1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
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. */
45 #include "insn-config.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 /* Functions and data structures for expanding case statements. */
68 /* Case label structure, used to hold info on labels within case
69 statements. We handle "range" labels; for a single-value label
70 as in C, the high and low limits are the same.
72 An AVL tree of case nodes is initially created, and later transformed
73 to a list linked via the RIGHT fields in the nodes. Nodes with
74 higher case values are later in the list.
76 Switch statements can be output in one of two forms. A branch table
77 is used if there are more than a few labels and the labels are dense
78 within the range between the smallest and largest case value. If a
79 branch table is used, no further manipulations are done with the case
82 The alternative to the use of a branch table is to generate a series
83 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
84 and PARENT fields to hold a binary tree. Initially the tree is
85 totally unbalanced, with everything on the right. We balance the tree
86 with nodes on the left having lower case values than the parent
87 and nodes on the right having higher values. We then output the tree
92 struct case_node
*left
; /* Left son in binary tree */
93 struct case_node
*right
; /* Right son in binary tree; also node chain */
94 struct case_node
*parent
; /* Parent of node in binary tree */
95 tree low
; /* Lowest index value for this label */
96 tree high
; /* Highest index value for this label */
97 tree code_label
; /* Label to jump to when node matches */
101 typedef struct case_node case_node
;
102 typedef struct case_node
*case_node_ptr
;
104 /* These are used by estimate_case_costs and balance_case_nodes. */
106 /* This must be a signed type, and non-ANSI compilers lack signed char. */
107 static short cost_table_
[129];
108 static int use_cost_table
;
109 static int cost_table_initialized
;
111 /* Special care is needed because we allow -1, but TREE_INT_CST_LOW
113 #define COST_TABLE(I) cost_table_[(unsigned HOST_WIDE_INT)((I) + 1)]
115 /* Stack of control and binding constructs we are currently inside.
117 These constructs begin when you call `expand_start_WHATEVER'
118 and end when you call `expand_end_WHATEVER'. This stack records
119 info about how the construct began that tells the end-function
120 what to do. It also may provide information about the construct
121 to alter the behavior of other constructs within the body.
122 For example, they may affect the behavior of C `break' and `continue'.
124 Each construct gets one `struct nesting' object.
125 All of these objects are chained through the `all' field.
126 `nesting_stack' points to the first object (innermost construct).
127 The position of an entry on `nesting_stack' is in its `depth' field.
129 Each type of construct has its own individual stack.
130 For example, loops have `loop_stack'. Each object points to the
131 next object of the same type through the `next' field.
133 Some constructs are visible to `break' exit-statements and others
134 are not. Which constructs are visible depends on the language.
135 Therefore, the data structure allows each construct to be visible
136 or not, according to the args given when the construct is started.
137 The construct is visible if the `exit_label' field is non-null.
138 In that case, the value should be a CODE_LABEL rtx. */
143 struct nesting
*next
;
148 /* For conds (if-then and if-then-else statements). */
151 /* Label for the end of the if construct.
152 There is none if EXITFLAG was not set
153 and no `else' has been seen yet. */
155 /* Label for the end of this alternative.
156 This may be the end of the if or the next else/elseif. */
162 /* Label at the top of the loop; place to loop back to. */
164 /* Label at the end of the whole construct. */
166 /* Label before a jump that branches to the end of the whole
167 construct. This is where destructors go if any. */
169 /* Label for `continue' statement to jump to;
170 this is in front of the stepper of the loop. */
173 /* For variable binding contours. */
176 /* Sequence number of this binding contour within the function,
177 in order of entry. */
178 int block_start_count
;
179 /* Nonzero => value to restore stack to on exit. */
181 /* The NOTE that starts this contour.
182 Used by expand_goto to check whether the destination
183 is within each contour or not. */
185 /* Innermost containing binding contour that has a stack level. */
186 struct nesting
*innermost_stack_block
;
187 /* List of cleanups to be run on exit from this contour.
188 This is a list of expressions to be evaluated.
189 The TREE_PURPOSE of each link is the ..._DECL node
190 which the cleanup pertains to. */
192 /* List of cleanup-lists of blocks containing this block,
193 as they were at the locus where this block appears.
194 There is an element for each containing block,
195 ordered innermost containing block first.
196 The tail of this list can be 0,
197 if all remaining elements would be empty lists.
198 The element's TREE_VALUE is the cleanup-list of that block,
199 which may be null. */
201 /* Chain of labels defined inside this binding contour.
202 For contours that have stack levels or cleanups. */
203 struct label_chain
*label_chain
;
204 /* Number of function calls seen, as of start of this block. */
205 int n_function_calls
;
206 /* Nonzero if this is associated with a EH region. */
207 int exception_region
;
208 /* The saved target_temp_slot_level from our outer block.
209 We may reset target_temp_slot_level to be the level of
210 this block, if that is done, target_temp_slot_level
211 reverts to the saved target_temp_slot_level at the very
213 int block_target_temp_slot_level
;
214 /* True if we are currently emitting insns in an area of
215 output code that is controlled by a conditional
216 expression. This is used by the cleanup handling code to
217 generate conditional cleanup actions. */
218 int conditional_code
;
219 /* A place to move the start of the exception region for any
220 of the conditional cleanups, must be at the end or after
221 the start of the last unconditional cleanup, and before any
222 conditional branch points. */
223 rtx last_unconditional_cleanup
;
224 /* When in a conditional context, this is the specific
225 cleanup list associated with last_unconditional_cleanup,
226 where we place the conditionalized cleanups. */
229 /* For switch (C) or case (Pascal) statements,
230 and also for dummies (see `expand_start_case_dummy'). */
233 /* The insn after which the case dispatch should finally
234 be emitted. Zero for a dummy. */
236 /* A list of case labels; it is first built as an AVL tree.
237 During expand_end_case, this is converted to a list, and may be
238 rearranged into a nearly balanced binary tree. */
239 struct case_node
*case_list
;
240 /* Label to jump to if no case matches. */
242 /* The expression to be dispatched on. */
244 /* Type that INDEX_EXPR should be converted to. */
246 /* Name of this kind of statement, for warnings. */
247 const char *printname
;
248 /* Used to save no_line_numbers till we see the first case label.
249 We set this to -1 when we see the first case label in this
251 int line_number_status
;
256 /* Allocate and return a new `struct nesting'. */
258 #define ALLOC_NESTING() \
259 (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
261 /* Pop the nesting stack element by element until we pop off
262 the element which is at the top of STACK.
263 Update all the other stacks, popping off elements from them
264 as we pop them from nesting_stack. */
266 #define POPSTACK(STACK) \
267 do { struct nesting *target = STACK; \
268 struct nesting *this; \
269 do { this = nesting_stack; \
270 if (loop_stack == this) \
271 loop_stack = loop_stack->next; \
272 if (cond_stack == this) \
273 cond_stack = cond_stack->next; \
274 if (block_stack == this) \
275 block_stack = block_stack->next; \
276 if (stack_block_stack == this) \
277 stack_block_stack = stack_block_stack->next; \
278 if (case_stack == this) \
279 case_stack = case_stack->next; \
280 nesting_depth = nesting_stack->depth - 1; \
281 nesting_stack = this->all; \
282 obstack_free (&stmt_obstack, this); } \
283 while (this != target); } while (0)
285 /* In some cases it is impossible to generate code for a forward goto
286 until the label definition is seen. This happens when it may be necessary
287 for the goto to reset the stack pointer: we don't yet know how to do that.
288 So expand_goto puts an entry on this fixup list.
289 Each time a binding contour that resets the stack is exited,
291 If the target label has now been defined, we can insert the proper code. */
295 /* Points to following fixup. */
296 struct goto_fixup
*next
;
297 /* Points to the insn before the jump insn.
298 If more code must be inserted, it goes after this insn. */
300 /* The LABEL_DECL that this jump is jumping to, or 0
301 for break, continue or return. */
303 /* The BLOCK for the place where this goto was found. */
305 /* The CODE_LABEL rtx that this is jumping to. */
307 /* Number of binding contours started in current function
308 before the label reference. */
309 int block_start_count
;
310 /* The outermost stack level that should be restored for this jump.
311 Each time a binding contour that resets the stack is exited,
312 if the target label is *not* yet defined, this slot is updated. */
314 /* List of lists of cleanup expressions to be run by this goto.
315 There is one element for each block that this goto is within.
316 The tail of this list can be 0,
317 if all remaining elements would be empty.
318 The TREE_VALUE contains the cleanup list of that block as of the
319 time this goto was seen.
320 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
321 tree cleanup_list_list
;
324 /* Within any binding contour that must restore a stack level,
325 all labels are recorded with a chain of these structures. */
329 /* Points to following fixup. */
330 struct label_chain
*next
;
336 /* Chain of all pending binding contours. */
337 struct nesting
*x_block_stack
;
339 /* If any new stacks are added here, add them to POPSTACKS too. */
341 /* Chain of all pending binding contours that restore stack levels
343 struct nesting
*x_stack_block_stack
;
345 /* Chain of all pending conditional statements. */
346 struct nesting
*x_cond_stack
;
348 /* Chain of all pending loops. */
349 struct nesting
*x_loop_stack
;
351 /* Chain of all pending case or switch statements. */
352 struct nesting
*x_case_stack
;
354 /* Separate chain including all of the above,
355 chained through the `all' field. */
356 struct nesting
*x_nesting_stack
;
358 /* Number of entries on nesting_stack now. */
361 /* Number of binding contours started so far in this function. */
362 int x_block_start_count
;
364 /* Each time we expand an expression-statement,
365 record the expr's type and its RTL value here. */
366 tree x_last_expr_type
;
367 rtx x_last_expr_value
;
369 /* Nonzero if within a ({...}) grouping, in which case we must
370 always compute a value for each expr-stmt in case it is the last one. */
371 int x_expr_stmts_for_value
;
373 /* Filename and line number of last line-number note,
374 whether we actually emitted it or not. */
375 const char *x_emit_filename
;
378 struct goto_fixup
*x_goto_fixup_chain
;
381 #define block_stack (cfun->stmt->x_block_stack)
382 #define stack_block_stack (cfun->stmt->x_stack_block_stack)
383 #define cond_stack (cfun->stmt->x_cond_stack)
384 #define loop_stack (cfun->stmt->x_loop_stack)
385 #define case_stack (cfun->stmt->x_case_stack)
386 #define nesting_stack (cfun->stmt->x_nesting_stack)
387 #define nesting_depth (cfun->stmt->x_nesting_depth)
388 #define current_block_start_count (cfun->stmt->x_block_start_count)
389 #define last_expr_type (cfun->stmt->x_last_expr_type)
390 #define last_expr_value (cfun->stmt->x_last_expr_value)
391 #define expr_stmts_for_value (cfun->stmt->x_expr_stmts_for_value)
392 #define emit_filename (cfun->stmt->x_emit_filename)
393 #define emit_lineno (cfun->stmt->x_emit_lineno)
394 #define goto_fixup_chain (cfun->stmt->x_goto_fixup_chain)
396 /* Non-zero if we are using EH to handle cleanus. */
397 static int using_eh_for_cleanups_p
= 0;
399 static int n_occurrences
PARAMS ((int, const char *));
400 static bool parse_input_constraint
PARAMS ((const char **, int, int, int,
401 int, const char * const *,
403 static void expand_goto_internal
PARAMS ((tree
, rtx
, rtx
));
404 static int expand_fixup
PARAMS ((tree
, rtx
, rtx
));
405 static rtx expand_nl_handler_label
PARAMS ((rtx
, rtx
));
406 static void expand_nl_goto_receiver
PARAMS ((void));
407 static void expand_nl_goto_receivers
PARAMS ((struct nesting
*));
408 static void fixup_gotos
PARAMS ((struct nesting
*, rtx
, tree
,
410 static bool check_operand_nalternatives
PARAMS ((tree
, tree
));
411 static bool check_unique_operand_names
PARAMS ((tree
, tree
));
412 static tree resolve_operand_names
PARAMS ((tree
, tree
, tree
,
414 static char *resolve_operand_name_1
PARAMS ((char *, tree
, tree
));
415 static void expand_null_return_1
PARAMS ((rtx
));
416 static void expand_value_return
PARAMS ((rtx
));
417 static int tail_recursion_args
PARAMS ((tree
, tree
));
418 static void expand_cleanups
PARAMS ((tree
, tree
, int, int));
419 static void check_seenlabel
PARAMS ((void));
420 static void do_jump_if_equal
PARAMS ((rtx
, rtx
, rtx
, int));
421 static int estimate_case_costs
PARAMS ((case_node_ptr
));
422 static void group_case_nodes
PARAMS ((case_node_ptr
));
423 static void balance_case_nodes
PARAMS ((case_node_ptr
*,
425 static int node_has_low_bound
PARAMS ((case_node_ptr
, tree
));
426 static int node_has_high_bound
PARAMS ((case_node_ptr
, tree
));
427 static int node_is_bounded
PARAMS ((case_node_ptr
, tree
));
428 static void emit_jump_if_reachable
PARAMS ((rtx
));
429 static void emit_case_nodes
PARAMS ((rtx
, case_node_ptr
, rtx
, tree
));
430 static struct case_node
*case_tree2list
PARAMS ((case_node
*, case_node
*));
431 static void mark_cond_nesting
PARAMS ((struct nesting
*));
432 static void mark_loop_nesting
PARAMS ((struct nesting
*));
433 static void mark_block_nesting
PARAMS ((struct nesting
*));
434 static void mark_case_nesting
PARAMS ((struct nesting
*));
435 static void mark_case_node
PARAMS ((struct case_node
*));
436 static void mark_goto_fixup
PARAMS ((struct goto_fixup
*));
437 static void free_case_nodes
PARAMS ((case_node_ptr
));
440 using_eh_for_cleanups ()
442 using_eh_for_cleanups_p
= 1;
445 /* Mark N (known to be a cond-nesting) for GC. */
448 mark_cond_nesting (n
)
453 ggc_mark_rtx (n
->exit_label
);
454 ggc_mark_rtx (n
->data
.cond
.endif_label
);
455 ggc_mark_rtx (n
->data
.cond
.next_label
);
461 /* Mark N (known to be a loop-nesting) for GC. */
464 mark_loop_nesting (n
)
470 ggc_mark_rtx (n
->exit_label
);
471 ggc_mark_rtx (n
->data
.loop
.start_label
);
472 ggc_mark_rtx (n
->data
.loop
.end_label
);
473 ggc_mark_rtx (n
->data
.loop
.alt_end_label
);
474 ggc_mark_rtx (n
->data
.loop
.continue_label
);
480 /* Mark N (known to be a block-nesting) for GC. */
483 mark_block_nesting (n
)
488 struct label_chain
*l
;
490 ggc_mark_rtx (n
->exit_label
);
491 ggc_mark_rtx (n
->data
.block
.stack_level
);
492 ggc_mark_rtx (n
->data
.block
.first_insn
);
493 ggc_mark_tree (n
->data
.block
.cleanups
);
494 ggc_mark_tree (n
->data
.block
.outer_cleanups
);
496 for (l
= n
->data
.block
.label_chain
; l
!= NULL
; l
= l
->next
)
499 ggc_mark_tree (l
->label
);
502 ggc_mark_rtx (n
->data
.block
.last_unconditional_cleanup
);
504 /* ??? cleanup_ptr never points outside the stack, does it? */
510 /* Mark N (known to be a case-nesting) for GC. */
513 mark_case_nesting (n
)
518 ggc_mark_rtx (n
->exit_label
);
519 ggc_mark_rtx (n
->data
.case_stmt
.start
);
521 ggc_mark_tree (n
->data
.case_stmt
.default_label
);
522 ggc_mark_tree (n
->data
.case_stmt
.index_expr
);
523 ggc_mark_tree (n
->data
.case_stmt
.nominal_type
);
525 mark_case_node (n
->data
.case_stmt
.case_list
);
538 ggc_mark_tree (c
->low
);
539 ggc_mark_tree (c
->high
);
540 ggc_mark_tree (c
->code_label
);
542 mark_case_node (c
->right
);
543 mark_case_node (c
->left
);
551 struct goto_fixup
*g
;
556 ggc_mark_rtx (g
->before_jump
);
557 ggc_mark_tree (g
->target
);
558 ggc_mark_tree (g
->context
);
559 ggc_mark_rtx (g
->target_rtl
);
560 ggc_mark_rtx (g
->stack_level
);
561 ggc_mark_tree (g
->cleanup_list_list
);
567 /* Clear out all parts of the state in F that can safely be discarded
568 after the function has been compiled, to let garbage collection
569 reclaim the memory. */
575 /* We're about to free the function obstack. If we hold pointers to
576 things allocated there, then we'll try to mark them when we do
577 GC. So, we clear them out here explicitly. */
587 struct stmt_status
*p
;
592 mark_block_nesting (p
->x_block_stack
);
593 mark_cond_nesting (p
->x_cond_stack
);
594 mark_loop_nesting (p
->x_loop_stack
);
595 mark_case_nesting (p
->x_case_stack
);
597 ggc_mark_tree (p
->x_last_expr_type
);
598 /* last_epxr_value is only valid if last_expr_type is nonzero. */
599 if (p
->x_last_expr_type
)
600 ggc_mark_rtx (p
->x_last_expr_value
);
602 mark_goto_fixup (p
->x_goto_fixup_chain
);
608 gcc_obstack_init (&stmt_obstack
);
612 init_stmt_for_function ()
614 cfun
->stmt
= (struct stmt_status
*) xmalloc (sizeof (struct stmt_status
));
616 /* We are not currently within any block, conditional, loop or case. */
618 stack_block_stack
= 0;
625 current_block_start_count
= 0;
627 /* No gotos have been expanded yet. */
628 goto_fixup_chain
= 0;
630 /* We are not processing a ({...}) grouping. */
631 expr_stmts_for_value
= 0;
633 last_expr_value
= NULL_RTX
;
636 /* Return nonzero if anything is pushed on the loop, condition, or case
641 return cond_stack
|| loop_stack
|| case_stack
;
644 /* Record the current file and line. Called from emit_line_note. */
646 set_file_and_line_for_stmt (file
, line
)
650 /* If we're outputting an inline function, and we add a line note,
651 there may be no CFUN->STMT information. So, there's no need to
655 emit_filename
= file
;
660 /* Emit a no-op instruction. */
667 last_insn
= get_last_insn ();
669 && (GET_CODE (last_insn
) == CODE_LABEL
670 || (GET_CODE (last_insn
) == NOTE
671 && prev_real_insn (last_insn
) == 0)))
672 emit_insn (gen_nop ());
675 /* Return the rtx-label that corresponds to a LABEL_DECL,
676 creating it if necessary. */
682 if (TREE_CODE (label
) != LABEL_DECL
)
685 if (!DECL_RTL_SET_P (label
))
686 SET_DECL_RTL (label
, gen_label_rtx ());
688 return DECL_RTL (label
);
692 /* Add an unconditional jump to LABEL as the next sequential instruction. */
698 do_pending_stack_adjust ();
699 emit_jump_insn (gen_jump (label
));
703 /* Emit code to jump to the address
704 specified by the pointer expression EXP. */
707 expand_computed_goto (exp
)
710 rtx x
= expand_expr (exp
, NULL_RTX
, VOIDmode
, 0);
712 #ifdef POINTERS_EXTEND_UNSIGNED
713 if (GET_MODE (x
) != Pmode
)
714 x
= convert_memory_address (Pmode
, x
);
718 do_pending_stack_adjust ();
719 emit_indirect_jump (x
);
721 current_function_has_computed_jump
= 1;
724 /* Handle goto statements and the labels that they can go to. */
726 /* Specify the location in the RTL code of a label LABEL,
727 which is a LABEL_DECL tree node.
729 This is used for the kind of label that the user can jump to with a
730 goto statement, and for alternatives of a switch or case statement.
731 RTL labels generated for loops and conditionals don't go through here;
732 they are generated directly at the RTL level, by other functions below.
734 Note that this has nothing to do with defining label *names*.
735 Languages vary in how they do that and what that even means. */
741 struct label_chain
*p
;
743 do_pending_stack_adjust ();
744 emit_label (label_rtx (label
));
745 if (DECL_NAME (label
))
746 LABEL_NAME (DECL_RTL (label
)) = IDENTIFIER_POINTER (DECL_NAME (label
));
748 if (stack_block_stack
!= 0)
750 p
= (struct label_chain
*) ggc_alloc (sizeof (struct label_chain
));
751 p
->next
= stack_block_stack
->data
.block
.label_chain
;
752 stack_block_stack
->data
.block
.label_chain
= p
;
757 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
758 from nested functions. */
761 declare_nonlocal_label (label
)
764 rtx slot
= assign_stack_local (Pmode
, GET_MODE_SIZE (Pmode
), 0);
766 nonlocal_labels
= tree_cons (NULL_TREE
, label
, nonlocal_labels
);
767 LABEL_PRESERVE_P (label_rtx (label
)) = 1;
768 if (nonlocal_goto_handler_slots
== 0)
770 emit_stack_save (SAVE_NONLOCAL
,
771 &nonlocal_goto_stack_level
,
772 PREV_INSN (tail_recursion_reentry
));
774 nonlocal_goto_handler_slots
775 = gen_rtx_EXPR_LIST (VOIDmode
, slot
, nonlocal_goto_handler_slots
);
778 /* Generate RTL code for a `goto' statement with target label LABEL.
779 LABEL should be a LABEL_DECL tree node that was or will later be
780 defined with `expand_label'. */
788 /* Check for a nonlocal goto to a containing function. */
789 context
= decl_function_context (label
);
790 if (context
!= 0 && context
!= current_function_decl
)
792 struct function
*p
= find_function_data (context
);
793 rtx label_ref
= gen_rtx_LABEL_REF (Pmode
, label_rtx (label
));
794 rtx handler_slot
, static_chain
, save_area
, insn
;
797 /* Find the corresponding handler slot for this label. */
798 handler_slot
= p
->x_nonlocal_goto_handler_slots
;
799 for (link
= p
->x_nonlocal_labels
; TREE_VALUE (link
) != label
;
800 link
= TREE_CHAIN (link
))
801 handler_slot
= XEXP (handler_slot
, 1);
802 handler_slot
= XEXP (handler_slot
, 0);
804 p
->has_nonlocal_label
= 1;
805 current_function_has_nonlocal_goto
= 1;
806 LABEL_REF_NONLOCAL_P (label_ref
) = 1;
808 /* Copy the rtl for the slots so that they won't be shared in
809 case the virtual stack vars register gets instantiated differently
810 in the parent than in the child. */
812 static_chain
= copy_to_reg (lookup_static_chain (label
));
814 /* Get addr of containing function's current nonlocal goto handler,
815 which will do any cleanups and then jump to the label. */
816 handler_slot
= copy_to_reg (replace_rtx (copy_rtx (handler_slot
),
817 virtual_stack_vars_rtx
,
820 /* Get addr of containing function's nonlocal save area. */
821 save_area
= p
->x_nonlocal_goto_stack_level
;
823 save_area
= replace_rtx (copy_rtx (save_area
),
824 virtual_stack_vars_rtx
, static_chain
);
826 #if HAVE_nonlocal_goto
827 if (HAVE_nonlocal_goto
)
828 emit_insn (gen_nonlocal_goto (static_chain
, handler_slot
,
829 save_area
, label_ref
));
833 /* Restore frame pointer for containing function.
834 This sets the actual hard register used for the frame pointer
835 to the location of the function's incoming static chain info.
