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, 2002 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.
2186 Provided just for backward-compatibility. expand_expr_stmt_value()
2187 should be used for new code. */
2190 expand_expr_stmt (exp
)
2193 expand_expr_stmt_value (exp
, -1, 1);
2196 /* Generate RTL to evaluate the expression EXP. WANT_VALUE tells
2197 whether to (1) save the value of the expression, (0) discard it or
2198 (-1) use expr_stmts_for_value to tell. The use of -1 is
2199 deprecated, and retained only for backward compatibility. */
2202 expand_expr_stmt_value (exp
, want_value
, maybe_last
)
2204 int want_value
, maybe_last
;
2209 if (want_value
== -1)
2210 want_value
= expr_stmts_for_value
!= 0;
2212 /* If -W, warn about statements with no side effects,
2213 except for an explicit cast to void (e.g. for assert()), and
2214 except for last statement in ({...}) where they may be useful. */
2216 && (expr_stmts_for_value
== 0 || ! maybe_last
)
2217 && exp
!= error_mark_node
)
2219 if (! TREE_SIDE_EFFECTS (exp
))
2221 if ((extra_warnings
|| warn_unused_value
)
2222 && !(TREE_CODE (exp
) == CONVERT_EXPR
2223 && VOID_TYPE_P (TREE_TYPE (exp
))))
2224 warning_with_file_and_line (emit_filename
, emit_lineno
,
2225 "statement with no effect");
2227 else if (warn_unused_value
)
2228 warn_if_unused_value (exp
);
2231 /* If EXP is of function type and we are expanding statements for
2232 value, convert it to pointer-to-function. */
2233 if (want_value
&& TREE_CODE (TREE_TYPE (exp
)) == FUNCTION_TYPE
)
2234 exp
= build1 (ADDR_EXPR
, build_pointer_type (TREE_TYPE (exp
)), exp
);
2236 /* The call to `expand_expr' could cause last_expr_type and
2237 last_expr_value to get reset. Therefore, we set last_expr_value
2238 and last_expr_type *after* calling expand_expr. */
2239 value
= expand_expr (exp
, want_value
? NULL_RTX
: const0_rtx
,
2241 type
= TREE_TYPE (exp
);
2243 /* If all we do is reference a volatile value in memory,
2244 copy it to a register to be sure it is actually touched. */
2245 if (value
&& GET_CODE (value
) == MEM
&& TREE_THIS_VOLATILE (exp
))
2247 if (TYPE_MODE (type
) == VOIDmode
)
2249 else if (TYPE_MODE (type
) != BLKmode
)
2250 value
= copy_to_reg (value
);
2253 rtx lab
= gen_label_rtx ();
2255 /* Compare the value with itself to reference it. */
2256 emit_cmp_and_jump_insns (value
, value
, EQ
,
2257 expand_expr (TYPE_SIZE (type
),
2258 NULL_RTX
, VOIDmode
, 0),
2264 /* If this expression is part of a ({...}) and is in memory, we may have
2265 to preserve temporaries. */
2266 preserve_temp_slots (value
);
2268 /* Free any temporaries used to evaluate this expression. Any temporary
2269 used as a result of this expression will already have been preserved
2275 last_expr_value
= value
;
2276 last_expr_type
= type
;
2282 /* Warn if EXP contains any computations whose results are not used.
2283 Return 1 if a warning is printed; 0 otherwise. */
2286 warn_if_unused_value (exp
)
2289 if (TREE_USED (exp
))
2292 /* Don't warn about void constructs. This includes casting to void,
2293 void function calls, and statement expressions with a final cast
2295 if (VOID_TYPE_P (TREE_TYPE (exp
)))
2298 /* If this is an expression with side effects, don't warn. */
2299 if (TREE_SIDE_EFFECTS (exp
))
2302 switch (TREE_CODE (exp
))
2304 case PREINCREMENT_EXPR
:
2305 case POSTINCREMENT_EXPR
:
2306 case PREDECREMENT_EXPR
:
2307 case POSTDECREMENT_EXPR
:
2312 case METHOD_CALL_EXPR
:
2314 case TRY_CATCH_EXPR
:
2315 case WITH_CLEANUP_EXPR
:
2320 /* For a binding, warn if no side effect within it. */
2321 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2324 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2326 case TRUTH_ORIF_EXPR
:
2327 case TRUTH_ANDIF_EXPR
:
2328 /* In && or ||, warn if 2nd operand has no side effect. */
2329 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2332 if (TREE_NO_UNUSED_WARNING (exp
))
2334 if (warn_if_unused_value (TREE_OPERAND (exp
, 0)))
2336 /* Let people do `(foo (), 0)' without a warning. */
2337 if (TREE_CONSTANT (TREE_OPERAND (exp
, 1)))
2339 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2343 case NON_LVALUE_EXPR
:
2344 /* Don't warn about conversions not explicit in the user's program. */
2345 if (TREE_NO_UNUSED_WARNING (exp
))
2347 /* Assignment to a cast usually results in a cast of a modify.
2348 Don't complain about that. There can be an arbitrary number of
2349 casts before the modify, so we must loop until we find the first
2350 non-cast expression and then test to see if that is a modify. */
2352 tree tem
= TREE_OPERAND (exp
, 0);
2354 while (TREE_CODE (tem
) == CONVERT_EXPR
|| TREE_CODE (tem
) == NOP_EXPR
)
2355 tem
= TREE_OPERAND (tem
, 0);
2357 if (TREE_CODE (tem
) == MODIFY_EXPR
|| TREE_CODE (tem
) == INIT_EXPR
2358 || TREE_CODE (tem
) == CALL_EXPR
)
2364 /* Don't warn about automatic dereferencing of references, since
2365 the user cannot control it. */
2366 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp
, 0))) == REFERENCE_TYPE
)
2367 return warn_if_unused_value (TREE_OPERAND (exp
, 0));
2371 /* Referencing a volatile value is a side effect, so don't warn. */
2373 || TREE_CODE_CLASS (TREE_CODE (exp
)) == 'r')
2374 && TREE_THIS_VOLATILE (exp
))
2377 /* If this is an expression which has no operands, there is no value
2378 to be unused. There are no such language-independent codes,
2379 but front ends may define such. */
2380 if (TREE_CODE_CLASS (TREE_CODE (exp
)) == 'e'
2381 && TREE_CODE_LENGTH (TREE_CODE (exp
)) == 0)
2385 warning_with_file_and_line (emit_filename
, emit_lineno
,
2386 "value computed is not used");
2391 /* Clear out the memory of the last expression evaluated. */
2399 /* Begin a statement which will return a value.
2400 Return the RTL_EXPR for this statement expr.
2401 The caller must save that value and pass it to expand_end_stmt_expr. */
2404 expand_start_stmt_expr ()
2408 /* Make the RTL_EXPR node temporary, not momentary,
2409 so that rtl_expr_chain doesn't become garbage. */
2410 t
= make_node (RTL_EXPR
);
2411 do_pending_stack_adjust ();
2412 start_sequence_for_rtl_expr (t
);
2414 expr_stmts_for_value
++;
2415 last_expr_value
= NULL_RTX
;
2419 /* Restore the previous state at the end of a statement that returns a value.
2420 Returns a tree node representing the statement's value and the
2421 insns to compute the value.
2423 The nodes of that expression have been freed by now, so we cannot use them.
2424 But we don't want to do that anyway; the expression has already been
2425 evaluated and now we just want to use the value. So generate a RTL_EXPR
2426 with the proper type and RTL value.
2428 If the last substatement was not an expression,
2429 return something with type `void'. */
2432 expand_end_stmt_expr (t
)
2437 if (! last_expr_value
|| ! last_expr_type
)
2439 last_expr_value
= const0_rtx
;
2440 last_expr_type
= void_type_node
;
2442 else if (GET_CODE (last_expr_value
) != REG
&& ! CONSTANT_P (last_expr_value
))
2443 /* Remove any possible QUEUED. */
2444 last_expr_value
= protect_from_queue (last_expr_value
, 0);
2448 TREE_TYPE (t
) = last_expr_type
;
2449 RTL_EXPR_RTL (t
) = last_expr_value
;
2450 RTL_EXPR_SEQUENCE (t
) = get_insns ();
2452 rtl_expr_chain
= tree_cons (NULL_TREE
, t
, rtl_expr_chain
);
2456 /* Don't consider deleting this expr or containing exprs at tree level. */
2457 TREE_SIDE_EFFECTS (t
) = 1;
2458 /* Propagate volatility of the actual RTL expr. */
2459 TREE_THIS_VOLATILE (t
) = volatile_refs_p (last_expr_value
);
2462 expr_stmts_for_value
--;
2467 /* Generate RTL for the start of an if-then. COND is the expression
2468 whose truth should be tested.
2470 If EXITFLAG is nonzero, this conditional is visible to
2471 `exit_something'. */
2474 expand_start_cond (cond
, exitflag
)
2478 struct nesting
*thiscond
= ALLOC_NESTING ();
2480 /* Make an entry on cond_stack for the cond we are entering. */
2482 thiscond
->next
= cond_stack
;
2483 thiscond
->all
= nesting_stack
;
2484 thiscond
->depth
= ++nesting_depth
;
2485 thiscond
->data
.cond
.next_label
= gen_label_rtx ();
2486 /* Before we encounter an `else', we don't need a separate exit label
2487 unless there are supposed to be exit statements
2488 to exit this conditional. */
2489 thiscond
->exit_label
= exitflag
? gen_label_rtx () : 0;
2490 thiscond
->data
.cond
.endif_label
= thiscond
->exit_label
;
2491 cond_stack
= thiscond
;
2492 nesting_stack
= thiscond
;
2494 do_jump (cond
, thiscond
->data
.cond
.next_label
, NULL_RTX
);
2497 /* Generate RTL between then-clause and the elseif-clause
2498 of an if-then-elseif-.... */
2501 expand_start_elseif (cond
)
2504 if (cond_stack
->data
.cond
.endif_label
== 0)
2505 cond_stack
->data
.cond
.endif_label
= gen_label_rtx ();
2506 emit_jump (cond_stack
->data
.cond
.endif_label
);
2507 emit_label (cond_stack
->data
.cond
.next_label
);
2508 cond_stack
->data
.cond
.next_label
= gen_label_rtx ();
2509 do_jump (cond
, cond_stack
->data
.cond
.next_label
, NULL_RTX
);
2512 /* Generate RTL between the then-clause and the else-clause
2513 of an if-then-else. */
2516 expand_start_else ()
2518 if (cond_stack
->data
.cond
.endif_label
== 0)
2519 cond_stack
->data
.cond
.endif_label
= gen_label_rtx ();
2521 emit_jump (cond_stack
->data
.cond
.endif_label
);
2522 emit_label (cond_stack
->data
.cond
.next_label
);
2523 cond_stack
->data
.cond
.next_label
= 0; /* No more _else or _elseif calls. */
2526 /* After calling expand_start_else, turn this "else" into an "else if"
2527 by providing another condition. */
2530 expand_elseif (cond
)
2533 cond_stack
->data
.cond
.next_label
= gen_label_rtx ();
2534 do_jump (cond
, cond_stack
->data
.cond
.next_label
, NULL_RTX
);
2537 /* Generate RTL for the end of an if-then.
2538 Pop the record for it off of cond_stack. */
2543 struct nesting
*thiscond
= cond_stack
;
2545 do_pending_stack_adjust ();
2546 if (thiscond
->data
.cond
.next_label
)
2547 emit_label (thiscond
->data
.cond
.next_label
);
2548 if (thiscond
->data
.cond
.endif_label
)
2549 emit_label (thiscond
->data
.cond
.endif_label
);
2551 POPSTACK (cond_stack
);
2555 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2556 loop should be exited by `exit_something'. This is a loop for which
2557 `expand_continue' will jump to the top of the loop.
2559 Make an entry on loop_stack to record the labels associated with
2563 expand_start_loop (exit_flag
)
2566 struct nesting
*thisloop
= ALLOC_NESTING ();
2568 /* Make an entry on loop_stack for the loop we are entering. */
2570 thisloop
->next
= loop_stack
;
2571 thisloop
->all
= nesting_stack
;
2572 thisloop
->depth
= ++nesting_depth
;
2573 thisloop
->data
.loop
.start_label
= gen_label_rtx ();
2574 thisloop
->data
.loop
.end_label
= gen_label_rtx ();
2575 thisloop
->data
.loop
.alt_end_label
= 0;
2576 thisloop
->data
.loop
.continue_label
= thisloop
->data
.loop
.start_label
;
2577 thisloop
->exit_label
= exit_flag
? thisloop
->data
.loop
.end_label
: 0;
2578 loop_stack
= thisloop
;
2579 nesting_stack
= thisloop
;
2581 do_pending_stack_adjust ();
2583 emit_note (NULL
, NOTE_INSN_LOOP_BEG
);
2584 emit_label (thisloop
->data
.loop
.start_label
);
2589 /* Like expand_start_loop but for a loop where the continuation point
2590 (for expand_continue_loop) will be specified explicitly. */
2593 expand_start_loop_continue_elsewhere (exit_flag
)
2596 struct nesting
*thisloop
= expand_start_loop (exit_flag
);
2597 loop_stack
->data
.loop
.continue_label
= gen_label_rtx ();
2601 /* Begin a null, aka do { } while (0) "loop". But since the contents
2602 of said loop can still contain a break, we must frob the loop nest. */
2605 expand_start_null_loop ()
2607 struct nesting
*thisloop
= ALLOC_NESTING ();
2609 /* Make an entry on loop_stack for the loop we are entering. */
2611 thisloop
->next
= loop_stack
;
2612 thisloop
->all
= nesting_stack
;
2613 thisloop
->depth
= ++nesting_depth
;
2614 thisloop
->data
.loop
.start_label
= emit_note (NULL
, NOTE_INSN_DELETED
);
2615 thisloop
->data
.loop
.end_label
= gen_label_rtx ();
2616 thisloop
->data
.loop
.alt_end_label
= NULL_RTX
;
2617 thisloop
->data
.loop
.continue_label
= thisloop
->data
.loop
.end_label
;
2618 thisloop
->exit_label
= thisloop
->data
.loop
.end_label
;
2619 loop_stack
= thisloop
;
2620 nesting_stack
= thisloop
;
2625 /* Specify the continuation point for a loop started with
2626 expand_start_loop_continue_elsewhere.
2627 Use this at the point in the code to which a continue statement
2631 expand_loop_continue_here ()
2633 do_pending_stack_adjust ();
2634 emit_note (NULL
, NOTE_INSN_LOOP_CONT
);
2635 emit_label (loop_stack
->data
.loop
.continue_label
);
2638 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2639 Pop the block off of loop_stack. */
2644 rtx start_label
= loop_stack
->data
.loop
.start_label
;
2645 rtx insn
= get_last_insn ();
2646 int needs_end_jump
= 1;
2648 /* Mark the continue-point at the top of the loop if none elsewhere. */
2649 if (start_label
== loop_stack
->data
.loop
.continue_label
)
2650 emit_note_before (NOTE_INSN_LOOP_CONT
, start_label
);
2652 do_pending_stack_adjust ();
2654 /* If optimizing, perhaps reorder the loop.
