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
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 2, 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 COPYING. If not, write to the Free
20 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
23 /* This file handles the generation of rtl code from tree structure
24 at the level of the function as a whole.
25 It creates the rtl expressions for parameters and auto variables
26 and has full responsibility for allocating stack slots.
28 `expand_function_start' is called at the beginning of a function,
29 before the function body is parsed, and `expand_function_end' is
30 called after parsing the body.
32 Call `assign_stack_local' to allocate a stack slot for a local variable.
33 This is usually done during the RTL generation for the function body,
34 but it can also be done in the reload pass when a pseudo-register does
35 not get a hard register. */
39 #include "coretypes.h"
50 #include "hard-reg-set.h"
51 #include "insn-config.h"
54 #include "basic-block.h"
59 #include "integrate.h"
60 #include "langhooks.h"
62 #include "cfglayout.h"
63 #include "tree-gimple.h"
64 #include "tree-pass.h"
70 #ifndef LOCAL_ALIGNMENT
71 #define LOCAL_ALIGNMENT(TYPE, ALIGNMENT) ALIGNMENT
74 #ifndef STACK_ALIGNMENT_NEEDED
75 #define STACK_ALIGNMENT_NEEDED 1
78 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
80 /* Some systems use __main in a way incompatible with its use in gcc, in these
81 cases use the macros NAME__MAIN to give a quoted symbol and SYMBOL__MAIN to
82 give the same symbol without quotes for an alternative entry point. You
83 must define both, or neither. */
85 #define NAME__MAIN "__main"
88 /* Round a value to the lowest integer less than it that is a multiple of
89 the required alignment. Avoid using division in case the value is
90 negative. Assume the alignment is a power of two. */
91 #define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1))
93 /* Similar, but round to the next highest integer that meets the
95 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
97 /* Nonzero if function being compiled doesn't contain any calls
98 (ignoring the prologue and epilogue). This is set prior to
99 local register allocation and is valid for the remaining
101 int current_function_is_leaf
;
103 /* Nonzero if function being compiled doesn't modify the stack pointer
104 (ignoring the prologue and epilogue). This is only valid after
105 pass_stack_ptr_mod has run. */
106 int current_function_sp_is_unchanging
;
108 /* Nonzero if the function being compiled is a leaf function which only
109 uses leaf registers. This is valid after reload (specifically after
110 sched2) and is useful only if the port defines LEAF_REGISTERS. */
111 int current_function_uses_only_leaf_regs
;
113 /* Nonzero once virtual register instantiation has been done.
114 assign_stack_local uses frame_pointer_rtx when this is nonzero.
115 calls.c:emit_library_call_value_1 uses it to set up
116 post-instantiation libcalls. */
117 int virtuals_instantiated
;
119 /* Assign unique numbers to labels generated for profiling, debugging, etc. */
120 static GTY(()) int funcdef_no
;
122 /* These variables hold pointers to functions to create and destroy
123 target specific, per-function data structures. */
124 struct machine_function
* (*init_machine_status
) (void);
126 /* The currently compiled function. */
127 struct function
*cfun
= 0;
129 /* These arrays record the INSN_UIDs of the prologue and epilogue insns. */
130 static VEC(int,heap
) *prologue
;
131 static VEC(int,heap
) *epilogue
;
133 /* Array of INSN_UIDs to hold the INSN_UIDs for each sibcall epilogue
135 static VEC(int,heap
) *sibcall_epilogue
;
137 /* In order to evaluate some expressions, such as function calls returning
138 structures in memory, we need to temporarily allocate stack locations.
139 We record each allocated temporary in the following structure.
141 Associated with each temporary slot is a nesting level. When we pop up
142 one level, all temporaries associated with the previous level are freed.
143 Normally, all temporaries are freed after the execution of the statement
144 in which they were created. However, if we are inside a ({...}) grouping,
145 the result may be in a temporary and hence must be preserved. If the
146 result could be in a temporary, we preserve it if we can determine which
147 one it is in. If we cannot determine which temporary may contain the
148 result, all temporaries are preserved. A temporary is preserved by
149 pretending it was allocated at the previous nesting level.
151 Automatic variables are also assigned temporary slots, at the nesting
152 level where they are defined. They are marked a "kept" so that
153 free_temp_slots will not free them. */
155 struct temp_slot
GTY(())
157 /* Points to next temporary slot. */
158 struct temp_slot
*next
;
159 /* Points to previous temporary slot. */
160 struct temp_slot
*prev
;
162 /* The rtx to used to reference the slot. */
164 /* The rtx used to represent the address if not the address of the
165 slot above. May be an EXPR_LIST if multiple addresses exist. */
167 /* The alignment (in bits) of the slot. */
169 /* The size, in units, of the slot. */
171 /* The type of the object in the slot, or zero if it doesn't correspond
172 to a type. We use this to determine whether a slot can be reused.
173 It can be reused if objects of the type of the new slot will always
174 conflict with objects of the type of the old slot. */
176 /* Nonzero if this temporary is currently in use. */
178 /* Nonzero if this temporary has its address taken. */
180 /* Nesting level at which this slot is being used. */
182 /* Nonzero if this should survive a call to free_temp_slots. */
184 /* The offset of the slot from the frame_pointer, including extra space
185 for alignment. This info is for combine_temp_slots. */
186 HOST_WIDE_INT base_offset
;
187 /* The size of the slot, including extra space for alignment. This
188 info is for combine_temp_slots. */
189 HOST_WIDE_INT full_size
;
192 /* Forward declarations. */
194 static rtx
assign_stack_local_1 (enum machine_mode
, HOST_WIDE_INT
, int,
196 static struct temp_slot
*find_temp_slot_from_address (rtx
);
197 static void pad_to_arg_alignment (struct args_size
*, int, struct args_size
*);
198 static void pad_below (struct args_size
*, enum machine_mode
, tree
);
199 static void reorder_blocks_1 (rtx
, tree
, VEC(tree
,heap
) **);
200 static int all_blocks (tree
, tree
*);
201 static tree
*get_block_vector (tree
, int *);
202 extern tree
debug_find_var_in_block_tree (tree
, tree
);
203 /* We always define `record_insns' even if it's not used so that we
204 can always export `prologue_epilogue_contains'. */
205 static void record_insns (rtx
, VEC(int,heap
) **) ATTRIBUTE_UNUSED
;
206 static int contains (rtx
, VEC(int,heap
) **);
208 static void emit_return_into_block (basic_block
);
210 #if defined(HAVE_epilogue) && defined(INCOMING_RETURN_ADDR_RTX)
211 static rtx
keep_stack_depressed (rtx
);
213 static void prepare_function_start (tree
);
214 static void do_clobber_return_reg (rtx
, void *);
215 static void do_use_return_reg (rtx
, void *);
216 static void set_insn_locators (rtx
, int) ATTRIBUTE_UNUSED
;
218 /* Pointer to chain of `struct function' for containing functions. */
219 struct function
*outer_function_chain
;
221 /* Given a function decl for a containing function,
222 return the `struct function' for it. */
225 find_function_data (tree decl
)
229 for (p
= outer_function_chain
; p
; p
= p
->outer
)
236 /* Save the current context for compilation of a nested function.
237 This is called from language-specific code. The caller should use
238 the enter_nested langhook to save any language-specific state,
239 since this function knows only about language-independent
243 push_function_context_to (tree context ATTRIBUTE_UNUSED
)
248 init_dummy_function_start ();
251 p
->outer
= outer_function_chain
;
252 outer_function_chain
= p
;
254 lang_hooks
.function
.enter_nested (p
);
260 push_function_context (void)
262 push_function_context_to (current_function_decl
);
265 /* Restore the last saved context, at the end of a nested function.
266 This function is called from language-specific code. */
269 pop_function_context_from (tree context ATTRIBUTE_UNUSED
)
271 struct function
*p
= outer_function_chain
;
274 outer_function_chain
= p
->outer
;
276 current_function_decl
= p
->decl
;
278 lang_hooks
.function
.leave_nested (p
);
280 /* Reset variables that have known state during rtx generation. */
281 virtuals_instantiated
= 0;
282 generating_concat_p
= 1;
286 pop_function_context (void)
288 pop_function_context_from (current_function_decl
);
291 /* Clear out all parts of the state in F that can safely be discarded
292 after the function has been parsed, but not compiled, to let
293 garbage collection reclaim the memory. */
296 free_after_parsing (struct function
*f
)
298 /* f->expr->forced_labels is used by code generation. */
299 /* f->emit->regno_reg_rtx is used by code generation. */
300 /* f->varasm is used by code generation. */
301 /* f->eh->eh_return_stub_label is used by code generation. */
303 lang_hooks
.function
.final (f
);
306 /* Clear out all parts of the state in F that can safely be discarded
307 after the function has been compiled, to let garbage collection
308 reclaim the memory. */
311 free_after_compilation (struct function
*f
)
313 VEC_free (int, heap
, prologue
);
314 VEC_free (int, heap
, epilogue
);
315 VEC_free (int, heap
, sibcall_epilogue
);
324 f
->x_avail_temp_slots
= NULL
;
325 f
->x_used_temp_slots
= NULL
;
326 f
->arg_offset_rtx
= NULL
;
327 f
->return_rtx
= NULL
;
328 f
->internal_arg_pointer
= NULL
;
329 f
->x_nonlocal_goto_handler_labels
= NULL
;
330 f
->x_return_label
= NULL
;
331 f
->x_naked_return_label
= NULL
;
332 f
->x_stack_slot_list
= NULL
;
333 f
->x_stack_check_probe_note
= NULL
;
334 f
->x_arg_pointer_save_area
= NULL
;
335 f
->x_parm_birth_insn
= NULL
;
336 f
->epilogue_delay_list
= NULL
;
339 /* Allocate fixed slots in the stack frame of the current function. */
341 /* Return size needed for stack frame based on slots so far allocated in
343 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
344 the caller may have to do that. */
347 get_func_frame_size (struct function
*f
)
349 if (FRAME_GROWS_DOWNWARD
)
350 return -f
->x_frame_offset
;
352 return f
->x_frame_offset
;
355 /* Return size needed for stack frame based on slots so far allocated.
356 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
357 the caller may have to do that. */
360 get_frame_size (void)
362 return get_func_frame_size (cfun
);
365 /* Issue an error message and return TRUE if frame OFFSET overflows in
366 the signed target pointer arithmetics for function FUNC. Otherwise
370 frame_offset_overflow (HOST_WIDE_INT offset
, tree func
)
372 unsigned HOST_WIDE_INT size
= FRAME_GROWS_DOWNWARD
? -offset
: offset
;
374 if (size
> ((unsigned HOST_WIDE_INT
) 1 << (GET_MODE_BITSIZE (Pmode
) - 1))
375 /* Leave room for the fixed part of the frame. */
376 - 64 * UNITS_PER_WORD
)
378 error ("%Jtotal size of local objects too large", func
);
385 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
386 with machine mode MODE.
388 ALIGN controls the amount of alignment for the address of the slot:
389 0 means according to MODE,
390 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
391 -2 means use BITS_PER_UNIT,
392 positive specifies alignment boundary in bits.
394 We do not round to stack_boundary here.
396 FUNCTION specifies the function to allocate in. */
399 assign_stack_local_1 (enum machine_mode mode
, HOST_WIDE_INT size
, int align
,
400 struct function
*function
)
403 int bigend_correction
= 0;
404 unsigned int alignment
;
405 int frame_off
, frame_alignment
, frame_phase
;
412 alignment
= BIGGEST_ALIGNMENT
;
414 alignment
= GET_MODE_ALIGNMENT (mode
);
416 /* Allow the target to (possibly) increase the alignment of this
418 type
= lang_hooks
.types
.type_for_mode (mode
, 0);
420 alignment
= LOCAL_ALIGNMENT (type
, alignment
);
422 alignment
/= BITS_PER_UNIT
;
424 else if (align
== -1)
426 alignment
= BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
;
427 size
= CEIL_ROUND (size
, alignment
);
429 else if (align
== -2)
430 alignment
= 1; /* BITS_PER_UNIT / BITS_PER_UNIT */
432 alignment
= align
/ BITS_PER_UNIT
;
434 if (FRAME_GROWS_DOWNWARD
)
435 function
->x_frame_offset
-= size
;
437 /* Ignore alignment we can't do with expected alignment of the boundary. */
438 if (alignment
* BITS_PER_UNIT
> PREFERRED_STACK_BOUNDARY
)
439 alignment
= PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
;
441 if (function
->stack_alignment_needed
< alignment
* BITS_PER_UNIT
)
442 function
->stack_alignment_needed
= alignment
* BITS_PER_UNIT
;
444 /* Calculate how many bytes the start of local variables is off from
446 frame_alignment
= PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
;
447 frame_off
= STARTING_FRAME_OFFSET
% frame_alignment
;
448 frame_phase
= frame_off
? frame_alignment
- frame_off
: 0;
450 /* Round the frame offset to the specified alignment. The default is
451 to always honor requests to align the stack but a port may choose to
452 do its own stack alignment by defining STACK_ALIGNMENT_NEEDED. */
453 if (STACK_ALIGNMENT_NEEDED
457 /* We must be careful here, since FRAME_OFFSET might be negative and
458 division with a negative dividend isn't as well defined as we might
459 like. So we instead assume that ALIGNMENT is a power of two and
460 use logical operations which are unambiguous. */
461 if (FRAME_GROWS_DOWNWARD
)
462 function
->x_frame_offset
463 = (FLOOR_ROUND (function
->x_frame_offset
- frame_phase
,
464 (unsigned HOST_WIDE_INT
) alignment
)
467 function
->x_frame_offset
468 = (CEIL_ROUND (function
->x_frame_offset
- frame_phase
,
469 (unsigned HOST_WIDE_INT
) alignment
)
473 /* On a big-endian machine, if we are allocating more space than we will use,
474 use the least significant bytes of those that are allocated. */
475 if (BYTES_BIG_ENDIAN
&& mode
!= BLKmode
&& GET_MODE_SIZE (mode
) < size
)
476 bigend_correction
= size
- GET_MODE_SIZE (mode
);
478 /* If we have already instantiated virtual registers, return the actual
479 address relative to the frame pointer. */
480 if (function
== cfun
&& virtuals_instantiated
)
481 addr
= plus_constant (frame_pointer_rtx
,
483 (frame_offset
+ bigend_correction
484 + STARTING_FRAME_OFFSET
, Pmode
));
486 addr
= plus_constant (virtual_stack_vars_rtx
,
488 (function
->x_frame_offset
+ bigend_correction
,
491 if (!FRAME_GROWS_DOWNWARD
)
492 function
->x_frame_offset
+= size
;
494 x
= gen_rtx_MEM (mode
, addr
);
495 MEM_NOTRAP_P (x
) = 1;
497 function
->x_stack_slot_list
498 = gen_rtx_EXPR_LIST (VOIDmode
, x
, function
->x_stack_slot_list
);
500 if (frame_offset_overflow (function
->x_frame_offset
, function
->decl
))
501 function
->x_frame_offset
= 0;
506 /* Wrapper around assign_stack_local_1; assign a local stack slot for the
510 assign_stack_local (enum machine_mode mode
, HOST_WIDE_INT size
, int align
)
512 return assign_stack_local_1 (mode
, size
, align
, cfun
);
516 /* Removes temporary slot TEMP from LIST. */
519 cut_slot_from_list (struct temp_slot
*temp
, struct temp_slot
**list
)
522 temp
->next
->prev
= temp
->prev
;
524 temp
->prev
->next
= temp
->next
;
528 temp
->prev
= temp
->next
= NULL
;
531 /* Inserts temporary slot TEMP to LIST. */
534 insert_slot_to_list (struct temp_slot
*temp
, struct temp_slot
**list
)
538 (*list
)->prev
= temp
;
543 /* Returns the list of used temp slots at LEVEL. */
545 static struct temp_slot
**
546 temp_slots_at_level (int level
)
548 if (level
>= (int) VEC_length (temp_slot_p
, used_temp_slots
))
549 VEC_safe_grow_cleared (temp_slot_p
, gc
, used_temp_slots
, level
+ 1);
551 return &(VEC_address (temp_slot_p
, used_temp_slots
)[level
]);
554 /* Returns the maximal temporary slot level. */
557 max_slot_level (void)
559 if (!used_temp_slots
)
562 return VEC_length (temp_slot_p
, used_temp_slots
) - 1;
565 /* Moves temporary slot TEMP to LEVEL. */
568 move_slot_to_level (struct temp_slot
*temp
, int level
)
570 cut_slot_from_list (temp
, temp_slots_at_level (temp
->level
));
571 insert_slot_to_list (temp
, temp_slots_at_level (level
));
575 /* Make temporary slot TEMP available. */
578 make_slot_available (struct temp_slot
*temp
)
580 cut_slot_from_list (temp
, temp_slots_at_level (temp
->level
));
581 insert_slot_to_list (temp
, &avail_temp_slots
);
586 /* Allocate a temporary stack slot and record it for possible later
589 MODE is the machine mode to be given to the returned rtx.
591 SIZE is the size in units of the space required. We do no rounding here
592 since assign_stack_local will do any required rounding.
594 KEEP is 1 if this slot is to be retained after a call to
595 free_temp_slots. Automatic variables for a block are allocated
596 with this flag. KEEP values of 2 or 3 were needed respectively
597 for variables whose lifetime is controlled by CLEANUP_POINT_EXPRs
598 or for SAVE_EXPRs, but they are now unused.
600 TYPE is the type that will be used for the stack slot. */
603 assign_stack_temp_for_type (enum machine_mode mode
, HOST_WIDE_INT size
,
607 struct temp_slot
*p
, *best_p
= 0, *selected
= NULL
, **pp
;
610 /* If SIZE is -1 it means that somebody tried to allocate a temporary
611 of a variable size. */
612 gcc_assert (size
!= -1);
614 /* These are now unused. */
615 gcc_assert (keep
<= 1);
618 align
= BIGGEST_ALIGNMENT
;
620 align
= GET_MODE_ALIGNMENT (mode
);
623 type
= lang_hooks
.types
.type_for_mode (mode
, 0);
626 align
= LOCAL_ALIGNMENT (type
, align
);
628 /* Try to find an available, already-allocated temporary of the proper
629 mode which meets the size and alignment requirements. Choose the
630 smallest one with the closest alignment.
632 If assign_stack_temp is called outside of the tree->rtl expansion,
633 we cannot reuse the stack slots (that may still refer to
634 VIRTUAL_STACK_VARS_REGNUM). */
635 if (!virtuals_instantiated
)
637 for (p
= avail_temp_slots
; p
; p
= p
->next
)
639 if (p
->align
>= align
&& p
->size
>= size
640 && GET_MODE (p
->slot
) == mode
641 && objects_must_conflict_p (p
->type
, type
)
642 && (best_p
== 0 || best_p
->size
> p
->size
643 || (best_p
->size
== p
->size
&& best_p
->align
> p
->align
)))
645 if (p
->align
== align
&& p
->size
== size
)
648 cut_slot_from_list (selected
, &avail_temp_slots
);
657 /* Make our best, if any, the one to use. */
661 cut_slot_from_list (selected
, &avail_temp_slots
);
663 /* If there are enough aligned bytes left over, make them into a new
664 temp_slot so that the extra bytes don't get wasted. Do this only
665 for BLKmode slots, so that we can be sure of the alignment. */
666 if (GET_MODE (best_p
->slot
) == BLKmode
)
668 int alignment
= best_p
->align
/ BITS_PER_UNIT
;
669 HOST_WIDE_INT rounded_size
= CEIL_ROUND (size
, alignment
);
671 if (best_p
->size
- rounded_size
>= alignment
)
673 p
= ggc_alloc (sizeof (struct temp_slot
));
674 p
->in_use
= p
->addr_taken
= 0;
675 p
->size
= best_p
->size
- rounded_size
;
676 p
->base_offset
= best_p
->base_offset
+ rounded_size
;
677 p
->full_size
= best_p
->full_size
- rounded_size
;
678 p
->slot
= adjust_address_nv (best_p
->slot
, BLKmode
, rounded_size
);
679 p
->align
= best_p
->align
;
681 p
->type
= best_p
->type
;
682 insert_slot_to_list (p
, &avail_temp_slots
);
684 stack_slot_list
= gen_rtx_EXPR_LIST (VOIDmode
, p
->slot
,
687 best_p
->size
= rounded_size
;
688 best_p
->full_size
= rounded_size
;
693 /* If we still didn't find one, make a new temporary. */
696 HOST_WIDE_INT frame_offset_old
= frame_offset
;
698 p
= ggc_alloc (sizeof (struct temp_slot
));
700 /* We are passing an explicit alignment request to assign_stack_local.
701 One side effect of that is assign_stack_local will not round SIZE
702 to ensure the frame offset remains suitably aligned.
704 So for requests which depended on the rounding of SIZE, we go ahead
705 and round it now. We also make sure ALIGNMENT is at least
706 BIGGEST_ALIGNMENT. */
707 gcc_assert (mode
!= BLKmode
|| align
== BIGGEST_ALIGNMENT
);
708 p
->slot
= assign_stack_local (mode
,
710 ? CEIL_ROUND (size
, (int) align
/ BITS_PER_UNIT
)
716 /* The following slot size computation is necessary because we don't
717 know the actual size of the temporary slot until assign_stack_local
718 has performed all the frame alignment and size rounding for the
719 requested temporary. Note that extra space added for alignment
720 can be either above or below this stack slot depending on which
721 way the frame grows. We include the extra space if and only if it
722 is above this slot. */
723 if (FRAME_GROWS_DOWNWARD
)
724 p
->size
= frame_offset_old
- frame_offset
;
728 /* Now define the fields used by combine_temp_slots. */
729 if (FRAME_GROWS_DOWNWARD
)
731 p
->base_offset
= frame_offset
;
732 p
->full_size
= frame_offset_old
- frame_offset
;
736 p
->base_offset
= frame_offset_old
;
737 p
->full_size
= frame_offset
- frame_offset_old
;
748 p
->level
= temp_slot_level
;
751 pp
= temp_slots_at_level (p
->level
);
752 insert_slot_to_list (p
, pp
);
754 /* Create a new MEM rtx to avoid clobbering MEM flags of old slots. */
755 slot
= gen_rtx_MEM (mode
, XEXP (p
->slot
, 0));
756 stack_slot_list
= gen_rtx_EXPR_LIST (VOIDmode
, slot
, stack_slot_list
);
758 /* If we know the alias set for the memory that will be used, use
759 it. If there's no TYPE, then we don't know anything about the
760 alias set for the memory. */
761 set_mem_alias_set (slot
, type
? get_alias_set (type
) : 0);
762 set_mem_align (slot
, align
);
764 /* If a type is specified, set the relevant flags. */
767 MEM_VOLATILE_P (slot
) = TYPE_VOLATILE (type
);
768 MEM_SET_IN_STRUCT_P (slot
, (AGGREGATE_TYPE_P (type
)
769 || TREE_CODE (type
) == COMPLEX_TYPE
));
771 MEM_NOTRAP_P (slot
) = 1;
776 /* Allocate a temporary stack slot and record it for possible later
777 reuse. First three arguments are same as in preceding function. */
780 assign_stack_temp (enum machine_mode mode
, HOST_WIDE_INT size
, int keep
)
782 return assign_stack_temp_for_type (mode
, size
, keep
, NULL_TREE
);
785 /* Assign a temporary.
