry (entry
);
6856 /*Equality function of the types_used_by_vars_entry hash table. */
6859 types_used_by_vars_eq (const void *x1
, const void *x2
)
6861 const struct types_used_by_vars_entry
*e1
=
6862 (const struct types_used_by_vars_entry
*) x1
;
6863 const struct types_used_by_vars_entry
*e2
=
6864 (const struct types_used_by_vars_entry
*)x2
;
6866 return (e1
->var_decl
== e2
->var_decl
&& e1
->type
== e2
->type
);
6869 /* Inserts an entry into the types_used_by_vars_hash hash table. */
6872 types_used_by_var_decl_insert (tree type
, tree var_decl
)
6874 if (type
!= NULL
&& var_decl
!= NULL
)
6877 struct types_used_by_vars_entry e
;
6878 e
.var_decl
= var_decl
;
6880 if (types_used_by_vars_hash
== NULL
)
6881 types_used_by_vars_hash
=
6882 htab_create_ggc (37, types_used_by_vars_do_hash
,
6883 types_used_by_vars_eq
, NULL
);
6884 slot
= htab_find_slot_with_hash (types_used_by_vars_hash
, &e
,
6885 hash_types_used_by_vars_entry (&e
), INSERT
);
6888 struct types_used_by_vars_entry
*entry
;
6889 entry
= ggc_alloc_types_used_by_vars_entry ();
6891 entry
->var_decl
= var_decl
;
6897 struct rtl_opt_pass pass_leaf_regs
=
6901 "*leaf_regs", /* name */
6903 rest_of_handle_check_leaf_regs
, /* execute */
6906 0, /* static_pass_number */
6907 TV_NONE
, /* tv_id */
6908 0, /* properties_required */
6909 0, /* properties_provided */
6910 0, /* properties_destroyed */
6911 0, /* todo_flags_start */
6912 0 /* todo_flags_finish */
6917 rest_of_handle_thread_prologue_and_epilogue (void)
6920 cleanup_cfg (CLEANUP_EXPENSIVE
);
6922 /* On some machines, the prologue and epilogue code, or parts thereof,
6923 can be represented as RTL. Doing so lets us schedule insns between
6924 it and the rest of the code and also allows delayed branch
6925 scheduling to operate in the epilogue. */
6926 thread_prologue_and_epilogue_insns ();
6928 /* The stack usage info is finalized during prologue expansion. */
6929 if (flag_stack_usage_info
)
6930 output_stack_usage ();
6935 struct rtl_opt_pass pass_thread_prologue_and_epilogue
=
6939 "pro_and_epilogue", /* name */
6941 rest_of_handle_thread_prologue_and_epilogue
, /* execute */
6944 0, /* static_pass_number */
6945 TV_THREAD_PROLOGUE_AND_EPILOGUE
, /* tv_id */
6946 0, /* properties_required */
6947 0, /* properties_provided */
6948 0, /* properties_destroyed */
6949 TODO_verify_flow
, /* todo_flags_start */
6951 TODO_df_finish
| TODO_verify_rtl_sharing
|
6952 TODO_ggc_collect
/* todo_flags_finish */
6957 /* This mini-pass fixes fall-out from SSA in asm statements that have
6958 in-out constraints. Say you start with
6961 asm ("": "+mr" (inout));
6964 which is transformed very early to use explicit output and match operands:
6967 asm ("": "=mr" (inout) : "0" (inout));
6970 Or, after SSA and copyprop,
6972 asm ("": "=mr" (inout_2) : "0" (inout_1));
6975 Clearly inout_2 and inout_1 can't be coalesced easily anymore, as
6976 they represent two separate values, so they will get different pseudo
6977 registers during expansion. Then, since the two operands need to match
6978 per the constraints, but use different pseudo registers, reload can
6979 only register a reload for these operands. But reloads can only be
6980 satisfied by hardregs, not by memory, so we need a register for this
6981 reload, just because we are presented with non-matching operands.
6982 So, even though we allow memory for this operand, no memory can be
6983 used for it, just because the two operands don't match. This can
6984 cause reload failures on register-starved targets.
6986 So it's a symptom of reload not being able to use memory for reloads
6987 or, alternatively it's also a symptom of both operands not coming into
6988 reload as matching (in which case the pseudo could go to memory just
6989 fine, as the alternative allows it, and no reload would be necessary).
