1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 88, 89, 92-98, 1999 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, 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
22 /* This file handles the generation of rtl code from tree structure
23 above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
24 It also creates the rtl expressions for parameters and auto variables
25 and has full responsibility for allocating stack slots.
27 The functions whose names start with `expand_' are called by the
28 parser to generate RTL instructions for various kinds of constructs.
30 Some control and binding constructs require calling several such
31 functions at different times. For example, a simple if-then
32 is expanded by calling `expand_start_cond' (with the condition-expression
33 as argument) before parsing the then-clause and calling `expand_end_cond'
34 after parsing the then-clause. */
44 #include "insn-flags.h"
45 #include "insn-config.h"
46 #include "insn-codes.h"
48 #include "hard-reg-set.h"
56 #define obstack_chunk_alloc xmalloc
57 #define obstack_chunk_free free
58 struct obstack stmt_obstack
;
60 /* Assume that case vectors are not pc-relative. */
61 #ifndef CASE_VECTOR_PC_RELATIVE
62 #define CASE_VECTOR_PC_RELATIVE 0
65 /* Filename and line number of last line-number note,
66 whether we actually emitted it or not. */
70 /* Nonzero if within a ({...}) grouping, in which case we must
71 always compute a value for each expr-stmt in case it is the last one. */
73 int expr_stmts_for_value
;
75 /* Each time we expand an expression-statement,
76 record the expr's type and its RTL value here. */
78 static tree last_expr_type
;
79 static rtx last_expr_value
;
81 /* Each time we expand the end of a binding contour (in `expand_end_bindings')
82 and we emit a new NOTE_INSN_BLOCK_END note, we save a pointer to it here.
83 This is used by the `remember_end_note' function to record the endpoint
84 of each generated block in its associated BLOCK node. */
86 static rtx last_block_end_note
;
88 /* Number of binding contours started so far in this function. */
90 int block_start_count
;
92 /* Nonzero if function being compiled needs to
93 return the address of where it has put a structure value. */
95 extern int current_function_returns_pcc_struct
;
97 /* Label that will go on parm cleanup code, if any.
98 Jumping to this label runs cleanup code for parameters, if
99 such code must be run. Following this code is the logical return label. */
101 extern rtx cleanup_label
;
103 /* Label that will go on function epilogue.
104 Jumping to this label serves as a "return" instruction
105 on machines which require execution of the epilogue on all returns. */
107 extern rtx return_label
;
109 /* Offset to end of allocated area of stack frame.
110 If stack grows down, this is the address of the last stack slot allocated.
111 If stack grows up, this is the address for the next slot. */
112 extern int frame_offset
;
114 /* Label to jump back to for tail recursion, or 0 if we have
115 not yet needed one for this function. */
116 extern rtx tail_recursion_label
;
118 /* Place after which to insert the tail_recursion_label if we need one. */
119 extern rtx tail_recursion_reentry
;
121 /* Location at which to save the argument pointer if it will need to be
122 referenced. There are two cases where this is done: if nonlocal gotos
123 exist, or if vars whose is an offset from the argument pointer will be
124 needed by inner routines. */
126 extern rtx arg_pointer_save_area
;
128 /* Chain of all RTL_EXPRs that have insns in them. */
129 extern tree rtl_expr_chain
;
131 /* Functions and data structures for expanding case statements. */
133 /* Case label structure, used to hold info on labels within case
134 statements. We handle "range" labels; for a single-value label
135 as in C, the high and low limits are the same.
137 An AVL tree of case nodes is initially created, and later transformed
138 to a list linked via the RIGHT fields in the nodes. Nodes with
139 higher case values are later in the list.
141 Switch statements can be output in one of two forms. A branch table
142 is used if there are more than a few labels and the labels are dense
143 within the range between the smallest and largest case value. If a
144 branch table is used, no further manipulations are done with the case
147 The alternative to the use of a branch table is to generate a series
148 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
149 and PARENT fields to hold a binary tree. Initially the tree is
150 totally unbalanced, with everything on the right. We balance the tree
151 with nodes on the left having lower case values than the parent
152 and nodes on the right having higher values. We then output the tree
157 struct case_node
*left
; /* Left son in binary tree */
158 struct case_node
*right
; /* Right son in binary tree; also node chain */
159 struct case_node
*parent
; /* Parent of node in binary tree */
160 tree low
; /* Lowest index value for this label */
161 tree high
; /* Highest index value for this label */
162 tree code_label
; /* Label to jump to when node matches */
166 typedef struct case_node case_node
;
167 typedef struct case_node
*case_node_ptr
;
169 /* These are used by estimate_case_costs and balance_case_nodes. */
171 /* This must be a signed type, and non-ANSI compilers lack signed char. */
172 static short *cost_table
;
173 static int use_cost_table
;
175 /* Stack of control and binding constructs we are currently inside.
177 These constructs begin when you call `expand_start_WHATEVER'
178 and end when you call `expand_end_WHATEVER'. This stack records
179 info about how the construct began that tells the end-function
180 what to do. It also may provide information about the construct
181 to alter the behavior of other constructs within the body.
182 For example, they may affect the behavior of C `break' and `continue'.
184 Each construct gets one `struct nesting' object.
185 All of these objects are chained through the `all' field.
186 `nesting_stack' points to the first object (innermost construct).
187 The position of an entry on `nesting_stack' is in its `depth' field.
189 Each type of construct has its own individual stack.
190 For example, loops have `loop_stack'. Each object points to the
191 next object of the same type through the `next' field.
193 Some constructs are visible to `break' exit-statements and others
194 are not. Which constructs are visible depends on the language.
195 Therefore, the data structure allows each construct to be visible
196 or not, according to the args given when the construct is started.
197 The construct is visible if the `exit_label' field is non-null.
198 In that case, the value should be a CODE_LABEL rtx. */
203 struct nesting
*next
;
208 /* For conds (if-then and if-then-else statements). */
211 /* Label for the end of the if construct.
212 There is none if EXITFLAG was not set
213 and no `else' has been seen yet. */
215 /* Label for the end of this alternative.
216 This may be the end of the if or the next else/elseif. */
222 /* Label at the top of the loop; place to loop back to. */
224 /* Label at the end of the whole construct. */
226 /* Label before a jump that branches to the end of the whole
227 construct. This is where destructors go if any. */
229 /* Label for `continue' statement to jump to;
230 this is in front of the stepper of the loop. */
233 /* For variable binding contours. */
236 /* Sequence number of this binding contour within the function,
237 in order of entry. */
238 int block_start_count
;
239 /* Nonzero => value to restore stack to on exit. */
241 /* The NOTE that starts this contour.
242 Used by expand_goto to check whether the destination
243 is within each contour or not. */
245 /* Innermost containing binding contour that has a stack level. */
246 struct nesting
*innermost_stack_block
;
247 /* List of cleanups to be run on exit from this contour.
248 This is a list of expressions to be evaluated.
249 The TREE_PURPOSE of each link is the ..._DECL node
250 which the cleanup pertains to. */
252 /* List of cleanup-lists of blocks containing this block,
253 as they were at the locus where this block appears.
254 There is an element for each containing block,
255 ordered innermost containing block first.
256 The tail of this list can be 0,
257 if all remaining elements would be empty lists.
258 The element's TREE_VALUE is the cleanup-list of that block,
259 which may be null. */
261 /* Chain of labels defined inside this binding contour.
262 For contours that have stack levels or cleanups. */
263 struct label_chain
*label_chain
;
264 /* Number of function calls seen, as of start of this block. */
265 int function_call_count
;
266 /* Nonzero if this is associated with a EH region. */
267 int exception_region
;
268 /* The saved target_temp_slot_level from our outer block.
