1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 1988, 1989, 1992 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
21 /* This file handles the generation of rtl code from tree structure
22 above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
23 It also creates the rtl expressions for parameters and auto variables
24 and has full responsibility for allocating stack slots.
26 The functions whose names start with `expand_' are called by the
27 parser to generate RTL instructions for various kinds of constructs.
29 Some control and binding constructs require calling several such
30 functions at different times. For example, a simple if-then
31 is expanded by calling `expand_start_cond' (with the condition-expression
32 as argument) before parsing the then-clause and calling `expand_end_cond'
33 after parsing the then-clause. */
44 #include "insn-flags.h"
45 #include "insn-config.h"
46 #include "insn-codes.h"
48 #include "hard-reg-set.h"
53 #define obstack_chunk_alloc xmalloc
54 #define obstack_chunk_free free
55 struct obstack stmt_obstack
;
57 extern int xmalloc ();
60 /* Filename and line number of last line-number note,
61 whether we actually emitted it or not. */
65 /* Nonzero if within a ({...}) grouping, in which case we must
66 always compute a value for each expr-stmt in case it is the last one. */
68 int expr_stmts_for_value
;
70 /* Each time we expand an expression-statement,
71 record the expr's type and its RTL value here. */
73 static tree last_expr_type
;
74 static rtx last_expr_value
;
76 /* Number of binding contours started so far in this function. */
78 int block_start_count
;
80 /* Nonzero if function being compiled needs to
81 return the address of where it has put a structure value. */
83 extern int current_function_returns_pcc_struct
;
85 /* Label that will go on parm cleanup code, if any.
86 Jumping to this label runs cleanup code for parameters, if
87 such code must be run. Following this code is the logical return label. */
89 extern rtx cleanup_label
;
91 /* Label that will go on function epilogue.
92 Jumping to this label serves as a "return" instruction
93 on machines which require execution of the epilogue on all returns. */
95 extern rtx return_label
;
97 /* List (chain of EXPR_LISTs) of pseudo-regs of SAVE_EXPRs.
98 So we can mark them all live at the end of the function, if nonopt. */
99 extern rtx save_expr_regs
;
101 /* Offset to end of allocated area of stack frame.
102 If stack grows down, this is the address of the last stack slot allocated.
103 If stack grows up, this is the address for the next slot. */
104 extern int frame_offset
;
106 /* Label to jump back to for tail recursion, or 0 if we have
107 not yet needed one for this function. */
108 extern rtx tail_recursion_label
;
110 /* Place after which to insert the tail_recursion_label if we need one. */
111 extern rtx tail_recursion_reentry
;
113 /* Location at which to save the argument pointer if it will need to be
114 referenced. There are two cases where this is done: if nonlocal gotos
115 exist, or if vars whose is an offset from the argument pointer will be
116 needed by inner routines. */
118 extern rtx arg_pointer_save_area
;
120 /* Chain of all RTL_EXPRs that have insns in them. */
121 extern tree rtl_expr_chain
;
123 #if 0 /* Turned off because 0 seems to work just as well. */
124 /* Cleanup lists are required for binding levels regardless of whether
125 that binding level has cleanups or not. This node serves as the
126 cleanup list whenever an empty list is required. */
127 static tree empty_cleanup_list
;
130 /* Functions and data structures for expanding case statements. */
132 /* Case label structure, used to hold info on labels within case
133 statements. We handle "range" labels; for a single-value label
134 as in C, the high and low limits are the same.
136 A chain of case nodes is initially maintained via the RIGHT fields
137 in the nodes. Nodes with higher case values are later in the list.
139 Switch statements can be output in one of two forms. A branch table
140 is used if there are more than a few labels and the labels are dense
141 within the range between the smallest and largest case value. If a
142 branch table is used, no further manipulations are done with the case
145 The alternative to the use of a branch table is to generate a series
146 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
147 and PARENT fields to hold a binary tree. Initially the tree is
148 totally unbalanced, with everything on the right. We balance the tree
149 with nodes on the left having lower case values than the parent
150 and nodes on the right having higher values. We then output the tree
155 struct case_node
*left
; /* Left son in binary tree */
156 struct case_node
*right
; /* Right son in binary tree; also node chain */
157 struct case_node
*parent
; /* Parent of node in binary tree */
158 tree low
; /* Lowest index value for this label */
159 tree high
; /* Highest index value for this label */
160 tree code_label
; /* Label to jump to when node matches */
163 typedef struct case_node case_node
;
164 typedef struct case_node
*case_node_ptr
;
166 /* These are used by estimate_case_costs and balance_case_nodes. */
168 /* This must be a signed type, and non-ANSI compilers lack signed char. */
169 static short *cost_table
;
170 static int use_cost_table
;
172 static int estimate_case_costs ();
173 static void balance_case_nodes ();
174 static void emit_case_nodes ();
175 static void group_case_nodes ();
176 static void emit_jump_if_reachable ();
178 static int warn_if_unused_value ();
179 static void expand_goto_internal ();
180 static int expand_fixup ();
182 void free_temp_slots ();
183 static void expand_cleanups ();
184 static void fixup_cleanups ();
185 static void expand_null_return_1 ();
186 static int tail_recursion_args ();
187 static void do_jump_if_equal ();
189 /* Stack of control and binding constructs we are currently inside.
191 These constructs begin when you call `expand_start_WHATEVER'
192 and end when you call `expand_end_WHATEVER'. This stack records
193 info about how the construct began that tells the end-function
194 what to do. It also may provide information about the construct
195 to alter the behavior of other constructs within the body.
196 For example, they may affect the behavior of C `break' and `continue'.
198 Each construct gets one `struct nesting' object.
199 All of these objects are chained through the `all' field.
200 `nesting_stack' points to the first object (innermost construct).
201 The position of an entry on `nesting_stack' is in its `depth' field.
203 Each type of construct has its own individual stack.
204 For example, loops have `loop_stack'. Each object points to the
205 next object of the same type through the `next' field.
207 Some constructs are visible to `break' exit-statements and others
208 are not. Which constructs are visible depends on the language.
209 Therefore, the data structure allows each construct to be visible
210 or not, according to the args given when the construct is started.
211 The construct is visible if the `exit_label' field is non-null.
212 In that case, the value should be a CODE_LABEL rtx. */
217 struct nesting
*next
;
222 /* For conds (if-then and if-then-else statements). */
225 /* Label for the end of the if construct.
226 There is none if EXITFLAG was not set
227 and no `else' has been seen yet. */
229 /* Label for the end of this alternative.
230 This may be the end of the if or the next else/elseif. */
236 /* Label at the top of the loop; place to loop back to. */
238 /* Label at the end of the whole construct. */
240 /* Label for `continue' statement to jump to;
241 this is in front of the stepper of the loop. */
244 /* For variable binding contours. */
247 /* Sequence number of this binding contour within the function,
248 in order of entry. */
249 int block_start_count
;
250 /* Nonzero => value to restore stack to on exit. */
252 /* The NOTE that starts this contour.
253 Used by expand_goto to check whether the destination
254 is within each contour or not. */
256 /* Innermost containing binding contour that has a stack level. */
257 struct nesting
*innermost_stack_block
;
258 /* List of cleanups to be run on exit from this contour.
259 This is a list of expressions to be evaluated.
260 The TREE_PURPOSE of each link is the ..._DECL node
261 which the cleanup pertains to. */
263 /* List of cleanup-lists of blocks containing this block,
264 as they were at the locus where this block appears.
265 There is an element for each containing block,
266 ordered innermost containing block first.
267 The tail of this list can be 0 (was empty_cleanup_list),
268 if all remaining elements would be empty lists.
269 The element's TREE_VALUE is the cleanup-list of that block,
270 which may be null. */
272 /* Chain of labels defined inside this binding contour.
273 For contours that have stack levels or cleanups. */
274 struct label_chain
*label_chain
;
275 /* Number of function calls seen, as of start of this block. */
276 int function_call_count
;
278 /* For switch (C) or case (Pascal) statements,
279 and also for dummies (see `expand_start_case_dummy'). */
282 /* The insn after which the case dispatch should finally
283 be emitted. Zero for a dummy. */
285 /* A list of case labels, kept in ascending order by value
286 as the list is built.
287 During expand_end_case, this list may be rearranged into a
288 nearly balanced binary tree. */
289 struct case_node
*case_list
;
290 /* Label to jump to if no case matches. */
292 /* The expression to be dispatched on. */
294 /* Type that INDEX_EXPR should be converted to. */
296 /* Number of range exprs in case statement. */
298 /* Name of this kind of statement, for warnings. */
300 /* Nonzero if a case label has been seen in this case stmt. */
303 /* For exception contours. */
306 /* List of exceptions raised. This is a TREE_LIST
307 of whatever you want. */
309 /* List of exceptions caught. This is also a TREE_LIST
310 of whatever you want. As a special case, it has the
311 value `void_type_node' if it handles default exceptions. */
314 /* First insn of TRY block, in case resumptive model is needed. */
316 /* Label for the catch clauses. */
318 /* Label for unhandled exceptions. */
320 /* Label at the end of whole construct. */
322 /* Label which "escapes" the exception construct.
323 Like EXIT_LABEL for BREAK construct, but for exceptions. */
329 /* Chain of all pending binding contours. */
330 struct nesting
*block_stack
;
332 /* Chain of all pending binding contours that restore stack levels
334 struct nesting
*stack_block_stack
;
336 /* Chain of all pending conditional statements. */
337 struct nesting
*cond_stack
;
339 /* Chain of all pending loops. */
340 struct nesting
*loop_stack
;
342 /* Chain of all pending case or switch statements. */
343 struct nesting
*case_stack
;
345 /* Chain of all pending exception contours. */
346 struct nesting
*except_stack
;
348 /* Separate chain including all of the above,
349 chained through the `all' field. */
350 struct nesting
*nesting_stack
;
352 /* Number of entries on nesting_stack now. */
355 /* Allocate and return a new `struct nesting'. */
357 #define ALLOC_NESTING() \
358 (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
360 /* Pop one of the sub-stacks, such as `loop_stack' or `cond_stack';
361 and pop off `nesting_stack' down to the same level. */
363 #define POPSTACK(STACK) \
364 do { int initial_depth = nesting_stack->depth; \
365 do { struct nesting *this = STACK; \
366 STACK = this->next; \
367 nesting_stack = this->all; \
368 nesting_depth = this->depth; \
369 obstack_free (&stmt_obstack, this); } \
370 while (nesting_depth > initial_depth); } while (0)
372 /* In some cases it is impossible to generate code for a forward goto
373 until the label definition is seen. This happens when it may be necessary
374 for the goto to reset the stack pointer: we don't yet know how to do that.
375 So expand_goto puts an entry on this fixup list.
376 Each time a binding contour that resets the stack is exited,
378 If the target label has now been defined, we can insert the proper code. */
382 /* Points to following fixup. */
383 struct goto_fixup
*next
;
384 /* Points to the insn before the jump insn.
385 If more code must be inserted, it goes after this insn. */
387 /* The LABEL_DECL that this jump is jumping to, or 0
388 for break, continue or return. */
390 /* The CODE_LABEL rtx that this is jumping to. */
392 /* Number of binding contours started in current function
393 before the label reference. */
394 int block_start_count
;
395 /* The outermost stack level that should be restored for this jump.
396 Each time a binding contour that resets the stack is exited,
397 if the target label is *not* yet defined, this slot is updated. */
399 /* List of lists of cleanup expressions to be run by this goto.
400 There is one element for each block that this goto is within.
401 The tail of this list can be 0 (was empty_cleanup_list),
402 if all remaining elements would be empty.
403 The TREE_VALUE contains the cleanup list of that block as of the
404 time this goto was seen.
405 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
406 tree cleanup_list_list
;
409 static struct goto_fixup
*goto_fixup_chain
;
411 /* Within any binding contour that must restore a stack level,
412 all labels are recorded with a chain of these structures. */
416 /* Points to following fixup. */
417 struct label_chain
*next
;
424 gcc_obstack_init (&stmt_obstack
);
426 empty_cleanup_list
= build_tree_list (NULL_TREE
, NULL_TREE
);
431 init_stmt_for_function ()
433 /* We are not currently within any block, conditional, loop or case. */
441 block_start_count
= 0;
443 /* No gotos have been expanded yet. */
444 goto_fixup_chain
= 0;
446 /* We are not processing a ({...}) grouping. */
447 expr_stmts_for_value
= 0;
455 p
->block_stack
= block_stack
;
456 p
->stack_block_stack
= stack_block_stack
;
457 p
->cond_stack
= cond_stack
;
458 p
->loop_stack
= loop_stack
;
459 p
->case_stack
= case_stack
;
460 p
->nesting_stack
= nesting_stack
;
461 p
->nesting_depth
= nesting_depth
;
462 p
->block_start_count
= block_start_count
;
463 p
->last_expr_type
= last_expr_type
;
464 p
->last_expr_value
= last_expr_value
;
465 p
->expr_stmts_for_value
= expr_stmts_for_value
;
466 p
->emit_filename
= emit_filename
;
467 p
->emit_lineno
= emit_lineno
;
468 p
->goto_fixup_chain
= goto_fixup_chain
;
472 restore_stmt_status (p
)
475 block_stack
= p
->block_stack
;
476 stack_block_stack
= p
->stack_block_stack
;
477 cond_stack
= p
->cond_stack
;
478 loop_stack
= p
->loop_stack
;
479 case_stack
= p
->case_stack
;
480 nesting_stack
= p
->nesting_stack
;
481 nesting_depth
= p
->nesting_depth
;
482 block_start_count
= p
->block_start_count
;
483 last_expr_type
= p
->last_expr_type
;
484 last_expr_value
= p
->last_expr_value
;
485 expr_stmts_for_value
= p
->expr_stmts_for_value
;
486 emit_filename
= p
->emit_filename
;
487 emit_lineno
= p
->emit_lineno
;
488 goto_fixup_chain
= p
->goto_fixup_chain
;
491 /* Emit a no-op instruction. */
496 rtx last_insn
= get_last_insn ();
498 && (GET_CODE (last_insn
) == CODE_LABEL
499 || prev_real_insn (last_insn
) == 0))
500 emit_insn (gen_nop ());
503 /* Return the rtx-label that corresponds to a LABEL_DECL,
504 creating it if necessary. */
510 if (TREE_CODE (label
) != LABEL_DECL
)
513 if (DECL_RTL (label
))
514 return DECL_RTL (label
);
516 return DECL_RTL (label
) = gen_label_rtx ();
519 /* Add an unconditional jump to LABEL as the next sequential instruction. */
525 do_pending_stack_adjust ();
526 emit_jump_insn (gen_jump (label
));
530 /* Emit code to jump to the address
531 specified by the pointer expression EXP. */
534 expand_computed_goto (exp
)
537 rtx x
= expand_expr (exp
, 0, VOIDmode
, 0);
539 emit_indirect_jump (x
);
543 /* Handle goto statements and the labels that they can go to. */
545 /* Specify the location in the RTL code of a label LABEL,
546 which is a LABEL_DECL tree node.
548 This is used for the kind of label that the user can jump to with a
549 goto statement, and for alternatives of a switch or case statement.
550 RTL labels generated for loops and conditionals don't go through here;
551 they are generated directly at the RTL level, by other functions below.
553 Note that this has nothing to do with defining label *names*.
554 Languages vary in how they do that and what that even means. */
560 struct label_chain
*p
;
562 do_pending_stack_adjust ();
563 emit_label (label_rtx (label
));
564 if (DECL_NAME (label
))
565 LABEL_NAME (DECL_RTL (label
)) = IDENTIFIER_POINTER (DECL_NAME (label
));
567 if (stack_block_stack
!= 0)
569 p
= (struct label_chain
*) oballoc (sizeof (struct label_chain
));
570 p
->next
= stack_block_stack
->data
.block
.label_chain
;
571 stack_block_stack
->data
.block
.label_chain
= p
;
576 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
577 from nested functions. */
580 declare_nonlocal_label (label
)
583 nonlocal_labels
= tree_cons (NULL_TREE
, label
, nonlocal_labels
);
584 LABEL_PRESERVE_P (label_rtx (label
)) = 1;
585 if (nonlocal_goto_handler_slot
== 0)
587 nonlocal_goto_handler_slot
588 = assign_stack_local (Pmode
, GET_MODE_SIZE (Pmode
), 0);
589 nonlocal_goto_stack_level
590 = assign_stack_local (Pmode
, GET_MODE_SIZE (Pmode
), 0);
591 emit_insn_before (gen_move_insn (nonlocal_goto_stack_level
,
593 tail_recursion_reentry
);
597 /* Generate RTL code for a `goto' statement with target label LABEL.
598 LABEL should be a LABEL_DECL tree node that was or will later be
599 defined with `expand_label'. */
605 /* Check for a nonlocal goto to a containing function. */
606 tree context
= decl_function_context (label
);
607 if (context
!= 0 && context
!= current_function_decl
)
609 struct function
*p
= find_function_data (context
);
611 p
->has_nonlocal_label
= 1;
612 #if HAVE_nonlocal_goto
613 if (HAVE_nonlocal_goto
)
614 emit_insn (gen_nonlocal_goto (lookup_static_chain (label
),
615 p
->nonlocal_goto_handler_slot
,
616 p
->nonlocal_goto_stack_level
,
617 gen_rtx (LABEL_REF
, Pmode
,
618 label_rtx (label
))));
622 /* Restore frame pointer for containing function.
623 This sets the actual hard register used for the frame pointer
624 to the location of the function's incoming static chain info.
625 The non-local goto handler will then adjust it to contain the
626 proper value and reload the argument pointer, if needed. */
627 emit_move_insn (frame_pointer_rtx
, lookup_static_chain (label
));
628 /* Get addr of containing function's current nonlocal goto handler,
629 which will do any cleanups and then jump to the label. */
630 temp
= copy_to_reg (p
->nonlocal_goto_handler_slot
);
631 /* Restore the stack pointer. Note this uses fp just restored. */
632 emit_move_insn (stack_pointer_rtx
, p
->nonlocal_goto_stack_level
);
633 /* Put in the static chain register the nonlocal label address. */
634 emit_move_insn (static_chain_rtx
,
635 gen_rtx (LABEL_REF
, Pmode
, label_rtx (label
)));
636 /* USE of frame_pointer_rtx added for consistency; not clear if
638 emit_insn (gen_rtx (USE
, VOIDmode
, frame_pointer_rtx
));
639 emit_insn (gen_rtx (USE
, VOIDmode
, stack_pointer_rtx
));
640 emit_insn (gen_rtx (USE
, VOIDmode
, static_chain_rtx
));
641 emit_indirect_jump (temp
);
645 expand_goto_internal (label
, label_rtx (label
), 0);
648 /* Generate RTL code for a `goto' statement with target label BODY.
