1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
5 This file is part of GNU CC.
7 GNU CC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GNU CC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNU CC; see the file COPYING. If not, write to
19 the Free Software Foundation, 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
22 /* This file handles the generation of rtl code from tree structure
23 above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
24 It also creates the rtl expressions for parameters and auto variables
25 and has full responsibility for allocating stack slots.
27 The functions whose names start with `expand_' are called by the
28 parser to generate RTL instructions for various kinds of constructs.
30 Some control and binding constructs require calling several such
31 functions at different times. For example, a simple if-then
32 is expanded by calling `expand_start_cond' (with the condition-expression
33 as argument) before parsing the then-clause and calling `expand_end_cond'
34 after parsing the then-clause. */
45 #include "insn-config.h"
47 #include "hard-reg-set.h"
56 #define obstack_chunk_alloc xmalloc
57 #define obstack_chunk_free free
58 struct obstack stmt_obstack
;
60 /* Assume that case vectors are not pc-relative. */
61 #ifndef CASE_VECTOR_PC_RELATIVE
62 #define CASE_VECTOR_PC_RELATIVE 0
65 /* Functions and data structures for expanding case statements. */
67 /* Case label structure, used to hold info on labels within case
68 statements. We handle "range" labels; for a single-value label
69 as in C, the high and low limits are the same.
71 An AVL tree of case nodes is initially created, and later transformed
72 to a list linked via the RIGHT fields in the nodes. Nodes with
73 higher case values are later in the list.
75 Switch statements can be output in one of two forms. A branch table
76 is used if there are more than a few labels and the labels are dense
77 within the range between the smallest and largest case value. If a
78 branch table is used, no further manipulations are done with the case
81 The alternative to the use of a branch table is to generate a series
82 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
83 and PARENT fields to hold a binary tree. Initially the tree is
84 totally unbalanced, with everything on the right. We balance the tree
85 with nodes on the left having lower case values than the parent
86 and nodes on the right having higher values. We then output the tree
91 struct case_node
*left
; /* Left son in binary tree */
92 struct case_node
*right
; /* Right son in binary tree; also node chain */
93 struct case_node
*parent
; /* Parent of node in binary tree */
94 tree low
; /* Lowest index value for this label */
95 tree high
; /* Highest index value for this label */
96 tree code_label
; /* Label to jump to when node matches */
100 typedef struct case_node case_node
;
101 typedef struct case_node
*case_node_ptr
;
103 /* These are used by estimate_case_costs and balance_case_nodes. */
105 /* This must be a signed type, and non-ANSI compilers lack signed char. */
106 static short cost_table_
[129];
107 static int use_cost_table
;
108 static int cost_table_initialized
;
110 /* Special care is needed because we allow -1, but TREE_INT_CST_LOW
112 #define COST_TABLE(I) cost_table_[(unsigned HOST_WIDE_INT)((I) + 1)]
114 /* Stack of control and binding constructs we are currently inside.
116 These constructs begin when you call `expand_start_WHATEVER'
117 and end when you call `expand_end_WHATEVER'. This stack records
118 info about how the construct began that tells the end-function
119 what to do. It also may provide information about the construct
120 to alter the behavior of other constructs within the body.
121 For example, they may affect the behavior of C `break' and `continue'.
123 Each construct gets one `struct nesting' object.
124 All of these objects are chained through the `all' field.
125 `nesting_stack' points to the first object (innermost construct).
126 The position of an entry on `nesting_stack' is in its `depth' field.
128 Each type of construct has its own individual stack.
129 For example, loops have `loop_stack'. Each object points to the
130 next object of the same type through the `next' field.
132 Some constructs are visible to `break' exit-statements and others
133 are not. Which constructs are visible depends on the language.
134 Therefore, the data structure allows each construct to be visible
135 or not, according to the args given when the construct is started.
136 The construct is visible if the `exit_label' field is non-null.
137 In that case, the value should be a CODE_LABEL rtx. */
142 struct nesting
*next
;
147 /* For conds (if-then and if-then-else statements). */
150 /* Label for the end of the if construct.
151 There is none if EXITFLAG was not set
152 and no `else' has been seen yet. */
154 /* Label for the end of this alternative.
155 This may be the end of the if or the next else/elseif. */
161 /* Label at the top of the loop; place to loop back to. */
163 /* Label at the end of the whole construct. */
165 /* Label before a jump that branches to the end of the whole
166 construct. This is where destructors go if any. */
168 /* Label for `continue' statement to jump to;
169 this is in front of the stepper of the loop. */
172 /* For variable binding contours. */
175 /* Sequence number of this binding contour within the function,
176 in order of entry. */
177 int block_start_count
;
178 /* Nonzero => value to restore stack to on exit. */
180 /* The NOTE that starts this contour.
181 Used by expand_goto to check whether the destination
182 is within each contour or not. */
184 /* Innermost containing binding contour that has a stack level. */
185 struct nesting
*innermost_stack_block
;
186 /* List of cleanups to be run on exit from this contour.
187 This is a list of expressions to be evaluated.
188 The TREE_PURPOSE of each link is the ..._DECL node
189 which the cleanup pertains to. */
191 /* List of cleanup-lists of blocks containing this block,
192 as they were at the locus where this block appears.
193 There is an element for each containing block,
194 ordered innermost containing block first.
195 The tail of this list can be 0,
196 if all remaining elements would be empty lists.
197 The element's TREE_VALUE is the cleanup-list of that block,
198 which may be null. */
200 /* Chain of labels defined inside this binding contour.
201 For contours that have stack levels or cleanups. */
202 struct label_chain
*label_chain
;
203 /* Number of function calls seen, as of start of this block. */
204 int n_function_calls
;
205 /* Nonzero if this is associated with a EH region. */
206 int exception_region
;
207 /* The saved target_temp_slot_level from our outer block.
208 We may reset target_temp_slot_level to be the level of
209 this block, if that is done, target_temp_slot_level
210 reverts to the saved target_temp_slot_level at the very
212 int block_target_temp_slot_level
;
213 /* True if we are currently emitting insns in an area of
214 output code that is controlled by a conditional
215 expression. This is used by the cleanup handling code to
216 generate conditional cleanup actions. */
217 int conditional_code
;
218 /* A place to move the start of the exception region for any
219 of the conditional cleanups, must be at the end or after
220 the start of the last unconditional cleanup, and before any
221 conditional branch points. */
222 rtx last_unconditional_cleanup
;
223 /* When in a conditional context, this is the specific
224 cleanup list associated with last_unconditional_cleanup,
225 where we place the conditionalized cleanups. */
228 /* For switch (C) or case (Pascal) statements,
229 and also for dummies (see `expand_start_case_dummy'). */
232 /* The insn after which the case dispatch should finally
233 be emitted. Zero for a dummy. */
235 /* A list of case labels; it is first built as an AVL tree.
236 During expand_end_case, this is converted to a list, and may be
237 rearranged into a nearly balanced binary tree. */
238 struct case_node
*case_list
;
239 /* Label to jump to if no case matches. */
241 /* The expression to be dispatched on. */
243 /* Type that INDEX_EXPR should be converted to. */
245 /* Name of this kind of statement, for warnings. */
246 const char *printname
;
247 /* Used to save no_line_numbers till we see the first case label.
248 We set this to -1 when we see the first case label in this
250 int line_number_status
;
255 /* Allocate and return a new `struct nesting'. */
257 #define ALLOC_NESTING() \
258 (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
260 /* Pop the nesting stack element by element until we pop off
261 the element which is at the top of STACK.
262 Update all the other stacks, popping off elements from them
263 as we pop them from nesting_stack. */
265 #define POPSTACK(STACK) \
266 do { struct nesting *target = STACK; \
267 struct nesting *this; \
268 do { this = nesting_stack; \
269 if (loop_stack == this) \
270 loop_stack = loop_stack->next; \
271 if (cond_stack == this) \
272 cond_stack = cond_stack->next; \
273 if (block_stack == this) \
274 block_stack = block_stack->next; \
275 if (stack_block_stack == this) \
276 stack_block_stack = stack_block_stack->next; \
277 if (case_stack == this) \
278 case_stack = case_stack->next; \
279 nesting_depth = nesting_stack->depth - 1; \
280 nesting_stack = this->all; \
281 obstack_free (&stmt_obstack, this); } \
282 while (this != target); } while (0)
284 /* In some cases it is impossible to generate code for a forward goto
285 until the label definition is seen. This happens when it may be necessary
286 for the goto to reset the stack pointer: we don't yet know how to do that.
287 So expand_goto puts an entry on this fixup list.
288 Each time a binding contour that resets the stack is exited,
290 If the target label has now been defined, we can insert the proper code. */
294 /* Points to following fixup. */
295 struct goto_fixup
*next
;
296 /* Points to the insn before the jump insn.
297 If more code must be inserted, it goes after this insn. */
299 /* The LABEL_DECL that this jump is jumping to, or 0
300 for break, continue or return. */
302 /* The BLOCK for the place where this goto was found. */
304 /* The CODE_LABEL rtx that this is jumping to. */
306 /* Number of binding contours started in current function
307 before the label reference. */
308 int block_start_count
;
309 /* The outermost stack level that should be restored for this jump.
310 Each time a binding contour that resets the stack is exited,
311 if the target label is *not* yet defined, this slot is updated. */
313 /* List of lists of cleanup expressions to be run by this goto.
314 There is one element for each block that this goto is within.
315 The tail of this list can be 0,
316 if all remaining elements would be empty.
317 The TREE_VALUE contains the cleanup list of that block as of the
318 time this goto was seen.
319 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
320 tree cleanup_list_list
;
323 /* Within any binding contour that must restore a stack level,
324 all labels are recorded with a chain of these structures. */
328 /* Points to following fixup. */
329 struct label_chain
*next
;
335 /* Chain of all pending binding contours. */
336 struct nesting
*x_block_stack
;
338 /* If any new stacks are added here, add them to POPSTACKS too. */
340 /* Chain of all pending binding contours that restore stack levels
342 struct nesting
*x_stack_block_stack
;
344 /* Chain of all pending conditional statements. */
345 struct nesting
*x_cond_stack
;
347 /* Chain of all pending loops. */
348 struct nesting
*x_loop_stack
;
350 /* Chain of all pending case or switch statements. */
351 struct nesting
*x_case_stack
;
353 /* Separate chain including all of the above,
354 chained through the `all' field. */
355 struct nesting
*x_nesting_stack
;
357 /* Number of entries on nesting_stack now. */
360 /* Number of binding contours started so far in this function. */
361 int x_block_start_count
;
363 /* Each time we expand an expression-statement,
364 record the expr's type and its RTL value here. */
365 tree x_last_expr_type
;
366 rtx x_last_expr_value
;
368 /* Nonzero if within a ({...}) grouping, in which case we must
369 always compute a value for each expr-stmt in case it is the last one. */
370 int x_expr_stmts_for_value
;
372 /* Filename and line number of last line-number note,
373 whether we actually emitted it or not. */
374 const char *x_emit_filename
;
377 struct goto_fixup
*x_goto_fixup_chain
;
380 #define block_stack (cfun->stmt->x_block_stack)
381 #define stack_block_stack (cfun->stmt->x_stack_block_stack)
382 #define cond_stack (cfun->stmt->x_cond_stack)
383 #define loop_stack (cfun->stmt->x_loop_stack)
384 #define case_stack (cfun->stmt->x_case_stack)
385 #define nesting_stack (cfun->stmt->x_nesting_stack)
386 #define nesting_depth (cfun->stmt->x_nesting_depth)
387 #define current_block_start_count (cfun->stmt->x_block_start_count)
388 #define last_expr_type (cfun->stmt->x_last_expr_type)
389 #define last_expr_value (cfun->stmt->x_last_expr_value)
390 #define expr_stmts_for_value (cfun->stmt->x_expr_stmts_for_value)
391 #define emit_filename (cfun->stmt->x_emit_filename)
392 #define emit_lineno (cfun->stmt->x_emit_lineno)
393 #define goto_fixup_chain (cfun->stmt->x_goto_fixup_chain)
395 /* Non-zero if we are using EH to handle cleanus. */
396 static int using_eh_for_cleanups_p
= 0;
398 static int n_occurrences
PARAMS ((int, const char *));
399 static void expand_goto_internal
PARAMS ((tree
, rtx
, rtx
));
400 static int expand_fixup
PARAMS ((tree
, rtx
, rtx
));
401 static rtx expand_nl_handler_label
PARAMS ((rtx
, rtx
));
402 static void expand_nl_goto_receiver
PARAMS ((void));
403 static void expand_nl_goto_receivers
PARAMS ((struct nesting
*));
404 static void fixup_gotos
PARAMS ((struct nesting
*, rtx
, tree
,
406 static void expand_null_return_1
PARAMS ((rtx
, int));
407 static void expand_value_return
PARAMS ((rtx
));
408 static int tail_recursion_args
PARAMS ((tree
, tree
));
409 static void expand_cleanups
PARAMS ((tree
, tree
, int, int));
410 static void check_seenlabel
PARAMS ((void));
411 static void do_jump_if_equal
PARAMS ((rtx
, rtx
, rtx
, int));
412 static int estimate_case_costs
PARAMS ((case_node_ptr
));
413 static void group_case_nodes
PARAMS ((case_node_ptr
));
414 static void balance_case_nodes
PARAMS ((case_node_ptr
*,
416 static int node_has_low_bound
PARAMS ((case_node_ptr
, tree
));
417 static int node_has_high_bound
PARAMS ((case_node_ptr
, tree
));
418 static int node_is_bounded
PARAMS ((case_node_ptr
, tree
));
419 static void emit_jump_if_reachable
PARAMS ((rtx
));
420 static void emit_case_nodes
PARAMS ((rtx
, case_node_ptr
, rtx
, tree
));
421 static struct case_node
*case_tree2list
PARAMS ((case_node
*, case_node
*));
422 static void mark_cond_nesting
PARAMS ((struct nesting
*));
423 static void mark_loop_nesting
PARAMS ((struct nesting
*));
424 static void mark_block_nesting
PARAMS ((struct nesting
*));
425 static void mark_case_nesting
PARAMS ((struct nesting
*));
426 static void mark_case_node
PARAMS ((struct case_node
*));
427 static void mark_goto_fixup
PARAMS ((struct goto_fixup
*));
428 static void free_case_nodes
PARAMS ((case_node_ptr
));
431 using_eh_for_cleanups ()
433 using_eh_for_cleanups_p
= 1;
436 /* Mark N (known to be a cond-nesting) for GC. */
439 mark_cond_nesting (n
)
444 ggc_mark_rtx (n
->exit_label
);
445 ggc_mark_rtx (n
->data
.cond
.endif_label
);
446 ggc_mark_rtx (n
->data
.cond
.next_label
);
452 /* Mark N (known to be a loop-nesting) for GC. */
455 mark_loop_nesting (n
)
461 ggc_mark_rtx (n
->exit_label
);
462 ggc_mark_rtx (n
->data
.loop
.start_label
);
463 ggc_mark_rtx (n
->data
.loop
.end_label
);
464 ggc_mark_rtx (n
->data
.loop
.alt_end_label
);
465 ggc_mark_rtx (n
->data
.loop
.continue_label
);
471 /* Mark N (known to be a block-nesting) for GC. */
474 mark_block_nesting (n
)
479 struct label_chain
*l
;
481 ggc_mark_rtx (n
->exit_label
);
482 ggc_mark_rtx (n
->data
.block
.stack_level
);
483 ggc_mark_rtx (n
->data
.block
.first_insn
);
484 ggc_mark_tree (n
->data
.block
.cleanups
);
485 ggc_mark_tree (n
->data
.block
.outer_cleanups
);
487 for (l
= n
->data
.block
.label_chain
; l
!= NULL
; l
= l
->next
)
490 ggc_mark_tree (l
->label
);
493 ggc_mark_rtx (n
->data
.block
.last_unconditional_cleanup
);
495 /* ??? cleanup_ptr never points outside the stack, does it? */
501 /* Mark N (known to be a case-nesting) for GC. */
504 mark_case_nesting (n
)
509 ggc_mark_rtx (n
->exit_label
);
510 ggc_mark_rtx (n
->data
.case_stmt
.start
);
512 ggc_mark_tree (n
->data
.case_stmt
.default_label
);
513 ggc_mark_tree (n
->data
.case_stmt
.index_expr
);
514 ggc_mark_tree (n
->data
.case_stmt
.nominal_type
);
516 mark_case_node (n
->data
.case_stmt
.case_list
);
529 ggc_mark_tree (c
->low
);
530 ggc_mark_tree (c
->high
);
531 ggc_mark_tree (c
->code_label
);
533 mark_case_node (c
->right
);
534 mark_case_node (c
->left
);
542 struct goto_fixup
*g
;
547 ggc_mark_rtx (g
->before_jump
);
548 ggc_mark_tree (g
->target
);
549 ggc_mark_tree (g
->context
);
550 ggc_mark_rtx (g
->target_rtl
);
551 ggc_mark_rtx (g
->stack_level
);
552 ggc_mark_tree (g
->cleanup_list_list
);
558 /* Clear out all parts of the state in F that can safely be discarded
559 after the function has been compiled, to let garbage collection
560 reclaim the memory. */
566 /* We're about to free the function obstack. If we hold pointers to
567 things allocated there, then we'll try to mark them when we do
568 GC. So, we clear them out here explicitly. */
578 struct stmt_status
*p
;
583 mark_block_nesting (p
->x_block_stack
);
584 mark_cond_nesting (p
->x_cond_stack
);
585 mark_loop_nesting (p
->x_loop_stack
);
586 mark_case_nesting (p
->x_case_stack
);
588 ggc_mark_tree (p
->x_last_expr_type
);
589 /* last_epxr_value is only valid if last_expr_type is nonzero. */
590 if (p
->x_last_expr_type
)
591 ggc_mark_rtx (p
->x_last_expr_value
);
593 mark_goto_fixup (p
->x_goto_fixup_chain
);
599 gcc_obstack_init (&stmt_obstack
);
603 init_stmt_for_function ()
605 cfun
->stmt
= (struct stmt_status
*) xmalloc (sizeof (struct stmt_status
));
607 /* We are not currently within any block, conditional, loop or case. */
609 stack_block_stack
= 0;
616 current_block_start_count
= 0;
618 /* No gotos have been expanded yet. */
619 goto_fixup_chain
= 0;
621 /* We are not processing a ({...}) grouping. */
622 expr_stmts_for_value
= 0;
624 last_expr_value
= NULL_RTX
;
627 /* Return nonzero if anything is pushed on the loop, condition, or case
632 return cond_stack
|| loop_stack
|| case_stack
;
635 /* Record the current file and line. Called from emit_line_note. */
637 set_file_and_line_for_stmt (file
, line
)
641 /* If we're outputting an inline function, and we add a line note,
642 there may be no CFUN->STMT information. So, there's no need to
646 emit_filename
= file
;
651 /* Emit a no-op instruction. */
658 last_insn
= get_last_insn ();
660 && (GET_CODE (last_insn
) == CODE_LABEL
661 || (GET_CODE (last_insn
) == NOTE
662 && prev_real_insn (last_insn
) == 0)))
663 emit_insn (gen_nop ());
666 /* Return the rtx-label that corresponds to a LABEL_DECL,
667 creating it if necessary. */
673 if (TREE_CODE (label
) != LABEL_DECL
)
676 if (!DECL_RTL_SET_P (label
))
677 SET_DECL_RTL (label
, gen_label_rtx ());
679 return DECL_RTL (label
);
683 /* Add an unconditional jump to LABEL as the next sequential instruction. */
689 do_pending_stack_adjust ();
690 emit_jump_insn (gen_jump (label
));
694 /* Emit code to jump to the address
695 specified by the pointer expression EXP. */
698 expand_computed_goto (exp
)
701 rtx x
= expand_expr (exp
, NULL_RTX
, VOIDmode
, 0);
703 #ifdef POINTERS_EXTEND_UNSIGNED
704 x
= convert_memory_address (Pmode
, x
);
708 /* Be sure the function is executable. */
709 if (current_function_check_memory_usage
)
710 emit_library_call (chkr_check_exec_libfunc
, LCT_CONST_MAKE_BLOCK
,
711 VOIDmode
, 1, x
, ptr_mode
);
713 do_pending_stack_adjust ();
714 emit_indirect_jump (x
);
716 current_function_has_computed_jump
= 1;
719 /* Handle goto statements and the labels that they can go to. */
721 /* Specify the location in the RTL code of a label LABEL,
722 which is a LABEL_DECL tree node.
724 This is used for the kind of label that the user can jump to with a
725 goto statement, and for alternatives of a switch or case statement.
726 RTL labels generated for loops and conditionals don't go through here;
727 they are generated directly at the RTL level, by other functions below.
729 Note that this has nothing to do with defining label *names*.
730 Languages vary in how they do that and what that even means. */
736 struct label_chain
*p
;
738 do_pending_stack_adjust ();
739 emit_label (label_rtx (label
));
740 if (DECL_NAME (label
))
741 LABEL_NAME (DECL_RTL (label
)) = IDENTIFIER_POINTER (DECL_NAME (label
));
743 if (stack_block_stack
!= 0)
745 p
= (struct label_chain
*) ggc_alloc (sizeof (struct label_chain
));
746 p
->next
= stack_block_stack
->data
.block
.label_chain
;
747 stack_block_stack
->data
.block
.label_chain
= p
;
752 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
753 from nested functions. */
756 declare_nonlocal_label (label
)
759 rtx slot
= assign_stack_local (Pmode
, GET_MODE_SIZE (Pmode
), 0);
761 nonlocal_labels
= tree_cons (NULL_TREE
, label
, nonlocal_labels
);
762 LABEL_PRESERVE_P (label_rtx (label
)) = 1;
763 if (nonlocal_goto_handler_slots
== 0)
765 emit_stack_save (SAVE_NONLOCAL
,
766 &nonlocal_goto_stack_level
,
767 PREV_INSN (tail_recursion_reentry
));
769 nonlocal_goto_handler_slots
770 = gen_rtx_EXPR_LIST (VOIDmode
, slot
, nonlocal_goto_handler_slots
);
773 /* Generate RTL code for a `goto' statement with target label LABEL.
774 LABEL should be a LABEL_DECL tree node that was or will later be
775 defined with `expand_label'. */
783 /* Check for a nonlocal goto to a containing function. */
784 context
= decl_function_context (label
);
785 if (context
!= 0 && context
!= current_function_decl
)
787 struct function
*p
= find_function_data (context
);
788 rtx label_ref
= gen_rtx_LABEL_REF (Pmode
, label_rtx (label
));
789 rtx handler_slot
, static_chain
, save_area
, insn
;
792 /* Find the corresponding handler slot for this label. */
793 handler_slot
= p
->x_nonlocal_goto_handler_slots
;
794 for (link
= p
->x_nonlocal_labels
; TREE_VALUE (link
) != label
;
795 link
= TREE_CHAIN (link
))
796 handler_slot
= XEXP (handler_slot
, 1);
797 handler_slot
= XEXP (handler_slot
, 0);
799 p
->has_nonlocal_label
= 1;
800 current_function_has_nonlocal_goto
= 1;
801 LABEL_REF_NONLOCAL_P (label_ref
) = 1;
803 /* Copy the rtl for the slots so that they won't be shared in
804 case the virtual stack vars register gets instantiated differently
805 in the parent than in the child. */
807 static_chain
= copy_to_reg (lookup_static_chain (label
));
809 /* Get addr of containing function's current nonlocal goto handler,
810 which will do any cleanups and then jump to the label. */
811 handler_slot
= copy_to_reg (replace_rtx (copy_rtx (handler_slot
),
812 virtual_stack_vars_rtx
,
815 /* Get addr of containing function's nonlocal save area. */
816 save_area
= p
->x_nonlocal_goto_stack_level
;
818 save_area
= replace_rtx (copy_rtx (save_area
),
819 virtual_stack_vars_rtx
, static_chain
);
821 #if HAVE_nonlocal_goto
822 if (HAVE_nonlocal_goto
)
823 emit_insn (gen_nonlocal_goto (static_chain
, handler_slot
,
824 save_area
, label_ref
));
828 /* Restore frame pointer for containing function.