269 We may reset target_temp_slot_level to be the level of
270 this block, if that is done, target_temp_slot_level
271 reverts to the saved target_temp_slot_level at the very
273 int target_temp_slot_level
;
274 /* True if we are currently emitting insns in an area of
275 output code that is controlled by a conditional
276 expression. This is used by the cleanup handling code to
277 generate conditional cleanup actions. */
278 int conditional_code
;
279 /* A place to move the start of the exception region for any
280 of the conditional cleanups, must be at the end or after
281 the start of the last unconditional cleanup, and before any
282 conditional branch points. */
283 rtx last_unconditional_cleanup
;
284 /* When in a conditional context, this is the specific
285 cleanup list associated with last_unconditional_cleanup,
286 where we place the conditionalized cleanups. */
289 /* For switch (C) or case (Pascal) statements,
290 and also for dummies (see `expand_start_case_dummy'). */
293 /* The insn after which the case dispatch should finally
294 be emitted. Zero for a dummy. */
296 /* A list of case labels; it is first built as an AVL tree.
297 During expand_end_case, this is converted to a list, and may be
298 rearranged into a nearly balanced binary tree. */
299 struct case_node
*case_list
;
300 /* Label to jump to if no case matches. */
302 /* The expression to be dispatched on. */
304 /* Type that INDEX_EXPR should be converted to. */
306 /* Number of range exprs in case statement. */
308 /* Name of this kind of statement, for warnings. */
310 /* Used to save no_line_numbers till we see the first case label.
311 We set this to -1 when we see the first case label in this
313 int line_number_status
;
318 /* Chain of all pending binding contours. */
319 struct nesting
*block_stack
;
321 /* If any new stacks are added here, add them to POPSTACKS too. */
323 /* Chain of all pending binding contours that restore stack levels
325 struct nesting
*stack_block_stack
;
327 /* Chain of all pending conditional statements. */
328 struct nesting
*cond_stack
;
330 /* Chain of all pending loops. */
331 struct nesting
*loop_stack
;
333 /* Chain of all pending case or switch statements. */
334 struct nesting
*case_stack
;
336 /* Separate chain including all of the above,
337 chained through the `all' field. */
338 struct nesting
*nesting_stack
;
340 /* Number of entries on nesting_stack now. */
343 /* Allocate and return a new `struct nesting'. */
345 #define ALLOC_NESTING() \
346 (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
348 /* Pop the nesting stack element by element until we pop off
349 the element which is at the top of STACK.
350 Update all the other stacks, popping off elements from them
351 as we pop them from nesting_stack. */
353 #define POPSTACK(STACK) \
354 do { struct nesting *target = STACK; \
355 struct nesting *this; \
356 do { this = nesting_stack; \
357 if (loop_stack == this) \
358 loop_stack = loop_stack->next; \
359 if (cond_stack == this) \
360 cond_stack = cond_stack->next; \
361 if (block_stack == this) \
362 block_stack = block_stack->next; \
363 if (stack_block_stack == this) \
364 stack_block_stack = stack_block_stack->next; \
365 if (case_stack == this) \
366 case_stack = case_stack->next; \
367 nesting_depth = nesting_stack->depth - 1; \
368 nesting_stack = this->all; \
369 obstack_free (&stmt_obstack, this); } \
370 while (this != target); } 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 BLOCK for the place where this goto was found. */
392 /* The CODE_LABEL rtx that this is jumping to. */
394 /* Number of binding contours started in current function
395 before the label reference. */
396 int block_start_count
;
397 /* The outermost stack level that should be restored for this jump.
398 Each time a binding contour that resets the stack is exited,
399 if the target label is *not* yet defined, this slot is updated. */
401 /* List of lists of cleanup expressions to be run by this goto.
402 There is one element for each block that this goto is within.
403 The tail of this list can be 0,
404 if all remaining elements would be empty.
405 The TREE_VALUE contains the cleanup list of that block as of the
406 time this goto was seen.
407 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
408 tree cleanup_list_list
;
411 static struct goto_fixup
*goto_fixup_chain
;
413 /* Within any binding contour that must restore a stack level,
414 all labels are recorded with a chain of these structures. */
418 /* Points to following fixup. */
419 struct label_chain
*next
;
424 /* Non-zero if we are using EH to handle cleanus. */
425 static int using_eh_for_cleanups_p
= 0;
428 static int n_occurrences
PROTO((int, char *));
429 static void expand_goto_internal
PROTO((tree
, rtx
, rtx
));
430 static int expand_fixup
PROTO((tree
, rtx
, rtx
));
431 static void expand_nl_handler_label
PROTO((rtx
, rtx
));
432 static void expand_nl_goto_receiver
PROTO((void));
433 static void expand_nl_goto_receivers
PROTO((struct nesting
*));
434 static void fixup_gotos
PROTO((struct nesting
*, rtx
, tree
,
436 static void expand_null_return_1
PROTO((rtx
, int));
437 static void expand_value_return
PROTO((rtx
));
438 static int tail_recursion_args
PROTO((tree
, tree
));
439 static void expand_cleanups
PROTO((tree
, tree
, int, int));
440 static void check_seenlabel
PROTO((void));
441 static void do_jump_if_equal
PROTO((rtx
, rtx
, rtx
, int));
442 static int estimate_case_costs
PROTO((case_node_ptr
));
443 static void group_case_nodes
PROTO((case_node_ptr
));
444 static void balance_case_nodes
PROTO((case_node_ptr
*,
446 static int node_has_low_bound
PROTO((case_node_ptr
, tree
));
447 static int node_has_high_bound
PROTO((case_node_ptr
, tree
));
448 static int node_is_bounded
PROTO((case_node_ptr
, tree
));
449 static void emit_jump_if_reachable
PROTO((rtx
));
450 static void emit_case_nodes
PROTO((rtx
, case_node_ptr
, rtx
, tree
));
451 static int add_case_node
PROTO((tree
, tree
, tree
, tree
*));
452 static struct case_node
*case_tree2list
PROTO((case_node
*, case_node
*));
455 using_eh_for_cleanups ()
457 using_eh_for_cleanups_p
= 1;
463 gcc_obstack_init (&stmt_obstack
);
468 init_stmt_for_function ()
470 /* We are not currently within any block, conditional, loop or case. */
472 stack_block_stack
= 0;
479 block_start_count
= 0;
481 /* No gotos have been expanded yet. */
482 goto_fixup_chain
= 0;
484 /* We are not processing a ({...}) grouping. */
485 expr_stmts_for_value
= 0;
488 init_eh_for_function ();
495 p
->block_stack
= block_stack
;
496 p
->stack_block_stack
= stack_block_stack
;
497 p
->cond_stack
= cond_stack
;
498 p
->loop_stack
= loop_stack
;
499 p
->case_stack
= case_stack
;
500 p
->nesting_stack
= nesting_stack
;
501 p
->nesting_depth
= nesting_depth
;
502 p
->block_start_count
= block_start_count
;
503 p
->last_expr_type
= last_expr_type
;
504 p
->last_expr_value
= last_expr_value
;
505 p
->expr_stmts_for_value
= expr_stmts_for_value
;
506 p
->emit_filename
= emit_filename
;
507 p
->emit_lineno
= emit_lineno
;
508 p
->goto_fixup_chain
= goto_fixup_chain
;
513 restore_stmt_status (p
)
516 block_stack
= p
->block_stack
;
517 stack_block_stack
= p
->stack_block_stack
;
518 cond_stack
= p
->cond_stack
;
519 loop_stack
= p
->loop_stack
;
520 case_stack
= p
->case_stack
;
521 nesting_stack
= p
->nesting_stack
;
522 nesting_depth
= p
->nesting_depth
;
523 block_start_count
= p
->block_start_count
;
524 last_expr_type
= p
->last_expr_type
;
525 last_expr_value
= p
->last_expr_value
;
526 expr_stmts_for_value
= p
->expr_stmts_for_value
;
527 emit_filename
= p
->emit_filename
;
528 emit_lineno
= p
->emit_lineno
;
529 goto_fixup_chain
= p
->goto_fixup_chain
;
530 restore_eh_status (p
);
533 /* Emit a no-op instruction. */
540 last_insn
= get_last_insn ();
542 && (GET_CODE (last_insn
) == CODE_LABEL
543 || (GET_CODE (last_insn
) == NOTE
544 && prev_real_insn (last_insn
) == 0)))
545 emit_insn (gen_nop ());
548 /* Return the rtx-label that corresponds to a LABEL_DECL,
549 creating it if necessary. */
555 if (TREE_CODE (label
) != LABEL_DECL
)
558 if (DECL_RTL (label
))
559 return DECL_RTL (label
);
561 return DECL_RTL (label
) = gen_label_rtx ();
564 /* Add an unconditional jump to LABEL as the next sequential instruction. */
570 do_pending_stack_adjust ();
571 emit_jump_insn (gen_jump (label
));
575 /* Emit code to jump to the address
576 specified by the pointer expression EXP. */
579 expand_computed_goto (exp
)
582 rtx x
= expand_expr (exp
, NULL_RTX
, VOIDmode
, 0);
584 #ifdef POINTERS_EXTEND_UNSIGNED
585 x
= convert_memory_address (Pmode
, x
);
589 /* Be sure the function is executable. */
590 if (current_function_check_memory_usage
)
591 emit_library_call (chkr_check_exec_libfunc
, 1,
592 VOIDmode
, 1, x
, ptr_mode
);
594 do_pending_stack_adjust ();
595 emit_indirect_jump (x
);
597 current_function_has_computed_jump
= 1;
600 /* Handle goto statements and the labels that they can go to. */
602 /* Specify the location in the RTL code of a label LABEL,
603 which is a LABEL_DECL tree node.
