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 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-flags.h"
46 #include "insn-config.h"
47 #include "insn-codes.h"
49 #include "hard-reg-set.h"
58 #define obstack_chunk_alloc xmalloc
59 #define obstack_chunk_free free
60 struct obstack stmt_obstack
;
62 /* Assume that case vectors are not pc-relative. */
63 #ifndef CASE_VECTOR_PC_RELATIVE
64 #define CASE_VECTOR_PC_RELATIVE 0
67 /* Functions and data structures for expanding case statements. */
69 /* Case label structure, used to hold info on labels within case
70 statements. We handle "range" labels; for a single-value label
71 as in C, the high and low limits are the same.
73 An AVL tree of case nodes is initially created, and later transformed
74 to a list linked via the RIGHT fields in the nodes. Nodes with
75 higher case values are later in the list.
77 Switch statements can be output in one of two forms. A branch table
78 is used if there are more than a few labels and the labels are dense
79 within the range between the smallest and largest case value. If a
80 branch table is used, no further manipulations are done with the case
83 The alternative to the use of a branch table is to generate a series
84 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
85 and PARENT fields to hold a binary tree. Initially the tree is
86 totally unbalanced, with everything on the right. We balance the tree
87 with nodes on the left having lower case values than the parent
88 and nodes on the right having higher values. We then output the tree
93 struct case_node
*left
; /* Left son in binary tree */
94 struct case_node
*right
; /* Right son in binary tree; also node chain */
95 struct case_node
*parent
; /* Parent of node in binary tree */
96 tree low
; /* Lowest index value for this label */
97 tree high
; /* Highest index value for this label */
98 tree code_label
; /* Label to jump to when node matches */
102 typedef struct case_node case_node
;
103 typedef struct case_node
*case_node_ptr
;
105 /* These are used by estimate_case_costs and balance_case_nodes. */
107 /* This must be a signed type, and non-ANSI compilers lack signed char. */
108 static short cost_table_
[129];
109 static short *cost_table
;
110 static int use_cost_table
;
112 /* Stack of control and binding constructs we are currently inside.
114 These constructs begin when you call `expand_start_WHATEVER'
115 and end when you call `expand_end_WHATEVER'. This stack records
116 info about how the construct began that tells the end-function
117 what to do. It also may provide information about the construct
118 to alter the behavior of other constructs within the body.
119 For example, they may affect the behavior of C `break' and `continue'.
121 Each construct gets one `struct nesting' object.
122 All of these objects are chained through the `all' field.
123 `nesting_stack' points to the first object (innermost construct).
124 The position of an entry on `nesting_stack' is in its `depth' field.
126 Each type of construct has its own individual stack.
127 For example, loops have `loop_stack'. Each object points to the
128 next object of the same type through the `next' field.
130 Some constructs are visible to `break' exit-statements and others
131 are not. Which constructs are visible depends on the language.
132 Therefore, the data structure allows each construct to be visible
133 or not, according to the args given when the construct is started.
134 The construct is visible if the `exit_label' field is non-null.
135 In that case, the value should be a CODE_LABEL rtx. */
140 struct nesting
*next
;
145 /* For conds (if-then and if-then-else statements). */
148 /* Label for the end of the if construct.
149 There is none if EXITFLAG was not set
150 and no `else' has been seen yet. */
152 /* Label for the end of this alternative.
153 This may be the end of the if or the next else/elseif. */
159 /* Label at the top of the loop; place to loop back to. */
161 /* Label at the end of the whole construct. */
163 /* Label before a jump that branches to the end of the whole
164 construct. This is where destructors go if any. */
166 /* Label for `continue' statement to jump to;
167 this is in front of the stepper of the loop. */
170 /* For variable binding contours. */
173 /* Sequence number of this binding contour within the function,
174 in order of entry. */
175 int block_start_count
;
176 /* Nonzero => value to restore stack to on exit. */
178 /* The NOTE that starts this contour.
179 Used by expand_goto to check whether the destination
180 is within each contour or not. */
182 /* Innermost containing binding contour that has a stack level. */
183 struct nesting
*innermost_stack_block
;
184 /* List of cleanups to be run on exit from this contour.
185 This is a list of expressions to be evaluated.
186 The TREE_PURPOSE of each link is the ..._DECL node
187 which the cleanup pertains to. */
189 /* List of cleanup-lists of blocks containing this block,
190 as they were at the locus where this block appears.
191 There is an element for each containing block,
192 ordered innermost containing block first.
193 The tail of this list can be 0,
194 if all remaining elements would be empty lists.
195 The element's TREE_VALUE is the cleanup-list of that block,
196 which may be null. */
198 /* Chain of labels defined inside this binding contour.
199 For contours that have stack levels or cleanups. */
200 struct label_chain
*label_chain
;
201 /* Number of function calls seen, as of start of this block. */
202 int n_function_calls
;
203 /* Nonzero if this is associated with a EH region. */
204 int exception_region
;
205 /* The saved target_temp_slot_level from our outer block.
206 We may reset target_temp_slot_level to be the level of
207 this block, if that is done, target_temp_slot_level
208 reverts to the saved target_temp_slot_level at the very
210 int block_target_temp_slot_level
;
211 /* True if we are currently emitting insns in an area of
212 output code that is controlled by a conditional
213 expression. This is used by the cleanup handling code to
214 generate conditional cleanup actions. */
215 int conditional_code
;
216 /* A place to move the start of the exception region for any
217 of the conditional cleanups, must be at the end or after
218 the start of the last unconditional cleanup, and before any
219 conditional branch points. */
220 rtx last_unconditional_cleanup
;
221 /* When in a conditional context, this is the specific
222 cleanup list associated with last_unconditional_cleanup,
223 where we place the conditionalized cleanups. */
226 /* For switch (C) or case (Pascal) statements,
227 and also for dummies (see `expand_start_case_dummy'). */
230 /* The insn after which the case dispatch should finally
231 be emitted. Zero for a dummy. */
233 /* A list of case labels; it is first built as an AVL tree.
234 During expand_end_case, this is converted to a list, and may be
235 rearranged into a nearly balanced binary tree. */
236 struct case_node
*case_list
;
237 /* Label to jump to if no case matches. */
239 /* The expression to be dispatched on. */
241 /* Type that INDEX_EXPR should be converted to. */
243 /* Number of range exprs in case statement. */
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 /* Character strings, each containing a single decimal digit. */
399 static char *digit_strings
[10];
401 static int n_occurrences
PARAMS ((int, const char *));
402 static void expand_goto_internal
PARAMS ((tree
, rtx
, rtx
));
403 static int expand_fixup
PARAMS ((tree
, rtx
, rtx
));
404 static rtx expand_nl_handler_label
PARAMS ((rtx
, rtx
));
405 static void expand_nl_goto_receiver
PARAMS ((void));
406 static void expand_nl_goto_receivers
PARAMS ((struct nesting
*));
407 static void fixup_gotos
PARAMS ((struct nesting
*, rtx
, tree
,
409 static void expand_null_return_1
PARAMS ((rtx
, int));
410 static void expand_value_return
PARAMS ((rtx
));
411 static int tail_recursion_args
PARAMS ((tree
, tree
));
412 static void expand_cleanups
PARAMS ((tree
, tree
, int, int));
413 static void check_seenlabel
PARAMS ((void));
414 static void do_jump_if_equal
PARAMS ((rtx
, rtx
, rtx
, int));
415 static int estimate_case_costs
PARAMS ((case_node_ptr
));
416 static void group_case_nodes
PARAMS ((case_node_ptr
));
417 static void balance_case_nodes
PARAMS ((case_node_ptr
*,
419 static int node_has_low_bound
PARAMS ((case_node_ptr
, tree
));
420 static int node_has_high_bound
PARAMS ((case_node_ptr
, tree
));
421 static int node_is_bounded
PARAMS ((case_node_ptr
, tree
));
422 static void emit_jump_if_reachable
PARAMS ((rtx
));
423 static void emit_case_nodes
PARAMS ((rtx
, case_node_ptr
, rtx
, tree
));
424 static int add_case_node
PARAMS ((tree
, tree
, tree
, tree
*));
425 static struct case_node
*case_tree2list
PARAMS ((case_node
*, case_node
*));
426 static void mark_cond_nesting
PARAMS ((struct nesting
*));
427 static void mark_loop_nesting
PARAMS ((struct nesting
*));
428 static void mark_block_nesting
PARAMS ((struct nesting
*));
429 static void mark_case_nesting
PARAMS ((struct nesting
*));
430 static void mark_case_node
PARAMS ((struct case_node
*));
431 static void mark_goto_fixup
PARAMS ((struct goto_fixup
*));
435 using_eh_for_cleanups ()
437 using_eh_for_cleanups_p
= 1;
440 /* Mark N (known to be a cond-nesting) for GC. */
443 mark_cond_nesting (n
)
448 ggc_mark_rtx (n
->exit_label
);
449 ggc_mark_rtx (n
->data
.cond
.endif_label
);
450 ggc_mark_rtx (n
->data
.cond
.next_label
);
456 /* Mark N (known to be a loop-nesting) for GC. */
459 mark_loop_nesting (n
)
465 ggc_mark_rtx (n
->exit_label
);
466 ggc_mark_rtx (n
->data
.loop
.start_label
);
467 ggc_mark_rtx (n
->data
.loop
.end_label
);
468 ggc_mark_rtx (n
->data
.loop
.alt_end_label
);
469 ggc_mark_rtx (n
->data
.loop
.continue_label
);
475 /* Mark N (known to be a block-nesting) for GC. */
478 mark_block_nesting (n
)
483 struct label_chain
*l
;
485 ggc_mark_rtx (n
->exit_label
);
486 ggc_mark_rtx (n
->data
.block
.stack_level
);
487 ggc_mark_rtx (n
->data
.block
.first_insn
);
488 ggc_mark_tree (n
->data
.block
.cleanups
);
489 ggc_mark_tree (n
->data
.block
.outer_cleanups
);
491 for (l
= n
->data
.block
.label_chain
; l
!= NULL
; l
= l
->next
)
492 ggc_mark_tree (l
->label
);
494 ggc_mark_rtx (n
->data
.block
.last_unconditional_cleanup
);
496 /* ??? cleanup_ptr never points outside the stack, does it? */
502 /* Mark N (known to be a case-nesting) for GC. */
505 mark_case_nesting (n
)
510 ggc_mark_rtx (n
->exit_label
);
511 ggc_mark_rtx (n
->data
.case_stmt
.start
);
513 ggc_mark_tree (n
->data
.case_stmt
.default_label
);
514 ggc_mark_tree (n
->data
.case_stmt
.index_expr
);
515 ggc_mark_tree (n
->data
.case_stmt
.nominal_type
);
517 mark_case_node (n
->data
.case_stmt
.case_list
);
530 ggc_mark_tree (c
->low
);
531 ggc_mark_tree (c
->high
);
532 ggc_mark_tree (c
->code_label
);
534 mark_case_node (c
->right
);
535 mark_case_node (c
->left
);
543 struct goto_fixup
*g
;
548 ggc_mark_rtx (g
->before_jump
);
549 ggc_mark_tree (g
->target
);
550 ggc_mark_tree (g
->context
);
551 ggc_mark_rtx (g
->target_rtl
);
552 ggc_mark_rtx (g
->stack_level
);
553 ggc_mark_tree (g
->cleanup_list_list
);
559 /* Clear out all parts of the state in F that can safely be discarded
560 after the function has been compiled, to let garbage collection
561 reclaim the memory. */
567 /* We're about to free the function obstack. If we hold pointers to
568 things allocated there, then we'll try to mark them when we do
569 GC. So, we clear them out here explicitly. */
579 struct stmt_status
*p
;
584 mark_block_nesting (p
->x_block_stack
);
585 mark_cond_nesting (p
->x_cond_stack
);
586 mark_loop_nesting (p
->x_loop_stack
);
587 mark_case_nesting (p
->x_case_stack
);
589 ggc_mark_tree (p
->x_last_expr_type
);
590 /* last_epxr_value is only valid if last_expr_type is nonzero. */
591 if (p
->x_last_expr_type
)
592 ggc_mark_rtx (p
->x_last_expr_value
);
594 mark_goto_fixup (p
->x_goto_fixup_chain
);
602 gcc_obstack_init (&stmt_obstack
);
604 for (i
= 0; i
< 10; i
++)
606 digit_strings
[i
] = ggc_alloc_string (NULL
, 1);
607 digit_strings
[i
][0] = '0' + i
;
609 ggc_add_string_root (digit_strings
, 10);
613 init_stmt_for_function ()
615 cfun
->stmt
= (struct stmt_status
*) xmalloc (sizeof (struct stmt_status
));
617 /* We are not currently within any block, conditional, loop or case. */
619 stack_block_stack
= 0;
626 current_block_start_count
= 0;
628 /* No gotos have been expanded yet. */
629 goto_fixup_chain
= 0;
631 /* We are not processing a ({...}) grouping. */
632 expr_stmts_for_value
= 0;
634 last_expr_value
= NULL_RTX
;
637 /* Return nonzero if anything is pushed on the loop, condition, or case
642 return cond_stack
|| loop_stack
|| case_stack
;
645 /* Record the current file and line. Called from emit_line_note. */
647 set_file_and_line_for_stmt (file
, line
)
651 /* If we're outputting an inline function, and we add a line note,
652 there may be no CFUN->STMT information. So, there's no need to
656 emit_filename
= file
;
661 /* Emit a no-op instruction. */
668 last_insn
= get_last_insn ();
670 && (GET_CODE (last_insn
) == CODE_LABEL
671 || (GET_CODE (last_insn
) == NOTE
672 && prev_real_insn (last_insn
) == 0)))
673 emit_insn (gen_nop ());
676 /* Return the rtx-label that corresponds to a LABEL_DECL,
677 creating it if necessary. */
683 if (TREE_CODE (label
) != LABEL_DECL
)
686 if (DECL_RTL (label
))
687 return DECL_RTL (label
);
689 return DECL_RTL (label
) = gen_label_rtx ();
692 /* Add an unconditional jump to LABEL as the next sequential instruction. */
698 do_pending_stack_adjust ();
699 emit_jump_insn (gen_jump (label
));
703 /* Emit code to jump to the address
704 specified by the pointer expression EXP. */
707 expand_computed_goto (exp
)
710 rtx x
= expand_expr (exp
, NULL_RTX
, VOIDmode
, 0);
712 #ifdef POINTERS_EXTEND_UNSIGNED
713 x
= convert_memory_address (Pmode
, x
);
717 /* Be sure the function is executable. */
718 if (current_function_check_memory_usage
)
719 emit_library_call (chkr_check_exec_libfunc
, 1,
720 VOIDmode
, 1, x
, ptr_mode
);
722 do_pending_stack_adjust ();
723 emit_indirect_jump (x
);
725 current_function_has_computed_jump
= 1;
728 /* Handle goto statements and the labels that they can go to. */
730 /* Specify the location in the RTL code of a label LABEL,
731 which is a LABEL_DECL tree node.
733 This is used for the kind of label that the user can jump to with a
734 goto statement, and for alternatives of a switch or case statement.
735 RTL labels generated for loops and conditionals don't go through here;
736 they are generated directly at the RTL level, by other functions below.
738 Note that this has nothing to do with defining label *names*.
739 Languages vary in how they do that and what that even means. */
745 struct label_chain
*p
;
747 do_pending_stack_adjust ();
748 emit_label (label_rtx (label
));
749 if (DECL_NAME (label
))
750 LABEL_NAME (DECL_RTL (label
)) = IDENTIFIER_POINTER (DECL_NAME (label
));
752 if (stack_block_stack
!= 0)
754 p
= (struct label_chain
*) oballoc (sizeof (struct label_chain
));
755 p
->next
= stack_block_stack
->data
.block
.label_chain
;
756 stack_block_stack
->data
.block
.label_chain
= p
;
761 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
762 from nested functions. */
765 declare_nonlocal_label (label
)
768 rtx slot
= assign_stack_local (Pmode
, GET_MODE_SIZE (Pmode
), 0);
770 nonlocal_labels
= tree_cons (NULL_TREE
, label
, nonlocal_labels
);
771 LABEL_PRESERVE_P (label_rtx (label
)) = 1;
772 if (nonlocal_goto_handler_slots
== 0)
774 emit_stack_save (SAVE_NONLOCAL
,
775 &nonlocal_goto_stack_level
,
776 PREV_INSN (tail_recursion_reentry
));
778 nonlocal_goto_handler_slots
779 = gen_rtx_EXPR_LIST (VOIDmode
, slot
, nonlocal_goto_handler_slots
);
782 /* Generate RTL code for a `goto' statement with target label LABEL.
783 LABEL should be a LABEL_DECL tree node that was or will later be
784 defined with `expand_label'. */
792 /* Check for a nonlocal goto to a containing function. */
793 context
= decl_function_context (label
);
794 if (context
!= 0 && context
!= current_function_decl
)
796 struct function
*p
= find_function_data (context
);
797 rtx label_ref
= gen_rtx_LABEL_REF (Pmode
, label_rtx (label
));
798 rtx handler_slot
, static_chain
, save_area
;
801 /* Find the corresponding handler slot for this label. */
802 handler_slot
= p
->x_nonlocal_goto_handler_slots
;
803 for (link
= p
->x_nonlocal_labels
; TREE_VALUE (link
) != label
;
804 link
= TREE_CHAIN (link
))
805 handler_slot
= XEXP (handler_slot
, 1);
806 handler_slot
= XEXP (handler_slot
, 0);
808 p
->has_nonlocal_label
= 1;
809 current_function_has_nonlocal_goto
= 1;
810 LABEL_REF_NONLOCAL_P (label_ref
) = 1;
812 /* Copy the rtl for the slots so that they won't be shared in
813 case the virtual stack vars register gets instantiated differently
814 in the parent than in the child. */
816 static_chain
= copy_to_reg (lookup_static_chain (label
));
818 /* Get addr of containing function's current nonlocal goto handler,
819 which will do any cleanups and then jump to the label. */
820 handler_slot
= copy_to_reg (replace_rtx (copy_rtx (handler_slot
),
821 virtual_stack_vars_rtx
,
824 /* Get addr of containing function's nonlocal save area. */
825 save_area
= p
->x_nonlocal_goto_stack_level
;
827 save_area
= replace_rtx (copy_rtx (save_area
),
828 virtual_stack_vars_rtx
, static_chain
);
830 #if HAVE_nonlocal_goto
831 if (HAVE_nonlocal_goto
)
832 emit_insn (gen_nonlocal_goto (static_chain
, handler_slot
,
833 save_area
, label_ref
));
837 /* Restore frame pointer for containing function.
838 This sets the actual hard register used for the frame pointer
839 to the location of the function's incoming static chain info.
840 The non-local goto handler will then adjust it to contain the
841 proper value and reload the argument pointer, if needed. */
842 emit_move_insn (hard_frame_pointer_rtx
, static_chain
);
843 emit_stack_restore (SAVE_NONLOCAL
, save_area
, NULL_RTX
);
845 /* USE of hard_frame_pointer_rtx added for consistency;
846 not clear if really needed. */
847 emit_insn (gen_rtx_USE (VOIDmode
, hard_frame_pointer_rtx
));
848 emit_insn (gen_rtx_USE (VOIDmode
, stack_pointer_rtx
));
849 emit_indirect_jump (handler_slot
);
853 expand_goto_internal (label
, label_rtx (label
), NULL_RTX
);
856 /* Generate RTL code for a `goto' statement with target label BODY.
857 LABEL should be a LABEL_REF.
858 LAST_INSN, if non-0, is the rtx we should consider as the last
859 insn emitted (for the purposes of cleaning up a return). */
862 expand_goto_internal (body
, label
, last_insn
)
867 struct nesting
*block
;
870 if (GET_CODE (label
) != CODE_LABEL
)
873 /* If label has already been defined, we can tell now
874 whether and how we must alter the stack level. */
876 if (PREV_INSN (label
) != 0)
878 /* Find the innermost pending block that contains the label.
879 (Check containment by comparing insn-uids.)
880 Then restore the outermost stack level within that block,
881 and do cleanups of all blocks contained in it. */
882 for (block
= block_stack
; block
; block
= block
->next
)
884 if (INSN_UID (block
->data
.block
.first_insn
) < INSN_UID (label
))
886 if (block
->data
.block
.stack_level
!= 0)
887 stack_level
= block
->data
.block
.stack_level
;
888 /* Execute the cleanups for blocks we are exiting. */
889 if (block
->data
.block
.cleanups
!= 0)
891 expand_cleanups (block
->data
.block
.cleanups
, NULL_TREE
, 1, 1);
892 do_pending_stack_adjust ();
898 /* Ensure stack adjust isn't done by emit_jump, as this
899 would clobber the stack pointer. This one should be
900 deleted as dead by flow. */
901 clear_pending_stack_adjust ();
902 do_pending_stack_adjust ();
904 /* Don't do this adjust if it's to the end label and this function
905 is to return with a depressed stack pointer. */
906 if (label
== return_label
907 && (((TREE_CODE (TREE_TYPE (current_function_decl
))
909 && (TYPE_RETURNS_STACK_DEPRESSED
910 (TREE_TYPE (current_function_decl
))))))
913 emit_stack_restore (SAVE_BLOCK
, stack_level
, NULL_RTX
);
916 if (body
!= 0 && DECL_TOO_LATE (body
))
917 error ("jump to `%s' invalidly jumps into binding contour",
918 IDENTIFIER_POINTER (DECL_NAME (body
)));
920 /* Label not yet defined: may need to put this goto
921 on the fixup list. */
922 else if (! expand_fixup (body
, label
, last_insn
))
924 /* No fixup needed. Record that the label is the target
925 of at least one goto that has no fixup. */
927 TREE_ADDRESSABLE (body
) = 1;
933 /* Generate if necessary a fixup for a goto
934 whose target label in tree structure (if any) is TREE_LABEL
935 and whose target in rtl is RTL_LABEL.
937 If LAST_INSN is nonzero, we pretend that the jump appears
938 after insn LAST_INSN instead of at the current point in the insn stream.
940 The fixup will be used later to insert insns just before the goto.
941 Those insns will restore the stack level as appropriate for the
942 target label, and will (in the case of C++) also invoke any object
943 destructors which have to be invoked when we exit the scopes which
944 are exited by the goto.
946 Value is nonzero if a fixup is made. */
949 expand_fixup (tree_label
, rtl_label
, last_insn
)
954 struct nesting
*block
, *end_block
;
956 /* See if we can recognize which block the label will be output in.
957 This is possible in some very common cases.
958 If we succeed, set END_BLOCK to that block.
959 Otherwise, set it to 0. */
962 && (rtl_label
== cond_stack
->data
.cond
.endif_label
963 || rtl_label
== cond_stack
->data
.cond
.next_label
))
964 end_block
= cond_stack
;
965 /* If we are in a loop, recognize certain labels which
966 are likely targets. This reduces the number of fixups
967 we need to create. */
969 && (rtl_label
== loop_stack
->data
.loop
.start_label
970 || rtl_label
== loop_stack
->data
.loop
.end_label
971 || rtl_label
== loop_stack
->data
.loop
.continue_label
))
972 end_block
= loop_stack
;
976 /* Now set END_BLOCK to the binding level to which we will return. */
980 struct nesting
*next_block
= end_block
->all
;
983 /* First see if the END_BLOCK is inside the innermost binding level.