786 If TYPE_OR_DECL is a decl, then we are doing it on behalf of the decl
787 and so that should be used in error messages. In either case, we
788 allocate of the given type.
789 KEEP is as for assign_stack_temp.
790 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
791 it is 0 if a register is OK.
792 DONT_PROMOTE is 1 if we should not promote values in register
796 assign_temp (tree type_or_decl
, int keep
, int memory_required
,
797 int dont_promote ATTRIBUTE_UNUSED
)
800 enum machine_mode mode
;
805 if (DECL_P (type_or_decl
))
806 decl
= type_or_decl
, type
= TREE_TYPE (decl
);
808 decl
= NULL
, type
= type_or_decl
;
810 mode
= TYPE_MODE (type
);
812 unsignedp
= TYPE_UNSIGNED (type
);
815 if (mode
== BLKmode
|| memory_required
)
817 HOST_WIDE_INT size
= int_size_in_bytes (type
);
820 /* Zero sized arrays are GNU C extension. Set size to 1 to avoid
821 problems with allocating the stack space. */
825 /* Unfortunately, we don't yet know how to allocate variable-sized
826 temporaries. However, sometimes we can find a fixed upper limit on
827 the size, so try that instead. */
829 size
= max_int_size_in_bytes (type
);
831 /* The size of the temporary may be too large to fit into an integer. */
832 /* ??? Not sure this should happen except for user silliness, so limit
833 this to things that aren't compiler-generated temporaries. The
834 rest of the time we'll die in assign_stack_temp_for_type. */
835 if (decl
&& size
== -1
836 && TREE_CODE (TYPE_SIZE_UNIT (type
)) == INTEGER_CST
)
838 error ("size of variable %q+D is too large", decl
);
842 tmp
= assign_stack_temp_for_type (mode
, size
, keep
, type
);
848 mode
= promote_mode (type
, mode
, &unsignedp
, 0);
851 return gen_reg_rtx (mode
);
854 /* Combine temporary stack slots which are adjacent on the stack.
856 This allows for better use of already allocated stack space. This is only
857 done for BLKmode slots because we can be sure that we won't have alignment
858 problems in this case. */
861 combine_temp_slots (void)
863 struct temp_slot
*p
, *q
, *next
, *next_q
;
866 /* We can't combine slots, because the information about which slot
867 is in which alias set will be lost. */
868 if (flag_strict_aliasing
)
871 /* If there are a lot of temp slots, don't do anything unless
872 high levels of optimization. */
873 if (! flag_expensive_optimizations
)
874 for (p
= avail_temp_slots
, num_slots
= 0; p
; p
= p
->next
, num_slots
++)
875 if (num_slots
> 100 || (num_slots
> 10 && optimize
== 0))
878 for (p
= avail_temp_slots
; p
; p
= next
)
884 if (GET_MODE (p
->slot
) != BLKmode
)
887 for (q
= p
->next
; q
; q
= next_q
)
893 if (GET_MODE (q
->slot
) != BLKmode
)
896 if (p
->base_offset
+ p
->full_size
== q
->base_offset
)
898 /* Q comes after P; combine Q into P. */
900 p
->full_size
+= q
->full_size
;
903 else if (q
->base_offset
+ q
->full_size
== p
->base_offset
)
905 /* P comes after Q; combine P into Q. */
907 q
->full_size
+= p
->full_size
;
912 cut_slot_from_list (q
, &avail_temp_slots
);
915 /* Either delete P or advance past it. */
917 cut_slot_from_list (p
, &avail_temp_slots
);
921 /* Find the temp slot corresponding to the object at address X. */
923 static struct temp_slot
*
924 find_temp_slot_from_address (rtx x
)
930 for (i
= max_slot_level (); i
>= 0; i
--)
931 for (p
= *temp_slots_at_level (i
); p
; p
= p
->next
)
933 if (XEXP (p
->slot
, 0) == x
935 || (GET_CODE (x
) == PLUS
936 && XEXP (x
, 0) == virtual_stack_vars_rtx
937 && GET_CODE (XEXP (x
, 1)) == CONST_INT
938 && INTVAL (XEXP (x
, 1)) >= p
->base_offset
939 && INTVAL (XEXP (x
, 1)) < p
->base_offset
+ p
->full_size
))
942 else if (p
->address
!= 0 && GET_CODE (p
->address
) == EXPR_LIST
)
943 for (next
= p
->address
; next
; next
= XEXP (next
, 1))
944 if (XEXP (next
, 0) == x
)
948 /* If we have a sum involving a register, see if it points to a temp
950 if (GET_CODE (x
) == PLUS
&& REG_P (XEXP (x
, 0))
951 && (p
= find_temp_slot_from_address (XEXP (x
, 0))) != 0)
953 else if (GET_CODE (x
) == PLUS
&& REG_P (XEXP (x
, 1))
954 && (p
= find_temp_slot_from_address (XEXP (x
, 1))) != 0)
960 /* Indicate that NEW is an alternate way of referring to the temp slot
961 that previously was known by OLD. */
964 update_temp_slot_address (rtx old
, rtx
new)
968 if (rtx_equal_p (old
, new))
971 p
= find_temp_slot_from_address (old
);
973 /* If we didn't find one, see if both OLD is a PLUS. If so, and NEW
974 is a register, see if one operand of the PLUS is a temporary
975 location. If so, NEW points into it. Otherwise, if both OLD and
976 NEW are a PLUS and if there is a register in common between them.
977 If so, try a recursive call on those values. */
980 if (GET_CODE (old
) != PLUS
)
985 update_temp_slot_address (XEXP (old
, 0), new);
986 update_temp_slot_address (XEXP (old
, 1), new);
989 else if (GET_CODE (new) != PLUS
)
992 if (rtx_equal_p (XEXP (old
, 0), XEXP (new, 0)))
993 update_temp_slot_address (XEXP (old
, 1), XEXP (new, 1));
994 else if (rtx_equal_p (XEXP (old
, 1), XEXP (new, 0)))
995 update_temp_slot_address (XEXP (old
, 0), XEXP (new, 1));
996 else if (rtx_equal_p (XEXP (old
, 0), XEXP (new, 1)))
997 update_temp_slot_address (XEXP (old
, 1), XEXP (new, 0));
998 else if (rtx_equal_p (XEXP (old
, 1), XEXP (new, 1)))
999 update_temp_slot_address (XEXP (old
, 0), XEXP (new, 0));
1004 /* Otherwise add an alias for the temp's address. */
1005 else if (p
->address
== 0)
1009 if (GET_CODE (p
->address
) != EXPR_LIST
)
1010 p
->address
= gen_rtx_EXPR_LIST (VOIDmode
, p
->address
, NULL_RTX
);
1012 p
->address
= gen_rtx_EXPR_LIST (VOIDmode
, new, p
->address
);
1016 /* If X could be a reference to a temporary slot, mark the fact that its
1017 address was taken. */
1020 mark_temp_addr_taken (rtx x
)
1022 struct temp_slot
*p
;
1027 /* If X is not in memory or is at a constant address, it cannot be in
1028 a temporary slot. */
1029 if (!MEM_P (x
) || CONSTANT_P (XEXP (x
, 0)))
1032 p
= find_temp_slot_from_address (XEXP (x
, 0));
1037 /* If X could be a reference to a temporary slot, mark that slot as
1038 belonging to the to one level higher than the current level. If X
1039 matched one of our slots, just mark that one. Otherwise, we can't
1040 easily predict which it is, so upgrade all of them. Kept slots
1041 need not be touched.
1043 This is called when an ({...}) construct occurs and a statement
1044 returns a value in memory. */
1047 preserve_temp_slots (rtx x
)
1049 struct temp_slot
*p
= 0, *next
;
1051 /* If there is no result, we still might have some objects whose address
1052 were taken, so we need to make sure they stay around. */
1055 for (p
= *temp_slots_at_level (temp_slot_level
); p
; p
= next
)
1060 move_slot_to_level (p
, temp_slot_level
- 1);
1066 /* If X is a register that is being used as a pointer, see if we have
1067 a temporary slot we know it points to. To be consistent with
1068 the code below, we really should preserve all non-kept slots
1069 if we can't find a match, but that seems to be much too costly. */
1070 if (REG_P (x
) && REG_POINTER (x
))
1071 p
= find_temp_slot_from_address (x
);
1073 /* If X is not in memory or is at a constant address, it cannot be in
1074 a temporary slot, but it can contain something whose address was
1076 if (p
== 0 && (!MEM_P (x
) || CONSTANT_P (XEXP (x
, 0))))
1078 for (p
= *temp_slots_at_level (temp_slot_level
); p
; p
= next
)
1083 move_slot_to_level (p
, temp_slot_level
- 1);
1089 /* First see if we can find a match. */
1091 p
= find_temp_slot_from_address (XEXP (x
, 0));
1095 /* Move everything at our level whose address was taken to our new
1096 level in case we used its address. */
1097 struct temp_slot
*q
;
1099 if (p
->level
== temp_slot_level
)
1101 for (q
= *temp_slots_at_level (temp_slot_level
); q
; q
= next
)
1105 if (p
!= q
&& q
->addr_taken
)
1106 move_slot_to_level (q
, temp_slot_level
- 1);
1109 move_slot_to_level (p
, temp_slot_level
- 1);
1115 /* Otherwise, preserve all non-kept slots at this level. */
1116 for (p
= *temp_slots_at_level (temp_slot_level
); p
; p
= next
)
1121 move_slot_to_level (p
, temp_slot_level
- 1);
1125 /* Free all temporaries used so far. This is normally called at the
1126 end of generating code for a statement. */
1129 free_temp_slots (void)
1131 struct temp_slot
*p
, *next
;
1133 for (p
= *temp_slots_at_level (temp_slot_level
); p
; p
= next
)
1138 make_slot_available (p
);
1141 combine_temp_slots ();
1144 /* Push deeper into the nesting level for stack temporaries. */
1147 push_temp_slots (void)
1152 /* Pop a temporary nesting level. All slots in use in the current level
1156 pop_temp_slots (void)
1158 struct temp_slot
*p
, *next
;
1160 for (p
= *temp_slots_at_level (temp_slot_level
); p
; p
= next
)
1163 make_slot_available (p
);
1166 combine_temp_slots ();
1171 /* Initialize temporary slots. */
1174 init_temp_slots (void)
1176 /* We have not allocated any temporaries yet. */
1177 avail_temp_slots
= 0;
1178 used_temp_slots
= 0;
1179 temp_slot_level
= 0;
1182 /* These routines are responsible for converting virtual register references
1183 to the actual hard register references once RTL generation is complete.
1185 The following four variables are used for communication between the
1186 routines. They contain the offsets of the virtual registers from their
1187 respective hard registers. */
1189 static int in_arg_offset
;
1190 static int var_offset
;
1191 static int dynamic_offset
;
1192 static int out_arg_offset
;
1193 static int cfa_offset
;
1195 /* In most machines, the stack pointer register is equivalent to the bottom
1198 #ifndef STACK_POINTER_OFFSET
1199 #define STACK_POINTER_OFFSET 0
1202 /* If not defined, pick an appropriate default for the offset of dynamically
1203 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
1204 REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
1206 #ifndef STACK_DYNAMIC_OFFSET
1208 /* The bottom of the stack points to the actual arguments. If
1209 REG_PARM_STACK_SPACE is defined, this includes the space for the register
1210 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
1211 stack space for register parameters is not pushed by the caller, but
1212 rather part of the fixed stack areas and hence not included in
1213 `current_function_outgoing_args_size'. Nevertheless, we must allow
1214 for it when allocating stack dynamic objects. */
1216 #if defined(REG_PARM_STACK_SPACE)
1217 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1218 ((ACCUMULATE_OUTGOING_ARGS \
1219 ? (current_function_outgoing_args_size \
1220 + (OUTGOING_REG_PARM_STACK_SPACE ? 0 : REG_PARM_STACK_SPACE (FNDECL))) \
1221 : 0) + (STACK_POINTER_OFFSET))
1223 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1224 ((ACCUMULATE_OUTGOING_ARGS ? current_function_outgoing_args_size : 0) \
1225 + (STACK_POINTER_OFFSET))
1230 /* Given a piece of RTX and a pointer to a HOST_WIDE_INT, if the RTX
1231 is a virtual register, return the equivalent hard register and set the
1232 offset indirectly through the pointer. Otherwise, return 0. */
1235 instantiate_new_reg (rtx x
, HOST_WIDE_INT
*poffset
)
1238 HOST_WIDE_INT offset
;
1240 if (x
== virtual_incoming_args_rtx
)
1241 new = arg_pointer_rtx
, offset
= in_arg_offset
;
1242 else if (x
== virtual_stack_vars_rtx
)
1243 new = frame_pointer_rtx
, offset
= var_offset
;
1244 else if (x
== virtual_stack_dynamic_rtx
)
1245 new = stack_pointer_rtx
, offset
= dynamic_offset
;
1246 else if (x
== virtual_outgoing_args_rtx
)
1247 new = stack_pointer_rtx
, offset
= out_arg_offset
;
1248 else if (x
== virtual_cfa_rtx
)
1250 #ifdef FRAME_POINTER_CFA_OFFSET
1251 new = frame_pointer_rtx
;
1253 new = arg_pointer_rtx
;
1255 offset
= cfa_offset
;
1264 /* A subroutine of instantiate_virtual_regs, called via for_each_rtx.
1265 Instantiate any virtual registers present inside of *LOC. The expression
1266 is simplified, as much as possible, but is not to be considered "valid"
1267 in any sense implied by the target. If any change is made, set CHANGED
1271 instantiate_virtual_regs_in_rtx (rtx
*loc
, void *data
)
1273 HOST_WIDE_INT offset
;
1274 bool *changed
= (bool *) data
;
1281 switch (GET_CODE (x
))
1284 new = instantiate_new_reg (x
, &offset
);
1287 *loc
= plus_constant (new, offset
);
1294 new = instantiate_new_reg (XEXP (x
, 0), &offset
);
1297 new = plus_constant (new, offset
);
1298 *loc
= simplify_gen_binary (PLUS
, GET_MODE (x
), new, XEXP (x
, 1));
1304 /* FIXME -- from old code */
1305 /* If we have (plus (subreg (virtual-reg)) (const_int)), we know
1306 we can commute the PLUS and SUBREG because pointers into the
1307 frame are well-behaved. */
1317 /* A subroutine of instantiate_virtual_regs_in_insn. Return true if X
1318 matches the predicate for insn CODE operand OPERAND. */
1321 safe_insn_predicate (int code
, int operand
, rtx x
)
1323 const struct insn_operand_data
*op_data
;
1328 op_data
= &insn_data
[code
].operand
[operand
];
1329 if (op_data
->predicate
== NULL
)
1332 return op_data
->predicate (x
, op_data
->mode
);
1335 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1336 registers present inside of insn. The result will be a valid insn. */
1339 instantiate_virtual_regs_in_insn (rtx insn
)
1341 HOST_WIDE_INT offset
;
1343 bool any_change
= false;
1344 rtx set
, new, x
, seq
;
1346 /* There are some special cases to be handled first. */
1347 set
= single_set (insn
);
1350 /* We're allowed to assign to a virtual register. This is interpreted
1351 to mean that the underlying register gets assigned the inverse
1352 transformation. This is used, for example, in the handling of
1354 new = instantiate_new_reg (SET_DEST (set
), &offset
);
1359 for_each_rtx (&SET_SRC (set
), instantiate_virtual_regs_in_rtx
, NULL
);
1360 x
= simplify_gen_binary (PLUS
, GET_MODE (new), SET_SRC (set
),
1362 x
= force_operand (x
, new);
1364 emit_move_insn (new, x
);
1369 emit_insn_before (seq
, insn
);
1374 /* Handle a straight copy from a virtual register by generating a
1375 new add insn. The difference between this and falling through
1376 to the generic case is avoiding a new pseudo and eliminating a
1377 move insn in the initial rtl stream. */
1378 new = instantiate_new_reg (SET_SRC (set
), &offset
);
1379 if (new && offset
!= 0
1380 && REG_P (SET_DEST (set
))
1381 && REGNO (SET_DEST (set
)) > LAST_VIRTUAL_REGISTER
)
1385 x
= expand_simple_binop (GET_MODE (SET_DEST (set
)), PLUS
,
1386 new, GEN_INT (offset
), SET_DEST (set
),
1387 1, OPTAB_LIB_WIDEN
);
1388 if (x
!= SET_DEST (set
))
1389 emit_move_insn (SET_DEST (set
), x
);
1394 emit_insn_before (seq
, insn
);
1399 extract_insn (insn
);
1400 insn_code
= INSN_CODE (insn
);
1402 /* Handle a plus involving a virtual register by determining if the
1403 operands remain valid if they're modified in place. */
1404 if (GET_CODE (SET_SRC (set
)) == PLUS
1405 && recog_data
.n_operands
>= 3
1406 && recog_data
.operand_loc
[1] == &XEXP (SET_SRC (set
), 0)
1407 && recog_data
.operand_loc
[2] == &XEXP (SET_SRC (set
), 1)
1408 && GET_CODE (recog_data
.operand
[2]) == CONST_INT
1409 && (new = instantiate_new_reg (recog_data
.operand
[1], &offset
)))
1411 offset
+= INTVAL (recog_data
.operand
[2]);
1413 /* If the sum is zero, then replace with a plain move. */
1415 && REG_P (SET_DEST (set
))
1416 && REGNO (SET_DEST (set
)) > LAST_VIRTUAL_REGISTER
)
1419 emit_move_insn (SET_DEST (set
), new);
1423 emit_insn_before (seq
, insn
);
1428 x
= gen_int_mode (offset
, recog_data
.operand_mode
[2]);
1430 /* Using validate_change and apply_change_group here leaves
1431 recog_data in an invalid state. Since we know exactly what
1432 we want to check, do those two by hand. */
1433 if (safe_insn_predicate (insn_code
, 1, new)
1434 && safe_insn_predicate (insn_code
, 2, x
))
1436 *recog_data
.operand_loc
[1] = recog_data
.operand
[1] = new;
1437 *recog_data
.operand_loc
[2] = recog_data
.operand
[2] = x
;
1440 /* Fall through into the regular operand fixup loop in
1441 order to take care of operands other than 1 and 2. */
1447 extract_insn (insn
);
1448 insn_code
= INSN_CODE (insn
);
1451 /* In the general case, we expect virtual registers to appear only in
1452 operands, and then only as either bare registers or inside memories. */
1453 for (i
= 0; i
< recog_data
.n_operands
; ++i
)
1455 x
= recog_data
.operand
[i
];
1456 switch (GET_CODE (x
))
1460 rtx addr
= XEXP (x
, 0);
1461 bool changed
= false;
1463 for_each_rtx (&addr
, instantiate_virtual_regs_in_rtx
, &changed
);
1468 x
= replace_equiv_address (x
, addr
);
1472 emit_insn_before (seq
, insn
);
1477 new = instantiate_new_reg (x
, &offset
);
1486 /* Careful, special mode predicates may have stuff in
1487 insn_data[insn_code].operand[i].mode that isn't useful
1488 to us for computing a new value. */
1489 /* ??? Recognize address_operand and/or "p" constraints
1490 to see if (plus new offset) is a valid before we put
1491 this through expand_simple_binop. */
1492 x
= expand_simple_binop (GET_MODE (x
), PLUS
, new,
1493 GEN_INT (offset
), NULL_RTX
,
1494 1, OPTAB_LIB_WIDEN
);
1497 emit_insn_before (seq
, insn
);
1502 new = instantiate_new_reg (SUBREG_REG (x
), &offset
);
1508 new = expand_simple_binop (GET_MODE (new), PLUS
, new,
1509 GEN_INT (offset
), NULL_RTX
,
1510 1, OPTAB_LIB_WIDEN
);
1513 emit_insn_before (seq
, insn
);
1515 x
= simplify_gen_subreg (recog_data
.operand_mode
[i
], new,
1516 GET_MODE (new), SUBREG_BYTE (x
));
1523 /* At this point, X contains the new value for the operand.
1524 Validate the new value vs the insn predicate. Note that
1525 asm insns will have insn_code -1 here. */
1526 if (!safe_insn_predicate (insn_code
, i
, x
))
1529 x
= force_reg (insn_data
[insn_code
].operand
[i
].mode
, x
);
1533 emit_insn_before (seq
, insn
);
1536 *recog_data
.operand_loc
[i
] = recog_data
.operand
[i
] = x
;
1542 /* Propagate operand changes into the duplicates. */
1543 for (i
= 0; i
< recog_data
.n_dups
; ++i
)
1544 *recog_data
.dup_loc
[i
]
1545 = copy_rtx (recog_data
.operand
[(unsigned)recog_data
.dup_num
[i
]]);
1547 /* Force re-recognition of the instruction for validation. */
1548 INSN_CODE (insn
) = -1;
1551 if (asm_noperands (PATTERN (insn
)) >= 0)
1553 if (!check_asm_operands (PATTERN (insn
)))
1555 error_for_asm (insn
, "impossible constraint in %<asm%>");
1561 if (recog_memoized (insn
) < 0)
1562 fatal_insn_not_found (insn
);
1566 /* Subroutine of instantiate_decls. Given RTL representing a decl,
1567 do any instantiation required. */
1570 instantiate_decl (rtx x
)
1577 /* If this is a CONCAT, recurse for the pieces. */
1578 if (GET_CODE (x
) == CONCAT
)
1580 instantiate_decl (XEXP (x
, 0));
1581 instantiate_decl (XEXP (x
, 1));
1585 /* If this is not a MEM, no need to do anything. Similarly if the
1586 address is a constant or a register that is not a virtual register. */
1591 if (CONSTANT_P (addr
)
1593 && (REGNO (addr
) < FIRST_VIRTUAL_REGISTER
1594 || REGNO (addr
) > LAST_VIRTUAL_REGISTER
)))
1597 for_each_rtx (&XEXP (x
, 0), instantiate_virtual_regs_in_rtx
, NULL
);
1600 /* Helper for instantiate_decls called via walk_tree: Process all decls
1601 in the given DECL_VALUE_EXPR. */
1604 instantiate_expr (tree
*tp
, int *walk_subtrees
, void *data ATTRIBUTE_UNUSED
)
1607 if (! EXPR_P (t
) && ! GIMPLE_STMT_P (t
))
1610 if (DECL_P (t
) && DECL_RTL_SET_P (t
))
1611 instantiate_decl (DECL_RTL (t
));
1616 /* Subroutine of instantiate_decls: Process all decls in the given
1617 BLOCK node and all its subblocks. */
1620 instantiate_decls_1 (tree let
)
1624 for (t
= BLOCK_VARS (let
); t
; t
= TREE_CHAIN (t
))
1626 if (DECL_RTL_SET_P (t
))
1627 instantiate_decl (DECL_RTL (t
));
1628 if (TREE_CODE (t
) == VAR_DECL
&& DECL_HAS_VALUE_EXPR_P (t
))
1630 tree v
= DECL_VALUE_EXPR (t
);
1631 walk_tree (&v
, instantiate_expr
, NULL
, NULL
);
1635 /* Process all subblocks. */
1636 for (t
= BLOCK_SUBBLOCKS (let
); t
; t
= TREE_CHAIN (t
))
1637 instantiate_decls_1 (t
);
1640 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
1641 all virtual registers in their DECL_RTL's. */
1644 instantiate_decls (tree fndecl
)
1648 /* Process all parameters of the function. */
1649 for (decl
= DECL_ARGUMENTS (fndecl
); decl
; decl
= TREE_CHAIN (decl
))
1651 instantiate_decl (DECL_RTL (decl
));
1652 instantiate_decl (DECL_INCOMING_RTL (decl
));
1653 if (DECL_HAS_VALUE_EXPR_P (decl
))
1655 tree v
= DECL_VALUE_EXPR (decl
);
1656 walk_tree (&v
, instantiate_expr
, NULL
, NULL
);
1660 /* Now process all variables defined in the function or its subblocks. */
1661 instantiate_decls_1 (DECL_INITIAL (fndecl
));
1664 /* Pass through the INSNS of function FNDECL and convert virtual register
1665 references to hard register references. */
1668 instantiate_virtual_regs (void)
1672 /* Compute the offsets to use for this function. */
1673 in_arg_offset
= FIRST_PARM_OFFSET (current_function_decl
);
1674 var_offset
= STARTING_FRAME_OFFSET
;
1675 dynamic_offset
= STACK_DYNAMIC_OFFSET (current_function_decl
);
1676 out_arg_offset
= STACK_POINTER_OFFSET
;
1677 #ifdef FRAME_POINTER_CFA_OFFSET
1678 cfa_offset
= FRAME_POINTER_CFA_OFFSET (current_function_decl
);
1680 cfa_offset
= ARG_POINTER_CFA_OFFSET (current_function_decl
);
1683 /* Initialize recognition, indicating that volatile is OK. */
1686 /* Scan through all the insns, instantiating every virtual register still
1688 for (insn
= get_insns (); insn
; insn
= NEXT_INSN (insn
))
1691 /* These patterns in the instruction stream can never be recognized.
