1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 88, 89, 92-98, 1999 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
22 /* This file handles the generation of rtl code from tree structure
23 above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
24 It also creates the rtl expressions for parameters and auto variables
25 and has full responsibility for allocating stack slots.
27 The functions whose names start with `expand_' are called by the
28 parser to generate RTL instructions for various kinds of constructs.
30 Some control and binding constructs require calling several such
31 functions at different times. For example, a simple if-then
32 is expanded by calling `expand_start_cond' (with the condition-expression
33 as argument) before parsing the then-clause and calling `expand_end_cond'
34 after parsing the then-clause. */
44 #include "insn-flags.h"
45 #include "insn-config.h"
46 #include "insn-codes.h"
48 #include "hard-reg-set.h"
57 #define obstack_chunk_alloc xmalloc
58 #define obstack_chunk_free free
59 struct obstack stmt_obstack
;
61 /* Assume that case vectors are not pc-relative. */
62 #ifndef CASE_VECTOR_PC_RELATIVE
63 #define CASE_VECTOR_PC_RELATIVE 0
66 /* Each time we expand the end of a binding contour (in `expand_end_bindings')
67 and we emit a new NOTE_INSN_BLOCK_END note, we save a pointer to it here.
68 This is used by the `remember_end_note' function to record the endpoint
69 of each generated block in its associated BLOCK node. */
71 static rtx last_block_end_note
;
73 /* Functions and data structures for expanding case statements. */
75 /* Case label structure, used to hold info on labels within case
76 statements. We handle "range" labels; for a single-value label
77 as in C, the high and low limits are the same.
79 An AVL tree of case nodes is initially created, and later transformed
80 to a list linked via the RIGHT fields in the nodes. Nodes with
81 higher case values are later in the list.
83 Switch statements can be output in one of two forms. A branch table
84 is used if there are more than a few labels and the labels are dense
85 within the range between the smallest and largest case value. If a
86 branch table is used, no further manipulations are done with the case
89 The alternative to the use of a branch table is to generate a series
90 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
91 and PARENT fields to hold a binary tree. Initially the tree is
92 totally unbalanced, with everything on the right. We balance the tree
93 with nodes on the left having lower case values than the parent
94 and nodes on the right having higher values. We then output the tree
99 struct case_node
*left
; /* Left son in binary tree */
100 struct case_node
*right
; /* Right son in binary tree; also node chain */
101 struct case_node
*parent
; /* Parent of node in binary tree */
102 tree low
; /* Lowest index value for this label */
103 tree high
; /* Highest index value for this label */
104 tree code_label
; /* Label to jump to when node matches */
108 typedef struct case_node case_node
;
109 typedef struct case_node
*case_node_ptr
;
111 /* These are used by estimate_case_costs and balance_case_nodes. */
113 /* This must be a signed type, and non-ANSI compilers lack signed char. */
114 static short *cost_table
;
115 static int use_cost_table
;
117 /* Stack of control and binding constructs we are currently inside.
119 These constructs begin when you call `expand_start_WHATEVER'
120 and end when you call `expand_end_WHATEVER'. This stack records
121 info about how the construct began that tells the end-function
122 what to do. It also may provide information about the construct
123 to alter the behavior of other constructs within the body.
124 For example, they may affect the behavior of C `break' and `continue'.
126 Each construct gets one `struct nesting' object.
127 All of these objects are chained through the `all' field.
128 `nesting_stack' points to the first object (innermost construct).
129 The position of an entry on `nesting_stack' is in its `depth' field.
131 Each type of construct has its own individual stack.
132 For example, loops have `loop_stack'. Each object points to the
133 next object of the same type through the `next' field.
135 Some constructs are visible to `break' exit-statements and others
136 are not. Which constructs are visible depends on the language.
137 Therefore, the data structure allows each construct to be visible
138 or not, according to the args given when the construct is started.
139 The construct is visible if the `exit_label' field is non-null.
140 In that case, the value should be a CODE_LABEL rtx. */
145 struct nesting
*next
;
150 /* For conds (if-then and if-then-else statements). */
153 /* Label for the end of the if construct.
154 There is none if EXITFLAG was not set
155 and no `else' has been seen yet. */
157 /* Label for the end of this alternative.
158 This may be the end of the if or the next else/elseif. */
164 /* Label at the top of the loop; place to loop back to. */
166 /* Label at the end of the whole construct. */
168 /* Label before a jump that branches to the end of the whole
169 construct. This is where destructors go if any. */
171 /* Label for `continue' statement to jump to;
172 this is in front of the stepper of the loop. */
175 /* For variable binding contours. */
178 /* Sequence number of this binding contour within the function,
179 in order of entry. */
180 int block_start_count
;
181 /* Nonzero => value to restore stack to on exit. */
183 /* The NOTE that starts this contour.
184 Used by expand_goto to check whether the destination
185 is within each contour or not. */
187 /* Innermost containing binding contour that has a stack level. */
188 struct nesting
*innermost_stack_block
;
189 /* List of cleanups to be run on exit from this contour.
190 This is a list of expressions to be evaluated.
191 The TREE_PURPOSE of each link is the ..._DECL node
192 which the cleanup pertains to. */
194 /* List of cleanup-lists of blocks containing this block,
195 as they were at the locus where this block appears.
196 There is an element for each containing block,
197 ordered innermost containing block first.
198 The tail of this list can be 0,
199 if all remaining elements would be empty lists.
200 The element's TREE_VALUE is the cleanup-list of that block,
201 which may be null. */
203 /* Chain of labels defined inside this binding contour.
204 For contours that have stack levels or cleanups. */
205 struct label_chain
*label_chain
;
206 /* Number of function calls seen, as of start of this block. */
207 int n_function_calls
;
208 /* Nonzero if this is associated with a EH region. */
209 int exception_region
;
210 /* The saved target_temp_slot_level from our outer block.
211 We may reset target_temp_slot_level to be the level of
212 this block, if that is done, target_temp_slot_level
213 reverts to the saved target_temp_slot_level at the very
215 int block_target_temp_slot_level
;
216 /* True if we are currently emitting insns in an area of
217 output code that is controlled by a conditional
218 expression. This is used by the cleanup handling code to
219 generate conditional cleanup actions. */
220 int conditional_code
;
221 /* A place to move the start of the exception region for any
222 of the conditional cleanups, must be at the end or after
223 the start of the last unconditional cleanup, and before any
224 conditional branch points. */
225 rtx last_unconditional_cleanup
;
226 /* When in a conditional context, this is the specific
227 cleanup list associated with last_unconditional_cleanup,
228 where we place the conditionalized cleanups. */
231 /* For switch (C) or case (Pascal) statements,
232 and also for dummies (see `expand_start_case_dummy'). */
235 /* The insn after which the case dispatch should finally
236 be emitted. Zero for a dummy. */
238 /* A list of case labels; it is first built as an AVL tree.
239 During expand_end_case, this is converted to a list, and may be
240 rearranged into a nearly balanced binary tree. */
241 struct case_node
*case_list
;
242 /* Label to jump to if no case matches. */
244 /* The expression to be dispatched on. */
246 /* Type that INDEX_EXPR should be converted to. */
248 /* Number of range exprs in case statement. */
250 /* Name of this kind of statement, for warnings. */
251 const char *printname
;
252 /* Used to save no_line_numbers till we see the first case label.
253 We set this to -1 when we see the first case label in this
255 int line_number_status
;
260 /* Allocate and return a new `struct nesting'. */
262 #define ALLOC_NESTING() \
263 (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
265 /* Pop the nesting stack element by element until we pop off
266 the element which is at the top of STACK.
267 Update all the other stacks, popping off elements from them
268 as we pop them from nesting_stack. */
270 #define POPSTACK(STACK) \
271 do { struct nesting *target = STACK; \
272 struct nesting *this; \
273 do { this = nesting_stack; \
274 if (loop_stack == this) \
275 loop_stack = loop_stack->next; \
276 if (cond_stack == this) \
277 cond_stack = cond_stack->next; \
278 if (block_stack == this) \
279 block_stack = block_stack->next; \
280 if (stack_block_stack == this) \
281 stack_block_stack = stack_block_stack->next; \
282 if (case_stack == this) \
283 case_stack = case_stack->next; \
284 nesting_depth = nesting_stack->depth - 1; \
285 nesting_stack = this->all; \
286 obstack_free (&stmt_obstack, this); } \
287 while (this != target); } while (0)
289 /* In some cases it is impossible to generate code for a forward goto
290 until the label definition is seen. This happens when it may be necessary
291 for the goto to reset the stack pointer: we don't yet know how to do that.
292 So expand_goto puts an entry on this fixup list.
293 Each time a binding contour that resets the stack is exited,
295 If the target label has now been defined, we can insert the proper code. */
299 /* Points to following fixup. */
300 struct goto_fixup
*next
;
301 /* Points to the insn before the jump insn.
302 If more code must be inserted, it goes after this insn. */
304 /* The LABEL_DECL that this jump is jumping to, or 0
305 for break, continue or return. */
307 /* The BLOCK for the place where this goto was found. */
309 /* The CODE_LABEL rtx that this is jumping to. */
311 /* Number of binding contours started in current function
312 before the label reference. */
313 int block_start_count
;
314 /* The outermost stack level that should be restored for this jump.
315 Each time a binding contour that resets the stack is exited,
316 if the target label is *not* yet defined, this slot is updated. */
318 /* List of lists of cleanup expressions to be run by this goto.
319 There is one element for each block that this goto is within.
320 The tail of this list can be 0,
321 if all remaining elements would be empty.
322 The TREE_VALUE contains the cleanup list of that block as of the
323 time this goto was seen.
324 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
325 tree cleanup_list_list
;
328 /* Within any binding contour that must restore a stack level,
329 all labels are recorded with a chain of these structures. */
333 /* Points to following fixup. */
334 struct label_chain
*next
;
340 /* Chain of all pending binding contours. */
341 struct nesting
*x_block_stack
;
343 /* If any new stacks are added here, add them to POPSTACKS too. */
345 /* Chain of all pending binding contours that restore stack levels
347 struct nesting
*x_stack_block_stack
;
349 /* Chain of all pending conditional statements. */
350 struct nesting
*x_cond_stack
;
352 /* Chain of all pending loops. */
353 struct nesting
*x_loop_stack
;
355 /* Chain of all pending case or switch statements. */
356 struct nesting
*x_case_stack
;
358 /* Separate chain including all of the above,
359 chained through the `all' field. */
360 struct nesting
*x_nesting_stack
;
362 /* Number of entries on nesting_stack now. */
365 /* Number of binding contours started so far in this function. */
366 int x_block_start_count
;
368 /* Each time we expand an expression-statement,
369 record the expr's type and its RTL value here. */
370 tree x_last_expr_type
;
371 rtx x_last_expr_value
;
373 /* Nonzero if within a ({...}) grouping, in which case we must
374 always compute a value for each expr-stmt in case it is the last one. */
375 int x_expr_stmts_for_value
;
377 /* Filename and line number of last line-number note,
378 whether we actually emitted it or not. */
379 char *x_emit_filename
;
382 struct goto_fixup
*x_goto_fixup_chain
;
385 #define block_stack (current_function->stmt->x_block_stack)
386 #define stack_block_stack (current_function->stmt->x_stack_block_stack)
387 #define cond_stack (current_function->stmt->x_cond_stack)
388 #define loop_stack (current_function->stmt->x_loop_stack)
389 #define case_stack (current_function->stmt->x_case_stack)
390 #define nesting_stack (current_function->stmt->x_nesting_stack)
391 #define nesting_depth (current_function->stmt->x_nesting_depth)
392 #define current_block_start_count (current_function->stmt->x_block_start_count)
393 #define last_expr_type (current_function->stmt->x_last_expr_type)
394 #define last_expr_value (current_function->stmt->x_last_expr_value)
395 #define expr_stmts_for_value (current_function->stmt->x_expr_stmts_for_value)
396 #define emit_filename (current_function->stmt->x_emit_filename)
397 #define emit_lineno (current_function->stmt->x_emit_lineno)
398 #define goto_fixup_chain (current_function->stmt->x_goto_fixup_chain)
400 /* Non-zero if we are using EH to handle cleanus. */
401 static int using_eh_for_cleanups_p
= 0;
404 static int n_occurrences
PROTO((int, const char *));
405 static void expand_goto_internal
PROTO((tree
, rtx
, rtx
));
406 static int expand_fixup
PROTO((tree
, rtx
, rtx
));
407 static rtx expand_nl_handler_label
PROTO((rtx
, rtx
));
408 static void expand_nl_goto_receiver
PROTO((void));
409 static void expand_nl_goto_receivers
PROTO((struct nesting
*));
410 static void fixup_gotos
PROTO((struct nesting
*, rtx
, tree
,
412 static void expand_null_return_1
PROTO((rtx
, int));
413 static void expand_value_return
PROTO((rtx
));
414 static int tail_recursion_args
PROTO((tree
, tree
));
415 static void expand_cleanups
PROTO((tree
, tree
, int, int));
416 static void check_seenlabel
PROTO((void));
417 static void do_jump_if_equal
PROTO((rtx
, rtx
, rtx
, int));
418 static int estimate_case_costs
PROTO((case_node_ptr
));
419 static void group_case_nodes
PROTO((case_node_ptr
));
420 static void balance_case_nodes
PROTO((case_node_ptr
*,
422 static int node_has_low_bound
PROTO((case_node_ptr
, tree
));
423 static int node_has_high_bound
PROTO((case_node_ptr
, tree
));
424 static int node_is_bounded
PROTO((case_node_ptr
, tree
));
425 static void emit_jump_if_reachable
PROTO((rtx
));
426 static void emit_case_nodes
PROTO((rtx
, case_node_ptr
, rtx
, tree
));
427 static int add_case_node
PROTO((tree
, tree
, tree
, tree
*));
428 static struct case_node
*case_tree2list
PROTO((case_node
*, case_node
*));
429 static void mark_cond_nesting
PROTO((struct nesting
*));
430 static void mark_loop_nesting
PROTO((struct nesting
*));
431 static void mark_block_nesting
PROTO((struct nesting
*));
432 static void mark_case_nesting
PROTO((struct nesting
*));
433 static void mark_goto_fixup
PROTO((struct goto_fixup
*));
437 using_eh_for_cleanups ()
439 using_eh_for_cleanups_p
= 1;
442 /* Mark N (known to be a cond-nesting) for GC. */
445 mark_cond_nesting (n
)
450 ggc_mark_rtx (n
->exit_label
);
451 ggc_mark_rtx (n
->data
.cond
.endif_label
);
452 ggc_mark_rtx (n
->data
.cond
.next_label
);
458 /* Mark N (known to be a loop-nesting) for GC. */
461 mark_loop_nesting (n
)
467 ggc_mark_rtx (n
->exit_label
);
468 ggc_mark_rtx (n
->data
.loop
.start_label
);
469 ggc_mark_rtx (n
->data
.loop
.end_label
);
470 ggc_mark_rtx (n
->data
.loop
.alt_end_label
);
471 ggc_mark_rtx (n
->data
.loop
.continue_label
);
477 /* Mark N (known to be a block-nesting) for GC. */
480 mark_block_nesting (n
)
485 struct label_chain
*l
;
487 ggc_mark_rtx (n
->exit_label
);
488 ggc_mark_rtx (n
->data
.block
.stack_level
);
489 ggc_mark_rtx (n
->data
.block
.first_insn
);
490 ggc_mark_tree (n
->data
.block
.cleanups
);
491 ggc_mark_tree (n
->data
.block
.outer_cleanups
);
493 for (l
= n
->data
.block
.label_chain
; l
!= NULL
; l
= l
->next
)
494 ggc_mark_tree (l
->label
);
496 ggc_mark_rtx (n
->data
.block
.last_unconditional_cleanup
);
498 /* ??? cleanup_ptr never points outside the stack, does it? */
504 /* Mark N (known to be a case-nesting) for GC. */
507 mark_case_nesting (n
)
512 struct case_node
*node
;
514 ggc_mark_rtx (n
->exit_label
);
515 ggc_mark_rtx (n
->data
.case_stmt
.start
);
517 node
= n
->data
.case_stmt
.case_list
;
520 ggc_mark_tree (node
->low
);
521 ggc_mark_tree (node
->high
);
522 ggc_mark_tree (node
->code_label
);
526 ggc_mark_tree (n
->data
.case_stmt
.default_label
);
527 ggc_mark_tree (n
->data
.case_stmt
.index_expr
);
528 ggc_mark_tree (n
->data
.case_stmt
.nominal_type
);
538 struct goto_fixup
*g
;
542 ggc_mark_rtx (g
->before_jump
);
543 ggc_mark_tree (g
->target
);
544 ggc_mark_tree (g
->context
);
545 ggc_mark_rtx (g
->target_rtl
);
546 ggc_mark_rtx (g
->stack_level
);
547 ggc_mark_tree (g
->cleanup_list_list
);
553 /* Clear out all parts of the state in F that can safely be discarded
554 after the function has been compiled, to let garbage collection
555 reclaim the memory. D is the declaration for the function just
556 compiled. Its output may have been deferred. */
559 free_stmt_status (f
, d
)
561 tree d ATTRIBUTE_UNUSED
;
563 /* We're about to free the function obstack. If we hold pointers to
564 things allocated there, then we'll try to mark them when we do
565 GC. So, we clear them out here explicitly. */
566 f
->stmt
->x_goto_fixup_chain
= 0;
573 struct stmt_status
*p
;
578 mark_block_nesting (p
->x_block_stack
);
579 mark_cond_nesting (p
->x_cond_stack
);
580 mark_loop_nesting (p
->x_loop_stack
);
581 mark_case_nesting (p
->x_case_stack
);
583 ggc_mark_tree (p
->x_last_expr_type
);
584 /* last_epxr_value is only valid if last_expr_type is nonzero. */
585 if (p
->x_last_expr_type
)
586 ggc_mark_rtx (p
->x_last_expr_value
);
588 mark_goto_fixup (p
->x_goto_fixup_chain
);
594 gcc_obstack_init (&stmt_obstack
);
599 init_stmt_for_function ()
601 current_function
->stmt
602 = (struct stmt_status
*) xmalloc (sizeof (struct stmt_status
));
604 /* We are not currently within any block, conditional, loop or case. */
606 stack_block_stack
= 0;
613 current_block_start_count
= 0;
615 /* No gotos have been expanded yet. */
616 goto_fixup_chain
= 0;
618 /* We are not processing a ({...}) grouping. */
619 expr_stmts_for_value
= 0;
621 last_expr_value
= NULL_RTX
;
623 init_eh_for_function ();
626 /* Return nonzero if anything is pushed on the loop, condition, or case
631 return cond_stack
|| loop_stack
|| case_stack
;
634 /* Record the current file and line. Called from emit_line_note. */
636 set_file_and_line_for_stmt (file
, line
)
640 emit_filename
= file
;
644 /* Emit a no-op instruction. */
651 last_insn
= get_last_insn ();
653 && (GET_CODE (last_insn
) == CODE_LABEL
654 || (GET_CODE (last_insn
) == NOTE
655 && prev_real_insn (last_insn
) == 0)))
656 emit_insn (gen_nop ());
659 /* Return the rtx-label that corresponds to a LABEL_DECL,
660 creating it if necessary. */
666 if (TREE_CODE (label
) != LABEL_DECL
)
669 if (DECL_RTL (label
))
670 return DECL_RTL (label
);
672 return DECL_RTL (label
) = gen_label_rtx ();
675 /* Add an unconditional jump to LABEL as the next sequential instruction. */
681 do_pending_stack_adjust ();
682 emit_jump_insn (gen_jump (label
));
686 /* Emit code to jump to the address
687 specified by the pointer expression EXP. */
690 expand_computed_goto (exp
)
693 rtx x
= expand_expr (exp
, NULL_RTX
, VOIDmode
, 0);
695 #ifdef POINTERS_EXTEND_UNSIGNED
696 x
= convert_memory_address (Pmode
, x
);
700 /* Be sure the function is executable. */
701 if (current_function_check_memory_usage
)
702 emit_library_call (chkr_check_exec_libfunc
, 1,
703 VOIDmode
, 1, x
, ptr_mode
);
705 do_pending_stack_adjust ();
706 emit_indirect_jump (x
);
708 current_function_has_computed_jump
= 1;
711 /* Handle goto statements and the labels that they can go to. */
713 /* Specify the location in the RTL code of a label LABEL,
714 which is a LABEL_DECL tree node.
716 This is used for the kind of label that the user can jump to with a
717 goto statement, and for alternatives of a switch or case statement.
718 RTL labels generated for loops and conditionals don't go through here;
719 they are generated directly at the RTL level, by other functions below.
721 Note that this has nothing to do with defining label *names*.
722 Languages vary in how they do that and what that even means. */
728 struct label_chain
*p
;
730 do_pending_stack_adjust ();
731 emit_label (label_rtx (label
));
732 if (DECL_NAME (label
))
733 LABEL_NAME (DECL_RTL (label
)) = IDENTIFIER_POINTER (DECL_NAME (label
));
735 if (stack_block_stack
!= 0)
737 p
= (struct label_chain
*) oballoc (sizeof (struct label_chain
));
738 p
->next
= stack_block_stack
->data
.block
.label_chain
;
739 stack_block_stack
->data
.block
.label_chain
= p
;
744 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
745 from nested functions. */
748 declare_nonlocal_label (label
)
751 rtx slot
= assign_stack_local (Pmode
, GET_MODE_SIZE (Pmode
), 0);
753 nonlocal_labels
= tree_cons (NULL_TREE
, label
, nonlocal_labels
);
754 LABEL_PRESERVE_P (label_rtx (label
)) = 1;
755 if (nonlocal_goto_handler_slots
== 0)
757 emit_stack_save (SAVE_NONLOCAL
,
758 &nonlocal_goto_stack_level
,
759 PREV_INSN (tail_recursion_reentry
));
761 nonlocal_goto_handler_slots
762 = gen_rtx_EXPR_LIST (VOIDmode
, slot
, nonlocal_goto_handler_slots
);
765 /* Generate RTL code for a `goto' statement with target label LABEL.
766 LABEL should be a LABEL_DECL tree node that was or will later be
767 defined with `expand_label'. */
775 /* Check for a nonlocal goto to a containing function. */
776 context
= decl_function_context (label
);
777 if (context
!= 0 && context
!= current_function_decl
)
779 struct function
*p
= find_function_data (context
);
780 rtx label_ref
= gen_rtx_LABEL_REF (Pmode
, label_rtx (label
));
781 rtx temp
, handler_slot
;
784 /* Find the corresponding handler slot for this label. */
785 handler_slot
= p
->x_nonlocal_goto_handler_slots
;
786 for (link
= p
->x_nonlocal_labels
; TREE_VALUE (link
) != label
;
787 link
= TREE_CHAIN (link
))
788 handler_slot
= XEXP (handler_slot
, 1);
789 handler_slot
= XEXP (handler_slot
, 0);
791 p
->has_nonlocal_label
= 1;
792 current_function_has_nonlocal_goto
= 1;
793 LABEL_REF_NONLOCAL_P (label_ref
) = 1;
795 /* Copy the rtl for the slots so that they won't be shared in
796 case the virtual stack vars register gets instantiated differently
797 in the parent than in the child. */
799 #if HAVE_nonlocal_goto
800 if (HAVE_nonlocal_goto
)
801 emit_insn (gen_nonlocal_goto (lookup_static_chain (label
),
802 copy_rtx (handler_slot
),
803 copy_rtx (p
->x_nonlocal_goto_stack_level
),
810 /* Restore frame pointer for containing function.
811 This sets the actual hard register used for the frame pointer
812 to the location of the function's incoming static chain info.