984 If so, then no cleanups or stack levels are relevant. */
985 while (next_block
&& next_block
!= block
)
986 next_block
= next_block
->all
;
991 /* Otherwise, set END_BLOCK to the innermost binding level
992 which is outside the relevant control-structure nesting. */
993 next_block
= block_stack
->next
;
994 for (block
= block_stack
; block
!= end_block
; block
= block
->all
)
995 if (block
== next_block
)
996 next_block
= next_block
->next
;
997 end_block
= next_block
;
1000 /* Does any containing block have a stack level or cleanups?
1001 If not, no fixup is needed, and that is the normal case
1002 (the only case, for standard C). */
1003 for (block
= block_stack
; block
!= end_block
; block
= block
->next
)
1004 if (block
->data
.block
.stack_level
!= 0
1005 || block
->data
.block
.cleanups
!= 0)
1008 if (block
!= end_block
)
1010 /* Ok, a fixup is needed. Add a fixup to the list of such. */
1011 struct goto_fixup
*fixup
1012 = (struct goto_fixup
*) ggc_alloc (sizeof (struct goto_fixup
));
1013 /* In case an old stack level is restored, make sure that comes
1014 after any pending stack adjust. */
1015 /* ?? If the fixup isn't to come at the present position,
1016 doing the stack adjust here isn't useful. Doing it with our
1017 settings at that location isn't useful either. Let's hope
1020 do_pending_stack_adjust ();
1021 fixup
->target
= tree_label
;
1022 fixup
->target_rtl
= rtl_label
;
1024 /* Create a BLOCK node and a corresponding matched set of
1025 NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes at
1026 this point. The notes will encapsulate any and all fixup
1027 code which we might later insert at this point in the insn
1028 stream. Also, the BLOCK node will be the parent (i.e. the
1029 `SUPERBLOCK') of any other BLOCK nodes which we might create
1030 later on when we are expanding the fixup code.
1032 Note that optimization passes (including expand_end_loop)
1033 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
1034 as a placeholder. */
1037 register rtx original_before_jump
1038 = last_insn
? last_insn
: get_last_insn ();
1043 block
= make_node (BLOCK
);
1044 TREE_USED (block
) = 1;
1046 if (!cfun
->x_whole_function_mode_p
)
1047 insert_block (block
);
1051 = BLOCK_CHAIN (DECL_INITIAL (current_function_decl
));
1052 BLOCK_CHAIN (DECL_INITIAL (current_function_decl
))
1057 start
= emit_note (NULL_PTR
, NOTE_INSN_BLOCK_BEG
);
1058 if (cfun
->x_whole_function_mode_p
)
1059 NOTE_BLOCK (start
) = block
;
1060 fixup
->before_jump
= emit_note (NULL_PTR
, NOTE_INSN_DELETED
);
1061 end
= emit_note (NULL_PTR
, NOTE_INSN_BLOCK_END
);
1062 if (cfun
->x_whole_function_mode_p
)
1063 NOTE_BLOCK (end
) = block
;
1064 fixup
->context
= block
;
1066 emit_insns_after (start
, original_before_jump
);
1069 fixup
->block_start_count
= current_block_start_count
;
1070 fixup
->stack_level
= 0;
1071 fixup
->cleanup_list_list
1072 = ((block
->data
.block
.outer_cleanups
1073 || block
->data
.block
.cleanups
)
1074 ? tree_cons (NULL_TREE
, block
->data
.block
.cleanups
,
1075 block
->data
.block
.outer_cleanups
)
1077 fixup
->next
= goto_fixup_chain
;
1078 goto_fixup_chain
= fixup
;
1084 /* Expand any needed fixups in the outputmost binding level of the
1085 function. FIRST_INSN is the first insn in the function. */
1088 expand_fixups (first_insn
)
1091 fixup_gotos (NULL_PTR
, NULL_RTX
, NULL_TREE
, first_insn
, 0);
1094 /* When exiting a binding contour, process all pending gotos requiring fixups.
1095 THISBLOCK is the structure that describes the block being exited.
1096 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1097 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1098 FIRST_INSN is the insn that began this contour.
1100 Gotos that jump out of this contour must restore the
1101 stack level and do the cleanups before actually jumping.
1103 DONT_JUMP_IN nonzero means report error there is a jump into this
1104 contour from before the beginning of the contour.
1105 This is also done if STACK_LEVEL is nonzero. */
1108 fixup_gotos (thisblock
, stack_level
, cleanup_list
, first_insn
, dont_jump_in
)
1109 struct nesting
*thisblock
;
1115 register struct goto_fixup
*f
, *prev
;
1117 /* F is the fixup we are considering; PREV is the previous one. */
1118 /* We run this loop in two passes so that cleanups of exited blocks
1119 are run first, and blocks that are exited are marked so
1122 for (prev
= 0, f
= goto_fixup_chain
; f
; prev
= f
, f
= f
->next
)
1124 /* Test for a fixup that is inactive because it is already handled. */
1125 if (f
->before_jump
== 0)
1127 /* Delete inactive fixup from the chain, if that is easy to do. */
1129 prev
->next
= f
->next
;
1131 /* Has this fixup's target label been defined?
1132 If so, we can finalize it. */
1133 else if (PREV_INSN (f
->target_rtl
) != 0)
1135 register rtx cleanup_insns
;
1137 /* If this fixup jumped into this contour from before the beginning
1138 of this contour, report an error. This code used to use
1139 the first non-label insn after f->target_rtl, but that's
1140 wrong since such can be added, by things like put_var_into_stack
1141 and have INSN_UIDs that are out of the range of the block. */
1142 /* ??? Bug: this does not detect jumping in through intermediate
1143 blocks that have stack levels or cleanups.
1144 It detects only a problem with the innermost block
1145 around the label. */
1147 && (dont_jump_in
|| stack_level
|| cleanup_list
)
1148 && INSN_UID (first_insn
) < INSN_UID (f
->target_rtl
)
1149 && INSN_UID (first_insn
) > INSN_UID (f
->before_jump
)
1150 && ! DECL_ERROR_ISSUED (f
->target
))
1152 error_with_decl (f
->target
,
1153 "label `%s' used before containing binding contour");
1154 /* Prevent multiple errors for one label. */
1155 DECL_ERROR_ISSUED (f
->target
) = 1;
1158 /* We will expand the cleanups into a sequence of their own and
1159 then later on we will attach this new sequence to the insn
1160 stream just ahead of the actual jump insn. */
1164 /* Temporarily restore the lexical context where we will
1165 logically be inserting the fixup code. We do this for the
1166 sake of getting the debugging information right. */
1169 set_block (f
->context
);
1171 /* Expand the cleanups for blocks this jump exits. */
1172 if (f
->cleanup_list_list
)
1175 for (lists
= f
->cleanup_list_list
; lists
; lists
= TREE_CHAIN (lists
))
1176 /* Marked elements correspond to blocks that have been closed.
1177 Do their cleanups. */
1178 if (TREE_ADDRESSABLE (lists
)
1179 && TREE_VALUE (lists
) != 0)
1181 expand_cleanups (TREE_VALUE (lists
), NULL_TREE
, 1, 1);
1182 /* Pop any pushes done in the cleanups,
1183 in case function is about to return. */
1184 do_pending_stack_adjust ();
1188 /* Restore stack level for the biggest contour that this
1189 jump jumps out of. */
1191 && ! (f
->target_rtl
== return_label
1192 && ((TREE_CODE (TREE_TYPE (current_function_decl
))
1194 && (TYPE_RETURNS_STACK_DEPRESSED
1195 (TREE_TYPE (current_function_decl
))))))
1196 emit_stack_restore (SAVE_BLOCK
, f
->stack_level
, f
->before_jump
);
1198 /* Finish up the sequence containing the insns which implement the
1199 necessary cleanups, and then attach that whole sequence to the
1200 insn stream just ahead of the actual jump insn. Attaching it
1201 at that point insures that any cleanups which are in fact
1202 implicit C++ object destructions (which must be executed upon
1203 leaving the block) appear (to the debugger) to be taking place
1204 in an area of the generated code where the object(s) being
1205 destructed are still "in scope". */
1207 cleanup_insns
= get_insns ();
1211 emit_insns_after (cleanup_insns
, f
->before_jump
);
1217 /* For any still-undefined labels, do the cleanups for this block now.
1218 We must do this now since items in the cleanup list may go out
1219 of scope when the block ends. */
1220 for (prev
= 0, f
= goto_fixup_chain
; f
; prev
= f
, f
= f
->next
)
1221 if (f
->before_jump
!= 0
1222 && PREV_INSN (f
->target_rtl
) == 0
1223 /* Label has still not appeared. If we are exiting a block with
1224 a stack level to restore, that started before the fixup,
1225 mark this stack level as needing restoration
1226 when the fixup is later finalized. */
1228 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1229 means the label is undefined. That's erroneous, but possible. */
1230 && (thisblock
->data
.block
.block_start_count
1231 <= f
->block_start_count
))
1233 tree lists
= f
->cleanup_list_list
;
1236 for (; lists
; lists
= TREE_CHAIN (lists
))
1237 /* If the following elt. corresponds to our containing block
1238 then the elt. must be for this block. */
1239 if (TREE_CHAIN (lists
) == thisblock
->data
.block
.outer_cleanups
)
1243 set_block (f
->context
);
1244 expand_cleanups (TREE_VALUE (lists
), NULL_TREE
, 1, 1);
1245 do_pending_stack_adjust ();
1246 cleanup_insns
= get_insns ();
1249 if (cleanup_insns
!= 0)
1251 = emit_insns_after (cleanup_insns
, f
->before_jump
);
1253 f
->cleanup_list_list
= TREE_CHAIN (lists
);
1257 f
->stack_level
= stack_level
;
1261 /* Return the number of times character C occurs in string S. */
1263 n_occurrences (c
, s
)
1273 /* Generate RTL for an asm statement (explicit assembler code).
1274 BODY is a STRING_CST node containing the assembler code text,
1275 or an ADDR_EXPR containing a STRING_CST. */
1281 if (current_function_check_memory_usage
)
1283 error ("`asm' cannot be used in function where memory usage is checked");
1287 if (TREE_CODE (body
) == ADDR_EXPR
)
1288 body
= TREE_OPERAND (body
, 0);
1290 emit_insn (gen_rtx_ASM_INPUT (VOIDmode
,
1291 TREE_STRING_POINTER (body
)));
1295 /* Generate RTL for an asm statement with arguments.
1296 STRING is the instruction template.
1297 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1298 Each output or input has an expression in the TREE_VALUE and
1299 a constraint-string in the TREE_PURPOSE.
1300 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1301 that is clobbered by this insn.
1303 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1304 Some elements of OUTPUTS may be replaced with trees representing temporary
1305 values. The caller should copy those temporary values to the originally
1308 VOL nonzero means the insn is volatile; don't optimize it. */
1311 expand_asm_operands (string
, outputs
, inputs
, clobbers
, vol
, filename
, line
)
1312 tree string
, outputs
, inputs
, clobbers
;
1314 const char *filename
;
1317 rtvec argvec
, constraints
;
1319 int ninputs
= list_length (inputs
);
1320 int noutputs
= list_length (outputs
);
1325 /* Vector of RTX's of evaluated output operands. */
1326 rtx
*output_rtx
= (rtx
*) alloca (noutputs
* sizeof (rtx
));
1327 int *inout_opnum
= (int *) alloca (noutputs
* sizeof (int));
1328 rtx
*real_output_rtx
= (rtx
*) alloca (noutputs
* sizeof (rtx
));
1329 enum machine_mode
*inout_mode
1330 = (enum machine_mode
*) alloca (noutputs
* sizeof (enum machine_mode
));
1331 /* The insn we have emitted. */
1333 int old_generating_concat_p
= generating_concat_p
;
1335 /* An ASM with no outputs needs to be treated as volatile, for now. */
1339 if (current_function_check_memory_usage
)
1341 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1345 #ifdef MD_ASM_CLOBBERS
1346 /* Sometimes we wish to automatically clobber registers across an asm.
1347 Case in point is when the i386 backend moved from cc0 to a hard reg --
1348 maintaining source-level compatability means automatically clobbering
1349 the flags register. */
1350 MD_ASM_CLOBBERS (clobbers
);
1353 if (current_function_check_memory_usage
)
1355 error ("`asm' cannot be used in function where memory usage is checked");
1359 /* Count the number of meaningful clobbered registers, ignoring what
1360 we would ignore later. */
1362 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
))
1364 const char *regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
1366 i
= decode_reg_name (regname
);
1367 if (i
>= 0 || i
== -4)
1370 error ("unknown register name `%s' in `asm'", regname
);
1375 /* Check that the number of alternatives is constant across all
1377 if (outputs
|| inputs
)
1379 tree tmp
= TREE_PURPOSE (outputs
? outputs
: inputs
);
1380 int nalternatives
= n_occurrences (',', TREE_STRING_POINTER (tmp
));
1383 if (nalternatives
+ 1 > MAX_RECOG_ALTERNATIVES
)
1385 error ("too many alternatives in `asm'");
1392 const char *constraint
= TREE_STRING_POINTER (TREE_PURPOSE (tmp
));
1394 if (n_occurrences (',', constraint
) != nalternatives
)
1396 error ("operand constraints for `asm' differ in number of alternatives");
1400 if (TREE_CHAIN (tmp
))
1401 tmp
= TREE_CHAIN (tmp
);
1403 tmp
= next
, next
= 0;
1407 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1409 tree val
= TREE_VALUE (tail
);
1410 tree type
= TREE_TYPE (val
);
1419 /* If there's an erroneous arg, emit no insn. */
1420 if (TREE_TYPE (val
) == error_mark_node
)
1423 /* Make sure constraint has `=' and does not have `+'. Also, see
1424 if it allows any register. Be liberal on the latter test, since
1425 the worst that happens if we get it wrong is we issue an error
1428 c_len
= strlen (TREE_STRING_POINTER (TREE_PURPOSE (tail
)));
1429 constraint
= TREE_STRING_POINTER (TREE_PURPOSE (tail
));
1431 /* Allow the `=' or `+' to not be at the beginning of the string,
1432 since it wasn't explicitly documented that way, and there is a
1433 large body of code that puts it last. Swap the character to
1434 the front, so as not to uglify any place else. */
1438 if ((p
= strchr (constraint
, '=')) != NULL
)
1440 if ((p
= strchr (constraint
, '+')) != NULL
)
1443 error ("output operand constraint lacks `='");
1447 if (p
!= constraint
)
1450 bcopy (constraint
, constraint
+1, p
-constraint
);
1453 warning ("output constraint `%c' for operand %d is not at the beginning", j
, i
);
1456 is_inout
= constraint
[0] == '+';
1457 /* Replace '+' with '='. */
1458 constraint
[0] = '=';
1459 /* Make sure we can specify the matching operand. */
1460 if (is_inout
&& i
> 9)
1462 error ("output operand constraint %d contains `+'", i
);
1466 for (j
= 1; j
< c_len
; j
++)
1467 switch (constraint
[j
])
1471 error ("operand constraint contains '+' or '=' at illegal position.");
1475 if (i
+ 1 == ninputs
+ noutputs
)
1477 error ("`%%' constraint used with last operand");
1482 case '?': case '!': case '*': case '&':
1483 case 'E': case 'F': case 'G': case 'H':
1484 case 's': case 'i': case 'n':
1485 case 'I': case 'J': case 'K': case 'L': case 'M':
1486 case 'N': case 'O': case 'P': case ',':
1489 case '0': case '1': case '2': case '3': case '4':
1490 case '5': case '6': case '7': case '8': case '9':
1491 error ("matching constraint not valid in output operand");
1494 case 'V': case 'm': case 'o':
1499 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1500 excepting those that expand_call created. So match memory
1515 if (! ISALPHA (constraint
[j
]))
1517 error ("invalid punctuation `%c' in constraint",
1521 if (REG_CLASS_FROM_LETTER (constraint
[j
]) != NO_REGS
)
1523 #ifdef EXTRA_CONSTRAINT
1526 /* Otherwise we can't assume anything about the nature of
1527 the constraint except that it isn't purely registers.
1528 Treat it like "g" and hope for the best. */
1536 /* If an output operand is not a decl or indirect ref and our constraint
1537 allows a register, make a temporary to act as an intermediate.
1538 Make the asm insn write into that, then our caller will copy it to
1539 the real output operand. Likewise for promoted variables. */
1541 generating_concat_p
= 0;
1543 real_output_rtx
[i
] = NULL_RTX
;
1544 if ((TREE_CODE (val
) == INDIRECT_REF
1547 && (allows_mem
|| GET_CODE (DECL_RTL (val
)) == REG
)
1548 && ! (GET_CODE (DECL_RTL (val
)) == REG
1549 && GET_MODE (DECL_RTL (val
)) != TYPE_MODE (type
)))
1554 mark_addressable (TREE_VALUE (tail
));
1557 = expand_expr (TREE_VALUE (tail
), NULL_RTX
, VOIDmode
,
1558 EXPAND_MEMORY_USE_WO
);
1560 if (! allows_reg
&& GET_CODE (output_rtx
[i
]) != MEM
)
1561 error ("output number %d not directly addressable", i
);
1562 if ((! allows_mem
&& GET_CODE (output_rtx
[i
]) == MEM
)
1563 || GET_CODE (output_rtx
[i
]) == CONCAT
)
1565 real_output_rtx
[i
] = protect_from_queue (output_rtx
[i
], 1);
1566 output_rtx
[i
] = gen_reg_rtx (GET_MODE (output_rtx
[i
]));
1568 emit_move_insn (output_rtx
[i
], real_output_rtx
[i
]);
1573 output_rtx
[i
] = assign_temp (type
, 0, 0, 1);
1574 TREE_VALUE (tail
) = make_tree (type
, output_rtx
[i
]);
1577 generating_concat_p
= old_generating_concat_p
;
1581 inout_mode
[ninout
] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail
)));
1582 inout_opnum
[ninout
++] = i
;
1587 if (ninputs
+ noutputs
> MAX_RECOG_OPERANDS
)
1589 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS
);
1593 /* Make vectors for the expression-rtx and constraint strings. */
1595 argvec
= rtvec_alloc (ninputs
);
1596 constraints
= rtvec_alloc (ninputs
);
1598 body
= gen_rtx_ASM_OPERANDS (VOIDmode
, TREE_STRING_POINTER (string
),
1599 empty_string
, 0, argvec
, constraints
,
1602 MEM_VOLATILE_P (body
) = vol
;
1604 /* Eval the inputs and put them into ARGVEC.
1605 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1608 for (tail
= inputs
; tail
; tail
= TREE_CHAIN (tail
))
1611 int allows_reg
= 0, allows_mem
= 0;
1612 char *constraint
, *orig_constraint
;
1616 /* If there's an erroneous arg, emit no insn,
1617 because the ASM_INPUT would get VOIDmode
1618 and that could cause a crash in reload. */
1619 if (TREE_TYPE (TREE_VALUE (tail
)) == error_mark_node
)
1622 /* ??? Can this happen, and does the error message make any sense? */
1623 if (TREE_PURPOSE (tail
) == NULL_TREE
)
1625 error ("hard register `%s' listed as input operand to `asm'",
1626 TREE_STRING_POINTER (TREE_VALUE (tail
)) );
1630 c_len
= strlen (TREE_STRING_POINTER (TREE_PURPOSE (tail
)));
1631 constraint
= TREE_STRING_POINTER (TREE_PURPOSE (tail
));
1632 orig_constraint
= constraint
;
1634 /* Make sure constraint has neither `=', `+', nor '&'. */
1636 for (j
= 0; j
< c_len
; j
++)
1637 switch (constraint
[j
])
1639 case '+': case '=': case '&':
1640 if (constraint
== orig_constraint
)
1642 error ("input operand constraint contains `%c'",
1649 if (constraint
== orig_constraint
1650 && i
+ 1 == ninputs
- ninout
)
1652 error ("`%%' constraint used with last operand");
1657 case 'V': case 'm': case 'o':
1662 case '?': case '!': case '*':
1663 case 'E': case 'F': case 'G': case 'H':
1664 case 's': case 'i': case 'n':
1665 case 'I': case 'J': case 'K': case 'L': case 'M':
1666 case 'N': case 'O': case 'P': case ',':
1669 /* Whether or not a numeric constraint allows a register is
1670 decided by the matching constraint, and so there is no need
1671 to do anything special with them. We must handle them in
1672 the default case, so that we don't unnecessarily force
1673 operands to memory. */
1674 case '0': case '1': case '2': case '3': case '4':
1675 case '5': case '6': case '7': case '8': case '9':
1676 if (constraint
[j
] >= '0' + noutputs
)
1679 ("matching constraint references invalid operand number");
1683 /* Try and find the real constraint for this dup. */
1684 if ((j
== 0 && c_len
== 1)
1685 || (j
== 1 && c_len
== 2 && constraint
[0] == '%'))
1689 for (j
= constraint
[j
] - '0'; j
> 0; --j
)
1692 c_len
= strlen (TREE_STRING_POINTER (TREE_PURPOSE (o
)));
1693 constraint
= TREE_STRING_POINTER (TREE_PURPOSE (o
));
1710 if (! ISALPHA (constraint
[j
]))
1712 error ("invalid punctuation `%c' in constraint",
1716 if (REG_CLASS_FROM_LETTER (constraint
[j
]) != NO_REGS
)
1718 #ifdef EXTRA_CONSTRAINT
1721 /* Otherwise we can't assume anything about the nature of
1722 the constraint except that it isn't purely registers.