836 The non-local goto handler will then adjust it to contain the
837 proper value and reload the argument pointer, if needed. */
838 emit_move_insn (hard_frame_pointer_rtx
, static_chain
);
839 emit_stack_restore (SAVE_NONLOCAL
, save_area
, NULL_RTX
);
841 /* USE of hard_frame_pointer_rtx added for consistency;
842 not clear if really needed. */
843 emit_insn (gen_rtx_USE (VOIDmode
, hard_frame_pointer_rtx
));
844 emit_insn (gen_rtx_USE (VOIDmode
, stack_pointer_rtx
));
845 emit_indirect_jump (handler_slot
);
848 /* Search backwards to the jump insn and mark it as a
850 for (insn
= get_last_insn (); insn
; insn
= PREV_INSN (insn
))
852 if (GET_CODE (insn
) == JUMP_INSN
)
854 REG_NOTES (insn
) = alloc_EXPR_LIST (REG_NON_LOCAL_GOTO
,
855 const0_rtx
, REG_NOTES (insn
));
858 else if (GET_CODE (insn
) == CALL_INSN
)
863 expand_goto_internal (label
, label_rtx (label
), NULL_RTX
);
866 /* Generate RTL code for a `goto' statement with target label BODY.
867 LABEL should be a LABEL_REF.
868 LAST_INSN, if non-0, is the rtx we should consider as the last
869 insn emitted (for the purposes of cleaning up a return). */
872 expand_goto_internal (body
, label
, last_insn
)
877 struct nesting
*block
;
880 if (GET_CODE (label
) != CODE_LABEL
)
883 /* If label has already been defined, we can tell now
884 whether and how we must alter the stack level. */
886 if (PREV_INSN (label
) != 0)
888 /* Find the innermost pending block that contains the label.
889 (Check containment by comparing insn-uids.)
890 Then restore the outermost stack level within that block,
891 and do cleanups of all blocks contained in it. */
892 for (block
= block_stack
; block
; block
= block
->next
)
894 if (INSN_UID (block
->data
.block
.first_insn
) < INSN_UID (label
))
896 if (block
->data
.block
.stack_level
!= 0)
897 stack_level
= block
->data
.block
.stack_level
;
898 /* Execute the cleanups for blocks we are exiting. */
899 if (block
->data
.block
.cleanups
!= 0)
901 expand_cleanups (block
->data
.block
.cleanups
, NULL_TREE
, 1, 1);
902 do_pending_stack_adjust ();
908 /* Ensure stack adjust isn't done by emit_jump, as this
909 would clobber the stack pointer. This one should be
910 deleted as dead by flow. */
911 clear_pending_stack_adjust ();
912 do_pending_stack_adjust ();
914 /* Don't do this adjust if it's to the end label and this function
915 is to return with a depressed stack pointer. */
916 if (label
== return_label
917 && (((TREE_CODE (TREE_TYPE (current_function_decl
))
919 && (TYPE_RETURNS_STACK_DEPRESSED
920 (TREE_TYPE (current_function_decl
))))))
923 emit_stack_restore (SAVE_BLOCK
, stack_level
, NULL_RTX
);
926 if (body
!= 0 && DECL_TOO_LATE (body
))
927 error ("jump to `%s' invalidly jumps into binding contour",
928 IDENTIFIER_POINTER (DECL_NAME (body
)));
930 /* Label not yet defined: may need to put this goto
931 on the fixup list. */
932 else if (! expand_fixup (body
, label
, last_insn
))
934 /* No fixup needed. Record that the label is the target
935 of at least one goto that has no fixup. */
937 TREE_ADDRESSABLE (body
) = 1;
943 /* Generate if necessary a fixup for a goto
944 whose target label in tree structure (if any) is TREE_LABEL
945 and whose target in rtl is RTL_LABEL.
947 If LAST_INSN is nonzero, we pretend that the jump appears
948 after insn LAST_INSN instead of at the current point in the insn stream.
950 The fixup will be used later to insert insns just before the goto.
951 Those insns will restore the stack level as appropriate for the
952 target label, and will (in the case of C++) also invoke any object
953 destructors which have to be invoked when we exit the scopes which
954 are exited by the goto.
956 Value is nonzero if a fixup is made. */
959 expand_fixup (tree_label
, rtl_label
, last_insn
)
964 struct nesting
*block
, *end_block
;
966 /* See if we can recognize which block the label will be output in.
967 This is possible in some very common cases.
968 If we succeed, set END_BLOCK to that block.
969 Otherwise, set it to 0. */
972 && (rtl_label
== cond_stack
->data
.cond
.endif_label
973 || rtl_label
== cond_stack
->data
.cond
.next_label
))
974 end_block
= cond_stack
;
975 /* If we are in a loop, recognize certain labels which
976 are likely targets. This reduces the number of fixups
977 we need to create. */
979 && (rtl_label
== loop_stack
->data
.loop
.start_label
980 || rtl_label
== loop_stack
->data
.loop
.end_label
981 || rtl_label
== loop_stack
->data
.loop
.continue_label
))
982 end_block
= loop_stack
;
986 /* Now set END_BLOCK to the binding level to which we will return. */
990 struct nesting
*next_block
= end_block
->all
;
993 /* First see if the END_BLOCK is inside the innermost binding level.
994 If so, then no cleanups or stack levels are relevant. */
995 while (next_block
&& next_block
!= block
)
996 next_block
= next_block
->all
;
1001 /* Otherwise, set END_BLOCK to the innermost binding level
1002 which is outside the relevant control-structure nesting. */
1003 next_block
= block_stack
->next
;
1004 for (block
= block_stack
; block
!= end_block
; block
= block
->all
)
1005 if (block
== next_block
)
1006 next_block
= next_block
->next
;
1007 end_block
= next_block
;
1010 /* Does any containing block have a stack level or cleanups?
1011 If not, no fixup is needed, and that is the normal case
1012 (the only case, for standard C). */
1013 for (block
= block_stack
; block
!= end_block
; block
= block
->next
)
1014 if (block
->data
.block
.stack_level
!= 0
1015 || block
->data
.block
.cleanups
!= 0)
1018 if (block
!= end_block
)
1020 /* Ok, a fixup is needed. Add a fixup to the list of such. */
1021 struct goto_fixup
*fixup
1022 = (struct goto_fixup
*) ggc_alloc (sizeof (struct goto_fixup
));
1023 /* In case an old stack level is restored, make sure that comes
1024 after any pending stack adjust. */
1025 /* ?? If the fixup isn't to come at the present position,
1026 doing the stack adjust here isn't useful. Doing it with our
1027 settings at that location isn't useful either. Let's hope
1030 do_pending_stack_adjust ();
1031 fixup
->target
= tree_label
;
1032 fixup
->target_rtl
= rtl_label
;
1034 /* Create a BLOCK node and a corresponding matched set of
1035 NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes at
1036 this point. The notes will encapsulate any and all fixup
1037 code which we might later insert at this point in the insn
1038 stream. Also, the BLOCK node will be the parent (i.e. the
1039 `SUPERBLOCK') of any other BLOCK nodes which we might create
1040 later on when we are expanding the fixup code.
1042 Note that optimization passes (including expand_end_loop)
1043 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
1044 as a placeholder. */
1047 rtx original_before_jump
1048 = last_insn
? last_insn
: get_last_insn ();
1053 block
= make_node (BLOCK
);
1054 TREE_USED (block
) = 1;
1056 if (!cfun
->x_whole_function_mode_p
)
1057 insert_block (block
);
1061 = BLOCK_CHAIN (DECL_INITIAL (current_function_decl
));
1062 BLOCK_CHAIN (DECL_INITIAL (current_function_decl
))
1067 start
= emit_note (NULL
, NOTE_INSN_BLOCK_BEG
);
1068 if (cfun
->x_whole_function_mode_p
)
1069 NOTE_BLOCK (start
) = block
;
1070 fixup
->before_jump
= emit_note (NULL
, NOTE_INSN_DELETED
);
1071 end
= emit_note (NULL
, NOTE_INSN_BLOCK_END
);
1072 if (cfun
->x_whole_function_mode_p
)
1073 NOTE_BLOCK (end
) = block
;
1074 fixup
->context
= block
;
1076 emit_insns_after (start
, original_before_jump
);
1079 fixup
->block_start_count
= current_block_start_count
;
1080 fixup
->stack_level
= 0;
1081 fixup
->cleanup_list_list
1082 = ((block
->data
.block
.outer_cleanups
1083 || block
->data
.block
.cleanups
)
1084 ? tree_cons (NULL_TREE
, block
->data
.block
.cleanups
,
1085 block
->data
.block
.outer_cleanups
)
1087 fixup
->next
= goto_fixup_chain
;
1088 goto_fixup_chain
= fixup
;
1094 /* Expand any needed fixups in the outputmost binding level of the
1095 function. FIRST_INSN is the first insn in the function. */
1098 expand_fixups (first_insn
)
1101 fixup_gotos (NULL
, NULL_RTX
, NULL_TREE
, first_insn
, 0);
1104 /* When exiting a binding contour, process all pending gotos requiring fixups.
1105 THISBLOCK is the structure that describes the block being exited.
1106 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1107 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1108 FIRST_INSN is the insn that began this contour.
1110 Gotos that jump out of this contour must restore the
1111 stack level and do the cleanups before actually jumping.
1113 DONT_JUMP_IN nonzero means report error there is a jump into this
1114 contour from before the beginning of the contour.
1115 This is also done if STACK_LEVEL is nonzero. */
1118 fixup_gotos (thisblock
, stack_level
, cleanup_list
, first_insn
, dont_jump_in
)
1119 struct nesting
*thisblock
;
1125 struct goto_fixup
*f
, *prev
;
1127 /* F is the fixup we are considering; PREV is the previous one. */
1128 /* We run this loop in two passes so that cleanups of exited blocks
1129 are run first, and blocks that are exited are marked so
1132 for (prev
= 0, f
= goto_fixup_chain
; f
; prev
= f
, f
= f
->next
)
1134 /* Test for a fixup that is inactive because it is already handled. */
1135 if (f
->before_jump
== 0)
1137 /* Delete inactive fixup from the chain, if that is easy to do. */
1139 prev
->next
= f
->next
;
1141 /* Has this fixup's target label been defined?
1142 If so, we can finalize it. */
1143 else if (PREV_INSN (f
->target_rtl
) != 0)
1147 /* If this fixup jumped into this contour from before the beginning
1148 of this contour, report an error. This code used to use
1149 the first non-label insn after f->target_rtl, but that's
1150 wrong since such can be added, by things like put_var_into_stack
1151 and have INSN_UIDs that are out of the range of the block. */
1152 /* ??? Bug: this does not detect jumping in through intermediate
1153 blocks that have stack levels or cleanups.
1154 It detects only a problem with the innermost block
1155 around the label. */
1157 && (dont_jump_in
|| stack_level
|| cleanup_list
)
1158 && INSN_UID (first_insn
) < INSN_UID (f
->target_rtl
)
1159 && INSN_UID (first_insn
) > INSN_UID (f
->before_jump
)
1160 && ! DECL_ERROR_ISSUED (f
->target
))
1162 error_with_decl (f
->target
,
1163 "label `%s' used before containing binding contour");
1164 /* Prevent multiple errors for one label. */
1165 DECL_ERROR_ISSUED (f
->target
) = 1;
1168 /* We will expand the cleanups into a sequence of their own and
1169 then later on we will attach this new sequence to the insn
1170 stream just ahead of the actual jump insn. */
1174 /* Temporarily restore the lexical context where we will
1175 logically be inserting the fixup code. We do this for the
1176 sake of getting the debugging information right. */
1179 set_block (f
->context
);
1181 /* Expand the cleanups for blocks this jump exits. */
1182 if (f
->cleanup_list_list
)
1185 for (lists
= f
->cleanup_list_list
; lists
; lists
= TREE_CHAIN (lists
))
1186 /* Marked elements correspond to blocks that have been closed.
1187 Do their cleanups. */
1188 if (TREE_ADDRESSABLE (lists
)
1189 && TREE_VALUE (lists
) != 0)
1191 expand_cleanups (TREE_VALUE (lists
), NULL_TREE
, 1, 1);
1192 /* Pop any pushes done in the cleanups,
1193 in case function is about to return. */
1194 do_pending_stack_adjust ();
1198 /* Restore stack level for the biggest contour that this
1199 jump jumps out of. */
1201 && ! (f
->target_rtl
== return_label
1202 && ((TREE_CODE (TREE_TYPE (current_function_decl
))
1204 && (TYPE_RETURNS_STACK_DEPRESSED
1205 (TREE_TYPE (current_function_decl
))))))
1206 emit_stack_restore (SAVE_BLOCK
, f
->stack_level
, f
->before_jump
);
1208 /* Finish up the sequence containing the insns which implement the
1209 necessary cleanups, and then attach that whole sequence to the
1210 insn stream just ahead of the actual jump insn. Attaching it
1211 at that point insures that any cleanups which are in fact
1212 implicit C++ object destructions (which must be executed upon
1213 leaving the block) appear (to the debugger) to be taking place
1214 in an area of the generated code where the object(s) being
1215 destructed are still "in scope". */
1217 cleanup_insns
= get_insns ();
1221 emit_insns_after (cleanup_insns
, f
->before_jump
);
1227 /* For any still-undefined labels, do the cleanups for this block now.
1228 We must do this now since items in the cleanup list may go out
1229 of scope when the block ends. */
1230 for (prev
= 0, f
= goto_fixup_chain
; f
; prev
= f
, f
= f
->next
)
1231 if (f
->before_jump
!= 0
1232 && PREV_INSN (f
->target_rtl
) == 0
1233 /* Label has still not appeared. If we are exiting a block with
1234 a stack level to restore, that started before the fixup,
1235 mark this stack level as needing restoration
1236 when the fixup is later finalized. */
1238 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1239 means the label is undefined. That's erroneous, but possible. */
1240 && (thisblock
->data
.block
.block_start_count
1241 <= f
->block_start_count
))
1243 tree lists
= f
->cleanup_list_list
;
1246 for (; lists
; lists
= TREE_CHAIN (lists
))
1247 /* If the following elt. corresponds to our containing block
1248 then the elt. must be for this block. */
1249 if (TREE_CHAIN (lists
) == thisblock
->data
.block
.outer_cleanups
)
1253 set_block (f
->context
);
1254 expand_cleanups (TREE_VALUE (lists
), NULL_TREE
, 1, 1);
1255 do_pending_stack_adjust ();
1256 cleanup_insns
= get_insns ();
1259 if (cleanup_insns
!= 0)
1261 = emit_insns_after (cleanup_insns
, f
->before_jump
);
1263 f
->cleanup_list_list
= TREE_CHAIN (lists
);
1267 f
->stack_level
= stack_level
;
1271 /* Return the number of times character C occurs in string S. */
1273 n_occurrences (c
, s
)
1283 /* Generate RTL for an asm statement (explicit assembler code).
1284 BODY is a STRING_CST node containing the assembler code text,
1285 or an ADDR_EXPR containing a STRING_CST. */
1291 if (TREE_CODE (body
) == ADDR_EXPR
)
1292 body
= TREE_OPERAND (body
, 0);
1294 emit_insn (gen_rtx_ASM_INPUT (VOIDmode
,
1295 TREE_STRING_POINTER (body
)));
1299 /* Parse the output constraint pointed to by *CONSTRAINT_P. It is the
1300 OPERAND_NUMth output operand, indexed from zero. There are NINPUTS
1301 inputs and NOUTPUTS outputs to this extended-asm. Upon return,
1302 *ALLOWS_MEM will be TRUE iff the constraint allows the use of a
1303 memory operand. Similarly, *ALLOWS_REG will be TRUE iff the
1304 constraint allows the use of a register operand. And, *IS_INOUT
1305 will be true if the operand is read-write, i.e., if it is used as
1306 an input as well as an output. If *CONSTRAINT_P is not in
1307 canonical form, it will be made canonical. (Note that `+' will be
1308 rpelaced with `=' as part of this process.)
1310 Returns TRUE if all went well; FALSE if an error occurred. */
1313 parse_output_constraint (constraint_p
, operand_num
, ninputs
, noutputs
,
1314 allows_mem
, allows_reg
, is_inout
)
1315 const char **constraint_p
;
1323 const char *constraint
= *constraint_p
;
1326 /* Assume the constraint doesn't allow the use of either a register
1328 *allows_mem
= false;
1329 *allows_reg
= false;
1331 /* Allow the `=' or `+' to not be at the beginning of the string,
1332 since it wasn't explicitly documented that way, and there is a
1333 large body of code that puts it last. Swap the character to
1334 the front, so as not to uglify any place else. */
1335 p
= strchr (constraint
, '=');
1337 p
= strchr (constraint
, '+');
1339 /* If the string doesn't contain an `=', issue an error
1343 error ("output operand constraint lacks `='");
1347 /* If the constraint begins with `+', then the operand is both read
1348 from and written to. */
1349 *is_inout
= (*p
== '+');
1351 /* Canonicalize the output constraint so that it begins with `='. */
1352 if (p
!= constraint
|| is_inout
)
1355 size_t c_len
= strlen (constraint
);
1357 if (p
!= constraint
)
1358 warning ("output constraint `%c' for operand %d is not at the beginning",
1361 /* Make a copy of the constraint. */
1362 buf
= alloca (c_len
+ 1);
1363 strcpy (buf
, constraint
);
1364 /* Swap the first character and the `=' or `+'. */
1365 buf
[p
- constraint
] = buf
[0];
1366 /* Make sure the first character is an `='. (Until we do this,
1367 it might be a `+'.) */
1369 /* Replace the constraint with the canonicalized string. */
1370 *constraint_p
= ggc_alloc_string (buf
, c_len
);
1371 constraint
= *constraint_p
;
1374 /* Loop through the constraint string. */
1375 for (p
= constraint
+ 1; *p
; ++p
)
1380 error ("operand constraint contains incorrectly positioned '+' or '='");
1384 if (operand_num
+ 1 == ninputs
+ noutputs
)
1386 error ("`%%' constraint used with last operand");
1391 case 'V': case 'm': case 'o':
1395 case '?': case '!': case '*': case '&': case '#':
1396 case 'E': case 'F': case 'G': case 'H':
1397 case 's': case 'i': case 'n':
1398 case 'I': case 'J': case 'K': case 'L': case 'M':
1399 case 'N': case 'O': case 'P': case ',':
1402 case '0': case '1': case '2': case '3': case '4':
1403 case '5': case '6': case '7': case '8': case '9':
1405 error ("matching constraint not valid in output operand");
1409 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1410 excepting those that expand_call created. So match memory
1427 if (REG_CLASS_FROM_LETTER (*p
) != NO_REGS
)
1429 #ifdef EXTRA_CONSTRAINT
1432 /* Otherwise we can't assume anything about the nature of
1433 the constraint except that it isn't purely registers.
1434 Treat it like "g" and hope for the best. */
1445 /* Similar, but for input constraints. */
1448 parse_input_constraint (constraint_p
, input_num
, ninputs
, noutputs
, ninout
,
1449 constraints
, allows_mem
, allows_reg
)
1450 const char **constraint_p
;
1455 const char * const * constraints
;
1459 const char *constraint
= *constraint_p
;
1460 const char *orig_constraint
= constraint
;
1461 size_t c_len
= strlen (constraint
);
1464 /* Assume the constraint doesn't allow the use of either
1465 a register or memory. */
1466 *allows_mem
= false;
1467 *allows_reg
= false;
1469 /* Make sure constraint has neither `=', `+', nor '&'. */
1471 for (j
= 0; j
< c_len
; j
++)
1472 switch (constraint
[j
])
1474 case '+': case '=': case '&':
1475 if (constraint
== orig_constraint
)
1477 error ("input operand constraint contains `%c'", constraint
[j
]);
1483 if (constraint
== orig_constraint
1484 && input_num
+ 1 == ninputs
- ninout
)
1486 error ("`%%' constraint used with last operand");
1491 case 'V': case 'm': case 'o':
1496 case '?': case '!': case '*': case '#':
1497 case 'E': case 'F': case 'G': case 'H':
1498 case 's': case 'i': case 'n':
1499 case 'I': case 'J': case 'K': case 'L': case 'M':
1500 case 'N': case 'O': case 'P': case ',':
1503 /* Whether or not a numeric constraint allows a register is
1504 decided by the matching constraint, and so there is no need
1505 to do anything special with them. We must handle them in
1506 the default case, so that we don't unnecessarily force
1507 operands to memory. */
1508 case '0': case '1': case '2': case '3': case '4':
1509 case '5': case '6': case '7': case '8': case '9':
1512 unsigned long match
;
1514 match
= strtoul (constraint
+ j
, &end
, 10);
1515 if (match
>= (unsigned long) noutputs
)
1517 error ("matching constraint references invalid operand number");
1521 /* Try and find the real constraint for this dup. Only do this
1522 if the matching constraint is the only alternative. */
1524 && (j
== 0 || (j
== 1 && constraint
[0] == '%')))
1526 constraint
= constraints
[match
];
1527 *constraint_p
= constraint
;
1528 c_len
= strlen (constraint
);
1533 j
= end
- constraint
;
1547 if (! ISALPHA (constraint
[j
]))
1549 error ("invalid punctuation `%c' in constraint", constraint
[j
]);
1552 if (REG_CLASS_FROM_LETTER (constraint
[j
]) != NO_REGS
)
1554 #ifdef EXTRA_CONSTRAINT
1557 /* Otherwise we can't assume anything about the nature of
1558 the constraint except that it isn't purely registers.
1559 Treat it like "g" and hope for the best. */
1570 /* Generate RTL for an asm statement with arguments.
1571 STRING is the instruction template.
1572 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1573 Each output or input has an expression in the TREE_VALUE and
1574 and a tree list in TREE_PURPOSE which in turn contains a constraint
1575 name in TREE_VALUE (or NULL_TREE) and a constraint string
1577 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1578 that is clobbered by this insn.
1580 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1581 Some elements of OUTPUTS may be replaced with trees representing temporary
1582 values. The caller should copy those temporary values to the originally
1585 VOL nonzero means the insn is volatile; don't optimize it. */
1588 expand_asm_operands (string
, outputs
, inputs
, clobbers
, vol
, filename
, line
)
1589 tree string
, outputs
, inputs
, clobbers
;
1591 const char *filename
;
1594 rtvec argvec
, constraintvec
;
1596 int ninputs
= list_length (inputs
);
1597 int noutputs
= list_length (outputs
);
1602 /* Vector of RTX's of evaluated output operands. */
1603 rtx
*output_rtx
= (rtx
*) alloca (noutputs
* sizeof (rtx
));
1604 int *inout_opnum
= (int *) alloca (noutputs
* sizeof (int));
1605 rtx
*real_output_rtx
= (rtx
*) alloca (noutputs
* sizeof (rtx
));
1606 enum machine_mode
*inout_mode
1607 = (enum machine_mode
*) alloca (noutputs
* sizeof (enum machine_mode
));
1608 const char **constraints
1609 = (const char **) alloca ((noutputs
+ ninputs
) * sizeof (const char *));
1610 /* The insn we have emitted. */
1612 int old_generating_concat_p
= generating_concat_p
;
1614 /* An ASM with no outputs needs to be treated as volatile, for now. */
1618 if (! check_operand_nalternatives (outputs
, inputs
))
1621 if (! check_unique_operand_names (outputs
, inputs
))
1624 string
= resolve_operand_names (string
, outputs
, inputs
, constraints
);
1626 #ifdef MD_ASM_CLOBBERS
1627 /* Sometimes we wish to automatically clobber registers across an asm.