2655 First, try to use a condjump near the end.
2656 expand_exit_loop_if_false ends loops with unconditional jumps,
2659 if (test) goto label;
2661 goto loop_stack->data.loop.end_label
2665 If we find such a pattern, we can end the loop earlier. */
2668 && GET_CODE (insn
) == CODE_LABEL
2669 && LABEL_NAME (insn
) == NULL
2670 && GET_CODE (PREV_INSN (insn
)) == BARRIER
)
2673 rtx jump
= PREV_INSN (PREV_INSN (label
));
2675 if (GET_CODE (jump
) == JUMP_INSN
2676 && GET_CODE (PATTERN (jump
)) == SET
2677 && SET_DEST (PATTERN (jump
)) == pc_rtx
2678 && GET_CODE (SET_SRC (PATTERN (jump
))) == LABEL_REF
2679 && (XEXP (SET_SRC (PATTERN (jump
)), 0)
2680 == loop_stack
->data
.loop
.end_label
))
2684 /* The test might be complex and reference LABEL multiple times,
2685 like the loop in loop_iterations to set vtop. To handle this,
2687 insn
= PREV_INSN (label
);
2688 reorder_insns (label
, label
, start_label
);
2690 for (prev
= PREV_INSN (jump
);; prev
= PREV_INSN (prev
))
2692 /* We ignore line number notes, but if we see any other note,
2693 in particular NOTE_INSN_BLOCK_*, NOTE_INSN_EH_REGION_*,
2694 NOTE_INSN_LOOP_*, we disable this optimization. */
2695 if (GET_CODE (prev
) == NOTE
)
2697 if (NOTE_LINE_NUMBER (prev
) < 0)
2701 if (GET_CODE (prev
) == CODE_LABEL
)
2703 if (GET_CODE (prev
) == JUMP_INSN
)
2705 if (GET_CODE (PATTERN (prev
)) == SET
2706 && SET_DEST (PATTERN (prev
)) == pc_rtx
2707 && GET_CODE (SET_SRC (PATTERN (prev
))) == IF_THEN_ELSE
2708 && (GET_CODE (XEXP (SET_SRC (PATTERN (prev
)), 1))
2710 && XEXP (XEXP (SET_SRC (PATTERN (prev
)), 1), 0) == label
)
2712 XEXP (XEXP (SET_SRC (PATTERN (prev
)), 1), 0)
2714 emit_note_after (NOTE_INSN_LOOP_END
, prev
);
2723 /* If the loop starts with a loop exit, roll that to the end where
2724 it will optimize together with the jump back.
2726 We look for the conditional branch to the exit, except that once
2727 we find such a branch, we don't look past 30 instructions.
2729 In more detail, if the loop presently looks like this (in pseudo-C):
2732 if (test) goto end_label;
2737 transform it to look like:
2743 if (test) goto end_label;
2744 goto newstart_label;
2747 Here, the `test' may actually consist of some reasonably complex
2748 code, terminating in a test. */
2753 ! (GET_CODE (insn
) == JUMP_INSN
2754 && GET_CODE (PATTERN (insn
)) == SET
2755 && SET_DEST (PATTERN (insn
)) == pc_rtx
2756 && GET_CODE (SET_SRC (PATTERN (insn
))) == IF_THEN_ELSE
))
2760 rtx last_test_insn
= NULL_RTX
;
2762 /* Scan insns from the top of the loop looking for a qualified
2763 conditional exit. */
2764 for (insn
= NEXT_INSN (loop_stack
->data
.loop
.start_label
); insn
;
2765 insn
= NEXT_INSN (insn
))
2767 if (GET_CODE (insn
) == NOTE
)
2770 && (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_BEG
2771 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_END
))
2772 /* The code that actually moves the exit test will
2773 carefully leave BLOCK notes in their original
2774 location. That means, however, that we can't debug
2775 the exit test itself. So, we refuse to move code
2776 containing BLOCK notes at low optimization levels. */
2779 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_EH_REGION_BEG
)
2781 else if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_EH_REGION_END
)
2785 /* We've come to the end of an EH region, but
2786 never saw the beginning of that region. That
2787 means that an EH region begins before the top
2788 of the loop, and ends in the middle of it. The
2789 existence of such a situation violates a basic
2790 assumption in this code, since that would imply
2791 that even when EH_REGIONS is zero, we might
2792 move code out of an exception region. */
2796 /* We must not walk into a nested loop. */
2797 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_LOOP_BEG
)
2800 /* We already know this INSN is a NOTE, so there's no
2801 point in looking at it to see if it's a JUMP. */
2805 if (GET_CODE (insn
) == JUMP_INSN
|| GET_CODE (insn
) == INSN
)
2808 if (last_test_insn
&& num_insns
> 30)
2812 /* We don't want to move a partial EH region. Consider:
2826 This isn't legal C++, but here's what it's supposed to
2827 mean: if cond() is true, stop looping. Otherwise,
2828 call bar, and keep looping. In addition, if cond
2829 throws an exception, catch it and keep looping. Such
2830 constructs are certainy legal in LISP.
2832 We should not move the `if (cond()) 0' test since then
2833 the EH-region for the try-block would be broken up.
2834 (In this case we would the EH_BEG note for the `try'
2835 and `if cond()' but not the call to bar() or the
2838 So we don't look for tests within an EH region. */
2841 if (GET_CODE (insn
) == JUMP_INSN
2842 && GET_CODE (PATTERN (insn
)) == SET
2843 && SET_DEST (PATTERN (insn
)) == pc_rtx
)
2845 /* This is indeed a jump. */
2846 rtx dest1
= NULL_RTX
;
2847 rtx dest2
= NULL_RTX
;
2848 rtx potential_last_test
;
2849 if (GET_CODE (SET_SRC (PATTERN (insn
))) == IF_THEN_ELSE
)
2851 /* A conditional jump. */
2852 dest1
= XEXP (SET_SRC (PATTERN (insn
)), 1);
2853 dest2
= XEXP (SET_SRC (PATTERN (insn
)), 2);
2854 potential_last_test
= insn
;
2858 /* An unconditional jump. */
2859 dest1
= SET_SRC (PATTERN (insn
));
2860 /* Include the BARRIER after the JUMP. */
2861 potential_last_test
= NEXT_INSN (insn
);
2865 if (dest1
&& GET_CODE (dest1
) == LABEL_REF
2866 && ((XEXP (dest1
, 0)
2867 == loop_stack
->data
.loop
.alt_end_label
)
2869 == loop_stack
->data
.loop
.end_label
)))
2871 last_test_insn
= potential_last_test
;
2875 /* If this was a conditional jump, there may be
2876 another label at which we should look. */
2883 if (last_test_insn
!= 0 && last_test_insn
!= get_last_insn ())
2885 /* We found one. Move everything from there up
2886 to the end of the loop, and add a jump into the loop
2887 to jump to there. */
2888 rtx newstart_label
= gen_label_rtx ();
2889 rtx start_move
= start_label
;
2892 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2893 then we want to move this note also. */
2894 if (GET_CODE (PREV_INSN (start_move
)) == NOTE
2895 && (NOTE_LINE_NUMBER (PREV_INSN (start_move
))
2896 == NOTE_INSN_LOOP_CONT
))
2897 start_move
= PREV_INSN (start_move
);
2899 emit_label_after (newstart_label
, PREV_INSN (start_move
));
2901 /* Actually move the insns. Start at the beginning, and
2902 keep copying insns until we've copied the
2904 for (insn
= start_move
; insn
; insn
= next_insn
)
2906 /* Figure out which insn comes after this one. We have
2907 to do this before we move INSN. */
2908 if (insn
== last_test_insn
)
2909 /* We've moved all the insns. */
2910 next_insn
= NULL_RTX
;
2912 next_insn
= NEXT_INSN (insn
);
2914 if (GET_CODE (insn
) == NOTE
2915 && (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_BEG
2916 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_END
))
2917 /* We don't want to move NOTE_INSN_BLOCK_BEGs or
2918 NOTE_INSN_BLOCK_ENDs because the correct generation
2919 of debugging information depends on these appearing
2920 in the same order in the RTL and in the tree
2921 structure, where they are represented as BLOCKs.
2922 So, we don't move block notes. Of course, moving
2923 the code inside the block is likely to make it
2924 impossible to debug the instructions in the exit
2925 test, but such is the price of optimization. */
2928 /* Move the INSN. */
2929 reorder_insns (insn
, insn
, get_last_insn ());
2932 emit_jump_insn_after (gen_jump (start_label
),
2933 PREV_INSN (newstart_label
));
2934 emit_barrier_after (PREV_INSN (newstart_label
));
2935 start_label
= newstart_label
;
2941 emit_jump (start_label
);
2942 emit_note (NULL
, NOTE_INSN_LOOP_END
);
2944 emit_label (loop_stack
->data
.loop
.end_label
);
2946 POPSTACK (loop_stack
);
2951 /* Finish a null loop, aka do { } while (0). */
2954 expand_end_null_loop ()
2956 do_pending_stack_adjust ();
2957 emit_label (loop_stack
->data
.loop
.end_label
);
2959 POPSTACK (loop_stack
);
2964 /* Generate a jump to the current loop's continue-point.
2965 This is usually the top of the loop, but may be specified
2966 explicitly elsewhere. If not currently inside a loop,
2967 return 0 and do nothing; caller will print an error message. */
2970 expand_continue_loop (whichloop
)
2971 struct nesting
*whichloop
;
2975 whichloop
= loop_stack
;
2978 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.continue_label
,
2983 /* Generate a jump to exit the current loop. If not currently inside a loop,
2984 return 0 and do nothing; caller will print an error message. */
2987 expand_exit_loop (whichloop
)
2988 struct nesting
*whichloop
;
2992 whichloop
= loop_stack
;
2995 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.end_label
, NULL_RTX
);
2999 /* Generate a conditional jump to exit the current loop if COND
3000 evaluates to zero. If not currently inside a loop,
3001 return 0 and do nothing; caller will print an error message. */
3004 expand_exit_loop_if_false (whichloop
, cond
)
3005 struct nesting
*whichloop
;
3008 rtx label
= gen_label_rtx ();
3013 whichloop
= loop_stack
;
3016 /* In order to handle fixups, we actually create a conditional jump
3017 around an unconditional branch to exit the loop. If fixups are
3018 necessary, they go before the unconditional branch. */
3020 do_jump (cond
, NULL_RTX
, label
);
3021 last_insn
= get_last_insn ();
3022 if (GET_CODE (last_insn
) == CODE_LABEL
)
3023 whichloop
->data
.loop
.alt_end_label
= last_insn
;
3024 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.end_label
,
3031 /* Return nonzero if the loop nest is empty. Else return zero. */
3034 stmt_loop_nest_empty ()
3036 /* cfun->stmt can be NULL if we are building a call to get the
3037 EH context for a setjmp/longjmp EH target and the current
3038 function was a deferred inline function. */
3039 return (cfun
->stmt
== NULL
|| loop_stack
== NULL
);
3042 /* Return non-zero if we should preserve sub-expressions as separate
3043 pseudos. We never do so if we aren't optimizing. We always do so
3044 if -fexpensive-optimizations.
3046 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
3047 the loop may still be a small one. */
3050 preserve_subexpressions_p ()
3054 if (flag_expensive_optimizations
)
3057 if (optimize
== 0 || cfun
== 0 || cfun
->stmt
== 0 || loop_stack
== 0)
3060 insn
= get_last_insn_anywhere ();
3063 && (INSN_UID (insn
) - INSN_UID (loop_stack
->data
.loop
.start_label
)
3064 < n_non_fixed_regs
* 3));
3068 /* Generate a jump to exit the current loop, conditional, binding contour
3069 or case statement. Not all such constructs are visible to this function,
3070 only those started with EXIT_FLAG nonzero. Individual languages use
3071 the EXIT_FLAG parameter to control which kinds of constructs you can
3074 If not currently inside anything that can be exited,
3075 return 0 and do nothing; caller will print an error message. */
3078 expand_exit_something ()
3082 for (n
= nesting_stack
; n
; n
= n
->all
)
3083 if (n
->exit_label
!= 0)
3085 expand_goto_internal (NULL_TREE
, n
->exit_label
, NULL_RTX
);
3092 /* Generate RTL to return from the current function, with no value.