1692 Fortunately, they shouldn't contain virtual registers either. */
1693 if (GET_CODE (PATTERN (insn
)) == USE
1694 || GET_CODE (PATTERN (insn
)) == CLOBBER
1695 || GET_CODE (PATTERN (insn
)) == ADDR_VEC
1696 || GET_CODE (PATTERN (insn
)) == ADDR_DIFF_VEC
1697 || GET_CODE (PATTERN (insn
)) == ASM_INPUT
)
1700 instantiate_virtual_regs_in_insn (insn
);
1702 if (INSN_DELETED_P (insn
))
1705 for_each_rtx (®_NOTES (insn
), instantiate_virtual_regs_in_rtx
, NULL
);
1707 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
1708 if (GET_CODE (insn
) == CALL_INSN
)
1709 for_each_rtx (&CALL_INSN_FUNCTION_USAGE (insn
),
1710 instantiate_virtual_regs_in_rtx
, NULL
);
1713 /* Instantiate the virtual registers in the DECLs for debugging purposes. */
1714 instantiate_decls (current_function_decl
);
1716 /* Indicate that, from now on, assign_stack_local should use
1717 frame_pointer_rtx. */
1718 virtuals_instantiated
= 1;
1722 struct tree_opt_pass pass_instantiate_virtual_regs
=
1726 instantiate_virtual_regs
, /* execute */
1729 0, /* static_pass_number */
1731 0, /* properties_required */
1732 0, /* properties_provided */
1733 0, /* properties_destroyed */
1734 0, /* todo_flags_start */
1735 TODO_dump_func
, /* todo_flags_finish */
1740 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
1741 This means a type for which function calls must pass an address to the
1742 function or get an address back from the function.
1743 EXP may be a type node or an expression (whose type is tested). */
1746 aggregate_value_p (tree exp
, tree fntype
)
1748 int i
, regno
, nregs
;
1751 tree type
= (TYPE_P (exp
)) ? exp
: TREE_TYPE (exp
);
1753 /* DECL node associated with FNTYPE when relevant, which we might need to
1754 check for by-invisible-reference returns, typically for CALL_EXPR input
1756 tree fndecl
= NULL_TREE
;
1759 switch (TREE_CODE (fntype
))
1762 fndecl
= get_callee_fndecl (fntype
);
1763 fntype
= fndecl
? TREE_TYPE (fndecl
) : 0;
1767 fntype
= TREE_TYPE (fndecl
);
1772 case IDENTIFIER_NODE
:
1776 /* We don't expect other rtl types here. */
1780 if (TREE_CODE (type
) == VOID_TYPE
)
1783 /* If the front end has decided that this needs to be passed by
1784 reference, do so. */
1785 if ((TREE_CODE (exp
) == PARM_DECL
|| TREE_CODE (exp
) == RESULT_DECL
)
1786 && DECL_BY_REFERENCE (exp
))
1789 /* If the EXPression is a CALL_EXPR, honor DECL_BY_REFERENCE set on the
1790 called function RESULT_DECL, meaning the function returns in memory by
1791 invisible reference. This check lets front-ends not set TREE_ADDRESSABLE
1792 on the function type, which used to be the way to request such a return
1793 mechanism but might now be causing troubles at gimplification time if
1794 temporaries with the function type need to be created. */
1795 if (TREE_CODE (exp
) == CALL_EXPR
&& fndecl
&& DECL_RESULT (fndecl
)
1796 && DECL_BY_REFERENCE (DECL_RESULT (fndecl
)))
1799 if (targetm
.calls
.return_in_memory (type
, fntype
))
1801 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
1802 and thus can't be returned in registers. */
1803 if (TREE_ADDRESSABLE (type
))
1805 if (flag_pcc_struct_return
&& AGGREGATE_TYPE_P (type
))
1807 /* Make sure we have suitable call-clobbered regs to return
1808 the value in; if not, we must return it in memory. */
1809 reg
= hard_function_value (type
, 0, fntype
, 0);
1811 /* If we have something other than a REG (e.g. a PARALLEL), then assume
1816 regno
= REGNO (reg
);
1817 nregs
= hard_regno_nregs
[regno
][TYPE_MODE (type
)];
1818 for (i
= 0; i
< nregs
; i
++)
1819 if (! call_used_regs
[regno
+ i
])
1824 /* Return true if we should assign DECL a pseudo register; false if it
1825 should live on the local stack. */
1828 use_register_for_decl (tree decl
)
1830 /* Honor volatile. */
1831 if (TREE_SIDE_EFFECTS (decl
))
1834 /* Honor addressability. */
1835 if (TREE_ADDRESSABLE (decl
))
1838 /* Only register-like things go in registers. */
1839 if (DECL_MODE (decl
) == BLKmode
)
1842 /* If -ffloat-store specified, don't put explicit float variables
1844 /* ??? This should be checked after DECL_ARTIFICIAL, but tree-ssa
1845 propagates values across these stores, and it probably shouldn't. */
1846 if (flag_float_store
&& FLOAT_TYPE_P (TREE_TYPE (decl
)))
1849 /* If we're not interested in tracking debugging information for
1850 this decl, then we can certainly put it in a register. */
1851 if (DECL_IGNORED_P (decl
))
1854 return (optimize
|| DECL_REGISTER (decl
));
1857 /* Return true if TYPE should be passed by invisible reference. */
1860 pass_by_reference (CUMULATIVE_ARGS
*ca
, enum machine_mode mode
,
1861 tree type
, bool named_arg
)
1865 /* If this type contains non-trivial constructors, then it is
1866 forbidden for the middle-end to create any new copies. */
1867 if (TREE_ADDRESSABLE (type
))
1870 /* GCC post 3.4 passes *all* variable sized types by reference. */
1871 if (!TYPE_SIZE (type
) || TREE_CODE (TYPE_SIZE (type
)) != INTEGER_CST
)
1875 return targetm
.calls
.pass_by_reference (ca
, mode
, type
, named_arg
);
1878 /* Return true if TYPE, which is passed by reference, should be callee
1879 copied instead of caller copied. */
1882 reference_callee_copied (CUMULATIVE_ARGS
*ca
, enum machine_mode mode
,
1883 tree type
, bool named_arg
)
1885 if (type
&& TREE_ADDRESSABLE (type
))
1887 return targetm
.calls
.callee_copies (ca
, mode
, type
, named_arg
);
1890 /* Structures to communicate between the subroutines of assign_parms.
1891 The first holds data persistent across all parameters, the second
1892 is cleared out for each parameter. */
1894 struct assign_parm_data_all
1896 CUMULATIVE_ARGS args_so_far
;
1897 struct args_size stack_args_size
;
1898 tree function_result_decl
;
1900 rtx first_conversion_insn
;
1901 rtx last_conversion_insn
;
1902 HOST_WIDE_INT pretend_args_size
;
1903 HOST_WIDE_INT extra_pretend_bytes
;
1904 int reg_parm_stack_space
;
1907 struct assign_parm_data_one
1913 enum machine_mode nominal_mode
;
1914 enum machine_mode passed_mode
;
1915 enum machine_mode promoted_mode
;
1916 struct locate_and_pad_arg_data locate
;
1918 BOOL_BITFIELD named_arg
: 1;
1919 BOOL_BITFIELD passed_pointer
: 1;
1920 BOOL_BITFIELD on_stack
: 1;
1921 BOOL_BITFIELD loaded_in_reg
: 1;
1924 /* A subroutine of assign_parms. Initialize ALL. */
1927 assign_parms_initialize_all (struct assign_parm_data_all
*all
)
1931 memset (all
, 0, sizeof (*all
));
1933 fntype
= TREE_TYPE (current_function_decl
);
1935 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
1936 INIT_CUMULATIVE_INCOMING_ARGS (all
->args_so_far
, fntype
, NULL_RTX
);
1938 INIT_CUMULATIVE_ARGS (all
->args_so_far
, fntype
, NULL_RTX
,
1939 current_function_decl
, -1);
1942 #ifdef REG_PARM_STACK_SPACE
1943 all
->reg_parm_stack_space
= REG_PARM_STACK_SPACE (current_function_decl
);
1947 /* If ARGS contains entries with complex types, split the entry into two
1948 entries of the component type. Return a new list of substitutions are
1949 needed, else the old list. */
1952 split_complex_args (tree args
)
1956 /* Before allocating memory, check for the common case of no complex. */
1957 for (p
= args
; p
; p
= TREE_CHAIN (p
))
1959 tree type
= TREE_TYPE (p
);
1960 if (TREE_CODE (type
) == COMPLEX_TYPE
1961 && targetm
.calls
.split_complex_arg (type
))
1967 args
= copy_list (args
);
1969 for (p
= args
; p
; p
= TREE_CHAIN (p
))
1971 tree type
= TREE_TYPE (p
);
1972 if (TREE_CODE (type
) == COMPLEX_TYPE
1973 && targetm
.calls
.split_complex_arg (type
))
1976 tree subtype
= TREE_TYPE (type
);
1977 bool addressable
= TREE_ADDRESSABLE (p
);
1979 /* Rewrite the PARM_DECL's type with its component. */
1980 TREE_TYPE (p
) = subtype
;
1981 DECL_ARG_TYPE (p
) = TREE_TYPE (DECL_ARG_TYPE (p
));
1982 DECL_MODE (p
) = VOIDmode
;
1983 DECL_SIZE (p
) = NULL
;
1984 DECL_SIZE_UNIT (p
) = NULL
;
1985 /* If this arg must go in memory, put it in a pseudo here.
1986 We can't allow it to go in memory as per normal parms,
1987 because the usual place might not have the imag part
1988 adjacent to the real part. */
1989 DECL_ARTIFICIAL (p
) = addressable
;
1990 DECL_IGNORED_P (p
) = addressable
;
1991 TREE_ADDRESSABLE (p
) = 0;
1994 /* Build a second synthetic decl. */
1995 decl
= build_decl (PARM_DECL
, NULL_TREE
, subtype
);
1996 DECL_ARG_TYPE (decl
) = DECL_ARG_TYPE (p
);
1997 DECL_ARTIFICIAL (decl
) = addressable
;
1998 DECL_IGNORED_P (decl
) = addressable
;
1999 layout_decl (decl
, 0);
2001 /* Splice it in; skip the new decl. */
2002 TREE_CHAIN (decl
) = TREE_CHAIN (p
);
2003 TREE_CHAIN (p
) = decl
;
2011 /* A subroutine of assign_parms. Adjust the parameter list to incorporate
2012 the hidden struct return argument, and (abi willing) complex args.
2013 Return the new parameter list. */
2016 assign_parms_augmented_arg_list (struct assign_parm_data_all
*all
)
2018 tree fndecl
= current_function_decl
;
2019 tree fntype
= TREE_TYPE (fndecl
);
2020 tree fnargs
= DECL_ARGUMENTS (fndecl
);
2022 /* If struct value address is treated as the first argument, make it so. */
2023 if (aggregate_value_p (DECL_RESULT (fndecl
), fndecl
)
2024 && ! current_function_returns_pcc_struct
2025 && targetm
.calls
.struct_value_rtx (TREE_TYPE (fndecl
), 1) == 0)
2027 tree type
= build_pointer_type (TREE_TYPE (fntype
));
2030 decl
= build_decl (PARM_DECL
, NULL_TREE
, type
);
2031 DECL_ARG_TYPE (decl
) = type
;
2032 DECL_ARTIFICIAL (decl
) = 1;
2033 DECL_IGNORED_P (decl
) = 1;
2035 TREE_CHAIN (decl
) = fnargs
;
2037 all
->function_result_decl
= decl
;
2040 all
->orig_fnargs
= fnargs
;
2042 /* If the target wants to split complex arguments into scalars, do so. */
2043 if (targetm
.calls
.split_complex_arg
)
2044 fnargs
= split_complex_args (fnargs
);
2049 /* A subroutine of assign_parms. Examine PARM and pull out type and mode
2050 data for the parameter. Incorporate ABI specifics such as pass-by-
2051 reference and type promotion. */
2054 assign_parm_find_data_types (struct assign_parm_data_all
*all
, tree parm
,
2055 struct assign_parm_data_one
*data
)
2057 tree nominal_type
, passed_type
;
2058 enum machine_mode nominal_mode
, passed_mode
, promoted_mode
;
2060 memset (data
, 0, sizeof (*data
));
2062 /* NAMED_ARG is a mis-nomer. We really mean 'non-varadic'. */
2063 if (!current_function_stdarg
)
2064 data
->named_arg
= 1; /* No varadic parms. */
2065 else if (TREE_CHAIN (parm
))
2066 data
->named_arg
= 1; /* Not the last non-varadic parm. */
2067 else if (targetm
.calls
.strict_argument_naming (&all
->args_so_far
))
2068 data
->named_arg
= 1; /* Only varadic ones are unnamed. */
2070 data
->named_arg
= 0; /* Treat as varadic. */
2072 nominal_type
= TREE_TYPE (parm
);
2073 passed_type
= DECL_ARG_TYPE (parm
);
2075 /* Look out for errors propagating this far. Also, if the parameter's
2076 type is void then its value doesn't matter. */
2077 if (TREE_TYPE (parm
) == error_mark_node
2078 /* This can happen after weird syntax errors
2079 or if an enum type is defined among the parms. */
2080 || TREE_CODE (parm
) != PARM_DECL
2081 || passed_type
== NULL
2082 || VOID_TYPE_P (nominal_type
))
2084 nominal_type
= passed_type
= void_type_node
;
2085 nominal_mode
= passed_mode
= promoted_mode
= VOIDmode
;
2089 /* Find mode of arg as it is passed, and mode of arg as it should be
2090 during execution of this function. */
2091 passed_mode
= TYPE_MODE (passed_type
);
2092 nominal_mode
= TYPE_MODE (nominal_type
);
2094 /* If the parm is to be passed as a transparent union, use the type of
2095 the first field for the tests below. We have already verified that
2096 the modes are the same. */
2097 if (TREE_CODE (passed_type
) == UNION_TYPE
2098 && TYPE_TRANSPARENT_UNION (passed_type
))
2099 passed_type
= TREE_TYPE (TYPE_FIELDS (passed_type
));
2101 /* See if this arg was passed by invisible reference. */
2102 if (pass_by_reference (&all
->args_so_far
, passed_mode
,
2103 passed_type
, data
->named_arg
))
2105 passed_type
= nominal_type
= build_pointer_type (passed_type
);
2106 data
->passed_pointer
= true;
2107 passed_mode
= nominal_mode
= Pmode
;
2110 /* Find mode as it is passed by the ABI. */
2111 promoted_mode
= passed_mode
;
2112 if (targetm
.calls
.promote_function_args (TREE_TYPE (current_function_decl
)))
2114 int unsignedp
= TYPE_UNSIGNED (passed_type
);
2115 promoted_mode
= promote_mode (passed_type
, promoted_mode
,
2120 data
->nominal_type
= nominal_type
;
2121 data
->passed_type
= passed_type
;
2122 data
->nominal_mode
= nominal_mode
;
2123 data
->passed_mode
= passed_mode
;
2124 data
->promoted_mode
= promoted_mode
;
2127 /* A subroutine of assign_parms. Invoke setup_incoming_varargs. */
2130 assign_parms_setup_varargs (struct assign_parm_data_all
*all
,
2131 struct assign_parm_data_one
*data
, bool no_rtl
)
2133 int varargs_pretend_bytes
= 0;
2135 targetm
.calls
.setup_incoming_varargs (&all
->args_so_far
,
2136 data
->promoted_mode
,
2138 &varargs_pretend_bytes
, no_rtl
);
2140 /* If the back-end has requested extra stack space, record how much is
2141 needed. Do not change pretend_args_size otherwise since it may be
2142 nonzero from an earlier partial argument. */
2143 if (varargs_pretend_bytes
> 0)
2144 all
->pretend_args_size
= varargs_pretend_bytes
;
2147 /* A subroutine of assign_parms. Set DATA->ENTRY_PARM corresponding to
2148 the incoming location of the current parameter. */
2151 assign_parm_find_entry_rtl (struct assign_parm_data_all
*all
,
2152 struct assign_parm_data_one
*data
)
2154 HOST_WIDE_INT pretend_bytes
= 0;
2158 if (data
->promoted_mode
== VOIDmode
)
2160 data
->entry_parm
= data
->stack_parm
= const0_rtx
;
2164 #ifdef FUNCTION_INCOMING_ARG
2165 entry_parm
= FUNCTION_INCOMING_ARG (all
->args_so_far
, data
->promoted_mode
,
2166 data
->passed_type
, data
->named_arg
);
2168 entry_parm
= FUNCTION_ARG (all
->args_so_far
, data
->promoted_mode
,
2169 data
->passed_type
, data
->named_arg
);
2172 if (entry_parm
== 0)
2173 data
->promoted_mode
= data
->passed_mode
;
2175 /* Determine parm's home in the stack, in case it arrives in the stack
2176 or we should pretend it did. Compute the stack position and rtx where
2177 the argument arrives and its size.
2179 There is one complexity here: If this was a parameter that would
2180 have been passed in registers, but wasn't only because it is
2181 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
2182 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
2183 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of 0
2184 as it was the previous time. */
2185 in_regs
= entry_parm
!= 0;
2186 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2189 if (!in_regs
&& !data
->named_arg
)
2191 if (targetm
.calls
.pretend_outgoing_varargs_named (&all
->args_so_far
))
2194 #ifdef FUNCTION_INCOMING_ARG
2195 tem
= FUNCTION_INCOMING_ARG (all
->args_so_far
, data
->promoted_mode
,
2196 data
->passed_type
, true);
2198 tem
= FUNCTION_ARG (all
->args_so_far
, data
->promoted_mode
,
2199 data
->passed_type
, true);
2201 in_regs
= tem
!= NULL
;
2205 /* If this parameter was passed both in registers and in the stack, use
2206 the copy on the stack. */
2207 if (targetm
.calls
.must_pass_in_stack (data
->promoted_mode
,
2215 partial
= targetm
.calls
.arg_partial_bytes (&all
->args_so_far
,
2216 data
->promoted_mode
,
2219 data
->partial
= partial
;
2221 /* The caller might already have allocated stack space for the
2222 register parameters. */
2223 if (partial
!= 0 && all
->reg_parm_stack_space
== 0)
2225 /* Part of this argument is passed in registers and part
2226 is passed on the stack. Ask the prologue code to extend
2227 the stack part so that we can recreate the full value.
2229 PRETEND_BYTES is the size of the registers we need to store.
2230 CURRENT_FUNCTION_PRETEND_ARGS_SIZE is the amount of extra
2231 stack space that the prologue should allocate.