1628 Case in point is when the i386 backend moved from cc0 to a hard reg --
1629 maintaining source-level compatibility means automatically clobbering
1630 the flags register. */
1631 MD_ASM_CLOBBERS (clobbers
);
1634 /* Count the number of meaningful clobbered registers, ignoring what
1635 we would ignore later. */
1637 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
))
1639 const char *regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
1641 i
= decode_reg_name (regname
);
1642 if (i
>= 0 || i
== -4)
1645 error ("unknown register name `%s' in `asm'", regname
);
1650 /* First pass over inputs and outputs checks validity and sets
1651 mark_addressable if needed. */
1654 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1656 tree val
= TREE_VALUE (tail
);
1657 tree type
= TREE_TYPE (val
);
1658 const char *constraint
;
1663 /* If there's an erroneous arg, emit no insn. */
1664 if (type
== error_mark_node
)
1667 /* Try to parse the output constraint. If that fails, there's
1668 no point in going further. */
1669 constraint
= constraints
[i
];
1670 if (!parse_output_constraint (&constraint
, i
, ninputs
, noutputs
,
1671 &allows_mem
, &allows_reg
, &is_inout
))
1678 && GET_CODE (DECL_RTL (val
)) == REG
1679 && GET_MODE (DECL_RTL (val
)) != TYPE_MODE (type
))))
1680 mark_addressable (val
);
1687 if (ninputs
+ noutputs
> MAX_RECOG_OPERANDS
)
1689 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS
);
1693 for (i
= 0, tail
= inputs
; tail
; i
++, tail
= TREE_CHAIN (tail
))
1695 bool allows_reg
, allows_mem
;
1696 const char *constraint
;
1698 /* If there's an erroneous arg, emit no insn, because the ASM_INPUT
1699 would get VOIDmode and that could cause a crash in reload. */
1700 if (TREE_TYPE (TREE_VALUE (tail
)) == error_mark_node
)
1703 constraint
= constraints
[i
+ noutputs
];
1704 if (! parse_input_constraint (&constraint
, i
, ninputs
, noutputs
, ninout
,
1705 constraints
, &allows_mem
, &allows_reg
))
1708 if (! allows_reg
&& allows_mem
)
1709 mark_addressable (TREE_VALUE (tail
));
1712 /* Second pass evaluates arguments. */
1715 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1717 tree val
= TREE_VALUE (tail
);
1718 tree type
= TREE_TYPE (val
);
1723 if (!parse_output_constraint (&constraints
[i
], i
, ninputs
,
1724 noutputs
, &allows_mem
, &allows_reg
,
1728 /* If an output operand is not a decl or indirect ref and our constraint
1729 allows a register, make a temporary to act as an intermediate.
1730 Make the asm insn write into that, then our caller will copy it to
1731 the real output operand. Likewise for promoted variables. */
1733 generating_concat_p
= 0;
1735 real_output_rtx
[i
] = NULL_RTX
;
1736 if ((TREE_CODE (val
) == INDIRECT_REF
1739 && (allows_mem
|| GET_CODE (DECL_RTL (val
)) == REG
)
1740 && ! (GET_CODE (DECL_RTL (val
)) == REG
1741 && GET_MODE (DECL_RTL (val
)) != TYPE_MODE (type
)))
1745 output_rtx
[i
] = expand_expr (val
, NULL_RTX
, VOIDmode
, EXPAND_WRITE
);
1747 if (! allows_reg
&& GET_CODE (output_rtx
[i
]) != MEM
)
1748 error ("output number %d not directly addressable", i
);
1749 if ((! allows_mem
&& GET_CODE (output_rtx
[i
]) == MEM
)
1750 || GET_CODE (output_rtx
[i
]) == CONCAT
)
1752 real_output_rtx
[i
] = protect_from_queue (output_rtx
[i
], 1);
1753 output_rtx
[i
] = gen_reg_rtx (GET_MODE (output_rtx
[i
]));
1755 emit_move_insn (output_rtx
[i
], real_output_rtx
[i
]);
1760 output_rtx
[i
] = assign_temp (type
, 0, 0, 1);
1761 TREE_VALUE (tail
) = make_tree (type
, output_rtx
[i
]);
1764 generating_concat_p
= old_generating_concat_p
;
1768 inout_mode
[ninout
] = TYPE_MODE (type
);
1769 inout_opnum
[ninout
++] = i
;
1773 /* Make vectors for the expression-rtx, constraint strings,
1774 and named operands. */
1776 argvec
= rtvec_alloc (ninputs
);
1777 constraintvec
= rtvec_alloc (ninputs
);
1779 body
= gen_rtx_ASM_OPERANDS ((noutputs
== 0 ? VOIDmode
1780 : GET_MODE (output_rtx
[0])),
1781 TREE_STRING_POINTER (string
),
1782 empty_string
, 0, argvec
, constraintvec
,
1785 MEM_VOLATILE_P (body
) = vol
;
1787 /* Eval the inputs and put them into ARGVEC.
1788 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1790 for (i
= 0, tail
= inputs
; tail
; tail
= TREE_CHAIN (tail
), ++i
)
1792 bool allows_reg
, allows_mem
;
1793 const char *constraint
;
1797 constraint
= constraints
[i
+ noutputs
];
1798 if (! parse_input_constraint (&constraint
, i
, ninputs
, noutputs
, ninout
,
1799 constraints
, &allows_mem
, &allows_reg
))
1802 generating_concat_p
= 0;
1804 val
= TREE_VALUE (tail
);
1805 type
= TREE_TYPE (val
);
1806 op
= expand_expr (val
, NULL_RTX
, VOIDmode
, 0);
1808 /* Never pass a CONCAT to an ASM. */
1809 if (GET_CODE (op
) == CONCAT
)
1810 op
= force_reg (GET_MODE (op
), op
);
1812 if (asm_operand_ok (op
, constraint
) <= 0)
1815 op
= force_reg (TYPE_MODE (type
), op
);
1816 else if (!allows_mem
)
1817 warning ("asm operand %d probably doesn't match constraints",
1819 else if (CONSTANT_P (op
))
1820 op
= force_const_mem (TYPE_MODE (type
), op
);
1821 else if (GET_CODE (op
) == REG
1822 || GET_CODE (op
) == SUBREG
1823 || GET_CODE (op
) == ADDRESSOF
1824 || GET_CODE (op
) == CONCAT
)
1826 tree qual_type
= build_qualified_type (type
,
1828 | TYPE_QUAL_CONST
));
1829 rtx memloc
= assign_temp (qual_type
, 1, 1, 1);
1831 emit_move_insn (memloc
, op
);
1835 else if (GET_CODE (op
) == MEM
&& MEM_VOLATILE_P (op
))
1837 /* We won't recognize volatile memory as available a
1838 memory_operand at this point. Ignore it. */
1840 else if (queued_subexp_p (op
))
1843 /* ??? Leave this only until we have experience with what
1844 happens in combine and elsewhere when constraints are
1846 warning ("asm operand %d probably doesn't match constraints",
1850 generating_concat_p
= old_generating_concat_p
;
1851 ASM_OPERANDS_INPUT (body
, i
) = op
;
1853 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body
, i
)
1854 = gen_rtx_ASM_INPUT (TYPE_MODE (type
), constraints
[i
+ noutputs
]);
1857 /* Protect all the operands from the queue now that they have all been
1860 generating_concat_p
= 0;
1862 for (i
= 0; i
< ninputs
- ninout
; i
++)
1863 ASM_OPERANDS_INPUT (body
, i
)
1864 = protect_from_queue (ASM_OPERANDS_INPUT (body
, i
), 0);
1866 for (i
= 0; i
< noutputs
; i
++)
1867 output_rtx
[i
] = protect_from_queue (output_rtx
[i
], 1);
1869 /* For in-out operands, copy output rtx to input rtx. */
1870 for (i
= 0; i
< ninout
; i
++)
1872 int j
= inout_opnum
[i
];
1875 ASM_OPERANDS_INPUT (body
, ninputs
- ninout
+ i
)
1878 sprintf (buffer
, "%d", j
);
1879 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body
, ninputs
- ninout
+ i
)
1880 = gen_rtx_ASM_INPUT (inout_mode
[i
], ggc_alloc_string (buffer
, -1));
1883 generating_concat_p
= old_generating_concat_p
;
1885 /* Now, for each output, construct an rtx
1886 (set OUTPUT (asm_operands INSN OUTPUTCONSTRAINT OUTPUTNUMBER
1887 ARGVEC CONSTRAINTS OPNAMES))
1888 If there is more than one, put them inside a PARALLEL. */
1890 if (noutputs
== 1 && nclobbers
== 0)
1892 ASM_OPERANDS_OUTPUT_CONSTRAINT (body
) = constraints
[0];
1893 insn
= emit_insn (gen_rtx_SET (VOIDmode
, output_rtx
[0], body
));
1896 else if (noutputs
== 0 && nclobbers
== 0)
1898 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1899 insn
= emit_insn (body
);
1910 body
= gen_rtx_PARALLEL (VOIDmode
, rtvec_alloc (num
+ nclobbers
));
1912 /* For each output operand, store a SET. */
1913 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1915 XVECEXP (body
, 0, i
)
1916 = gen_rtx_SET (VOIDmode
,
1918 gen_rtx_ASM_OPERANDS
1919 (GET_MODE (output_rtx
[i
]),
1920 TREE_STRING_POINTER (string
),
1921 constraints
[i
], i
, argvec
, constraintvec
,
1924 MEM_VOLATILE_P (SET_SRC (XVECEXP (body
, 0, i
))) = vol
;
1927 /* If there are no outputs (but there are some clobbers)
1928 store the bare ASM_OPERANDS into the PARALLEL. */
1931 XVECEXP (body
, 0, i
++) = obody
;
1933 /* Store (clobber REG) for each clobbered register specified. */
1935 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
))
1937 const char *regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
1938 int j
= decode_reg_name (regname
);
1942 if (j
== -3) /* `cc', which is not a register */
1945 if (j
== -4) /* `memory', don't cache memory across asm */
1947 XVECEXP (body
, 0, i
++)
1948 = gen_rtx_CLOBBER (VOIDmode
,
1951 gen_rtx_SCRATCH (VOIDmode
)));
1955 /* Ignore unknown register, error already signaled. */
1959 /* Use QImode since that's guaranteed to clobber just one reg. */
1960 XVECEXP (body
, 0, i
++)
1961 = gen_rtx_CLOBBER (VOIDmode
, gen_rtx_REG (QImode
, j
));
1964 insn
= emit_insn (body
);
1967 /* For any outputs that needed reloading into registers, spill them
1968 back to where they belong. */
1969 for (i
= 0; i
< noutputs
; ++i
)
1970 if (real_output_rtx
[i
])
1971 emit_move_insn (real_output_rtx
[i
], output_rtx
[i
]);
1976 /* A subroutine of expand_asm_operands. Check that all operands have
1977 the same number of alternatives. Return true if so. */
1980 check_operand_nalternatives (outputs
, inputs
)
1981 tree outputs
, inputs
;
1983 if (outputs
|| inputs
)
1985 tree tmp
= TREE_PURPOSE (outputs
? outputs
: inputs
);
1987 = n_occurrences (',', TREE_STRING_POINTER (TREE_VALUE (tmp
)));
1990 if (nalternatives
+ 1 > MAX_RECOG_ALTERNATIVES
)
1992 error ("too many alternatives in `asm'");
1999 const char *constraint
2000 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tmp
)));
2002 if (n_occurrences (',', constraint
) != nalternatives
)
2004 error ("operand constraints for `asm' differ in number of alternatives");
2008 if (TREE_CHAIN (tmp
))
2009 tmp
= TREE_CHAIN (tmp
);
2011 tmp
= next
, next
= 0;
2018 /* A subroutine of expand_asm_operands. Check that all operand names
2019 are unique. Return true if so. We rely on the fact that these names
2020 are identifiers, and so have been canonicalized by get_identifier,
2021 so all we need are pointer comparisons. */
2024 check_unique_operand_names (outputs
, inputs
)
2025 tree outputs
, inputs
;
2029 for (i
= outputs
; i
; i
= TREE_CHAIN (i
))
2031 tree i_name
= TREE_PURPOSE (TREE_PURPOSE (i
));
2035 for (j
= TREE_CHAIN (i
); j
; j
= TREE_CHAIN (j
))
2036 if (i_name
== TREE_PURPOSE (TREE_PURPOSE (j
)))
2040 for (i
= inputs
; i
; i
= TREE_CHAIN (i
))
2042 tree i_name
= TREE_PURPOSE (TREE_PURPOSE (i
));
2046 for (j
= TREE_CHAIN (i
); j
; j
= TREE_CHAIN (j
))
2047 if (i_name
== TREE_PURPOSE (TREE_PURPOSE (j
)))
2049 for (j
= outputs
; j
; j
= TREE_CHAIN (j
))
2050 if (i_name
== TREE_PURPOSE (TREE_PURPOSE (j
)))
2057 error ("duplicate asm operand name '%s'",
2058 IDENTIFIER_POINTER (TREE_PURPOSE (TREE_PURPOSE (i
))));
2062 /* A subroutine of expand_asm_operands. Resolve the names of the operands
2063 in *POUTPUTS and *PINPUTS to numbers, and replace the name expansions in
2064 STRING and in the constraints to those numbers. */
2067 resolve_operand_names (string
, outputs
, inputs
, pconstraints
)
2069 tree outputs
, inputs
;
2070 const char **pconstraints
;
2072 char *buffer
= xstrdup (TREE_STRING_POINTER (string
));
2076 /* Assume that we will not need extra space to perform the substitution.
2077 This because we get to remove '[' and ']', which means we cannot have
2078 a problem until we have more than 999 operands. */
2081 while ((p
= strchr (p
, '%')) != NULL
)
2085 else if (ISALPHA (p
[1]) && p
[2] == '[')
2093 p
= resolve_operand_name_1 (p
, outputs
, inputs
);
2096 string
= build_string (strlen (buffer
), buffer
);
2099 /* Collect output constraints here because it's convenient.
2100 There should be no named operands here; this is verified
2101 in expand_asm_operand. */
2102 for (t
= outputs
; t
; t
= TREE_CHAIN (t
), pconstraints
++)
2103 *pconstraints
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t
)));
2105 /* Substitute [<name>] in input constraint strings. */
2106 for (t
= inputs
; t
; t
= TREE_CHAIN (t
), pconstraints
++)
2108 const char *c
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t
)));
2109 if (strchr (c
, '[') == NULL
)
2113 p
= buffer
= xstrdup (c
);
2114 while ((p
= strchr (p
, '[')) != NULL
)
2115 p
= resolve_operand_name_1 (p
, outputs
, inputs
);
2117 *pconstraints
= ggc_alloc_string (buffer
, -1);
2125 /* A subroutine of resolve_operand_names. P points to the '[' for a
2126 potential named operand of the form [<name>]. In place, replace
2127 the name and brackets with a number. Return a pointer to the
2128 balance of the string after substitution. */
2131 resolve_operand_name_1 (p
, outputs
, inputs
)
2133 tree outputs
, inputs
;
2140 /* Collect the operand name. */
2141 q
= strchr (p
, ']');
2144 error ("missing close brace for named operand");
2145 return strchr (p
, '\0');
2149 /* Resolve the name to a number. */
2150 for (op
= 0, t
= outputs
; t
; t
= TREE_CHAIN (t
), op
++)
2152 const char *c
= IDENTIFIER_POINTER (TREE_PURPOSE (TREE_PURPOSE (t
)));
2153 if (strncmp (c
, p
+ 1, len
) == 0 && c
[len
] == '\0')
2156 for (t
= inputs
; t
; t
= TREE_CHAIN (t
), op
++)
2158 const char *c
= IDENTIFIER_POINTER (TREE_PURPOSE (TREE_PURPOSE (t
)));
2159 if (strncmp (c
, p
+ 1, len
) == 0 && c
[len
] == '\0')
2164 error ("undefined named operand '%s'", p
+ 1);
2168 /* Replace the name with the number. Unfortunately, not all libraries
2169 get the return value of sprintf correct, so search for the end of the
2170 generated string by hand. */
2171 sprintf (p
, "%d", op
);
2172 p
= strchr (p
, '\0');
2174 /* Verify the no extra buffer space assumption. */
2178 /* Shift the rest of the buffer down to fill the gap. */
2179 memmove (p
, q
+ 1, strlen (q
+ 1) + 1);
2184 /* Generate RTL to evaluate the expression EXP
2185 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
2188 expand_expr_stmt (exp
)
2191 /* If -W, warn about statements with no side effects,
2192 except for an explicit cast to void (e.g. for assert()), and
2193 except inside a ({...}) where they may be useful. */
2194 if (expr_stmts_for_value
== 0 && exp
!= error_mark_node
)
2196 if (! TREE_SIDE_EFFECTS (exp
))
2198 if ((extra_warnings
|| warn_unused_value
)
2199 && !(TREE_CODE (exp
) == CONVERT_EXPR
2200 && VOID_TYPE_P (TREE_TYPE (exp
))))
2201 warning_with_file_and_line (emit_filename
, emit_lineno
,
2202 "statement with no effect");
2204 else if (warn_unused_value
)
2205 warn_if_unused_value (exp
);
2208 /* If EXP is of function type and we are expanding statements for
2209 value, convert it to pointer-to-function. */
2210 if (expr_stmts_for_value
&& TREE_CODE (TREE_TYPE (exp
)) == FUNCTION_TYPE
)
2211 exp
= build1 (ADDR_EXPR
, build_pointer_type (TREE_TYPE (exp
)), exp
);
2213 /* The call to `expand_expr' could cause last_expr_type and
2214 last_expr_value to get reset. Therefore, we set last_expr_value
2215 and last_expr_type *after* calling expand_expr. */
2216 last_expr_value
= expand_expr (exp
,
2217 (expr_stmts_for_value
2218 ? NULL_RTX
: const0_rtx
),
2220 last_expr_type
= TREE_TYPE (exp
);
2222 /* If all we do is reference a volatile value in memory,
2223 copy it to a register to be sure it is actually touched. */
2224 if (last_expr_value
!= 0 && GET_CODE (last_expr_value
) == MEM
2225 && TREE_THIS_VOLATILE (exp
))
2227 if (TYPE_MODE (TREE_TYPE (exp
)) == VOIDmode
)
2229 else if (TYPE_MODE (TREE_TYPE (exp
)) != BLKmode
)
2230 copy_to_reg (last_expr_value
);
2233 rtx lab
= gen_label_rtx ();
2235 /* Compare the value with itself to reference it. */
2236 emit_cmp_and_jump_insns (last_expr_value
, last_expr_value
, EQ
,
2237 expand_expr (TYPE_SIZE (last_expr_type
),
2238 NULL_RTX
, VOIDmode
, 0),
2244 /* If this expression is part of a ({...}) and is in memory, we may have
2245 to preserve temporaries. */
2246 preserve_temp_slots (last_expr_value
);
2248 /* Free any temporaries used to evaluate this expression. Any temporary
2249 used as a result of this expression will already have been preserved
2256 /* Warn if EXP contains any computations whose results are not used.
2257 Return 1 if a warning is printed; 0 otherwise. */
2260 warn_if_unused_value (exp
)
2263 if (TREE_USED (exp
))
2266 /* Don't warn about void constructs. This includes casting to void,
2267 void function calls, and statement expressions with a final cast
2269 if (VOID_TYPE_P (TREE_TYPE (exp
)))
2272 /* If this is an expression with side effects, don't warn. */
2273 if (TREE_SIDE_EFFECTS (exp
))
2276 switch (TREE_CODE (exp
))
2278 case PREINCREMENT_EXPR
:
2279 case POSTINCREMENT_EXPR
:
2280 case PREDECREMENT_EXPR
:
2281 case POSTDECREMENT_EXPR
:
2286 case METHOD_CALL_EXPR
:
2288 case TRY_CATCH_EXPR
:
2289 case WITH_CLEANUP_EXPR
:
2294 /* For a binding, warn if no side effect within it. */
2295 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2298 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2300 case TRUTH_ORIF_EXPR
:
2301 case TRUTH_ANDIF_EXPR
:
2302 /* In && or ||, warn if 2nd operand has no side effect. */
2303 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2306 if (TREE_NO_UNUSED_WARNING (exp
))
2308 if (warn_if_unused_value (TREE_OPERAND (exp
, 0)))
2310 /* Let people do `(foo (), 0)' without a warning. */
2311 if (TREE_CONSTANT (TREE_OPERAND (exp
, 1)))
2313 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2317 case NON_LVALUE_EXPR
:
2318 /* Don't warn about conversions not explicit in the user's program. */
2319 if (TREE_NO_UNUSED_WARNING (exp
))
2321 /* Assignment to a cast usually results in a cast of a modify.
2322 Don't complain about that. There can be an arbitrary number of
2323 casts before the modify, so we must loop until we find the first
2324 non-cast expression and then test to see if that is a modify. */
2326 tree tem
= TREE_OPERAND (exp
, 0);
2328 while (TREE_CODE (tem
) == CONVERT_EXPR
|| TREE_CODE (tem
) == NOP_EXPR
)
2329 tem
= TREE_OPERAND (tem
, 0);
2331 if (TREE_CODE (tem
) == MODIFY_EXPR
|| TREE_CODE (tem
) == INIT_EXPR
2332 || TREE_CODE (tem
) == CALL_EXPR
)
2338 /* Don't warn about automatic dereferencing of references, since
2339 the user cannot control it. */
2340 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp
, 0))) == REFERENCE_TYPE
)
2341 return warn_if_unused_value (TREE_OPERAND (exp
, 0));
2345 /* Referencing a volatile value is a side effect, so don't warn. */
2347 || TREE_CODE_CLASS (TREE_CODE (exp
)) == 'r')
2348 && TREE_THIS_VOLATILE (exp
))
2351 /* If this is an expression which has no operands, there is no value
2352 to be unused. There are no such language-independent codes,
2353 but front ends may define such. */
2354 if (TREE_CODE_CLASS (TREE_CODE (exp
)) == 'e'
2355 && TREE_CODE_LENGTH (TREE_CODE (exp
)) == 0)
2359 warning_with_file_and_line (emit_filename
, emit_lineno
,
2360 "value computed is not used");
2365 /* Clear out the memory of the last expression evaluated. */
2373 /* Begin a statement which will return a value.
2374 Return the RTL_EXPR for this statement expr.
2375 The caller must save that value and pass it to expand_end_stmt_expr. */
2378 expand_start_stmt_expr ()
2382 /* Make the RTL_EXPR node temporary, not momentary,
2383 so that rtl_expr_chain doesn't become garbage. */
2384 t
= make_node (RTL_EXPR
);
2385 do_pending_stack_adjust ();
2386 start_sequence_for_rtl_expr (t
);
2388 expr_stmts_for_value
++;
2392 /* Restore the previous state at the end of a statement that returns a value.
2393 Returns a tree node representing the statement's value and the
2394 insns to compute the value.
2396 The nodes of that expression have been freed by now, so we cannot use them.
2397 But we don't want to do that anyway; the expression has already been
2398 evaluated and now we just want to use the value. So generate a RTL_EXPR
2399 with the proper type and RTL value.
2401 If the last substatement was not an expression,
2402 return something with type `void'. */
2405 expand_end_stmt_expr (t
)
2410 if (last_expr_type
== 0)
2412 last_expr_type
= void_type_node
;
2413 last_expr_value
= const0_rtx
;
2415 else if (last_expr_value
== 0)
2416 /* There are some cases where this can happen, such as when the
2417 statement is void type. */
2418 last_expr_value
= const0_rtx
;
2419 else if (GET_CODE (last_expr_value
) != REG
&& ! CONSTANT_P (last_expr_value
))
2420 /* Remove any possible QUEUED. */
2421 last_expr_value
= protect_from_queue (last_expr_value
, 0);
2425 TREE_TYPE (t
) = last_expr_type
;
2426 RTL_EXPR_RTL (t
) = last_expr_value
;
2427 RTL_EXPR_SEQUENCE (t
) = get_insns ();
2429 rtl_expr_chain
= tree_cons (NULL_TREE
, t
, rtl_expr_chain
);
2433 /* Don't consider deleting this expr or containing exprs at tree level. */
2434 TREE_SIDE_EFFECTS (t
) = 1;
2435 /* Propagate volatility of the actual RTL expr. */
2436 TREE_THIS_VOLATILE (t
) = volatile_refs_p (last_expr_value
);
2439 expr_stmts_for_value
--;
2444 /* Generate RTL for the start of an if-then. COND is the expression
2445 whose truth should be tested.