605 This is used for the kind of label that the user can jump to with a
606 goto statement, and for alternatives of a switch or case statement.
607 RTL labels generated for loops and conditionals don't go through here;
608 they are generated directly at the RTL level, by other functions below.
610 Note that this has nothing to do with defining label *names*.
611 Languages vary in how they do that and what that even means. */
617 struct label_chain
*p
;
619 do_pending_stack_adjust ();
620 emit_label (label_rtx (label
));
621 if (DECL_NAME (label
))
622 LABEL_NAME (DECL_RTL (label
)) = IDENTIFIER_POINTER (DECL_NAME (label
));
624 if (stack_block_stack
!= 0)
626 p
= (struct label_chain
*) oballoc (sizeof (struct label_chain
));
627 p
->next
= stack_block_stack
->data
.block
.label_chain
;
628 stack_block_stack
->data
.block
.label_chain
= p
;
633 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
634 from nested functions. */
637 declare_nonlocal_label (label
)
640 rtx slot
= assign_stack_local (Pmode
, GET_MODE_SIZE (Pmode
), 0);
642 nonlocal_labels
= tree_cons (NULL_TREE
, label
, nonlocal_labels
);
643 LABEL_PRESERVE_P (label_rtx (label
)) = 1;
644 if (nonlocal_goto_handler_slots
== 0)
646 emit_stack_save (SAVE_NONLOCAL
,
647 &nonlocal_goto_stack_level
,
648 PREV_INSN (tail_recursion_reentry
));
650 nonlocal_goto_handler_slots
651 = gen_rtx_EXPR_LIST (VOIDmode
, slot
, nonlocal_goto_handler_slots
);
654 /* Generate RTL code for a `goto' statement with target label LABEL.
655 LABEL should be a LABEL_DECL tree node that was or will later be
656 defined with `expand_label'. */
664 /* Check for a nonlocal goto to a containing function. */
665 context
= decl_function_context (label
);
666 if (context
!= 0 && context
!= current_function_decl
)
668 struct function
*p
= find_function_data (context
);
669 rtx label_ref
= gen_rtx_LABEL_REF (Pmode
, label_rtx (label
));
670 rtx temp
, handler_slot
;
673 /* Find the corresponding handler slot for this label. */
674 handler_slot
= p
->nonlocal_goto_handler_slots
;
675 for (link
= p
->nonlocal_labels
; TREE_VALUE (link
) != label
;
676 link
= TREE_CHAIN (link
))
677 handler_slot
= XEXP (handler_slot
, 1);
678 handler_slot
= XEXP (handler_slot
, 0);
680 p
->has_nonlocal_label
= 1;
681 current_function_has_nonlocal_goto
= 1;
682 LABEL_REF_NONLOCAL_P (label_ref
) = 1;
684 /* Copy the rtl for the slots so that they won't be shared in
685 case the virtual stack vars register gets instantiated differently
686 in the parent than in the child. */
688 #if HAVE_nonlocal_goto
689 if (HAVE_nonlocal_goto
)
690 emit_insn (gen_nonlocal_goto (lookup_static_chain (label
),
691 copy_rtx (handler_slot
),
692 copy_rtx (p
->nonlocal_goto_stack_level
),
699 /* Restore frame pointer for containing function.
700 This sets the actual hard register used for the frame pointer
701 to the location of the function's incoming static chain info.
702 The non-local goto handler will then adjust it to contain the
703 proper value and reload the argument pointer, if needed. */
704 emit_move_insn (hard_frame_pointer_rtx
, lookup_static_chain (label
));
706 /* We have now loaded the frame pointer hardware register with
707 the address of that corresponds to the start of the virtual
708 stack vars. So replace virtual_stack_vars_rtx in all
709 addresses we use with stack_pointer_rtx. */
711 /* Get addr of containing function's current nonlocal goto handler,
712 which will do any cleanups and then jump to the label. */
713 addr
= copy_rtx (handler_slot
);
714 temp
= copy_to_reg (replace_rtx (addr
, virtual_stack_vars_rtx
,
715 hard_frame_pointer_rtx
));
717 /* Restore the stack pointer. Note this uses fp just restored. */
718 addr
= p
->nonlocal_goto_stack_level
;
720 addr
= replace_rtx (copy_rtx (addr
),
721 virtual_stack_vars_rtx
,
722 hard_frame_pointer_rtx
);
724 emit_stack_restore (SAVE_NONLOCAL
, addr
, NULL_RTX
);
726 /* USE of hard_frame_pointer_rtx added for consistency; not clear if
728 emit_insn (gen_rtx_USE (VOIDmode
, hard_frame_pointer_rtx
));
729 emit_insn (gen_rtx_USE (VOIDmode
, stack_pointer_rtx
));
730 emit_indirect_jump (temp
);
734 expand_goto_internal (label
, label_rtx (label
), NULL_RTX
);
737 /* Generate RTL code for a `goto' statement with target label BODY.
738 LABEL should be a LABEL_REF.
739 LAST_INSN, if non-0, is the rtx we should consider as the last
740 insn emitted (for the purposes of cleaning up a return). */
743 expand_goto_internal (body
, label
, last_insn
)
748 struct nesting
*block
;
751 if (GET_CODE (label
) != CODE_LABEL
)
754 /* If label has already been defined, we can tell now
755 whether and how we must alter the stack level. */
757 if (PREV_INSN (label
) != 0)
759 /* Find the innermost pending block that contains the label.
760 (Check containment by comparing insn-uids.)
761 Then restore the outermost stack level within that block,
762 and do cleanups of all blocks contained in it. */
763 for (block
= block_stack
; block
; block
= block
->next
)
765 if (INSN_UID (block
->data
.block
.first_insn
) < INSN_UID (label
))
767 if (block
->data
.block
.stack_level
!= 0)
768 stack_level
= block
->data
.block
.stack_level
;
769 /* Execute the cleanups for blocks we are exiting. */
770 if (block
->data
.block
.cleanups
!= 0)
772 expand_cleanups (block
->data
.block
.cleanups
, NULL_TREE
, 1, 1);
773 do_pending_stack_adjust ();
779 /* Ensure stack adjust isn't done by emit_jump, as this
780 would clobber the stack pointer. This one should be
781 deleted as dead by flow. */
782 clear_pending_stack_adjust ();
783 do_pending_stack_adjust ();
784 emit_stack_restore (SAVE_BLOCK
, stack_level
, NULL_RTX
);
787 if (body
!= 0 && DECL_TOO_LATE (body
))
788 error ("jump to `%s' invalidly jumps into binding contour",
789 IDENTIFIER_POINTER (DECL_NAME (body
)));
791 /* Label not yet defined: may need to put this goto
792 on the fixup list. */
793 else if (! expand_fixup (body
, label
, last_insn
))
795 /* No fixup needed. Record that the label is the target
796 of at least one goto that has no fixup. */
798 TREE_ADDRESSABLE (body
) = 1;
804 /* Generate if necessary a fixup for a goto
805 whose target label in tree structure (if any) is TREE_LABEL
806 and whose target in rtl is RTL_LABEL.
