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 emit_stack_save (SAVE_NONLOCAL
,
590 &nonlocal_goto_stack_level
,
591 PREV_INSN (tail_recursion_reentry
));
595 /* Generate RTL code for a `goto' statement with target label LABEL.
596 LABEL should be a LABEL_DECL tree node that was or will later be
597 defined with `expand_label'. */
603 /* Check for a nonlocal goto to a containing function. */
604 tree context
= decl_function_context (label
);
605 if (context
!= 0 && context
!= current_function_decl
)
607 struct function
*p
= find_function_data (context
);
609 p
->has_nonlocal_label
= 1;
611 /* Copy the rtl for the slots so that they won't be shared in
612 case the virtual stack vars register gets instantiated differently
613 in the parent than in the child. */
615 #if HAVE_nonlocal_goto
616 if (HAVE_nonlocal_goto
)
617 emit_insn (gen_nonlocal_goto (lookup_static_chain (label
),
618 copy_rtx (p
->nonlocal_goto_handler_slot
),
619 copy_rtx (p
->nonlocal_goto_stack_level
),
620 gen_rtx (LABEL_REF
, Pmode
,
621 label_rtx (label
))));
627 /* Restore frame pointer for containing function.
628 This sets the actual hard register used for the frame pointer
629 to the location of the function's incoming static chain info.
630 The non-local goto handler will then adjust it to contain the
631 proper value and reload the argument pointer, if needed. */
632 emit_move_insn (frame_pointer_rtx
, lookup_static_chain (label
));
634 /* We have now loaded the frame pointer hardware register with
635 the address of that corresponds to the start of the virtual
636 stack vars. So replace virtual_stack_vars_rtx in all
637 addresses we use with stack_pointer_rtx. */
639 /* Get addr of containing function's current nonlocal goto handler,
640 which will do any cleanups and then jump to the label. */
641 addr
= copy_rtx (p
->nonlocal_goto_handler_slot
);
642 temp
= copy_to_reg (replace_rtx (addr
, virtual_stack_vars_rtx
,
645 /* Restore the stack pointer. Note this uses fp just restored. */
646 addr
= p
->nonlocal_goto_stack_level
;
648 addr
= replace_rtx (copy_rtx (p
->nonlocal_goto_stack_level
),
649 replace_rtx (addr
, virtual_stack_vars_rtx
,
652 emit_stack_restore (SAVE_NONLOCAL
, addr
, 0);
654 /* Put in the static chain register the nonlocal label address. */
655 emit_move_insn (static_chain_rtx
,
656 gen_rtx (LABEL_REF
, Pmode
, label_rtx (label
)));
657 /* USE of frame_pointer_rtx added for consistency; not clear if
659 emit_insn (gen_rtx (USE
, VOIDmode
, frame_pointer_rtx
));
660 emit_insn (gen_rtx (USE
, VOIDmode
, stack_pointer_rtx
));
661 emit_insn (gen_rtx (USE
, VOIDmode
, static_chain_rtx
));
662 emit_indirect_jump (temp
);
666 expand_goto_internal (label
, label_rtx (label
), 0);
669 /* Generate RTL code for a `goto' statement with target label BODY.
670 LABEL should be a LABEL_REF.
671 LAST_INSN, if non-0, is the rtx we should consider as the last
672 insn emitted (for the purposes of cleaning up a return). */
675 expand_goto_internal (body
, label
, last_insn
)
680 struct nesting
*block
;
683 if (GET_CODE (label
) != CODE_LABEL
)
686 /* If label has already been defined, we can tell now
687 whether and how we must alter the stack level. */
689 if (PREV_INSN (label
) != 0)
691 /* Find the innermost pending block that contains the label.
692 (Check containment by comparing insn-uids.)
693 Then restore the outermost stack level within that block,
694 and do cleanups of all blocks contained in it. */
695 for (block
= block_stack
; block
; block
= block
->next
)
697 if (INSN_UID (block
->data
.block
.first_insn
) < INSN_UID (label
))
699 if (block
->data
.block
.stack_level
!= 0)
700 stack_level
= block
->data
.block
.stack_level
;
701 /* Execute the cleanups for blocks we are exiting. */
702 if (block
->data
.block
.cleanups
!= 0)
704 expand_cleanups (block
->data
.block
.cleanups
, 0);
705 do_pending_stack_adjust ();
711 /* Ensure stack adjust isn't done by emit_jump, as this would clobber
712 the stack pointer. This one should be deleted as dead by flow. */
713 clear_pending_stack_adjust ();
714 do_pending_stack_adjust ();
715 emit_stack_restore (SAVE_BLOCK
, stack_level
, 0);
718 if (body
!= 0 && DECL_TOO_LATE (body
))
719 error ("jump to `%s' invalidly jumps into binding contour",
720 IDENTIFIER_POINTER (DECL_NAME (body
)));
722 /* Label not yet defined: may need to put this goto
723 on the fixup list. */
724 else if (! expand_fixup (body
, label
, last_insn
))
726 /* No fixup needed. Record that the label is the target
727 of at least one goto that has no fixup. */
729 TREE_ADDRESSABLE (body
) = 1;
735 /* Generate if necessary a fixup for a goto
736 whose target label in tree structure (if any) is TREE_LABEL
737 and whose target in rtl is RTL_LABEL.
739 If LAST_INSN is nonzero, we pretend that the jump appears
740 after insn LAST_INSN instead of at the current point in the insn stream.
742 The fixup will be used later to insert insns at this point
743 to restore the stack level as appropriate for the target label.
745 Value is nonzero if a fixup is made. */
748 expand_fixup (tree_label
, rtl_label
, last_insn
)
753 struct nesting
*block
, *end_block
;
755 /* See if we can recognize which block the label will be output in.
756 This is possible in some very common cases.
757 If we succeed, set END_BLOCK to that block.
758 Otherwise, set it to 0. */
761 && (rtl_label
== cond_stack
->data
.cond
.endif_label
762 || rtl_label
== cond_stack
->data
.cond
.next_label
))
763 end_block
= cond_stack
;
764 /* If we are in a loop, recognize certain labels which
765 are likely targets. This reduces the number of fixups
766 we need to create. */
768 && (rtl_label
== loop_stack
->data
.loop
.start_label
769 || rtl_label
== loop_stack
->data
.loop
.end_label
770 || rtl_label
== loop_stack
->data
.loop
.continue_label
))
771 end_block
= loop_stack
;
775 /* Now set END_BLOCK to the binding level to which we will return. */
779 struct nesting
*next_block
= end_block
->all
;
782 /* First see if the END_BLOCK is inside the innermost binding level.
783 If so, then no cleanups or stack levels are relevant. */
784 while (next_block
&& next_block
!= block
)
785 next_block
= next_block
->all
;
790 /* Otherwise, set END_BLOCK to the innermost binding level
791 which is outside the relevant control-structure nesting. */
792 next_block
= block_stack
->next
;
793 for (block
= block_stack
; block
!= end_block
; block
= block
->all
)
794 if (block
== next_block
)
795 next_block
= next_block
->next
;
796 end_block
= next_block
;
799 /* Does any containing block have a stack level or cleanups?
800 If not, no fixup is needed, and that is the normal case
801 (the only case, for standard C). */
802 for (block
= block_stack
; block
!= end_block
; block
= block
->next
)
803 if (block
->data
.block
.stack_level
!= 0
804 || block
->data
.block
.cleanups
!= 0)
807 if (block
!= end_block
)
809 /* Ok, a fixup is needed. Add a fixup to the list of such. */
810 struct goto_fixup
*fixup
811 = (struct goto_fixup
*) oballoc (sizeof (struct goto_fixup
));
812 /* In case an old stack level is restored, make sure that comes
813 after any pending stack adjust. */
814 /* ?? If the fixup isn't to come at the present position,
815 doing the stack adjust here isn't useful. Doing it with our
816 settings at that location isn't useful either. Let's hope
819 do_pending_stack_adjust ();
820 fixup
->before_jump
= last_insn
? last_insn
: get_last_insn ();
821 fixup
->target
= tree_label
;
822 fixup
->target_rtl
= rtl_label
;
823 fixup
->block_start_count
= block_start_count
;
824 fixup
->stack_level
= 0;
825 fixup
->cleanup_list_list
826 = (((block
->data
.block
.outer_cleanups
828 && block
->data
.block
.outer_cleanups
!= empty_cleanup_list
831 || block
->data
.block
.cleanups
)
832 ? tree_cons (0, block
->data
.block
.cleanups
,
833 block
->data
.block
.outer_cleanups
)
835 fixup
->next
= goto_fixup_chain
;
836 goto_fixup_chain
= fixup
;
842 /* When exiting a binding contour, process all pending gotos requiring fixups.
843 THISBLOCK is the structure that describes the block being exited.
844 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
845 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
846 FIRST_INSN is the insn that began this contour.
848 Gotos that jump out of this contour must restore the
849 stack level and do the cleanups before actually jumping.
851 DONT_JUMP_IN nonzero means report error there is a jump into this
852 contour from before the beginning of the contour.
853 This is also done if STACK_LEVEL is nonzero. */
856 fixup_gotos (thisblock
, stack_level
, cleanup_list
, first_insn
, dont_jump_in
)
857 struct nesting
*thisblock
;
863 register struct goto_fixup
*f
, *prev
;
865 /* F is the fixup we are considering; PREV is the previous one. */
866 /* We run this loop in two passes so that cleanups of exited blocks
867 are run first, and blocks that are exited are marked so
870 for (prev
= 0, f
= goto_fixup_chain
; f
; prev
= f
, f
= f
->next
)
872 /* Test for a fixup that is inactive because it is already handled. */
873 if (f
->before_jump
== 0)
875 /* Delete inactive fixup from the chain, if that is easy to do. */
877 prev
->next
= f
->next
;
879 /* Has this fixup's target label been defined?
880 If so, we can finalize it. */
881 else if (PREV_INSN (f
->target_rtl
) != 0)
883 /* Get the first non-label after the label
884 this goto jumps to. If that's before this scope begins,
885 we don't have a jump into the scope. */
886 rtx after_label
= f
->target_rtl
;
887 while (after_label
!= 0 && GET_CODE (after_label
) == CODE_LABEL
)
888 after_label
= NEXT_INSN (after_label
);
890 /* If this fixup jumped into this contour from before the beginning
891 of this contour, report an error. */
892 /* ??? Bug: this does not detect jumping in through intermediate
893 blocks that have stack levels or cleanups.
894 It detects only a problem with the innermost block
897 && (dont_jump_in
|| stack_level
|| cleanup_list
)
898 /* If AFTER_LABEL is 0, it means the jump goes to the end
899 of the rtl, which means it jumps into this scope. */
901 || INSN_UID (first_insn
) < INSN_UID (after_label
))
902 && INSN_UID (first_insn
) > INSN_UID (f
->before_jump
)
903 && ! TREE_REGDECL (f
->target
))
905 error_with_decl (f
->target
,
906 "label `%s' used before containing binding contour");
907 /* Prevent multiple errors for one label. */
908 TREE_REGDECL (f
->target
) = 1;
911 /* Execute cleanups for blocks this jump exits. */
912 if (f
->cleanup_list_list
)
915 for (lists
= f
->cleanup_list_list
; lists
; lists
= TREE_CHAIN (lists
))
916 /* Marked elements correspond to blocks that have been closed.
917 Do their cleanups. */
918 if (TREE_ADDRESSABLE (lists
)
919 && TREE_VALUE (lists
) != 0)
920 fixup_cleanups (TREE_VALUE (lists
), &f
->before_jump
);
923 /* Restore stack level for the biggest contour that this
924 jump jumps out of. */
926 emit_stack_restore (SAVE_BLOCK
, f
->stack_level
, f
->before_jump
);
931 /* Mark the cleanups of exited blocks so that they are executed
932 by the code above. */
933 for (prev
= 0, f
= goto_fixup_chain
; f
; prev
= f
, f
= f
->next
)
934 if (f
->before_jump
!= 0
935 && PREV_INSN (f
->target_rtl
) == 0
936 /* Label has still not appeared. If we are exiting a block with
937 a stack level to restore, that started before the fixup,
938 mark this stack level as needing restoration
939 when the fixup is later finalized.
940 Also mark the cleanup_list_list element for F
941 that corresponds to this block, so that ultimately
942 this block's cleanups will be executed by the code above. */
944 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared,
945 it means the label is undefined. That's erroneous, but possible. */
946 && (thisblock
->data
.block
.block_start_count
947 <= f
->block_start_count
))
949 tree lists
= f
->cleanup_list_list
;
950 for (; lists
; lists
= TREE_CHAIN (lists
))
951 /* If the following elt. corresponds to our containing block
952 then the elt. must be for this block. */
953 if (TREE_CHAIN (lists
) == thisblock
->data
.block
.outer_cleanups
)
954 TREE_ADDRESSABLE (lists
) = 1;
957 f
->stack_level
= stack_level
;
961 /* Generate RTL for an asm statement (explicit assembler code).
962 BODY is a STRING_CST node containing the assembler code text,
963 or an ADDR_EXPR containing a STRING_CST. */
969 if (TREE_CODE (body
) == ADDR_EXPR
)
970 body
= TREE_OPERAND (body
, 0);
972 emit_insn (gen_rtx (ASM_INPUT
, VOIDmode
,
973 TREE_STRING_POINTER (body
)));
977 /* Generate RTL for an asm statement with arguments.
978 STRING is the instruction template.
979 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
980 Each output or input has an expression in the TREE_VALUE and
981 a constraint-string in the TREE_PURPOSE.
982 CLOBBERS is a list of STRING_CST nodes each naming a hard register
983 that is clobbered by this insn.
985 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
986 Some elements of OUTPUTS may be replaced with trees representing temporary
987 values. The caller should copy those temporary values to the originally
990 VOL nonzero means the insn is volatile; don't optimize it. */
993 expand_asm_operands (string
, outputs
, inputs
, clobbers
, vol
, filename
, line
)
994 tree string
, outputs
, inputs
, clobbers
;
999 rtvec argvec
, constraints
;
1001 int ninputs
= list_length (inputs
);
1002 int noutputs
= list_length (outputs
);
1003 int nclobbers
= list_length (clobbers
);
1006 /* Vector of RTX's of evaluated output operands. */
1007 rtx
*output_rtx
= (rtx
*) alloca (noutputs
* sizeof (rtx
));
1008 /* The insn we have emitted. */
1013 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1015 tree val
= TREE_VALUE (tail
);
1020 /* If there's an erroneous arg, emit no insn. */
1021 if (TREE_TYPE (val
) == error_mark_node
)
1024 /* Make sure constraint has `=' and does not have `+'. */
1027 for (j
= 0; j
< TREE_STRING_LENGTH (TREE_PURPOSE (tail
)); j
++)
1029 if (TREE_STRING_POINTER (TREE_PURPOSE (tail
))[j
] == '+')
1031 error ("output operand constraint contains `+'");
1034 if (TREE_STRING_POINTER (TREE_PURPOSE (tail
))[j
] == '=')
1039 error ("output operand constraint lacks `='");
1043 /* If an output operand is not a variable or indirect ref,
1045 create a SAVE_EXPR which is a pseudo-reg
1046 to act as an intermediate temporary.
1047 Make the asm insn write into that, then copy it to
1048 the real output operand. */
1050 while (TREE_CODE (val
) == COMPONENT_REF
1051 || TREE_CODE (val
) == ARRAY_REF
)
1052 val
= TREE_OPERAND (val
, 0);
1054 if (TREE_CODE (val
) != VAR_DECL
1055 && TREE_CODE (val
) != PARM_DECL
1056 && TREE_CODE (val
) != INDIRECT_REF
)
1057 TREE_VALUE (tail
) = save_expr (TREE_VALUE (tail
));
1059 output_rtx
[i
] = expand_expr (TREE_VALUE (tail
), 0, VOIDmode
, 0);
1062 if (ninputs
+ noutputs
> MAX_RECOG_OPERANDS
)
1064 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS
);
1068 /* Make vectors for the expression-rtx and constraint strings. */
1070 argvec
= rtvec_alloc (ninputs
);
1071 constraints
= rtvec_alloc (ninputs
);
1073 body
= gen_rtx (ASM_OPERANDS
, VOIDmode
,
1074 TREE_STRING_POINTER (string
), "", 0, argvec
, constraints
,
1076 MEM_VOLATILE_P (body
) = vol
;
1078 /* Eval the inputs and put them into ARGVEC.