2447 If EXITFLAG is nonzero, this conditional is visible to
2448 `exit_something'. */
2451 expand_start_cond (cond
, exitflag
)
2455 struct nesting
*thiscond
= ALLOC_NESTING ();
2457 /* Make an entry on cond_stack for the cond we are entering. */
2459 thiscond
->next
= cond_stack
;
2460 thiscond
->all
= nesting_stack
;
2461 thiscond
->depth
= ++nesting_depth
;
2462 thiscond
->data
.cond
.next_label
= gen_label_rtx ();
2463 /* Before we encounter an `else', we don't need a separate exit label
2464 unless there are supposed to be exit statements
2465 to exit this conditional. */
2466 thiscond
->exit_label
= exitflag
? gen_label_rtx () : 0;
2467 thiscond
->data
.cond
.endif_label
= thiscond
->exit_label
;
2468 cond_stack
= thiscond
;
2469 nesting_stack
= thiscond
;
2471 do_jump (cond
, thiscond
->data
.cond
.next_label
, NULL_RTX
);
2474 /* Generate RTL between then-clause and the elseif-clause
2475 of an if-then-elseif-.... */
2478 expand_start_elseif (cond
)
2481 if (cond_stack
->data
.cond
.endif_label
== 0)
2482 cond_stack
->data
.cond
.endif_label
= gen_label_rtx ();
2483 emit_jump (cond_stack
->data
.cond
.endif_label
);
2484 emit_label (cond_stack
->data
.cond
.next_label
);
2485 cond_stack
->data
.cond
.next_label
= gen_label_rtx ();
2486 do_jump (cond
, cond_stack
->data
.cond
.next_label
, NULL_RTX
);
2489 /* Generate RTL between the then-clause and the else-clause
2490 of an if-then-else. */
2493 expand_start_else ()
2495 if (cond_stack
->data
.cond
.endif_label
== 0)
2496 cond_stack
->data
.cond
.endif_label
= gen_label_rtx ();
2498 emit_jump (cond_stack
->data
.cond
.endif_label
);
2499 emit_label (cond_stack
->data
.cond
.next_label
);
2500 cond_stack
->data
.cond
.next_label
= 0; /* No more _else or _elseif calls. */
2503 /* After calling expand_start_else, turn this "else" into an "else if"
2504 by providing another condition. */
2507 expand_elseif (cond
)
2510 cond_stack
->data
.cond
.next_label
= gen_label_rtx ();
2511 do_jump (cond
, cond_stack
->data
.cond
.next_label
, NULL_RTX
);
2514 /* Generate RTL for the end of an if-then.
2515 Pop the record for it off of cond_stack. */
2520 struct nesting
*thiscond
= cond_stack
;
2522 do_pending_stack_adjust ();
2523 if (thiscond
->data
.cond
.next_label
)
2524 emit_label (thiscond
->data
.cond
.next_label
);
2525 if (thiscond
->data
.cond
.endif_label
)
2526 emit_label (thiscond
->data
.cond
.endif_label
);
2528 POPSTACK (cond_stack
);
2532 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2533 loop should be exited by `exit_something'. This is a loop for which
2534 `expand_continue' will jump to the top of the loop.
2536 Make an entry on loop_stack to record the labels associated with
2540 expand_start_loop (exit_flag
)
2543 struct nesting
*thisloop
= ALLOC_NESTING ();
2545 /* Make an entry on loop_stack for the loop we are entering. */
2547 thisloop
->next
= loop_stack
;
2548 thisloop
->all
= nesting_stack
;
2549 thisloop
->depth
= ++nesting_depth
;
2550 thisloop
->data
.loop
.start_label
= gen_label_rtx ();
2551 thisloop
->data
.loop
.end_label
= gen_label_rtx ();
2552 thisloop
->data
.loop
.alt_end_label
= 0;
2553 thisloop
->data
.loop
.continue_label
= thisloop
->data
.loop
.start_label
;
2554 thisloop
->exit_label
= exit_flag
? thisloop
->data
.loop
.end_label
: 0;
2555 loop_stack
= thisloop
;
2556 nesting_stack
= thisloop
;
2558 do_pending_stack_adjust ();
2560 emit_note (NULL
, NOTE_INSN_LOOP_BEG
);
2561 emit_label (thisloop
->data
.loop
.start_label
);
2566 /* Like expand_start_loop but for a loop where the continuation point
2567 (for expand_continue_loop) will be specified explicitly. */
2570 expand_start_loop_continue_elsewhere (exit_flag
)
2573 struct nesting
*thisloop
= expand_start_loop (exit_flag
);
2574 loop_stack
->data
.loop
.continue_label
= gen_label_rtx ();
2578 /* Begin a null, aka do { } while (0) "loop". But since the contents
2579 of said loop can still contain a break, we must frob the loop nest. */
2582 expand_start_null_loop ()
2584 struct nesting
*thisloop
= ALLOC_NESTING ();
2586 /* Make an entry on loop_stack for the loop we are entering. */
2588 thisloop
->next
= loop_stack
;
2589 thisloop
->all
= nesting_stack
;
2590 thisloop
->depth
= ++nesting_depth
;
2591 thisloop
->data
.loop
.start_label
= emit_note (NULL
, NOTE_INSN_DELETED
);
2592 thisloop
->data
.loop
.end_label
= gen_label_rtx ();
2593 thisloop
->data
.loop
.alt_end_label
= NULL_RTX
;
2594 thisloop
->data
.loop
.continue_label
= thisloop
->data
.loop
.end_label
;
2595 thisloop
->exit_label
= thisloop
->data
.loop
.end_label
;
2596 loop_stack
= thisloop
;
2597 nesting_stack
= thisloop
;
2602 /* Specify the continuation point for a loop started with
2603 expand_start_loop_continue_elsewhere.
2604 Use this at the point in the code to which a continue statement
2608 expand_loop_continue_here ()
2610 do_pending_stack_adjust ();
2611 emit_note (NULL
, NOTE_INSN_LOOP_CONT
);
2612 emit_label (loop_stack
->data
.loop
.continue_label
);
2615 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2616 Pop the block off of loop_stack. */
2621 rtx start_label
= loop_stack
->data
.loop
.start_label
;
2622 rtx insn
= get_last_insn ();
2623 int needs_end_jump
= 1;
2625 /* Mark the continue-point at the top of the loop if none elsewhere. */
2626 if (start_label
== loop_stack
->data
.loop
.continue_label
)
2627 emit_note_before (NOTE_INSN_LOOP_CONT
, start_label
);
2629 do_pending_stack_adjust ();
2631 /* If optimizing, perhaps reorder the loop.
2632 First, try to use a condjump near the end.
2633 expand_exit_loop_if_false ends loops with unconditional jumps,
2636 if (test) goto label;
2638 goto loop_stack->data.loop.end_label
2642 If we find such a pattern, we can end the loop earlier. */
2645 && GET_CODE (insn
) == CODE_LABEL
2646 && LABEL_NAME (insn
) == NULL
2647 && GET_CODE (PREV_INSN (insn
)) == BARRIER
)
2650 rtx jump
= PREV_INSN (PREV_INSN (label
));
2652 if (GET_CODE (jump
) == JUMP_INSN
2653 && GET_CODE (PATTERN (jump
)) == SET
2654 && SET_DEST (PATTERN (jump
)) == pc_rtx
2655 && GET_CODE (SET_SRC (PATTERN (jump
))) == LABEL_REF
2656 && (XEXP (SET_SRC (PATTERN (jump
)), 0)
2657 == loop_stack
->data
.loop
.end_label
))
2661 /* The test might be complex and reference LABEL multiple times,
2662 like the loop in loop_iterations to set vtop. To handle this,
2664 insn
= PREV_INSN (label
);
2665 reorder_insns (label
, label
, start_label
);
2667 for (prev
= PREV_INSN (jump
);; prev
= PREV_INSN (prev
))
2669 /* We ignore line number notes, but if we see any other note,
2670 in particular NOTE_INSN_BLOCK_*, NOTE_INSN_EH_REGION_*,
2671 NOTE_INSN_LOOP_*, we disable this optimization. */
2672 if (GET_CODE (prev
) == NOTE
)
2674 if (NOTE_LINE_NUMBER (prev
) < 0)
2678 if (GET_CODE (prev
) == CODE_LABEL
)
2680 if (GET_CODE (prev
) == JUMP_INSN
)
2682 if (GET_CODE (PATTERN (prev
)) == SET
2683 && SET_DEST (PATTERN (prev
)) == pc_rtx
2684 && GET_CODE (SET_SRC (PATTERN (prev
))) == IF_THEN_ELSE
2685 && (GET_CODE (XEXP (SET_SRC (PATTERN (prev
)), 1))
2687 && XEXP (XEXP (SET_SRC (PATTERN (prev
)), 1), 0) == label
)
2689 XEXP (XEXP (SET_SRC (PATTERN (prev
)), 1), 0)
2691 emit_note_after (NOTE_INSN_LOOP_END
, prev
);
2700 /* If the loop starts with a loop exit, roll that to the end where
2701 it will optimize together with the jump back.
2703 We look for the conditional branch to the exit, except that once
2704 we find such a branch, we don't look past 30 instructions.
2706 In more detail, if the loop presently looks like this (in pseudo-C):
2709 if (test) goto end_label;
2714 transform it to look like:
2720 if (test) goto end_label;
2721 goto newstart_label;
2724 Here, the `test' may actually consist of some reasonably complex
2725 code, terminating in a test. */
2730 ! (GET_CODE (insn
) == JUMP_INSN
2731 && GET_CODE (PATTERN (insn
)) == SET
2732 && SET_DEST (PATTERN (insn
)) == pc_rtx
2733 && GET_CODE (SET_SRC (PATTERN (insn
))) == IF_THEN_ELSE
))
2737 rtx last_test_insn
= NULL_RTX
;
2739 /* Scan insns from the top of the loop looking for a qualified
2740 conditional exit. */
2741 for (insn
= NEXT_INSN (loop_stack
->data
.loop
.start_label
); insn
;
2742 insn
= NEXT_INSN (insn
))
2744 if (GET_CODE (insn
) == NOTE
)
2747 && (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_BEG
2748 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_END
))
2749 /* The code that actually moves the exit test will
2750 carefully leave BLOCK notes in their original
2751 location. That means, however, that we can't debug
2752 the exit test itself. So, we refuse to move code
2753 containing BLOCK notes at low optimization levels. */
2756 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_EH_REGION_BEG
)
2758 else if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_EH_REGION_END
)
2762 /* We've come to the end of an EH region, but
2763 never saw the beginning of that region. That
2764 means that an EH region begins before the top
2765 of the loop, and ends in the middle of it. The
2766 existence of such a situation violates a basic
2767 assumption in this code, since that would imply
2768 that even when EH_REGIONS is zero, we might
2769 move code out of an exception region. */
2773 /* We must not walk into a nested loop. */
2774 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_LOOP_BEG
)
2777 /* We already know this INSN is a NOTE, so there's no
2778 point in looking at it to see if it's a JUMP. */
2782 if (GET_CODE (insn
) == JUMP_INSN
|| GET_CODE (insn
) == INSN
)
2785 if (last_test_insn
&& num_insns
> 30)
2789 /* We don't want to move a partial EH region. Consider:
2803 This isn't legal C++, but here's what it's supposed to
2804 mean: if cond() is true, stop looping. Otherwise,
2805 call bar, and keep looping. In addition, if cond
2806 throws an exception, catch it and keep looping. Such
2807 constructs are certainy legal in LISP.
2809 We should not move the `if (cond()) 0' test since then
2810 the EH-region for the try-block would be broken up.
2811 (In this case we would the EH_BEG note for the `try'
2812 and `if cond()' but not the call to bar() or the
2815 So we don't look for tests within an EH region. */
2818 if (GET_CODE (insn
) == JUMP_INSN
2819 && GET_CODE (PATTERN (insn
)) == SET
2820 && SET_DEST (PATTERN (insn
)) == pc_rtx
)
2822 /* This is indeed a jump. */
2823 rtx dest1
= NULL_RTX
;
2824 rtx dest2
= NULL_RTX
;
2825 rtx potential_last_test
;
2826 if (GET_CODE (SET_SRC (PATTERN (insn
))) == IF_THEN_ELSE
)
2828 /* A conditional jump. */
2829 dest1
= XEXP (SET_SRC (PATTERN (insn
)), 1);
2830 dest2
= XEXP (SET_SRC (PATTERN (insn
)), 2);
2831 potential_last_test
= insn
;
2835 /* An unconditional jump. */
2836 dest1
= SET_SRC (PATTERN (insn
));
2837 /* Include the BARRIER after the JUMP. */
2838 potential_last_test
= NEXT_INSN (insn
);
2842 if (dest1
&& GET_CODE (dest1
) == LABEL_REF
2843 && ((XEXP (dest1
, 0)
2844 == loop_stack
->data
.loop
.alt_end_label
)
2846 == loop_stack
->data
.loop
.end_label
)))
2848 last_test_insn
= potential_last_test
;
2852 /* If this was a conditional jump, there may be
2853 another label at which we should look. */
2860 if (last_test_insn
!= 0 && last_test_insn
!= get_last_insn ())
2862 /* We found one. Move everything from there up
2863 to the end of the loop, and add a jump into the loop
2864 to jump to there. */
2865 rtx newstart_label
= gen_label_rtx ();
2866 rtx start_move
= start_label
;
2869 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2870 then we want to move this note also. */
2871 if (GET_CODE (PREV_INSN (start_move
)) == NOTE
2872 && (NOTE_LINE_NUMBER (PREV_INSN (start_move
))
2873 == NOTE_INSN_LOOP_CONT
))
2874 start_move
= PREV_INSN (start_move
);
2876 emit_label_after (newstart_label
, PREV_INSN (start_move
));
2878 /* Actually move the insns. Start at the beginning, and
2879 keep copying insns until we've copied the
2881 for (insn
= start_move
; insn
; insn
= next_insn
)
2883 /* Figure out which insn comes after this one. We have
2884 to do this before we move INSN. */
2885 if (insn
== last_test_insn
)
2886 /* We've moved all the insns. */
2887 next_insn
= NULL_RTX
;
2889 next_insn
= NEXT_INSN (insn
);
2891 if (GET_CODE (insn
) == NOTE
2892 && (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_BEG
2893 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_END
))
2894 /* We don't want to move NOTE_INSN_BLOCK_BEGs or
2895 NOTE_INSN_BLOCK_ENDs because the correct generation
2896 of debugging information depends on these appearing
2897 in the same order in the RTL and in the tree
2898 structure, where they are represented as BLOCKs.
2899 So, we don't move block notes. Of course, moving
2900 the code inside the block is likely to make it
2901 impossible to debug the instructions in the exit
2902 test, but such is the price of optimization. */
2905 /* Move the INSN. */
2906 reorder_insns (insn
, insn
, get_last_insn ());
2909 emit_jump_insn_after (gen_jump (start_label
),
2910 PREV_INSN (newstart_label
));
2911 emit_barrier_after (PREV_INSN (newstart_label
));
2912 start_label
= newstart_label
;
2918 emit_jump (start_label
);
2919 emit_note (NULL
, NOTE_INSN_LOOP_END
);
2921 emit_label (loop_stack
->data
.loop
.end_label
);
2923 POPSTACK (loop_stack
);
2928 /* Finish a null loop, aka do { } while (0). */
2931 expand_end_null_loop ()
2933 do_pending_stack_adjust ();
2934 emit_label (loop_stack
->data
.loop
.end_label
);
2936 POPSTACK (loop_stack
);
2941 /* Generate a jump to the current loop's continue-point.
2942 This is usually the top of the loop, but may be specified
2943 explicitly elsewhere. If not currently inside a loop,
2944 return 0 and do nothing; caller will print an error message. */
2947 expand_continue_loop (whichloop
)
2948 struct nesting
*whichloop
;
2952 whichloop
= loop_stack
;
2955 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.continue_label
,
2960 /* Generate a jump to exit the current loop. If not currently inside a loop,
2961 return 0 and do nothing; caller will print an error message. */
2964 expand_exit_loop (whichloop
)
2965 struct nesting
*whichloop
;
2969 whichloop
= loop_stack
;
2972 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.end_label
, NULL_RTX
);
2976 /* Generate a conditional jump to exit the current loop if COND
2977 evaluates to zero. If not currently inside a loop,
2978 return 0 and do nothing; caller will print an error message. */
2981 expand_exit_loop_if_false (whichloop
, cond
)
2982 struct nesting
*whichloop
;
2985 rtx label
= gen_label_rtx ();
2990 whichloop
= loop_stack
;
2993 /* In order to handle fixups, we actually create a conditional jump
2994 around an unconditional branch to exit the loop. If fixups are
2995 necessary, they go before the unconditional branch. */
2997 do_jump (cond
, NULL_RTX
, label
);
2998 last_insn
= get_last_insn ();
2999 if (GET_CODE (last_insn
) == CODE_LABEL
)
3000 whichloop
->data
.loop
.alt_end_label
= last_insn
;
3001 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.end_label
,
3008 /* Return nonzero if the loop nest is empty. Else return zero. */
3011 stmt_loop_nest_empty ()
3013 /* cfun->stmt can be NULL if we are building a call to get the
3014 EH context for a setjmp/longjmp EH target and the current
3015 function was a deferred inline function. */
3016 return (cfun
->stmt
== NULL
|| loop_stack
== NULL
);
3019 /* Return non-zero if we should preserve sub-expressions as separate
3020 pseudos. We never do so if we aren't optimizing. We always do so
3021 if -fexpensive-optimizations.
3023 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
3024 the loop may still be a small one. */
3027 preserve_subexpressions_p ()
3031 if (flag_expensive_optimizations
)
3034 if (optimize
== 0 || cfun
== 0 || cfun
->stmt
== 0 || loop_stack
== 0)
3037 insn
= get_last_insn_anywhere ();
3040 && (INSN_UID (insn
) - INSN_UID (loop_stack
->data
.loop
.start_label
)
3041 < n_non_fixed_regs
* 3));
3045 /* Generate a jump to exit the current loop, conditional, binding contour
3046 or case statement. Not all such constructs are visible to this function,
3047 only those started with EXIT_FLAG nonzero. Individual languages use
3048 the EXIT_FLAG parameter to control which kinds of constructs you can
3051 If not currently inside anything that can be exited,
3052 return 0 and do nothing; caller will print an error message. */
3055 expand_exit_something ()
3059 for (n
= nesting_stack
; n
; n
= n
->all
)
3060 if (n
->exit_label
!= 0)
3062 expand_goto_internal (NULL_TREE
, n
->exit_label
, NULL_RTX
);
3069 /* Generate RTL to return from the current function, with no value.