649 LABEL should be a LABEL_REF.
650 LAST_INSN, if non-0, is the rtx we should consider as the last
651 insn emitted (for the purposes of cleaning up a return). */
654 expand_goto_internal (body
, label
, last_insn
)
659 struct nesting
*block
;
662 if (GET_CODE (label
) != CODE_LABEL
)
665 /* If label has already been defined, we can tell now
666 whether and how we must alter the stack level. */
668 if (PREV_INSN (label
) != 0)
670 /* Find the innermost pending block that contains the label.
671 (Check containment by comparing insn-uids.)
672 Then restore the outermost stack level within that block,
673 and do cleanups of all blocks contained in it. */
674 for (block
= block_stack
; block
; block
= block
->next
)
676 if (INSN_UID (block
->data
.block
.first_insn
) < INSN_UID (label
))
678 if (block
->data
.block
.stack_level
!= 0)
679 stack_level
= block
->data
.block
.stack_level
;
680 /* Execute the cleanups for blocks we are exiting. */
681 if (block
->data
.block
.cleanups
!= 0)
683 expand_cleanups (block
->data
.block
.cleanups
, 0);
684 do_pending_stack_adjust ();
690 /* Ensure stack adjust isn't done by emit_jump, as this would clobber
691 the stack pointer. This one should be deleted as dead by flow. */
692 clear_pending_stack_adjust ();
693 do_pending_stack_adjust ();
694 emit_move_insn (stack_pointer_rtx
, stack_level
);
697 if (body
!= 0 && DECL_TOO_LATE (body
))
698 error ("jump to `%s' invalidly jumps into binding contour",
699 IDENTIFIER_POINTER (DECL_NAME (body
)));
701 /* Label not yet defined: may need to put this goto
702 on the fixup list. */
703 else if (! expand_fixup (body
, label
, last_insn
))
705 /* No fixup needed. Record that the label is the target
706 of at least one goto that has no fixup. */
708 TREE_ADDRESSABLE (body
) = 1;
714 /* Generate if necessary a fixup for a goto
715 whose target label in tree structure (if any) is TREE_LABEL
716 and whose target in rtl is RTL_LABEL.
718 If LAST_INSN is nonzero, we pretend that the jump appears
719 after insn LAST_INSN instead of at the current point in the insn stream.
721 The fixup will be used later to insert insns at this point
722 to restore the stack level as appropriate for the target label.
724 Value is nonzero if a fixup is made. */
727 expand_fixup (tree_label
, rtl_label
, last_insn
)
732 struct nesting
*block
, *end_block
;
734 /* See if we can recognize which block the label will be output in.
735 This is possible in some very common cases.
736 If we succeed, set END_BLOCK to that block.
737 Otherwise, set it to 0. */
740 && (rtl_label
== cond_stack
->data
.cond
.endif_label
741 || rtl_label
== cond_stack
->data
.cond
.next_label
))
742 end_block
= cond_stack
;
743 /* If we are in a loop, recognize certain labels which
744 are likely targets. This reduces the number of fixups
745 we need to create. */
747 && (rtl_label
== loop_stack
->data
.loop
.start_label
748 || rtl_label
== loop_stack
->data
.loop
.end_label
749 || rtl_label
== loop_stack
->data
.loop
.continue_label
))
750 end_block
= loop_stack
;
754 /* Now set END_BLOCK to the binding level to which we will return. */
758 struct nesting
*next_block
= end_block
->all
;
761 /* First see if the END_BLOCK is inside the innermost binding level.
762 If so, then no cleanups or stack levels are relevant. */
763 while (next_block
&& next_block
!= block
)
764 next_block
= next_block
->all
;
769 /* Otherwise, set END_BLOCK to the innermost binding level
770 which is outside the relevant control-structure nesting. */
771 next_block
= block_stack
->next
;
772 for (block
= block_stack
; block
!= end_block
; block
= block
->all
)
773 if (block
== next_block
)
774 next_block
= next_block
->next
;
775 end_block
= next_block
;
778 /* Does any containing block have a stack level or cleanups?
779 If not, no fixup is needed, and that is the normal case
780 (the only case, for standard C). */
781 for (block
= block_stack
; block
!= end_block
; block
= block
->next
)
782 if (block
->data
.block
.stack_level
!= 0
783 || block
->data
.block
.cleanups
!= 0)
786 if (block
!= end_block
)
788 /* Ok, a fixup is needed. Add a fixup to the list of such. */
789 struct goto_fixup
*fixup
790 = (struct goto_fixup
*) oballoc (sizeof (struct goto_fixup
));
791 /* In case an old stack level is restored, make sure that comes
792 after any pending stack adjust. */
793 /* ?? If the fixup isn't to come at the present position,
794 doing the stack adjust here isn't useful. Doing it with our
795 settings at that location isn't useful either. Let's hope
798 do_pending_stack_adjust ();
799 fixup
->before_jump
= last_insn
? last_insn
: get_last_insn ();
800 fixup
->target
= tree_label
;
801 fixup
->target_rtl
= rtl_label
;
802 fixup
->block_start_count
= block_start_count
;
803 fixup
->stack_level
= 0;
804 fixup
->cleanup_list_list
805 = (((block
->data
.block
.outer_cleanups
807 && block
->data
.block
.outer_cleanups
!= empty_cleanup_list
810 || block
->data
.block
.cleanups
)
811 ? tree_cons (0, block
->data
.block
.cleanups
,
812 block
->data
.block
.outer_cleanups
)
814 fixup
->next
= goto_fixup_chain
;
815 goto_fixup_chain
= fixup
;
821 /* When exiting a binding contour, process all pending gotos requiring fixups.
822 THISBLOCK is the structure that describes the block being exited.
823 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
824 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
825 FIRST_INSN is the insn that began this contour.
827 Gotos that jump out of this contour must restore the
828 stack level and do the cleanups before actually jumping.
830 DONT_JUMP_IN nonzero means report error there is a jump into this
831 contour from before the beginning of the contour.
832 This is also done if STACK_LEVEL is nonzero. */
835 fixup_gotos (thisblock
, stack_level
, cleanup_list
, first_insn
, dont_jump_in
)
836 struct nesting
*thisblock
;
842 register struct goto_fixup
*f
, *prev
;
844 /* F is the fixup we are considering; PREV is the previous one. */
845 /* We run this loop in two passes so that cleanups of exited blocks
846 are run first, and blocks that are exited are marked so
849 for (prev
= 0, f
= goto_fixup_chain
; f
; prev
= f
, f
= f
->next
)
851 /* Test for a fixup that is inactive because it is already handled. */
852 if (f
->before_jump
== 0)
854 /* Delete inactive fixup from the chain, if that is easy to do. */
856 prev
->next
= f
->next
;
858 /* Has this fixup's target label been defined?
859 If so, we can finalize it. */
860 else if (PREV_INSN (f
->target_rtl
) != 0)
862 /* Get the first non-label after the label
863 this goto jumps to. If that's before this scope begins,
864 we don't have a jump into the scope. */
865 rtx after_label
= f
->target_rtl
;
866 while (after_label
!= 0 && GET_CODE (after_label
) == CODE_LABEL
)
867 after_label
= NEXT_INSN (after_label
);
869 /* If this fixup jumped into this contour from before the beginning
870 of this contour, report an error. */
871 /* ??? Bug: this does not detect jumping in through intermediate
872 blocks that have stack levels or cleanups.
873 It detects only a problem with the innermost block
876 && (dont_jump_in
|| stack_level
|| cleanup_list
)
877 /* If AFTER_LABEL is 0, it means the jump goes to the end
878 of the rtl, which means it jumps into this scope. */
880 || INSN_UID (first_insn
) < INSN_UID (after_label
))
881 && INSN_UID (first_insn
) > INSN_UID (f
->before_jump
)
882 && ! TREE_REGDECL (f
->target
))
884 error_with_decl (f
->target
,
885 "label `%s' used before containing binding contour");
886 /* Prevent multiple errors for one label. */
887 TREE_REGDECL (f
->target
) = 1;
890 /* Execute cleanups for blocks this jump exits. */
891 if (f
->cleanup_list_list
)
894 for (lists
= f
->cleanup_list_list
; lists
; lists
= TREE_CHAIN (lists
))
895 /* Marked elements correspond to blocks that have been closed.
896 Do their cleanups. */
897 if (TREE_ADDRESSABLE (lists
)
898 && TREE_VALUE (lists
) != 0)
899 fixup_cleanups (TREE_VALUE (lists
), &f
->before_jump
);
902 /* Restore stack level for the biggest contour that this
903 jump jumps out of. */
905 emit_insn_after (gen_move_insn (stack_pointer_rtx
, f
->stack_level
),
911 /* Mark the cleanups of exited blocks so that they are executed
912 by the code above. */
913 for (prev
= 0, f
= goto_fixup_chain
; f
; prev
= f
, f
= f
->next
)
914 if (f
->before_jump
!= 0
915 && PREV_INSN (f
->target_rtl
) == 0
916 /* Label has still not appeared. If we are exiting a block with
917 a stack level to restore, that started before the fixup,
918 mark this stack level as needing restoration
919 when the fixup is later finalized.
920 Also mark the cleanup_list_list element for F
921 that corresponds to this block, so that ultimately
922 this block's cleanups will be executed by the code above. */
924 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared,
925 it means the label is undefined. That's erroneous, but possible. */
926 && (thisblock
->data
.block
.block_start_count
927 <= f
->block_start_count
))
929 tree lists
= f
->cleanup_list_list
;
930 for (; lists
; lists
= TREE_CHAIN (lists
))
931 /* If the following elt. corresponds to our containing block
932 then the elt. must be for this block. */
933 if (TREE_CHAIN (lists
) == thisblock
->data
.block
.outer_cleanups
)
934 TREE_ADDRESSABLE (lists
) = 1;
937 f
->stack_level
= stack_level
;
941 /* Generate RTL for an asm statement (explicit assembler code).
942 BODY is a STRING_CST node containing the assembler code text,
943 or an ADDR_EXPR containing a STRING_CST. */
949 if (TREE_CODE (body
) == ADDR_EXPR
)
950 body
= TREE_OPERAND (body
, 0);
952 emit_insn (gen_rtx (ASM_INPUT
, VOIDmode
,
953 TREE_STRING_POINTER (body
)));
957 /* Generate RTL for an asm statement with arguments.
958 STRING is the instruction template.
959 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
960 Each output or input has an expression in the TREE_VALUE and
961 a constraint-string in the TREE_PURPOSE.
962 CLOBBERS is a list of STRING_CST nodes each naming a hard register
963 that is clobbered by this insn.
965 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
966 Some elements of OUTPUTS may be replaced with trees representing temporary
967 values. The caller should copy those temporary values to the originally
970 VOL nonzero means the insn is volatile; don't optimize it. */
973 expand_asm_operands (string
, outputs
, inputs
, clobbers
, vol
, filename
, line
)
974 tree string
, outputs
, inputs
, clobbers
;
979 rtvec argvec
, constraints
;
981 int ninputs
= list_length (inputs
);
982 int noutputs
= list_length (outputs
);
983 int nclobbers
= list_length (clobbers
);
986 /* Vector of RTX's of evaluated output operands. */
987 rtx
*output_rtx
= (rtx
*) alloca (noutputs
* sizeof (rtx
));
988 /* The insn we have emitted. */
993 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
995 tree val
= TREE_VALUE (tail
);
1000 /* If there's an erroneous arg, emit no insn. */
1001 if (TREE_TYPE (val
) == error_mark_node
)
1004 /* Make sure constraint has `=' and does not have `+'. */
1007 for (j
= 0; j
< TREE_STRING_LENGTH (TREE_PURPOSE (tail
)); j
++)
1009 if (TREE_STRING_POINTER (TREE_PURPOSE (tail
))[j
] == '+')
1011 error ("output operand constraint contains `+'");
1014 if (TREE_STRING_POINTER (TREE_PURPOSE (tail
))[j
] == '=')
1019 error ("output operand constraint lacks `='");
1023 /* If an output operand is not a variable or indirect ref,
1025 create a SAVE_EXPR which is a pseudo-reg
1026 to act as an intermediate temporary.
1027 Make the asm insn write into that, then copy it to
1028 the real output operand. */
1030 while (TREE_CODE (val
) == COMPONENT_REF
1031 || TREE_CODE (val
) == ARRAY_REF
)
1032 val
= TREE_OPERAND (val
, 0);
1034 if (TREE_CODE (val
) != VAR_DECL
1035 && TREE_CODE (val
) != PARM_DECL
1036 && TREE_CODE (val
) != INDIRECT_REF
)
1037 TREE_VALUE (tail
) = save_expr (TREE_VALUE (tail
));
1039 output_rtx
[i
] = expand_expr (TREE_VALUE (tail
), 0, VOIDmode
, 0);
1042 if (ninputs
+ noutputs
> MAX_RECOG_OPERANDS
)
1044 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS
);
1048 /* Make vectors for the expression-rtx and constraint strings. */
1050 argvec
= rtvec_alloc (ninputs
);
1051 constraints
= rtvec_alloc (ninputs
);
1053 body
= gen_rtx (ASM_OPERANDS
, VOIDmode
,
1054 TREE_STRING_POINTER (string
), "", 0, argvec
, constraints
,
1056 MEM_VOLATILE_P (body
) = vol
;
1058 /* Eval the inputs and put them into ARGVEC.
1059 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1062 for (tail
= inputs
; tail
; tail
= TREE_CHAIN (tail
))
1066 /* If there's an erroneous arg, emit no insn,
1067 because the ASM_INPUT would get VOIDmode
1068 and that could cause a crash in reload. */
1069 if (TREE_TYPE (TREE_VALUE (tail
)) == error_mark_node
)
1071 if (TREE_PURPOSE (tail
) == NULL_TREE
)
1073 error ("hard register `%s' listed as input operand to `asm'",
1074 TREE_STRING_POINTER (TREE_VALUE (tail
)) );
1078 /* Make sure constraint has neither `=' nor `+'. */
1080 for (j
= 0; j
< TREE_STRING_LENGTH (TREE_PURPOSE (tail
)); j
++)
1081 if (TREE_STRING_POINTER (TREE_PURPOSE (tail
))[j
] == '='
1082 || TREE_STRING_POINTER (TREE_PURPOSE (tail
))[j
] == '+')
1084 error ("input operand constraint contains `%c'",
1085 TREE_STRING_POINTER (TREE_PURPOSE (tail
))[j
]);
1089 XVECEXP (body
, 3, i
) /* argvec */
1090 = expand_expr (TREE_VALUE (tail
), 0, VOIDmode
, 0);
1091 XVECEXP (body
, 4, i
) /* constraints */
1092 = gen_rtx (ASM_INPUT
, TYPE_MODE (TREE_TYPE (TREE_VALUE (tail
))),
1093 TREE_STRING_POINTER (TREE_PURPOSE (tail
)));
1097 /* Protect all the operands from the queue,
1098 now that they have all been evaluated. */
1100 for (i
= 0; i
< ninputs
; i
++)
1101 XVECEXP (body
, 3, i
) = protect_from_queue (XVECEXP (body
, 3, i
), 0);
1103 for (i
= 0; i
< noutputs
; i
++)
1104 output_rtx
[i
] = protect_from_queue (output_rtx
[i
], 1);
1106 /* Now, for each output, construct an rtx
1107 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1108 ARGVEC CONSTRAINTS))
1109 If there is more than one, put them inside a PARALLEL. */
1111 if (noutputs
== 1 && nclobbers
== 0)
1113 XSTR (body
, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs
));
1114 insn
= emit_insn (gen_rtx (SET
, VOIDmode
, output_rtx
[0], body
));
1116 else if (noutputs
== 0 && nclobbers
== 0)
1118 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1119 insn
= emit_insn (body
);
1125 if (num
== 0) num
= 1;
1126 body
= gen_rtx (PARALLEL
, VOIDmode
, rtvec_alloc (num
+ nclobbers
));
1128 /* For each output operand, store a SET. */
1130 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1132 XVECEXP (body
, 0, i
)
1133 = gen_rtx (SET
, VOIDmode
,
1135 gen_rtx (ASM_OPERANDS
, VOIDmode
,
1136 TREE_STRING_POINTER (string
),
1137 TREE_STRING_POINTER (TREE_PURPOSE (tail
)),
1138 i
, argvec
, constraints
,
1140 MEM_VOLATILE_P (SET_SRC (XVECEXP (body
, 0, i
))) = vol
;
1143 /* If there are no outputs (but there are some clobbers)
1144 store the bare ASM_OPERANDS into the PARALLEL. */
1147 XVECEXP (body
, 0, i
++) = obody
;
1149 /* Store (clobber REG) for each clobbered register specified. */
1151 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1153 char *regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
1154 int j
= decode_reg_name (regname
);
1158 error ("unknown register name `%s' in `asm'", regname
);
1162 /* Use QImode since that's guaranteed to clobber just one reg. */
1163 XVECEXP (body
, 0, i
)
1164 = gen_rtx (CLOBBER
, VOIDmode
, gen_rtx (REG
, QImode
, j
));
1167 insn
= emit_insn (body
);
1173 /* Generate RTL to evaluate the expression EXP
1174 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1177 expand_expr_stmt (exp
)
1180 /* If -W, warn about statements with no side effects,
1181 except for an explicit cast to void (e.g. for assert()), and
1182 except inside a ({...}) where they may be useful. */
1183 if (expr_stmts_for_value
== 0 && exp
!= error_mark_node
)
1185 if (! TREE_SIDE_EFFECTS (exp
) && (extra_warnings
|| warn_unused
)
1186 && !(TREE_CODE (exp
) == CONVERT_EXPR
1187 && TREE_TYPE (exp
) == void_type_node
))
1188 warning_with_file_and_line (emit_filename
, emit_lineno
,
1189 "statement with no effect");
1190 else if (warn_unused
)
1191 warn_if_unused_value (exp
);
1193 last_expr_type
= TREE_TYPE (exp
);
1194 if (! flag_syntax_only
)
1195 last_expr_value
= expand_expr (exp
, expr_stmts_for_value
? 0 : const0_rtx
,
1198 /* If all we do is reference a volatile value in memory,
1199 copy it to a register to be sure it is actually touched. */
1200 if (last_expr_value
!= 0 && GET_CODE (last_expr_value
) == MEM
1201 && TREE_THIS_VOLATILE (exp
))
1203 if (TYPE_MODE (TREE_TYPE (exp
)) != BLKmode
)
1204 copy_to_reg (last_expr_value
);
1206 /* This case needs to be written. */
1210 /* If this expression is part of a ({...}) and is in memory, we may have
1211 to preserve temporaries. */
1212 preserve_temp_slots (last_expr_value
);
1214 /* Free any temporaries used to evaluate this expression. Any temporary
1215 used as a result of this expression will already have been preserved
1222 /* Warn if EXP contains any computations whose results are not used.