808 If LAST_INSN is nonzero, we pretend that the jump appears
809 after insn LAST_INSN instead of at the current point in the insn stream.
811 The fixup will be used later to insert insns just before the goto.
812 Those insns will restore the stack level as appropriate for the
813 target label, and will (in the case of C++) also invoke any object
814 destructors which have to be invoked when we exit the scopes which
815 are exited by the goto.
817 Value is nonzero if a fixup is made. */
820 expand_fixup (tree_label
, rtl_label
, last_insn
)
825 struct nesting
*block
, *end_block
;
827 /* See if we can recognize which block the label will be output in.
828 This is possible in some very common cases.
829 If we succeed, set END_BLOCK to that block.
830 Otherwise, set it to 0. */
833 && (rtl_label
== cond_stack
->data
.cond
.endif_label
834 || rtl_label
== cond_stack
->data
.cond
.next_label
))
835 end_block
= cond_stack
;
836 /* If we are in a loop, recognize certain labels which
837 are likely targets. This reduces the number of fixups
838 we need to create. */
840 && (rtl_label
== loop_stack
->data
.loop
.start_label
841 || rtl_label
== loop_stack
->data
.loop
.end_label
842 || rtl_label
== loop_stack
->data
.loop
.continue_label
))
843 end_block
= loop_stack
;
847 /* Now set END_BLOCK to the binding level to which we will return. */
851 struct nesting
*next_block
= end_block
->all
;
854 /* First see if the END_BLOCK is inside the innermost binding level.
855 If so, then no cleanups or stack levels are relevant. */
856 while (next_block
&& next_block
!= block
)
857 next_block
= next_block
->all
;
862 /* Otherwise, set END_BLOCK to the innermost binding level
863 which is outside the relevant control-structure nesting. */
864 next_block
= block_stack
->next
;
865 for (block
= block_stack
; block
!= end_block
; block
= block
->all
)
866 if (block
== next_block
)
867 next_block
= next_block
->next
;
868 end_block
= next_block
;
871 /* Does any containing block have a stack level or cleanups?
872 If not, no fixup is needed, and that is the normal case
873 (the only case, for standard C). */
874 for (block
= block_stack
; block
!= end_block
; block
= block
->next
)
875 if (block
->data
.block
.stack_level
!= 0
876 || block
->data
.block
.cleanups
!= 0)
879 if (block
!= end_block
)
881 /* Ok, a fixup is needed. Add a fixup to the list of such. */
882 struct goto_fixup
*fixup
883 = (struct goto_fixup
*) oballoc (sizeof (struct goto_fixup
));
884 /* In case an old stack level is restored, make sure that comes
885 after any pending stack adjust. */
886 /* ?? If the fixup isn't to come at the present position,
887 doing the stack adjust here isn't useful. Doing it with our
888 settings at that location isn't useful either. Let's hope
891 do_pending_stack_adjust ();
892 fixup
->target
= tree_label
;
893 fixup
->target_rtl
= rtl_label
;
895 /* Create a BLOCK node and a corresponding matched set of
896 NOTE_INSN_BEGIN_BLOCK and NOTE_INSN_END_BLOCK notes at
897 this point. The notes will encapsulate any and all fixup
898 code which we might later insert at this point in the insn
899 stream. Also, the BLOCK node will be the parent (i.e. the
900 `SUPERBLOCK') of any other BLOCK nodes which we might create
901 later on when we are expanding the fixup code.
903 Note that optimization passes (including expand_end_loop)
904 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
908 register rtx original_before_jump
909 = last_insn
? last_insn
: get_last_insn ();
914 start
= emit_note (NULL_PTR
, NOTE_INSN_BLOCK_BEG
);
915 fixup
->before_jump
= emit_note (NULL_PTR
, NOTE_INSN_DELETED
);
916 last_block_end_note
= emit_note (NULL_PTR
, NOTE_INSN_BLOCK_END
);
917 fixup
->context
= poplevel (1, 0, 0); /* Create the BLOCK node now! */
919 emit_insns_after (start
, original_before_jump
);
922 fixup
->block_start_count
= block_start_count
;
923 fixup
->stack_level
= 0;
924 fixup
->cleanup_list_list
925 = ((block
->data
.block
.outer_cleanups
926 || block
->data
.block
.cleanups
)
927 ? tree_cons (NULL_TREE
, block
->data
.block
.cleanups
,
928 block
->data
.block
.outer_cleanups
)
930 fixup
->next
= goto_fixup_chain
;
931 goto_fixup_chain
= fixup
;
939 /* Expand any needed fixups in the outputmost binding level of the
940 function. FIRST_INSN is the first insn in the function. */
943 expand_fixups (first_insn
)
946 fixup_gotos (NULL_PTR
, NULL_RTX
, NULL_TREE
, first_insn
, 0);
949 /* When exiting a binding contour, process all pending gotos requiring fixups.
950 THISBLOCK is the structure that describes the block being exited.
951 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
952 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
953 FIRST_INSN is the insn that began this contour.
955 Gotos that jump out of this contour must restore the
956 stack level and do the cleanups before actually jumping.
958 DONT_JUMP_IN nonzero means report error there is a jump into this
959 contour from before the beginning of the contour.
960 This is also done if STACK_LEVEL is nonzero. */
963 fixup_gotos (thisblock
, stack_level
, cleanup_list
, first_insn
, dont_jump_in
)
964 struct nesting
*thisblock
;
970 register struct goto_fixup
*f
, *prev
;
972 /* F is the fixup we are considering; PREV is the previous one. */
973 /* We run this loop in two passes so that cleanups of exited blocks
974 are run first, and blocks that are exited are marked so
977 for (prev
= 0, f
= goto_fixup_chain
; f
; prev
= f
, f
= f
->next
)
979 /* Test for a fixup that is inactive because it is already handled. */
980 if (f
->before_jump
== 0)
982 /* Delete inactive fixup from the chain, if that is easy to do. */
984 prev
->next
= f
->next
;
986 /* Has this fixup's target label been defined?
987 If so, we can finalize it. */
988 else if (PREV_INSN (f
->target_rtl
) != 0)
990 register rtx cleanup_insns
;
992 /* Get the first non-label after the label
993 this goto jumps to. If that's before this scope begins,
994 we don't have a jump into the scope. */
995 rtx after_label
= f
->target_rtl
;
996 while (after_label
!= 0 && GET_CODE (after_label
) == CODE_LABEL
)
997 after_label
= NEXT_INSN (after_label
);
999 /* If this fixup jumped into this contour from before the beginning
1000 of this contour, report an error. */
1001 /* ??? Bug: this does not detect jumping in through intermediate
1002 blocks that have stack levels or cleanups.
1003 It detects only a problem with the innermost block
1004 around the label. */
1006 && (dont_jump_in
|| stack_level
|| cleanup_list
)
1007 /* If AFTER_LABEL is 0, it means the jump goes to the end
1008 of the rtl, which means it jumps into this scope. */
1009 && (after_label
== 0
1010 || INSN_UID (first_insn
) < INSN_UID (after_label
))
1011 && INSN_UID (first_insn
) > INSN_UID (f
->before_jump
)
1012 && ! DECL_ERROR_ISSUED (f
->target
))
1014 error_with_decl (f
->target
,
1015 "label `%s' used before containing binding contour");
1016 /* Prevent multiple errors for one label. */
1017 DECL_ERROR_ISSUED (f
->target
) = 1;
1020 /* We will expand the cleanups into a sequence of their own and
1021 then later on we will attach this new sequence to the insn
1022 stream just ahead of the actual jump insn. */
1026 /* Temporarily restore the lexical context where we will
1027 logically be inserting the fixup code. We do this for the
1028 sake of getting the debugging information right. */
1031 set_block (f
->context
);
1033 /* Expand the cleanups for blocks this jump exits. */
1034 if (f
->cleanup_list_list
)
1037 for (lists
= f
->cleanup_list_list
; lists
; lists
= TREE_CHAIN (lists
))
1038 /* Marked elements correspond to blocks that have been closed.