3070 (That is, we do not do anything about returning any value.) */
3073 expand_null_return ()
3075 rtx last_insn
= get_last_insn ();
3077 /* If this function was declared to return a value, but we
3078 didn't, clobber the return registers so that they are not
3079 propagated live to the rest of the function. */
3080 clobber_return_register ();
3082 expand_null_return_1 (last_insn
);
3085 /* Generate RTL to return from the current function, with value VAL. */
3088 expand_value_return (val
)
3091 rtx last_insn
= get_last_insn ();
3092 rtx return_reg
= DECL_RTL (DECL_RESULT (current_function_decl
));
3094 /* Copy the value to the return location
3095 unless it's already there. */
3097 if (return_reg
!= val
)
3099 tree type
= TREE_TYPE (DECL_RESULT (current_function_decl
));
3100 #ifdef PROMOTE_FUNCTION_RETURN
3101 int unsignedp
= TREE_UNSIGNED (type
);
3102 enum machine_mode old_mode
3103 = DECL_MODE (DECL_RESULT (current_function_decl
));
3104 enum machine_mode mode
3105 = promote_mode (type
, old_mode
, &unsignedp
, 1);
3107 if (mode
!= old_mode
)
3108 val
= convert_modes (mode
, old_mode
, val
, unsignedp
);
3110 if (GET_CODE (return_reg
) == PARALLEL
)
3111 emit_group_load (return_reg
, val
, int_size_in_bytes (type
));
3113 emit_move_insn (return_reg
, val
);
3116 expand_null_return_1 (last_insn
);
3119 /* Output a return with no value. If LAST_INSN is nonzero,
3120 pretend that the return takes place after LAST_INSN. */
3123 expand_null_return_1 (last_insn
)
3126 rtx end_label
= cleanup_label
? cleanup_label
: return_label
;
3128 clear_pending_stack_adjust ();
3129 do_pending_stack_adjust ();
3133 end_label
= return_label
= gen_label_rtx ();
3134 expand_goto_internal (NULL_TREE
, end_label
, last_insn
);
3137 /* Generate RTL to evaluate the expression RETVAL and return it
3138 from the current function. */
3141 expand_return (retval
)
3144 /* If there are any cleanups to be performed, then they will
3145 be inserted following LAST_INSN. It is desirable
3146 that the last_insn, for such purposes, should be the
3147 last insn before computing the return value. Otherwise, cleanups
3148 which call functions can clobber the return value. */
3149 /* ??? rms: I think that is erroneous, because in C++ it would
3150 run destructors on variables that might be used in the subsequent
3151 computation of the return value. */
3157 /* If function wants no value, give it none. */
3158 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl
))) == VOID_TYPE
)
3160 expand_expr (retval
, NULL_RTX
, VOIDmode
, 0);
3162 expand_null_return ();
3166 if (retval
== error_mark_node
)
3168 /* Treat this like a return of no value from a function that
3170 expand_null_return ();
3173 else if (TREE_CODE (retval
) == RESULT_DECL
)
3174 retval_rhs
= retval
;
3175 else if ((TREE_CODE (retval
) == MODIFY_EXPR
|| TREE_CODE (retval
) == INIT_EXPR
)
3176 && TREE_CODE (TREE_OPERAND (retval
, 0)) == RESULT_DECL
)
3177 retval_rhs
= TREE_OPERAND (retval
, 1);
3178 else if (VOID_TYPE_P (TREE_TYPE (retval
)))
3179 /* Recognize tail-recursive call to void function. */
3180 retval_rhs
= retval
;
3182 retval_rhs
= NULL_TREE
;
3184 last_insn
= get_last_insn ();
3186 /* Distribute return down conditional expr if either of the sides
3187 may involve tail recursion (see test below). This enhances the number
3188 of tail recursions we see. Don't do this always since it can produce
3189 sub-optimal code in some cases and we distribute assignments into
3190 conditional expressions when it would help. */
3192 if (optimize
&& retval_rhs
!= 0
3193 && frame_offset
== 0
3194 && TREE_CODE (retval_rhs
) == COND_EXPR
3195 && (TREE_CODE (TREE_OPERAND (retval_rhs
, 1)) == CALL_EXPR
3196 || TREE_CODE (TREE_OPERAND (retval_rhs
, 2)) == CALL_EXPR
))
3198 rtx label
= gen_label_rtx ();
3201 do_jump (TREE_OPERAND (retval_rhs
, 0), label
, NULL_RTX
);
3202 start_cleanup_deferral ();
3203 expr
= build (MODIFY_EXPR
, TREE_TYPE (TREE_TYPE (current_function_decl
)),
3204 DECL_RESULT (current_function_decl
),
3205 TREE_OPERAND (retval_rhs
, 1));
3206 TREE_SIDE_EFFECTS (expr
) = 1;
3207 expand_return (expr
);
3210 expr
= build (MODIFY_EXPR
, TREE_TYPE (TREE_TYPE (current_function_decl
)),
3211 DECL_RESULT (current_function_decl
),
3212 TREE_OPERAND (retval_rhs
, 2));
3213 TREE_SIDE_EFFECTS (expr
) = 1;
3214 expand_return (expr
);
3215 end_cleanup_deferral ();
3219 result_rtl
= DECL_RTL (DECL_RESULT (current_function_decl
));
3221 /* If the result is an aggregate that is being returned in one (or more)
3222 registers, load the registers here. The compiler currently can't handle
3223 copying a BLKmode value into registers. We could put this code in a
3224 more general area (for use by everyone instead of just function
3225 call/return), but until this feature is generally usable it is kept here
3226 (and in expand_call). The value must go into a pseudo in case there
3227 are cleanups that will clobber the real return register. */
3230 && TYPE_MODE (TREE_TYPE (retval_rhs
)) == BLKmode
3231 && GET_CODE (result_rtl
) == REG
)
3234 unsigned HOST_WIDE_INT bitpos
, xbitpos
;
3235 unsigned HOST_WIDE_INT big_endian_correction
= 0;
3236 unsigned HOST_WIDE_INT bytes
3237 = int_size_in_bytes (TREE_TYPE (retval_rhs
));
3238 int n_regs
= (bytes
+ UNITS_PER_WORD
- 1) / UNITS_PER_WORD
;
3239 unsigned int bitsize
3240 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs
)), BITS_PER_WORD
);
3241 rtx
*result_pseudos
= (rtx
*) alloca (sizeof (rtx
) * n_regs
);
3242 rtx result_reg
, src
= NULL_RTX
, dst
= NULL_RTX
;
3243 rtx result_val
= expand_expr (retval_rhs
, NULL_RTX
, VOIDmode
, 0);
3244 enum machine_mode tmpmode
, result_reg_mode
;
3248 expand_null_return ();
3252 /* Structures whose size is not a multiple of a word are aligned
3253 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
3254 machine, this means we must skip the empty high order bytes when
3255 calculating the bit offset. */
3256 if (BYTES_BIG_ENDIAN
3257 && !FUNCTION_ARG_REG_LITTLE_ENDIAN
3258 && bytes
% UNITS_PER_WORD
)
3259 big_endian_correction
= (BITS_PER_WORD
- ((bytes
% UNITS_PER_WORD
)
3262 /* Copy the structure BITSIZE bits at a time. */
3263 for (bitpos
= 0, xbitpos
= big_endian_correction
;
3264 bitpos
< bytes
* BITS_PER_UNIT
;
3265 bitpos
+= bitsize
, xbitpos
+= bitsize
)
3267 /* We need a new destination pseudo each time xbitpos is
3268 on a word boundary and when xbitpos == big_endian_correction
3269 (the first time through). */
3270 if (xbitpos
% BITS_PER_WORD
== 0
3271 || xbitpos
== big_endian_correction
)
3273 /* Generate an appropriate register. */
3274 dst
= gen_reg_rtx (word_mode
);
3275 result_pseudos
[xbitpos
/ BITS_PER_WORD
] = dst
;
3277 /* Clear the destination before we move anything into it. */
3278 emit_move_insn (dst
, CONST0_RTX (GET_MODE (dst
)));
3281 /* We need a new source operand each time bitpos is on a word
3283 if (bitpos
% BITS_PER_WORD
== 0)
3284 src
= operand_subword_force (result_val
,
3285 bitpos
/ BITS_PER_WORD
,
3288 /* Use bitpos for the source extraction (left justified) and
3289 xbitpos for the destination store (right justified). */
3290 store_bit_field (dst
, bitsize
, xbitpos
% BITS_PER_WORD
, word_mode
,
3291 extract_bit_field (src
, bitsize
,
3292 bitpos
% BITS_PER_WORD
, 1,
3293 NULL_RTX
, word_mode
, word_mode
,
3298 /* Find the smallest integer mode large enough to hold the
3299 entire structure and use that mode instead of BLKmode
3300 on the USE insn for the return register. */
3301 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
3302 tmpmode
!= VOIDmode
;
3303 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
3304 /* Have we found a large enough mode? */
3305 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
3308 /* No suitable mode found. */
3309 if (tmpmode
== VOIDmode
)
3312 PUT_MODE (result_rtl
, tmpmode
);
3314 if (GET_MODE_SIZE (tmpmode
) < GET_MODE_SIZE (word_mode
))
3315 result_reg_mode
= word_mode
;
3317 result_reg_mode
= tmpmode
;
3318 result_reg
= gen_reg_rtx (result_reg_mode
);
3321 for (i
= 0; i
< n_regs
; i
++)
3322 emit_move_insn (operand_subword (result_reg
, i
, 0, result_reg_mode
),
3325 if (tmpmode
!= result_reg_mode
)
3326 result_reg
= gen_lowpart (tmpmode
, result_reg
);
3328 expand_value_return (result_reg
);
3330 else if (retval_rhs
!= 0
3331 && !VOID_TYPE_P (TREE_TYPE (retval_rhs
))
3332 && (GET_CODE (result_rtl
) == REG
3333 || (GET_CODE (result_rtl
) == PARALLEL
)))
3335 /* Calculate the return value into a temporary (usually a pseudo
3337 tree ot
= TREE_TYPE (DECL_RESULT (current_function_decl
));
3338 tree nt
= build_qualified_type (ot
, TYPE_QUALS (ot
) | TYPE_QUAL_CONST
);
3340 val
= assign_temp (nt
, 0, 0, 1);
3341 val
= expand_expr (retval_rhs
, val
, GET_MODE (val
), 0);
3342 val
= force_not_mem (val
);
3344 /* Return the calculated value, doing cleanups first. */
3345 expand_value_return (val
);
3349 /* No cleanups or no hard reg used;
3350 calculate value into hard return reg. */
3351 expand_expr (retval
, const0_rtx
, VOIDmode
, 0);
3353 expand_value_return (result_rtl
);
3357 /* Return 1 if the end of the generated RTX is not a barrier.
3358 This means code already compiled can drop through. */
3361 drop_through_at_end_p ()
3363 rtx insn
= get_last_insn ();
3364 while (insn
&& GET_CODE (insn
) == NOTE
)
3365 insn
= PREV_INSN (insn
);
3366 return insn
&& GET_CODE (insn
) != BARRIER
;
3369 /* Attempt to optimize a potential tail recursion call into a goto.
3370 ARGUMENTS are the arguments to a CALL_EXPR; LAST_INSN indicates
3371 where to place the jump to the tail recursion label.
3373 Return TRUE if the call was optimized into a goto. */
3376 optimize_tail_recursion (arguments
, last_insn
)
3380 /* Finish checking validity, and if valid emit code to set the
3381 argument variables for the new call. */
3382 if (tail_recursion_args (arguments
, DECL_ARGUMENTS (current_function_decl
)))
3384 if (tail_recursion_label
== 0)
3386 tail_recursion_label
= gen_label_rtx ();
3387 emit_label_after (tail_recursion_label
,
3388 tail_recursion_reentry
);
3391 expand_goto_internal (NULL_TREE
, tail_recursion_label
, last_insn
);
3398 /* Emit code to alter this function's formal parms for a tail-recursive call.
3399 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3400 FORMALS is the chain of decls of formals.
3401 Return 1 if this can be done;
3402 otherwise return 0 and do not emit any code. */
3405 tail_recursion_args (actuals
, formals
)
3406 tree actuals
, formals
;
3408 tree a
= actuals
, f
= formals
;
3412 /* Check that number and types of actuals are compatible
3413 with the formals. This is not always true in valid C code.
3414 Also check that no formal needs to be addressable
3415 and that all formals are scalars. */
3417 /* Also count the args. */
3419 for (a
= actuals
, f
= formals
, i
= 0; a
&& f
; a
= TREE_CHAIN (a
), f
= TREE_CHAIN (f
), i
++)
3421 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a
)))
3422 != TYPE_MAIN_VARIANT (TREE_TYPE (f
)))
3424 if (GET_CODE (DECL_RTL (f
)) != REG
|| DECL_MODE (f
) == BLKmode
)
3427 if (a
!= 0 || f
!= 0)
3430 /* Compute all the actuals. */
3432 argvec
= (rtx
*) alloca (i
* sizeof (rtx
));
3434 for (a
= actuals
, i
= 0; a
; a
= TREE_CHAIN (a
), i
++)
3435 argvec
[i
] = expand_expr (TREE_VALUE (a
), NULL_RTX
, VOIDmode
, 0);
3437 /* Find which actual values refer to current values of previous formals.
3438 Copy each of them now, before any formal is changed. */
3440 for (a
= actuals
, i
= 0; a
; a
= TREE_CHAIN (a
), i
++)
3444 for (f
= formals
, j
= 0; j
< i
; f
= TREE_CHAIN (f
), j
++)
3445 if (reg_mentioned_p (DECL_RTL (f
), argvec
[i
]))
3451 argvec
[i
] = copy_to_reg (argvec
[i
]);
3454 /* Store the values of the actuals into the formals. */
3456 for (f
= formals
, a
= actuals
, i
= 0; f
;
3457 f
= TREE_CHAIN (f
), a
= TREE_CHAIN (a
), i
++)
3459 if (GET_MODE (DECL_RTL (f
)) == GET_MODE (argvec
[i
]))
3460 emit_move_insn (DECL_RTL (f
), argvec
[i
]);
3462 convert_move (DECL_RTL (f
), argvec
[i
],
3463 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a
))));
3470 /* Generate the RTL code for entering a binding contour.
3471 The variables are declared one by one, by calls to `expand_decl'.
3473 FLAGS is a bitwise or of the following flags:
3475 1 - Nonzero if this construct should be visible to
3478 2 - Nonzero if this contour does not require a
3479 NOTE_INSN_BLOCK_BEG note. Virtually all calls from
3480 language-independent code should set this flag because they
3481 will not create corresponding BLOCK nodes. (There should be
3482 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
3483 and BLOCKs.) If this flag is set, MARK_ENDS should be zero
3484 when expand_end_bindings is called.
3486 If we are creating a NOTE_INSN_BLOCK_BEG note, a BLOCK may
3487 optionally be supplied. If so, it becomes the NOTE_BLOCK for the
3491 expand_start_bindings_and_block (flags
, block
)
3495 struct nesting
*thisblock
= ALLOC_NESTING ();
3497 int exit_flag
= ((flags
& 1) != 0);
3498 int block_flag
= ((flags
& 2) == 0);
3500 /* If a BLOCK is supplied, then the caller should be requesting a
3501 NOTE_INSN_BLOCK_BEG note. */
3502 if (!block_flag
&& block
)
3505 /* Create a note to mark the beginning of the block. */
3508 note
= emit_note (NULL
, NOTE_INSN_BLOCK_BEG
);
3509 NOTE_BLOCK (note
) = block
;
3512 note
= emit_note (NULL
, NOTE_INSN_DELETED
);
3514 /* Make an entry on block_stack for the block we are entering. */
3516 thisblock
->next
= block_stack
;
3517 thisblock
->all
= nesting_stack
;
3518 thisblock
->depth
= ++nesting_depth
;
3519 thisblock
->data
.block
.stack_level
= 0;
3520 thisblock
->data
.block
.cleanups
= 0;
3521 thisblock
->data
.block
.n_function_calls
= 0;
3522 thisblock
->data
.block
.exception_region
= 0;
3523 thisblock
->data
.block
.block_target_temp_slot_level
= target_temp_slot_level
;
3525 thisblock
->data
.block
.conditional_code
= 0;
3526 thisblock
->data
.block
.last_unconditional_cleanup
= note
;
3527 /* When we insert instructions after the last unconditional cleanup,
3528 we don't adjust last_insn. That means that a later add_insn will
3529 clobber the instructions we've just added. The easiest way to
3530 fix this is to just insert another instruction here, so that the
3531 instructions inserted after the last unconditional cleanup are
3532 never the last instruction. */
3533 emit_note (NULL
, NOTE_INSN_DELETED
);
3534 thisblock
->data
.block
.cleanup_ptr
= &thisblock
->data
.block
.cleanups
;
3537 && !(block_stack
->data
.block
.cleanups
== NULL_TREE
3538 && block_stack
->data
.block
.outer_cleanups
== NULL_TREE
))
3539 thisblock
->data
.block
.outer_cleanups
3540 = tree_cons (NULL_TREE
, block_stack
->data
.block
.cleanups
,
3541 block_stack
->data
.block
.outer_cleanups
);
3543 thisblock
->data
.block
.outer_cleanups
= 0;
3544 thisblock
->data
.block
.label_chain
= 0;
3545 thisblock
->data
.block
.innermost_stack_block
= stack_block_stack
;
3546 thisblock
->data
.block
.first_insn
= note
;
3547 thisblock
->data
.block
.block_start_count
= ++current_block_start_count
;
3548 thisblock
->exit_label
= exit_flag
? gen_label_rtx () : 0;
3549 block_stack
= thisblock
;
3550 nesting_stack
= thisblock
;
3552 /* Make a new level for allocating stack slots. */
3556 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3557 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3558 expand_expr are made. After we end the region, we know that all
3559 space for all temporaries that were created by TARGET_EXPRs will be
3560 destroyed and their space freed for reuse. */
3563 expand_start_target_temps ()
3565 /* This is so that even if the result is preserved, the space
3566 allocated will be freed, as we know that it is no longer in use. */
3569 /* Start a new binding layer that will keep track of all cleanup
3570 actions to be performed. */
3571 expand_start_bindings (2);
3573 target_temp_slot_level
= temp_slot_level
;
3577 expand_end_target_temps ()
3579 expand_end_bindings (NULL_TREE
, 0, 0);
3581 /* This is so that even if the result is preserved, the space
3582 allocated will be freed, as we know that it is no longer in use. */
3586 /* Given a pointer to a BLOCK node return non-zero if (and only if) the node
3587 in question represents the outermost pair of curly braces (i.e. the "body
3588 block") of a function or method.
3590 For any BLOCK node representing a "body block" of a function or method, the
3591 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
3592 represents the outermost (function) scope for the function or method (i.e.
3593 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
3594 *that* node in turn will point to the relevant FUNCTION_DECL node. */
3597 is_body_block (stmt
)
3600 if (TREE_CODE (stmt
) == BLOCK
)
3602 tree parent
= BLOCK_SUPERCONTEXT (stmt
);
3604 if (parent
&& TREE_CODE (parent
) == BLOCK
)
3606 tree grandparent
= BLOCK_SUPERCONTEXT (parent
);
3608 if (grandparent
&& TREE_CODE (grandparent
) == FUNCTION_DECL
)
3616 /* True if we are currently emitting insns in an area of output code
3617 that is controlled by a conditional expression. This is used by
3618 the cleanup handling code to generate conditional cleanup actions. */
3621 conditional_context ()
3623 return block_stack
&& block_stack
->data
.block
.conditional_code
;
3626 /* Return an opaque pointer to the current nesting level, so frontend code
3627 can check its own sanity. */
3630 current_nesting_level ()
3632 return cfun
? block_stack
: 0;
3635 /* Emit a handler label for a nonlocal goto handler.
3636 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3639 expand_nl_handler_label (slot
, before_insn
)
3640 rtx slot
, before_insn
;
3643 rtx handler_label
= gen_label_rtx ();
3645 /* Don't let cleanup_cfg delete the handler. */
3646 LABEL_PRESERVE_P (handler_label
) = 1;
3649 emit_move_insn (slot
, gen_rtx_LABEL_REF (Pmode
, handler_label
));
3650 insns
= get_insns ();
3652 emit_insns_before (insns
, before_insn
);
3654 emit_label (handler_label
);
3656 return handler_label
;
3659 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3662 expand_nl_goto_receiver ()
3664 #ifdef HAVE_nonlocal_goto
3665 if (! HAVE_nonlocal_goto
)
3667 /* First adjust our frame pointer to its actual value. It was
3668 previously set to the start of the virtual area corresponding to
3669 the stacked variables when we branched here and now needs to be
3670 adjusted to the actual hardware fp value.
3672 Assignments are to virtual registers are converted by
3673 instantiate_virtual_regs into the corresponding assignment
3674 to the underlying register (fp in this case) that makes
3675 the original assignment true.
3676 So the following insn will actually be
3677 decrementing fp by STARTING_FRAME_OFFSET. */
3678 emit_move_insn (virtual_stack_vars_rtx
, hard_frame_pointer_rtx
);
3680 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3681 if (fixed_regs
[ARG_POINTER_REGNUM
])
3683 #ifdef ELIMINABLE_REGS
3684 /* If the argument pointer can be eliminated in favor of the
3685 frame pointer, we don't need to restore it. We assume here
3686 that if such an elimination is present, it can always be used.
3687 This is the case on all known machines; if we don't make this
3688 assumption, we do unnecessary saving on many machines. */
3689 static const struct elims
{const int from
, to
;} elim_regs
[] = ELIMINABLE_REGS
;
3692 for (i
= 0; i
< ARRAY_SIZE (elim_regs
); i
++)
3693 if (elim_regs
[i
].from
== ARG_POINTER_REGNUM
3694 && elim_regs
[i
].to
== HARD_FRAME_POINTER_REGNUM
)
3697 if (i
== ARRAY_SIZE (elim_regs
))
3700 /* Now restore our arg pointer from the address at which it
3701 was saved in our stack frame. */
3702 emit_move_insn (virtual_incoming_args_rtx
,
3703 copy_to_reg (get_arg_pointer_save_area (cfun
)));
3708 #ifdef HAVE_nonlocal_goto_receiver
3709 if (HAVE_nonlocal_goto_receiver
)
3710 emit_insn (gen_nonlocal_goto_receiver ());
3714 /* Make handlers for nonlocal gotos taking place in the function calls in
3718 expand_nl_goto_receivers (thisblock
)
3719 struct nesting
*thisblock
;
3722 rtx afterward
= gen_label_rtx ();
3727 /* Record the handler address in the stack slot for that purpose,
3728 during this block, saving and restoring the outer value. */
3729 if (thisblock
->next
!= 0)
3730 for (slot
= nonlocal_goto_handler_slots
; slot
; slot
= XEXP (slot
, 1))
3732 rtx save_receiver
= gen_reg_rtx (Pmode
);
3733 emit_move_insn (XEXP (slot
, 0), save_receiver
);
3736 emit_move_insn (save_receiver
, XEXP (slot
, 0));
3737 insns
= get_insns ();
3739 emit_insns_before (insns
, thisblock
->data
.block
.first_insn
);
3742 /* Jump around the handlers; they run only when specially invoked. */
3743 emit_jump (afterward
);
3745 /* Make a separate handler for each label. */
3746 link
= nonlocal_labels
;
3747 slot
= nonlocal_goto_handler_slots
;
3748 label_list
= NULL_RTX
;
3749 for (; link
; link
= TREE_CHAIN (link
), slot
= XEXP (slot
, 1))
3750 /* Skip any labels we shouldn't be able to jump to from here,
3751 we generate one special handler for all of them below which just calls
3753 if (! DECL_TOO_LATE (TREE_VALUE (link
)))
3756 lab
= expand_nl_handler_label (XEXP (slot
, 0),
3757 thisblock
->data
.block
.first_insn
);
3758 label_list
= gen_rtx_EXPR_LIST (VOIDmode
, lab
, label_list
);
3760 expand_nl_goto_receiver ();
3762 /* Jump to the "real" nonlocal label. */
3763 expand_goto (TREE_VALUE (link
));
3766 /* A second pass over all nonlocal labels; this time we handle those
3767 we should not be able to jump to at this point. */
3768 link
= nonlocal_labels
;
3769 slot
= nonlocal_goto_handler_slots
;
3771 for (; link
; link
= TREE_CHAIN (link
), slot
= XEXP (slot
, 1))
3772 if (DECL_TOO_LATE (TREE_VALUE (link
)))
3775 lab
= expand_nl_handler_label (XEXP (slot
, 0),
3776 thisblock
->data
.block
.first_insn
);
3777 label_list
= gen_rtx_EXPR_LIST (VOIDmode
, lab
, label_list
);
3783 expand_nl_goto_receiver ();
3784 emit_library_call (gen_rtx_SYMBOL_REF (Pmode
, "abort"), LCT_NORETURN
,
3789 nonlocal_goto_handler_labels
= label_list
;
3790 emit_label (afterward
);
3793 /* Warn about any unused VARS (which may contain nodes other than
3794 VAR_DECLs, but such nodes are ignored). The nodes are connected
3795 via the TREE_CHAIN field. */
3798 warn_about_unused_variables (vars
)
3803 if (warn_unused_variable
)
3804 for (decl
= vars
; decl
; decl
= TREE_CHAIN (decl
))
3805 if (TREE_CODE (decl
) == VAR_DECL
3806 && ! TREE_USED (decl
)
3807 && ! DECL_IN_SYSTEM_HEADER (decl
)
3808 && DECL_NAME (decl
) && ! DECL_ARTIFICIAL (decl
))
3809 warning_with_decl (decl
, "unused variable `%s'");
3812 /* Generate RTL code to terminate a binding contour.
3814 VARS is the chain of VAR_DECL nodes for the variables bound in this
3815 contour. There may actually be other nodes in this chain, but any
3816 nodes other than VAR_DECLS are ignored.
3818 MARK_ENDS is nonzero if we should put a note at the beginning
3819 and end of this binding contour.
3821 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3822 (That is true automatically if the contour has a saved stack level.) */
3825 expand_end_bindings (vars
, mark_ends
, dont_jump_in
)
3830 struct nesting
*thisblock
= block_stack
;
3832 /* If any of the variables in this scope were not used, warn the
3834 warn_about_unused_variables (vars
);
3836 if (thisblock
->exit_label
)
3838 do_pending_stack_adjust ();
3839 emit_label (thisblock
->exit_label
);
3842 /* If necessary, make handlers for nonlocal gotos taking
3843 place in the function calls in this block. */
3844 if (function_call_count
!= thisblock
->data
.block
.n_function_calls
3846 /* Make handler for outermost block
3847 if there were any nonlocal gotos to this function. */
3848 && (thisblock
->next
== 0 ? current_function_has_nonlocal_label
3849 /* Make handler for inner block if it has something
3850 special to do when you jump out of it. */
3851 : (thisblock
->data
.block
.cleanups
!= 0
3852 || thisblock
->data
.block
.stack_level
!= 0)))
3853 expand_nl_goto_receivers (thisblock
);
3855 /* Don't allow jumping into a block that has a stack level.
3856 Cleanups are allowed, though. */
3858 || thisblock
->data
.block
.stack_level
!= 0)
3860 struct label_chain
*chain
;
3862 /* Any labels in this block are no longer valid to go to.