1723 Treat it like "g" and hope for the best. */
1731 if (! allows_reg
&& allows_mem
)
1732 mark_addressable (TREE_VALUE (tail
));
1734 op
= expand_expr (TREE_VALUE (tail
), NULL_RTX
, VOIDmode
, 0);
1736 /* Never pass a CONCAT to an ASM. */
1737 generating_concat_p
= 0;
1738 if (GET_CODE (op
) == CONCAT
)
1739 op
= force_reg (GET_MODE (op
), op
);
1741 if (asm_operand_ok (op
, constraint
) <= 0)
1744 op
= force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail
))), op
);
1745 else if (!allows_mem
)
1746 warning ("asm operand %d probably doesn't match constraints", i
);
1747 else if (CONSTANT_P (op
))
1748 op
= force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail
))),
1750 else if (GET_CODE (op
) == REG
1751 || GET_CODE (op
) == SUBREG
1752 || GET_CODE (op
) == CONCAT
)
1754 tree type
= TREE_TYPE (TREE_VALUE (tail
));
1755 rtx memloc
= assign_temp (type
, 1, 1, 1);
1757 emit_move_insn (memloc
, op
);
1761 else if (GET_CODE (op
) == MEM
&& MEM_VOLATILE_P (op
))
1762 /* We won't recognize volatile memory as available a
1763 memory_operand at this point. Ignore it. */
1765 else if (queued_subexp_p (op
))
1768 /* ??? Leave this only until we have experience with what
1769 happens in combine and elsewhere when constraints are
1771 warning ("asm operand %d probably doesn't match constraints", i
);
1773 generating_concat_p
= old_generating_concat_p
;
1774 XVECEXP (body
, 3, i
) = op
;
1776 XVECEXP (body
, 4, i
) /* constraints */
1777 = gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail
))),
1782 /* Protect all the operands from the queue now that they have all been
1785 generating_concat_p
= 0;
1787 for (i
= 0; i
< ninputs
- ninout
; i
++)
1788 XVECEXP (body
, 3, i
) = protect_from_queue (XVECEXP (body
, 3, i
), 0);
1790 for (i
= 0; i
< noutputs
; i
++)
1791 output_rtx
[i
] = protect_from_queue (output_rtx
[i
], 1);
1793 /* For in-out operands, copy output rtx to input rtx. */
1794 for (i
= 0; i
< ninout
; i
++)
1796 int j
= inout_opnum
[i
];
1798 XVECEXP (body
, 3, ninputs
- ninout
+ i
) /* argvec */
1800 XVECEXP (body
, 4, ninputs
- ninout
+ i
) /* constraints */
1801 = gen_rtx_ASM_INPUT (inout_mode
[i
], digit_strings
[j
]);
1804 generating_concat_p
= old_generating_concat_p
;
1806 /* Now, for each output, construct an rtx
1807 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1808 ARGVEC CONSTRAINTS))
1809 If there is more than one, put them inside a PARALLEL. */
1811 if (noutputs
== 1 && nclobbers
== 0)
1813 XSTR (body
, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs
));
1814 insn
= emit_insn (gen_rtx_SET (VOIDmode
, output_rtx
[0], body
));
1817 else if (noutputs
== 0 && nclobbers
== 0)
1819 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1820 insn
= emit_insn (body
);
1831 body
= gen_rtx_PARALLEL (VOIDmode
, rtvec_alloc (num
+ nclobbers
));
1833 /* For each output operand, store a SET. */
1834 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1836 XVECEXP (body
, 0, i
)
1837 = gen_rtx_SET (VOIDmode
,
1839 gen_rtx_ASM_OPERANDS
1841 TREE_STRING_POINTER (string
),
1842 TREE_STRING_POINTER (TREE_PURPOSE (tail
)),
1843 i
, argvec
, constraints
,
1846 MEM_VOLATILE_P (SET_SRC (XVECEXP (body
, 0, i
))) = vol
;
1849 /* If there are no outputs (but there are some clobbers)
1850 store the bare ASM_OPERANDS into the PARALLEL. */
1853 XVECEXP (body
, 0, i
++) = obody
;
1855 /* Store (clobber REG) for each clobbered register specified. */
1857 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
))
1859 const char *regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
1860 int j
= decode_reg_name (regname
);
1864 if (j
== -3) /* `cc', which is not a register */
1867 if (j
== -4) /* `memory', don't cache memory across asm */
1869 XVECEXP (body
, 0, i
++)
1870 = gen_rtx_CLOBBER (VOIDmode
,
1873 gen_rtx_SCRATCH (VOIDmode
)));
1877 /* Ignore unknown register, error already signaled. */
1881 /* Use QImode since that's guaranteed to clobber just one reg. */
1882 XVECEXP (body
, 0, i
++)
1883 = gen_rtx_CLOBBER (VOIDmode
, gen_rtx_REG (QImode
, j
));
1886 insn
= emit_insn (body
);
1889 /* For any outputs that needed reloading into registers, spill them
1890 back to where they belong. */
1891 for (i
= 0; i
< noutputs
; ++i
)
1892 if (real_output_rtx
[i
])
1893 emit_move_insn (real_output_rtx
[i
], output_rtx
[i
]);
1898 /* Generate RTL to evaluate the expression EXP
1899 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1902 expand_expr_stmt (exp
)
1905 /* If -W, warn about statements with no side effects,
1906 except for an explicit cast to void (e.g. for assert()), and
1907 except inside a ({...}) where they may be useful. */
1908 if (expr_stmts_for_value
== 0 && exp
!= error_mark_node
)
1910 if (! TREE_SIDE_EFFECTS (exp
)
1911 && (extra_warnings
|| warn_unused_value
)
1912 && !(TREE_CODE (exp
) == CONVERT_EXPR
1913 && VOID_TYPE_P (TREE_TYPE (exp
))))
1914 warning_with_file_and_line (emit_filename
, emit_lineno
,
1915 "statement with no effect");
1916 else if (warn_unused_value
)
1917 warn_if_unused_value (exp
);
1920 /* If EXP is of function type and we are expanding statements for
1921 value, convert it to pointer-to-function. */
1922 if (expr_stmts_for_value
&& TREE_CODE (TREE_TYPE (exp
)) == FUNCTION_TYPE
)
1923 exp
= build1 (ADDR_EXPR
, build_pointer_type (TREE_TYPE (exp
)), exp
);
1925 last_expr_type
= TREE_TYPE (exp
);
1926 last_expr_value
= expand_expr (exp
,
1927 (expr_stmts_for_value
1928 ? NULL_RTX
: const0_rtx
),
1931 /* If all we do is reference a volatile value in memory,
1932 copy it to a register to be sure it is actually touched. */
1933 if (last_expr_value
!= 0 && GET_CODE (last_expr_value
) == MEM
1934 && TREE_THIS_VOLATILE (exp
))
1936 if (TYPE_MODE (TREE_TYPE (exp
)) == VOIDmode
)
1938 else if (TYPE_MODE (TREE_TYPE (exp
)) != BLKmode
)
1939 copy_to_reg (last_expr_value
);
1942 rtx lab
= gen_label_rtx ();
1944 /* Compare the value with itself to reference it. */
1945 emit_cmp_and_jump_insns (last_expr_value
, last_expr_value
, EQ
,
1946 expand_expr (TYPE_SIZE (last_expr_type
),
1947 NULL_RTX
, VOIDmode
, 0),
1949 TYPE_ALIGN (last_expr_type
) / BITS_PER_UNIT
,
1955 /* If this expression is part of a ({...}) and is in memory, we may have
1956 to preserve temporaries. */
1957 preserve_temp_slots (last_expr_value
);
1959 /* Free any temporaries used to evaluate this expression. Any temporary
1960 used as a result of this expression will already have been preserved
1967 /* Warn if EXP contains any computations whose results are not used.
1968 Return 1 if a warning is printed; 0 otherwise. */
1971 warn_if_unused_value (exp
)
1974 if (TREE_USED (exp
))
1977 switch (TREE_CODE (exp
))
1979 case PREINCREMENT_EXPR
:
1980 case POSTINCREMENT_EXPR
:
1981 case PREDECREMENT_EXPR
:
1982 case POSTDECREMENT_EXPR
:
1987 case METHOD_CALL_EXPR
:
1989 case TRY_CATCH_EXPR
:
1990 case WITH_CLEANUP_EXPR
:
1992 /* We don't warn about COND_EXPR because it may be a useful
1993 construct if either arm contains a side effect. */
1998 /* For a binding, warn if no side effect within it. */
1999 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2002 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2004 case TRUTH_ORIF_EXPR
:
2005 case TRUTH_ANDIF_EXPR
:
2006 /* In && or ||, warn if 2nd operand has no side effect. */
2007 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2010 if (TREE_NO_UNUSED_WARNING (exp
))
2012 if (warn_if_unused_value (TREE_OPERAND (exp
, 0)))
2014 /* Let people do `(foo (), 0)' without a warning. */
2015 if (TREE_CONSTANT (TREE_OPERAND (exp
, 1)))
2017 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2021 case NON_LVALUE_EXPR
:
2022 /* Don't warn about values cast to void. */
2023 if (VOID_TYPE_P (TREE_TYPE (exp
)))
2025 /* Don't warn about conversions not explicit in the user's program. */
2026 if (TREE_NO_UNUSED_WARNING (exp
))
2028 /* Assignment to a cast usually results in a cast of a modify.
2029 Don't complain about that. There can be an arbitrary number of
2030 casts before the modify, so we must loop until we find the first
2031 non-cast expression and then test to see if that is a modify. */
2033 tree tem
= TREE_OPERAND (exp
, 0);
2035 while (TREE_CODE (tem
) == CONVERT_EXPR
|| TREE_CODE (tem
) == NOP_EXPR
)
2036 tem
= TREE_OPERAND (tem
, 0);
2038 if (TREE_CODE (tem
) == MODIFY_EXPR
|| TREE_CODE (tem
) == INIT_EXPR
2039 || TREE_CODE (tem
) == CALL_EXPR
)
2045 /* Don't warn about automatic dereferencing of references, since
2046 the user cannot control it. */
2047 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp
, 0))) == REFERENCE_TYPE
)
2048 return warn_if_unused_value (TREE_OPERAND (exp
, 0));
2052 /* Referencing a volatile value is a side effect, so don't warn. */
2054 || TREE_CODE_CLASS (TREE_CODE (exp
)) == 'r')
2055 && TREE_THIS_VOLATILE (exp
))
2058 /* If this is an expression which has no operands, there is no value
2059 to be unused. There are no such language-independent codes,
2060 but front ends may define such. */
2061 if (TREE_CODE_CLASS (TREE_CODE (exp
)) == 'e'
2062 && TREE_CODE_LENGTH (TREE_CODE (exp
)) == 0)
2066 warning_with_file_and_line (emit_filename
, emit_lineno
,
2067 "value computed is not used");
2072 /* Clear out the memory of the last expression evaluated. */
2080 /* Begin a statement which will return a value.
2081 Return the RTL_EXPR for this statement expr.
2082 The caller must save that value and pass it to expand_end_stmt_expr. */
2085 expand_start_stmt_expr ()
2090 /* Make the RTL_EXPR node temporary, not momentary,
2091 so that rtl_expr_chain doesn't become garbage. */
2092 momentary
= suspend_momentary ();
2093 t
= make_node (RTL_EXPR
);
2094 resume_momentary (momentary
);
2095 do_pending_stack_adjust ();
2096 start_sequence_for_rtl_expr (t
);
2098 expr_stmts_for_value
++;
2102 /* Restore the previous state at the end of a statement that returns a value.
2103 Returns a tree node representing the statement's value and the
2104 insns to compute the value.
2106 The nodes of that expression have been freed by now, so we cannot use them.
2107 But we don't want to do that anyway; the expression has already been
2108 evaluated and now we just want to use the value. So generate a RTL_EXPR
2109 with the proper type and RTL value.
2111 If the last substatement was not an expression,
2112 return something with type `void'. */
2115 expand_end_stmt_expr (t
)
2120 if (last_expr_type
== 0)
2122 last_expr_type
= void_type_node
;
2123 last_expr_value
= const0_rtx
;
2125 else if (last_expr_value
== 0)
2126 /* There are some cases where this can happen, such as when the
2127 statement is void type. */
2128 last_expr_value
= const0_rtx
;
2129 else if (GET_CODE (last_expr_value
) != REG
&& ! CONSTANT_P (last_expr_value
))
2130 /* Remove any possible QUEUED. */
2131 last_expr_value
= protect_from_queue (last_expr_value
, 0);
2135 TREE_TYPE (t
) = last_expr_type
;
2136 RTL_EXPR_RTL (t
) = last_expr_value
;
2137 RTL_EXPR_SEQUENCE (t
) = get_insns ();
2139 rtl_expr_chain
= tree_cons (NULL_TREE
, t
, rtl_expr_chain
);
2143 /* Don't consider deleting this expr or containing exprs at tree level. */
2144 TREE_SIDE_EFFECTS (t
) = 1;
2145 /* Propagate volatility of the actual RTL expr. */
2146 TREE_THIS_VOLATILE (t
) = volatile_refs_p (last_expr_value
);
2149 expr_stmts_for_value
--;
2154 /* Generate RTL for the start of an if-then. COND is the expression
2155 whose truth should be tested.
2157 If EXITFLAG is nonzero, this conditional is visible to
2158 `exit_something'. */
2161 expand_start_cond (cond
, exitflag
)
2165 struct nesting
*thiscond
= ALLOC_NESTING ();
2167 /* Make an entry on cond_stack for the cond we are entering. */
2169 thiscond
->next
= cond_stack
;
2170 thiscond
->all
= nesting_stack
;
2171 thiscond
->depth
= ++nesting_depth
;
2172 thiscond
->data
.cond
.next_label
= gen_label_rtx ();
2173 /* Before we encounter an `else', we don't need a separate exit label
2174 unless there are supposed to be exit statements
2175 to exit this conditional. */
2176 thiscond
->exit_label
= exitflag
? gen_label_rtx () : 0;
2177 thiscond
->data
.cond
.endif_label
= thiscond
->exit_label
;
2178 cond_stack
= thiscond
;
2179 nesting_stack
= thiscond
;
2181 do_jump (cond
, thiscond
->data
.cond
.next_label
, NULL_RTX
);
2184 /* Generate RTL between then-clause and the elseif-clause
2185 of an if-then-elseif-.... */
2188 expand_start_elseif (cond
)
2191 if (cond_stack
->data
.cond
.endif_label
== 0)
2192 cond_stack
->data
.cond
.endif_label
= gen_label_rtx ();
2193 emit_jump (cond_stack
->data
.cond
.endif_label
);
2194 emit_label (cond_stack
->data
.cond
.next_label
);
2195 cond_stack
->data
.cond
.next_label
= gen_label_rtx ();
2196 do_jump (cond
, cond_stack
->data
.cond
.next_label
, NULL_RTX
);
2199 /* Generate RTL between the then-clause and the else-clause
2200 of an if-then-else. */
2203 expand_start_else ()
2205 if (cond_stack
->data
.cond
.endif_label
== 0)
2206 cond_stack
->data
.cond
.endif_label
= gen_label_rtx ();
2208 emit_jump (cond_stack
->data
.cond
.endif_label
);
2209 emit_label (cond_stack
->data
.cond
.next_label
);
2210 cond_stack
->data
.cond
.next_label
= 0; /* No more _else or _elseif calls. */
2213 /* After calling expand_start_else, turn this "else" into an "else if"
2214 by providing another condition. */
2217 expand_elseif (cond
)
2220 cond_stack
->data
.cond
.next_label
= gen_label_rtx ();
2221 do_jump (cond
, cond_stack
->data
.cond
.next_label
, NULL_RTX
);
2224 /* Generate RTL for the end of an if-then.
2225 Pop the record for it off of cond_stack. */
2230 struct nesting
*thiscond
= cond_stack
;
2232 do_pending_stack_adjust ();
2233 if (thiscond
->data
.cond
.next_label
)
2234 emit_label (thiscond
->data
.cond
.next_label
);
2235 if (thiscond
->data
.cond
.endif_label
)
2236 emit_label (thiscond
->data
.cond
.endif_label
);
2238 POPSTACK (cond_stack
);
2242 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2243 loop should be exited by `exit_something'. This is a loop for which
2244 `expand_continue' will jump to the top of the loop.
2246 Make an entry on loop_stack to record the labels associated with
2250 expand_start_loop (exit_flag
)
2253 register struct nesting
*thisloop
= ALLOC_NESTING ();
2255 /* Make an entry on loop_stack for the loop we are entering. */
2257 thisloop
->next
= loop_stack
;
2258 thisloop
->all
= nesting_stack
;
2259 thisloop
->depth
= ++nesting_depth
;
2260 thisloop
->data
.loop
.start_label
= gen_label_rtx ();
2261 thisloop
->data
.loop
.end_label
= gen_label_rtx ();
2262 thisloop
->data
.loop
.alt_end_label
= 0;
2263 thisloop
->data
.loop
.continue_label
= thisloop
->data
.loop
.start_label
;
2264 thisloop
->exit_label
= exit_flag
? thisloop
->data
.loop
.end_label
: 0;
2265 loop_stack
= thisloop
;
2266 nesting_stack
= thisloop
;
2268 do_pending_stack_adjust ();
2270 emit_note (NULL_PTR
, NOTE_INSN_LOOP_BEG
);
2271 emit_label (thisloop
->data
.loop
.start_label
);
2276 /* Like expand_start_loop but for a loop where the continuation point
2277 (for expand_continue_loop) will be specified explicitly. */
2280 expand_start_loop_continue_elsewhere (exit_flag
)
2283 struct nesting
*thisloop
= expand_start_loop (exit_flag
);
2284 loop_stack
->data
.loop
.continue_label
= gen_label_rtx ();
2288 /* Specify the continuation point for a loop started with
2289 expand_start_loop_continue_elsewhere.
2290 Use this at the point in the code to which a continue statement
2294 expand_loop_continue_here ()
2296 do_pending_stack_adjust ();
2297 emit_note (NULL_PTR
, NOTE_INSN_LOOP_CONT
);
2298 emit_label (loop_stack
->data
.loop
.continue_label
);
2301 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2302 Pop the block off of loop_stack. */
2307 rtx start_label
= loop_stack
->data
.loop
.start_label
;
2308 rtx insn
= get_last_insn ();
2309 int needs_end_jump
= 1;
2311 /* Mark the continue-point at the top of the loop if none elsewhere. */
2312 if (start_label
== loop_stack
->data
.loop
.continue_label
)
2313 emit_note_before (NOTE_INSN_LOOP_CONT
, start_label
);
2315 do_pending_stack_adjust ();
2317 /* If optimizing, perhaps reorder the loop.
2318 First, try to use a condjump near the end.
2319 expand_exit_loop_if_false ends loops with unconditional jumps,
2322 if (test) goto label;
2324 goto loop_stack->data.loop.end_label
2328 If we find such a pattern, we can end the loop earlier. */
2331 && GET_CODE (insn
) == CODE_LABEL
2332 && LABEL_NAME (insn
) == NULL
2333 && GET_CODE (PREV_INSN (insn
)) == BARRIER
)
2336 rtx jump
= PREV_INSN (PREV_INSN (label
));
2338 if (GET_CODE (jump
) == JUMP_INSN
2339 && GET_CODE (PATTERN (jump
)) == SET
2340 && SET_DEST (PATTERN (jump
)) == pc_rtx
2341 && GET_CODE (SET_SRC (PATTERN (jump
))) == LABEL_REF
2342 && (XEXP (SET_SRC (PATTERN (jump
)), 0)
2343 == loop_stack
->data
.loop
.end_label
))
2347 /* The test might be complex and reference LABEL multiple times,
2348 like the loop in loop_iterations to set vtop. To handle this,
2350 insn
= PREV_INSN (label
);
2351 reorder_insns (label
, label
, start_label
);
2353 for (prev
= PREV_INSN (jump
);; prev
= PREV_INSN (prev
))
2355 /* We ignore line number notes, but if we see any other note,
2356 in particular NOTE_INSN_BLOCK_*, NOTE_INSN_EH_REGION_*,
2357 NOTE_INSN_LOOP_*, we disable this optimization. */
2358 if (GET_CODE (prev
) == NOTE
)
2360 if (NOTE_LINE_NUMBER (prev
) < 0)
2364 if (GET_CODE (prev
) == CODE_LABEL
)
2366 if (GET_CODE (prev
) == JUMP_INSN
)
2368 if (GET_CODE (PATTERN (prev
)) == SET
2369 && SET_DEST (PATTERN (prev
)) == pc_rtx
2370 && GET_CODE (SET_SRC (PATTERN (prev
))) == IF_THEN_ELSE
2371 && (GET_CODE (XEXP (SET_SRC (PATTERN (prev
)), 1))
2373 && XEXP (XEXP (SET_SRC (PATTERN (prev
)), 1), 0) == label
)
2375 XEXP (XEXP (SET_SRC (PATTERN (prev
)), 1), 0)
2377 emit_note_after (NOTE_INSN_LOOP_END
, prev
);
2386 /* If the loop starts with a loop exit, roll that to the end where
2387 it will optimize together with the jump back.
2389 We look for the conditional branch to the exit, except that once
2390 we find such a branch, we don't look past 30 instructions.
2392 In more detail, if the loop presently looks like this (in pseudo-C):
2395 if (test) goto end_label;
2400 transform it to look like:
2406 if (test) goto end_label;
2407 goto newstart_label;
2410 Here, the `test' may actually consist of some reasonably complex
2411 code, terminating in a test. */
2416 ! (GET_CODE (insn
) == JUMP_INSN
2417 && GET_CODE (PATTERN (insn
)) == SET
2418 && SET_DEST (PATTERN (insn
)) == pc_rtx
2419 && GET_CODE (SET_SRC (PATTERN (insn
))) == IF_THEN_ELSE
))
2423 rtx last_test_insn
= NULL_RTX
;
2425 /* Scan insns from the top of the loop looking for a qualified
2426 conditional exit. */
2427 for (insn
= NEXT_INSN (loop_stack
->data
.loop
.start_label
); insn
;
2428 insn
= NEXT_INSN (insn
))
2430 if (GET_CODE (insn
) == NOTE
)
2433 && (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_BEG
2434 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_END
))
2435 /* The code that actually moves the exit test will
2436 carefully leave BLOCK notes in their original
2437 location. That means, however, that we can't debug
2438 the exit test itself. So, we refuse to move code
2439 containing BLOCK notes at low optimization levels. */
2442 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_EH_REGION_BEG
)
2444 else if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_EH_REGION_END
)
2448 /* We've come to the end of an EH region, but
2449 never saw the beginning of that region. That
2450 means that an EH region begins before the top
2451 of the loop, and ends in the middle of it. The
2452 existence of such a situation violates a basic
2453 assumption in this code, since that would imply
2454 that even when EH_REGIONS is zero, we might
2455 move code out of an exception region. */
2459 /* We must not walk into a nested loop. */
2460 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_LOOP_BEG
)
2463 /* We already know this INSN is a NOTE, so there's no
2464 point in looking at it to see if it's a JUMP. */
2468 if (GET_CODE (insn
) == JUMP_INSN
|| GET_CODE (insn
) == INSN
)
2471 if (last_test_insn
&& num_insns
> 30)
2475 /* We don't want to move a partial EH region. Consider:
2489 This isn't legal C++, but here's what it's supposed to
2490 mean: if cond() is true, stop looping. Otherwise,
2491 call bar, and keep looping. In addition, if cond
2492 throws an exception, catch it and keep looping. Such
2493 constructs are certainy legal in LISP.
2495 We should not move the `if (cond()) 0' test since then
2496 the EH-region for the try-block would be broken up.