3093 (That is, we do not do anything about returning any value.) */
3096 expand_null_return ()
3098 rtx last_insn
= get_last_insn ();
3100 /* If this function was declared to return a value, but we
3101 didn't, clobber the return registers so that they are not
3102 propagated live to the rest of the function. */
3103 clobber_return_register ();
3105 expand_null_return_1 (last_insn
);
3108 /* Generate RTL to return from the current function, with value VAL. */
3111 expand_value_return (val
)
3114 rtx last_insn
= get_last_insn ();
3115 rtx return_reg
= DECL_RTL (DECL_RESULT (current_function_decl
));
3117 /* Copy the value to the return location
3118 unless it's already there. */
3120 if (return_reg
!= val
)
3122 tree type
= TREE_TYPE (DECL_RESULT (current_function_decl
));
3123 #ifdef PROMOTE_FUNCTION_RETURN
3124 int unsignedp
= TREE_UNSIGNED (type
);
3125 enum machine_mode old_mode
3126 = DECL_MODE (DECL_RESULT (current_function_decl
));
3127 enum machine_mode mode
3128 = promote_mode (type
, old_mode
, &unsignedp
, 1);
3130 if (mode
!= old_mode
)
3131 val
= convert_modes (mode
, old_mode
, val
, unsignedp
);
3133 if (GET_CODE (return_reg
) == PARALLEL
)
3134 emit_group_load (return_reg
, val
, int_size_in_bytes (type
));
3136 emit_move_insn (return_reg
, val
);
3139 expand_null_return_1 (last_insn
);
3142 /* Output a return with no value. If LAST_INSN is nonzero,
3143 pretend that the return takes place after LAST_INSN. */
3146 expand_null_return_1 (last_insn
)
3149 rtx end_label
= cleanup_label
? cleanup_label
: return_label
;
3151 clear_pending_stack_adjust ();
3152 do_pending_stack_adjust ();
3156 end_label
= return_label
= gen_label_rtx ();
3157 expand_goto_internal (NULL_TREE
, end_label
, last_insn
);
3160 /* Generate RTL to evaluate the expression RETVAL and return it
3161 from the current function. */
3164 expand_return (retval
)
3167 /* If there are any cleanups to be performed, then they will
3168 be inserted following LAST_INSN. It is desirable
3169 that the last_insn, for such purposes, should be the
3170 last insn before computing the return value. Otherwise, cleanups
3171 which call functions can clobber the return value. */
3172 /* ??? rms: I think that is erroneous, because in C++ it would
3173 run destructors on variables that might be used in the subsequent
3174 computation of the return value. */
3180 /* If function wants no value, give it none. */
3181 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl
))) == VOID_TYPE
)
3183 expand_expr (retval
, NULL_RTX
, VOIDmode
, 0);
3185 expand_null_return ();
3189 if (retval
== error_mark_node
)
3191 /* Treat this like a return of no value from a function that
3193 expand_null_return ();
3196 else if (TREE_CODE (retval
) == RESULT_DECL
)
3197 retval_rhs
= retval
;
3198 else if ((TREE_CODE (retval
) == MODIFY_EXPR
|| TREE_CODE (retval
) == INIT_EXPR
)
3199 && TREE_CODE (TREE_OPERAND (retval
, 0)) == RESULT_DECL
)
3200 retval_rhs
= TREE_OPERAND (retval
, 1);
3201 else if (VOID_TYPE_P (TREE_TYPE (retval
)))
3202 /* Recognize tail-recursive call to void function. */
3203 retval_rhs
= retval
;
3205 retval_rhs
= NULL_TREE
;
3207 last_insn
= get_last_insn ();
3209 /* Distribute return down conditional expr if either of the sides
3210 may involve tail recursion (see test below). This enhances the number
3211 of tail recursions we see. Don't do this always since it can produce
3212 sub-optimal code in some cases and we distribute assignments into
3213 conditional expressions when it would help. */
3215 if (optimize
&& retval_rhs
!= 0
3216 && frame_offset
== 0
3217 && TREE_CODE (retval_rhs
) == COND_EXPR
3218 && (TREE_CODE (TREE_OPERAND (retval_rhs
, 1)) == CALL_EXPR
3219 || TREE_CODE (TREE_OPERAND (retval_rhs
, 2)) == CALL_EXPR
))
3221 rtx label
= gen_label_rtx ();
3224 do_jump (TREE_OPERAND (retval_rhs
, 0), label
, NULL_RTX
);
3225 start_cleanup_deferral ();
3226 expr
= build (MODIFY_EXPR
, TREE_TYPE (TREE_TYPE (current_function_decl
)),
3227 DECL_RESULT (current_function_decl
),
3228 TREE_OPERAND (retval_rhs
, 1));
3229 TREE_SIDE_EFFECTS (expr
) = 1;
3230 expand_return (expr
);
3233 expr
= build (MODIFY_EXPR
, TREE_TYPE (TREE_TYPE (current_function_decl
)),
3234 DECL_RESULT (current_function_decl
),
3235 TREE_OPERAND (retval_rhs
, 2));
3236 TREE_SIDE_EFFECTS (expr
) = 1;
3237 expand_return (expr
);
3238 end_cleanup_deferral ();
3242 result_rtl
= DECL_RTL (DECL_RESULT (current_function_decl
));
3244 /* If the result is an aggregate that is being returned in one (or more)
3245 registers, load the registers here. The compiler currently can't handle
3246 copying a BLKmode value into registers. We could put this code in a
3247 more general area (for use by everyone instead of just function
3248 call/return), but until this feature is generally usable it is kept here
3249 (and in expand_call). The value must go into a pseudo in case there
3250 are cleanups that will clobber the real return register. */
3253 && TYPE_MODE (TREE_TYPE (retval_rhs
)) == BLKmode
3254 && GET_CODE (result_rtl
) == REG
)
3257 unsigned HOST_WIDE_INT bitpos
, xbitpos
;
3258 unsigned HOST_WIDE_INT big_endian_correction
= 0;
3259 unsigned HOST_WIDE_INT bytes
3260 = int_size_in_bytes (TREE_TYPE (retval_rhs
));
3261 int n_regs
= (bytes
+ UNITS_PER_WORD
- 1) / UNITS_PER_WORD
;
3262 unsigned int bitsize
3263 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs
)), BITS_PER_WORD
);
3264 rtx
*result_pseudos
= (rtx
*) alloca (sizeof (rtx
) * n_regs
);
3265 rtx result_reg
, src
= NULL_RTX
, dst
= NULL_RTX
;
3266 rtx result_val
= expand_expr (retval_rhs
, NULL_RTX
, VOIDmode
, 0);
3267 enum machine_mode tmpmode
, result_reg_mode
;
3271 expand_null_return ();
3275 /* Structures whose size is not a multiple of a word are aligned
3276 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
3277 machine, this means we must skip the empty high order bytes when
3278 calculating the bit offset. */
3279 if (BYTES_BIG_ENDIAN
3280 && !FUNCTION_ARG_REG_LITTLE_ENDIAN
3281 && bytes
% UNITS_PER_WORD
)
3282 big_endian_correction
= (BITS_PER_WORD
- ((bytes
% UNITS_PER_WORD
)
3285 /* Copy the structure BITSIZE bits at a time. */
3286 for (bitpos
= 0, xbitpos
= big_endian_correction
;
3287 bitpos
< bytes
* BITS_PER_UNIT
;
3288 bitpos
+= bitsize
, xbitpos
+= bitsize
)
3290 /* We need a new destination pseudo each time xbitpos is
3291 on a word boundary and when xbitpos == big_endian_correction
3292 (the first time through). */
3293 if (xbitpos
% BITS_PER_WORD
== 0
3294 || xbitpos
== big_endian_correction
)
3296 /* Generate an appropriate register. */
3297 dst
= gen_reg_rtx (word_mode
);
3298 result_pseudos
[xbitpos
/ BITS_PER_WORD
] = dst
;
3300 /* Clear the destination before we move anything into it. */
3301 emit_move_insn (dst
, CONST0_RTX (GET_MODE (dst
)));
3304 /* We need a new source operand each time bitpos is on a word
3306 if (bitpos
% BITS_PER_WORD
== 0)
3307 src
= operand_subword_force (result_val
,
3308 bitpos
/ BITS_PER_WORD
,
3311 /* Use bitpos for the source extraction (left justified) and
3312 xbitpos for the destination store (right justified). */
3313 store_bit_field (dst
, bitsize
, xbitpos
% BITS_PER_WORD
, word_mode
,
3314 extract_bit_field (src
, bitsize
,
3315 bitpos
% BITS_PER_WORD
, 1,
3316 NULL_RTX
, word_mode
, word_mode
,
3321 /* Find the smallest integer mode large enough to hold the
3322 entire structure and use that mode instead of BLKmode
3323 on the USE insn for the return register. */
3324 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
3325 tmpmode
!= VOIDmode
;
3326 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
3327 /* Have we found a large enough mode? */
3328 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
3331 /* No suitable mode found. */
3332 if (tmpmode
== VOIDmode
)
3335 PUT_MODE (result_rtl
, tmpmode
);
3337 if (GET_MODE_SIZE (tmpmode
) < GET_MODE_SIZE (word_mode
))
3338 result_reg_mode
= word_mode
;
3340 result_reg_mode
= tmpmode
;
3341 result_reg
= gen_reg_rtx (result_reg_mode
);
3344 for (i
= 0; i
< n_regs
; i
++)
3345 emit_move_insn (operand_subword (result_reg
, i
, 0, result_reg_mode
),
3348 if (tmpmode
!= result_reg_mode
)
3349 result_reg
= gen_lowpart (tmpmode
, result_reg
);
3351 expand_value_return (result_reg
);
3353 else if (retval_rhs
!= 0
3354 && !VOID_TYPE_P (TREE_TYPE (retval_rhs
))
3355 && (GET_CODE (result_rtl
) == REG
3356 || (GET_CODE (result_rtl
) == PARALLEL
)))
3358 /* Calculate the return value into a temporary (usually a pseudo
3360 tree ot
= TREE_TYPE (DECL_RESULT (current_function_decl
));
3361 tree nt
= build_qualified_type (ot
, TYPE_QUALS (ot
) | TYPE_QUAL_CONST
);
3363 val
= assign_temp (nt
, 0, 0, 1);
3364 val
= expand_expr (retval_rhs
, val
, GET_MODE (val
), 0);
3365 val
= force_not_mem (val
);
3367 /* Return the calculated value, doing cleanups first. */
3368 expand_value_return (val
);
3372 /* No cleanups or no hard reg used;
3373 calculate value into hard return reg. */
3374 expand_expr (retval
, const0_rtx
, VOIDmode
, 0);
3376 expand_value_return (result_rtl
);
3380 /* Return 1 if the end of the generated RTX is not a barrier.
3381 This means code already compiled can drop through. */
3384 drop_through_at_end_p ()
3386 rtx insn
= get_last_insn ();
3387 while (insn
&& GET_CODE (insn
) == NOTE
)
3388 insn
= PREV_INSN (insn
);
3389 return insn
&& GET_CODE (insn
) != BARRIER
;
3392 /* Attempt to optimize a potential tail recursion call into a goto.
3393 ARGUMENTS are the arguments to a CALL_EXPR; LAST_INSN indicates
3394 where to place the jump to the tail recursion label.
3396 Return TRUE if the call was optimized into a goto. */
3399 optimize_tail_recursion (arguments
, last_insn
)
3403 /* Finish checking validity, and if valid emit code to set the
3404 argument variables for the new call. */
3405 if (tail_recursion_args (arguments
, DECL_ARGUMENTS (current_function_decl
)))
3407 if (tail_recursion_label
== 0)
3409 tail_recursion_label
= gen_label_rtx ();
3410 emit_label_after (tail_recursion_label
,
3411 tail_recursion_reentry
);
3414 expand_goto_internal (NULL_TREE
, tail_recursion_label
, last_insn
);
3421 /* Emit code to alter this function's formal parms for a tail-recursive call.
3422 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3423 FORMALS is the chain of decls of formals.
3424 Return 1 if this can be done;
3425 otherwise return 0 and do not emit any code. */
3428 tail_recursion_args (actuals
, formals
)
3429 tree actuals
, formals
;
3431 tree a
= actuals
, f
= formals
;
3435 /* Check that number and types of actuals are compatible
3436 with the formals. This is not always true in valid C code.
3437 Also check that no formal needs to be addressable
3438 and that all formals are scalars. */
3440 /* Also count the args. */
3442 for (a
= actuals
, f
= formals
, i
= 0; a
&& f
; a
= TREE_CHAIN (a
), f
= TREE_CHAIN (f
), i
++)
3444 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a
)))
3445 != TYPE_MAIN_VARIANT (TREE_TYPE (f
)))
3447 if (GET_CODE (DECL_RTL (f
)) != REG
|| DECL_MODE (f
) == BLKmode
)
3450 if (a
!= 0 || f
!= 0)
3453 /* Compute all the actuals. */
3455 argvec
= (rtx
*) alloca (i
* sizeof (rtx
));
3457 for (a
= actuals
, i
= 0; a
; a
= TREE_CHAIN (a
), i
++)
3458 argvec
[i
] = expand_expr (TREE_VALUE (a
), NULL_RTX
, VOIDmode
, 0);
3460 /* Find which actual values refer to current values of previous formals.
3461 Copy each of them now, before any formal is changed. */
3463 for (a
= actuals
, i
= 0; a
; a
= TREE_CHAIN (a
), i
++)
3467 for (f
= formals
, j
= 0; j
< i
; f
= TREE_CHAIN (f
), j
++)
3468 if (reg_mentioned_p (DECL_RTL (f
), argvec
[i
]))
3474 argvec
[i
] = copy_to_reg (argvec
[i
]);
3477 /* Store the values of the actuals into the formals. */
3479 for (f
= formals
, a
= actuals
, i
= 0; f
;
3480 f
= TREE_CHAIN (f
), a
= TREE_CHAIN (a
), i
++)
3482 if (GET_MODE (DECL_RTL (f
)) == GET_MODE (argvec
[i
]))
3483 emit_move_insn (DECL_RTL (f
), argvec
[i
]);
3485 convert_move (DECL_RTL (f
), argvec
[i
],
3486 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a
))));
3493 /* Generate the RTL code for entering a binding contour.
3494 The variables are declared one by one, by calls to `expand_decl'.
3496 FLAGS is a bitwise or of the following flags:
3498 1 - Nonzero if this construct should be visible to
3501 2 - Nonzero if this contour does not require a
3502 NOTE_INSN_BLOCK_BEG note. Virtually all calls from
3503 language-independent code should set this flag because they
3504 will not create corresponding BLOCK nodes. (There should be
3505 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
3506 and BLOCKs.) If this flag is set, MARK_ENDS should be zero
3507 when expand_end_bindings is called.
3509 If we are creating a NOTE_INSN_BLOCK_BEG note, a BLOCK may
3510 optionally be supplied. If so, it becomes the NOTE_BLOCK for the
3514 expand_start_bindings_and_block (flags
, block
)
3518 struct nesting
*thisblock
= ALLOC_NESTING ();
3520 int exit_flag
= ((flags
& 1) != 0);
3521 int block_flag
= ((flags
& 2) == 0);
3523 /* If a BLOCK is supplied, then the caller should be requesting a
3524 NOTE_INSN_BLOCK_BEG note. */
3525 if (!block_flag
&& block
)
3528 /* Create a note to mark the beginning of the block. */
3531 note
= emit_note (NULL
, NOTE_INSN_BLOCK_BEG
);
3532 NOTE_BLOCK (note
) = block
;
3535 note
= emit_note (NULL
, NOTE_INSN_DELETED
);
3537 /* Make an entry on block_stack for the block we are entering. */
3539 thisblock
->next
= block_stack
;
3540 thisblock
->all
= nesting_stack
;
3541 thisblock
->depth
= ++nesting_depth
;
3542 thisblock
->data
.block
.stack_level
= 0;
3543 thisblock
->data
.block
.cleanups
= 0;
3544 thisblock
->data
.block
.n_function_calls
= 0;
3545 thisblock
->data
.block
.exception_region
= 0;
3546 thisblock
->data
.block
.block_target_temp_slot_level
= target_temp_slot_level
;
3548 thisblock
->data
.block
.conditional_code
= 0;
3549 thisblock
->data
.block
.last_unconditional_cleanup
= note
;
3550 /* When we insert instructions after the last unconditional cleanup,
3551 we don't adjust last_insn. That means that a later add_insn will
3552 clobber the instructions we've just added. The easiest way to
3553 fix this is to just insert another instruction here, so that the
3554 instructions inserted after the last unconditional cleanup are
3555 never the last instruction. */
3556 emit_note (NULL
, NOTE_INSN_DELETED
);
3557 thisblock
->data
.block
.cleanup_ptr
= &thisblock
->data
.block
.cleanups
;
3560 && !(block_stack
->data
.block
.cleanups
== NULL_TREE
3561 && block_stack
->data
.block
.outer_cleanups
== NULL_TREE
))
3562 thisblock
->data
.block
.outer_cleanups
3563 = tree_cons (NULL_TREE
, block_stack
->data
.block
.cleanups
,
3564 block_stack
->data
.block
.outer_cleanups
);
3566 thisblock
->data
.block
.outer_cleanups
= 0;
3567 thisblock
->data
.block
.label_chain
= 0;
3568 thisblock
->data
.block
.innermost_stack_block
= stack_block_stack
;
3569 thisblock
->data
.block
.first_insn
= note
;
3570 thisblock
->data
.block
.block_start_count
= ++current_block_start_count
;
3571 thisblock
->exit_label
= exit_flag
? gen_label_rtx () : 0;
3572 block_stack
= thisblock
;
3573 nesting_stack
= thisblock
;
3575 /* Make a new level for allocating stack slots. */
3579 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3580 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3581 expand_expr are made. After we end the region, we know that all
3582 space for all temporaries that were created by TARGET_EXPRs will be
3583 destroyed and their space freed for reuse. */
3586 expand_start_target_temps ()
3588 /* This is so that even if the result is preserved, the space
3589 allocated will be freed, as we know that it is no longer in use. */
3592 /* Start a new binding layer that will keep track of all cleanup
3593 actions to be performed. */
3594 expand_start_bindings (2);
3596 target_temp_slot_level
= temp_slot_level
;
3600 expand_end_target_temps ()
3602 expand_end_bindings (NULL_TREE
, 0, 0);
3604 /* This is so that even if the result is preserved, the space
3605 allocated will be freed, as we know that it is no longer in use. */
3609 /* Given a pointer to a BLOCK node return non-zero if (and only if) the node
3610 in question represents the outermost pair of curly braces (i.e. the "body
3611 block") of a function or method.
3613 For any BLOCK node representing a "body block" of a function or method, the
3614 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
3615 represents the outermost (function) scope for the function or method (i.e.
3616 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
3617 *that* node in turn will point to the relevant FUNCTION_DECL node. */
3620 is_body_block (stmt
)
3623 if (TREE_CODE (stmt
) == BLOCK
)
3625 tree parent
= BLOCK_SUPERCONTEXT (stmt
);
3627 if (parent
&& TREE_CODE (parent
) == BLOCK
)
3629 tree grandparent
= BLOCK_SUPERCONTEXT (parent
);
3631 if (grandparent
&& TREE_CODE (grandparent
) == FUNCTION_DECL
)
3639 /* True if we are currently emitting insns in an area of output code
3640 that is controlled by a conditional expression. This is used by
3641 the cleanup handling code to generate conditional cleanup actions. */
3644 conditional_context ()
3646 return block_stack
&& block_stack
->data
.block
.conditional_code
;
3649 /* Return an opaque pointer to the current nesting level, so frontend code
3650 can check its own sanity. */
3653 current_nesting_level ()
3655 return cfun
? block_stack
: 0;
3658 /* Emit a handler label for a nonlocal goto handler.
3659 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3662 expand_nl_handler_label (slot
, before_insn
)
3663 rtx slot
, before_insn
;
3666 rtx handler_label
= gen_label_rtx ();
3668 /* Don't let cleanup_cfg delete the handler. */
3669 LABEL_PRESERVE_P (handler_label
) = 1;
3672 emit_move_insn (slot
, gen_rtx_LABEL_REF (Pmode
, handler_label
));
3673 insns
= get_insns ();
3675 emit_insns_before (insns
, before_insn
);
3677 emit_label (handler_label
);
3679 return handler_label
;
3682 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3685 expand_nl_goto_receiver ()
3687 #ifdef HAVE_nonlocal_goto
3688 if (! HAVE_nonlocal_goto
)
3690 /* First adjust our frame pointer to its actual value. It was
3691 previously set to the start of the virtual area corresponding to
3692 the stacked variables when we branched here and now needs to be
3693 adjusted to the actual hardware fp value.