1039 Do their cleanups. */
1040 if (TREE_ADDRESSABLE (lists
)
1041 && TREE_VALUE (lists
) != 0)
1043 expand_cleanups (TREE_VALUE (lists
), NULL_TREE
, 1, 1);
1044 /* Pop any pushes done in the cleanups,
1045 in case function is about to return. */
1046 do_pending_stack_adjust ();
1050 /* Restore stack level for the biggest contour that this
1051 jump jumps out of. */
1053 emit_stack_restore (SAVE_BLOCK
, f
->stack_level
, f
->before_jump
);
1055 /* Finish up the sequence containing the insns which implement the
1056 necessary cleanups, and then attach that whole sequence to the
1057 insn stream just ahead of the actual jump insn. Attaching it
1058 at that point insures that any cleanups which are in fact
1059 implicit C++ object destructions (which must be executed upon
1060 leaving the block) appear (to the debugger) to be taking place
1061 in an area of the generated code where the object(s) being
1062 destructed are still "in scope". */
1064 cleanup_insns
= get_insns ();
1068 emit_insns_after (cleanup_insns
, f
->before_jump
);
1075 /* For any still-undefined labels, do the cleanups for this block now.
1076 We must do this now since items in the cleanup list may go out
1077 of scope when the block ends. */
1078 for (prev
= 0, f
= goto_fixup_chain
; f
; prev
= f
, f
= f
->next
)
1079 if (f
->before_jump
!= 0
1080 && PREV_INSN (f
->target_rtl
) == 0
1081 /* Label has still not appeared. If we are exiting a block with
1082 a stack level to restore, that started before the fixup,
1083 mark this stack level as needing restoration
1084 when the fixup is later finalized. */
1086 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1087 means the label is undefined. That's erroneous, but possible. */
1088 && (thisblock
->data
.block
.block_start_count
1089 <= f
->block_start_count
))
1091 tree lists
= f
->cleanup_list_list
;
1094 for (; lists
; lists
= TREE_CHAIN (lists
))
1095 /* If the following elt. corresponds to our containing block
1096 then the elt. must be for this block. */
1097 if (TREE_CHAIN (lists
) == thisblock
->data
.block
.outer_cleanups
)
1101 set_block (f
->context
);
1102 expand_cleanups (TREE_VALUE (lists
), NULL_TREE
, 1, 1);
1103 do_pending_stack_adjust ();
1104 cleanup_insns
= get_insns ();
1107 if (cleanup_insns
!= 0)
1109 = emit_insns_after (cleanup_insns
, f
->before_jump
);
1111 f
->cleanup_list_list
= TREE_CHAIN (lists
);
1115 f
->stack_level
= stack_level
;
1119 /* Return the number of times character C occurs in string S. */
1121 n_occurrences (c
, s
)
1131 /* Generate RTL for an asm statement (explicit assembler code).
1132 BODY is a STRING_CST node containing the assembler code text,
1133 or an ADDR_EXPR containing a STRING_CST. */
1139 if (current_function_check_memory_usage
)
1141 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1145 if (TREE_CODE (body
) == ADDR_EXPR
)
1146 body
= TREE_OPERAND (body
, 0);
1148 emit_insn (gen_rtx_ASM_INPUT (VOIDmode
,
1149 TREE_STRING_POINTER (body
)));
1153 /* Generate RTL for an asm statement with arguments.
1154 STRING is the instruction template.
1155 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1156 Each output or input has an expression in the TREE_VALUE and
1157 a constraint-string in the TREE_PURPOSE.
1158 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1159 that is clobbered by this insn.
1161 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1162 Some elements of OUTPUTS may be replaced with trees representing temporary
1163 values. The caller should copy those temporary values to the originally
1166 VOL nonzero means the insn is volatile; don't optimize it. */
1169 expand_asm_operands (string
, outputs
, inputs
, clobbers
, vol
, filename
, line
)
1170 tree string
, outputs
, inputs
, clobbers
;
1175 rtvec argvec
, constraints
;
1177 int ninputs
= list_length (inputs
);
1178 int noutputs
= list_length (outputs
);
1183 /* Vector of RTX's of evaluated output operands. */
1184 rtx
*output_rtx
= (rtx
*) alloca (noutputs
* sizeof (rtx
));
1185 int *inout_opnum
= (int *) alloca (noutputs
* sizeof (int));
1186 enum machine_mode
*inout_mode
1187 = (enum machine_mode
*) alloca (noutputs
* sizeof (enum machine_mode
));
1188 /* The insn we have emitted. */
1191 /* An ASM with no outputs needs to be treated as volatile, for now. */
1195 if (current_function_check_memory_usage
)
1197 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1201 /* Count the number of meaningful clobbered registers, ignoring what
1202 we would ignore later. */
1204 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
))
1206 char *regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
1207 i
= decode_reg_name (regname
);
1208 if (i
>= 0 || i
== -4)
1211 error ("unknown register name `%s' in `asm'", regname
);
1216 /* Check that the number of alternatives is constant across all
1218 if (outputs
|| inputs
)
1220 tree tmp
= TREE_PURPOSE (outputs
? outputs
: inputs
);
1221 int nalternatives
= n_occurrences (',', TREE_STRING_POINTER (tmp
));
1224 if (nalternatives
+ 1 > MAX_RECOG_ALTERNATIVES
)
1226 error ("too many alternatives in `asm'");
1233 char *constraint
= TREE_STRING_POINTER (TREE_PURPOSE (tmp
));
1234 if (n_occurrences (',', constraint
) != nalternatives
)
1236 error ("operand constraints for `asm' differ in number of alternatives");
1239 if (TREE_CHAIN (tmp
))
1240 tmp
= TREE_CHAIN (tmp
);
1242 tmp
= next
, next
= 0;
1246 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1248 tree val
= TREE_VALUE (tail
);
1249 tree type
= TREE_TYPE (val
);
1258 /* If there's an erroneous arg, emit no insn. */
1259 if (TREE_TYPE (val
) == error_mark_node
)
1262 /* Make sure constraint has `=' and does not have `+'. Also, see
1263 if it allows any register. Be liberal on the latter test, since
1264 the worst that happens if we get it wrong is we issue an error
1267 c_len
= TREE_STRING_LENGTH (TREE_PURPOSE (tail
)) - 1;
1268 constraint
= TREE_STRING_POINTER (TREE_PURPOSE (tail
));
1270 /* Allow the `=' or `+' to not be at the beginning of the string,
1271 since it wasn't explicitly documented that way, and there is a
1272 large body of code that puts it last. Swap the character to
1273 the front, so as not to uglify any place else. */
1277 if ((p
= strchr (constraint
, '=')) != NULL
)
1279 if ((p
= strchr (constraint
, '+')) != NULL
)
1282 error ("output operand constraint lacks `='");
1286 if (p
!= constraint
)
1289 bcopy (constraint
, constraint
+1, p
-constraint
);
1292 warning ("output constraint `%c' for operand %d is not at the beginning", j
, i
);
1295 is_inout
= constraint
[0] == '+';
1296 /* Replace '+' with '='. */
1297 constraint
[0] = '=';
1298 /* Make sure we can specify the matching operand. */
1299 if (is_inout
&& i
> 9)
1301 error ("output operand constraint %d contains `+'", i
);
1305 for (j
= 1; j
< c_len
; j
++)
1306 switch (constraint
[j
])
1310 error ("operand constraint contains '+' or '=' at illegal position.");
1314 if (i
+ 1 == ninputs
+ noutputs
)
1316 error ("`%%' constraint used with last operand");
1321 case '?': case '!': case '*': case '&':
1322 case 'E': case 'F': case 'G': case 'H':
1323 case 's': case 'i': case 'n':
1324 case 'I': case 'J': case 'K': case 'L': case 'M':
1325 case 'N': case 'O': case 'P': case ',':
1326 #ifdef EXTRA_CONSTRAINT
1327 case 'Q': case 'R': case 'S': case 'T': case 'U':
1331 case '0': case '1': case '2': case '3': case '4':
1332 case '5': case '6': case '7': case '8': case '9':
1333 error ("matching constraint not valid in output operand");
1336 case 'V': case 'm': case 'o':
1341 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1342 excepting those that expand_call created. So match memory
1358 /* If an output operand is not a decl or indirect ref and our constraint
1359 allows a register, make a temporary to act as an intermediate.