2233 Internally, gcc assumes that the argument pointer is aligned
2234 to STACK_BOUNDARY bits. This is used both for alignment
2235 optimizations (see init_emit) and to locate arguments that are
2236 aligned to more than PARM_BOUNDARY bits. We must preserve this
2237 invariant by rounding CURRENT_FUNCTION_PRETEND_ARGS_SIZE up to
2238 a stack boundary. */
2240 /* We assume at most one partial arg, and it must be the first
2241 argument on the stack. */
2242 gcc_assert (!all
->extra_pretend_bytes
&& !all
->pretend_args_size
);
2244 pretend_bytes
= partial
;
2245 all
->pretend_args_size
= CEIL_ROUND (pretend_bytes
, STACK_BYTES
);
2247 /* We want to align relative to the actual stack pointer, so
2248 don't include this in the stack size until later. */
2249 all
->extra_pretend_bytes
= all
->pretend_args_size
;
2253 locate_and_pad_parm (data
->promoted_mode
, data
->passed_type
, in_regs
,
2254 entry_parm
? data
->partial
: 0, current_function_decl
,
2255 &all
->stack_args_size
, &data
->locate
);
2257 /* Adjust offsets to include the pretend args. */
2258 pretend_bytes
= all
->extra_pretend_bytes
- pretend_bytes
;
2259 data
->locate
.slot_offset
.constant
+= pretend_bytes
;
2260 data
->locate
.offset
.constant
+= pretend_bytes
;
2262 data
->entry_parm
= entry_parm
;
2265 /* A subroutine of assign_parms. If there is actually space on the stack
2266 for this parm, count it in stack_args_size and return true. */
2269 assign_parm_is_stack_parm (struct assign_parm_data_all
*all
,
2270 struct assign_parm_data_one
*data
)
2272 /* Trivially true if we've no incoming register. */
2273 if (data
->entry_parm
== NULL
)
2275 /* Also true if we're partially in registers and partially not,
2276 since we've arranged to drop the entire argument on the stack. */
2277 else if (data
->partial
!= 0)
2279 /* Also true if the target says that it's passed in both registers
2280 and on the stack. */
2281 else if (GET_CODE (data
->entry_parm
) == PARALLEL
2282 && XEXP (XVECEXP (data
->entry_parm
, 0, 0), 0) == NULL_RTX
)
2284 /* Also true if the target says that there's stack allocated for
2285 all register parameters. */
2286 else if (all
->reg_parm_stack_space
> 0)
2288 /* Otherwise, no, this parameter has no ABI defined stack slot. */
2292 all
->stack_args_size
.constant
+= data
->locate
.size
.constant
;
2293 if (data
->locate
.size
.var
)
2294 ADD_PARM_SIZE (all
->stack_args_size
, data
->locate
.size
.var
);
2299 /* A subroutine of assign_parms. Given that this parameter is allocated
2300 stack space by the ABI, find it. */
2303 assign_parm_find_stack_rtl (tree parm
, struct assign_parm_data_one
*data
)
2305 rtx offset_rtx
, stack_parm
;
2306 unsigned int align
, boundary
;
2308 /* If we're passing this arg using a reg, make its stack home the
2309 aligned stack slot. */
2310 if (data
->entry_parm
)
2311 offset_rtx
= ARGS_SIZE_RTX (data
->locate
.slot_offset
);
2313 offset_rtx
= ARGS_SIZE_RTX (data
->locate
.offset
);
2315 stack_parm
= current_function_internal_arg_pointer
;
2316 if (offset_rtx
!= const0_rtx
)
2317 stack_parm
= gen_rtx_PLUS (Pmode
, stack_parm
, offset_rtx
);
2318 stack_parm
= gen_rtx_MEM (data
->promoted_mode
, stack_parm
);
2320 set_mem_attributes (stack_parm
, parm
, 1);
2322 boundary
= data
->locate
.boundary
;
2323 align
= BITS_PER_UNIT
;
2325 /* If we're padding upward, we know that the alignment of the slot
2326 is FUNCTION_ARG_BOUNDARY. If we're using slot_offset, we're
2327 intentionally forcing upward padding. Otherwise we have to come
2328 up with a guess at the alignment based on OFFSET_RTX. */
2329 if (data
->locate
.where_pad
!= downward
|| data
->entry_parm
)
2331 else if (GET_CODE (offset_rtx
) == CONST_INT
)
2333 align
= INTVAL (offset_rtx
) * BITS_PER_UNIT
| boundary
;
2334 align
= align
& -align
;
2336 set_mem_align (stack_parm
, align
);
2338 if (data
->entry_parm
)
2339 set_reg_attrs_for_parm (data
->entry_parm
, stack_parm
);
2341 data
->stack_parm
= stack_parm
;
2344 /* A subroutine of assign_parms. Adjust DATA->ENTRY_RTL such that it's
2345 always valid and contiguous. */
2348 assign_parm_adjust_entry_rtl (struct assign_parm_data_one
*data
)
2350 rtx entry_parm
= data
->entry_parm
;
2351 rtx stack_parm
= data
->stack_parm
;
2353 /* If this parm was passed part in regs and part in memory, pretend it
2354 arrived entirely in memory by pushing the register-part onto the stack.
2355 In the special case of a DImode or DFmode that is split, we could put
2356 it together in a pseudoreg directly, but for now that's not worth
2358 if (data
->partial
!= 0)
2360 /* Handle calls that pass values in multiple non-contiguous
2361 locations. The Irix 6 ABI has examples of this. */
2362 if (GET_CODE (entry_parm
) == PARALLEL
)
2363 emit_group_store (validize_mem (stack_parm
), entry_parm
,
2365 int_size_in_bytes (data
->passed_type
));
2368 gcc_assert (data
->partial
% UNITS_PER_WORD
== 0);
2369 move_block_from_reg (REGNO (entry_parm
), validize_mem (stack_parm
),
2370 data
->partial
/ UNITS_PER_WORD
);
2373 entry_parm
= stack_parm
;
2376 /* If we didn't decide this parm came in a register, by default it came
2378 else if (entry_parm
== NULL
)
2379 entry_parm
= stack_parm
;
2381 /* When an argument is passed in multiple locations, we can't make use
2382 of this information, but we can save some copying if the whole argument
2383 is passed in a single register. */
2384 else if (GET_CODE (entry_parm
) == PARALLEL
2385 && data
->nominal_mode
!= BLKmode
2386 && data
->passed_mode
!= BLKmode
)
2388 size_t i
, len
= XVECLEN (entry_parm
, 0);
2390 for (i
= 0; i
< len
; i
++)
2391 if (XEXP (XVECEXP (entry_parm
, 0, i
), 0) != NULL_RTX
2392 && REG_P (XEXP (XVECEXP (entry_parm
, 0, i
), 0))
2393 && (GET_MODE (XEXP (XVECEXP (entry_parm
, 0, i
), 0))
2394 == data
->passed_mode
)
2395 && INTVAL (XEXP (XVECEXP (entry_parm
, 0, i
), 1)) == 0)
2397 entry_parm
= XEXP (XVECEXP (entry_parm
, 0, i
), 0);
2402 data
->entry_parm
= entry_parm
;
2405 /* A subroutine of assign_parms. Adjust DATA->STACK_RTL such that it's
2406 always valid and properly aligned. */
2409 assign_parm_adjust_stack_rtl (struct assign_parm_data_one
*data
)
2411 rtx stack_parm
= data
->stack_parm
;
2413 /* If we can't trust the parm stack slot to be aligned enough for its
2414 ultimate type, don't use that slot after entry. We'll make another
2415 stack slot, if we need one. */
2417 && ((STRICT_ALIGNMENT
2418 && GET_MODE_ALIGNMENT (data
->nominal_mode
) > MEM_ALIGN (stack_parm
))
2419 || (data
->nominal_type
2420 && TYPE_ALIGN (data
->nominal_type
) > MEM_ALIGN (stack_parm
)
2421 && MEM_ALIGN (stack_parm
) < PREFERRED_STACK_BOUNDARY
)))
2424 /* If parm was passed in memory, and we need to convert it on entry,
2425 don't store it back in that same slot. */
2426 else if (data
->entry_parm
== stack_parm
2427 && data
->nominal_mode
!= BLKmode
2428 && data
->nominal_mode
!= data
->passed_mode
)
2431 /* If stack protection is in effect for this function, don't leave any
2432 pointers in their passed stack slots. */
2433 else if (cfun
->stack_protect_guard
2434 && (flag_stack_protect
== 2
2435 || data
->passed_pointer
2436 || POINTER_TYPE_P (data
->nominal_type
)))
2439 data
->stack_parm
= stack_parm
;
2442 /* A subroutine of assign_parms. Return true if the current parameter
2443 should be stored as a BLKmode in the current frame. */
2446 assign_parm_setup_block_p (struct assign_parm_data_one
*data
)
2448 if (data
->nominal_mode
== BLKmode
)
2450 if (GET_CODE (data
->entry_parm
) == PARALLEL
)
2453 #ifdef BLOCK_REG_PADDING
2454 /* Only assign_parm_setup_block knows how to deal with register arguments
2455 that are padded at the least significant end. */
2456 if (REG_P (data
->entry_parm
)
2457 && GET_MODE_SIZE (data
->promoted_mode
) < UNITS_PER_WORD
2458 && (BLOCK_REG_PADDING (data
->passed_mode
, data
->passed_type
, 1)
2459 == (BYTES_BIG_ENDIAN
? upward
: downward
)))
2466 /* A subroutine of assign_parms. Arrange for the parameter to be
2467 present and valid in DATA->STACK_RTL. */
2470 assign_parm_setup_block (struct assign_parm_data_all
*all
,
2471 tree parm
, struct assign_parm_data_one
*data
)
2473 rtx entry_parm
= data
->entry_parm
;
2474 rtx stack_parm
= data
->stack_parm
;
2476 HOST_WIDE_INT size_stored
;
2477 rtx orig_entry_parm
= entry_parm
;
2479 if (GET_CODE (entry_parm
) == PARALLEL
)
2480 entry_parm
= emit_group_move_into_temps (entry_parm
);
2482 /* If we've a non-block object that's nevertheless passed in parts,
2483 reconstitute it in register operations rather than on the stack. */
2484 if (GET_CODE (entry_parm
) == PARALLEL
2485 && data
->nominal_mode
!= BLKmode
)
2487 rtx elt0
= XEXP (XVECEXP (orig_entry_parm
, 0, 0), 0);
2489 if ((XVECLEN (entry_parm
, 0) > 1
2490 || hard_regno_nregs
[REGNO (elt0
)][GET_MODE (elt0
)] > 1)
2491 && use_register_for_decl (parm
))
2493 rtx parmreg
= gen_reg_rtx (data
->nominal_mode
);
2495 push_to_sequence2 (all
->first_conversion_insn
,
2496 all
->last_conversion_insn
);
2498 /* For values returned in multiple registers, handle possible
2499 incompatible calls to emit_group_store.
2501 For example, the following would be invalid, and would have to
2502 be fixed by the conditional below:
2504 emit_group_store ((reg:SF), (parallel:DF))
2505 emit_group_store ((reg:SI), (parallel:DI))
2507 An example of this are doubles in e500 v2:
2508 (parallel:DF (expr_list (reg:SI) (const_int 0))
2509 (expr_list (reg:SI) (const_int 4))). */
2510 if (data
->nominal_mode
!= data
->passed_mode
)
2512 rtx t
= gen_reg_rtx (GET_MODE (entry_parm
));
2513 emit_group_store (t
, entry_parm
, NULL_TREE
,
2514 GET_MODE_SIZE (GET_MODE (entry_parm
)));
2515 convert_move (parmreg
, t
, 0);
2518 emit_group_store (parmreg
, entry_parm
, data
->nominal_type
,
2519 int_size_in_bytes (data
->nominal_type
));
2521 all
->first_conversion_insn
= get_insns ();
2522 all
->last_conversion_insn
= get_last_insn ();
2525 SET_DECL_RTL (parm
, parmreg
);
2530 size
= int_size_in_bytes (data
->passed_type
);
2531 size_stored
= CEIL_ROUND (size
, UNITS_PER_WORD
);
2532 if (stack_parm
== 0)
2534 DECL_ALIGN (parm
) = MAX (DECL_ALIGN (parm
), BITS_PER_WORD
);
2535 stack_parm
= assign_stack_local (BLKmode
, size_stored
,
2537 if (GET_MODE_SIZE (GET_MODE (entry_parm
)) == size
)
2538 PUT_MODE (stack_parm
, GET_MODE (entry_parm
));
2539 set_mem_attributes (stack_parm
, parm
, 1);
2542 /* If a BLKmode arrives in registers, copy it to a stack slot. Handle
2543 calls that pass values in multiple non-contiguous locations. */
2544 if (REG_P (entry_parm
) || GET_CODE (entry_parm
) == PARALLEL
)
2548 /* Note that we will be storing an integral number of words.
2549 So we have to be careful to ensure that we allocate an
2550 integral number of words. We do this above when we call
2551 assign_stack_local if space was not allocated in the argument
2552 list. If it was, this will not work if PARM_BOUNDARY is not
2553 a multiple of BITS_PER_WORD. It isn't clear how to fix this
2554 if it becomes a problem. Exception is when BLKmode arrives
2555 with arguments not conforming to word_mode. */
2557 if (data
->stack_parm
== 0)
2559 else if (GET_CODE (entry_parm
) == PARALLEL
)
2562 gcc_assert (!size
|| !(PARM_BOUNDARY
% BITS_PER_WORD
));
2564 mem
= validize_mem (stack_parm
);
2566 /* Handle values in multiple non-contiguous locations. */
2567 if (GET_CODE (entry_parm
) == PARALLEL
)
2569 push_to_sequence2 (all
->first_conversion_insn
,
2570 all
->last_conversion_insn
);
2571 emit_group_store (mem
, entry_parm
, data
->passed_type
, size
);
2572 all
->first_conversion_insn
= get_insns ();
2573 all
->last_conversion_insn
= get_last_insn ();
2580 /* If SIZE is that of a mode no bigger than a word, just use
2581 that mode's store operation. */
2582 else if (size
<= UNITS_PER_WORD
)
2584 enum machine_mode mode
2585 = mode_for_size (size
* BITS_PER_UNIT
, MODE_INT
, 0);
2588 #ifdef BLOCK_REG_PADDING
2589 && (size
== UNITS_PER_WORD
2590 || (BLOCK_REG_PADDING (mode
, data
->passed_type
, 1)
2591 != (BYTES_BIG_ENDIAN
? upward
: downward
)))
2595 rtx reg
= gen_rtx_REG (mode
, REGNO (entry_parm
));
2596 emit_move_insn (change_address (mem
, mode
, 0), reg
);
2599 /* Blocks smaller than a word on a BYTES_BIG_ENDIAN
2600 machine must be aligned to the left before storing
2601 to memory. Note that the previous test doesn't
2602 handle all cases (e.g. SIZE == 3). */
2603 else if (size
!= UNITS_PER_WORD
2604 #ifdef BLOCK_REG_PADDING
2605 && (BLOCK_REG_PADDING (mode
, data
->passed_type
, 1)
2613 int by
= (UNITS_PER_WORD
- size
) * BITS_PER_UNIT
;
2614 rtx reg
= gen_rtx_REG (word_mode
, REGNO (entry_parm
));
2616 x
= expand_shift (LSHIFT_EXPR
, word_mode
, reg
,
2617 build_int_cst (NULL_TREE
, by
),
2619 tem
= change_address (mem
, word_mode
, 0);
2620 emit_move_insn (tem
, x
);
2623 move_block_from_reg (REGNO (entry_parm
), mem
,
2624 size_stored
/ UNITS_PER_WORD
);
2627 move_block_from_reg (REGNO (entry_parm
), mem
,
2628 size_stored
/ UNITS_PER_WORD
);
2630 else if (data
->stack_parm
== 0)
2632 push_to_sequence2 (all
->first_conversion_insn
, all
->last_conversion_insn
);
2633 emit_block_move (stack_parm
, data
->entry_parm
, GEN_INT (size
),
2635 all
->first_conversion_insn
= get_insns ();
2636 all
->last_conversion_insn
= get_last_insn ();
2640 data
->stack_parm
= stack_parm
;
2641 SET_DECL_RTL (parm
, stack_parm
);
2644 /* A subroutine of assign_parms. Allocate a pseudo to hold the current
2645 parameter. Get it there. Perform all ABI specified conversions. */
2648 assign_parm_setup_reg (struct assign_parm_data_all
*all
, tree parm
,
2649 struct assign_parm_data_one
*data
)
2652 enum machine_mode promoted_nominal_mode
;
2653 int unsignedp
= TYPE_UNSIGNED (TREE_TYPE (parm
));
2654 bool did_conversion
= false;
2656 /* Store the parm in a pseudoregister during the function, but we may
2657 need to do it in a wider mode. */
2659 /* This is not really promoting for a call. However we need to be
2660 consistent with assign_parm_find_data_types and expand_expr_real_1. */
2661 promoted_nominal_mode
2662 = promote_mode (data
->nominal_type
, data
->nominal_mode
, &unsignedp
, 1);
2664 parmreg
= gen_reg_rtx (promoted_nominal_mode
);
2666 if (!DECL_ARTIFICIAL (parm
))
2667 mark_user_reg (parmreg
);
2669 /* If this was an item that we received a pointer to,
2670 set DECL_RTL appropriately. */
2671 if (data
->passed_pointer
)
2673 rtx x
= gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data
->passed_type
)), parmreg
);
2674 set_mem_attributes (x
, parm
, 1);
2675 SET_DECL_RTL (parm
, x
);
2678 SET_DECL_RTL (parm
, parmreg
);
2680 /* Copy the value into the register. */
2681 if (data
->nominal_mode
!= data
->passed_mode
2682 || promoted_nominal_mode
!= data
->promoted_mode
)
2686 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
2687 mode, by the caller. We now have to convert it to
2688 NOMINAL_MODE, if different. However, PARMREG may be in
2689 a different mode than NOMINAL_MODE if it is being stored
2692 If ENTRY_PARM is a hard register, it might be in a register
2693 not valid for operating in its mode (e.g., an odd-numbered
2694 register for a DFmode). In that case, moves are the only
2695 thing valid, so we can't do a convert from there. This
2696 occurs when the calling sequence allow such misaligned
2699 In addition, the conversion may involve a call, which could
2700 clobber parameters which haven't been copied to pseudo
2701 registers yet. Therefore, we must first copy the parm to
2702 a pseudo reg here, and save the conversion until after all
2703 parameters have been moved. */
2705 rtx tempreg
= gen_reg_rtx (GET_MODE (data
->entry_parm
));
2707 emit_move_insn (tempreg
, validize_mem (data
->entry_parm
));
2709 push_to_sequence2 (all
->first_conversion_insn
, all
->last_conversion_insn
);
2710 tempreg
= convert_to_mode (data
->nominal_mode
, tempreg
, unsignedp
);
2712 if (GET_CODE (tempreg
) == SUBREG
2713 && GET_MODE (tempreg
) == data
->nominal_mode
2714 && REG_P (SUBREG_REG (tempreg
))
2715 && data
->nominal_mode
== data
->passed_mode
2716 && GET_MODE (SUBREG_REG (tempreg
)) == GET_MODE (data
->entry_parm
)
2717 && GET_MODE_SIZE (GET_MODE (tempreg
))
2718 < GET_MODE_SIZE (GET_MODE (data
->entry_parm
)))
2720 /* The argument is already sign/zero extended, so note it
2722 SUBREG_PROMOTED_VAR_P (tempreg
) = 1;
2723 SUBREG_PROMOTED_UNSIGNED_SET (tempreg
, unsignedp
);
2726 /* TREE_USED gets set erroneously during expand_assignment. */
2727 save_tree_used
= TREE_USED (parm
);
2728 expand_assignment (parm
, make_tree (data
->nominal_type
, tempreg
), false);
2729 TREE_USED (parm
) = save_tree_used
;
2730 all
->first_conversion_insn
= get_insns ();
2731 all
->last_conversion_insn
= get_last_insn ();
2734 did_conversion
= true;
2737 emit_move_insn (parmreg
, validize_mem (data
->entry_parm
));
2739 /* If we were passed a pointer but the actual value can safely live
2740 in a register, put it in one. */
2741 if (data
->passed_pointer
2742 && TYPE_MODE (TREE_TYPE (parm
)) != BLKmode
2743 /* If by-reference argument was promoted, demote it. */
2744 && (TYPE_MODE (TREE_TYPE (parm
)) != GET_MODE (DECL_RTL (parm
))
2745 || use_register_for_decl (parm
)))
2747 /* We can't use nominal_mode, because it will have been set to
2748 Pmode above. We must use the actual mode of the parm. */
2749 parmreg
= gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm
)));
2750 mark_user_reg (parmreg
);
2752 if (GET_MODE (parmreg
) != GET_MODE (DECL_RTL (parm
)))
2754 rtx tempreg
= gen_reg_rtx (GET_MODE (DECL_RTL (parm
)));
2755 int unsigned_p
= TYPE_UNSIGNED (TREE_TYPE (parm
));
2757 push_to_sequence2 (all
->first_conversion_insn
,
2758 all
->last_conversion_insn
);
2759 emit_move_insn (tempreg
, DECL_RTL (parm
));
2760 tempreg
= convert_to_mode (GET_MODE (parmreg
), tempreg
, unsigned_p
);
2761 emit_move_insn (parmreg
, tempreg
);
2762 all
->first_conversion_insn
= get_insns ();
2763 all
->last_conversion_insn
= get_last_insn ();
2766 did_conversion
= true;
2769 emit_move_insn (parmreg
, DECL_RTL (parm
));
2771 SET_DECL_RTL (parm
, parmreg
);
2773 /* STACK_PARM is the pointer, not the parm, and PARMREG is
2775 data
->stack_parm
= NULL
;
2778 /* Mark the register as eliminable if we did no conversion and it was
2779 copied from memory at a fixed offset, and the arg pointer was not
2780 copied to a pseudo-reg. If the arg pointer is a pseudo reg or the
2781 offset formed an invalid address, such memory-equivalences as we
2782 make here would screw up life analysis for it. */
2783 if (data
->nominal_mode
== data
->passed_mode
2785 && data
->stack_parm
!= 0
2786 && MEM_P (data
->stack_parm
)
2787 && data
->locate
.offset
.var
== 0
2788 && reg_mentioned_p (virtual_incoming_args_rtx
,
2789 XEXP (data
->stack_parm
, 0)))
2791 rtx linsn
= get_last_insn ();
2794 /* Mark complex types separately. */
2795 if (GET_CODE (parmreg
) == CONCAT
)
2797 enum machine_mode submode
2798 = GET_MODE_INNER (GET_MODE (parmreg
));
2799 int regnor
= REGNO (XEXP (parmreg
, 0));
2800 int regnoi
= REGNO (XEXP (parmreg
, 1));
2801 rtx stackr
= adjust_address_nv (data
->stack_parm
, submode
, 0);
2802 rtx stacki
= adjust_address_nv (data
->stack_parm
, submode
,
2803 GET_MODE_SIZE (submode
));
2805 /* Scan backwards for the set of the real and
2807 for (sinsn
= linsn
; sinsn
!= 0;
2808 sinsn
= prev_nonnote_insn (sinsn
))
2810 set
= single_set (sinsn
);
2814 if (SET_DEST (set
) == regno_reg_rtx
[regnoi
])
2815 set_unique_reg_note (sinsn
, REG_EQUIV
, stacki
);
2816 else if (SET_DEST (set
) == regno_reg_rtx
[regnor
])
2817 set_unique_reg_note (sinsn
, REG_EQUIV
, stackr
);
2820 else if ((set
= single_set (linsn
)) != 0