813 The non-local goto handler will then adjust it to contain the
814 proper value and reload the argument pointer, if needed. */
815 emit_move_insn (hard_frame_pointer_rtx
, lookup_static_chain (label
));
817 /* We have now loaded the frame pointer hardware register with
818 the address of that corresponds to the start of the virtual
819 stack vars. So replace virtual_stack_vars_rtx in all
820 addresses we use with stack_pointer_rtx. */
822 /* Get addr of containing function's current nonlocal goto handler,
823 which will do any cleanups and then jump to the label. */
824 addr
= copy_rtx (handler_slot
);
825 temp
= copy_to_reg (replace_rtx (addr
, virtual_stack_vars_rtx
,
826 hard_frame_pointer_rtx
));
828 /* Restore the stack pointer. Note this uses fp just restored. */
829 addr
= p
->x_nonlocal_goto_stack_level
;
831 addr
= replace_rtx (copy_rtx (addr
),
832 virtual_stack_vars_rtx
,
833 hard_frame_pointer_rtx
);
835 emit_stack_restore (SAVE_NONLOCAL
, addr
, NULL_RTX
);
837 /* USE of hard_frame_pointer_rtx added for consistency; not clear if
839 emit_insn (gen_rtx_USE (VOIDmode
, hard_frame_pointer_rtx
));
840 emit_insn (gen_rtx_USE (VOIDmode
, stack_pointer_rtx
));
841 emit_indirect_jump (temp
);
845 expand_goto_internal (label
, label_rtx (label
), NULL_RTX
);
848 /* Generate RTL code for a `goto' statement with target label BODY.
849 LABEL should be a LABEL_REF.
850 LAST_INSN, if non-0, is the rtx we should consider as the last
851 insn emitted (for the purposes of cleaning up a return). */
854 expand_goto_internal (body
, label
, last_insn
)
859 struct nesting
*block
;
862 if (GET_CODE (label
) != CODE_LABEL
)
865 /* If label has already been defined, we can tell now
866 whether and how we must alter the stack level. */
868 if (PREV_INSN (label
) != 0)
870 /* Find the innermost pending block that contains the label.
871 (Check containment by comparing insn-uids.)
872 Then restore the outermost stack level within that block,
873 and do cleanups of all blocks contained in it. */
874 for (block
= block_stack
; block
; block
= block
->next
)
876 if (INSN_UID (block
->data
.block
.first_insn
) < INSN_UID (label
))
878 if (block
->data
.block
.stack_level
!= 0)
879 stack_level
= block
->data
.block
.stack_level
;
880 /* Execute the cleanups for blocks we are exiting. */
881 if (block
->data
.block
.cleanups
!= 0)
883 expand_cleanups (block
->data
.block
.cleanups
, NULL_TREE
, 1, 1);
884 do_pending_stack_adjust ();
890 /* Ensure stack adjust isn't done by emit_jump, as this
891 would clobber the stack pointer. This one should be
892 deleted as dead by flow. */
893 clear_pending_stack_adjust ();
894 do_pending_stack_adjust ();
895 emit_stack_restore (SAVE_BLOCK
, stack_level
, NULL_RTX
);
898 if (body
!= 0 && DECL_TOO_LATE (body
))
899 error ("jump to `%s' invalidly jumps into binding contour",
900 IDENTIFIER_POINTER (DECL_NAME (body
)));
902 /* Label not yet defined: may need to put this goto
903 on the fixup list. */
904 else if (! expand_fixup (body
, label
, last_insn
))
906 /* No fixup needed. Record that the label is the target
907 of at least one goto that has no fixup. */
909 TREE_ADDRESSABLE (body
) = 1;
915 /* Generate if necessary a fixup for a goto
916 whose target label in tree structure (if any) is TREE_LABEL
917 and whose target in rtl is RTL_LABEL.
919 If LAST_INSN is nonzero, we pretend that the jump appears
920 after insn LAST_INSN instead of at the current point in the insn stream.
922 The fixup will be used later to insert insns just before the goto.
923 Those insns will restore the stack level as appropriate for the
924 target label, and will (in the case of C++) also invoke any object
925 destructors which have to be invoked when we exit the scopes which
926 are exited by the goto.
928 Value is nonzero if a fixup is made. */
931 expand_fixup (tree_label
, rtl_label
, last_insn
)
936 struct nesting
*block
, *end_block
;
938 /* See if we can recognize which block the label will be output in.
939 This is possible in some very common cases.
940 If we succeed, set END_BLOCK to that block.
941 Otherwise, set it to 0. */
944 && (rtl_label
== cond_stack
->data
.cond
.endif_label
945 || rtl_label
== cond_stack
->data
.cond
.next_label
))
946 end_block
= cond_stack
;
947 /* If we are in a loop, recognize certain labels which
948 are likely targets. This reduces the number of fixups
949 we need to create. */
951 && (rtl_label
== loop_stack
->data
.loop
.start_label
952 || rtl_label
== loop_stack
->data
.loop
.end_label
953 || rtl_label
== loop_stack
->data
.loop
.continue_label
))
954 end_block
= loop_stack
;
958 /* Now set END_BLOCK to the binding level to which we will return. */
962 struct nesting
*next_block
= end_block
->all
;
965 /* First see if the END_BLOCK is inside the innermost binding level.
966 If so, then no cleanups or stack levels are relevant. */
967 while (next_block
&& next_block
!= block
)
968 next_block
= next_block
->all
;
973 /* Otherwise, set END_BLOCK to the innermost binding level
974 which is outside the relevant control-structure nesting. */
975 next_block
= block_stack
->next
;
976 for (block
= block_stack
; block
!= end_block
; block
= block
->all
)
977 if (block
== next_block
)
978 next_block
= next_block
->next
;
979 end_block
= next_block
;
982 /* Does any containing block have a stack level or cleanups?
983 If not, no fixup is needed, and that is the normal case
984 (the only case, for standard C). */
985 for (block
= block_stack
; block
!= end_block
; block
= block
->next
)
986 if (block
->data
.block
.stack_level
!= 0
987 || block
->data
.block
.cleanups
!= 0)
990 if (block
!= end_block
)
992 /* Ok, a fixup is needed. Add a fixup to the list of such. */
993 struct goto_fixup
*fixup
994 = (struct goto_fixup
*) oballoc (sizeof (struct goto_fixup
));
995 /* In case an old stack level is restored, make sure that comes
996 after any pending stack adjust. */
997 /* ?? If the fixup isn't to come at the present position,
998 doing the stack adjust here isn't useful. Doing it with our
999 settings at that location isn't useful either. Let's hope
1002 do_pending_stack_adjust ();
1003 fixup
->target
= tree_label
;
1004 fixup
->target_rtl
= rtl_label
;
1006 /* Create a BLOCK node and a corresponding matched set of
1007 NOTE_INSN_BEGIN_BLOCK and NOTE_INSN_END_BLOCK notes at
1008 this point. The notes will encapsulate any and all fixup
1009 code which we might later insert at this point in the insn
1010 stream. Also, the BLOCK node will be the parent (i.e. the
1011 `SUPERBLOCK') of any other BLOCK nodes which we might create
1012 later on when we are expanding the fixup code.
1014 Note that optimization passes (including expand_end_loop)
1015 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
1016 as a placeholder. */
1019 register rtx original_before_jump
1020 = last_insn
? last_insn
: get_last_insn ();
1025 start
= emit_note (NULL_PTR
, NOTE_INSN_BLOCK_BEG
);
1026 fixup
->before_jump
= emit_note (NULL_PTR
, NOTE_INSN_DELETED
);
1027 last_block_end_note
= emit_note (NULL_PTR
, NOTE_INSN_BLOCK_END
);
1028 fixup
->context
= poplevel (1, 0, 0); /* Create the BLOCK node now! */
1030 emit_insns_after (start
, original_before_jump
);
1033 fixup
->block_start_count
= current_block_start_count
;
1034 fixup
->stack_level
= 0;
1035 fixup
->cleanup_list_list
1036 = ((block
->data
.block
.outer_cleanups
1037 || block
->data
.block
.cleanups
)
1038 ? tree_cons (NULL_TREE
, block
->data
.block
.cleanups
,
1039 block
->data
.block
.outer_cleanups
)
1041 fixup
->next
= goto_fixup_chain
;
1042 goto_fixup_chain
= fixup
;
1050 /* Expand any needed fixups in the outputmost binding level of the
1051 function. FIRST_INSN is the first insn in the function. */
1054 expand_fixups (first_insn
)
1057 fixup_gotos (NULL_PTR
, NULL_RTX
, NULL_TREE
, first_insn
, 0);
1060 /* When exiting a binding contour, process all pending gotos requiring fixups.
1061 THISBLOCK is the structure that describes the block being exited.
1062 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1063 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1064 FIRST_INSN is the insn that began this contour.
1066 Gotos that jump out of this contour must restore the
1067 stack level and do the cleanups before actually jumping.
1069 DONT_JUMP_IN nonzero means report error there is a jump into this
1070 contour from before the beginning of the contour.
1071 This is also done if STACK_LEVEL is nonzero. */
1074 fixup_gotos (thisblock
, stack_level
, cleanup_list
, first_insn
, dont_jump_in
)
1075 struct nesting
*thisblock
;
1081 register struct goto_fixup
*f
, *prev
;
1083 /* F is the fixup we are considering; PREV is the previous one. */
1084 /* We run this loop in two passes so that cleanups of exited blocks
1085 are run first, and blocks that are exited are marked so
1088 for (prev
= 0, f
= goto_fixup_chain
; f
; prev
= f
, f
= f
->next
)
1090 /* Test for a fixup that is inactive because it is already handled. */
1091 if (f
->before_jump
== 0)
1093 /* Delete inactive fixup from the chain, if that is easy to do. */
1095 prev
->next
= f
->next
;
1097 /* Has this fixup's target label been defined?
1098 If so, we can finalize it. */
1099 else if (PREV_INSN (f
->target_rtl
) != 0)
1101 register rtx cleanup_insns
;
1103 /* Get the first non-label after the label
1104 this goto jumps to. If that's before this scope begins,
1105 we don't have a jump into the scope. */
1106 rtx after_label
= f
->target_rtl
;
1107 while (after_label
!= 0 && GET_CODE (after_label
) == CODE_LABEL
)
1108 after_label
= NEXT_INSN (after_label
);
1110 /* If this fixup jumped into this contour from before the beginning
1111 of this contour, report an error. */
1112 /* ??? Bug: this does not detect jumping in through intermediate
1113 blocks that have stack levels or cleanups.
1114 It detects only a problem with the innermost block
1115 around the label. */
1117 && (dont_jump_in
|| stack_level
|| cleanup_list
)
1118 /* If AFTER_LABEL is 0, it means the jump goes to the end
1119 of the rtl, which means it jumps into this scope. */
1120 && (after_label
== 0
1121 || INSN_UID (first_insn
) < INSN_UID (after_label
))
1122 && INSN_UID (first_insn
) > INSN_UID (f
->before_jump
)
1123 && ! DECL_ERROR_ISSUED (f
->target
))
1125 error_with_decl (f
->target
,
1126 "label `%s' used before containing binding contour");
1127 /* Prevent multiple errors for one label. */
1128 DECL_ERROR_ISSUED (f
->target
) = 1;
1131 /* We will expand the cleanups into a sequence of their own and
1132 then later on we will attach this new sequence to the insn
1133 stream just ahead of the actual jump insn. */
1137 /* Temporarily restore the lexical context where we will
1138 logically be inserting the fixup code. We do this for the
1139 sake of getting the debugging information right. */
1142 set_block (f
->context
);
1144 /* Expand the cleanups for blocks this jump exits. */
1145 if (f
->cleanup_list_list
)
1148 for (lists
= f
->cleanup_list_list
; lists
; lists
= TREE_CHAIN (lists
))
1149 /* Marked elements correspond to blocks that have been closed.
1150 Do their cleanups. */
1151 if (TREE_ADDRESSABLE (lists
)
1152 && TREE_VALUE (lists
) != 0)
1154 expand_cleanups (TREE_VALUE (lists
), NULL_TREE
, 1, 1);
1155 /* Pop any pushes done in the cleanups,
1156 in case function is about to return. */
1157 do_pending_stack_adjust ();
1161 /* Restore stack level for the biggest contour that this
1162 jump jumps out of. */
1164 emit_stack_restore (SAVE_BLOCK
, f
->stack_level
, f
->before_jump
);
1166 /* Finish up the sequence containing the insns which implement the
1167 necessary cleanups, and then attach that whole sequence to the
1168 insn stream just ahead of the actual jump insn. Attaching it
1169 at that point insures that any cleanups which are in fact
1170 implicit C++ object destructions (which must be executed upon
1171 leaving the block) appear (to the debugger) to be taking place
1172 in an area of the generated code where the object(s) being
1173 destructed are still "in scope". */
1175 cleanup_insns
= get_insns ();
1179 emit_insns_after (cleanup_insns
, f
->before_jump
);
1186 /* For any still-undefined labels, do the cleanups for this block now.
1187 We must do this now since items in the cleanup list may go out
1188 of scope when the block ends. */
1189 for (prev
= 0, f
= goto_fixup_chain
; f
; prev
= f
, f
= f
->next
)
1190 if (f
->before_jump
!= 0
1191 && PREV_INSN (f
->target_rtl
) == 0
1192 /* Label has still not appeared. If we are exiting a block with
1193 a stack level to restore, that started before the fixup,
1194 mark this stack level as needing restoration
1195 when the fixup is later finalized. */
1197 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1198 means the label is undefined. That's erroneous, but possible. */
1199 && (thisblock
->data
.block
.block_start_count
1200 <= f
->block_start_count
))
1202 tree lists
= f
->cleanup_list_list
;
1205 for (; lists
; lists
= TREE_CHAIN (lists
))
1206 /* If the following elt. corresponds to our containing block
1207 then the elt. must be for this block. */
1208 if (TREE_CHAIN (lists
) == thisblock
->data
.block
.outer_cleanups
)
1212 set_block (f
->context
);
1213 expand_cleanups (TREE_VALUE (lists
), NULL_TREE
, 1, 1);
1214 do_pending_stack_adjust ();
1215 cleanup_insns
= get_insns ();
1218 if (cleanup_insns
!= 0)
1220 = emit_insns_after (cleanup_insns
, f
->before_jump
);
1222 f
->cleanup_list_list
= TREE_CHAIN (lists
);
1226 f
->stack_level
= stack_level
;
1230 /* Return the number of times character C occurs in string S. */
1232 n_occurrences (c
, s
)
1242 /* Generate RTL for an asm statement (explicit assembler code).
1243 BODY is a STRING_CST node containing the assembler code text,
1244 or an ADDR_EXPR containing a STRING_CST. */
1250 if (current_function_check_memory_usage
)
1252 error ("`asm' cannot be used in function where memory usage is checked");
1256 if (TREE_CODE (body
) == ADDR_EXPR
)
1257 body
= TREE_OPERAND (body
, 0);
1259 emit_insn (gen_rtx_ASM_INPUT (VOIDmode
,
1260 TREE_STRING_POINTER (body
)));
1264 /* Generate RTL for an asm statement with arguments.
1265 STRING is the instruction template.
1266 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1267 Each output or input has an expression in the TREE_VALUE and
1268 a constraint-string in the TREE_PURPOSE.
1269 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1270 that is clobbered by this insn.
1272 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1273 Some elements of OUTPUTS may be replaced with trees representing temporary
1274 values. The caller should copy those temporary values to the originally
1277 VOL nonzero means the insn is volatile; don't optimize it. */
1280 expand_asm_operands (string
, outputs
, inputs
, clobbers
, vol
, filename
, line
)
1281 tree string
, outputs
, inputs
, clobbers
;
1286 rtvec argvec
, constraints
;
1288 int ninputs
= list_length (inputs
);
1289 int noutputs
= list_length (outputs
);
1294 /* Vector of RTX's of evaluated output operands. */
1295 rtx
*output_rtx
= (rtx
*) alloca (noutputs
* sizeof (rtx
));
1296 int *inout_opnum
= (int *) alloca (noutputs
* sizeof (int));
1297 rtx
*real_output_rtx
= (rtx
*) alloca (noutputs
* sizeof (rtx
));
1298 enum machine_mode
*inout_mode
1299 = (enum machine_mode
*) alloca (noutputs
* sizeof (enum machine_mode
));
1300 /* The insn we have emitted. */
1303 /* An ASM with no outputs needs to be treated as volatile, for now. */
1307 if (current_function_check_memory_usage
)
1309 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1313 #ifdef MD_ASM_CLOBBERS
1314 /* Sometimes we wish to automatically clobber registers across an asm.
1315 Case in point is when the i386 backend moved from cc0 to a hard reg --
1316 maintaining source-level compatability means automatically clobbering
1317 the flags register. */
1318 MD_ASM_CLOBBERS (clobbers
);
1321 if (current_function_check_memory_usage
)
1323 error ("`asm' cannot be used in function where memory usage is checked");
1327 /* Count the number of meaningful clobbered registers, ignoring what
1328 we would ignore later. */
1330 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
))
1332 char *regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
1333 i
= decode_reg_name (regname
);
1334 if (i
>= 0 || i
== -4)
1337 error ("unknown register name `%s' in `asm'", regname
);
1342 /* Check that the number of alternatives is constant across all
1344 if (outputs
|| inputs
)
1346 tree tmp
= TREE_PURPOSE (outputs
? outputs
: inputs
);
1347 int nalternatives
= n_occurrences (',', TREE_STRING_POINTER (tmp
));
1350 if (nalternatives
+ 1 > MAX_RECOG_ALTERNATIVES
)
1352 error ("too many alternatives in `asm'");
1359 char *constraint
= TREE_STRING_POINTER (TREE_PURPOSE (tmp
));
1360 if (n_occurrences (',', constraint
) != nalternatives
)
1362 error ("operand constraints for `asm' differ in number of alternatives");
1365 if (TREE_CHAIN (tmp
))
1366 tmp
= TREE_CHAIN (tmp
);
1368 tmp
= next
, next
= 0;
1372 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1374 tree val
= TREE_VALUE (tail
);
1375 tree type
= TREE_TYPE (val
);
1384 /* If there's an erroneous arg, emit no insn. */
1385 if (TREE_TYPE (val
) == error_mark_node
)
1388 /* Make sure constraint has `=' and does not have `+'. Also, see
1389 if it allows any register. Be liberal on the latter test, since
1390 the worst that happens if we get it wrong is we issue an error
1393 c_len
= TREE_STRING_LENGTH (TREE_PURPOSE (tail
)) - 1;
1394 constraint
= TREE_STRING_POINTER (TREE_PURPOSE (tail
));
1396 /* Allow the `=' or `+' to not be at the beginning of the string,
1397 since it wasn't explicitly documented that way, and there is a
1398 large body of code that puts it last. Swap the character to
1399 the front, so as not to uglify any place else. */
1403 if ((p
= strchr (constraint
, '=')) != NULL
)
1405 if ((p
= strchr (constraint
, '+')) != NULL
)
1408 error ("output operand constraint lacks `='");
1412 if (p
!= constraint
)
1415 bcopy (constraint
, constraint
+1, p
-constraint
);
1418 warning ("output constraint `%c' for operand %d is not at the beginning", j
, i
);
1421 is_inout
= constraint
[0] == '+';
1422 /* Replace '+' with '='. */
1423 constraint
[0] = '=';
1424 /* Make sure we can specify the matching operand. */
1425 if (is_inout
&& i
> 9)
1427 error ("output operand constraint %d contains `+'", i
);
1431 for (j
= 1; j
< c_len
; j
++)
1432 switch (constraint
[j
])
1436 error ("operand constraint contains '+' or '=' at illegal position.");
1440 if (i
+ 1 == ninputs
+ noutputs
)
1442 error ("`%%' constraint used with last operand");
1447 case '?': case '!': case '*': case '&':
1448 case 'E': case 'F': case 'G': case 'H':
1449 case 's': case 'i': case 'n':
1450 case 'I': case 'J': case 'K': case 'L': case 'M':
1451 case 'N': case 'O': case 'P': case ',':
1452 #ifdef EXTRA_CONSTRAINT
1453 case 'Q': case 'R': case 'S': case 'T': case 'U':
1457 case '0': case '1': case '2': case '3': case '4':
1458 case '5': case '6': case '7': case '8': case '9':
1459 error ("matching constraint not valid in output operand");
1462 case 'V': case 'm': case 'o':
1467 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1468 excepting those that expand_call created. So match memory
1484 /* If an output operand is not a decl or indirect ref and our constraint
1485 allows a register, make a temporary to act as an intermediate.
1486 Make the asm insn write into that, then our caller will copy it to
1487 the real output operand. Likewise for promoted variables. */
1489 real_output_rtx
[i
] = NULL_RTX
;
1490 if ((TREE_CODE (val
) == INDIRECT_REF
1492 || (TREE_CODE_CLASS (TREE_CODE (val
)) == 'd'
1493 && (allows_mem
|| GET_CODE (DECL_RTL (val
)) == REG
)
1494 && ! (GET_CODE (DECL_RTL (val
)) == REG
1495 && GET_MODE (DECL_RTL (val
)) != TYPE_MODE (type
)))
1500 mark_addressable (TREE_VALUE (tail
));
1503 = expand_expr (TREE_VALUE (tail
), NULL_RTX
, VOIDmode
,
1504 EXPAND_MEMORY_USE_WO
);
1506 if (! allows_reg
&& GET_CODE (output_rtx
[i
]) != MEM
)
1507 error ("output number %d not directly addressable", i
);
1508 if (! allows_mem
&& GET_CODE (output_rtx
[i
]) == MEM
)
1510 real_output_rtx
[i
] = protect_from_queue (output_rtx
[i
], 1);
1511 output_rtx
[i
] = gen_reg_rtx (GET_MODE (output_rtx
[i
]));
1513 emit_move_insn (output_rtx
[i
], real_output_rtx
[i
]);
1518 output_rtx
[i
] = assign_temp (type
, 0, 0, 0);
1519 TREE_VALUE (tail
) = make_tree (type
, output_rtx
[i
]);
1524 inout_mode
[ninout
] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail
)));
1525 inout_opnum
[ninout
++] = i
;
1530 if (ninputs
+ noutputs
> MAX_RECOG_OPERANDS
)
1532 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS
);
1536 /* Make vectors for the expression-rtx and constraint strings. */
1538 argvec
= rtvec_alloc (ninputs
);
1539 constraints
= rtvec_alloc (ninputs
);
1541 body
= gen_rtx_ASM_OPERANDS (VOIDmode
,
1542 TREE_STRING_POINTER (string
), "", 0, argvec
,
1543 constraints
, filename
, line
);
1545 MEM_VOLATILE_P (body
) = vol
;
1547 /* Eval the inputs and put them into ARGVEC.