2497 (In this case we would the EH_BEG note for the `try'
2498 and `if cond()' but not the call to bar() or the
2501 So we don't look for tests within an EH region. */
2504 if (GET_CODE (insn
) == JUMP_INSN
2505 && GET_CODE (PATTERN (insn
)) == SET
2506 && SET_DEST (PATTERN (insn
)) == pc_rtx
)
2508 /* This is indeed a jump. */
2509 rtx dest1
= NULL_RTX
;
2510 rtx dest2
= NULL_RTX
;
2511 rtx potential_last_test
;
2512 if (GET_CODE (SET_SRC (PATTERN (insn
))) == IF_THEN_ELSE
)
2514 /* A conditional jump. */
2515 dest1
= XEXP (SET_SRC (PATTERN (insn
)), 1);
2516 dest2
= XEXP (SET_SRC (PATTERN (insn
)), 2);
2517 potential_last_test
= insn
;
2521 /* An unconditional jump. */
2522 dest1
= SET_SRC (PATTERN (insn
));
2523 /* Include the BARRIER after the JUMP. */
2524 potential_last_test
= NEXT_INSN (insn
);
2528 if (dest1
&& GET_CODE (dest1
) == LABEL_REF
2529 && ((XEXP (dest1
, 0)
2530 == loop_stack
->data
.loop
.alt_end_label
)
2532 == loop_stack
->data
.loop
.end_label
)))
2534 last_test_insn
= potential_last_test
;
2538 /* If this was a conditional jump, there may be
2539 another label at which we should look. */
2546 if (last_test_insn
!= 0 && last_test_insn
!= get_last_insn ())
2548 /* We found one. Move everything from there up
2549 to the end of the loop, and add a jump into the loop
2550 to jump to there. */
2551 register rtx newstart_label
= gen_label_rtx ();
2552 register rtx start_move
= start_label
;
2555 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2556 then we want to move this note also. */
2557 if (GET_CODE (PREV_INSN (start_move
)) == NOTE
2558 && (NOTE_LINE_NUMBER (PREV_INSN (start_move
))
2559 == NOTE_INSN_LOOP_CONT
))
2560 start_move
= PREV_INSN (start_move
);
2562 emit_label_after (newstart_label
, PREV_INSN (start_move
));
2564 /* Actually move the insns. Start at the beginning, and
2565 keep copying insns until we've copied the
2567 for (insn
= start_move
; insn
; insn
= next_insn
)
2569 /* Figure out which insn comes after this one. We have
2570 to do this before we move INSN. */
2571 if (insn
== last_test_insn
)
2572 /* We've moved all the insns. */
2573 next_insn
= NULL_RTX
;
2575 next_insn
= NEXT_INSN (insn
);
2577 if (GET_CODE (insn
) == NOTE
2578 && (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_BEG
2579 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_END
))
2580 /* We don't want to move NOTE_INSN_BLOCK_BEGs or
2581 NOTE_INSN_BLOCK_ENDs because the correct generation
2582 of debugging information depends on these appearing
2583 in the same order in the RTL and in the tree
2584 structure, where they are represented as BLOCKs.
2585 So, we don't move block notes. Of course, moving
2586 the code inside the block is likely to make it
2587 impossible to debug the instructions in the exit
2588 test, but such is the price of optimization. */
2591 /* Move the INSN. */
2592 reorder_insns (insn
, insn
, get_last_insn ());
2595 emit_jump_insn_after (gen_jump (start_label
),
2596 PREV_INSN (newstart_label
));
2597 emit_barrier_after (PREV_INSN (newstart_label
));
2598 start_label
= newstart_label
;
2604 emit_jump (start_label
);
2605 emit_note (NULL_PTR
, NOTE_INSN_LOOP_END
);
2607 emit_label (loop_stack
->data
.loop
.end_label
);
2609 POPSTACK (loop_stack
);
2614 /* Generate a jump to the current loop's continue-point.
2615 This is usually the top of the loop, but may be specified
2616 explicitly elsewhere. If not currently inside a loop,
2617 return 0 and do nothing; caller will print an error message. */
2620 expand_continue_loop (whichloop
)
2621 struct nesting
*whichloop
;
2625 whichloop
= loop_stack
;
2628 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.continue_label
,
2633 /* Generate a jump to exit the current loop. If not currently inside a loop,
2634 return 0 and do nothing; caller will print an error message. */
2637 expand_exit_loop (whichloop
)
2638 struct nesting
*whichloop
;
2642 whichloop
= loop_stack
;
2645 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.end_label
, NULL_RTX
);
2649 /* Generate a conditional jump to exit the current loop if COND
2650 evaluates to zero. If not currently inside a loop,
2651 return 0 and do nothing; caller will print an error message. */
2654 expand_exit_loop_if_false (whichloop
, cond
)
2655 struct nesting
*whichloop
;
2658 rtx label
= gen_label_rtx ();
2663 whichloop
= loop_stack
;
2666 /* In order to handle fixups, we actually create a conditional jump
2667 around a unconditional branch to exit the loop. If fixups are
2668 necessary, they go before the unconditional branch. */
2670 do_jump (cond
, NULL_RTX
, label
);
2671 last_insn
= get_last_insn ();
2672 if (GET_CODE (last_insn
) == CODE_LABEL
)
2673 whichloop
->data
.loop
.alt_end_label
= last_insn
;
2674 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.end_label
,
2681 /* Return nonzero if the loop nest is empty. Else return zero. */
2684 stmt_loop_nest_empty ()
2686 /* cfun->stmt can be NULL if we are building a call to get the
2687 EH context for a setjmp/longjmp EH target and the current
2688 function was a deferred inline function. */
2689 return (cfun
->stmt
== NULL
|| loop_stack
== NULL
);
2692 /* Return non-zero if we should preserve sub-expressions as separate
2693 pseudos. We never do so if we aren't optimizing. We always do so
2694 if -fexpensive-optimizations.
2696 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2697 the loop may still be a small one. */
2700 preserve_subexpressions_p ()
2704 if (flag_expensive_optimizations
)
2707 if (optimize
== 0 || cfun
== 0 || cfun
->stmt
== 0 || loop_stack
== 0)
2710 insn
= get_last_insn_anywhere ();
2713 && (INSN_UID (insn
) - INSN_UID (loop_stack
->data
.loop
.start_label
)
2714 < n_non_fixed_regs
* 3));
2718 /* Generate a jump to exit the current loop, conditional, binding contour
2719 or case statement. Not all such constructs are visible to this function,
2720 only those started with EXIT_FLAG nonzero. Individual languages use
2721 the EXIT_FLAG parameter to control which kinds of constructs you can
2724 If not currently inside anything that can be exited,
2725 return 0 and do nothing; caller will print an error message. */
2728 expand_exit_something ()
2732 for (n
= nesting_stack
; n
; n
= n
->all
)
2733 if (n
->exit_label
!= 0)
2735 expand_goto_internal (NULL_TREE
, n
->exit_label
, NULL_RTX
);
2742 /* Generate RTL to return from the current function, with no value.
2743 (That is, we do not do anything about returning any value.) */
2746 expand_null_return ()
2748 struct nesting
*block
= block_stack
;
2749 rtx last_insn
= get_last_insn ();
2751 /* If this function was declared to return a value, but we
2752 didn't, clobber the return registers so that they are not
2753 propogated live to the rest of the function. */
2754 clobber_return_register ();
2756 /* Does any pending block have cleanups? */
2757 while (block
&& block
->data
.block
.cleanups
== 0)
2758 block
= block
->next
;
2760 /* If yes, use a goto to return, since that runs cleanups. */
2762 expand_null_return_1 (last_insn
, block
!= 0);
2765 /* Generate RTL to return from the current function, with value VAL. */
2768 expand_value_return (val
)
2771 struct nesting
*block
= block_stack
;
2772 rtx last_insn
= get_last_insn ();
2773 rtx return_reg
= DECL_RTL (DECL_RESULT (current_function_decl
));
2775 /* Copy the value to the return location
2776 unless it's already there. */
2778 if (return_reg
!= val
)
2780 tree type
= TREE_TYPE (DECL_RESULT (current_function_decl
));
2781 #ifdef PROMOTE_FUNCTION_RETURN
2782 int unsignedp
= TREE_UNSIGNED (type
);
2783 enum machine_mode old_mode
2784 = DECL_MODE (DECL_RESULT (current_function_decl
));
2785 enum machine_mode mode
2786 = promote_mode (type
, old_mode
, &unsignedp
, 1);
2788 if (mode
!= old_mode
)
2789 val
= convert_modes (mode
, old_mode
, val
, unsignedp
);
2791 if (GET_CODE (return_reg
) == PARALLEL
)
2792 emit_group_load (return_reg
, val
, int_size_in_bytes (type
),
2795 emit_move_insn (return_reg
, val
);
2798 /* Does any pending block have cleanups? */
2800 while (block
&& block
->data
.block
.cleanups
== 0)
2801 block
= block
->next
;
2803 /* If yes, use a goto to return, since that runs cleanups.
2804 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2806 expand_null_return_1 (last_insn
, block
!= 0);
2809 /* Output a return with no value. If LAST_INSN is nonzero,
2810 pretend that the return takes place after LAST_INSN.
2811 If USE_GOTO is nonzero then don't use a return instruction;
2812 go to the return label instead. This causes any cleanups
2813 of pending blocks to be executed normally. */
2816 expand_null_return_1 (last_insn
, use_goto
)
2820 rtx end_label
= cleanup_label
? cleanup_label
: return_label
;
2822 clear_pending_stack_adjust ();
2823 do_pending_stack_adjust ();
2826 /* PCC-struct return always uses an epilogue. */
2827 if (current_function_returns_pcc_struct
|| use_goto
)
2830 end_label
= return_label
= gen_label_rtx ();
2831 expand_goto_internal (NULL_TREE
, end_label
, last_insn
);
2835 /* Otherwise output a simple return-insn if one is available,
2836 unless it won't do the job. */
2838 if (HAVE_return
&& use_goto
== 0 && cleanup_label
== 0)
2840 emit_jump_insn (gen_return ());
2846 /* Otherwise jump to the epilogue. */
2847 expand_goto_internal (NULL_TREE
, end_label
, last_insn
);
2850 /* Generate RTL to evaluate the expression RETVAL and return it
2851 from the current function. */
2854 expand_return (retval
)
2857 /* If there are any cleanups to be performed, then they will
2858 be inserted following LAST_INSN. It is desirable
2859 that the last_insn, for such purposes, should be the
2860 last insn before computing the return value. Otherwise, cleanups
2861 which call functions can clobber the return value. */
2862 /* ??? rms: I think that is erroneous, because in C++ it would
2863 run destructors on variables that might be used in the subsequent
2864 computation of the return value. */
2866 rtx result_rtl
= DECL_RTL (DECL_RESULT (current_function_decl
));
2867 register rtx val
= 0;
2871 /* If function wants no value, give it none. */
2872 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl
))) == VOID_TYPE
)
2874 expand_expr (retval
, NULL_RTX
, VOIDmode
, 0);
2876 expand_null_return ();
2880 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2881 /* This is not sufficient. We also need to watch for cleanups of the
2882 expression we are about to expand. Unfortunately, we cannot know
2883 if it has cleanups until we expand it, and we want to change how we
2884 expand it depending upon if we need cleanups. We can't win. */
2886 cleanups
= any_pending_cleanups (1);
2891 if (retval
== error_mark_node
)
2892 retval_rhs
= NULL_TREE
;
2893 else if (TREE_CODE (retval
) == RESULT_DECL
)
2894 retval_rhs
= retval
;
2895 else if ((TREE_CODE (retval
) == MODIFY_EXPR
|| TREE_CODE (retval
) == INIT_EXPR
)
2896 && TREE_CODE (TREE_OPERAND (retval
, 0)) == RESULT_DECL
)
2897 retval_rhs
= TREE_OPERAND (retval
, 1);
2898 else if (VOID_TYPE_P (TREE_TYPE (retval
)))
2899 /* Recognize tail-recursive call to void function. */
2900 retval_rhs
= retval
;
2902 retval_rhs
= NULL_TREE
;
2904 /* Only use `last_insn' if there are cleanups which must be run. */
2905 if (cleanups
|| cleanup_label
!= 0)
2906 last_insn
= get_last_insn ();
2908 /* Distribute return down conditional expr if either of the sides
2909 may involve tail recursion (see test below). This enhances the number
2910 of tail recursions we see. Don't do this always since it can produce
2911 sub-optimal code in some cases and we distribute assignments into
2912 conditional expressions when it would help. */
2914 if (optimize
&& retval_rhs
!= 0
2915 && frame_offset
== 0
2916 && TREE_CODE (retval_rhs
) == COND_EXPR
2917 && (TREE_CODE (TREE_OPERAND (retval_rhs
, 1)) == CALL_EXPR
2918 || TREE_CODE (TREE_OPERAND (retval_rhs
, 2)) == CALL_EXPR
))
2920 rtx label
= gen_label_rtx ();
2923 do_jump (TREE_OPERAND (retval_rhs
, 0), label
, NULL_RTX
);
2924 start_cleanup_deferral ();
2925 expr
= build (MODIFY_EXPR
, TREE_TYPE (TREE_TYPE (current_function_decl
)),
2926 DECL_RESULT (current_function_decl
),
2927 TREE_OPERAND (retval_rhs
, 1));
2928 TREE_SIDE_EFFECTS (expr
) = 1;
2929 expand_return (expr
);
2932 expr
= build (MODIFY_EXPR
, TREE_TYPE (TREE_TYPE (current_function_decl
)),
2933 DECL_RESULT (current_function_decl
),
2934 TREE_OPERAND (retval_rhs
, 2));
2935 TREE_SIDE_EFFECTS (expr
) = 1;
2936 expand_return (expr
);
2937 end_cleanup_deferral ();
2941 /* If the result is an aggregate that is being returned in one (or more)
2942 registers, load the registers here. The compiler currently can't handle
2943 copying a BLKmode value into registers. We could put this code in a
2944 more general area (for use by everyone instead of just function
2945 call/return), but until this feature is generally usable it is kept here
2946 (and in expand_call). The value must go into a pseudo in case there
2947 are cleanups that will clobber the real return register. */
2950 && TYPE_MODE (TREE_TYPE (retval_rhs
)) == BLKmode
2951 && GET_CODE (result_rtl
) == REG
)
2954 unsigned HOST_WIDE_INT bitpos
, xbitpos
;
2955 unsigned HOST_WIDE_INT big_endian_correction
= 0;
2956 unsigned HOST_WIDE_INT bytes
2957 = int_size_in_bytes (TREE_TYPE (retval_rhs
));
2958 int n_regs
= (bytes
+ UNITS_PER_WORD
- 1) / UNITS_PER_WORD
;
2959 unsigned int bitsize
2960 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs
)), BITS_PER_WORD
);
2961 rtx
*result_pseudos
= (rtx
*) alloca (sizeof (rtx
) * n_regs
);
2962 rtx result_reg
, src
= NULL_RTX
, dst
= NULL_RTX
;
2963 rtx result_val
= expand_expr (retval_rhs
, NULL_RTX
, VOIDmode
, 0);
2964 enum machine_mode tmpmode
, result_reg_mode
;
2966 /* Structures whose size is not a multiple of a word are aligned
2967 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
2968 machine, this means we must skip the empty high order bytes when
2969 calculating the bit offset. */
2970 if (BYTES_BIG_ENDIAN
&& bytes
% UNITS_PER_WORD
)
2971 big_endian_correction
= (BITS_PER_WORD
- ((bytes
% UNITS_PER_WORD
)
2974 /* Copy the structure BITSIZE bits at a time. */
2975 for (bitpos
= 0, xbitpos
= big_endian_correction
;
2976 bitpos
< bytes
* BITS_PER_UNIT
;
2977 bitpos
+= bitsize
, xbitpos
+= bitsize
)
2979 /* We need a new destination pseudo each time xbitpos is
2980 on a word boundary and when xbitpos == big_endian_correction
2981 (the first time through). */
2982 if (xbitpos
% BITS_PER_WORD
== 0
2983 || xbitpos
== big_endian_correction
)
2985 /* Generate an appropriate register. */
2986 dst
= gen_reg_rtx (word_mode
);
2987 result_pseudos
[xbitpos
/ BITS_PER_WORD
] = dst
;
2989 /* Clobber the destination before we move anything into it. */
2990 emit_insn (gen_rtx_CLOBBER (VOIDmode
, dst
));
2993 /* We need a new source operand each time bitpos is on a word
2995 if (bitpos
% BITS_PER_WORD
== 0)
2996 src
= operand_subword_force (result_val
,
2997 bitpos
/ BITS_PER_WORD
,
3000 /* Use bitpos for the source extraction (left justified) and
3001 xbitpos for the destination store (right justified). */
3002 store_bit_field (dst
, bitsize
, xbitpos
% BITS_PER_WORD
, word_mode
,
3003 extract_bit_field (src
, bitsize
,
3004 bitpos
% BITS_PER_WORD
, 1,
3005 NULL_RTX
, word_mode
, word_mode
,
3006 bitsize
, BITS_PER_WORD
),
3007 bitsize
, BITS_PER_WORD
);
3010 /* Find the smallest integer mode large enough to hold the
3011 entire structure and use that mode instead of BLKmode
3012 on the USE insn for the return register. */
3013 bytes
= int_size_in_bytes (TREE_TYPE (retval_rhs
));
3014 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
3015 tmpmode
!= VOIDmode
;
3016 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
3018 /* Have we found a large enough mode? */
3019 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
3023 /* No suitable mode found. */
3024 if (tmpmode
== VOIDmode
)
3027 PUT_MODE (result_rtl
, tmpmode
);
3029 if (GET_MODE_SIZE (tmpmode
) < GET_MODE_SIZE (word_mode
))
3030 result_reg_mode
= word_mode
;
3032 result_reg_mode
= tmpmode
;
3033 result_reg
= gen_reg_rtx (result_reg_mode
);
3036 for (i
= 0; i
< n_regs
; i
++)
3037 emit_move_insn (operand_subword (result_reg
, i
, 0, result_reg_mode
),
3040 if (tmpmode
!= result_reg_mode
)
3041 result_reg
= gen_lowpart (tmpmode
, result_reg
);
3043 expand_value_return (result_reg
);
3047 && !VOID_TYPE_P (TREE_TYPE (retval_rhs
))
3048 && (GET_CODE (result_rtl
) == REG
3049 || (GET_CODE (result_rtl
) == PARALLEL
)))
3051 /* Calculate the return value into a temporary (usually a pseudo
3053 val
= assign_temp (TREE_TYPE (DECL_RESULT (current_function_decl
)),
3055 val
= expand_expr (retval_rhs
, val
, GET_MODE (val
), 0);
3056 val
= force_not_mem (val
);
3058 /* Return the calculated value, doing cleanups first. */
3059 expand_value_return (val
);
3063 /* No cleanups or no hard reg used;
3064 calculate value into hard return reg. */
3065 expand_expr (retval
, const0_rtx
, VOIDmode
, 0);
3067 expand_value_return (result_rtl
);
3071 /* Return 1 if the end of the generated RTX is not a barrier.
3072 This means code already compiled can drop through. */
3075 drop_through_at_end_p ()
3077 rtx insn
= get_last_insn ();
3078 while (insn
&& GET_CODE (insn
) == NOTE
)
3079 insn
= PREV_INSN (insn
);
3080 return insn
&& GET_CODE (insn
) != BARRIER
;
3083 /* Attempt to optimize a potential tail recursion call into a goto.
3084 ARGUMENTS are the arguments to a CALL_EXPR; LAST_INSN indicates
3085 where to place the jump to the tail recursion label.
3087 Return TRUE if the call was optimized into a goto. */
3090 optimize_tail_recursion (arguments
, last_insn
)
3094 /* Finish checking validity, and if valid emit code to set the
3095 argument variables for the new call. */
3096 if (tail_recursion_args (arguments
, DECL_ARGUMENTS (current_function_decl
)))
3098 if (tail_recursion_label
== 0)
3100 tail_recursion_label
= gen_label_rtx ();
3101 emit_label_after (tail_recursion_label
,
3102 tail_recursion_reentry
);
3105 expand_goto_internal (NULL_TREE
, tail_recursion_label
, last_insn
);
3112 /* Emit code to alter this function's formal parms for a tail-recursive call.
3113 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3114 FORMALS is the chain of decls of formals.
3115 Return 1 if this can be done;
3116 otherwise return 0 and do not emit any code. */
3119 tail_recursion_args (actuals
, formals
)
3120 tree actuals
, formals
;
3122 register tree a
= actuals
, f
= formals
;
3124 register rtx
*argvec
;
3126 /* Check that number and types of actuals are compatible
3127 with the formals. This is not always true in valid C code.
3128 Also check that no formal needs to be addressable
3129 and that all formals are scalars. */
3131 /* Also count the args. */
3133 for (a
= actuals
, f
= formals
, i
= 0; a
&& f
; a
= TREE_CHAIN (a
), f
= TREE_CHAIN (f
), i
++)
3135 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a
)))
3136 != TYPE_MAIN_VARIANT (TREE_TYPE (f
)))
3138 if (GET_CODE (DECL_RTL (f
)) != REG
|| DECL_MODE (f
) == BLKmode
)
3141 if (a
!= 0 || f
!= 0)
3144 /* Compute all the actuals. */
3146 argvec
= (rtx
*) alloca (i
* sizeof (rtx
));
3148 for (a
= actuals
, i
= 0; a
; a
= TREE_CHAIN (a
), i
++)
3149 argvec
[i
] = expand_expr (TREE_VALUE (a
), NULL_RTX
, VOIDmode
, 0);
3151 /* Find which actual values refer to current values of previous formals.
3152 Copy each of them now, before any formal is changed. */
3154 for (a
= actuals
, i
= 0; a
; a
= TREE_CHAIN (a
), i
++)
3158 for (f
= formals
, j
= 0; j
< i
; f
= TREE_CHAIN (f
), j
++)
3159 if (reg_mentioned_p (DECL_RTL (f
), argvec
[i
]))
3165 argvec
[i
] = copy_to_reg (argvec
[i
]);
3168 /* Store the values of the actuals into the formals. */
3170 for (f
= formals
, a
= actuals
, i
= 0; f
;
3171 f
= TREE_CHAIN (f
), a
= TREE_CHAIN (a
), i
++)
3173 if (GET_MODE (DECL_RTL (f
)) == GET_MODE (argvec
[i
]))
3174 emit_move_insn (DECL_RTL (f
), argvec
[i
]);
3176 convert_move (DECL_RTL (f
), argvec
[i
],
3177 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a
))));
3184 /* Generate the RTL code for entering a binding contour.
3185 The variables are declared one by one, by calls to `expand_decl'.
3187 FLAGS is a bitwise or of the following flags:
3189 1 - Nonzero if this construct should be visible to
3192 2 - Nonzero if this contour does not require a
3193 NOTE_INSN_BLOCK_BEG note. Virtually all calls from
3194 language-independent code should set this flag because they
3195 will not create corresponding BLOCK nodes. (There should be
3196 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
3197 and BLOCKs.) If this flag is set, MARK_ENDS should be zero
3198 when expand_end_bindings is called.