829 This sets the actual hard register used for the frame pointer
830 to the location of the function's incoming static chain info.
831 The non-local goto handler will then adjust it to contain the
832 proper value and reload the argument pointer, if needed. */
833 emit_move_insn (hard_frame_pointer_rtx
, static_chain
);
834 emit_stack_restore (SAVE_NONLOCAL
, save_area
, NULL_RTX
);
836 /* USE of hard_frame_pointer_rtx added for consistency;
837 not clear if really needed. */
838 emit_insn (gen_rtx_USE (VOIDmode
, hard_frame_pointer_rtx
));
839 emit_insn (gen_rtx_USE (VOIDmode
, stack_pointer_rtx
));
840 emit_indirect_jump (handler_slot
);
843 /* Search backwards to the jump insn and mark it as a
845 for (insn
= get_last_insn (); insn
; insn
= PREV_INSN (insn
))
847 if (GET_CODE (insn
) == JUMP_INSN
)
849 REG_NOTES (insn
) = alloc_EXPR_LIST (REG_NON_LOCAL_GOTO
,
850 const0_rtx
, REG_NOTES (insn
));
853 else if (GET_CODE (insn
) == CALL_INSN
)
858 expand_goto_internal (label
, label_rtx (label
), NULL_RTX
);
861 /* Generate RTL code for a `goto' statement with target label BODY.
862 LABEL should be a LABEL_REF.
863 LAST_INSN, if non-0, is the rtx we should consider as the last
864 insn emitted (for the purposes of cleaning up a return). */
867 expand_goto_internal (body
, label
, last_insn
)
872 struct nesting
*block
;
875 if (GET_CODE (label
) != CODE_LABEL
)
878 /* If label has already been defined, we can tell now
879 whether and how we must alter the stack level. */
881 if (PREV_INSN (label
) != 0)
883 /* Find the innermost pending block that contains the label.
884 (Check containment by comparing insn-uids.)
885 Then restore the outermost stack level within that block,
886 and do cleanups of all blocks contained in it. */
887 for (block
= block_stack
; block
; block
= block
->next
)
889 if (INSN_UID (block
->data
.block
.first_insn
) < INSN_UID (label
))
891 if (block
->data
.block
.stack_level
!= 0)
892 stack_level
= block
->data
.block
.stack_level
;
893 /* Execute the cleanups for blocks we are exiting. */
894 if (block
->data
.block
.cleanups
!= 0)
896 expand_cleanups (block
->data
.block
.cleanups
, NULL_TREE
, 1, 1);
897 do_pending_stack_adjust ();
903 /* Ensure stack adjust isn't done by emit_jump, as this
904 would clobber the stack pointer. This one should be
905 deleted as dead by flow. */
906 clear_pending_stack_adjust ();
907 do_pending_stack_adjust ();
909 /* Don't do this adjust if it's to the end label and this function
910 is to return with a depressed stack pointer. */
911 if (label
== return_label
912 && (((TREE_CODE (TREE_TYPE (current_function_decl
))
914 && (TYPE_RETURNS_STACK_DEPRESSED
915 (TREE_TYPE (current_function_decl
))))))
918 emit_stack_restore (SAVE_BLOCK
, stack_level
, NULL_RTX
);
921 if (body
!= 0 && DECL_TOO_LATE (body
))
922 error ("jump to `%s' invalidly jumps into binding contour",
923 IDENTIFIER_POINTER (DECL_NAME (body
)));
925 /* Label not yet defined: may need to put this goto
926 on the fixup list. */
927 else if (! expand_fixup (body
, label
, last_insn
))
929 /* No fixup needed. Record that the label is the target
930 of at least one goto that has no fixup. */
932 TREE_ADDRESSABLE (body
) = 1;
938 /* Generate if necessary a fixup for a goto
939 whose target label in tree structure (if any) is TREE_LABEL
940 and whose target in rtl is RTL_LABEL.
942 If LAST_INSN is nonzero, we pretend that the jump appears
943 after insn LAST_INSN instead of at the current point in the insn stream.
945 The fixup will be used later to insert insns just before the goto.
946 Those insns will restore the stack level as appropriate for the
947 target label, and will (in the case of C++) also invoke any object
948 destructors which have to be invoked when we exit the scopes which
949 are exited by the goto.
951 Value is nonzero if a fixup is made. */
954 expand_fixup (tree_label
, rtl_label
, last_insn
)
959 struct nesting
*block
, *end_block
;
961 /* See if we can recognize which block the label will be output in.
962 This is possible in some very common cases.
963 If we succeed, set END_BLOCK to that block.
964 Otherwise, set it to 0. */
967 && (rtl_label
== cond_stack
->data
.cond
.endif_label
968 || rtl_label
== cond_stack
->data
.cond
.next_label
))
969 end_block
= cond_stack
;
970 /* If we are in a loop, recognize certain labels which
971 are likely targets. This reduces the number of fixups
972 we need to create. */
974 && (rtl_label
== loop_stack
->data
.loop
.start_label
975 || rtl_label
== loop_stack
->data
.loop
.end_label
976 || rtl_label
== loop_stack
->data
.loop
.continue_label
))
977 end_block
= loop_stack
;
981 /* Now set END_BLOCK to the binding level to which we will return. */
985 struct nesting
*next_block
= end_block
->all
;
988 /* First see if the END_BLOCK is inside the innermost binding level.
989 If so, then no cleanups or stack levels are relevant. */
990 while (next_block
&& next_block
!= block
)
991 next_block
= next_block
->all
;
996 /* Otherwise, set END_BLOCK to the innermost binding level
997 which is outside the relevant control-structure nesting. */
998 next_block
= block_stack
->next
;
999 for (block
= block_stack
; block
!= end_block
; block
= block
->all
)
1000 if (block
== next_block
)
1001 next_block
= next_block
->next
;
1002 end_block
= next_block
;
1005 /* Does any containing block have a stack level or cleanups?
1006 If not, no fixup is needed, and that is the normal case
1007 (the only case, for standard C). */
1008 for (block
= block_stack
; block
!= end_block
; block
= block
->next
)
1009 if (block
->data
.block
.stack_level
!= 0
1010 || block
->data
.block
.cleanups
!= 0)
1013 if (block
!= end_block
)
1015 /* Ok, a fixup is needed. Add a fixup to the list of such. */
1016 struct goto_fixup
*fixup
1017 = (struct goto_fixup
*) ggc_alloc (sizeof (struct goto_fixup
));
1018 /* In case an old stack level is restored, make sure that comes
1019 after any pending stack adjust. */
1020 /* ?? If the fixup isn't to come at the present position,
1021 doing the stack adjust here isn't useful. Doing it with our
1022 settings at that location isn't useful either. Let's hope
1025 do_pending_stack_adjust ();
1026 fixup
->target
= tree_label
;
1027 fixup
->target_rtl
= rtl_label
;
1029 /* Create a BLOCK node and a corresponding matched set of
1030 NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes at
1031 this point. The notes will encapsulate any and all fixup
1032 code which we might later insert at this point in the insn
1033 stream. Also, the BLOCK node will be the parent (i.e. the
1034 `SUPERBLOCK') of any other BLOCK nodes which we might create
1035 later on when we are expanding the fixup code.
1037 Note that optimization passes (including expand_end_loop)
1038 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
1039 as a placeholder. */
1042 register rtx original_before_jump
1043 = last_insn
? last_insn
: get_last_insn ();
1048 block
= make_node (BLOCK
);
1049 TREE_USED (block
) = 1;
1051 if (!cfun
->x_whole_function_mode_p
)
1052 insert_block (block
);
1056 = BLOCK_CHAIN (DECL_INITIAL (current_function_decl
));
1057 BLOCK_CHAIN (DECL_INITIAL (current_function_decl
))
1062 start
= emit_note (NULL
, NOTE_INSN_BLOCK_BEG
);
1063 if (cfun
->x_whole_function_mode_p
)
1064 NOTE_BLOCK (start
) = block
;
1065 fixup
->before_jump
= emit_note (NULL
, NOTE_INSN_DELETED
);
1066 end
= emit_note (NULL
, NOTE_INSN_BLOCK_END
);
1067 if (cfun
->x_whole_function_mode_p
)
1068 NOTE_BLOCK (end
) = block
;
1069 fixup
->context
= block
;
1071 emit_insns_after (start
, original_before_jump
);
1074 fixup
->block_start_count
= current_block_start_count
;
1075 fixup
->stack_level
= 0;
1076 fixup
->cleanup_list_list
1077 = ((block
->data
.block
.outer_cleanups
1078 || block
->data
.block
.cleanups
)
1079 ? tree_cons (NULL_TREE
, block
->data
.block
.cleanups
,
1080 block
->data
.block
.outer_cleanups
)
1082 fixup
->next
= goto_fixup_chain
;
1083 goto_fixup_chain
= fixup
;
1089 /* Expand any needed fixups in the outputmost binding level of the
1090 function. FIRST_INSN is the first insn in the function. */
1093 expand_fixups (first_insn
)
1096 fixup_gotos (NULL
, NULL_RTX
, NULL_TREE
, first_insn
, 0);
1099 /* When exiting a binding contour, process all pending gotos requiring fixups.
1100 THISBLOCK is the structure that describes the block being exited.
1101 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1102 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1103 FIRST_INSN is the insn that began this contour.
1105 Gotos that jump out of this contour must restore the
1106 stack level and do the cleanups before actually jumping.
1108 DONT_JUMP_IN nonzero means report error there is a jump into this
1109 contour from before the beginning of the contour.
1110 This is also done if STACK_LEVEL is nonzero. */
1113 fixup_gotos (thisblock
, stack_level
, cleanup_list
, first_insn
, dont_jump_in
)
1114 struct nesting
*thisblock
;
1120 register struct goto_fixup
*f
, *prev
;
1122 /* F is the fixup we are considering; PREV is the previous one. */
1123 /* We run this loop in two passes so that cleanups of exited blocks
1124 are run first, and blocks that are exited are marked so
1127 for (prev
= 0, f
= goto_fixup_chain
; f
; prev
= f
, f
= f
->next
)
1129 /* Test for a fixup that is inactive because it is already handled. */
1130 if (f
->before_jump
== 0)
1132 /* Delete inactive fixup from the chain, if that is easy to do. */
1134 prev
->next
= f
->next
;
1136 /* Has this fixup's target label been defined?
1137 If so, we can finalize it. */
1138 else if (PREV_INSN (f
->target_rtl
) != 0)
1140 register rtx cleanup_insns
;
1142 /* If this fixup jumped into this contour from before the beginning
1143 of this contour, report an error. This code used to use
1144 the first non-label insn after f->target_rtl, but that's
1145 wrong since such can be added, by things like put_var_into_stack
1146 and have INSN_UIDs that are out of the range of the block. */
1147 /* ??? Bug: this does not detect jumping in through intermediate
1148 blocks that have stack levels or cleanups.
1149 It detects only a problem with the innermost block
1150 around the label. */
1152 && (dont_jump_in
|| stack_level
|| cleanup_list
)
1153 && INSN_UID (first_insn
) < INSN_UID (f
->target_rtl
)
1154 && INSN_UID (first_insn
) > INSN_UID (f
->before_jump
)
1155 && ! DECL_ERROR_ISSUED (f
->target
))
1157 error_with_decl (f
->target
,
1158 "label `%s' used before containing binding contour");
1159 /* Prevent multiple errors for one label. */
1160 DECL_ERROR_ISSUED (f
->target
) = 1;
1163 /* We will expand the cleanups into a sequence of their own and
1164 then later on we will attach this new sequence to the insn
1165 stream just ahead of the actual jump insn. */
1169 /* Temporarily restore the lexical context where we will
1170 logically be inserting the fixup code. We do this for the
1171 sake of getting the debugging information right. */
1174 set_block (f
->context
);
1176 /* Expand the cleanups for blocks this jump exits. */
1177 if (f
->cleanup_list_list
)
1180 for (lists
= f
->cleanup_list_list
; lists
; lists
= TREE_CHAIN (lists
))
1181 /* Marked elements correspond to blocks that have been closed.
1182 Do their cleanups. */
1183 if (TREE_ADDRESSABLE (lists
)
1184 && TREE_VALUE (lists
) != 0)
1186 expand_cleanups (TREE_VALUE (lists
), NULL_TREE
, 1, 1);
1187 /* Pop any pushes done in the cleanups,
1188 in case function is about to return. */
1189 do_pending_stack_adjust ();
1193 /* Restore stack level for the biggest contour that this
1194 jump jumps out of. */
1196 && ! (f
->target_rtl
== return_label
1197 && ((TREE_CODE (TREE_TYPE (current_function_decl
))
1199 && (TYPE_RETURNS_STACK_DEPRESSED
1200 (TREE_TYPE (current_function_decl
))))))
1201 emit_stack_restore (SAVE_BLOCK
, f
->stack_level
, f
->before_jump
);
1203 /* Finish up the sequence containing the insns which implement the
1204 necessary cleanups, and then attach that whole sequence to the
1205 insn stream just ahead of the actual jump insn. Attaching it
1206 at that point insures that any cleanups which are in fact
1207 implicit C++ object destructions (which must be executed upon
1208 leaving the block) appear (to the debugger) to be taking place
1209 in an area of the generated code where the object(s) being
1210 destructed are still "in scope". */
1212 cleanup_insns
= get_insns ();
1216 emit_insns_after (cleanup_insns
, f
->before_jump
);
1222 /* For any still-undefined labels, do the cleanups for this block now.
1223 We must do this now since items in the cleanup list may go out
1224 of scope when the block ends. */
1225 for (prev
= 0, f
= goto_fixup_chain
; f
; prev
= f
, f
= f
->next
)
1226 if (f
->before_jump
!= 0
1227 && PREV_INSN (f
->target_rtl
) == 0
1228 /* Label has still not appeared. If we are exiting a block with
1229 a stack level to restore, that started before the fixup,
1230 mark this stack level as needing restoration
1231 when the fixup is later finalized. */
1233 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1234 means the label is undefined. That's erroneous, but possible. */
1235 && (thisblock
->data
.block
.block_start_count
1236 <= f
->block_start_count
))
1238 tree lists
= f
->cleanup_list_list
;
1241 for (; lists
; lists
= TREE_CHAIN (lists
))
1242 /* If the following elt. corresponds to our containing block
1243 then the elt. must be for this block. */
1244 if (TREE_CHAIN (lists
) == thisblock
->data
.block
.outer_cleanups
)
1248 set_block (f
->context
);
1249 expand_cleanups (TREE_VALUE (lists
), NULL_TREE
, 1, 1);
1250 do_pending_stack_adjust ();
1251 cleanup_insns
= get_insns ();
1254 if (cleanup_insns
!= 0)
1256 = emit_insns_after (cleanup_insns
, f
->before_jump
);
1258 f
->cleanup_list_list
= TREE_CHAIN (lists
);
1262 f
->stack_level
= stack_level
;
1266 /* Return the number of times character C occurs in string S. */
1268 n_occurrences (c
, s
)
1278 /* Generate RTL for an asm statement (explicit assembler code).
1279 BODY is a STRING_CST node containing the assembler code text,
1280 or an ADDR_EXPR containing a STRING_CST. */
1286 if (current_function_check_memory_usage
)
1288 error ("`asm' cannot be used in function where memory usage is checked");
1292 if (TREE_CODE (body
) == ADDR_EXPR
)
1293 body
= TREE_OPERAND (body
, 0);
1295 emit_insn (gen_rtx_ASM_INPUT (VOIDmode
,
1296 TREE_STRING_POINTER (body
)));
1300 /* Parse the output constraint pointed to by *CONSTRAINT_P. It is the
1301 OPERAND_NUMth output operand, indexed from zero. There are NINPUTS
1302 inputs and NOUTPUTS outputs to this extended-asm. Upon return,
1303 *ALLOWS_MEM will be TRUE iff the constraint allows the use of a
1304 memory operand. Similarly, *ALLOWS_REG will be TRUE iff the
1305 constraint allows the use of a register operand. And, *IS_INOUT
1306 will be true if the operand is read-write, i.e., if it is used as
1307 an input as well as an output. If *CONSTRAINT_P is not in
1308 canonical form, it will be made canonical. (Note that `+' will be
1309 rpelaced with `=' as part of this process.)
1311 Returns TRUE if all went well; FALSE if an error occurred. */
1314 parse_output_constraint (constraint_p
,
1321 const char **constraint_p
;
1329 const char *constraint
= *constraint_p
;
1332 /* Assume the constraint doesn't allow the use of either a register
1334 *allows_mem
= false;
1335 *allows_reg
= false;
1337 /* Allow the `=' or `+' to not be at the beginning of the string,
1338 since it wasn't explicitly documented that way, and there is a
1339 large body of code that puts it last. Swap the character to
1340 the front, so as not to uglify any place else. */
1341 p
= strchr (constraint
, '=');
1343 p
= strchr (constraint
, '+');
1345 /* If the string doesn't contain an `=', issue an error
1349 error ("output operand constraint lacks `='");
1353 /* If the constraint begins with `+', then the operand is both read
1354 from and written to. */
1355 *is_inout
= (*p
== '+');
1357 /* Make sure we can specify the matching operand. */
1358 if (*is_inout
&& operand_num
> 9)
1360 error ("output operand constraint %d contains `+'",
1365 /* Canonicalize the output constraint so that it begins with `='. */
1366 if (p
!= constraint
|| is_inout
)
1369 size_t c_len
= strlen (constraint
);
1371 if (p
!= constraint
)
1372 warning ("output constraint `%c' for operand %d is not at the beginning",
1375 /* Make a copy of the constraint. */
1376 buf
= alloca (c_len
+ 1);
1377 strcpy (buf
, constraint
);
1378 /* Swap the first character and the `=' or `+'. */
1379 buf
[p
- constraint
] = buf
[0];
1380 /* Make sure the first character is an `='. (Until we do this,
1381 it might be a `+'.) */
1383 /* Replace the constraint with the canonicalized string. */
1384 *constraint_p
= ggc_alloc_string (buf
, c_len
);
1385 constraint
= *constraint_p
;
1388 /* Loop through the constraint string. */
1389 for (p
= constraint
+ 1; *p
; ++p
)
1394 error ("operand constraint contains '+' or '=' at illegal position.");
1398 if (operand_num
+ 1 == ninputs
+ noutputs
)
1400 error ("`%%' constraint used with last operand");
1405 case 'V': case 'm': case 'o':
1409 case '?': case '!': case '*': case '&': case '#':
1410 case 'E': case 'F': case 'G': case 'H':
1411 case 's': case 'i': case 'n':
1412 case 'I': case 'J': case 'K': case 'L': case 'M':
1413 case 'N': case 'O': case 'P': case ',':
1416 case '0': case '1': case '2': case '3': case '4':
1417 case '5': case '6': case '7': case '8': case '9':
1418 error ("matching constraint not valid in output operand");
1422 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1423 excepting those that expand_call created. So match memory
1440 if (REG_CLASS_FROM_LETTER (*p
) != NO_REGS
)
1442 #ifdef EXTRA_CONSTRAINT
1445 /* Otherwise we can't assume anything about the nature of
1446 the constraint except that it isn't purely registers.
1447 Treat it like "g" and hope for the best. */
1458 /* Generate RTL for an asm statement with arguments.
1459 STRING is the instruction template.
1460 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1461 Each output or input has an expression in the TREE_VALUE and
1462 a constraint-string in the TREE_PURPOSE.
1463 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1464 that is clobbered by this insn.
1466 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1467 Some elements of OUTPUTS may be replaced with trees representing temporary
1468 values. The caller should copy those temporary values to the originally
1471 VOL nonzero means the insn is volatile; don't optimize it. */
1474 expand_asm_operands (string
, outputs
, inputs
, clobbers
, vol
, filename
, line
)
1475 tree string
, outputs
, inputs
, clobbers
;
1477 const char *filename
;
1480 rtvec argvec
, constraints
;
1482 int ninputs
= list_length (inputs
);
1483 int noutputs
= list_length (outputs
);
1488 /* Vector of RTX's of evaluated output operands. */
1489 rtx
*output_rtx
= (rtx
*) alloca (noutputs
* sizeof (rtx
));
1490 int *inout_opnum
= (int *) alloca (noutputs
* sizeof (int));
1491 rtx
*real_output_rtx
= (rtx
*) alloca (noutputs
* sizeof (rtx
));
1492 enum machine_mode
*inout_mode
1493 = (enum machine_mode
*) alloca (noutputs
* sizeof (enum machine_mode
));
1494 const char **output_constraints
1495 = alloca (noutputs
* sizeof (const char *));
1496 /* The insn we have emitted. */
1498 int old_generating_concat_p
= generating_concat_p
;
1500 /* An ASM with no outputs needs to be treated as volatile, for now. */
1504 if (current_function_check_memory_usage
)
1506 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1510 #ifdef MD_ASM_CLOBBERS
1511 /* Sometimes we wish to automatically clobber registers across an asm.
1512 Case in point is when the i386 backend moved from cc0 to a hard reg --
1513 maintaining source-level compatability means automatically clobbering
1514 the flags register. */
1515 MD_ASM_CLOBBERS (clobbers
);
1518 if (current_function_check_memory_usage
)
1520 error ("`asm' cannot be used in function where memory usage is checked");
1524 /* Count the number of meaningful clobbered registers, ignoring what
1525 we would ignore later. */
1527 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
))
1529 const char *regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
1531 i
= decode_reg_name (regname
);
1532 if (i
>= 0 || i
== -4)
1535 error ("unknown register name `%s' in `asm'", regname
);
1540 /* Check that the number of alternatives is constant across all
1542 if (outputs
|| inputs
)
1544 tree tmp
= TREE_PURPOSE (outputs
? outputs
: inputs
);
1545 int nalternatives
= n_occurrences (',', TREE_STRING_POINTER (tmp
));
1548 if (nalternatives
+ 1 > MAX_RECOG_ALTERNATIVES
)
1550 error ("too many alternatives in `asm'");
1557 const char *constraint
= TREE_STRING_POINTER (TREE_PURPOSE (tmp
));
1559 if (n_occurrences (',', constraint
) != nalternatives
)
1561 error ("operand constraints for `asm' differ in number of alternatives");
1565 if (TREE_CHAIN (tmp
))
1566 tmp
= TREE_CHAIN (tmp
);
1568 tmp
= next
, next
= 0;
1572 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1574 tree val
= TREE_VALUE (tail
);
1575 tree type
= TREE_TYPE (val
);
1576 const char *constraint
;
1581 /* If there's an erroneous arg, emit no insn. */
1582 if (type
== error_mark_node
)
1585 /* Make sure constraint has `=' and does not have `+'. Also, see
1586 if it allows any register. Be liberal on the latter test, since
1587 the worst that happens if we get it wrong is we issue an error
1590 constraint
= TREE_STRING_POINTER (TREE_PURPOSE (tail
));
1591 output_constraints
[i
] = constraint
;
1593 /* Try to parse the output constraint. If that fails, there's
1594 no point in going further. */
1595 if (!parse_output_constraint (&output_constraints
[i
],
1604 /* If an output operand is not a decl or indirect ref and our constraint
1605 allows a register, make a temporary to act as an intermediate.