1548 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1551 for (tail
= inputs
; tail
; tail
= TREE_CHAIN (tail
))
1554 int allows_reg
= 0, allows_mem
= 0;
1555 char *constraint
, *orig_constraint
;
1559 /* If there's an erroneous arg, emit no insn,
1560 because the ASM_INPUT would get VOIDmode
1561 and that could cause a crash in reload. */
1562 if (TREE_TYPE (TREE_VALUE (tail
)) == error_mark_node
)
1565 /* ??? Can this happen, and does the error message make any sense? */
1566 if (TREE_PURPOSE (tail
) == NULL_TREE
)
1568 error ("hard register `%s' listed as input operand to `asm'",
1569 TREE_STRING_POINTER (TREE_VALUE (tail
)) );
1573 c_len
= TREE_STRING_LENGTH (TREE_PURPOSE (tail
)) - 1;
1574 constraint
= TREE_STRING_POINTER (TREE_PURPOSE (tail
));
1575 orig_constraint
= constraint
;
1577 /* Make sure constraint has neither `=', `+', nor '&'. */
1579 for (j
= 0; j
< c_len
; j
++)
1580 switch (constraint
[j
])
1582 case '+': case '=': case '&':
1583 if (constraint
== orig_constraint
)
1585 error ("input operand constraint contains `%c'", constraint
[j
]);
1591 if (constraint
== orig_constraint
1592 && i
+ 1 == ninputs
- ninout
)
1594 error ("`%%' constraint used with last operand");
1599 case 'V': case 'm': case 'o':
1604 case '?': case '!': case '*':
1605 case 'E': case 'F': case 'G': case 'H': case 'X':
1606 case 's': case 'i': case 'n':
1607 case 'I': case 'J': case 'K': case 'L': case 'M':
1608 case 'N': case 'O': case 'P': case ',':
1609 #ifdef EXTRA_CONSTRAINT
1610 case 'Q': case 'R': case 'S': case 'T': case 'U':
1614 /* Whether or not a numeric constraint allows a register is
1615 decided by the matching constraint, and so there is no need
1616 to do anything special with them. We must handle them in
1617 the default case, so that we don't unnecessarily force
1618 operands to memory. */
1619 case '0': case '1': case '2': case '3': case '4':
1620 case '5': case '6': case '7': case '8': case '9':
1621 if (constraint
[j
] >= '0' + noutputs
)
1624 ("matching constraint references invalid operand number");
1628 /* Try and find the real constraint for this dup. */
1629 if ((j
== 0 && c_len
== 1)
1630 || (j
== 1 && c_len
== 2 && constraint
[0] == '%'))
1633 for (j
= constraint
[j
] - '0'; j
> 0; --j
)
1636 c_len
= TREE_STRING_LENGTH (TREE_PURPOSE (o
)) - 1;
1637 constraint
= TREE_STRING_POINTER (TREE_PURPOSE (o
));
1642 /* ... fall through ... */
1655 if (! allows_reg
&& allows_mem
)
1656 mark_addressable (TREE_VALUE (tail
));
1658 op
= expand_expr (TREE_VALUE (tail
), NULL_RTX
, VOIDmode
, 0);
1660 if (asm_operand_ok (op
, constraint
) <= 0)
1663 op
= force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail
))), op
);
1664 else if (!allows_mem
)
1665 warning ("asm operand %d probably doesn't match constraints", i
);
1666 else if (CONSTANT_P (op
))
1667 op
= force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail
))),
1669 else if (GET_CODE (op
) == REG
1670 || GET_CODE (op
) == SUBREG
1671 || GET_CODE (op
) == CONCAT
)
1673 tree type
= TREE_TYPE (TREE_VALUE (tail
));
1674 rtx memloc
= assign_temp (type
, 1, 1, 1);
1676 emit_move_insn (memloc
, op
);
1679 else if (GET_CODE (op
) == MEM
&& MEM_VOLATILE_P (op
))
1680 /* We won't recognize volatile memory as available a
1681 memory_operand at this point. Ignore it. */
1683 else if (queued_subexp_p (op
))
1686 /* ??? Leave this only until we have experience with what
1687 happens in combine and elsewhere when constraints are
1689 warning ("asm operand %d probably doesn't match constraints", i
);
1691 XVECEXP (body
, 3, i
) = op
;
1693 XVECEXP (body
, 4, i
) /* constraints */
1694 = gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail
))),
1699 /* Protect all the operands from the queue,
1700 now that they have all been evaluated. */
1702 for (i
= 0; i
< ninputs
- ninout
; i
++)
1703 XVECEXP (body
, 3, i
) = protect_from_queue (XVECEXP (body
, 3, i
), 0);
1705 for (i
= 0; i
< noutputs
; i
++)
1706 output_rtx
[i
] = protect_from_queue (output_rtx
[i
], 1);
1708 /* For in-out operands, copy output rtx to input rtx. */
1709 for (i
= 0; i
< ninout
; i
++)
1711 static char match
[9+1][2]
1712 = {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9"};
1713 int j
= inout_opnum
[i
];
1715 XVECEXP (body
, 3, ninputs
- ninout
+ i
) /* argvec */
1717 XVECEXP (body
, 4, ninputs
- ninout
+ i
) /* constraints */
1718 = gen_rtx_ASM_INPUT (inout_mode
[i
], match
[j
]);
1721 /* Now, for each output, construct an rtx
1722 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1723 ARGVEC CONSTRAINTS))
1724 If there is more than one, put them inside a PARALLEL. */
1726 if (noutputs
== 1 && nclobbers
== 0)
1728 XSTR (body
, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs
));
1729 insn
= emit_insn (gen_rtx_SET (VOIDmode
, output_rtx
[0], body
));
1731 else if (noutputs
== 0 && nclobbers
== 0)
1733 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1734 insn
= emit_insn (body
);
1740 if (num
== 0) num
= 1;
1741 body
= gen_rtx_PARALLEL (VOIDmode
, rtvec_alloc (num
+ nclobbers
));
1743 /* For each output operand, store a SET. */
1745 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1747 XVECEXP (body
, 0, i
)
1748 = gen_rtx_SET (VOIDmode
,
1750 gen_rtx_ASM_OPERANDS
1752 TREE_STRING_POINTER (string
),
1753 TREE_STRING_POINTER (TREE_PURPOSE (tail
)),
1754 i
, argvec
, constraints
,
1757 MEM_VOLATILE_P (SET_SRC (XVECEXP (body
, 0, i
))) = vol
;
1760 /* If there are no outputs (but there are some clobbers)
1761 store the bare ASM_OPERANDS into the PARALLEL. */
1764 XVECEXP (body
, 0, i
++) = obody
;
1766 /* Store (clobber REG) for each clobbered register specified. */
1768 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
))
1770 char *regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
1771 int j
= decode_reg_name (regname
);
1775 if (j
== -3) /* `cc', which is not a register */
1778 if (j
== -4) /* `memory', don't cache memory across asm */
1780 XVECEXP (body
, 0, i
++)
1781 = gen_rtx_CLOBBER (VOIDmode
,
1784 gen_rtx_SCRATCH (VOIDmode
)));
1788 /* Ignore unknown register, error already signaled. */
1792 /* Use QImode since that's guaranteed to clobber just one reg. */
1793 XVECEXP (body
, 0, i
++)
1794 = gen_rtx_CLOBBER (VOIDmode
, gen_rtx_REG (QImode
, j
));
1797 insn
= emit_insn (body
);
1800 /* For any outputs that needed reloading into registers, spill them
1801 back to where they belong. */
1802 for (i
= 0; i
< noutputs
; ++i
)
1803 if (real_output_rtx
[i
])
1804 emit_move_insn (real_output_rtx
[i
], output_rtx
[i
]);
1809 /* Generate RTL to evaluate the expression EXP
1810 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1813 expand_expr_stmt (exp
)
1816 /* If -W, warn about statements with no side effects,
1817 except for an explicit cast to void (e.g. for assert()), and
1818 except inside a ({...}) where they may be useful. */
1819 if (expr_stmts_for_value
== 0 && exp
!= error_mark_node
)
1821 if (! TREE_SIDE_EFFECTS (exp
) && (extra_warnings
|| warn_unused
)
1822 && !(TREE_CODE (exp
) == CONVERT_EXPR
1823 && TREE_TYPE (exp
) == void_type_node
))
1824 warning_with_file_and_line (emit_filename
, emit_lineno
,
1825 "statement with no effect");
1826 else if (warn_unused
)
1827 warn_if_unused_value (exp
);
1830 /* If EXP is of function type and we are expanding statements for
1831 value, convert it to pointer-to-function. */
1832 if (expr_stmts_for_value
&& TREE_CODE (TREE_TYPE (exp
)) == FUNCTION_TYPE
)
1833 exp
= build1 (ADDR_EXPR
, build_pointer_type (TREE_TYPE (exp
)), exp
);
1835 last_expr_type
= TREE_TYPE (exp
);
1836 last_expr_value
= expand_expr (exp
,
1837 (expr_stmts_for_value
1838 ? NULL_RTX
: const0_rtx
),
1841 /* If all we do is reference a volatile value in memory,
1842 copy it to a register to be sure it is actually touched. */
1843 if (last_expr_value
!= 0 && GET_CODE (last_expr_value
) == MEM
1844 && TREE_THIS_VOLATILE (exp
))
1846 if (TYPE_MODE (TREE_TYPE (exp
)) == VOIDmode
)
1848 else if (TYPE_MODE (TREE_TYPE (exp
)) != BLKmode
)
1849 copy_to_reg (last_expr_value
);
1852 rtx lab
= gen_label_rtx ();
1854 /* Compare the value with itself to reference it. */
1855 emit_cmp_and_jump_insns (last_expr_value
, last_expr_value
, EQ
,
1856 expand_expr (TYPE_SIZE (last_expr_type
),
1857 NULL_RTX
, VOIDmode
, 0),
1859 TYPE_ALIGN (last_expr_type
) / BITS_PER_UNIT
,
1865 /* If this expression is part of a ({...}) and is in memory, we may have
1866 to preserve temporaries. */
1867 preserve_temp_slots (last_expr_value
);
1869 /* Free any temporaries used to evaluate this expression. Any temporary
1870 used as a result of this expression will already have been preserved
1877 /* Warn if EXP contains any computations whose results are not used.
1878 Return 1 if a warning is printed; 0 otherwise. */
1881 warn_if_unused_value (exp
)
1884 if (TREE_USED (exp
))
1887 switch (TREE_CODE (exp
))
1889 case PREINCREMENT_EXPR
:
1890 case POSTINCREMENT_EXPR
:
1891 case PREDECREMENT_EXPR
:
1892 case POSTDECREMENT_EXPR
:
1897 case METHOD_CALL_EXPR
:
1899 case TRY_CATCH_EXPR
:
1900 case WITH_CLEANUP_EXPR
:
1902 /* We don't warn about COND_EXPR because it may be a useful
1903 construct if either arm contains a side effect. */
1908 /* For a binding, warn if no side effect within it. */
1909 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
1912 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
1914 case TRUTH_ORIF_EXPR
:
1915 case TRUTH_ANDIF_EXPR
:
1916 /* In && or ||, warn if 2nd operand has no side effect. */
1917 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
1920 if (TREE_NO_UNUSED_WARNING (exp
))
1922 if (warn_if_unused_value (TREE_OPERAND (exp
, 0)))
1924 /* Let people do `(foo (), 0)' without a warning. */
1925 if (TREE_CONSTANT (TREE_OPERAND (exp
, 1)))
1927 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
1931 case NON_LVALUE_EXPR
:
1932 /* Don't warn about values cast to void. */
1933 if (TREE_TYPE (exp
) == void_type_node
)
1935 /* Don't warn about conversions not explicit in the user's program. */
1936 if (TREE_NO_UNUSED_WARNING (exp
))
1938 /* Assignment to a cast usually results in a cast of a modify.
1939 Don't complain about that. There can be an arbitrary number of
1940 casts before the modify, so we must loop until we find the first
1941 non-cast expression and then test to see if that is a modify. */
1943 tree tem
= TREE_OPERAND (exp
, 0);
1945 while (TREE_CODE (tem
) == CONVERT_EXPR
|| TREE_CODE (tem
) == NOP_EXPR
)
1946 tem
= TREE_OPERAND (tem
, 0);
1948 if (TREE_CODE (tem
) == MODIFY_EXPR
|| TREE_CODE (tem
) == INIT_EXPR
1949 || TREE_CODE (tem
) == CALL_EXPR
)
1955 /* Don't warn about automatic dereferencing of references, since
1956 the user cannot control it. */
1957 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp
, 0))) == REFERENCE_TYPE
)
1958 return warn_if_unused_value (TREE_OPERAND (exp
, 0));
1959 /* ... fall through ... */
1962 /* Referencing a volatile value is a side effect, so don't warn. */
1963 if ((TREE_CODE_CLASS (TREE_CODE (exp
)) == 'd'
1964 || TREE_CODE_CLASS (TREE_CODE (exp
)) == 'r')
1965 && TREE_THIS_VOLATILE (exp
))
1968 warning_with_file_and_line (emit_filename
, emit_lineno
,
1969 "value computed is not used");
1974 /* Clear out the memory of the last expression evaluated. */
1982 /* Begin a statement which will return a value.
1983 Return the RTL_EXPR for this statement expr.
1984 The caller must save that value and pass it to expand_end_stmt_expr. */
1987 expand_start_stmt_expr ()
1992 /* Make the RTL_EXPR node temporary, not momentary,
1993 so that rtl_expr_chain doesn't become garbage. */
1994 momentary
= suspend_momentary ();
1995 t
= make_node (RTL_EXPR
);
1996 resume_momentary (momentary
);
1997 do_pending_stack_adjust ();
1998 start_sequence_for_rtl_expr (t
);
2000 expr_stmts_for_value
++;
2004 /* Restore the previous state at the end of a statement that returns a value.
2005 Returns a tree node representing the statement's value and the
2006 insns to compute the value.
2008 The nodes of that expression have been freed by now, so we cannot use them.
2009 But we don't want to do that anyway; the expression has already been
2010 evaluated and now we just want to use the value. So generate a RTL_EXPR
2011 with the proper type and RTL value.
2013 If the last substatement was not an expression,
2014 return something with type `void'. */
2017 expand_end_stmt_expr (t
)
2022 if (last_expr_type
== 0)
2024 last_expr_type
= void_type_node
;
2025 last_expr_value
= const0_rtx
;
2027 else if (last_expr_value
== 0)
2028 /* There are some cases where this can happen, such as when the
2029 statement is void type. */
2030 last_expr_value
= const0_rtx
;
2031 else if (GET_CODE (last_expr_value
) != REG
&& ! CONSTANT_P (last_expr_value
))
2032 /* Remove any possible QUEUED. */
2033 last_expr_value
= protect_from_queue (last_expr_value
, 0);
2037 TREE_TYPE (t
) = last_expr_type
;
2038 RTL_EXPR_RTL (t
) = last_expr_value
;
2039 RTL_EXPR_SEQUENCE (t
) = get_insns ();
2041 rtl_expr_chain
= tree_cons (NULL_TREE
, t
, rtl_expr_chain
);
2045 /* Don't consider deleting this expr or containing exprs at tree level. */
2046 TREE_SIDE_EFFECTS (t
) = 1;
2047 /* Propagate volatility of the actual RTL expr. */
2048 TREE_THIS_VOLATILE (t
) = volatile_refs_p (last_expr_value
);
2051 expr_stmts_for_value
--;
2056 /* Generate RTL for the start of an if-then. COND is the expression
2057 whose truth should be tested.
2059 If EXITFLAG is nonzero, this conditional is visible to
2060 `exit_something'. */
2063 expand_start_cond (cond
, exitflag
)
2067 struct nesting
*thiscond
= ALLOC_NESTING ();
2069 /* Make an entry on cond_stack for the cond we are entering. */
2071 thiscond
->next
= cond_stack
;
2072 thiscond
->all
= nesting_stack
;
2073 thiscond
->depth
= ++nesting_depth
;
2074 thiscond
->data
.cond
.next_label
= gen_label_rtx ();
2075 /* Before we encounter an `else', we don't need a separate exit label
2076 unless there are supposed to be exit statements
2077 to exit this conditional. */
2078 thiscond
->exit_label
= exitflag
? gen_label_rtx () : 0;
2079 thiscond
->data
.cond
.endif_label
= thiscond
->exit_label
;
2080 cond_stack
= thiscond
;
2081 nesting_stack
= thiscond
;
2083 do_jump (cond
, thiscond
->data
.cond
.next_label
, NULL_RTX
);
2086 /* Generate RTL between then-clause and the elseif-clause
2087 of an if-then-elseif-.... */
2090 expand_start_elseif (cond
)
2093 if (cond_stack
->data
.cond
.endif_label
== 0)
2094 cond_stack
->data
.cond
.endif_label
= gen_label_rtx ();
2095 emit_jump (cond_stack
->data
.cond
.endif_label
);
2096 emit_label (cond_stack
->data
.cond
.next_label
);
2097 cond_stack
->data
.cond
.next_label
= gen_label_rtx ();
2098 do_jump (cond
, cond_stack
->data
.cond
.next_label
, NULL_RTX
);
2101 /* Generate RTL between the then-clause and the else-clause
2102 of an if-then-else. */
2105 expand_start_else ()
2107 if (cond_stack
->data
.cond
.endif_label
== 0)
2108 cond_stack
->data
.cond
.endif_label
= gen_label_rtx ();
2110 emit_jump (cond_stack
->data
.cond
.endif_label
);
2111 emit_label (cond_stack
->data
.cond
.next_label
);
2112 cond_stack
->data
.cond
.next_label
= 0; /* No more _else or _elseif calls. */
2115 /* After calling expand_start_else, turn this "else" into an "else if"
2116 by providing another condition. */
2119 expand_elseif (cond
)
2122 cond_stack
->data
.cond
.next_label
= gen_label_rtx ();
2123 do_jump (cond
, cond_stack
->data
.cond
.next_label
, NULL_RTX
);
2126 /* Generate RTL for the end of an if-then.
2127 Pop the record for it off of cond_stack. */
2132 struct nesting
*thiscond
= cond_stack
;
2134 do_pending_stack_adjust ();
2135 if (thiscond
->data
.cond
.next_label
)
2136 emit_label (thiscond
->data
.cond
.next_label
);
2137 if (thiscond
->data
.cond
.endif_label
)
2138 emit_label (thiscond
->data
.cond
.endif_label
);
2140 POPSTACK (cond_stack
);
2146 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2147 loop should be exited by `exit_something'. This is a loop for which
2148 `expand_continue' will jump to the top of the loop.
2150 Make an entry on loop_stack to record the labels associated with
2154 expand_start_loop (exit_flag
)
2157 register struct nesting
*thisloop
= ALLOC_NESTING ();
2159 /* Make an entry on loop_stack for the loop we are entering. */
2161 thisloop
->next
= loop_stack
;
2162 thisloop
->all
= nesting_stack
;
2163 thisloop
->depth
= ++nesting_depth
;
2164 thisloop
->data
.loop
.start_label
= gen_label_rtx ();
2165 thisloop
->data
.loop
.end_label
= gen_label_rtx ();
2166 thisloop
->data
.loop
.alt_end_label
= 0;
2167 thisloop
->data
.loop
.continue_label
= thisloop
->data
.loop
.start_label
;
2168 thisloop
->exit_label
= exit_flag
? thisloop
->data
.loop
.end_label
: 0;
2169 loop_stack
= thisloop
;
2170 nesting_stack
= thisloop
;
2172 do_pending_stack_adjust ();
2174 emit_note (NULL_PTR
, NOTE_INSN_LOOP_BEG
);
2175 emit_label (thisloop
->data
.loop
.start_label
);
2180 /* Like expand_start_loop but for a loop where the continuation point
2181 (for expand_continue_loop) will be specified explicitly. */
2184 expand_start_loop_continue_elsewhere (exit_flag
)
2187 struct nesting
*thisloop
= expand_start_loop (exit_flag
);
2188 loop_stack
->data
.loop
.continue_label
= gen_label_rtx ();
2192 /* Specify the continuation point for a loop started with
2193 expand_start_loop_continue_elsewhere.
2194 Use this at the point in the code to which a continue statement
2198 expand_loop_continue_here ()
2200 do_pending_stack_adjust ();
2201 emit_note (NULL_PTR
, NOTE_INSN_LOOP_CONT
);
2202 emit_label (loop_stack
->data
.loop
.continue_label
);
2205 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2206 Pop the block off of loop_stack. */
2211 rtx start_label
= loop_stack
->data
.loop
.start_label
;
2212 rtx insn
= get_last_insn ();
2213 int needs_end_jump
= 1;
2215 /* Mark the continue-point at the top of the loop if none elsewhere. */
2216 if (start_label
== loop_stack
->data
.loop
.continue_label
)
2217 emit_note_before (NOTE_INSN_LOOP_CONT
, start_label
);
2219 do_pending_stack_adjust ();
2221 /* If optimizing, perhaps reorder the loop.
2222 First, try to use a condjump near the end.
2223 expand_exit_loop_if_false ends loops with unconditional jumps,
2226 if (test) goto label;
2228 goto loop_stack->data.loop.end_label
2232 If we find such a pattern, we can end the loop earlier. */
2235 && GET_CODE (insn
) == CODE_LABEL
2236 && LABEL_NAME (insn
) == NULL
2237 && GET_CODE (PREV_INSN (insn
)) == BARRIER
)
2240 rtx jump
= PREV_INSN (PREV_INSN (label
));
2242 if (GET_CODE (jump
) == JUMP_INSN
2243 && GET_CODE (PATTERN (jump
)) == SET
2244 && SET_DEST (PATTERN (jump
)) == pc_rtx
2245 && GET_CODE (SET_SRC (PATTERN (jump
))) == LABEL_REF
2246 && (XEXP (SET_SRC (PATTERN (jump
)), 0)
2247 == loop_stack
->data
.loop
.end_label
))
2251 /* The test might be complex and reference LABEL multiple times,
2252 like the loop in loop_iterations to set vtop. To handle this,
2254 insn
= PREV_INSN (label
);
2255 reorder_insns (label
, label
, start_label
);
2257 for (prev
= PREV_INSN (jump
); ; prev
= PREV_INSN (prev
))
2259 /* We ignore line number notes, but if we see any other note,
2260 in particular NOTE_INSN_BLOCK_*, NOTE_INSN_EH_REGION_*,
2261 NOTE_INSN_LOOP_*, we disable this optimization. */
2262 if (GET_CODE (prev
) == NOTE
)
2264 if (NOTE_LINE_NUMBER (prev
) < 0)
2268 if (GET_CODE (prev
) == CODE_LABEL
)
2270 if (GET_CODE (prev
) == JUMP_INSN
)
2272 if (GET_CODE (PATTERN (prev
)) == SET
2273 && SET_DEST (PATTERN (prev
)) == pc_rtx
2274 && GET_CODE (SET_SRC (PATTERN (prev
))) == IF_THEN_ELSE
2275 && (GET_CODE (XEXP (SET_SRC (PATTERN (prev
)), 1))
2277 && XEXP (XEXP (SET_SRC (PATTERN (prev
)), 1), 0) == label
)
2279 XEXP (XEXP (SET_SRC (PATTERN (prev
)), 1), 0)
2281 emit_note_after (NOTE_INSN_LOOP_END
, prev
);
2290 /* If the loop starts with a loop exit, roll that to the end where
2291 it will optimize together with the jump back.
2293 We look for the conditional branch to the exit, except that once
2294 we find such a branch, we don't look past 30 instructions.
2296 In more detail, if the loop presently looks like this (in pseudo-C):
2299 if (test) goto end_label;
2304 transform it to look like:
2310 if (test) goto end_label;
2311 goto newstart_label;
2314 Here, the `test' may actually consist of some reasonably complex
2315 code, terminating in a test. */
2320 ! (GET_CODE (insn
) == JUMP_INSN
2321 && GET_CODE (PATTERN (insn
)) == SET
2322 && SET_DEST (PATTERN (insn
)) == pc_rtx
2323 && GET_CODE (SET_SRC (PATTERN (insn
))) == IF_THEN_ELSE
))
2327 rtx last_test_insn
= NULL_RTX
;
2329 /* Scan insns from the top of the loop looking for a qualified
2330 conditional exit. */
2331 for (insn
= NEXT_INSN (loop_stack
->data
.loop
.start_label
); insn
;
2332 insn
= NEXT_INSN (insn
))
2334 if (GET_CODE (insn
) == NOTE
)
2337 && (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_BEG
2338 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_END
))
2339 /* The code that actually moves the exit test will
2340 carefully leave BLOCK notes in their original
2341 location. That means, however, that we can't debug
2342 the exit test itself. So, we refuse to move code
2343 containing BLOCK notes at low optimization levels. */
2346 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_EH_REGION_BEG
)
2348 else if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_EH_REGION_END
)
2352 /* We've come to the end of an EH region, but
2353 never saw the beginning of that region. That
2354 means that an EH region begins before the top
2355 of the loop, and ends in the middle of it. The
2356 existence of such a situation violates a basic
2357 assumption in this code, since that would imply
2358 that even when EH_REGIONS is zero, we might
2359 move code out of an exception region. */
2363 /* We must not walk into a nested loop. */
2364 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_LOOP_BEG
)
2367 /* We already know this INSN is a NOTE, so there's no
2368 point in looking at it to see if it's a JUMP. */
2372 if (GET_CODE (insn
) == JUMP_INSN
|| GET_CODE (insn
) == INSN
)
2375 if (last_test_insn
&& num_insns
> 30)
2379 /* We don't want to move a partial EH region. Consider:
2393 This isn't legal C++, but here's what it's supposed to
2394 mean: if cond() is true, stop looping. Otherwise,
2395 call bar, and keep looping. In addition, if cond
2396 throws an exception, catch it and keep looping. Such
2397 constructs are certainy legal in LISP.