1223 Return 1 if a warning is printed; 0 otherwise. */
1226 warn_if_unused_value (exp
)
1229 if (TREE_USED (exp
))
1232 switch (TREE_CODE (exp
))
1234 case PREINCREMENT_EXPR
:
1235 case POSTINCREMENT_EXPR
:
1236 case PREDECREMENT_EXPR
:
1237 case POSTDECREMENT_EXPR
:
1242 case METHOD_CALL_EXPR
:
1245 case ANTI_WRAPPER_EXPR
:
1246 case WITH_CLEANUP_EXPR
:
1248 /* We don't warn about COND_EXPR because it may be a useful
1249 construct if either arm contains a side effect. */
1254 /* For a binding, warn if no side effect within it. */
1255 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
1257 case TRUTH_ORIF_EXPR
:
1258 case TRUTH_ANDIF_EXPR
:
1259 /* In && or ||, warn if 2nd operand has no side effect. */
1260 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
1263 if (warn_if_unused_value (TREE_OPERAND (exp
, 0)))
1265 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
1269 case NON_LVALUE_EXPR
:
1270 /* Don't warn about values cast to void. */
1271 if (TREE_TYPE (exp
) == void_type_node
)
1273 /* Don't warn about conversions not explicit in the user's program. */
1274 if (TREE_NO_UNUSED_WARNING (exp
))
1276 /* Assignment to a cast usually results in a cast of a modify.
1277 Don't complain about that. */
1278 if (TREE_CODE (TREE_OPERAND (exp
, 0)) == MODIFY_EXPR
)
1280 /* Sometimes it results in a cast of a cast of a modify.
1281 Don't complain about that. */
1282 if ((TREE_CODE (TREE_OPERAND (exp
, 0)) == CONVERT_EXPR
1283 || TREE_CODE (TREE_OPERAND (exp
, 0)) == NOP_EXPR
)
1284 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp
, 0), 0)) == MODIFY_EXPR
)
1288 warning_with_file_and_line (emit_filename
, emit_lineno
,
1289 "value computed is not used");
1294 /* Clear out the memory of the last expression evaluated. */
1302 /* Begin a statement which will return a value.
1303 Return the RTL_EXPR for this statement expr.
1304 The caller must save that value and pass it to expand_end_stmt_expr. */
1307 expand_start_stmt_expr ()
1309 /* Make the RTL_EXPR node temporary, not momentary,
1310 so that rtl_expr_chain doesn't become garbage. */
1311 int momentary
= suspend_momentary ();
1312 tree t
= make_node (RTL_EXPR
);
1313 resume_momentary (momentary
);
1316 expr_stmts_for_value
++;
1320 /* Restore the previous state at the end of a statement that returns a value.
1321 Returns a tree node representing the statement's value and the
1322 insns to compute the value.
1324 The nodes of that expression have been freed by now, so we cannot use them.
1325 But we don't want to do that anyway; the expression has already been
1326 evaluated and now we just want to use the value. So generate a RTL_EXPR
1327 with the proper type and RTL value.
1329 If the last substatement was not an expression,
1330 return something with type `void'. */
1333 expand_end_stmt_expr (t
)
1338 if (last_expr_type
== 0)
1340 last_expr_type
= void_type_node
;
1341 last_expr_value
= const0_rtx
;
1343 else if (last_expr_value
== 0)
1344 /* There are some cases where this can happen, such as when the
1345 statement is void type. */
1346 last_expr_value
= const0_rtx
;
1347 else if (GET_CODE (last_expr_value
) != REG
&& ! CONSTANT_P (last_expr_value
))
1348 /* Remove any possible QUEUED. */
1349 last_expr_value
= protect_from_queue (last_expr_value
, 0);
1353 TREE_TYPE (t
) = last_expr_type
;
1354 RTL_EXPR_RTL (t
) = last_expr_value
;
1355 RTL_EXPR_SEQUENCE (t
) = get_insns ();
1357 rtl_expr_chain
= tree_cons (NULL_TREE
, t
, rtl_expr_chain
);
1361 /* Don't consider deleting this expr or containing exprs at tree level. */
1362 TREE_SIDE_EFFECTS (t
) = 1;
1363 /* Propagate volatility of the actual RTL expr. */
1364 TREE_THIS_VOLATILE (t
) = volatile_refs_p (last_expr_value
);
1367 expr_stmts_for_value
--;
1372 /* The exception handling nesting looks like this:
1375 { <-- exception handler block
1377 <-- in an exception handler
1379 : <-- in a TRY block
1380 : <-- in an exception handler
1385 : <-- in an except block
1386 : <-- in an exception handler
1392 /* Return nonzero iff in a try block at level LEVEL. */
1395 in_try_block (level
)
1398 struct nesting
*n
= except_stack
;
1401 while (n
&& n
->data
.except_stmt
.after_label
!= 0)
1412 /* Return nonzero iff in an except block at level LEVEL. */
1415 in_except_block (level
)
1418 struct nesting
*n
= except_stack
;
1421 while (n
&& n
->data
.except_stmt
.after_label
== 0)
1432 /* Return nonzero iff in an exception handler at level LEVEL. */
1435 in_exception_handler (level
)
1438 struct nesting
*n
= except_stack
;
1439 while (n
&& level
--)
1444 /* Record the fact that the current exception nesting raises
1445 exception EX. If not in an exception handler, return 0. */
1452 if (except_stack
== 0)
1454 raises_ptr
= &except_stack
->data
.except_stmt
.raised
;
1455 if (! value_member (ex
, *raises_ptr
))
1456 *raises_ptr
= tree_cons (NULL_TREE
, ex
, *raises_ptr
);
1460 /* Generate RTL for the start of a try block.
1462 TRY_CLAUSE is the condition to test to enter the try block. */
1465 expand_start_try (try_clause
, exitflag
, escapeflag
)
1470 struct nesting
*thishandler
= ALLOC_NESTING ();
1472 /* Make an entry on cond_stack for the cond we are entering. */
1474 thishandler
->next
= except_stack
;
1475 thishandler
->all
= nesting_stack
;
1476 thishandler
->depth
= ++nesting_depth
;
1477 thishandler
->data
.except_stmt
.raised
= 0;
1478 thishandler
->data
.except_stmt
.handled
= 0;
1479 thishandler
->data
.except_stmt
.first_insn
= get_insns ();
1480 thishandler
->data
.except_stmt
.except_label
= gen_label_rtx ();
1481 thishandler
->data
.except_stmt
.unhandled_label
= 0;
1482 thishandler
->data
.except_stmt
.after_label
= 0;
1483 thishandler
->data
.except_stmt
.escape_label
1484 = escapeflag
? thishandler
->data
.except_stmt
.except_label
: 0;
1485 thishandler
->exit_label
= exitflag
? gen_label_rtx () : 0;
1486 except_stack
= thishandler
;
1487 nesting_stack
= thishandler
;
1489 do_jump (try_clause
, thishandler
->data
.except_stmt
.except_label
, NULL
);
1492 /* End of a TRY block. Nothing to do for now. */
1497 except_stack
->data
.except_stmt
.after_label
= gen_label_rtx ();
1498 expand_goto_internal (NULL
, except_stack
->data
.except_stmt
.after_label
, 0);
1501 /* Start an `except' nesting contour.
1502 EXITFLAG says whether this contour should be able to `exit' something.
1503 ESCAPEFLAG says whether this contour should be escapable. */
1506 expand_start_except (exitflag
, escapeflag
)
1513 /* An `exit' from catch clauses goes out to next exit level,
1514 if there is one. Otherwise, it just goes to the end
1515 of the construct. */
1516 for (n
= except_stack
->next
; n
; n
= n
->next
)
1517 if (n
->exit_label
!= 0)
1519 except_stack
->exit_label
= n
->exit_label
;
1523 except_stack
->exit_label
= except_stack
->data
.except_stmt
.after_label
;
1528 /* An `escape' from catch clauses goes out to next escape level,
1529 if there is one. Otherwise, it just goes to the end
1530 of the construct. */
1531 for (n
= except_stack
->next
; n
; n
= n
->next
)
1532 if (n
->data
.except_stmt
.escape_label
!= 0)
1534 except_stack
->data
.except_stmt
.escape_label
1535 = n
->data
.except_stmt
.escape_label
;
1539 except_stack
->data
.except_stmt
.escape_label
1540 = except_stack
->data
.except_stmt
.after_label
;
1542 do_pending_stack_adjust ();
1543 emit_label (except_stack
->data
.except_stmt
.except_label
);
1546 /* Generate code to `escape' from an exception contour. This
1547 is like `exiting', but does not conflict with constructs which
1550 Return nonzero if this contour is escapable, otherwise
1551 return zero, and language-specific code will emit the
1552 appropriate error message. */
1554 expand_escape_except ()
1558 for (n
= except_stack
; n
; n
= n
->next
)
1559 if (n
->data
.except_stmt
.escape_label
!= 0)
1561 expand_goto_internal (0, n
->data
.except_stmt
.escape_label
, 0);
1568 /* Finish processing and `except' contour.
1569 Culls out all exceptions which might be raise but not
1570 handled, and returns the list to the caller.
1571 Language-specific code is responsible for dealing with these
1575 expand_end_except ()
1578 tree raised
= NULL_TREE
;
1580 do_pending_stack_adjust ();
1581 emit_label (except_stack
->data
.except_stmt
.after_label
);
1583 n
= except_stack
->next
;
1586 /* Propagate exceptions raised but not handled to next
1588 tree handled
= except_stack
->data
.except_stmt
.raised
;
1589 if (handled
!= void_type_node
)
1591 tree prev
= NULL_TREE
;
1592 raised
= except_stack
->data
.except_stmt
.raised
;
1596 for (this_raise
= raised
, prev
= 0; this_raise
;
1597 this_raise
= TREE_CHAIN (this_raise
))
1599 if (value_member (TREE_VALUE (this_raise
), handled
))
1602 TREE_CHAIN (prev
) = TREE_CHAIN (this_raise
);
1605 raised
= TREE_CHAIN (raised
);
1606 if (raised
== NULL_TREE
)
1613 handled
= TREE_CHAIN (handled
);
1615 if (prev
== NULL_TREE
)
1618 TREE_CHAIN (prev
) = n
->data
.except_stmt
.raised
;
1620 n
->data
.except_stmt
.raised
= raised
;
1624 POPSTACK (except_stack
);
1629 /* Record that exception EX is caught by this exception handler.
1630 Return nonzero if in exception handling construct, otherwise return 0. */
1637 if (except_stack
== 0)
1639 raises_ptr
= &except_stack
->data
.except_stmt
.handled
;
1640 if (*raises_ptr
!= void_type_node
1642 && ! value_member (ex
, *raises_ptr
))
1643 *raises_ptr
= tree_cons (NULL_TREE
, ex
, *raises_ptr
);
1647 /* Record that this exception handler catches all exceptions.
1648 Return nonzero if in exception handling construct, otherwise return 0. */
1651 expand_catch_default ()
1653 if (except_stack
== 0)
1655 except_stack
->data
.except_stmt
.handled
= void_type_node
;
1662 if (except_stack
== 0 || except_stack
->data
.except_stmt
.after_label
== 0)
1664 expand_goto_internal (0, except_stack
->data
.except_stmt
.after_label
, 0);
1668 /* Generate RTL for the start of an if-then. COND is the expression
1669 whose truth should be tested.
1671 If EXITFLAG is nonzero, this conditional is visible to
1672 `exit_something'. */
1675 expand_start_cond (cond
, exitflag
)
1679 struct nesting
*thiscond
= ALLOC_NESTING ();
1681 /* Make an entry on cond_stack for the cond we are entering. */
1683 thiscond
->next
= cond_stack
;
1684 thiscond
->all
= nesting_stack
;
1685 thiscond
->depth
= ++nesting_depth
;
1686 thiscond
->data
.cond
.next_label
= gen_label_rtx ();
1687 /* Before we encounter an `else', we don't need a separate exit label
1688 unless there are supposed to be exit statements
1689 to exit this conditional. */
1690 thiscond
->exit_label
= exitflag
? gen_label_rtx () : 0;
1691 thiscond
->data
.cond
.endif_label
= thiscond
->exit_label
;
1692 cond_stack
= thiscond
;
1693 nesting_stack
= thiscond
;
1695 do_jump (cond
, thiscond
->data
.cond
.next_label
, NULL
);
1698 /* Generate RTL between then-clause and the elseif-clause
1699 of an if-then-elseif-.... */
1702 expand_start_elseif (cond
)
1705 if (cond_stack
->data
.cond
.endif_label
== 0)
1706 cond_stack
->data
.cond
.endif_label
= gen_label_rtx ();
1707 emit_jump (cond_stack
->data
.cond
.endif_label
);
1708 emit_label (cond_stack
->data
.cond
.next_label
);
1709 cond_stack
->data
.cond
.next_label
= gen_label_rtx ();
1710 do_jump (cond
, cond_stack
->data
.cond
.next_label
, NULL
);
1713 /* Generate RTL between the then-clause and the else-clause
1714 of an if-then-else. */
1717 expand_start_else ()
1719 if (cond_stack
->data
.cond
.endif_label
== 0)
1720 cond_stack
->data
.cond
.endif_label
= gen_label_rtx ();
1721 emit_jump (cond_stack
->data
.cond
.endif_label
);
1722 emit_label (cond_stack
->data
.cond
.next_label
);
1723 cond_stack
->data
.cond
.next_label
= 0; /* No more _else or _elseif calls. */
1726 /* Generate RTL for the end of an if-then.
1727 Pop the record for it off of cond_stack. */
1732 struct nesting
*thiscond
= cond_stack
;
1734 do_pending_stack_adjust ();
1735 if (thiscond
->data
.cond
.next_label
)
1736 emit_label (thiscond
->data
.cond
.next_label
);
1737 if (thiscond
->data
.cond
.endif_label
)
1738 emit_label (thiscond
->data
.cond
.endif_label
);
1740 POPSTACK (cond_stack
);
1744 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
1745 loop should be exited by `exit_something'. This is a loop for which
1746 `expand_continue' will jump to the top of the loop.
1748 Make an entry on loop_stack to record the labels associated with
1752 expand_start_loop (exit_flag
)
1755 register struct nesting
*thisloop
= ALLOC_NESTING ();
1757 /* Make an entry on loop_stack for the loop we are entering. */
1759 thisloop
->next
= loop_stack
;
1760 thisloop
->all
= nesting_stack
;
1761 thisloop
->depth
= ++nesting_depth
;
1762 thisloop
->data
.loop
.start_label
= gen_label_rtx ();
1763 thisloop
->data
.loop
.end_label
= gen_label_rtx ();
1764 thisloop
->data
.loop
.continue_label
= thisloop
->data
.loop
.start_label
;
1765 thisloop
->exit_label
= exit_flag
? thisloop
->data
.loop
.end_label
: 0;
1766 loop_stack
= thisloop
;
1767 nesting_stack
= thisloop
;
1769 do_pending_stack_adjust ();
1771 emit_note (0, NOTE_INSN_LOOP_BEG
);
1772 emit_label (thisloop
->data
.loop
.start_label
);
1777 /* Like expand_start_loop but for a loop where the continuation point
1778 (for expand_continue_loop) will be specified explicitly. */
1781 expand_start_loop_continue_elsewhere (exit_flag
)
1784 struct nesting
*thisloop
= expand_start_loop (exit_flag
);
1785 loop_stack
->data
.loop
.continue_label
= gen_label_rtx ();
1789 /* Specify the continuation point for a loop started with
1790 expand_start_loop_continue_elsewhere.
1791 Use this at the point in the code to which a continue statement
1795 expand_loop_continue_here ()
1797 do_pending_stack_adjust ();
1798 emit_note (0, NOTE_INSN_LOOP_CONT
);
1799 emit_label (loop_stack
->data
.loop
.continue_label
);
1802 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
1803 Pop the block off of loop_stack. */
1808 register rtx insn
= get_last_insn ();
1809 register rtx start_label
= loop_stack
->data
.loop
.start_label
;
1810 rtx last_test_insn
= 0;
1813 /* Mark the continue-point at the top of the loop if none elsewhere. */
1814 if (start_label
== loop_stack
->data
.loop
.continue_label
)
1815 emit_note_before (NOTE_INSN_LOOP_CONT
, start_label
);
1817 do_pending_stack_adjust ();
1819 /* If optimizing, perhaps reorder the loop. If the loop
1820 starts with a conditional exit, roll that to the end
1821 where it will optimize together with the jump back.
1823 We look for the last conditional branch to the exit that we encounter
1824 before hitting 30 insns or a CALL_INSN. If we see an unconditional
1825 branch to the exit first, use it.