1606 Make the asm insn write into that, then our caller will copy it to
1607 the real output operand. Likewise for promoted variables. */
1609 generating_concat_p
= 0;
1611 real_output_rtx
[i
] = NULL_RTX
;
1612 if ((TREE_CODE (val
) == INDIRECT_REF
1615 && (allows_mem
|| GET_CODE (DECL_RTL (val
)) == REG
)
1616 && ! (GET_CODE (DECL_RTL (val
)) == REG
1617 && GET_MODE (DECL_RTL (val
)) != TYPE_MODE (type
)))
1622 mark_addressable (TREE_VALUE (tail
));
1625 = expand_expr (TREE_VALUE (tail
), NULL_RTX
, VOIDmode
,
1626 EXPAND_MEMORY_USE_WO
);
1628 if (! allows_reg
&& GET_CODE (output_rtx
[i
]) != MEM
)
1629 error ("output number %d not directly addressable", i
);
1630 if ((! allows_mem
&& GET_CODE (output_rtx
[i
]) == MEM
)
1631 || GET_CODE (output_rtx
[i
]) == CONCAT
)
1633 real_output_rtx
[i
] = protect_from_queue (output_rtx
[i
], 1);
1634 output_rtx
[i
] = gen_reg_rtx (GET_MODE (output_rtx
[i
]));
1636 emit_move_insn (output_rtx
[i
], real_output_rtx
[i
]);
1641 output_rtx
[i
] = assign_temp (type
, 0, 0, 1);
1642 TREE_VALUE (tail
) = make_tree (type
, output_rtx
[i
]);
1645 generating_concat_p
= old_generating_concat_p
;
1649 inout_mode
[ninout
] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail
)));
1650 inout_opnum
[ninout
++] = i
;
1655 if (ninputs
+ noutputs
> MAX_RECOG_OPERANDS
)
1657 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS
);
1661 /* Make vectors for the expression-rtx and constraint strings. */
1663 argvec
= rtvec_alloc (ninputs
);
1664 constraints
= rtvec_alloc (ninputs
);
1666 body
= gen_rtx_ASM_OPERANDS ((noutputs
== 0 ? VOIDmode
1667 : GET_MODE (output_rtx
[0])),
1668 TREE_STRING_POINTER (string
),
1669 empty_string
, 0, argvec
, constraints
,
1672 MEM_VOLATILE_P (body
) = vol
;
1674 /* Eval the inputs and put them into ARGVEC.
1675 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1678 for (tail
= inputs
; tail
; tail
= TREE_CHAIN (tail
))
1681 int allows_reg
= 0, allows_mem
= 0;
1682 const char *constraint
, *orig_constraint
;
1686 /* If there's an erroneous arg, emit no insn,
1687 because the ASM_INPUT would get VOIDmode
1688 and that could cause a crash in reload. */
1689 if (TREE_TYPE (TREE_VALUE (tail
)) == error_mark_node
)
1692 /* ??? Can this happen, and does the error message make any sense? */
1693 if (TREE_PURPOSE (tail
) == NULL_TREE
)
1695 error ("hard register `%s' listed as input operand to `asm'",
1696 TREE_STRING_POINTER (TREE_VALUE (tail
)) );
1700 constraint
= TREE_STRING_POINTER (TREE_PURPOSE (tail
));
1701 c_len
= strlen (constraint
);
1702 orig_constraint
= constraint
;
1704 /* Make sure constraint has neither `=', `+', nor '&'. */
1706 for (j
= 0; j
< c_len
; j
++)
1707 switch (constraint
[j
])
1709 case '+': case '=': case '&':
1710 if (constraint
== orig_constraint
)
1712 error ("input operand constraint contains `%c'",
1719 if (constraint
== orig_constraint
1720 && i
+ 1 == ninputs
- ninout
)
1722 error ("`%%' constraint used with last operand");
1727 case 'V': case 'm': case 'o':
1732 case '?': case '!': case '*': case '#':
1733 case 'E': case 'F': case 'G': case 'H':
1734 case 's': case 'i': case 'n':
1735 case 'I': case 'J': case 'K': case 'L': case 'M':
1736 case 'N': case 'O': case 'P': case ',':
1739 /* Whether or not a numeric constraint allows a register is
1740 decided by the matching constraint, and so there is no need
1741 to do anything special with them. We must handle them in
1742 the default case, so that we don't unnecessarily force
1743 operands to memory. */
1744 case '0': case '1': case '2': case '3': case '4':
1745 case '5': case '6': case '7': case '8': case '9':
1746 if (constraint
[j
] >= '0' + noutputs
)
1749 ("matching constraint references invalid operand number");
1753 /* Try and find the real constraint for this dup. */
1754 if ((j
== 0 && c_len
== 1)
1755 || (j
== 1 && c_len
== 2 && constraint
[0] == '%'))
1759 for (j
= constraint
[j
] - '0'; j
> 0; --j
)
1762 constraint
= TREE_STRING_POINTER (TREE_PURPOSE (o
));
1763 c_len
= strlen (constraint
);
1780 if (! ISALPHA (constraint
[j
]))
1782 error ("invalid punctuation `%c' in constraint",
1786 if (REG_CLASS_FROM_LETTER (constraint
[j
]) != NO_REGS
)
1788 #ifdef EXTRA_CONSTRAINT
1791 /* Otherwise we can't assume anything about the nature of
1792 the constraint except that it isn't purely registers.
1793 Treat it like "g" and hope for the best. */
1801 if (! allows_reg
&& allows_mem
)
1802 mark_addressable (TREE_VALUE (tail
));
1804 op
= expand_expr (TREE_VALUE (tail
), NULL_RTX
, VOIDmode
, 0);
1806 /* Never pass a CONCAT to an ASM. */
1807 generating_concat_p
= 0;
1808 if (GET_CODE (op
) == CONCAT
)
1809 op
= force_reg (GET_MODE (op
), op
);
1811 if (asm_operand_ok (op
, constraint
) <= 0)
1814 op
= force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail
))), op
);
1815 else if (!allows_mem
)
1816 warning ("asm operand %d probably doesn't match constraints", i
);
1817 else if (CONSTANT_P (op
))
1818 op
= force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail
))),
1820 else if (GET_CODE (op
) == REG
1821 || GET_CODE (op
) == SUBREG
1822 || GET_CODE (op
) == ADDRESSOF
1823 || GET_CODE (op
) == CONCAT
)
1825 tree type
= TREE_TYPE (TREE_VALUE (tail
));
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
))
1836 /* We won't recognize volatile memory as available a
1837 memory_operand at this point. Ignore it. */
1839 else if (queued_subexp_p (op
))
1842 /* ??? Leave this only until we have experience with what
1843 happens in combine and elsewhere when constraints are
1845 warning ("asm operand %d probably doesn't match constraints", i
);
1847 generating_concat_p
= old_generating_concat_p
;
1848 ASM_OPERANDS_INPUT (body
, i
) = op
;
1850 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body
, i
)
1851 = gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail
))),
1856 /* Protect all the operands from the queue now that they have all been
1859 generating_concat_p
= 0;
1861 for (i
= 0; i
< ninputs
- ninout
; i
++)
1862 ASM_OPERANDS_INPUT (body
, i
)
1863 = protect_from_queue (ASM_OPERANDS_INPUT (body
, i
), 0);
1865 for (i
= 0; i
< noutputs
; i
++)
1866 output_rtx
[i
] = protect_from_queue (output_rtx
[i
], 1);
1868 /* For in-out operands, copy output rtx to input rtx. */
1869 for (i
= 0; i
< ninout
; i
++)
1871 int j
= inout_opnum
[i
];
1873 ASM_OPERANDS_INPUT (body
, ninputs
- ninout
+ i
)
1875 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body
, ninputs
- ninout
+ i
)
1876 = gen_rtx_ASM_INPUT (inout_mode
[i
], digit_string (j
));
1879 generating_concat_p
= old_generating_concat_p
;
1881 /* Now, for each output, construct an rtx
1882 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1883 ARGVEC CONSTRAINTS))
1884 If there is more than one, put them inside a PARALLEL. */
1886 if (noutputs
== 1 && nclobbers
== 0)
1888 ASM_OPERANDS_OUTPUT_CONSTRAINT (body
)
1889 = output_constraints
[0];
1890 insn
= emit_insn (gen_rtx_SET (VOIDmode
, output_rtx
[0], body
));
1893 else if (noutputs
== 0 && nclobbers
== 0)
1895 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1896 insn
= emit_insn (body
);
1907 body
= gen_rtx_PARALLEL (VOIDmode
, rtvec_alloc (num
+ nclobbers
));
1909 /* For each output operand, store a SET. */
1910 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1912 XVECEXP (body
, 0, i
)
1913 = gen_rtx_SET (VOIDmode
,
1915 gen_rtx_ASM_OPERANDS
1916 (GET_MODE (output_rtx
[i
]),
1917 TREE_STRING_POINTER (string
),
1918 output_constraints
[i
],
1919 i
, argvec
, constraints
,
1922 MEM_VOLATILE_P (SET_SRC (XVECEXP (body
, 0, i
))) = vol
;
1925 /* If there are no outputs (but there are some clobbers)
1926 store the bare ASM_OPERANDS into the PARALLEL. */
1929 XVECEXP (body
, 0, i
++) = obody
;
1931 /* Store (clobber REG) for each clobbered register specified. */
1933 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
))
1935 const char *regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
1936 int j
= decode_reg_name (regname
);
1940 if (j
== -3) /* `cc', which is not a register */
1943 if (j
== -4) /* `memory', don't cache memory across asm */
1945 XVECEXP (body
, 0, i
++)
1946 = gen_rtx_CLOBBER (VOIDmode
,
1949 gen_rtx_SCRATCH (VOIDmode
)));
1953 /* Ignore unknown register, error already signaled. */
1957 /* Use QImode since that's guaranteed to clobber just one reg. */
1958 XVECEXP (body
, 0, i
++)
1959 = gen_rtx_CLOBBER (VOIDmode
, gen_rtx_REG (QImode
, j
));
1962 insn
= emit_insn (body
);
1965 /* For any outputs that needed reloading into registers, spill them
1966 back to where they belong. */
1967 for (i
= 0; i
< noutputs
; ++i
)
1968 if (real_output_rtx
[i
])
1969 emit_move_insn (real_output_rtx
[i
], output_rtx
[i
]);
1974 /* Generate RTL to evaluate the expression EXP
1975 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1978 expand_expr_stmt (exp
)
1981 /* If -W, warn about statements with no side effects,
1982 except for an explicit cast to void (e.g. for assert()), and
1983 except inside a ({...}) where they may be useful. */
1984 if (expr_stmts_for_value
== 0 && exp
!= error_mark_node
)
1986 if (! TREE_SIDE_EFFECTS (exp
))
1988 if ((extra_warnings
|| warn_unused_value
)
1989 && !(TREE_CODE (exp
) == CONVERT_EXPR
1990 && VOID_TYPE_P (TREE_TYPE (exp
))))
1991 warning_with_file_and_line (emit_filename
, emit_lineno
,
1992 "statement with no effect");
1994 else if (warn_unused_value
)
1995 warn_if_unused_value (exp
);
1998 /* If EXP is of function type and we are expanding statements for
1999 value, convert it to pointer-to-function. */
2000 if (expr_stmts_for_value
&& TREE_CODE (TREE_TYPE (exp
)) == FUNCTION_TYPE
)
2001 exp
= build1 (ADDR_EXPR
, build_pointer_type (TREE_TYPE (exp
)), exp
);
2003 /* The call to `expand_expr' could cause last_expr_type and
2004 last_expr_value to get reset. Therefore, we set last_expr_value
2005 and last_expr_type *after* calling expand_expr. */
2006 last_expr_value
= expand_expr (exp
,
2007 (expr_stmts_for_value
2008 ? NULL_RTX
: const0_rtx
),
2010 last_expr_type
= TREE_TYPE (exp
);
2012 /* If all we do is reference a volatile value in memory,
2013 copy it to a register to be sure it is actually touched. */
2014 if (last_expr_value
!= 0 && GET_CODE (last_expr_value
) == MEM
2015 && TREE_THIS_VOLATILE (exp
))
2017 if (TYPE_MODE (TREE_TYPE (exp
)) == VOIDmode
)
2019 else if (TYPE_MODE (TREE_TYPE (exp
)) != BLKmode
)
2020 copy_to_reg (last_expr_value
);
2023 rtx lab
= gen_label_rtx ();
2025 /* Compare the value with itself to reference it. */
2026 emit_cmp_and_jump_insns (last_expr_value
, last_expr_value
, EQ
,
2027 expand_expr (TYPE_SIZE (last_expr_type
),
2028 NULL_RTX
, VOIDmode
, 0),
2030 TYPE_ALIGN (last_expr_type
) / BITS_PER_UNIT
,
2036 /* If this expression is part of a ({...}) and is in memory, we may have
2037 to preserve temporaries. */
2038 preserve_temp_slots (last_expr_value
);
2040 /* Free any temporaries used to evaluate this expression. Any temporary
2041 used as a result of this expression will already have been preserved
2048 /* Warn if EXP contains any computations whose results are not used.
2049 Return 1 if a warning is printed; 0 otherwise. */
2052 warn_if_unused_value (exp
)
2055 if (TREE_USED (exp
))
2058 /* Don't warn about void constructs. This includes casting to void,
2059 void function calls, and statement expressions with a final cast
2061 if (VOID_TYPE_P (TREE_TYPE (exp
)))
2064 /* If this is an expression with side effects, don't warn. */
2065 if (TREE_SIDE_EFFECTS (exp
))
2068 switch (TREE_CODE (exp
))
2070 case PREINCREMENT_EXPR
:
2071 case POSTINCREMENT_EXPR
:
2072 case PREDECREMENT_EXPR
:
2073 case POSTDECREMENT_EXPR
:
2078 case METHOD_CALL_EXPR
:
2080 case TRY_CATCH_EXPR
:
2081 case WITH_CLEANUP_EXPR
:
2086 /* For a binding, warn if no side effect within it. */
2087 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2090 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2092 case TRUTH_ORIF_EXPR
:
2093 case TRUTH_ANDIF_EXPR
:
2094 /* In && or ||, warn if 2nd operand has no side effect. */
2095 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2098 if (TREE_NO_UNUSED_WARNING (exp
))
2100 if (warn_if_unused_value (TREE_OPERAND (exp
, 0)))
2102 /* Let people do `(foo (), 0)' without a warning. */
2103 if (TREE_CONSTANT (TREE_OPERAND (exp
, 1)))
2105 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2109 case NON_LVALUE_EXPR
:
2110 /* Don't warn about conversions not explicit in the user's program. */
2111 if (TREE_NO_UNUSED_WARNING (exp
))
2113 /* Assignment to a cast usually results in a cast of a modify.
2114 Don't complain about that. There can be an arbitrary number of
2115 casts before the modify, so we must loop until we find the first
2116 non-cast expression and then test to see if that is a modify. */
2118 tree tem
= TREE_OPERAND (exp
, 0);
2120 while (TREE_CODE (tem
) == CONVERT_EXPR
|| TREE_CODE (tem
) == NOP_EXPR
)
2121 tem
= TREE_OPERAND (tem
, 0);
2123 if (TREE_CODE (tem
) == MODIFY_EXPR
|| TREE_CODE (tem
) == INIT_EXPR
2124 || TREE_CODE (tem
) == CALL_EXPR
)
2130 /* Don't warn about automatic dereferencing of references, since
2131 the user cannot control it. */
2132 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp
, 0))) == REFERENCE_TYPE
)
2133 return warn_if_unused_value (TREE_OPERAND (exp
, 0));
2137 /* Referencing a volatile value is a side effect, so don't warn. */
2139 || TREE_CODE_CLASS (TREE_CODE (exp
)) == 'r')
2140 && TREE_THIS_VOLATILE (exp
))
2143 /* If this is an expression which has no operands, there is no value
2144 to be unused. There are no such language-independent codes,
2145 but front ends may define such. */
2146 if (TREE_CODE_CLASS (TREE_CODE (exp
)) == 'e'
2147 && TREE_CODE_LENGTH (TREE_CODE (exp
)) == 0)
2151 warning_with_file_and_line (emit_filename
, emit_lineno
,
2152 "value computed is not used");
2157 /* Clear out the memory of the last expression evaluated. */
2165 /* Begin a statement which will return a value.
2166 Return the RTL_EXPR for this statement expr.
2167 The caller must save that value and pass it to expand_end_stmt_expr. */
2170 expand_start_stmt_expr ()
2174 /* Make the RTL_EXPR node temporary, not momentary,
2175 so that rtl_expr_chain doesn't become garbage. */
2176 t
= make_node (RTL_EXPR
);
2177 do_pending_stack_adjust ();
2178 start_sequence_for_rtl_expr (t
);
2180 expr_stmts_for_value
++;
2184 /* Restore the previous state at the end of a statement that returns a value.
2185 Returns a tree node representing the statement's value and the
2186 insns to compute the value.
2188 The nodes of that expression have been freed by now, so we cannot use them.
2189 But we don't want to do that anyway; the expression has already been
2190 evaluated and now we just want to use the value. So generate a RTL_EXPR
2191 with the proper type and RTL value.
2193 If the last substatement was not an expression,
2194 return something with type `void'. */
2197 expand_end_stmt_expr (t
)
2202 if (last_expr_type
== 0)
2204 last_expr_type
= void_type_node
;
2205 last_expr_value
= const0_rtx
;
2207 else if (last_expr_value
== 0)
2208 /* There are some cases where this can happen, such as when the
2209 statement is void type. */
2210 last_expr_value
= const0_rtx
;
2211 else if (GET_CODE (last_expr_value
) != REG
&& ! CONSTANT_P (last_expr_value
))
2212 /* Remove any possible QUEUED. */
2213 last_expr_value
= protect_from_queue (last_expr_value
, 0);
2217 TREE_TYPE (t
) = last_expr_type
;
2218 RTL_EXPR_RTL (t
) = last_expr_value
;
2219 RTL_EXPR_SEQUENCE (t
) = get_insns ();
2221 rtl_expr_chain
= tree_cons (NULL_TREE
, t
, rtl_expr_chain
);
2225 /* Don't consider deleting this expr or containing exprs at tree level. */
2226 TREE_SIDE_EFFECTS (t
) = 1;
2227 /* Propagate volatility of the actual RTL expr. */
2228 TREE_THIS_VOLATILE (t
) = volatile_refs_p (last_expr_value
);
2231 expr_stmts_for_value
--;
2236 /* Generate RTL for the start of an if-then. COND is the expression
2237 whose truth should be tested.
2239 If EXITFLAG is nonzero, this conditional is visible to
2240 `exit_something'. */
2243 expand_start_cond (cond
, exitflag
)
2247 struct nesting
*thiscond
= ALLOC_NESTING ();
2249 /* Make an entry on cond_stack for the cond we are entering. */
2251 thiscond
->next
= cond_stack
;
2252 thiscond
->all
= nesting_stack
;
2253 thiscond
->depth
= ++nesting_depth
;
2254 thiscond
->data
.cond
.next_label
= gen_label_rtx ();
2255 /* Before we encounter an `else', we don't need a separate exit label
2256 unless there are supposed to be exit statements
2257 to exit this conditional. */
2258 thiscond
->exit_label
= exitflag
? gen_label_rtx () : 0;
2259 thiscond
->data
.cond
.endif_label
= thiscond
->exit_label
;
2260 cond_stack
= thiscond
;
2261 nesting_stack
= thiscond
;
2263 do_jump (cond
, thiscond
->data
.cond
.next_label
, NULL_RTX
);
2266 /* Generate RTL between then-clause and the elseif-clause
2267 of an if-then-elseif-.... */
2270 expand_start_elseif (cond
)
2273 if (cond_stack
->data
.cond
.endif_label
== 0)
2274 cond_stack
->data
.cond
.endif_label
= gen_label_rtx ();
2275 emit_jump (cond_stack
->data
.cond
.endif_label
);
2276 emit_label (cond_stack
->data
.cond
.next_label
);
2277 cond_stack
->data
.cond
.next_label
= gen_label_rtx ();
2278 do_jump (cond
, cond_stack
->data
.cond
.next_label
, NULL_RTX
);
2281 /* Generate RTL between the then-clause and the else-clause
2282 of an if-then-else. */
2285 expand_start_else ()
2287 if (cond_stack
->data
.cond
.endif_label
== 0)
2288 cond_stack
->data
.cond
.endif_label
= gen_label_rtx ();
2290 emit_jump (cond_stack
->data
.cond
.endif_label
);
2291 emit_label (cond_stack
->data
.cond
.next_label
);
2292 cond_stack
->data
.cond
.next_label
= 0; /* No more _else or _elseif calls. */
2295 /* After calling expand_start_else, turn this "else" into an "else if"
2296 by providing another condition. */
2299 expand_elseif (cond
)
2302 cond_stack
->data
.cond
.next_label
= gen_label_rtx ();
2303 do_jump (cond
, cond_stack
->data
.cond
.next_label
, NULL_RTX
);
2306 /* Generate RTL for the end of an if-then.
2307 Pop the record for it off of cond_stack. */
2312 struct nesting
*thiscond
= cond_stack
;
2314 do_pending_stack_adjust ();
2315 if (thiscond
->data
.cond
.next_label
)
2316 emit_label (thiscond
->data
.cond
.next_label
);
2317 if (thiscond
->data
.cond
.endif_label
)
2318 emit_label (thiscond
->data
.cond
.endif_label
);
2320 POPSTACK (cond_stack
);
2324 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2325 loop should be exited by `exit_something'. This is a loop for which
2326 `expand_continue' will jump to the top of the loop.
2328 Make an entry on loop_stack to record the labels associated with
2332 expand_start_loop (exit_flag
)
2335 register struct nesting
*thisloop
= ALLOC_NESTING ();
2337 /* Make an entry on loop_stack for the loop we are entering. */
2339 thisloop
->next
= loop_stack
;
2340 thisloop
->all
= nesting_stack
;
2341 thisloop
->depth
= ++nesting_depth
;
2342 thisloop
->data
.loop
.start_label
= gen_label_rtx ();
2343 thisloop
->data
.loop
.end_label
= gen_label_rtx ();
2344 thisloop
->data
.loop
.alt_end_label
= 0;
2345 thisloop
->data
.loop
.continue_label
= thisloop
->data
.loop
.start_label
;
2346 thisloop
->exit_label
= exit_flag
? thisloop
->data
.loop
.end_label
: 0;
2347 loop_stack
= thisloop
;
2348 nesting_stack
= thisloop
;
2350 do_pending_stack_adjust ();
2352 emit_note (NULL
, NOTE_INSN_LOOP_BEG
);
2353 emit_label (thisloop
->data
.loop
.start_label
);
2358 /* Like expand_start_loop but for a loop where the continuation point
2359 (for expand_continue_loop) will be specified explicitly. */
2362 expand_start_loop_continue_elsewhere (exit_flag
)
2365 struct nesting
*thisloop
= expand_start_loop (exit_flag
);
2366 loop_stack
->data
.loop
.continue_label
= gen_label_rtx ();
2370 /* Begin a null, aka do { } while (0) "loop". But since the contents
2371 of said loop can still contain a break, we must frob the loop nest. */
2374 expand_start_null_loop ()
2376 register struct nesting
*thisloop
= ALLOC_NESTING ();
2378 /* Make an entry on loop_stack for the loop we are entering. */
2380 thisloop
->next
= loop_stack
;
2381 thisloop
->all
= nesting_stack
;
2382 thisloop
->depth
= ++nesting_depth
;
2383 thisloop
->data
.loop
.start_label
= emit_note (NULL
, NOTE_INSN_DELETED
);
2384 thisloop
->data
.loop
.end_label
= gen_label_rtx ();
2385 thisloop
->data
.loop
.alt_end_label
= NULL_RTX
;
2386 thisloop
->data
.loop
.continue_label
= thisloop
->data
.loop
.end_label
;
2387 thisloop
->exit_label
= thisloop
->data
.loop
.end_label
;
2388 loop_stack
= thisloop
;
2389 nesting_stack
= thisloop
;
2394 /* Specify the continuation point for a loop started with
2395 expand_start_loop_continue_elsewhere.