2399 We should not move the `if (cond()) 0' test since then
2400 the EH-region for the try-block would be broken up.
2401 (In this case we would the EH_BEG note for the `try'
2402 and `if cond()' but not the call to bar() or the
2405 So we don't look for tests within an EH region. */
2408 if (GET_CODE (insn
) == JUMP_INSN
2409 && GET_CODE (PATTERN (insn
)) == SET
2410 && SET_DEST (PATTERN (insn
)) == pc_rtx
)
2412 /* This is indeed a jump. */
2413 rtx dest1
= NULL_RTX
;
2414 rtx dest2
= NULL_RTX
;
2415 rtx potential_last_test
;
2416 if (GET_CODE (SET_SRC (PATTERN (insn
))) == IF_THEN_ELSE
)
2418 /* A conditional jump. */
2419 dest1
= XEXP (SET_SRC (PATTERN (insn
)), 1);
2420 dest2
= XEXP (SET_SRC (PATTERN (insn
)), 2);
2421 potential_last_test
= insn
;
2425 /* An unconditional jump. */
2426 dest1
= SET_SRC (PATTERN (insn
));
2427 /* Include the BARRIER after the JUMP. */
2428 potential_last_test
= NEXT_INSN (insn
);
2432 if (dest1
&& GET_CODE (dest1
) == LABEL_REF
2433 && ((XEXP (dest1
, 0)
2434 == loop_stack
->data
.loop
.alt_end_label
)
2436 == loop_stack
->data
.loop
.end_label
)))
2438 last_test_insn
= potential_last_test
;
2442 /* If this was a conditional jump, there may be
2443 another label at which we should look. */
2450 if (last_test_insn
!= 0 && last_test_insn
!= get_last_insn ())
2452 /* We found one. Move everything from there up
2453 to the end of the loop, and add a jump into the loop
2454 to jump to there. */
2455 register rtx newstart_label
= gen_label_rtx ();
2456 register rtx start_move
= start_label
;
2459 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2460 then we want to move this note also. */
2461 if (GET_CODE (PREV_INSN (start_move
)) == NOTE
2462 && (NOTE_LINE_NUMBER (PREV_INSN (start_move
))
2463 == NOTE_INSN_LOOP_CONT
))
2464 start_move
= PREV_INSN (start_move
);
2466 emit_label_after (newstart_label
, PREV_INSN (start_move
));
2468 /* Actually move the insns. Start at the beginning, and
2469 keep copying insns until we've copied the
2471 for (insn
= start_move
; insn
; insn
= next_insn
)
2473 /* Figure out which insn comes after this one. We have
2474 to do this before we move INSN. */
2475 if (insn
== last_test_insn
)
2476 /* We've moved all the insns. */
2477 next_insn
= NULL_RTX
;
2479 next_insn
= NEXT_INSN (insn
);
2481 if (GET_CODE (insn
) == NOTE
2482 && (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_BEG
2483 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_END
))
2484 /* We don't want to move NOTE_INSN_BLOCK_BEGs or
2485 NOTE_INSN_BLOCK_ENDs because the correct generation
2486 of debugging information depends on these appearing
2487 in the same order in the RTL and in the tree
2488 structure, where they are represented as BLOCKs.
2489 So, we don't move block notes. Of course, moving
2490 the code inside the block is likely to make it
2491 impossible to debug the instructions in the exit
2492 test, but such is the price of optimization. */
2495 /* Move the INSN. */
2496 reorder_insns (insn
, insn
, get_last_insn ());
2499 emit_jump_insn_after (gen_jump (start_label
),
2500 PREV_INSN (newstart_label
));
2501 emit_barrier_after (PREV_INSN (newstart_label
));
2502 start_label
= newstart_label
;
2508 emit_jump (start_label
);
2509 emit_note (NULL_PTR
, NOTE_INSN_LOOP_END
);
2511 emit_label (loop_stack
->data
.loop
.end_label
);
2513 POPSTACK (loop_stack
);
2518 /* Generate a jump to the current loop's continue-point.
2519 This is usually the top of the loop, but may be specified
2520 explicitly elsewhere. If not currently inside a loop,
2521 return 0 and do nothing; caller will print an error message. */
2524 expand_continue_loop (whichloop
)
2525 struct nesting
*whichloop
;
2529 whichloop
= loop_stack
;
2532 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.continue_label
,
2537 /* Generate a jump to exit the current loop. If not currently inside a loop,
2538 return 0 and do nothing; caller will print an error message. */
2541 expand_exit_loop (whichloop
)
2542 struct nesting
*whichloop
;
2546 whichloop
= loop_stack
;
2549 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.end_label
, NULL_RTX
);
2553 /* Generate a conditional jump to exit the current loop if COND
2554 evaluates to zero. If not currently inside a loop,
2555 return 0 and do nothing; caller will print an error message. */
2558 expand_exit_loop_if_false (whichloop
, cond
)
2559 struct nesting
*whichloop
;
2562 rtx label
= gen_label_rtx ();
2567 whichloop
= loop_stack
;
2570 /* In order to handle fixups, we actually create a conditional jump
2571 around a unconditional branch to exit the loop. If fixups are
2572 necessary, they go before the unconditional branch. */
2575 do_jump (cond
, NULL_RTX
, label
);
2576 last_insn
= get_last_insn ();
2577 if (GET_CODE (last_insn
) == CODE_LABEL
)
2578 whichloop
->data
.loop
.alt_end_label
= last_insn
;
2579 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.end_label
,
2586 /* Return nonzero if the loop nest is empty. Else return zero. */
2589 stmt_loop_nest_empty ()
2591 return (loop_stack
== NULL
);
2594 /* Return non-zero if we should preserve sub-expressions as separate
2595 pseudos. We never do so if we aren't optimizing. We always do so
2596 if -fexpensive-optimizations.
2598 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2599 the loop may still be a small one. */
2602 preserve_subexpressions_p ()
2606 if (flag_expensive_optimizations
)
2609 if (optimize
== 0 || current_function
== 0 || loop_stack
== 0)
2612 insn
= get_last_insn_anywhere ();
2615 && (INSN_UID (insn
) - INSN_UID (loop_stack
->data
.loop
.start_label
)
2616 < n_non_fixed_regs
* 3));
2620 /* Generate a jump to exit the current loop, conditional, binding contour
2621 or case statement. Not all such constructs are visible to this function,
2622 only those started with EXIT_FLAG nonzero. Individual languages use
2623 the EXIT_FLAG parameter to control which kinds of constructs you can
2626 If not currently inside anything that can be exited,
2627 return 0 and do nothing; caller will print an error message. */
2630 expand_exit_something ()
2634 for (n
= nesting_stack
; n
; n
= n
->all
)
2635 if (n
->exit_label
!= 0)
2637 expand_goto_internal (NULL_TREE
, n
->exit_label
, NULL_RTX
);
2644 /* Generate RTL to return from the current function, with no value.
2645 (That is, we do not do anything about returning any value.) */
2648 expand_null_return ()
2650 struct nesting
*block
= block_stack
;
2653 /* Does any pending block have cleanups? */
2655 while (block
&& block
->data
.block
.cleanups
== 0)
2656 block
= block
->next
;
2658 /* If yes, use a goto to return, since that runs cleanups. */
2660 expand_null_return_1 (last_insn
, block
!= 0);
2663 /* Generate RTL to return from the current function, with value VAL. */
2666 expand_value_return (val
)
2669 struct nesting
*block
= block_stack
;
2670 rtx last_insn
= get_last_insn ();
2671 rtx return_reg
= DECL_RTL (DECL_RESULT (current_function_decl
));
2673 /* Copy the value to the return location
2674 unless it's already there. */
2676 if (return_reg
!= val
)
2678 #ifdef PROMOTE_FUNCTION_RETURN
2679 tree type
= TREE_TYPE (DECL_RESULT (current_function_decl
));
2680 int unsignedp
= TREE_UNSIGNED (type
);
2681 enum machine_mode mode
2682 = promote_mode (type
, DECL_MODE (DECL_RESULT (current_function_decl
)),
2685 if (GET_MODE (val
) != VOIDmode
&& GET_MODE (val
) != mode
)
2686 convert_move (return_reg
, val
, unsignedp
);
2689 emit_move_insn (return_reg
, val
);
2691 if (GET_CODE (return_reg
) == REG
2692 && REGNO (return_reg
) < FIRST_PSEUDO_REGISTER
)
2693 emit_insn (gen_rtx_USE (VOIDmode
, return_reg
));
2694 /* Handle calls that return values in multiple non-contiguous locations.
2695 The Irix 6 ABI has examples of this. */
2696 else if (GET_CODE (return_reg
) == PARALLEL
)
2700 for (i
= 0; i
< XVECLEN (return_reg
, 0); i
++)
2702 rtx x
= XEXP (XVECEXP (return_reg
, 0, i
), 0);
2704 if (GET_CODE (x
) == REG
2705 && REGNO (x
) < FIRST_PSEUDO_REGISTER
)
2706 emit_insn (gen_rtx_USE (VOIDmode
, x
));
2710 /* Does any pending block have cleanups? */
2712 while (block
&& block
->data
.block
.cleanups
== 0)
2713 block
= block
->next
;
2715 /* If yes, use a goto to return, since that runs cleanups.
2716 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2718 expand_null_return_1 (last_insn
, block
!= 0);
2721 /* Output a return with no value. If LAST_INSN is nonzero,
2722 pretend that the return takes place after LAST_INSN.
2723 If USE_GOTO is nonzero then don't use a return instruction;
2724 go to the return label instead. This causes any cleanups
2725 of pending blocks to be executed normally. */
2728 expand_null_return_1 (last_insn
, use_goto
)
2732 rtx end_label
= cleanup_label
? cleanup_label
: return_label
;
2734 clear_pending_stack_adjust ();
2735 do_pending_stack_adjust ();
2738 /* PCC-struct return always uses an epilogue. */
2739 if (current_function_returns_pcc_struct
|| use_goto
)
2742 end_label
= return_label
= gen_label_rtx ();
2743 expand_goto_internal (NULL_TREE
, end_label
, last_insn
);
2747 /* Otherwise output a simple return-insn if one is available,
2748 unless it won't do the job. */
2750 if (HAVE_return
&& use_goto
== 0 && cleanup_label
== 0)
2752 emit_jump_insn (gen_return ());
2758 /* Otherwise jump to the epilogue. */
2759 expand_goto_internal (NULL_TREE
, end_label
, last_insn
);
2762 /* Generate RTL to evaluate the expression RETVAL and return it
2763 from the current function. */
2766 expand_return (retval
)
2769 /* If there are any cleanups to be performed, then they will
2770 be inserted following LAST_INSN. It is desirable
2771 that the last_insn, for such purposes, should be the
2772 last insn before computing the return value. Otherwise, cleanups
2773 which call functions can clobber the return value. */
2774 /* ??? rms: I think that is erroneous, because in C++ it would
2775 run destructors on variables that might be used in the subsequent
2776 computation of the return value. */
2778 register rtx val
= 0;
2783 /* If function wants no value, give it none. */
2784 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl
))) == VOID_TYPE
)
2786 expand_expr (retval
, NULL_RTX
, VOIDmode
, 0);
2788 expand_null_return ();
2792 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2793 /* This is not sufficient. We also need to watch for cleanups of the
2794 expression we are about to expand. Unfortunately, we cannot know
2795 if it has cleanups until we expand it, and we want to change how we
2796 expand it depending upon if we need cleanups. We can't win. */
2798 cleanups
= any_pending_cleanups (1);
2803 if (TREE_CODE (retval
) == RESULT_DECL
)
2804 retval_rhs
= retval
;
2805 else if ((TREE_CODE (retval
) == MODIFY_EXPR
|| TREE_CODE (retval
) == INIT_EXPR
)
2806 && TREE_CODE (TREE_OPERAND (retval
, 0)) == RESULT_DECL
)
2807 retval_rhs
= TREE_OPERAND (retval
, 1);
2808 else if (TREE_TYPE (retval
) == void_type_node
)
2809 /* Recognize tail-recursive call to void function. */
2810 retval_rhs
= retval
;
2812 retval_rhs
= NULL_TREE
;
2814 /* Only use `last_insn' if there are cleanups which must be run. */
2815 if (cleanups
|| cleanup_label
!= 0)
2816 last_insn
= get_last_insn ();
2818 /* Distribute return down conditional expr if either of the sides
2819 may involve tail recursion (see test below). This enhances the number
2820 of tail recursions we see. Don't do this always since it can produce
2821 sub-optimal code in some cases and we distribute assignments into
2822 conditional expressions when it would help. */
2824 if (optimize
&& retval_rhs
!= 0
2825 && frame_offset
== 0
2826 && TREE_CODE (retval_rhs
) == COND_EXPR
2827 && (TREE_CODE (TREE_OPERAND (retval_rhs
, 1)) == CALL_EXPR
2828 || TREE_CODE (TREE_OPERAND (retval_rhs
, 2)) == CALL_EXPR
))
2830 rtx label
= gen_label_rtx ();
2833 do_jump (TREE_OPERAND (retval_rhs
, 0), label
, NULL_RTX
);
2834 start_cleanup_deferral ();
2835 expr
= build (MODIFY_EXPR
, TREE_TYPE (TREE_TYPE (current_function_decl
)),
2836 DECL_RESULT (current_function_decl
),
2837 TREE_OPERAND (retval_rhs
, 1));
2838 TREE_SIDE_EFFECTS (expr
) = 1;
2839 expand_return (expr
);
2842 expr
= build (MODIFY_EXPR
, TREE_TYPE (TREE_TYPE (current_function_decl
)),
2843 DECL_RESULT (current_function_decl
),
2844 TREE_OPERAND (retval_rhs
, 2));
2845 TREE_SIDE_EFFECTS (expr
) = 1;
2846 expand_return (expr
);
2847 end_cleanup_deferral ();
2851 /* Attempt to optimize the call if it is tail recursive. */
2852 if (optimize_tail_recursion (retval_rhs
, last_insn
))
2856 /* This optimization is safe if there are local cleanups
2857 because expand_null_return takes care of them.
2858 ??? I think it should also be safe when there is a cleanup label,
2859 because expand_null_return takes care of them, too.
2860 Any reason why not? */
2861 if (HAVE_return
&& cleanup_label
== 0
2862 && ! current_function_returns_pcc_struct
2863 && BRANCH_COST
<= 1)
2865 /* If this is return x == y; then generate
2866 if (x == y) return 1; else return 0;
2867 if we can do it with explicit return insns and branches are cheap,
2868 but not if we have the corresponding scc insn. */
2871 switch (TREE_CODE (retval_rhs
))
2897 case TRUTH_ANDIF_EXPR
:
2898 case TRUTH_ORIF_EXPR
:
2899 case TRUTH_AND_EXPR
:
2901 case TRUTH_NOT_EXPR
:
2902 case TRUTH_XOR_EXPR
:
2905 op0
= gen_label_rtx ();
2906 jumpifnot (retval_rhs
, op0
);
2907 expand_value_return (const1_rtx
);
2909 expand_value_return (const0_rtx
);
2918 #endif /* HAVE_return */
2920 /* If the result is an aggregate that is being returned in one (or more)
2921 registers, load the registers here. The compiler currently can't handle
2922 copying a BLKmode value into registers. We could put this code in a
2923 more general area (for use by everyone instead of just function
2924 call/return), but until this feature is generally usable it is kept here
2925 (and in expand_call). The value must go into a pseudo in case there
2926 are cleanups that will clobber the real return register. */
2929 && TYPE_MODE (TREE_TYPE (retval_rhs
)) == BLKmode
2930 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl
))) == REG
)
2932 int i
, bitpos
, xbitpos
;
2933 int big_endian_correction
= 0;
2934 int bytes
= int_size_in_bytes (TREE_TYPE (retval_rhs
));
2935 int n_regs
= (bytes
+ UNITS_PER_WORD
- 1) / UNITS_PER_WORD
;
2936 int bitsize
= MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs
)),
2937 (unsigned int)BITS_PER_WORD
);
2938 rtx
*result_pseudos
= (rtx
*) alloca (sizeof (rtx
) * n_regs
);
2939 rtx result_reg
, src
= NULL_RTX
, dst
= NULL_RTX
;
2940 rtx result_val
= expand_expr (retval_rhs
, NULL_RTX
, VOIDmode
, 0);
2941 enum machine_mode tmpmode
, result_reg_mode
;
2943 /* Structures whose size is not a multiple of a word are aligned
2944 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
2945 machine, this means we must skip the empty high order bytes when
2946 calculating the bit offset. */
2947 if (BYTES_BIG_ENDIAN
&& bytes
% UNITS_PER_WORD
)
2948 big_endian_correction
= (BITS_PER_WORD
- ((bytes
% UNITS_PER_WORD
)
2951 /* Copy the structure BITSIZE bits at a time. */
2952 for (bitpos
= 0, xbitpos
= big_endian_correction
;
2953 bitpos
< bytes
* BITS_PER_UNIT
;
2954 bitpos
+= bitsize
, xbitpos
+= bitsize
)
2956 /* We need a new destination pseudo each time xbitpos is
2957 on a word boundary and when xbitpos == big_endian_correction
2958 (the first time through). */
2959 if (xbitpos
% BITS_PER_WORD
== 0
2960 || xbitpos
== big_endian_correction
)
2962 /* Generate an appropriate register. */
2963 dst
= gen_reg_rtx (word_mode
);
2964 result_pseudos
[xbitpos
/ BITS_PER_WORD
] = dst
;
2966 /* Clobber the destination before we move anything into it. */
2967 emit_insn (gen_rtx_CLOBBER (VOIDmode
, dst
));
2970 /* We need a new source operand each time bitpos is on a word
2972 if (bitpos
% BITS_PER_WORD
== 0)
2973 src
= operand_subword_force (result_val
,
2974 bitpos
/ BITS_PER_WORD
,
2977 /* Use bitpos for the source extraction (left justified) and
2978 xbitpos for the destination store (right justified). */
2979 store_bit_field (dst
, bitsize
, xbitpos
% BITS_PER_WORD
, word_mode
,
2980 extract_bit_field (src
, bitsize
,
2981 bitpos
% BITS_PER_WORD
, 1,
2982 NULL_RTX
, word_mode
,
2984 bitsize
/ BITS_PER_UNIT
,
2986 bitsize
/ BITS_PER_UNIT
, BITS_PER_WORD
);
2989 /* Find the smallest integer mode large enough to hold the
2990 entire structure and use that mode instead of BLKmode
2991 on the USE insn for the return register. */
2992 bytes
= int_size_in_bytes (TREE_TYPE (retval_rhs
));
2993 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
2994 tmpmode
!= VOIDmode
;
2995 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
2997 /* Have we found a large enough mode? */
2998 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
3002 /* No suitable mode found. */
3003 if (tmpmode
== VOIDmode
)
3006 PUT_MODE (DECL_RTL (DECL_RESULT (current_function_decl
)), tmpmode
);
3008 if (GET_MODE_SIZE (tmpmode
) < GET_MODE_SIZE (word_mode
))
3009 result_reg_mode
= word_mode
;
3011 result_reg_mode
= tmpmode
;
3012 result_reg
= gen_reg_rtx (result_reg_mode
);
3015 for (i
= 0; i
< n_regs
; i
++)
3016 emit_move_insn (operand_subword (result_reg
, i
, 0, result_reg_mode
),
3019 if (tmpmode
!= result_reg_mode
)
3020 result_reg
= gen_lowpart (tmpmode
, result_reg
);
3022 expand_value_return (result_reg
);
3026 && TREE_TYPE (retval_rhs
) != void_type_node
3027 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl
))) == REG
)
3029 /* Calculate the return value into a pseudo reg. */
3030 val
= gen_reg_rtx (DECL_MODE (DECL_RESULT (current_function_decl
)));
3031 val
= expand_expr (retval_rhs
, val
, GET_MODE (val
), 0);
3032 val
= force_not_mem (val
);
3034 /* Return the calculated value, doing cleanups first. */
3035 expand_value_return (val
);
3039 /* No cleanups or no hard reg used;
3040 calculate value into hard return reg. */
3041 expand_expr (retval
, const0_rtx
, VOIDmode
, 0);
3043 expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl
)));
3047 /* Return 1 if the end of the generated RTX is not a barrier.
3048 This means code already compiled can drop through. */
3051 drop_through_at_end_p ()
3053 rtx insn
= get_last_insn ();
3054 while (insn
&& GET_CODE (insn
) == NOTE
)
3055 insn
= PREV_INSN (insn
);
3056 return insn
&& GET_CODE (insn
) != BARRIER
;
3059 /* Test CALL_EXPR to determine if it is a potential tail recursion call
3060 and emit code to optimize the tail recursion. LAST_INSN indicates where
3061 to place the jump to the tail recursion label. Return TRUE if the
3062 call was optimized into a goto.
3064 This is only used by expand_return, but expand_call is expected to
3068 optimize_tail_recursion (call_expr
, last_insn
)
3072 /* For tail-recursive call to current function,
3073 just jump back to the beginning.
3074 It's unsafe if any auto variable in this function
3075 has its address taken; for simplicity,
3076 require stack frame to be empty. */
3077 if (optimize
&& call_expr
!= 0
3078 && frame_offset
== 0
3079 && TREE_CODE (call_expr
) == CALL_EXPR
3080 && TREE_CODE (TREE_OPERAND (call_expr
, 0)) == ADDR_EXPR
3081 && TREE_OPERAND (TREE_OPERAND (call_expr
, 0), 0) == current_function_decl
3082 /* Finish checking validity, and if valid emit code
3083 to set the argument variables for the new call. */
3084 && tail_recursion_args (TREE_OPERAND (call_expr
, 1),
3085 DECL_ARGUMENTS (current_function_decl
)))
3087 if (tail_recursion_label
== 0)
3089 tail_recursion_label
= gen_label_rtx ();
3090 emit_label_after (tail_recursion_label
,
3091 tail_recursion_reentry
);
3094 expand_goto_internal (NULL_TREE
, tail_recursion_label
, last_insn
);
3102 /* Emit code to alter this function's formal parms for a tail-recursive call.
3103 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3104 FORMALS is the chain of decls of formals.
3105 Return 1 if this can be done;
3106 otherwise return 0 and do not emit any code. */
3109 tail_recursion_args (actuals
, formals
)
3110 tree actuals
, formals
;
3112 register tree a
= actuals
, f
= formals
;
3114 register rtx
*argvec
;
3116 /* Check that number and types of actuals are compatible
3117 with the formals. This is not always true in valid C code.
3118 Also check that no formal needs to be addressable
3119 and that all formals are scalars. */
3121 /* Also count the args. */
3123 for (a
= actuals
, f
= formals
, i
= 0; a
&& f
; a
= TREE_CHAIN (a
), f
= TREE_CHAIN (f
), i
++)
3125 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a
)))
3126 != TYPE_MAIN_VARIANT (TREE_TYPE (f
)))
3128 if (GET_CODE (DECL_RTL (f
)) != REG
|| DECL_MODE (f
) == BLKmode
)
3131 if (a
!= 0 || f
!= 0)
3134 /* Compute all the actuals. */
3136 argvec
= (rtx
*) alloca (i
* sizeof (rtx
));
3138 for (a
= actuals
, i
= 0; a
; a
= TREE_CHAIN (a
), i
++)
3139 argvec
[i
] = expand_expr (TREE_VALUE (a
), NULL_RTX
, VOIDmode
, 0);
3141 /* Find which actual values refer to current values of previous formals.