1360 Make the asm insn write into that, then our caller will copy it to
1361 the real output operand. Likewise for promoted variables. */
1363 if ((TREE_CODE (val
) == INDIRECT_REF
1365 || (TREE_CODE_CLASS (TREE_CODE (val
)) == 'd'
1366 && (allows_mem
|| GET_CODE (DECL_RTL (val
)) == REG
)
1367 && ! (GET_CODE (DECL_RTL (val
)) == REG
1368 && GET_MODE (DECL_RTL (val
)) != TYPE_MODE (type
)))
1373 mark_addressable (TREE_VALUE (tail
));
1376 = expand_expr (TREE_VALUE (tail
), NULL_RTX
, VOIDmode
,
1377 EXPAND_MEMORY_USE_WO
);
1379 if (! allows_reg
&& GET_CODE (output_rtx
[i
]) != MEM
)
1380 error ("output number %d not directly addressable", i
);
1381 if (! allows_mem
&& GET_CODE (output_rtx
[i
]) == MEM
)
1382 error ("output number %d not restored to memory", i
);
1386 output_rtx
[i
] = assign_temp (type
, 0, 0, 0);
1387 TREE_VALUE (tail
) = make_tree (type
, output_rtx
[i
]);
1392 inout_mode
[ninout
] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail
)));
1393 inout_opnum
[ninout
++] = i
;
1398 if (ninputs
+ noutputs
> MAX_RECOG_OPERANDS
)
1400 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS
);
1404 /* Make vectors for the expression-rtx and constraint strings. */
1406 argvec
= rtvec_alloc (ninputs
);
1407 constraints
= rtvec_alloc (ninputs
);
1409 body
= gen_rtx_ASM_OPERANDS (VOIDmode
,
1410 TREE_STRING_POINTER (string
), "", 0, argvec
,
1411 constraints
, filename
, line
);
1413 MEM_VOLATILE_P (body
) = vol
;
1415 /* Eval the inputs and put them into ARGVEC.
1416 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1419 for (tail
= inputs
; tail
; tail
= TREE_CHAIN (tail
))
1422 int allows_reg
= 0, allows_mem
= 0;
1423 char *constraint
, *orig_constraint
;
1427 /* If there's an erroneous arg, emit no insn,
1428 because the ASM_INPUT would get VOIDmode
1429 and that could cause a crash in reload. */
1430 if (TREE_TYPE (TREE_VALUE (tail
)) == error_mark_node
)
1433 /* ??? Can this happen, and does the error message make any sense? */
1434 if (TREE_PURPOSE (tail
) == NULL_TREE
)
1436 error ("hard register `%s' listed as input operand to `asm'",
1437 TREE_STRING_POINTER (TREE_VALUE (tail
)) );
1441 c_len
= TREE_STRING_LENGTH (TREE_PURPOSE (tail
)) - 1;
1442 constraint
= TREE_STRING_POINTER (TREE_PURPOSE (tail
));
1443 orig_constraint
= constraint
;
1445 /* Make sure constraint has neither `=', `+', nor '&'. */
1447 for (j
= 0; j
< c_len
; j
++)
1448 switch (constraint
[j
])
1450 case '+': case '=': case '&':
1451 if (constraint
== orig_constraint
)
1453 error ("input operand constraint contains `%c'", constraint
[j
]);
1459 if (constraint
== orig_constraint
1460 && i
+ 1 == ninputs
- ninout
)
1462 error ("`%%' constraint used with last operand");
1467 case 'V': case 'm': case 'o':
1472 case '?': case '!': case '*':
1473 case 'E': case 'F': case 'G': case 'H': case 'X':
1474 case 's': case 'i': case 'n':
1475 case 'I': case 'J': case 'K': case 'L': case 'M':
1476 case 'N': case 'O': case 'P': case ',':
1477 #ifdef EXTRA_CONSTRAINT
1478 case 'Q': case 'R': case 'S': case 'T': case 'U':
1482 /* Whether or not a numeric constraint allows a register is
1483 decided by the matching constraint, and so there is no need
1484 to do anything special with them. We must handle them in
1485 the default case, so that we don't unnecessarily force
1486 operands to memory. */
1487 case '0': case '1': case '2': case '3': case '4':
1488 case '5': case '6': case '7': case '8': case '9':
1489 if (constraint
[j
] >= '0' + noutputs
)
1492 ("matching constraint references invalid operand number");
1496 /* Try and find the real constraint for this dup. */
1497 if ((j
== 0 && c_len
== 1)
1498 || (j
== 1 && c_len
== 2 && constraint
[0] == '%'))
1501 for (j
= constraint
[j
] - '0'; j
> 0; --j
)
1504 c_len
= TREE_STRING_LENGTH (TREE_PURPOSE (o
)) - 1;
1505 constraint
= TREE_STRING_POINTER (TREE_PURPOSE (o
));
1510 /* ... fall through ... */
1523 if (! allows_reg
&& allows_mem
)
1524 mark_addressable (TREE_VALUE (tail
));
1526 op
= expand_expr (TREE_VALUE (tail
), NULL_RTX
, VOIDmode
, 0);
1528 if (asm_operand_ok (op
, constraint
) <= 0)
1531 op
= force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail
))), op
);
1532 else if (!allows_mem
)
1533 warning ("asm operand %d probably doesn't match constraints", i
);
1534 else if (CONSTANT_P (op
))
1535 op
= force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail
))),
1537 else if (GET_CODE (op
) == REG
1538 || GET_CODE (op
) == SUBREG
1539 || GET_CODE (op
) == CONCAT
)
1541 tree type
= TREE_TYPE (TREE_VALUE (tail
));
1542 rtx memloc
= assign_temp (type
, 1, 1, 1);
1544 emit_move_insn (memloc
, op
);
1547 else if (GET_CODE (op
) == MEM
&& MEM_VOLATILE_P (op
))
1548 /* We won't recognize volatile memory as available a
1549 memory_operand at this point. Ignore it. */
1551 else if (queued_subexp_p (op
))
1554 /* ??? Leave this only until we have experience with what
1555 happens in combine and elsewhere when constraints are
1557 warning ("asm operand %d probably doesn't match constraints", i
);
1559 XVECEXP (body
, 3, i
) = op
;
1561 XVECEXP (body
, 4, i
) /* constraints */
1562 = gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail
))),
1567 /* Protect all the operands from the queue,
1568 now that they have all been evaluated. */
1570 for (i
= 0; i
< ninputs
- ninout
; i
++)
1571 XVECEXP (body
, 3, i
) = protect_from_queue (XVECEXP (body
, 3, i
), 0);
1573 for (i
= 0; i
< noutputs
; i
++)
1574 output_rtx
[i
] = protect_from_queue (output_rtx
[i
], 1);
1576 /* For in-out operands, copy output rtx to input rtx. */
1577 for (i
= 0; i
< ninout
; i
++)
1579 static char match
[9+1][2]
1580 = {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9"};
1581 int j
= inout_opnum
[i
];
1583 XVECEXP (body
, 3, ninputs
- ninout
+ i
) /* argvec */
1585 XVECEXP (body
, 4, ninputs
- ninout
+ i
) /* constraints */
1586 = gen_rtx_ASM_INPUT (inout_mode
[j
], match
[j
]);
1589 /* Now, for each output, construct an rtx
1590 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1591 ARGVEC CONSTRAINTS))
1592 If there is more than one, put them inside a PARALLEL. */
1594 if (noutputs
== 1 && nclobbers
== 0)
1596 XSTR (body
, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs
));
1597 insn
= emit_insn (gen_rtx_SET (VOIDmode
, output_rtx
[0], body
));
1599 else if (noutputs
== 0 && nclobbers
== 0)
1601 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1602 insn
= emit_insn (body
);
1608 if (num
== 0) num
= 1;
1609 body
= gen_rtx_PARALLEL (VOIDmode
, rtvec_alloc (num
+ nclobbers
));
1611 /* For each output operand, store a SET. */
1613 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1615 XVECEXP (body
, 0, i
)
1616 = gen_rtx_SET (VOIDmode
,
1618 gen_rtx_ASM_OPERANDS (VOIDmode
,
1619 TREE_STRING_POINTER (string
),
1620 TREE_STRING_POINTER (TREE_PURPOSE (tail