1079 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1082 for (tail
= inputs
; tail
; tail
= TREE_CHAIN (tail
))
1086 /* If there's an erroneous arg, emit no insn,
1087 because the ASM_INPUT would get VOIDmode
1088 and that could cause a crash in reload. */
1089 if (TREE_TYPE (TREE_VALUE (tail
)) == error_mark_node
)
1091 if (TREE_PURPOSE (tail
) == NULL_TREE
)
1093 error ("hard register `%s' listed as input operand to `asm'",
1094 TREE_STRING_POINTER (TREE_VALUE (tail
)) );
1098 /* Make sure constraint has neither `=' nor `+'. */
1100 for (j
= 0; j
< TREE_STRING_LENGTH (TREE_PURPOSE (tail
)); j
++)
1101 if (TREE_STRING_POINTER (TREE_PURPOSE (tail
))[j
] == '='
1102 || TREE_STRING_POINTER (TREE_PURPOSE (tail
))[j
] == '+')
1104 error ("input operand constraint contains `%c'",
1105 TREE_STRING_POINTER (TREE_PURPOSE (tail
))[j
]);
1109 XVECEXP (body
, 3, i
) /* argvec */
1110 = expand_expr (TREE_VALUE (tail
), 0, VOIDmode
, 0);
1111 XVECEXP (body
, 4, i
) /* constraints */
1112 = gen_rtx (ASM_INPUT
, TYPE_MODE (TREE_TYPE (TREE_VALUE (tail
))),
1113 TREE_STRING_POINTER (TREE_PURPOSE (tail
)));
1117 /* Protect all the operands from the queue,
1118 now that they have all been evaluated. */
1120 for (i
= 0; i
< ninputs
; i
++)
1121 XVECEXP (body
, 3, i
) = protect_from_queue (XVECEXP (body
, 3, i
), 0);
1123 for (i
= 0; i
< noutputs
; i
++)
1124 output_rtx
[i
] = protect_from_queue (output_rtx
[i
], 1);
1126 /* Now, for each output, construct an rtx
1127 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1128 ARGVEC CONSTRAINTS))
1129 If there is more than one, put them inside a PARALLEL. */
1131 if (noutputs
== 1 && nclobbers
== 0)
1133 XSTR (body
, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs
));
1134 insn
= emit_insn (gen_rtx (SET
, VOIDmode
, output_rtx
[0], body
));
1136 else if (noutputs
== 0 && nclobbers
== 0)
1138 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1139 insn
= emit_insn (body
);
1145 if (num
== 0) num
= 1;
1146 body
= gen_rtx (PARALLEL
, VOIDmode
, rtvec_alloc (num
+ nclobbers
));
1148 /* For each output operand, store a SET. */
1150 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1152 XVECEXP (body
, 0, i
)
1153 = gen_rtx (SET
, VOIDmode
,
1155 gen_rtx (ASM_OPERANDS
, VOIDmode
,
1156 TREE_STRING_POINTER (string
),
1157 TREE_STRING_POINTER (TREE_PURPOSE (tail
)),
1158 i
, argvec
, constraints
,
1160 MEM_VOLATILE_P (SET_SRC (XVECEXP (body
, 0, i
))) = vol
;
1163 /* If there are no outputs (but there are some clobbers)
1164 store the bare ASM_OPERANDS into the PARALLEL. */
1167 XVECEXP (body
, 0, i
++) = obody
;
1169 /* Store (clobber REG) for each clobbered register specified. */
1171 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1173 char *regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
1174 int j
= decode_reg_name (regname
);
1181 error ("unknown register name `%s' in `asm'", regname
);
1185 /* Use QImode since that's guaranteed to clobber just one reg. */
1186 XVECEXP (body
, 0, i
)
1187 = gen_rtx (CLOBBER
, VOIDmode
, gen_rtx (REG
, QImode
, j
));
1190 insn
= emit_insn (body
);
1196 /* Generate RTL to evaluate the expression EXP
1197 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1200 expand_expr_stmt (exp
)
1203 /* If -W, warn about statements with no side effects,
1204 except for an explicit cast to void (e.g. for assert()), and
1205 except inside a ({...}) where they may be useful. */
1206 if (expr_stmts_for_value
== 0 && exp
!= error_mark_node
)
1208 if (! TREE_SIDE_EFFECTS (exp
) && (extra_warnings
|| warn_unused
)
1209 && !(TREE_CODE (exp
) == CONVERT_EXPR
1210 && TREE_TYPE (exp
) == void_type_node
))
1211 warning_with_file_and_line (emit_filename
, emit_lineno
,
1212 "statement with no effect");
1213 else if (warn_unused
)
1214 warn_if_unused_value (exp
);
1216 last_expr_type
= TREE_TYPE (exp
);
1217 if (! flag_syntax_only
)
1218 last_expr_value
= expand_expr (exp
, expr_stmts_for_value
? 0 : const0_rtx
,
1221 /* If all we do is reference a volatile value in memory,
1222 copy it to a register to be sure it is actually touched. */
1223 if (last_expr_value
!= 0 && GET_CODE (last_expr_value
) == MEM
1224 && TREE_THIS_VOLATILE (exp
))
1226 if (TYPE_MODE (TREE_TYPE (exp
)) != BLKmode
)
1227 copy_to_reg (last_expr_value
);
1230 rtx lab
= gen_label_rtx ();
1232 /* Compare the value with itself to reference it. */
1233 emit_cmp_insn (last_expr_value
, last_expr_value
, EQ
,
1234 expand_expr (TYPE_SIZE (last_expr_type
),
1237 TYPE_ALIGN (last_expr_type
) / BITS_PER_UNIT
);
1238 emit_jump_insn ((*bcc_gen_fctn
[(int) EQ
]) (lab
));
1243 /* If this expression is part of a ({...}) and is in memory, we may have
1244 to preserve temporaries. */
1245 preserve_temp_slots (last_expr_value
);
1247 /* Free any temporaries used to evaluate this expression. Any temporary
1248 used as a result of this expression will already have been preserved
1255 /* Warn if EXP contains any computations whose results are not used.
1256 Return 1 if a warning is printed; 0 otherwise. */
1259 warn_if_unused_value (exp
)
1262 if (TREE_USED (exp
))
1265 switch (TREE_CODE (exp
))
1267 case PREINCREMENT_EXPR
:
1268 case POSTINCREMENT_EXPR
:
1269 case PREDECREMENT_EXPR
:
1270 case POSTDECREMENT_EXPR
:
1275 case METHOD_CALL_EXPR
:
1278 case ANTI_WRAPPER_EXPR
:
1279 case WITH_CLEANUP_EXPR
:
1281 /* We don't warn about COND_EXPR because it may be a useful
1282 construct if either arm contains a side effect. */
1287 /* For a binding, warn if no side effect within it. */
1288 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
1290 case TRUTH_ORIF_EXPR
:
1291 case TRUTH_ANDIF_EXPR
:
1292 /* In && or ||, warn if 2nd operand has no side effect. */
1293 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
1296 if (warn_if_unused_value (TREE_OPERAND (exp
, 0)))
1298 /* Let people do `(foo (), 0)' without a warning. */
1299 if (TREE_CONSTANT (TREE_OPERAND (exp
, 1)))
1301 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
1305 case NON_LVALUE_EXPR
:
1306 /* Don't warn about values cast to void. */
1307 if (TREE_TYPE (exp
) == void_type_node
)
1309 /* Don't warn about conversions not explicit in the user's program. */
1310 if (TREE_NO_UNUSED_WARNING (exp
))
1312 /* Assignment to a cast usually results in a cast of a modify.
1313 Don't complain about that. */
1314 if (TREE_CODE (TREE_OPERAND (exp
, 0)) == MODIFY_EXPR
)
1316 /* Sometimes it results in a cast of a cast of a modify.
1317 Don't complain about that. */
1318 if ((TREE_CODE (TREE_OPERAND (exp
, 0)) == CONVERT_EXPR
1319 || TREE_CODE (TREE_OPERAND (exp
, 0)) == NOP_EXPR
)
1320 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp
, 0), 0)) == MODIFY_EXPR
)
1324 /* Referencing a volatile value is a side effect, so don't warn. */
1325 if ((TREE_CODE_CLASS (TREE_CODE (exp
)) == 'd'
1326 || TREE_CODE_CLASS (TREE_CODE (exp
)) == 'r')
1327 && TREE_THIS_VOLATILE (exp
))
1329 warning_with_file_and_line (emit_filename
, emit_lineno
,
1330 "value computed is not used");
1335 /* Clear out the memory of the last expression evaluated. */
1343 /* Begin a statement which will return a value.
1344 Return the RTL_EXPR for this statement expr.
1345 The caller must save that value and pass it to expand_end_stmt_expr. */
1348 expand_start_stmt_expr ()
1350 /* Make the RTL_EXPR node temporary, not momentary,
1351 so that rtl_expr_chain doesn't become garbage. */
1352 int momentary
= suspend_momentary ();
1353 tree t
= make_node (RTL_EXPR
);
1354 resume_momentary (momentary
);
1357 expr_stmts_for_value
++;
1361 /* Restore the previous state at the end of a statement that returns a value.
1362 Returns a tree node representing the statement's value and the
1363 insns to compute the value.
1365 The nodes of that expression have been freed by now, so we cannot use them.
1366 But we don't want to do that anyway; the expression has already been
1367 evaluated and now we just want to use the value. So generate a RTL_EXPR
1368 with the proper type and RTL value.
1370 If the last substatement was not an expression,
1371 return something with type `void'. */
1374 expand_end_stmt_expr (t
)
1379 if (last_expr_type
== 0)
1381 last_expr_type
= void_type_node
;
1382 last_expr_value
= const0_rtx
;
1384 else if (last_expr_value
== 0)
1385 /* There are some cases where this can happen, such as when the
1386 statement is void type. */
1387 last_expr_value
= const0_rtx
;
1388 else if (GET_CODE (last_expr_value
) != REG
&& ! CONSTANT_P (last_expr_value
))
1389 /* Remove any possible QUEUED. */
1390 last_expr_value
= protect_from_queue (last_expr_value
, 0);
1394 TREE_TYPE (t
) = last_expr_type
;
1395 RTL_EXPR_RTL (t
) = last_expr_value
;
1396 RTL_EXPR_SEQUENCE (t
) = get_insns ();
1398 rtl_expr_chain
= tree_cons (NULL_TREE
, t
, rtl_expr_chain
);
1402 /* Don't consider deleting this expr or containing exprs at tree level. */
1403 TREE_SIDE_EFFECTS (t
) = 1;
1404 /* Propagate volatility of the actual RTL expr. */
1405 TREE_THIS_VOLATILE (t
) = volatile_refs_p (last_expr_value
);
1408 expr_stmts_for_value
--;
1413 /* The exception handling nesting looks like this:
1416 { <-- exception handler block
1418 <-- in an exception handler
1420 : <-- in a TRY block
1421 : <-- in an exception handler
1426 : <-- in an except block
1427 : <-- in an exception handler
1433 /* Return nonzero iff in a try block at level LEVEL. */
1436 in_try_block (level
)
1439 struct nesting
*n
= except_stack
;
1442 while (n
&& n
->data
.except_stmt
.after_label
!= 0)
1453 /* Return nonzero iff in an except block at level LEVEL. */
1456 in_except_block (level
)
1459 struct nesting
*n
= except_stack
;
1462 while (n
&& n
->data
.except_stmt
.after_label
== 0)
1473 /* Return nonzero iff in an exception handler at level LEVEL. */
1476 in_exception_handler (level
)
1479 struct nesting
*n
= except_stack
;
1480 while (n
&& level
--)
1485 /* Record the fact that the current exception nesting raises
1486 exception EX. If not in an exception handler, return 0. */
1493 if (except_stack
== 0)
1495 raises_ptr
= &except_stack
->data
.except_stmt
.raised
;
1496 if (! value_member (ex
, *raises_ptr
))
1497 *raises_ptr
= tree_cons (NULL_TREE
, ex
, *raises_ptr
);
1501 /* Generate RTL for the start of a try block.
1503 TRY_CLAUSE is the condition to test to enter the try block. */
1506 expand_start_try (try_clause
, exitflag
, escapeflag
)
1511 struct nesting
*thishandler
= ALLOC_NESTING ();
1513 /* Make an entry on cond_stack for the cond we are entering. */
1515 thishandler
->next
= except_stack
;
1516 thishandler
->all
= nesting_stack
;
1517 thishandler
->depth
= ++nesting_depth
;
1518 thishandler
->data
.except_stmt
.raised
= 0;
1519 thishandler
->data
.except_stmt
.handled
= 0;
1520 thishandler
->data
.except_stmt
.first_insn
= get_insns ();
1521 thishandler
->data
.except_stmt
.except_label
= gen_label_rtx ();
1522 thishandler
->data
.except_stmt
.unhandled_label
= 0;
1523 thishandler
->data
.except_stmt
.after_label
= 0;
1524 thishandler
->data
.except_stmt
.escape_label
1525 = escapeflag
? thishandler
->data
.except_stmt
.except_label
: 0;
1526 thishandler
->exit_label
= exitflag
? gen_label_rtx () : 0;
1527 except_stack
= thishandler
;
1528 nesting_stack
= thishandler
;
1530 do_jump (try_clause
, thishandler
->data
.except_stmt
.except_label
, NULL
);
1533 /* End of a TRY block. Nothing to do for now. */
1538 except_stack
->data
.except_stmt
.after_label
= gen_label_rtx ();
1539 expand_goto_internal (NULL
, except_stack
->data
.except_stmt
.after_label
, 0);
1542 /* Start an `except' nesting contour.
1543 EXITFLAG says whether this contour should be able to `exit' something.
1544 ESCAPEFLAG says whether this contour should be escapable. */
1547 expand_start_except (exitflag
, escapeflag
)
1554 /* An `exit' from catch clauses goes out to next exit level,
1555 if there is one. Otherwise, it just goes to the end
1556 of the construct. */
1557 for (n
= except_stack
->next
; n
; n
= n
->next
)
1558 if (n
->exit_label
!= 0)
1560 except_stack
->exit_label
= n
->exit_label
;
1564 except_stack
->exit_label
= except_stack
->data
.except_stmt
.after_label
;
1569 /* An `escape' from catch clauses goes out to next escape level,
1570 if there is one. Otherwise, it just goes to the end
1571 of the construct. */
1572 for (n
= except_stack
->next
; n
; n
= n
->next
)
1573 if (n
->data
.except_stmt
.escape_label
!= 0)
1575 except_stack
->data
.except_stmt
.escape_label
1576 = n
->data
.except_stmt
.escape_label
;
1580 except_stack
->data
.except_stmt
.escape_label
1581 = except_stack
->data
.except_stmt
.after_label
;
1583 do_pending_stack_adjust ();
1584 emit_label (except_stack
->data
.except_stmt
.except_label
);
1587 /* Generate code to `escape' from an exception contour. This
1588 is like `exiting', but does not conflict with constructs which
1591 Return nonzero if this contour is escapable, otherwise
1592 return zero, and language-specific code will emit the
1593 appropriate error message. */
1595 expand_escape_except ()
1599 for (n
= except_stack
; n
; n
= n
->next
)
1600 if (n
->data
.except_stmt
.escape_label
!= 0)
1602 expand_goto_internal (0, n
->data
.except_stmt
.escape_label
, 0);
1609 /* Finish processing and `except' contour.
1610 Culls out all exceptions which might be raise but not
1611 handled, and returns the list to the caller.
1612 Language-specific code is responsible for dealing with these
1616 expand_end_except ()
1619 tree raised
= NULL_TREE
;
1621 do_pending_stack_adjust ();
1622 emit_label (except_stack
->data
.except_stmt
.after_label
);
1624 n
= except_stack
->next
;
1627 /* Propagate exceptions raised but not handled to next
1629 tree handled
= except_stack
->data
.except_stmt
.raised
;
1630 if (handled
!= void_type_node
)
1632 tree prev
= NULL_TREE
;
1633 raised
= except_stack
->data
.except_stmt
.raised
;
1637 for (this_raise
= raised
, prev
= 0; this_raise
;
1638 this_raise
= TREE_CHAIN (this_raise
))
1640 if (value_member (TREE_VALUE (this_raise
), handled
))
1643 TREE_CHAIN (prev
) = TREE_CHAIN (this_raise
);
1646 raised
= TREE_CHAIN (raised
);
1647 if (raised
== NULL_TREE
)
1654 handled
= TREE_CHAIN (handled
);
1656 if (prev
== NULL_TREE
)
1659 TREE_CHAIN (prev
) = n
->data
.except_stmt
.raised
;
1661 n
->data
.except_stmt
.raised
= raised
;
1665 POPSTACK (except_stack
);
1670 /* Record that exception EX is caught by this exception handler.