3695 Assignments are to virtual registers are converted by
3696 instantiate_virtual_regs into the corresponding assignment
3697 to the underlying register (fp in this case) that makes
3698 the original assignment true.
3699 So the following insn will actually be
3700 decrementing fp by STARTING_FRAME_OFFSET. */
3701 emit_move_insn (virtual_stack_vars_rtx
, hard_frame_pointer_rtx
);
3703 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3704 if (fixed_regs
[ARG_POINTER_REGNUM
])
3706 #ifdef ELIMINABLE_REGS
3707 /* If the argument pointer can be eliminated in favor of the
3708 frame pointer, we don't need to restore it. We assume here
3709 that if such an elimination is present, it can always be used.
3710 This is the case on all known machines; if we don't make this
3711 assumption, we do unnecessary saving on many machines. */
3712 static const struct elims
{const int from
, to
;} elim_regs
[] = ELIMINABLE_REGS
;
3715 for (i
= 0; i
< ARRAY_SIZE (elim_regs
); i
++)
3716 if (elim_regs
[i
].from
== ARG_POINTER_REGNUM
3717 && elim_regs
[i
].to
== HARD_FRAME_POINTER_REGNUM
)
3720 if (i
== ARRAY_SIZE (elim_regs
))
3723 /* Now restore our arg pointer from the address at which it
3724 was saved in our stack frame. */
3725 emit_move_insn (virtual_incoming_args_rtx
,
3726 copy_to_reg (get_arg_pointer_save_area (cfun
)));
3731 #ifdef HAVE_nonlocal_goto_receiver
3732 if (HAVE_nonlocal_goto_receiver
)
3733 emit_insn (gen_nonlocal_goto_receiver ());
3737 /* Make handlers for nonlocal gotos taking place in the function calls in
3741 expand_nl_goto_receivers (thisblock
)
3742 struct nesting
*thisblock
;
3745 rtx afterward
= gen_label_rtx ();
3750 /* Record the handler address in the stack slot for that purpose,
3751 during this block, saving and restoring the outer value. */
3752 if (thisblock
->next
!= 0)
3753 for (slot
= nonlocal_goto_handler_slots
; slot
; slot
= XEXP (slot
, 1))
3755 rtx save_receiver
= gen_reg_rtx (Pmode
);
3756 emit_move_insn (XEXP (slot
, 0), save_receiver
);
3759 emit_move_insn (save_receiver
, XEXP (slot
, 0));
3760 insns
= get_insns ();
3762 emit_insns_before (insns
, thisblock
->data
.block
.first_insn
);
3765 /* Jump around the handlers; they run only when specially invoked. */
3766 emit_jump (afterward
);
3768 /* Make a separate handler for each label. */
3769 link
= nonlocal_labels
;
3770 slot
= nonlocal_goto_handler_slots
;
3771 label_list
= NULL_RTX
;
3772 for (; link
; link
= TREE_CHAIN (link
), slot
= XEXP (slot
, 1))
3773 /* Skip any labels we shouldn't be able to jump to from here,
3774 we generate one special handler for all of them below which just calls
3776 if (! DECL_TOO_LATE (TREE_VALUE (link
)))
3779 lab
= expand_nl_handler_label (XEXP (slot
, 0),
3780 thisblock
->data
.block
.first_insn
);
3781 label_list
= gen_rtx_EXPR_LIST (VOIDmode
, lab
, label_list
);
3783 expand_nl_goto_receiver ();
3785 /* Jump to the "real" nonlocal label. */
3786 expand_goto (TREE_VALUE (link
));
3789 /* A second pass over all nonlocal labels; this time we handle those
3790 we should not be able to jump to at this point. */
3791 link
= nonlocal_labels
;
3792 slot
= nonlocal_goto_handler_slots
;
3794 for (; link
; link
= TREE_CHAIN (link
), slot
= XEXP (slot
, 1))
3795 if (DECL_TOO_LATE (TREE_VALUE (link
)))
3798 lab
= expand_nl_handler_label (XEXP (slot
, 0),
3799 thisblock
->data
.block
.first_insn
);
3800 label_list
= gen_rtx_EXPR_LIST (VOIDmode
, lab
, label_list
);
3806 expand_nl_goto_receiver ();
3807 emit_library_call (gen_rtx_SYMBOL_REF (Pmode
, "abort"), LCT_NORETURN
,
3812 nonlocal_goto_handler_labels
= label_list
;
3813 emit_label (afterward
);
3816 /* Warn about any unused VARS (which may contain nodes other than
3817 VAR_DECLs, but such nodes are ignored). The nodes are connected
3818 via the TREE_CHAIN field. */
3821 warn_about_unused_variables (vars
)
3826 if (warn_unused_variable
)
3827 for (decl
= vars
; decl
; decl
= TREE_CHAIN (decl
))
3828 if (TREE_CODE (decl
) == VAR_DECL
3829 && ! TREE_USED (decl
)
3830 && ! DECL_IN_SYSTEM_HEADER (decl
)
3831 && DECL_NAME (decl
) && ! DECL_ARTIFICIAL (decl
))
3832 warning_with_decl (decl
, "unused variable `%s'");
3835 /* Generate RTL code to terminate a binding contour.
3837 VARS is the chain of VAR_DECL nodes for the variables bound in this
3838 contour. There may actually be other nodes in this chain, but any
3839 nodes other than VAR_DECLS are ignored.
3841 MARK_ENDS is nonzero if we should put a note at the beginning
3842 and end of this binding contour.
3844 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3845 (That is true automatically if the contour has a saved stack level.) */
3848 expand_end_bindings (vars
, mark_ends
, dont_jump_in
)
3853 struct nesting
*thisblock
= block_stack
;
3855 /* If any of the variables in this scope were not used, warn the
3857 warn_about_unused_variables (vars
);
3859 if (thisblock
->exit_label
)
3861 do_pending_stack_adjust ();
3862 emit_label (thisblock
->exit_label
);
3865 /* If necessary, make handlers for nonlocal gotos taking
3866 place in the function calls in this block. */
3867 if (function_call_count
!= thisblock
->data
.block
.n_function_calls
3869 /* Make handler for outermost block
3870 if there were any nonlocal gotos to this function. */
3871 && (thisblock
->next
== 0 ? current_function_has_nonlocal_label
3872 /* Make handler for inner block if it has something
3873 special to do when you jump out of it. */
3874 : (thisblock
->data
.block
.cleanups
!= 0
3875 || thisblock
->data
.block
.stack_level
!= 0)))
3876 expand_nl_goto_receivers (thisblock
);
3878 /* Don't allow jumping into a block that has a stack level.
3879 Cleanups are allowed, though. */
3881 || thisblock
->data
.block
.stack_level
!= 0)
3883 struct label_chain
*chain
;
3885 /* Any labels in this block are no longer valid to go to.
3886 Mark them to cause an error message. */
3887 for (chain
= thisblock
->data
.block
.label_chain
; chain
; chain
= chain
->next
)
3889 DECL_TOO_LATE (chain
->label
) = 1;
3890 /* If any goto without a fixup came to this label,
3891 that must be an error, because gotos without fixups
3892 come from outside all saved stack-levels. */
3893 if (TREE_ADDRESSABLE (chain
->label
))
3894 error_with_decl (chain
->label
,
3895 "label `%s' used before containing binding contour");
3899 /* Restore stack level in effect before the block
3900 (only if variable-size objects allocated). */
3901 /* Perform any cleanups associated with the block. */
3903 if (thisblock
->data
.block
.stack_level
!= 0
3904 || thisblock
->data
.block
.cleanups
!= 0)
3909 /* Don't let cleanups affect ({...}) constructs. */
3910 int old_expr_stmts_for_value
= expr_stmts_for_value
;
3911 rtx old_last_expr_value
= last_expr_value
;
3912 tree old_last_expr_type
= last_expr_type
;
3913 expr_stmts_for_value
= 0;
3915 /* Only clean up here if this point can actually be reached. */
3916 insn
= get_last_insn ();
3917 if (GET_CODE (insn
) == NOTE
)
3918 insn
= prev_nonnote_insn (insn
);
3919 reachable
= (! insn
|| GET_CODE (insn
) != BARRIER
);
3921 /* Do the cleanups. */
3922 expand_cleanups (thisblock
->data
.block
.cleanups
, NULL_TREE
, 0, reachable
);
3924 do_pending_stack_adjust ();
3926 expr_stmts_for_value
= old_expr_stmts_for_value
;
3927 last_expr_value
= old_last_expr_value
;
3928 last_expr_type
= old_last_expr_type
;
3930 /* Restore the stack level. */
3932 if (reachable
&& thisblock
->data
.block
.stack_level
!= 0)
3934 emit_stack_restore (thisblock
->next
? SAVE_BLOCK
: SAVE_FUNCTION
,
3935 thisblock
->data
.block
.stack_level
, NULL_RTX
);
3936 if (nonlocal_goto_handler_slots
!= 0)
3937 emit_stack_save (SAVE_NONLOCAL
, &nonlocal_goto_stack_level
,
3941 /* Any gotos out of this block must also do these things.
3942 Also report any gotos with fixups that came to labels in this
3944 fixup_gotos (thisblock
,
3945 thisblock
->data
.block
.stack_level
,
3946 thisblock
->data
.block
.cleanups
,
3947 thisblock
->data
.block
.first_insn
,
3951 /* Mark the beginning and end of the scope if requested.
3952 We do this now, after running cleanups on the variables
3953 just going out of scope, so they are in scope for their cleanups. */
3957 rtx note
= emit_note (NULL
, NOTE_INSN_BLOCK_END
);
3958 NOTE_BLOCK (note
) = NOTE_BLOCK (thisblock
->data
.block
.first_insn
);
3961 /* Get rid of the beginning-mark if we don't make an end-mark. */
3962 NOTE_LINE_NUMBER (thisblock
->data
.block
.first_insn
) = NOTE_INSN_DELETED
;
3964 /* Restore the temporary level of TARGET_EXPRs. */
3965 target_temp_slot_level
= thisblock
->data
.block
.block_target_temp_slot_level
;
3967 /* Restore block_stack level for containing block. */
3969 stack_block_stack
= thisblock
->data
.block
.innermost_stack_block
;
3970 POPSTACK (block_stack
);
3972 /* Pop the stack slot nesting and free any slots at this level. */
3976 /* Generate code to save the stack pointer at the start of the current block
3977 and set up to restore it on exit. */
3980 save_stack_pointer ()
3982 struct nesting
*thisblock
= block_stack
;
3984 if (thisblock
->data
.block
.stack_level
== 0)
3986 emit_stack_save (thisblock
->next
? SAVE_BLOCK
: SAVE_FUNCTION
,
3987 &thisblock
->data
.block
.stack_level
,
3988 thisblock
->data
.block
.first_insn
);
3989 stack_block_stack
= thisblock
;
3993 /* Generate RTL for the automatic variable declaration DECL.
3994 (Other kinds of declarations are simply ignored if seen here.) */
4000 struct nesting
*thisblock
;
4003 type
= TREE_TYPE (decl
);
4005 /* For a CONST_DECL, set mode, alignment, and sizes from those of the
4006 type in case this node is used in a reference. */
4007 if (TREE_CODE (decl
) == CONST_DECL
)
4009 DECL_MODE (decl
) = TYPE_MODE (type
);
4010 DECL_ALIGN (decl
) = TYPE_ALIGN (type
);
4011 DECL_SIZE (decl
) = TYPE_SIZE (type
);
4012 DECL_SIZE_UNIT (decl
) = TYPE_SIZE_UNIT (type
);
4016 /* Otherwise, only automatic variables need any expansion done. Static and
4017 external variables, and external functions, will be handled by
4018 `assemble_variable' (called from finish_decl). TYPE_DECL requires
4019 nothing. PARM_DECLs are handled in `assign_parms'. */
4020 if (TREE_CODE (decl
) != VAR_DECL
)
4023 if (TREE_STATIC (decl
) || DECL_EXTERNAL (decl
))
4026 thisblock
= block_stack
;
4028 /* Create the RTL representation for the variable. */
4030 if (type
== error_mark_node
)
4031 SET_DECL_RTL (decl
, gen_rtx_MEM (BLKmode
, const0_rtx
));
4033 else if (DECL_SIZE (decl
) == 0)
4034 /* Variable with incomplete type. */
4037 if (DECL_INITIAL (decl
) == 0)
4038 /* Error message was already done; now avoid a crash. */
4039 x
= gen_rtx_MEM (BLKmode
, const0_rtx
);
4041 /* An initializer is going to decide the size of this array.
4042 Until we know the size, represent its address with a reg. */
4043 x
= gen_rtx_MEM (BLKmode
, gen_reg_rtx (Pmode
));
4045 set_mem_attributes (x
, decl
, 1);
4046 SET_DECL_RTL (decl
, x
);
4048 else if (DECL_MODE (decl
) != BLKmode
4049 /* If -ffloat-store, don't put explicit float vars
4051 && !(flag_float_store
4052 && TREE_CODE (type
) == REAL_TYPE
)
4053 && ! TREE_THIS_VOLATILE (decl
)
4054 && (DECL_REGISTER (decl
) || optimize
))
4056 /* Automatic variable that can go in a register. */
4057 int unsignedp
= TREE_UNSIGNED (type
);
4058 enum machine_mode reg_mode
4059 = promote_mode (type
, DECL_MODE (decl
), &unsignedp
, 0);
4061 SET_DECL_RTL (decl
, gen_reg_rtx (reg_mode
));
4063 if (GET_CODE (DECL_RTL (decl
)) == REG
)
4064 REGNO_DECL (REGNO (DECL_RTL (decl
))) = decl
;
4065 else if (GET_CODE (DECL_RTL (decl
)) == CONCAT
)
4067 REGNO_DECL (REGNO (XEXP (DECL_RTL (decl
), 0))) = decl
;
4068 REGNO_DECL (REGNO (XEXP (DECL_RTL (decl
), 1))) = decl
;
4071 mark_user_reg (DECL_RTL (decl
));
4073 if (POINTER_TYPE_P (type
))
4074 mark_reg_pointer (DECL_RTL (decl
),
4075 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl
))));
4077 maybe_set_unchanging (DECL_RTL (decl
), decl
);
4079 /* If something wants our address, try to use ADDRESSOF. */
4080 if (TREE_ADDRESSABLE (decl
))
4081 put_var_into_stack (decl
);
4084 else if (TREE_CODE (DECL_SIZE_UNIT (decl
)) == INTEGER_CST
4085 && ! (flag_stack_check
&& ! STACK_CHECK_BUILTIN
4086 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl
),
4087 STACK_CHECK_MAX_VAR_SIZE
)))
4089 /* Variable of fixed size that goes on the stack. */
4094 /* If we previously made RTL for this decl, it must be an array
4095 whose size was determined by the initializer.