2396 Use this at the point in the code to which a continue statement
2400 expand_loop_continue_here ()
2402 do_pending_stack_adjust ();
2403 emit_note (NULL
, NOTE_INSN_LOOP_CONT
);
2404 emit_label (loop_stack
->data
.loop
.continue_label
);
2407 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2408 Pop the block off of loop_stack. */
2413 rtx start_label
= loop_stack
->data
.loop
.start_label
;
2414 rtx insn
= get_last_insn ();
2415 int needs_end_jump
= 1;
2417 /* Mark the continue-point at the top of the loop if none elsewhere. */
2418 if (start_label
== loop_stack
->data
.loop
.continue_label
)
2419 emit_note_before (NOTE_INSN_LOOP_CONT
, start_label
);
2421 do_pending_stack_adjust ();
2423 /* If optimizing, perhaps reorder the loop.
2424 First, try to use a condjump near the end.
2425 expand_exit_loop_if_false ends loops with unconditional jumps,
2428 if (test) goto label;
2430 goto loop_stack->data.loop.end_label
2434 If we find such a pattern, we can end the loop earlier. */
2437 && GET_CODE (insn
) == CODE_LABEL
2438 && LABEL_NAME (insn
) == NULL
2439 && GET_CODE (PREV_INSN (insn
)) == BARRIER
)
2442 rtx jump
= PREV_INSN (PREV_INSN (label
));
2444 if (GET_CODE (jump
) == JUMP_INSN
2445 && GET_CODE (PATTERN (jump
)) == SET
2446 && SET_DEST (PATTERN (jump
)) == pc_rtx
2447 && GET_CODE (SET_SRC (PATTERN (jump
))) == LABEL_REF
2448 && (XEXP (SET_SRC (PATTERN (jump
)), 0)
2449 == loop_stack
->data
.loop
.end_label
))
2453 /* The test might be complex and reference LABEL multiple times,
2454 like the loop in loop_iterations to set vtop. To handle this,
2456 insn
= PREV_INSN (label
);
2457 reorder_insns (label
, label
, start_label
);
2459 for (prev
= PREV_INSN (jump
);; prev
= PREV_INSN (prev
))
2461 /* We ignore line number notes, but if we see any other note,
2462 in particular NOTE_INSN_BLOCK_*, NOTE_INSN_EH_REGION_*,
2463 NOTE_INSN_LOOP_*, we disable this optimization. */
2464 if (GET_CODE (prev
) == NOTE
)
2466 if (NOTE_LINE_NUMBER (prev
) < 0)
2470 if (GET_CODE (prev
) == CODE_LABEL
)
2472 if (GET_CODE (prev
) == JUMP_INSN
)
2474 if (GET_CODE (PATTERN (prev
)) == SET
2475 && SET_DEST (PATTERN (prev
)) == pc_rtx
2476 && GET_CODE (SET_SRC (PATTERN (prev
))) == IF_THEN_ELSE
2477 && (GET_CODE (XEXP (SET_SRC (PATTERN (prev
)), 1))
2479 && XEXP (XEXP (SET_SRC (PATTERN (prev
)), 1), 0) == label
)
2481 XEXP (XEXP (SET_SRC (PATTERN (prev
)), 1), 0)
2483 emit_note_after (NOTE_INSN_LOOP_END
, prev
);
2492 /* If the loop starts with a loop exit, roll that to the end where
2493 it will optimize together with the jump back.
2495 We look for the conditional branch to the exit, except that once
2496 we find such a branch, we don't look past 30 instructions.
2498 In more detail, if the loop presently looks like this (in pseudo-C):
2501 if (test) goto end_label;
2506 transform it to look like:
2512 if (test) goto end_label;
2513 goto newstart_label;
2516 Here, the `test' may actually consist of some reasonably complex
2517 code, terminating in a test. */
2522 ! (GET_CODE (insn
) == JUMP_INSN
2523 && GET_CODE (PATTERN (insn
)) == SET
2524 && SET_DEST (PATTERN (insn
)) == pc_rtx
2525 && GET_CODE (SET_SRC (PATTERN (insn
))) == IF_THEN_ELSE
))
2529 rtx last_test_insn
= NULL_RTX
;
2531 /* Scan insns from the top of the loop looking for a qualified
2532 conditional exit. */
2533 for (insn
= NEXT_INSN (loop_stack
->data
.loop
.start_label
); insn
;
2534 insn
= NEXT_INSN (insn
))
2536 if (GET_CODE (insn
) == NOTE
)
2539 && (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_BEG
2540 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_END
))
2541 /* The code that actually moves the exit test will
2542 carefully leave BLOCK notes in their original
2543 location. That means, however, that we can't debug
2544 the exit test itself. So, we refuse to move code
2545 containing BLOCK notes at low optimization levels. */
2548 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_EH_REGION_BEG
)
2550 else if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_EH_REGION_END
)
2554 /* We've come to the end of an EH region, but
2555 never saw the beginning of that region. That
2556 means that an EH region begins before the top
2557 of the loop, and ends in the middle of it. The
2558 existence of such a situation violates a basic
2559 assumption in this code, since that would imply
2560 that even when EH_REGIONS is zero, we might
2561 move code out of an exception region. */
2565 /* We must not walk into a nested loop. */
2566 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_LOOP_BEG
)
2569 /* We already know this INSN is a NOTE, so there's no
2570 point in looking at it to see if it's a JUMP. */
2574 if (GET_CODE (insn
) == JUMP_INSN
|| GET_CODE (insn
) == INSN
)
2577 if (last_test_insn
&& num_insns
> 30)
2581 /* We don't want to move a partial EH region. Consider:
2595 This isn't legal C++, but here's what it's supposed to
2596 mean: if cond() is true, stop looping. Otherwise,
2597 call bar, and keep looping. In addition, if cond
2598 throws an exception, catch it and keep looping. Such
2599 constructs are certainy legal in LISP.
2601 We should not move the `if (cond()) 0' test since then
2602 the EH-region for the try-block would be broken up.
2603 (In this case we would the EH_BEG note for the `try'
2604 and `if cond()' but not the call to bar() or the
2607 So we don't look for tests within an EH region. */
2610 if (GET_CODE (insn
) == JUMP_INSN
2611 && GET_CODE (PATTERN (insn
)) == SET
2612 && SET_DEST (PATTERN (insn
)) == pc_rtx
)
2614 /* This is indeed a jump. */
2615 rtx dest1
= NULL_RTX
;
2616 rtx dest2
= NULL_RTX
;
2617 rtx potential_last_test
;
2618 if (GET_CODE (SET_SRC (PATTERN (insn
))) == IF_THEN_ELSE
)
2620 /* A conditional jump. */
2621 dest1
= XEXP (SET_SRC (PATTERN (insn
)), 1);
2622 dest2
= XEXP (SET_SRC (PATTERN (insn
)), 2);
2623 potential_last_test
= insn
;
2627 /* An unconditional jump. */
2628 dest1
= SET_SRC (PATTERN (insn
));
2629 /* Include the BARRIER after the JUMP. */
2630 potential_last_test
= NEXT_INSN (insn
);
2634 if (dest1
&& GET_CODE (dest1
) == LABEL_REF
2635 && ((XEXP (dest1
, 0)
2636 == loop_stack
->data
.loop
.alt_end_label
)
2638 == loop_stack
->data
.loop
.end_label
)))
2640 last_test_insn
= potential_last_test
;
2644 /* If this was a conditional jump, there may be
2645 another label at which we should look. */
2652 if (last_test_insn
!= 0 && last_test_insn
!= get_last_insn ())
2654 /* We found one. Move everything from there up
2655 to the end of the loop, and add a jump into the loop
2656 to jump to there. */
2657 register rtx newstart_label
= gen_label_rtx ();
2658 register rtx start_move
= start_label
;
2661 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2662 then we want to move this note also. */
2663 if (GET_CODE (PREV_INSN (start_move
)) == NOTE
2664 && (NOTE_LINE_NUMBER (PREV_INSN (start_move
))
2665 == NOTE_INSN_LOOP_CONT
))
2666 start_move
= PREV_INSN (start_move
);
2668 emit_label_after (newstart_label
, PREV_INSN (start_move
));
2670 /* Actually move the insns. Start at the beginning, and
2671 keep copying insns until we've copied the
2673 for (insn
= start_move
; insn
; insn
= next_insn
)
2675 /* Figure out which insn comes after this one. We have
2676 to do this before we move INSN. */
2677 if (insn
== last_test_insn
)
2678 /* We've moved all the insns. */
2679 next_insn
= NULL_RTX
;
2681 next_insn
= NEXT_INSN (insn
);
2683 if (GET_CODE (insn
) == NOTE
2684 && (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_BEG
2685 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_END
))
2686 /* We don't want to move NOTE_INSN_BLOCK_BEGs or
2687 NOTE_INSN_BLOCK_ENDs because the correct generation
2688 of debugging information depends on these appearing
2689 in the same order in the RTL and in the tree
2690 structure, where they are represented as BLOCKs.
2691 So, we don't move block notes. Of course, moving
2692 the code inside the block is likely to make it
2693 impossible to debug the instructions in the exit
2694 test, but such is the price of optimization. */
2697 /* Move the INSN. */
2698 reorder_insns (insn
, insn
, get_last_insn ());
2701 emit_jump_insn_after (gen_jump (start_label
),
2702 PREV_INSN (newstart_label
));
2703 emit_barrier_after (PREV_INSN (newstart_label
));
2704 start_label
= newstart_label
;
2710 emit_jump (start_label
);
2711 emit_note (NULL
, NOTE_INSN_LOOP_END
);
2713 emit_label (loop_stack
->data
.loop
.end_label
);
2715 POPSTACK (loop_stack
);
2720 /* Finish a null loop, aka do { } while (0). */
2723 expand_end_null_loop ()
2725 do_pending_stack_adjust ();
2726 emit_label (loop_stack
->data
.loop
.end_label
);
2728 POPSTACK (loop_stack
);
2733 /* Generate a jump to the current loop's continue-point.
2734 This is usually the top of the loop, but may be specified
2735 explicitly elsewhere. If not currently inside a loop,
2736 return 0 and do nothing; caller will print an error message. */
2739 expand_continue_loop (whichloop
)
2740 struct nesting
*whichloop
;
2744 whichloop
= loop_stack
;
2747 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.continue_label
,
2752 /* Generate a jump to exit the current loop. If not currently inside a loop,
2753 return 0 and do nothing; caller will print an error message. */
2756 expand_exit_loop (whichloop
)
2757 struct nesting
*whichloop
;
2761 whichloop
= loop_stack
;
2764 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.end_label
, NULL_RTX
);
2768 /* Generate a conditional jump to exit the current loop if COND
2769 evaluates to zero. If not currently inside a loop,
2770 return 0 and do nothing; caller will print an error message. */
2773 expand_exit_loop_if_false (whichloop
, cond
)
2774 struct nesting
*whichloop
;
2777 rtx label
= gen_label_rtx ();
2782 whichloop
= loop_stack
;
2785 /* In order to handle fixups, we actually create a conditional jump
2786 around a unconditional branch to exit the loop. If fixups are
2787 necessary, they go before the unconditional branch. */
2789 do_jump (cond
, NULL_RTX
, label
);
2790 last_insn
= get_last_insn ();
2791 if (GET_CODE (last_insn
) == CODE_LABEL
)
2792 whichloop
->data
.loop
.alt_end_label
= last_insn
;
2793 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.end_label
,
2800 /* Return nonzero if the loop nest is empty. Else return zero. */
2803 stmt_loop_nest_empty ()
2805 /* cfun->stmt can be NULL if we are building a call to get the
2806 EH context for a setjmp/longjmp EH target and the current
2807 function was a deferred inline function. */
2808 return (cfun
->stmt
== NULL
|| loop_stack
== NULL
);
2811 /* Return non-zero if we should preserve sub-expressions as separate
2812 pseudos. We never do so if we aren't optimizing. We always do so
2813 if -fexpensive-optimizations.
2815 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2816 the loop may still be a small one. */
2819 preserve_subexpressions_p ()
2823 if (flag_expensive_optimizations
)
2826 if (optimize
== 0 || cfun
== 0 || cfun
->stmt
== 0 || loop_stack
== 0)
2829 insn
= get_last_insn_anywhere ();
2832 && (INSN_UID (insn
) - INSN_UID (loop_stack
->data
.loop
.start_label
)
2833 < n_non_fixed_regs
* 3));
2837 /* Generate a jump to exit the current loop, conditional, binding contour
2838 or case statement. Not all such constructs are visible to this function,
2839 only those started with EXIT_FLAG nonzero. Individual languages use
2840 the EXIT_FLAG parameter to control which kinds of constructs you can
2843 If not currently inside anything that can be exited,
2844 return 0 and do nothing; caller will print an error message. */
2847 expand_exit_something ()
2851 for (n
= nesting_stack
; n
; n
= n
->all
)
2852 if (n
->exit_label
!= 0)
2854 expand_goto_internal (NULL_TREE
, n
->exit_label
, NULL_RTX
);
2861 /* Generate RTL to return from the current function, with no value.
2862 (That is, we do not do anything about returning any value.) */
2865 expand_null_return ()
2867 struct nesting
*block
= block_stack
;
2868 rtx last_insn
= get_last_insn ();
2870 /* If this function was declared to return a value, but we
2871 didn't, clobber the return registers so that they are not
2872 propogated live to the rest of the function. */
2873 clobber_return_register ();
2875 /* Does any pending block have cleanups? */
2876 while (block
&& block
->data
.block
.cleanups
== 0)
2877 block
= block
->next
;
2879 /* If yes, use a goto to return, since that runs cleanups. */
2881 expand_null_return_1 (last_insn
, block
!= 0);
2884 /* Generate RTL to return from the current function, with value VAL. */
2887 expand_value_return (val
)
2890 struct nesting
*block
= block_stack
;
2891 rtx last_insn
= get_last_insn ();
2892 rtx return_reg
= DECL_RTL (DECL_RESULT (current_function_decl
));
2894 /* Copy the value to the return location
2895 unless it's already there. */
2897 if (return_reg
!= val
)
2899 tree type
= TREE_TYPE (DECL_RESULT (current_function_decl
));
2900 #ifdef PROMOTE_FUNCTION_RETURN
2901 int unsignedp
= TREE_UNSIGNED (type
);
2902 enum machine_mode old_mode
2903 = DECL_MODE (DECL_RESULT (current_function_decl
));
2904 enum machine_mode mode
2905 = promote_mode (type
, old_mode
, &unsignedp
, 1);
2907 if (mode
!= old_mode
)
2908 val
= convert_modes (mode
, old_mode
, val
, unsignedp
);
2910 if (GET_CODE (return_reg
) == PARALLEL
)
2911 emit_group_load (return_reg
, val
, int_size_in_bytes (type
),
2914 emit_move_insn (return_reg
, val
);
2917 /* Does any pending block have cleanups? */
2919 while (block
&& block
->data
.block
.cleanups
== 0)
2920 block
= block
->next
;
2922 /* If yes, use a goto to return, since that runs cleanups.
2923 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2925 expand_null_return_1 (last_insn
, block
!= 0);
2928 /* Output a return with no value. If LAST_INSN is nonzero,
2929 pretend that the return takes place after LAST_INSN.
2930 If USE_GOTO is nonzero then don't use a return instruction;
2931 go to the return label instead. This causes any cleanups
2932 of pending blocks to be executed normally. */
2935 expand_null_return_1 (last_insn
, use_goto
)
2939 rtx end_label
= cleanup_label
? cleanup_label
: return_label
;
2941 clear_pending_stack_adjust ();
2942 do_pending_stack_adjust ();
2945 /* PCC-struct return always uses an epilogue. */
2946 if (current_function_returns_pcc_struct
|| use_goto
)
2949 end_label
= return_label
= gen_label_rtx ();
2950 expand_goto_internal (NULL_TREE
, end_label
, last_insn
);
2954 /* Otherwise output a simple return-insn if one is available,
2955 unless it won't do the job. */
2957 if (HAVE_return
&& use_goto
== 0 && cleanup_label
== 0)
2959 emit_jump_insn (gen_return ());
2965 /* Otherwise jump to the epilogue. */
2966 expand_goto_internal (NULL_TREE
, end_label
, last_insn
);
2969 /* Generate RTL to evaluate the expression RETVAL and return it
2970 from the current function. */
2973 expand_return (retval
)
2976 /* If there are any cleanups to be performed, then they will
2977 be inserted following LAST_INSN. It is desirable
2978 that the last_insn, for such purposes, should be the
2979 last insn before computing the return value. Otherwise, cleanups
2980 which call functions can clobber the return value. */
2981 /* ??? rms: I think that is erroneous, because in C++ it would
2982 run destructors on variables that might be used in the subsequent
2983 computation of the return value. */
2986 register rtx val
= 0;
2989 /* If function wants no value, give it none. */
2990 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl
))) == VOID_TYPE
)
2992 expand_expr (retval
, NULL_RTX
, VOIDmode
, 0);
2994 expand_null_return ();
2998 if (retval
== error_mark_node
)
3000 /* Treat this like a return of no value from a function that
3002 expand_null_return ();
3005 else if (TREE_CODE (retval
) == RESULT_DECL
)
3006 retval_rhs
= retval
;
3007 else if ((TREE_CODE (retval
) == MODIFY_EXPR
|| TREE_CODE (retval
) == INIT_EXPR
)
3008 && TREE_CODE (TREE_OPERAND (retval
, 0)) == RESULT_DECL
)
3009 retval_rhs
= TREE_OPERAND (retval
, 1);
3010 else if (VOID_TYPE_P (TREE_TYPE (retval
)))
3011 /* Recognize tail-recursive call to void function. */
3012 retval_rhs
= retval
;
3014 retval_rhs
= NULL_TREE
;
3016 last_insn
= get_last_insn ();
3018 /* Distribute return down conditional expr if either of the sides
3019 may involve tail recursion (see test below). This enhances the number
3020 of tail recursions we see. Don't do this always since it can produce
3021 sub-optimal code in some cases and we distribute assignments into
3022 conditional expressions when it would help. */
3024 if (optimize
&& retval_rhs
!= 0
3025 && frame_offset
== 0
3026 && TREE_CODE (retval_rhs
) == COND_EXPR
3027 && (TREE_CODE (TREE_OPERAND (retval_rhs
, 1)) == CALL_EXPR
3028 || TREE_CODE (TREE_OPERAND (retval_rhs
, 2)) == CALL_EXPR
))
3030 rtx label
= gen_label_rtx ();
3033 do_jump (TREE_OPERAND (retval_rhs
, 0), label
, NULL_RTX
);
3034 start_cleanup_deferral ();
3035 expr
= build (MODIFY_EXPR
, TREE_TYPE (TREE_TYPE (current_function_decl
)),
3036 DECL_RESULT (current_function_decl
),
3037 TREE_OPERAND (retval_rhs
, 1));
3038 TREE_SIDE_EFFECTS (expr
) = 1;
3039 expand_return (expr
);
3042 expr
= build (MODIFY_EXPR
, TREE_TYPE (TREE_TYPE (current_function_decl
)),
3043 DECL_RESULT (current_function_decl
),
3044 TREE_OPERAND (retval_rhs
, 2));
3045 TREE_SIDE_EFFECTS (expr
) = 1;
3046 expand_return (expr
);
3047 end_cleanup_deferral ();
3051 result_rtl
= DECL_RTL (DECL_RESULT (current_function_decl
));
3053 /* If the result is an aggregate that is being returned in one (or more)
3054 registers, load the registers here. The compiler currently can't handle
3055 copying a BLKmode value into registers. We could put this code in a
3056 more general area (for use by everyone instead of just function
3057 call/return), but until this feature is generally usable it is kept here
3058 (and in expand_call). The value must go into a pseudo in case there
3059 are cleanups that will clobber the real return register. */
3062 && TYPE_MODE (TREE_TYPE (retval_rhs
)) == BLKmode
3063 && GET_CODE (result_rtl
) == REG
)
3066 unsigned HOST_WIDE_INT bitpos
, xbitpos
;
3067 unsigned HOST_WIDE_INT big_endian_correction
= 0;
3068 unsigned HOST_WIDE_INT bytes
3069 = int_size_in_bytes (TREE_TYPE (retval_rhs
));
3070 int n_regs
= (bytes
+ UNITS_PER_WORD
- 1) / UNITS_PER_WORD
;
3071 unsigned int bitsize
3072 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs
)), BITS_PER_WORD
);
3073 rtx
*result_pseudos
= (rtx
*) alloca (sizeof (rtx
) * n_regs
);
3074 rtx result_reg
, src
= NULL_RTX
, dst
= NULL_RTX
;
3075 rtx result_val
= expand_expr (retval_rhs
, NULL_RTX
, VOIDmode
, 0);
3076 enum machine_mode tmpmode
, result_reg_mode
;
3080 expand_null_return ();
3084 /* Structures whose size is not a multiple of a word are aligned
3085 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
3086 machine, this means we must skip the empty high order bytes when
3087 calculating the bit offset. */
3088 if (BYTES_BIG_ENDIAN
&& bytes
% UNITS_PER_WORD
)
3089 big_endian_correction
= (BITS_PER_WORD
- ((bytes
% UNITS_PER_WORD
)
3092 /* Copy the structure BITSIZE bits at a time. */
3093 for (bitpos
= 0, xbitpos
= big_endian_correction
;
3094 bitpos
< bytes
* BITS_PER_UNIT
;
3095 bitpos
+= bitsize
, xbitpos
+= bitsize
)
3097 /* We need a new destination pseudo each time xbitpos is
3098 on a word boundary and when xbitpos == big_endian_correction
3099 (the first time through). */
3100 if (xbitpos
% BITS_PER_WORD
== 0
3101 || xbitpos
== big_endian_correction
)
3103 /* Generate an appropriate register. */
3104 dst
= gen_reg_rtx (word_mode
);
3105 result_pseudos
[xbitpos
/ BITS_PER_WORD
] = dst
;
3107 /* Clobber the destination before we move anything into it. */
3108 emit_insn (gen_rtx_CLOBBER (VOIDmode
, dst
));
3111 /* We need a new source operand each time bitpos is on a word
3113 if (bitpos
% BITS_PER_WORD
== 0)
3114 src
= operand_subword_force (result_val
,
3115 bitpos
/ BITS_PER_WORD
,
3118 /* Use bitpos for the source extraction (left justified) and
3119 xbitpos for the destination store (right justified). */
3120 store_bit_field (dst
, bitsize
, xbitpos
% BITS_PER_WORD
, word_mode
,
3121 extract_bit_field (src
, bitsize
,
3122 bitpos
% BITS_PER_WORD
, 1,
3123 NULL_RTX
, word_mode
, word_mode
,
3124 bitsize
, BITS_PER_WORD
),
3125 bitsize
, BITS_PER_WORD
);
3128 /* Find the smallest integer mode large enough to hold the
3129 entire structure and use that mode instead of BLKmode
3130 on the USE insn for the return register. */
3131 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
3132 tmpmode
!= VOIDmode
;
3133 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
3134 /* Have we found a large enough mode? */
3135 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
3138 /* No suitable mode found. */
3139 if (tmpmode
== VOIDmode
)
3142 PUT_MODE (result_rtl
, tmpmode
);
3144 if (GET_MODE_SIZE (tmpmode
) < GET_MODE_SIZE (word_mode
))
3145 result_reg_mode
= word_mode
;
3147 result_reg_mode
= tmpmode
;
3148 result_reg
= gen_reg_rtx (result_reg_mode
);
3151 for (i
= 0; i
< n_regs
; i
++)
3152 emit_move_insn (operand_subword (result_reg
, i
, 0, result_reg_mode
),
3155 if (tmpmode
!= result_reg_mode
)
3156 result_reg
= gen_lowpart (tmpmode
, result_reg
);
3158 expand_value_return (result_reg
);
3160 else if (retval_rhs
!= 0
3161 && !VOID_TYPE_P (TREE_TYPE (retval_rhs
))
3162 && (GET_CODE (result_rtl
) == REG
3163 || (GET_CODE (result_rtl
) == PARALLEL
)))
3165 /* Calculate the return value into a temporary (usually a pseudo
3167 tree ot
= TREE_TYPE (DECL_RESULT (current_function_decl
));
3168 tree nt
= build_qualified_type (ot
, TYPE_QUALS (ot
) | TYPE_QUAL_CONST
);
3170 val
= assign_temp (nt
, 0, 0, 1);
3171 val
= expand_expr (retval_rhs
, val
, GET_MODE (val
), 0);
3172 val
= force_not_mem (val
);
3174 /* Return the calculated value, doing cleanups first. */
3175 expand_value_return (val
);
3179 /* No cleanups or no hard reg used;
3180 calculate value into hard return reg. */
3181 expand_expr (retval
, const0_rtx
, VOIDmode
, 0);
3183 expand_value_return (result_rtl
);
3187 /* Return 1 if the end of the generated RTX is not a barrier.