1671 Return nonzero if in exception handling construct, otherwise return 0. */
1678 if (except_stack
== 0)
1680 raises_ptr
= &except_stack
->data
.except_stmt
.handled
;
1681 if (*raises_ptr
!= void_type_node
1683 && ! value_member (ex
, *raises_ptr
))
1684 *raises_ptr
= tree_cons (NULL_TREE
, ex
, *raises_ptr
);
1688 /* Record that this exception handler catches all exceptions.
1689 Return nonzero if in exception handling construct, otherwise return 0. */
1692 expand_catch_default ()
1694 if (except_stack
== 0)
1696 except_stack
->data
.except_stmt
.handled
= void_type_node
;
1703 if (except_stack
== 0 || except_stack
->data
.except_stmt
.after_label
== 0)
1705 expand_goto_internal (0, except_stack
->data
.except_stmt
.after_label
, 0);
1709 /* Generate RTL for the start of an if-then. COND is the expression
1710 whose truth should be tested.
1712 If EXITFLAG is nonzero, this conditional is visible to
1713 `exit_something'. */
1716 expand_start_cond (cond
, exitflag
)
1720 struct nesting
*thiscond
= ALLOC_NESTING ();
1722 /* Make an entry on cond_stack for the cond we are entering. */
1724 thiscond
->next
= cond_stack
;
1725 thiscond
->all
= nesting_stack
;
1726 thiscond
->depth
= ++nesting_depth
;
1727 thiscond
->data
.cond
.next_label
= gen_label_rtx ();
1728 /* Before we encounter an `else', we don't need a separate exit label
1729 unless there are supposed to be exit statements
1730 to exit this conditional. */
1731 thiscond
->exit_label
= exitflag
? gen_label_rtx () : 0;
1732 thiscond
->data
.cond
.endif_label
= thiscond
->exit_label
;
1733 cond_stack
= thiscond
;
1734 nesting_stack
= thiscond
;
1736 do_jump (cond
, thiscond
->data
.cond
.next_label
, NULL
);
1739 /* Generate RTL between then-clause and the elseif-clause
1740 of an if-then-elseif-.... */
1743 expand_start_elseif (cond
)
1746 if (cond_stack
->data
.cond
.endif_label
== 0)
1747 cond_stack
->data
.cond
.endif_label
= gen_label_rtx ();
1748 emit_jump (cond_stack
->data
.cond
.endif_label
);
1749 emit_label (cond_stack
->data
.cond
.next_label
);
1750 cond_stack
->data
.cond
.next_label
= gen_label_rtx ();
1751 do_jump (cond
, cond_stack
->data
.cond
.next_label
, NULL
);
1754 /* Generate RTL between the then-clause and the else-clause
1755 of an if-then-else. */
1758 expand_start_else ()
1760 if (cond_stack
->data
.cond
.endif_label
== 0)
1761 cond_stack
->data
.cond
.endif_label
= gen_label_rtx ();
1762 emit_jump (cond_stack
->data
.cond
.endif_label
);
1763 emit_label (cond_stack
->data
.cond
.next_label
);
1764 cond_stack
->data
.cond
.next_label
= 0; /* No more _else or _elseif calls. */
1767 /* Generate RTL for the end of an if-then.
1768 Pop the record for it off of cond_stack. */
1773 struct nesting
*thiscond
= cond_stack
;
1775 do_pending_stack_adjust ();
1776 if (thiscond
->data
.cond
.next_label
)
1777 emit_label (thiscond
->data
.cond
.next_label
);
1778 if (thiscond
->data
.cond
.endif_label
)
1779 emit_label (thiscond
->data
.cond
.endif_label
);
1781 POPSTACK (cond_stack
);
1785 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
1786 loop should be exited by `exit_something'. This is a loop for which
1787 `expand_continue' will jump to the top of the loop.
1789 Make an entry on loop_stack to record the labels associated with
1793 expand_start_loop (exit_flag
)
1796 register struct nesting
*thisloop
= ALLOC_NESTING ();
1798 /* Make an entry on loop_stack for the loop we are entering. */
1800 thisloop
->next
= loop_stack
;
1801 thisloop
->all
= nesting_stack
;
1802 thisloop
->depth
= ++nesting_depth
;
1803 thisloop
->data
.loop
.start_label
= gen_label_rtx ();
1804 thisloop
->data
.loop
.end_label
= gen_label_rtx ();
1805 thisloop
->data
.loop
.continue_label
= thisloop
->data
.loop
.start_label
;
1806 thisloop
->exit_label
= exit_flag
? thisloop
->data
.loop
.end_label
: 0;
1807 loop_stack
= thisloop
;
1808 nesting_stack
= thisloop
;
1810 do_pending_stack_adjust ();
1812 emit_note (0, NOTE_INSN_LOOP_BEG
);
1813 emit_label (thisloop
->data
.loop
.start_label
);
1818 /* Like expand_start_loop but for a loop where the continuation point
1819 (for expand_continue_loop) will be specified explicitly. */
1822 expand_start_loop_continue_elsewhere (exit_flag
)
1825 struct nesting
*thisloop
= expand_start_loop (exit_flag
);
1826 loop_stack
->data
.loop
.continue_label
= gen_label_rtx ();
1830 /* Specify the continuation point for a loop started with
1831 expand_start_loop_continue_elsewhere.
1832 Use this at the point in the code to which a continue statement
1836 expand_loop_continue_here ()
1838 do_pending_stack_adjust ();
1839 emit_note (0, NOTE_INSN_LOOP_CONT
);
1840 emit_label (loop_stack
->data
.loop
.continue_label
);
1843 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
1844 Pop the block off of loop_stack. */
1849 register rtx insn
= get_last_insn ();
1850 register rtx start_label
= loop_stack
->data
.loop
.start_label
;
1851 rtx last_test_insn
= 0;
1854 /* Mark the continue-point at the top of the loop if none elsewhere. */
1855 if (start_label
== loop_stack
->data
.loop
.continue_label
)
1856 emit_note_before (NOTE_INSN_LOOP_CONT
, start_label
);
1858 do_pending_stack_adjust ();
1860 /* If optimizing, perhaps reorder the loop. If the loop
1861 starts with a conditional exit, roll that to the end
1862 where it will optimize together with the jump back.
1864 We look for the last conditional branch to the exit that we encounter
1865 before hitting 30 insns or a CALL_INSN. If we see an unconditional
1866 branch to the exit first, use it.
1868 We must also stop at NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes
1869 because moving them is not valid. */
1873 ! (GET_CODE (insn
) == JUMP_INSN
1874 && GET_CODE (PATTERN (insn
)) == SET
1875 && SET_DEST (PATTERN (insn
)) == pc_rtx
1876 && GET_CODE (SET_SRC (PATTERN (insn
))) == IF_THEN_ELSE
))
1878 /* Scan insns from the top of the loop looking for a qualified
1879 conditional exit. */
1880 for (insn
= NEXT_INSN (loop_stack
->data
.loop
.start_label
); insn
;
1881 insn
= NEXT_INSN (insn
))
1883 if (GET_CODE (insn
) == CALL_INSN
|| GET_CODE (insn
) == CODE_LABEL
)
1886 if (GET_CODE (insn
) == NOTE
1887 && (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_BEG
1888 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_END
))
1891 if (GET_CODE (insn
) == JUMP_INSN
|| GET_CODE (insn
) == INSN
)
1894 if (last_test_insn
&& num_insns
> 30)
1897 if (GET_CODE (insn
) == JUMP_INSN
&& GET_CODE (PATTERN (insn
)) == SET
1898 && SET_DEST (PATTERN (insn
)) == pc_rtx
1899 && GET_CODE (SET_SRC (PATTERN (insn
))) == IF_THEN_ELSE
1900 && ((GET_CODE (XEXP (SET_SRC (PATTERN (insn
)), 1)) == LABEL_REF
1901 && (XEXP (XEXP (SET_SRC (PATTERN (insn
)), 1), 0)
1902 == loop_stack
->data
.loop
.end_label
))
1903 || (GET_CODE (XEXP (SET_SRC (PATTERN (insn
)), 2)) == LABEL_REF
1904 && (XEXP (XEXP (SET_SRC (PATTERN (insn
)), 2), 0)
1905 == loop_stack
->data
.loop
.end_label
))))
1906 last_test_insn
= insn
;
1908 if (last_test_insn
== 0 && GET_CODE (insn
) == JUMP_INSN
1909 && GET_CODE (PATTERN (insn
)) == SET
1910 && SET_DEST (PATTERN (insn
)) == pc_rtx
1911 && GET_CODE (SET_SRC (PATTERN (insn
))) == LABEL_REF
1912 && (XEXP (SET_SRC (PATTERN (insn
)), 0)
1913 == loop_stack
->data
.loop
.end_label
))
1914 /* Include BARRIER. */
1915 last_test_insn
= NEXT_INSN (insn
);
1918 if (last_test_insn
!= 0 && last_test_insn
!= get_last_insn ())
1920 /* We found one. Move everything from there up
1921 to the end of the loop, and add a jump into the loop
1922 to jump to there. */
1923 register rtx newstart_label
= gen_label_rtx ();
1924 register rtx start_move
= start_label
;
1926 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
1927 then we want to move this note also. */
1928 if (GET_CODE (PREV_INSN (start_move
)) == NOTE
1929 && (NOTE_LINE_NUMBER (PREV_INSN (start_move
))
1930 == NOTE_INSN_LOOP_CONT
))
1931 start_move
= PREV_INSN (start_move
);
1933 emit_label_after (newstart_label
, PREV_INSN (start_move
));
1934 reorder_insns (start_move
, last_test_insn
, get_last_insn ());
1935 emit_jump_insn_after (gen_jump (start_label
),
1936 PREV_INSN (newstart_label
));
1937 emit_barrier_after (PREV_INSN (newstart_label
));
1938 start_label
= newstart_label
;
1942 emit_jump (start_label
);
1943 emit_note (0, NOTE_INSN_LOOP_END
);
1944 emit_label (loop_stack
->data
.loop
.end_label
);
1946 POPSTACK (loop_stack
);
1951 /* Generate a jump to the current loop's continue-point.
1952 This is usually the top of the loop, but may be specified
1953 explicitly elsewhere. If not currently inside a loop,
1954 return 0 and do nothing; caller will print an error message. */
1957 expand_continue_loop (whichloop
)
1958 struct nesting
*whichloop
;
1962 whichloop
= loop_stack
;
1965 expand_goto_internal (0, whichloop
->data
.loop
.continue_label
, 0);
1969 /* Generate a jump to exit the current loop. If not currently inside a loop,
1970 return 0 and do nothing; caller will print an error message. */
1973 expand_exit_loop (whichloop
)
1974 struct nesting
*whichloop
;
1978 whichloop
= loop_stack
;
1981 expand_goto_internal (0, whichloop
->data
.loop
.end_label
, 0);
1985 /* Generate a conditional jump to exit the current loop if COND
1986 evaluates to zero. If not currently inside a loop,
1987 return 0 and do nothing; caller will print an error message. */
1990 expand_exit_loop_if_false (whichloop
, cond
)
1991 struct nesting
*whichloop
;
1996 whichloop
= loop_stack
;
1999 do_jump (cond
, whichloop
->data
.loop
.end_label
, NULL
);
2003 /* Return non-zero if we should preserve sub-expressions as separate
2004 pseudos. We never do so if we aren't optimizing. We always do so
2005 if -fexpensive-optimizations.
2007 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2008 the loop may still be a small one. */
2011 preserve_subexpressions_p ()
2015 if (flag_expensive_optimizations
)
2018 if (optimize
== 0 || loop_stack
== 0)
2021 insn
= get_last_insn_anywhere ();
2024 && (INSN_UID (insn
) - INSN_UID (loop_stack
->data
.loop
.start_label
)
2025 < n_non_fixed_regs
* 3));
2029 /* Generate a jump to exit the current loop, conditional, binding contour
2030 or case statement. Not all such constructs are visible to this function,
2031 only those started with EXIT_FLAG nonzero. Individual languages use
2032 the EXIT_FLAG parameter to control which kinds of constructs you can
2035 If not currently inside anything that can be exited,
2036 return 0 and do nothing; caller will print an error message. */
2039 expand_exit_something ()
2043 for (n
= nesting_stack
; n
; n
= n
->all
)
2044 if (n
->exit_label
!= 0)
2046 expand_goto_internal (0, n
->exit_label
, 0);
2053 /* Generate RTL to return from the current function, with no value.
2054 (That is, we do not do anything about returning any value.) */
2057 expand_null_return ()
2059 struct nesting
*block
= block_stack
;
2062 /* Does any pending block have cleanups? */
2064 while (block
&& block
->data
.block
.cleanups
== 0)
2065 block
= block
->next
;
2067 /* If yes, use a goto to return, since that runs cleanups. */
2069 expand_null_return_1 (last_insn
, block
!= 0);
2072 /* Generate RTL to return from the current function, with value VAL. */
2075 expand_value_return (val
)
2078 struct nesting
*block
= block_stack
;
2079 rtx last_insn
= get_last_insn ();
2080 rtx return_reg
= DECL_RTL (DECL_RESULT (current_function_decl
));
2082 /* Copy the value to the return location
2083 unless it's already there. */
2085 if (return_reg
!= val
)
2086 emit_move_insn (return_reg
, val
);
2087 if (GET_CODE (return_reg
) == REG
2088 && REGNO (return_reg
) < FIRST_PSEUDO_REGISTER
)
2089 emit_insn (gen_rtx (USE
, VOIDmode
, return_reg
));
2091 /* Does any pending block have cleanups? */
2093 while (block
&& block
->data
.block
.cleanups
== 0)
2094 block
= block
->next
;
2096 /* If yes, use a goto to return, since that runs cleanups.
2097 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2099 expand_null_return_1 (last_insn
, block
!= 0);
2102 /* Output a return with no value. If LAST_INSN is nonzero,
2103 pretend that the return takes place after LAST_INSN.
2104 If USE_GOTO is nonzero then don't use a return instruction;
2105 go to the return label instead. This causes any cleanups
2106 of pending blocks to be executed normally. */
2109 expand_null_return_1 (last_insn
, use_goto
)
2113 rtx end_label
= cleanup_label
? cleanup_label
: return_label
;
2115 clear_pending_stack_adjust ();
2116 do_pending_stack_adjust ();
2119 /* PCC-struct return always uses an epilogue. */
2120 if (current_function_returns_pcc_struct
|| use_goto
)
2123 end_label
= return_label
= gen_label_rtx ();
2124 expand_goto_internal (0, end_label
, last_insn
);
2128 /* Otherwise output a simple return-insn if one is available,
2129 unless it won't do the job. */
2131 if (HAVE_return
&& use_goto
== 0 && cleanup_label
== 0)
2133 emit_jump_insn (gen_return ());
2139 /* Otherwise jump to the epilogue. */
2140 expand_goto_internal (0, end_label
, last_insn
);
2143 /* Generate RTL to evaluate the expression RETVAL and return it
2144 from the current function. */
2147 expand_return (retval
)
2150 /* If there are any cleanups to be performed, then they will
2151 be inserted following LAST_INSN. It is desirable
2152 that the last_insn, for such purposes, should be the
2153 last insn before computing the return value. Otherwise, cleanups
2154 which call functions can clobber the return value. */
2155 /* ??? rms: I think that is erroneous, because in C++ it would
2156 run destructors on variables that might be used in the subsequent
2157 computation of the return value. */
2159 register rtx val
= 0;
2163 struct nesting
*block
;
2165 /* If function wants no value, give it none. */
2166 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl
))) == VOID_TYPE
)
2168 expand_expr (retval
, 0, VOIDmode
, 0);
2169 expand_null_return ();
2173 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2174 cleanups
= any_pending_cleanups (1);
2176 if (TREE_CODE (retval
) == RESULT_DECL
)
2177 retval_rhs
= retval
;
2178 else if ((TREE_CODE (retval
) == MODIFY_EXPR
|| TREE_CODE (retval
) == INIT_EXPR
)
2179 && TREE_CODE (TREE_OPERAND (retval
, 0)) == RESULT_DECL
)
2180 retval_rhs
= TREE_OPERAND (retval
, 1);
2181 else if (TREE_TYPE (retval
) == void_type_node
)
2182 /* Recognize tail-recursive call to void function. */
2183 retval_rhs
= retval
;
2185 retval_rhs
= NULL_TREE
;
2187 /* Only use `last_insn' if there are cleanups which must be run. */
2188 if (cleanups
|| cleanup_label
!= 0)
2189 last_insn
= get_last_insn ();
2191 /* Distribute return down conditional expr if either of the sides
2192 may involve tail recursion (see test below). This enhances the number
2193 of tail recursions we see. Don't do this always since it can produce
2194 sub-optimal code in some cases and we distribute assignments into
2195 conditional expressions when it would help. */
2197 if (optimize
&& retval_rhs
!= 0
2198 && frame_offset
== 0
2199 && TREE_CODE (retval_rhs
) == COND_EXPR
2200 && (TREE_CODE (TREE_OPERAND (retval_rhs
, 1)) == CALL_EXPR
2201 || TREE_CODE (TREE_OPERAND (retval_rhs
, 2)) == CALL_EXPR
))
2203 rtx label
= gen_label_rtx ();
2204 do_jump (TREE_OPERAND (retval_rhs
, 0), label
, 0);
2205 expand_return (build (MODIFY_EXPR
, TREE_TYPE (current_function_decl
),
2206 DECL_RESULT (current_function_decl
),
2207 TREE_OPERAND (retval_rhs
, 1)));
2209 expand_return (build (MODIFY_EXPR
, TREE_TYPE (current_function_decl
),
2210 DECL_RESULT (current_function_decl
),
2211 TREE_OPERAND (retval_rhs
, 2)));
2215 /* For tail-recursive call to current function,
2216 just jump back to the beginning.