4096 The old address was a register; set that register now
4097 to the proper address. */
4098 if (DECL_RTL_SET_P (decl
))
4100 if (GET_CODE (DECL_RTL (decl
)) != MEM
4101 || GET_CODE (XEXP (DECL_RTL (decl
), 0)) != REG
)
4103 oldaddr
= XEXP (DECL_RTL (decl
), 0);
4106 /* Set alignment we actually gave this decl. */
4107 DECL_ALIGN (decl
) = (DECL_MODE (decl
) == BLKmode
? BIGGEST_ALIGNMENT
4108 : GET_MODE_BITSIZE (DECL_MODE (decl
)));
4109 DECL_USER_ALIGN (decl
) = 0;
4111 x
= assign_temp (TREE_TYPE (decl
), 1, 1, 1);
4112 set_mem_attributes (x
, decl
, 1);
4113 SET_DECL_RTL (decl
, x
);
4117 addr
= force_operand (XEXP (DECL_RTL (decl
), 0), oldaddr
);
4118 if (addr
!= oldaddr
)
4119 emit_move_insn (oldaddr
, addr
);
4123 /* Dynamic-size object: must push space on the stack. */
4125 rtx address
, size
, x
;
4127 /* Record the stack pointer on entry to block, if have
4128 not already done so. */
4129 do_pending_stack_adjust ();
4130 save_stack_pointer ();
4132 /* In function-at-a-time mode, variable_size doesn't expand this,
4134 if (TREE_CODE (type
) == ARRAY_TYPE
&& TYPE_DOMAIN (type
))
4135 expand_expr (TYPE_MAX_VALUE (TYPE_DOMAIN (type
)),
4136 const0_rtx
, VOIDmode
, 0);
4138 /* Compute the variable's size, in bytes. */
4139 size
= expand_expr (DECL_SIZE_UNIT (decl
), NULL_RTX
, VOIDmode
, 0);
4142 /* Allocate space on the stack for the variable. Note that
4143 DECL_ALIGN says how the variable is to be aligned and we
4144 cannot use it to conclude anything about the alignment of
4146 address
= allocate_dynamic_stack_space (size
, NULL_RTX
,
4147 TYPE_ALIGN (TREE_TYPE (decl
)));
4149 /* Reference the variable indirect through that rtx. */
4150 x
= gen_rtx_MEM (DECL_MODE (decl
), address
);
4151 set_mem_attributes (x
, decl
, 1);
4152 SET_DECL_RTL (decl
, x
);
4155 /* Indicate the alignment we actually gave this variable. */
4156 #ifdef STACK_BOUNDARY
4157 DECL_ALIGN (decl
) = STACK_BOUNDARY
;
4159 DECL_ALIGN (decl
) = BIGGEST_ALIGNMENT
;
4161 DECL_USER_ALIGN (decl
) = 0;
4165 /* Emit code to perform the initialization of a declaration DECL. */
4168 expand_decl_init (decl
)
4171 int was_used
= TREE_USED (decl
);
4173 /* If this is a CONST_DECL, we don't have to generate any code. Likewise
4174 for static decls. */
4175 if (TREE_CODE (decl
) == CONST_DECL
4176 || TREE_STATIC (decl
))
4179 /* Compute and store the initial value now. */
4181 if (DECL_INITIAL (decl
) == error_mark_node
)
4183 enum tree_code code
= TREE_CODE (TREE_TYPE (decl
));
4185 if (code
== INTEGER_TYPE
|| code
== REAL_TYPE
|| code
== ENUMERAL_TYPE
4186 || code
== POINTER_TYPE
|| code
== REFERENCE_TYPE
)
4187 expand_assignment (decl
, convert (TREE_TYPE (decl
), integer_zero_node
),
4191 else if (DECL_INITIAL (decl
) && TREE_CODE (DECL_INITIAL (decl
)) != TREE_LIST
)
4193 emit_line_note (DECL_SOURCE_FILE (decl
), DECL_SOURCE_LINE (decl
));
4194 expand_assignment (decl
, DECL_INITIAL (decl
), 0, 0);
4198 /* Don't let the initialization count as "using" the variable. */
4199 TREE_USED (decl
) = was_used
;
4201 /* Free any temporaries we made while initializing the decl. */
4202 preserve_temp_slots (NULL_RTX
);
4206 /* CLEANUP is an expression to be executed at exit from this binding contour;
4207 for example, in C++, it might call the destructor for this variable.
4209 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
4210 CLEANUP multiple times, and have the correct semantics. This
4211 happens in exception handling, for gotos, returns, breaks that
4212 leave the current scope.
4214 If CLEANUP is nonzero and DECL is zero, we record a cleanup
4215 that is not associated with any particular variable. */
4218 expand_decl_cleanup (decl
, cleanup
)
4221 struct nesting
*thisblock
;
4223 /* Error if we are not in any block. */
4224 if (cfun
== 0 || block_stack
== 0)
4227 thisblock
= block_stack
;
4229 /* Record the cleanup if there is one. */
4235 tree
*cleanups
= &thisblock
->data
.block
.cleanups
;
4236 int cond_context
= conditional_context ();
4240 rtx flag
= gen_reg_rtx (word_mode
);
4245 emit_move_insn (flag
, const0_rtx
);
4246 set_flag_0
= get_insns ();
4249 thisblock
->data
.block
.last_unconditional_cleanup
4250 = emit_insns_after (set_flag_0
,
4251 thisblock
->data
.block
.last_unconditional_cleanup
);
4253 emit_move_insn (flag
, const1_rtx
);
4255 cond
= build_decl (VAR_DECL
, NULL_TREE
, type_for_mode (word_mode
, 1));
4256 SET_DECL_RTL (cond
, flag
);
4258 /* Conditionalize the cleanup. */
4259 cleanup
= build (COND_EXPR
, void_type_node
,
4260 truthvalue_conversion (cond
),
4261 cleanup
, integer_zero_node
);
4262 cleanup
= fold (cleanup
);
4264 cleanups
= thisblock
->data
.block
.cleanup_ptr
;
4267 cleanup
= unsave_expr (cleanup
);
4269 t
= *cleanups
= tree_cons (decl
, cleanup
, *cleanups
);
4272 /* If this block has a cleanup, it belongs in stack_block_stack. */
4273 stack_block_stack
= thisblock
;
4280 if (! using_eh_for_cleanups_p
)
4281 TREE_ADDRESSABLE (t
) = 1;
4283 expand_eh_region_start ();
4290 thisblock
->data
.block
.last_unconditional_cleanup
4291 = emit_insns_after (seq
,
4292 thisblock
->data
.block
.last_unconditional_cleanup
);
4296 thisblock
->data
.block
.last_unconditional_cleanup
4298 /* When we insert instructions after the last unconditional cleanup,
4299 we don't adjust last_insn. That means that a later add_insn will
4300 clobber the instructions we've just added. The easiest way to
4301 fix this is to just insert another instruction here, so that the
4302 instructions inserted after the last unconditional cleanup are
4303 never the last instruction. */
4304 emit_note (NULL
, NOTE_INSN_DELETED
);
4305 thisblock
->data
.block
.cleanup_ptr
= &thisblock
->data
.block
.cleanups
;
4311 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4312 DECL_ELTS is the list of elements that belong to DECL's type.
4313 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4316 expand_anon_union_decl (decl
, cleanup
, decl_elts
)
4317 tree decl
, cleanup
, decl_elts
;
4319 struct nesting
*thisblock
= cfun
== 0 ? 0 : block_stack
;
4323 /* If any of the elements are addressable, so is the entire union. */
4324 for (t
= decl_elts
; t
; t
= TREE_CHAIN (t
))
4325 if (TREE_ADDRESSABLE (TREE_VALUE (t
)))
4327 TREE_ADDRESSABLE (decl
) = 1;
4332 expand_decl_cleanup (decl
, cleanup
);
4333 x
= DECL_RTL (decl
);
4335 /* Go through the elements, assigning RTL to each. */
4336 for (t
= decl_elts
; t
; t
= TREE_CHAIN (t
))
4338 tree decl_elt
= TREE_VALUE (t
);
4339 tree cleanup_elt
= TREE_PURPOSE (t
);
4340 enum machine_mode mode
= TYPE_MODE (TREE_TYPE (decl_elt
));
4342 /* Propagate the union's alignment to the elements. */
4343 DECL_ALIGN (decl_elt
) = DECL_ALIGN (decl
);
4344 DECL_USER_ALIGN (decl_elt
) = DECL_USER_ALIGN (decl
);
4346 /* If the element has BLKmode and the union doesn't, the union is
4347 aligned such that the element doesn't need to have BLKmode, so
4348 change the element's mode to the appropriate one for its size. */
4349 if (mode
== BLKmode
&& DECL_MODE (decl
) != BLKmode
)
4350 DECL_MODE (decl_elt
) = mode
4351 = mode_for_size_tree (DECL_SIZE (decl_elt
), MODE_INT
, 1);
4353 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4354 instead create a new MEM rtx with the proper mode. */
4355 if (GET_CODE (x
) == MEM
)
4357 if (mode
== GET_MODE (x
))
4358 SET_DECL_RTL (decl_elt
, x
);
4360 SET_DECL_RTL (decl_elt
, adjust_address_nv (x
, mode
, 0));
4362 else if (GET_CODE (x
) == REG
)
4364 if (mode
== GET_MODE (x
))
4365 SET_DECL_RTL (decl_elt
, x
);
4367 SET_DECL_RTL (decl_elt
, gen_lowpart_SUBREG (mode
, x
));
4372 /* Record the cleanup if there is one. */
4375 thisblock
->data
.block
.cleanups
4376 = tree_cons (decl_elt
, cleanup_elt
,
4377 thisblock
->data
.block
.cleanups
);
4381 /* Expand a list of cleanups LIST.
4382 Elements may be expressions or may be nested lists.
4384 If DONT_DO is nonnull, then any list-element
4385 whose TREE_PURPOSE matches DONT_DO is omitted.
4386 This is sometimes used to avoid a cleanup associated with
4387 a value that is being returned out of the scope.
4389 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
4390 goto and handle protection regions specially in that case.
4392 If REACHABLE, we emit code, otherwise just inform the exception handling
4393 code about this finalization. */
4396 expand_cleanups (list
, dont_do
, in_fixup
, reachable
)
4403 for (tail
= list
; tail
; tail
= TREE_CHAIN (tail
))
4404 if (dont_do
== 0 || TREE_PURPOSE (tail
) != dont_do
)
4406 if (TREE_CODE (TREE_VALUE (tail
)) == TREE_LIST
)
4407 expand_cleanups (TREE_VALUE (tail
), dont_do
, in_fixup
, reachable
);
4410 if (! in_fixup
&& using_eh_for_cleanups_p
)
4411 expand_eh_region_end_cleanup (TREE_VALUE (tail
));
4415 /* Cleanups may be run multiple times. For example,
4416 when exiting a binding contour, we expand the
4417 cleanups associated with that contour. When a goto
4418 within that binding contour has a target outside that
4419 contour, it will expand all cleanups from its scope to
4420 the target. Though the cleanups are expanded multiple
4421 times, the control paths are non-overlapping so the
4422 cleanups will not be executed twice. */
4424 /* We may need to protect from outer cleanups. */
4425 if (in_fixup
&& using_eh_for_cleanups_p
)
4427 expand_eh_region_start ();
4429 expand_expr (TREE_VALUE (tail
), const0_rtx
, VOIDmode
, 0);
4431 expand_eh_region_end_fixup (TREE_VALUE (tail
));
4434 expand_expr (TREE_VALUE (tail
), const0_rtx
, VOIDmode
, 0);
4442 /* Mark when the context we are emitting RTL for as a conditional
4443 context, so that any cleanup actions we register with
4444 expand_decl_init will be properly conditionalized when those
4445 cleanup actions are later performed. Must be called before any
4446 expression (tree) is expanded that is within a conditional context. */
4449 start_cleanup_deferral ()
4451 /* block_stack can be NULL if we are inside the parameter list. It is
4452 OK to do nothing, because cleanups aren't possible here. */
4454 ++block_stack
->data
.block
.conditional_code
;
4457 /* Mark the end of a conditional region of code. Because cleanup
4458 deferrals may be nested, we may still be in a conditional region
4459 after we end the currently deferred cleanups, only after we end all
4460 deferred cleanups, are we back in unconditional code. */
4463 end_cleanup_deferral ()
4465 /* block_stack can be NULL if we are inside the parameter list. It is
4466 OK to do nothing, because cleanups aren't possible here. */
4468 --block_stack
->data
.block
.conditional_code
;
4471 /* Move all cleanups from the current block_stack
4472 to the containing block_stack, where they are assumed to
4473 have been created. If anything can cause a temporary to
4474 be created, but not expanded for more than one level of
4475 block_stacks, then this code will have to change. */
4480 struct nesting
*block
= block_stack
;
4481 struct nesting
*outer
= block
->next
;
4483 outer
->data
.block
.cleanups
4484 = chainon (block
->data
.block
.cleanups
,
4485 outer
->data
.block
.cleanups
);
4486 block
->data
.block
.cleanups
= 0;
4490 last_cleanup_this_contour ()
4492 if (block_stack
== 0)
4495 return block_stack
->data
.block
.cleanups
;
4498 /* Return 1 if there are any pending cleanups at this point.
4499 If THIS_CONTOUR is nonzero, check the current contour as well.
4500 Otherwise, look only at the contours that enclose this one. */
4503 any_pending_cleanups (this_contour
)
4506 struct nesting
*block
;
4508 if (cfun
== NULL
|| cfun
->stmt
== NULL
|| block_stack
== 0)
4511 if (this_contour
&& block_stack
->data
.block
.cleanups
!= NULL
)
4513 if (block_stack
->data
.block
.cleanups
== 0
4514 && block_stack
->data
.block
.outer_cleanups
== 0)
4517 for (block
= block_stack
->next
; block
; block
= block
->next
)
4518 if (block
->data
.block
.cleanups
!= 0)
4524 /* Enter a case (Pascal) or switch (C) statement.
4525 Push a block onto case_stack and nesting_stack
4526 to accumulate the case-labels that are seen
4527 and to record the labels generated for the statement.
4529 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4530 Otherwise, this construct is transparent for `exit_something'.
4532 EXPR is the index-expression to be dispatched on.
4533 TYPE is its nominal type. We could simply convert EXPR to this type,
4534 but instead we take short cuts. */
4537 expand_start_case (exit_flag
, expr
, type
, printname
)
4541 const char *printname
;
4543 struct nesting
*thiscase
= ALLOC_NESTING ();
4545 /* Make an entry on case_stack for the case we are entering. */
4547 thiscase
->next
= case_stack
;
4548 thiscase
->all
= nesting_stack
;
4549 thiscase
->depth
= ++nesting_depth
;
4550 thiscase
->exit_label
= exit_flag
? gen_label_rtx () : 0;
4551 thiscase
->data
.case_stmt
.case_list
= 0;
4552 thiscase
->data
.case_stmt
.index_expr
= expr
;
4553 thiscase
->data
.case_stmt
.nominal_type
= type
;
4554 thiscase
->data
.case_stmt
.default_label
= 0;
4555 thiscase
->data
.case_stmt
.printname
= printname
;
4556 thiscase
->data
.case_stmt
.line_number_status
= force_line_numbers ();
4557 case_stack
= thiscase
;
4558 nesting_stack
= thiscase
;
4560 do_pending_stack_adjust ();
4562 /* Make sure case_stmt.start points to something that won't
4563 need any transformation before expand_end_case. */
4564 if (GET_CODE (get_last_insn ()) != NOTE
)
4565 emit_note (NULL
, NOTE_INSN_DELETED
);
4567 thiscase
->data
.case_stmt
.start
= get_last_insn ();
4569 start_cleanup_deferral ();
4572 /* Start a "dummy case statement" within which case labels are invalid
4573 and are not connected to any larger real case statement.