2821 && SET_DEST (set
) == parmreg
)
2822 set_unique_reg_note (linsn
, REG_EQUIV
, data
->stack_parm
);
2825 /* For pointer data type, suggest pointer register. */
2826 if (POINTER_TYPE_P (TREE_TYPE (parm
)))
2827 mark_reg_pointer (parmreg
,
2828 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm
))));
2831 /* A subroutine of assign_parms. Allocate stack space to hold the current
2832 parameter. Get it there. Perform all ABI specified conversions. */
2835 assign_parm_setup_stack (struct assign_parm_data_all
*all
, tree parm
,
2836 struct assign_parm_data_one
*data
)
2838 /* Value must be stored in the stack slot STACK_PARM during function
2840 bool to_conversion
= false;
2842 if (data
->promoted_mode
!= data
->nominal_mode
)
2844 /* Conversion is required. */
2845 rtx tempreg
= gen_reg_rtx (GET_MODE (data
->entry_parm
));
2847 emit_move_insn (tempreg
, validize_mem (data
->entry_parm
));
2849 push_to_sequence2 (all
->first_conversion_insn
, all
->last_conversion_insn
);
2850 to_conversion
= true;
2852 data
->entry_parm
= convert_to_mode (data
->nominal_mode
, tempreg
,
2853 TYPE_UNSIGNED (TREE_TYPE (parm
)));
2855 if (data
->stack_parm
)
2856 /* ??? This may need a big-endian conversion on sparc64. */
2858 = adjust_address (data
->stack_parm
, data
->nominal_mode
, 0);
2861 if (data
->entry_parm
!= data
->stack_parm
)
2865 if (data
->stack_parm
== 0)
2868 = assign_stack_local (GET_MODE (data
->entry_parm
),
2869 GET_MODE_SIZE (GET_MODE (data
->entry_parm
)),
2870 TYPE_ALIGN (data
->passed_type
));
2871 set_mem_attributes (data
->stack_parm
, parm
, 1);
2874 dest
= validize_mem (data
->stack_parm
);
2875 src
= validize_mem (data
->entry_parm
);
2879 /* Use a block move to handle potentially misaligned entry_parm. */
2881 push_to_sequence2 (all
->first_conversion_insn
,
2882 all
->last_conversion_insn
);
2883 to_conversion
= true;
2885 emit_block_move (dest
, src
,
2886 GEN_INT (int_size_in_bytes (data
->passed_type
)),
2890 emit_move_insn (dest
, src
);
2895 all
->first_conversion_insn
= get_insns ();
2896 all
->last_conversion_insn
= get_last_insn ();
2900 SET_DECL_RTL (parm
, data
->stack_parm
);
2903 /* A subroutine of assign_parms. If the ABI splits complex arguments, then
2904 undo the frobbing that we did in assign_parms_augmented_arg_list. */
2907 assign_parms_unsplit_complex (struct assign_parm_data_all
*all
, tree fnargs
)
2910 tree orig_fnargs
= all
->orig_fnargs
;
2912 for (parm
= orig_fnargs
; parm
; parm
= TREE_CHAIN (parm
))
2914 if (TREE_CODE (TREE_TYPE (parm
)) == COMPLEX_TYPE
2915 && targetm
.calls
.split_complex_arg (TREE_TYPE (parm
)))
2917 rtx tmp
, real
, imag
;
2918 enum machine_mode inner
= GET_MODE_INNER (DECL_MODE (parm
));
2920 real
= DECL_RTL (fnargs
);
2921 imag
= DECL_RTL (TREE_CHAIN (fnargs
));
2922 if (inner
!= GET_MODE (real
))
2924 real
= gen_lowpart_SUBREG (inner
, real
);
2925 imag
= gen_lowpart_SUBREG (inner
, imag
);
2928 if (TREE_ADDRESSABLE (parm
))
2931 HOST_WIDE_INT size
= int_size_in_bytes (TREE_TYPE (parm
));
2933 /* split_complex_arg put the real and imag parts in
2934 pseudos. Move them to memory. */
2935 tmp
= assign_stack_local (DECL_MODE (parm
), size
,
2936 TYPE_ALIGN (TREE_TYPE (parm
)));
2937 set_mem_attributes (tmp
, parm
, 1);
2938 rmem
= adjust_address_nv (tmp
, inner
, 0);
2939 imem
= adjust_address_nv (tmp
, inner
, GET_MODE_SIZE (inner
));
2940 push_to_sequence2 (all
->first_conversion_insn
,
2941 all
->last_conversion_insn
);
2942 emit_move_insn (rmem
, real
);
2943 emit_move_insn (imem
, imag
);
2944 all
->first_conversion_insn
= get_insns ();
2945 all
->last_conversion_insn
= get_last_insn ();
2949 tmp
= gen_rtx_CONCAT (DECL_MODE (parm
), real
, imag
);
2950 SET_DECL_RTL (parm
, tmp
);
2952 real
= DECL_INCOMING_RTL (fnargs
);
2953 imag
= DECL_INCOMING_RTL (TREE_CHAIN (fnargs
));
2954 if (inner
!= GET_MODE (real
))
2956 real
= gen_lowpart_SUBREG (inner
, real
);
2957 imag
= gen_lowpart_SUBREG (inner
, imag
);
2959 tmp
= gen_rtx_CONCAT (DECL_MODE (parm
), real
, imag
);
2960 set_decl_incoming_rtl (parm
, tmp
);
2961 fnargs
= TREE_CHAIN (fnargs
);
2965 SET_DECL_RTL (parm
, DECL_RTL (fnargs
));
2966 set_decl_incoming_rtl (parm
, DECL_INCOMING_RTL (fnargs
));
2968 /* Set MEM_EXPR to the original decl, i.e. to PARM,
2969 instead of the copy of decl, i.e. FNARGS. */
2970 if (DECL_INCOMING_RTL (parm
) && MEM_P (DECL_INCOMING_RTL (parm
)))
2971 set_mem_expr (DECL_INCOMING_RTL (parm
), parm
);
2974 fnargs
= TREE_CHAIN (fnargs
);
2978 /* Assign RTL expressions to the function's parameters. This may involve
2979 copying them into registers and using those registers as the DECL_RTL. */
2982 assign_parms (tree fndecl
)
2984 struct assign_parm_data_all all
;
2987 current_function_internal_arg_pointer
2988 = targetm
.calls
.internal_arg_pointer ();
2990 assign_parms_initialize_all (&all
);
2991 fnargs
= assign_parms_augmented_arg_list (&all
);
2993 for (parm
= fnargs
; parm
; parm
= TREE_CHAIN (parm
))
2995 struct assign_parm_data_one data
;
2997 /* Extract the type of PARM; adjust it according to ABI. */
2998 assign_parm_find_data_types (&all
, parm
, &data
);
3000 /* Early out for errors and void parameters. */
3001 if (data
.passed_mode
== VOIDmode
)
3003 SET_DECL_RTL (parm
, const0_rtx
);
3004 DECL_INCOMING_RTL (parm
) = DECL_RTL (parm
);
3008 if (current_function_stdarg
&& !TREE_CHAIN (parm
))
3009 assign_parms_setup_varargs (&all
, &data
, false);
3011 /* Find out where the parameter arrives in this function. */
3012 assign_parm_find_entry_rtl (&all
, &data
);
3014 /* Find out where stack space for this parameter might be. */
3015 if (assign_parm_is_stack_parm (&all
, &data
))
3017 assign_parm_find_stack_rtl (parm
, &data
);
3018 assign_parm_adjust_entry_rtl (&data
);
3021 /* Record permanently how this parm was passed. */
3022 set_decl_incoming_rtl (parm
, data
.entry_parm
);
3024 /* Update info on where next arg arrives in registers. */
3025 FUNCTION_ARG_ADVANCE (all
.args_so_far
, data
.promoted_mode
,
3026 data
.passed_type
, data
.named_arg
);
3028 assign_parm_adjust_stack_rtl (&data
);
3030 if (assign_parm_setup_block_p (&data
))
3031 assign_parm_setup_block (&all
, parm
, &data
);
3032 else if (data
.passed_pointer
|| use_register_for_decl (parm
))
3033 assign_parm_setup_reg (&all
, parm
, &data
);
3035 assign_parm_setup_stack (&all
, parm
, &data
);
3038 if (targetm
.calls
.split_complex_arg
&& fnargs
!= all
.orig_fnargs
)
3039 assign_parms_unsplit_complex (&all
, fnargs
);
3041 /* Output all parameter conversion instructions (possibly including calls)
3042 now that all parameters have been copied out of hard registers. */
3043 emit_insn (all
.first_conversion_insn
);
3045 /* If we are receiving a struct value address as the first argument, set up
3046 the RTL for the function result. As this might require code to convert
3047 the transmitted address to Pmode, we do this here to ensure that possible
3048 preliminary conversions of the address have been emitted already. */
3049 if (all
.function_result_decl
)
3051 tree result
= DECL_RESULT (current_function_decl
);
3052 rtx addr
= DECL_RTL (all
.function_result_decl
);
3055 if (DECL_BY_REFERENCE (result
))
3059 addr
= convert_memory_address (Pmode
, addr
);
3060 x
= gen_rtx_MEM (DECL_MODE (result
), addr
);
3061 set_mem_attributes (x
, result
, 1);
3063 SET_DECL_RTL (result
, x
);
3066 /* We have aligned all the args, so add space for the pretend args. */
3067 current_function_pretend_args_size
= all
.pretend_args_size
;
3068 all
.stack_args_size
.constant
+= all
.extra_pretend_bytes
;
3069 current_function_args_size
= all
.stack_args_size
.constant
;
3071 /* Adjust function incoming argument size for alignment and
3074 #ifdef REG_PARM_STACK_SPACE
3075 current_function_args_size
= MAX (current_function_args_size
,
3076 REG_PARM_STACK_SPACE (fndecl
));
3079 current_function_args_size
= CEIL_ROUND (current_function_args_size
,
3080 PARM_BOUNDARY
/ BITS_PER_UNIT
);
3082 #ifdef ARGS_GROW_DOWNWARD
3083 current_function_arg_offset_rtx
3084 = (all
.stack_args_size
.var
== 0 ? GEN_INT (-all
.stack_args_size
.constant
)
3085 : expand_expr (size_diffop (all
.stack_args_size
.var
,
3086 size_int (-all
.stack_args_size
.constant
)),
3087 NULL_RTX
, VOIDmode
, 0));
3089 current_function_arg_offset_rtx
= ARGS_SIZE_RTX (all
.stack_args_size
);
3092 /* See how many bytes, if any, of its args a function should try to pop
3095 current_function_pops_args
= RETURN_POPS_ARGS (fndecl
, TREE_TYPE (fndecl
),
3096 current_function_args_size
);
3098 /* For stdarg.h function, save info about
3099 regs and stack space used by the named args. */
3101 current_function_args_info
= all
.args_so_far
;
3103 /* Set the rtx used for the function return value. Put this in its
3104 own variable so any optimizers that need this information don't have
3105 to include tree.h. Do this here so it gets done when an inlined
3106 function gets output. */
3108 current_function_return_rtx
3109 = (DECL_RTL_SET_P (DECL_RESULT (fndecl
))
3110 ? DECL_RTL (DECL_RESULT (fndecl
)) : NULL_RTX
);
3112 /* If scalar return value was computed in a pseudo-reg, or was a named
3113 return value that got dumped to the stack, copy that to the hard
3115 if (DECL_RTL_SET_P (DECL_RESULT (fndecl
)))
3117 tree decl_result
= DECL_RESULT (fndecl
);
3118 rtx decl_rtl
= DECL_RTL (decl_result
);
3120 if (REG_P (decl_rtl
)
3121 ? REGNO (decl_rtl
) >= FIRST_PSEUDO_REGISTER
3122 : DECL_REGISTER (decl_result
))
3126 real_decl_rtl
= targetm
.calls
.function_value (TREE_TYPE (decl_result
),
3128 REG_FUNCTION_VALUE_P (real_decl_rtl
) = 1;
3129 /* The delay slot scheduler assumes that current_function_return_rtx
3130 holds the hard register containing the return value, not a
3131 temporary pseudo. */
3132 current_function_return_rtx
= real_decl_rtl
;
3137 /* A subroutine of gimplify_parameters, invoked via walk_tree.
3138 For all seen types, gimplify their sizes. */
3141 gimplify_parm_type (tree
*tp
, int *walk_subtrees
, void *data
)
3148 if (POINTER_TYPE_P (t
))
3150 else if (TYPE_SIZE (t
) && !TREE_CONSTANT (TYPE_SIZE (t
))
3151 && !TYPE_SIZES_GIMPLIFIED (t
))
3153 gimplify_type_sizes (t
, (tree
*) data
);
3161 /* Gimplify the parameter list for current_function_decl. This involves
3162 evaluating SAVE_EXPRs of variable sized parameters and generating code
3163 to implement callee-copies reference parameters. Returns a list of
3164 statements to add to the beginning of the function, or NULL if nothing
3168 gimplify_parameters (void)
3170 struct assign_parm_data_all all
;
3171 tree fnargs
, parm
, stmts
= NULL
;
3173 assign_parms_initialize_all (&all
);
3174 fnargs
= assign_parms_augmented_arg_list (&all
);
3176 for (parm
= fnargs
; parm
; parm
= TREE_CHAIN (parm
))
3178 struct assign_parm_data_one data
;
3180 /* Extract the type of PARM; adjust it according to ABI. */
3181 assign_parm_find_data_types (&all
, parm
, &data
);
3183 /* Early out for errors and void parameters. */
3184 if (data
.passed_mode
== VOIDmode
|| DECL_SIZE (parm
) == NULL
)
3187 /* Update info on where next arg arrives in registers. */
3188 FUNCTION_ARG_ADVANCE (all
.args_so_far
, data
.promoted_mode
,
3189 data
.passed_type
, data
.named_arg
);
3191 /* ??? Once upon a time variable_size stuffed parameter list
3192 SAVE_EXPRs (amongst others) onto a pending sizes list. This
3193 turned out to be less than manageable in the gimple world.
3194 Now we have to hunt them down ourselves. */
3195 walk_tree_without_duplicates (&data
.passed_type
,
3196 gimplify_parm_type
, &stmts
);
3198 if (!TREE_CONSTANT (DECL_SIZE (parm
)))
3200 gimplify_one_sizepos (&DECL_SIZE (parm
), &stmts
);
3201 gimplify_one_sizepos (&DECL_SIZE_UNIT (parm
), &stmts
);
3204 if (data
.passed_pointer
)
3206 tree type
= TREE_TYPE (data
.passed_type
);
3207 if (reference_callee_copied (&all
.args_so_far
, TYPE_MODE (type
),
3208 type
, data
.named_arg
))
3212 /* For constant sized objects, this is trivial; for
3213 variable-sized objects, we have to play games. */
3214 if (TREE_CONSTANT (DECL_SIZE (parm
)))
3216 local
= create_tmp_var (type
, get_name (parm
));
3217 DECL_IGNORED_P (local
) = 0;
3221 tree ptr_type
, addr
;
3223 ptr_type
= build_pointer_type (type
);
3224 addr
= create_tmp_var (ptr_type
, get_name (parm
));
3225 DECL_IGNORED_P (addr
) = 0;
3226 local
= build_fold_indirect_ref (addr
);
3228 t
= built_in_decls
[BUILT_IN_ALLOCA
];
3229 t
= build_call_expr (t
, 1, DECL_SIZE_UNIT (parm
));
3230 t
= fold_convert (ptr_type
, t
);
3231 t
= build_gimple_modify_stmt (addr
, t
);
3232 gimplify_and_add (t
, &stmts
);
3235 t
= build_gimple_modify_stmt (local
, parm
);
3236 gimplify_and_add (t
, &stmts
);
3238 SET_DECL_VALUE_EXPR (parm
, local
);
3239 DECL_HAS_VALUE_EXPR_P (parm
) = 1;
3247 /* Compute the size and offset from the start of the stacked arguments for a
3248 parm passed in mode PASSED_MODE and with type TYPE.
3250 INITIAL_OFFSET_PTR points to the current offset into the stacked
3253 The starting offset and size for this parm are returned in
3254 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
3255 nonzero, the offset is that of stack slot, which is returned in
3256 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
3257 padding required from the initial offset ptr to the stack slot.
3259 IN_REGS is nonzero if the argument will be passed in registers. It will
3260 never be set if REG_PARM_STACK_SPACE is not defined.
3262 FNDECL is the function in which the argument was defined.
3264 There are two types of rounding that are done. The first, controlled by
3265 FUNCTION_ARG_BOUNDARY, forces the offset from the start of the argument
3266 list to be aligned to the specific boundary (in bits). This rounding
3267 affects the initial and starting offsets, but not the argument size.
3269 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
3270 optionally rounds the size of the parm to PARM_BOUNDARY. The
3271 initial offset is not affected by this rounding, while the size always
3272 is and the starting offset may be. */
3274 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
3275 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
3276 callers pass in the total size of args so far as
3277 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
3280 locate_and_pad_parm (enum machine_mode passed_mode
, tree type
, int in_regs
,
3281 int partial
, tree fndecl ATTRIBUTE_UNUSED
,
3282 struct args_size
*initial_offset_ptr
,
3283 struct locate_and_pad_arg_data
*locate
)
3286 enum direction where_pad
;
3287 unsigned int boundary
;
3288 int reg_parm_stack_space
= 0;
3289 int part_size_in_regs
;
3291 #ifdef REG_PARM_STACK_SPACE
3292 reg_parm_stack_space
= REG_PARM_STACK_SPACE (fndecl
);
3294 /* If we have found a stack parm before we reach the end of the
3295 area reserved for registers, skip that area. */
3298 if (reg_parm_stack_space
> 0)
3300 if (initial_offset_ptr
->var
)
3302 initial_offset_ptr
->var
3303 = size_binop (MAX_EXPR
, ARGS_SIZE_TREE (*initial_offset_ptr
),
3304 ssize_int (reg_parm_stack_space
));
3305 initial_offset_ptr
->constant
= 0;
3307 else if (initial_offset_ptr
->constant
< reg_parm_stack_space
)
3308 initial_offset_ptr
->constant
= reg_parm_stack_space
;
3311 #endif /* REG_PARM_STACK_SPACE */
3313 part_size_in_regs
= (reg_parm_stack_space
== 0 ? partial
: 0);
3316 = type
? size_in_bytes (type
) : size_int (GET_MODE_SIZE (passed_mode
));
3317 where_pad
= FUNCTION_ARG_PADDING (passed_mode
, type
);
3318 boundary
= FUNCTION_ARG_BOUNDARY (passed_mode
, type
);
3319 locate
->where_pad
= where_pad
;
3320 locate
->boundary
= boundary
;
3322 /* Remember if the outgoing parameter requires extra alignment on the
3323 calling function side. */
3324 if (boundary
> PREFERRED_STACK_BOUNDARY
)
3325 boundary
= PREFERRED_STACK_BOUNDARY
;
3326 if (cfun
->stack_alignment_needed
< boundary
)
3327 cfun
->stack_alignment_needed
= boundary
;
3329 #ifdef ARGS_GROW_DOWNWARD
3330 locate
->slot_offset
.constant
= -initial_offset_ptr
->constant
;
3331 if (initial_offset_ptr
->var
)
3332 locate
->slot_offset
.var
= size_binop (MINUS_EXPR
, ssize_int (0),
3333 initial_offset_ptr
->var
);
3337 if (where_pad
!= none
3338 && (!host_integerp (sizetree
, 1)
3339 || (tree_low_cst (sizetree
, 1) * BITS_PER_UNIT
) % PARM_BOUNDARY
))
3340 s2
= round_up (s2
, PARM_BOUNDARY
/ BITS_PER_UNIT
);
3341 SUB_PARM_SIZE (locate
->slot_offset
, s2
);
3344 locate
->slot_offset
.constant
+= part_size_in_regs
;
3347 #ifdef REG_PARM_STACK_SPACE
3348 || REG_PARM_STACK_SPACE (fndecl
) > 0
3351 pad_to_arg_alignment (&locate
->slot_offset
, boundary
,
3352 &locate
->alignment_pad
);
3354 locate
->size
.constant
= (-initial_offset_ptr
->constant
3355 - locate
->slot_offset
.constant
);
3356 if (initial_offset_ptr
->var
)
3357 locate
->size
.var
= size_binop (MINUS_EXPR
,
3358 size_binop (MINUS_EXPR
,
3360 initial_offset_ptr
->var
),
3361 locate
->slot_offset
.var
);
3363 /* Pad_below needs the pre-rounded size to know how much to pad
3365 locate
->offset
= locate
->slot_offset
;
3366 if (where_pad
== downward
)
3367 pad_below (&locate
->offset
, passed_mode
, sizetree
);
3369 #else /* !ARGS_GROW_DOWNWARD */
3371 #ifdef REG_PARM_STACK_SPACE
3372 || REG_PARM_STACK_SPACE (fndecl
) > 0
3375 pad_to_arg_alignment (initial_offset_ptr
, boundary
,
3376 &locate
->alignment_pad
);
3377 locate
->slot_offset
= *initial_offset_ptr
;
3379 #ifdef PUSH_ROUNDING
3380 if (passed_mode
!= BLKmode
)
3381 sizetree
= size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree
)));
3384 /* Pad_below needs the pre-rounded size to know how much to pad below
3385 so this must be done before rounding up. */
3386 locate
->offset
= locate
->slot_offset
;
3387 if (where_pad
== downward
)
3388 pad_below (&locate
->offset
, passed_mode
, sizetree
);
3390 if (where_pad
!= none
3391 && (!host_integerp (sizetree
, 1)
3392 || (tree_low_cst (sizetree
, 1) * BITS_PER_UNIT
) % PARM_BOUNDARY
))
3393 sizetree
= round_up (sizetree
, PARM_BOUNDARY
/ BITS_PER_UNIT
);
3395 ADD_PARM_SIZE (locate
->size
, sizetree
);
3397 locate
->size
.constant
-= part_size_in_regs
;
3398 #endif /* ARGS_GROW_DOWNWARD */
3401 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
3402 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
3405 pad_to_arg_alignment (struct args_size
*offset_ptr
, int boundary
,
3406 struct args_size
*alignment_pad
)
3408 tree save_var
= NULL_TREE
;
3409 HOST_WIDE_INT save_constant
= 0;
3410 int boundary_in_bytes
= boundary
/ BITS_PER_UNIT
;
3411 HOST_WIDE_INT sp_offset
= STACK_POINTER_OFFSET
;
3413 #ifdef SPARC_STACK_BOUNDARY_HACK
3414 /* ??? The SPARC port may claim a STACK_BOUNDARY higher than
3415 the real alignment of %sp. However, when it does this, the
3416 alignment of %sp+STACK_POINTER_OFFSET is STACK_BOUNDARY. */
3417 if (SPARC_STACK_BOUNDARY_HACK
)
3421 if (boundary
> PARM_BOUNDARY
&& boundary
> STACK_BOUNDARY
)
3423 save_var
= offset_ptr
->var
;
3424 save_constant
= offset_ptr
->constant
;
3427 alignment_pad
->var
= NULL_TREE
;
3428 alignment_pad
->constant
= 0;
3430 if (boundary
> BITS_PER_UNIT
)
3432 if (offset_ptr
->var
)
3434 tree sp_offset_tree
= ssize_int (sp_offset
);
3435 tree offset
= size_binop (PLUS_EXPR
,
3436 ARGS_SIZE_TREE (*offset_ptr
),
3438 #ifdef ARGS_GROW_DOWNWARD
3439 tree rounded
= round_down (offset
, boundary
/ BITS_PER_UNIT
);
3441 tree rounded
= round_up (offset
, boundary
/ BITS_PER_UNIT
);
3444 offset_ptr
->var
= size_binop (MINUS_EXPR
, rounded
, sp_offset_tree
);
3445 /* ARGS_SIZE_TREE includes constant term. */
3446 offset_ptr
->constant
= 0;
3447 if (boundary
> PARM_BOUNDARY
&& boundary
> STACK_BOUNDARY
)
3448 alignment_pad
->var
= size_binop (MINUS_EXPR