3188 This means code already compiled can drop through. */
3191 drop_through_at_end_p ()
3193 rtx insn
= get_last_insn ();
3194 while (insn
&& GET_CODE (insn
) == NOTE
)
3195 insn
= PREV_INSN (insn
);
3196 return insn
&& GET_CODE (insn
) != BARRIER
;
3199 /* Attempt to optimize a potential tail recursion call into a goto.
3200 ARGUMENTS are the arguments to a CALL_EXPR; LAST_INSN indicates
3201 where to place the jump to the tail recursion label.
3203 Return TRUE if the call was optimized into a goto. */
3206 optimize_tail_recursion (arguments
, last_insn
)
3210 /* Finish checking validity, and if valid emit code to set the
3211 argument variables for the new call. */
3212 if (tail_recursion_args (arguments
, DECL_ARGUMENTS (current_function_decl
)))
3214 if (tail_recursion_label
== 0)
3216 tail_recursion_label
= gen_label_rtx ();
3217 emit_label_after (tail_recursion_label
,
3218 tail_recursion_reentry
);
3221 expand_goto_internal (NULL_TREE
, tail_recursion_label
, last_insn
);
3228 /* Emit code to alter this function's formal parms for a tail-recursive call.
3229 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3230 FORMALS is the chain of decls of formals.
3231 Return 1 if this can be done;
3232 otherwise return 0 and do not emit any code. */
3235 tail_recursion_args (actuals
, formals
)
3236 tree actuals
, formals
;
3238 register tree a
= actuals
, f
= formals
;
3240 register rtx
*argvec
;
3242 /* Check that number and types of actuals are compatible
3243 with the formals. This is not always true in valid C code.
3244 Also check that no formal needs to be addressable
3245 and that all formals are scalars. */
3247 /* Also count the args. */
3249 for (a
= actuals
, f
= formals
, i
= 0; a
&& f
; a
= TREE_CHAIN (a
), f
= TREE_CHAIN (f
), i
++)
3251 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a
)))
3252 != TYPE_MAIN_VARIANT (TREE_TYPE (f
)))
3254 if (GET_CODE (DECL_RTL (f
)) != REG
|| DECL_MODE (f
) == BLKmode
)
3257 if (a
!= 0 || f
!= 0)
3260 /* Compute all the actuals. */
3262 argvec
= (rtx
*) alloca (i
* sizeof (rtx
));
3264 for (a
= actuals
, i
= 0; a
; a
= TREE_CHAIN (a
), i
++)
3265 argvec
[i
] = expand_expr (TREE_VALUE (a
), NULL_RTX
, VOIDmode
, 0);
3267 /* Find which actual values refer to current values of previous formals.
3268 Copy each of them now, before any formal is changed. */
3270 for (a
= actuals
, i
= 0; a
; a
= TREE_CHAIN (a
), i
++)
3274 for (f
= formals
, j
= 0; j
< i
; f
= TREE_CHAIN (f
), j
++)
3275 if (reg_mentioned_p (DECL_RTL (f
), argvec
[i
]))
3281 argvec
[i
] = copy_to_reg (argvec
[i
]);
3284 /* Store the values of the actuals into the formals. */
3286 for (f
= formals
, a
= actuals
, i
= 0; f
;
3287 f
= TREE_CHAIN (f
), a
= TREE_CHAIN (a
), i
++)
3289 if (GET_MODE (DECL_RTL (f
)) == GET_MODE (argvec
[i
]))
3290 emit_move_insn (DECL_RTL (f
), argvec
[i
]);
3292 convert_move (DECL_RTL (f
), argvec
[i
],
3293 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a
))));
3300 /* Generate the RTL code for entering a binding contour.
3301 The variables are declared one by one, by calls to `expand_decl'.
3303 FLAGS is a bitwise or of the following flags:
3305 1 - Nonzero if this construct should be visible to
3308 2 - Nonzero if this contour does not require a
3309 NOTE_INSN_BLOCK_BEG note. Virtually all calls from
3310 language-independent code should set this flag because they
3311 will not create corresponding BLOCK nodes. (There should be
3312 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
3313 and BLOCKs.) If this flag is set, MARK_ENDS should be zero
3314 when expand_end_bindings is called.
3316 If we are creating a NOTE_INSN_BLOCK_BEG note, a BLOCK may
3317 optionally be supplied. If so, it becomes the NOTE_BLOCK for the
3321 expand_start_bindings_and_block (flags
, block
)
3325 struct nesting
*thisblock
= ALLOC_NESTING ();
3327 int exit_flag
= ((flags
& 1) != 0);
3328 int block_flag
= ((flags
& 2) == 0);
3330 /* If a BLOCK is supplied, then the caller should be requesting a
3331 NOTE_INSN_BLOCK_BEG note. */
3332 if (!block_flag
&& block
)
3335 /* Create a note to mark the beginning of the block. */
3338 note
= emit_note (NULL
, NOTE_INSN_BLOCK_BEG
);
3339 NOTE_BLOCK (note
) = block
;
3342 note
= emit_note (NULL
, NOTE_INSN_DELETED
);
3344 /* Make an entry on block_stack for the block we are entering. */
3346 thisblock
->next
= block_stack
;
3347 thisblock
->all
= nesting_stack
;
3348 thisblock
->depth
= ++nesting_depth
;
3349 thisblock
->data
.block
.stack_level
= 0;
3350 thisblock
->data
.block
.cleanups
= 0;
3351 thisblock
->data
.block
.n_function_calls
= 0;
3352 thisblock
->data
.block
.exception_region
= 0;
3353 thisblock
->data
.block
.block_target_temp_slot_level
= target_temp_slot_level
;
3355 thisblock
->data
.block
.conditional_code
= 0;
3356 thisblock
->data
.block
.last_unconditional_cleanup
= note
;
3357 /* When we insert instructions after the last unconditional cleanup,
3358 we don't adjust last_insn. That means that a later add_insn will
3359 clobber the instructions we've just added. The easiest way to
3360 fix this is to just insert another instruction here, so that the
3361 instructions inserted after the last unconditional cleanup are
3362 never the last instruction. */
3363 emit_note (NULL
, NOTE_INSN_DELETED
);
3364 thisblock
->data
.block
.cleanup_ptr
= &thisblock
->data
.block
.cleanups
;
3367 && !(block_stack
->data
.block
.cleanups
== NULL_TREE
3368 && block_stack
->data
.block
.outer_cleanups
== NULL_TREE
))
3369 thisblock
->data
.block
.outer_cleanups
3370 = tree_cons (NULL_TREE
, block_stack
->data
.block
.cleanups
,
3371 block_stack
->data
.block
.outer_cleanups
);
3373 thisblock
->data
.block
.outer_cleanups
= 0;
3374 thisblock
->data
.block
.label_chain
= 0;
3375 thisblock
->data
.block
.innermost_stack_block
= stack_block_stack
;
3376 thisblock
->data
.block
.first_insn
= note
;
3377 thisblock
->data
.block
.block_start_count
= ++current_block_start_count
;
3378 thisblock
->exit_label
= exit_flag
? gen_label_rtx () : 0;
3379 block_stack
= thisblock
;
3380 nesting_stack
= thisblock
;
3382 /* Make a new level for allocating stack slots. */
3386 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3387 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3388 expand_expr are made. After we end the region, we know that all
3389 space for all temporaries that were created by TARGET_EXPRs will be
3390 destroyed and their space freed for reuse. */
3393 expand_start_target_temps ()
3395 /* This is so that even if the result is preserved, the space
3396 allocated will be freed, as we know that it is no longer in use. */
3399 /* Start a new binding layer that will keep track of all cleanup
3400 actions to be performed. */
3401 expand_start_bindings (2);
3403 target_temp_slot_level
= temp_slot_level
;
3407 expand_end_target_temps ()
3409 expand_end_bindings (NULL_TREE
, 0, 0);
3411 /* This is so that even if the result is preserved, the space
3412 allocated will be freed, as we know that it is no longer in use. */
3416 /* Given a pointer to a BLOCK node return non-zero if (and only if) the node
3417 in question represents the outermost pair of curly braces (i.e. the "body
3418 block") of a function or method.
3420 For any BLOCK node representing a "body block" of a function or method, the
3421 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
3422 represents the outermost (function) scope for the function or method (i.e.
3423 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
3424 *that* node in turn will point to the relevant FUNCTION_DECL node. */
3427 is_body_block (stmt
)
3430 if (TREE_CODE (stmt
) == BLOCK
)
3432 tree parent
= BLOCK_SUPERCONTEXT (stmt
);
3434 if (parent
&& TREE_CODE (parent
) == BLOCK
)
3436 tree grandparent
= BLOCK_SUPERCONTEXT (parent
);
3438 if (grandparent
&& TREE_CODE (grandparent
) == FUNCTION_DECL
)
3446 /* True if we are currently emitting insns in an area of output code
3447 that is controlled by a conditional expression. This is used by
3448 the cleanup handling code to generate conditional cleanup actions. */
3451 conditional_context ()
3453 return block_stack
&& block_stack
->data
.block
.conditional_code
;
3456 /* Return an opaque pointer to the current nesting level, so frontend code
3457 can check its own sanity. */
3460 current_nesting_level ()
3462 return cfun
? block_stack
: 0;
3465 /* Emit a handler label for a nonlocal goto handler.
3466 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3469 expand_nl_handler_label (slot
, before_insn
)
3470 rtx slot
, before_insn
;
3473 rtx handler_label
= gen_label_rtx ();
3475 /* Don't let cleanup_cfg delete the handler. */
3476 LABEL_PRESERVE_P (handler_label
) = 1;
3479 emit_move_insn (slot
, gen_rtx_LABEL_REF (Pmode
, handler_label
));
3480 insns
= get_insns ();
3482 emit_insns_before (insns
, before_insn
);
3484 emit_label (handler_label
);
3486 return handler_label
;
3489 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3492 expand_nl_goto_receiver ()
3494 #ifdef HAVE_nonlocal_goto
3495 if (! HAVE_nonlocal_goto
)
3497 /* First adjust our frame pointer to its actual value. It was
3498 previously set to the start of the virtual area corresponding to
3499 the stacked variables when we branched here and now needs to be
3500 adjusted to the actual hardware fp value.
3502 Assignments are to virtual registers are converted by
3503 instantiate_virtual_regs into the corresponding assignment
3504 to the underlying register (fp in this case) that makes
3505 the original assignment true.
3506 So the following insn will actually be
3507 decrementing fp by STARTING_FRAME_OFFSET. */
3508 emit_move_insn (virtual_stack_vars_rtx
, hard_frame_pointer_rtx
);
3510 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3511 if (fixed_regs
[ARG_POINTER_REGNUM
])
3513 #ifdef ELIMINABLE_REGS
3514 /* If the argument pointer can be eliminated in favor of the
3515 frame pointer, we don't need to restore it. We assume here
3516 that if such an elimination is present, it can always be used.
3517 This is the case on all known machines; if we don't make this
3518 assumption, we do unnecessary saving on many machines. */
3519 static struct elims
{int from
, to
;} elim_regs
[] = ELIMINABLE_REGS
;
3522 for (i
= 0; i
< ARRAY_SIZE (elim_regs
); i
++)
3523 if (elim_regs
[i
].from
== ARG_POINTER_REGNUM
3524 && elim_regs
[i
].to
== HARD_FRAME_POINTER_REGNUM
)
3527 if (i
== ARRAY_SIZE (elim_regs
))
3530 /* Now restore our arg pointer from the address at which it
3531 was saved in our stack frame.
3532 If there hasn't be space allocated for it yet, make
3534 if (arg_pointer_save_area
== 0)
3535 arg_pointer_save_area
3536 = assign_stack_local (Pmode
, GET_MODE_SIZE (Pmode
), 0);
3537 emit_move_insn (virtual_incoming_args_rtx
,
3538 /* We need a pseudo here, or else
3539 instantiate_virtual_regs_1 complains. */
3540 copy_to_reg (arg_pointer_save_area
));
3545 #ifdef HAVE_nonlocal_goto_receiver
3546 if (HAVE_nonlocal_goto_receiver
)
3547 emit_insn (gen_nonlocal_goto_receiver ());
3551 /* Make handlers for nonlocal gotos taking place in the function calls in
3555 expand_nl_goto_receivers (thisblock
)
3556 struct nesting
*thisblock
;
3559 rtx afterward
= gen_label_rtx ();
3564 /* Record the handler address in the stack slot for that purpose,
3565 during this block, saving and restoring the outer value. */
3566 if (thisblock
->next
!= 0)
3567 for (slot
= nonlocal_goto_handler_slots
; slot
; slot
= XEXP (slot
, 1))
3569 rtx save_receiver
= gen_reg_rtx (Pmode
);
3570 emit_move_insn (XEXP (slot
, 0), save_receiver
);
3573 emit_move_insn (save_receiver
, XEXP (slot
, 0));
3574 insns
= get_insns ();
3576 emit_insns_before (insns
, thisblock
->data
.block
.first_insn
);
3579 /* Jump around the handlers; they run only when specially invoked. */
3580 emit_jump (afterward
);
3582 /* Make a separate handler for each label. */
3583 link
= nonlocal_labels
;
3584 slot
= nonlocal_goto_handler_slots
;
3585 label_list
= NULL_RTX
;
3586 for (; link
; link
= TREE_CHAIN (link
), slot
= XEXP (slot
, 1))
3587 /* Skip any labels we shouldn't be able to jump to from here,
3588 we generate one special handler for all of them below which just calls
3590 if (! DECL_TOO_LATE (TREE_VALUE (link
)))
3593 lab
= expand_nl_handler_label (XEXP (slot
, 0),
3594 thisblock
->data
.block
.first_insn
);
3595 label_list
= gen_rtx_EXPR_LIST (VOIDmode
, lab
, label_list
);
3597 expand_nl_goto_receiver ();
3599 /* Jump to the "real" nonlocal label. */
3600 expand_goto (TREE_VALUE (link
));
3603 /* A second pass over all nonlocal labels; this time we handle those
3604 we should not be able to jump to at this point. */
3605 link
= nonlocal_labels
;
3606 slot
= nonlocal_goto_handler_slots
;
3608 for (; link
; link
= TREE_CHAIN (link
), slot
= XEXP (slot
, 1))
3609 if (DECL_TOO_LATE (TREE_VALUE (link
)))
3612 lab
= expand_nl_handler_label (XEXP (slot
, 0),
3613 thisblock
->data
.block
.first_insn
);
3614 label_list
= gen_rtx_EXPR_LIST (VOIDmode
, lab
, label_list
);
3620 expand_nl_goto_receiver ();
3621 emit_library_call (gen_rtx_SYMBOL_REF (Pmode
, "abort"), 0,
3626 nonlocal_goto_handler_labels
= label_list
;
3627 emit_label (afterward
);
3630 /* Warn about any unused VARS (which may contain nodes other than
3631 VAR_DECLs, but such nodes are ignored). The nodes are connected
3632 via the TREE_CHAIN field. */
3635 warn_about_unused_variables (vars
)
3640 if (warn_unused_variable
)
3641 for (decl
= vars
; decl
; decl
= TREE_CHAIN (decl
))
3642 if (TREE_CODE (decl
) == VAR_DECL
3643 && ! TREE_USED (decl
)
3644 && ! DECL_IN_SYSTEM_HEADER (decl
)
3645 && DECL_NAME (decl
) && ! DECL_ARTIFICIAL (decl
))
3646 warning_with_decl (decl
, "unused variable `%s'");
3649 /* Generate RTL code to terminate a binding contour.
3651 VARS is the chain of VAR_DECL nodes for the variables bound in this
3652 contour. There may actually be other nodes in this chain, but any
3653 nodes other than VAR_DECLS are ignored.
3655 MARK_ENDS is nonzero if we should put a note at the beginning
3656 and end of this binding contour.
3658 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3659 (That is true automatically if the contour has a saved stack level.) */
3662 expand_end_bindings (vars
, mark_ends
, dont_jump_in
)
3667 register struct nesting
*thisblock
= block_stack
;
3669 /* If any of the variables in this scope were not used, warn the
3671 warn_about_unused_variables (vars
);
3673 if (thisblock
->exit_label
)
3675 do_pending_stack_adjust ();
3676 emit_label (thisblock
->exit_label
);
3679 /* If necessary, make handlers for nonlocal gotos taking
3680 place in the function calls in this block. */
3681 if (function_call_count
!= thisblock
->data
.block
.n_function_calls
3683 /* Make handler for outermost block
3684 if there were any nonlocal gotos to this function. */
3685 && (thisblock
->next
== 0 ? current_function_has_nonlocal_label
3686 /* Make handler for inner block if it has something
3687 special to do when you jump out of it. */
3688 : (thisblock
->data
.block
.cleanups
!= 0
3689 || thisblock
->data
.block
.stack_level
!= 0)))
3690 expand_nl_goto_receivers (thisblock
);
3692 /* Don't allow jumping into a block that has a stack level.
3693 Cleanups are allowed, though. */
3695 || thisblock
->data
.block
.stack_level
!= 0)
3697 struct label_chain
*chain
;
3699 /* Any labels in this block are no longer valid to go to.
3700 Mark them to cause an error message. */
3701 for (chain
= thisblock
->data
.block
.label_chain
; chain
; chain
= chain
->next
)
3703 DECL_TOO_LATE (chain
->label
) = 1;
3704 /* If any goto without a fixup came to this label,
3705 that must be an error, because gotos without fixups
3706 come from outside all saved stack-levels. */
3707 if (TREE_ADDRESSABLE (chain
->label
))
3708 error_with_decl (chain
->label
,
3709 "label `%s' used before containing binding contour");
3713 /* Restore stack level in effect before the block
3714 (only if variable-size objects allocated). */
3715 /* Perform any cleanups associated with the block. */
3717 if (thisblock
->data
.block
.stack_level
!= 0
3718 || thisblock
->data
.block
.cleanups
!= 0)
3723 /* Don't let cleanups affect ({...}) constructs. */
3724 int old_expr_stmts_for_value
= expr_stmts_for_value
;
3725 rtx old_last_expr_value
= last_expr_value
;
3726 tree old_last_expr_type
= last_expr_type
;
3727 expr_stmts_for_value
= 0;
3729 /* Only clean up here if this point can actually be reached. */
3730 insn
= get_last_insn ();
3731 if (GET_CODE (insn
) == NOTE
)
3732 insn
= prev_nonnote_insn (insn
);
3733 reachable
= (! insn
|| GET_CODE (insn
) != BARRIER
);
3735 /* Do the cleanups. */
3736 expand_cleanups (thisblock
->data
.block
.cleanups
, NULL_TREE
, 0, reachable
);
3738 do_pending_stack_adjust ();
3740 expr_stmts_for_value
= old_expr_stmts_for_value
;
3741 last_expr_value
= old_last_expr_value
;
3742 last_expr_type
= old_last_expr_type
;
3744 /* Restore the stack level. */
3746 if (reachable
&& thisblock
->data
.block
.stack_level
!= 0)
3748 emit_stack_restore (thisblock
->next
? SAVE_BLOCK
: SAVE_FUNCTION
,
3749 thisblock
->data
.block
.stack_level
, NULL_RTX
);
3750 if (nonlocal_goto_handler_slots
!= 0)
3751 emit_stack_save (SAVE_NONLOCAL
, &nonlocal_goto_stack_level
,
3755 /* Any gotos out of this block must also do these things.
3756 Also report any gotos with fixups that came to labels in this
3758 fixup_gotos (thisblock
,
3759 thisblock
->data
.block
.stack_level
,
3760 thisblock
->data
.block
.cleanups
,
3761 thisblock
->data
.block
.first_insn
,
3765 /* Mark the beginning and end of the scope if requested.
3766 We do this now, after running cleanups on the variables
3767 just going out of scope, so they are in scope for their cleanups. */
3771 rtx note
= emit_note (NULL
, NOTE_INSN_BLOCK_END
);
3772 NOTE_BLOCK (note
) = NOTE_BLOCK (thisblock
->data
.block
.first_insn
);
3775 /* Get rid of the beginning-mark if we don't make an end-mark. */
3776 NOTE_LINE_NUMBER (thisblock
->data
.block
.first_insn
) = NOTE_INSN_DELETED
;
3778 /* Restore the temporary level of TARGET_EXPRs. */
3779 target_temp_slot_level
= thisblock
->data
.block
.block_target_temp_slot_level
;
3781 /* Restore block_stack level for containing block. */
3783 stack_block_stack
= thisblock
->data
.block
.innermost_stack_block
;
3784 POPSTACK (block_stack
);
3786 /* Pop the stack slot nesting and free any slots at this level. */
3790 /* Generate code to save the stack pointer at the start of the current block
3791 and set up to restore it on exit. */
3794 save_stack_pointer ()
3796 struct nesting
*thisblock
= block_stack
;
3798 if (thisblock
->data
.block
.stack_level
== 0)
3800 emit_stack_save (thisblock
->next
? SAVE_BLOCK
: SAVE_FUNCTION
,
3801 &thisblock
->data
.block
.stack_level
,
3802 thisblock
->data
.block
.first_insn
);
3803 stack_block_stack
= thisblock
;
3807 /* Generate RTL for the automatic variable declaration DECL.
3808 (Other kinds of declarations are simply ignored if seen here.) */
3814 struct nesting
*thisblock
;
3817 type
= TREE_TYPE (decl
);
3819 /* For a CONST_DECL, set mode, alignment, and sizes from those of the
3820 type in case this node is used in a reference. */
3821 if (TREE_CODE (decl
) == CONST_DECL
)
3823 DECL_MODE (decl
) = TYPE_MODE (type
);
3824 DECL_ALIGN (decl
) = TYPE_ALIGN (type
);
3825 DECL_SIZE (decl
) = TYPE_SIZE (type
);
3826 DECL_SIZE_UNIT (decl
) = TYPE_SIZE_UNIT (type
);
3830 /* Otherwise, only automatic variables need any expansion done. Static and
3831 external variables, and external functions, will be handled by
3832 `assemble_variable' (called from finish_decl). TYPE_DECL requires
3833 nothing. PARM_DECLs are handled in `assign_parms'. */
3834 if (TREE_CODE (decl
) != VAR_DECL
)
3837 if (TREE_STATIC (decl
) || DECL_EXTERNAL (decl
))
3840 thisblock
= block_stack
;
3842 /* Create the RTL representation for the variable. */
3844 if (type
== error_mark_node
)
3845 SET_DECL_RTL (decl
, gen_rtx_MEM (BLKmode
, const0_rtx
));
3847 else if (DECL_SIZE (decl
) == 0)
3848 /* Variable with incomplete type. */
3850 if (DECL_INITIAL (decl
) == 0)
3851 /* Error message was already done; now avoid a crash. */
3852 SET_DECL_RTL (decl
, gen_rtx_MEM (BLKmode
, const0_rtx
));
3854 /* An initializer is going to decide the size of this array.