4574 This can be used if you don't want to let a case statement jump
4575 into the middle of certain kinds of constructs. */
4578 expand_start_case_dummy ()
4580 struct nesting
*thiscase
= ALLOC_NESTING ();
4582 /* Make an entry on case_stack for the dummy. */
4584 thiscase
->next
= case_stack
;
4585 thiscase
->all
= nesting_stack
;
4586 thiscase
->depth
= ++nesting_depth
;
4587 thiscase
->exit_label
= 0;
4588 thiscase
->data
.case_stmt
.case_list
= 0;
4589 thiscase
->data
.case_stmt
.start
= 0;
4590 thiscase
->data
.case_stmt
.nominal_type
= 0;
4591 thiscase
->data
.case_stmt
.default_label
= 0;
4592 case_stack
= thiscase
;
4593 nesting_stack
= thiscase
;
4594 start_cleanup_deferral ();
4597 /* End a dummy case statement. */
4600 expand_end_case_dummy ()
4602 end_cleanup_deferral ();
4603 POPSTACK (case_stack
);
4606 /* Return the data type of the index-expression
4607 of the innermost case statement, or null if none. */
4610 case_index_expr_type ()
4613 return TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4620 /* If this is the first label, warn if any insns have been emitted. */
4621 if (case_stack
->data
.case_stmt
.line_number_status
>= 0)
4625 restore_line_number_status
4626 (case_stack
->data
.case_stmt
.line_number_status
);
4627 case_stack
->data
.case_stmt
.line_number_status
= -1;
4629 for (insn
= case_stack
->data
.case_stmt
.start
;
4631 insn
= NEXT_INSN (insn
))
4633 if (GET_CODE (insn
) == CODE_LABEL
)
4635 if (GET_CODE (insn
) != NOTE
4636 && (GET_CODE (insn
) != INSN
|| GET_CODE (PATTERN (insn
)) != USE
))
4639 insn
= PREV_INSN (insn
);
4640 while (insn
&& (GET_CODE (insn
) != NOTE
|| NOTE_LINE_NUMBER (insn
) < 0));
4642 /* If insn is zero, then there must have been a syntax error. */
4644 warning_with_file_and_line (NOTE_SOURCE_FILE (insn
),
4645 NOTE_LINE_NUMBER (insn
),
4646 "unreachable code at beginning of %s",
4647 case_stack
->data
.case_stmt
.printname
);
4654 /* Accumulate one case or default label inside a case or switch statement.
4655 VALUE is the value of the case (a null pointer, for a default label).
4656 The function CONVERTER, when applied to arguments T and V,
4657 converts the value V to the type T.
4659 If not currently inside a case or switch statement, return 1 and do
4660 nothing. The caller will print a language-specific error message.
4661 If VALUE is a duplicate or overlaps, return 2 and do nothing
4662 except store the (first) duplicate node in *DUPLICATE.
4663 If VALUE is out of range, return 3 and do nothing.
4664 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4665 Return 0 on success.
4667 Extended to handle range statements. */
4670 pushcase (value
, converter
, label
, duplicate
)
4672 tree (*converter
) PARAMS ((tree
, tree
));
4679 /* Fail if not inside a real case statement. */
4680 if (! (case_stack
&& case_stack
->data
.case_stmt
.start
))
4683 if (stack_block_stack
4684 && stack_block_stack
->depth
> case_stack
->depth
)
4687 index_type
= TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4688 nominal_type
= case_stack
->data
.case_stmt
.nominal_type
;
4690 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4691 if (index_type
== error_mark_node
)
4694 /* Convert VALUE to the type in which the comparisons are nominally done. */
4696 value
= (*converter
) (nominal_type
, value
);
4700 /* Fail if this value is out of range for the actual type of the index
4701 (which may be narrower than NOMINAL_TYPE). */
4703 && (TREE_CONSTANT_OVERFLOW (value
)
4704 || ! int_fits_type_p (value
, index_type
)))
4707 return add_case_node (value
, value
, label
, duplicate
);
4710 /* Like pushcase but this case applies to all values between VALUE1 and
4711 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4712 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4713 starts at VALUE1 and ends at the highest value of the index type.
4714 If both are NULL, this case applies to all values.
4716 The return value is the same as that of pushcase but there is one
4717 additional error code: 4 means the specified range was empty. */
4720 pushcase_range (value1
, value2
, converter
, label
, duplicate
)
4721 tree value1
, value2
;
4722 tree (*converter
) PARAMS ((tree
, tree
));
4729 /* Fail if not inside a real case statement. */
4730 if (! (case_stack
&& case_stack
->data
.case_stmt
.start
))
4733 if (stack_block_stack
4734 && stack_block_stack
->depth
> case_stack
->depth
)
4737 index_type
= TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4738 nominal_type
= case_stack
->data
.case_stmt
.nominal_type
;
4740 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4741 if (index_type
== error_mark_node
)
4746 /* Convert VALUEs to type in which the comparisons are nominally done
4747 and replace any unspecified value with the corresponding bound. */
4749 value1
= TYPE_MIN_VALUE (index_type
);
4751 value2
= TYPE_MAX_VALUE (index_type
);
4753 /* Fail if the range is empty. Do this before any conversion since
4754 we want to allow out-of-range empty ranges. */
4755 if (value2
!= 0 && tree_int_cst_lt (value2
, value1
))
4758 /* If the max was unbounded, use the max of the nominal_type we are
4759 converting to. Do this after the < check above to suppress false
4762 value2
= TYPE_MAX_VALUE (nominal_type
);
4764 value1
= (*converter
) (nominal_type
, value1
);
4765 value2
= (*converter
) (nominal_type
, value2
);
4767 /* Fail if these values are out of range. */
4768 if (TREE_CONSTANT_OVERFLOW (value1
)
4769 || ! int_fits_type_p (value1
, index_type
))
4772 if (TREE_CONSTANT_OVERFLOW (value2
)
4773 || ! int_fits_type_p (value2
, index_type
))
4776 return add_case_node (value1
, value2
, label
, duplicate
);
4779 /* Do the actual insertion of a case label for pushcase and pushcase_range
4780 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4781 slowdown for large switch statements. */
4784 add_case_node (low
, high
, label
, duplicate
)
4789 struct case_node
*p
, **q
, *r
;
4791 /* If there's no HIGH value, then this is not a case range; it's
4792 just a simple case label. But that's just a degenerate case
4797 /* Handle default labels specially. */
4800 if (case_stack
->data
.case_stmt
.default_label
!= 0)
4802 *duplicate
= case_stack
->data
.case_stmt
.default_label
;
4805 case_stack
->data
.case_stmt
.default_label
= label
;
4806 expand_label (label
);
4810 q
= &case_stack
->data
.case_stmt
.case_list
;
4817 /* Keep going past elements distinctly greater than HIGH. */
4818 if (tree_int_cst_lt (high
, p
->low
))
4821 /* or distinctly less than LOW. */
4822 else if (tree_int_cst_lt (p
->high
, low
))
4827 /* We have an overlap; this is an error. */
4828 *duplicate
= p
->code_label
;
4833 /* Add this label to the chain, and succeed. */
4835 r
= (struct case_node
*) xmalloc (sizeof (struct case_node
));
4838 /* If the bounds are equal, turn this into the one-value case. */
4839 if (tree_int_cst_equal (low
, high
))
4844 r
->code_label
= label
;
4845 expand_label (label
);
4855 struct case_node
*s
;
4861 if (! (b
= p
->balance
))
4862 /* Growth propagation from left side. */
4869 if ((p
->left
= s
= r
->right
))
4878 if ((r
->parent
= s
))
4886 case_stack
->data
.case_stmt
.case_list
= r
;
4889 /* r->balance == +1 */
4894 struct case_node
*t
= r
->right
;
4896 if ((p
->left
= s
= t
->right
))
4900 if ((r
->right
= s
= t
->left
))
4914 if ((t
->parent
= s
))
4922 case_stack
->data
.case_stmt
.case_list
= t
;
4929 /* p->balance == +1; growth of left side balances the node. */
4939 if (! (b
= p
->balance
))
4940 /* Growth propagation from right side. */
4948 if ((p
->right
= s
= r
->left
))
4956 if ((r
->parent
= s
))
4965 case_stack
->data
.case_stmt
.case_list
= r
;
4969 /* r->balance == -1 */
4973 struct case_node
*t
= r
->left
;
4975 if ((p
->right
= s
= t
->left
))
4980 if ((r
->left
= s
= t
->right
))
4994 if ((t
->parent
= s
))
5003 case_stack
->data
.case_stmt
.case_list
= t
;
5009 /* p->balance == -1; growth of right side balances the node. */
5022 /* Returns the number of possible values of TYPE.
5023 Returns -1 if the number is unknown, variable, or if the number does not
5024 fit in a HOST_WIDE_INT.
5025 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
5026 do not increase monotonically (there may be duplicates);
5027 to 1 if the values increase monotonically, but not always by 1;
5028 otherwise sets it to 0. */
5031 all_cases_count (type
, spareness
)
5036 HOST_WIDE_INT count
, minval
, lastval
;
5040 switch (TREE_CODE (type
))
5047 count
= 1 << BITS_PER_UNIT
;
5052 if (TYPE_MAX_VALUE (type
) != 0
5053 && 0 != (t
= fold (build (MINUS_EXPR
, type
, TYPE_MAX_VALUE (type
),
5054 TYPE_MIN_VALUE (type
))))
5055 && 0 != (t
= fold (build (PLUS_EXPR
, type
, t
,
5056 convert (type
, integer_zero_node
))))
5057 && host_integerp (t
, 1))
5058 count
= tree_low_cst (t
, 1);
5064 /* Don't waste time with enumeral types with huge values. */
5065 if (! host_integerp (TYPE_MIN_VALUE (type
), 0)
5066 || TYPE_MAX_VALUE (type
) == 0
5067 || ! host_integerp (TYPE_MAX_VALUE (type
), 0))
5070 lastval
= minval
= tree_low_cst (TYPE_MIN_VALUE (type
), 0);
5073 for (t
= TYPE_VALUES (type
); t
!= NULL_TREE
; t
= TREE_CHAIN (t
))
5075 HOST_WIDE_INT thisval
= tree_low_cst (TREE_VALUE (t
), 0);
5077 if (*spareness
== 2 || thisval
< lastval
)
5079 else if (thisval
!= minval
+ count
)
5089 #define BITARRAY_TEST(ARRAY, INDEX) \
5090 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
5091 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
5092 #define BITARRAY_SET(ARRAY, INDEX) \
5093 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
5094 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
5096 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
5097 with the case values we have seen, assuming the case expression
5099 SPARSENESS is as determined by all_cases_count.
5101 The time needed is proportional to COUNT, unless
5102 SPARSENESS is 2, in which case quadratic time is needed. */
5105 mark_seen_cases (type
, cases_seen
, count
, sparseness
)
5107 unsigned char *cases_seen
;
5108 HOST_WIDE_INT count
;
5111 tree next_node_to_try
= NULL_TREE
;
5112 HOST_WIDE_INT next_node_offset
= 0;
5114 struct case_node
*n
, *root
= case_stack
->data
.case_stmt
.case_list
;
5115 tree val
= make_node (INTEGER_CST
);
5117 TREE_TYPE (val
) = type
;
5121 else if (sparseness
== 2)
5124 unsigned HOST_WIDE_INT xlo
;
5126 /* This less efficient loop is only needed to handle
5127 duplicate case values (multiple enum constants
5128 with the same value). */
5129 TREE_TYPE (val
) = TREE_TYPE (root
->low
);
5130 for (t
= TYPE_VALUES (type
), xlo
= 0; t
!= NULL_TREE
;
5131 t
= TREE_CHAIN (t
), xlo
++)
5133 TREE_INT_CST_LOW (val
) = TREE_INT_CST_LOW (TREE_VALUE (t
));
5134 TREE_INT_CST_HIGH (val
) = TREE_INT_CST_HIGH (TREE_VALUE (t
));
5138 /* Keep going past elements distinctly greater than VAL. */
5139 if (tree_int_cst_lt (val
, n
->low
))
5142 /* or distinctly less than VAL. */
5143 else if (tree_int_cst_lt (n
->high
, val
))
5148 /* We have found a matching range. */
5149 BITARRAY_SET (cases_seen
, xlo
);
5159 case_stack
->data
.case_stmt
.case_list
= root
= case_tree2list (root
, 0);
5161 for (n
= root
; n
; n
= n
->right
)
5163 TREE_INT_CST_LOW (val
) = TREE_INT_CST_LOW (n
->low
);
5164 TREE_INT_CST_HIGH (val
) = TREE_INT_CST_HIGH (n
->low
);
5165 while (! tree_int_cst_lt (n
->high
, val
))
5167 /* Calculate (into xlo) the "offset" of the integer (val).
5168 The element with lowest value has offset 0, the next smallest
5169 element has offset 1, etc. */
5171 unsigned HOST_WIDE_INT xlo
;
5175 if (sparseness
&& TYPE_VALUES (type
) != NULL_TREE
)
5177 /* The TYPE_VALUES will be in increasing order, so
5178 starting searching where we last ended. */
5179 t
= next_node_to_try
;
5180 xlo
= next_node_offset
;
5186 t
= TYPE_VALUES (type
);
5189 if (tree_int_cst_equal (val
, TREE_VALUE (t
)))
5191 next_node_to_try
= TREE_CHAIN (t
);
5192 next_node_offset
= xlo
+ 1;
5197 if (t
== next_node_to_try
)
5206 t
= TYPE_MIN_VALUE (type
);
5208 neg_double (TREE_INT_CST_LOW (t
), TREE_INT_CST_HIGH (t
),
5212 add_double (xlo
, xhi
,
5213 TREE_INT_CST_LOW (val
), TREE_INT_CST_HIGH (val
),
5217 if (xhi
== 0 && xlo
< (unsigned HOST_WIDE_INT
) count
)
5218 BITARRAY_SET (cases_seen
, xlo
);
5220 add_double (TREE_INT_CST_LOW (val
), TREE_INT_CST_HIGH (val
),
5222 &TREE_INT_CST_LOW (val
), &TREE_INT_CST_HIGH (val
));
5228 /* Called when the index of a switch statement is an enumerated type
5229 and there is no default label.
5231 Checks that all enumeration literals are covered by the case
5232 expressions of a switch. Also, warn if there are any extra
5233 switch cases that are *not* elements of the enumerated type.
5235 If all enumeration literals were covered by the case expressions,
5236 turn one of the expressions into the default expression since it should
5237 not be possible to fall through such a switch. */
5240 check_for_full_enumeration_handling (type
)
5243 struct case_node
*n
;
5246 /* True iff the selector type is a numbered set mode. */
5249 /* The number of possible selector values. */
5252 /* For each possible selector value. a one iff it has been matched
5253 by a case value alternative. */
5254 unsigned char *cases_seen
;
5256 /* The allocated size of cases_seen, in chars. */
5257 HOST_WIDE_INT bytes_needed
;
5262 size
= all_cases_count (type
, &sparseness
);
5263 bytes_needed
= (size
+ HOST_BITS_PER_CHAR
) / HOST_BITS_PER_CHAR
;
5265 if (size
> 0 && size
< 600000
5266 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5267 this optimization if we don't have enough memory rather than
5268 aborting, as xmalloc would do. */
5270 (unsigned char *) really_call_calloc (bytes_needed
, 1)) != NULL
)
5273 tree v
= TYPE_VALUES (type
);
5275 /* The time complexity of this code is normally O(N), where
5276 N being the number of members in the enumerated type.
5277 However, if type is a ENUMERAL_TYPE whose values do not
5278 increase monotonically, O(N*log(N)) time may be needed. */
5280 mark_seen_cases (type
, cases_seen
, size
, sparseness
);
5282 for (i
= 0; v
!= NULL_TREE
&& i
< size
; i
++, v
= TREE_CHAIN (v
))
5283 if (BITARRAY_TEST (cases_seen
, i
) == 0)
5284 warning ("enumeration value `%s' not handled in switch",
5285 IDENTIFIER_POINTER (TREE_PURPOSE (v
)));
5290 /* Now we go the other way around; we warn if there are case
5291 expressions that don't correspond to enumerators. This can
5292 occur since C and C++ don't enforce type-checking of
5293 assignments to enumeration variables. */
5295 if (case_stack
->data
.case_stmt
.case_list
5296 && case_stack
->data
.case_stmt
.case_list
->left
)
5297 case_stack
->data
.case_stmt
.case_list
5298 = case_tree2list (case_stack
->data
.case_stmt
.case_list
, 0);
5300 for (n
= case_stack
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5302 for (chain
= TYPE_VALUES (type
);
5303 chain
&& !tree_int_cst_equal (n
->low
, TREE_VALUE (chain
));
5304 chain
= TREE_CHAIN (chain
))
5309 if (TYPE_NAME (type
) == 0)
5310 warning ("case value `%ld' not in enumerated type",
5311 (long) TREE_INT_CST_LOW (n
->low
));
5313 warning ("case value `%ld' not in enumerated type `%s'",
5314 (long) TREE_INT_CST_LOW (n
->low
),
5315 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type
))
5318 : DECL_NAME (TYPE_NAME (type
))));
5320 if (!tree_int_cst_equal (n
->low
, n
->high
))
5322 for (chain
= TYPE_VALUES (type
);
5323 chain
&& !tree_int_cst_equal (n
->high
, TREE_VALUE (chain
));
5324 chain
= TREE_CHAIN (chain
))
5329 if (TYPE_NAME (type
) == 0)
5330 warning ("case value `%ld' not in enumerated type",
5331 (long) TREE_INT_CST_LOW (n
->high
));
5333 warning ("case value `%ld' not in enumerated type `%s'",
5334 (long) TREE_INT_CST_LOW (n
->high
),
5335 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type
))
5338 : DECL_NAME (TYPE_NAME (type
))));
5344 /* Free CN, and its children. */
5347 free_case_nodes (cn
)
5352 free_case_nodes (cn
->left
);
5353 free_case_nodes (cn
->right
);
5360 /* Terminate a case (Pascal) or switch (C) statement
5361 in which ORIG_INDEX is the expression to be tested.