3200 If we are creating a NOTE_INSN_BLOCK_BEG note, a BLOCK may
3201 optionally be supplied. If so, it becomes the NOTE_BLOCK for the
3205 expand_start_bindings_and_block (flags
, block
)
3209 struct nesting
*thisblock
= ALLOC_NESTING ();
3211 int exit_flag
= ((flags
& 1) != 0);
3212 int block_flag
= ((flags
& 2) == 0);
3214 /* If a BLOCK is supplied, then the caller should be requesting a
3215 NOTE_INSN_BLOCK_BEG note. */
3216 if (!block_flag
&& block
)
3219 /* Create a note to mark the beginning of the block. */
3222 note
= emit_note (NULL_PTR
, NOTE_INSN_BLOCK_BEG
);
3223 NOTE_BLOCK (note
) = block
;
3226 note
= emit_note (NULL_PTR
, NOTE_INSN_DELETED
);
3228 /* Make an entry on block_stack for the block we are entering. */
3230 thisblock
->next
= block_stack
;
3231 thisblock
->all
= nesting_stack
;
3232 thisblock
->depth
= ++nesting_depth
;
3233 thisblock
->data
.block
.stack_level
= 0;
3234 thisblock
->data
.block
.cleanups
= 0;
3235 thisblock
->data
.block
.n_function_calls
= 0;
3236 thisblock
->data
.block
.exception_region
= 0;
3237 thisblock
->data
.block
.block_target_temp_slot_level
= target_temp_slot_level
;
3239 thisblock
->data
.block
.conditional_code
= 0;
3240 thisblock
->data
.block
.last_unconditional_cleanup
= note
;
3241 /* When we insert instructions after the last unconditional cleanup,
3242 we don't adjust last_insn. That means that a later add_insn will
3243 clobber the instructions we've just added. The easiest way to
3244 fix this is to just insert another instruction here, so that the
3245 instructions inserted after the last unconditional cleanup are
3246 never the last instruction. */
3247 emit_note (NULL_PTR
, NOTE_INSN_DELETED
);
3248 thisblock
->data
.block
.cleanup_ptr
= &thisblock
->data
.block
.cleanups
;
3251 && !(block_stack
->data
.block
.cleanups
== NULL_TREE
3252 && block_stack
->data
.block
.outer_cleanups
== NULL_TREE
))
3253 thisblock
->data
.block
.outer_cleanups
3254 = tree_cons (NULL_TREE
, block_stack
->data
.block
.cleanups
,
3255 block_stack
->data
.block
.outer_cleanups
);
3257 thisblock
->data
.block
.outer_cleanups
= 0;
3258 thisblock
->data
.block
.label_chain
= 0;
3259 thisblock
->data
.block
.innermost_stack_block
= stack_block_stack
;
3260 thisblock
->data
.block
.first_insn
= note
;
3261 thisblock
->data
.block
.block_start_count
= ++current_block_start_count
;
3262 thisblock
->exit_label
= exit_flag
? gen_label_rtx () : 0;
3263 block_stack
= thisblock
;
3264 nesting_stack
= thisblock
;
3266 /* Make a new level for allocating stack slots. */
3270 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3271 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3272 expand_expr are made. After we end the region, we know that all
3273 space for all temporaries that were created by TARGET_EXPRs will be
3274 destroyed and their space freed for reuse. */
3277 expand_start_target_temps ()
3279 /* This is so that even if the result is preserved, the space
3280 allocated will be freed, as we know that it is no longer in use. */
3283 /* Start a new binding layer that will keep track of all cleanup
3284 actions to be performed. */
3285 expand_start_bindings (2);
3287 target_temp_slot_level
= temp_slot_level
;
3291 expand_end_target_temps ()
3293 expand_end_bindings (NULL_TREE
, 0, 0);
3295 /* This is so that even if the result is preserved, the space
3296 allocated will be freed, as we know that it is no longer in use. */
3300 /* Given a pointer to a BLOCK node return non-zero if (and only if) the node
3301 in question represents the outermost pair of curly braces (i.e. the "body
3302 block") of a function or method.
3304 For any BLOCK node representing a "body block" of a function or method, the
3305 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
3306 represents the outermost (function) scope for the function or method (i.e.
3307 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
3308 *that* node in turn will point to the relevant FUNCTION_DECL node. */
3311 is_body_block (stmt
)
3314 if (TREE_CODE (stmt
) == BLOCK
)
3316 tree parent
= BLOCK_SUPERCONTEXT (stmt
);
3318 if (parent
&& TREE_CODE (parent
) == BLOCK
)
3320 tree grandparent
= BLOCK_SUPERCONTEXT (parent
);
3322 if (grandparent
&& TREE_CODE (grandparent
) == FUNCTION_DECL
)
3330 /* Mark top block of block_stack as an implicit binding for an
3331 exception region. This is used to prevent infinite recursion when
3332 ending a binding with expand_end_bindings. It is only ever called
3333 by expand_eh_region_start, as that it the only way to create a
3334 block stack for a exception region. */
3337 mark_block_as_eh_region ()
3339 block_stack
->data
.block
.exception_region
= 1;
3340 if (block_stack
->next
3341 && block_stack
->next
->data
.block
.conditional_code
)
3343 block_stack
->data
.block
.conditional_code
3344 = block_stack
->next
->data
.block
.conditional_code
;
3345 block_stack
->data
.block
.last_unconditional_cleanup
3346 = block_stack
->next
->data
.block
.last_unconditional_cleanup
;
3347 block_stack
->data
.block
.cleanup_ptr
3348 = block_stack
->next
->data
.block
.cleanup_ptr
;
3352 /* True if we are currently emitting insns in an area of output code
3353 that is controlled by a conditional expression. This is used by
3354 the cleanup handling code to generate conditional cleanup actions. */
3357 conditional_context ()
3359 return block_stack
&& block_stack
->data
.block
.conditional_code
;
3362 /* Mark top block of block_stack as not for an implicit binding for an
3363 exception region. This is only ever done by expand_eh_region_end
3364 to let expand_end_bindings know that it is being called explicitly
3365 to end the binding layer for just the binding layer associated with
3366 the exception region, otherwise expand_end_bindings would try and
3367 end all implicit binding layers for exceptions regions, and then
3368 one normal binding layer. */
3371 mark_block_as_not_eh_region ()
3373 block_stack
->data
.block
.exception_region
= 0;
3376 /* True if the top block of block_stack was marked as for an exception
3377 region by mark_block_as_eh_region. */
3382 return cfun
&& block_stack
&& block_stack
->data
.block
.exception_region
;
3385 /* Emit a handler label for a nonlocal goto handler.
3386 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3389 expand_nl_handler_label (slot
, before_insn
)
3390 rtx slot
, before_insn
;
3393 rtx handler_label
= gen_label_rtx ();
3395 /* Don't let jump_optimize delete the handler. */
3396 LABEL_PRESERVE_P (handler_label
) = 1;
3399 emit_move_insn (slot
, gen_rtx_LABEL_REF (Pmode
, handler_label
));
3400 insns
= get_insns ();
3402 emit_insns_before (insns
, before_insn
);
3404 emit_label (handler_label
);
3406 return handler_label
;
3409 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3412 expand_nl_goto_receiver ()
3414 #ifdef HAVE_nonlocal_goto
3415 if (! HAVE_nonlocal_goto
)
3417 /* First adjust our frame pointer to its actual value. It was
3418 previously set to the start of the virtual area corresponding to
3419 the stacked variables when we branched here and now needs to be
3420 adjusted to the actual hardware fp value.
3422 Assignments are to virtual registers are converted by
3423 instantiate_virtual_regs into the corresponding assignment
3424 to the underlying register (fp in this case) that makes
3425 the original assignment true.
3426 So the following insn will actually be
3427 decrementing fp by STARTING_FRAME_OFFSET. */
3428 emit_move_insn (virtual_stack_vars_rtx
, hard_frame_pointer_rtx
);
3430 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3431 if (fixed_regs
[ARG_POINTER_REGNUM
])
3433 #ifdef ELIMINABLE_REGS
3434 /* If the argument pointer can be eliminated in favor of the
3435 frame pointer, we don't need to restore it. We assume here
3436 that if such an elimination is present, it can always be used.
3437 This is the case on all known machines; if we don't make this
3438 assumption, we do unnecessary saving on many machines. */
3439 static struct elims
{int from
, to
;} elim_regs
[] = ELIMINABLE_REGS
;
3442 for (i
= 0; i
< ARRAY_SIZE (elim_regs
); i
++)
3443 if (elim_regs
[i
].from
== ARG_POINTER_REGNUM
3444 && elim_regs
[i
].to
== HARD_FRAME_POINTER_REGNUM
)
3447 if (i
== ARRAY_SIZE (elim_regs
))
3450 /* Now restore our arg pointer from the address at which it
3451 was saved in our stack frame.
3452 If there hasn't be space allocated for it yet, make
3454 if (arg_pointer_save_area
== 0)
3455 arg_pointer_save_area
3456 = assign_stack_local (Pmode
, GET_MODE_SIZE (Pmode
), 0);
3457 emit_move_insn (virtual_incoming_args_rtx
,
3458 /* We need a pseudo here, or else
3459 instantiate_virtual_regs_1 complains. */
3460 copy_to_reg (arg_pointer_save_area
));
3465 #ifdef HAVE_nonlocal_goto_receiver
3466 if (HAVE_nonlocal_goto_receiver
)
3467 emit_insn (gen_nonlocal_goto_receiver ());
3471 /* Make handlers for nonlocal gotos taking place in the function calls in
3475 expand_nl_goto_receivers (thisblock
)
3476 struct nesting
*thisblock
;
3479 rtx afterward
= gen_label_rtx ();
3484 /* Record the handler address in the stack slot for that purpose,
3485 during this block, saving and restoring the outer value. */
3486 if (thisblock
->next
!= 0)
3487 for (slot
= nonlocal_goto_handler_slots
; slot
; slot
= XEXP (slot
, 1))
3489 rtx save_receiver
= gen_reg_rtx (Pmode
);
3490 emit_move_insn (XEXP (slot
, 0), save_receiver
);
3493 emit_move_insn (save_receiver
, XEXP (slot
, 0));
3494 insns
= get_insns ();
3496 emit_insns_before (insns
, thisblock
->data
.block
.first_insn
);
3499 /* Jump around the handlers; they run only when specially invoked. */
3500 emit_jump (afterward
);
3502 /* Make a separate handler for each label. */
3503 link
= nonlocal_labels
;
3504 slot
= nonlocal_goto_handler_slots
;
3505 label_list
= NULL_RTX
;
3506 for (; link
; link
= TREE_CHAIN (link
), slot
= XEXP (slot
, 1))
3507 /* Skip any labels we shouldn't be able to jump to from here,
3508 we generate one special handler for all of them below which just calls
3510 if (! DECL_TOO_LATE (TREE_VALUE (link
)))
3513 lab
= expand_nl_handler_label (XEXP (slot
, 0),
3514 thisblock
->data
.block
.first_insn
);
3515 label_list
= gen_rtx_EXPR_LIST (VOIDmode
, lab
, label_list
);
3517 expand_nl_goto_receiver ();
3519 /* Jump to the "real" nonlocal label. */
3520 expand_goto (TREE_VALUE (link
));
3523 /* A second pass over all nonlocal labels; this time we handle those
3524 we should not be able to jump to at this point. */
3525 link
= nonlocal_labels
;
3526 slot
= nonlocal_goto_handler_slots
;
3528 for (; link
; link
= TREE_CHAIN (link
), slot
= XEXP (slot
, 1))
3529 if (DECL_TOO_LATE (TREE_VALUE (link
)))
3532 lab
= expand_nl_handler_label (XEXP (slot
, 0),
3533 thisblock
->data
.block
.first_insn
);
3534 label_list
= gen_rtx_EXPR_LIST (VOIDmode
, lab
, label_list
);
3540 expand_nl_goto_receiver ();
3541 emit_library_call (gen_rtx_SYMBOL_REF (Pmode
, "abort"), 0,
3546 nonlocal_goto_handler_labels
= label_list
;
3547 emit_label (afterward
);
3550 /* Warn about any unused VARS (which may contain nodes other than
3551 VAR_DECLs, but such nodes are ignored). The nodes are connected
3552 via the TREE_CHAIN field. */
3555 warn_about_unused_variables (vars
)
3560 if (warn_unused_variable
)
3561 for (decl
= vars
; decl
; decl
= TREE_CHAIN (decl
))
3562 if (TREE_CODE (decl
) == VAR_DECL
3563 && ! TREE_USED (decl
)
3564 && ! DECL_IN_SYSTEM_HEADER (decl
)
3565 && DECL_NAME (decl
) && ! DECL_ARTIFICIAL (decl
))
3566 warning_with_decl (decl
, "unused variable `%s'");
3569 /* Generate RTL code to terminate a binding contour.
3571 VARS is the chain of VAR_DECL nodes for the variables bound in this
3572 contour. There may actually be other nodes in this chain, but any
3573 nodes other than VAR_DECLS are ignored.
3575 MARK_ENDS is nonzero if we should put a note at the beginning
3576 and end of this binding contour.
3578 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3579 (That is true automatically if the contour has a saved stack level.) */
3582 expand_end_bindings (vars
, mark_ends
, dont_jump_in
)
3587 register struct nesting
*thisblock
;
3589 while (block_stack
->data
.block
.exception_region
)
3591 /* Because we don't need or want a new temporary level and
3592 because we didn't create one in expand_eh_region_start,
3593 create a fake one now to avoid removing one in
3594 expand_end_bindings. */
3597 block_stack
->data
.block
.exception_region
= 0;
3599 expand_end_bindings (NULL_TREE
, 0, 0);
3602 /* Since expand_eh_region_start does an expand_start_bindings, we
3603 have to first end all the bindings that were created by
3604 expand_eh_region_start. */
3606 thisblock
= block_stack
;
3608 /* If any of the variables in this scope were not used, warn the
3610 warn_about_unused_variables (vars
);
3612 if (thisblock
->exit_label
)
3614 do_pending_stack_adjust ();
3615 emit_label (thisblock
->exit_label
);
3618 /* If necessary, make handlers for nonlocal gotos taking
3619 place in the function calls in this block. */
3620 if (function_call_count
!= thisblock
->data
.block
.n_function_calls
3622 /* Make handler for outermost block
3623 if there were any nonlocal gotos to this function. */
3624 && (thisblock
->next
== 0 ? current_function_has_nonlocal_label
3625 /* Make handler for inner block if it has something
3626 special to do when you jump out of it. */
3627 : (thisblock
->data
.block
.cleanups
!= 0
3628 || thisblock
->data
.block
.stack_level
!= 0)))
3629 expand_nl_goto_receivers (thisblock
);
3631 /* Don't allow jumping into a block that has a stack level.
3632 Cleanups are allowed, though. */
3634 || thisblock
->data
.block
.stack_level
!= 0)
3636 struct label_chain
*chain
;
3638 /* Any labels in this block are no longer valid to go to.
3639 Mark them to cause an error message. */
3640 for (chain
= thisblock
->data
.block
.label_chain
; chain
; chain
= chain
->next
)
3642 DECL_TOO_LATE (chain
->label
) = 1;
3643 /* If any goto without a fixup came to this label,
3644 that must be an error, because gotos without fixups
3645 come from outside all saved stack-levels. */
3646 if (TREE_ADDRESSABLE (chain
->label
))
3647 error_with_decl (chain
->label
,
3648 "label `%s' used before containing binding contour");
3652 /* Restore stack level in effect before the block
3653 (only if variable-size objects allocated). */
3654 /* Perform any cleanups associated with the block. */
3656 if (thisblock
->data
.block
.stack_level
!= 0
3657 || thisblock
->data
.block
.cleanups
!= 0)
3662 /* Don't let cleanups affect ({...}) constructs. */
3663 int old_expr_stmts_for_value
= expr_stmts_for_value
;
3664 rtx old_last_expr_value
= last_expr_value
;
3665 tree old_last_expr_type
= last_expr_type
;
3666 expr_stmts_for_value
= 0;
3668 /* Only clean up here if this point can actually be reached. */
3669 insn
= get_last_insn ();
3670 if (GET_CODE (insn
) == NOTE
)
3671 insn
= prev_nonnote_insn (insn
);
3672 reachable
= (! insn
|| GET_CODE (insn
) != BARRIER
);
3674 /* Do the cleanups. */
3675 expand_cleanups (thisblock
->data
.block
.cleanups
, NULL_TREE
, 0, reachable
);
3677 do_pending_stack_adjust ();
3679 expr_stmts_for_value
= old_expr_stmts_for_value
;
3680 last_expr_value
= old_last_expr_value
;
3681 last_expr_type
= old_last_expr_type
;
3683 /* Restore the stack level. */
3685 if (reachable
&& thisblock
->data
.block
.stack_level
!= 0)
3687 emit_stack_restore (thisblock
->next
? SAVE_BLOCK
: SAVE_FUNCTION
,
3688 thisblock
->data
.block
.stack_level
, NULL_RTX
);
3689 if (nonlocal_goto_handler_slots
!= 0)
3690 emit_stack_save (SAVE_NONLOCAL
, &nonlocal_goto_stack_level
,
3694 /* Any gotos out of this block must also do these things.
3695 Also report any gotos with fixups that came to labels in this
3697 fixup_gotos (thisblock
,
3698 thisblock
->data
.block
.stack_level
,
3699 thisblock
->data
.block
.cleanups
,
3700 thisblock
->data
.block
.first_insn
,
3704 /* Mark the beginning and end of the scope if requested.
3705 We do this now, after running cleanups on the variables
3706 just going out of scope, so they are in scope for their cleanups. */
3710 rtx note
= emit_note (NULL_PTR
, NOTE_INSN_BLOCK_END
);
3711 NOTE_BLOCK (note
) = NOTE_BLOCK (thisblock
->data
.block
.first_insn
);
3714 /* Get rid of the beginning-mark if we don't make an end-mark. */
3715 NOTE_LINE_NUMBER (thisblock
->data
.block
.first_insn
) = NOTE_INSN_DELETED
;
3717 /* Restore the temporary level of TARGET_EXPRs. */
3718 target_temp_slot_level
= thisblock
->data
.block
.block_target_temp_slot_level
;
3720 /* Restore block_stack level for containing block. */
3722 stack_block_stack
= thisblock
->data
.block
.innermost_stack_block
;
3723 POPSTACK (block_stack
);
3725 /* Pop the stack slot nesting and free any slots at this level. */
3729 /* Generate code to save the stack pointer at the start of the current block
3730 and set up to restore it on exit. */
3733 save_stack_pointer ()
3735 struct nesting
*thisblock
= block_stack
;
3737 if (thisblock
->data
.block
.stack_level
== 0)
3739 emit_stack_save (thisblock
->next
? SAVE_BLOCK
: SAVE_FUNCTION
,
3740 &thisblock
->data
.block
.stack_level
,
3741 thisblock
->data
.block
.first_insn
);
3742 stack_block_stack
= thisblock
;
3746 /* Generate RTL for the automatic variable declaration DECL.
3747 (Other kinds of declarations are simply ignored if seen here.) */
3753 struct nesting
*thisblock
;
3756 type
= TREE_TYPE (decl
);
3758 /* Only automatic variables need any expansion done.
3759 Static and external variables, and external functions,
3760 will be handled by `assemble_variable' (called from finish_decl).
3761 TYPE_DECL and CONST_DECL require nothing.
3762 PARM_DECLs are handled in `assign_parms'. */
3764 if (TREE_CODE (decl
) != VAR_DECL
)
3766 if (TREE_STATIC (decl
) || DECL_EXTERNAL (decl
))
3769 thisblock
= block_stack
;
3771 /* Create the RTL representation for the variable. */
3773 if (type
== error_mark_node
)
3774 DECL_RTL (decl
) = gen_rtx_MEM (BLKmode
, const0_rtx
);
3775 else if (DECL_SIZE (decl
) == 0)
3776 /* Variable with incomplete type. */
3778 if (DECL_INITIAL (decl
) == 0)
3779 /* Error message was already done; now avoid a crash. */
3780 DECL_RTL (decl
) = assign_stack_temp (DECL_MODE (decl
), 0, 1);
3782 /* An initializer is going to decide the size of this array.
3783 Until we know the size, represent its address with a reg. */
3784 DECL_RTL (decl
) = gen_rtx_MEM (BLKmode
, gen_reg_rtx (Pmode
));
3786 set_mem_attributes (DECL_RTL (decl
), decl
, 1);
3788 else if (DECL_MODE (decl
) != BLKmode
3789 /* If -ffloat-store, don't put explicit float vars
3791 && !(flag_float_store
3792 && TREE_CODE (type
) == REAL_TYPE
)
3793 && ! TREE_THIS_VOLATILE (decl
)
3794 && ! TREE_ADDRESSABLE (decl
)
3795 && (DECL_REGISTER (decl
) || optimize
)
3796 /* if -fcheck-memory-usage, check all variables. */
3797 && ! current_function_check_memory_usage
)
3799 /* Automatic variable that can go in a register. */
3800 int unsignedp
= TREE_UNSIGNED (type
);
3801 enum machine_mode reg_mode
3802 = promote_mode (type
, DECL_MODE (decl
), &unsignedp
, 0);
3804 DECL_RTL (decl
) = gen_reg_rtx (reg_mode
);
3805 mark_user_reg (DECL_RTL (decl
));
3807 if (POINTER_TYPE_P (type
))
3808 mark_reg_pointer (DECL_RTL (decl
),
3809 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl
))));
3811 maybe_set_unchanging (DECL_RTL (decl
), decl
);
3814 else if (TREE_CODE (DECL_SIZE_UNIT (decl
)) == INTEGER_CST
3815 && ! (flag_stack_check
&& ! STACK_CHECK_BUILTIN
3816 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl
),
3817 STACK_CHECK_MAX_VAR_SIZE
)))
3819 /* Variable of fixed size that goes on the stack. */
3823 /* If we previously made RTL for this decl, it must be an array
3824 whose size was determined by the initializer.