1827 We must also stop at NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes
1828 because moving them is not valid. */
1832 ! (GET_CODE (insn
) == JUMP_INSN
1833 && GET_CODE (PATTERN (insn
)) == SET
1834 && SET_DEST (PATTERN (insn
)) == pc_rtx
1835 && GET_CODE (SET_SRC (PATTERN (insn
))) == IF_THEN_ELSE
))
1837 /* Scan insns from the top of the loop looking for a qualified
1838 conditional exit. */
1839 for (insn
= NEXT_INSN (loop_stack
->data
.loop
.start_label
); insn
;
1840 insn
= NEXT_INSN (insn
))
1842 if (GET_CODE (insn
) == CALL_INSN
|| GET_CODE (insn
) == CODE_LABEL
)
1845 if (GET_CODE (insn
) == NOTE
1846 && (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_BEG
1847 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_END
))
1850 if (GET_CODE (insn
) == JUMP_INSN
|| GET_CODE (insn
) == INSN
)
1853 if (last_test_insn
&& num_insns
> 30)
1856 if (GET_CODE (insn
) == JUMP_INSN
&& GET_CODE (PATTERN (insn
)) == SET
1857 && SET_DEST (PATTERN (insn
)) == pc_rtx
1858 && GET_CODE (SET_SRC (PATTERN (insn
))) == IF_THEN_ELSE
1859 && ((GET_CODE (XEXP (SET_SRC (PATTERN (insn
)), 1)) == LABEL_REF
1860 && (XEXP (XEXP (SET_SRC (PATTERN (insn
)), 1), 0)
1861 == loop_stack
->data
.loop
.end_label
))
1862 || (GET_CODE (XEXP (SET_SRC (PATTERN (insn
)), 2)) == LABEL_REF
1863 && (XEXP (XEXP (SET_SRC (PATTERN (insn
)), 2), 0)
1864 == loop_stack
->data
.loop
.end_label
))))
1865 last_test_insn
= insn
;
1867 if (last_test_insn
== 0 && GET_CODE (insn
) == JUMP_INSN
1868 && GET_CODE (PATTERN (insn
)) == SET
1869 && SET_DEST (PATTERN (insn
)) == pc_rtx
1870 && GET_CODE (SET_SRC (PATTERN (insn
))) == LABEL_REF
1871 && (XEXP (SET_SRC (PATTERN (insn
)), 0)
1872 == loop_stack
->data
.loop
.end_label
))
1873 /* Include BARRIER. */
1874 last_test_insn
= NEXT_INSN (insn
);
1877 if (last_test_insn
!= 0 && last_test_insn
!= get_last_insn ())
1879 /* We found one. Move everything from there up
1880 to the end of the loop, and add a jump into the loop
1881 to jump to there. */
1882 register rtx newstart_label
= gen_label_rtx ();
1883 register rtx start_move
= start_label
;
1885 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
1886 then we want to move this note also. */
1887 if (GET_CODE (PREV_INSN (start_move
)) == NOTE
1888 && (NOTE_LINE_NUMBER (PREV_INSN (start_move
))
1889 == NOTE_INSN_LOOP_CONT
))
1890 start_move
= PREV_INSN (start_move
);
1892 emit_label_after (newstart_label
, PREV_INSN (start_move
));
1893 reorder_insns (start_move
, last_test_insn
, get_last_insn ());
1894 emit_jump_insn_after (gen_jump (start_label
),
1895 PREV_INSN (newstart_label
));
1896 emit_barrier_after (PREV_INSN (newstart_label
));
1897 start_label
= newstart_label
;
1901 emit_jump (start_label
);
1902 emit_note (0, NOTE_INSN_LOOP_END
);
1903 emit_label (loop_stack
->data
.loop
.end_label
);
1905 POPSTACK (loop_stack
);
1910 /* Generate a jump to the current loop's continue-point.
1911 This is usually the top of the loop, but may be specified
1912 explicitly elsewhere. If not currently inside a loop,
1913 return 0 and do nothing; caller will print an error message. */
1916 expand_continue_loop (whichloop
)
1917 struct nesting
*whichloop
;
1921 whichloop
= loop_stack
;
1924 expand_goto_internal (0, whichloop
->data
.loop
.continue_label
, 0);
1928 /* Generate a jump to exit the current loop. If not currently inside a loop,
1929 return 0 and do nothing; caller will print an error message. */
1932 expand_exit_loop (whichloop
)
1933 struct nesting
*whichloop
;
1937 whichloop
= loop_stack
;
1940 expand_goto_internal (0, whichloop
->data
.loop
.end_label
, 0);
1944 /* Generate a conditional jump to exit the current loop if COND
1945 evaluates to zero. If not currently inside a loop,
1946 return 0 and do nothing; caller will print an error message. */
1949 expand_exit_loop_if_false (whichloop
, cond
)
1950 struct nesting
*whichloop
;
1955 whichloop
= loop_stack
;
1958 do_jump (cond
, whichloop
->data
.loop
.end_label
, NULL
);
1962 /* Return non-zero if we should preserve sub-expressions as separate
1963 pseudos. We never do so if we aren't optimizing. We always do so
1964 if -fexpensive-optimizations.
1966 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
1967 the loop may still be a small one. */
1970 preserve_subexpressions_p ()
1974 if (flag_expensive_optimizations
)
1977 if (optimize
== 0 || loop_stack
== 0)
1980 insn
= get_last_insn_anywhere ();
1983 && (INSN_UID (insn
) - INSN_UID (loop_stack
->data
.loop
.start_label
)
1984 < n_non_fixed_regs
* 3));
1988 /* Generate a jump to exit the current loop, conditional, binding contour
1989 or case statement. Not all such constructs are visible to this function,
1990 only those started with EXIT_FLAG nonzero. Individual languages use
1991 the EXIT_FLAG parameter to control which kinds of constructs you can
1994 If not currently inside anything that can be exited,
1995 return 0 and do nothing; caller will print an error message. */
1998 expand_exit_something ()
2002 for (n
= nesting_stack
; n
; n
= n
->all
)
2003 if (n
->exit_label
!= 0)
2005 expand_goto_internal (0, n
->exit_label
, 0);
2012 /* Generate RTL to return from the current function, with no value.
2013 (That is, we do not do anything about returning any value.) */
2016 expand_null_return ()
2018 struct nesting
*block
= block_stack
;
2021 /* Does any pending block have cleanups? */
2023 while (block
&& block
->data
.block
.cleanups
== 0)
2024 block
= block
->next
;
2026 /* If yes, use a goto to return, since that runs cleanups. */
2028 expand_null_return_1 (last_insn
, block
!= 0);
2031 /* Generate RTL to return from the current function, with value VAL. */
2034 expand_value_return (val
)
2037 struct nesting
*block
= block_stack
;
2038 rtx last_insn
= get_last_insn ();
2039 rtx return_reg
= DECL_RTL (DECL_RESULT (current_function_decl
));
2041 /* Copy the value to the return location
2042 unless it's already there. */
2044 if (return_reg
!= val
)
2045 emit_move_insn (return_reg
, val
);
2046 if (GET_CODE (return_reg
) == REG
2047 && REGNO (return_reg
) < FIRST_PSEUDO_REGISTER
)
2048 emit_insn (gen_rtx (USE
, VOIDmode
, return_reg
));
2050 /* Does any pending block have cleanups? */
2052 while (block
&& block
->data
.block
.cleanups
== 0)
2053 block
= block
->next
;
2055 /* If yes, use a goto to return, since that runs cleanups.
2056 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2058 expand_null_return_1 (last_insn
, block
!= 0);
2061 /* Output a return with no value. If LAST_INSN is nonzero,
2062 pretend that the return takes place after LAST_INSN.
2063 If USE_GOTO is nonzero then don't use a return instruction;
2064 go to the return label instead. This causes any cleanups
2065 of pending blocks to be executed normally. */
2068 expand_null_return_1 (last_insn
, use_goto
)
2072 rtx end_label
= cleanup_label
? cleanup_label
: return_label
;
2074 clear_pending_stack_adjust ();
2075 do_pending_stack_adjust ();
2078 /* PCC-struct return always uses an epilogue. */
2079 if (current_function_returns_pcc_struct
|| use_goto
)
2082 end_label
= return_label
= gen_label_rtx ();
2083 expand_goto_internal (0, end_label
, last_insn
);
2087 /* Otherwise output a simple return-insn if one is available,
2088 unless it won't do the job. */
2090 if (HAVE_return
&& use_goto
== 0 && cleanup_label
== 0)
2092 emit_jump_insn (gen_return ());
2098 /* Otherwise jump to the epilogue. */
2099 expand_goto_internal (0, end_label
, last_insn
);
2102 /* Generate RTL to evaluate the expression RETVAL and return it
2103 from the current function. */
2106 expand_return (retval
)
2109 /* If there are any cleanups to be performed, then they will
2110 be inserted following LAST_INSN. It is desirable
2111 that the last_insn, for such purposes, should be the
2112 last insn before computing the return value. Otherwise, cleanups
2113 which call functions can clobber the return value. */
2114 /* ??? rms: I think that is erroneous, because in C++ it would
2115 run destructors on variables that might be used in the subsequent
2116 computation of the return value. */
2118 register rtx val
= 0;
2122 struct nesting
*block
;
2124 /* If function wants no value, give it none. */
2125 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl
))) == VOID_TYPE
)
2127 expand_expr (retval
, 0, VOIDmode
, 0);
2128 expand_null_return ();
2132 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2133 cleanups
= any_pending_cleanups (1);
2135 if (TREE_CODE (retval
) == RESULT_DECL
)
2136 retval_rhs
= retval
;
2137 else if ((TREE_CODE (retval
) == MODIFY_EXPR
|| TREE_CODE (retval
) == INIT_EXPR
)
2138 && TREE_CODE (TREE_OPERAND (retval
, 0)) == RESULT_DECL
)
2139 retval_rhs
= TREE_OPERAND (retval
, 1);
2140 else if (TREE_TYPE (retval
) == void_type_node
)
2141 /* Recognize tail-recursive call to void function. */
2142 retval_rhs
= retval
;
2144 retval_rhs
= NULL_TREE
;
2146 /* Only use `last_insn' if there are cleanups which must be run. */
2147 if (cleanups
|| cleanup_label
!= 0)
2148 last_insn
= get_last_insn ();
2150 /* Distribute return down conditional expr if either of the sides
2151 may involve tail recursion (see test below). This enhances the number
2152 of tail recursions we see. Don't do this always since it can produce
2153 sub-optimal code in some cases and we distribute assignments into
2154 conditional expressions when it would help. */
2156 if (optimize
&& retval_rhs
!= 0
2157 && frame_offset
== 0
2158 && TREE_CODE (retval_rhs
) == COND_EXPR
2159 && (TREE_CODE (TREE_OPERAND (retval_rhs
, 1)) == CALL_EXPR
2160 || TREE_CODE (TREE_OPERAND (retval_rhs
, 2)) == CALL_EXPR
))
2162 rtx label
= gen_label_rtx ();
2163 do_jump (TREE_OPERAND (retval_rhs
, 0), label
, 0);
2164 expand_return (build (MODIFY_EXPR
, TREE_TYPE (current_function_decl
),
2165 DECL_RESULT (current_function_decl
),
2166 TREE_OPERAND (retval_rhs
, 1)));
2168 expand_return (build (MODIFY_EXPR
, TREE_TYPE (current_function_decl
),
2169 DECL_RESULT (current_function_decl
),
2170 TREE_OPERAND (retval_rhs
, 2)));
2174 /* For tail-recursive call to current function,
2175 just jump back to the beginning.
2176 It's unsafe if any auto variable in this function
2177 has its address taken; for simplicity,
2178 require stack frame to be empty. */
2179 if (optimize
&& retval_rhs
!= 0
2180 && frame_offset
== 0
2181 && TREE_CODE (retval_rhs
) == CALL_EXPR
2182 && TREE_CODE (TREE_OPERAND (retval_rhs
, 0)) == ADDR_EXPR
2183 && TREE_OPERAND (TREE_OPERAND (retval_rhs
, 0), 0) == current_function_decl
2184 /* Finish checking validity, and if valid emit code
2185 to set the argument variables for the new call. */
2186 && tail_recursion_args (TREE_OPERAND (retval_rhs
, 1),
2187 DECL_ARGUMENTS (current_function_decl
)))
2189 if (tail_recursion_label
== 0)
2191 tail_recursion_label
= gen_label_rtx ();
2192 emit_label_after (tail_recursion_label
,
2193 tail_recursion_reentry
);
2195 expand_goto_internal (0, tail_recursion_label
, last_insn
);
2200 /* This optimization is safe if there are local cleanups
2201 because expand_null_return takes care of them.
2202 ??? I think it should also be safe when there is a cleanup label,
2203 because expand_null_return takes care of them, too.
2204 Any reason why not? */
2205 if (HAVE_return
&& cleanup_label
== 0
2206 && ! current_function_returns_pcc_struct
)
2208 /* If this is return x == y; then generate
2209 if (x == y) return 1; else return 0;
2210 if we can do it with explicit return insns. */
2212 switch (TREE_CODE (retval_rhs
))
2220 case TRUTH_ANDIF_EXPR
:
2221 case TRUTH_ORIF_EXPR
:
2222 case TRUTH_AND_EXPR
:
2224 case TRUTH_NOT_EXPR
:
2225 op0
= gen_label_rtx ();
2226 jumpifnot (retval_rhs
, op0
);
2227 expand_value_return (const1_rtx
);
2229 expand_value_return (const0_rtx
);
2233 #endif /* HAVE_return */
2237 && TREE_TYPE (retval_rhs
) != void_type_node
2238 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl
))) == REG
)
2240 /* Calculate the return value into a pseudo reg. */
2241 val
= expand_expr (retval_rhs
, 0, VOIDmode
, 0);
2243 /* All temporaries have now been used. */
2245 /* Return the calculated value, doing cleanups first. */
2246 expand_value_return (val
);
2250 /* No cleanups or no hard reg used;
2251 calculate value into hard return reg. */
2252 expand_expr (retval
, 0, VOIDmode
, 0);
2255 expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl
)));
2259 /* Return 1 if the end of the generated RTX is not a barrier.
2260 This means code already compiled can drop through. */
2263 drop_through_at_end_p ()
2265 rtx insn
= get_last_insn ();
2266 while (insn
&& GET_CODE (insn
) == NOTE
)
2267 insn
= PREV_INSN (insn
);
2268 return insn
&& GET_CODE (insn
) != BARRIER
;
2271 /* Emit code to alter this function's formal parms for a tail-recursive call.
2272 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
2273 FORMALS is the chain of decls of formals.
2274 Return 1 if this can be done;
2275 otherwise return 0 and do not emit any code. */
2278 tail_recursion_args (actuals
, formals
)
2279 tree actuals
, formals
;
2281 register tree a
= actuals
, f
= formals
;
2283 register rtx
*argvec
;
2285 /* Check that number and types of actuals are compatible
2286 with the formals. This is not always true in valid C code.
2287 Also check that no formal needs to be addressable
2288 and that all formals are scalars. */
2290 /* Also count the args. */
2292 for (a
= actuals
, f
= formals
, i
= 0; a
&& f
; a
= TREE_CHAIN (a
), f
= TREE_CHAIN (f
), i
++)
2294 if (TREE_TYPE (TREE_VALUE (a
)) != TREE_TYPE (f
))
2296 if (GET_CODE (DECL_RTL (f
)) != REG
|| DECL_MODE (f
) == BLKmode
)
2299 if (a
!= 0 || f
!= 0)
2302 /* Compute all the actuals. */
2304 argvec
= (rtx
*) alloca (i
* sizeof (rtx
));
2306 for (a
= actuals
, i
= 0; a
; a
= TREE_CHAIN (a
), i
++)
2307 argvec
[i
] = expand_expr (TREE_VALUE (a
), 0, VOIDmode
, 0);
2309 /* Find which actual values refer to current values of previous formals.
2310 Copy each of them now, before any formal is changed. */
2312 for (a
= actuals
, i
= 0; a
; a
= TREE_CHAIN (a
), i
++)
2316 for (f
= formals
, j
= 0; j
< i
; f
= TREE_CHAIN (f
), j
++)
2317 if (reg_mentioned_p (DECL_RTL (f
), argvec
[i
]))
2318 { copy
= 1; break; }
2320 argvec
[i
] = copy_to_reg (argvec
[i
]);
2323 /* Store the values of the actuals into the formals. */
2325 for (f
= formals
, a
= actuals
, i
= 0; f
;
2326 f
= TREE_CHAIN (f
), a
= TREE_CHAIN (a
), i
++)
2328 if (DECL_MODE (f
) == GET_MODE (argvec
[i
]))
2329 emit_move_insn (DECL_RTL (f
), argvec
[i
]);
2331 convert_move (DECL_RTL (f
), argvec
[i
],
2332 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a
))));
2339 /* Generate the RTL code for entering a binding contour.
2340 The variables are declared one by one, by calls to `expand_decl'.
2342 EXIT_FLAG is nonzero if this construct should be visible to
2343 `exit_something'. */
2346 expand_start_bindings (exit_flag
)
2349 struct nesting
*thisblock
= ALLOC_NESTING ();
2351 rtx note
= emit_note (0, NOTE_INSN_BLOCK_BEG
);
2353 /* Make an entry on block_stack for the block we are entering. */
2355 thisblock
->next
= block_stack
;
2356 thisblock
->all
= nesting_stack
;
2357 thisblock
->depth
= ++nesting_depth
;
2358 thisblock
->data
.block
.stack_level
= 0;
2359 thisblock
->data
.block
.cleanups
= 0;
2360 thisblock
->data
.block
.function_call_count
= 0;
2364 if (block_stack
->data
.block
.cleanups
== NULL_TREE
2365 && (block_stack
->data
.block
.outer_cleanups
== NULL_TREE
2366 || block_stack
->data
.block
.outer_cleanups
== empty_cleanup_list
))
2367 thisblock
->data
.block
.outer_cleanups
= empty_cleanup_list
;
2369 thisblock
->data
.block
.outer_cleanups
2370 = tree_cons (NULL_TREE
, block_stack
->data
.block
.cleanups
,
2371 block_stack
->data
.block
.outer_cleanups
);
2374 thisblock
->data
.block
.outer_cleanups
= 0;
2378 && !(block_stack
->data
.block
.cleanups
== NULL_TREE
2379 && block_stack
->data
.block
.outer_cleanups
== NULL_TREE
))
2380 thisblock
->data
.block
.outer_cleanups
2381 = tree_cons (NULL_TREE
, block_stack
->data
.block
.cleanups
,
2382 block_stack
->data
.block
.outer_cleanups
);
2384 thisblock
->data
.block
.outer_cleanups
= 0;
2386 thisblock
->data
.block
.label_chain
= 0;
2387 thisblock
->data
.block
.innermost_stack_block
= stack_block_stack
;
2388 thisblock
->data
.block
.first_insn
= note
;
2389 thisblock
->data
.block
.block_start_count
= ++block_start_count
;
2390 thisblock
->exit_label
= exit_flag
? gen_label_rtx () : 0;
2391 block_stack
= thisblock
;
2392 nesting_stack
= thisblock
;
2394 /* Make a new level for allocating stack slots. */
2398 /* Generate RTL code to terminate a binding contour.