3142 Copy each of them now, before any formal is changed. */
3144 for (a
= actuals
, i
= 0; a
; a
= TREE_CHAIN (a
), i
++)
3148 for (f
= formals
, j
= 0; j
< i
; f
= TREE_CHAIN (f
), j
++)
3149 if (reg_mentioned_p (DECL_RTL (f
), argvec
[i
]))
3150 { copy
= 1; break; }
3152 argvec
[i
] = copy_to_reg (argvec
[i
]);
3155 /* Store the values of the actuals into the formals. */
3157 for (f
= formals
, a
= actuals
, i
= 0; f
;
3158 f
= TREE_CHAIN (f
), a
= TREE_CHAIN (a
), i
++)
3160 if (GET_MODE (DECL_RTL (f
)) == GET_MODE (argvec
[i
]))
3161 emit_move_insn (DECL_RTL (f
), argvec
[i
]);
3163 convert_move (DECL_RTL (f
), argvec
[i
],
3164 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a
))));
3171 /* Generate the RTL code for entering a binding contour.
3172 The variables are declared one by one, by calls to `expand_decl'.
3174 EXIT_FLAG is nonzero if this construct should be visible to
3175 `exit_something'. */
3178 expand_start_bindings (exit_flag
)
3181 struct nesting
*thisblock
= ALLOC_NESTING ();
3182 rtx note
= emit_note (NULL_PTR
, NOTE_INSN_BLOCK_BEG
);
3184 /* Make an entry on block_stack for the block we are entering. */
3186 thisblock
->next
= block_stack
;
3187 thisblock
->all
= nesting_stack
;
3188 thisblock
->depth
= ++nesting_depth
;
3189 thisblock
->data
.block
.stack_level
= 0;
3190 thisblock
->data
.block
.cleanups
= 0;
3191 thisblock
->data
.block
.n_function_calls
= 0;
3192 thisblock
->data
.block
.exception_region
= 0;
3193 thisblock
->data
.block
.block_target_temp_slot_level
= target_temp_slot_level
;
3195 thisblock
->data
.block
.conditional_code
= 0;
3196 thisblock
->data
.block
.last_unconditional_cleanup
= note
;
3197 thisblock
->data
.block
.cleanup_ptr
= &thisblock
->data
.block
.cleanups
;
3200 && !(block_stack
->data
.block
.cleanups
== NULL_TREE
3201 && block_stack
->data
.block
.outer_cleanups
== NULL_TREE
))
3202 thisblock
->data
.block
.outer_cleanups
3203 = tree_cons (NULL_TREE
, block_stack
->data
.block
.cleanups
,
3204 block_stack
->data
.block
.outer_cleanups
);
3206 thisblock
->data
.block
.outer_cleanups
= 0;
3207 thisblock
->data
.block
.label_chain
= 0;
3208 thisblock
->data
.block
.innermost_stack_block
= stack_block_stack
;
3209 thisblock
->data
.block
.first_insn
= note
;
3210 thisblock
->data
.block
.block_start_count
= ++current_block_start_count
;
3211 thisblock
->exit_label
= exit_flag
? gen_label_rtx () : 0;
3212 block_stack
= thisblock
;
3213 nesting_stack
= thisblock
;
3215 /* Make a new level for allocating stack slots. */
3219 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3220 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3221 expand_expr are made. After we end the region, we know that all
3222 space for all temporaries that were created by TARGET_EXPRs will be
3223 destroyed and their space freed for reuse. */
3226 expand_start_target_temps ()
3228 /* This is so that even if the result is preserved, the space
3229 allocated will be freed, as we know that it is no longer in use. */
3232 /* Start a new binding layer that will keep track of all cleanup
3233 actions to be performed. */
3234 expand_start_bindings (0);
3236 target_temp_slot_level
= temp_slot_level
;
3240 expand_end_target_temps ()
3242 expand_end_bindings (NULL_TREE
, 0, 0);
3244 /* This is so that even if the result is preserved, the space
3245 allocated will be freed, as we know that it is no longer in use. */
3249 /* Mark top block of block_stack as an implicit binding for an
3250 exception region. This is used to prevent infinite recursion when
3251 ending a binding with expand_end_bindings. It is only ever called
3252 by expand_eh_region_start, as that it the only way to create a
3253 block stack for a exception region. */
3256 mark_block_as_eh_region ()
3258 block_stack
->data
.block
.exception_region
= 1;
3259 if (block_stack
->next
3260 && block_stack
->next
->data
.block
.conditional_code
)
3262 block_stack
->data
.block
.conditional_code
3263 = block_stack
->next
->data
.block
.conditional_code
;
3264 block_stack
->data
.block
.last_unconditional_cleanup
3265 = block_stack
->next
->data
.block
.last_unconditional_cleanup
;
3266 block_stack
->data
.block
.cleanup_ptr
3267 = block_stack
->next
->data
.block
.cleanup_ptr
;
3271 /* True if we are currently emitting insns in an area of output code
3272 that is controlled by a conditional expression. This is used by
3273 the cleanup handling code to generate conditional cleanup actions. */
3276 conditional_context ()
3278 return block_stack
&& block_stack
->data
.block
.conditional_code
;
3281 /* Mark top block of block_stack as not for an implicit binding for an
3282 exception region. This is only ever done by expand_eh_region_end
3283 to let expand_end_bindings know that it is being called explicitly
3284 to end the binding layer for just the binding layer associated with
3285 the exception region, otherwise expand_end_bindings would try and
3286 end all implicit binding layers for exceptions regions, and then
3287 one normal binding layer. */
3290 mark_block_as_not_eh_region ()
3292 block_stack
->data
.block
.exception_region
= 0;
3295 /* True if the top block of block_stack was marked as for an exception
3296 region by mark_block_as_eh_region. */
3301 return (current_function
&& block_stack
3302 && block_stack
->data
.block
.exception_region
);
3305 /* Given a pointer to a BLOCK node, save a pointer to the most recently
3306 generated NOTE_INSN_BLOCK_END in the BLOCK_END_NOTE field of the given
3310 remember_end_note (block
)
3311 register tree block
;
3313 BLOCK_END_NOTE (block
) = last_block_end_note
;
3314 last_block_end_note
= NULL_RTX
;
3317 /* Emit a handler label for a nonlocal goto handler.
3318 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3321 expand_nl_handler_label (slot
, before_insn
)
3322 rtx slot
, before_insn
;
3325 rtx handler_label
= gen_label_rtx ();
3327 /* Don't let jump_optimize delete the handler. */
3328 LABEL_PRESERVE_P (handler_label
) = 1;
3331 emit_move_insn (slot
, gen_rtx_LABEL_REF (Pmode
, handler_label
));
3332 insns
= get_insns ();
3334 emit_insns_before (insns
, before_insn
);
3336 emit_label (handler_label
);
3338 return handler_label
;
3341 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3344 expand_nl_goto_receiver ()
3346 #ifdef HAVE_nonlocal_goto
3347 if (! HAVE_nonlocal_goto
)
3349 /* First adjust our frame pointer to its actual value. It was
3350 previously set to the start of the virtual area corresponding to
3351 the stacked variables when we branched here and now needs to be
3352 adjusted to the actual hardware fp value.
3354 Assignments are to virtual registers are converted by
3355 instantiate_virtual_regs into the corresponding assignment
3356 to the underlying register (fp in this case) that makes
3357 the original assignment true.
3358 So the following insn will actually be
3359 decrementing fp by STARTING_FRAME_OFFSET. */
3360 emit_move_insn (virtual_stack_vars_rtx
, hard_frame_pointer_rtx
);
3362 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3363 if (fixed_regs
[ARG_POINTER_REGNUM
])
3365 #ifdef ELIMINABLE_REGS
3366 /* If the argument pointer can be eliminated in favor of the
3367 frame pointer, we don't need to restore it. We assume here
3368 that if such an elimination is present, it can always be used.
3369 This is the case on all known machines; if we don't make this
3370 assumption, we do unnecessary saving on many machines. */
3371 static struct elims
{int from
, to
;} elim_regs
[] = ELIMINABLE_REGS
;
3374 for (i
= 0; i
< sizeof elim_regs
/ sizeof elim_regs
[0]; i
++)
3375 if (elim_regs
[i
].from
== ARG_POINTER_REGNUM
3376 && elim_regs
[i
].to
== HARD_FRAME_POINTER_REGNUM
)
3379 if (i
== sizeof elim_regs
/ sizeof elim_regs
[0])
3382 /* Now restore our arg pointer from the address at which it
3383 was saved in our stack frame.
3384 If there hasn't be space allocated for it yet, make
3386 if (arg_pointer_save_area
== 0)
3387 arg_pointer_save_area
3388 = assign_stack_local (Pmode
, GET_MODE_SIZE (Pmode
), 0);
3389 emit_move_insn (virtual_incoming_args_rtx
,
3390 /* We need a pseudo here, or else
3391 instantiate_virtual_regs_1 complains. */
3392 copy_to_reg (arg_pointer_save_area
));
3397 #ifdef HAVE_nonlocal_goto_receiver
3398 if (HAVE_nonlocal_goto_receiver
)
3399 emit_insn (gen_nonlocal_goto_receiver ());
3403 /* Make handlers for nonlocal gotos taking place in the function calls in
3407 expand_nl_goto_receivers (thisblock
)
3408 struct nesting
*thisblock
;
3411 rtx afterward
= gen_label_rtx ();
3416 /* Record the handler address in the stack slot for that purpose,
3417 during this block, saving and restoring the outer value. */
3418 if (thisblock
->next
!= 0)
3419 for (slot
= nonlocal_goto_handler_slots
; slot
; slot
= XEXP (slot
, 1))
3421 rtx save_receiver
= gen_reg_rtx (Pmode
);
3422 emit_move_insn (XEXP (slot
, 0), save_receiver
);
3425 emit_move_insn (save_receiver
, XEXP (slot
, 0));
3426 insns
= get_insns ();
3428 emit_insns_before (insns
, thisblock
->data
.block
.first_insn
);
3431 /* Jump around the handlers; they run only when specially invoked. */
3432 emit_jump (afterward
);
3434 /* Make a separate handler for each label. */
3435 link
= nonlocal_labels
;
3436 slot
= nonlocal_goto_handler_slots
;
3437 label_list
= NULL_RTX
;
3438 for (; link
; link
= TREE_CHAIN (link
), slot
= XEXP (slot
, 1))
3439 /* Skip any labels we shouldn't be able to jump to from here,
3440 we generate one special handler for all of them below which just calls
3442 if (! DECL_TOO_LATE (TREE_VALUE (link
)))
3445 lab
= expand_nl_handler_label (XEXP (slot
, 0),
3446 thisblock
->data
.block
.first_insn
);
3447 label_list
= gen_rtx_EXPR_LIST (VOIDmode
, lab
, label_list
);
3449 expand_nl_goto_receiver ();
3451 /* Jump to the "real" nonlocal label. */
3452 expand_goto (TREE_VALUE (link
));
3455 /* A second pass over all nonlocal labels; this time we handle those
3456 we should not be able to jump to at this point. */
3457 link
= nonlocal_labels
;
3458 slot
= nonlocal_goto_handler_slots
;
3460 for (; link
; link
= TREE_CHAIN (link
), slot
= XEXP (slot
, 1))
3461 if (DECL_TOO_LATE (TREE_VALUE (link
)))
3464 lab
= expand_nl_handler_label (XEXP (slot
, 0),
3465 thisblock
->data
.block
.first_insn
);
3466 label_list
= gen_rtx_EXPR_LIST (VOIDmode
, lab
, label_list
);
3472 expand_nl_goto_receiver ();
3473 emit_library_call (gen_rtx_SYMBOL_REF (Pmode
, "abort"), 0,
3478 nonlocal_goto_handler_labels
= label_list
;
3479 emit_label (afterward
);
3482 /* Generate RTL code to terminate a binding contour.
3484 VARS is the chain of VAR_DECL nodes for the variables bound in this
3485 contour. There may actually be other nodes in this chain, but any
3486 nodes other than VAR_DECLS are ignored.
3488 MARK_ENDS is nonzero if we should put a note at the beginning
3489 and end of this binding contour.
3491 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3492 (That is true automatically if the contour has a saved stack level.) */
3495 expand_end_bindings (vars
, mark_ends
, dont_jump_in
)
3500 register struct nesting
*thisblock
;
3503 while (block_stack
->data
.block
.exception_region
)
3505 /* Because we don't need or want a new temporary level and
3506 because we didn't create one in expand_eh_region_start,
3507 create a fake one now to avoid removing one in
3508 expand_end_bindings. */
3511 block_stack
->data
.block
.exception_region
= 0;
3513 expand_end_bindings (NULL_TREE
, 0, 0);
3516 /* Since expand_eh_region_start does an expand_start_bindings, we
3517 have to first end all the bindings that were created by
3518 expand_eh_region_start. */
3520 thisblock
= block_stack
;
3523 for (decl
= vars
; decl
; decl
= TREE_CHAIN (decl
))
3524 if (TREE_CODE (decl
) == VAR_DECL
3525 && ! TREE_USED (decl
)
3526 && ! DECL_IN_SYSTEM_HEADER (decl
)
3527 && DECL_NAME (decl
) && ! DECL_ARTIFICIAL (decl
))
3528 warning_with_decl (decl
, "unused variable `%s'");
3530 if (thisblock
->exit_label
)
3532 do_pending_stack_adjust ();
3533 emit_label (thisblock
->exit_label
);
3536 /* If necessary, make handlers for nonlocal gotos taking
3537 place in the function calls in this block. */
3538 if (function_call_count
!= thisblock
->data
.block
.n_function_calls
3540 /* Make handler for outermost block
3541 if there were any nonlocal gotos to this function. */
3542 && (thisblock
->next
== 0 ? current_function_has_nonlocal_label
3543 /* Make handler for inner block if it has something
3544 special to do when you jump out of it. */
3545 : (thisblock
->data
.block
.cleanups
!= 0
3546 || thisblock
->data
.block
.stack_level
!= 0)))
3547 expand_nl_goto_receivers (thisblock
);
3549 /* Don't allow jumping into a block that has a stack level.
3550 Cleanups are allowed, though. */
3552 || thisblock
->data
.block
.stack_level
!= 0)
3554 struct label_chain
*chain
;
3556 /* Any labels in this block are no longer valid to go to.
3557 Mark them to cause an error message. */
3558 for (chain
= thisblock
->data
.block
.label_chain
; chain
; chain
= chain
->next
)
3560 DECL_TOO_LATE (chain
->label
) = 1;
3561 /* If any goto without a fixup came to this label,
3562 that must be an error, because gotos without fixups
3563 come from outside all saved stack-levels. */
3564 if (TREE_ADDRESSABLE (chain
->label
))
3565 error_with_decl (chain
->label
,
3566 "label `%s' used before containing binding contour");
3570 /* Restore stack level in effect before the block
3571 (only if variable-size objects allocated). */
3572 /* Perform any cleanups associated with the block. */
3574 if (thisblock
->data
.block
.stack_level
!= 0
3575 || thisblock
->data
.block
.cleanups
!= 0)
3577 /* Only clean up here if this point can actually be reached. */
3578 int reachable
= GET_CODE (get_last_insn ()) != BARRIER
;
3580 /* Don't let cleanups affect ({...}) constructs. */
3581 int old_expr_stmts_for_value
= expr_stmts_for_value
;
3582 rtx old_last_expr_value
= last_expr_value
;
3583 tree old_last_expr_type
= last_expr_type
;
3584 expr_stmts_for_value
= 0;
3586 /* Do the cleanups. */
3587 expand_cleanups (thisblock
->data
.block
.cleanups
, NULL_TREE
, 0, reachable
);
3589 do_pending_stack_adjust ();
3591 expr_stmts_for_value
= old_expr_stmts_for_value
;
3592 last_expr_value
= old_last_expr_value
;
3593 last_expr_type
= old_last_expr_type
;
3595 /* Restore the stack level. */
3597 if (reachable
&& thisblock
->data
.block
.stack_level
!= 0)
3599 emit_stack_restore (thisblock
->next
? SAVE_BLOCK
: SAVE_FUNCTION
,
3600 thisblock
->data
.block
.stack_level
, NULL_RTX
);
3601 if (nonlocal_goto_handler_slots
!= 0)
3602 emit_stack_save (SAVE_NONLOCAL
, &nonlocal_goto_stack_level
,
3606 /* Any gotos out of this block must also do these things.
3607 Also report any gotos with fixups that came to labels in this
3609 fixup_gotos (thisblock
,
3610 thisblock
->data
.block
.stack_level
,
3611 thisblock
->data
.block
.cleanups
,
3612 thisblock
->data
.block
.first_insn
,
3616 /* Mark the beginning and end of the scope if requested.
3617 We do this now, after running cleanups on the variables
3618 just going out of scope, so they are in scope for their cleanups. */
3621 last_block_end_note
= emit_note (NULL_PTR
, NOTE_INSN_BLOCK_END
);
3623 /* Get rid of the beginning-mark if we don't make an end-mark. */
3624 NOTE_LINE_NUMBER (thisblock
->data
.block
.first_insn
) = NOTE_INSN_DELETED
;
3626 /* If doing stupid register allocation, make sure lives of all
3627 register variables declared here extend thru end of scope. */
3630 for (decl
= vars
; decl
; decl
= TREE_CHAIN (decl
))
3631 if (TREE_CODE (decl
) == VAR_DECL
&& DECL_RTL (decl
))
3632 use_variable (DECL_RTL (decl
));
3634 /* Restore the temporary level of TARGET_EXPRs. */
3635 target_temp_slot_level
= thisblock
->data
.block
.block_target_temp_slot_level
;
3637 /* Restore block_stack level for containing block. */
3639 stack_block_stack
= thisblock
->data
.block
.innermost_stack_block
;
3640 POPSTACK (block_stack
);
3642 /* Pop the stack slot nesting and free any slots at this level. */
3646 /* Generate RTL for the automatic variable declaration DECL.
3647 (Other kinds of declarations are simply ignored if seen here.) */
3653 struct nesting
*thisblock
;
3656 type
= TREE_TYPE (decl
);
3658 /* Only automatic variables need any expansion done.
3659 Static and external variables, and external functions,
3660 will be handled by `assemble_variable' (called from finish_decl).
3661 TYPE_DECL and CONST_DECL require nothing.
3662 PARM_DECLs are handled in `assign_parms'. */
3664 if (TREE_CODE (decl
) != VAR_DECL
)
3666 if (TREE_STATIC (decl
) || DECL_EXTERNAL (decl
))
3669 thisblock
= block_stack
;
3671 /* Create the RTL representation for the variable. */
3673 if (type
== error_mark_node
)
3674 DECL_RTL (decl
) = gen_rtx_MEM (BLKmode
, const0_rtx
);
3675 else if (DECL_SIZE (decl
) == 0)
3676 /* Variable with incomplete type. */
3678 if (DECL_INITIAL (decl
) == 0)
3679 /* Error message was already done; now avoid a crash. */
3680 DECL_RTL (decl
) = assign_stack_temp (DECL_MODE (decl
), 0, 1);
3682 /* An initializer is going to decide the size of this array.
3683 Until we know the size, represent its address with a reg. */
3684 DECL_RTL (decl
) = gen_rtx_MEM (BLKmode
, gen_reg_rtx (Pmode
));
3685 MEM_SET_IN_STRUCT_P (DECL_RTL (decl
), AGGREGATE_TYPE_P (type
));
3687 else if (DECL_MODE (decl
) != BLKmode
3688 /* If -ffloat-store, don't put explicit float vars
3690 && !(flag_float_store
3691 && TREE_CODE (type
) == REAL_TYPE
)
3692 && ! TREE_THIS_VOLATILE (decl
)
3693 && ! TREE_ADDRESSABLE (decl
)
3694 && (DECL_REGISTER (decl
) || ! obey_regdecls
)
3695 /* if -fcheck-memory-usage, check all variables. */
3696 && ! current_function_check_memory_usage
)
3698 /* Automatic variable that can go in a register. */
3699 int unsignedp
= TREE_UNSIGNED (type
);
3700 enum machine_mode reg_mode
3701 = promote_mode (type
, DECL_MODE (decl
), &unsignedp
, 0);
3703 DECL_RTL (decl
) = gen_reg_rtx (reg_mode
);
3704 mark_user_reg (DECL_RTL (decl
));
3706 if (POINTER_TYPE_P (type
))
3707 mark_reg_pointer (DECL_RTL (decl
),
3708 (TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl
)))
3712 else if (TREE_CODE (DECL_SIZE (decl
)) == INTEGER_CST
3713 && ! (flag_stack_check
&& ! STACK_CHECK_BUILTIN
3714 && (TREE_INT_CST_HIGH (DECL_SIZE (decl
)) != 0
3715 || (TREE_INT_CST_LOW (DECL_SIZE (decl
))
3716 > STACK_CHECK_MAX_VAR_SIZE
* BITS_PER_UNIT
))))
3718 /* Variable of fixed size that goes on the stack. */
3722 /* If we previously made RTL for this decl, it must be an array
3723 whose size was determined by the initializer.
3724 The old address was a register; set that register now
3725 to the proper address. */
3726 if (DECL_RTL (decl
) != 0)
3728 if (GET_CODE (DECL_RTL (decl
)) != MEM
3729 || GET_CODE (XEXP (DECL_RTL (decl
), 0)) != REG
)
3731 oldaddr
= XEXP (DECL_RTL (decl
), 0);
3734 DECL_RTL (decl
) = assign_temp (TREE_TYPE (decl
), 1, 1, 1);
3735 MEM_SET_IN_STRUCT_P (DECL_RTL (decl
),
3736 AGGREGATE_TYPE_P (TREE_TYPE (decl
)));
3738 /* Set alignment we actually gave this decl. */
3739 DECL_ALIGN (decl
) = (DECL_MODE (decl
) == BLKmode
? BIGGEST_ALIGNMENT
3740 : GET_MODE_BITSIZE (DECL_MODE (decl
)));
3744 addr
= force_operand (XEXP (DECL_RTL (decl
), 0), oldaddr
);
3745 if (addr
!= oldaddr
)
3746 emit_move_insn (oldaddr
, addr
);
3749 /* If this is a memory ref that contains aggregate components,
3750 mark it as such for cse and loop optimize. */
3751 MEM_SET_IN_STRUCT_P (DECL_RTL (decl
),
3752 AGGREGATE_TYPE_P (TREE_TYPE (decl
)));
3754 /* If this is in memory because of -ffloat-store,
3755 set the volatile bit, to prevent optimizations from
3756 undoing the effects. */
3757 if (flag_float_store
&& TREE_CODE (type
) == REAL_TYPE
)
3758 MEM_VOLATILE_P (DECL_RTL (decl
)) = 1;
3761 MEM_ALIAS_SET (DECL_RTL (decl
)) = get_alias_set (decl
);
3764 /* Dynamic-size object: must push space on the stack. */
3768 /* Record the stack pointer on entry to block, if have
3769 not already done so. */
3770 if (thisblock
->data
.block
.stack_level
== 0)
3772 do_pending_stack_adjust ();
3773 emit_stack_save (thisblock
->next
? SAVE_BLOCK
: SAVE_FUNCTION
,
3774 &thisblock
->data
.block
.stack_level
,
3775 thisblock
->data
.block
.first_insn
);
3776 stack_block_stack
= thisblock
;
3779 /* Compute the variable's size, in bytes. */
3780 size
= expand_expr (size_binop (CEIL_DIV_EXPR
,
3782 size_int (BITS_PER_UNIT
)),
3783 NULL_RTX
, VOIDmode
, 0);
3786 /* Allocate space on the stack for the variable. Note that
3787 DECL_ALIGN says how the variable is to be aligned and we
3788 cannot use it to conclude anything about the alignment of
3790 address
= allocate_dynamic_stack_space (size
, NULL_RTX
,
3791 TYPE_ALIGN (TREE_TYPE (decl
)));
3793 /* Reference the variable indirect through that rtx. */
3794 DECL_RTL (decl
) = gen_rtx_MEM (DECL_MODE (decl
), address
);
3796 /* If this is a memory ref that contains aggregate components,
3797 mark it as such for cse and loop optimize. */
3798 MEM_SET_IN_STRUCT_P (DECL_RTL (decl
),
3799 AGGREGATE_TYPE_P (TREE_TYPE (decl
)));
3801 /* Indicate the alignment we actually gave this variable. */
3802 #ifdef STACK_BOUNDARY
3803 DECL_ALIGN (decl
) = STACK_BOUNDARY
;
3805 DECL_ALIGN (decl
) = BIGGEST_ALIGNMENT
;
3809 if (TREE_THIS_VOLATILE (decl
))
3810 MEM_VOLATILE_P (DECL_RTL (decl
)) = 1;
3811 #if 0 /* A variable is not necessarily unchanging
3812 just because it is const. RTX_UNCHANGING_P
3813 means no change in the function,
3814 not merely no change in the variable's scope.