6990 We fix the latter problem here, by transforming
6992 asm ("": "=mr" (inout_2) : "0" (inout_1));
6997 asm ("": "=mr" (inout_2) : "0" (inout_2)); */
7000 match_asm_constraints_1 (rtx insn
, rtx
*p_sets
, int noutputs
)
7003 bool changed
= false;
7004 rtx op
= SET_SRC (p_sets
[0]);
7005 int ninputs
= ASM_OPERANDS_INPUT_LENGTH (op
);
7006 rtvec inputs
= ASM_OPERANDS_INPUT_VEC (op
);
7007 bool *output_matched
= XALLOCAVEC (bool, noutputs
);
7009 memset (output_matched
, 0, noutputs
* sizeof (bool));
7010 for (i
= 0; i
< ninputs
; i
++)
7012 rtx input
, output
, insns
;
7013 const char *constraint
= ASM_OPERANDS_INPUT_CONSTRAINT (op
, i
);
7017 if (*constraint
== '%')
7020 match
= strtoul (constraint
, &end
, 10);
7021 if (end
== constraint
)
7024 gcc_assert (match
< noutputs
);
7025 output
= SET_DEST (p_sets
[match
]);
7026 input
= RTVEC_ELT (inputs
, i
);
7027 /* Only do the transformation for pseudos. */
7028 if (! REG_P (output
)
7029 || rtx_equal_p (output
, input
)
7030 || (GET_MODE (input
) != VOIDmode
7031 && GET_MODE (input
) != GET_MODE (output
)))
7034 /* We can't do anything if the output is also used as input,
7035 as we're going to overwrite it. */
7036 for (j
= 0; j
< ninputs
; j
++)
7037 if (reg_overlap_mentioned_p (output
, RTVEC_ELT (inputs
, j
)))
7042 /* Avoid changing the same input several times. For
7043 asm ("" : "=mr" (out1), "=mr" (out2) : "0" (in), "1" (in));
7044 only change in once (to out1), rather than changing it
7045 first to out1 and afterwards to out2. */
7048 for (j
= 0; j
< noutputs
; j
++)
7049 if (output_matched
[j
] && input
== SET_DEST (p_sets
[j
]))
7054 output_matched
[match
] = true;
7057 emit_move_insn (output
, input
);
7058 insns
= get_insns ();
7060 emit_insn_before (insns
, insn
);
7062 /* Now replace all mentions of the input with output. We can't
7063 just replace the occurrence in inputs[i], as the register might
7064 also be used in some other input (or even in an address of an
7065 output), which would mean possibly increasing the number of
7066 inputs by one (namely 'output' in addition), which might pose
7067 a too complicated problem for reload to solve. E.g. this situation:
7069 asm ("" : "=r" (output), "=m" (input) : "0" (input))
7071 Here 'input' is used in two occurrences as input (once for the
7072 input operand, once for the address in the second output operand).
7073 If we would replace only the occurrence of the input operand (to
7074 make the matching) we would be left with this:
7077 asm ("" : "=r" (output), "=m" (input) : "0" (output))
7079 Now we suddenly have two different input values (containing the same
7080 value, but different pseudos) where we formerly had only one.
7081 With more complicated asms this might lead to reload failures
7082 which wouldn't have happen without this pass. So, iterate over
7083 all operands and replace all occurrences of the register used. */
7084 for (j
= 0; j
< noutputs
; j
++)
7085 if (!rtx_equal_p (SET_DEST (p_sets
[j
]), input
)
7086 && reg_overlap_mentioned_p (input
, SET_DEST (p_sets
[j
])))
7087 SET_DEST (p_sets
[j
]) = replace_rtx (SET_DEST (p_sets
[j
]),
7089 for (j
= 0; j
< ninputs
; j
++)
7090 if (reg_overlap_mentioned_p (input
, RTVEC_ELT (inputs
, j
)))
7091 RTVEC_ELT (inputs
, j
) = replace_rtx (RTVEC_ELT (inputs
, j
),
7098 df_insn_rescan (insn
);
7102 rest_of_match_asm_constraints (void)
7105 rtx insn
, pat
, *p_sets
;
7108 if (!crtl
->has_asm_statement
)
7111 df_set_flags (DF_DEFER_INSN_RESCAN
);
7114 FOR_BB_INSNS (bb
, insn
)
7119 pat
= PATTERN (insn
);
7120 if (GET_CODE (pat
) == PARALLEL
)
7121 p_sets
= &XVECEXP (pat
, 0, 0), noutputs
= XVECLEN (pat
, 0);
7122 else if (GET_CODE (pat
) == SET
)
7123 p_sets
= &PATTERN (insn
), noutputs
= 1;
7127 if (GET_CODE (*p_sets
) == SET
7128 && GET_CODE (SET_SRC (*p_sets
)) == ASM_OPERANDS
)
7129 match_asm_constraints_1 (insn
, p_sets
, noutputs
);
7133 return TODO_df_finish
;
7136 struct rtl_opt_pass pass_match_asm_constraints
=
7140 "asmcons", /* name */
7142 rest_of_match_asm_constraints
, /* execute */
7145 0, /* static_pass_number */
7146 TV_NONE
, /* tv_id */
7147 0, /* properties_required */
7148 0, /* properties_provided */
7149 0, /* properties_destroyed */
7150 0, /* todo_flags_start */
7151 0 /* todo_flags_finish */
7156 #include "gt-function.h"