2399 VARS is the chain of VAR_DECL nodes
2400 for the variables bound in this contour.
2401 MARK_ENDS is nonzero if we should put a note at the beginning
2402 and end of this binding contour.
2404 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
2405 (That is true automatically if the contour has a saved stack level.) */
2408 expand_end_bindings (vars
, mark_ends
, dont_jump_in
)
2413 register struct nesting
*thisblock
= block_stack
;
2417 for (decl
= vars
; decl
; decl
= TREE_CHAIN (decl
))
2418 if (! TREE_USED (decl
) && TREE_CODE (decl
) == VAR_DECL
)
2419 warning_with_decl (decl
, "unused variable `%s'");
2421 /* Mark the beginning and end of the scope if requested. */
2424 emit_note (0, NOTE_INSN_BLOCK_END
);
2426 /* Get rid of the beginning-mark if we don't make an end-mark. */
2427 NOTE_LINE_NUMBER (thisblock
->data
.block
.first_insn
) = NOTE_INSN_DELETED
;
2429 if (thisblock
->exit_label
)
2431 do_pending_stack_adjust ();
2432 emit_label (thisblock
->exit_label
);
2435 /* If necessary, make a handler for nonlocal gotos taking
2436 place in the function calls in this block. */
2437 if (function_call_count
!= thisblock
->data
.block
.function_call_count
2439 /* Make handler for outermost block
2440 if there were any nonlocal gotos to this function. */
2441 && (thisblock
->next
== 0 ? current_function_has_nonlocal_label
2442 /* Make handler for inner block if it has something
2443 special to do when you jump out of it. */
2444 : (thisblock
->data
.block
.cleanups
!= 0
2445 || thisblock
->data
.block
.stack_level
!= 0)))
2448 rtx afterward
= gen_label_rtx ();
2449 rtx handler_label
= gen_label_rtx ();
2450 rtx save_receiver
= gen_reg_rtx (Pmode
);
2452 /* Don't let jump_optimize delete the handler. */
2453 LABEL_PRESERVE_P (handler_label
) = 1;
2455 /* Record the handler address in the stack slot for that purpose,
2456 during this block, saving and restoring the outer value. */
2457 if (thisblock
->next
!= 0)
2459 emit_move_insn (nonlocal_goto_handler_slot
, save_receiver
);
2460 emit_insn_before (gen_move_insn (save_receiver
,
2461 nonlocal_goto_handler_slot
),
2462 thisblock
->data
.block
.first_insn
);
2464 emit_insn_before (gen_move_insn (nonlocal_goto_handler_slot
,
2465 gen_rtx (LABEL_REF
, Pmode
,
2467 thisblock
->data
.block
.first_insn
);
2469 /* Jump around the handler; it runs only when specially invoked. */
2470 emit_jump (afterward
);
2471 emit_label (handler_label
);
2473 #ifdef HAVE_nonlocal_goto
2474 if (! HAVE_nonlocal_goto
)
2476 /* First adjust our frame pointer to its actual value. It was
2477 previously set to the start of the virtual area corresponding to
2478 the stacked variables when we branched here and now needs to be
2479 adjusted to the actual hardware fp value.
2481 Assignments are to virtual registers are converted by
2482 instantiate_virtual_regs into the corresponding assignment
2483 to the underlying register (fp in this case) that makes
2484 the original assignment true.
2485 So the following insn will actually be
2486 decrementing fp by STARTING_FRAME_OFFSET. */
2487 emit_move_insn (virtual_stack_vars_rtx
, frame_pointer_rtx
);
2489 #if ARG_POINTER_REGNUM != FRAME_POINTER_REGNUM
2490 if (fixed_regs
[ARG_POINTER_REGNUM
])
2492 /* Now restore our arg pointer from the address at which it was saved
2494 If there hasn't be space allocated for it yet, make some now. */
2495 if (arg_pointer_save_area
== 0)
2496 arg_pointer_save_area
2497 = assign_stack_local (Pmode
, GET_MODE_SIZE (Pmode
), 0);
2498 emit_move_insn (virtual_incoming_args_rtx
,
2499 /* We need a pseudo here,
2500 or else instantiate_virtual_regs_1 complains. */
2501 copy_to_reg (arg_pointer_save_area
));
2505 /* The handler expects the desired label address in the static chain
2506 register. It tests the address and does an appropriate jump
2507 to whatever label is desired. */
2508 for (link
= nonlocal_labels
; link
; link
= TREE_CHAIN (link
))
2509 /* Skip any labels we shouldn't be able to jump to from here. */
2510 if (! DECL_TOO_LATE (TREE_VALUE (link
)))
2512 rtx not_this
= gen_label_rtx ();
2513 rtx
this = gen_label_rtx ();
2514 do_jump_if_equal (static_chain_rtx
,
2515 gen_rtx (LABEL_REF
, Pmode
, DECL_RTL (TREE_VALUE (link
))),
2517 emit_jump (not_this
);
2519 expand_goto (TREE_VALUE (link
));
2520 emit_label (not_this
);
2522 /* If label is not recognized, abort. */
2523 emit_library_call (gen_rtx (SYMBOL_REF
, Pmode
, "abort"), 0,
2525 emit_label (afterward
);
2528 /* Don't allow jumping into a block that has cleanups or a stack level. */
2530 || thisblock
->data
.block
.stack_level
!= 0
2531 || thisblock
->data
.block
.cleanups
!= 0)
2533 struct label_chain
*chain
;
2535 /* Any labels in this block are no longer valid to go to.
2536 Mark them to cause an error message. */
2537 for (chain
= thisblock
->data
.block
.label_chain
; chain
; chain
= chain
->next
)
2539 DECL_TOO_LATE (chain
->label
) = 1;
2540 /* If any goto without a fixup came to this label,
2541 that must be an error, because gotos without fixups
2542 come from outside all saved stack-levels and all cleanups. */
2543 if (TREE_ADDRESSABLE (chain
->label
))
2544 error_with_decl (chain
->label
,
2545 "label `%s' used before containing binding contour");
2549 /* Restore stack level in effect before the block
2550 (only if variable-size objects allocated). */
2551 /* Perform any cleanups associated with the block. */
2553 if (thisblock
->data
.block
.stack_level
!= 0
2554 || thisblock
->data
.block
.cleanups
!= 0)
2556 /* Don't let cleanups affect ({...}) constructs. */
2557 int old_expr_stmts_for_value
= expr_stmts_for_value
;
2558 rtx old_last_expr_value
= last_expr_value
;
2559 tree old_last_expr_type
= last_expr_type
;
2560 expr_stmts_for_value
= 0;
2562 /* Do the cleanups. */
2563 expand_cleanups (thisblock
->data
.block
.cleanups
, 0);
2564 do_pending_stack_adjust ();
2566 expr_stmts_for_value
= old_expr_stmts_for_value
;
2567 last_expr_value
= old_last_expr_value
;
2568 last_expr_type
= old_last_expr_type
;
2570 /* Restore the stack level. */
2572 if (thisblock
->data
.block
.stack_level
!= 0)
2574 emit_move_insn (stack_pointer_rtx
,
2575 thisblock
->data
.block
.stack_level
);
2576 if (nonlocal_goto_stack_level
!= 0)
2577 emit_move_insn (nonlocal_goto_stack_level
, stack_pointer_rtx
);
2580 /* Any gotos out of this block must also do these things.
2581 Also report any gotos with fixups that came to labels in this level. */
2582 fixup_gotos (thisblock
,
2583 thisblock
->data
.block
.stack_level
,
2584 thisblock
->data
.block
.cleanups
,
2585 thisblock
->data
.block
.first_insn
,
2589 /* If doing stupid register allocation, make sure lives of all
2590 register variables declared here extend thru end of scope. */
2593 for (decl
= vars
; decl
; decl
= TREE_CHAIN (decl
))
2595 rtx rtl
= DECL_RTL (decl
);
2596 if (TREE_CODE (decl
) == VAR_DECL
&& rtl
!= 0)
2600 /* Restore block_stack level for containing block. */
2602 stack_block_stack
= thisblock
->data
.block
.innermost_stack_block
;
2603 POPSTACK (block_stack
);
2605 /* Pop the stack slot nesting and free any slots at this level. */
2609 /* Generate RTL for the automatic variable declaration DECL.
2610 (Other kinds of declarations are simply ignored if seen here.)
2611 CLEANUP is an expression to be executed at exit from this binding contour;
2612 for example, in C++, it might call the destructor for this variable.
2614 If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them
2615 either before or after calling `expand_decl' but before compiling
2616 any subsequent expressions. This is because CLEANUP may be expanded
2617 more than once, on different branches of execution.
2618 For the same reason, CLEANUP may not contain a CALL_EXPR
2619 except as its topmost node--else `preexpand_calls' would get confused.
2621 If CLEANUP is nonzero and DECL is zero, we record a cleanup
2622 that is not associated with any particular variable.
2624 There is no special support here for C++ constructors.
2625 They should be handled by the proper code in DECL_INITIAL. */
2631 struct nesting
*thisblock
= block_stack
;
2632 tree type
= TREE_TYPE (decl
);
2634 /* Only automatic variables need any expansion done.
2635 Static and external variables, and external functions,
2636 will be handled by `assemble_variable' (called from finish_decl).
2637 TYPE_DECL and CONST_DECL require nothing.
2638 PARM_DECLs are handled in `assign_parms'. */
2640 if (TREE_CODE (decl
) != VAR_DECL
)
2642 if (TREE_STATIC (decl
) || TREE_EXTERNAL (decl
))
2645 /* Create the RTL representation for the variable. */
2647 if (type
== error_mark_node
)
2648 DECL_RTL (decl
) = gen_rtx (MEM
, BLKmode
, const0_rtx
);
2649 else if (DECL_SIZE (decl
) == 0)
2650 /* Variable with incomplete type. */
2652 if (DECL_INITIAL (decl
) == 0)
2653 /* Error message was already done; now avoid a crash. */
2654 DECL_RTL (decl
) = assign_stack_temp (DECL_MODE (decl
), 0, 1);
2656 /* An initializer is going to decide the size of this array.
2657 Until we know the size, represent its address with a reg. */
2658 DECL_RTL (decl
) = gen_rtx (MEM
, BLKmode
, gen_reg_rtx (Pmode
));
2660 else if (DECL_MODE (decl
) != BLKmode
2661 /* If -ffloat-store, don't put explicit float vars
2663 && !(flag_float_store
2664 && TREE_CODE (type
) == REAL_TYPE
)
2665 && ! TREE_THIS_VOLATILE (decl
)
2666 && ! TREE_ADDRESSABLE (decl
)
2667 && (TREE_REGDECL (decl
) || ! obey_regdecls
))
2669 /* Automatic variable that can go in a register. */
2670 DECL_RTL (decl
) = gen_reg_rtx (DECL_MODE (decl
));
2671 if (TREE_CODE (type
) == POINTER_TYPE
)
2672 mark_reg_pointer (DECL_RTL (decl
));
2673 REG_USERVAR_P (DECL_RTL (decl
)) = 1;
2675 else if (TREE_CODE (DECL_SIZE (decl
)) == INTEGER_CST
)
2677 /* Variable of fixed size that goes on the stack. */
2681 /* If we previously made RTL for this decl, it must be an array
2682 whose size was determined by the initializer.
2683 The old address was a register; set that register now
2684 to the proper address. */
2685 if (DECL_RTL (decl
) != 0)
2687 if (GET_CODE (DECL_RTL (decl
)) != MEM
2688 || GET_CODE (XEXP (DECL_RTL (decl
), 0)) != REG
)
2690 oldaddr
= XEXP (DECL_RTL (decl
), 0);
2694 = assign_stack_temp (DECL_MODE (decl
),
2695 ((TREE_INT_CST_LOW (DECL_SIZE (decl
))
2696 + BITS_PER_UNIT
- 1)
2700 /* Set alignment we actually gave this decl. */
2701 DECL_ALIGN (decl
) = (DECL_MODE (decl
) == BLKmode
? BIGGEST_ALIGNMENT
2702 : GET_MODE_BITSIZE (DECL_MODE (decl
)));
2706 addr
= force_operand (XEXP (DECL_RTL (decl
), 0), oldaddr
);
2707 if (addr
!= oldaddr
)
2708 emit_move_insn (oldaddr
, addr
);
2711 /* If this is a memory ref that contains aggregate components,
2712 mark it as such for cse and loop optimize. */
2713 MEM_IN_STRUCT_P (DECL_RTL (decl
))
2714 = (TREE_CODE (TREE_TYPE (decl
)) == ARRAY_TYPE
2715 || TREE_CODE (TREE_TYPE (decl
)) == RECORD_TYPE
2716 || TREE_CODE (TREE_TYPE (decl
)) == UNION_TYPE
);
2718 /* If this is in memory because of -ffloat-store,
2719 set the volatile bit, to prevent optimizations from
2720 undoing the effects. */
2721 if (flag_float_store
&& TREE_CODE (type
) == REAL_TYPE
)
2722 MEM_VOLATILE_P (DECL_RTL (decl
)) = 1;
2726 /* Dynamic-size object: must push space on the stack. */
2730 /* Record the stack pointer on entry to block, if have
2731 not already done so. */
2732 if (thisblock
->data
.block
.stack_level
== 0)
2734 do_pending_stack_adjust ();
2735 thisblock
->data
.block
.stack_level
2736 = copy_to_reg (stack_pointer_rtx
);
2737 stack_block_stack
= thisblock
;
2740 /* Compute the variable's size, in bytes. */
2741 size
= expand_expr (size_binop (CEIL_DIV_EXPR
,
2743 size_int (BITS_PER_UNIT
)),
2747 /* Allocate space on the stack for the variable. */
2748 address
= allocate_dynamic_stack_space (size
, 0, DECL_ALIGN (decl
));
2750 if (nonlocal_goto_stack_level
!= 0)
2751 emit_move_insn (nonlocal_goto_stack_level
, stack_pointer_rtx
);
2753 /* Reference the variable indirect through that rtx. */
2754 DECL_RTL (decl
) = gen_rtx (MEM
, DECL_MODE (decl
), address
);
2756 /* Indicate the alignment we actually gave this variable. */
2757 #ifdef STACK_BOUNDARY
2758 DECL_ALIGN (decl
) = STACK_BOUNDARY
;
2760 DECL_ALIGN (decl
) = BIGGEST_ALIGNMENT
;
2764 if (TREE_THIS_VOLATILE (decl
))
2765 MEM_VOLATILE_P (DECL_RTL (decl
)) = 1;
2766 if (TREE_READONLY (decl
))
2767 RTX_UNCHANGING_P (DECL_RTL (decl
)) = 1;
2769 /* If doing stupid register allocation, make sure life of any
2770 register variable starts here, at the start of its scope. */
2773 use_variable (DECL_RTL (decl
));
2776 /* Emit code to perform the initialization of a declaration DECL. */
2779 expand_decl_init (decl
)
2782 int was_used
= TREE_USED (decl
);
2784 if (TREE_STATIC (decl
))
2787 /* Compute and store the initial value now. */
2789 if (DECL_INITIAL (decl
) == error_mark_node
)
2791 enum tree_code code
= TREE_CODE (TREE_TYPE (decl
));
2792 if (code
== INTEGER_TYPE
|| code
== REAL_TYPE
|| code
== ENUMERAL_TYPE
2793 || code
== POINTER_TYPE
)
2794 expand_assignment (decl
, convert (TREE_TYPE (decl
), integer_zero_node
),
2798 else if (DECL_INITIAL (decl
) && TREE_CODE (DECL_INITIAL (decl
)) != TREE_LIST
)
2800 emit_line_note (DECL_SOURCE_FILE (decl
), DECL_SOURCE_LINE (decl
));
2801 expand_assignment (decl
, DECL_INITIAL (decl
), 0, 0);
2805 /* Don't let the initialization count as "using" the variable. */
2806 TREE_USED (decl
) = was_used
;
2808 /* Free any temporaries we made while initializing the decl. */
2812 /* CLEANUP is an expression to be executed at exit from this binding contour;
2813 for example, in C++, it might call the destructor for this variable.
2815 If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them
2816 either before or after calling `expand_decl' but before compiling
2817 any subsequent expressions. This is because CLEANUP may be expanded
2818 more than once, on different branches of execution.
2819 For the same reason, CLEANUP may not contain a CALL_EXPR
2820 except as its topmost node--else `preexpand_calls' would get confused.