3825 The old address was a register; set that register now
3826 to the proper address. */
3827 if (DECL_RTL (decl
) != 0)
3829 if (GET_CODE (DECL_RTL (decl
)) != MEM
3830 || GET_CODE (XEXP (DECL_RTL (decl
), 0)) != REG
)
3832 oldaddr
= XEXP (DECL_RTL (decl
), 0);
3835 DECL_RTL (decl
) = assign_temp (TREE_TYPE (decl
), 1, 1, 1);
3837 /* Set alignment we actually gave this decl. */
3838 DECL_ALIGN (decl
) = (DECL_MODE (decl
) == BLKmode
? BIGGEST_ALIGNMENT
3839 : GET_MODE_BITSIZE (DECL_MODE (decl
)));
3840 DECL_USER_ALIGN (decl
) = 0;
3844 addr
= force_operand (XEXP (DECL_RTL (decl
), 0), oldaddr
);
3845 if (addr
!= oldaddr
)
3846 emit_move_insn (oldaddr
, addr
);
3850 /* Dynamic-size object: must push space on the stack. */
3854 /* Record the stack pointer on entry to block, if have
3855 not already done so. */
3856 do_pending_stack_adjust ();
3857 save_stack_pointer ();
3859 /* In function-at-a-time mode, variable_size doesn't expand this,
3861 if (TREE_CODE (type
) == ARRAY_TYPE
&& TYPE_DOMAIN (type
))
3862 expand_expr (TYPE_MAX_VALUE (TYPE_DOMAIN (type
)),
3863 const0_rtx
, VOIDmode
, 0);
3865 /* Compute the variable's size, in bytes. */
3866 size
= expand_expr (DECL_SIZE_UNIT (decl
), NULL_RTX
, VOIDmode
, 0);
3869 /* Allocate space on the stack for the variable. Note that
3870 DECL_ALIGN says how the variable is to be aligned and we
3871 cannot use it to conclude anything about the alignment of
3873 address
= allocate_dynamic_stack_space (size
, NULL_RTX
,
3874 TYPE_ALIGN (TREE_TYPE (decl
)));
3876 /* Reference the variable indirect through that rtx. */
3877 DECL_RTL (decl
) = gen_rtx_MEM (DECL_MODE (decl
), address
);
3879 set_mem_attributes (DECL_RTL (decl
), decl
, 1);
3881 /* Indicate the alignment we actually gave this variable. */
3882 #ifdef STACK_BOUNDARY
3883 DECL_ALIGN (decl
) = STACK_BOUNDARY
;
3885 DECL_ALIGN (decl
) = BIGGEST_ALIGNMENT
;
3887 DECL_USER_ALIGN (decl
) = 0;
3891 /* Emit code to perform the initialization of a declaration DECL. */
3894 expand_decl_init (decl
)
3897 int was_used
= TREE_USED (decl
);
3899 /* If this is a CONST_DECL, we don't have to generate any code, but
3900 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3901 to be set while in the obstack containing the constant. If we don't
3902 do this, we can lose if we have functions nested three deep and the middle
3903 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3904 the innermost function is the first to expand that STRING_CST. */
3905 if (TREE_CODE (decl
) == CONST_DECL
)
3907 if (DECL_INITIAL (decl
) && TREE_CONSTANT (DECL_INITIAL (decl
)))
3908 expand_expr (DECL_INITIAL (decl
), NULL_RTX
, VOIDmode
,
3909 EXPAND_INITIALIZER
);
3913 if (TREE_STATIC (decl
))
3916 /* Compute and store the initial value now. */
3918 if (DECL_INITIAL (decl
) == error_mark_node
)
3920 enum tree_code code
= TREE_CODE (TREE_TYPE (decl
));
3922 if (code
== INTEGER_TYPE
|| code
== REAL_TYPE
|| code
== ENUMERAL_TYPE
3923 || code
== POINTER_TYPE
|| code
== REFERENCE_TYPE
)
3924 expand_assignment (decl
, convert (TREE_TYPE (decl
), integer_zero_node
),
3928 else if (DECL_INITIAL (decl
) && TREE_CODE (DECL_INITIAL (decl
)) != TREE_LIST
)
3930 emit_line_note (DECL_SOURCE_FILE (decl
), DECL_SOURCE_LINE (decl
));
3931 expand_assignment (decl
, DECL_INITIAL (decl
), 0, 0);
3935 /* Don't let the initialization count as "using" the variable. */
3936 TREE_USED (decl
) = was_used
;
3938 /* Free any temporaries we made while initializing the decl. */
3939 preserve_temp_slots (NULL_RTX
);
3943 /* CLEANUP is an expression to be executed at exit from this binding contour;
3944 for example, in C++, it might call the destructor for this variable.
3946 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
3947 CLEANUP multiple times, and have the correct semantics. This
3948 happens in exception handling, for gotos, returns, breaks that
3949 leave the current scope.
3951 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3952 that is not associated with any particular variable. */
3955 expand_decl_cleanup (decl
, cleanup
)
3958 struct nesting
*thisblock
;
3960 /* Error if we are not in any block. */
3961 if (cfun
== 0 || block_stack
== 0)
3964 thisblock
= block_stack
;
3966 /* Record the cleanup if there is one. */
3972 tree
*cleanups
= &thisblock
->data
.block
.cleanups
;
3973 int cond_context
= conditional_context ();
3977 rtx flag
= gen_reg_rtx (word_mode
);
3982 emit_move_insn (flag
, const0_rtx
);
3983 set_flag_0
= get_insns ();
3986 thisblock
->data
.block
.last_unconditional_cleanup
3987 = emit_insns_after (set_flag_0
,
3988 thisblock
->data
.block
.last_unconditional_cleanup
);
3990 emit_move_insn (flag
, const1_rtx
);
3992 /* All cleanups must be on the function_obstack. */
3993 push_obstacks_nochange ();
3994 resume_temporary_allocation ();
3996 cond
= build_decl (VAR_DECL
, NULL_TREE
, type_for_mode (word_mode
, 1));
3997 DECL_RTL (cond
) = flag
;
3999 /* Conditionalize the cleanup. */
4000 cleanup
= build (COND_EXPR
, void_type_node
,
4001 truthvalue_conversion (cond
),
4002 cleanup
, integer_zero_node
);
4003 cleanup
= fold (cleanup
);
4007 cleanups
= thisblock
->data
.block
.cleanup_ptr
;
4010 /* All cleanups must be on the function_obstack. */
4011 push_obstacks_nochange ();
4012 resume_temporary_allocation ();
4013 cleanup
= unsave_expr (cleanup
);
4016 t
= *cleanups
= temp_tree_cons (decl
, cleanup
, *cleanups
);
4019 /* If this block has a cleanup, it belongs in stack_block_stack. */
4020 stack_block_stack
= thisblock
;
4027 /* If this was optimized so that there is no exception region for the
4028 cleanup, then mark the TREE_LIST node, so that we can later tell
4029 if we need to call expand_eh_region_end. */
4030 if (! using_eh_for_cleanups_p
4031 || expand_eh_region_start_tree (decl
, cleanup
))
4032 TREE_ADDRESSABLE (t
) = 1;
4033 /* If that started a new EH region, we're in a new block. */
4034 thisblock
= block_stack
;
4041 thisblock
->data
.block
.last_unconditional_cleanup
4042 = emit_insns_after (seq
,
4043 thisblock
->data
.block
.last_unconditional_cleanup
);
4047 thisblock
->data
.block
.last_unconditional_cleanup
4049 /* When we insert instructions after the last unconditional cleanup,
4050 we don't adjust last_insn. That means that a later add_insn will
4051 clobber the instructions we've just added. The easiest way to
4052 fix this is to just insert another instruction here, so that the
4053 instructions inserted after the last unconditional cleanup are
4054 never the last instruction. */
4055 emit_note (NULL_PTR
, NOTE_INSN_DELETED
);
4056 thisblock
->data
.block
.cleanup_ptr
= &thisblock
->data
.block
.cleanups
;
4062 /* Like expand_decl_cleanup, but suppress generating an exception handler
4063 to perform the cleanup. */
4067 expand_decl_cleanup_no_eh (decl
, cleanup
)
4070 int save_eh
= using_eh_for_cleanups_p
;
4073 using_eh_for_cleanups_p
= 0;
4074 result
= expand_decl_cleanup (decl
, cleanup
);
4075 using_eh_for_cleanups_p
= save_eh
;
4081 /* Arrange for the top element of the dynamic cleanup chain to be
4082 popped if we exit the current binding contour. DECL is the
4083 associated declaration, if any, otherwise NULL_TREE. If the
4084 current contour is left via an exception, then __sjthrow will pop
4085 the top element off the dynamic cleanup chain. The code that
4086 avoids doing the action we push into the cleanup chain in the
4087 exceptional case is contained in expand_cleanups.
4089 This routine is only used by expand_eh_region_start, and that is
4090 the only way in which an exception region should be started. This
4091 routine is only used when using the setjmp/longjmp codegen method
4092 for exception handling. */
4095 expand_dcc_cleanup (decl
)
4098 struct nesting
*thisblock
;
4101 /* Error if we are not in any block. */
4102 if (cfun
== 0 || block_stack
== 0)
4104 thisblock
= block_stack
;
4106 /* Record the cleanup for the dynamic handler chain. */
4108 /* All cleanups must be on the function_obstack. */
4109 push_obstacks_nochange ();
4110 resume_temporary_allocation ();
4111 cleanup
= make_node (POPDCC_EXPR
);
4114 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4115 thisblock
->data
.block
.cleanups
4116 = temp_tree_cons (decl
, cleanup
, thisblock
->data
.block
.cleanups
);
4118 /* If this block has a cleanup, it belongs in stack_block_stack. */
4119 stack_block_stack
= thisblock
;
4123 /* Arrange for the top element of the dynamic handler chain to be
4124 popped if we exit the current binding contour. DECL is the
4125 associated declaration, if any, otherwise NULL_TREE. If the current
4126 contour is left via an exception, then __sjthrow will pop the top
4127 element off the dynamic handler chain. The code that avoids doing
4128 the action we push into the handler chain in the exceptional case
4129 is contained in expand_cleanups.
4131 This routine is only used by expand_eh_region_start, and that is
4132 the only way in which an exception region should be started. This
4133 routine is only used when using the setjmp/longjmp codegen method
4134 for exception handling. */
4137 expand_dhc_cleanup (decl
)
4140 struct nesting
*thisblock
;
4143 /* Error if we are not in any block. */
4144 if (cfun
== 0 || block_stack
== 0)
4146 thisblock
= block_stack
;
4148 /* Record the cleanup for the dynamic handler chain. */
4150 /* All cleanups must be on the function_obstack. */
4151 push_obstacks_nochange ();
4152 resume_temporary_allocation ();
4153 cleanup
= make_node (POPDHC_EXPR
);
4156 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4157 thisblock
->data
.block
.cleanups
4158 = temp_tree_cons (decl
, cleanup
, thisblock
->data
.block
.cleanups
);
4160 /* If this block has a cleanup, it belongs in stack_block_stack. */
4161 stack_block_stack
= thisblock
;
4165 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4166 DECL_ELTS is the list of elements that belong to DECL's type.
4167 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4170 expand_anon_union_decl (decl
, cleanup
, decl_elts
)
4171 tree decl
, cleanup
, decl_elts
;
4173 struct nesting
*thisblock
= cfun
== 0 ? 0 : block_stack
;
4177 /* If any of the elements are addressable, so is the entire union. */
4178 for (t
= decl_elts
; t
; t
= TREE_CHAIN (t
))
4179 if (TREE_ADDRESSABLE (TREE_VALUE (t
)))
4181 TREE_ADDRESSABLE (decl
) = 1;
4186 expand_decl_cleanup (decl
, cleanup
);
4187 x
= DECL_RTL (decl
);
4189 /* Go through the elements, assigning RTL to each. */
4190 for (t
= decl_elts
; t
; t
= TREE_CHAIN (t
))
4192 tree decl_elt
= TREE_VALUE (t
);
4193 tree cleanup_elt
= TREE_PURPOSE (t
);
4194 enum machine_mode mode
= TYPE_MODE (TREE_TYPE (decl_elt
));
4196 /* Propagate the union's alignment to the elements. */
4197 DECL_ALIGN (decl_elt
) = DECL_ALIGN (decl
);
4198 DECL_USER_ALIGN (decl_elt
) = DECL_USER_ALIGN (decl
);
4200 /* If the element has BLKmode and the union doesn't, the union is
4201 aligned such that the element doesn't need to have BLKmode, so
4202 change the element's mode to the appropriate one for its size. */
4203 if (mode
== BLKmode
&& DECL_MODE (decl
) != BLKmode
)
4204 DECL_MODE (decl_elt
) = mode
4205 = mode_for_size_tree (DECL_SIZE (decl_elt
), MODE_INT
, 1);
4207 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4208 instead create a new MEM rtx with the proper mode. */
4209 if (GET_CODE (x
) == MEM
)
4211 if (mode
== GET_MODE (x
))
4212 DECL_RTL (decl_elt
) = x
;
4215 DECL_RTL (decl_elt
) = gen_rtx_MEM (mode
, copy_rtx (XEXP (x
, 0)));
4216 MEM_COPY_ATTRIBUTES (DECL_RTL (decl_elt
), x
);
4219 else if (GET_CODE (x
) == REG
)
4221 if (mode
== GET_MODE (x
))
4222 DECL_RTL (decl_elt
) = x
;
4224 DECL_RTL (decl_elt
) = gen_rtx_SUBREG (mode
, x
, 0);
4229 /* Record the cleanup if there is one. */
4232 thisblock
->data
.block
.cleanups
4233 = temp_tree_cons (decl_elt
, cleanup_elt
,
4234 thisblock
->data
.block
.cleanups
);
4238 /* Expand a list of cleanups LIST.
4239 Elements may be expressions or may be nested lists.
4241 If DONT_DO is nonnull, then any list-element
4242 whose TREE_PURPOSE matches DONT_DO is omitted.
4243 This is sometimes used to avoid a cleanup associated with
4244 a value that is being returned out of the scope.
4246 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
4247 goto and handle protection regions specially in that case.
4249 If REACHABLE, we emit code, otherwise just inform the exception handling
4250 code about this finalization. */
4253 expand_cleanups (list
, dont_do
, in_fixup
, reachable
)
4260 for (tail
= list
; tail
; tail
= TREE_CHAIN (tail
))
4261 if (dont_do
== 0 || TREE_PURPOSE (tail
) != dont_do
)
4263 if (TREE_CODE (TREE_VALUE (tail
)) == TREE_LIST
)
4264 expand_cleanups (TREE_VALUE (tail
), dont_do
, in_fixup
, reachable
);
4269 tree cleanup
= TREE_VALUE (tail
);
4271 /* See expand_d{h,c}c_cleanup for why we avoid this. */
4272 if (TREE_CODE (cleanup
) != POPDHC_EXPR
4273 && TREE_CODE (cleanup
) != POPDCC_EXPR
4274 /* See expand_eh_region_start_tree for this case. */
4275 && ! TREE_ADDRESSABLE (tail
))
4277 cleanup
= protect_with_terminate (cleanup
);
4278 expand_eh_region_end (cleanup
);
4284 /* Cleanups may be run multiple times. For example,
4285 when exiting a binding contour, we expand the
4286 cleanups associated with that contour. When a goto
4287 within that binding contour has a target outside that
4288 contour, it will expand all cleanups from its scope to
4289 the target. Though the cleanups are expanded multiple
4290 times, the control paths are non-overlapping so the
4291 cleanups will not be executed twice. */
4293 /* We may need to protect fixups with rethrow regions. */
4294 int protect
= (in_fixup
&& ! TREE_ADDRESSABLE (tail
));
4297 expand_fixup_region_start ();
4299 /* The cleanup might contain try-blocks, so we have to
4300 preserve our current queue. */
4302 expand_expr (TREE_VALUE (tail
), const0_rtx
, VOIDmode
, 0);
4305 expand_fixup_region_end (TREE_VALUE (tail
));
4312 /* Mark when the context we are emitting RTL for as a conditional
4313 context, so that any cleanup actions we register with
4314 expand_decl_init will be properly conditionalized when those
4315 cleanup actions are later performed. Must be called before any
4316 expression (tree) is expanded that is within a conditional context. */
4319 start_cleanup_deferral ()
4321 /* block_stack can be NULL if we are inside the parameter list. It is
4322 OK to do nothing, because cleanups aren't possible here. */
4324 ++block_stack
->data
.block
.conditional_code
;
4327 /* Mark the end of a conditional region of code. Because cleanup
4328 deferrals may be nested, we may still be in a conditional region
4329 after we end the currently deferred cleanups, only after we end all
4330 deferred cleanups, are we back in unconditional code. */
4333 end_cleanup_deferral ()
4335 /* block_stack can be NULL if we are inside the parameter list. It is
4336 OK to do nothing, because cleanups aren't possible here. */
4338 --block_stack
->data
.block
.conditional_code
;
4341 /* Move all cleanups from the current block_stack
4342 to the containing block_stack, where they are assumed to
4343 have been created. If anything can cause a temporary to
4344 be created, but not expanded for more than one level of
4345 block_stacks, then this code will have to change. */
4350 struct nesting
*block
= block_stack
;
4351 struct nesting
*outer
= block
->next
;
4353 outer
->data
.block
.cleanups
4354 = chainon (block
->data
.block
.cleanups
,
4355 outer
->data
.block
.cleanups
);
4356 block
->data
.block
.cleanups
= 0;
4360 last_cleanup_this_contour ()
4362 if (block_stack
== 0)
4365 return block_stack
->data
.block
.cleanups
;
4368 /* Return 1 if there are any pending cleanups at this point.
4369 If THIS_CONTOUR is nonzero, check the current contour as well.
4370 Otherwise, look only at the contours that enclose this one. */
4373 any_pending_cleanups (this_contour
)
4376 struct nesting
*block
;
4378 if (cfun
== NULL
|| cfun
->stmt
== NULL
|| block_stack
== 0)
4381 if (this_contour
&& block_stack
->data
.block
.cleanups
!= NULL
)
4383 if (block_stack
->data
.block
.cleanups
== 0
4384 && block_stack
->data
.block
.outer_cleanups
== 0)
4387 for (block
= block_stack
->next
; block
; block
= block
->next
)
4388 if (block
->data
.block
.cleanups
!= 0)
4394 /* Enter a case (Pascal) or switch (C) statement.
4395 Push a block onto case_stack and nesting_stack
4396 to accumulate the case-labels that are seen
4397 and to record the labels generated for the statement.
4399 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4400 Otherwise, this construct is transparent for `exit_something'.
4402 EXPR is the index-expression to be dispatched on.
4403 TYPE is its nominal type. We could simply convert EXPR to this type,
4404 but instead we take short cuts. */
4407 expand_start_case (exit_flag
, expr
, type
, printname
)
4411 const char *printname
;
4413 register struct nesting
*thiscase
= ALLOC_NESTING ();
4415 /* Make an entry on case_stack for the case we are entering. */
4417 thiscase
->next
= case_stack
;
4418 thiscase
->all
= nesting_stack
;
4419 thiscase
->depth
= ++nesting_depth
;
4420 thiscase
->exit_label
= exit_flag
? gen_label_rtx () : 0;
4421 thiscase
->data
.case_stmt
.case_list
= 0;
4422 thiscase
->data
.case_stmt
.index_expr
= expr
;
4423 thiscase
->data
.case_stmt
.nominal_type
= type
;
4424 thiscase
->data
.case_stmt
.default_label
= 0;
4425 thiscase
->data
.case_stmt
.num_ranges
= 0;
4426 thiscase
->data
.case_stmt
.printname
= printname
;
4427 thiscase
->data
.case_stmt
.line_number_status
= force_line_numbers ();
4428 case_stack
= thiscase
;
4429 nesting_stack
= thiscase
;
4431 do_pending_stack_adjust ();
4433 /* Make sure case_stmt.start points to something that won't
4434 need any transformation before expand_end_case. */
4435 if (GET_CODE (get_last_insn ()) != NOTE
)
4436 emit_note (NULL_PTR
, NOTE_INSN_DELETED
);
4438 thiscase
->data
.case_stmt
.start
= get_last_insn ();
4440 start_cleanup_deferral ();
4443 /* Start a "dummy case statement" within which case labels are invalid
4444 and are not connected to any larger real case statement.
4445 This can be used if you don't want to let a case statement jump
4446 into the middle of certain kinds of constructs. */
4449 expand_start_case_dummy ()
4451 register struct nesting
*thiscase
= ALLOC_NESTING ();
4453 /* Make an entry on case_stack for the dummy. */
4455 thiscase
->next
= case_stack
;
4456 thiscase
->all
= nesting_stack
;
4457 thiscase
->depth
= ++nesting_depth
;
4458 thiscase
->exit_label
= 0;
4459 thiscase
->data
.case_stmt
.case_list
= 0;
4460 thiscase
->data
.case_stmt
.start
= 0;
4461 thiscase
->data
.case_stmt
.nominal_type
= 0;
4462 thiscase
->data
.case_stmt
.default_label
= 0;
4463 thiscase
->data
.case_stmt
.num_ranges
= 0;
4464 case_stack
= thiscase
;
4465 nesting_stack
= thiscase
;
4466 start_cleanup_deferral ();
4469 /* End a dummy case statement. */
4472 expand_end_case_dummy ()
4474 end_cleanup_deferral ();
4475 POPSTACK (case_stack
);
4478 /* Return the data type of the index-expression
4479 of the innermost case statement, or null if none. */
4482 case_index_expr_type ()
4485 return TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4492 /* If this is the first label, warn if any insns have been emitted. */
4493 if (case_stack
->data
.case_stmt
.line_number_status
>= 0)
4497 restore_line_number_status
4498 (case_stack
->data
.case_stmt
.line_number_status
);
4499 case_stack
->data
.case_stmt
.line_number_status
= -1;
4501 for (insn
= case_stack
->data
.case_stmt
.start
;
4503 insn
= NEXT_INSN (insn
))
4505 if (GET_CODE (insn
) == CODE_LABEL
)
4507 if (GET_CODE (insn
) != NOTE
4508 && (GET_CODE (insn
) != INSN
|| GET_CODE (PATTERN (insn
)) != USE
))
4511 insn
= PREV_INSN (insn
);
4512 while (insn
&& (GET_CODE (insn
) != NOTE
|| NOTE_LINE_NUMBER (insn
) < 0));
4514 /* If insn is zero, then there must have been a syntax error. */
4516 warning_with_file_and_line (NOTE_SOURCE_FILE (insn
),
4517 NOTE_LINE_NUMBER (insn
),
4518 "unreachable code at beginning of %s",
4519 case_stack
->data
.case_stmt
.printname
);
4526 /* Accumulate one case or default label inside a case or switch statement.
4527 VALUE is the value of the case (a null pointer, for a default label).
4528 The function CONVERTER, when applied to arguments T and V,
4529 converts the value V to the type T.
4531 If not currently inside a case or switch statement, return 1 and do
4532 nothing. The caller will print a language-specific error message.
4533 If VALUE is a duplicate or overlaps, return 2 and do nothing
4534 except store the (first) duplicate node in *DUPLICATE.
4535 If VALUE is out of range, return 3 and do nothing.
4536 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4537 Return 0 on success.
4539 Extended to handle range statements. */
4542 pushcase (value
, converter
, label
, duplicate
)
4543 register tree value
;
4544 tree (*converter
) PARAMS ((tree
, tree
));
4545 register tree label
;
4551 /* Fail if not inside a real case statement. */
4552 if (! (case_stack
&& case_stack
->data
.case_stmt
.start
))
4555 if (stack_block_stack
4556 && stack_block_stack
->depth
> case_stack
->depth
)
4559 index_type
= TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4560 nominal_type
= case_stack
->data
.case_stmt
.nominal_type
;
4562 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4563 if (index_type
== error_mark_node
)
4566 /* Convert VALUE to the type in which the comparisons are nominally done. */
4568 value
= (*converter
) (nominal_type
, value
);
4572 /* Fail if this value is out of range for the actual type of the index
4573 (which may be narrower than NOMINAL_TYPE). */
4575 && (TREE_CONSTANT_OVERFLOW (value
)
4576 || ! int_fits_type_p (value
, index_type
)))
4579 /* Fail if this is a duplicate or overlaps another entry. */
4582 if (case_stack
->data
.case_stmt
.default_label
!= 0)
4584 *duplicate
= case_stack
->data
.case_stmt
.default_label
;
4587 case_stack
->data
.case_stmt
.default_label
= label
;
4590 return add_case_node (value
, value
, label
, duplicate
);
4592 expand_label (label
);
4596 /* Like pushcase but this case applies to all values between VALUE1 and
4597 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4598 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4599 starts at VALUE1 and ends at the highest value of the index type.