2217 It's unsafe if any auto variable in this function
2218 has its address taken; for simplicity,
2219 require stack frame to be empty. */
2220 if (optimize
&& retval_rhs
!= 0
2221 && frame_offset
== 0
2222 && TREE_CODE (retval_rhs
) == CALL_EXPR
2223 && TREE_CODE (TREE_OPERAND (retval_rhs
, 0)) == ADDR_EXPR
2224 && TREE_OPERAND (TREE_OPERAND (retval_rhs
, 0), 0) == current_function_decl
2225 /* Finish checking validity, and if valid emit code
2226 to set the argument variables for the new call. */
2227 && tail_recursion_args (TREE_OPERAND (retval_rhs
, 1),
2228 DECL_ARGUMENTS (current_function_decl
)))
2230 if (tail_recursion_label
== 0)
2232 tail_recursion_label
= gen_label_rtx ();
2233 emit_label_after (tail_recursion_label
,
2234 tail_recursion_reentry
);
2236 expand_goto_internal (0, tail_recursion_label
, last_insn
);
2241 /* This optimization is safe if there are local cleanups
2242 because expand_null_return takes care of them.
2243 ??? I think it should also be safe when there is a cleanup label,
2244 because expand_null_return takes care of them, too.
2245 Any reason why not? */
2246 if (HAVE_return
&& cleanup_label
== 0
2247 && ! current_function_returns_pcc_struct
)
2249 /* If this is return x == y; then generate
2250 if (x == y) return 1; else return 0;
2251 if we can do it with explicit return insns. */
2253 switch (TREE_CODE (retval_rhs
))
2261 case TRUTH_ANDIF_EXPR
:
2262 case TRUTH_ORIF_EXPR
:
2263 case TRUTH_AND_EXPR
:
2265 case TRUTH_NOT_EXPR
:
2266 op0
= gen_label_rtx ();
2267 jumpifnot (retval_rhs
, op0
);
2268 expand_value_return (const1_rtx
);
2270 expand_value_return (const0_rtx
);
2274 #endif /* HAVE_return */
2278 && TREE_TYPE (retval_rhs
) != void_type_node
2279 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl
))) == REG
)
2281 /* Calculate the return value into a pseudo reg. */
2282 val
= expand_expr (retval_rhs
, 0, VOIDmode
, 0);
2284 /* All temporaries have now been used. */
2286 /* Return the calculated value, doing cleanups first. */
2287 expand_value_return (val
);
2291 /* No cleanups or no hard reg used;
2292 calculate value into hard return reg. */
2293 expand_expr (retval
, 0, VOIDmode
, 0);
2296 expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl
)));
2300 /* Return 1 if the end of the generated RTX is not a barrier.
2301 This means code already compiled can drop through. */
2304 drop_through_at_end_p ()
2306 rtx insn
= get_last_insn ();
2307 while (insn
&& GET_CODE (insn
) == NOTE
)
2308 insn
= PREV_INSN (insn
);
2309 return insn
&& GET_CODE (insn
) != BARRIER
;
2312 /* Emit code to alter this function's formal parms for a tail-recursive call.
2313 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
2314 FORMALS is the chain of decls of formals.
2315 Return 1 if this can be done;
2316 otherwise return 0 and do not emit any code. */
2319 tail_recursion_args (actuals
, formals
)
2320 tree actuals
, formals
;
2322 register tree a
= actuals
, f
= formals
;
2324 register rtx
*argvec
;
2326 /* Check that number and types of actuals are compatible
2327 with the formals. This is not always true in valid C code.
2328 Also check that no formal needs to be addressable
2329 and that all formals are scalars. */
2331 /* Also count the args. */
2333 for (a
= actuals
, f
= formals
, i
= 0; a
&& f
; a
= TREE_CHAIN (a
), f
= TREE_CHAIN (f
), i
++)
2335 if (TREE_TYPE (TREE_VALUE (a
)) != TREE_TYPE (f
))
2337 if (GET_CODE (DECL_RTL (f
)) != REG
|| DECL_MODE (f
) == BLKmode
)
2340 if (a
!= 0 || f
!= 0)
2343 /* Compute all the actuals. */
2345 argvec
= (rtx
*) alloca (i
* sizeof (rtx
));
2347 for (a
= actuals
, i
= 0; a
; a
= TREE_CHAIN (a
), i
++)
2348 argvec
[i
] = expand_expr (TREE_VALUE (a
), 0, VOIDmode
, 0);
2350 /* Find which actual values refer to current values of previous formals.
2351 Copy each of them now, before any formal is changed. */
2353 for (a
= actuals
, i
= 0; a
; a
= TREE_CHAIN (a
), i
++)
2357 for (f
= formals
, j
= 0; j
< i
; f
= TREE_CHAIN (f
), j
++)
2358 if (reg_mentioned_p (DECL_RTL (f
), argvec
[i
]))
2359 { copy
= 1; break; }
2361 argvec
[i
] = copy_to_reg (argvec
[i
]);
2364 /* Store the values of the actuals into the formals. */
2366 for (f
= formals
, a
= actuals
, i
= 0; f
;
2367 f
= TREE_CHAIN (f
), a
= TREE_CHAIN (a
), i
++)
2369 if (DECL_MODE (f
) == GET_MODE (argvec
[i
]))
2370 emit_move_insn (DECL_RTL (f
), argvec
[i
]);
2372 convert_move (DECL_RTL (f
), argvec
[i
],
2373 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a
))));
2380 /* Generate the RTL code for entering a binding contour.
2381 The variables are declared one by one, by calls to `expand_decl'.
2383 EXIT_FLAG is nonzero if this construct should be visible to
2384 `exit_something'. */
2387 expand_start_bindings (exit_flag
)
2390 struct nesting
*thisblock
= ALLOC_NESTING ();
2392 rtx note
= emit_note (0, NOTE_INSN_BLOCK_BEG
);
2394 /* Make an entry on block_stack for the block we are entering. */
2396 thisblock
->next
= block_stack
;
2397 thisblock
->all
= nesting_stack
;
2398 thisblock
->depth
= ++nesting_depth
;
2399 thisblock
->data
.block
.stack_level
= 0;
2400 thisblock
->data
.block
.cleanups
= 0;
2401 thisblock
->data
.block
.function_call_count
= 0;
2405 if (block_stack
->data
.block
.cleanups
== NULL_TREE
2406 && (block_stack
->data
.block
.outer_cleanups
== NULL_TREE
2407 || block_stack
->data
.block
.outer_cleanups
== empty_cleanup_list
))
2408 thisblock
->data
.block
.outer_cleanups
= empty_cleanup_list
;
2410 thisblock
->data
.block
.outer_cleanups
2411 = tree_cons (NULL_TREE
, block_stack
->data
.block
.cleanups
,
2412 block_stack
->data
.block
.outer_cleanups
);
2415 thisblock
->data
.block
.outer_cleanups
= 0;
2419 && !(block_stack
->data
.block
.cleanups
== NULL_TREE
2420 && block_stack
->data
.block
.outer_cleanups
== NULL_TREE
))
2421 thisblock
->data
.block
.outer_cleanups
2422 = tree_cons (NULL_TREE
, block_stack
->data
.block
.cleanups
,
2423 block_stack
->data
.block
.outer_cleanups
);
2425 thisblock
->data
.block
.outer_cleanups
= 0;
2427 thisblock
->data
.block
.label_chain
= 0;
2428 thisblock
->data
.block
.innermost_stack_block
= stack_block_stack
;
2429 thisblock
->data
.block
.first_insn
= note
;
2430 thisblock
->data
.block
.block_start_count
= ++block_start_count
;
2431 thisblock
->exit_label
= exit_flag
? gen_label_rtx () : 0;
2432 block_stack
= thisblock
;
2433 nesting_stack
= thisblock
;
2435 /* Make a new level for allocating stack slots. */
2439 /* Generate RTL code to terminate a binding contour.
2440 VARS is the chain of VAR_DECL nodes
2441 for the variables bound in this contour.
2442 MARK_ENDS is nonzero if we should put a note at the beginning
2443 and end of this binding contour.
2445 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
2446 (That is true automatically if the contour has a saved stack level.) */
2449 expand_end_bindings (vars
, mark_ends
, dont_jump_in
)
2454 register struct nesting
*thisblock
= block_stack
;
2458 for (decl
= vars
; decl
; decl
= TREE_CHAIN (decl
))
2459 if (! TREE_USED (decl
) && TREE_CODE (decl
) == VAR_DECL
)
2460 warning_with_decl (decl
, "unused variable `%s'");
2462 /* Mark the beginning and end of the scope if requested. */
2465 emit_note (0, NOTE_INSN_BLOCK_END
);
2467 /* Get rid of the beginning-mark if we don't make an end-mark. */
2468 NOTE_LINE_NUMBER (thisblock
->data
.block
.first_insn
) = NOTE_INSN_DELETED
;
2470 if (thisblock
->exit_label
)
2472 do_pending_stack_adjust ();
2473 emit_label (thisblock
->exit_label
);
2476 /* If necessary, make a handler for nonlocal gotos taking
2477 place in the function calls in this block. */
2478 if (function_call_count
!= thisblock
->data
.block
.function_call_count
2480 /* Make handler for outermost block
2481 if there were any nonlocal gotos to this function. */
2482 && (thisblock
->next
== 0 ? current_function_has_nonlocal_label
2483 /* Make handler for inner block if it has something
2484 special to do when you jump out of it. */
2485 : (thisblock
->data
.block
.cleanups
!= 0
2486 || thisblock
->data
.block
.stack_level
!= 0)))
2489 rtx afterward
= gen_label_rtx ();
2490 rtx handler_label
= gen_label_rtx ();
2491 rtx save_receiver
= gen_reg_rtx (Pmode
);
2493 /* Don't let jump_optimize delete the handler. */
2494 LABEL_PRESERVE_P (handler_label
) = 1;
2496 /* Record the handler address in the stack slot for that purpose,
2497 during this block, saving and restoring the outer value. */
2498 if (thisblock
->next
!= 0)
2500 emit_move_insn (nonlocal_goto_handler_slot
, save_receiver
);
2501 emit_insn_before (gen_move_insn (save_receiver
,
2502 nonlocal_goto_handler_slot
),
2503 thisblock
->data
.block
.first_insn
);
2505 emit_insn_before (gen_move_insn (nonlocal_goto_handler_slot
,
2506 gen_rtx (LABEL_REF
, Pmode
,
2508 thisblock
->data
.block
.first_insn
);
2510 /* Jump around the handler; it runs only when specially invoked. */
2511 emit_jump (afterward
);
2512 emit_label (handler_label
);
2514 #ifdef HAVE_nonlocal_goto
2515 if (! HAVE_nonlocal_goto
)
2517 /* First adjust our frame pointer to its actual value. It was
2518 previously set to the start of the virtual area corresponding to
2519 the stacked variables when we branched here and now needs to be
2520 adjusted to the actual hardware fp value.
2522 Assignments are to virtual registers are converted by
2523 instantiate_virtual_regs into the corresponding assignment
2524 to the underlying register (fp in this case) that makes
2525 the original assignment true.
2526 So the following insn will actually be
2527 decrementing fp by STARTING_FRAME_OFFSET. */
2528 emit_move_insn (virtual_stack_vars_rtx
, frame_pointer_rtx
);
2530 #if ARG_POINTER_REGNUM != FRAME_POINTER_REGNUM
2531 if (fixed_regs
[ARG_POINTER_REGNUM
])
2533 /* Now restore our arg pointer from the address at which it was saved
2535 If there hasn't be space allocated for it yet, make some now. */
2536 if (arg_pointer_save_area
== 0)
2537 arg_pointer_save_area
2538 = assign_stack_local (Pmode
, GET_MODE_SIZE (Pmode
), 0);
2539 emit_move_insn (virtual_incoming_args_rtx
,
2540 /* We need a pseudo here,
2541 or else instantiate_virtual_regs_1 complains. */
2542 copy_to_reg (arg_pointer_save_area
));
2546 /* The handler expects the desired label address in the static chain
2547 register. It tests the address and does an appropriate jump
2548 to whatever label is desired. */
2549 for (link
= nonlocal_labels
; link
; link
= TREE_CHAIN (link
))
2550 /* Skip any labels we shouldn't be able to jump to from here. */
2551 if (! DECL_TOO_LATE (TREE_VALUE (link
)))
2553 rtx not_this
= gen_label_rtx ();
2554 rtx
this = gen_label_rtx ();
2555 do_jump_if_equal (static_chain_rtx
,
2556 gen_rtx (LABEL_REF
, Pmode
, DECL_RTL (TREE_VALUE (link
))),
2558 emit_jump (not_this
);
2560 expand_goto (TREE_VALUE (link
));
2561 emit_label (not_this
);
2563 /* If label is not recognized, abort. */
2564 emit_library_call (gen_rtx (SYMBOL_REF
, Pmode
, "abort"), 0,
2566 emit_label (afterward
);
2569 /* Don't allow jumping into a block that has cleanups or a stack level. */
2571 || thisblock
->data
.block
.stack_level
!= 0
2572 || thisblock
->data
.block
.cleanups
!= 0)
2574 struct label_chain
*chain
;
2576 /* Any labels in this block are no longer valid to go to.
2577 Mark them to cause an error message. */
2578 for (chain
= thisblock
->data
.block
.label_chain
; chain
; chain
= chain
->next
)
2580 DECL_TOO_LATE (chain
->label
) = 1;
2581 /* If any goto without a fixup came to this label,
2582 that must be an error, because gotos without fixups
2583 come from outside all saved stack-levels and all cleanups. */
2584 if (TREE_ADDRESSABLE (chain
->label
))
2585 error_with_decl (chain
->label
,
2586 "label `%s' used before containing binding contour");
2590 /* Restore stack level in effect before the block
2591 (only if variable-size objects allocated). */
2592 /* Perform any cleanups associated with the block. */
2594 if (thisblock
->data
.block
.stack_level
!= 0
2595 || thisblock
->data
.block
.cleanups
!= 0)
2597 /* Don't let cleanups affect ({...}) constructs. */
2598 int old_expr_stmts_for_value
= expr_stmts_for_value
;
2599 rtx old_last_expr_value
= last_expr_value
;
2600 tree old_last_expr_type
= last_expr_type
;
2601 expr_stmts_for_value
= 0;
2603 /* Do the cleanups. */
2604 expand_cleanups (thisblock
->data
.block
.cleanups
, 0);
2605 do_pending_stack_adjust ();
2607 expr_stmts_for_value
= old_expr_stmts_for_value
;
2608 last_expr_value
= old_last_expr_value
;
2609 last_expr_type
= old_last_expr_type
;
2611 /* Restore the stack level. */
2613 if (thisblock
->data
.block
.stack_level
!= 0)
2615 emit_stack_restore (thisblock
->next
? SAVE_BLOCK
: SAVE_FUNCTION
,
2616 thisblock
->data
.block
.stack_level
, 0);
2617 if (nonlocal_goto_handler_slot
!= 0)
2618 emit_stack_save (SAVE_NONLOCAL
, &nonlocal_goto_stack_level
, 0);
2621 /* Any gotos out of this block must also do these things.