3815 It is correct to set RTX_UNCHANGING_P if the variable's scope
3816 is the whole function. There's no convenient way to test that. */
3817 if (TREE_READONLY (decl
))
3818 RTX_UNCHANGING_P (DECL_RTL (decl
)) = 1;
3821 /* If doing stupid register allocation, make sure life of any
3822 register variable starts here, at the start of its scope. */
3825 use_variable (DECL_RTL (decl
));
3830 /* Emit code to perform the initialization of a declaration DECL. */
3833 expand_decl_init (decl
)
3836 int was_used
= TREE_USED (decl
);
3838 /* If this is a CONST_DECL, we don't have to generate any code, but
3839 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3840 to be set while in the obstack containing the constant. If we don't
3841 do this, we can lose if we have functions nested three deep and the middle
3842 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3843 the innermost function is the first to expand that STRING_CST. */
3844 if (TREE_CODE (decl
) == CONST_DECL
)
3846 if (DECL_INITIAL (decl
) && TREE_CONSTANT (DECL_INITIAL (decl
)))
3847 expand_expr (DECL_INITIAL (decl
), NULL_RTX
, VOIDmode
,
3848 EXPAND_INITIALIZER
);
3852 if (TREE_STATIC (decl
))
3855 /* Compute and store the initial value now. */
3857 if (DECL_INITIAL (decl
) == error_mark_node
)
3859 enum tree_code code
= TREE_CODE (TREE_TYPE (decl
));
3861 if (code
== INTEGER_TYPE
|| code
== REAL_TYPE
|| code
== ENUMERAL_TYPE
3862 || code
== POINTER_TYPE
|| code
== REFERENCE_TYPE
)
3863 expand_assignment (decl
, convert (TREE_TYPE (decl
), integer_zero_node
),
3867 else if (DECL_INITIAL (decl
) && TREE_CODE (DECL_INITIAL (decl
)) != TREE_LIST
)
3869 emit_line_note (DECL_SOURCE_FILE (decl
), DECL_SOURCE_LINE (decl
));
3870 expand_assignment (decl
, DECL_INITIAL (decl
), 0, 0);
3874 /* Don't let the initialization count as "using" the variable. */
3875 TREE_USED (decl
) = was_used
;
3877 /* Free any temporaries we made while initializing the decl. */
3878 preserve_temp_slots (NULL_RTX
);
3882 /* CLEANUP is an expression to be executed at exit from this binding contour;
3883 for example, in C++, it might call the destructor for this variable.
3885 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
3886 CLEANUP multiple times, and have the correct semantics. This
3887 happens in exception handling, for gotos, returns, breaks that
3888 leave the current scope.
3890 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3891 that is not associated with any particular variable. */
3894 expand_decl_cleanup (decl
, cleanup
)
3897 struct nesting
*thisblock
;
3899 /* Error if we are not in any block. */
3900 if (current_function
== 0 || block_stack
== 0)
3903 thisblock
= block_stack
;
3905 /* Record the cleanup if there is one. */
3911 tree
*cleanups
= &thisblock
->data
.block
.cleanups
;
3912 int cond_context
= conditional_context ();
3916 rtx flag
= gen_reg_rtx (word_mode
);
3921 emit_move_insn (flag
, const0_rtx
);
3922 set_flag_0
= get_insns ();
3925 thisblock
->data
.block
.last_unconditional_cleanup
3926 = emit_insns_after (set_flag_0
,
3927 thisblock
->data
.block
.last_unconditional_cleanup
);
3929 emit_move_insn (flag
, const1_rtx
);
3931 /* All cleanups must be on the function_obstack. */
3932 push_obstacks_nochange ();
3933 resume_temporary_allocation ();
3935 cond
= build_decl (VAR_DECL
, NULL_TREE
, type_for_mode (word_mode
, 1));
3936 DECL_RTL (cond
) = flag
;
3938 /* Conditionalize the cleanup. */
3939 cleanup
= build (COND_EXPR
, void_type_node
,
3940 truthvalue_conversion (cond
),
3941 cleanup
, integer_zero_node
);
3942 cleanup
= fold (cleanup
);
3946 cleanups
= thisblock
->data
.block
.cleanup_ptr
;
3949 /* All cleanups must be on the function_obstack. */
3950 push_obstacks_nochange ();
3951 resume_temporary_allocation ();
3952 cleanup
= unsave_expr (cleanup
);
3955 t
= *cleanups
= temp_tree_cons (decl
, cleanup
, *cleanups
);
3958 /* If this block has a cleanup, it belongs in stack_block_stack. */
3959 stack_block_stack
= thisblock
;
3966 /* If this was optimized so that there is no exception region for the
3967 cleanup, then mark the TREE_LIST node, so that we can later tell
3968 if we need to call expand_eh_region_end. */
3969 if (! using_eh_for_cleanups_p
3970 || expand_eh_region_start_tree (decl
, cleanup
))
3971 TREE_ADDRESSABLE (t
) = 1;
3972 /* If that started a new EH region, we're in a new block. */
3973 thisblock
= block_stack
;
3980 thisblock
->data
.block
.last_unconditional_cleanup
3981 = emit_insns_after (seq
,
3982 thisblock
->data
.block
.last_unconditional_cleanup
);
3986 thisblock
->data
.block
.last_unconditional_cleanup
3988 thisblock
->data
.block
.cleanup_ptr
= &thisblock
->data
.block
.cleanups
;
3994 /* Like expand_decl_cleanup, but suppress generating an exception handler
3995 to perform the cleanup. */
3998 expand_decl_cleanup_no_eh (decl
, cleanup
)
4001 int save_eh
= using_eh_for_cleanups_p
;
4004 using_eh_for_cleanups_p
= 0;
4005 result
= expand_decl_cleanup (decl
, cleanup
);
4006 using_eh_for_cleanups_p
= save_eh
;
4011 /* Arrange for the top element of the dynamic cleanup chain to be
4012 popped if we exit the current binding contour. DECL is the
4013 associated declaration, if any, otherwise NULL_TREE. If the
4014 current contour is left via an exception, then __sjthrow will pop
4015 the top element off the dynamic cleanup chain. The code that
4016 avoids doing the action we push into the cleanup chain in the
4017 exceptional case is contained in expand_cleanups.
4019 This routine is only used by expand_eh_region_start, and that is
4020 the only way in which an exception region should be started. This
4021 routine is only used when using the setjmp/longjmp codegen method
4022 for exception handling. */
4025 expand_dcc_cleanup (decl
)
4028 struct nesting
*thisblock
;
4031 /* Error if we are not in any block. */
4032 if (current_function
== 0 || block_stack
== 0)
4034 thisblock
= block_stack
;
4036 /* Record the cleanup for the dynamic handler chain. */
4038 /* All cleanups must be on the function_obstack. */
4039 push_obstacks_nochange ();
4040 resume_temporary_allocation ();
4041 cleanup
= make_node (POPDCC_EXPR
);
4044 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4045 thisblock
->data
.block
.cleanups
4046 = temp_tree_cons (decl
, cleanup
, thisblock
->data
.block
.cleanups
);
4048 /* If this block has a cleanup, it belongs in stack_block_stack. */
4049 stack_block_stack
= thisblock
;
4053 /* Arrange for the top element of the dynamic handler chain to be
4054 popped if we exit the current binding contour. DECL is the
4055 associated declaration, if any, otherwise NULL_TREE. If the current
4056 contour is left via an exception, then __sjthrow will pop the top
4057 element off the dynamic handler chain. The code that avoids doing
4058 the action we push into the handler chain in the exceptional case
4059 is contained in expand_cleanups.
4061 This routine is only used by expand_eh_region_start, and that is
4062 the only way in which an exception region should be started. This
4063 routine is only used when using the setjmp/longjmp codegen method
4064 for exception handling. */
4067 expand_dhc_cleanup (decl
)
4070 struct nesting
*thisblock
;
4073 /* Error if we are not in any block. */
4074 if (current_function
== 0 || block_stack
== 0)
4076 thisblock
= block_stack
;
4078 /* Record the cleanup for the dynamic handler chain. */
4080 /* All cleanups must be on the function_obstack. */
4081 push_obstacks_nochange ();
4082 resume_temporary_allocation ();
4083 cleanup
= make_node (POPDHC_EXPR
);
4086 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4087 thisblock
->data
.block
.cleanups
4088 = temp_tree_cons (decl
, cleanup
, thisblock
->data
.block
.cleanups
);
4090 /* If this block has a cleanup, it belongs in stack_block_stack. */
4091 stack_block_stack
= thisblock
;
4095 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4096 DECL_ELTS is the list of elements that belong to DECL's type.
4097 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4100 expand_anon_union_decl (decl
, cleanup
, decl_elts
)
4101 tree decl
, cleanup
, decl_elts
;
4103 struct nesting
*thisblock
= current_function
== 0 ? 0 : block_stack
;
4107 expand_decl_cleanup (decl
, cleanup
);
4108 x
= DECL_RTL (decl
);
4112 tree decl_elt
= TREE_VALUE (decl_elts
);
4113 tree cleanup_elt
= TREE_PURPOSE (decl_elts
);
4114 enum machine_mode mode
= TYPE_MODE (TREE_TYPE (decl_elt
));
4116 /* Propagate the union's alignment to the elements. */
4117 DECL_ALIGN (decl_elt
) = DECL_ALIGN (decl
);
4119 /* If the element has BLKmode and the union doesn't, the union is
4120 aligned such that the element doesn't need to have BLKmode, so
4121 change the element's mode to the appropriate one for its size. */
4122 if (mode
== BLKmode
&& DECL_MODE (decl
) != BLKmode
)
4123 DECL_MODE (decl_elt
) = mode
4124 = mode_for_size (TREE_INT_CST_LOW (DECL_SIZE (decl_elt
)),
4127 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4128 instead create a new MEM rtx with the proper mode. */
4129 if (GET_CODE (x
) == MEM
)
4131 if (mode
== GET_MODE (x
))
4132 DECL_RTL (decl_elt
) = x
;
4135 DECL_RTL (decl_elt
) = gen_rtx_MEM (mode
, copy_rtx (XEXP (x
, 0)));
4136 MEM_COPY_ATTRIBUTES (DECL_RTL (decl_elt
), x
);
4137 RTX_UNCHANGING_P (DECL_RTL (decl_elt
)) = RTX_UNCHANGING_P (x
);
4140 else if (GET_CODE (x
) == REG
)
4142 if (mode
== GET_MODE (x
))
4143 DECL_RTL (decl_elt
) = x
;
4145 DECL_RTL (decl_elt
) = gen_rtx_SUBREG (mode
, x
, 0);
4150 /* Record the cleanup if there is one. */
4153 thisblock
->data
.block
.cleanups
4154 = temp_tree_cons (decl_elt
, cleanup_elt
,
4155 thisblock
->data
.block
.cleanups
);
4157 decl_elts
= TREE_CHAIN (decl_elts
);
4161 /* Expand a list of cleanups LIST.
4162 Elements may be expressions or may be nested lists.
4164 If DONT_DO is nonnull, then any list-element
4165 whose TREE_PURPOSE matches DONT_DO is omitted.
4166 This is sometimes used to avoid a cleanup associated with
4167 a value that is being returned out of the scope.
4169 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
4170 goto and handle protection regions specially in that case.
4172 If REACHABLE, we emit code, otherwise just inform the exception handling
4173 code about this finalization. */
4176 expand_cleanups (list
, dont_do
, in_fixup
, reachable
)
4183 for (tail
= list
; tail
; tail
= TREE_CHAIN (tail
))
4184 if (dont_do
== 0 || TREE_PURPOSE (tail
) != dont_do
)
4186 if (TREE_CODE (TREE_VALUE (tail
)) == TREE_LIST
)
4187 expand_cleanups (TREE_VALUE (tail
), dont_do
, in_fixup
, reachable
);
4192 tree cleanup
= TREE_VALUE (tail
);
4194 /* See expand_d{h,c}c_cleanup for why we avoid this. */
4195 if (TREE_CODE (cleanup
) != POPDHC_EXPR
4196 && TREE_CODE (cleanup
) != POPDCC_EXPR
4197 /* See expand_eh_region_start_tree for this case. */
4198 && ! TREE_ADDRESSABLE (tail
))
4200 cleanup
= protect_with_terminate (cleanup
);
4201 expand_eh_region_end (cleanup
);
4207 /* Cleanups may be run multiple times. For example,
4208 when exiting a binding contour, we expand the
4209 cleanups associated with that contour. When a goto
4210 within that binding contour has a target outside that
4211 contour, it will expand all cleanups from its scope to
4212 the target. Though the cleanups are expanded multiple
4213 times, the control paths are non-overlapping so the
4214 cleanups will not be executed twice. */
4216 /* We may need to protect fixups with rethrow regions. */
4217 int protect
= (in_fixup
&& ! TREE_ADDRESSABLE (tail
));
4220 expand_fixup_region_start ();
4222 expand_expr (TREE_VALUE (tail
), const0_rtx
, VOIDmode
, 0);
4224 expand_fixup_region_end (TREE_VALUE (tail
));
4231 /* Mark when the context we are emitting RTL for as a conditional
4232 context, so that any cleanup actions we register with
4233 expand_decl_init will be properly conditionalized when those
4234 cleanup actions are later performed. Must be called before any
4235 expression (tree) is expanded that is within a conditional context. */
4238 start_cleanup_deferral ()
4240 /* block_stack can be NULL if we are inside the parameter list. It is
4241 OK to do nothing, because cleanups aren't possible here. */
4243 ++block_stack
->data
.block
.conditional_code
;
4246 /* Mark the end of a conditional region of code. Because cleanup
4247 deferrals may be nested, we may still be in a conditional region
4248 after we end the currently deferred cleanups, only after we end all
4249 deferred cleanups, are we back in unconditional code. */
4252 end_cleanup_deferral ()
4254 /* block_stack can be NULL if we are inside the parameter list. It is
4255 OK to do nothing, because cleanups aren't possible here. */
4257 --block_stack
->data
.block
.conditional_code
;
4260 /* Move all cleanups from the current block_stack
4261 to the containing block_stack, where they are assumed to
4262 have been created. If anything can cause a temporary to
4263 be created, but not expanded for more than one level of
4264 block_stacks, then this code will have to change. */
4269 struct nesting
*block
= block_stack
;
4270 struct nesting
*outer
= block
->next
;
4272 outer
->data
.block
.cleanups
4273 = chainon (block
->data
.block
.cleanups
,
4274 outer
->data
.block
.cleanups
);
4275 block
->data
.block
.cleanups
= 0;
4279 last_cleanup_this_contour ()
4281 if (block_stack
== 0)
4284 return block_stack
->data
.block
.cleanups
;
4287 /* Return 1 if there are any pending cleanups at this point.
4288 If THIS_CONTOUR is nonzero, check the current contour as well.
4289 Otherwise, look only at the contours that enclose this one. */
4292 any_pending_cleanups (this_contour
)
4295 struct nesting
*block
;
4297 if (block_stack
== 0)
4300 if (this_contour
&& block_stack
->data
.block
.cleanups
!= NULL
)
4302 if (block_stack
->data
.block
.cleanups
== 0
4303 && block_stack
->data
.block
.outer_cleanups
== 0)
4306 for (block
= block_stack
->next
; block
; block
= block
->next
)
4307 if (block
->data
.block
.cleanups
!= 0)
4313 /* Enter a case (Pascal) or switch (C) statement.
4314 Push a block onto case_stack and nesting_stack
4315 to accumulate the case-labels that are seen
4316 and to record the labels generated for the statement.
4318 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4319 Otherwise, this construct is transparent for `exit_something'.
4321 EXPR is the index-expression to be dispatched on.
4322 TYPE is its nominal type. We could simply convert EXPR to this type,
4323 but instead we take short cuts. */
4326 expand_start_case (exit_flag
, expr
, type
, printname
)
4330 const char *printname
;
4332 register struct nesting
*thiscase
= ALLOC_NESTING ();
4334 /* Make an entry on case_stack for the case we are entering. */
4336 thiscase
->next
= case_stack
;
4337 thiscase
->all
= nesting_stack
;
4338 thiscase
->depth
= ++nesting_depth
;
4339 thiscase
->exit_label
= exit_flag
? gen_label_rtx () : 0;
4340 thiscase
->data
.case_stmt
.case_list
= 0;
4341 thiscase
->data
.case_stmt
.index_expr
= expr
;
4342 thiscase
->data
.case_stmt
.nominal_type
= type
;
4343 thiscase
->data
.case_stmt
.default_label
= 0;
4344 thiscase
->data
.case_stmt
.num_ranges
= 0;
4345 thiscase
->data
.case_stmt
.printname
= printname
;
4346 thiscase
->data
.case_stmt
.line_number_status
= force_line_numbers ();
4347 case_stack
= thiscase
;
4348 nesting_stack
= thiscase
;
4350 do_pending_stack_adjust ();
4352 /* Make sure case_stmt.start points to something that won't
4353 need any transformation before expand_end_case. */
4354 if (GET_CODE (get_last_insn ()) != NOTE
)
4355 emit_note (NULL_PTR
, NOTE_INSN_DELETED
);
4357 thiscase
->data
.case_stmt
.start
= get_last_insn ();
4359 start_cleanup_deferral ();
4363 /* Start a "dummy case statement" within which case labels are invalid
4364 and are not connected to any larger real case statement.
4365 This can be used if you don't want to let a case statement jump
4366 into the middle of certain kinds of constructs. */
4369 expand_start_case_dummy ()
4371 register struct nesting
*thiscase
= ALLOC_NESTING ();
4373 /* Make an entry on case_stack for the dummy. */
4375 thiscase
->next
= case_stack
;
4376 thiscase
->all
= nesting_stack
;
4377 thiscase
->depth
= ++nesting_depth
;
4378 thiscase
->exit_label
= 0;
4379 thiscase
->data
.case_stmt
.case_list
= 0;
4380 thiscase
->data
.case_stmt
.start
= 0;
4381 thiscase
->data
.case_stmt
.nominal_type
= 0;
4382 thiscase
->data
.case_stmt
.default_label
= 0;
4383 thiscase
->data
.case_stmt
.num_ranges
= 0;
4384 case_stack
= thiscase
;
4385 nesting_stack
= thiscase
;
4386 start_cleanup_deferral ();
4389 /* End a dummy case statement. */
4392 expand_end_case_dummy ()
4394 end_cleanup_deferral ();
4395 POPSTACK (case_stack
);
4398 /* Return the data type of the index-expression
4399 of the innermost case statement, or null if none. */
4402 case_index_expr_type ()
4405 return TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4412 /* If this is the first label, warn if any insns have been emitted. */
4413 if (case_stack
->data
.case_stmt
.line_number_status
>= 0)
4417 restore_line_number_status
4418 (case_stack
->data
.case_stmt
.line_number_status
);
4419 case_stack
->data
.case_stmt
.line_number_status
= -1;
4421 for (insn
= case_stack
->data
.case_stmt
.start
;
4423 insn
= NEXT_INSN (insn
))
4425 if (GET_CODE (insn
) == CODE_LABEL
)
4427 if (GET_CODE (insn
) != NOTE
4428 && (GET_CODE (insn
) != INSN
|| GET_CODE (PATTERN (insn
)) != USE
))
4431 insn
= PREV_INSN (insn
);
4432 while (insn
&& (GET_CODE (insn
) != NOTE
|| NOTE_LINE_NUMBER (insn
) < 0));
4434 /* If insn is zero, then there must have been a syntax error. */
4436 warning_with_file_and_line (NOTE_SOURCE_FILE(insn
),
4437 NOTE_LINE_NUMBER(insn
),
4438 "unreachable code at beginning of %s",
4439 case_stack
->data
.case_stmt
.printname
);
4446 /* Accumulate one case or default label inside a case or switch statement.
4447 VALUE is the value of the case (a null pointer, for a default label).
4448 The function CONVERTER, when applied to arguments T and V,
4449 converts the value V to the type T.
4451 If not currently inside a case or switch statement, return 1 and do
4452 nothing. The caller will print a language-specific error message.
4453 If VALUE is a duplicate or overlaps, return 2 and do nothing
4454 except store the (first) duplicate node in *DUPLICATE.
4455 If VALUE is out of range, return 3 and do nothing.
4456 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4457 Return 0 on success.
4459 Extended to handle range statements. */
4462 pushcase (value
, converter
, label
, duplicate
)
4463 register tree value
;
4464 tree (*converter
) PROTO((tree
, tree
));
4465 register tree label
;
4471 /* Fail if not inside a real case statement. */
4472 if (! (case_stack
&& case_stack
->data
.case_stmt
.start
))
4475 if (stack_block_stack
4476 && stack_block_stack
->depth
> case_stack
->depth
)
4479 index_type
= TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4480 nominal_type
= case_stack
->data
.case_stmt
.nominal_type
;
4482 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4483 if (index_type
== error_mark_node
)
4486 /* Convert VALUE to the type in which the comparisons are nominally done. */
4488 value
= (*converter
) (nominal_type
, value
);
4492 /* Fail if this value is out of range for the actual type of the index
4493 (which may be narrower than NOMINAL_TYPE). */
4494 if (value
!= 0 && ! int_fits_type_p (value
, index_type
))
4497 /* Fail if this is a duplicate or overlaps another entry. */
4500 if (case_stack
->data
.case_stmt
.default_label
!= 0)
4502 *duplicate
= case_stack
->data
.case_stmt
.default_label
;
4505 case_stack
->data
.case_stmt
.default_label
= label
;
4508 return add_case_node (value
, value
, label
, duplicate
);
4510 expand_label (label
);
4514 /* Like pushcase but this case applies to all values between VALUE1 and
4515 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4516 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4517 starts at VALUE1 and ends at the highest value of the index type.