, offset_ptr
->var
,
3453 offset_ptr
->constant
= -sp_offset
+
3454 #ifdef ARGS_GROW_DOWNWARD
3455 FLOOR_ROUND (offset_ptr
->constant
+ sp_offset
, boundary_in_bytes
);
3457 CEIL_ROUND (offset_ptr
->constant
+ sp_offset
, boundary_in_bytes
);
3459 if (boundary
> PARM_BOUNDARY
&& boundary
> STACK_BOUNDARY
)
3460 alignment_pad
->constant
= offset_ptr
->constant
- save_constant
;
3466 pad_below (struct args_size
*offset_ptr
, enum machine_mode passed_mode
, tree sizetree
)
3468 if (passed_mode
!= BLKmode
)
3470 if (GET_MODE_BITSIZE (passed_mode
) % PARM_BOUNDARY
)
3471 offset_ptr
->constant
3472 += (((GET_MODE_BITSIZE (passed_mode
) + PARM_BOUNDARY
- 1)
3473 / PARM_BOUNDARY
* PARM_BOUNDARY
/ BITS_PER_UNIT
)
3474 - GET_MODE_SIZE (passed_mode
));
3478 if (TREE_CODE (sizetree
) != INTEGER_CST
3479 || (TREE_INT_CST_LOW (sizetree
) * BITS_PER_UNIT
) % PARM_BOUNDARY
)
3481 /* Round the size up to multiple of PARM_BOUNDARY bits. */
3482 tree s2
= round_up (sizetree
, PARM_BOUNDARY
/ BITS_PER_UNIT
);
3484 ADD_PARM_SIZE (*offset_ptr
, s2
);
3485 SUB_PARM_SIZE (*offset_ptr
, sizetree
);
3491 /* True if register REGNO was alive at a place where `setjmp' was
3492 called and was set more than once or is an argument. Such regs may
3493 be clobbered by `longjmp'. */
3496 regno_clobbered_at_setjmp (bitmap setjmp_crosses
, int regno
)
3498 /* There appear to be cases where some local vars never reach the
3499 backend but have bogus regnos. */
3500 if (regno
>= max_reg_num ())
3503 return ((REG_N_SETS (regno
) > 1
3504 || REGNO_REG_SET_P (df_get_live_out (ENTRY_BLOCK_PTR
), regno
))
3505 && REGNO_REG_SET_P (setjmp_crosses
, regno
));
3508 /* Walk the tree of blocks describing the binding levels within a
3509 function and warn about variables the might be killed by setjmp or
3510 vfork. This is done after calling flow_analysis before register
3511 allocation since that will clobber the pseudo-regs to hard
3515 setjmp_vars_warning (bitmap setjmp_crosses
, tree block
)
3519 for (decl
= BLOCK_VARS (block
); decl
; decl
= TREE_CHAIN (decl
))
3521 if (TREE_CODE (decl
) == VAR_DECL
3522 && DECL_RTL_SET_P (decl
)
3523 && REG_P (DECL_RTL (decl
))
3524 && regno_clobbered_at_setjmp (setjmp_crosses
, REGNO (DECL_RTL (decl
))))
3525 warning (OPT_Wclobbered
, "variable %q+D might be clobbered by"
3526 " %<longjmp%> or %<vfork%>", decl
);
3529 for (sub
= BLOCK_SUBBLOCKS (block
); sub
; sub
= TREE_CHAIN (sub
))
3530 setjmp_vars_warning (setjmp_crosses
, sub
);
3533 /* Do the appropriate part of setjmp_vars_warning
3534 but for arguments instead of local variables. */
3537 setjmp_args_warning (bitmap setjmp_crosses
)
3540 for (decl
= DECL_ARGUMENTS (current_function_decl
);
3541 decl
; decl
= TREE_CHAIN (decl
))
3542 if (DECL_RTL (decl
) != 0
3543 && REG_P (DECL_RTL (decl
))
3544 && regno_clobbered_at_setjmp (setjmp_crosses
, REGNO (DECL_RTL (decl
))))
3545 warning (OPT_Wclobbered
,
3546 "argument %q+D might be clobbered by %<longjmp%> or %<vfork%>",
3550 /* Generate warning messages for variables live across setjmp. */
3553 generate_setjmp_warnings (void)
3555 bitmap setjmp_crosses
= regstat_get_setjmp_crosses ();
3557 if (n_basic_blocks
== NUM_FIXED_BLOCKS
3558 || bitmap_empty_p (setjmp_crosses
))
3561 setjmp_vars_warning (setjmp_crosses
, DECL_INITIAL (current_function_decl
));
3562 setjmp_args_warning (setjmp_crosses
);
3566 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
3567 and create duplicate blocks. */
3568 /* ??? Need an option to either create block fragments or to create
3569 abstract origin duplicates of a source block. It really depends
3570 on what optimization has been performed. */
3573 reorder_blocks (void)
3575 tree block
= DECL_INITIAL (current_function_decl
);
3576 VEC(tree
,heap
) *block_stack
;
3578 if (block
== NULL_TREE
)
3581 block_stack
= VEC_alloc (tree
, heap
, 10);
3583 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
3584 clear_block_marks (block
);
3586 /* Prune the old trees away, so that they don't get in the way. */
3587 BLOCK_SUBBLOCKS (block
) = NULL_TREE
;
3588 BLOCK_CHAIN (block
) = NULL_TREE
;
3590 /* Recreate the block tree from the note nesting. */
3591 reorder_blocks_1 (get_insns (), block
, &block_stack
);
3592 BLOCK_SUBBLOCKS (block
) = blocks_nreverse (BLOCK_SUBBLOCKS (block
));
3594 VEC_free (tree
, heap
, block_stack
);
3597 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
3600 clear_block_marks (tree block
)
3604 TREE_ASM_WRITTEN (block
) = 0;
3605 clear_block_marks (BLOCK_SUBBLOCKS (block
));
3606 block
= BLOCK_CHAIN (block
);
3611 reorder_blocks_1 (rtx insns
, tree current_block
, VEC(tree
,heap
) **p_block_stack
)
3615 for (insn
= insns
; insn
; insn
= NEXT_INSN (insn
))
3619 if (NOTE_KIND (insn
) == NOTE_INSN_BLOCK_BEG
)
3621 tree block
= NOTE_BLOCK (insn
);
3624 origin
= (BLOCK_FRAGMENT_ORIGIN (block
)
3625 ? BLOCK_FRAGMENT_ORIGIN (block
)
3628 /* If we have seen this block before, that means it now
3629 spans multiple address regions. Create a new fragment. */
3630 if (TREE_ASM_WRITTEN (block
))
3632 tree new_block
= copy_node (block
);
3634 BLOCK_FRAGMENT_ORIGIN (new_block
) = origin
;
3635 BLOCK_FRAGMENT_CHAIN (new_block
)
3636 = BLOCK_FRAGMENT_CHAIN (origin
);
3637 BLOCK_FRAGMENT_CHAIN (origin
) = new_block
;
3639 NOTE_BLOCK (insn
) = new_block
;
3643 BLOCK_SUBBLOCKS (block
) = 0;
3644 TREE_ASM_WRITTEN (block
) = 1;
3645 /* When there's only one block for the entire function,
3646 current_block == block and we mustn't do this, it
3647 will cause infinite recursion. */
3648 if (block
!= current_block
)
3650 if (block
!= origin
)
3651 gcc_assert (BLOCK_SUPERCONTEXT (origin
) == current_block
);
3653 BLOCK_SUPERCONTEXT (block
) = current_block
;
3654 BLOCK_CHAIN (block
) = BLOCK_SUBBLOCKS (current_block
);
3655 BLOCK_SUBBLOCKS (current_block
) = block
;
3656 current_block
= origin
;
3658 VEC_safe_push (tree
, heap
, *p_block_stack
, block
);
3660 else if (NOTE_KIND (insn
) == NOTE_INSN_BLOCK_END
)
3662 NOTE_BLOCK (insn
) = VEC_pop (tree
, *p_block_stack
);
3663 BLOCK_SUBBLOCKS (current_block
)
3664 = blocks_nreverse (BLOCK_SUBBLOCKS (current_block
));
3665 current_block
= BLOCK_SUPERCONTEXT (current_block
);
3671 /* Reverse the order of elements in the chain T of blocks,
3672 and return the new head of the chain (old last element). */
3675 blocks_nreverse (tree t
)
3677 tree prev
= 0, decl
, next
;
3678 for (decl
= t
; decl
; decl
= next
)
3680 next
= BLOCK_CHAIN (decl
);
3681 BLOCK_CHAIN (decl
) = prev
;
3687 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
3688 non-NULL, list them all into VECTOR, in a depth-first preorder
3689 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
3693 all_blocks (tree block
, tree
*vector
)
3699 TREE_ASM_WRITTEN (block
) = 0;
3701 /* Record this block. */
3703 vector
[n_blocks
] = block
;
3707 /* Record the subblocks, and their subblocks... */
3708 n_blocks
+= all_blocks (BLOCK_SUBBLOCKS (block
),
3709 vector
? vector
+ n_blocks
: 0);
3710 block
= BLOCK_CHAIN (block
);
3716 /* Return a vector containing all the blocks rooted at BLOCK. The
3717 number of elements in the vector is stored in N_BLOCKS_P. The
3718 vector is dynamically allocated; it is the caller's responsibility
3719 to call `free' on the pointer returned. */
3722 get_block_vector (tree block
, int *n_blocks_p
)
3726 *n_blocks_p
= all_blocks (block
, NULL
);
3727 block_vector
= XNEWVEC (tree
, *n_blocks_p
);
3728 all_blocks (block
, block_vector
);
3730 return block_vector
;
3733 static GTY(()) int next_block_index
= 2;
3735 /* Set BLOCK_NUMBER for all the blocks in FN. */
3738 number_blocks (tree fn
)
3744 /* For SDB and XCOFF debugging output, we start numbering the blocks
3745 from 1 within each function, rather than keeping a running
3747 #if defined (SDB_DEBUGGING_INFO) || defined (XCOFF_DEBUGGING_INFO)
3748 if (write_symbols
== SDB_DEBUG
|| write_symbols
== XCOFF_DEBUG
)
3749 next_block_index
= 1;
3752 block_vector
= get_block_vector (DECL_INITIAL (fn
), &n_blocks
);
3754 /* The top-level BLOCK isn't numbered at all. */
3755 for (i
= 1; i
< n_blocks
; ++i
)
3756 /* We number the blocks from two. */
3757 BLOCK_NUMBER (block_vector
[i
]) = next_block_index
++;
3759 free (block_vector
);
3764 /* If VAR is present in a subblock of BLOCK, return the subblock. */
3767 debug_find_var_in_block_tree (tree var
, tree block
)
3771 for (t
= BLOCK_VARS (block
); t
; t
= TREE_CHAIN (t
))
3775 for (t
= BLOCK_SUBBLOCKS (block
); t
; t
= TREE_CHAIN (t
))
3777 tree ret
= debug_find_var_in_block_tree (var
, t
);
3786 /* Return value of funcdef and increase it. */
3788 get_next_funcdef_no (void)
3790 return funcdef_no
++;
3793 /* Allocate a function structure for FNDECL and set its contents
3797 allocate_struct_function (tree fndecl
)
3800 tree fntype
= fndecl
? TREE_TYPE (fndecl
) : NULL_TREE
;
3802 cfun
= ggc_alloc_cleared (sizeof (struct function
));
3804 cfun
->stack_alignment_needed
= STACK_BOUNDARY
;
3805 cfun
->preferred_stack_boundary
= STACK_BOUNDARY
;
3807 current_function_funcdef_no
= get_next_funcdef_no ();
3809 cfun
->function_frequency
= FUNCTION_FREQUENCY_NORMAL
;
3811 init_eh_for_function ();
3813 lang_hooks
.function
.init (cfun
);
3814 if (init_machine_status
)
3815 cfun
->machine
= (*init_machine_status
) ();
3820 DECL_STRUCT_FUNCTION (fndecl
) = cfun
;
3821 cfun
->decl
= fndecl
;
3823 result
= DECL_RESULT (fndecl
);
3824 if (aggregate_value_p (result
, fndecl
))
3826 #ifdef PCC_STATIC_STRUCT_RETURN
3827 current_function_returns_pcc_struct
= 1;
3829 current_function_returns_struct
= 1;
3832 current_function_returns_pointer
= POINTER_TYPE_P (TREE_TYPE (result
));
3834 current_function_stdarg
3836 && TYPE_ARG_TYPES (fntype
) != 0
3837 && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype
)))
3838 != void_type_node
));
3840 /* Assume all registers in stdarg functions need to be saved. */
3841 cfun
->va_list_gpr_size
= VA_LIST_MAX_GPR_SIZE
;
3842 cfun
->va_list_fpr_size
= VA_LIST_MAX_FPR_SIZE
;
3845 /* Reset cfun, and other non-struct-function variables to defaults as
3846 appropriate for emitting rtl at the start of a function. */
3849 prepare_function_start (tree fndecl
)
3851 if (fndecl
&& DECL_STRUCT_FUNCTION (fndecl
))
3852 cfun
= DECL_STRUCT_FUNCTION (fndecl
);
3854 allocate_struct_function (fndecl
);
3856 init_varasm_status (cfun
);
3859 cse_not_expected
= ! optimize
;
3861 /* Caller save not needed yet. */
3862 caller_save_needed
= 0;
3864 /* We haven't done register allocation yet. */
3867 /* Indicate that we have not instantiated virtual registers yet. */
3868 virtuals_instantiated
= 0;
3870 /* Indicate that we want CONCATs now. */
3871 generating_concat_p
= 1;
3873 /* Indicate we have no need of a frame pointer yet. */
3874 frame_pointer_needed
= 0;
3877 /* Initialize the rtl expansion mechanism so that we can do simple things
3878 like generate sequences. This is used to provide a context during global
3879 initialization of some passes. */
3881 init_dummy_function_start (void)
3883 prepare_function_start (NULL
);
3886 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
3887 and initialize static variables for generating RTL for the statements
3891 init_function_start (tree subr
)
3893 prepare_function_start (subr
);
3895 /* Warn if this value is an aggregate type,
3896 regardless of which calling convention we are using for it. */
3897 if (AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr
))))
3898 warning (OPT_Waggregate_return
, "function returns an aggregate");
3901 /* Make sure all values used by the optimization passes have sane
3904 init_function_for_compilation (void)
3908 /* No prologue/epilogue insns yet. Make sure that these vectors are
3910 gcc_assert (VEC_length (int, prologue
) == 0);
3911 gcc_assert (VEC_length (int, epilogue
) == 0);
3912 gcc_assert (VEC_length (int, sibcall_epilogue
) == 0);
3916 struct tree_opt_pass pass_init_function
=
3920 init_function_for_compilation
, /* execute */
3923 0, /* static_pass_number */
3925 0, /* properties_required */
3926 0, /* properties_provided */
3927 0, /* properties_destroyed */
3928 0, /* todo_flags_start */
3929 0, /* todo_flags_finish */
3935 expand_main_function (void)
3937 #if (defined(INVOKE__main) \
3938 || (!defined(HAS_INIT_SECTION) \
3939 && !defined(INIT_SECTION_ASM_OP) \
3940 && !defined(INIT_ARRAY_SECTION_ASM_OP)))
3941 emit_library_call (init_one_libfunc (NAME__MAIN
), LCT_NORMAL
, VOIDmode
, 0);
3945 /* Expand code to initialize the stack_protect_guard. This is invoked at
3946 the beginning of a function to be protected. */
3948 #ifndef HAVE_stack_protect_set
3949 # define HAVE_stack_protect_set 0
3950 # define gen_stack_protect_set(x,y) (gcc_unreachable (), NULL_RTX)
3954 stack_protect_prologue (void)
3956 tree guard_decl
= targetm
.stack_protect_guard ();
3959 /* Avoid expand_expr here, because we don't want guard_decl pulled
3960 into registers unless absolutely necessary. And we know that
3961 cfun->stack_protect_guard is a local stack slot, so this skips
3963 x
= validize_mem (DECL_RTL (cfun
->stack_protect_guard
));
3964 y
= validize_mem (DECL_RTL (guard_decl
));
3966 /* Allow the target to copy from Y to X without leaking Y into a
3968 if (HAVE_stack_protect_set
)
3970 rtx insn
= gen_stack_protect_set (x
, y
);
3978 /* Otherwise do a straight move. */
3979 emit_move_insn (x
, y
);
3982 /* Expand code to verify the stack_protect_guard. This is invoked at
3983 the end of a function to be protected. */
3985 #ifndef HAVE_stack_protect_test
3986 # define HAVE_stack_protect_test 0
3987 # define gen_stack_protect_test(x, y, z) (gcc_unreachable (), NULL_RTX)
3991 stack_protect_epilogue (void)
3993 tree guard_decl
= targetm
.stack_protect_guard ();
3994 rtx label
= gen_label_rtx ();
3997 /* Avoid expand_expr here, because we don't want guard_decl pulled
3998 into registers unless absolutely necessary. And we know that
3999 cfun->stack_protect_guard is a local stack slot, so this skips
4001 x
= validize_mem (DECL_RTL (cfun
->stack_protect_guard
));
4002 y
= validize_mem (DECL_RTL (guard_decl
));
4004 /* Allow the target to compare Y with X without leaking either into
4006 switch (HAVE_stack_protect_test
!= 0)
4009 tmp
= gen_stack_protect_test (x
, y
, label
);
4018 emit_cmp_and_jump_insns (x
, y
, EQ
, NULL_RTX
, ptr_mode
, 1, label
);
4022 /* The noreturn predictor has been moved to the tree level. The rtl-level
4023 predictors estimate this branch about 20%, which isn't enough to get
4024 things moved out of line. Since this is the only extant case of adding
4025 a noreturn function at the rtl level, it doesn't seem worth doing ought
4026 except adding the prediction by hand. */
4027 tmp
= get_last_insn ();
4029 predict_insn_def (tmp
, PRED_NORETURN
, TAKEN
);
4031 expand_expr_stmt (targetm
.stack_protect_fail ());
4035 /* Start the RTL for a new function, and set variables used for
4037 SUBR is the FUNCTION_DECL node.
4038 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
4039 the function's parameters, which must be run at any return statement. */
4042 expand_function_start (tree subr
)
4044 /* Make sure volatile mem refs aren't considered
4045 valid operands of arithmetic insns. */
4046 init_recog_no_volatile ();
4048 current_function_profile
4050 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr
));
4052 current_function_limit_stack
4053 = (stack_limit_rtx
!= NULL_RTX
&& ! DECL_NO_LIMIT_STACK (subr
));
4055 /* Make the label for return statements to jump to. Do not special
4056 case machines with special return instructions -- they will be
4057 handled later during jump, ifcvt, or epilogue creation. */
4058 return_label
= gen_label_rtx ();
4060 /* Initialize rtx used to return the value. */
4061 /* Do this before assign_parms so that we copy the struct value address
4062 before any library calls that assign parms might generate. */
4064 /* Decide whether to return the value in memory or in a register. */
4065 if (aggregate_value_p (DECL_RESULT (subr
), subr
))
4067 /* Returning something that won't go in a register. */
4068 rtx value_address
= 0;
4070 #ifdef PCC_STATIC_STRUCT_RETURN
4071 if (current_function_returns_pcc_struct
)
4073 int size
= int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr
)));
4074 value_address
= assemble_static_space (size
);
4079 rtx sv
= targetm
.calls
.struct_value_rtx (TREE_TYPE (subr
), 2);
4080 /* Expect to be passed the address of a place to store the value.
4081 If it is passed as an argument, assign_parms will take care of
4085 value_address
= gen_reg_rtx (Pmode
);
4086 emit_move_insn (value_address
, sv
);
4091 rtx x
= value_address
;
4092 if (!DECL_BY_REFERENCE (DECL_RESULT (subr
)))
4094 x
= gen_rtx_MEM (DECL_MODE (DECL_RESULT (subr
)), x
);
4095 set_mem_attributes (x
, DECL_RESULT (subr
), 1);
4097 SET_DECL_RTL (DECL_RESULT (subr
), x
);
4100 else if (DECL_MODE (DECL_RESULT (subr
)) == VOIDmode
)
4101 /* If return mode is void, this decl rtl should not be used. */
4102 SET_DECL_RTL (DECL_RESULT (subr
), NULL_RTX
);
4105 /* Compute the return values into a pseudo reg, which we will copy
4106 into the true return register after the cleanups are done. */
4107 tree return_type
= TREE_TYPE (DECL_RESULT (subr
));
4108 if (TYPE_MODE (return_type
) != BLKmode
4109 && targetm
.calls
.return_in_msb (return_type
))
4110 /* expand_function_end will insert the appropriate padding in
4111 this case. Use the return value's natural (unpadded) mode
4112 within the function proper. */
4113 SET_DECL_RTL (DECL_RESULT (subr
),
4114 gen_reg_rtx (TYPE_MODE (return_type
)));
4117 /* In order to figure out what mode to use for the pseudo, we
4118 figure out what the mode of the eventual return register will
4119 actually be, and use that. */
4120 rtx hard_reg
= hard_function_value (return_type
, subr
, 0, 1);
4122 /* Structures that are returned in registers are not
4123 aggregate_value_p, so we may see a PARALLEL or a REG. */
4124 if (REG_P (hard_reg
))
4125 SET_DECL_RTL (DECL_RESULT (subr
),
4126 gen_reg_rtx (GET_MODE (hard_reg
)));
4129 gcc_assert (GET_CODE (hard_reg
) == PARALLEL
);
4130 SET_DECL_RTL (DECL_RESULT (subr
), gen_group_rtx (hard_reg
));
4134 /* Set DECL_REGISTER flag so that expand_function_end will copy the
4135 result to the real return register(s). */
4136 DECL_REGISTER (DECL_RESULT (subr
)) = 1;
4139 /* Initialize rtx for parameters and local variables.
4140 In some cases this requires emitting insns. */
4141 assign_parms (subr
);
4143 /* If function gets a static chain arg, store it. */
4144 if (cfun
->static_chain_decl
)
4146 tree parm
= cfun
->static_chain_decl
;
4147 rtx local
= gen_reg_rtx (Pmode
);
4149 set_decl_incoming_rtl (parm
, static_chain_incoming_rtx
);
4150 SET_DECL_RTL (parm
, local
);
4151 mark_reg_pointer (local
, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm
))));
4153 emit_move_insn (local
, static_chain_incoming_rtx
);
4156 /* If the function receives a non-local goto, then store the
4157 bits we need to restore the frame pointer. */
4158 if (cfun
->nonlocal_goto_save_area
)
4163 /* ??? We need to do this save early. Unfortunately here is
4164 before the frame variable gets declared. Help out... */
4165 expand_var (TREE_OPERAND (cfun
->nonlocal_goto_save_area
, 0));
4167 t_save
= build4 (ARRAY_REF
, ptr_type_node
,
4168 cfun
->nonlocal_goto_save_area
,
4169 integer_zero_node
, NULL_TREE
, NULL_TREE
);
4170 r_save
= expand_expr (t_save
, NULL_RTX
, VOIDmode
, EXPAND_WRITE
);
4171 r_save
= convert_memory_address (Pmode
, r_save
);
4173 emit_move_insn (r_save
, virtual_stack_vars_rtx
);
4174 update_nonlocal_goto_save_area ();
4177 /* The following was moved from init_function_start.