3855 Until we know the size, represent its address with a reg. */
3856 SET_DECL_RTL (decl
, gen_rtx_MEM (BLKmode
, gen_reg_rtx (Pmode
)));
3858 set_mem_attributes (DECL_RTL (decl
), decl
, 1);
3860 else if (DECL_MODE (decl
) != BLKmode
3861 /* If -ffloat-store, don't put explicit float vars
3863 && !(flag_float_store
3864 && TREE_CODE (type
) == REAL_TYPE
)
3865 && ! TREE_THIS_VOLATILE (decl
)
3866 && (DECL_REGISTER (decl
) || optimize
)
3867 /* if -fcheck-memory-usage, check all variables. */
3868 && ! current_function_check_memory_usage
)
3870 /* Automatic variable that can go in a register. */
3871 int unsignedp
= TREE_UNSIGNED (type
);
3872 enum machine_mode reg_mode
3873 = promote_mode (type
, DECL_MODE (decl
), &unsignedp
, 0);
3875 SET_DECL_RTL (decl
, gen_reg_rtx (reg_mode
));
3876 mark_user_reg (DECL_RTL (decl
));
3878 if (POINTER_TYPE_P (type
))
3879 mark_reg_pointer (DECL_RTL (decl
),
3880 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl
))));
3882 maybe_set_unchanging (DECL_RTL (decl
), decl
);
3884 /* If something wants our address, try to use ADDRESSOF. */
3885 if (TREE_ADDRESSABLE (decl
))
3886 put_var_into_stack (decl
);
3889 else if (TREE_CODE (DECL_SIZE_UNIT (decl
)) == INTEGER_CST
3890 && ! (flag_stack_check
&& ! STACK_CHECK_BUILTIN
3891 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl
),
3892 STACK_CHECK_MAX_VAR_SIZE
)))
3894 /* Variable of fixed size that goes on the stack. */
3898 /* If we previously made RTL for this decl, it must be an array
3899 whose size was determined by the initializer.
3900 The old address was a register; set that register now
3901 to the proper address. */
3902 if (DECL_RTL_SET_P (decl
))
3904 if (GET_CODE (DECL_RTL (decl
)) != MEM
3905 || GET_CODE (XEXP (DECL_RTL (decl
), 0)) != REG
)
3907 oldaddr
= XEXP (DECL_RTL (decl
), 0);
3911 assign_temp (TREE_TYPE (decl
), 1, 1, 1));
3913 /* Set alignment we actually gave this decl. */
3914 DECL_ALIGN (decl
) = (DECL_MODE (decl
) == BLKmode
? BIGGEST_ALIGNMENT
3915 : GET_MODE_BITSIZE (DECL_MODE (decl
)));
3916 DECL_USER_ALIGN (decl
) = 0;
3920 addr
= force_operand (XEXP (DECL_RTL (decl
), 0), oldaddr
);
3921 if (addr
!= oldaddr
)
3922 emit_move_insn (oldaddr
, addr
);
3926 /* Dynamic-size object: must push space on the stack. */
3930 /* Record the stack pointer on entry to block, if have
3931 not already done so. */
3932 do_pending_stack_adjust ();
3933 save_stack_pointer ();
3935 /* In function-at-a-time mode, variable_size doesn't expand this,
3937 if (TREE_CODE (type
) == ARRAY_TYPE
&& TYPE_DOMAIN (type
))
3938 expand_expr (TYPE_MAX_VALUE (TYPE_DOMAIN (type
)),
3939 const0_rtx
, VOIDmode
, 0);
3941 /* Compute the variable's size, in bytes. */
3942 size
= expand_expr (DECL_SIZE_UNIT (decl
), NULL_RTX
, VOIDmode
, 0);
3945 /* Allocate space on the stack for the variable. Note that
3946 DECL_ALIGN says how the variable is to be aligned and we
3947 cannot use it to conclude anything about the alignment of
3949 address
= allocate_dynamic_stack_space (size
, NULL_RTX
,
3950 TYPE_ALIGN (TREE_TYPE (decl
)));
3952 /* Reference the variable indirect through that rtx. */
3953 SET_DECL_RTL (decl
, gen_rtx_MEM (DECL_MODE (decl
), address
));
3955 set_mem_attributes (DECL_RTL (decl
), decl
, 1);
3957 /* Indicate the alignment we actually gave this variable. */
3958 #ifdef STACK_BOUNDARY
3959 DECL_ALIGN (decl
) = STACK_BOUNDARY
;
3961 DECL_ALIGN (decl
) = BIGGEST_ALIGNMENT
;
3963 DECL_USER_ALIGN (decl
) = 0;
3967 /* Emit code to perform the initialization of a declaration DECL. */
3970 expand_decl_init (decl
)
3973 int was_used
= TREE_USED (decl
);
3975 /* If this is a CONST_DECL, we don't have to generate any code, but
3976 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3977 to be set while in the obstack containing the constant. If we don't
3978 do this, we can lose if we have functions nested three deep and the middle
3979 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3980 the innermost function is the first to expand that STRING_CST. */
3981 if (TREE_CODE (decl
) == CONST_DECL
)
3983 if (DECL_INITIAL (decl
) && TREE_CONSTANT (DECL_INITIAL (decl
)))
3984 expand_expr (DECL_INITIAL (decl
), NULL_RTX
, VOIDmode
,
3985 EXPAND_INITIALIZER
);
3989 if (TREE_STATIC (decl
))
3992 /* Compute and store the initial value now. */
3994 if (DECL_INITIAL (decl
) == error_mark_node
)
3996 enum tree_code code
= TREE_CODE (TREE_TYPE (decl
));
3998 if (code
== INTEGER_TYPE
|| code
== REAL_TYPE
|| code
== ENUMERAL_TYPE
3999 || code
== POINTER_TYPE
|| code
== REFERENCE_TYPE
)
4000 expand_assignment (decl
, convert (TREE_TYPE (decl
), integer_zero_node
),
4004 else if (DECL_INITIAL (decl
) && TREE_CODE (DECL_INITIAL (decl
)) != TREE_LIST
)
4006 emit_line_note (DECL_SOURCE_FILE (decl
), DECL_SOURCE_LINE (decl
));
4007 expand_assignment (decl
, DECL_INITIAL (decl
), 0, 0);
4011 /* Don't let the initialization count as "using" the variable. */
4012 TREE_USED (decl
) = was_used
;
4014 /* Free any temporaries we made while initializing the decl. */
4015 preserve_temp_slots (NULL_RTX
);
4019 /* CLEANUP is an expression to be executed at exit from this binding contour;
4020 for example, in C++, it might call the destructor for this variable.
4022 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
4023 CLEANUP multiple times, and have the correct semantics. This
4024 happens in exception handling, for gotos, returns, breaks that
4025 leave the current scope.
4027 If CLEANUP is nonzero and DECL is zero, we record a cleanup
4028 that is not associated with any particular variable. */
4031 expand_decl_cleanup (decl
, cleanup
)
4034 struct nesting
*thisblock
;
4036 /* Error if we are not in any block. */
4037 if (cfun
== 0 || block_stack
== 0)
4040 thisblock
= block_stack
;
4042 /* Record the cleanup if there is one. */
4048 tree
*cleanups
= &thisblock
->data
.block
.cleanups
;
4049 int cond_context
= conditional_context ();
4053 rtx flag
= gen_reg_rtx (word_mode
);
4058 emit_move_insn (flag
, const0_rtx
);
4059 set_flag_0
= get_insns ();
4062 thisblock
->data
.block
.last_unconditional_cleanup
4063 = emit_insns_after (set_flag_0
,
4064 thisblock
->data
.block
.last_unconditional_cleanup
);
4066 emit_move_insn (flag
, const1_rtx
);
4068 cond
= build_decl (VAR_DECL
, NULL_TREE
, type_for_mode (word_mode
, 1));
4069 SET_DECL_RTL (cond
, flag
);
4071 /* Conditionalize the cleanup. */
4072 cleanup
= build (COND_EXPR
, void_type_node
,
4073 truthvalue_conversion (cond
),
4074 cleanup
, integer_zero_node
);
4075 cleanup
= fold (cleanup
);
4077 cleanups
= thisblock
->data
.block
.cleanup_ptr
;
4080 cleanup
= unsave_expr (cleanup
);
4082 t
= *cleanups
= tree_cons (decl
, cleanup
, *cleanups
);
4085 /* If this block has a cleanup, it belongs in stack_block_stack. */
4086 stack_block_stack
= thisblock
;
4093 if (! using_eh_for_cleanups_p
)
4094 TREE_ADDRESSABLE (t
) = 1;
4096 expand_eh_region_start ();
4103 thisblock
->data
.block
.last_unconditional_cleanup
4104 = emit_insns_after (seq
,
4105 thisblock
->data
.block
.last_unconditional_cleanup
);
4109 thisblock
->data
.block
.last_unconditional_cleanup
4111 /* When we insert instructions after the last unconditional cleanup,
4112 we don't adjust last_insn. That means that a later add_insn will
4113 clobber the instructions we've just added. The easiest way to
4114 fix this is to just insert another instruction here, so that the
4115 instructions inserted after the last unconditional cleanup are
4116 never the last instruction. */
4117 emit_note (NULL
, NOTE_INSN_DELETED
);
4118 thisblock
->data
.block
.cleanup_ptr
= &thisblock
->data
.block
.cleanups
;
4124 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4125 DECL_ELTS is the list of elements that belong to DECL's type.
4126 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4129 expand_anon_union_decl (decl
, cleanup
, decl_elts
)
4130 tree decl
, cleanup
, decl_elts
;
4132 struct nesting
*thisblock
= cfun
== 0 ? 0 : block_stack
;
4136 /* If any of the elements are addressable, so is the entire union. */
4137 for (t
= decl_elts
; t
; t
= TREE_CHAIN (t
))
4138 if (TREE_ADDRESSABLE (TREE_VALUE (t
)))
4140 TREE_ADDRESSABLE (decl
) = 1;
4145 expand_decl_cleanup (decl
, cleanup
);
4146 x
= DECL_RTL (decl
);
4148 /* Go through the elements, assigning RTL to each. */
4149 for (t
= decl_elts
; t
; t
= TREE_CHAIN (t
))
4151 tree decl_elt
= TREE_VALUE (t
);
4152 tree cleanup_elt
= TREE_PURPOSE (t
);
4153 enum machine_mode mode
= TYPE_MODE (TREE_TYPE (decl_elt
));
4155 /* Propagate the union's alignment to the elements. */
4156 DECL_ALIGN (decl_elt
) = DECL_ALIGN (decl
);
4157 DECL_USER_ALIGN (decl_elt
) = DECL_USER_ALIGN (decl
);
4159 /* If the element has BLKmode and the union doesn't, the union is
4160 aligned such that the element doesn't need to have BLKmode, so
4161 change the element's mode to the appropriate one for its size. */
4162 if (mode
== BLKmode
&& DECL_MODE (decl
) != BLKmode
)
4163 DECL_MODE (decl_elt
) = mode
4164 = mode_for_size_tree (DECL_SIZE (decl_elt
), MODE_INT
, 1);
4166 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4167 instead create a new MEM rtx with the proper mode. */
4168 if (GET_CODE (x
) == MEM
)
4170 if (mode
== GET_MODE (x
))
4171 SET_DECL_RTL (decl_elt
, x
);
4173 SET_DECL_RTL (decl_elt
, adjust_address_nv (x
, mode
, 0));
4175 else if (GET_CODE (x
) == REG
)
4177 if (mode
== GET_MODE (x
))
4178 SET_DECL_RTL (decl_elt
, x
);
4180 SET_DECL_RTL (decl_elt
, gen_lowpart_SUBREG (mode
, x
));
4185 /* Record the cleanup if there is one. */
4188 thisblock
->data
.block
.cleanups
4189 = tree_cons (decl_elt
, cleanup_elt
,
4190 thisblock
->data
.block
.cleanups
);
4194 /* Expand a list of cleanups LIST.
4195 Elements may be expressions or may be nested lists.
4197 If DONT_DO is nonnull, then any list-element
4198 whose TREE_PURPOSE matches DONT_DO is omitted.
4199 This is sometimes used to avoid a cleanup associated with
4200 a value that is being returned out of the scope.
4202 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
4203 goto and handle protection regions specially in that case.
4205 If REACHABLE, we emit code, otherwise just inform the exception handling
4206 code about this finalization. */
4209 expand_cleanups (list
, dont_do
, in_fixup
, reachable
)
4216 for (tail
= list
; tail
; tail
= TREE_CHAIN (tail
))
4217 if (dont_do
== 0 || TREE_PURPOSE (tail
) != dont_do
)
4219 if (TREE_CODE (TREE_VALUE (tail
)) == TREE_LIST
)
4220 expand_cleanups (TREE_VALUE (tail
), dont_do
, in_fixup
, reachable
);
4223 if (! in_fixup
&& using_eh_for_cleanups_p
)
4224 expand_eh_region_end_cleanup (TREE_VALUE (tail
));
4228 /* Cleanups may be run multiple times. For example,
4229 when exiting a binding contour, we expand the
4230 cleanups associated with that contour. When a goto
4231 within that binding contour has a target outside that
4232 contour, it will expand all cleanups from its scope to
4233 the target. Though the cleanups are expanded multiple
4234 times, the control paths are non-overlapping so the
4235 cleanups will not be executed twice. */
4237 /* We may need to protect from outer cleanups. */
4238 if (in_fixup
&& using_eh_for_cleanups_p
)
4240 expand_eh_region_start ();
4242 expand_expr (TREE_VALUE (tail
), const0_rtx
, VOIDmode
, 0);
4244 expand_eh_region_end_fixup (TREE_VALUE (tail
));
4247 expand_expr (TREE_VALUE (tail
), const0_rtx
, VOIDmode
, 0);
4255 /* Mark when the context we are emitting RTL for as a conditional
4256 context, so that any cleanup actions we register with
4257 expand_decl_init will be properly conditionalized when those
4258 cleanup actions are later performed. Must be called before any
4259 expression (tree) is expanded that is within a conditional context. */
4262 start_cleanup_deferral ()
4264 /* block_stack can be NULL if we are inside the parameter list. It is
4265 OK to do nothing, because cleanups aren't possible here. */
4267 ++block_stack
->data
.block
.conditional_code
;
4270 /* Mark the end of a conditional region of code. Because cleanup
4271 deferrals may be nested, we may still be in a conditional region
4272 after we end the currently deferred cleanups, only after we end all
4273 deferred cleanups, are we back in unconditional code. */
4276 end_cleanup_deferral ()
4278 /* block_stack can be NULL if we are inside the parameter list. It is
4279 OK to do nothing, because cleanups aren't possible here. */
4281 --block_stack
->data
.block
.conditional_code
;
4284 /* Move all cleanups from the current block_stack
4285 to the containing block_stack, where they are assumed to
4286 have been created. If anything can cause a temporary to
4287 be created, but not expanded for more than one level of
4288 block_stacks, then this code will have to change. */
4293 struct nesting
*block
= block_stack
;
4294 struct nesting
*outer
= block
->next
;
4296 outer
->data
.block
.cleanups
4297 = chainon (block
->data
.block
.cleanups
,
4298 outer
->data
.block
.cleanups
);
4299 block
->data
.block
.cleanups
= 0;
4303 last_cleanup_this_contour ()
4305 if (block_stack
== 0)
4308 return block_stack
->data
.block
.cleanups
;
4311 /* Return 1 if there are any pending cleanups at this point.
4312 If THIS_CONTOUR is nonzero, check the current contour as well.
4313 Otherwise, look only at the contours that enclose this one. */
4316 any_pending_cleanups (this_contour
)
4319 struct nesting
*block
;
4321 if (cfun
== NULL
|| cfun
->stmt
== NULL
|| block_stack
== 0)
4324 if (this_contour
&& block_stack
->data
.block
.cleanups
!= NULL
)
4326 if (block_stack
->data
.block
.cleanups
== 0
4327 && block_stack
->data
.block
.outer_cleanups
== 0)
4330 for (block
= block_stack
->next
; block
; block
= block
->next
)
4331 if (block
->data
.block
.cleanups
!= 0)
4337 /* Enter a case (Pascal) or switch (C) statement.
4338 Push a block onto case_stack and nesting_stack
4339 to accumulate the case-labels that are seen
4340 and to record the labels generated for the statement.
4342 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4343 Otherwise, this construct is transparent for `exit_something'.
4345 EXPR is the index-expression to be dispatched on.
4346 TYPE is its nominal type. We could simply convert EXPR to this type,
4347 but instead we take short cuts. */
4350 expand_start_case (exit_flag
, expr
, type
, printname
)
4354 const char *printname
;
4356 register struct nesting
*thiscase
= ALLOC_NESTING ();
4358 /* Make an entry on case_stack for the case we are entering. */
4360 thiscase
->next
= case_stack
;
4361 thiscase
->all
= nesting_stack
;
4362 thiscase
->depth
= ++nesting_depth
;
4363 thiscase
->exit_label
= exit_flag
? gen_label_rtx () : 0;
4364 thiscase
->data
.case_stmt
.case_list
= 0;
4365 thiscase
->data
.case_stmt
.index_expr
= expr
;
4366 thiscase
->data
.case_stmt
.nominal_type
= type
;
4367 thiscase
->data
.case_stmt
.default_label
= 0;
4368 thiscase
->data
.case_stmt
.printname
= printname
;
4369 thiscase
->data
.case_stmt
.line_number_status
= force_line_numbers ();
4370 case_stack
= thiscase
;
4371 nesting_stack
= thiscase
;
4373 do_pending_stack_adjust ();
4375 /* Make sure case_stmt.start points to something that won't
4376 need any transformation before expand_end_case. */
4377 if (GET_CODE (get_last_insn ()) != NOTE
)
4378 emit_note (NULL
, NOTE_INSN_DELETED
);
4380 thiscase
->data
.case_stmt
.start
= get_last_insn ();
4382 start_cleanup_deferral ();
4385 /* Start a "dummy case statement" within which case labels are invalid
4386 and are not connected to any larger real case statement.
4387 This can be used if you don't want to let a case statement jump
4388 into the middle of certain kinds of constructs. */
4391 expand_start_case_dummy ()
4393 register struct nesting
*thiscase
= ALLOC_NESTING ();
4395 /* Make an entry on case_stack for the dummy. */
4397 thiscase
->next
= case_stack
;
4398 thiscase
->all
= nesting_stack
;
4399 thiscase
->depth
= ++nesting_depth
;
4400 thiscase
->exit_label
= 0;
4401 thiscase
->data
.case_stmt
.case_list
= 0;
4402 thiscase
->data
.case_stmt
.start
= 0;
4403 thiscase
->data
.case_stmt
.nominal_type
= 0;
4404 thiscase
->data
.case_stmt
.default_label
= 0;
4405 case_stack
= thiscase
;
4406 nesting_stack
= thiscase
;
4407 start_cleanup_deferral ();
4410 /* End a dummy case statement. */
4413 expand_end_case_dummy ()
4415 end_cleanup_deferral ();
4416 POPSTACK (case_stack
);
4419 /* Return the data type of the index-expression
4420 of the innermost case statement, or null if none. */
4423 case_index_expr_type ()
4426 return TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4433 /* If this is the first label, warn if any insns have been emitted. */
4434 if (case_stack
->data
.case_stmt
.line_number_status
>= 0)
4438 restore_line_number_status
4439 (case_stack
->data
.case_stmt
.line_number_status
);
4440 case_stack
->data
.case_stmt
.line_number_status
= -1;
4442 for (insn
= case_stack
->data
.case_stmt
.start
;
4444 insn
= NEXT_INSN (insn
))
4446 if (GET_CODE (insn
) == CODE_LABEL
)
4448 if (GET_CODE (insn
) != NOTE
4449 && (GET_CODE (insn
) != INSN
|| GET_CODE (PATTERN (insn
)) != USE
))
4452 insn
= PREV_INSN (insn
);
4453 while (insn
&& (GET_CODE (insn
) != NOTE
|| NOTE_LINE_NUMBER (insn
) < 0));
4455 /* If insn is zero, then there must have been a syntax error. */
4457 warning_with_file_and_line (NOTE_SOURCE_FILE (insn
),
4458 NOTE_LINE_NUMBER (insn
),
4459 "unreachable code at beginning of %s",
4460 case_stack
->data
.case_stmt
.printname
);
4467 /* Accumulate one case or default label inside a case or switch statement.
4468 VALUE is the value of the case (a null pointer, for a default label).
4469 The function CONVERTER, when applied to arguments T and V,
4470 converts the value V to the type T.
4472 If not currently inside a case or switch statement, return 1 and do
4473 nothing. The caller will print a language-specific error message.
4474 If VALUE is a duplicate or overlaps, return 2 and do nothing
4475 except store the (first) duplicate node in *DUPLICATE.
4476 If VALUE is out of range, return 3 and do nothing.
4477 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4478 Return 0 on success.
4480 Extended to handle range statements. */
4483 pushcase (value
, converter
, label
, duplicate
)
4484 register tree value
;
4485 tree (*converter
) PARAMS ((tree
, tree
));
4486 register tree label
;
4492 /* Fail if not inside a real case statement. */
4493 if (! (case_stack
&& case_stack
->data
.case_stmt
.start
))
4496 if (stack_block_stack
4497 && stack_block_stack
->depth
> case_stack
->depth
)
4500 index_type
= TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4501 nominal_type
= case_stack
->data
.case_stmt
.nominal_type
;
4503 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4504 if (index_type
== error_mark_node
)
4507 /* Convert VALUE to the type in which the comparisons are nominally done. */
4509 value
= (*converter
) (nominal_type
, value
);
4513 /* Fail if this value is out of range for the actual type of the index
4514 (which may be narrower than NOMINAL_TYPE). */
4516 && (TREE_CONSTANT_OVERFLOW (value
)
4517 || ! int_fits_type_p (value
, index_type
)))
4520 return add_case_node (value
, value
, label
, duplicate
);
4523 /* Like pushcase but this case applies to all values between VALUE1 and
4524 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4525 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4526 starts at VALUE1 and ends at the highest value of the index type.