2622 Also report any gotos with fixups that came to labels in this
2624 fixup_gotos (thisblock
,
2625 thisblock
->data
.block
.stack_level
,
2626 thisblock
->data
.block
.cleanups
,
2627 thisblock
->data
.block
.first_insn
,
2631 /* If doing stupid register allocation, make sure lives of all
2632 register variables declared here extend thru end of scope. */
2635 for (decl
= vars
; decl
; decl
= TREE_CHAIN (decl
))
2637 rtx rtl
= DECL_RTL (decl
);
2638 if (TREE_CODE (decl
) == VAR_DECL
&& rtl
!= 0)
2642 /* Restore block_stack level for containing block. */
2644 stack_block_stack
= thisblock
->data
.block
.innermost_stack_block
;
2645 POPSTACK (block_stack
);
2647 /* Pop the stack slot nesting and free any slots at this level. */
2651 /* Generate RTL for the automatic variable declaration DECL.
2652 (Other kinds of declarations are simply ignored if seen here.)
2653 CLEANUP is an expression to be executed at exit from this binding contour;
2654 for example, in C++, it might call the destructor for this variable.
2656 If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them
2657 either before or after calling `expand_decl' but before compiling
2658 any subsequent expressions. This is because CLEANUP may be expanded
2659 more than once, on different branches of execution.
2660 For the same reason, CLEANUP may not contain a CALL_EXPR
2661 except as its topmost node--else `preexpand_calls' would get confused.
2663 If CLEANUP is nonzero and DECL is zero, we record a cleanup
2664 that is not associated with any particular variable.
2666 There is no special support here for C++ constructors.
2667 They should be handled by the proper code in DECL_INITIAL. */
2673 struct nesting
*thisblock
= block_stack
;
2674 tree type
= TREE_TYPE (decl
);
2676 /* Only automatic variables need any expansion done.
2677 Static and external variables, and external functions,
2678 will be handled by `assemble_variable' (called from finish_decl).
2679 TYPE_DECL and CONST_DECL require nothing.
2680 PARM_DECLs are handled in `assign_parms'. */
2682 if (TREE_CODE (decl
) != VAR_DECL
)
2684 if (TREE_STATIC (decl
) || TREE_EXTERNAL (decl
))
2687 /* Create the RTL representation for the variable. */
2689 if (type
== error_mark_node
)
2690 DECL_RTL (decl
) = gen_rtx (MEM
, BLKmode
, const0_rtx
);
2691 else if (DECL_SIZE (decl
) == 0)
2692 /* Variable with incomplete type. */
2694 if (DECL_INITIAL (decl
) == 0)
2695 /* Error message was already done; now avoid a crash. */
2696 DECL_RTL (decl
) = assign_stack_temp (DECL_MODE (decl
), 0, 1);
2698 /* An initializer is going to decide the size of this array.
2699 Until we know the size, represent its address with a reg. */
2700 DECL_RTL (decl
) = gen_rtx (MEM
, BLKmode
, gen_reg_rtx (Pmode
));
2702 else if (DECL_MODE (decl
) != BLKmode
2703 /* If -ffloat-store, don't put explicit float vars
2705 && !(flag_float_store
2706 && TREE_CODE (type
) == REAL_TYPE
)
2707 && ! TREE_THIS_VOLATILE (decl
)
2708 && ! TREE_ADDRESSABLE (decl
)
2709 && (TREE_REGDECL (decl
) || ! obey_regdecls
))
2711 /* Automatic variable that can go in a register. */
2712 DECL_RTL (decl
) = gen_reg_rtx (DECL_MODE (decl
));
2713 if (TREE_CODE (type
) == POINTER_TYPE
)
2714 mark_reg_pointer (DECL_RTL (decl
));
2715 REG_USERVAR_P (DECL_RTL (decl
)) = 1;
2717 else if (TREE_CODE (DECL_SIZE (decl
)) == INTEGER_CST
)
2719 /* Variable of fixed size that goes on the stack. */
2723 /* If we previously made RTL for this decl, it must be an array
2724 whose size was determined by the initializer.
2725 The old address was a register; set that register now
2726 to the proper address. */
2727 if (DECL_RTL (decl
) != 0)
2729 if (GET_CODE (DECL_RTL (decl
)) != MEM
2730 || GET_CODE (XEXP (DECL_RTL (decl
), 0)) != REG
)
2732 oldaddr
= XEXP (DECL_RTL (decl
), 0);
2736 = assign_stack_temp (DECL_MODE (decl
),
2737 ((TREE_INT_CST_LOW (DECL_SIZE (decl
))
2738 + BITS_PER_UNIT
- 1)
2742 /* Set alignment we actually gave this decl. */
2743 DECL_ALIGN (decl
) = (DECL_MODE (decl
) == BLKmode
? BIGGEST_ALIGNMENT
2744 : GET_MODE_BITSIZE (DECL_MODE (decl
)));
2748 addr
= force_operand (XEXP (DECL_RTL (decl
), 0), oldaddr
);
2749 if (addr
!= oldaddr
)
2750 emit_move_insn (oldaddr
, addr
);
2753 /* If this is a memory ref that contains aggregate components,
2754 mark it as such for cse and loop optimize. */
2755 MEM_IN_STRUCT_P (DECL_RTL (decl
))
2756 = (TREE_CODE (TREE_TYPE (decl
)) == ARRAY_TYPE
2757 || TREE_CODE (TREE_TYPE (decl
)) == RECORD_TYPE
2758 || TREE_CODE (TREE_TYPE (decl
)) == UNION_TYPE
);
2760 /* If this is in memory because of -ffloat-store,
2761 set the volatile bit, to prevent optimizations from
2762 undoing the effects. */
2763 if (flag_float_store
&& TREE_CODE (type
) == REAL_TYPE
)
2764 MEM_VOLATILE_P (DECL_RTL (decl
)) = 1;
2768 /* Dynamic-size object: must push space on the stack. */
2772 /* Record the stack pointer on entry to block, if have
2773 not already done so. */
2774 if (thisblock
->data
.block
.stack_level
== 0)
2776 do_pending_stack_adjust ();
2777 emit_stack_save (thisblock
->next
? SAVE_BLOCK
: SAVE_FUNCTION
,
2778 &thisblock
->data
.block
.stack_level
,
2779 thisblock
->data
.block
.first_insn
);
2780 stack_block_stack
= thisblock
;
2783 /* Compute the variable's size, in bytes. */
2784 size
= expand_expr (size_binop (CEIL_DIV_EXPR
,
2786 size_int (BITS_PER_UNIT
)),
2790 /* This is equivalent to calling alloca. */
2791 current_function_calls_alloca
= 1;
2793 /* Allocate space on the stack for the variable. */
2794 address
= allocate_dynamic_stack_space (size
, 0, DECL_ALIGN (decl
));
2796 if (nonlocal_goto_handler_slot
!= 0)
2797 emit_stack_save (SAVE_NONLOCAL
, &nonlocal_goto_stack_level
, 0);
2799 /* Reference the variable indirect through that rtx. */
2800 DECL_RTL (decl
) = gen_rtx (MEM
, DECL_MODE (decl
), address
);
2802 /* If this is a memory ref that contains aggregate components,
2803 mark it as such for cse and loop optimize. */
2804 MEM_IN_STRUCT_P (DECL_RTL (decl
))
2805 = (TREE_CODE (TREE_TYPE (decl
)) == ARRAY_TYPE
2806 || TREE_CODE (TREE_TYPE (decl
)) == RECORD_TYPE
2807 || TREE_CODE (TREE_TYPE (decl
)) == UNION_TYPE
);
2809 /* Indicate the alignment we actually gave this variable. */
2810 #ifdef STACK_BOUNDARY
2811 DECL_ALIGN (decl
) = STACK_BOUNDARY
;
2813 DECL_ALIGN (decl
) = BIGGEST_ALIGNMENT
;
2817 if (TREE_THIS_VOLATILE (decl
))
2818 MEM_VOLATILE_P (DECL_RTL (decl
)) = 1;
2819 if (TREE_READONLY (decl
))
2820 RTX_UNCHANGING_P (DECL_RTL (decl
)) = 1;
2822 /* If doing stupid register allocation, make sure life of any
2823 register variable starts here, at the start of its scope. */
2826 use_variable (DECL_RTL (decl
));
2829 /* Emit code to perform the initialization of a declaration DECL. */
2832 expand_decl_init (decl
)
2835 int was_used
= TREE_USED (decl
);
2837 if (TREE_STATIC (decl
))
2840 /* Compute and store the initial value now. */
2842 if (DECL_INITIAL (decl
) == error_mark_node
)
2844 enum tree_code code
= TREE_CODE (TREE_TYPE (decl
));
2845 if (code
== INTEGER_TYPE
|| code
== REAL_TYPE
|| code
== ENUMERAL_TYPE
2846 || code
== POINTER_TYPE
)
2847 expand_assignment (decl
, convert (TREE_TYPE (decl
), integer_zero_node
),
2851 else if (DECL_INITIAL (decl
) && TREE_CODE (DECL_INITIAL (decl
)) != TREE_LIST
)
2853 emit_line_note (DECL_SOURCE_FILE (decl
), DECL_SOURCE_LINE (decl
));
2854 expand_assignment (decl
, DECL_INITIAL (decl
), 0, 0);
2858 /* Don't let the initialization count as "using" the variable. */
2859 TREE_USED (decl
) = was_used
;
2861 /* Free any temporaries we made while initializing the decl. */
2865 /* CLEANUP is an expression to be executed at exit from this binding contour;
2866 for example, in C++, it might call the destructor for this variable.
2868 If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them
2869 either before or after calling `expand_decl' but before compiling
2870 any subsequent expressions. This is because CLEANUP may be expanded
2871 more than once, on different branches of execution.
2872 For the same reason, CLEANUP may not contain a CALL_EXPR
2873 except as its topmost node--else `preexpand_calls' would get confused.
2875 If CLEANUP is nonzero and DECL is zero, we record a cleanup
2876 that is not associated with any particular variable. */
2879 expand_decl_cleanup (decl
, cleanup
)
2882 struct nesting
*thisblock
= block_stack
;
2884 /* Error if we are not in any block. */
2888 /* Record the cleanup if there is one. */
2892 thisblock
->data
.block
.cleanups
2893 = temp_tree_cons (decl
, cleanup
, thisblock
->data
.block
.cleanups
);
2894 /* If this block has a cleanup, it belongs in stack_block_stack. */
2895 stack_block_stack
= thisblock
;
2900 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
2901 DECL_ELTS is the list of elements that belong to DECL's type.
2902 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
2905 expand_anon_union_decl (decl
, cleanup
, decl_elts
)
2906 tree decl
, cleanup
, decl_elts
;
2908 struct nesting
*thisblock
= block_stack
;
2911 expand_decl (decl
, cleanup
);
2912 x
= DECL_RTL (decl
);
2916 tree decl_elt
= TREE_VALUE (decl_elts
);
2917 tree cleanup_elt
= TREE_PURPOSE (decl_elts
);
2918 enum machine_mode mode
= TYPE_MODE (TREE_TYPE (decl_elt
));
2920 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
2921 instead create a new MEM rtx with the proper mode. */
2922 if (GET_CODE (x
) == MEM
)
2924 if (mode
== GET_MODE (x
))
2925 DECL_RTL (decl_elt
) = x
;
2928 DECL_RTL (decl_elt
) = gen_rtx (MEM
, mode
, copy_rtx (XEXP (x
, 0)));
2929 MEM_IN_STRUCT_P (DECL_RTL (decl_elt
)) = MEM_IN_STRUCT_P (x
);
2930 RTX_UNCHANGING_P (DECL_RTL (decl_elt
)) = RTX_UNCHANGING_P (x
);
2933 else if (GET_CODE (x
) == REG
)
2935 if (mode
== GET_MODE (x
))
2936 DECL_RTL (decl_elt
) = x
;
2938 DECL_RTL (decl_elt
) = gen_rtx (SUBREG
, mode
, x
, 0);
2943 /* Record the cleanup if there is one. */
2946 thisblock
->data
.block
.cleanups
2947 = temp_tree_cons (decl_elt
, cleanup_elt
,
2948 thisblock
->data
.block
.cleanups
);
2950 decl_elts
= TREE_CHAIN (decl_elts
);
2954 /* Expand a list of cleanups LIST.
2955 Elements may be expressions or may be nested lists.
2957 If DONT_DO is nonnull, then any list-element
2958 whose TREE_PURPOSE matches DONT_DO is omitted.
2959 This is sometimes used to avoid a cleanup associated with
2960 a value that is being returned out of the scope. */
2963 expand_cleanups (list
, dont_do
)
2968 for (tail
= list
; tail
; tail
= TREE_CHAIN (tail
))
2969 if (dont_do
== 0 || TREE_PURPOSE (tail
) != dont_do
)
2971 if (TREE_CODE (TREE_VALUE (tail
)) == TREE_LIST
)
2972 expand_cleanups (TREE_VALUE (tail
), dont_do
);
2975 /* Cleanups may be run multiple times. For example,
2976 when exiting a binding contour, we expand the
2977 cleanups associated with that contour. When a goto
2978 within that binding contour has a target outside that
2979 contour, it will expand all cleanups from its scope to
2980 the target. Though the cleanups are expanded multiple
2981 times, the control paths are non-overlapping so the
2982 cleanups will not be executed twice. */
2983 expand_expr (TREE_VALUE (tail
), const0_rtx
, VOIDmode
, 0);
2989 /* Expand a list of cleanups for a goto fixup.
2990 The expansion is put into the insn chain after the insn *BEFORE_JUMP
2991 and *BEFORE_JUMP is set to the insn that now comes before the jump. */
2994 fixup_cleanups (list
, before_jump
)
2998 rtx beyond_jump
= get_last_insn ();
2999 rtx new_before_jump
;
3001 expand_cleanups (list
, 0);
3002 /* Pop any pushes done in the cleanups,
3003 in case function is about to return. */
3004 do_pending_stack_adjust ();
3006 new_before_jump
= get_last_insn ();
3008 if (beyond_jump
!= new_before_jump
)
3010 /* If cleanups expand to nothing, don't reorder. */
3011 reorder_insns (NEXT_INSN (beyond_jump
), new_before_jump
, *before_jump
);
3012 *before_jump
= new_before_jump
;
3016 /* Move all cleanups from the current block_stack
3017 to the containing block_stack, where they are assumed to
3018 have been created. If anything can cause a temporary to
3019 be created, but not expanded for more than one level of
3020 block_stacks, then this code will have to change. */
3025 struct nesting
*block
= block_stack
;
3026 struct nesting
*outer
= block
->next
;
3028 outer
->data
.block
.cleanups
3029 = chainon (block
->data
.block
.cleanups
,
3030 outer
->data
.block
.cleanups
);
3031 block
->data
.block
.cleanups
= 0;
3035 last_cleanup_this_contour ()
3037 if (block_stack
== 0)
3040 return block_stack
->data
.block
.cleanups
;
3043 /* Return 1 if there are any pending cleanups at this point.
3044 If THIS_CONTOUR is nonzero, check the current contour as well.
3045 Otherwise, look only at the contours that enclose this one. */
3048 any_pending_cleanups (this_contour
)
3051 struct nesting
*block
;
3053 if (block_stack
== 0)
3056 if (this_contour
&& block_stack
->data
.block
.cleanups
!= NULL
)
3058 if (block_stack
->data
.block
.cleanups
== 0
3059 && (block_stack
->data
.block
.outer_cleanups
== 0
3061 || block_stack
->data
.block
.outer_cleanups
== empty_cleanup_list
3066 for (block
= block_stack
->next
; block
; block
= block
->next
)
3067 if (block
->data
.block
.cleanups
!= 0)
3073 /* Enter a case (Pascal) or switch (C) statement.
3074 Push a block onto case_stack and nesting_stack
3075 to accumulate the case-labels that are seen
3076 and to record the labels generated for the statement.