4178 The move is supposed to make sdb output more accurate. */
4179 /* Indicate the beginning of the function body,
4180 as opposed to parm setup. */
4181 emit_note (NOTE_INSN_FUNCTION_BEG
);
4183 gcc_assert (NOTE_P (get_last_insn ()));
4185 parm_birth_insn
= get_last_insn ();
4187 if (current_function_profile
)
4190 PROFILE_HOOK (current_function_funcdef_no
);
4194 /* After the display initializations is where the stack checking
4196 if(flag_stack_check
)
4197 stack_check_probe_note
= emit_note (NOTE_INSN_DELETED
);
4199 /* Make sure there is a line number after the function entry setup code. */
4200 force_next_line_note ();
4203 /* Undo the effects of init_dummy_function_start. */
4205 expand_dummy_function_end (void)
4207 /* End any sequences that failed to be closed due to syntax errors. */
4208 while (in_sequence_p ())
4211 /* Outside function body, can't compute type's actual size
4212 until next function's body starts. */
4214 free_after_parsing (cfun
);
4215 free_after_compilation (cfun
);
4219 /* Call DOIT for each hard register used as a return value from
4220 the current function. */
4223 diddle_return_value (void (*doit
) (rtx
, void *), void *arg
)
4225 rtx outgoing
= current_function_return_rtx
;
4230 if (REG_P (outgoing
))
4231 (*doit
) (outgoing
, arg
);
4232 else if (GET_CODE (outgoing
) == PARALLEL
)
4236 for (i
= 0; i
< XVECLEN (outgoing
, 0); i
++)
4238 rtx x
= XEXP (XVECEXP (outgoing
, 0, i
), 0);
4240 if (REG_P (x
) && REGNO (x
) < FIRST_PSEUDO_REGISTER
)
4247 do_clobber_return_reg (rtx reg
, void *arg ATTRIBUTE_UNUSED
)
4249 emit_insn (gen_rtx_CLOBBER (VOIDmode
, reg
));
4253 clobber_return_register (void)
4255 diddle_return_value (do_clobber_return_reg
, NULL
);
4257 /* In case we do use pseudo to return value, clobber it too. */
4258 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl
)))
4260 tree decl_result
= DECL_RESULT (current_function_decl
);
4261 rtx decl_rtl
= DECL_RTL (decl_result
);
4262 if (REG_P (decl_rtl
) && REGNO (decl_rtl
) >= FIRST_PSEUDO_REGISTER
)
4264 do_clobber_return_reg (decl_rtl
, NULL
);
4270 do_use_return_reg (rtx reg
, void *arg ATTRIBUTE_UNUSED
)
4272 emit_insn (gen_rtx_USE (VOIDmode
, reg
));
4276 use_return_register (void)
4278 diddle_return_value (do_use_return_reg
, NULL
);
4281 /* Possibly warn about unused parameters. */
4283 do_warn_unused_parameter (tree fn
)
4287 for (decl
= DECL_ARGUMENTS (fn
);
4288 decl
; decl
= TREE_CHAIN (decl
))
4289 if (!TREE_USED (decl
) && TREE_CODE (decl
) == PARM_DECL
4290 && DECL_NAME (decl
) && !DECL_ARTIFICIAL (decl
))
4291 warning (OPT_Wunused_parameter
, "unused parameter %q+D", decl
);
4294 static GTY(()) rtx initial_trampoline
;
4296 /* Generate RTL for the end of the current function. */
4299 expand_function_end (void)
4303 /* If arg_pointer_save_area was referenced only from a nested
4304 function, we will not have initialized it yet. Do that now. */
4305 if (arg_pointer_save_area
&& ! cfun
->arg_pointer_save_area_init
)
4306 get_arg_pointer_save_area (cfun
);
4308 /* If we are doing stack checking and this function makes calls,
4309 do a stack probe at the start of the function to ensure we have enough
4310 space for another stack frame. */
4311 if (flag_stack_check
&& ! STACK_CHECK_BUILTIN
)
4315 for (insn
= get_insns (); insn
; insn
= NEXT_INSN (insn
))
4319 probe_stack_range (STACK_CHECK_PROTECT
,
4320 GEN_INT (STACK_CHECK_MAX_FRAME_SIZE
));
4323 emit_insn_before (seq
, stack_check_probe_note
);
4328 /* Possibly warn about unused parameters.
4329 When frontend does unit-at-a-time, the warning is already
4330 issued at finalization time. */
4331 if (warn_unused_parameter
4332 && !lang_hooks
.callgraph
.expand_function
)
4333 do_warn_unused_parameter (current_function_decl
);
4335 /* End any sequences that failed to be closed due to syntax errors. */
4336 while (in_sequence_p ())
4339 clear_pending_stack_adjust ();
4340 do_pending_stack_adjust ();
4342 /* Output a linenumber for the end of the function.
4343 SDB depends on this. */
4344 force_next_line_note ();
4345 set_curr_insn_source_location (input_location
);
4347 /* Before the return label (if any), clobber the return
4348 registers so that they are not propagated live to the rest of
4349 the function. This can only happen with functions that drop
4350 through; if there had been a return statement, there would
4351 have either been a return rtx, or a jump to the return label.
4353 We delay actual code generation after the current_function_value_rtx
4355 clobber_after
= get_last_insn ();
4357 /* Output the label for the actual return from the function. */
4358 emit_label (return_label
);
4360 if (USING_SJLJ_EXCEPTIONS
)
4362 /* Let except.c know where it should emit the call to unregister
4363 the function context for sjlj exceptions. */
4364 if (flag_exceptions
)
4365 sjlj_emit_function_exit_after (get_last_insn ());
4369 /* We want to ensure that instructions that may trap are not
4370 moved into the epilogue by scheduling, because we don't
4371 always emit unwind information for the epilogue. */
4372 if (flag_non_call_exceptions
)
4373 emit_insn (gen_blockage ());
4376 /* If this is an implementation of throw, do what's necessary to
4377 communicate between __builtin_eh_return and the epilogue. */
4378 expand_eh_return ();
4380 /* If scalar return value was computed in a pseudo-reg, or was a named
4381 return value that got dumped to the stack, copy that to the hard
4383 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl
)))
4385 tree decl_result
= DECL_RESULT (current_function_decl
);
4386 rtx decl_rtl
= DECL_RTL (decl_result
);
4388 if (REG_P (decl_rtl
)
4389 ? REGNO (decl_rtl
) >= FIRST_PSEUDO_REGISTER
4390 : DECL_REGISTER (decl_result
))
4392 rtx real_decl_rtl
= current_function_return_rtx
;
4394 /* This should be set in assign_parms. */
4395 gcc_assert (REG_FUNCTION_VALUE_P (real_decl_rtl
));
4397 /* If this is a BLKmode structure being returned in registers,
4398 then use the mode computed in expand_return. Note that if
4399 decl_rtl is memory, then its mode may have been changed,
4400 but that current_function_return_rtx has not. */
4401 if (GET_MODE (real_decl_rtl
) == BLKmode
)
4402 PUT_MODE (real_decl_rtl
, GET_MODE (decl_rtl
));
4404 /* If a non-BLKmode return value should be padded at the least
4405 significant end of the register, shift it left by the appropriate
4406 amount. BLKmode results are handled using the group load/store
4408 if (TYPE_MODE (TREE_TYPE (decl_result
)) != BLKmode
4409 && targetm
.calls
.return_in_msb (TREE_TYPE (decl_result
)))
4411 emit_move_insn (gen_rtx_REG (GET_MODE (decl_rtl
),
4412 REGNO (real_decl_rtl
)),
4414 shift_return_value (GET_MODE (decl_rtl
), true, real_decl_rtl
);
4416 /* If a named return value dumped decl_return to memory, then
4417 we may need to re-do the PROMOTE_MODE signed/unsigned
4419 else if (GET_MODE (real_decl_rtl
) != GET_MODE (decl_rtl
))
4421 int unsignedp
= TYPE_UNSIGNED (TREE_TYPE (decl_result
));
4423 if (targetm
.calls
.promote_function_return (TREE_TYPE (current_function_decl
)))
4424 promote_mode (TREE_TYPE (decl_result
), GET_MODE (decl_rtl
),
4427 convert_move (real_decl_rtl
, decl_rtl
, unsignedp
);
4429 else if (GET_CODE (real_decl_rtl
) == PARALLEL
)
4431 /* If expand_function_start has created a PARALLEL for decl_rtl,
4432 move the result to the real return registers. Otherwise, do
4433 a group load from decl_rtl for a named return. */
4434 if (GET_CODE (decl_rtl
) == PARALLEL
)
4435 emit_group_move (real_decl_rtl
, decl_rtl
);
4437 emit_group_load (real_decl_rtl
, decl_rtl
,
4438 TREE_TYPE (decl_result
),
4439 int_size_in_bytes (TREE_TYPE (decl_result
)));
4441 /* In the case of complex integer modes smaller than a word, we'll
4442 need to generate some non-trivial bitfield insertions. Do that
4443 on a pseudo and not the hard register. */
4444 else if (GET_CODE (decl_rtl
) == CONCAT
4445 && GET_MODE_CLASS (GET_MODE (decl_rtl
)) == MODE_COMPLEX_INT
4446 && GET_MODE_BITSIZE (GET_MODE (decl_rtl
)) <= BITS_PER_WORD
)
4448 int old_generating_concat_p
;
4451 old_generating_concat_p
= generating_concat_p
;
4452 generating_concat_p
= 0;
4453 tmp
= gen_reg_rtx (GET_MODE (decl_rtl
));
4454 generating_concat_p
= old_generating_concat_p
;
4456 emit_move_insn (tmp
, decl_rtl
);
4457 emit_move_insn (real_decl_rtl
, tmp
);
4460 emit_move_insn (real_decl_rtl
, decl_rtl
);
4464 /* If returning a structure, arrange to return the address of the value
4465 in a place where debuggers expect to find it.
4467 If returning a structure PCC style,
4468 the caller also depends on this value.
4469 And current_function_returns_pcc_struct is not necessarily set. */
4470 if (current_function_returns_struct
4471 || current_function_returns_pcc_struct
)
4473 rtx value_address
= DECL_RTL (DECL_RESULT (current_function_decl
));
4474 tree type
= TREE_TYPE (DECL_RESULT (current_function_decl
));
4477 if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl
)))
4478 type
= TREE_TYPE (type
);
4480 value_address
= XEXP (value_address
, 0);
4482 outgoing
= targetm
.calls
.function_value (build_pointer_type (type
),
4483 current_function_decl
, true);
4485 /* Mark this as a function return value so integrate will delete the
4486 assignment and USE below when inlining this function. */
4487 REG_FUNCTION_VALUE_P (outgoing
) = 1;
4489 /* The address may be ptr_mode and OUTGOING may be Pmode. */
4490 value_address
= convert_memory_address (GET_MODE (outgoing
),
4493 emit_move_insn (outgoing
, value_address
);
4495 /* Show return register used to hold result (in this case the address
4497 current_function_return_rtx
= outgoing
;
4500 /* Emit the actual code to clobber return register. */
4505 clobber_return_register ();
4506 expand_naked_return ();
4510 emit_insn_after (seq
, clobber_after
);
4513 /* Output the label for the naked return from the function. */
4514 emit_label (naked_return_label
);
4516 /* @@@ This is a kludge. We want to ensure that instructions that
4517 may trap are not moved into the epilogue by scheduling, because
4518 we don't always emit unwind information for the epilogue. */
4519 if (! USING_SJLJ_EXCEPTIONS
&& flag_non_call_exceptions
)
4520 emit_insn (gen_blockage ());
4522 /* If stack protection is enabled for this function, check the guard. */
4523 if (cfun
->stack_protect_guard
)
4524 stack_protect_epilogue ();
4526 /* If we had calls to alloca, and this machine needs
4527 an accurate stack pointer to exit the function,
4528 insert some code to save and restore the stack pointer. */
4529 if (! EXIT_IGNORE_STACK
4530 && current_function_calls_alloca
)
4534 emit_stack_save (SAVE_FUNCTION
, &tem
, parm_birth_insn
);
4535 emit_stack_restore (SAVE_FUNCTION
, tem
, NULL_RTX
);
4538 /* ??? This should no longer be necessary since stupid is no longer with
4539 us, but there are some parts of the compiler (eg reload_combine, and
4540 sh mach_dep_reorg) that still try and compute their own lifetime info
4541 instead of using the general framework. */
4542 use_return_register ();
4546 get_arg_pointer_save_area (struct function
*f
)
4548 rtx ret
= f
->x_arg_pointer_save_area
;
4552 ret
= assign_stack_local_1 (Pmode
, GET_MODE_SIZE (Pmode
), 0, f
);
4553 f
->x_arg_pointer_save_area
= ret
;
4556 if (f
== cfun
&& ! f
->arg_pointer_save_area_init
)
4560 /* Save the arg pointer at the beginning of the function. The
4561 generated stack slot may not be a valid memory address, so we
4562 have to check it and fix it if necessary. */
4564 emit_move_insn (validize_mem (ret
), virtual_incoming_args_rtx
);
4568 push_topmost_sequence ();
4569 emit_insn_after (seq
, entry_of_function ());
4570 pop_topmost_sequence ();
4576 /* Extend a vector that records the INSN_UIDs of INSNS
4577 (a list of one or more insns). */
4580 record_insns (rtx insns
, VEC(int,heap
) **vecp
)
4584 for (tmp
= insns
; tmp
!= NULL_RTX
; tmp
= NEXT_INSN (tmp
))
4585 VEC_safe_push (int, heap
, *vecp
, INSN_UID (tmp
));
4588 /* Set the locator of the insn chain starting at INSN to LOC. */
4590 set_insn_locators (rtx insn
, int loc
)
4592 while (insn
!= NULL_RTX
)
4595 INSN_LOCATOR (insn
) = loc
;
4596 insn
= NEXT_INSN (insn
);
4600 /* Determine how many INSN_UIDs in VEC are part of INSN. Because we can
4601 be running after reorg, SEQUENCE rtl is possible. */
4604 contains (rtx insn
, VEC(int,heap
) **vec
)
4608 if (NONJUMP_INSN_P (insn
)
4609 && GET_CODE (PATTERN (insn
)) == SEQUENCE
)
4612 for (i
= XVECLEN (PATTERN (insn
), 0) - 1; i
>= 0; i
--)
4613 for (j
= VEC_length (int, *vec
) - 1; j
>= 0; --j
)
4614 if (INSN_UID (XVECEXP (PATTERN (insn
), 0, i
))
4615 == VEC_index (int, *vec
, j
))
4621 for (j
= VEC_length (int, *vec
) - 1; j
>= 0; --j
)
4622 if (INSN_UID (insn
) == VEC_index (int, *vec
, j
))
4629 prologue_epilogue_contains (rtx insn
)
4631 if (contains (insn
, &prologue
))
4633 if (contains (insn
, &epilogue
))
4639 sibcall_epilogue_contains (rtx insn
)
4641 if (sibcall_epilogue
)
4642 return contains (insn
, &sibcall_epilogue
);
4647 /* Insert gen_return at the end of block BB. This also means updating
4648 block_for_insn appropriately. */
4651 emit_return_into_block (basic_block bb
)
4653 emit_jump_insn_after (gen_return (), BB_END (bb
));
4655 #endif /* HAVE_return */
4657 #if defined(HAVE_epilogue) && defined(INCOMING_RETURN_ADDR_RTX)
4659 /* These functions convert the epilogue into a variant that does not
4660 modify the stack pointer. This is used in cases where a function
4661 returns an object whose size is not known until it is computed.
4662 The called function leaves the object on the stack, leaves the
4663 stack depressed, and returns a pointer to the object.
4665 What we need to do is track all modifications and references to the
4666 stack pointer, deleting the modifications and changing the
4667 references to point to the location the stack pointer would have
4668 pointed to had the modifications taken place.
4670 These functions need to be portable so we need to make as few
4671 assumptions about the epilogue as we can. However, the epilogue
4672 basically contains three things: instructions to reset the stack
4673 pointer, instructions to reload registers, possibly including the
4674 frame pointer, and an instruction to return to the caller.
4676 We must be sure of what a relevant epilogue insn is doing. We also
4677 make no attempt to validate the insns we make since if they are
4678 invalid, we probably can't do anything valid. The intent is that
4679 these routines get "smarter" as more and more machines start to use
4680 them and they try operating on different epilogues.
4682 We use the following structure to track what the part of the
4683 epilogue that we've already processed has done. We keep two copies
4684 of the SP equivalence, one for use during the insn we are
4685 processing and one for use in the next insn. The difference is
4686 because one part of a PARALLEL may adjust SP and the other may use
4691 rtx sp_equiv_reg
; /* REG that SP is set from, perhaps SP. */
4692 HOST_WIDE_INT sp_offset
; /* Offset from SP_EQUIV_REG of present SP. */
4693 rtx new_sp_equiv_reg
; /* REG to be used at end of insn. */
4694 HOST_WIDE_INT new_sp_offset
; /* Offset to be used at end of insn. */
4695 rtx equiv_reg_src
; /* If nonzero, the value that SP_EQUIV_REG
4696 should be set to once we no longer need
4698 rtx const_equiv
[FIRST_PSEUDO_REGISTER
]; /* Any known constant equivalences
4702 static void handle_epilogue_set (rtx
, struct epi_info
*);
4703 static void update_epilogue_consts (rtx
, rtx
, void *);
4704 static void emit_equiv_load (struct epi_info
*);
4706 /* Modify INSN, a list of one or more insns that is part of the epilogue, to
4707 no modifications to the stack pointer. Return the new list of insns. */
4710 keep_stack_depressed (rtx insns
)
4713 struct epi_info info
;
4716 /* If the epilogue is just a single instruction, it must be OK as is. */
4717 if (NEXT_INSN (insns
) == NULL_RTX
)
4720 /* Otherwise, start a sequence, initialize the information we have, and
4721 process all the insns we were given. */
4724 info
.sp_equiv_reg
= stack_pointer_rtx
;
4726 info
.equiv_reg_src
= 0;
4728 for (j
= 0; j
< FIRST_PSEUDO_REGISTER
; j
++)
4729 info
.const_equiv
[j
] = 0;
4733 while (insn
!= NULL_RTX
)
4735 next
= NEXT_INSN (insn
);
4744 /* If this insn references the register that SP is equivalent to and
4745 we have a pending load to that register, we must force out the load
4746 first and then indicate we no longer know what SP's equivalent is. */
4747 if (info
.equiv_reg_src
!= 0
4748 && reg_referenced_p (info
.sp_equiv_reg
, PATTERN (insn
)))
4750 emit_equiv_load (&info
);
4751 info
.sp_equiv_reg
= 0;
4754 info
.new_sp_equiv_reg
= info
.sp_equiv_reg
;
4755 info
.new_sp_offset
= info
.sp_offset
;
4757 /* If this is a (RETURN) and the return address is on the stack,
4758 update the address and change to an indirect jump. */
4759 if (GET_CODE (PATTERN (insn
)) == RETURN
4760 || (GET_CODE (PATTERN (insn
)) == PARALLEL
4761 && GET_CODE (XVECEXP (PATTERN (insn
), 0, 0)) == RETURN
))
4763 rtx retaddr
= INCOMING_RETURN_ADDR_RTX
;
4765 HOST_WIDE_INT offset
= 0;
4766 rtx jump_insn
, jump_set
;
4768 /* If the return address is in a register, we can emit the insn
4769 unchanged. Otherwise, it must be a MEM and we see what the
4770 base register and offset are. In any case, we have to emit any
4771 pending load to the equivalent reg of SP, if any. */
4772 if (REG_P (retaddr
))
4774 emit_equiv_load (&info
);
4782 gcc_assert (MEM_P (retaddr
));
4784 ret_ptr
= XEXP (retaddr
, 0);
4786 if (REG_P (ret_ptr
))
4788 base
= gen_rtx_REG (Pmode
, REGNO (ret_ptr
));
4793 gcc_assert (GET_CODE (ret_ptr
) == PLUS
4794 && REG_P (XEXP (ret_ptr
, 0))
4795 && GET_CODE (XEXP (ret_ptr
, 1)) == CONST_INT
);
4796 base
= gen_rtx_REG (Pmode
, REGNO (XEXP (ret_ptr
, 0)));
4797 offset
= INTVAL (XEXP (ret_ptr
, 1));
4801 /* If the base of the location containing the return pointer
4802 is SP, we must update it with the replacement address. Otherwise,
4803 just build the necessary MEM. */
4804 retaddr
= plus_constant (base
, offset
);
4805 if (base
== stack_pointer_rtx
)
4806 retaddr
= simplify_replace_rtx (retaddr
, stack_pointer_rtx
,
4807 plus_constant (info
.sp_equiv_reg
,
4810 retaddr
= gen_rtx_MEM (Pmode
, retaddr
);
4811 MEM_NOTRAP_P (retaddr
) = 1;
4813 /* If there is a pending load to the equivalent register for SP
4814 and we reference that register, we must load our address into
4815 a scratch register and then do that load. */
4816 if (info
.equiv_reg_src
4817 && reg_overlap_mentioned_p (info
.equiv_reg_src
, retaddr
))
4822 for (regno
= 0; regno
< FIRST_PSEUDO_REGISTER
; regno
++)
4823 if (HARD_REGNO_MODE_OK (regno
, Pmode
)
4824 && !fixed_regs
[regno
]
4825 && TEST_HARD_REG_BIT (regs_invalidated_by_call
, regno
)
4827 (DF_LR_IN (EXIT_BLOCK_PTR
), regno
)
4828 && !refers_to_regno_p (regno
,
4829 end_hard_regno (Pmode
, regno
),
4830 info
.equiv_reg_src
, NULL
)
4831 && info
.const_equiv
[regno
] == 0)
4834 gcc_assert (regno
< FIRST_PSEUDO_REGISTER
);
4836 reg
= gen_rtx_REG (Pmode
, regno
);
4837 emit_move_insn (reg
, retaddr
);
4841 emit_equiv_load (&info
);
4842 jump_insn
= emit_jump_insn (gen_indirect_jump (retaddr
));
4844 /* Show the SET in the above insn is a RETURN. */
4845 jump_set
= single_set (jump_insn
);
4846 gcc_assert (jump_set
);
4847 SET_IS_RETURN_P (jump_set
) = 1;
4850 /* If SP is not mentioned in the pattern and its equivalent register, if
4851 any, is not modified, just emit it. Otherwise, if neither is set,
4852 replace the reference to SP and emit the insn. If none of those are
4853 true, handle each SET individually. */
4854 else if (!reg_mentioned_p (stack_pointer_rtx
, PATTERN (insn
))
4855 && (info
.sp_equiv_reg
== stack_pointer_rtx
4856 || !reg_set_p (info
.sp_equiv_reg
, insn
)))
4858 else if (! reg_set_p (stack_pointer_rtx
, insn
)
4859 && (info
.sp_equiv_reg
== stack_pointer_rtx
4860 || !reg_set_p (info
.sp_equiv_reg
, insn
)))
4864 changed
= validate_replace_rtx (stack_pointer_rtx
,
4865 plus_constant (info
.sp_equiv_reg
,
4868 gcc_assert (changed
);
4872 else if (GET_CODE (PATTERN (insn
)) == SET
)
4873 handle_epilogue_set (PATTERN (insn
), &info
);
4874 else if (GET_CODE (PATTERN (insn
)) == PARALLEL
)
4876 for (j
= 0; j
< XVECLEN (PATTERN (insn
), 0); j
++)
4877 if (GET_CODE (XVECEXP (PATTERN (insn
), 0, j
)) == SET
)
4878 handle_epilogue_set (XVECEXP (PATTERN (insn
), 0, j
), &info
);
4883 info
.sp_equiv_reg
= info
.new_sp_equiv_reg
;
4884 info
.sp_offset
= info
.new_sp_offset
;
4886 /* Now update any constants this insn sets. */
4887 note_stores (PATTERN (insn
), update_epilogue_consts
, &info
);
4891 insns
= get_insns ();
4896 /* SET is a SET from an insn in the epilogue. P is a pointer to the epi_info
4897 structure that contains information about what we've seen so far. We
4898 process this SET by either updating that data or by emitting one or
4902 handle_epilogue_set (rtx set
, struct epi_info
*p
)
4904 /* First handle the case where we are setting SP. Record what it is being
4905 set from, which we must be able to determine */
4906 if (reg_set_p (stack_pointer_rtx
, set
))
4908 gcc_assert (SET_DEST (set
) == stack_pointer_rtx
);
4910 if (GET_CODE (SET_SRC (set
)) == PLUS
)
4912 p
->new_sp_equiv_reg
= XEXP (SET_SRC (set
), 0);
4913 if (GET_CODE (XEXP (SET_SRC (set
), 1)) == CONST_INT
)
4914 p
->new_sp_offset
= INTVAL (XEXP (SET_SRC (set
), 1));
4917 gcc_assert (REG_P (XEXP (SET_SRC (set
), 1))
4918 && (REGNO (XEXP (SET_SRC (set
), 1))
4919 < FIRST_PSEUDO_REGISTER
)
4920 && p
->const_equiv
[REGNO (XEXP (SET_SRC (set
), 1))]);
4922 = INTVAL (p
->const_equiv
[REGNO (XEXP (SET_SRC (set
), 1))]);
4926 p
->new_sp_equiv_reg
= SET_SRC (set
), p
->new_sp_offset
= 0;
4928 /* If we are adjusting SP, we adjust from the old data. */
4929 if (p
->new_sp_equiv_reg
== stack_pointer_rtx
)
4931 p
->new_sp_equiv_reg
= p
->sp_equiv_reg
;
4932 p
->new_sp_offset
+= p
->sp_offset
;
4935 gcc_assert (p
->new_sp_equiv_reg
&& REG_P (p
->new_sp_equiv_reg
));
4940 /* Next handle the case where we are setting SP's equivalent
4941 register. We must not already have a value to set it to. We
4942 could update, but there seems little point in handling that case.