4518 If both are NULL, this case applies to all values.
4520 The return value is the same as that of pushcase but there is one
4521 additional error code: 4 means the specified range was empty. */
4524 pushcase_range (value1
, value2
, converter
, label
, duplicate
)
4525 register tree value1
, value2
;
4526 tree (*converter
) PROTO((tree
, tree
));
4527 register tree label
;
4533 /* Fail if not inside a real case statement. */
4534 if (! (case_stack
&& case_stack
->data
.case_stmt
.start
))
4537 if (stack_block_stack
4538 && stack_block_stack
->depth
> case_stack
->depth
)
4541 index_type
= TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4542 nominal_type
= case_stack
->data
.case_stmt
.nominal_type
;
4544 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4545 if (index_type
== error_mark_node
)
4550 /* Convert VALUEs to type in which the comparisons are nominally done
4551 and replace any unspecified value with the corresponding bound. */
4553 value1
= TYPE_MIN_VALUE (index_type
);
4555 value2
= TYPE_MAX_VALUE (index_type
);
4557 /* Fail if the range is empty. Do this before any conversion since
4558 we want to allow out-of-range empty ranges. */
4559 if (value2
&& tree_int_cst_lt (value2
, value1
))
4562 value1
= (*converter
) (nominal_type
, value1
);
4564 /* If the max was unbounded, use the max of the nominal_type we are
4565 converting to. Do this after the < check above to suppress false
4568 value2
= TYPE_MAX_VALUE (nominal_type
);
4569 value2
= (*converter
) (nominal_type
, value2
);
4571 /* Fail if these values are out of range. */
4572 if (TREE_CONSTANT_OVERFLOW (value1
)
4573 || ! int_fits_type_p (value1
, index_type
))
4576 if (TREE_CONSTANT_OVERFLOW (value2
)
4577 || ! int_fits_type_p (value2
, index_type
))
4580 return add_case_node (value1
, value2
, label
, duplicate
);
4583 /* Do the actual insertion of a case label for pushcase and pushcase_range
4584 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4585 slowdown for large switch statements. */
4588 add_case_node (low
, high
, label
, duplicate
)
4593 struct case_node
*p
, **q
, *r
;
4595 q
= &case_stack
->data
.case_stmt
.case_list
;
4602 /* Keep going past elements distinctly greater than HIGH. */
4603 if (tree_int_cst_lt (high
, p
->low
))
4606 /* or distinctly less than LOW. */
4607 else if (tree_int_cst_lt (p
->high
, low
))
4612 /* We have an overlap; this is an error. */
4613 *duplicate
= p
->code_label
;
4618 /* Add this label to the chain, and succeed.
4619 Copy LOW, HIGH so they are on temporary rather than momentary
4620 obstack and will thus survive till the end of the case statement. */
4622 r
= (struct case_node
*) oballoc (sizeof (struct case_node
));
4623 r
->low
= copy_node (low
);
4625 /* If the bounds are equal, turn this into the one-value case. */
4627 if (tree_int_cst_equal (low
, high
))
4631 r
->high
= copy_node (high
);
4632 case_stack
->data
.case_stmt
.num_ranges
++;
4635 r
->code_label
= label
;
4636 expand_label (label
);
4646 struct case_node
*s
;
4652 if (! (b
= p
->balance
))
4653 /* Growth propagation from left side. */
4660 if ((p
->left
= s
= r
->right
))
4669 if ((r
->parent
= s
))
4677 case_stack
->data
.case_stmt
.case_list
= r
;
4680 /* r->balance == +1 */
4685 struct case_node
*t
= r
->right
;
4687 if ((p
->left
= s
= t
->right
))
4691 if ((r
->right
= s
= t
->left
))
4705 if ((t
->parent
= s
))
4713 case_stack
->data
.case_stmt
.case_list
= t
;
4720 /* p->balance == +1; growth of left side balances the node. */
4730 if (! (b
= p
->balance
))
4731 /* Growth propagation from right side. */
4739 if ((p
->right
= s
= r
->left
))
4747 if ((r
->parent
= s
))
4756 case_stack
->data
.case_stmt
.case_list
= r
;
4760 /* r->balance == -1 */
4764 struct case_node
*t
= r
->left
;
4766 if ((p
->right
= s
= t
->left
))
4771 if ((r
->left
= s
= t
->right
))
4785 if ((t
->parent
= s
))
4794 case_stack
->data
.case_stmt
.case_list
= t
;
4800 /* p->balance == -1; growth of right side balances the node. */
4814 /* Returns the number of possible values of TYPE.
4815 Returns -1 if the number is unknown or variable.
4816 Returns -2 if the number does not fit in a HOST_WIDE_INT.
4817 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4818 do not increase monotonically (there may be duplicates);
4819 to 1 if the values increase monotonically, but not always by 1;
4820 otherwise sets it to 0. */
4823 all_cases_count (type
, spareness
)
4827 HOST_WIDE_INT count
;
4830 switch (TREE_CODE (type
))
4837 count
= 1 << BITS_PER_UNIT
;
4841 if (TREE_CODE (TYPE_MIN_VALUE (type
)) != INTEGER_CST
4842 || TYPE_MAX_VALUE (type
) == NULL
4843 || TREE_CODE (TYPE_MAX_VALUE (type
)) != INTEGER_CST
)
4848 = TREE_INT_CST_LOW (TYPE_MAX_VALUE (type))
4849 - TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + 1
4850 but with overflow checking. */
4851 tree mint
= TYPE_MIN_VALUE (type
);
4852 tree maxt
= TYPE_MAX_VALUE (type
);
4853 HOST_WIDE_INT lo
, hi
;
4854 neg_double(TREE_INT_CST_LOW (mint
), TREE_INT_CST_HIGH (mint
),
4856 add_double(TREE_INT_CST_LOW (maxt
), TREE_INT_CST_HIGH (maxt
),
4858 add_double (lo
, hi
, 1, 0, &lo
, &hi
);
4859 if (hi
!= 0 || lo
< 0)
4866 for (t
= TYPE_VALUES (type
); t
!= NULL_TREE
; t
= TREE_CHAIN (t
))
4868 if (TREE_CODE (TYPE_MIN_VALUE (type
)) != INTEGER_CST
4869 || TREE_CODE (TREE_VALUE (t
)) != INTEGER_CST
4870 || TREE_INT_CST_LOW (TYPE_MIN_VALUE (type
)) + count
4871 != TREE_INT_CST_LOW (TREE_VALUE (t
)))
4875 if (*spareness
== 1)
4877 tree prev
= TREE_VALUE (TYPE_VALUES (type
));
4878 for (t
= TYPE_VALUES (type
); t
= TREE_CHAIN (t
), t
!= NULL_TREE
; )
4880 if (! tree_int_cst_lt (prev
, TREE_VALUE (t
)))
4885 prev
= TREE_VALUE (t
);
4894 #define BITARRAY_TEST(ARRAY, INDEX) \
4895 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4896 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4897 #define BITARRAY_SET(ARRAY, INDEX) \
4898 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4899 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4901 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4902 with the case values we have seen, assuming the case expression
4904 SPARSENESS is as determined by all_cases_count.
4906 The time needed is proportional to COUNT, unless
4907 SPARSENESS is 2, in which case quadratic time is needed. */
4910 mark_seen_cases (type
, cases_seen
, count
, sparseness
)
4912 unsigned char *cases_seen
;
4916 tree next_node_to_try
= NULL_TREE
;
4917 long next_node_offset
= 0;
4919 register struct case_node
*n
, *root
= case_stack
->data
.case_stmt
.case_list
;
4920 tree val
= make_node (INTEGER_CST
);
4921 TREE_TYPE (val
) = type
;
4924 else if (sparseness
== 2)
4929 /* This less efficient loop is only needed to handle
4930 duplicate case values (multiple enum constants
4931 with the same value). */
4932 TREE_TYPE (val
) = TREE_TYPE (root
->low
);
4933 for (t
= TYPE_VALUES (type
), xlo
= 0; t
!= NULL_TREE
;
4934 t
= TREE_CHAIN (t
), xlo
++)
4936 TREE_INT_CST_LOW (val
) = TREE_INT_CST_LOW (TREE_VALUE (t
));
4937 TREE_INT_CST_HIGH (val
) = TREE_INT_CST_HIGH (TREE_VALUE (t
));
4941 /* Keep going past elements distinctly greater than VAL. */
4942 if (tree_int_cst_lt (val
, n
->low
))
4945 /* or distinctly less than VAL. */
4946 else if (tree_int_cst_lt (n
->high
, val
))
4951 /* We have found a matching range. */
4952 BITARRAY_SET (cases_seen
, xlo
);
4962 case_stack
->data
.case_stmt
.case_list
= root
= case_tree2list (root
, 0);
4963 for (n
= root
; n
; n
= n
->right
)
4965 TREE_INT_CST_LOW (val
) = TREE_INT_CST_LOW (n
->low
);
4966 TREE_INT_CST_HIGH (val
) = TREE_INT_CST_HIGH (n
->low
);
4967 while ( ! tree_int_cst_lt (n
->high
, val
))
4969 /* Calculate (into xlo) the "offset" of the integer (val).
4970 The element with lowest value has offset 0, the next smallest
4971 element has offset 1, etc. */
4973 HOST_WIDE_INT xlo
, xhi
;
4975 if (sparseness
&& TYPE_VALUES (type
) != NULL_TREE
)
4977 /* The TYPE_VALUES will be in increasing order, so
4978 starting searching where we last ended. */
4979 t
= next_node_to_try
;
4980 xlo
= next_node_offset
;
4986 t
= TYPE_VALUES (type
);
4989 if (tree_int_cst_equal (val
, TREE_VALUE (t
)))
4991 next_node_to_try
= TREE_CHAIN (t
);
4992 next_node_offset
= xlo
+ 1;
4997 if (t
== next_node_to_try
)
5006 t
= TYPE_MIN_VALUE (type
);
5008 neg_double (TREE_INT_CST_LOW (t
), TREE_INT_CST_HIGH (t
),
5012 add_double (xlo
, xhi
,
5013 TREE_INT_CST_LOW (val
), TREE_INT_CST_HIGH (val
),
5017 if (xhi
== 0 && xlo
>= 0 && xlo
< count
)
5018 BITARRAY_SET (cases_seen
, xlo
);
5019 add_double (TREE_INT_CST_LOW (val
), TREE_INT_CST_HIGH (val
),
5021 &TREE_INT_CST_LOW (val
), &TREE_INT_CST_HIGH (val
));
5027 /* Called when the index of a switch statement is an enumerated type
5028 and there is no default label.
5030 Checks that all enumeration literals are covered by the case
5031 expressions of a switch. Also, warn if there are any extra
5032 switch cases that are *not* elements of the enumerated type.
5034 If all enumeration literals were covered by the case expressions,
5035 turn one of the expressions into the default expression since it should
5036 not be possible to fall through such a switch. */
5039 check_for_full_enumeration_handling (type
)
5042 register struct case_node
*n
;
5043 register tree chain
;
5044 #if 0 /* variable used by 'if 0'ed code below. */
5045 register struct case_node
**l
;
5049 /* True iff the selector type is a numbered set mode. */
5052 /* The number of possible selector values. */
5055 /* For each possible selector value. a one iff it has been matched
5056 by a case value alternative. */
5057 unsigned char *cases_seen
;
5059 /* The allocated size of cases_seen, in chars. */
5065 size
= all_cases_count (type
, &sparseness
);
5066 bytes_needed
= (size
+ HOST_BITS_PER_CHAR
) / HOST_BITS_PER_CHAR
;
5068 if (size
> 0 && size
< 600000
5069 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5070 this optimization if we don't have enough memory rather than
5071 aborting, as xmalloc would do. */
5072 && (cases_seen
= (unsigned char *) calloc (bytes_needed
, 1)) != NULL
)
5075 tree v
= TYPE_VALUES (type
);
5077 /* The time complexity of this code is normally O(N), where
5078 N being the number of members in the enumerated type.
5079 However, if type is a ENUMERAL_TYPE whose values do not
5080 increase monotonically, O(N*log(N)) time may be needed. */
5082 mark_seen_cases (type
, cases_seen
, size
, sparseness
);
5084 for (i
= 0; v
!= NULL_TREE
&& i
< size
; i
++, v
= TREE_CHAIN (v
))
5086 if (BITARRAY_TEST(cases_seen
, i
) == 0)
5087 warning ("enumeration value `%s' not handled in switch",
5088 IDENTIFIER_POINTER (TREE_PURPOSE (v
)));
5094 /* Now we go the other way around; we warn if there are case
5095 expressions that don't correspond to enumerators. This can
5096 occur since C and C++ don't enforce type-checking of
5097 assignments to enumeration variables. */
5099 if (case_stack
->data
.case_stmt
.case_list
5100 && case_stack
->data
.case_stmt
.case_list
->left
)
5101 case_stack
->data
.case_stmt
.case_list
5102 = case_tree2list (case_stack
->data
.case_stmt
.case_list
, 0);
5104 for (n
= case_stack
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5106 for (chain
= TYPE_VALUES (type
);
5107 chain
&& !tree_int_cst_equal (n
->low
, TREE_VALUE (chain
));
5108 chain
= TREE_CHAIN (chain
))
5113 if (TYPE_NAME (type
) == 0)
5114 warning ("case value `%ld' not in enumerated type",
5115 (long) TREE_INT_CST_LOW (n
->low
));
5117 warning ("case value `%ld' not in enumerated type `%s'",
5118 (long) TREE_INT_CST_LOW (n
->low
),
5119 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type
))
5122 : DECL_NAME (TYPE_NAME (type
))));
5124 if (!tree_int_cst_equal (n
->low
, n
->high
))
5126 for (chain
= TYPE_VALUES (type
);
5127 chain
&& !tree_int_cst_equal (n
->high
, TREE_VALUE (chain
));
5128 chain
= TREE_CHAIN (chain
))
5133 if (TYPE_NAME (type
) == 0)
5134 warning ("case value `%ld' not in enumerated type",
5135 (long) TREE_INT_CST_LOW (n
->high
));
5137 warning ("case value `%ld' not in enumerated type `%s'",
5138 (long) TREE_INT_CST_LOW (n
->high
),
5139 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type
))
5142 : DECL_NAME (TYPE_NAME (type
))));
5148 /* ??? This optimization is disabled because it causes valid programs to
5149 fail. ANSI C does not guarantee that an expression with enum type
5150 will have a value that is the same as one of the enumeration literals. */
5152 /* If all values were found as case labels, make one of them the default
5153 label. Thus, this switch will never fall through. We arbitrarily pick
5154 the last one to make the default since this is likely the most
5155 efficient choice. */
5159 for (l
= &case_stack
->data
.case_stmt
.case_list
;
5164 case_stack
->data
.case_stmt
.default_label
= (*l
)->code_label
;
5171 /* Terminate a case (Pascal) or switch (C) statement
5172 in which ORIG_INDEX is the expression to be tested.
5173 Generate the code to test it and jump to the right place. */
5176 expand_end_case (orig_index
)
5179 tree minval
= NULL_TREE
, maxval
= NULL_TREE
, range
, orig_minval
;
5180 rtx default_label
= 0;
5181 register struct case_node
*n
;
5189 register struct nesting
*thiscase
= case_stack
;
5190 tree index_expr
, index_type
;
5193 table_label
= gen_label_rtx ();
5194 index_expr
= thiscase
->data
.case_stmt
.index_expr
;
5195 index_type
= TREE_TYPE (index_expr
);
5196 unsignedp
= TREE_UNSIGNED (index_type
);
5198 do_pending_stack_adjust ();
5200 /* This might get an spurious warning in the presence of a syntax error;
5201 it could be fixed by moving the call to check_seenlabel after the
5202 check for error_mark_node, and copying the code of check_seenlabel that
5203 deals with case_stack->data.case_stmt.line_number_status /
5204 restore_line_number_status in front of the call to end_cleanup_deferral;
5205 However, this might miss some useful warnings in the presence of
5206 non-syntax errors. */
5209 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5210 if (index_type
!= error_mark_node
)
5212 /* If switch expression was an enumerated type, check that all
5213 enumeration literals are covered by the cases.
5214 No sense trying this if there's a default case, however. */
5216 if (!thiscase
->data
.case_stmt
.default_label
5217 && TREE_CODE (TREE_TYPE (orig_index
)) == ENUMERAL_TYPE
5218 && TREE_CODE (index_expr
) != INTEGER_CST
)
5219 check_for_full_enumeration_handling (TREE_TYPE (orig_index
));
5221 /* If we don't have a default-label, create one here,
5222 after the body of the switch. */
5223 if (thiscase
->data
.case_stmt
.default_label
== 0)
5225 thiscase
->data
.case_stmt
.default_label
5226 = build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
5227 expand_label (thiscase
->data
.case_stmt
.default_label
);
5229 default_label
= label_rtx (thiscase
->data
.case_stmt
.default_label
);
5231 before_case
= get_last_insn ();
5233 if (thiscase
->data
.case_stmt
.case_list
5234 && thiscase
->data
.case_stmt
.case_list
->left
)
5235 thiscase
->data
.case_stmt
.case_list
5236 = case_tree2list(thiscase
->data
.case_stmt
.case_list
, 0);
5238 /* Simplify the case-list before we count it. */
5239 group_case_nodes (thiscase
->data
.case_stmt
.case_list
);
5241 /* Get upper and lower bounds of case values.
5242 Also convert all the case values to the index expr's data type. */
5245 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5247 /* Check low and high label values are integers. */
5248 if (TREE_CODE (n
->low
) != INTEGER_CST
)
5250 if (TREE_CODE (n
->high
) != INTEGER_CST
)
5253 n
->low
= convert (index_type
, n
->low
);
5254 n
->high
= convert (index_type
, n
->high
);
5256 /* Count the elements and track the largest and smallest
5257 of them (treating them as signed even if they are not). */
5265 if (INT_CST_LT (n
->low
, minval
))
5267 if (INT_CST_LT (maxval
, n
->high
))
5270 /* A range counts double, since it requires two compares. */
5271 if (! tree_int_cst_equal (n
->low
, n
->high
))
5275 orig_minval
= minval
;
5277 /* Compute span of values. */
5279 range
= fold (build (MINUS_EXPR
, index_type
, maxval
, minval
));
5281 end_cleanup_deferral ();
5285 expand_expr (index_expr
, const0_rtx
, VOIDmode
, 0);
5287 emit_jump (default_label
);
5290 /* If range of values is much bigger than number of values,
5291 make a sequence of conditional branches instead of a dispatch.
5292 If the switch-index is a constant, do it this way
5293 because we can optimize it. */
5295 #ifndef CASE_VALUES_THRESHOLD
5297 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
5299 /* If machine does not have a case insn that compares the
5300 bounds, this means extra overhead for dispatch tables
5301 which raises the threshold for using them. */
5302 #define CASE_VALUES_THRESHOLD 5
5303 #endif /* HAVE_casesi */
5304 #endif /* CASE_VALUES_THRESHOLD */
5306 else if (TREE_INT_CST_HIGH (range
) != 0
5307 || count
< (unsigned int) CASE_VALUES_THRESHOLD
5308 || ((unsigned HOST_WIDE_INT
) (TREE_INT_CST_LOW (range
))
5310 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5313 || TREE_CODE (index_expr
) == INTEGER_CST
5314 /* These will reduce to a constant. */
5315 || (TREE_CODE (index_expr
) == CALL_EXPR
5316 && TREE_CODE (TREE_OPERAND (index_expr
, 0)) == ADDR_EXPR
5317 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr
, 0), 0)) == FUNCTION_DECL
5318 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr
, 0), 0)) == BUILT_IN_CLASSIFY_TYPE
)
5319 || (TREE_CODE (index_expr
) == COMPOUND_EXPR
5320 && TREE_CODE (TREE_OPERAND (index_expr
, 1)) == INTEGER_CST
))
5322 index
= expand_expr (index_expr
, NULL_RTX
, VOIDmode
, 0);
5324 /* If the index is a short or char that we do not have
5325 an insn to handle comparisons directly, convert it to
5326 a full integer now, rather than letting each comparison
5327 generate the conversion. */
5329 if (GET_MODE_CLASS (GET_MODE (index
)) == MODE_INT
5330 && (cmp_optab
->handlers
[(int) GET_MODE(index
)].insn_code
5331 == CODE_FOR_nothing
))
5333 enum machine_mode wider_mode
;
5334 for (wider_mode
= GET_MODE (index
); wider_mode
!= VOIDmode
;
5335 wider_mode
= GET_MODE_WIDER_MODE (wider_mode
))
5336 if (cmp_optab
->handlers
[(int) wider_mode
].insn_code
5337 != CODE_FOR_nothing
)
5339 index
= convert_to_mode (wider_mode
, index
, unsignedp
);
5345 do_pending_stack_adjust ();
5347 index
= protect_from_queue (index
, 0);
5348 if (GET_CODE (index
) == MEM
)
5349 index
= copy_to_reg (index
);
5350 if (GET_CODE (index
) == CONST_INT
5351 || TREE_CODE (index_expr
) == INTEGER_CST
)
5353 /* Make a tree node with the proper constant value
5354 if we don't already have one. */
5355 if (TREE_CODE (index_expr
) != INTEGER_CST
)
5358 = build_int_2 (INTVAL (index
),
5359 unsignedp
|| INTVAL (index
) >= 0 ? 0 : -1);
5360 index_expr
= convert (index_type
, index_expr
);
5363 /* For constant index expressions we need only
5364 issue a unconditional branch to the appropriate
5365 target code. The job of removing any unreachable
5366 code is left to the optimisation phase if the
5367 "-O" option is specified. */
5368 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5369 if (! tree_int_cst_lt (index_expr
, n
->low
)
5370 && ! tree_int_cst_lt (n
->high
, index_expr
))
5374 emit_jump (label_rtx (n
->code_label
));
5376 emit_jump (default_label
);
5380 /* If the index expression is not constant we generate
5381 a binary decision tree to select the appropriate
5382 target code. This is done as follows:
5384 The list of cases is rearranged into a binary tree,
5385 nearly optimal assuming equal probability for each case.
5387 The tree is transformed into RTL, eliminating
5388 redundant test conditions at the same time.