3078 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
3079 Otherwise, this construct is transparent for `exit_something'.
3081 EXPR is the index-expression to be dispatched on.
3082 TYPE is its nominal type. We could simply convert EXPR to this type,
3083 but instead we take short cuts. */
3086 expand_start_case (exit_flag
, expr
, type
, printname
)
3092 register struct nesting
*thiscase
= ALLOC_NESTING ();
3094 /* Make an entry on case_stack for the case we are entering. */
3096 thiscase
->next
= case_stack
;
3097 thiscase
->all
= nesting_stack
;
3098 thiscase
->depth
= ++nesting_depth
;
3099 thiscase
->exit_label
= exit_flag
? gen_label_rtx () : 0;
3100 thiscase
->data
.case_stmt
.case_list
= 0;
3101 thiscase
->data
.case_stmt
.index_expr
= expr
;
3102 thiscase
->data
.case_stmt
.nominal_type
= type
;
3103 thiscase
->data
.case_stmt
.default_label
= 0;
3104 thiscase
->data
.case_stmt
.num_ranges
= 0;
3105 thiscase
->data
.case_stmt
.printname
= printname
;
3106 thiscase
->data
.case_stmt
.seenlabel
= 0;
3107 case_stack
= thiscase
;
3108 nesting_stack
= thiscase
;
3110 do_pending_stack_adjust ();
3112 /* Make sure case_stmt.start points to something that won't
3113 need any transformation before expand_end_case. */
3114 if (GET_CODE (get_last_insn ()) != NOTE
)
3115 emit_note (0, NOTE_INSN_DELETED
);
3117 thiscase
->data
.case_stmt
.start
= get_last_insn ();
3120 /* Start a "dummy case statement" within which case labels are invalid
3121 and are not connected to any larger real case statement.
3122 This can be used if you don't want to let a case statement jump
3123 into the middle of certain kinds of constructs. */
3126 expand_start_case_dummy ()
3128 register struct nesting
*thiscase
= ALLOC_NESTING ();
3130 /* Make an entry on case_stack for the dummy. */
3132 thiscase
->next
= case_stack
;
3133 thiscase
->all
= nesting_stack
;
3134 thiscase
->depth
= ++nesting_depth
;
3135 thiscase
->exit_label
= 0;
3136 thiscase
->data
.case_stmt
.case_list
= 0;
3137 thiscase
->data
.case_stmt
.start
= 0;
3138 thiscase
->data
.case_stmt
.nominal_type
= 0;
3139 thiscase
->data
.case_stmt
.default_label
= 0;
3140 thiscase
->data
.case_stmt
.num_ranges
= 0;
3141 case_stack
= thiscase
;
3142 nesting_stack
= thiscase
;
3145 /* End a dummy case statement. */
3148 expand_end_case_dummy ()
3150 POPSTACK (case_stack
);
3153 /* Return the data type of the index-expression
3154 of the innermost case statement, or null if none. */
3157 case_index_expr_type ()
3160 return TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
3164 /* Accumulate one case or default label inside a case or switch statement.
3165 VALUE is the value of the case (a null pointer, for a default label).
3167 If not currently inside a case or switch statement, return 1 and do
3168 nothing. The caller will print a language-specific error message.
3169 If VALUE is a duplicate or overlaps, return 2 and do nothing
3170 except store the (first) duplicate node in *DUPLICATE.
3171 If VALUE is out of range, return 3 and do nothing.
3172 If we are jumping into the scope of a cleaup or var-sized array, return 5.
3173 Return 0 on success.
3175 Extended to handle range statements. */
3178 pushcase (value
, label
, duplicate
)
3179 register tree value
;
3180 register tree label
;
3183 register struct case_node
**l
;
3184 register struct case_node
*n
;
3188 /* Fail if not inside a real case statement. */
3189 if (! (case_stack
&& case_stack
->data
.case_stmt
.start
))
3192 if (stack_block_stack
3193 && stack_block_stack
->depth
> case_stack
->depth
)
3196 index_type
= TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
3197 nominal_type
= case_stack
->data
.case_stmt
.nominal_type
;
3199 /* If the index is erroneous, avoid more problems: pretend to succeed. */
3200 if (index_type
== error_mark_node
)
3203 /* Convert VALUE to the type in which the comparisons are nominally done. */
3205 value
= convert (nominal_type
, value
);
3207 /* If this is the first label, warn if any insns have been emitted. */
3208 if (case_stack
->data
.case_stmt
.seenlabel
== 0)
3211 for (insn
= case_stack
->data
.case_stmt
.start
;
3213 insn
= NEXT_INSN (insn
))
3215 if (GET_CODE (insn
) == CODE_LABEL
)
3217 if (GET_CODE (insn
) != NOTE
3218 && (GET_CODE (insn
) != INSN
|| GET_CODE (PATTERN (insn
)) != USE
))
3220 warning ("unreachable code at beginning of %s",
3221 case_stack
->data
.case_stmt
.printname
);
3226 case_stack
->data
.case_stmt
.seenlabel
= 1;
3228 /* Fail if this value is out of range for the actual type of the index
3229 (which may be narrower than NOMINAL_TYPE). */
3230 if (value
!= 0 && ! int_fits_type_p (value
, index_type
))
3233 /* Fail if this is a duplicate or overlaps another entry. */
3236 if (case_stack
->data
.case_stmt
.default_label
!= 0)
3238 *duplicate
= case_stack
->data
.case_stmt
.default_label
;
3241 case_stack
->data
.case_stmt
.default_label
= label
;
3245 /* Find the elt in the chain before which to insert the new value,
3246 to keep the chain sorted in increasing order.
3247 But report an error if this element is a duplicate. */
3248 for (l
= &case_stack
->data
.case_stmt
.case_list
;
3249 /* Keep going past elements distinctly less than VALUE. */
3250 *l
!= 0 && tree_int_cst_lt ((*l
)->high
, value
);
3255 /* Element we will insert before must be distinctly greater;
3256 overlap means error. */
3257 if (! tree_int_cst_lt (value
, (*l
)->low
))
3259 *duplicate
= (*l
)->code_label
;
3264 /* Add this label to the chain, and succeed.
3265 Copy VALUE so it is on temporary rather than momentary
3266 obstack and will thus survive till the end of the case statement. */
3267 n
= (struct case_node
*) oballoc (sizeof (struct case_node
));
3270 n
->high
= n
->low
= copy_node (value
);
3271 n
->code_label
= label
;
3275 expand_label (label
);
3279 /* Like pushcase but this case applies to all values
3280 between VALUE1 and VALUE2 (inclusive).
3281 The return value is the same as that of pushcase
3282 but there is one additional error code:
3283 4 means the specified range was empty. */
3286 pushcase_range (value1
, value2
, label
, duplicate
)
3287 register tree value1
, value2
;
3288 register tree label
;
3291 register struct case_node
**l
;
3292 register struct case_node
*n
;
3296 /* Fail if not inside a real case statement. */
3297 if (! (case_stack
&& case_stack
->data
.case_stmt
.start
))
3300 if (stack_block_stack
3301 && stack_block_stack
->depth
> case_stack
->depth
)
3304 index_type
= TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
3305 nominal_type
= case_stack
->data
.case_stmt
.nominal_type
;
3307 /* If the index is erroneous, avoid more problems: pretend to succeed. */
3308 if (index_type
== error_mark_node
)
3311 /* If this is the first label, warn if any insns have been emitted. */
3312 if (case_stack
->data
.case_stmt
.seenlabel
== 0)
3315 for (insn
= case_stack
->data
.case_stmt
.start
;
3317 insn
= NEXT_INSN (insn
))
3319 if (GET_CODE (insn
) == CODE_LABEL
)
3321 if (GET_CODE (insn
) != NOTE
3322 && (GET_CODE (insn
) != INSN
|| GET_CODE (PATTERN (insn
)) != USE
))
3324 warning ("unreachable code at beginning of %s",
3325 case_stack
->data
.case_stmt
.printname
);
3330 case_stack
->data
.case_stmt
.seenlabel
= 1;
3332 /* Convert VALUEs to type in which the comparisons are nominally done. */
3333 if (value1
== 0) /* Negative infinity. */
3334 value1
= TYPE_MIN_VALUE(index_type
);
3335 value1
= convert (nominal_type
, value1
);
3337 if (value2
== 0) /* Positive infinity. */
3338 value2
= TYPE_MAX_VALUE(index_type
);
3339 value2
= convert (nominal_type
, value2
);
3341 /* Fail if these values are out of range. */
3342 if (! int_fits_type_p (value1
, index_type
))
3345 if (! int_fits_type_p (value2
, index_type
))
3348 /* Fail if the range is empty. */
3349 if (tree_int_cst_lt (value2
, value1
))
3352 /* If the bounds are equal, turn this into the one-value case. */
3353 if (tree_int_cst_equal (value1
, value2
))
3354 return pushcase (value1
, label
, duplicate
);
3356 /* Find the elt in the chain before which to insert the new value,
3357 to keep the chain sorted in increasing order.
3358 But report an error if this element is a duplicate. */
3359 for (l
= &case_stack
->data
.case_stmt
.case_list
;
3360 /* Keep going past elements distinctly less than this range. */
3361 *l
!= 0 && tree_int_cst_lt ((*l
)->high
, value1
);
3366 /* Element we will insert before must be distinctly greater;
3367 overlap means error. */
3368 if (! tree_int_cst_lt (value2
, (*l
)->low
))
3370 *duplicate
= (*l
)->code_label
;
3375 /* Add this label to the chain, and succeed.
3376 Copy VALUE1, VALUE2 so they are on temporary rather than momentary
3377 obstack and will thus survive till the end of the case statement. */
3379 n
= (struct case_node
*) oballoc (sizeof (struct case_node
));
3382 n
->low
= copy_node (value1
);
3383 n
->high
= copy_node (value2
);
3384 n
->code_label
= label
;
3387 expand_label (label
);
3389 case_stack
->data
.case_stmt
.num_ranges
++;
3394 /* Called when the index of a switch statement is an enumerated type
3395 and there is no default label.
3397 Checks that all enumeration literals are covered by the case
3398 expressions of a switch. Also, warn if there are any extra
3399 switch cases that are *not* elements of the enumerated type.
3401 If all enumeration literals were covered by the case expressions,
3402 turn one of the expressions into the default expression since it should
3403 not be possible to fall through such a switch. */
3406 check_for_full_enumeration_handling (type
)
3409 register struct case_node
*n
;
3410 register struct case_node
**l
;
3411 register tree chain
;
3414 /* The time complexity of this loop is currently O(N * M), with
3415 N being the number of enumerals in the enumerated type, and
3416 M being the number of case expressions in the switch. */
3418 for (chain
= TYPE_VALUES (type
);
3420 chain
= TREE_CHAIN (chain
))
3422 /* Find a match between enumeral and case expression, if possible.
3423 Quit looking when we've gone too far (since case expressions
3424 are kept sorted in ascending order). Warn about enumerals not
3425 handled in the switch statement case expression list. */
3427 for (n
= case_stack
->data
.case_stmt
.case_list
;
3428 n
&& tree_int_cst_lt (n
->high
, TREE_VALUE (chain
));
3432 if (!(n
&& tree_int_cst_equal (n
->low
, TREE_VALUE (chain
))))
3435 warning ("enumerated value `%s' not handled in switch",
3436 IDENTIFIER_POINTER (TREE_PURPOSE (chain
)));
3441 /* Now we go the other way around; we warn if there are case
3442 expressions that don't correspond to enumerals. This can
3443 occur since C and C++ don't enforce type-checking of
3444 assignments to enumeration variables. */
3447 for (n
= case_stack
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
3449 for (chain
= TYPE_VALUES (type
);
3450 chain
&& !tree_int_cst_equal (n
->low
, TREE_VALUE (chain
));
3451 chain
= TREE_CHAIN (chain
))
3455 warning ("case value `%d' not in enumerated type `%s'",
3456 TREE_INT_CST_LOW (n
->low
),
3457 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type
))
3460 : DECL_NAME (TYPE_NAME (type
))));
3463 /* If all values were found as case labels, make one of them the default
3464 label. Thus, this switch will never fall through. We arbitrarily pick
3465 the last one to make the default since this is likely the most
3466 efficient choice. */
3470 for (l
= &case_stack
->data
.case_stmt
.case_list
;
3475 case_stack
->data
.case_stmt
.default_label
= (*l
)->code_label
;
3480 /* Terminate a case (Pascal) or switch (C) statement
3481 in which CASE_INDEX is the expression to be tested.
3482 Generate the code to test it and jump to the right place. */
3485 expand_end_case (orig_index
)
3488 tree minval
, maxval
, range
;
3489 rtx default_label
= 0;
3490 register struct case_node
*n
;
3493 rtx table_label
= gen_label_rtx ();
3498 register struct nesting
*thiscase
= case_stack
;
3499 tree index_expr
= thiscase
->data
.case_stmt
.index_expr
;
3500 int unsignedp
= TREE_UNSIGNED (TREE_TYPE (index_expr
));
3502 do_pending_stack_adjust ();
3504 /* An ERROR_MARK occurs for various reasons including invalid data type. */
3505 if (TREE_TYPE (index_expr
) != error_mark_node
)
3507 /* If switch expression was an enumerated type, check that all
3508 enumeration literals are covered by the cases.
3509 No sense trying this if there's a default case, however. */
3511 if (!thiscase
->data
.case_stmt
.default_label
3512 && TREE_CODE (TREE_TYPE (orig_index
)) == ENUMERAL_TYPE
3513 && TREE_CODE (index_expr
) != INTEGER_CST
)
3514 check_for_full_enumeration_handling (TREE_TYPE (orig_index
));
3516 /* If this is the first label, warn if any insns have been emitted. */
3517 if (thiscase
->data
.case_stmt
.seenlabel
== 0)
3520 for (insn
= get_last_insn ();
3521 insn
!= case_stack
->data
.case_stmt
.start
;
3522 insn
= PREV_INSN (insn
))
3523 if (GET_CODE (insn
) != NOTE
3524 && (GET_CODE (insn
) != INSN
|| GET_CODE (PATTERN (insn
))!= USE
))
3526 warning ("unreachable code at beginning of %s",
3527 case_stack
->data
.case_stmt
.printname
);
3532 /* If we don't have a default-label, create one here,
3533 after the body of the switch. */
3534 if (thiscase
->data
.case_stmt
.default_label
== 0)
3536 thiscase
->data
.case_stmt
.default_label
3537 = build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
3538 expand_label (thiscase
->data
.case_stmt
.default_label
);
3540 default_label
= label_rtx (thiscase
->data
.case_stmt
.default_label
);
3542 before_case
= get_last_insn ();
3544 /* Simplify the case-list before we count it. */
3545 group_case_nodes (thiscase
->data
.case_stmt
.case_list
);
3547 /* Get upper and lower bounds of case values.
3548 Also convert all the case values to the index expr's data type. */
3551 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
3553 /* Check low and high label values are integers. */
3554 if (TREE_CODE (n
->low
) != INTEGER_CST
)
3556 if (TREE_CODE (n
->high
) != INTEGER_CST
)
3559 n
->low
= convert (TREE_TYPE (index_expr
), n
->low
);
3560 n
->high
= convert (TREE_TYPE (index_expr
), n
->high
);
3562 /* Count the elements and track the largest and smallest
3563 of them (treating them as signed even if they are not). */
3571 if (INT_CST_LT (n
->low
, minval
))
3573 if (INT_CST_LT (maxval
, n
->high
))
3576 /* A range counts double, since it requires two compares. */
3577 if (! tree_int_cst_equal (n
->low
, n
->high
))
3581 /* Compute span of values. */
3583 range
= fold (build (MINUS_EXPR
, TREE_TYPE (index_expr
),
3586 if (count
== 0 || TREE_CODE (TREE_TYPE (index_expr
)) == ERROR_MARK
)
3588 expand_expr (index_expr
, const0_rtx
, VOIDmode
, 0);
3590 emit_jump (default_label
);
3592 /* If range of values is much bigger than number of values,
3593 make a sequence of conditional branches instead of a dispatch.