4600 If both are NULL, this case applies to all values.
4602 The return value is the same as that of pushcase but there is one
4603 additional error code: 4 means the specified range was empty. */
4606 pushcase_range (value1
, value2
, converter
, label
, duplicate
)
4607 register tree value1
, value2
;
4608 tree (*converter
) PARAMS ((tree
, tree
));
4609 register tree label
;
4615 /* Fail if not inside a real case statement. */
4616 if (! (case_stack
&& case_stack
->data
.case_stmt
.start
))
4619 if (stack_block_stack
4620 && stack_block_stack
->depth
> case_stack
->depth
)
4623 index_type
= TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4624 nominal_type
= case_stack
->data
.case_stmt
.nominal_type
;
4626 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4627 if (index_type
== error_mark_node
)
4632 /* Convert VALUEs to type in which the comparisons are nominally done
4633 and replace any unspecified value with the corresponding bound. */
4635 value1
= TYPE_MIN_VALUE (index_type
);
4637 value2
= TYPE_MAX_VALUE (index_type
);
4639 /* Fail if the range is empty. Do this before any conversion since
4640 we want to allow out-of-range empty ranges. */
4641 if (value2
!= 0 && tree_int_cst_lt (value2
, value1
))
4644 /* If the max was unbounded, use the max of the nominal_type we are
4645 converting to. Do this after the < check above to suppress false
4648 value2
= TYPE_MAX_VALUE (nominal_type
);
4650 value1
= (*converter
) (nominal_type
, value1
);
4651 value2
= (*converter
) (nominal_type
, value2
);
4653 /* Fail if these values are out of range. */
4654 if (TREE_CONSTANT_OVERFLOW (value1
)
4655 || ! int_fits_type_p (value1
, index_type
))
4658 if (TREE_CONSTANT_OVERFLOW (value2
)
4659 || ! int_fits_type_p (value2
, index_type
))
4662 return add_case_node (value1
, value2
, label
, duplicate
);
4665 /* Do the actual insertion of a case label for pushcase and pushcase_range
4666 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4667 slowdown for large switch statements. */
4670 add_case_node (low
, high
, label
, duplicate
)
4675 struct case_node
*p
, **q
, *r
;
4677 q
= &case_stack
->data
.case_stmt
.case_list
;
4684 /* Keep going past elements distinctly greater than HIGH. */
4685 if (tree_int_cst_lt (high
, p
->low
))
4688 /* or distinctly less than LOW. */
4689 else if (tree_int_cst_lt (p
->high
, low
))
4694 /* We have an overlap; this is an error. */
4695 *duplicate
= p
->code_label
;
4700 /* Add this label to the chain, and succeed.
4701 Copy LOW, HIGH so they are on temporary rather than momentary
4702 obstack and will thus survive till the end of the case statement. */
4704 r
= (struct case_node
*) oballoc (sizeof (struct case_node
));
4705 r
->low
= copy_node (low
);
4707 /* If the bounds are equal, turn this into the one-value case. */
4709 if (tree_int_cst_equal (low
, high
))
4713 r
->high
= copy_node (high
);
4714 case_stack
->data
.case_stmt
.num_ranges
++;
4717 r
->code_label
= label
;
4718 expand_label (label
);
4728 struct case_node
*s
;
4734 if (! (b
= p
->balance
))
4735 /* Growth propagation from left side. */
4742 if ((p
->left
= s
= r
->right
))
4751 if ((r
->parent
= s
))
4759 case_stack
->data
.case_stmt
.case_list
= r
;
4762 /* r->balance == +1 */
4767 struct case_node
*t
= r
->right
;
4769 if ((p
->left
= s
= t
->right
))
4773 if ((r
->right
= s
= t
->left
))
4787 if ((t
->parent
= s
))
4795 case_stack
->data
.case_stmt
.case_list
= t
;
4802 /* p->balance == +1; growth of left side balances the node. */
4812 if (! (b
= p
->balance
))
4813 /* Growth propagation from right side. */
4821 if ((p
->right
= s
= r
->left
))
4829 if ((r
->parent
= s
))
4838 case_stack
->data
.case_stmt
.case_list
= r
;
4842 /* r->balance == -1 */
4846 struct case_node
*t
= r
->left
;
4848 if ((p
->right
= s
= t
->left
))
4853 if ((r
->left
= s
= t
->right
))
4867 if ((t
->parent
= s
))
4876 case_stack
->data
.case_stmt
.case_list
= t
;
4882 /* p->balance == -1; growth of right side balances the node. */
4895 /* Returns the number of possible values of TYPE.
4896 Returns -1 if the number is unknown, variable, or if the number does not
4897 fit in a HOST_WIDE_INT.
4898 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4899 do not increase monotonically (there may be duplicates);
4900 to 1 if the values increase monotonically, but not always by 1;
4901 otherwise sets it to 0. */
4904 all_cases_count (type
, spareness
)
4909 HOST_WIDE_INT count
, minval
, lastval
;
4913 switch (TREE_CODE (type
))
4920 count
= 1 << BITS_PER_UNIT
;
4925 if (TYPE_MAX_VALUE (type
) != 0
4926 && 0 != (t
= fold (build (MINUS_EXPR
, type
, TYPE_MAX_VALUE (type
),
4927 TYPE_MIN_VALUE (type
))))
4928 && 0 != (t
= fold (build (PLUS_EXPR
, type
, t
,
4929 convert (type
, integer_zero_node
))))
4930 && host_integerp (t
, 1))
4931 count
= tree_low_cst (t
, 1);
4937 /* Don't waste time with enumeral types with huge values. */
4938 if (! host_integerp (TYPE_MIN_VALUE (type
), 0)
4939 || TYPE_MAX_VALUE (type
) == 0
4940 || ! host_integerp (TYPE_MAX_VALUE (type
), 0))
4943 lastval
= minval
= tree_low_cst (TYPE_MIN_VALUE (type
), 0);
4946 for (t
= TYPE_VALUES (type
); t
!= NULL_TREE
; t
= TREE_CHAIN (t
))
4948 HOST_WIDE_INT thisval
= tree_low_cst (TREE_VALUE (t
), 0);
4950 if (*spareness
== 2 || thisval
< lastval
)
4952 else if (thisval
!= minval
+ count
)
4962 #define BITARRAY_TEST(ARRAY, INDEX) \
4963 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4964 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4965 #define BITARRAY_SET(ARRAY, INDEX) \
4966 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4967 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4969 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4970 with the case values we have seen, assuming the case expression
4972 SPARSENESS is as determined by all_cases_count.
4974 The time needed is proportional to COUNT, unless
4975 SPARSENESS is 2, in which case quadratic time is needed. */
4978 mark_seen_cases (type
, cases_seen
, count
, sparseness
)
4980 unsigned char *cases_seen
;
4981 HOST_WIDE_INT count
;
4984 tree next_node_to_try
= NULL_TREE
;
4985 HOST_WIDE_INT next_node_offset
= 0;
4987 register struct case_node
*n
, *root
= case_stack
->data
.case_stmt
.case_list
;
4988 tree val
= make_node (INTEGER_CST
);
4990 TREE_TYPE (val
) = type
;
4994 else if (sparseness
== 2)
4997 unsigned HOST_WIDE_INT xlo
;
4999 /* This less efficient loop is only needed to handle
5000 duplicate case values (multiple enum constants
5001 with the same value). */
5002 TREE_TYPE (val
) = TREE_TYPE (root
->low
);
5003 for (t
= TYPE_VALUES (type
), xlo
= 0; t
!= NULL_TREE
;
5004 t
= TREE_CHAIN (t
), xlo
++)
5006 TREE_INT_CST_LOW (val
) = TREE_INT_CST_LOW (TREE_VALUE (t
));
5007 TREE_INT_CST_HIGH (val
) = TREE_INT_CST_HIGH (TREE_VALUE (t
));
5011 /* Keep going past elements distinctly greater than VAL. */
5012 if (tree_int_cst_lt (val
, n
->low
))
5015 /* or distinctly less than VAL. */
5016 else if (tree_int_cst_lt (n
->high
, val
))
5021 /* We have found a matching range. */
5022 BITARRAY_SET (cases_seen
, xlo
);
5032 case_stack
->data
.case_stmt
.case_list
= root
= case_tree2list (root
, 0);
5034 for (n
= root
; n
; n
= n
->right
)
5036 TREE_INT_CST_LOW (val
) = TREE_INT_CST_LOW (n
->low
);
5037 TREE_INT_CST_HIGH (val
) = TREE_INT_CST_HIGH (n
->low
);
5038 while (! tree_int_cst_lt (n
->high
, val
))
5040 /* Calculate (into xlo) the "offset" of the integer (val).
5041 The element with lowest value has offset 0, the next smallest
5042 element has offset 1, etc. */
5044 unsigned HOST_WIDE_INT xlo
;
5048 if (sparseness
&& TYPE_VALUES (type
) != NULL_TREE
)
5050 /* The TYPE_VALUES will be in increasing order, so
5051 starting searching where we last ended. */
5052 t
= next_node_to_try
;
5053 xlo
= next_node_offset
;
5059 t
= TYPE_VALUES (type
);
5062 if (tree_int_cst_equal (val
, TREE_VALUE (t
)))
5064 next_node_to_try
= TREE_CHAIN (t
);
5065 next_node_offset
= xlo
+ 1;
5070 if (t
== next_node_to_try
)
5079 t
= TYPE_MIN_VALUE (type
);
5081 neg_double (TREE_INT_CST_LOW (t
), TREE_INT_CST_HIGH (t
),
5085 add_double (xlo
, xhi
,
5086 TREE_INT_CST_LOW (val
), TREE_INT_CST_HIGH (val
),
5090 if (xhi
== 0 && xlo
< (unsigned HOST_WIDE_INT
) count
)
5091 BITARRAY_SET (cases_seen
, xlo
);
5093 add_double (TREE_INT_CST_LOW (val
), TREE_INT_CST_HIGH (val
),
5095 &TREE_INT_CST_LOW (val
), &TREE_INT_CST_HIGH (val
));
5101 /* Called when the index of a switch statement is an enumerated type
5102 and there is no default label.
5104 Checks that all enumeration literals are covered by the case
5105 expressions of a switch. Also, warn if there are any extra
5106 switch cases that are *not* elements of the enumerated type.
5108 If all enumeration literals were covered by the case expressions,
5109 turn one of the expressions into the default expression since it should
5110 not be possible to fall through such a switch. */
5113 check_for_full_enumeration_handling (type
)
5116 register struct case_node
*n
;
5117 register tree chain
;
5118 #if 0 /* variable used by 'if 0'ed code below. */
5119 register struct case_node
**l
;
5123 /* True iff the selector type is a numbered set mode. */
5126 /* The number of possible selector values. */
5129 /* For each possible selector value. a one iff it has been matched
5130 by a case value alternative. */
5131 unsigned char *cases_seen
;
5133 /* The allocated size of cases_seen, in chars. */
5134 HOST_WIDE_INT bytes_needed
;
5139 size
= all_cases_count (type
, &sparseness
);
5140 bytes_needed
= (size
+ HOST_BITS_PER_CHAR
) / HOST_BITS_PER_CHAR
;
5142 if (size
> 0 && size
< 600000
5143 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5144 this optimization if we don't have enough memory rather than
5145 aborting, as xmalloc would do. */
5146 && (cases_seen
= (unsigned char *) calloc (bytes_needed
, 1)) != NULL
)
5149 tree v
= TYPE_VALUES (type
);
5151 /* The time complexity of this code is normally O(N), where
5152 N being the number of members in the enumerated type.
5153 However, if type is a ENUMERAL_TYPE whose values do not
5154 increase monotonically, O(N*log(N)) time may be needed. */
5156 mark_seen_cases (type
, cases_seen
, size
, sparseness
);
5158 for (i
= 0; v
!= NULL_TREE
&& i
< size
; i
++, v
= TREE_CHAIN (v
))
5159 if (BITARRAY_TEST (cases_seen
, i
) == 0)
5160 warning ("enumeration value `%s' not handled in switch",
5161 IDENTIFIER_POINTER (TREE_PURPOSE (v
)));
5166 /* Now we go the other way around; we warn if there are case
5167 expressions that don't correspond to enumerators. This can
5168 occur since C and C++ don't enforce type-checking of
5169 assignments to enumeration variables. */
5171 if (case_stack
->data
.case_stmt
.case_list
5172 && case_stack
->data
.case_stmt
.case_list
->left
)
5173 case_stack
->data
.case_stmt
.case_list
5174 = case_tree2list (case_stack
->data
.case_stmt
.case_list
, 0);
5176 for (n
= case_stack
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5178 for (chain
= TYPE_VALUES (type
);
5179 chain
&& !tree_int_cst_equal (n
->low
, TREE_VALUE (chain
));
5180 chain
= TREE_CHAIN (chain
))
5185 if (TYPE_NAME (type
) == 0)
5186 warning ("case value `%ld' not in enumerated type",
5187 (long) TREE_INT_CST_LOW (n
->low
));
5189 warning ("case value `%ld' not in enumerated type `%s'",
5190 (long) TREE_INT_CST_LOW (n
->low
),
5191 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type
))
5194 : DECL_NAME (TYPE_NAME (type
))));
5196 if (!tree_int_cst_equal (n
->low
, n
->high
))
5198 for (chain
= TYPE_VALUES (type
);
5199 chain
&& !tree_int_cst_equal (n
->high
, TREE_VALUE (chain
));
5200 chain
= TREE_CHAIN (chain
))
5205 if (TYPE_NAME (type
) == 0)
5206 warning ("case value `%ld' not in enumerated type",
5207 (long) TREE_INT_CST_LOW (n
->high
));
5209 warning ("case value `%ld' not in enumerated type `%s'",
5210 (long) TREE_INT_CST_LOW (n
->high
),
5211 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type
))
5214 : DECL_NAME (TYPE_NAME (type
))));
5220 /* ??? This optimization is disabled because it causes valid programs to
5221 fail. ANSI C does not guarantee that an expression with enum type
5222 will have a value that is the same as one of the enumeration literals. */
5224 /* If all values were found as case labels, make one of them the default
5225 label. Thus, this switch will never fall through. We arbitrarily pick
5226 the last one to make the default since this is likely the most
5227 efficient choice. */
5231 for (l
= &case_stack
->data
.case_stmt
.case_list
;
5236 case_stack
->data
.case_stmt
.default_label
= (*l
)->code_label
;
5243 /* Terminate a case (Pascal) or switch (C) statement
5244 in which ORIG_INDEX is the expression to be tested.
5245 Generate the code to test it and jump to the right place. */
5248 expand_end_case (orig_index
)
5251 tree minval
= NULL_TREE
, maxval
= NULL_TREE
, range
= NULL_TREE
, orig_minval
;
5252 rtx default_label
= 0;
5253 register struct case_node
*n
;
5261 register struct nesting
*thiscase
= case_stack
;
5262 tree index_expr
, index_type
;
5265 /* Don't crash due to previous errors. */
5266 if (thiscase
== NULL
)
5269 table_label
= gen_label_rtx ();
5270 index_expr
= thiscase
->data
.case_stmt
.index_expr
;
5271 index_type
= TREE_TYPE (index_expr
);
5272 unsignedp
= TREE_UNSIGNED (index_type
);
5274 do_pending_stack_adjust ();
5276 /* This might get an spurious warning in the presence of a syntax error;
5277 it could be fixed by moving the call to check_seenlabel after the
5278 check for error_mark_node, and copying the code of check_seenlabel that
5279 deals with case_stack->data.case_stmt.line_number_status /
5280 restore_line_number_status in front of the call to end_cleanup_deferral;
5281 However, this might miss some useful warnings in the presence of
5282 non-syntax errors. */
5285 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5286 if (index_type
!= error_mark_node
)
5288 /* If switch expression was an enumerated type, check that all
5289 enumeration literals are covered by the cases.
5290 No sense trying this if there's a default case, however. */
5292 if (!thiscase
->data
.case_stmt
.default_label
5293 && TREE_CODE (TREE_TYPE (orig_index
)) == ENUMERAL_TYPE
5294 && TREE_CODE (index_expr
) != INTEGER_CST
)
5295 check_for_full_enumeration_handling (TREE_TYPE (orig_index
));
5297 /* If we don't have a default-label, create one here,
5298 after the body of the switch. */
5299 if (thiscase
->data
.case_stmt
.default_label
== 0)
5301 thiscase
->data
.case_stmt
.default_label
5302 = build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
5303 expand_label (thiscase
->data
.case_stmt
.default_label
);
5305 default_label
= label_rtx (thiscase
->data
.case_stmt
.default_label
);
5307 before_case
= get_last_insn ();
5309 if (thiscase
->data
.case_stmt
.case_list
5310 && thiscase
->data
.case_stmt
.case_list
->left
)
5311 thiscase
->data
.case_stmt
.case_list
5312 = case_tree2list (thiscase
->data
.case_stmt
.case_list
, 0);
5314 /* Simplify the case-list before we count it. */
5315 group_case_nodes (thiscase
->data
.case_stmt
.case_list
);
5317 /* Get upper and lower bounds of case values.
5318 Also convert all the case values to the index expr's data type. */
5321 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5323 /* Check low and high label values are integers. */
5324 if (TREE_CODE (n
->low
) != INTEGER_CST
)
5326 if (TREE_CODE (n
->high
) != INTEGER_CST
)
5329 n
->low
= convert (index_type
, n
->low
);
5330 n
->high
= convert (index_type
, n
->high
);
5332 /* Count the elements and track the largest and smallest
5333 of them (treating them as signed even if they are not). */
5341 if (INT_CST_LT (n
->low
, minval
))
5343 if (INT_CST_LT (maxval
, n
->high
))
5346 /* A range counts double, since it requires two compares. */
5347 if (! tree_int_cst_equal (n
->low
, n
->high
))
5351 orig_minval
= minval
;
5353 /* Compute span of values. */
5355 range
= fold (build (MINUS_EXPR
, index_type
, maxval
, minval
));
5357 end_cleanup_deferral ();
5361 expand_expr (index_expr
, const0_rtx
, VOIDmode
, 0);
5363 emit_jump (default_label
);
5366 /* If range of values is much bigger than number of values,
5367 make a sequence of conditional branches instead of a dispatch.
5368 If the switch-index is a constant, do it this way
5369 because we can optimize it. */
5371 #ifndef CASE_VALUES_THRESHOLD
5373 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
5375 /* If machine does not have a case insn that compares the
5376 bounds, this means extra overhead for dispatch tables
5377 which raises the threshold for using them. */
5378 #define CASE_VALUES_THRESHOLD 5
5379 #endif /* HAVE_casesi */
5380 #endif /* CASE_VALUES_THRESHOLD */
5382 else if (count
< CASE_VALUES_THRESHOLD
5383 || compare_tree_int (range
, 10 * count
) > 0
5384 /* RANGE may be signed, and really large ranges will show up
5385 as negative numbers. */
5386 || compare_tree_int (range
, 0) < 0
5387 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5390 || TREE_CODE (index_expr
) == INTEGER_CST
5391 /* These will reduce to a constant. */
5392 || (TREE_CODE (index_expr
) == CALL_EXPR
5393 && TREE_CODE (TREE_OPERAND (index_expr
, 0)) == ADDR_EXPR
5394 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr
, 0), 0)) == FUNCTION_DECL
5395 && DECL_BUILT_IN_CLASS (TREE_OPERAND (TREE_OPERAND (index_expr
, 0), 0)) == BUILT_IN_NORMAL
5396 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr
, 0), 0)) == BUILT_IN_CLASSIFY_TYPE
)
5397 || (TREE_CODE (index_expr
) == COMPOUND_EXPR
5398 && TREE_CODE (TREE_OPERAND (index_expr
, 1)) == INTEGER_CST
))
5400 index
= expand_expr (index_expr
, NULL_RTX
, VOIDmode
, 0);
5402 /* If the index is a short or char that we do not have
5403 an insn to handle comparisons directly, convert it to
5404 a full integer now, rather than letting each comparison
5405 generate the conversion. */
5407 if (GET_MODE_CLASS (GET_MODE (index
)) == MODE_INT
5408 && (cmp_optab
->handlers
[(int) GET_MODE (index
)].insn_code
5409 == CODE_FOR_nothing
))
5411 enum machine_mode wider_mode
;
5412 for (wider_mode
= GET_MODE (index
); wider_mode
!= VOIDmode
;
5413 wider_mode
= GET_MODE_WIDER_MODE (wider_mode
))
5414 if (cmp_optab
->handlers
[(int) wider_mode
].insn_code
5415 != CODE_FOR_nothing
)
5417 index
= convert_to_mode (wider_mode
, index
, unsignedp
);
5423 do_pending_stack_adjust ();
5425 index
= protect_from_queue (index
, 0);
5426 if (GET_CODE (index
) == MEM
)
5427 index
= copy_to_reg (index
);
5428 if (GET_CODE (index
) == CONST_INT
5429 || TREE_CODE (index_expr
) == INTEGER_CST
)
5431 /* Make a tree node with the proper constant value
5432 if we don't already have one. */
5433 if (TREE_CODE (index_expr
) != INTEGER_CST
)
5436 = build_int_2 (INTVAL (index
),
5437 unsignedp
|| INTVAL (index
) >= 0 ? 0 : -1);
5438 index_expr
= convert (index_type
, index_expr
);
5441 /* For constant index expressions we need only
5442 issue a unconditional branch to the appropriate
5443 target code. The job of removing any unreachable
5444 code is left to the optimisation phase if the
5445 "-O" option is specified. */
5446 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5447 if (! tree_int_cst_lt (index_expr
, n
->low
)
5448 && ! tree_int_cst_lt (n
->high
, index_expr
))
5452 emit_jump (label_rtx (n
->code_label
));
5454 emit_jump (default_label
);
5458 /* If the index expression is not constant we generate
5459 a binary decision tree to select the appropriate
5460 target code. This is done as follows:
5462 The list of cases is rearranged into a binary tree,
5463 nearly optimal assuming equal probability for each case.
5465 The tree is transformed into RTL, eliminating
5466 redundant test conditions at the same time.