3863 Mark them to cause an error message. */
3864 for (chain
= thisblock
->data
.block
.label_chain
; chain
; chain
= chain
->next
)
3866 DECL_TOO_LATE (chain
->label
) = 1;
3867 /* If any goto without a fixup came to this label,
3868 that must be an error, because gotos without fixups
3869 come from outside all saved stack-levels. */
3870 if (TREE_ADDRESSABLE (chain
->label
))
3871 error_with_decl (chain
->label
,
3872 "label `%s' used before containing binding contour");
3876 /* Restore stack level in effect before the block
3877 (only if variable-size objects allocated). */
3878 /* Perform any cleanups associated with the block. */
3880 if (thisblock
->data
.block
.stack_level
!= 0
3881 || thisblock
->data
.block
.cleanups
!= 0)
3886 /* Don't let cleanups affect ({...}) constructs. */
3887 int old_expr_stmts_for_value
= expr_stmts_for_value
;
3888 rtx old_last_expr_value
= last_expr_value
;
3889 tree old_last_expr_type
= last_expr_type
;
3890 expr_stmts_for_value
= 0;
3892 /* Only clean up here if this point can actually be reached. */
3893 insn
= get_last_insn ();
3894 if (GET_CODE (insn
) == NOTE
)
3895 insn
= prev_nonnote_insn (insn
);
3896 reachable
= (! insn
|| GET_CODE (insn
) != BARRIER
);
3898 /* Do the cleanups. */
3899 expand_cleanups (thisblock
->data
.block
.cleanups
, NULL_TREE
, 0, reachable
);
3901 do_pending_stack_adjust ();
3903 expr_stmts_for_value
= old_expr_stmts_for_value
;
3904 last_expr_value
= old_last_expr_value
;
3905 last_expr_type
= old_last_expr_type
;
3907 /* Restore the stack level. */
3909 if (reachable
&& thisblock
->data
.block
.stack_level
!= 0)
3911 emit_stack_restore (thisblock
->next
? SAVE_BLOCK
: SAVE_FUNCTION
,
3912 thisblock
->data
.block
.stack_level
, NULL_RTX
);
3913 if (nonlocal_goto_handler_slots
!= 0)
3914 emit_stack_save (SAVE_NONLOCAL
, &nonlocal_goto_stack_level
,
3918 /* Any gotos out of this block must also do these things.
3919 Also report any gotos with fixups that came to labels in this
3921 fixup_gotos (thisblock
,
3922 thisblock
->data
.block
.stack_level
,
3923 thisblock
->data
.block
.cleanups
,
3924 thisblock
->data
.block
.first_insn
,
3928 /* Mark the beginning and end of the scope if requested.
3929 We do this now, after running cleanups on the variables
3930 just going out of scope, so they are in scope for their cleanups. */
3934 rtx note
= emit_note (NULL
, NOTE_INSN_BLOCK_END
);
3935 NOTE_BLOCK (note
) = NOTE_BLOCK (thisblock
->data
.block
.first_insn
);
3938 /* Get rid of the beginning-mark if we don't make an end-mark. */
3939 NOTE_LINE_NUMBER (thisblock
->data
.block
.first_insn
) = NOTE_INSN_DELETED
;
3941 /* Restore the temporary level of TARGET_EXPRs. */
3942 target_temp_slot_level
= thisblock
->data
.block
.block_target_temp_slot_level
;
3944 /* Restore block_stack level for containing block. */
3946 stack_block_stack
= thisblock
->data
.block
.innermost_stack_block
;
3947 POPSTACK (block_stack
);
3949 /* Pop the stack slot nesting and free any slots at this level. */
3953 /* Generate code to save the stack pointer at the start of the current block
3954 and set up to restore it on exit. */
3957 save_stack_pointer ()
3959 struct nesting
*thisblock
= block_stack
;
3961 if (thisblock
->data
.block
.stack_level
== 0)
3963 emit_stack_save (thisblock
->next
? SAVE_BLOCK
: SAVE_FUNCTION
,
3964 &thisblock
->data
.block
.stack_level
,
3965 thisblock
->data
.block
.first_insn
);
3966 stack_block_stack
= thisblock
;
3970 /* Generate RTL for the automatic variable declaration DECL.
3971 (Other kinds of declarations are simply ignored if seen here.) */
3977 struct nesting
*thisblock
;
3980 type
= TREE_TYPE (decl
);
3982 /* For a CONST_DECL, set mode, alignment, and sizes from those of the
3983 type in case this node is used in a reference. */
3984 if (TREE_CODE (decl
) == CONST_DECL
)
3986 DECL_MODE (decl
) = TYPE_MODE (type
);
3987 DECL_ALIGN (decl
) = TYPE_ALIGN (type
);
3988 DECL_SIZE (decl
) = TYPE_SIZE (type
);
3989 DECL_SIZE_UNIT (decl
) = TYPE_SIZE_UNIT (type
);
3993 /* Otherwise, only automatic variables need any expansion done. Static and
3994 external variables, and external functions, will be handled by
3995 `assemble_variable' (called from finish_decl). TYPE_DECL requires
3996 nothing. PARM_DECLs are handled in `assign_parms'. */
3997 if (TREE_CODE (decl
) != VAR_DECL
)
4000 if (TREE_STATIC (decl
) || DECL_EXTERNAL (decl
))
4003 thisblock
= block_stack
;
4005 /* Create the RTL representation for the variable. */
4007 if (type
== error_mark_node
)
4008 SET_DECL_RTL (decl
, gen_rtx_MEM (BLKmode
, const0_rtx
));
4010 else if (DECL_SIZE (decl
) == 0)
4011 /* Variable with incomplete type. */
4014 if (DECL_INITIAL (decl
) == 0)
4015 /* Error message was already done; now avoid a crash. */
4016 x
= gen_rtx_MEM (BLKmode
, const0_rtx
);
4018 /* An initializer is going to decide the size of this array.
4019 Until we know the size, represent its address with a reg. */
4020 x
= gen_rtx_MEM (BLKmode
, gen_reg_rtx (Pmode
));
4022 set_mem_attributes (x
, decl
, 1);
4023 SET_DECL_RTL (decl
, x
);
4025 else if (DECL_MODE (decl
) != BLKmode
4026 /* If -ffloat-store, don't put explicit float vars
4028 && !(flag_float_store
4029 && TREE_CODE (type
) == REAL_TYPE
)
4030 && ! TREE_THIS_VOLATILE (decl
)
4031 && (DECL_REGISTER (decl
) || optimize
))
4033 /* Automatic variable that can go in a register. */
4034 int unsignedp
= TREE_UNSIGNED (type
);
4035 enum machine_mode reg_mode
4036 = promote_mode (type
, DECL_MODE (decl
), &unsignedp
, 0);
4038 SET_DECL_RTL (decl
, gen_reg_rtx (reg_mode
));
4040 if (GET_CODE (DECL_RTL (decl
)) == REG
)
4041 REGNO_DECL (REGNO (DECL_RTL (decl
))) = decl
;
4042 else if (GET_CODE (DECL_RTL (decl
)) == CONCAT
)
4044 REGNO_DECL (REGNO (XEXP (DECL_RTL (decl
), 0))) = decl
;
4045 REGNO_DECL (REGNO (XEXP (DECL_RTL (decl
), 1))) = decl
;
4048 mark_user_reg (DECL_RTL (decl
));
4050 if (POINTER_TYPE_P (type
))
4051 mark_reg_pointer (DECL_RTL (decl
),
4052 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl
))));
4054 maybe_set_unchanging (DECL_RTL (decl
), decl
);
4056 /* If something wants our address, try to use ADDRESSOF. */
4057 if (TREE_ADDRESSABLE (decl
))
4058 put_var_into_stack (decl
);
4061 else if (TREE_CODE (DECL_SIZE_UNIT (decl
)) == INTEGER_CST
4062 && ! (flag_stack_check
&& ! STACK_CHECK_BUILTIN
4063 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl
),
4064 STACK_CHECK_MAX_VAR_SIZE
)))
4066 /* Variable of fixed size that goes on the stack. */
4071 /* If we previously made RTL for this decl, it must be an array
4072 whose size was determined by the initializer.
4073 The old address was a register; set that register now
4074 to the proper address. */
4075 if (DECL_RTL_SET_P (decl
))
4077 if (GET_CODE (DECL_RTL (decl
)) != MEM
4078 || GET_CODE (XEXP (DECL_RTL (decl
), 0)) != REG
)
4080 oldaddr
= XEXP (DECL_RTL (decl
), 0);
4083 /* Set alignment we actually gave this decl. */
4084 DECL_ALIGN (decl
) = (DECL_MODE (decl
) == BLKmode
? BIGGEST_ALIGNMENT
4085 : GET_MODE_BITSIZE (DECL_MODE (decl
)));
4086 DECL_USER_ALIGN (decl
) = 0;
4088 x
= assign_temp (TREE_TYPE (decl
), 1, 1, 1);
4089 set_mem_attributes (x
, decl
, 1);
4090 SET_DECL_RTL (decl
, x
);
4094 addr
= force_operand (XEXP (DECL_RTL (decl
), 0), oldaddr
);
4095 if (addr
!= oldaddr
)
4096 emit_move_insn (oldaddr
, addr
);
4100 /* Dynamic-size object: must push space on the stack. */
4102 rtx address
, size
, x
;
4104 /* Record the stack pointer on entry to block, if have
4105 not already done so. */
4106 do_pending_stack_adjust ();
4107 save_stack_pointer ();
4109 /* In function-at-a-time mode, variable_size doesn't expand this,
4111 if (TREE_CODE (type
) == ARRAY_TYPE
&& TYPE_DOMAIN (type
))
4112 expand_expr (TYPE_MAX_VALUE (TYPE_DOMAIN (type
)),
4113 const0_rtx
, VOIDmode
, 0);
4115 /* Compute the variable's size, in bytes. */
4116 size
= expand_expr (DECL_SIZE_UNIT (decl
), NULL_RTX
, VOIDmode
, 0);
4119 /* Allocate space on the stack for the variable. Note that
4120 DECL_ALIGN says how the variable is to be aligned and we
4121 cannot use it to conclude anything about the alignment of
4123 address
= allocate_dynamic_stack_space (size
, NULL_RTX
,
4124 TYPE_ALIGN (TREE_TYPE (decl
)));
4126 /* Reference the variable indirect through that rtx. */
4127 x
= gen_rtx_MEM (DECL_MODE (decl
), address
);
4128 set_mem_attributes (x
, decl
, 1);
4129 SET_DECL_RTL (decl
, x
);
4132 /* Indicate the alignment we actually gave this variable. */
4133 #ifdef STACK_BOUNDARY
4134 DECL_ALIGN (decl
) = STACK_BOUNDARY
;
4136 DECL_ALIGN (decl
) = BIGGEST_ALIGNMENT
;
4138 DECL_USER_ALIGN (decl
) = 0;
4142 /* Emit code to perform the initialization of a declaration DECL. */
4145 expand_decl_init (decl
)
4148 int was_used
= TREE_USED (decl
);
4150 /* If this is a CONST_DECL, we don't have to generate any code. Likewise
4151 for static decls. */
4152 if (TREE_CODE (decl
) == CONST_DECL
4153 || TREE_STATIC (decl
))
4156 /* Compute and store the initial value now. */
4158 if (DECL_INITIAL (decl
) == error_mark_node
)
4160 enum tree_code code
= TREE_CODE (TREE_TYPE (decl
));
4162 if (code
== INTEGER_TYPE
|| code
== REAL_TYPE
|| code
== ENUMERAL_TYPE
4163 || code
== POINTER_TYPE
|| code
== REFERENCE_TYPE
)
4164 expand_assignment (decl
, convert (TREE_TYPE (decl
), integer_zero_node
),
4168 else if (DECL_INITIAL (decl
) && TREE_CODE (DECL_INITIAL (decl
)) != TREE_LIST
)
4170 emit_line_note (DECL_SOURCE_FILE (decl
), DECL_SOURCE_LINE (decl
));
4171 expand_assignment (decl
, DECL_INITIAL (decl
), 0, 0);
4175 /* Don't let the initialization count as "using" the variable. */
4176 TREE_USED (decl
) = was_used
;
4178 /* Free any temporaries we made while initializing the decl. */
4179 preserve_temp_slots (NULL_RTX
);
4183 /* CLEANUP is an expression to be executed at exit from this binding contour;
4184 for example, in C++, it might call the destructor for this variable.
4186 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
4187 CLEANUP multiple times, and have the correct semantics. This
4188 happens in exception handling, for gotos, returns, breaks that
4189 leave the current scope.
4191 If CLEANUP is nonzero and DECL is zero, we record a cleanup
4192 that is not associated with any particular variable. */
4195 expand_decl_cleanup (decl
, cleanup
)
4198 struct nesting
*thisblock
;
4200 /* Error if we are not in any block. */
4201 if (cfun
== 0 || block_stack
== 0)
4204 thisblock
= block_stack
;
4206 /* Record the cleanup if there is one. */
4212 tree
*cleanups
= &thisblock
->data
.block
.cleanups
;
4213 int cond_context
= conditional_context ();
4217 rtx flag
= gen_reg_rtx (word_mode
);
4222 emit_move_insn (flag
, const0_rtx
);
4223 set_flag_0
= get_insns ();
4226 thisblock
->data
.block
.last_unconditional_cleanup
4227 = emit_insns_after (set_flag_0
,
4228 thisblock
->data
.block
.last_unconditional_cleanup
);
4230 emit_move_insn (flag
, const1_rtx
);
4232 cond
= build_decl (VAR_DECL
, NULL_TREE
, type_for_mode (word_mode
, 1));
4233 SET_DECL_RTL (cond
, flag
);
4235 /* Conditionalize the cleanup. */
4236 cleanup
= build (COND_EXPR
, void_type_node
,
4237 truthvalue_conversion (cond
),
4238 cleanup
, integer_zero_node
);
4239 cleanup
= fold (cleanup
);
4241 cleanups
= thisblock
->data
.block
.cleanup_ptr
;
4244 cleanup
= unsave_expr (cleanup
);
4246 t
= *cleanups
= tree_cons (decl
, cleanup
, *cleanups
);
4249 /* If this block has a cleanup, it belongs in stack_block_stack. */
4250 stack_block_stack
= thisblock
;
4257 if (! using_eh_for_cleanups_p
)
4258 TREE_ADDRESSABLE (t
) = 1;
4260 expand_eh_region_start ();
4267 thisblock
->data
.block
.last_unconditional_cleanup
4268 = emit_insns_after (seq
,
4269 thisblock
->data
.block
.last_unconditional_cleanup
);
4273 thisblock
->data
.block
.last_unconditional_cleanup
4275 /* When we insert instructions after the last unconditional cleanup,
4276 we don't adjust last_insn. That means that a later add_insn will
4277 clobber the instructions we've just added. The easiest way to
4278 fix this is to just insert another instruction here, so that the
4279 instructions inserted after the last unconditional cleanup are
4280 never the last instruction. */
4281 emit_note (NULL
, NOTE_INSN_DELETED
);
4282 thisblock
->data
.block
.cleanup_ptr
= &thisblock
->data
.block
.cleanups
;
4288 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4289 DECL_ELTS is the list of elements that belong to DECL's type.
4290 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4293 expand_anon_union_decl (decl
, cleanup
, decl_elts
)
4294 tree decl
, cleanup
, decl_elts
;
4296 struct nesting
*thisblock
= cfun
== 0 ? 0 : block_stack
;
4300 /* If any of the elements are addressable, so is the entire union. */
4301 for (t
= decl_elts
; t
; t
= TREE_CHAIN (t
))
4302 if (TREE_ADDRESSABLE (TREE_VALUE (t
)))
4304 TREE_ADDRESSABLE (decl
) = 1;
4309 expand_decl_cleanup (decl
, cleanup
);
4310 x
= DECL_RTL (decl
);
4312 /* Go through the elements, assigning RTL to each. */
4313 for (t
= decl_elts
; t
; t
= TREE_CHAIN (t
))
4315 tree decl_elt
= TREE_VALUE (t
);
4316 tree cleanup_elt
= TREE_PURPOSE (t
);
4317 enum machine_mode mode
= TYPE_MODE (TREE_TYPE (decl_elt
));
4319 /* Propagate the union's alignment to the elements. */
4320 DECL_ALIGN (decl_elt
) = DECL_ALIGN (decl
);
4321 DECL_USER_ALIGN (decl_elt
) = DECL_USER_ALIGN (decl
);
4323 /* If the element has BLKmode and the union doesn't, the union is
4324 aligned such that the element doesn't need to have BLKmode, so
4325 change the element's mode to the appropriate one for its size. */
4326 if (mode
== BLKmode
&& DECL_MODE (decl
) != BLKmode
)
4327 DECL_MODE (decl_elt
) = mode
4328 = mode_for_size_tree (DECL_SIZE (decl_elt
), MODE_INT
, 1);
4330 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4331 instead create a new MEM rtx with the proper mode. */
4332 if (GET_CODE (x
) == MEM
)
4334 if (mode
== GET_MODE (x
))
4335 SET_DECL_RTL (decl_elt
, x
);
4337 SET_DECL_RTL (decl_elt
, adjust_address_nv (x
, mode
, 0));
4339 else if (GET_CODE (x
) == REG
)
4341 if (mode
== GET_MODE (x
))
4342 SET_DECL_RTL (decl_elt
, x
);
4344 SET_DECL_RTL (decl_elt
, gen_lowpart_SUBREG (mode
, x
));
4349 /* Record the cleanup if there is one. */
4352 thisblock
->data
.block
.cleanups
4353 = tree_cons (decl_elt
, cleanup_elt
,
4354 thisblock
->data
.block
.cleanups
);
4358 /* Expand a list of cleanups LIST.
4359 Elements may be expressions or may be nested lists.
4361 If DONT_DO is nonnull, then any list-element
4362 whose TREE_PURPOSE matches DONT_DO is omitted.
4363 This is sometimes used to avoid a cleanup associated with
4364 a value that is being returned out of the scope.
4366 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
4367 goto and handle protection regions specially in that case.
4369 If REACHABLE, we emit code, otherwise just inform the exception handling
4370 code about this finalization. */
4373 expand_cleanups (list
, dont_do
, in_fixup
, reachable
)
4380 for (tail
= list
; tail
; tail
= TREE_CHAIN (tail
))
4381 if (dont_do
== 0 || TREE_PURPOSE (tail
) != dont_do
)
4383 if (TREE_CODE (TREE_VALUE (tail
)) == TREE_LIST
)
4384 expand_cleanups (TREE_VALUE (tail
), dont_do
, in_fixup
, reachable
);
4387 if (! in_fixup
&& using_eh_for_cleanups_p
)
4388 expand_eh_region_end_cleanup (TREE_VALUE (tail
));
4392 /* Cleanups may be run multiple times. For example,
4393 when exiting a binding contour, we expand the
4394 cleanups associated with that contour. When a goto
4395 within that binding contour has a target outside that
4396 contour, it will expand all cleanups from its scope to
4397 the target. Though the cleanups are expanded multiple
4398 times, the control paths are non-overlapping so the
4399 cleanups will not be executed twice. */
4401 /* We may need to protect from outer cleanups. */
4402 if (in_fixup
&& using_eh_for_cleanups_p
)
4404 expand_eh_region_start ();
4406 expand_expr (TREE_VALUE (tail
), const0_rtx
, VOIDmode
, 0);
4408 expand_eh_region_end_fixup (TREE_VALUE (tail
));
4411 expand_expr (TREE_VALUE (tail
), const0_rtx
, VOIDmode
, 0);
4419 /* Mark when the context we are emitting RTL for as a conditional
4420 context, so that any cleanup actions we register with
4421 expand_decl_init will be properly conditionalized when those
4422 cleanup actions are later performed. Must be called before any
4423 expression (tree) is expanded that is within a conditional context. */
4426 start_cleanup_deferral ()
4428 /* block_stack can be NULL if we are inside the parameter list. It is
4429 OK to do nothing, because cleanups aren't possible here. */
4431 ++block_stack
->data
.block
.conditional_code
;
4434 /* Mark the end of a conditional region of code. Because cleanup
4435 deferrals may be nested, we may still be in a conditional region
4436 after we end the currently deferred cleanups, only after we end all
4437 deferred cleanups, are we back in unconditional code. */
4440 end_cleanup_deferral ()
4442 /* block_stack can be NULL if we are inside the parameter list. It is
4443 OK to do nothing, because cleanups aren't possible here. */
4445 --block_stack
->data
.block
.conditional_code
;
4448 /* Move all cleanups from the current block_stack
4449 to the containing block_stack, where they are assumed to
4450 have been created. If anything can cause a temporary to
4451 be created, but not expanded for more than one level of
4452 block_stacks, then this code will have to change. */
4457 struct nesting
*block
= block_stack
;
4458 struct nesting
*outer
= block
->next
;
4460 outer
->data
.block
.cleanups
4461 = chainon (block
->data
.block
.cleanups
,
4462 outer
->data
.block
.cleanups
);
4463 block
->data
.block
.cleanups
= 0;
4467 last_cleanup_this_contour ()
4469 if (block_stack
== 0)
4472 return block_stack
->data
.block
.cleanups
;
4475 /* Return 1 if there are any pending cleanups at this point.
4476 If THIS_CONTOUR is nonzero, check the current contour as well.
4477 Otherwise, look only at the contours that enclose this one. */
4480 any_pending_cleanups (this_contour
)
4483 struct nesting
*block
;
4485 if (cfun
== NULL
|| cfun
->stmt
== NULL
|| block_stack
== 0)
4488 if (this_contour
&& block_stack
->data
.block
.cleanups
!= NULL
)
4490 if (block_stack
->data
.block
.cleanups
== 0
4491 && block_stack
->data
.block
.outer_cleanups
== 0)
4494 for (block
= block_stack
->next
; block
; block
= block
->next
)
4495 if (block
->data
.block
.cleanups
!= 0)
4501 /* Enter a case (Pascal) or switch (C) statement.
4502 Push a block onto case_stack and nesting_stack
4503 to accumulate the case-labels that are seen
4504 and to record the labels generated for the statement.
4506 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4507 Otherwise, this construct is transparent for `exit_something'.
4509 EXPR is the index-expression to be dispatched on.
4510 TYPE is its nominal type. We could simply convert EXPR to this type,
4511 but instead we take short cuts. */
4514 expand_start_case (exit_flag
, expr
, type
, printname
)
4518 const char *printname
;
4520 struct nesting
*thiscase
= ALLOC_NESTING ();
4522 /* Make an entry on case_stack for the case we are entering. */
4524 thiscase
->next
= case_stack
;
4525 thiscase
->all
= nesting_stack
;
4526 thiscase
->depth
= ++nesting_depth
;
4527 thiscase
->exit_label
= exit_flag
? gen_label_rtx () : 0;
4528 thiscase
->data
.case_stmt
.case_list
= 0;
4529 thiscase
->data
.case_stmt
.index_expr
= expr
;
4530 thiscase
->data
.case_stmt
.nominal_type
= type
;
4531 thiscase
->data
.case_stmt
.default_label
= 0;
4532 thiscase
->data
.case_stmt
.printname
= printname
;
4533 thiscase
->data
.case_stmt
.line_number_status
= force_line_numbers ();
4534 case_stack
= thiscase
;
4535 nesting_stack
= thiscase
;
4537 do_pending_stack_adjust ();
4539 /* Make sure case_stmt.start points to something that won't
4540 need any transformation before expand_end_case. */
4541 if (GET_CODE (get_last_insn ()) != NOTE
)
4542 emit_note (NULL
, NOTE_INSN_DELETED
);
4544 thiscase
->data
.case_stmt
.start
= get_last_insn ();
4546 start_cleanup_deferral ();
4549 /* Start a "dummy case statement" within which case labels are invalid
4550 and are not connected to any larger real case statement.