4527 If both are NULL, this case applies to all values.
4529 The return value is the same as that of pushcase but there is one
4530 additional error code: 4 means the specified range was empty. */
4533 pushcase_range (value1
, value2
, converter
, label
, duplicate
)
4534 register tree value1
, value2
;
4535 tree (*converter
) PARAMS ((tree
, tree
));
4536 register tree label
;
4542 /* Fail if not inside a real case statement. */
4543 if (! (case_stack
&& case_stack
->data
.case_stmt
.start
))
4546 if (stack_block_stack
4547 && stack_block_stack
->depth
> case_stack
->depth
)
4550 index_type
= TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4551 nominal_type
= case_stack
->data
.case_stmt
.nominal_type
;
4553 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4554 if (index_type
== error_mark_node
)
4559 /* Convert VALUEs to type in which the comparisons are nominally done
4560 and replace any unspecified value with the corresponding bound. */
4562 value1
= TYPE_MIN_VALUE (index_type
);
4564 value2
= TYPE_MAX_VALUE (index_type
);
4566 /* Fail if the range is empty. Do this before any conversion since
4567 we want to allow out-of-range empty ranges. */
4568 if (value2
!= 0 && tree_int_cst_lt (value2
, value1
))
4571 /* If the max was unbounded, use the max of the nominal_type we are
4572 converting to. Do this after the < check above to suppress false
4575 value2
= TYPE_MAX_VALUE (nominal_type
);
4577 value1
= (*converter
) (nominal_type
, value1
);
4578 value2
= (*converter
) (nominal_type
, value2
);
4580 /* Fail if these values are out of range. */
4581 if (TREE_CONSTANT_OVERFLOW (value1
)
4582 || ! int_fits_type_p (value1
, index_type
))
4585 if (TREE_CONSTANT_OVERFLOW (value2
)
4586 || ! int_fits_type_p (value2
, index_type
))
4589 return add_case_node (value1
, value2
, label
, duplicate
);
4592 /* Do the actual insertion of a case label for pushcase and pushcase_range
4593 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4594 slowdown for large switch statements. */
4597 add_case_node (low
, high
, label
, duplicate
)
4602 struct case_node
*p
, **q
, *r
;
4604 /* If there's no HIGH value, then this is not a case range; it's
4605 just a simple case label. But that's just a degenerate case
4610 /* Handle default labels specially. */
4613 if (case_stack
->data
.case_stmt
.default_label
!= 0)
4615 *duplicate
= case_stack
->data
.case_stmt
.default_label
;
4618 case_stack
->data
.case_stmt
.default_label
= label
;
4619 expand_label (label
);
4623 q
= &case_stack
->data
.case_stmt
.case_list
;
4630 /* Keep going past elements distinctly greater than HIGH. */
4631 if (tree_int_cst_lt (high
, p
->low
))
4634 /* or distinctly less than LOW. */
4635 else if (tree_int_cst_lt (p
->high
, low
))
4640 /* We have an overlap; this is an error. */
4641 *duplicate
= p
->code_label
;
4646 /* Add this label to the chain, and succeed. */
4648 r
= (struct case_node
*) xmalloc (sizeof (struct case_node
));
4651 /* If the bounds are equal, turn this into the one-value case. */
4652 if (tree_int_cst_equal (low
, high
))
4657 r
->code_label
= label
;
4658 expand_label (label
);
4668 struct case_node
*s
;
4674 if (! (b
= p
->balance
))
4675 /* Growth propagation from left side. */
4682 if ((p
->left
= s
= r
->right
))
4691 if ((r
->parent
= s
))
4699 case_stack
->data
.case_stmt
.case_list
= r
;
4702 /* r->balance == +1 */
4707 struct case_node
*t
= r
->right
;
4709 if ((p
->left
= s
= t
->right
))
4713 if ((r
->right
= s
= t
->left
))
4727 if ((t
->parent
= s
))
4735 case_stack
->data
.case_stmt
.case_list
= t
;
4742 /* p->balance == +1; growth of left side balances the node. */
4752 if (! (b
= p
->balance
))
4753 /* Growth propagation from right side. */
4761 if ((p
->right
= s
= r
->left
))
4769 if ((r
->parent
= s
))
4778 case_stack
->data
.case_stmt
.case_list
= r
;
4782 /* r->balance == -1 */
4786 struct case_node
*t
= r
->left
;
4788 if ((p
->right
= s
= t
->left
))
4793 if ((r
->left
= s
= t
->right
))
4807 if ((t
->parent
= s
))
4816 case_stack
->data
.case_stmt
.case_list
= t
;
4822 /* p->balance == -1; growth of right side balances the node. */
4835 /* Returns the number of possible values of TYPE.
4836 Returns -1 if the number is unknown, variable, or if the number does not
4837 fit in a HOST_WIDE_INT.
4838 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4839 do not increase monotonically (there may be duplicates);
4840 to 1 if the values increase monotonically, but not always by 1;
4841 otherwise sets it to 0. */
4844 all_cases_count (type
, spareness
)
4849 HOST_WIDE_INT count
, minval
, lastval
;
4853 switch (TREE_CODE (type
))
4860 count
= 1 << BITS_PER_UNIT
;
4865 if (TYPE_MAX_VALUE (type
) != 0
4866 && 0 != (t
= fold (build (MINUS_EXPR
, type
, TYPE_MAX_VALUE (type
),
4867 TYPE_MIN_VALUE (type
))))
4868 && 0 != (t
= fold (build (PLUS_EXPR
, type
, t
,
4869 convert (type
, integer_zero_node
))))
4870 && host_integerp (t
, 1))
4871 count
= tree_low_cst (t
, 1);
4877 /* Don't waste time with enumeral types with huge values. */
4878 if (! host_integerp (TYPE_MIN_VALUE (type
), 0)
4879 || TYPE_MAX_VALUE (type
) == 0
4880 || ! host_integerp (TYPE_MAX_VALUE (type
), 0))
4883 lastval
= minval
= tree_low_cst (TYPE_MIN_VALUE (type
), 0);
4886 for (t
= TYPE_VALUES (type
); t
!= NULL_TREE
; t
= TREE_CHAIN (t
))
4888 HOST_WIDE_INT thisval
= tree_low_cst (TREE_VALUE (t
), 0);
4890 if (*spareness
== 2 || thisval
< lastval
)
4892 else if (thisval
!= minval
+ count
)
4902 #define BITARRAY_TEST(ARRAY, INDEX) \
4903 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4904 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4905 #define BITARRAY_SET(ARRAY, INDEX) \
4906 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4907 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4909 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4910 with the case values we have seen, assuming the case expression
4912 SPARSENESS is as determined by all_cases_count.
4914 The time needed is proportional to COUNT, unless
4915 SPARSENESS is 2, in which case quadratic time is needed. */
4918 mark_seen_cases (type
, cases_seen
, count
, sparseness
)
4920 unsigned char *cases_seen
;
4921 HOST_WIDE_INT count
;
4924 tree next_node_to_try
= NULL_TREE
;
4925 HOST_WIDE_INT next_node_offset
= 0;
4927 register struct case_node
*n
, *root
= case_stack
->data
.case_stmt
.case_list
;
4928 tree val
= make_node (INTEGER_CST
);
4930 TREE_TYPE (val
) = type
;
4934 else if (sparseness
== 2)
4937 unsigned HOST_WIDE_INT xlo
;
4939 /* This less efficient loop is only needed to handle
4940 duplicate case values (multiple enum constants
4941 with the same value). */
4942 TREE_TYPE (val
) = TREE_TYPE (root
->low
);
4943 for (t
= TYPE_VALUES (type
), xlo
= 0; t
!= NULL_TREE
;
4944 t
= TREE_CHAIN (t
), xlo
++)
4946 TREE_INT_CST_LOW (val
) = TREE_INT_CST_LOW (TREE_VALUE (t
));
4947 TREE_INT_CST_HIGH (val
) = TREE_INT_CST_HIGH (TREE_VALUE (t
));
4951 /* Keep going past elements distinctly greater than VAL. */
4952 if (tree_int_cst_lt (val
, n
->low
))
4955 /* or distinctly less than VAL. */
4956 else if (tree_int_cst_lt (n
->high
, val
))
4961 /* We have found a matching range. */
4962 BITARRAY_SET (cases_seen
, xlo
);
4972 case_stack
->data
.case_stmt
.case_list
= root
= case_tree2list (root
, 0);
4974 for (n
= root
; n
; n
= n
->right
)
4976 TREE_INT_CST_LOW (val
) = TREE_INT_CST_LOW (n
->low
);
4977 TREE_INT_CST_HIGH (val
) = TREE_INT_CST_HIGH (n
->low
);
4978 while (! tree_int_cst_lt (n
->high
, val
))
4980 /* Calculate (into xlo) the "offset" of the integer (val).
4981 The element with lowest value has offset 0, the next smallest
4982 element has offset 1, etc. */
4984 unsigned HOST_WIDE_INT xlo
;
4988 if (sparseness
&& TYPE_VALUES (type
) != NULL_TREE
)
4990 /* The TYPE_VALUES will be in increasing order, so
4991 starting searching where we last ended. */
4992 t
= next_node_to_try
;
4993 xlo
= next_node_offset
;
4999 t
= TYPE_VALUES (type
);
5002 if (tree_int_cst_equal (val
, TREE_VALUE (t
)))
5004 next_node_to_try
= TREE_CHAIN (t
);
5005 next_node_offset
= xlo
+ 1;
5010 if (t
== next_node_to_try
)
5019 t
= TYPE_MIN_VALUE (type
);
5021 neg_double (TREE_INT_CST_LOW (t
), TREE_INT_CST_HIGH (t
),
5025 add_double (xlo
, xhi
,
5026 TREE_INT_CST_LOW (val
), TREE_INT_CST_HIGH (val
),
5030 if (xhi
== 0 && xlo
< (unsigned HOST_WIDE_INT
) count
)
5031 BITARRAY_SET (cases_seen
, xlo
);
5033 add_double (TREE_INT_CST_LOW (val
), TREE_INT_CST_HIGH (val
),
5035 &TREE_INT_CST_LOW (val
), &TREE_INT_CST_HIGH (val
));
5041 /* Called when the index of a switch statement is an enumerated type
5042 and there is no default label.
5044 Checks that all enumeration literals are covered by the case
5045 expressions of a switch. Also, warn if there are any extra
5046 switch cases that are *not* elements of the enumerated type.
5048 If all enumeration literals were covered by the case expressions,
5049 turn one of the expressions into the default expression since it should
5050 not be possible to fall through such a switch. */
5053 check_for_full_enumeration_handling (type
)
5056 register struct case_node
*n
;
5057 register tree chain
;
5058 #if 0 /* variable used by 'if 0'ed code below. */
5059 register struct case_node
**l
;
5063 /* True iff the selector type is a numbered set mode. */
5066 /* The number of possible selector values. */
5069 /* For each possible selector value. a one iff it has been matched
5070 by a case value alternative. */
5071 unsigned char *cases_seen
;
5073 /* The allocated size of cases_seen, in chars. */
5074 HOST_WIDE_INT bytes_needed
;
5079 size
= all_cases_count (type
, &sparseness
);
5080 bytes_needed
= (size
+ HOST_BITS_PER_CHAR
) / HOST_BITS_PER_CHAR
;
5082 if (size
> 0 && size
< 600000
5083 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5084 this optimization if we don't have enough memory rather than
5085 aborting, as xmalloc would do. */
5087 (unsigned char *) really_call_calloc (bytes_needed
, 1)) != NULL
)
5090 tree v
= TYPE_VALUES (type
);
5092 /* The time complexity of this code is normally O(N), where
5093 N being the number of members in the enumerated type.
5094 However, if type is a ENUMERAL_TYPE whose values do not
5095 increase monotonically, O(N*log(N)) time may be needed. */
5097 mark_seen_cases (type
, cases_seen
, size
, sparseness
);
5099 for (i
= 0; v
!= NULL_TREE
&& i
< size
; i
++, v
= TREE_CHAIN (v
))
5100 if (BITARRAY_TEST (cases_seen
, i
) == 0)
5101 warning ("enumeration value `%s' not handled in switch",
5102 IDENTIFIER_POINTER (TREE_PURPOSE (v
)));
5107 /* Now we go the other way around; we warn if there are case
5108 expressions that don't correspond to enumerators. This can
5109 occur since C and C++ don't enforce type-checking of
5110 assignments to enumeration variables. */
5112 if (case_stack
->data
.case_stmt
.case_list
5113 && case_stack
->data
.case_stmt
.case_list
->left
)
5114 case_stack
->data
.case_stmt
.case_list
5115 = case_tree2list (case_stack
->data
.case_stmt
.case_list
, 0);
5117 for (n
= case_stack
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5119 for (chain
= TYPE_VALUES (type
);
5120 chain
&& !tree_int_cst_equal (n
->low
, TREE_VALUE (chain
));
5121 chain
= TREE_CHAIN (chain
))
5126 if (TYPE_NAME (type
) == 0)
5127 warning ("case value `%ld' not in enumerated type",
5128 (long) TREE_INT_CST_LOW (n
->low
));
5130 warning ("case value `%ld' not in enumerated type `%s'",
5131 (long) TREE_INT_CST_LOW (n
->low
),
5132 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type
))
5135 : DECL_NAME (TYPE_NAME (type
))));
5137 if (!tree_int_cst_equal (n
->low
, n
->high
))
5139 for (chain
= TYPE_VALUES (type
);
5140 chain
&& !tree_int_cst_equal (n
->high
, TREE_VALUE (chain
));
5141 chain
= TREE_CHAIN (chain
))
5146 if (TYPE_NAME (type
) == 0)
5147 warning ("case value `%ld' not in enumerated type",
5148 (long) TREE_INT_CST_LOW (n
->high
));
5150 warning ("case value `%ld' not in enumerated type `%s'",
5151 (long) TREE_INT_CST_LOW (n
->high
),
5152 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type
))
5155 : DECL_NAME (TYPE_NAME (type
))));
5161 /* ??? This optimization is disabled because it causes valid programs to
5162 fail. ANSI C does not guarantee that an expression with enum type
5163 will have a value that is the same as one of the enumeration literals. */
5165 /* If all values were found as case labels, make one of them the default
5166 label. Thus, this switch will never fall through. We arbitrarily pick
5167 the last one to make the default since this is likely the most
5168 efficient choice. */
5172 for (l
= &case_stack
->data
.case_stmt
.case_list
;
5177 case_stack
->data
.case_stmt
.default_label
= (*l
)->code_label
;
5183 /* Free CN, and its children. */
5186 free_case_nodes (cn
)
5191 free_case_nodes (cn
->left
);
5192 free_case_nodes (cn
->right
);
5198 /* Terminate a case (Pascal) or switch (C) statement
5199 in which ORIG_INDEX is the expression to be tested.
5200 Generate the code to test it and jump to the right place. */
5203 expand_end_case (orig_index
)
5206 tree minval
= NULL_TREE
, maxval
= NULL_TREE
, range
= NULL_TREE
, orig_minval
;
5207 rtx default_label
= 0;
5208 register struct case_node
*n
;
5216 register struct nesting
*thiscase
= case_stack
;
5217 tree index_expr
, index_type
;
5220 /* Don't crash due to previous errors. */
5221 if (thiscase
== NULL
)
5224 table_label
= gen_label_rtx ();
5225 index_expr
= thiscase
->data
.case_stmt
.index_expr
;
5226 index_type
= TREE_TYPE (index_expr
);
5227 unsignedp
= TREE_UNSIGNED (index_type
);
5229 do_pending_stack_adjust ();
5231 /* This might get an spurious warning in the presence of a syntax error;
5232 it could be fixed by moving the call to check_seenlabel after the
5233 check for error_mark_node, and copying the code of check_seenlabel that
5234 deals with case_stack->data.case_stmt.line_number_status /
5235 restore_line_number_status in front of the call to end_cleanup_deferral;
5236 However, this might miss some useful warnings in the presence of
5237 non-syntax errors. */
5240 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5241 if (index_type
!= error_mark_node
)
5243 /* If switch expression was an enumerated type, check that all
5244 enumeration literals are covered by the cases.
5245 No sense trying this if there's a default case, however. */
5247 if (!thiscase
->data
.case_stmt
.default_label
5248 && TREE_CODE (TREE_TYPE (orig_index
)) == ENUMERAL_TYPE
5249 && TREE_CODE (index_expr
) != INTEGER_CST
)
5250 check_for_full_enumeration_handling (TREE_TYPE (orig_index
));
5252 /* If we don't have a default-label, create one here,
5253 after the body of the switch. */
5254 if (thiscase
->data
.case_stmt
.default_label
== 0)
5256 thiscase
->data
.case_stmt
.default_label
5257 = build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
5258 expand_label (thiscase
->data
.case_stmt
.default_label
);
5260 default_label
= label_rtx (thiscase
->data
.case_stmt
.default_label
);
5262 before_case
= get_last_insn ();
5264 if (thiscase
->data
.case_stmt
.case_list
5265 && thiscase
->data
.case_stmt
.case_list
->left
)
5266 thiscase
->data
.case_stmt
.case_list
5267 = case_tree2list (thiscase
->data
.case_stmt
.case_list
, 0);
5269 /* Simplify the case-list before we count it. */
5270 group_case_nodes (thiscase
->data
.case_stmt
.case_list
);
5272 /* Get upper and lower bounds of case values.
5273 Also convert all the case values to the index expr's data type. */
5276 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5278 /* Check low and high label values are integers. */
5279 if (TREE_CODE (n
->low
) != INTEGER_CST
)
5281 if (TREE_CODE (n
->high
) != INTEGER_CST
)
5284 n
->low
= convert (index_type
, n
->low
);
5285 n
->high
= convert (index_type
, n
->high
);
5287 /* Count the elements and track the largest and smallest
5288 of them (treating them as signed even if they are not). */
5296 if (INT_CST_LT (n
->low
, minval
))
5298 if (INT_CST_LT (maxval
, n
->high
))
5301 /* A range counts double, since it requires two compares. */
5302 if (! tree_int_cst_equal (n
->low
, n
->high
))
5306 orig_minval
= minval
;
5308 /* Compute span of values. */
5310 range
= fold (build (MINUS_EXPR
, index_type
, maxval
, minval
));
5312 end_cleanup_deferral ();
5316 expand_expr (index_expr
, const0_rtx
, VOIDmode
, 0);
5318 emit_jump (default_label
);
5321 /* If range of values is much bigger than number of values,
5322 make a sequence of conditional branches instead of a dispatch.
5323 If the switch-index is a constant, do it this way
5324 because we can optimize it. */
5326 #ifndef CASE_VALUES_THRESHOLD
5328 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
5330 /* If machine does not have a case insn that compares the
5331 bounds, this means extra overhead for dispatch tables
5332 which raises the threshold for using them. */
5333 #define CASE_VALUES_THRESHOLD 5
5334 #endif /* HAVE_casesi */
5335 #endif /* CASE_VALUES_THRESHOLD */
5337 else if (count
< CASE_VALUES_THRESHOLD
5338 || compare_tree_int (range
, 10 * count
) > 0
5339 /* RANGE may be signed, and really large ranges will show up
5340 as negative numbers. */
5341 || compare_tree_int (range
, 0) < 0
5342 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5345 || TREE_CODE (index_expr
) == INTEGER_CST
5346 /* These will reduce to a constant. */
5347 || (TREE_CODE (index_expr
) == CALL_EXPR
5348 && TREE_CODE (TREE_OPERAND (index_expr
, 0)) == ADDR_EXPR
5349 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr
, 0), 0)) == FUNCTION_DECL
5350 && DECL_BUILT_IN_CLASS (TREE_OPERAND (TREE_OPERAND (index_expr
, 0), 0)) == BUILT_IN_NORMAL
5351 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr
, 0), 0)) == BUILT_IN_CLASSIFY_TYPE
)
5352 || (TREE_CODE (index_expr
) == COMPOUND_EXPR
5353 && TREE_CODE (TREE_OPERAND (index_expr
, 1)) == INTEGER_CST
))
5355 index
= expand_expr (index_expr
, NULL_RTX
, VOIDmode
, 0);
5357 /* If the index is a short or char that we do not have
5358 an insn to handle comparisons directly, convert it to
5359 a full integer now, rather than letting each comparison
5360 generate the conversion. */
5362 if (GET_MODE_CLASS (GET_MODE (index
)) == MODE_INT
5363 && (cmp_optab
->handlers
[(int) GET_MODE (index
)].insn_code
5364 == CODE_FOR_nothing
))
5366 enum machine_mode wider_mode
;
5367 for (wider_mode
= GET_MODE (index
); wider_mode
!= VOIDmode
;
5368 wider_mode
= GET_MODE_WIDER_MODE (wider_mode
))
5369 if (cmp_optab
->handlers
[(int) wider_mode
].insn_code
5370 != CODE_FOR_nothing
)
5372 index
= convert_to_mode (wider_mode
, index
, unsignedp
);
5378 do_pending_stack_adjust ();
5380 index
= protect_from_queue (index
, 0);
5381 if (GET_CODE (index
) == MEM
)
5382 index
= copy_to_reg (index
);
5383 if (GET_CODE (index
) == CONST_INT
5384 || TREE_CODE (index_expr
) == INTEGER_CST
)
5386 /* Make a tree node with the proper constant value
5387 if we don't already have one. */
5388 if (TREE_CODE (index_expr
) != INTEGER_CST
)
5391 = build_int_2 (INTVAL (index
),
5392 unsignedp
|| INTVAL (index
) >= 0 ? 0 : -1);
5393 index_expr
= convert (index_type
, index_expr
);
5396 /* For constant index expressions we need only
5397 issue a unconditional branch to the appropriate
5398 target code. The job of removing any unreachable
5399 code is left to the optimisation phase if the
5400 "-O" option is specified. */
5401 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5402 if (! tree_int_cst_lt (index_expr
, n
->low
)
5403 && ! tree_int_cst_lt (n
->high
, index_expr
))
5407 emit_jump (label_rtx (n
->code_label
));
5409 emit_jump (default_label
);
5413 /* If the index expression is not constant we generate
5414 a binary decision tree to select the appropriate
5415 target code. This is done as follows:
5417 The list of cases is rearranged into a binary tree,
5418 nearly optimal assuming equal probability for each case.
5420 The tree is transformed into RTL, eliminating
5421 redundant test conditions at the same time.
5423 If program flow could reach the end of the
5424 decision tree an unconditional jump to the
5425 default code is emitted. */
5428 = (TREE_CODE (TREE_TYPE (orig_index
)) != ENUMERAL_TYPE
5429 && estimate_case_costs (thiscase
->data
.case_stmt
.case_list
));
5430 balance_case_nodes (&thiscase
->data
.case_stmt
.case_list
, NULL
);
5431 emit_case_nodes (index
, thiscase
->data
.case_stmt
.case_list
,
5432 default_label
, index_type
);
5433 emit_jump_if_reachable (default_label
);
5442 enum machine_mode index_mode
= SImode
;
5443 int index_bits
= GET_MODE_BITSIZE (index_mode
);
5445 enum machine_mode op_mode
;
5447 /* Convert the index to SImode. */
5448 if (GET_MODE_BITSIZE (TYPE_MODE (index_type
))
5449 > GET_MODE_BITSIZE (index_mode
))
5451 enum machine_mode omode
= TYPE_MODE (index_type
);
5452 rtx rangertx
= expand_expr (range
, NULL_RTX
, VOIDmode
, 0);
5454 /* We must handle the endpoints in the original mode. */
5455 index_expr
= build (MINUS_EXPR
, index_type
,
5456 index_expr
, minval
);
5457 minval
= integer_zero_node
;
5458 index
= expand_expr (index_expr
, NULL_RTX
, VOIDmode
, 0);
5459 emit_cmp_and_jump_insns (rangertx
, index
, LTU
, NULL_RTX
,
5460 omode
, 1, 0, default_label
);
5461 /* Now we can safely truncate. */
5462 index
= convert_to_mode (index_mode
, index
, 0);
5466 if (TYPE_MODE (index_type
) != index_mode
)
5468 index_expr
= convert (type_for_size (index_bits
, 0),
5470 index_type
= TREE_TYPE (index_expr
);
5473 index
= expand_expr (index_expr
, NULL_RTX
, VOIDmode
, 0);
5476 index
= protect_from_queue (index
, 0);
5477 do_pending_stack_adjust ();
5479 op_mode
= insn_data
[(int) CODE_FOR_casesi
].operand
[0].mode
;
5480 if (! (*insn_data
[(int) CODE_FOR_casesi
].operand
[0].predicate
)
5482 index
= copy_to_mode_reg (op_mode
, index
);
5484 op1
= expand_expr (minval
, NULL_RTX
, VOIDmode
, 0);
5486 op_mode
= insn_data
[(int) CODE_FOR_casesi
].operand
[1].mode
;
5487 op1
= convert_modes (op_mode
, TYPE_MODE (TREE_TYPE (minval
)),
5488 op1
, TREE_UNSIGNED (TREE_TYPE (minval
)));
5489 if (! (*insn_data
[(int) CODE_FOR_casesi
].operand
[1].predicate
)
5491 op1
= copy_to_mode_reg (op_mode
, op1
);
5493 op2
= expand_expr (range
, NULL_RTX
, VOIDmode
, 0);
5495 op_mode
= insn_data
[(int) CODE_FOR_casesi
].operand
[2].mode
;
5496 op2
= convert_modes (op_mode
, TYPE_MODE (TREE_TYPE (range
)),
5497 op2
, TREE_UNSIGNED (TREE_TYPE (range
)));
5498 if (! (*insn_data
[(int) CODE_FOR_casesi
].operand
[2].predicate
)
5500 op2
= copy_to_mode_reg (op_mode
, op2
);
5502 emit_jump_insn (gen_casesi (index
, op1
, op2
,
5503 table_label
, default_label
));
5507 #ifdef HAVE_tablejump
5508 if (! win
&& HAVE_tablejump
)
5510 index_type
= thiscase
->data
.case_stmt
.nominal_type
;
5511 index_expr
= fold (build (MINUS_EXPR
, index_type
,
5512 convert (index_type
, index_expr
),
5513 convert (index_type
, minval
)));
5514 index
= expand_expr (index_expr
, NULL_RTX
, VOIDmode
, 0);
5516 index
= protect_from_queue (index
, 0);
5517 do_pending_stack_adjust ();
5519 do_tablejump (index
, TYPE_MODE (index_type
),
5520 convert_modes (TYPE_MODE (index_type
),
5521 TYPE_MODE (TREE_TYPE (range
)),
5522 expand_expr (range
, NULL_RTX
,
5524 TREE_UNSIGNED (TREE_TYPE (range
))),
5525 table_label
, default_label
);
5532 /* Get table of labels to jump to, in order of case index. */
5534 ncases
= TREE_INT_CST_LOW (range
) + 1;
5535 labelvec
= (rtx
*) alloca (ncases
* sizeof (rtx
));
5536 memset ((char *) labelvec
, 0, ncases
* sizeof (rtx
));
5538 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5540 register HOST_WIDE_INT i
5541 = TREE_INT_CST_LOW (n
->low
) - TREE_INT_CST_LOW (orig_minval
);
5546 = gen_rtx_LABEL_REF (Pmode
, label_rtx (n
->code_label
));
5547 if (i
+ TREE_INT_CST_LOW (orig_minval
)
5548 == TREE_INT_CST_LOW (n
->high
))
5554 /* Fill in the gaps with the default. */
5555 for (i
= 0; i
< ncases
; i
++)
5556 if (labelvec
[i
] == 0)
5557 labelvec
[i
] = gen_rtx_LABEL_REF (Pmode
, default_label
);
5559 /* Output the table */
5560 emit_label (table_label
);
5562 if (CASE_VECTOR_PC_RELATIVE
|| flag_pic
)
5563 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE
,
5564 gen_rtx_LABEL_REF (Pmode
, table_label
),
5565 gen_rtvec_v (ncases
, labelvec
),
5566 const0_rtx
, const0_rtx
));
5568 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE
,
5569 gen_rtvec_v (ncases
, labelvec
)));
5571 /* If the case insn drops through the table,
5572 after the table we must jump to the default-label.