)),
1621 i
, argvec
, constraints
,
1623 MEM_VOLATILE_P (SET_SRC (XVECEXP (body
, 0, i
))) = vol
;
1626 /* If there are no outputs (but there are some clobbers)
1627 store the bare ASM_OPERANDS into the PARALLEL. */
1630 XVECEXP (body
, 0, i
++) = obody
;
1632 /* Store (clobber REG) for each clobbered register specified. */
1634 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
))
1636 char *regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
1637 int j
= decode_reg_name (regname
);
1641 if (j
== -3) /* `cc', which is not a register */
1644 if (j
== -4) /* `memory', don't cache memory across asm */
1646 XVECEXP (body
, 0, i
++)
1647 = gen_rtx_CLOBBER (VOIDmode
,
1648 gen_rtx_MEM (BLKmode
,
1649 gen_rtx_SCRATCH (VOIDmode
)));
1653 /* Ignore unknown register, error already signaled. */
1657 /* Use QImode since that's guaranteed to clobber just one reg. */
1658 XVECEXP (body
, 0, i
++)
1659 = gen_rtx_CLOBBER (VOIDmode
, gen_rtx_REG (QImode
, j
));
1662 insn
= emit_insn (body
);
1668 /* Generate RTL to evaluate the expression EXP
1669 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1672 expand_expr_stmt (exp
)
1675 /* If -W, warn about statements with no side effects,
1676 except for an explicit cast to void (e.g. for assert()), and
1677 except inside a ({...}) where they may be useful. */
1678 if (expr_stmts_for_value
== 0 && exp
!= error_mark_node
)
1680 if (! TREE_SIDE_EFFECTS (exp
) && (extra_warnings
|| warn_unused
)
1681 && !(TREE_CODE (exp
) == CONVERT_EXPR
1682 && TREE_TYPE (exp
) == void_type_node
))
1683 warning_with_file_and_line (emit_filename
, emit_lineno
,
1684 "statement with no effect");
1685 else if (warn_unused
)
1686 warn_if_unused_value (exp
);
1689 /* If EXP is of function type and we are expanding statements for
1690 value, convert it to pointer-to-function. */
1691 if (expr_stmts_for_value
&& TREE_CODE (TREE_TYPE (exp
)) == FUNCTION_TYPE
)
1692 exp
= build1 (ADDR_EXPR
, build_pointer_type (TREE_TYPE (exp
)), exp
);
1694 last_expr_type
= TREE_TYPE (exp
);
1695 if (flag_syntax_only
&& ! expr_stmts_for_value
)
1696 last_expr_value
= 0;
1698 last_expr_value
= expand_expr (exp
,
1699 (expr_stmts_for_value
1700 ? NULL_RTX
: const0_rtx
),
1703 /* If all we do is reference a volatile value in memory,
1704 copy it to a register to be sure it is actually touched. */
1705 if (last_expr_value
!= 0 && GET_CODE (last_expr_value
) == MEM
1706 && TREE_THIS_VOLATILE (exp
))
1708 if (TYPE_MODE (TREE_TYPE (exp
)) == VOIDmode
)
1710 else if (TYPE_MODE (TREE_TYPE (exp
)) != BLKmode
)
1711 copy_to_reg (last_expr_value
);
1714 rtx lab
= gen_label_rtx ();
1716 /* Compare the value with itself to reference it. */
1717 emit_cmp_and_jump_insns (last_expr_value
, last_expr_value
, EQ
,
1718 expand_expr (TYPE_SIZE (last_expr_type
),
1719 NULL_RTX
, VOIDmode
, 0),
1721 TYPE_ALIGN (last_expr_type
) / BITS_PER_UNIT
,
1727 /* If this expression is part of a ({...}) and is in memory, we may have
1728 to preserve temporaries. */
1729 preserve_temp_slots (last_expr_value
);
1731 /* Free any temporaries used to evaluate this expression. Any temporary
1732 used as a result of this expression will already have been preserved
1739 /* Warn if EXP contains any computations whose results are not used.
1740 Return 1 if a warning is printed; 0 otherwise. */
1743 warn_if_unused_value (exp
)
1746 if (TREE_USED (exp
))
1749 switch (TREE_CODE (exp
))
1751 case PREINCREMENT_EXPR
:
1752 case POSTINCREMENT_EXPR
:
1753 case PREDECREMENT_EXPR
:
1754 case POSTDECREMENT_EXPR
:
1759 case METHOD_CALL_EXPR
:
1761 case TRY_CATCH_EXPR
:
1762 case WITH_CLEANUP_EXPR
:
1764 /* We don't warn about COND_EXPR because it may be a useful
1765 construct if either arm contains a side effect. */
1770 /* For a binding, warn if no side effect within it. */
1771 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
1774 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
1776 case TRUTH_ORIF_EXPR
:
1777 case TRUTH_ANDIF_EXPR
:
1778 /* In && or ||, warn if 2nd operand has no side effect. */
1779 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
1782 if (TREE_NO_UNUSED_WARNING (exp
))
1784 if (warn_if_unused_value (TREE_OPERAND (exp
, 0)))
1786 /* Let people do `(foo (), 0)' without a warning. */
1787 if (TREE_CONSTANT (TREE_OPERAND (exp
, 1)))
1789 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
1793 case NON_LVALUE_EXPR
:
1794 /* Don't warn about values cast to void. */
1795 if (TREE_TYPE (exp
) == void_type_node
)
1797 /* Don't warn about conversions not explicit in the user's program. */
1798 if (TREE_NO_UNUSED_WARNING (exp
))
1800 /* Assignment to a cast usually results in a cast of a modify.
1801 Don't complain about that. There can be an arbitrary number of
1802 casts before the modify, so we must loop until we find the first
1803 non-cast expression and then test to see if that is a modify. */
1805 tree tem
= TREE_OPERAND (exp
, 0);
1807 while (TREE_CODE (tem
) == CONVERT_EXPR
|| TREE_CODE (tem
) == NOP_EXPR
)
1808 tem
= TREE_OPERAND (tem
, 0);
1810 if (TREE_CODE (tem
) == MODIFY_EXPR
|| TREE_CODE (tem
) == INIT_EXPR
1811 || TREE_CODE (tem
) == CALL_EXPR
)
1817 /* Don't warn about automatic dereferencing of references, since
1818 the user cannot control it. */
1819 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp
, 0))) == REFERENCE_TYPE
)
1820 return warn_if_unused_value (TREE_OPERAND (exp
, 0));
1821 /* ... fall through ... */
1824 /* Referencing a volatile value is a side effect, so don't warn. */
1825 if ((TREE_CODE_CLASS (TREE_CODE (exp
)) == 'd'
1826 || TREE_CODE_CLASS (TREE_CODE (exp
)) == 'r')
1827 && TREE_THIS_VOLATILE (exp
))
1830 warning_with_file_and_line (emit_filename
, emit_lineno
,
1831 "value computed is not used");
1836 /* Clear out the memory of the last expression evaluated. */
1844 /* Begin a statement which will return a value.
1845 Return the RTL_EXPR for this statement expr.
1846 The caller must save that value and pass it to expand_end_stmt_expr. */
1849 expand_start_stmt_expr ()
1854 /* Make the RTL_EXPR node temporary, not momentary,
1855 so that rtl_expr_chain doesn't become garbage. */
1856 momentary
= suspend_momentary ();
1857 t
= make_node (RTL_EXPR
);
1858 resume_momentary (momentary
);
1859 do_pending_stack_adjust ();
1860 start_sequence_for_rtl_expr (t
);
1862 expr_stmts_for_value
++;
1866 /* Restore the previous state at the end of a statement that returns a value.
1867 Returns a tree node representing the statement's value and the
1868 insns to compute the value.
1870 The nodes of that expression have been freed by now, so we cannot use them.
1871 But we don't want to do that anyway; the expression has already been
1872 evaluated and now we just want to use the value. So generate a RTL_EXPR
1873 with the proper type and RTL value.