2822 If CLEANUP is nonzero and DECL is zero, we record a cleanup
2823 that is not associated with any particular variable. */
2826 expand_decl_cleanup (decl
, cleanup
)
2829 struct nesting
*thisblock
= block_stack
;
2831 /* Error if we are not in any block. */
2835 /* Record the cleanup if there is one. */
2839 thisblock
->data
.block
.cleanups
2840 = temp_tree_cons (decl
, cleanup
, thisblock
->data
.block
.cleanups
);
2841 /* If this block has a cleanup, it belongs in stack_block_stack. */
2842 stack_block_stack
= thisblock
;
2847 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
2848 DECL_ELTS is the list of elements that belong to DECL's type.
2849 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
2852 expand_anon_union_decl (decl
, cleanup
, decl_elts
)
2853 tree decl
, cleanup
, decl_elts
;
2855 struct nesting
*thisblock
= block_stack
;
2858 expand_decl (decl
, cleanup
);
2859 x
= DECL_RTL (decl
);
2863 tree decl_elt
= TREE_VALUE (decl_elts
);
2864 tree cleanup_elt
= TREE_PURPOSE (decl_elts
);
2865 enum machine_mode mode
= TYPE_MODE (TREE_TYPE (decl_elt
));
2867 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
2868 instead create a new MEM rtx with the proper mode. */
2869 if (GET_CODE (x
) == MEM
)
2871 if (mode
== GET_MODE (x
))
2872 DECL_RTL (decl_elt
) = x
;
2875 DECL_RTL (decl_elt
) = gen_rtx (MEM
, mode
, copy_rtx (XEXP (x
, 0)));
2876 MEM_IN_STRUCT_P (DECL_RTL (decl_elt
)) = MEM_IN_STRUCT_P (x
);
2877 RTX_UNCHANGING_P (DECL_RTL (decl_elt
)) = RTX_UNCHANGING_P (x
);
2880 else if (GET_CODE (x
) == REG
)
2882 if (mode
== GET_MODE (x
))
2883 DECL_RTL (decl_elt
) = x
;
2885 DECL_RTL (decl_elt
) = gen_rtx (SUBREG
, mode
, x
, 0);
2890 /* Record the cleanup if there is one. */
2893 thisblock
->data
.block
.cleanups
2894 = temp_tree_cons (decl_elt
, cleanup_elt
,
2895 thisblock
->data
.block
.cleanups
);
2897 decl_elts
= TREE_CHAIN (decl_elts
);
2901 /* Expand a list of cleanups LIST.
2902 Elements may be expressions or may be nested lists.
2904 If DONT_DO is nonnull, then any list-element
2905 whose TREE_PURPOSE matches DONT_DO is omitted.
2906 This is sometimes used to avoid a cleanup associated with
2907 a value that is being returned out of the scope. */
2910 expand_cleanups (list
, dont_do
)
2915 for (tail
= list
; tail
; tail
= TREE_CHAIN (tail
))
2916 if (dont_do
== 0 || TREE_PURPOSE (tail
) != dont_do
)
2918 if (TREE_CODE (TREE_VALUE (tail
)) == TREE_LIST
)
2919 expand_cleanups (TREE_VALUE (tail
), dont_do
);
2922 /* Cleanups may be run multiple times. For example,
2923 when exiting a binding contour, we expand the
2924 cleanups associated with that contour. When a goto
2925 within that binding contour has a target outside that
2926 contour, it will expand all cleanups from its scope to
2927 the target. Though the cleanups are expanded multiple
2928 times, the control paths are non-overlapping so the
2929 cleanups will not be executed twice. */
2930 expand_expr (TREE_VALUE (tail
), const0_rtx
, VOIDmode
, 0);
2936 /* Expand a list of cleanups for a goto fixup.
2937 The expansion is put into the insn chain after the insn *BEFORE_JUMP
2938 and *BEFORE_JUMP is set to the insn that now comes before the jump. */
2941 fixup_cleanups (list
, before_jump
)
2945 rtx beyond_jump
= get_last_insn ();
2946 rtx new_before_jump
;
2948 expand_cleanups (list
, 0);
2949 /* Pop any pushes done in the cleanups,
2950 in case function is about to return. */
2951 do_pending_stack_adjust ();
2953 new_before_jump
= get_last_insn ();
2955 if (beyond_jump
!= new_before_jump
)
2957 /* If cleanups expand to nothing, don't reorder. */
2958 reorder_insns (NEXT_INSN (beyond_jump
), new_before_jump
, *before_jump
);
2959 *before_jump
= new_before_jump
;
2963 /* Move all cleanups from the current block_stack
2964 to the containing block_stack, where they are assumed to
2965 have been created. If anything can cause a temporary to
2966 be created, but not expanded for more than one level of
2967 block_stacks, then this code will have to change. */
2972 struct nesting
*block
= block_stack
;
2973 struct nesting
*outer
= block
->next
;
2975 outer
->data
.block
.cleanups
2976 = chainon (block
->data
.block
.cleanups
,
2977 outer
->data
.block
.cleanups
);
2978 block
->data
.block
.cleanups
= 0;
2982 last_cleanup_this_contour ()
2984 if (block_stack
== 0)
2987 return block_stack
->data
.block
.cleanups
;
2990 /* Return 1 if there are any pending cleanups at this point.
2991 If THIS_CONTOUR is nonzero, check the current contour as well.
2992 Otherwise, look only at the contours that enclose this one. */
2995 any_pending_cleanups (this_contour
)
2998 struct nesting
*block
;
3000 if (block_stack
== 0)
3003 if (this_contour
&& block_stack
->data
.block
.cleanups
!= NULL
)
3005 if (block_stack
->data
.block
.cleanups
== 0
3006 && (block_stack
->data
.block
.outer_cleanups
== 0
3008 || block_stack
->data
.block
.outer_cleanups
== empty_cleanup_list
3013 for (block
= block_stack
->next
; block
; block
= block
->next
)
3014 if (block
->data
.block
.cleanups
!= 0)
3020 /* Enter a case (Pascal) or switch (C) statement.
3021 Push a block onto case_stack and nesting_stack
3022 to accumulate the case-labels that are seen
3023 and to record the labels generated for the statement.
3025 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
3026 Otherwise, this construct is transparent for `exit_something'.
3028 EXPR is the index-expression to be dispatched on.
3029 TYPE is its nominal type. We could simply convert EXPR to this type,
3030 but instead we take short cuts. */
3033 expand_start_case (exit_flag
, expr
, type
, printname
)
3039 register struct nesting
*thiscase
= ALLOC_NESTING ();
3041 /* Make an entry on case_stack for the case we are entering. */
3043 thiscase
->next
= case_stack
;
3044 thiscase
->all
= nesting_stack
;
3045 thiscase
->depth
= ++nesting_depth
;
3046 thiscase
->exit_label
= exit_flag
? gen_label_rtx () : 0;
3047 thiscase
->data
.case_stmt
.case_list
= 0;
3048 thiscase
->data
.case_stmt
.index_expr
= expr
;
3049 thiscase
->data
.case_stmt
.nominal_type
= type
;
3050 thiscase
->data
.case_stmt
.default_label
= 0;
3051 thiscase
->data
.case_stmt
.num_ranges
= 0;
3052 thiscase
->data
.case_stmt
.printname
= printname
;
3053 thiscase
->data
.case_stmt
.seenlabel
= 0;
3054 case_stack
= thiscase
;
3055 nesting_stack
= thiscase
;
3057 do_pending_stack_adjust ();
3059 /* Make sure case_stmt.start points to something that won't
3060 need any transformation before expand_end_case. */
3061 if (GET_CODE (get_last_insn ()) != NOTE
)
3062 emit_note (0, NOTE_INSN_DELETED
);
3064 thiscase
->data
.case_stmt
.start
= get_last_insn ();
3067 /* Start a "dummy case statement" within which case labels are invalid
3068 and are not connected to any larger real case statement.
3069 This can be used if you don't want to let a case statement jump
3070 into the middle of certain kinds of constructs. */
3073 expand_start_case_dummy ()
3075 register struct nesting
*thiscase
= ALLOC_NESTING ();
3077 /* Make an entry on case_stack for the dummy. */
3079 thiscase
->next
= case_stack
;
3080 thiscase
->all
= nesting_stack
;
3081 thiscase
->depth
= ++nesting_depth
;
3082 thiscase
->exit_label
= 0;
3083 thiscase
->data
.case_stmt
.case_list
= 0;
3084 thiscase
->data
.case_stmt
.start
= 0;
3085 thiscase
->data
.case_stmt
.nominal_type
= 0;
3086 thiscase
->data
.case_stmt
.default_label
= 0;
3087 thiscase
->data
.case_stmt
.num_ranges
= 0;
3088 case_stack
= thiscase
;
3089 nesting_stack
= thiscase
;
3092 /* End a dummy case statement. */
3095 expand_end_case_dummy ()
3097 POPSTACK (case_stack
);
3100 /* Return the data type of the index-expression
3101 of the innermost case statement, or null if none. */
3104 case_index_expr_type ()
3107 return TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
3111 /* Accumulate one case or default label inside a case or switch statement.
3112 VALUE is the value of the case (a null pointer, for a default label).
3114 If not currently inside a case or switch statement, return 1 and do
3115 nothing. The caller will print a language-specific error message.
3116 If VALUE is a duplicate or overlaps, return 2 and do nothing
3117 except store the (first) duplicate node in *DUPLICATE.
3118 If VALUE is out of range, return 3 and do nothing.
3119 If we are jumping into the scope of a cleaup or var-sized array, return 5.
3120 Return 0 on success.
3122 Extended to handle range statements. */
3125 pushcase (value
, label
, duplicate
)
3126 register tree value
;
3127 register tree label
;
3130 register struct case_node
**l
;
3131 register struct case_node
*n
;
3135 /* Fail if not inside a real case statement. */
3136 if (! (case_stack
&& case_stack
->data
.case_stmt
.start
))
3139 if (stack_block_stack
3140 && stack_block_stack
->depth
> case_stack
->depth
)
3143 index_type
= TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
3144 nominal_type
= case_stack
->data
.case_stmt
.nominal_type
;
3146 /* If the index is erroneous, avoid more problems: pretend to succeed. */
3147 if (index_type
== error_mark_node
)
3150 /* Convert VALUE to the type in which the comparisons are nominally done. */
3152 value
= convert (nominal_type
, value
);
3154 /* If this is the first label, warn if any insns have been emitted. */
3155 if (case_stack
->data
.case_stmt
.seenlabel
== 0)
3158 for (insn
= case_stack
->data
.case_stmt
.start
;
3160 insn
= NEXT_INSN (insn
))
3162 if (GET_CODE (insn
) == CODE_LABEL
)
3164 if (GET_CODE (insn
) != NOTE
3165 && (GET_CODE (insn
) != INSN
|| GET_CODE (PATTERN (insn
)) != USE
))
3167 warning ("unreachable code at beginning of %s",
3168 case_stack
->data
.case_stmt
.printname
);
3173 case_stack
->data
.case_stmt
.seenlabel
= 1;
3175 /* Fail if this value is out of range for the actual type of the index
3176 (which may be narrower than NOMINAL_TYPE). */
3177 if (value
!= 0 && ! int_fits_type_p (value
, index_type
))
3180 /* Fail if this is a duplicate or overlaps another entry. */
3183 if (case_stack
->data
.case_stmt
.default_label
!= 0)
3185 *duplicate
= case_stack
->data
.case_stmt
.default_label
;
3188 case_stack
->data
.case_stmt
.default_label
= label
;
3192 /* Find the elt in the chain before which to insert the new value,
3193 to keep the chain sorted in increasing order.
3194 But report an error if this element is a duplicate. */
3195 for (l
= &case_stack
->data
.case_stmt
.case_list
;
3196 /* Keep going past elements distinctly less than VALUE. */
3197 *l
!= 0 && tree_int_cst_lt ((*l
)->high
, value
);
3202 /* Element we will insert before must be distinctly greater;
3203 overlap means error. */
3204 if (! tree_int_cst_lt (value
, (*l
)->low
))
3206 *duplicate
= (*l
)->code_label
;
3211 /* Add this label to the chain, and succeed.
3212 Copy VALUE so it is on temporary rather than momentary
3213 obstack and will thus survive till the end of the case statement. */
3214 n
= (struct case_node
*) oballoc (sizeof (struct case_node
));
3217 n
->high
= n
->low
= copy_node (value
);
3218 n
->code_label
= label
;
3222 expand_label (label
);
3226 /* Like pushcase but this case applies to all values
3227 between VALUE1 and VALUE2 (inclusive).
3228 The return value is the same as that of pushcase
3229 but there is one additional error code:
3230 4 means the specified range was empty. */
3233 pushcase_range (value1
, value2
, label
, duplicate
)
3234 register tree value1
, value2
;
3235 register tree label
;
3238 register struct case_node
**l
;
3239 register struct case_node
*n
;
3243 /* Fail if not inside a real case statement. */
3244 if (! (case_stack
&& case_stack
->data
.case_stmt
.start
))
3247 if (stack_block_stack
3248 && stack_block_stack
->depth
> case_stack
->depth
)
3251 index_type
= TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
3252 nominal_type
= case_stack
->data
.case_stmt
.nominal_type
;
3254 /* If the index is erroneous, avoid more problems: pretend to succeed. */
3255 if (index_type
== error_mark_node
)
3258 /* If this is the first label, warn if any insns have been emitted. */
3259 if (case_stack
->data
.case_stmt
.seenlabel
== 0)
3262 for (insn
= case_stack
->data
.case_stmt
.start
;
3264 insn
= NEXT_INSN (insn
))
3266 if (GET_CODE (insn
) == CODE_LABEL
)
3268 if (GET_CODE (insn
) != NOTE
3269 && (GET_CODE (insn
) != INSN
|| GET_CODE (PATTERN (insn
)) != USE
))
3271 warning ("unreachable code at beginning of %s",
3272 case_stack
->data
.case_stmt
.printname
);
3277 case_stack
->data
.case_stmt
.seenlabel
= 1;
3279 /* Convert VALUEs to type in which the comparisons are nominally done. */
3280 if (value1
== 0) /* Negative infinity. */
3281 value1
= TYPE_MIN_VALUE(index_type
);
3282 value1
= convert (nominal_type
, value1
);
3284 if (value2
== 0) /* Positive infinity. */
3285 value2
= TYPE_MAX_VALUE(index_type
);
3286 value2
= convert (nominal_type
, value2
);
3288 /* Fail if these values are out of range. */
3289 if (! int_fits_type_p (value1
, index_type
))
3292 if (! int_fits_type_p (value2
, index_type
))
3295 /* Fail if the range is empty. */
3296 if (tree_int_cst_lt (value2
, value1
))
3299 /* If the bounds are equal, turn this into the one-value case. */
3300 if (tree_int_cst_equal (value1
, value2
))
3301 return pushcase (value1
, label
, duplicate
);
3303 /* Find the elt in the chain before which to insert the new value,
3304 to keep the chain sorted in increasing order.
3305 But report an error if this element is a duplicate. */
3306 for (l
= &case_stack
->data
.case_stmt
.case_list
;
3307 /* Keep going past elements distinctly less than this range. */
3308 *l
!= 0 && tree_int_cst_lt ((*l
)->high
, value1
);
3313 /* Element we will insert before must be distinctly greater;
3314 overlap means error. */
3315 if (! tree_int_cst_lt (value2
, (*l
)->low
))
3317 *duplicate
= (*l
)->code_label
;
3322 /* Add this label to the chain, and succeed.
3323 Copy VALUE1, VALUE2 so they are on temporary rather than momentary
3324 obstack and will thus survive till the end of the case statement. */
3326 n
= (struct case_node
*) oballoc (sizeof (struct case_node
));
3329 n
->low
= copy_node (value1
);
3330 n
->high
= copy_node (value2
);
3331 n
->code_label
= label
;
3334 expand_label (label
);
3336 case_stack
->data
.case_stmt
.num_ranges
++;
3341 /* Called when the index of a switch statement is an enumerated type
3342 and there is no default label.
3344 Checks that all enumeration literals are covered by the case
3345 expressions of a switch. Also, warn if there are any extra
3346 switch cases that are *not* elements of the enumerated type.
3348 If all enumeration literals were covered by the case expressions,
3349 turn one of the expressions into the default expression since it should
3350 not be possible to fall through such a switch. */
3353 check_for_full_enumeration_handling (type
)
3356 register struct case_node
*n
;
3357 register struct case_node
**l
;
3358 register tree chain
;
3361 /* The time complexity of this loop is currently O(N * M), with
3362 N being the number of enumerals in the enumerated type, and
3363 M being the number of case expressions in the switch. */
3365 for (chain
= TYPE_VALUES (type
);
3367 chain
= TREE_CHAIN (chain
))
3369 /* Find a match between enumeral and case expression, if possible.
3370 Quit looking when we've gone too far (since case expressions
3371 are kept sorted in ascending order). Warn about enumerals not
3372 handled in the switch statement case expression list. */
3374 for (n
= case_stack
->data
.case_stmt
.case_list
;
3375 n
&& tree_int_cst_lt (n
->high
, TREE_VALUE (chain
));
3379 if (!(n
&& tree_int_cst_equal (n
->low
, TREE_VALUE (chain
))))
3382 warning ("enumerated value `%s' not handled in switch",
3383 IDENTIFIER_POINTER (TREE_PURPOSE (chain
)));
3388 /* Now we go the other way around; we warn if there are case
3389 expressions that don't correspond to enumerals. This can
3390 occur since C and C++ don't enforce type-checking of
3391 assignments to enumeration variables. */
3394 for (n
= case_stack
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
3396 for (chain
= TYPE_VALUES (type
);
3397 chain
&& !tree_int_cst_equal (n
->low
, TREE_VALUE (chain
));
3398 chain
= TREE_CHAIN (chain
))
3402 warning ("case value `%d' not in enumerated type `%s'",
3403 TREE_INT_CST_LOW (n
->low
),
3404 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type
))
3407 : DECL_NAME (TYPE_NAME (type
))));
3410 /* If all values were found as case labels, make one of them the default
3411 label. Thus, this switch will never fall through. We arbitrarily pick
3412 the last one to make the default since this is likely the most
3413 efficient choice. */
3417 for (l
= &case_stack
->data
.case_stmt
.case_list
;
3422 case_stack
->data
.case_stmt
.default_label
= (*l
)->code_label
;
3427 /* Terminate a case (Pascal) or switch (C) statement
3428 in which CASE_INDEX is the expression to be tested.
3429 Generate the code to test it and jump to the right place. */
3432 expand_end_case (orig_index
)
3435 tree minval
, maxval
, range
;
3436 rtx default_label
= 0;
3437 register struct case_node
*n
;
3440 rtx table_label
= gen_label_rtx ();
3445 register struct nesting
*thiscase
= case_stack
;
3446 tree index_expr
= thiscase
->data
.case_stmt
.index_expr
;
3447 int unsignedp
= TREE_UNSIGNED (TREE_TYPE (index_expr
));
3449 do_pending_stack_adjust ();
3451 /* An ERROR_MARK occurs for various reasons including invalid data type. */
3452 if (TREE_TYPE (index_expr
) != error_mark_node
)
3454 /* If switch expression was an enumerated type, check that all
3455 enumeration literals are covered by the cases.