5468 If program flow could reach the end of the
5469 decision tree an unconditional jump to the
5470 default code is emitted. */
5473 = (TREE_CODE (TREE_TYPE (orig_index
)) != ENUMERAL_TYPE
5474 && estimate_case_costs (thiscase
->data
.case_stmt
.case_list
));
5475 balance_case_nodes (&thiscase
->data
.case_stmt
.case_list
,
5477 emit_case_nodes (index
, thiscase
->data
.case_stmt
.case_list
,
5478 default_label
, index_type
);
5479 emit_jump_if_reachable (default_label
);
5488 enum machine_mode index_mode
= SImode
;
5489 int index_bits
= GET_MODE_BITSIZE (index_mode
);
5491 enum machine_mode op_mode
;
5493 /* Convert the index to SImode. */
5494 if (GET_MODE_BITSIZE (TYPE_MODE (index_type
))
5495 > GET_MODE_BITSIZE (index_mode
))
5497 enum machine_mode omode
= TYPE_MODE (index_type
);
5498 rtx rangertx
= expand_expr (range
, NULL_RTX
, VOIDmode
, 0);
5500 /* We must handle the endpoints in the original mode. */
5501 index_expr
= build (MINUS_EXPR
, index_type
,
5502 index_expr
, minval
);
5503 minval
= integer_zero_node
;
5504 index
= expand_expr (index_expr
, NULL_RTX
, VOIDmode
, 0);
5505 emit_cmp_and_jump_insns (rangertx
, index
, LTU
, NULL_RTX
,
5506 omode
, 1, 0, default_label
);
5507 /* Now we can safely truncate. */
5508 index
= convert_to_mode (index_mode
, index
, 0);
5512 if (TYPE_MODE (index_type
) != index_mode
)
5514 index_expr
= convert (type_for_size (index_bits
, 0),
5516 index_type
= TREE_TYPE (index_expr
);
5519 index
= expand_expr (index_expr
, NULL_RTX
, VOIDmode
, 0);
5522 index
= protect_from_queue (index
, 0);
5523 do_pending_stack_adjust ();
5525 op_mode
= insn_data
[(int) CODE_FOR_casesi
].operand
[0].mode
;
5526 if (! (*insn_data
[(int) CODE_FOR_casesi
].operand
[0].predicate
)
5528 index
= copy_to_mode_reg (op_mode
, index
);
5530 op1
= expand_expr (minval
, NULL_RTX
, VOIDmode
, 0);
5532 op_mode
= insn_data
[(int) CODE_FOR_casesi
].operand
[1].mode
;
5533 if (! (*insn_data
[(int) CODE_FOR_casesi
].operand
[1].predicate
)
5535 op1
= copy_to_mode_reg (op_mode
, op1
);
5537 op2
= expand_expr (range
, NULL_RTX
, VOIDmode
, 0);
5539 op_mode
= insn_data
[(int) CODE_FOR_casesi
].operand
[2].mode
;
5540 if (! (*insn_data
[(int) CODE_FOR_casesi
].operand
[2].predicate
)
5542 op2
= copy_to_mode_reg (op_mode
, op2
);
5544 emit_jump_insn (gen_casesi (index
, op1
, op2
,
5545 table_label
, default_label
));
5549 #ifdef HAVE_tablejump
5550 if (! win
&& HAVE_tablejump
)
5552 index_type
= thiscase
->data
.case_stmt
.nominal_type
;
5553 index_expr
= fold (build (MINUS_EXPR
, index_type
,
5554 convert (index_type
, index_expr
),
5555 convert (index_type
, minval
)));
5556 index
= expand_expr (index_expr
, NULL_RTX
, VOIDmode
, 0);
5558 index
= protect_from_queue (index
, 0);
5559 do_pending_stack_adjust ();
5561 do_tablejump (index
, TYPE_MODE (index_type
),
5562 expand_expr (range
, NULL_RTX
, VOIDmode
, 0),
5563 table_label
, default_label
);
5570 /* Get table of labels to jump to, in order of case index. */
5572 ncases
= TREE_INT_CST_LOW (range
) + 1;
5573 labelvec
= (rtx
*) alloca (ncases
* sizeof (rtx
));
5574 bzero ((char *) labelvec
, ncases
* sizeof (rtx
));
5576 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5578 register HOST_WIDE_INT i
5579 = TREE_INT_CST_LOW (n
->low
) - TREE_INT_CST_LOW (orig_minval
);
5584 = gen_rtx_LABEL_REF (Pmode
, label_rtx (n
->code_label
));
5585 if (i
+ TREE_INT_CST_LOW (orig_minval
)
5586 == TREE_INT_CST_LOW (n
->high
))
5592 /* Fill in the gaps with the default. */
5593 for (i
= 0; i
< ncases
; i
++)
5594 if (labelvec
[i
] == 0)
5595 labelvec
[i
] = gen_rtx_LABEL_REF (Pmode
, default_label
);
5597 /* Output the table */
5598 emit_label (table_label
);
5600 if (CASE_VECTOR_PC_RELATIVE
|| flag_pic
)
5601 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE
,
5602 gen_rtx_LABEL_REF (Pmode
, table_label
),
5603 gen_rtvec_v (ncases
, labelvec
),
5604 const0_rtx
, const0_rtx
));
5606 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE
,
5607 gen_rtvec_v (ncases
, labelvec
)));
5609 /* If the case insn drops through the table,
5610 after the table we must jump to the default-label.
5611 Otherwise record no drop-through after the table. */
5612 #ifdef CASE_DROPS_THROUGH
5613 emit_jump (default_label
);
5619 before_case
= squeeze_notes (NEXT_INSN (before_case
), get_last_insn ());
5620 reorder_insns (before_case
, get_last_insn (),
5621 thiscase
->data
.case_stmt
.start
);
5624 end_cleanup_deferral ();
5626 if (thiscase
->exit_label
)
5627 emit_label (thiscase
->exit_label
);
5629 POPSTACK (case_stack
);
5634 /* Convert the tree NODE into a list linked by the right field, with the left
5635 field zeroed. RIGHT is used for recursion; it is a list to be placed
5636 rightmost in the resulting list. */
5638 static struct case_node
*
5639 case_tree2list (node
, right
)
5640 struct case_node
*node
, *right
;
5642 struct case_node
*left
;
5645 right
= case_tree2list (node
->right
, right
);
5647 node
->right
= right
;
5648 if ((left
= node
->left
))
5651 return case_tree2list (left
, node
);
5657 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5660 do_jump_if_equal (op1
, op2
, label
, unsignedp
)
5661 rtx op1
, op2
, label
;
5664 if (GET_CODE (op1
) == CONST_INT
5665 && GET_CODE (op2
) == CONST_INT
)
5667 if (INTVAL (op1
) == INTVAL (op2
))
5672 enum machine_mode mode
= GET_MODE (op1
);
5673 if (mode
== VOIDmode
)
5674 mode
= GET_MODE (op2
);
5675 emit_cmp_and_jump_insns (op1
, op2
, EQ
, NULL_RTX
, mode
, unsignedp
,
5680 /* Not all case values are encountered equally. This function
5681 uses a heuristic to weight case labels, in cases where that
5682 looks like a reasonable thing to do.
5684 Right now, all we try to guess is text, and we establish the
5687 chars above space: 16
5696 If we find any cases in the switch that are not either -1 or in the range
5697 of valid ASCII characters, or are control characters other than those
5698 commonly used with "\", don't treat this switch scanning text.
5700 Return 1 if these nodes are suitable for cost estimation, otherwise
5704 estimate_case_costs (node
)
5707 tree min_ascii
= build_int_2 (-1, -1);
5708 tree max_ascii
= convert (TREE_TYPE (node
->high
), build_int_2 (127, 0));
5712 /* If we haven't already made the cost table, make it now. Note that the
5713 lower bound of the table is -1, not zero. */
5715 if (cost_table
== NULL
)
5717 cost_table
= cost_table_
+ 1;
5719 for (i
= 0; i
< 128; i
++)
5723 else if (ISPUNCT (i
))
5725 else if (ISCNTRL (i
))
5729 cost_table
[' '] = 8;
5730 cost_table
['\t'] = 4;
5731 cost_table
['\0'] = 4;
5732 cost_table
['\n'] = 2;
5733 cost_table
['\f'] = 1;
5734 cost_table
['\v'] = 1;
5735 cost_table
['\b'] = 1;
5738 /* See if all the case expressions look like text. It is text if the
5739 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5740 as signed arithmetic since we don't want to ever access cost_table with a
5741 value less than -1. Also check that none of the constants in a range
5742 are strange control characters. */
5744 for (n
= node
; n
; n
= n
->right
)
5746 if ((INT_CST_LT (n
->low
, min_ascii
)) || INT_CST_LT (max_ascii
, n
->high
))
5749 for (i
= (HOST_WIDE_INT
) TREE_INT_CST_LOW (n
->low
);
5750 i
<= (HOST_WIDE_INT
) TREE_INT_CST_LOW (n
->high
); i
++)
5751 if (cost_table
[i
] < 0)
5755 /* All interesting values are within the range of interesting
5756 ASCII characters. */
5760 /* Scan an ordered list of case nodes
5761 combining those with consecutive values or ranges.
5763 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5766 group_case_nodes (head
)
5769 case_node_ptr node
= head
;
5773 rtx lb
= next_real_insn (label_rtx (node
->code_label
));
5775 case_node_ptr np
= node
;
5777 /* Try to group the successors of NODE with NODE. */
5778 while (((np
= np
->right
) != 0)
5779 /* Do they jump to the same place? */
5780 && ((lb2
= next_real_insn (label_rtx (np
->code_label
))) == lb
5781 || (lb
!= 0 && lb2
!= 0
5782 && simplejump_p (lb
)
5783 && simplejump_p (lb2
)
5784 && rtx_equal_p (SET_SRC (PATTERN (lb
)),
5785 SET_SRC (PATTERN (lb2
)))))
5786 /* Are their ranges consecutive? */
5787 && tree_int_cst_equal (np
->low
,
5788 fold (build (PLUS_EXPR
,
5789 TREE_TYPE (node
->high
),
5792 /* An overflow is not consecutive. */
5793 && tree_int_cst_lt (node
->high
,
5794 fold (build (PLUS_EXPR
,
5795 TREE_TYPE (node
->high
),
5797 integer_one_node
))))
5799 node
->high
= np
->high
;
5801 /* NP is the first node after NODE which can't be grouped with it.
5802 Delete the nodes in between, and move on to that node. */
5808 /* Take an ordered list of case nodes
5809 and transform them into a near optimal binary tree,
5810 on the assumption that any target code selection value is as
5811 likely as any other.
5813 The transformation is performed by splitting the ordered
5814 list into two equal sections plus a pivot. The parts are
5815 then attached to the pivot as left and right branches. Each
5816 branch is then transformed recursively. */
5819 balance_case_nodes (head
, parent
)
5820 case_node_ptr
*head
;
5821 case_node_ptr parent
;
5823 register case_node_ptr np
;
5831 register case_node_ptr
*npp
;
5834 /* Count the number of entries on branch. Also count the ranges. */
5838 if (!tree_int_cst_equal (np
->low
, np
->high
))
5842 cost
+= cost_table
[TREE_INT_CST_LOW (np
->high
)];
5846 cost
+= cost_table
[TREE_INT_CST_LOW (np
->low
)];
5854 /* Split this list if it is long enough for that to help. */
5859 /* Find the place in the list that bisects the list's total cost,
5860 Here I gets half the total cost. */
5865 /* Skip nodes while their cost does not reach that amount. */
5866 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
5867 i
-= cost_table
[TREE_INT_CST_LOW ((*npp
)->high
)];
5868 i
-= cost_table
[TREE_INT_CST_LOW ((*npp
)->low
)];
5871 npp
= &(*npp
)->right
;
5876 /* Leave this branch lopsided, but optimize left-hand
5877 side and fill in `parent' fields for right-hand side. */
5879 np
->parent
= parent
;
5880 balance_case_nodes (&np
->left
, np
);
5881 for (; np
->right
; np
= np
->right
)
5882 np
->right
->parent
= np
;
5886 /* If there are just three nodes, split at the middle one. */
5888 npp
= &(*npp
)->right
;
5891 /* Find the place in the list that bisects the list's total cost,
5892 where ranges count as 2.
5893 Here I gets half the total cost. */
5894 i
= (i
+ ranges
+ 1) / 2;
5897 /* Skip nodes while their cost does not reach that amount. */
5898 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
5903 npp
= &(*npp
)->right
;
5908 np
->parent
= parent
;
5911 /* Optimize each of the two split parts. */
5912 balance_case_nodes (&np
->left
, np
);
5913 balance_case_nodes (&np
->right
, np
);
5917 /* Else leave this branch as one level,
5918 but fill in `parent' fields. */
5920 np
->parent
= parent
;
5921 for (; np
->right
; np
= np
->right
)
5922 np
->right
->parent
= np
;
5927 /* Search the parent sections of the case node tree
5928 to see if a test for the lower bound of NODE would be redundant.
5929 INDEX_TYPE is the type of the index expression.
5931 The instructions to generate the case decision tree are
5932 output in the same order as nodes are processed so it is
5933 known that if a parent node checks the range of the current
5934 node minus one that the current node is bounded at its lower
5935 span. Thus the test would be redundant. */
5938 node_has_low_bound (node
, index_type
)
5943 case_node_ptr pnode
;
5945 /* If the lower bound of this node is the lowest value in the index type,
5946 we need not test it. */
5948 if (tree_int_cst_equal (node
->low
, TYPE_MIN_VALUE (index_type
)))
5951 /* If this node has a left branch, the value at the left must be less
5952 than that at this node, so it cannot be bounded at the bottom and
5953 we need not bother testing any further. */
5958 low_minus_one
= fold (build (MINUS_EXPR
, TREE_TYPE (node
->low
),
5959 node
->low
, integer_one_node
));
5961 /* If the subtraction above overflowed, we can't verify anything.
5962 Otherwise, look for a parent that tests our value - 1. */
5964 if (! tree_int_cst_lt (low_minus_one
, node
->low
))
5967 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
5968 if (tree_int_cst_equal (low_minus_one
, pnode
->high
))
5974 /* Search the parent sections of the case node tree
5975 to see if a test for the upper bound of NODE would be redundant.
5976 INDEX_TYPE is the type of the index expression.
5978 The instructions to generate the case decision tree are
5979 output in the same order as nodes are processed so it is
5980 known that if a parent node checks the range of the current
5981 node plus one that the current node is bounded at its upper
5982 span. Thus the test would be redundant. */
5985 node_has_high_bound (node
, index_type
)
5990 case_node_ptr pnode
;
5992 /* If there is no upper bound, obviously no test is needed. */
5994 if (TYPE_MAX_VALUE (index_type
) == NULL
)
5997 /* If the upper bound of this node is the highest value in the type
5998 of the index expression, we need not test against it. */
6000 if (tree_int_cst_equal (node
->high
, TYPE_MAX_VALUE (index_type
)))
6003 /* If this node has a right branch, the value at the right must be greater
6004 than that at this node, so it cannot be bounded at the top and
6005 we need not bother testing any further. */
6010 high_plus_one
= fold (build (PLUS_EXPR
, TREE_TYPE (node
->high
),
6011 node
->high
, integer_one_node
));
6013 /* If the addition above overflowed, we can't verify anything.
6014 Otherwise, look for a parent that tests our value + 1. */
6016 if (! tree_int_cst_lt (node
->high
, high_plus_one
))
6019 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
6020 if (tree_int_cst_equal (high_plus_one
, pnode
->low
))
6026 /* Search the parent sections of the
6027 case node tree to see if both tests for the upper and lower
6028 bounds of NODE would be redundant. */
6031 node_is_bounded (node
, index_type
)
6035 return (node_has_low_bound (node
, index_type
)
6036 && node_has_high_bound (node
, index_type
));
6039 /* Emit an unconditional jump to LABEL unless it would be dead code. */
6042 emit_jump_if_reachable (label
)
6045 if (GET_CODE (get_last_insn ()) != BARRIER
)
6049 /* Emit step-by-step code to select a case for the value of INDEX.
6050 The thus generated decision tree follows the form of the
6051 case-node binary tree NODE, whose nodes represent test conditions.
6052 INDEX_TYPE is the type of the index of the switch.
6054 Care is taken to prune redundant tests from the decision tree
6055 by detecting any boundary conditions already checked by
6056 emitted rtx. (See node_has_high_bound, node_has_low_bound
6057 and node_is_bounded, above.)
6059 Where the test conditions can be shown to be redundant we emit
6060 an unconditional jump to the target code. As a further
6061 optimization, the subordinates of a tree node are examined to
6062 check for bounded nodes. In this case conditional and/or
6063 unconditional jumps as a result of the boundary check for the
6064 current node are arranged to target the subordinates associated
6065 code for out of bound conditions on the current node.
6067 We can assume that when control reaches the code generated here,
6068 the index value has already been compared with the parents
6069 of this node, and determined to be on the same side of each parent
6070 as this node is. Thus, if this node tests for the value 51,
6071 and a parent tested for 52, we don't need to consider
6072 the possibility of a value greater than 51. If another parent
6073 tests for the value 50, then this node need not test anything. */
6076 emit_case_nodes (index
, node
, default_label
, index_type
)
6082 /* If INDEX has an unsigned type, we must make unsigned branches. */
6083 int unsignedp
= TREE_UNSIGNED (index_type
);
6084 enum machine_mode mode
= GET_MODE (index
);
6086 /* See if our parents have already tested everything for us.
6087 If they have, emit an unconditional jump for this node. */
6088 if (node_is_bounded (node
, index_type
))
6089 emit_jump (label_rtx (node
->code_label
));
6091 else if (tree_int_cst_equal (node
->low
, node
->high
))
6093 /* Node is single valued. First see if the index expression matches
6094 this node and then check our children, if any. */
6096 do_jump_if_equal (index
, expand_expr (node
->low
, NULL_RTX
, VOIDmode
, 0),
6097 label_rtx (node
->code_label
), unsignedp
);
6099 if (node
->right
!= 0 && node
->left
!= 0)
6101 /* This node has children on both sides.
6102 Dispatch to one side or the other
6103 by comparing the index value with this node's value.
6104 If one subtree is bounded, check that one first,
6105 so we can avoid real branches in the tree. */
6107 if (node_is_bounded (node
->right
, index_type
))
6109 emit_cmp_and_jump_insns (index
,
6110 expand_expr (node
->high
, NULL_RTX
,
6112 GT
, NULL_RTX
, mode
, unsignedp
, 0,
6113 label_rtx (node
->right
->code_label
));
6114 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6117 else if (node_is_bounded (node
->left
, index_type
))
6119 emit_cmp_and_jump_insns (index
,
6120 expand_expr (node
->high
, NULL_RTX
,
6122 LT
, NULL_RTX
, mode
, unsignedp
, 0,
6123 label_rtx (node
->left
->code_label
));
6124 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6129 /* Neither node is bounded. First distinguish the two sides;
6130 then emit the code for one side at a time. */
6132 tree test_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
6134 /* See if the value is on the right. */
6135 emit_cmp_and_jump_insns (index
,
6136 expand_expr (node
->high
, NULL_RTX
,
6138 GT
, NULL_RTX
, mode
, unsignedp
, 0,
6139 label_rtx (test_label
));
6141 /* Value must be on the left.
6142 Handle the left-hand subtree. */
6143 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6144 /* If left-hand subtree does nothing,
6146 emit_jump_if_reachable (default_label
);
6148 /* Code branches here for the right-hand subtree. */
6149 expand_label (test_label
);
6150 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6154 else if (node
->right
!= 0 && node
->left
== 0)
6156 /* Here we have a right child but no left so we issue conditional
6157 branch to default and process the right child.
6159 Omit the conditional branch to default if we it avoid only one
6160 right child; it costs too much space to save so little time. */
6162 if (node
->right
->right
|| node
->right
->left
6163 || !tree_int_cst_equal (node
->right
->low
, node
->right
->high
))
6165 if (!node_has_low_bound (node
, index_type
))
6167 emit_cmp_and_jump_insns (index
,
6168 expand_expr (node
->high
, NULL_RTX
,
6170 LT
, NULL_RTX
, mode
, unsignedp
, 0,
6174 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6177 /* We cannot process node->right normally
6178 since we haven't ruled out the numbers less than
6179 this node's value. So handle node->right explicitly. */
6180 do_jump_if_equal (index
,
6181 expand_expr (node
->right
->low
, NULL_RTX
,
6183 label_rtx (node
->right
->code_label
), unsignedp
);
6186 else if (node
->right
== 0 && node
->left
!= 0)
6188 /* Just one subtree, on the left. */
6190 #if 0 /* The following code and comment were formerly part
6191 of the condition here, but they didn't work
6192 and I don't understand what the idea was. -- rms. */
6193 /* If our "most probable entry" is less probable
6194 than the default label, emit a jump to
6195 the default label using condition codes
6196 already lying around. With no right branch,
6197 a branch-greater-than will get us to the default
6200 && cost_table
[TREE_INT_CST_LOW (node
->high
)] < 12)
6203 if (node
->left
->left
|| node
->left
->right
6204 || !tree_int_cst_equal (node
->left
->low
, node
->left
->high
))
6206 if (!node_has_high_bound (node
, index_type
))
6208 emit_cmp_and_jump_insns (index
, expand_expr (node
->high
,
6211 GT
, NULL_RTX
, mode
, unsignedp
, 0,
6215 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6218 /* We cannot process node->left normally
6219 since we haven't ruled out the numbers less than
6220 this node's value. So handle node->left explicitly. */
6221 do_jump_if_equal (index
,
6222 expand_expr (node
->left
->low
, NULL_RTX
,
6224 label_rtx (node
->left
->code_label
), unsignedp
);
6229 /* Node is a range. These cases are very similar to those for a single
6230 value, except that we do not start by testing whether this node
6231 is the one to branch to. */
6233 if (node
->right
!= 0 && node
->left
!= 0)
6235 /* Node has subtrees on both sides.
6236 If the right-hand subtree is bounded,
6237 test for it first, since we can go straight there.
6238 Otherwise, we need to make a branch in the control structure,
6239 then handle the two subtrees. */
6240 tree test_label
= 0;
6242 if (node_is_bounded (node
->right
, index_type
))
6243 /* Right hand node is fully bounded so we can eliminate any
6244 testing and branch directly to the target code. */
6245 emit_cmp_and_jump_insns (index
, expand_expr (node
->high
, NULL_RTX
,
6247 GT
, NULL_RTX
, mode
, unsignedp
, 0,
6248 label_rtx (node
->right
->code_label
));
6251 /* Right hand node requires testing.
6252 Branch to a label where we will handle it later. */
6254 test_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
6255 emit_cmp_and_jump_insns (index
,
6256 expand_expr (node
->high
, NULL_RTX
,
6258 GT
, NULL_RTX
, mode
, unsignedp
, 0,
6259 label_rtx (test_label
));
6262 /* Value belongs to this node or to the left-hand subtree. */
6264 emit_cmp_and_jump_insns (index
, 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
,
6292 expand_expr (node
->low
, NULL_RTX
,
6294 LT
, NULL_RTX
, mode
, unsignedp
, 0,
6298 /* Value belongs to this node or to the right-hand subtree. */
6300 emit_cmp_and_jump_insns (index
, expand_expr (node
->high
, NULL_RTX
,
6302 LE
, NULL_RTX
, mode
, unsignedp
, 0,
6303 label_rtx (node
->code_label
));
6305 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6308 else if (node
->right
== 0 && node
->left
!= 0)
6310 /* Deal with values to the right of this node,
6311 if they are possible. */
6312 if (!node_has_high_bound (node
, index_type
))
6314 emit_cmp_and_jump_insns (index
,
6315 expand_expr (node
->high
, NULL_RTX
,
6317 GT
, NULL_RTX
, mode
, unsignedp
, 0,
6321 /* Value belongs to this node or to the left-hand subtree. */
6323 emit_cmp_and_jump_insns (index
,
6324 expand_expr (node
->low
, NULL_RTX
,
6326 GE
, NULL_RTX
, mode
, unsignedp
, 0,
6327 label_rtx (node
->code_label
));
6329 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6334 /* Node has no children so we check low and high bounds to remove
6335 redundant tests. Only one of the bounds can exist,
6336 since otherwise this node is bounded--a case tested already. */
6338 if (!node_has_high_bound (node
, index_type
))
6340 emit_cmp_and_jump_insns (index
,
6341 expand_expr (node
->high
, NULL_RTX
,
6343 GT
, NULL_RTX
, mode
, unsignedp
, 0,
6347 if (!node_has_low_bound (node
, index_type
))
6349 emit_cmp_and_jump_insns (index
,
6350 expand_expr (node
->low
, NULL_RTX
,
6352 LT
, NULL_RTX
, mode
, unsignedp
, 0,
6356 emit_jump (label_rtx (node
->code_label
));