5390 If program flow could reach the end of the
5391 decision tree an unconditional jump to the
5392 default code is emitted. */
5395 = (TREE_CODE (TREE_TYPE (orig_index
)) != ENUMERAL_TYPE
5396 && estimate_case_costs (thiscase
->data
.case_stmt
.case_list
));
5397 balance_case_nodes (&thiscase
->data
.case_stmt
.case_list
,
5399 emit_case_nodes (index
, thiscase
->data
.case_stmt
.case_list
,
5400 default_label
, index_type
);
5401 emit_jump_if_reachable (default_label
);
5410 enum machine_mode index_mode
= SImode
;
5411 int index_bits
= GET_MODE_BITSIZE (index_mode
);
5413 enum machine_mode op_mode
;
5415 /* Convert the index to SImode. */
5416 if (GET_MODE_BITSIZE (TYPE_MODE (index_type
))
5417 > GET_MODE_BITSIZE (index_mode
))
5419 enum machine_mode omode
= TYPE_MODE (index_type
);
5420 rtx rangertx
= expand_expr (range
, NULL_RTX
, VOIDmode
, 0);
5422 /* We must handle the endpoints in the original mode. */
5423 index_expr
= build (MINUS_EXPR
, index_type
,
5424 index_expr
, minval
);
5425 minval
= integer_zero_node
;
5426 index
= expand_expr (index_expr
, NULL_RTX
, VOIDmode
, 0);
5427 emit_cmp_and_jump_insns (rangertx
, index
, LTU
, NULL_RTX
,
5428 omode
, 1, 0, default_label
);
5429 /* Now we can safely truncate. */
5430 index
= convert_to_mode (index_mode
, index
, 0);
5434 if (TYPE_MODE (index_type
) != index_mode
)
5436 index_expr
= convert (type_for_size (index_bits
, 0),
5438 index_type
= TREE_TYPE (index_expr
);
5441 index
= expand_expr (index_expr
, NULL_RTX
, VOIDmode
, 0);
5444 index
= protect_from_queue (index
, 0);
5445 do_pending_stack_adjust ();
5447 op_mode
= insn_operand_mode
[(int)CODE_FOR_casesi
][0];
5448 if (! (*insn_operand_predicate
[(int)CODE_FOR_casesi
][0])
5450 index
= copy_to_mode_reg (op_mode
, index
);
5452 op1
= expand_expr (minval
, NULL_RTX
, VOIDmode
, 0);
5454 op_mode
= insn_operand_mode
[(int)CODE_FOR_casesi
][1];
5455 if (! (*insn_operand_predicate
[(int)CODE_FOR_casesi
][1])
5457 op1
= copy_to_mode_reg (op_mode
, op1
);
5459 op2
= expand_expr (range
, NULL_RTX
, VOIDmode
, 0);
5461 op_mode
= insn_operand_mode
[(int)CODE_FOR_casesi
][2];
5462 if (! (*insn_operand_predicate
[(int)CODE_FOR_casesi
][2])
5464 op2
= copy_to_mode_reg (op_mode
, op2
);
5466 emit_jump_insn (gen_casesi (index
, op1
, op2
,
5467 table_label
, default_label
));
5471 #ifdef HAVE_tablejump
5472 if (! win
&& HAVE_tablejump
)
5474 index_expr
= convert (thiscase
->data
.case_stmt
.nominal_type
,
5475 fold (build (MINUS_EXPR
, index_type
,
5476 index_expr
, minval
)));
5477 index_type
= TREE_TYPE (index_expr
);
5478 index
= expand_expr (index_expr
, NULL_RTX
, VOIDmode
, 0);
5480 index
= protect_from_queue (index
, 0);
5481 do_pending_stack_adjust ();
5483 do_tablejump (index
, TYPE_MODE (index_type
),
5484 expand_expr (range
, NULL_RTX
, VOIDmode
, 0),
5485 table_label
, default_label
);
5492 /* Get table of labels to jump to, in order of case index. */
5494 ncases
= TREE_INT_CST_LOW (range
) + 1;
5495 labelvec
= (rtx
*) alloca (ncases
* sizeof (rtx
));
5496 bzero ((char *) labelvec
, ncases
* sizeof (rtx
));
5498 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5500 register HOST_WIDE_INT i
5501 = TREE_INT_CST_LOW (n
->low
) - TREE_INT_CST_LOW (orig_minval
);
5506 = gen_rtx_LABEL_REF (Pmode
, label_rtx (n
->code_label
));
5507 if (i
+ TREE_INT_CST_LOW (orig_minval
)
5508 == TREE_INT_CST_LOW (n
->high
))
5514 /* Fill in the gaps with the default. */
5515 for (i
= 0; i
< ncases
; i
++)
5516 if (labelvec
[i
] == 0)
5517 labelvec
[i
] = gen_rtx_LABEL_REF (Pmode
, default_label
);
5519 /* Output the table */
5520 emit_label (table_label
);
5522 if (CASE_VECTOR_PC_RELATIVE
|| flag_pic
)
5523 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE
,
5524 gen_rtx_LABEL_REF (Pmode
, table_label
),
5525 gen_rtvec_v (ncases
, labelvec
),
5526 const0_rtx
, const0_rtx
));
5528 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE
,
5529 gen_rtvec_v (ncases
, labelvec
)));
5531 /* If the case insn drops through the table,
5532 after the table we must jump to the default-label.
5533 Otherwise record no drop-through after the table. */
5534 #ifdef CASE_DROPS_THROUGH
5535 emit_jump (default_label
);
5541 before_case
= squeeze_notes (NEXT_INSN (before_case
), get_last_insn ());
5542 reorder_insns (before_case
, get_last_insn (),
5543 thiscase
->data
.case_stmt
.start
);
5546 end_cleanup_deferral ();
5548 if (thiscase
->exit_label
)
5549 emit_label (thiscase
->exit_label
);
5551 POPSTACK (case_stack
);
5556 /* Convert the tree NODE into a list linked by the right field, with the left
5557 field zeroed. RIGHT is used for recursion; it is a list to be placed
5558 rightmost in the resulting list. */
5560 static struct case_node
*
5561 case_tree2list (node
, right
)
5562 struct case_node
*node
, *right
;
5564 struct case_node
*left
;
5567 right
= case_tree2list (node
->right
, right
);
5569 node
->right
= right
;
5570 if ((left
= node
->left
))
5573 return case_tree2list (left
, node
);
5579 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5582 do_jump_if_equal (op1
, op2
, label
, unsignedp
)
5583 rtx op1
, op2
, label
;
5586 if (GET_CODE (op1
) == CONST_INT
5587 && GET_CODE (op2
) == CONST_INT
)
5589 if (INTVAL (op1
) == INTVAL (op2
))
5594 enum machine_mode mode
= GET_MODE (op1
);
5595 if (mode
== VOIDmode
)
5596 mode
= GET_MODE (op2
);
5597 emit_cmp_and_jump_insns (op1
, op2
, EQ
, NULL_RTX
, mode
, unsignedp
,
5602 /* Not all case values are encountered equally. This function
5603 uses a heuristic to weight case labels, in cases where that
5604 looks like a reasonable thing to do.
5606 Right now, all we try to guess is text, and we establish the
5609 chars above space: 16
5618 If we find any cases in the switch that are not either -1 or in the range
5619 of valid ASCII characters, or are control characters other than those
5620 commonly used with "\", don't treat this switch scanning text.
5622 Return 1 if these nodes are suitable for cost estimation, otherwise
5626 estimate_case_costs (node
)
5629 tree min_ascii
= build_int_2 (-1, -1);
5630 tree max_ascii
= convert (TREE_TYPE (node
->high
), build_int_2 (127, 0));
5634 /* If we haven't already made the cost table, make it now. Note that the
5635 lower bound of the table is -1, not zero. */
5637 if (cost_table
== NULL
)
5639 cost_table
= ((short *) xcalloc (129, sizeof (short))) + 1;
5641 for (i
= 0; i
< 128; i
++)
5645 else if (ISPUNCT (i
))
5647 else if (ISCNTRL (i
))
5651 cost_table
[' '] = 8;
5652 cost_table
['\t'] = 4;
5653 cost_table
['\0'] = 4;
5654 cost_table
['\n'] = 2;
5655 cost_table
['\f'] = 1;
5656 cost_table
['\v'] = 1;
5657 cost_table
['\b'] = 1;
5660 /* See if all the case expressions look like text. It is text if the
5661 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5662 as signed arithmetic since we don't want to ever access cost_table with a
5663 value less than -1. Also check that none of the constants in a range
5664 are strange control characters. */
5666 for (n
= node
; n
; n
= n
->right
)
5668 if ((INT_CST_LT (n
->low
, min_ascii
)) || INT_CST_LT (max_ascii
, n
->high
))
5671 for (i
= TREE_INT_CST_LOW (n
->low
); i
<= TREE_INT_CST_LOW (n
->high
); i
++)
5672 if (cost_table
[i
] < 0)
5676 /* All interesting values are within the range of interesting
5677 ASCII characters. */
5681 /* Scan an ordered list of case nodes
5682 combining those with consecutive values or ranges.
5684 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5687 group_case_nodes (head
)
5690 case_node_ptr node
= head
;
5694 rtx lb
= next_real_insn (label_rtx (node
->code_label
));
5696 case_node_ptr np
= node
;
5698 /* Try to group the successors of NODE with NODE. */
5699 while (((np
= np
->right
) != 0)
5700 /* Do they jump to the same place? */
5701 && ((lb2
= next_real_insn (label_rtx (np
->code_label
))) == lb
5702 || (lb
!= 0 && lb2
!= 0
5703 && simplejump_p (lb
)
5704 && simplejump_p (lb2
)
5705 && rtx_equal_p (SET_SRC (PATTERN (lb
)),
5706 SET_SRC (PATTERN (lb2
)))))
5707 /* Are their ranges consecutive? */
5708 && tree_int_cst_equal (np
->low
,
5709 fold (build (PLUS_EXPR
,
5710 TREE_TYPE (node
->high
),
5713 /* An overflow is not consecutive. */
5714 && tree_int_cst_lt (node
->high
,
5715 fold (build (PLUS_EXPR
,
5716 TREE_TYPE (node
->high
),
5718 integer_one_node
))))
5720 node
->high
= np
->high
;
5722 /* NP is the first node after NODE which can't be grouped with it.
5723 Delete the nodes in between, and move on to that node. */
5729 /* Take an ordered list of case nodes
5730 and transform them into a near optimal binary tree,
5731 on the assumption that any target code selection value is as
5732 likely as any other.
5734 The transformation is performed by splitting the ordered
5735 list into two equal sections plus a pivot. The parts are
5736 then attached to the pivot as left and right branches. Each
5737 branch is then transformed recursively. */
5740 balance_case_nodes (head
, parent
)
5741 case_node_ptr
*head
;
5742 case_node_ptr parent
;
5744 register case_node_ptr np
;
5752 register case_node_ptr
*npp
;
5755 /* Count the number of entries on branch. Also count the ranges. */
5759 if (!tree_int_cst_equal (np
->low
, np
->high
))
5763 cost
+= cost_table
[TREE_INT_CST_LOW (np
->high
)];
5767 cost
+= cost_table
[TREE_INT_CST_LOW (np
->low
)];
5775 /* Split this list if it is long enough for that to help. */
5780 /* Find the place in the list that bisects the list's total cost,
5781 Here I gets half the total cost. */
5786 /* Skip nodes while their cost does not reach that amount. */
5787 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
5788 i
-= cost_table
[TREE_INT_CST_LOW ((*npp
)->high
)];
5789 i
-= cost_table
[TREE_INT_CST_LOW ((*npp
)->low
)];
5792 npp
= &(*npp
)->right
;
5797 /* Leave this branch lopsided, but optimize left-hand
5798 side and fill in `parent' fields for right-hand side. */
5800 np
->parent
= parent
;
5801 balance_case_nodes (&np
->left
, np
);
5802 for (; np
->right
; np
= np
->right
)
5803 np
->right
->parent
= np
;
5807 /* If there are just three nodes, split at the middle one. */
5809 npp
= &(*npp
)->right
;
5812 /* Find the place in the list that bisects the list's total cost,
5813 where ranges count as 2.
5814 Here I gets half the total cost. */
5815 i
= (i
+ ranges
+ 1) / 2;
5818 /* Skip nodes while their cost does not reach that amount. */
5819 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
5824 npp
= &(*npp
)->right
;
5829 np
->parent
= parent
;
5832 /* Optimize each of the two split parts. */
5833 balance_case_nodes (&np
->left
, np
);
5834 balance_case_nodes (&np
->right
, np
);
5838 /* Else leave this branch as one level,
5839 but fill in `parent' fields. */
5841 np
->parent
= parent
;
5842 for (; np
->right
; np
= np
->right
)
5843 np
->right
->parent
= np
;
5848 /* Search the parent sections of the case node tree
5849 to see if a test for the lower bound of NODE would be redundant.
5850 INDEX_TYPE is the type of the index expression.
5852 The instructions to generate the case decision tree are
5853 output in the same order as nodes are processed so it is
5854 known that if a parent node checks the range of the current
5855 node minus one that the current node is bounded at its lower
5856 span. Thus the test would be redundant. */
5859 node_has_low_bound (node
, index_type
)
5864 case_node_ptr pnode
;
5866 /* If the lower bound of this node is the lowest value in the index type,
5867 we need not test it. */
5869 if (tree_int_cst_equal (node
->low
, TYPE_MIN_VALUE (index_type
)))
5872 /* If this node has a left branch, the value at the left must be less
5873 than that at this node, so it cannot be bounded at the bottom and
5874 we need not bother testing any further. */
5879 low_minus_one
= fold (build (MINUS_EXPR
, TREE_TYPE (node
->low
),
5880 node
->low
, integer_one_node
));
5882 /* If the subtraction above overflowed, we can't verify anything.
5883 Otherwise, look for a parent that tests our value - 1. */
5885 if (! tree_int_cst_lt (low_minus_one
, node
->low
))
5888 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
5889 if (tree_int_cst_equal (low_minus_one
, pnode
->high
))
5895 /* Search the parent sections of the case node tree
5896 to see if a test for the upper bound of NODE would be redundant.
5897 INDEX_TYPE is the type of the index expression.
5899 The instructions to generate the case decision tree are
5900 output in the same order as nodes are processed so it is
5901 known that if a parent node checks the range of the current
5902 node plus one that the current node is bounded at its upper
5903 span. Thus the test would be redundant. */
5906 node_has_high_bound (node
, index_type
)
5911 case_node_ptr pnode
;
5913 /* If there is no upper bound, obviously no test is needed. */
5915 if (TYPE_MAX_VALUE (index_type
) == NULL
)
5918 /* If the upper bound of this node is the highest value in the type
5919 of the index expression, we need not test against it. */
5921 if (tree_int_cst_equal (node
->high
, TYPE_MAX_VALUE (index_type
)))
5924 /* If this node has a right branch, the value at the right must be greater
5925 than that at this node, so it cannot be bounded at the top and
5926 we need not bother testing any further. */
5931 high_plus_one
= fold (build (PLUS_EXPR
, TREE_TYPE (node
->high
),
5932 node
->high
, integer_one_node
));
5934 /* If the addition above overflowed, we can't verify anything.
5935 Otherwise, look for a parent that tests our value + 1. */
5937 if (! tree_int_cst_lt (node
->high
, high_plus_one
))
5940 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
5941 if (tree_int_cst_equal (high_plus_one
, pnode
->low
))
5947 /* Search the parent sections of the
5948 case node tree to see if both tests for the upper and lower
5949 bounds of NODE would be redundant. */
5952 node_is_bounded (node
, index_type
)
5956 return (node_has_low_bound (node
, index_type
)
5957 && node_has_high_bound (node
, index_type
));
5960 /* Emit an unconditional jump to LABEL unless it would be dead code. */
5963 emit_jump_if_reachable (label
)
5966 if (GET_CODE (get_last_insn ()) != BARRIER
)
5970 /* Emit step-by-step code to select a case for the value of INDEX.
5971 The thus generated decision tree follows the form of the
5972 case-node binary tree NODE, whose nodes represent test conditions.
5973 INDEX_TYPE is the type of the index of the switch.
5975 Care is taken to prune redundant tests from the decision tree
5976 by detecting any boundary conditions already checked by
5977 emitted rtx. (See node_has_high_bound, node_has_low_bound
5978 and node_is_bounded, above.)
5980 Where the test conditions can be shown to be redundant we emit
5981 an unconditional jump to the target code. As a further
5982 optimization, the subordinates of a tree node are examined to
5983 check for bounded nodes. In this case conditional and/or
5984 unconditional jumps as a result of the boundary check for the
5985 current node are arranged to target the subordinates associated
5986 code for out of bound conditions on the current node.
5988 We can assume that when control reaches the code generated here,
5989 the index value has already been compared with the parents
5990 of this node, and determined to be on the same side of each parent
5991 as this node is. Thus, if this node tests for the value 51,
5992 and a parent tested for 52, we don't need to consider
5993 the possibility of a value greater than 51. If another parent
5994 tests for the value 50, then this node need not test anything. */
5997 emit_case_nodes (index
, node
, default_label
, index_type
)
6003 /* If INDEX has an unsigned type, we must make unsigned branches. */
6004 int unsignedp
= TREE_UNSIGNED (index_type
);
6005 typedef rtx
rtx_fn ();
6006 enum machine_mode mode
= GET_MODE (index
);
6008 /* See if our parents have already tested everything for us.
6009 If they have, emit an unconditional jump for this node. */
6010 if (node_is_bounded (node
, index_type
))
6011 emit_jump (label_rtx (node
->code_label
));
6013 else if (tree_int_cst_equal (node
->low
, node
->high
))
6015 /* Node is single valued. First see if the index expression matches
6016 this node and then check our children, if any. */
6018 do_jump_if_equal (index
, expand_expr (node
->low
, NULL_RTX
, VOIDmode
, 0),
6019 label_rtx (node
->code_label
), unsignedp
);
6021 if (node
->right
!= 0 && node
->left
!= 0)
6023 /* This node has children on both sides.
6024 Dispatch to one side or the other
6025 by comparing the index value with this node's value.
6026 If one subtree is bounded, check that one first,
6027 so we can avoid real branches in the tree. */
6029 if (node_is_bounded (node
->right
, index_type
))
6031 emit_cmp_and_jump_insns (index
, expand_expr (node
->high
, NULL_RTX
,
6033 GT
, NULL_RTX
, mode
, unsignedp
, 0,
6034 label_rtx (node
->right
->code_label
));
6035 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6038 else if (node_is_bounded (node
->left
, index_type
))
6040 emit_cmp_and_jump_insns (index
, expand_expr (node
->high
, NULL_RTX
,
6042 LT
, NULL_RTX
, mode
, unsignedp
, 0,
6043 label_rtx (node
->left
->code_label
));
6044 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6049 /* Neither node is bounded. First distinguish the two sides;
6050 then emit the code for one side at a time. */
6053 = build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
6055 /* See if the value is on the right. */
6056 emit_cmp_and_jump_insns (index
, expand_expr (node
->high
, NULL_RTX
,
6058 GT
, NULL_RTX
, mode
, unsignedp
, 0,
6059 label_rtx (test_label
));
6061 /* Value must be on the left.
6062 Handle the left-hand subtree. */
6063 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6064 /* If left-hand subtree does nothing,
6066 emit_jump_if_reachable (default_label
);
6068 /* Code branches here for the right-hand subtree. */
6069 expand_label (test_label
);
6070 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6074 else if (node
->right
!= 0 && node
->left
== 0)
6076 /* Here we have a right child but no left so we issue conditional
6077 branch to default and process the right child.
6079 Omit the conditional branch to default if we it avoid only one
6080 right child; it costs too much space to save so little time. */
6082 if (node
->right
->right
|| node
->right
->left
6083 || !tree_int_cst_equal (node
->right
->low
, node
->right
->high
))
6085 if (!node_has_low_bound (node
, index_type
))
6087 emit_cmp_and_jump_insns (index
, expand_expr (node
->high
,
6090 LT
, NULL_RTX
, mode
, unsignedp
, 0,
6094 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6097 /* We cannot process node->right normally
6098 since we haven't ruled out the numbers less than
6099 this node's value. So handle node->right explicitly. */
6100 do_jump_if_equal (index
,
6101 expand_expr (node
->right
->low
, NULL_RTX
,
6103 label_rtx (node
->right
->code_label
), unsignedp
);
6106 else if (node
->right
== 0 && node
->left
!= 0)
6108 /* Just one subtree, on the left. */
6110 #if 0 /* The following code and comment were formerly part
6111 of the condition here, but they didn't work
6112 and I don't understand what the idea was. -- rms. */
6113 /* If our "most probable entry" is less probable
6114 than the default label, emit a jump to
6115 the default label using condition codes
6116 already lying around. With no right branch,
6117 a branch-greater-than will get us to the default
6120 && cost_table
[TREE_INT_CST_LOW (node
->high
)] < 12)
6123 if (node
->left
->left
|| node
->left
->right
6124 || !tree_int_cst_equal (node
->left
->low
, node
->left
->high
))
6126 if (!node_has_high_bound (node
, index_type
))
6128 emit_cmp_and_jump_insns (index
, expand_expr (node
->high
,
6131 GT
, NULL_RTX
, mode
, unsignedp
, 0,
6135 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6138 /* We cannot process node->left normally
6139 since we haven't ruled out the numbers less than
6140 this node's value. So handle node->left explicitly. */
6141 do_jump_if_equal (index
,
6142 expand_expr (node
->left
->low
, NULL_RTX
,
6144 label_rtx (node
->left
->code_label
), unsignedp
);
6149 /* Node is a range. These cases are very similar to those for a single
6150 value, except that we do not start by testing whether this node
6151 is the one to branch to. */
6153 if (node
->right
!= 0 && node
->left
!= 0)
6155 /* Node has subtrees on both sides.
6156 If the right-hand subtree is bounded,
6157 test for it first, since we can go straight there.
6158 Otherwise, we need to make a branch in the control structure,
6159 then handle the two subtrees. */
6160 tree test_label
= 0;
6163 if (node_is_bounded (node
->right
, index_type
))
6164 /* Right hand node is fully bounded so we can eliminate any
6165 testing and branch directly to the target code. */
6166 emit_cmp_and_jump_insns (index
, expand_expr (node
->high
, NULL_RTX
,
6168 GT
, NULL_RTX
, mode
, unsignedp
, 0,
6169 label_rtx (node
->right
->code_label
));
6172 /* Right hand node requires testing.
6173 Branch to a label where we will handle it later. */
6175 test_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
6176 emit_cmp_and_jump_insns (index
, expand_expr (node
->high
, NULL_RTX
,
6178 GT
, NULL_RTX
, mode
, unsignedp
, 0,
6179 label_rtx (test_label
));
6182 /* Value belongs to this node or to the left-hand subtree. */
6184 emit_cmp_and_jump_insns (index
, expand_expr (node
->low
, NULL_RTX
,
6186 GE
, NULL_RTX
, mode
, unsignedp
, 0,
6187 label_rtx (node
->code_label
));
6189 /* Handle the left-hand subtree. */
6190 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6192 /* If right node had to be handled later, do that now. */
6196 /* If the left-hand subtree fell through,
6197 don't let it fall into the right-hand subtree. */
6198 emit_jump_if_reachable (default_label
);
6200 expand_label (test_label
);
6201 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6205 else if (node
->right
!= 0 && node
->left
== 0)
6207 /* Deal with values to the left of this node,
6208 if they are possible. */
6209 if (!node_has_low_bound (node
, index_type
))
6211 emit_cmp_and_jump_insns (index
, expand_expr (node
->low
, NULL_RTX
,
6213 LT
, NULL_RTX
, mode
, unsignedp
, 0,
6217 /* Value belongs to this node or to the right-hand subtree. */
6219 emit_cmp_and_jump_insns (index
, expand_expr (node
->high
, NULL_RTX
,
6221 LE
, NULL_RTX
, mode
, unsignedp
, 0,
6222 label_rtx (node
->code_label
));
6224 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6227 else if (node
->right
== 0 && node
->left
!= 0)
6229 /* Deal with values to the right of this node,
6230 if they are possible. */
6231 if (!node_has_high_bound (node
, index_type
))
6233 emit_cmp_and_jump_insns (index
, expand_expr (node
->high
, NULL_RTX
,
6235 GT
, NULL_RTX
, mode
, unsignedp
, 0,
6239 /* Value belongs to this node or to the left-hand subtree. */
6241 emit_cmp_and_jump_insns (index
, expand_expr (node
->low
, NULL_RTX
,
6243 GE
, NULL_RTX
, mode
, unsignedp
, 0,
6244 label_rtx (node
->code_label
));
6246 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6251 /* Node has no children so we check low and high bounds to remove
6252 redundant tests. Only one of the bounds can exist,
6253 since otherwise this node is bounded--a case tested already. */
6255 if (!node_has_high_bound (node
, index_type
))
6257 emit_cmp_and_jump_insns (index
, expand_expr (node
->high
, NULL_RTX
,
6259 GT
, NULL_RTX
, mode
, unsignedp
, 0,
6263 if (!node_has_low_bound (node
, index_type
))
6265 emit_cmp_and_jump_insns (index
, expand_expr (node
->low
, NULL_RTX
,
6267 LT
, NULL_RTX
, mode
, unsignedp
, 0,
6271 emit_jump (label_rtx (node
->code_label
));
6276 /* These routines are used by the loop unrolling code. They copy BLOCK trees
6277 so that the debugging info will be correct for the unrolled loop. */
6279 /* Indexed by block number, contains a pointer to the N'th block node.
6281 Allocated by the call to identify_blocks, then released after the call
6282 to reorder_blocks in the function unroll_block_trees. */
6284 static tree
*block_vector
;
6287 find_loop_tree_blocks ()
6289 tree block
= DECL_INITIAL (current_function_decl
);
6291 block_vector
= identify_blocks (block
, get_insns ());
6295 unroll_block_trees ()
6297 tree block
= DECL_INITIAL (current_function_decl
);
6299 reorder_blocks (block_vector
, block
, get_insns ());
6301 /* Release any memory allocated by identify_blocks. */
6303 free (block_vector
);