3456 No sense trying this if there's a default case, however. */
3458 if (!thiscase
->data
.case_stmt
.default_label
3459 && TREE_CODE (TREE_TYPE (orig_index
)) == ENUMERAL_TYPE
3460 && TREE_CODE (index_expr
) != INTEGER_CST
)
3461 check_for_full_enumeration_handling (TREE_TYPE (orig_index
));
3463 /* If this is the first label, warn if any insns have been emitted. */
3464 if (thiscase
->data
.case_stmt
.seenlabel
== 0)
3467 for (insn
= get_last_insn ();
3468 insn
!= case_stack
->data
.case_stmt
.start
;
3469 insn
= PREV_INSN (insn
))
3470 if (GET_CODE (insn
) != NOTE
3471 && (GET_CODE (insn
) != INSN
|| GET_CODE (PATTERN (insn
))!= USE
))
3473 warning ("unreachable code at beginning of %s",
3474 case_stack
->data
.case_stmt
.printname
);
3479 /* If we don't have a default-label, create one here,
3480 after the body of the switch. */
3481 if (thiscase
->data
.case_stmt
.default_label
== 0)
3483 thiscase
->data
.case_stmt
.default_label
3484 = build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
3485 expand_label (thiscase
->data
.case_stmt
.default_label
);
3487 default_label
= label_rtx (thiscase
->data
.case_stmt
.default_label
);
3489 before_case
= get_last_insn ();
3491 /* Simplify the case-list before we count it. */
3492 group_case_nodes (thiscase
->data
.case_stmt
.case_list
);
3494 /* Get upper and lower bounds of case values.
3495 Also convert all the case values to the index expr's data type. */
3498 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
3500 /* Check low and high label values are integers. */
3501 if (TREE_CODE (n
->low
) != INTEGER_CST
)
3503 if (TREE_CODE (n
->high
) != INTEGER_CST
)
3506 n
->low
= convert (TREE_TYPE (index_expr
), n
->low
);
3507 n
->high
= convert (TREE_TYPE (index_expr
), n
->high
);
3509 /* Count the elements and track the largest and smallest
3510 of them (treating them as signed even if they are not). */
3518 if (INT_CST_LT (n
->low
, minval
))
3520 if (INT_CST_LT (maxval
, n
->high
))
3523 /* A range counts double, since it requires two compares. */
3524 if (! tree_int_cst_equal (n
->low
, n
->high
))
3528 /* Compute span of values. */
3530 range
= fold (build (MINUS_EXPR
, TREE_TYPE (index_expr
),
3533 if (count
== 0 || TREE_CODE (TREE_TYPE (index_expr
)) == ERROR_MARK
)
3535 expand_expr (index_expr
, const0_rtx
, VOIDmode
, 0);
3537 emit_jump (default_label
);
3539 /* If range of values is much bigger than number of values,
3540 make a sequence of conditional branches instead of a dispatch.
3541 If the switch-index is a constant, do it this way
3542 because we can optimize it. */
3543 else if (TREE_INT_CST_HIGH (range
) != 0
3545 || (HAVE_casesi
? count
< 4 : count
< 5)
3547 /* If machine does not have a case insn that compares the
3548 bounds, this means extra overhead for dispatch tables
3549 which raises the threshold for using them. */
3552 || (unsigned) (TREE_INT_CST_LOW (range
)) > 10 * count
3553 || TREE_CODE (index_expr
) == INTEGER_CST
3554 /* These will reduce to a constant. */
3555 || (TREE_CODE (index_expr
) == CALL_EXPR
3556 && TREE_CODE (TREE_OPERAND (index_expr
, 0)) == ADDR_EXPR
3557 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr
, 0), 0)) == FUNCTION_DECL
3558 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr
, 0), 0)) == BUILT_IN_CLASSIFY_TYPE
)
3559 || (TREE_CODE (index_expr
) == COMPOUND_EXPR
3560 && TREE_CODE (TREE_OPERAND (index_expr
, 1)) == INTEGER_CST
))
3562 index
= expand_expr (index_expr
, 0, VOIDmode
, 0);
3564 /* If the index is a short or char that we do not have
3565 an insn to handle comparisons directly, convert it to
3566 a full integer now, rather than letting each comparison
3567 generate the conversion. */
3569 if (GET_MODE_CLASS (GET_MODE (index
)) == MODE_INT
3570 && (cmp_optab
->handlers
[(int) GET_MODE(index
)].insn_code
3571 == CODE_FOR_nothing
))
3573 enum machine_mode wider_mode
;
3574 for (wider_mode
= GET_MODE (index
); wider_mode
!= VOIDmode
;
3575 wider_mode
= GET_MODE_WIDER_MODE (wider_mode
))
3576 if (cmp_optab
->handlers
[(int) wider_mode
].insn_code
3577 != CODE_FOR_nothing
)
3579 index
= convert_to_mode (wider_mode
, index
, unsignedp
);
3585 do_pending_stack_adjust ();
3587 index
= protect_from_queue (index
, 0);
3588 if (GET_CODE (index
) == MEM
)
3589 index
= copy_to_reg (index
);
3590 if (GET_CODE (index
) == CONST_INT
3591 || TREE_CODE (index_expr
) == INTEGER_CST
)
3593 /* Make a tree node with the proper constant value
3594 if we don't already have one. */
3595 if (TREE_CODE (index_expr
) != INTEGER_CST
)
3598 = build_int_2 (INTVAL (index
),
3599 !unsignedp
&& INTVAL (index
) >= 0 ? 0 : -1);
3600 index_expr
= convert (TREE_TYPE (index_expr
), index_expr
);
3603 /* For constant index expressions we need only
3604 issue a unconditional branch to the appropriate
3605 target code. The job of removing any unreachable
3606 code is left to the optimisation phase if the
3607 "-O" option is specified. */
3608 for (n
= thiscase
->data
.case_stmt
.case_list
;
3612 if (! tree_int_cst_lt (index_expr
, n
->low
)
3613 && ! tree_int_cst_lt (n
->high
, index_expr
))
3617 emit_jump (label_rtx (n
->code_label
));
3619 emit_jump (default_label
);
3623 /* If the index expression is not constant we generate
3624 a binary decision tree to select the appropriate
3625 target code. This is done as follows:
3627 The list of cases is rearranged into a binary tree,
3628 nearly optimal assuming equal probability for each case.
3630 The tree is transformed into RTL, eliminating
3631 redundant test conditions at the same time.
3633 If program flow could reach the end of the
3634 decision tree an unconditional jump to the
3635 default code is emitted. */
3638 = (TREE_CODE (TREE_TYPE (orig_index
)) != ENUMERAL_TYPE
3639 && default_label
!= 0
3640 && estimate_case_costs (thiscase
->data
.case_stmt
.case_list
));
3641 balance_case_nodes (&thiscase
->data
.case_stmt
.case_list
, 0);
3642 emit_case_nodes (index
, thiscase
->data
.case_stmt
.case_list
,
3643 default_label
, TREE_TYPE (index_expr
));
3644 emit_jump_if_reachable (default_label
);
3653 enum machine_mode index_mode
= SImode
;
3654 int index_bits
= GET_MODE_BITSIZE (index_mode
);
3656 /* Convert the index to SImode. */
3657 if (GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (index_expr
)))
3658 > GET_MODE_BITSIZE (index_mode
))
3660 index_expr
= build (MINUS_EXPR
, TREE_TYPE (index_expr
),
3661 index_expr
, minval
);
3662 minval
= integer_zero_node
;
3664 if (TYPE_MODE (TREE_TYPE (index_expr
)) != index_mode
)
3665 index_expr
= convert (type_for_size (index_bits
, 0),
3667 index
= expand_expr (index_expr
, 0, VOIDmode
, 0);
3669 index
= protect_from_queue (index
, 0);
3670 do_pending_stack_adjust ();
3672 emit_jump_insn (gen_casesi (index
, expand_expr (minval
, 0, VOIDmode
, 0),
3673 expand_expr (range
, 0, VOIDmode
, 0),
3674 table_label
, default_label
));
3678 #ifdef HAVE_tablejump
3679 if (! win
&& HAVE_tablejump
)
3681 index_expr
= convert (thiscase
->data
.case_stmt
.nominal_type
,
3682 fold (build (MINUS_EXPR
,
3683 TREE_TYPE (index_expr
),
3684 index_expr
, minval
)));
3685 index
= expand_expr (index_expr
, 0, VOIDmode
, 0);
3687 /* convert_to_mode calls protect_from_queue. */
3688 index
= convert_to_mode (Pmode
, index
, 1);
3689 do_pending_stack_adjust ();
3691 do_tablejump (index
, Pmode
,
3692 gen_rtx (CONST_INT
, VOIDmode
,
3693 TREE_INT_CST_LOW (range
)),
3694 table_label
, default_label
);
3701 /* Get table of labels to jump to, in order of case index. */
3703 ncases
= TREE_INT_CST_LOW (range
) + 1;
3704 labelvec
= (rtx
*) alloca (ncases
* sizeof (rtx
));
3705 bzero (labelvec
, ncases
* sizeof (rtx
));
3707 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
3710 = TREE_INT_CST_LOW (n
->low
) - TREE_INT_CST_LOW (minval
);
3715 = gen_rtx (LABEL_REF
, Pmode
, label_rtx (n
->code_label
));
3716 if (i
+ TREE_INT_CST_LOW (minval
)
3717 == TREE_INT_CST_LOW (n
->high
))
3723 /* Fill in the gaps with the default. */
3724 for (i
= 0; i
< ncases
; i
++)
3725 if (labelvec
[i
] == 0)
3726 labelvec
[i
] = gen_rtx (LABEL_REF
, Pmode
, default_label
);
3728 /* Output the table */
3729 emit_label (table_label
);
3731 /* This would be a lot nicer if CASE_VECTOR_PC_RELATIVE
3732 were an expression, instead of a an #ifdef/#ifndef. */
3734 #ifdef CASE_VECTOR_PC_RELATIVE
3738 emit_jump_insn (gen_rtx (ADDR_DIFF_VEC
, CASE_VECTOR_MODE
,
3739 gen_rtx (LABEL_REF
, Pmode
, table_label
),
3740 gen_rtvec_v (ncases
, labelvec
)));
3742 emit_jump_insn (gen_rtx (ADDR_VEC
, CASE_VECTOR_MODE
,
3743 gen_rtvec_v (ncases
, labelvec
)));
3745 /* If the case insn drops through the table,
3746 after the table we must jump to the default-label.
3747 Otherwise record no drop-through after the table. */
3748 #ifdef CASE_DROPS_THROUGH
3749 emit_jump (default_label
);
3755 before_case
= squeeze_notes (NEXT_INSN (before_case
), get_last_insn ());
3756 reorder_insns (before_case
, get_last_insn (),
3757 thiscase
->data
.case_stmt
.start
);
3759 if (thiscase
->exit_label
)
3760 emit_label (thiscase
->exit_label
);
3762 POPSTACK (case_stack
);
3767 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
3770 do_jump_if_equal (op1
, op2
, label
, unsignedp
)
3771 rtx op1
, op2
, label
;
3774 if (GET_CODE (op1
) == CONST_INT
3775 && GET_CODE (op2
) == CONST_INT
)
3777 if (INTVAL (op1
) == INTVAL (op2
))
3782 enum machine_mode mode
= GET_MODE (op1
);
3783 if (mode
== VOIDmode
)
3784 mode
= GET_MODE (op2
);
3785 emit_cmp_insn (op1
, op2
, EQ
, 0, mode
, unsignedp
, 0);
3786 emit_jump_insn (gen_beq (label
));
3790 /* Not all case values are encountered equally. This function
3791 uses a heuristic to weight case labels, in cases where that
3792 looks like a reasonable thing to do.
3794 Right now, all we try to guess is text, and we establish the
3797 chars above space: 16
3806 If we find any cases in the switch that are not either -1 or in the range
3807 of valid ASCII characters, or are control characters other than those
3808 commonly used with "\", don't treat this switch scanning text.
3810 Return 1 if these nodes are suitable for cost estimation, otherwise
3814 estimate_case_costs (node
)
3817 tree min_ascii
= build_int_2 (-1, -1);
3818 tree max_ascii
= convert (TREE_TYPE (node
->high
), build_int_2 (127, 0));
3822 /* If we haven't already made the cost table, make it now. Note that the
3823 lower bound of the table is -1, not zero. */
3825 if (cost_table
== NULL
)
3827 cost_table
= ((short *) xmalloc (129 * sizeof (short))) + 1;
3828 bzero (cost_table
- 1, 129 * sizeof (short));
3830 for (i
= 0; i
< 128; i
++)
3834 else if (ispunct (i
))
3836 else if (iscntrl (i
))
3840 cost_table
[' '] = 8;
3841 cost_table
['\t'] = 4;
3842 cost_table
['\0'] = 4;
3843 cost_table
['\n'] = 2;
3844 cost_table
['\f'] = 1;
3845 cost_table
['\v'] = 1;
3846 cost_table
['\b'] = 1;
3849 /* See if all the case expressions look like text. It is text if the
3850 constant is >= -1 and the highest constant is <= 127. Do all comparisons
3851 as signed arithmetic since we don't want to ever access cost_table with a
3852 value less than -1. Also check that none of the constants in a range
3853 are strange control characters. */
3855 for (n
= node
; n
; n
= n
->right
)
3857 if ((INT_CST_LT (n
->low
, min_ascii
)) || INT_CST_LT (max_ascii
, n
->high
))
3860 for (i
= TREE_INT_CST_LOW (n
->low
); i
<= TREE_INT_CST_LOW (n
->high
); i
++)
3861 if (cost_table
[i
] < 0)
3865 /* All interesting values are within the range of interesting
3866 ASCII characters. */
3870 /* Scan an ordered list of case nodes
3871 combining those with consecutive values or ranges.
3873 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
3876 group_case_nodes (head
)
3879 case_node_ptr node
= head
;
3883 rtx lb
= next_real_insn (label_rtx (node
->code_label
));
3884 case_node_ptr np
= node
;
3886 /* Try to group the successors of NODE with NODE. */
3887 while (((np
= np
->right
) != 0)
3888 /* Do they jump to the same place? */
3889 && next_real_insn (label_rtx (np
->code_label
)) == lb
3890 /* Are their ranges consecutive? */
3891 && tree_int_cst_equal (np
->low
,
3892 fold (build (PLUS_EXPR
,
3893 TREE_TYPE (node
->high
),
3896 /* An overflow is not consecutive. */
3897 && tree_int_cst_lt (node
->high
,
3898 fold (build (PLUS_EXPR
,
3899 TREE_TYPE (node
->high
),
3901 integer_one_node
))))
3903 node
->high
= np
->high
;
3905 /* NP is the first node after NODE which can't be grouped with it.
3906 Delete the nodes in between, and move on to that node. */
3912 /* Take an ordered list of case nodes
3913 and transform them into a near optimal binary tree,
3914 on the assumtion that any target code selection value is as
3915 likely as any other.
3917 The transformation is performed by splitting the ordered
3918 list into two equal sections plus a pivot. The parts are
3919 then attached to the pivot as left and right branches. Each
3920 branch is is then transformed recursively. */
3923 balance_case_nodes (head
, parent
)
3924 case_node_ptr
*head
;
3925 case_node_ptr parent
;
3927 register case_node_ptr np
;
3935 register case_node_ptr
*npp
;
3938 /* Count the number of entries on branch. Also count the ranges. */
3942 if (!tree_int_cst_equal (np
->low
, np
->high
))
3946 cost
+= cost_table
[TREE_INT_CST_LOW (np
->high
)];
3950 cost
+= cost_table
[TREE_INT_CST_LOW (np
->low
)];
3958 /* Split this list if it is long enough for that to help. */
3963 /* Find the place in the list that bisects the list's total cost,
3964 Here I gets half the total cost. */
3969 /* Skip nodes while their cost does not reach that amount. */
3970 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
3971 i
-= cost_table
[TREE_INT_CST_LOW ((*npp
)->high
)];
3972 i
-= cost_table
[TREE_INT_CST_LOW ((*npp
)->low
)];
3975 npp
= &(*npp
)->right
;
3980 /* Leave this branch lopsided, but optimize left-hand
3981 side and fill in `parent' fields for right-hand side. */
3983 np
->parent
= parent
;
3984 balance_case_nodes (&np
->left
, np
);
3985 for (; np
->right
; np
= np
->right
)
3986 np
->right
->parent
= np
;
3990 /* If there are just three nodes, split at the middle one. */
3992 npp
= &(*npp
)->right
;
3995 /* Find the place in the list that bisects the list's total cost,
3996 where ranges count as 2.
3997 Here I gets half the total cost. */
3998 i
= (i
+ ranges
+ 1) / 2;
4001 /* Skip nodes while their cost does not reach that amount. */
4002 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
4007 npp
= &(*npp
)->right
;
4012 np
->parent
= parent
;
4015 /* Optimize each of the two split parts. */
4016 balance_case_nodes (&np
->left
, np
);
4017 balance_case_nodes (&np
->right
, np
);
4021 /* Else leave this branch as one level,
4022 but fill in `parent' fields. */
4024 np
->parent
= parent
;
4025 for (; np
->right
; np
= np
->right
)
4026 np
->right
->parent
= np
;
4031 /* Search the parent sections of the case node tree
4032 to see if a test for the lower bound of NODE would be redundant.
4033 INDEX_TYPE is the type of the index expression.
4035 The instructions to generate the case decision tree are
4036 output in the same order as nodes are processed so it is
4037 known that if a parent node checks the range of the current
4038 node minus one that the current node is bounded at its lower
4039 span. Thus the test would be redundant. */
4042 node_has_low_bound (node
, index_type
)
4047 case_node_ptr pnode
;
4049 /* If the lower bound of this node is the lowest value in the index type,
4050 we need not test it. */
4052 if (tree_int_cst_equal (node
->low
, TYPE_MIN_VALUE (index_type
)))
4055 /* If this node has a left branch, the value at the left must be less
4056 than that at this node, so it cannot be bounded at the bottom and
4057 we need not bother testing any further. */
4062 low_minus_one
= fold (build (MINUS_EXPR
, TREE_TYPE (node
->low
),
4063 node
->low
, integer_one_node
));
4065 /* If the subtraction above overflowed, we can't verify anything.