4943 Note that we have to allow for the case where we are setting the
4944 register set in the previous part of a PARALLEL inside a single
4945 insn. But use the old offset for any updates within this insn.
4946 We must allow for the case where the register is being set in a
4947 different (usually wider) mode than Pmode). */
4948 else if (p
->new_sp_equiv_reg
!= 0 && reg_set_p (p
->new_sp_equiv_reg
, set
))
4950 gcc_assert (!p
->equiv_reg_src
4951 && REG_P (p
->new_sp_equiv_reg
)
4952 && REG_P (SET_DEST (set
))
4953 && (GET_MODE_BITSIZE (GET_MODE (SET_DEST (set
)))
4955 && REGNO (p
->new_sp_equiv_reg
) == REGNO (SET_DEST (set
)));
4957 = simplify_replace_rtx (SET_SRC (set
), stack_pointer_rtx
,
4958 plus_constant (p
->sp_equiv_reg
,
4962 /* Otherwise, replace any references to SP in the insn to its new value
4963 and emit the insn. */
4966 SET_SRC (set
) = simplify_replace_rtx (SET_SRC (set
), stack_pointer_rtx
,
4967 plus_constant (p
->sp_equiv_reg
,
4969 SET_DEST (set
) = simplify_replace_rtx (SET_DEST (set
), stack_pointer_rtx
,
4970 plus_constant (p
->sp_equiv_reg
,
4976 /* Update the tracking information for registers set to constants. */
4979 update_epilogue_consts (rtx dest
, rtx x
, void *data
)
4981 struct epi_info
*p
= (struct epi_info
*) data
;
4984 if (!REG_P (dest
) || REGNO (dest
) >= FIRST_PSEUDO_REGISTER
)
4987 /* If we are either clobbering a register or doing a partial set,
4988 show we don't know the value. */
4989 else if (GET_CODE (x
) == CLOBBER
|| ! rtx_equal_p (dest
, SET_DEST (x
)))
4990 p
->const_equiv
[REGNO (dest
)] = 0;
4992 /* If we are setting it to a constant, record that constant. */
4993 else if (GET_CODE (SET_SRC (x
)) == CONST_INT
)
4994 p
->const_equiv
[REGNO (dest
)] = SET_SRC (x
);
4996 /* If this is a binary operation between a register we have been tracking
4997 and a constant, see if we can compute a new constant value. */
4998 else if (ARITHMETIC_P (SET_SRC (x
))
4999 && REG_P (XEXP (SET_SRC (x
), 0))
5000 && REGNO (XEXP (SET_SRC (x
), 0)) < FIRST_PSEUDO_REGISTER
5001 && p
->const_equiv
[REGNO (XEXP (SET_SRC (x
), 0))] != 0
5002 && GET_CODE (XEXP (SET_SRC (x
), 1)) == CONST_INT
5003 && 0 != (new = simplify_binary_operation
5004 (GET_CODE (SET_SRC (x
)), GET_MODE (dest
),
5005 p
->const_equiv
[REGNO (XEXP (SET_SRC (x
), 0))],
5006 XEXP (SET_SRC (x
), 1)))
5007 && GET_CODE (new) == CONST_INT
)
5008 p
->const_equiv
[REGNO (dest
)] = new;
5010 /* Otherwise, we can't do anything with this value. */
5012 p
->const_equiv
[REGNO (dest
)] = 0;
5015 /* Emit an insn to do the load shown in p->equiv_reg_src, if needed. */
5018 emit_equiv_load (struct epi_info
*p
)
5020 if (p
->equiv_reg_src
!= 0)
5022 rtx dest
= p
->sp_equiv_reg
;
5024 if (GET_MODE (p
->equiv_reg_src
) != GET_MODE (dest
))
5025 dest
= gen_rtx_REG (GET_MODE (p
->equiv_reg_src
),
5026 REGNO (p
->sp_equiv_reg
));
5028 emit_move_insn (dest
, p
->equiv_reg_src
);
5029 p
->equiv_reg_src
= 0;
5034 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
5035 this into place with notes indicating where the prologue ends and where
5036 the epilogue begins. Update the basic block information when possible. */
5039 thread_prologue_and_epilogue_insns (void)
5043 #if defined (HAVE_sibcall_epilogue) || defined (HAVE_epilogue) || defined (HAVE_return) || defined (HAVE_prologue)
5046 #if defined (HAVE_epilogue) || defined(HAVE_return)
5047 rtx epilogue_end
= NULL_RTX
;
5051 #ifdef HAVE_prologue
5055 seq
= gen_prologue ();
5058 /* Insert an explicit USE for the frame pointer
5059 if the profiling is on and the frame pointer is required. */
5060 if (current_function_profile
&& frame_pointer_needed
)
5061 emit_insn (gen_rtx_USE (VOIDmode
, hard_frame_pointer_rtx
));
5063 /* Retain a map of the prologue insns. */
5064 record_insns (seq
, &prologue
);
5065 emit_note (NOTE_INSN_PROLOGUE_END
);
5067 #ifndef PROFILE_BEFORE_PROLOGUE
5068 /* Ensure that instructions are not moved into the prologue when
5069 profiling is on. The call to the profiling routine can be
5070 emitted within the live range of a call-clobbered register. */
5071 if (current_function_profile
)
5072 emit_insn (gen_blockage ());
5077 set_insn_locators (seq
, prologue_locator
);
5079 /* Can't deal with multiple successors of the entry block
5080 at the moment. Function should always have at least one
5082 gcc_assert (single_succ_p (ENTRY_BLOCK_PTR
));
5084 insert_insn_on_edge (seq
, single_succ_edge (ENTRY_BLOCK_PTR
));
5089 /* If the exit block has no non-fake predecessors, we don't need
5091 FOR_EACH_EDGE (e
, ei
, EXIT_BLOCK_PTR
->preds
)
5092 if ((e
->flags
& EDGE_FAKE
) == 0)
5098 if (optimize
&& HAVE_return
)
5100 /* If we're allowed to generate a simple return instruction,
5101 then by definition we don't need a full epilogue. Examine
5102 the block that falls through to EXIT. If it does not
5103 contain any code, examine its predecessors and try to
5104 emit (conditional) return instructions. */
5109 FOR_EACH_EDGE (e
, ei
, EXIT_BLOCK_PTR
->preds
)
5110 if (e
->flags
& EDGE_FALLTHRU
)
5116 /* Verify that there are no active instructions in the last block. */
5117 label
= BB_END (last
);
5118 while (label
&& !LABEL_P (label
))
5120 if (active_insn_p (label
))
5122 label
= PREV_INSN (label
);
5125 if (BB_HEAD (last
) == label
&& LABEL_P (label
))
5129 for (ei2
= ei_start (last
->preds
); (e
= ei_safe_edge (ei2
)); )
5131 basic_block bb
= e
->src
;
5134 if (bb
== ENTRY_BLOCK_PTR
)
5141 if (!JUMP_P (jump
) || JUMP_LABEL (jump
) != label
)
5147 /* If we have an unconditional jump, we can replace that
5148 with a simple return instruction. */
5149 if (simplejump_p (jump
))
5151 emit_return_into_block (bb
);
5155 /* If we have a conditional jump, we can try to replace
5156 that with a conditional return instruction. */
5157 else if (condjump_p (jump
))
5159 if (! redirect_jump (jump
, 0, 0))
5165 /* If this block has only one successor, it both jumps
5166 and falls through to the fallthru block, so we can't
5168 if (single_succ_p (bb
))
5180 /* Fix up the CFG for the successful change we just made. */
5181 redirect_edge_succ (e
, EXIT_BLOCK_PTR
);
5184 /* Emit a return insn for the exit fallthru block. Whether
5185 this is still reachable will be determined later. */
5187 emit_barrier_after (BB_END (last
));
5188 emit_return_into_block (last
);
5189 epilogue_end
= BB_END (last
);
5190 single_succ_edge (last
)->flags
&= ~EDGE_FALLTHRU
;
5195 /* Find the edge that falls through to EXIT. Other edges may exist
5196 due to RETURN instructions, but those don't need epilogues.
5197 There really shouldn't be a mixture -- either all should have
5198 been converted or none, however... */
5200 FOR_EACH_EDGE (e
, ei
, EXIT_BLOCK_PTR
->preds
)
5201 if (e
->flags
& EDGE_FALLTHRU
)
5206 #ifdef HAVE_epilogue
5210 epilogue_end
= emit_note (NOTE_INSN_EPILOGUE_BEG
);
5212 seq
= gen_epilogue ();
5214 #ifdef INCOMING_RETURN_ADDR_RTX
5215 /* If this function returns with the stack depressed and we can support
5216 it, massage the epilogue to actually do that. */
5217 if (TREE_CODE (TREE_TYPE (current_function_decl
)) == FUNCTION_TYPE
5218 && TYPE_RETURNS_STACK_DEPRESSED (TREE_TYPE (current_function_decl
)))
5219 seq
= keep_stack_depressed (seq
);
5222 emit_jump_insn (seq
);
5224 /* Retain a map of the epilogue insns. */
5225 record_insns (seq
, &epilogue
);
5226 set_insn_locators (seq
, epilogue_locator
);
5231 insert_insn_on_edge (seq
, e
);
5239 if (! next_active_insn (BB_END (e
->src
)))
5241 /* We have a fall-through edge to the exit block, the source is not
5242 at the end of the function, and there will be an assembler epilogue
5243 at the end of the function.
5244 We can't use force_nonfallthru here, because that would try to
5245 use return. Inserting a jump 'by hand' is extremely messy, so
5246 we take advantage of cfg_layout_finalize using
5247 fixup_fallthru_exit_predecessor. */
5248 cfg_layout_initialize (0);
5249 FOR_EACH_BB (cur_bb
)
5250 if (cur_bb
->index
>= NUM_FIXED_BLOCKS
5251 && cur_bb
->next_bb
->index
>= NUM_FIXED_BLOCKS
)
5252 cur_bb
->aux
= cur_bb
->next_bb
;
5253 cfg_layout_finalize ();
5258 commit_edge_insertions ();
5260 #ifdef HAVE_sibcall_epilogue
5261 /* Emit sibling epilogues before any sibling call sites. */
5262 for (ei
= ei_start (EXIT_BLOCK_PTR
->preds
); (e
= ei_safe_edge (ei
)); )
5264 basic_block bb
= e
->src
;
5265 rtx insn
= BB_END (bb
);
5268 || ! SIBLING_CALL_P (insn
))
5275 emit_insn (gen_sibcall_epilogue ());
5279 /* Retain a map of the epilogue insns. Used in life analysis to
5280 avoid getting rid of sibcall epilogue insns. Do this before we
5281 actually emit the sequence. */
5282 record_insns (seq
, &sibcall_epilogue
);
5283 set_insn_locators (seq
, epilogue_locator
);
5285 emit_insn_before (seq
, insn
);
5290 #ifdef HAVE_epilogue
5295 /* Similarly, move any line notes that appear after the epilogue.
5296 There is no need, however, to be quite so anal about the existence
5297 of such a note. Also possibly move
5298 NOTE_INSN_FUNCTION_BEG notes, as those can be relevant for debug
5300 for (insn
= epilogue_end
; insn
; insn
= next
)
5302 next
= NEXT_INSN (insn
);
5304 && (NOTE_KIND (insn
) == NOTE_INSN_FUNCTION_BEG
))
5305 reorder_insns (insn
, insn
, PREV_INSN (epilogue_end
));
5310 /* Threading the prologue and epilogue changes the artificial refs
5311 in the entry and exit blocks. */
5312 epilogue_completed
= 1;
5313 df_update_entry_exit_and_calls ();
5316 /* Reposition the prologue-end and epilogue-begin notes after instruction
5317 scheduling and delayed branch scheduling. */
5320 reposition_prologue_and_epilogue_notes (void)
5322 #if defined (HAVE_prologue) || defined (HAVE_epilogue)
5323 rtx insn
, last
, note
;
5326 if ((len
= VEC_length (int, prologue
)) > 0)
5330 /* Scan from the beginning until we reach the last prologue insn.
5331 We apparently can't depend on basic_block_{head,end} after
5333 for (insn
= get_insns (); insn
; insn
= NEXT_INSN (insn
))
5337 if (NOTE_KIND (insn
) == NOTE_INSN_PROLOGUE_END
)
5340 else if (contains (insn
, &prologue
))
5350 /* Find the prologue-end note if we haven't already, and
5351 move it to just after the last prologue insn. */
5354 for (note
= last
; (note
= NEXT_INSN (note
));)
5356 && NOTE_KIND (note
) == NOTE_INSN_PROLOGUE_END
)
5360 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
5362 last
= NEXT_INSN (last
);
5363 reorder_insns (note
, note
, last
);
5367 if ((len
= VEC_length (int, epilogue
)) > 0)
5371 /* Scan from the end until we reach the first epilogue insn.
5372 We apparently can't depend on basic_block_{head,end} after
5374 for (insn
= get_last_insn (); insn
; insn
= PREV_INSN (insn
))
5378 if (NOTE_KIND (insn
) == NOTE_INSN_EPILOGUE_BEG
)
5381 else if (contains (insn
, &epilogue
))
5391 /* Find the epilogue-begin note if we haven't already, and
5392 move it to just before the first epilogue insn. */
5395 for (note
= insn
; (note
= PREV_INSN (note
));)
5397 && NOTE_KIND (note
) == NOTE_INSN_EPILOGUE_BEG
)
5401 if (PREV_INSN (last
) != note
)
5402 reorder_insns (note
, note
, PREV_INSN (last
));
5405 #endif /* HAVE_prologue or HAVE_epilogue */
5408 /* Returns the name of the current function. */
5410 current_function_name (void)
5412 return lang_hooks
.decl_printable_name (cfun
->decl
, 2);
5415 /* Returns the raw (mangled) name of the current function. */
5417 current_function_assembler_name (void)
5419 return IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (cfun
->decl
));
5424 rest_of_handle_check_leaf_regs (void)
5426 #ifdef LEAF_REGISTERS
5427 current_function_uses_only_leaf_regs
5428 = optimize
> 0 && only_leaf_regs_used () && leaf_function_p ();
5433 /* Insert a TYPE into the used types hash table of CFUN. */
5435 used_types_insert_helper (tree type
, struct function
*func
)
5437 if (type
!= NULL
&& func
!= NULL
)
5441 if (func
->used_types_hash
== NULL
)
5442 func
->used_types_hash
= htab_create_ggc (37, htab_hash_pointer
,
5443 htab_eq_pointer
, NULL
);
5444 slot
= htab_find_slot (func
->used_types_hash
, type
, INSERT
);
5450 /* Given a type, insert it into the used hash table in cfun. */
5452 used_types_insert (tree t
)
5454 while (POINTER_TYPE_P (t
) || TREE_CODE (t
) == ARRAY_TYPE
)
5456 t
= TYPE_MAIN_VARIANT (t
);
5457 if (debug_info_level
> DINFO_LEVEL_NONE
)
5458 used_types_insert_helper (t
, cfun
);
5461 struct tree_opt_pass pass_leaf_regs
=
5465 rest_of_handle_check_leaf_regs
, /* execute */
5468 0, /* static_pass_number */
5470 0, /* properties_required */
5471 0, /* properties_provided */
5472 0, /* properties_destroyed */
5473 0, /* todo_flags_start */
5474 0, /* todo_flags_finish */
5479 rest_of_handle_thread_prologue_and_epilogue (void)
5482 cleanup_cfg (CLEANUP_EXPENSIVE
);
5483 /* On some machines, the prologue and epilogue code, or parts thereof,
5484 can be represented as RTL. Doing so lets us schedule insns between
5485 it and the rest of the code and also allows delayed branch
5486 scheduling to operate in the epilogue. */
5488 thread_prologue_and_epilogue_insns ();
5492 struct tree_opt_pass pass_thread_prologue_and_epilogue
=
5494 "pro_and_epilogue", /* name */
5496 rest_of_handle_thread_prologue_and_epilogue
, /* execute */
5499 0, /* static_pass_number */
5500 TV_THREAD_PROLOGUE_AND_EPILOGUE
, /* tv_id */
5501 0, /* properties_required */
5502 0, /* properties_provided */
5503 0, /* properties_destroyed */
5504 TODO_verify_flow
, /* todo_flags_start */
5507 TODO_ggc_collect
, /* todo_flags_finish */
5512 /* This mini-pass fixes fall-out from SSA in asm statements that have
5513 in-out constraints. Say you start with
5516 asm ("": "+mr" (inout));
5519 which is transformed very early to use explicit output and match operands:
5522 asm ("": "=mr" (inout) : "0" (inout));
5525 Or, after SSA and copyprop,
5527 asm ("": "=mr" (inout_2) : "0" (inout_1));
5530 Clearly inout_2 and inout_1 can't be coalesced easily anymore, as
5531 they represent two separate values, so they will get different pseudo
5532 registers during expansion. Then, since the two operands need to match
5533 per the constraints, but use different pseudo registers, reload can
5534 only register a reload for these operands. But reloads can only be
5535 satisfied by hardregs, not by memory, so we need a register for this
5536 reload, just because we are presented with non-matching operands.
5537 So, even though we allow memory for this operand, no memory can be
5538 used for it, just because the two operands don't match. This can
5539 cause reload failures on register-starved targets.
5541 So it's a symptom of reload not being able to use memory for reloads
5542 or, alternatively it's also a symptom of both operands not coming into
5543 reload as matching (in which case the pseudo could go to memory just
5544 fine, as the alternative allows it, and no reload would be necessary).
5545 We fix the latter problem here, by transforming
5547 asm ("": "=mr" (inout_2) : "0" (inout_1));
5552 asm ("": "=mr" (inout_2) : "0" (inout_2)); */
5555 match_asm_constraints_1 (rtx insn
, rtx
*p_sets
, int noutputs
)
5558 bool changed
= false;
5559 rtx op
= SET_SRC (p_sets
[0]);
5560 int ninputs
= ASM_OPERANDS_INPUT_LENGTH (op
);
5561 rtvec inputs
= ASM_OPERANDS_INPUT_VEC (op
);
5563 for (i
= 0; i
< ninputs
; i
++)
5565 rtx input
, output
, insns
;
5566 const char *constraint
= ASM_OPERANDS_INPUT_CONSTRAINT (op
, i
);
5570 match
= strtoul (constraint
, &end
, 10);
5571 if (end
== constraint
)
5574 gcc_assert (match
< noutputs
);
5575 output
= SET_DEST (p_sets
[match
]);
5576 input
= RTVEC_ELT (inputs
, i
);
5577 if (rtx_equal_p (output
, input
)
5578 || (GET_MODE (input
) != VOIDmode
5579 && GET_MODE (input
) != GET_MODE (output
)))
5583 emit_move_insn (copy_rtx (output
), input
);
5584 RTVEC_ELT (inputs
, i
) = copy_rtx (output
);
5585 insns
= get_insns ();
5588 emit_insn_before (insns
, insn
);
5593 df_insn_rescan (insn
);
5597 rest_of_match_asm_constraints (void)
5600 rtx insn
, pat
, *p_sets
;
5603 if (!cfun
->has_asm_statement
)
5606 df_set_flags (DF_DEFER_INSN_RESCAN
);
5609 FOR_BB_INSNS (bb
, insn
)
5614 pat
= PATTERN (insn
);
5615 if (GET_CODE (pat
) == PARALLEL
)
5616 p_sets
= &XVECEXP (pat
, 0, 0), noutputs
= XVECLEN (pat
, 0);
5617 else if (GET_CODE (pat
) == SET
)
5618 p_sets
= &PATTERN (insn
), noutputs
= 1;
5622 if (GET_CODE (*p_sets
) == SET
5623 && GET_CODE (SET_SRC (*p_sets
)) == ASM_OPERANDS
)
5624 match_asm_constraints_1 (insn
, p_sets
, noutputs
);
5628 return TODO_df_finish
;
5631 struct tree_opt_pass pass_match_asm_constraints
=
5633 "asmcons", /* name */
5635 rest_of_match_asm_constraints
, /* execute */
5638 0, /* static_pass_number */
5640 0, /* properties_required */
5641 0, /* properties_provided */
5642 0, /* properties_destroyed */
5643 0, /* todo_flags_start */
5644 TODO_dump_func
, /* todo_flags_finish */
5649 #include "gt-function.h"