4551 This can be used if you don't want to let a case statement jump
4552 into the middle of certain kinds of constructs. */
4555 expand_start_case_dummy ()
4557 struct nesting
*thiscase
= ALLOC_NESTING ();
4559 /* Make an entry on case_stack for the dummy. */
4561 thiscase
->next
= case_stack
;
4562 thiscase
->all
= nesting_stack
;
4563 thiscase
->depth
= ++nesting_depth
;
4564 thiscase
->exit_label
= 0;
4565 thiscase
->data
.case_stmt
.case_list
= 0;
4566 thiscase
->data
.case_stmt
.start
= 0;
4567 thiscase
->data
.case_stmt
.nominal_type
= 0;
4568 thiscase
->data
.case_stmt
.default_label
= 0;
4569 case_stack
= thiscase
;
4570 nesting_stack
= thiscase
;
4571 start_cleanup_deferral ();
4574 /* End a dummy case statement. */
4577 expand_end_case_dummy ()
4579 end_cleanup_deferral ();
4580 POPSTACK (case_stack
);
4583 /* Return the data type of the index-expression
4584 of the innermost case statement, or null if none. */
4587 case_index_expr_type ()
4590 return TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4597 /* If this is the first label, warn if any insns have been emitted. */
4598 if (case_stack
->data
.case_stmt
.line_number_status
>= 0)
4602 restore_line_number_status
4603 (case_stack
->data
.case_stmt
.line_number_status
);
4604 case_stack
->data
.case_stmt
.line_number_status
= -1;
4606 for (insn
= case_stack
->data
.case_stmt
.start
;
4608 insn
= NEXT_INSN (insn
))
4610 if (GET_CODE (insn
) == CODE_LABEL
)
4612 if (GET_CODE (insn
) != NOTE
4613 && (GET_CODE (insn
) != INSN
|| GET_CODE (PATTERN (insn
)) != USE
))
4616 insn
= PREV_INSN (insn
);
4617 while (insn
&& (GET_CODE (insn
) != NOTE
|| NOTE_LINE_NUMBER (insn
) < 0));
4619 /* If insn is zero, then there must have been a syntax error. */
4621 warning_with_file_and_line (NOTE_SOURCE_FILE (insn
),
4622 NOTE_LINE_NUMBER (insn
),
4623 "unreachable code at beginning of %s",
4624 case_stack
->data
.case_stmt
.printname
);
4631 /* Accumulate one case or default label inside a case or switch statement.
4632 VALUE is the value of the case (a null pointer, for a default label).
4633 The function CONVERTER, when applied to arguments T and V,
4634 converts the value V to the type T.
4636 If not currently inside a case or switch statement, return 1 and do
4637 nothing. The caller will print a language-specific error message.
4638 If VALUE is a duplicate or overlaps, return 2 and do nothing
4639 except store the (first) duplicate node in *DUPLICATE.
4640 If VALUE is out of range, return 3 and do nothing.
4641 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4642 Return 0 on success.
4644 Extended to handle range statements. */
4647 pushcase (value
, converter
, label
, duplicate
)
4649 tree (*converter
) PARAMS ((tree
, tree
));
4656 /* Fail if not inside a real case statement. */
4657 if (! (case_stack
&& case_stack
->data
.case_stmt
.start
))
4660 if (stack_block_stack
4661 && stack_block_stack
->depth
> case_stack
->depth
)
4664 index_type
= TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4665 nominal_type
= case_stack
->data
.case_stmt
.nominal_type
;
4667 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4668 if (index_type
== error_mark_node
)
4671 /* Convert VALUE to the type in which the comparisons are nominally done. */
4673 value
= (*converter
) (nominal_type
, value
);
4677 /* Fail if this value is out of range for the actual type of the index
4678 (which may be narrower than NOMINAL_TYPE). */
4680 && (TREE_CONSTANT_OVERFLOW (value
)
4681 || ! int_fits_type_p (value
, index_type
)))
4684 return add_case_node (value
, value
, label
, duplicate
);
4687 /* Like pushcase but this case applies to all values between VALUE1 and
4688 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4689 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4690 starts at VALUE1 and ends at the highest value of the index type.
4691 If both are NULL, this case applies to all values.
4693 The return value is the same as that of pushcase but there is one
4694 additional error code: 4 means the specified range was empty. */
4697 pushcase_range (value1
, value2
, converter
, label
, duplicate
)
4698 tree value1
, value2
;
4699 tree (*converter
) PARAMS ((tree
, tree
));
4706 /* Fail if not inside a real case statement. */
4707 if (! (case_stack
&& case_stack
->data
.case_stmt
.start
))
4710 if (stack_block_stack
4711 && stack_block_stack
->depth
> case_stack
->depth
)
4714 index_type
= TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4715 nominal_type
= case_stack
->data
.case_stmt
.nominal_type
;
4717 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4718 if (index_type
== error_mark_node
)
4723 /* Convert VALUEs to type in which the comparisons are nominally done
4724 and replace any unspecified value with the corresponding bound. */
4726 value1
= TYPE_MIN_VALUE (index_type
);
4728 value2
= TYPE_MAX_VALUE (index_type
);
4730 /* Fail if the range is empty. Do this before any conversion since
4731 we want to allow out-of-range empty ranges. */
4732 if (value2
!= 0 && tree_int_cst_lt (value2
, value1
))
4735 /* If the max was unbounded, use the max of the nominal_type we are
4736 converting to. Do this after the < check above to suppress false
4739 value2
= TYPE_MAX_VALUE (nominal_type
);
4741 value1
= (*converter
) (nominal_type
, value1
);
4742 value2
= (*converter
) (nominal_type
, value2
);
4744 /* Fail if these values are out of range. */
4745 if (TREE_CONSTANT_OVERFLOW (value1
)
4746 || ! int_fits_type_p (value1
, index_type
))
4749 if (TREE_CONSTANT_OVERFLOW (value2
)
4750 || ! int_fits_type_p (value2
, index_type
))
4753 return add_case_node (value1
, value2
, label
, duplicate
);
4756 /* Do the actual insertion of a case label for pushcase and pushcase_range
4757 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4758 slowdown for large switch statements. */
4761 add_case_node (low
, high
, label
, duplicate
)
4766 struct case_node
*p
, **q
, *r
;
4768 /* If there's no HIGH value, then this is not a case range; it's
4769 just a simple case label. But that's just a degenerate case
4774 /* Handle default labels specially. */
4777 if (case_stack
->data
.case_stmt
.default_label
!= 0)
4779 *duplicate
= case_stack
->data
.case_stmt
.default_label
;
4782 case_stack
->data
.case_stmt
.default_label
= label
;
4783 expand_label (label
);
4787 q
= &case_stack
->data
.case_stmt
.case_list
;
4794 /* Keep going past elements distinctly greater than HIGH. */
4795 if (tree_int_cst_lt (high
, p
->low
))
4798 /* or distinctly less than LOW. */
4799 else if (tree_int_cst_lt (p
->high
, low
))
4804 /* We have an overlap; this is an error. */
4805 *duplicate
= p
->code_label
;
4810 /* Add this label to the chain, and succeed. */
4812 r
= (struct case_node
*) xmalloc (sizeof (struct case_node
));
4815 /* If the bounds are equal, turn this into the one-value case. */
4816 if (tree_int_cst_equal (low
, high
))
4821 r
->code_label
= label
;
4822 expand_label (label
);
4832 struct case_node
*s
;
4838 if (! (b
= p
->balance
))
4839 /* Growth propagation from left side. */
4846 if ((p
->left
= s
= r
->right
))
4855 if ((r
->parent
= s
))
4863 case_stack
->data
.case_stmt
.case_list
= r
;
4866 /* r->balance == +1 */
4871 struct case_node
*t
= r
->right
;
4873 if ((p
->left
= s
= t
->right
))
4877 if ((r
->right
= s
= t
->left
))
4891 if ((t
->parent
= s
))
4899 case_stack
->data
.case_stmt
.case_list
= t
;
4906 /* p->balance == +1; growth of left side balances the node. */
4916 if (! (b
= p
->balance
))
4917 /* Growth propagation from right side. */
4925 if ((p
->right
= s
= r
->left
))
4933 if ((r
->parent
= s
))
4942 case_stack
->data
.case_stmt
.case_list
= r
;
4946 /* r->balance == -1 */
4950 struct case_node
*t
= r
->left
;
4952 if ((p
->right
= s
= t
->left
))
4957 if ((r
->left
= s
= t
->right
))
4971 if ((t
->parent
= s
))
4980 case_stack
->data
.case_stmt
.case_list
= t
;
4986 /* p->balance == -1; growth of right side balances the node. */
4999 /* Returns the number of possible values of TYPE.
5000 Returns -1 if the number is unknown, variable, or if the number does not
5001 fit in a HOST_WIDE_INT.
5002 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
5003 do not increase monotonically (there may be duplicates);
5004 to 1 if the values increase monotonically, but not always by 1;
5005 otherwise sets it to 0. */
5008 all_cases_count (type
, spareness
)
5013 HOST_WIDE_INT count
, minval
, lastval
;
5017 switch (TREE_CODE (type
))
5024 count
= 1 << BITS_PER_UNIT
;
5029 if (TYPE_MAX_VALUE (type
) != 0
5030 && 0 != (t
= fold (build (MINUS_EXPR
, type
, TYPE_MAX_VALUE (type
),
5031 TYPE_MIN_VALUE (type
))))
5032 && 0 != (t
= fold (build (PLUS_EXPR
, type
, t
,
5033 convert (type
, integer_zero_node
))))
5034 && host_integerp (t
, 1))
5035 count
= tree_low_cst (t
, 1);
5041 /* Don't waste time with enumeral types with huge values. */
5042 if (! host_integerp (TYPE_MIN_VALUE (type
), 0)
5043 || TYPE_MAX_VALUE (type
) == 0
5044 || ! host_integerp (TYPE_MAX_VALUE (type
), 0))
5047 lastval
= minval
= tree_low_cst (TYPE_MIN_VALUE (type
), 0);
5050 for (t
= TYPE_VALUES (type
); t
!= NULL_TREE
; t
= TREE_CHAIN (t
))
5052 HOST_WIDE_INT thisval
= tree_low_cst (TREE_VALUE (t
), 0);
5054 if (*spareness
== 2 || thisval
< lastval
)
5056 else if (thisval
!= minval
+ count
)
5066 #define BITARRAY_TEST(ARRAY, INDEX) \
5067 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
5068 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
5069 #define BITARRAY_SET(ARRAY, INDEX) \
5070 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
5071 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
5073 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
5074 with the case values we have seen, assuming the case expression
5076 SPARSENESS is as determined by all_cases_count.
5078 The time needed is proportional to COUNT, unless
5079 SPARSENESS is 2, in which case quadratic time is needed. */
5082 mark_seen_cases (type
, cases_seen
, count
, sparseness
)
5084 unsigned char *cases_seen
;
5085 HOST_WIDE_INT count
;
5088 tree next_node_to_try
= NULL_TREE
;
5089 HOST_WIDE_INT next_node_offset
= 0;
5091 struct case_node
*n
, *root
= case_stack
->data
.case_stmt
.case_list
;
5092 tree val
= make_node (INTEGER_CST
);
5094 TREE_TYPE (val
) = type
;
5098 else if (sparseness
== 2)
5101 unsigned HOST_WIDE_INT xlo
;
5103 /* This less efficient loop is only needed to handle
5104 duplicate case values (multiple enum constants
5105 with the same value). */
5106 TREE_TYPE (val
) = TREE_TYPE (root
->low
);
5107 for (t
= TYPE_VALUES (type
), xlo
= 0; t
!= NULL_TREE
;
5108 t
= TREE_CHAIN (t
), xlo
++)
5110 TREE_INT_CST_LOW (val
) = TREE_INT_CST_LOW (TREE_VALUE (t
));
5111 TREE_INT_CST_HIGH (val
) = TREE_INT_CST_HIGH (TREE_VALUE (t
));
5115 /* Keep going past elements distinctly greater than VAL. */
5116 if (tree_int_cst_lt (val
, n
->low
))
5119 /* or distinctly less than VAL. */
5120 else if (tree_int_cst_lt (n
->high
, val
))
5125 /* We have found a matching range. */
5126 BITARRAY_SET (cases_seen
, xlo
);
5136 case_stack
->data
.case_stmt
.case_list
= root
= case_tree2list (root
, 0);
5138 for (n
= root
; n
; n
= n
->right
)
5140 TREE_INT_CST_LOW (val
) = TREE_INT_CST_LOW (n
->low
);
5141 TREE_INT_CST_HIGH (val
) = TREE_INT_CST_HIGH (n
->low
);
5142 while (! tree_int_cst_lt (n
->high
, val
))
5144 /* Calculate (into xlo) the "offset" of the integer (val).
5145 The element with lowest value has offset 0, the next smallest
5146 element has offset 1, etc. */
5148 unsigned HOST_WIDE_INT xlo
;
5152 if (sparseness
&& TYPE_VALUES (type
) != NULL_TREE
)
5154 /* The TYPE_VALUES will be in increasing order, so
5155 starting searching where we last ended. */
5156 t
= next_node_to_try
;
5157 xlo
= next_node_offset
;
5163 t
= TYPE_VALUES (type
);
5166 if (tree_int_cst_equal (val
, TREE_VALUE (t
)))
5168 next_node_to_try
= TREE_CHAIN (t
);
5169 next_node_offset
= xlo
+ 1;
5174 if (t
== next_node_to_try
)
5183 t
= TYPE_MIN_VALUE (type
);
5185 neg_double (TREE_INT_CST_LOW (t
), TREE_INT_CST_HIGH (t
),
5189 add_double (xlo
, xhi
,
5190 TREE_INT_CST_LOW (val
), TREE_INT_CST_HIGH (val
),
5194 if (xhi
== 0 && xlo
< (unsigned HOST_WIDE_INT
) count
)
5195 BITARRAY_SET (cases_seen
, xlo
);
5197 add_double (TREE_INT_CST_LOW (val
), TREE_INT_CST_HIGH (val
),
5199 &TREE_INT_CST_LOW (val
), &TREE_INT_CST_HIGH (val
));
5205 /* Called when the index of a switch statement is an enumerated type
5206 and there is no default label.
5208 Checks that all enumeration literals are covered by the case
5209 expressions of a switch. Also, warn if there are any extra
5210 switch cases that are *not* elements of the enumerated type.
5212 If all enumeration literals were covered by the case expressions,
5213 turn one of the expressions into the default expression since it should
5214 not be possible to fall through such a switch. */
5217 check_for_full_enumeration_handling (type
)
5220 struct case_node
*n
;
5223 /* True iff the selector type is a numbered set mode. */
5226 /* The number of possible selector values. */
5229 /* For each possible selector value. a one iff it has been matched
5230 by a case value alternative. */
5231 unsigned char *cases_seen
;
5233 /* The allocated size of cases_seen, in chars. */
5234 HOST_WIDE_INT bytes_needed
;
5239 size
= all_cases_count (type
, &sparseness
);
5240 bytes_needed
= (size
+ HOST_BITS_PER_CHAR
) / HOST_BITS_PER_CHAR
;
5242 if (size
> 0 && size
< 600000
5243 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5244 this optimization if we don't have enough memory rather than
5245 aborting, as xmalloc would do. */
5247 (unsigned char *) really_call_calloc (bytes_needed
, 1)) != NULL
)
5250 tree v
= TYPE_VALUES (type
);
5252 /* The time complexity of this code is normally O(N), where
5253 N being the number of members in the enumerated type.
5254 However, if type is a ENUMERAL_TYPE whose values do not
5255 increase monotonically, O(N*log(N)) time may be needed. */
5257 mark_seen_cases (type
, cases_seen
, size
, sparseness
);
5259 for (i
= 0; v
!= NULL_TREE
&& i
< size
; i
++, v
= TREE_CHAIN (v
))
5260 if (BITARRAY_TEST (cases_seen
, i
) == 0)
5261 warning ("enumeration value `%s' not handled in switch",
5262 IDENTIFIER_POINTER (TREE_PURPOSE (v
)));
5267 /* Now we go the other way around; we warn if there are case
5268 expressions that don't correspond to enumerators. This can
5269 occur since C and C++ don't enforce type-checking of
5270 assignments to enumeration variables. */
5272 if (case_stack
->data
.case_stmt
.case_list
5273 && case_stack
->data
.case_stmt
.case_list
->left
)
5274 case_stack
->data
.case_stmt
.case_list
5275 = case_tree2list (case_stack
->data
.case_stmt
.case_list
, 0);
5277 for (n
= case_stack
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5279 for (chain
= TYPE_VALUES (type
);
5280 chain
&& !tree_int_cst_equal (n
->low
, TREE_VALUE (chain
));
5281 chain
= TREE_CHAIN (chain
))
5286 if (TYPE_NAME (type
) == 0)
5287 warning ("case value `%ld' not in enumerated type",
5288 (long) TREE_INT_CST_LOW (n
->low
));
5290 warning ("case value `%ld' not in enumerated type `%s'",
5291 (long) TREE_INT_CST_LOW (n
->low
),
5292 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type
))
5295 : DECL_NAME (TYPE_NAME (type
))));
5297 if (!tree_int_cst_equal (n
->low
, n
->high
))
5299 for (chain
= TYPE_VALUES (type
);
5300 chain
&& !tree_int_cst_equal (n
->high
, TREE_VALUE (chain
));
5301 chain
= TREE_CHAIN (chain
))
5306 if (TYPE_NAME (type
) == 0)
5307 warning ("case value `%ld' not in enumerated type",
5308 (long) TREE_INT_CST_LOW (n
->high
));
5310 warning ("case value `%ld' not in enumerated type `%s'",
5311 (long) TREE_INT_CST_LOW (n
->high
),
5312 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type
))
5315 : DECL_NAME (TYPE_NAME (type
))));
5321 /* Free CN, and its children. */
5324 free_case_nodes (cn
)
5329 free_case_nodes (cn
->left
);
5330 free_case_nodes (cn
->right
);
5337 /* Terminate a case (Pascal) or switch (C) statement
5338 in which ORIG_INDEX is the expression to be tested.
5339 Generate the code to test it and jump to the right place. */
5342 expand_end_case (orig_index
)
5345 tree minval
= NULL_TREE
, maxval
= NULL_TREE
, range
= NULL_TREE
;
5346 rtx default_label
= 0;
5347 struct case_node
*n
;
5354 rtx before_case
, end
;
5355 struct nesting
*thiscase
= case_stack
;
5356 tree index_expr
, index_type
;
5359 /* Don't crash due to previous errors. */
5360 if (thiscase
== NULL
)
5363 table_label
= gen_label_rtx ();
5364 index_expr
= thiscase
->data
.case_stmt
.index_expr
;
5365 index_type
= TREE_TYPE (index_expr
);
5366 unsignedp
= TREE_UNSIGNED (index_type
);
5368 do_pending_stack_adjust ();
5370 /* This might get an spurious warning in the presence of a syntax error;
5371 it could be fixed by moving the call to check_seenlabel after the
5372 check for error_mark_node, and copying the code of check_seenlabel that
5373 deals with case_stack->data.case_stmt.line_number_status /
5374 restore_line_number_status in front of the call to end_cleanup_deferral;
5375 However, this might miss some useful warnings in the presence of
5376 non-syntax errors. */
5379 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5380 if (index_type
!= error_mark_node
)
5382 /* If switch expression was an enumerated type, check that all
5383 enumeration literals are covered by the cases.
5384 No sense trying this if there's a default case, however. */
5386 if (!thiscase
->data
.case_stmt
.default_label
5387 && TREE_CODE (TREE_TYPE (orig_index
)) == ENUMERAL_TYPE
5388 && TREE_CODE (index_expr
) != INTEGER_CST
)
5389 check_for_full_enumeration_handling (TREE_TYPE (orig_index
));
5391 /* If we don't have a default-label, create one here,
5392 after the body of the switch. */
5393 if (thiscase
->data
.case_stmt
.default_label
== 0)
5395 thiscase
->data
.case_stmt
.default_label
5396 = build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
5397 expand_label (thiscase
->data
.case_stmt
.default_label
);
5399 default_label
= label_rtx (thiscase
->data
.case_stmt
.default_label
);
5401 before_case
= get_last_insn ();
5403 if (thiscase
->data
.case_stmt
.case_list
5404 && thiscase
->data
.case_stmt
.case_list
->left
)
5405 thiscase
->data
.case_stmt
.case_list
5406 = case_tree2list (thiscase
->data
.case_stmt
.case_list
, 0);
5408 /* Simplify the case-list before we count it. */
5409 group_case_nodes (thiscase
->data
.case_stmt
.case_list
);
5411 /* Get upper and lower bounds of case values.
5412 Also convert all the case values to the index expr's data type. */
5415 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5417 /* Check low and high label values are integers. */
5418 if (TREE_CODE (n
->low
) != INTEGER_CST
)
5420 if (TREE_CODE (n
->high
) != INTEGER_CST
)
5423 n
->low
= convert (index_type
, n
->low
);
5424 n
->high
= convert (index_type
, n
->high
);
5426 /* Count the elements and track the largest and smallest
5427 of them (treating them as signed even if they are not). */
5435 if (INT_CST_LT (n
->low
, minval
))
5437 if (INT_CST_LT (maxval
, n
->high
))
5440 /* A range counts double, since it requires two compares. */
5441 if (! tree_int_cst_equal (n
->low
, n
->high
))
5445 /* Compute span of values. */
5447 range
= fold (build (MINUS_EXPR
, index_type
, maxval
, minval
));
5449 end_cleanup_deferral ();
5453 expand_expr (index_expr
, const0_rtx
, VOIDmode
, 0);
5455 emit_jump (default_label
);
5458 /* If range of values is much bigger than number of values,
5459 make a sequence of conditional branches instead of a dispatch.
5460 If the switch-index is a constant, do it this way
5461 because we can optimize it. */
5463 else if (count
< case_values_threshold ()
5464 || compare_tree_int (range
, 10 * count
) > 0
5465 /* RANGE may be signed, and really large ranges will show up
5466 as negative numbers. */
5467 || compare_tree_int (range
, 0) < 0
5468 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5471 || TREE_CODE (index_expr
) == INTEGER_CST
5472 || (TREE_CODE (index_expr
) == COMPOUND_EXPR
5473 && TREE_CODE (TREE_OPERAND (index_expr
, 1)) == INTEGER_CST
))
5475 index
= expand_expr (index_expr
, NULL_RTX
, VOIDmode
, 0);
5477 /* If the index is a short or char that we do not have
5478 an insn to handle comparisons directly, convert it to
5479 a full integer now, rather than letting each comparison
5480 generate the conversion. */
5482 if (GET_MODE_CLASS (GET_MODE (index
)) == MODE_INT
5483 && ! have_insn_for (COMPARE
, GET_MODE (index
)))
5485 enum machine_mode wider_mode
;
5486 for (wider_mode
= GET_MODE (index
); wider_mode
!= VOIDmode
;
5487 wider_mode
= GET_MODE_WIDER_MODE (wider_mode
))
5488 if (have_insn_for (COMPARE
, wider_mode
))
5490 index
= convert_to_mode (wider_mode
, index
, unsignedp
);
5496 do_pending_stack_adjust ();
5498 index
= protect_from_queue (index
, 0);
5499 if (GET_CODE (index
) == MEM
)
5500 index
= copy_to_reg (index
);
5501 if (GET_CODE (index
) == CONST_INT
5502 || TREE_CODE (index_expr
) == INTEGER_CST
)
5504 /* Make a tree node with the proper constant value
5505 if we don't already have one. */
5506 if (TREE_CODE (index_expr
) != INTEGER_CST
)
5509 = build_int_2 (INTVAL (index
),
5510 unsignedp
|| INTVAL (index
) >= 0 ? 0 : -1);
5511 index_expr
= convert (index_type
, index_expr
);
5514 /* For constant index expressions we need only
5515 issue an unconditional branch to the appropriate
5516 target code. The job of removing any unreachable
5517 code is left to the optimisation phase if the
5518 "-O" option is specified. */
5519 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5520 if (! tree_int_cst_lt (index_expr
, n
->low
)
5521 && ! tree_int_cst_lt (n
->high
, index_expr
))
5525 emit_jump (label_rtx (n
->code_label
));
5527 emit_jump (default_label
);
5531 /* If the index expression is not constant we generate
5532 a binary decision tree to select the appropriate
5533 target code. This is done as follows:
5535 The list of cases is rearranged into a binary tree,
5536 nearly optimal assuming equal probability for each case.
5538 The tree is transformed into RTL, eliminating
5539 redundant test conditions at the same time.