5362 Generate the code to test it and jump to the right place. */
5365 expand_end_case (orig_index
)
5368 tree minval
= NULL_TREE
, maxval
= NULL_TREE
, range
= NULL_TREE
;
5369 rtx default_label
= 0;
5370 struct case_node
*n
;
5377 rtx before_case
, end
;
5378 struct nesting
*thiscase
= case_stack
;
5379 tree index_expr
, index_type
;
5382 /* Don't crash due to previous errors. */
5383 if (thiscase
== NULL
)
5386 table_label
= gen_label_rtx ();
5387 index_expr
= thiscase
->data
.case_stmt
.index_expr
;
5388 index_type
= TREE_TYPE (index_expr
);
5389 unsignedp
= TREE_UNSIGNED (index_type
);
5391 do_pending_stack_adjust ();
5393 /* This might get an spurious warning in the presence of a syntax error;
5394 it could be fixed by moving the call to check_seenlabel after the
5395 check for error_mark_node, and copying the code of check_seenlabel that
5396 deals with case_stack->data.case_stmt.line_number_status /
5397 restore_line_number_status in front of the call to end_cleanup_deferral;
5398 However, this might miss some useful warnings in the presence of
5399 non-syntax errors. */
5402 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5403 if (index_type
!= error_mark_node
)
5405 /* If switch expression was an enumerated type, check that all
5406 enumeration literals are covered by the cases.
5407 No sense trying this if there's a default case, however. */
5409 if (!thiscase
->data
.case_stmt
.default_label
5410 && TREE_CODE (TREE_TYPE (orig_index
)) == ENUMERAL_TYPE
5411 && TREE_CODE (index_expr
) != INTEGER_CST
)
5412 check_for_full_enumeration_handling (TREE_TYPE (orig_index
));
5414 /* If we don't have a default-label, create one here,
5415 after the body of the switch. */
5416 if (thiscase
->data
.case_stmt
.default_label
== 0)
5418 thiscase
->data
.case_stmt
.default_label
5419 = build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
5420 expand_label (thiscase
->data
.case_stmt
.default_label
);
5422 default_label
= label_rtx (thiscase
->data
.case_stmt
.default_label
);
5424 before_case
= get_last_insn ();
5426 if (thiscase
->data
.case_stmt
.case_list
5427 && thiscase
->data
.case_stmt
.case_list
->left
)
5428 thiscase
->data
.case_stmt
.case_list
5429 = case_tree2list (thiscase
->data
.case_stmt
.case_list
, 0);
5431 /* Simplify the case-list before we count it. */
5432 group_case_nodes (thiscase
->data
.case_stmt
.case_list
);
5434 /* Get upper and lower bounds of case values.
5435 Also convert all the case values to the index expr's data type. */
5438 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5440 /* Check low and high label values are integers. */
5441 if (TREE_CODE (n
->low
) != INTEGER_CST
)
5443 if (TREE_CODE (n
->high
) != INTEGER_CST
)
5446 n
->low
= convert (index_type
, n
->low
);
5447 n
->high
= convert (index_type
, n
->high
);
5449 /* Count the elements and track the largest and smallest
5450 of them (treating them as signed even if they are not). */
5458 if (INT_CST_LT (n
->low
, minval
))
5460 if (INT_CST_LT (maxval
, n
->high
))
5463 /* A range counts double, since it requires two compares. */
5464 if (! tree_int_cst_equal (n
->low
, n
->high
))
5468 /* Compute span of values. */
5470 range
= fold (build (MINUS_EXPR
, index_type
, maxval
, minval
));
5472 end_cleanup_deferral ();
5476 expand_expr (index_expr
, const0_rtx
, VOIDmode
, 0);
5478 emit_jump (default_label
);
5481 /* If range of values is much bigger than number of values,
5482 make a sequence of conditional branches instead of a dispatch.
5483 If the switch-index is a constant, do it this way
5484 because we can optimize it. */
5486 else if (count
< case_values_threshold ()
5487 || compare_tree_int (range
, 10 * count
) > 0
5488 /* RANGE may be signed, and really large ranges will show up
5489 as negative numbers. */
5490 || compare_tree_int (range
, 0) < 0
5491 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5494 || TREE_CODE (index_expr
) == INTEGER_CST
5495 || (TREE_CODE (index_expr
) == COMPOUND_EXPR
5496 && TREE_CODE (TREE_OPERAND (index_expr
, 1)) == INTEGER_CST
))
5498 index
= expand_expr (index_expr
, NULL_RTX
, VOIDmode
, 0);
5500 /* If the index is a short or char that we do not have
5501 an insn to handle comparisons directly, convert it to
5502 a full integer now, rather than letting each comparison
5503 generate the conversion. */
5505 if (GET_MODE_CLASS (GET_MODE (index
)) == MODE_INT
5506 && ! have_insn_for (COMPARE
, GET_MODE (index
)))
5508 enum machine_mode wider_mode
;
5509 for (wider_mode
= GET_MODE (index
); wider_mode
!= VOIDmode
;
5510 wider_mode
= GET_MODE_WIDER_MODE (wider_mode
))
5511 if (have_insn_for (COMPARE
, wider_mode
))
5513 index
= convert_to_mode (wider_mode
, index
, unsignedp
);
5519 do_pending_stack_adjust ();
5521 index
= protect_from_queue (index
, 0);
5522 if (GET_CODE (index
) == MEM
)
5523 index
= copy_to_reg (index
);
5524 if (GET_CODE (index
) == CONST_INT
5525 || TREE_CODE (index_expr
) == INTEGER_CST
)
5527 /* Make a tree node with the proper constant value
5528 if we don't already have one. */
5529 if (TREE_CODE (index_expr
) != INTEGER_CST
)
5532 = build_int_2 (INTVAL (index
),
5533 unsignedp
|| INTVAL (index
) >= 0 ? 0 : -1);
5534 index_expr
= convert (index_type
, index_expr
);
5537 /* For constant index expressions we need only
5538 issue an unconditional branch to the appropriate
5539 target code. The job of removing any unreachable
5540 code is left to the optimisation phase if the
5541 "-O" option is specified. */
5542 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5543 if (! tree_int_cst_lt (index_expr
, n
->low
)
5544 && ! tree_int_cst_lt (n
->high
, index_expr
))
5548 emit_jump (label_rtx (n
->code_label
));
5550 emit_jump (default_label
);
5554 /* If the index expression is not constant we generate
5555 a binary decision tree to select the appropriate
5556 target code. This is done as follows:
5558 The list of cases is rearranged into a binary tree,
5559 nearly optimal assuming equal probability for each case.
5561 The tree is transformed into RTL, eliminating
5562 redundant test conditions at the same time.
5564 If program flow could reach the end of the
5565 decision tree an unconditional jump to the
5566 default code is emitted. */
5569 = (TREE_CODE (TREE_TYPE (orig_index
)) != ENUMERAL_TYPE
5570 && estimate_case_costs (thiscase
->data
.case_stmt
.case_list
));
5571 balance_case_nodes (&thiscase
->data
.case_stmt
.case_list
, NULL
);
5572 emit_case_nodes (index
, thiscase
->data
.case_stmt
.case_list
,
5573 default_label
, index_type
);
5574 emit_jump_if_reachable (default_label
);
5579 if (! try_casesi (index_type
, index_expr
, minval
, range
,
5580 table_label
, default_label
))
5582 index_type
= thiscase
->data
.case_stmt
.nominal_type
;
5584 /* Index jumptables from zero for suitable values of
5585 minval to avoid a subtraction. */
5587 && compare_tree_int (minval
, 0) > 0
5588 && compare_tree_int (minval
, 3) < 0)
5590 minval
= integer_zero_node
;
5594 if (! try_tablejump (index_type
, index_expr
, minval
, range
,
5595 table_label
, default_label
))
5599 /* Get table of labels to jump to, in order of case index. */
5601 ncases
= tree_low_cst (range
, 0) + 1;
5602 labelvec
= (rtx
*) alloca (ncases
* sizeof (rtx
));
5603 memset ((char *) labelvec
, 0, ncases
* sizeof (rtx
));
5605 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5607 /* Compute the low and high bounds relative to the minimum
5608 value since that should fit in a HOST_WIDE_INT while the
5609 actual values may not. */
5611 = tree_low_cst (fold (build (MINUS_EXPR
, index_type
,
5612 n
->low
, minval
)), 1);
5613 HOST_WIDE_INT i_high
5614 = tree_low_cst (fold (build (MINUS_EXPR
, index_type
,
5615 n
->high
, minval
)), 1);
5618 for (i
= i_low
; i
<= i_high
; i
++)
5620 = gen_rtx_LABEL_REF (Pmode
, label_rtx (n
->code_label
));
5623 /* Fill in the gaps with the default. */
5624 for (i
= 0; i
< ncases
; i
++)
5625 if (labelvec
[i
] == 0)
5626 labelvec
[i
] = gen_rtx_LABEL_REF (Pmode
, default_label
);
5628 /* Output the table */
5629 emit_label (table_label
);
5631 if (CASE_VECTOR_PC_RELATIVE
|| flag_pic
)
5632 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE
,
5633 gen_rtx_LABEL_REF (Pmode
, table_label
),
5634 gen_rtvec_v (ncases
, labelvec
),
5635 const0_rtx
, const0_rtx
));
5637 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE
,
5638 gen_rtvec_v (ncases
, labelvec
)));
5640 /* If the case insn drops through the table,
5641 after the table we must jump to the default-label.
5642 Otherwise record no drop-through after the table. */
5643 #ifdef CASE_DROPS_THROUGH
5644 emit_jump (default_label
);
5650 before_case
= NEXT_INSN (before_case
);
5651 end
= get_last_insn ();
5652 if (squeeze_notes (&before_case
, &end
))
5654 reorder_insns (before_case
, end
,
5655 thiscase
->data
.case_stmt
.start
);
5658 end_cleanup_deferral ();
5660 if (thiscase
->exit_label
)
5661 emit_label (thiscase
->exit_label
);
5663 free_case_nodes (case_stack
->data
.case_stmt
.case_list
);
5664 POPSTACK (case_stack
);
5669 /* Convert the tree NODE into a list linked by the right field, with the left
5670 field zeroed. RIGHT is used for recursion; it is a list to be placed
5671 rightmost in the resulting list. */
5673 static struct case_node
*
5674 case_tree2list (node
, right
)
5675 struct case_node
*node
, *right
;
5677 struct case_node
*left
;
5680 right
= case_tree2list (node
->right
, right
);
5682 node
->right
= right
;
5683 if ((left
= node
->left
))
5686 return case_tree2list (left
, node
);
5692 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5695 do_jump_if_equal (op1
, op2
, label
, unsignedp
)
5696 rtx op1
, op2
, label
;
5699 if (GET_CODE (op1
) == CONST_INT
&& GET_CODE (op2
) == CONST_INT
)
5701 if (INTVAL (op1
) == INTVAL (op2
))
5705 emit_cmp_and_jump_insns (op1
, op2
, EQ
, NULL_RTX
,
5706 (GET_MODE (op1
) == VOIDmode
5707 ? GET_MODE (op2
) : GET_MODE (op1
)),
5711 /* Not all case values are encountered equally. This function
5712 uses a heuristic to weight case labels, in cases where that
5713 looks like a reasonable thing to do.
5715 Right now, all we try to guess is text, and we establish the
5718 chars above space: 16
5727 If we find any cases in the switch that are not either -1 or in the range
5728 of valid ASCII characters, or are control characters other than those
5729 commonly used with "\", don't treat this switch scanning text.
5731 Return 1 if these nodes are suitable for cost estimation, otherwise
5735 estimate_case_costs (node
)
5738 tree min_ascii
= integer_minus_one_node
;
5739 tree max_ascii
= convert (TREE_TYPE (node
->high
), build_int_2 (127, 0));
5743 /* If we haven't already made the cost table, make it now. Note that the
5744 lower bound of the table is -1, not zero. */
5746 if (! cost_table_initialized
)
5748 cost_table_initialized
= 1;
5750 for (i
= 0; i
< 128; i
++)
5753 COST_TABLE (i
) = 16;
5754 else if (ISPUNCT (i
))
5756 else if (ISCNTRL (i
))
5757 COST_TABLE (i
) = -1;
5760 COST_TABLE (' ') = 8;
5761 COST_TABLE ('\t') = 4;
5762 COST_TABLE ('\0') = 4;
5763 COST_TABLE ('\n') = 2;
5764 COST_TABLE ('\f') = 1;
5765 COST_TABLE ('\v') = 1;
5766 COST_TABLE ('\b') = 1;
5769 /* See if all the case expressions look like text. It is text if the
5770 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5771 as signed arithmetic since we don't want to ever access cost_table with a
5772 value less than -1. Also check that none of the constants in a range
5773 are strange control characters. */
5775 for (n
= node
; n
; n
= n
->right
)
5777 if ((INT_CST_LT (n
->low
, min_ascii
)) || INT_CST_LT (max_ascii
, n
->high
))
5780 for (i
= (HOST_WIDE_INT
) TREE_INT_CST_LOW (n
->low
);
5781 i
<= (HOST_WIDE_INT
) TREE_INT_CST_LOW (n
->high
); i
++)
5782 if (COST_TABLE (i
) < 0)
5786 /* All interesting values are within the range of interesting
5787 ASCII characters. */
5791 /* Scan an ordered list of case nodes
5792 combining those with consecutive values or ranges.
5794 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5797 group_case_nodes (head
)
5800 case_node_ptr node
= head
;
5804 rtx lb
= next_real_insn (label_rtx (node
->code_label
));
5806 case_node_ptr np
= node
;
5808 /* Try to group the successors of NODE with NODE. */
5809 while (((np
= np
->right
) != 0)
5810 /* Do they jump to the same place? */
5811 && ((lb2
= next_real_insn (label_rtx (np
->code_label
))) == lb
5812 || (lb
!= 0 && lb2
!= 0
5813 && simplejump_p (lb
)
5814 && simplejump_p (lb2
)
5815 && rtx_equal_p (SET_SRC (PATTERN (lb
)),
5816 SET_SRC (PATTERN (lb2
)))))
5817 /* Are their ranges consecutive? */
5818 && tree_int_cst_equal (np
->low
,
5819 fold (build (PLUS_EXPR
,
5820 TREE_TYPE (node
->high
),
5823 /* An overflow is not consecutive. */
5824 && tree_int_cst_lt (node
->high
,
5825 fold (build (PLUS_EXPR
,
5826 TREE_TYPE (node
->high
),
5828 integer_one_node
))))
5830 node
->high
= np
->high
;
5832 /* NP is the first node after NODE which can't be grouped with it.