3594 If the switch-index is a constant, do it this way
3595 because we can optimize it. */
3596 else if (TREE_INT_CST_HIGH (range
) != 0
3598 || (HAVE_casesi
? count
< 4 : count
< 5)
3600 /* If machine does not have a case insn that compares the
3601 bounds, this means extra overhead for dispatch tables
3602 which raises the threshold for using them. */
3605 || (unsigned) (TREE_INT_CST_LOW (range
)) > 10 * count
3606 || TREE_CODE (index_expr
) == INTEGER_CST
3607 /* These will reduce to a constant. */
3608 || (TREE_CODE (index_expr
) == CALL_EXPR
3609 && TREE_CODE (TREE_OPERAND (index_expr
, 0)) == ADDR_EXPR
3610 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr
, 0), 0)) == FUNCTION_DECL
3611 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr
, 0), 0)) == BUILT_IN_CLASSIFY_TYPE
)
3612 || (TREE_CODE (index_expr
) == COMPOUND_EXPR
3613 && TREE_CODE (TREE_OPERAND (index_expr
, 1)) == INTEGER_CST
))
3615 index
= expand_expr (index_expr
, 0, VOIDmode
, 0);
3617 /* If the index is a short or char that we do not have
3618 an insn to handle comparisons directly, convert it to
3619 a full integer now, rather than letting each comparison
3620 generate the conversion. */
3622 if (GET_MODE_CLASS (GET_MODE (index
)) == MODE_INT
3623 && (cmp_optab
->handlers
[(int) GET_MODE(index
)].insn_code
3624 == CODE_FOR_nothing
))
3626 enum machine_mode wider_mode
;
3627 for (wider_mode
= GET_MODE (index
); wider_mode
!= VOIDmode
;
3628 wider_mode
= GET_MODE_WIDER_MODE (wider_mode
))
3629 if (cmp_optab
->handlers
[(int) wider_mode
].insn_code
3630 != CODE_FOR_nothing
)
3632 index
= convert_to_mode (wider_mode
, index
, unsignedp
);
3638 do_pending_stack_adjust ();
3640 index
= protect_from_queue (index
, 0);
3641 if (GET_CODE (index
) == MEM
)
3642 index
= copy_to_reg (index
);
3643 if (GET_CODE (index
) == CONST_INT
3644 || TREE_CODE (index_expr
) == INTEGER_CST
)
3646 /* Make a tree node with the proper constant value
3647 if we don't already have one. */
3648 if (TREE_CODE (index_expr
) != INTEGER_CST
)
3651 = build_int_2 (INTVAL (index
),
3652 !unsignedp
&& INTVAL (index
) >= 0 ? 0 : -1);
3653 index_expr
= convert (TREE_TYPE (index_expr
), index_expr
);
3656 /* For constant index expressions we need only
3657 issue a unconditional branch to the appropriate
3658 target code. The job of removing any unreachable
3659 code is left to the optimisation phase if the
3660 "-O" option is specified. */
3661 for (n
= thiscase
->data
.case_stmt
.case_list
;
3665 if (! tree_int_cst_lt (index_expr
, n
->low
)
3666 && ! tree_int_cst_lt (n
->high
, index_expr
))
3670 emit_jump (label_rtx (n
->code_label
));
3672 emit_jump (default_label
);
3676 /* If the index expression is not constant we generate
3677 a binary decision tree to select the appropriate
3678 target code. This is done as follows:
3680 The list of cases is rearranged into a binary tree,
3681 nearly optimal assuming equal probability for each case.
3683 The tree is transformed into RTL, eliminating
3684 redundant test conditions at the same time.
3686 If program flow could reach the end of the
3687 decision tree an unconditional jump to the
3688 default code is emitted. */
3691 = (TREE_CODE (TREE_TYPE (orig_index
)) != ENUMERAL_TYPE
3692 && estimate_case_costs (thiscase
->data
.case_stmt
.case_list
));
3693 balance_case_nodes (&thiscase
->data
.case_stmt
.case_list
, 0);
3694 emit_case_nodes (index
, thiscase
->data
.case_stmt
.case_list
,
3695 default_label
, TREE_TYPE (index_expr
));
3696 emit_jump_if_reachable (default_label
);
3705 enum machine_mode index_mode
= SImode
;
3706 int index_bits
= GET_MODE_BITSIZE (index_mode
);
3708 /* Convert the index to SImode. */
3709 if (GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (index_expr
)))
3710 > GET_MODE_BITSIZE (index_mode
))
3712 enum machine_mode omode
= TYPE_MODE (TREE_TYPE (index_expr
));
3713 rtx rangertx
= expand_expr (range
, 0, VOIDmode
, 0);
3715 /* We must handle the endpoints in the original mode. */
3716 index_expr
= build (MINUS_EXPR
, TREE_TYPE (index_expr
),
3717 index_expr
, minval
);
3718 minval
= integer_zero_node
;
3719 index
= expand_expr (index_expr
, 0, VOIDmode
, 0);
3720 emit_cmp_insn (rangertx
, index
, LTU
, 0, omode
, 0, 0);
3721 emit_jump_insn (gen_bltu (default_label
));
3722 /* Now we can safely truncate. */
3723 index
= convert_to_mode (index_mode
, index
, 0);
3727 if (TYPE_MODE (TREE_TYPE (index_expr
)) != index_mode
)
3728 index_expr
= convert (type_for_size (index_bits
, 0),
3730 index
= expand_expr (index_expr
, 0, VOIDmode
, 0);
3733 index
= protect_from_queue (index
, 0);
3734 do_pending_stack_adjust ();
3736 emit_jump_insn (gen_casesi (index
, expand_expr (minval
, 0, VOIDmode
, 0),
3737 expand_expr (range
, 0, VOIDmode
, 0),
3738 table_label
, default_label
));
3742 #ifdef HAVE_tablejump
3743 if (! win
&& HAVE_tablejump
)
3745 index_expr
= convert (thiscase
->data
.case_stmt
.nominal_type
,
3746 fold (build (MINUS_EXPR
,
3747 TREE_TYPE (index_expr
),
3748 index_expr
, minval
)));
3749 index
= expand_expr (index_expr
, 0, VOIDmode
, 0);
3751 index
= protect_from_queue (index
, 0);
3752 do_pending_stack_adjust ();
3754 do_tablejump (index
, TYPE_MODE (TREE_TYPE (index_expr
)),
3755 expand_expr (range
, 0, VOIDmode
, 0),
3756 table_label
, default_label
);
3763 /* Get table of labels to jump to, in order of case index. */
3765 ncases
= TREE_INT_CST_LOW (range
) + 1;
3766 labelvec
= (rtx
*) alloca (ncases
* sizeof (rtx
));
3767 bzero (labelvec
, ncases
* sizeof (rtx
));
3769 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
3772 = TREE_INT_CST_LOW (n
->low
) - TREE_INT_CST_LOW (minval
);
3777 = gen_rtx (LABEL_REF
, Pmode
, label_rtx (n
->code_label
));
3778 if (i
+ TREE_INT_CST_LOW (minval
)
3779 == TREE_INT_CST_LOW (n
->high
))
3785 /* Fill in the gaps with the default. */
3786 for (i
= 0; i
< ncases
; i
++)
3787 if (labelvec
[i
] == 0)
3788 labelvec
[i
] = gen_rtx (LABEL_REF
, Pmode
, default_label
);
3790 /* Output the table */
3791 emit_label (table_label
);
3793 /* This would be a lot nicer if CASE_VECTOR_PC_RELATIVE
3794 were an expression, instead of a an #ifdef/#ifndef. */
3796 #ifdef CASE_VECTOR_PC_RELATIVE
3800 emit_jump_insn (gen_rtx (ADDR_DIFF_VEC
, CASE_VECTOR_MODE
,
3801 gen_rtx (LABEL_REF
, Pmode
, table_label
),
3802 gen_rtvec_v (ncases
, labelvec
)));
3804 emit_jump_insn (gen_rtx (ADDR_VEC
, CASE_VECTOR_MODE
,
3805 gen_rtvec_v (ncases
, labelvec
)));
3807 /* If the case insn drops through the table,
3808 after the table we must jump to the default-label.
3809 Otherwise record no drop-through after the table. */
3810 #ifdef CASE_DROPS_THROUGH
3811 emit_jump (default_label
);
3817 before_case
= squeeze_notes (NEXT_INSN (before_case
), get_last_insn ());
3818 reorder_insns (before_case
, get_last_insn (),
3819 thiscase
->data
.case_stmt
.start
);
3821 if (thiscase
->exit_label
)
3822 emit_label (thiscase
->exit_label
);
3824 POPSTACK (case_stack
);
3829 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
3832 do_jump_if_equal (op1
, op2
, label
, unsignedp
)
3833 rtx op1
, op2
, label
;
3836 if (GET_CODE (op1
) == CONST_INT
3837 && GET_CODE (op2
) == CONST_INT
)
3839 if (INTVAL (op1
) == INTVAL (op2
))
3844 enum machine_mode mode
= GET_MODE (op1
);
3845 if (mode
== VOIDmode
)
3846 mode
= GET_MODE (op2
);
3847 emit_cmp_insn (op1
, op2
, EQ
, 0, mode
, unsignedp
, 0);
3848 emit_jump_insn (gen_beq (label
));
3852 /* Not all case values are encountered equally. This function
3853 uses a heuristic to weight case labels, in cases where that
3854 looks like a reasonable thing to do.
3856 Right now, all we try to guess is text, and we establish the
3859 chars above space: 16
3868 If we find any cases in the switch that are not either -1 or in the range
3869 of valid ASCII characters, or are control characters other than those
3870 commonly used with "\", don't treat this switch scanning text.
3872 Return 1 if these nodes are suitable for cost estimation, otherwise
3876 estimate_case_costs (node
)
3879 tree min_ascii
= build_int_2 (-1, -1);
3880 tree max_ascii
= convert (TREE_TYPE (node
->high
), build_int_2 (127, 0));
3884 /* If we haven't already made the cost table, make it now. Note that the
3885 lower bound of the table is -1, not zero. */
3887 if (cost_table
== NULL
)
3889 cost_table
= ((short *) xmalloc (129 * sizeof (short))) + 1;
3890 bzero (cost_table
- 1, 129 * sizeof (short));
3892 for (i
= 0; i
< 128; i
++)
3896 else if (ispunct (i
))
3898 else if (iscntrl (i
))
3902 cost_table
[' '] = 8;
3903 cost_table
['\t'] = 4;
3904 cost_table
['\0'] = 4;
3905 cost_table
['\n'] = 2;
3906 cost_table
['\f'] = 1;
3907 cost_table
['\v'] = 1;
3908 cost_table
['\b'] = 1;
3911 /* See if all the case expressions look like text. It is text if the
3912 constant is >= -1 and the highest constant is <= 127. Do all comparisons
3913 as signed arithmetic since we don't want to ever access cost_table with a
3914 value less than -1. Also check that none of the constants in a range
3915 are strange control characters. */
3917 for (n
= node
; n
; n
= n
->right
)
3919 if ((INT_CST_LT (n
->low
, min_ascii
)) || INT_CST_LT (max_ascii
, n
->high
))
3922 for (i
= TREE_INT_CST_LOW (n
->low
); i
<= TREE_INT_CST_LOW (n
->high
); i
++)
3923 if (cost_table
[i
] < 0)
3927 /* All interesting values are within the range of interesting
3928 ASCII characters. */
3932 /* Scan an ordered list of case nodes
3933 combining those with consecutive values or ranges.
3935 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
3938 group_case_nodes (head
)
3941 case_node_ptr node
= head
;
3945 rtx lb
= next_real_insn (label_rtx (node
->code_label
));
3946 case_node_ptr np
= node
;
3948 /* Try to group the successors of NODE with NODE. */
3949 while (((np
= np
->right
) != 0)
3950 /* Do they jump to the same place? */
3951 && next_real_insn (label_rtx (np
->code_label
)) == lb
3952 /* Are their ranges consecutive? */
3953 && tree_int_cst_equal (np
->low
,
3954 fold (build (PLUS_EXPR
,
3955 TREE_TYPE (node
->high
),
3958 /* An overflow is not consecutive. */
3959 && tree_int_cst_lt (node
->high
,
3960 fold (build (PLUS_EXPR
,
3961 TREE_TYPE (node
->high
),
3963 integer_one_node
))))
3965 node
->high
= np
->high
;
3967 /* NP is the first node after NODE which can't be grouped with it.
3968 Delete the nodes in between, and move on to that node. */
3974 /* Take an ordered list of case nodes
3975 and transform them into a near optimal binary tree,
3976 on the assumption that any target code selection value is as
3977 likely as any other.
3979 The transformation is performed by splitting the ordered
3980 list into two equal sections plus a pivot. The parts are
3981 then attached to the pivot as left and right branches. Each
3982 branch is is then transformed recursively. */
3985 balance_case_nodes (head
, parent
)
3986 case_node_ptr
*head
;
3987 case_node_ptr parent
;
3989 register case_node_ptr np
;
3997 register case_node_ptr
*npp
;
4000 /* Count the number of entries on branch. Also count the ranges. */
4004 if (!tree_int_cst_equal (np
->low
, np
->high
))
4008 cost
+= cost_table
[TREE_INT_CST_LOW (np
->high
)];
4012 cost
+= cost_table
[TREE_INT_CST_LOW (np
->low
)];
4020 /* Split this list if it is long enough for that to help. */
4025 /* Find the place in the list that bisects the list's total cost,
4026 Here I gets half the total cost. */
4031 /* Skip nodes while their cost does not reach that amount. */
4032 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
4033 i
-= cost_table
[TREE_INT_CST_LOW ((*npp
)->high
)];
4034 i
-= cost_table
[TREE_INT_CST_LOW ((*npp
)->low
)];
4037 npp
= &(*npp
)->right
;
4042 /* Leave this branch lopsided, but optimize left-hand
4043 side and fill in `parent' fields for right-hand side. */
4045 np
->parent
= parent
;
4046 balance_case_nodes (&np
->left
, np
);
4047 for (; np
->right
; np
= np
->right
)
4048 np
->right
->parent
= np
;
4052 /* If there are just three nodes, split at the middle one. */
4054 npp
= &(*npp
)->right
;
4057 /* Find the place in the list that bisects the list's total cost,
4058 where ranges count as 2.
4059 Here I gets half the total cost. */
4060 i
= (i
+ ranges
+ 1) / 2;
4063 /* Skip nodes while their cost does not reach that amount. */
4064 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
4069 npp
= &(*npp
)->right
;
4074 np
->parent
= parent
;
4077 /* Optimize each of the two split parts. */
4078 balance_case_nodes (&np
->left
, np
);
4079 balance_case_nodes (&np
->right
, np
);
4083 /* Else leave this branch as one level,
4084 but fill in `parent' fields. */
4086 np
->parent
= parent
;
4087 for (; np
->right
; np
= np
->right
)
4088 np
->right
->parent
= np
;
4093 /* Search the parent sections of the case node tree
4094 to see if a test for the lower bound of NODE would be redundant.
4095 INDEX_TYPE is the type of the index expression.
4097 The instructions to generate the case decision tree are
4098 output in the same order as nodes are processed so it is
4099 known that if a parent node checks the range of the current
4100 node minus one that the current node is bounded at its lower
4101 span. Thus the test would be redundant. */
4104 node_has_low_bound (node
, index_type
)
4109 case_node_ptr pnode
;
4111 /* If the lower bound of this node is the lowest value in the index type,
4112 we need not test it. */
4114 if (tree_int_cst_equal (node
->low
, TYPE_MIN_VALUE (index_type
)))
4117 /* If this node has a left branch, the value at the left must be less
4118 than that at this node, so it cannot be bounded at the bottom and
4119 we need not bother testing any further. */
4124 low_minus_one
= fold (build (MINUS_EXPR
, TREE_TYPE (node
->low
),
4125 node
->low
, integer_one_node
));
4127 /* If the subtraction above overflowed, we can't verify anything.
4128 Otherwise, look for a parent that tests our value - 1. */
4130 if (! tree_int_cst_lt (low_minus_one
, node
->low
))
4133 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
4134 if (tree_int_cst_equal (low_minus_one
, pnode
->high
))
4140 /* Search the parent sections of the case node tree
4141 to see if a test for the upper bound of NODE would be redundant.
4142 INDEX_TYPE is the type of the index expression.
4144 The instructions to generate the case decision tree are
4145 output in the same order as nodes are processed so it is
4146 known that if a parent node checks the range of the current
4147 node plus one that the current node is bounded at its upper
4148 span. Thus the test would be redundant. */
4151 node_has_high_bound (node
, index_type
)
4156 case_node_ptr pnode
;
4158 /* If the upper bound of this node is the highest value in the type
4159 of the index expression, we need not test against it. */
4161 if (tree_int_cst_equal (node
->high
, TYPE_MAX_VALUE (index_type
)))
4164 /* If this node has a right branch, the value at the right must be greater
4165 than that at this node, so it cannot be bounded at the top and
4166 we need not bother testing any further. */
4171 high_plus_one
= fold (build (PLUS_EXPR
, TREE_TYPE (node
->high
),
4172 node
->high
, integer_one_node
));
4174 /* If the addition above overflowed, we can't verify anything.