5541 If program flow could reach the end of the
5542 decision tree an unconditional jump to the
5543 default code is emitted. */
5546 = (TREE_CODE (TREE_TYPE (orig_index
)) != ENUMERAL_TYPE
5547 && estimate_case_costs (thiscase
->data
.case_stmt
.case_list
));
5548 balance_case_nodes (&thiscase
->data
.case_stmt
.case_list
, NULL
);
5549 emit_case_nodes (index
, thiscase
->data
.case_stmt
.case_list
,
5550 default_label
, index_type
);
5551 emit_jump_if_reachable (default_label
);
5556 if (! try_casesi (index_type
, index_expr
, minval
, range
,
5557 table_label
, default_label
))
5559 index_type
= thiscase
->data
.case_stmt
.nominal_type
;
5561 /* Index jumptables from zero for suitable values of
5562 minval to avoid a subtraction. */
5564 && compare_tree_int (minval
, 0) > 0
5565 && compare_tree_int (minval
, 3) < 0)
5567 minval
= integer_zero_node
;
5571 if (! try_tablejump (index_type
, index_expr
, minval
, range
,
5572 table_label
, default_label
))
5576 /* Get table of labels to jump to, in order of case index. */
5578 ncases
= tree_low_cst (range
, 0) + 1;
5579 labelvec
= (rtx
*) alloca (ncases
* sizeof (rtx
));
5580 memset ((char *) labelvec
, 0, ncases
* sizeof (rtx
));
5582 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5584 /* Compute the low and high bounds relative to the minimum
5585 value since that should fit in a HOST_WIDE_INT while the
5586 actual values may not. */
5588 = tree_low_cst (fold (build (MINUS_EXPR
, index_type
,
5589 n
->low
, minval
)), 1);
5590 HOST_WIDE_INT i_high
5591 = tree_low_cst (fold (build (MINUS_EXPR
, index_type
,
5592 n
->high
, minval
)), 1);
5595 for (i
= i_low
; i
<= i_high
; i
++)
5597 = gen_rtx_LABEL_REF (Pmode
, label_rtx (n
->code_label
));
5600 /* Fill in the gaps with the default. */
5601 for (i
= 0; i
< ncases
; i
++)
5602 if (labelvec
[i
] == 0)
5603 labelvec
[i
] = gen_rtx_LABEL_REF (Pmode
, default_label
);
5605 /* Output the table */
5606 emit_label (table_label
);
5608 if (CASE_VECTOR_PC_RELATIVE
|| flag_pic
)
5609 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE
,
5610 gen_rtx_LABEL_REF (Pmode
, table_label
),
5611 gen_rtvec_v (ncases
, labelvec
),
5612 const0_rtx
, const0_rtx
));
5614 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE
,
5615 gen_rtvec_v (ncases
, labelvec
)));
5617 /* If the case insn drops through the table,
5618 after the table we must jump to the default-label.
5619 Otherwise record no drop-through after the table. */
5620 #ifdef CASE_DROPS_THROUGH
5621 emit_jump (default_label
);
5627 before_case
= NEXT_INSN (before_case
);
5628 end
= get_last_insn ();
5629 if (squeeze_notes (&before_case
, &end
))
5631 reorder_insns (before_case
, end
,
5632 thiscase
->data
.case_stmt
.start
);
5635 end_cleanup_deferral ();
5637 if (thiscase
->exit_label
)
5638 emit_label (thiscase
->exit_label
);
5640 free_case_nodes (case_stack
->data
.case_stmt
.case_list
);
5641 POPSTACK (case_stack
);
5646 /* Convert the tree NODE into a list linked by the right field, with the left
5647 field zeroed. RIGHT is used for recursion; it is a list to be placed
5648 rightmost in the resulting list. */
5650 static struct case_node
*
5651 case_tree2list (node
, right
)
5652 struct case_node
*node
, *right
;
5654 struct case_node
*left
;
5657 right
= case_tree2list (node
->right
, right
);
5659 node
->right
= right
;
5660 if ((left
= node
->left
))
5663 return case_tree2list (left
, node
);
5669 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5672 do_jump_if_equal (op1
, op2
, label
, unsignedp
)
5673 rtx op1
, op2
, label
;
5676 if (GET_CODE (op1
) == CONST_INT
&& GET_CODE (op2
) == CONST_INT
)
5678 if (INTVAL (op1
) == INTVAL (op2
))
5682 emit_cmp_and_jump_insns (op1
, op2
, EQ
, NULL_RTX
,
5683 (GET_MODE (op1
) == VOIDmode
5684 ? GET_MODE (op2
) : GET_MODE (op1
)),
5688 /* Not all case values are encountered equally. This function
5689 uses a heuristic to weight case labels, in cases where that
5690 looks like a reasonable thing to do.
5692 Right now, all we try to guess is text, and we establish the
5695 chars above space: 16
5704 If we find any cases in the switch that are not either -1 or in the range
5705 of valid ASCII characters, or are control characters other than those
5706 commonly used with "\", don't treat this switch scanning text.
5708 Return 1 if these nodes are suitable for cost estimation, otherwise
5712 estimate_case_costs (node
)
5715 tree min_ascii
= integer_minus_one_node
;
5716 tree max_ascii
= convert (TREE_TYPE (node
->high
), build_int_2 (127, 0));
5720 /* If we haven't already made the cost table, make it now. Note that the
5721 lower bound of the table is -1, not zero. */
5723 if (! cost_table_initialized
)
5725 cost_table_initialized
= 1;
5727 for (i
= 0; i
< 128; i
++)
5730 COST_TABLE (i
) = 16;
5731 else if (ISPUNCT (i
))
5733 else if (ISCNTRL (i
))
5734 COST_TABLE (i
) = -1;
5737 COST_TABLE (' ') = 8;
5738 COST_TABLE ('\t') = 4;
5739 COST_TABLE ('\0') = 4;
5740 COST_TABLE ('\n') = 2;
5741 COST_TABLE ('\f') = 1;
5742 COST_TABLE ('\v') = 1;
5743 COST_TABLE ('\b') = 1;
5746 /* See if all the case expressions look like text. It is text if the
5747 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5748 as signed arithmetic since we don't want to ever access cost_table with a
5749 value less than -1. Also check that none of the constants in a range
5750 are strange control characters. */
5752 for (n
= node
; n
; n
= n
->right
)
5754 if ((INT_CST_LT (n
->low
, min_ascii
)) || INT_CST_LT (max_ascii
, n
->high
))
5757 for (i
= (HOST_WIDE_INT
) TREE_INT_CST_LOW (n
->low
);
5758 i
<= (HOST_WIDE_INT
) TREE_INT_CST_LOW (n
->high
); i
++)
5759 if (COST_TABLE (i
) < 0)
5763 /* All interesting values are within the range of interesting
5764 ASCII characters. */
5768 /* Scan an ordered list of case nodes
5769 combining those with consecutive values or ranges.
5771 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5774 group_case_nodes (head
)
5777 case_node_ptr node
= head
;
5781 rtx lb
= next_real_insn (label_rtx (node
->code_label
));
5783 case_node_ptr np
= node
;
5785 /* Try to group the successors of NODE with NODE. */
5786 while (((np
= np
->right
) != 0)
5787 /* Do they jump to the same place? */
5788 && ((lb2
= next_real_insn (label_rtx (np
->code_label
))) == lb
5789 || (lb
!= 0 && lb2
!= 0
5790 && simplejump_p (lb
)
5791 && simplejump_p (lb2
)
5792 && rtx_equal_p (SET_SRC (PATTERN (lb
)),
5793 SET_SRC (PATTERN (lb2
)))))
5794 /* Are their ranges consecutive? */
5795 && tree_int_cst_equal (np
->low
,
5796 fold (build (PLUS_EXPR
,
5797 TREE_TYPE (node
->high
),
5800 /* An overflow is not consecutive. */
5801 && tree_int_cst_lt (node
->high
,
5802 fold (build (PLUS_EXPR
,
5803 TREE_TYPE (node
->high
),
5805 integer_one_node
))))
5807 node
->high
= np
->high
;
5809 /* NP is the first node after NODE which can't be grouped with it.
5810 Delete the nodes in between, and move on to that node. */
5816 /* Take an ordered list of case nodes
5817 and transform them into a near optimal binary tree,
5818 on the assumption that any target code selection value is as
5819 likely as any other.
5821 The transformation is performed by splitting the ordered
5822 list into two equal sections plus a pivot. The parts are
5823 then attached to the pivot as left and right branches. Each
5824 branch is then transformed recursively. */
5827 balance_case_nodes (head
, parent
)
5828 case_node_ptr
*head
;
5829 case_node_ptr parent
;
5842 /* Count the number of entries on branch. Also count the ranges. */
5846 if (!tree_int_cst_equal (np
->low
, np
->high
))
5850 cost
+= COST_TABLE (TREE_INT_CST_LOW (np
->high
));
5854 cost
+= COST_TABLE (TREE_INT_CST_LOW (np
->low
));
5862 /* Split this list if it is long enough for that to help. */
5867 /* Find the place in the list that bisects the list's total cost,
5868 Here I gets half the total cost. */
5873 /* Skip nodes while their cost does not reach that amount. */
5874 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
5875 i
-= COST_TABLE (TREE_INT_CST_LOW ((*npp
)->high
));
5876 i
-= COST_TABLE (TREE_INT_CST_LOW ((*npp
)->low
));
5879 npp
= &(*npp
)->right
;
5884 /* Leave this branch lopsided, but optimize left-hand
5885 side and fill in `parent' fields for right-hand side. */
5887 np
->parent
= parent
;
5888 balance_case_nodes (&np
->left
, np
);
5889 for (; np
->right
; np
= np
->right
)
5890 np
->right
->parent
= np
;
5894 /* If there are just three nodes, split at the middle one. */
5896 npp
= &(*npp
)->right
;
5899 /* Find the place in the list that bisects the list's total cost,
5900 where ranges count as 2.
5901 Here I gets half the total cost. */
5902 i
= (i
+ ranges
+ 1) / 2;
5905 /* Skip nodes while their cost does not reach that amount. */
5906 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
5911 npp
= &(*npp
)->right
;
5916 np
->parent
= parent
;
5919 /* Optimize each of the two split parts. */
5920 balance_case_nodes (&np
->left
, np
);
5921 balance_case_nodes (&np
->right
, np
);
5925 /* Else leave this branch as one level,
5926 but fill in `parent' fields. */
5928 np
->parent
= parent
;
5929 for (; np
->right
; np
= np
->right
)
5930 np
->right
->parent
= np
;
5935 /* Search the parent sections of the case node tree
5936 to see if a test for the lower bound of NODE would be redundant.
5937 INDEX_TYPE is the type of the index expression.
5939 The instructions to generate the case decision tree are
5940 output in the same order as nodes are processed so it is
5941 known that if a parent node checks the range of the current
5942 node minus one that the current node is bounded at its lower
5943 span. Thus the test would be redundant. */
5946 node_has_low_bound (node
, index_type
)
5951 case_node_ptr pnode
;
5953 /* If the lower bound of this node is the lowest value in the index type,
5954 we need not test it. */
5956 if (tree_int_cst_equal (node
->low
, TYPE_MIN_VALUE (index_type
)))
5959 /* If this node has a left branch, the value at the left must be less
5960 than that at this node, so it cannot be bounded at the bottom and
5961 we need not bother testing any further. */
5966 low_minus_one
= fold (build (MINUS_EXPR
, TREE_TYPE (node
->low
),
5967 node
->low
, integer_one_node
));
5969 /* If the subtraction above overflowed, we can't verify anything.
5970 Otherwise, look for a parent that tests our value - 1. */
5972 if (! tree_int_cst_lt (low_minus_one
, node
->low
))
5975 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
5976 if (tree_int_cst_equal (low_minus_one
, pnode
->high
))
5982 /* Search the parent sections of the case node tree
5983 to see if a test for the upper bound of NODE would be redundant.
5984 INDEX_TYPE is the type of the index expression.
5986 The instructions to generate the case decision tree are
5987 output in the same order as nodes are processed so it is
5988 known that if a parent node checks the range of the current
5989 node plus one that the current node is bounded at its upper
5990 span. Thus the test would be redundant. */
5993 node_has_high_bound (node
, index_type
)
5998 case_node_ptr pnode
;
6000 /* If there is no upper bound, obviously no test is needed. */
6002 if (TYPE_MAX_VALUE (index_type
) == NULL
)
6005 /* If the upper bound of this node is the highest value in the type
6006 of the index expression, we need not test against it. */
6008 if (tree_int_cst_equal (node
->high
, TYPE_MAX_VALUE (index_type
)))
6011 /* If this node has a right branch, the value at the right must be greater
6012 than that at this node, so it cannot be bounded at the top and
6013 we need not bother testing any further. */
6018 high_plus_one
= fold (build (PLUS_EXPR
, TREE_TYPE (node
->high
),
6019 node
->high
, integer_one_node
));
6021 /* If the addition above overflowed, we can't verify anything.
6022 Otherwise, look for a parent that tests our value + 1. */
6024 if (! tree_int_cst_lt (node
->high
, high_plus_one
))
6027 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
6028 if (tree_int_cst_equal (high_plus_one
, pnode
->low
))
6034 /* Search the parent sections of the
6035 case node tree to see if both tests for the upper and lower
6036 bounds of NODE would be redundant. */
6039 node_is_bounded (node
, index_type
)
6043 return (node_has_low_bound (node
, index_type
)
6044 && node_has_high_bound (node
, index_type
));
6047 /* Emit an unconditional jump to LABEL unless it would be dead code. */
6050 emit_jump_if_reachable (label
)
6053 if (GET_CODE (get_last_insn ()) != BARRIER
)
6057 /* Emit step-by-step code to select a case for the value of INDEX.
6058 The thus generated decision tree follows the form of the
6059 case-node binary tree NODE, whose nodes represent test conditions.
6060 INDEX_TYPE is the type of the index of the switch.
6062 Care is taken to prune redundant tests from the decision tree
6063 by detecting any boundary conditions already checked by
6064 emitted rtx. (See node_has_high_bound, node_has_low_bound
6065 and node_is_bounded, above.)
6067 Where the test conditions can be shown to be redundant we emit
6068 an unconditional jump to the target code. As a further
6069 optimization, the subordinates of a tree node are examined to
6070 check for bounded nodes. In this case conditional and/or
6071 unconditional jumps as a result of the boundary check for the
6072 current node are arranged to target the subordinates associated
6073 code for out of bound conditions on the current node.
6075 We can assume that when control reaches the code generated here,
6076 the index value has already been compared with the parents
6077 of this node, and determined to be on the same side of each parent
6078 as this node is. Thus, if this node tests for the value 51,
6079 and a parent tested for 52, we don't need to consider
6080 the possibility of a value greater than 51. If another parent
6081 tests for the value 50, then this node need not test anything. */
6084 emit_case_nodes (index
, node
, default_label
, index_type
)
6090 /* If INDEX has an unsigned type, we must make unsigned branches. */
6091 int unsignedp
= TREE_UNSIGNED (index_type
);
6092 enum machine_mode mode
= GET_MODE (index
);
6093 enum machine_mode imode
= TYPE_MODE (index_type
);
6095 /* See if our parents have already tested everything for us.
6096 If they have, emit an unconditional jump for this node. */
6097 if (node_is_bounded (node
, index_type
))
6098 emit_jump (label_rtx (node
->code_label
));
6100 else if (tree_int_cst_equal (node
->low
, node
->high
))
6102 /* Node is single valued. First see if the index expression matches
6103 this node and then check our children, if any. */
6105 do_jump_if_equal (index
,
6106 convert_modes (mode
, imode
,
6107 expand_expr (node
->low
, NULL_RTX
,
6110 label_rtx (node
->code_label
), unsignedp
);
6112 if (node
->right
!= 0 && node
->left
!= 0)
6114 /* This node has children on both sides.
6115 Dispatch to one side or the other
6116 by comparing the index value with this node's value.
6117 If one subtree is bounded, check that one first,
6118 so we can avoid real branches in the tree. */
6120 if (node_is_bounded (node
->right
, index_type
))
6122 emit_cmp_and_jump_insns (index
,
6125 expand_expr (node
->high
, NULL_RTX
,
6128 GT
, NULL_RTX
, mode
, unsignedp
,
6129 label_rtx (node
->right
->code_label
));
6130 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6133 else if (node_is_bounded (node
->left
, index_type
))
6135 emit_cmp_and_jump_insns (index
,
6138 expand_expr (node
->high
, NULL_RTX
,
6141 LT
, NULL_RTX
, mode
, unsignedp
,
6142 label_rtx (node
->left
->code_label
));
6143 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6148 /* Neither node is bounded. First distinguish the two sides;
6149 then emit the code for one side at a time. */
6151 tree test_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
6153 /* See if the value is on the right. */
6154 emit_cmp_and_jump_insns (index
,
6157 expand_expr (node
->high
, NULL_RTX
,
6160 GT
, NULL_RTX
, mode
, unsignedp
,
6161 label_rtx (test_label
));
6163 /* Value must be on the left.
6164 Handle the left-hand subtree. */
6165 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6166 /* If left-hand subtree does nothing,
6168 emit_jump_if_reachable (default_label
);
6170 /* Code branches here for the right-hand subtree. */
6171 expand_label (test_label
);
6172 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6176 else if (node
->right
!= 0 && node
->left
== 0)
6178 /* Here we have a right child but no left so we issue conditional
6179 branch to default and process the right child.
6181 Omit the conditional branch to default if we it avoid only one
6182 right child; it costs too much space to save so little time. */
6184 if (node
->right
->right
|| node
->right
->left
6185 || !tree_int_cst_equal (node
->right
->low
, node
->right
->high
))
6187 if (!node_has_low_bound (node
, index_type
))
6189 emit_cmp_and_jump_insns (index
,
6192 expand_expr (node
->high
, NULL_RTX
,
6195 LT
, NULL_RTX
, mode
, unsignedp
,
6199 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6202 /* We cannot process node->right normally
6203 since we haven't ruled out the numbers less than
6204 this node's value. So handle node->right explicitly. */
6205 do_jump_if_equal (index
,
6208 expand_expr (node
->right
->low
, NULL_RTX
,
6211 label_rtx (node
->right
->code_label
), unsignedp
);
6214 else if (node
->right
== 0 && node
->left
!= 0)
6216 /* Just one subtree, on the left. */
6217 if (node
->left
->left
|| node
->left
->right
6218 || !tree_int_cst_equal (node
->left
->low
, node
->left
->high
))
6220 if (!node_has_high_bound (node
, index_type
))
6222 emit_cmp_and_jump_insns (index
,
6225 expand_expr (node
->high
, NULL_RTX
,
6228 GT
, NULL_RTX
, mode
, unsignedp
,
6232 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6235 /* We cannot process node->left normally
6236 since we haven't ruled out the numbers less than
6237 this node's value. So handle node->left explicitly. */
6238 do_jump_if_equal (index
,
6241 expand_expr (node
->left
->low
, NULL_RTX
,
6244 label_rtx (node
->left
->code_label
), unsignedp
);
6249 /* Node is a range. These cases are very similar to those for a single
6250 value, except that we do not start by testing whether this node
6251 is the one to branch to. */
6253 if (node
->right
!= 0 && node
->left
!= 0)
6255 /* Node has subtrees on both sides.
6256 If the right-hand subtree is bounded,
6257 test for it first, since we can go straight there.
6258 Otherwise, we need to make a branch in the control structure,
6259 then handle the two subtrees. */
6260 tree test_label
= 0;
6262 if (node_is_bounded (node
->right
, index_type
))
6263 /* Right hand node is fully bounded so we can eliminate any
6264 testing and branch directly to the target code. */
6265 emit_cmp_and_jump_insns (index
,
6268 expand_expr (node
->high
, NULL_RTX
,
6271 GT
, NULL_RTX
, mode
, unsignedp
,
6272 label_rtx (node
->right
->code_label
));
6275 /* Right hand node requires testing.
6276 Branch to a label where we will handle it later. */
6278 test_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
6279 emit_cmp_and_jump_insns (index
,
6282 expand_expr (node
->high
, NULL_RTX
,
6285 GT
, NULL_RTX
, mode
, unsignedp
,
6286 label_rtx (test_label
));
6289 /* Value belongs to this node or to the left-hand subtree. */
6291 emit_cmp_and_jump_insns (index
,
6294 expand_expr (node
->low
, NULL_RTX
,
6297 GE
, NULL_RTX
, mode
, unsignedp
,
6298 label_rtx (node
->code_label
));
6300 /* Handle the left-hand subtree. */
6301 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6303 /* If right node had to be handled later, do that now. */
6307 /* If the left-hand subtree fell through,
6308 don't let it fall into the right-hand subtree. */
6309 emit_jump_if_reachable (default_label
);
6311 expand_label (test_label
);
6312 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6316 else if (node
->right
!= 0 && node
->left
== 0)
6318 /* Deal with values to the left of this node,
6319 if they are possible. */
6320 if (!node_has_low_bound (node
, index_type
))
6322 emit_cmp_and_jump_insns (index
,
6325 expand_expr (node
->low
, NULL_RTX
,
6328 LT
, NULL_RTX
, mode
, unsignedp
,
6332 /* Value belongs to this node or to the right-hand subtree. */
6334 emit_cmp_and_jump_insns (index
,
6337 expand_expr (node
->high
, NULL_RTX
,
6340 LE
, NULL_RTX
, mode
, unsignedp
,
6341 label_rtx (node
->code_label
));
6343 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6346 else if (node
->right
== 0 && node
->left
!= 0)
6348 /* Deal with values to the right of this node,
6349 if they are possible. */
6350 if (!node_has_high_bound (node
, index_type
))
6352 emit_cmp_and_jump_insns (index
,
6355 expand_expr (node
->high
, NULL_RTX
,
6358 GT
, NULL_RTX
, mode
, unsignedp
,
6362 /* Value belongs to this node or to the left-hand subtree. */
6364 emit_cmp_and_jump_insns (index
,
6367 expand_expr (node
->low
, NULL_RTX
,
6370 GE
, NULL_RTX
, mode
, unsignedp
,
6371 label_rtx (node
->code_label
));
6373 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6378 /* Node has no children so we check low and high bounds to remove
6379 redundant tests. Only one of the bounds can exist,
6380 since otherwise this node is bounded--a case tested already. */
6381 int high_bound
= node_has_high_bound (node
, index_type
);
6382 int low_bound
= node_has_low_bound (node
, index_type
);
6384 if (!high_bound
&& low_bound
)
6386 emit_cmp_and_jump_insns (index
,
6389 expand_expr (node
->high
, NULL_RTX
,
6392 GT
, NULL_RTX
, mode
, unsignedp
,
6396 else if (!low_bound
&& high_bound
)
6398 emit_cmp_and_jump_insns (index
,
6401 expand_expr (node
->low
, NULL_RTX
,
6404 LT
, NULL_RTX
, mode
, unsignedp
,
6407 else if (!low_bound
&& !high_bound
)
6409 /* Widen LOW and HIGH to the same width as INDEX. */
6410 tree type
= type_for_mode (mode
, unsignedp
);
6411 tree low
= build1 (CONVERT_EXPR
, type
, node
->low
);
6412 tree high
= build1 (CONVERT_EXPR
, type
, node
->high
);
6413 rtx low_rtx
, new_index
, new_bound
;
6415 /* Instead of doing two branches, emit one unsigned branch for
6416 (index-low) > (high-low). */
6417 low_rtx
= expand_expr (low
, NULL_RTX
, mode
, 0);
6418 new_index
= expand_simple_binop (mode
, MINUS
, index
, low_rtx
,
6419 NULL_RTX
, unsignedp
,
6421 new_bound
= expand_expr (fold (build (MINUS_EXPR
, type
,
6425 emit_cmp_and_jump_insns (new_index
, new_bound
, GT
, NULL_RTX
,
6426 mode
, 1, default_label
);
6429 emit_jump (label_rtx (node
->code_label
));