5833 Delete the nodes in between, and move on to that node. */
5839 /* Take an ordered list of case nodes
5840 and transform them into a near optimal binary tree,
5841 on the assumption that any target code selection value is as
5842 likely as any other.
5844 The transformation is performed by splitting the ordered
5845 list into two equal sections plus a pivot. The parts are
5846 then attached to the pivot as left and right branches. Each
5847 branch is then transformed recursively. */
5850 balance_case_nodes (head
, parent
)
5851 case_node_ptr
*head
;
5852 case_node_ptr parent
;
5865 /* Count the number of entries on branch. Also count the ranges. */
5869 if (!tree_int_cst_equal (np
->low
, np
->high
))
5873 cost
+= COST_TABLE (TREE_INT_CST_LOW (np
->high
));
5877 cost
+= COST_TABLE (TREE_INT_CST_LOW (np
->low
));
5885 /* Split this list if it is long enough for that to help. */
5890 /* Find the place in the list that bisects the list's total cost,
5891 Here I gets half the total cost. */
5896 /* Skip nodes while their cost does not reach that amount. */
5897 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
5898 i
-= COST_TABLE (TREE_INT_CST_LOW ((*npp
)->high
));
5899 i
-= COST_TABLE (TREE_INT_CST_LOW ((*npp
)->low
));
5902 npp
= &(*npp
)->right
;
5907 /* Leave this branch lopsided, but optimize left-hand
5908 side and fill in `parent' fields for right-hand side. */
5910 np
->parent
= parent
;
5911 balance_case_nodes (&np
->left
, np
);
5912 for (; np
->right
; np
= np
->right
)
5913 np
->right
->parent
= np
;
5917 /* If there are just three nodes, split at the middle one. */
5919 npp
= &(*npp
)->right
;
5922 /* Find the place in the list that bisects the list's total cost,
5923 where ranges count as 2.
5924 Here I gets half the total cost. */
5925 i
= (i
+ ranges
+ 1) / 2;
5928 /* Skip nodes while their cost does not reach that amount. */
5929 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
5934 npp
= &(*npp
)->right
;
5939 np
->parent
= parent
;
5942 /* Optimize each of the two split parts. */
5943 balance_case_nodes (&np
->left
, np
);
5944 balance_case_nodes (&np
->right
, np
);
5948 /* Else leave this branch as one level,
5949 but fill in `parent' fields. */
5951 np
->parent
= parent
;
5952 for (; np
->right
; np
= np
->right
)
5953 np
->right
->parent
= np
;
5958 /* Search the parent sections of the case node tree
5959 to see if a test for the lower bound of NODE would be redundant.
5960 INDEX_TYPE is the type of the index expression.
5962 The instructions to generate the case decision tree are
5963 output in the same order as nodes are processed so it is
5964 known that if a parent node checks the range of the current
5965 node minus one that the current node is bounded at its lower
5966 span. Thus the test would be redundant. */
5969 node_has_low_bound (node
, index_type
)
5974 case_node_ptr pnode
;
5976 /* If the lower bound of this node is the lowest value in the index type,
5977 we need not test it. */
5979 if (tree_int_cst_equal (node
->low
, TYPE_MIN_VALUE (index_type
)))
5982 /* If this node has a left branch, the value at the left must be less
5983 than that at this node, so it cannot be bounded at the bottom and
5984 we need not bother testing any further. */
5989 low_minus_one
= fold (build (MINUS_EXPR
, TREE_TYPE (node
->low
),
5990 node
->low
, integer_one_node
));
5992 /* If the subtraction above overflowed, we can't verify anything.
5993 Otherwise, look for a parent that tests our value - 1. */
5995 if (! tree_int_cst_lt (low_minus_one
, node
->low
))
5998 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
5999 if (tree_int_cst_equal (low_minus_one
, pnode
->high
))
6005 /* Search the parent sections of the case node tree
6006 to see if a test for the upper bound of NODE would be redundant.
6007 INDEX_TYPE is the type of the index expression.
6009 The instructions to generate the case decision tree are
6010 output in the same order as nodes are processed so it is
6011 known that if a parent node checks the range of the current
6012 node plus one that the current node is bounded at its upper
6013 span. Thus the test would be redundant. */
6016 node_has_high_bound (node
, index_type
)
6021 case_node_ptr pnode
;
6023 /* If there is no upper bound, obviously no test is needed. */
6025 if (TYPE_MAX_VALUE (index_type
) == NULL
)
6028 /* If the upper bound of this node is the highest value in the type
6029 of the index expression, we need not test against it. */
6031 if (tree_int_cst_equal (node
->high
, TYPE_MAX_VALUE (index_type
)))
6034 /* If this node has a right branch, the value at the right must be greater
6035 than that at this node, so it cannot be bounded at the top and
6036 we need not bother testing any further. */
6041 high_plus_one
= fold (build (PLUS_EXPR
, TREE_TYPE (node
->high
),
6042 node
->high
, integer_one_node
));
6044 /* If the addition above overflowed, we can't verify anything.
6045 Otherwise, look for a parent that tests our value + 1. */
6047 if (! tree_int_cst_lt (node
->high
, high_plus_one
))
6050 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
6051 if (tree_int_cst_equal (high_plus_one
, pnode
->low
))
6057 /* Search the parent sections of the
6058 case node tree to see if both tests for the upper and lower
6059 bounds of NODE would be redundant. */
6062 node_is_bounded (node
, index_type
)
6066 return (node_has_low_bound (node
, index_type
)
6067 && node_has_high_bound (node
, index_type
));
6070 /* Emit an unconditional jump to LABEL unless it would be dead code. */
6073 emit_jump_if_reachable (label
)
6076 if (GET_CODE (get_last_insn ()) != BARRIER
)
6080 /* Emit step-by-step code to select a case for the value of INDEX.
6081 The thus generated decision tree follows the form of the
6082 case-node binary tree NODE, whose nodes represent test conditions.
6083 INDEX_TYPE is the type of the index of the switch.
6085 Care is taken to prune redundant tests from the decision tree
6086 by detecting any boundary conditions already checked by
6087 emitted rtx. (See node_has_high_bound, node_has_low_bound
6088 and node_is_bounded, above.)
6090 Where the test conditions can be shown to be redundant we emit
6091 an unconditional jump to the target code. As a further
6092 optimization, the subordinates of a tree node are examined to
6093 check for bounded nodes. In this case conditional and/or
6094 unconditional jumps as a result of the boundary check for the
6095 current node are arranged to target the subordinates associated
6096 code for out of bound conditions on the current node.
6098 We can assume that when control reaches the code generated here,
6099 the index value has already been compared with the parents
6100 of this node, and determined to be on the same side of each parent
6101 as this node is. Thus, if this node tests for the value 51,
6102 and a parent tested for 52, we don't need to consider
6103 the possibility of a value greater than 51. If another parent
6104 tests for the value 50, then this node need not test anything. */
6107 emit_case_nodes (index
, node
, default_label
, index_type
)
6113 /* If INDEX has an unsigned type, we must make unsigned branches. */
6114 int unsignedp
= TREE_UNSIGNED (index_type
);
6115 enum machine_mode mode
= GET_MODE (index
);
6116 enum machine_mode imode
= TYPE_MODE (index_type
);
6118 /* See if our parents have already tested everything for us.
6119 If they have, emit an unconditional jump for this node. */
6120 if (node_is_bounded (node
, index_type
))
6121 emit_jump (label_rtx (node
->code_label
));
6123 else if (tree_int_cst_equal (node
->low
, node
->high
))
6125 /* Node is single valued. First see if the index expression matches
6126 this node and then check our children, if any. */
6128 do_jump_if_equal (index
,
6129 convert_modes (mode
, imode
,
6130 expand_expr (node
->low
, NULL_RTX
,
6133 label_rtx (node
->code_label
), unsignedp
);
6135 if (node
->right
!= 0 && node
->left
!= 0)
6137 /* This node has children on both sides.
6138 Dispatch to one side or the other
6139 by comparing the index value with this node's value.
6140 If one subtree is bounded, check that one first,
6141 so we can avoid real branches in the tree. */
6143 if (node_is_bounded (node
->right
, index_type
))
6145 emit_cmp_and_jump_insns (index
,
6148 expand_expr (node
->high
, NULL_RTX
,
6151 GT
, NULL_RTX
, mode
, unsignedp
,
6152 label_rtx (node
->right
->code_label
));
6153 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6156 else if (node_is_bounded (node
->left
, index_type
))
6158 emit_cmp_and_jump_insns (index
,
6161 expand_expr (node
->high
, NULL_RTX
,
6164 LT
, NULL_RTX
, mode
, unsignedp
,
6165 label_rtx (node
->left
->code_label
));
6166 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6171 /* Neither node is bounded. First distinguish the two sides;
6172 then emit the code for one side at a time. */
6174 tree test_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
6176 /* See if the value is on the right. */
6177 emit_cmp_and_jump_insns (index
,
6180 expand_expr (node
->high
, NULL_RTX
,
6183 GT
, NULL_RTX
, mode
, unsignedp
,
6184 label_rtx (test_label
));
6186 /* Value must be on the left.
6187 Handle the left-hand subtree. */
6188 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6189 /* If left-hand subtree does nothing,
6191 emit_jump_if_reachable (default_label
);
6193 /* Code branches here for the right-hand subtree. */
6194 expand_label (test_label
);
6195 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6199 else if (node
->right
!= 0 && node
->left
== 0)
6201 /* Here we have a right child but no left so we issue conditional
6202 branch to default and process the right child.
6204 Omit the conditional branch to default if we it avoid only one
6205 right child; it costs too much space to save so little time. */
6207 if (node
->right
->right
|| node
->right
->left
6208 || !tree_int_cst_equal (node
->right
->low
, node
->right
->high
))
6210 if (!node_has_low_bound (node
, index_type
))
6212 emit_cmp_and_jump_insns (index
,
6215 expand_expr (node
->high
, NULL_RTX
,
6218 LT
, NULL_RTX
, mode
, unsignedp
,
6222 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6225 /* We cannot process node->right normally
6226 since we haven't ruled out the numbers less than
6227 this node's value. So handle node->right explicitly. */
6228 do_jump_if_equal (index
,
6231 expand_expr (node
->right
->low
, NULL_RTX
,
6234 label_rtx (node
->right
->code_label
), unsignedp
);
6237 else if (node
->right
== 0 && node
->left
!= 0)
6239 /* Just one subtree, on the left. */
6240 if (node
->left
->left
|| node
->left
->right
6241 || !tree_int_cst_equal (node
->left
->low
, node
->left
->high
))
6243 if (!node_has_high_bound (node
, index_type
))
6245 emit_cmp_and_jump_insns (index
,
6248 expand_expr (node
->high
, NULL_RTX
,
6251 GT
, NULL_RTX
, mode
, unsignedp
,
6255 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6258 /* We cannot process node->left normally
6259 since we haven't ruled out the numbers less than
6260 this node's value. So handle node->left explicitly. */
6261 do_jump_if_equal (index
,
6264 expand_expr (node
->left
->low
, NULL_RTX
,
6267 label_rtx (node
->left
->code_label
), unsignedp
);
6272 /* Node is a range. These cases are very similar to those for a single
6273 value, except that we do not start by testing whether this node
6274 is the one to branch to. */
6276 if (node
->right
!= 0 && node
->left
!= 0)
6278 /* Node has subtrees on both sides.
6279 If the right-hand subtree is bounded,
6280 test for it first, since we can go straight there.
6281 Otherwise, we need to make a branch in the control structure,
6282 then handle the two subtrees. */
6283 tree test_label
= 0;
6285 if (node_is_bounded (node
->right
, index_type
))
6286 /* Right hand node is fully bounded so we can eliminate any
6287 testing and branch directly to the target code. */
6288 emit_cmp_and_jump_insns (index
,
6291 expand_expr (node
->high
, NULL_RTX
,
6294 GT
, NULL_RTX
, mode
, unsignedp
,
6295 label_rtx (node
->right
->code_label
));
6298 /* Right hand node requires testing.
6299 Branch to a label where we will handle it later. */
6301 test_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
6302 emit_cmp_and_jump_insns (index
,
6305 expand_expr (node
->high
, NULL_RTX
,
6308 GT
, NULL_RTX
, mode
, unsignedp
,
6309 label_rtx (test_label
));
6312 /* Value belongs to this node or to the left-hand subtree. */
6314 emit_cmp_and_jump_insns (index
,
6317 expand_expr (node
->low
, NULL_RTX
,
6320 GE
, NULL_RTX
, mode
, unsignedp
,
6321 label_rtx (node
->code_label
));
6323 /* Handle the left-hand subtree. */
6324 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6326 /* If right node had to be handled later, do that now. */
6330 /* If the left-hand subtree fell through,
6331 don't let it fall into the right-hand subtree. */
6332 emit_jump_if_reachable (default_label
);
6334 expand_label (test_label
);
6335 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6339 else if (node
->right
!= 0 && node
->left
== 0)
6341 /* Deal with values to the left of this node,
6342 if they are possible. */
6343 if (!node_has_low_bound (node
, index_type
))
6345 emit_cmp_and_jump_insns (index
,
6348 expand_expr (node
->low
, NULL_RTX
,
6351 LT
, NULL_RTX
, mode
, unsignedp
,
6355 /* Value belongs to this node or to the right-hand subtree. */
6357 emit_cmp_and_jump_insns (index
,
6360 expand_expr (node
->high
, NULL_RTX
,
6363 LE
, NULL_RTX
, mode
, unsignedp
,
6364 label_rtx (node
->code_label
));
6366 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6369 else if (node
->right
== 0 && node
->left
!= 0)
6371 /* Deal with values to the right of this node,
6372 if they are possible. */
6373 if (!node_has_high_bound (node
, index_type
))
6375 emit_cmp_and_jump_insns (index
,
6378 expand_expr (node
->high
, NULL_RTX
,
6381 GT
, NULL_RTX
, mode
, unsignedp
,
6385 /* Value belongs to this node or to the left-hand subtree. */
6387 emit_cmp_and_jump_insns (index
,
6390 expand_expr (node
->low
, NULL_RTX
,
6393 GE
, NULL_RTX
, mode
, unsignedp
,
6394 label_rtx (node
->code_label
));
6396 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6401 /* Node has no children so we check low and high bounds to remove
6402 redundant tests. Only one of the bounds can exist,
6403 since otherwise this node is bounded--a case tested already. */
6404 int high_bound
= node_has_high_bound (node
, index_type
);
6405 int low_bound
= node_has_low_bound (node
, index_type
);
6407 if (!high_bound
&& low_bound
)
6409 emit_cmp_and_jump_insns (index
,
6412 expand_expr (node
->high
, NULL_RTX
,
6415 GT
, NULL_RTX
, mode
, unsignedp
,
6419 else if (!low_bound
&& high_bound
)
6421 emit_cmp_and_jump_insns (index
,
6424 expand_expr (node
->low
, NULL_RTX
,
6427 LT
, NULL_RTX
, mode
, unsignedp
,
6430 else if (!low_bound
&& !high_bound
)
6432 /* Widen LOW and HIGH to the same width as INDEX. */
6433 tree type
= type_for_mode (mode
, unsignedp
);
6434 tree low
= build1 (CONVERT_EXPR
, type
, node
->low
);
6435 tree high
= build1 (CONVERT_EXPR
, type
, node
->high
);
6436 rtx low_rtx
, new_index
, new_bound
;
6438 /* Instead of doing two branches, emit one unsigned branch for
6439 (index-low) > (high-low). */
6440 low_rtx
= expand_expr (low
, NULL_RTX
, mode
, 0);
6441 new_index
= expand_simple_binop (mode
, MINUS
, index
, low_rtx
,
6442 NULL_RTX
, unsignedp
,
6444 new_bound
= expand_expr (fold (build (MINUS_EXPR
, type
,
6448 emit_cmp_and_jump_insns (new_index
, new_bound
, GT
, NULL_RTX
,
6449 mode
, 1, default_label
);
6452 emit_jump (label_rtx (node
->code_label
));