4066 Otherwise, look for a parent that tests our value - 1. */
4068 if (! tree_int_cst_lt (low_minus_one
, node
->low
))
4071 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
4072 if (tree_int_cst_equal (low_minus_one
, pnode
->high
))
4078 /* Search the parent sections of the case node tree
4079 to see if a test for the upper bound of NODE would be redundant.
4080 INDEX_TYPE is the type of the index expression.
4082 The instructions to generate the case decision tree are
4083 output in the same order as nodes are processed so it is
4084 known that if a parent node checks the range of the current
4085 node plus one that the current node is bounded at its upper
4086 span. Thus the test would be redundant. */
4089 node_has_high_bound (node
, index_type
)
4094 case_node_ptr pnode
;
4096 /* If the upper bound of this node is the highest value in the type
4097 of the index expression, we need not test against it. */
4099 if (tree_int_cst_equal (node
->high
, TYPE_MAX_VALUE (index_type
)))
4102 /* If this node has a right branch, the value at the right must be greater
4103 than that at this node, so it cannot be bounded at the top and
4104 we need not bother testing any further. */
4109 high_plus_one
= fold (build (PLUS_EXPR
, TREE_TYPE (node
->high
),
4110 node
->high
, integer_one_node
));
4112 /* If the addition above overflowed, we can't verify anything.
4113 Otherwise, look for a parent that tests our value + 1. */
4115 if (! tree_int_cst_lt (node
->high
, high_plus_one
))
4118 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
4119 if (tree_int_cst_equal (high_plus_one
, pnode
->low
))
4125 /* Search the parent sections of the
4126 case node tree to see if both tests for the upper and lower
4127 bounds of NODE would be redundant. */
4130 node_is_bounded (node
, index_type
)
4134 return (node_has_low_bound (node
, index_type
)
4135 && node_has_high_bound (node
, index_type
));
4138 /* Emit an unconditional jump to LABEL unless it would be dead code. */
4141 emit_jump_if_reachable (label
)
4144 if (GET_CODE (get_last_insn ()) != BARRIER
)
4148 /* Emit step-by-step code to select a case for the value of INDEX.
4149 The thus generated decision tree follows the form of the
4150 case-node binary tree NODE, whose nodes represent test conditions.
4151 INDEX_TYPE is the type of the index of the switch.
4153 Care is taken to prune redundant tests from the decision tree
4154 by detecting any boundary conditions already checked by
4155 emitted rtx. (See node_has_high_bound, node_has_low_bound
4156 and node_is_bounded, above.)
4158 Where the test conditions can be shown to be redundant we emit
4159 an unconditional jump to the target code. As a further
4160 optimization, the subordinates of a tree node are examined to
4161 check for bounded nodes. In this case conditional and/or
4162 unconditional jumps as a result of the boundary check for the
4163 current node are arranged to target the subordinates associated
4164 code for out of bound conditions on the current node node.
4166 We can asume that when control reaches the code generated here,
4167 the index value has already been compared with the parents
4168 of this node, and determined to be on the same side of each parent
4169 as this node is. Thus, if this node tests for the value 51,
4170 and a parent tested for 52, we don't need to consider
4171 the possibility of a value greater than 51. If another parent
4172 tests for the value 50, then this node need not test anything. */
4175 emit_case_nodes (index
, node
, default_label
, index_type
)
4181 /* If INDEX has an unsigned type, we must make unsigned branches. */
4182 int unsignedp
= TREE_UNSIGNED (index_type
);
4183 typedef rtx
rtx_function ();
4184 rtx_function
*gen_bgt_pat
= unsignedp
? gen_bgtu
: gen_bgt
;
4185 rtx_function
*gen_bge_pat
= unsignedp
? gen_bgeu
: gen_bge
;
4186 rtx_function
*gen_blt_pat
= unsignedp
? gen_bltu
: gen_blt
;
4187 rtx_function
*gen_ble_pat
= unsignedp
? gen_bleu
: gen_ble
;
4188 enum machine_mode mode
= GET_MODE (index
);
4190 /* See if our parents have already tested everything for us.
4191 If they have, emit an unconditional jump for this node. */
4192 if (node_is_bounded (node
, index_type
))
4193 emit_jump (label_rtx (node
->code_label
));
4195 else if (tree_int_cst_equal (node
->low
, node
->high
))
4197 /* Node is single valued. First see if the index expression matches
4198 this node and then check our children, if any. */
4200 do_jump_if_equal (index
, expand_expr (node
->low
, 0, VOIDmode
, 0),
4201 label_rtx (node
->code_label
), unsignedp
);
4203 if (node
->right
!= 0 && node
->left
!= 0)
4205 /* This node has children on both sides.
4206 Dispatch to one side or the other
4207 by comparing the index value with this node's value.
4208 If one subtree is bounded, check that one first,
4209 so we can avoid real branches in the tree. */
4211 if (node_is_bounded (node
->right
, index_type
))
4213 emit_cmp_insn (index
, expand_expr (node
->high
, 0, VOIDmode
, 0),
4214 GT
, 0, mode
, unsignedp
, 0);
4216 emit_jump_insn ((*gen_bgt_pat
) (label_rtx (node
->right
->code_label
)));
4217 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
4220 else if (node_is_bounded (node
->left
, index_type
))
4222 emit_cmp_insn (index
, expand_expr (node
->high
, 0,
4224 LT
, 0, mode
, unsignedp
, 0);
4225 emit_jump_insn ((*gen_blt_pat
) (label_rtx (node
->left
->code_label
)));
4226 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
4231 /* Neither node is bounded. First distinguish the two sides;
4232 then emit the code for one side at a time. */
4235 = build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
4237 /* See if the value is on the right. */
4238 emit_cmp_insn (index
, expand_expr (node
->high
, 0,
4240 GT
, 0, mode
, unsignedp
, 0);
4241 emit_jump_insn ((*gen_bgt_pat
) (label_rtx (test_label
)));
4243 /* Value must be on the left.
4244 Handle the left-hand subtree. */
4245 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
4246 /* If left-hand subtree does nothing,
4248 emit_jump_if_reachable (default_label
);
4250 /* Code branches here for the right-hand subtree. */
4251 expand_label (test_label
);
4252 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
4256 else if (node
->right
!= 0 && node
->left
== 0)
4258 /* Here we have a right child but no left so we issue conditional
4259 branch to default and process the right child.
4261 Omit the conditional branch to default if we it avoid only one
4262 right child; it costs too much space to save so little time. */
4264 if (node
->right
->right
|| node
->right
->left
4265 || !tree_int_cst_equal (node
->right
->low
, node
->right
->high
))
4267 if (!node_has_low_bound (node
, index_type
))
4269 emit_cmp_insn (index
, expand_expr (node
->high
, 0, VOIDmode
, 0),
4270 LT
, 0, mode
, unsignedp
, 0);
4271 emit_jump_insn ((*gen_blt_pat
) (default_label
));
4274 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
4277 /* We cannot process node->right normally
4278 since we haven't ruled out the numbers less than
4279 this node's value. So handle node->right explicitly. */
4280 do_jump_if_equal (index
,
4281 expand_expr (node
->right
->low
, 0, VOIDmode
, 0),
4282 label_rtx (node
->right
->code_label
), unsignedp
);
4285 else if (node
->right
== 0 && node
->left
!= 0)
4287 /* Just one subtree, on the left. */
4289 #if 0 /* The following code and comment were formerly part
4290 of the condition here, but they didn't work
4291 and I don't understand what the idea was. -- rms. */
4292 /* If our "most probable entry" is less probable
4293 than the default label, emit a jump to
4294 the default label using condition codes
4295 already lying around. With no right branch,
4296 a branch-greater-than will get us to the default
4299 && cost_table
[TREE_INT_CST_LOW (node
->high
)] < 12)
4302 if (node
->left
->left
|| node
->left
->right
4303 || !tree_int_cst_equal (node
->left
->low
, node
->left
->high
))
4305 if (!node_has_high_bound (node
, index_type
))
4307 emit_cmp_insn (index
, expand_expr (node
->high
, 0, VOIDmode
, 0),
4308 GT
, 0, mode
, unsignedp
, 0);
4309 emit_jump_insn ((*gen_bgt_pat
) (default_label
));
4312 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
4315 /* We cannot process node->left normally
4316 since we haven't ruled out the numbers less than
4317 this node's value. So handle node->left explicitly. */
4318 do_jump_if_equal (index
,
4319 expand_expr (node
->left
->low
, 0, VOIDmode
, 0),
4320 label_rtx (node
->left
->code_label
), unsignedp
);
4325 /* Node is a range. These cases are very similar to those for a single
4326 value, except that we do not start by testing whether this node
4327 is the one to branch to. */
4329 if (node
->right
!= 0 && node
->left
!= 0)
4331 /* Node has subtrees on both sides.
4332 If the right-hand subtree is bounded,
4333 test for it first, since we can go straight there.
4334 Otherwise, we need to make a branch in the control structure,
4335 then handle the two subtrees. */
4336 tree test_label
= 0;
4338 emit_cmp_insn (index
, expand_expr (node
->high
, 0, VOIDmode
, 0),
4339 GT
, 0, mode
, unsignedp
, 0);
4341 if (node_is_bounded (node
->right
, index_type
))
4342 /* Right hand node is fully bounded so we can eliminate any
4343 testing and branch directly to the target code. */
4344 emit_jump_insn ((*gen_bgt_pat
) (label_rtx (node
->right
->code_label
)));
4347 /* Right hand node requires testing.
4348 Branch to a label where we will handle it later. */
4350 test_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
4351 emit_jump_insn ((*gen_bgt_pat
) (label_rtx (test_label
)));
4354 /* Value belongs to this node or to the left-hand subtree. */
4356 emit_cmp_insn (index
, expand_expr (node
->low
, 0, VOIDmode
, 0),
4357 GE
, 0, mode
, unsignedp
, 0);
4358 emit_jump_insn ((*gen_bge_pat
) (label_rtx (node
->code_label
)));
4360 /* Handle the left-hand subtree. */
4361 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
4363 /* If right node had to be handled later, do that now. */
4367 /* If the left-hand subtree fell through,
4368 don't let it fall into the right-hand subtree. */
4369 emit_jump_if_reachable (default_label
);
4371 expand_label (test_label
);
4372 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
4376 else if (node
->right
!= 0 && node
->left
== 0)
4378 /* Deal with values to the left of this node,
4379 if they are possible. */
4380 if (!node_has_low_bound (node
, index_type
))
4382 emit_cmp_insn (index
, expand_expr (node
->low
, 0, VOIDmode
, 0),
4383 LT
, 0, mode
, unsignedp
, 0);
4384 emit_jump_insn ((*gen_blt_pat
) (default_label
));
4387 /* Value belongs to this node or to the right-hand subtree. */
4389 emit_cmp_insn (index
, expand_expr (node
->high
, 0, VOIDmode
, 0),
4390 LE
, 0, mode
, unsignedp
, 0);
4391 emit_jump_insn ((*gen_ble_pat
) (label_rtx (node
->code_label
)));
4393 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
4396 else if (node
->right
== 0 && node
->left
!= 0)
4398 /* Deal with values to the right of this node,
4399 if they are possible. */
4400 if (!node_has_high_bound (node
, index_type
))
4402 emit_cmp_insn (index
, expand_expr (node
->high
, 0, VOIDmode
, 0),
4403 GT
, 0, mode
, unsignedp
, 0);
4404 emit_jump_insn ((*gen_bgt_pat
) (default_label
));
4407 /* Value belongs to this node or to the left-hand subtree. */
4409 emit_cmp_insn (index
, expand_expr (node
->low
, 0, VOIDmode
, 0),
4410 GE
, 0, mode
, unsignedp
, 0);
4411 emit_jump_insn ((*gen_bge_pat
) (label_rtx (node
->code_label
)));
4413 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
4418 /* Node has no children so we check low and high bounds to remove
4419 redundant tests. Only one of the bounds can exist,
4420 since otherwise this node is bounded--a case tested already. */
4422 if (!node_has_high_bound (node
, index_type
))
4424 emit_cmp_insn (index
, expand_expr (node
->high
, 0, VOIDmode
, 0),
4425 GT
, 0, mode
, unsignedp
, 0);
4426 emit_jump_insn ((*gen_bgt_pat
) (default_label
));
4429 if (!node_has_low_bound (node
, index_type
))
4431 emit_cmp_insn (index
, expand_expr (node
->low
, 0, VOIDmode
, 0),
4432 LT
, 0, mode
, unsignedp
, 0);
4433 emit_jump_insn ((*gen_blt_pat
) (default_label
));
4436 emit_jump (label_rtx (node
->code_label
));
4441 /* These routines are used by the loop unrolling code. They copy BLOCK trees
4442 so that the debugging info will be correct for the unrolled loop. */
4444 /* Indexed by loop number, contains pointer to the first block in the loop,
4445 or zero if none. Only valid if doing loop unrolling and outputting debugger
4448 tree
*loop_number_first_block
;
4450 /* Indexed by loop number, contains pointer to the last block in the loop,
4451 only valid if loop_number_first_block is nonzero. */
4453 tree
*loop_number_last_block
;
4455 /* Indexed by loop number, contains nesting level of first block in the
4456 loop, if any. Only valid if doing loop unrolling and outputting debugger
4459 int *loop_number_block_level
;
4461 /* Scan the function looking for loops, and walk the BLOCK tree at the
4462 same time. Record the first and last BLOCK tree corresponding to each
4463 loop. This function is similar to find_and_verify_loops in loop.c. */
4466 find_loop_tree_blocks (f
)
4470 int current_loop
= -1;
4473 int block_level
, tree_level
;
4474 tree tree_block
, parent_tree_block
;
4476 tree_block
= DECL_INITIAL (current_function_decl
);
4477 parent_tree_block
= 0;
4481 /* Find boundaries of loops, and save the first and last BLOCK tree
4482 corresponding to each loop. */
4484 for (insn
= f
; insn
; insn
= NEXT_INSN (insn
))
4486 if (GET_CODE (insn
) == NOTE
)
4487 switch (NOTE_LINE_NUMBER (insn
))
4489 case NOTE_INSN_LOOP_BEG
:
4490 loop_number_block_level
[++next_loop
] = block_level
;
4491 loop_number_first_block
[next_loop
] = 0;
4492 current_loop
= next_loop
;
4495 case NOTE_INSN_LOOP_END
:
4496 if (current_loop
== -1)
4499 current_loop
= loop_outer_loop
[current_loop
];
4502 case NOTE_INSN_BLOCK_BEG
:
4503 if (tree_level
< block_level
)
4505 /* We have seen two NOTE_INSN_BLOCK_BEG notes in a row, so
4506 we must now visit the subtree of the current block. */
4507 parent_tree_block
= tree_block
;
4508 tree_block
= BLOCK_SUBBLOCKS (tree_block
);
4511 else if (tree_level
> block_level
)
4514 /* Save this block tree here for all nested loops for which
4515 this is the topmost block. */
4516 for (loop
= current_loop
;
4517 loop
!= -1 && block_level
== loop_number_block_level
[loop
];
4518 loop
= loop_outer_loop
[loop
])
4520 if (loop_number_first_block
[loop
] == 0)
4521 loop_number_first_block
[loop
] = tree_block
;
4522 loop_number_last_block
[loop
] = tree_block
;
4528 case NOTE_INSN_BLOCK_END
:
4530 if (tree_level
> block_level
)
4532 /* We have seen two NOTE_INSN_BLOCK_END notes in a row, so
4533 we must now visit the parent of the current tree. */
4534 if (tree_block
!= 0 || parent_tree_block
== 0)
4536 tree_block
= parent_tree_block
;
4537 parent_tree_block
= BLOCK_SUPERCONTEXT (parent_tree_block
);
4540 tree_block
= BLOCK_CHAIN (tree_block
);
4546 /* This routine will make COPIES-1 copies of all BLOCK trees that correspond
4547 to BLOCK_BEG notes inside the loop LOOP_NUMBER.
4549 Note that we only copy the topmost level of tree nodes; they will share
4550 pointers to the same subblocks. */
4553 unroll_block_trees (loop_number
, copies
)
4559 /* First check whether there are any blocks that need to be copied. */
4560 if (loop_number_first_block
[loop_number
])
4562 tree first_block
= loop_number_first_block
[loop_number
];
4563 tree last_block
= loop_number_last_block
[loop_number
];
4564 tree last_block_created
= 0;
4566 for (i
= 0; i
< copies
- 1; i
++)
4568 tree block
= first_block
;
4569 tree insert_after
= last_block
;
4572 /* Copy every block between first_block and last_block inclusive,
4573 inserting the new blocks after last_block. */
4576 tree new_block
= make_node (BLOCK
);
4577 BLOCK_VARS (new_block
) = BLOCK_VARS (block
);
4578 BLOCK_TYPE_TAGS (new_block
) = BLOCK_TYPE_TAGS (block
);
4579 BLOCK_SUBBLOCKS (new_block
) = BLOCK_SUBBLOCKS (block
);
4580 BLOCK_SUPERCONTEXT (new_block
) = BLOCK_SUPERCONTEXT (block
);
4581 TREE_USED (new_block
) = TREE_USED (block
);
4583 /* Insert the new block after the insertion point, and move
4584 the insertion point to the new block. This ensures that
4585 the copies are inserted in the right order. */
4586 BLOCK_CHAIN (new_block
) = BLOCK_CHAIN (insert_after
);
4587 BLOCK_CHAIN (insert_after
) = new_block
;
4588 insert_after
= new_block
;
4590 copied_block
= block
;
4591 block
= BLOCK_CHAIN (block
);
4593 while (copied_block
!= last_block
);
4595 /* Remember the last block created, so that we can update the
4596 info in the tables. */
4597 if (last_block_created
== 0)
4598 last_block_created
= insert_after
;
4601 /* For all nested loops for which LAST_BLOCK was originally the last
4602 block, update the tables to indicate that LAST_BLOCK_CREATED is
4603 now the last block in the loop. */
4604 for (i
= loop_number
; last_block
== loop_number_last_block
[i
];
4605 i
= loop_outer_loop
[i
])
4606 loop_number_last_block
[i
] = last_block_created
;