4175 Otherwise, look for a parent that tests our value + 1. */
4177 if (! tree_int_cst_lt (node
->high
, high_plus_one
))
4180 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
4181 if (tree_int_cst_equal (high_plus_one
, pnode
->low
))
4187 /* Search the parent sections of the
4188 case node tree to see if both tests for the upper and lower
4189 bounds of NODE would be redundant. */
4192 node_is_bounded (node
, index_type
)
4196 return (node_has_low_bound (node
, index_type
)
4197 && node_has_high_bound (node
, index_type
));
4200 /* Emit an unconditional jump to LABEL unless it would be dead code. */
4203 emit_jump_if_reachable (label
)
4206 if (GET_CODE (get_last_insn ()) != BARRIER
)
4210 /* Emit step-by-step code to select a case for the value of INDEX.
4211 The thus generated decision tree follows the form of the
4212 case-node binary tree NODE, whose nodes represent test conditions.
4213 INDEX_TYPE is the type of the index of the switch.
4215 Care is taken to prune redundant tests from the decision tree
4216 by detecting any boundary conditions already checked by
4217 emitted rtx. (See node_has_high_bound, node_has_low_bound
4218 and node_is_bounded, above.)
4220 Where the test conditions can be shown to be redundant we emit
4221 an unconditional jump to the target code. As a further
4222 optimization, the subordinates of a tree node are examined to
4223 check for bounded nodes. In this case conditional and/or
4224 unconditional jumps as a result of the boundary check for the
4225 current node are arranged to target the subordinates associated
4226 code for out of bound conditions on the current node node.
4228 We can asume that when control reaches the code generated here,
4229 the index value has already been compared with the parents
4230 of this node, and determined to be on the same side of each parent
4231 as this node is. Thus, if this node tests for the value 51,
4232 and a parent tested for 52, we don't need to consider
4233 the possibility of a value greater than 51. If another parent
4234 tests for the value 50, then this node need not test anything. */
4237 emit_case_nodes (index
, node
, default_label
, index_type
)
4243 /* If INDEX has an unsigned type, we must make unsigned branches. */
4244 int unsignedp
= TREE_UNSIGNED (index_type
);
4245 typedef rtx
rtx_function ();
4246 rtx_function
*gen_bgt_pat
= unsignedp
? gen_bgtu
: gen_bgt
;
4247 rtx_function
*gen_bge_pat
= unsignedp
? gen_bgeu
: gen_bge
;
4248 rtx_function
*gen_blt_pat
= unsignedp
? gen_bltu
: gen_blt
;
4249 rtx_function
*gen_ble_pat
= unsignedp
? gen_bleu
: gen_ble
;
4250 enum machine_mode mode
= GET_MODE (index
);
4252 /* See if our parents have already tested everything for us.
4253 If they have, emit an unconditional jump for this node. */
4254 if (node_is_bounded (node
, index_type
))
4255 emit_jump (label_rtx (node
->code_label
));
4257 else if (tree_int_cst_equal (node
->low
, node
->high
))
4259 /* Node is single valued. First see if the index expression matches
4260 this node and then check our children, if any. */
4262 do_jump_if_equal (index
, expand_expr (node
->low
, 0, VOIDmode
, 0),
4263 label_rtx (node
->code_label
), unsignedp
);
4265 if (node
->right
!= 0 && node
->left
!= 0)
4267 /* This node has children on both sides.
4268 Dispatch to one side or the other
4269 by comparing the index value with this node's value.
4270 If one subtree is bounded, check that one first,
4271 so we can avoid real branches in the tree. */
4273 if (node_is_bounded (node
->right
, index_type
))
4275 emit_cmp_insn (index
, expand_expr (node
->high
, 0, VOIDmode
, 0),
4276 GT
, 0, mode
, unsignedp
, 0);
4278 emit_jump_insn ((*gen_bgt_pat
) (label_rtx (node
->right
->code_label
)));
4279 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
4282 else if (node_is_bounded (node
->left
, index_type
))
4284 emit_cmp_insn (index
, expand_expr (node
->high
, 0,
4286 LT
, 0, mode
, unsignedp
, 0);
4287 emit_jump_insn ((*gen_blt_pat
) (label_rtx (node
->left
->code_label
)));
4288 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
4293 /* Neither node is bounded. First distinguish the two sides;
4294 then emit the code for one side at a time. */
4297 = build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
4299 /* See if the value is on the right. */
4300 emit_cmp_insn (index
, expand_expr (node
->high
, 0,
4302 GT
, 0, mode
, unsignedp
, 0);
4303 emit_jump_insn ((*gen_bgt_pat
) (label_rtx (test_label
)));
4305 /* Value must be on the left.
4306 Handle the left-hand subtree. */
4307 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
4308 /* If left-hand subtree does nothing,
4310 emit_jump_if_reachable (default_label
);
4312 /* Code branches here for the right-hand subtree. */
4313 expand_label (test_label
);
4314 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
4318 else if (node
->right
!= 0 && node
->left
== 0)
4320 /* Here we have a right child but no left so we issue conditional
4321 branch to default and process the right child.
4323 Omit the conditional branch to default if we it avoid only one
4324 right child; it costs too much space to save so little time. */
4326 if (node
->right
->right
|| node
->right
->left
4327 || !tree_int_cst_equal (node
->right
->low
, node
->right
->high
))
4329 if (!node_has_low_bound (node
, index_type
))
4331 emit_cmp_insn (index
, expand_expr (node
->high
, 0, VOIDmode
, 0),
4332 LT
, 0, mode
, unsignedp
, 0);
4333 emit_jump_insn ((*gen_blt_pat
) (default_label
));
4336 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
4339 /* We cannot process node->right normally
4340 since we haven't ruled out the numbers less than
4341 this node's value. So handle node->right explicitly. */
4342 do_jump_if_equal (index
,
4343 expand_expr (node
->right
->low
, 0, VOIDmode
, 0),
4344 label_rtx (node
->right
->code_label
), unsignedp
);
4347 else if (node
->right
== 0 && node
->left
!= 0)
4349 /* Just one subtree, on the left. */
4351 #if 0 /* The following code and comment were formerly part
4352 of the condition here, but they didn't work
4353 and I don't understand what the idea was. -- rms. */
4354 /* If our "most probable entry" is less probable
4355 than the default label, emit a jump to
4356 the default label using condition codes
4357 already lying around. With no right branch,
4358 a branch-greater-than will get us to the default
4361 && cost_table
[TREE_INT_CST_LOW (node
->high
)] < 12)
4364 if (node
->left
->left
|| node
->left
->right
4365 || !tree_int_cst_equal (node
->left
->low
, node
->left
->high
))
4367 if (!node_has_high_bound (node
, index_type
))
4369 emit_cmp_insn (index
, expand_expr (node
->high
, 0, VOIDmode
, 0),
4370 GT
, 0, mode
, unsignedp
, 0);
4371 emit_jump_insn ((*gen_bgt_pat
) (default_label
));
4374 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
4377 /* We cannot process node->left normally
4378 since we haven't ruled out the numbers less than
4379 this node's value. So handle node->left explicitly. */
4380 do_jump_if_equal (index
,
4381 expand_expr (node
->left
->low
, 0, VOIDmode
, 0),
4382 label_rtx (node
->left
->code_label
), unsignedp
);
4387 /* Node is a range. These cases are very similar to those for a single
4388 value, except that we do not start by testing whether this node
4389 is the one to branch to. */
4391 if (node
->right
!= 0 && node
->left
!= 0)
4393 /* Node has subtrees on both sides.
4394 If the right-hand subtree is bounded,
4395 test for it first, since we can go straight there.
4396 Otherwise, we need to make a branch in the control structure,
4397 then handle the two subtrees. */
4398 tree test_label
= 0;
4400 emit_cmp_insn (index
, expand_expr (node
->high
, 0, VOIDmode
, 0),
4401 GT
, 0, mode
, unsignedp
, 0);
4403 if (node_is_bounded (node
->right
, index_type
))
4404 /* Right hand node is fully bounded so we can eliminate any
4405 testing and branch directly to the target code. */
4406 emit_jump_insn ((*gen_bgt_pat
) (label_rtx (node
->right
->code_label
)));
4409 /* Right hand node requires testing.
4410 Branch to a label where we will handle it later. */
4412 test_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
4413 emit_jump_insn ((*gen_bgt_pat
) (label_rtx (test_label
)));
4416 /* Value belongs to this node or to the left-hand subtree. */
4418 emit_cmp_insn (index
, expand_expr (node
->low
, 0, VOIDmode
, 0),
4419 GE
, 0, mode
, unsignedp
, 0);
4420 emit_jump_insn ((*gen_bge_pat
) (label_rtx (node
->code_label
)));
4422 /* Handle the left-hand subtree. */
4423 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
4425 /* If right node had to be handled later, do that now. */
4429 /* If the left-hand subtree fell through,
4430 don't let it fall into the right-hand subtree. */
4431 emit_jump_if_reachable (default_label
);
4433 expand_label (test_label
);
4434 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
4438 else if (node
->right
!= 0 && node
->left
== 0)
4440 /* Deal with values to the left of this node,
4441 if they are possible. */
4442 if (!node_has_low_bound (node
, index_type
))
4444 emit_cmp_insn (index
, expand_expr (node
->low
, 0, VOIDmode
, 0),
4445 LT
, 0, mode
, unsignedp
, 0);
4446 emit_jump_insn ((*gen_blt_pat
) (default_label
));
4449 /* Value belongs to this node or to the right-hand subtree. */
4451 emit_cmp_insn (index
, expand_expr (node
->high
, 0, VOIDmode
, 0),
4452 LE
, 0, mode
, unsignedp
, 0);
4453 emit_jump_insn ((*gen_ble_pat
) (label_rtx (node
->code_label
)));
4455 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
4458 else if (node
->right
== 0 && node
->left
!= 0)
4460 /* Deal with values to the right of this node,
4461 if they are possible. */
4462 if (!node_has_high_bound (node
, index_type
))
4464 emit_cmp_insn (index
, expand_expr (node
->high
, 0, VOIDmode
, 0),
4465 GT
, 0, mode
, unsignedp
, 0);
4466 emit_jump_insn ((*gen_bgt_pat
) (default_label
));
4469 /* Value belongs to this node or to the left-hand subtree. */
4471 emit_cmp_insn (index
, expand_expr (node
->low
, 0, VOIDmode
, 0),
4472 GE
, 0, mode
, unsignedp
, 0);
4473 emit_jump_insn ((*gen_bge_pat
) (label_rtx (node
->code_label
)));
4475 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
4480 /* Node has no children so we check low and high bounds to remove
4481 redundant tests. Only one of the bounds can exist,
4482 since otherwise this node is bounded--a case tested already. */
4484 if (!node_has_high_bound (node
, index_type
))
4486 emit_cmp_insn (index
, expand_expr (node
->high
, 0, VOIDmode
, 0),
4487 GT
, 0, mode
, unsignedp
, 0);
4488 emit_jump_insn ((*gen_bgt_pat
) (default_label
));
4491 if (!node_has_low_bound (node
, index_type
))
4493 emit_cmp_insn (index
, expand_expr (node
->low
, 0, VOIDmode
, 0),
4494 LT
, 0, mode
, unsignedp
, 0);
4495 emit_jump_insn ((*gen_blt_pat
) (default_label
));
4498 emit_jump (label_rtx (node
->code_label
));
4503 /* These routines are used by the loop unrolling code. They copy BLOCK trees
4504 so that the debugging info will be correct for the unrolled loop. */
4506 /* Indexed by loop number, contains pointer to the first block in the loop,
4507 or zero if none. Only valid if doing loop unrolling and outputting debugger
4510 tree
*loop_number_first_block
;
4512 /* Indexed by loop number, contains pointer to the last block in the loop,
4513 only valid if loop_number_first_block is nonzero. */
4515 tree
*loop_number_last_block
;
4517 /* Indexed by loop number, contains nesting level of first block in the
4518 loop, if any. Only valid if doing loop unrolling and outputting debugger
4521 int *loop_number_block_level
;
4523 /* Scan the function looking for loops, and walk the BLOCK tree at the
4524 same time. Record the first and last BLOCK tree corresponding to each
4525 loop. This function is similar to find_and_verify_loops in loop.c. */
4528 find_loop_tree_blocks (f
)
4532 int current_loop
= -1;
4535 int block_level
, tree_level
;
4536 tree tree_block
, parent_tree_block
;
4538 tree_block
= DECL_INITIAL (current_function_decl
);
4539 parent_tree_block
= 0;
4543 /* Find boundaries of loops, and save the first and last BLOCK tree
4544 corresponding to each loop. */
4546 for (insn
= f
; insn
; insn
= NEXT_INSN (insn
))
4548 if (GET_CODE (insn
) == NOTE
)
4549 switch (NOTE_LINE_NUMBER (insn
))
4551 case NOTE_INSN_LOOP_BEG
:
4552 loop_number_block_level
[++next_loop
] = block_level
;
4553 loop_number_first_block
[next_loop
] = 0;
4554 current_loop
= next_loop
;
4557 case NOTE_INSN_LOOP_END
:
4558 if (current_loop
== -1)
4561 current_loop
= loop_outer_loop
[current_loop
];
4564 case NOTE_INSN_BLOCK_BEG
:
4565 if (tree_level
< block_level
)
4567 /* We have seen two NOTE_INSN_BLOCK_BEG notes in a row, so
4568 we must now visit the subtree of the current block. */
4569 parent_tree_block
= tree_block
;
4570 tree_block
= BLOCK_SUBBLOCKS (tree_block
);
4573 else if (tree_level
> block_level
)
4576 /* Save this block tree here for all nested loops for which
4577 this is the topmost block. */
4578 for (loop
= current_loop
;
4579 loop
!= -1 && block_level
== loop_number_block_level
[loop
];
4580 loop
= loop_outer_loop
[loop
])
4582 if (loop_number_first_block
[loop
] == 0)
4583 loop_number_first_block
[loop
] = tree_block
;
4584 loop_number_last_block
[loop
] = tree_block
;
4590 case NOTE_INSN_BLOCK_END
:
4592 if (tree_level
> block_level
)
4594 /* We have seen two NOTE_INSN_BLOCK_END notes in a row, so
4595 we must now visit the parent of the current tree. */
4596 if (tree_block
!= 0 || parent_tree_block
== 0)
4598 tree_block
= parent_tree_block
;
4599 parent_tree_block
= BLOCK_SUPERCONTEXT (parent_tree_block
);
4602 tree_block
= BLOCK_CHAIN (tree_block
);
4608 /* This routine will make COPIES-1 copies of all BLOCK trees that correspond
4609 to BLOCK_BEG notes inside the loop LOOP_NUMBER.
4611 Note that we only copy the topmost level of tree nodes; they will share
4612 pointers to the same subblocks. */
4615 unroll_block_trees (loop_number
, copies
)
4621 /* First check whether there are any blocks that need to be copied. */
4622 if (loop_number_first_block
[loop_number
])
4624 tree first_block
= loop_number_first_block
[loop_number
];
4625 tree last_block
= loop_number_last_block
[loop_number
];
4626 tree last_block_created
= 0;
4628 for (i
= 0; i
< copies
- 1; i
++)
4630 tree block
= first_block
;
4631 tree insert_after
= last_block
;
4634 /* Copy every block between first_block and last_block inclusive,
4635 inserting the new blocks after last_block. */
4638 tree new_block
= make_node (BLOCK
);
4639 BLOCK_VARS (new_block
) = BLOCK_VARS (block
);
4640 BLOCK_TYPE_TAGS (new_block
) = BLOCK_TYPE_TAGS (block
);
4641 BLOCK_SUBBLOCKS (new_block
) = BLOCK_SUBBLOCKS (block
);
4642 BLOCK_SUPERCONTEXT (new_block
) = BLOCK_SUPERCONTEXT (block
);
4643 TREE_USED (new_block
) = TREE_USED (block
);
4645 /* Insert the new block after the insertion point, and move
4646 the insertion point to the new block. This ensures that
4647 the copies are inserted in the right order. */
4648 BLOCK_CHAIN (new_block
) = BLOCK_CHAIN (insert_after
);
4649 BLOCK_CHAIN (insert_after
) = new_block
;
4650 insert_after
= new_block
;
4652 copied_block
= block
;
4653 block
= BLOCK_CHAIN (block
);
4655 while (copied_block
!= last_block
);
4657 /* Remember the last block created, so that we can update the
4658 info in the tables. */
4659 if (last_block_created
== 0)
4660 last_block_created
= insert_after
;
4663 /* For all nested loops for which LAST_BLOCK was originally the last
4664 block, update the tables to indicate that LAST_BLOCK_CREATED is
4665 now the last block in the loop. */
4666 for (i
= loop_number
; last_block
== loop_number_last_block
[i
];
4667 i
= loop_outer_loop
[i
])
4668 loop_number_last_block
[i
] = last_block_created
;