5573 Otherwise record no drop-through after the table. */
5574 #ifdef CASE_DROPS_THROUGH
5575 emit_jump (default_label
);
5581 before_case
= squeeze_notes (NEXT_INSN (before_case
), get_last_insn ());
5582 reorder_insns (before_case
, get_last_insn (),
5583 thiscase
->data
.case_stmt
.start
);
5586 end_cleanup_deferral ();
5588 if (thiscase
->exit_label
)
5589 emit_label (thiscase
->exit_label
);
5591 free_case_nodes (case_stack
->data
.case_stmt
.case_list
);
5592 POPSTACK (case_stack
);
5597 /* Convert the tree NODE into a list linked by the right field, with the left
5598 field zeroed. RIGHT is used for recursion; it is a list to be placed
5599 rightmost in the resulting list. */
5601 static struct case_node
*
5602 case_tree2list (node
, right
)
5603 struct case_node
*node
, *right
;
5605 struct case_node
*left
;
5608 right
= case_tree2list (node
->right
, right
);
5610 node
->right
= right
;
5611 if ((left
= node
->left
))
5614 return case_tree2list (left
, node
);
5620 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5623 do_jump_if_equal (op1
, op2
, label
, unsignedp
)
5624 rtx op1
, op2
, label
;
5627 if (GET_CODE (op1
) == CONST_INT
5628 && GET_CODE (op2
) == CONST_INT
)
5630 if (INTVAL (op1
) == INTVAL (op2
))
5635 enum machine_mode mode
= GET_MODE (op1
);
5636 if (mode
== VOIDmode
)
5637 mode
= GET_MODE (op2
);
5638 emit_cmp_and_jump_insns (op1
, op2
, EQ
, NULL_RTX
, mode
, unsignedp
,
5643 /* Not all case values are encountered equally. This function
5644 uses a heuristic to weight case labels, in cases where that
5645 looks like a reasonable thing to do.
5647 Right now, all we try to guess is text, and we establish the
5650 chars above space: 16
5659 If we find any cases in the switch that are not either -1 or in the range
5660 of valid ASCII characters, or are control characters other than those
5661 commonly used with "\", don't treat this switch scanning text.
5663 Return 1 if these nodes are suitable for cost estimation, otherwise
5667 estimate_case_costs (node
)
5670 tree min_ascii
= integer_minus_one_node
;
5671 tree max_ascii
= convert (TREE_TYPE (node
->high
), build_int_2 (127, 0));
5675 /* If we haven't already made the cost table, make it now. Note that the
5676 lower bound of the table is -1, not zero. */
5678 if (! cost_table_initialized
)
5680 cost_table_initialized
= 1;
5682 for (i
= 0; i
< 128; i
++)
5685 COST_TABLE (i
) = 16;
5686 else if (ISPUNCT (i
))
5688 else if (ISCNTRL (i
))
5689 COST_TABLE (i
) = -1;
5692 COST_TABLE (' ') = 8;
5693 COST_TABLE ('\t') = 4;
5694 COST_TABLE ('\0') = 4;
5695 COST_TABLE ('\n') = 2;
5696 COST_TABLE ('\f') = 1;
5697 COST_TABLE ('\v') = 1;
5698 COST_TABLE ('\b') = 1;
5701 /* See if all the case expressions look like text. It is text if the
5702 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5703 as signed arithmetic since we don't want to ever access cost_table with a
5704 value less than -1. Also check that none of the constants in a range
5705 are strange control characters. */
5707 for (n
= node
; n
; n
= n
->right
)
5709 if ((INT_CST_LT (n
->low
, min_ascii
)) || INT_CST_LT (max_ascii
, n
->high
))
5712 for (i
= (HOST_WIDE_INT
) TREE_INT_CST_LOW (n
->low
);
5713 i
<= (HOST_WIDE_INT
) TREE_INT_CST_LOW (n
->high
); i
++)
5714 if (COST_TABLE (i
) < 0)
5718 /* All interesting values are within the range of interesting
5719 ASCII characters. */
5723 /* Scan an ordered list of case nodes
5724 combining those with consecutive values or ranges.
5726 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5729 group_case_nodes (head
)
5732 case_node_ptr node
= head
;
5736 rtx lb
= next_real_insn (label_rtx (node
->code_label
));
5738 case_node_ptr np
= node
;
5740 /* Try to group the successors of NODE with NODE. */
5741 while (((np
= np
->right
) != 0)
5742 /* Do they jump to the same place? */
5743 && ((lb2
= next_real_insn (label_rtx (np
->code_label
))) == lb
5744 || (lb
!= 0 && lb2
!= 0
5745 && simplejump_p (lb
)
5746 && simplejump_p (lb2
)
5747 && rtx_equal_p (SET_SRC (PATTERN (lb
)),
5748 SET_SRC (PATTERN (lb2
)))))
5749 /* Are their ranges consecutive? */
5750 && tree_int_cst_equal (np
->low
,
5751 fold (build (PLUS_EXPR
,
5752 TREE_TYPE (node
->high
),
5755 /* An overflow is not consecutive. */
5756 && tree_int_cst_lt (node
->high
,
5757 fold (build (PLUS_EXPR
,
5758 TREE_TYPE (node
->high
),
5760 integer_one_node
))))
5762 node
->high
= np
->high
;
5764 /* NP is the first node after NODE which can't be grouped with it.
5765 Delete the nodes in between, and move on to that node. */
5771 /* Take an ordered list of case nodes
5772 and transform them into a near optimal binary tree,
5773 on the assumption that any target code selection value is as
5774 likely as any other.
5776 The transformation is performed by splitting the ordered
5777 list into two equal sections plus a pivot. The parts are
5778 then attached to the pivot as left and right branches. Each
5779 branch is then transformed recursively. */
5782 balance_case_nodes (head
, parent
)
5783 case_node_ptr
*head
;
5784 case_node_ptr parent
;
5786 register case_node_ptr np
;
5794 register case_node_ptr
*npp
;
5797 /* Count the number of entries on branch. Also count the ranges. */
5801 if (!tree_int_cst_equal (np
->low
, np
->high
))
5805 cost
+= COST_TABLE (TREE_INT_CST_LOW (np
->high
));
5809 cost
+= COST_TABLE (TREE_INT_CST_LOW (np
->low
));
5817 /* Split this list if it is long enough for that to help. */
5822 /* Find the place in the list that bisects the list's total cost,
5823 Here I gets half the total cost. */
5828 /* Skip nodes while their cost does not reach that amount. */
5829 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
5830 i
-= COST_TABLE (TREE_INT_CST_LOW ((*npp
)->high
));
5831 i
-= COST_TABLE (TREE_INT_CST_LOW ((*npp
)->low
));
5834 npp
= &(*npp
)->right
;
5839 /* Leave this branch lopsided, but optimize left-hand
5840 side and fill in `parent' fields for right-hand side. */
5842 np
->parent
= parent
;
5843 balance_case_nodes (&np
->left
, np
);
5844 for (; np
->right
; np
= np
->right
)
5845 np
->right
->parent
= np
;
5849 /* If there are just three nodes, split at the middle one. */
5851 npp
= &(*npp
)->right
;
5854 /* Find the place in the list that bisects the list's total cost,
5855 where ranges count as 2.
5856 Here I gets half the total cost. */
5857 i
= (i
+ ranges
+ 1) / 2;
5860 /* Skip nodes while their cost does not reach that amount. */
5861 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
5866 npp
= &(*npp
)->right
;
5871 np
->parent
= parent
;
5874 /* Optimize each of the two split parts. */
5875 balance_case_nodes (&np
->left
, np
);
5876 balance_case_nodes (&np
->right
, np
);
5880 /* Else leave this branch as one level,
5881 but fill in `parent' fields. */
5883 np
->parent
= parent
;
5884 for (; np
->right
; np
= np
->right
)
5885 np
->right
->parent
= np
;
5890 /* Search the parent sections of the case node tree
5891 to see if a test for the lower bound of NODE would be redundant.
5892 INDEX_TYPE is the type of the index expression.
5894 The instructions to generate the case decision tree are
5895 output in the same order as nodes are processed so it is
5896 known that if a parent node checks the range of the current
5897 node minus one that the current node is bounded at its lower
5898 span. Thus the test would be redundant. */
5901 node_has_low_bound (node
, index_type
)
5906 case_node_ptr pnode
;
5908 /* If the lower bound of this node is the lowest value in the index type,
5909 we need not test it. */
5911 if (tree_int_cst_equal (node
->low
, TYPE_MIN_VALUE (index_type
)))
5914 /* If this node has a left branch, the value at the left must be less
5915 than that at this node, so it cannot be bounded at the bottom and
5916 we need not bother testing any further. */
5921 low_minus_one
= fold (build (MINUS_EXPR
, TREE_TYPE (node
->low
),
5922 node
->low
, integer_one_node
));
5924 /* If the subtraction above overflowed, we can't verify anything.
5925 Otherwise, look for a parent that tests our value - 1. */
5927 if (! tree_int_cst_lt (low_minus_one
, node
->low
))
5930 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
5931 if (tree_int_cst_equal (low_minus_one
, pnode
->high
))
5937 /* Search the parent sections of the case node tree
5938 to see if a test for the upper bound of NODE would be redundant.
5939 INDEX_TYPE is the type of the index expression.
5941 The instructions to generate the case decision tree are
5942 output in the same order as nodes are processed so it is
5943 known that if a parent node checks the range of the current
5944 node plus one that the current node is bounded at its upper
5945 span. Thus the test would be redundant. */
5948 node_has_high_bound (node
, index_type
)
5953 case_node_ptr pnode
;
5955 /* If there is no upper bound, obviously no test is needed. */
5957 if (TYPE_MAX_VALUE (index_type
) == NULL
)
5960 /* If the upper bound of this node is the highest value in the type
5961 of the index expression, we need not test against it. */
5963 if (tree_int_cst_equal (node
->high
, TYPE_MAX_VALUE (index_type
)))
5966 /* If this node has a right branch, the value at the right must be greater
5967 than that at this node, so it cannot be bounded at the top and
5968 we need not bother testing any further. */
5973 high_plus_one
= fold (build (PLUS_EXPR
, TREE_TYPE (node
->high
),
5974 node
->high
, integer_one_node
));
5976 /* If the addition above overflowed, we can't verify anything.
5977 Otherwise, look for a parent that tests our value + 1. */
5979 if (! tree_int_cst_lt (node
->high
, high_plus_one
))
5982 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
5983 if (tree_int_cst_equal (high_plus_one
, pnode
->low
))
5989 /* Search the parent sections of the
5990 case node tree to see if both tests for the upper and lower
5991 bounds of NODE would be redundant. */
5994 node_is_bounded (node
, index_type
)
5998 return (node_has_low_bound (node
, index_type
)
5999 && node_has_high_bound (node
, index_type
));
6002 /* Emit an unconditional jump to LABEL unless it would be dead code. */
6005 emit_jump_if_reachable (label
)
6008 if (GET_CODE (get_last_insn ()) != BARRIER
)
6012 /* Emit step-by-step code to select a case for the value of INDEX.
6013 The thus generated decision tree follows the form of the
6014 case-node binary tree NODE, whose nodes represent test conditions.
6015 INDEX_TYPE is the type of the index of the switch.
6017 Care is taken to prune redundant tests from the decision tree
6018 by detecting any boundary conditions already checked by
6019 emitted rtx. (See node_has_high_bound, node_has_low_bound
6020 and node_is_bounded, above.)
6022 Where the test conditions can be shown to be redundant we emit
6023 an unconditional jump to the target code. As a further
6024 optimization, the subordinates of a tree node are examined to
6025 check for bounded nodes. In this case conditional and/or
6026 unconditional jumps as a result of the boundary check for the
6027 current node are arranged to target the subordinates associated
6028 code for out of bound conditions on the current node.
6030 We can assume that when control reaches the code generated here,
6031 the index value has already been compared with the parents
6032 of this node, and determined to be on the same side of each parent
6033 as this node is. Thus, if this node tests for the value 51,
6034 and a parent tested for 52, we don't need to consider
6035 the possibility of a value greater than 51. If another parent
6036 tests for the value 50, then this node need not test anything. */
6039 emit_case_nodes (index
, node
, default_label
, index_type
)
6045 /* If INDEX has an unsigned type, we must make unsigned branches. */
6046 int unsignedp
= TREE_UNSIGNED (index_type
);
6047 enum machine_mode mode
= GET_MODE (index
);
6048 enum machine_mode imode
= TYPE_MODE (index_type
);
6050 /* See if our parents have already tested everything for us.
6051 If they have, emit an unconditional jump for this node. */
6052 if (node_is_bounded (node
, index_type
))
6053 emit_jump (label_rtx (node
->code_label
));
6055 else if (tree_int_cst_equal (node
->low
, node
->high
))
6057 /* Node is single valued. First see if the index expression matches
6058 this node and then check our children, if any. */
6060 do_jump_if_equal (index
,
6061 convert_modes (mode
, imode
,
6062 expand_expr (node
->low
, NULL_RTX
,
6065 label_rtx (node
->code_label
), unsignedp
);
6067 if (node
->right
!= 0 && node
->left
!= 0)
6069 /* This node has children on both sides.
6070 Dispatch to one side or the other
6071 by comparing the index value with this node's value.
6072 If one subtree is bounded, check that one first,
6073 so we can avoid real branches in the tree. */
6075 if (node_is_bounded (node
->right
, index_type
))
6077 emit_cmp_and_jump_insns (index
,
6080 expand_expr (node
->high
, NULL_RTX
,
6083 GT
, NULL_RTX
, mode
, unsignedp
, 0,
6084 label_rtx (node
->right
->code_label
));
6085 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6088 else if (node_is_bounded (node
->left
, index_type
))
6090 emit_cmp_and_jump_insns (index
,
6093 expand_expr (node
->high
, NULL_RTX
,
6096 LT
, NULL_RTX
, mode
, unsignedp
, 0,
6097 label_rtx (node
->left
->code_label
));
6098 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6103 /* Neither node is bounded. First distinguish the two sides;
6104 then emit the code for one side at a time. */
6106 tree test_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
6108 /* See if the value is on the right. */
6109 emit_cmp_and_jump_insns (index
,
6112 expand_expr (node
->high
, NULL_RTX
,
6115 GT
, NULL_RTX
, mode
, unsignedp
, 0,
6116 label_rtx (test_label
));
6118 /* Value must be on the left.
6119 Handle the left-hand subtree. */
6120 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6121 /* If left-hand subtree does nothing,
6123 emit_jump_if_reachable (default_label
);
6125 /* Code branches here for the right-hand subtree. */
6126 expand_label (test_label
);
6127 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6131 else if (node
->right
!= 0 && node
->left
== 0)
6133 /* Here we have a right child but no left so we issue conditional
6134 branch to default and process the right child.
6136 Omit the conditional branch to default if we it avoid only one
6137 right child; it costs too much space to save so little time. */
6139 if (node
->right
->right
|| node
->right
->left
6140 || !tree_int_cst_equal (node
->right
->low
, node
->right
->high
))
6142 if (!node_has_low_bound (node
, index_type
))
6144 emit_cmp_and_jump_insns (index
,
6147 expand_expr (node
->high
, NULL_RTX
,
6150 LT
, NULL_RTX
, mode
, unsignedp
, 0,
6154 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6157 /* We cannot process node->right normally
6158 since we haven't ruled out the numbers less than
6159 this node's value. So handle node->right explicitly. */
6160 do_jump_if_equal (index
,
6163 expand_expr (node
->right
->low
, NULL_RTX
,
6166 label_rtx (node
->right
->code_label
), unsignedp
);
6169 else if (node
->right
== 0 && node
->left
!= 0)
6171 /* Just one subtree, on the left. */
6173 #if 0 /* The following code and comment were formerly part
6174 of the condition here, but they didn't work
6175 and I don't understand what the idea was. -- rms. */
6176 /* If our "most probable entry" is less probable
6177 than the default label, emit a jump to
6178 the default label using condition codes
6179 already lying around. With no right branch,
6180 a branch-greater-than will get us to the default
6183 && COST_TABLE (TREE_INT_CST_LOW (node
->high
)) < 12)
6186 if (node
->left
->left
|| node
->left
->right
6187 || !tree_int_cst_equal (node
->left
->low
, node
->left
->high
))
6189 if (!node_has_high_bound (node
, index_type
))
6191 emit_cmp_and_jump_insns (index
,
6194 expand_expr (node
->high
, NULL_RTX
,
6197 GT
, NULL_RTX
, mode
, unsignedp
, 0,
6201 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6204 /* We cannot process node->left normally
6205 since we haven't ruled out the numbers less than
6206 this node's value. So handle node->left explicitly. */
6207 do_jump_if_equal (index
,
6210 expand_expr (node
->left
->low
, NULL_RTX
,
6213 label_rtx (node
->left
->code_label
), unsignedp
);
6218 /* Node is a range. These cases are very similar to those for a single
6219 value, except that we do not start by testing whether this node
6220 is the one to branch to. */
6222 if (node
->right
!= 0 && node
->left
!= 0)
6224 /* Node has subtrees on both sides.
6225 If the right-hand subtree is bounded,
6226 test for it first, since we can go straight there.
6227 Otherwise, we need to make a branch in the control structure,
6228 then handle the two subtrees. */
6229 tree test_label
= 0;
6231 if (node_is_bounded (node
->right
, index_type
))
6232 /* Right hand node is fully bounded so we can eliminate any
6233 testing and branch directly to the target code. */
6234 emit_cmp_and_jump_insns (index
,
6237 expand_expr (node
->high
, NULL_RTX
,
6240 GT
, NULL_RTX
, mode
, unsignedp
, 0,
6241 label_rtx (node
->right
->code_label
));
6244 /* Right hand node requires testing.
6245 Branch to a label where we will handle it later. */
6247 test_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
6248 emit_cmp_and_jump_insns (index
,
6251 expand_expr (node
->high
, NULL_RTX
,
6254 GT
, NULL_RTX
, mode
, unsignedp
, 0,
6255 label_rtx (test_label
));
6258 /* Value belongs to this node or to the left-hand subtree. */
6260 emit_cmp_and_jump_insns (index
,
6263 expand_expr (node
->low
, NULL_RTX
,
6266 GE
, NULL_RTX
, mode
, unsignedp
, 0,
6267 label_rtx (node
->code_label
));
6269 /* Handle the left-hand subtree. */
6270 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6272 /* If right node had to be handled later, do that now. */
6276 /* If the left-hand subtree fell through,
6277 don't let it fall into the right-hand subtree. */
6278 emit_jump_if_reachable (default_label
);
6280 expand_label (test_label
);
6281 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6285 else if (node
->right
!= 0 && node
->left
== 0)
6287 /* Deal with values to the left of this node,
6288 if they are possible. */
6289 if (!node_has_low_bound (node
, index_type
))
6291 emit_cmp_and_jump_insns (index
,
6294 expand_expr (node
->low
, NULL_RTX
,
6297 LT
, NULL_RTX
, mode
, unsignedp
, 0,
6301 /* Value belongs to this node or to the right-hand subtree. */
6303 emit_cmp_and_jump_insns (index
,
6306 expand_expr (node
->high
, NULL_RTX
,
6309 LE
, NULL_RTX
, mode
, unsignedp
, 0,
6310 label_rtx (node
->code_label
));
6312 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6315 else if (node
->right
== 0 && node
->left
!= 0)
6317 /* Deal with values to the right of this node,
6318 if they are possible. */
6319 if (!node_has_high_bound (node
, index_type
))
6321 emit_cmp_and_jump_insns (index
,
6324 expand_expr (node
->high
, NULL_RTX
,
6327 GT
, NULL_RTX
, mode
, unsignedp
, 0,
6331 /* Value belongs to this node or to the left-hand subtree. */
6333 emit_cmp_and_jump_insns (index
,
6336 expand_expr (node
->low
, NULL_RTX
,
6339 GE
, NULL_RTX
, mode
, unsignedp
, 0,
6340 label_rtx (node
->code_label
));
6342 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6347 /* Node has no children so we check low and high bounds to remove
6348 redundant tests. Only one of the bounds can exist,
6349 since otherwise this node is bounded--a case tested already. */
6350 int high_bound
= node_has_high_bound (node
, index_type
);
6351 int low_bound
= node_has_low_bound (node
, index_type
);
6353 if (!high_bound
&& low_bound
)
6355 emit_cmp_and_jump_insns (index
,
6358 expand_expr (node
->high
, NULL_RTX
,
6361 GT
, NULL_RTX
, mode
, unsignedp
, 0,
6365 else if (!low_bound
&& high_bound
)
6367 emit_cmp_and_jump_insns (index
,
6370 expand_expr (node
->low
, NULL_RTX
,
6373 LT
, NULL_RTX
, mode
, unsignedp
, 0,
6376 else if (!low_bound
&& !high_bound
)
6378 /* Widen LOW and HIGH to the same width as INDEX. */
6379 tree type
= type_for_mode (mode
, unsignedp
);
6380 tree low
= build1 (CONVERT_EXPR
, type
, node
->low
);
6381 tree high
= build1 (CONVERT_EXPR
, type
, node
->high
);
6382 rtx new_index
, new_bound
;
6384 /* Instead of doing two branches, emit one unsigned branch for
6385 (index-low) > (high-low). */
6386 new_index
= expand_binop (mode
, sub_optab
, index
,
6387 expand_expr (low
, NULL_RTX
, mode
, 0),
6388 NULL_RTX
, unsignedp
, OPTAB_WIDEN
);
6389 new_bound
= expand_expr (fold (build (MINUS_EXPR
, type
,
6393 emit_cmp_and_jump_insns (new_index
, new_bound
, GT
, NULL_RTX
,
6394 mode
, 1, 0, default_label
);
6397 emit_jump (label_rtx (node
->code_label
));