1875 If the last substatement was not an expression,
1876 return something with type `void'. */
1879 expand_end_stmt_expr (t
)
1884 if (last_expr_type
== 0)
1886 last_expr_type
= void_type_node
;
1887 last_expr_value
= const0_rtx
;
1889 else if (last_expr_value
== 0)
1890 /* There are some cases where this can happen, such as when the
1891 statement is void type. */
1892 last_expr_value
= const0_rtx
;
1893 else if (GET_CODE (last_expr_value
) != REG
&& ! CONSTANT_P (last_expr_value
))
1894 /* Remove any possible QUEUED. */
1895 last_expr_value
= protect_from_queue (last_expr_value
, 0);
1899 TREE_TYPE (t
) = last_expr_type
;
1900 RTL_EXPR_RTL (t
) = last_expr_value
;
1901 RTL_EXPR_SEQUENCE (t
) = get_insns ();
1903 rtl_expr_chain
= tree_cons (NULL_TREE
, t
, rtl_expr_chain
);
1907 /* Don't consider deleting this expr or containing exprs at tree level. */
1908 TREE_SIDE_EFFECTS (t
) = 1;
1909 /* Propagate volatility of the actual RTL expr. */
1910 TREE_THIS_VOLATILE (t
) = volatile_refs_p (last_expr_value
);
1913 expr_stmts_for_value
--;
1918 /* Generate RTL for the start of an if-then. COND is the expression
1919 whose truth should be tested.
1921 If EXITFLAG is nonzero, this conditional is visible to
1922 `exit_something'. */
1925 expand_start_cond (cond
, exitflag
)
1929 struct nesting
*thiscond
= ALLOC_NESTING ();
1931 /* Make an entry on cond_stack for the cond we are entering. */
1933 thiscond
->next
= cond_stack
;
1934 thiscond
->all
= nesting_stack
;
1935 thiscond
->depth
= ++nesting_depth
;
1936 thiscond
->data
.cond
.next_label
= gen_label_rtx ();
1937 /* Before we encounter an `else', we don't need a separate exit label
1938 unless there are supposed to be exit statements
1939 to exit this conditional. */
1940 thiscond
->exit_label
= exitflag
? gen_label_rtx () : 0;
1941 thiscond
->data
.cond
.endif_label
= thiscond
->exit_label
;
1942 cond_stack
= thiscond
;
1943 nesting_stack
= thiscond
;
1945 do_jump (cond
, thiscond
->data
.cond
.next_label
, NULL_RTX
);
1948 /* Generate RTL between then-clause and the elseif-clause
1949 of an if-then-elseif-.... */
1952 expand_start_elseif (cond
)
1955 if (cond_stack
->data
.cond
.endif_label
== 0)
1956 cond_stack
->data
.cond
.endif_label
= gen_label_rtx ();
1957 emit_jump (cond_stack
->data
.cond
.endif_label
);
1958 emit_label (cond_stack
->data
.cond
.next_label
);
1959 cond_stack
->data
.cond
.next_label
= gen_label_rtx ();
1960 do_jump (cond
, cond_stack
->data
.cond
.next_label
, NULL_RTX
);
1963 /* Generate RTL between the then-clause and the else-clause
1964 of an if-then-else. */
1967 expand_start_else ()
1969 if (cond_stack
->data
.cond
.endif_label
== 0)
1970 cond_stack
->data
.cond
.endif_label
= gen_label_rtx ();
1972 emit_jump (cond_stack
->data
.cond
.endif_label
);
1973 emit_label (cond_stack
->data
.cond
.next_label
);
1974 cond_stack
->data
.cond
.next_label
= 0; /* No more _else or _elseif calls. */
1977 /* After calling expand_start_else, turn this "else" into an "else if"
1978 by providing another condition. */
1981 expand_elseif (cond
)
1984 cond_stack
->data
.cond
.next_label
= gen_label_rtx ();
1985 do_jump (cond
, cond_stack
->data
.cond
.next_label
, NULL_RTX
);
1988 /* Generate RTL for the end of an if-then.
1989 Pop the record for it off of cond_stack. */
1994 struct nesting
*thiscond
= cond_stack
;
1996 do_pending_stack_adjust ();
1997 if (thiscond
->data
.cond
.next_label
)
1998 emit_label (thiscond
->data
.cond
.next_label
);
1999 if (thiscond
->data
.cond
.endif_label
)
2000 emit_label (thiscond
->data
.cond
.endif_label
);
2002 POPSTACK (cond_stack
);
2008 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2009 loop should be exited by `exit_something'. This is a loop for which
2010 `expand_continue' will jump to the top of the loop.
2012 Make an entry on loop_stack to record the labels associated with
2016 expand_start_loop (exit_flag
)
2019 register struct nesting
*thisloop
= ALLOC_NESTING ();
2021 /* Make an entry on loop_stack for the loop we are entering. */
2023 thisloop
->next
= loop_stack
;
2024 thisloop
->all
= nesting_stack
;
2025 thisloop
->depth
= ++nesting_depth
;
2026 thisloop
->data
.loop
.start_label
= gen_label_rtx ();
2027 thisloop
->data
.loop
.end_label
= gen_label_rtx ();
2028 thisloop
->data
.loop
.alt_end_label
= 0;
2029 thisloop
->data
.loop
.continue_label
= thisloop
->data
.loop
.start_label
;
2030 thisloop
->exit_label
= exit_flag
? thisloop
->data
.loop
.end_label
: 0;
2031 loop_stack
= thisloop
;
2032 nesting_stack
= thisloop
;
2034 do_pending_stack_adjust ();
2036 emit_note (NULL_PTR
, NOTE_INSN_LOOP_BEG
);
2037 emit_label (thisloop
->data
.loop
.start_label
);
2042 /* Like expand_start_loop but for a loop where the continuation point
2043 (for expand_continue_loop) will be specified explicitly. */
2046 expand_start_loop_continue_elsewhere (exit_flag
)
2049 struct nesting
*thisloop
= expand_start_loop (exit_flag
);
2050 loop_stack
->data
.loop
.continue_label
= gen_label_rtx ();
2054 /* Specify the continuation point for a loop started with
2055 expand_start_loop_continue_elsewhere.
2056 Use this at the point in the code to which a continue statement
2060 expand_loop_continue_here ()
2062 do_pending_stack_adjust ();
2063 emit_note (NULL_PTR
, NOTE_INSN_LOOP_CONT
);
2064 emit_label (loop_stack
->data
.loop
.continue_label
);
2067 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2068 Pop the block off of loop_stack. */
2073 rtx start_label
= loop_stack
->data
.loop
.start_label
;
2074 rtx insn
= get_last_insn ();
2076 /* Mark the continue-point at the top of the loop if none elsewhere. */
2077 if (start_label
== loop_stack
->data
.loop
.continue_label
)
2078 emit_note_before (NOTE_INSN_LOOP_CONT
, start_label
);
2080 do_pending_stack_adjust ();
2082 /* If optimizing, perhaps reorder the loop. If the loop starts with
2083 a loop exit, roll that to the end where it will optimize together
2086 We look for the conditional branch to the exit, except that once
2087 we find such a branch, we don't look past 30 instructions.
2089 In more detail, if the loop presently looks like this (in pseudo-C):
2092 if (test) goto end_label;
2097 transform it to look like:
2103 if (test) goto end_label;
2104 goto newstart_label;
2107 Here, the `test' may actually consist of some reasonably complex
2108 code, terminating in a test. */
2112 ! (GET_CODE (insn
) == JUMP_INSN
2113 && GET_CODE (PATTERN (insn
)) == SET
2114 && SET_DEST (PATTERN (insn
)) == pc_rtx
2115 && GET_CODE (SET_SRC (PATTERN (insn
))) == IF_THEN_ELSE
))
2119 rtx last_test_insn
= NULL_RTX
;
2121 /* Scan insns from the top of the loop looking for a qualified
2122 conditional exit. */
2123 for (insn
= NEXT_INSN (loop_stack
->data
.loop
.start_label
); insn
;
2124 insn
= NEXT_INSN (insn
))
2126 if (GET_CODE (insn
) == NOTE
)
2129 && (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_BEG
2130 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_END
))
2131 /* The code that actually moves the exit test will
2132 carefully leave BLOCK notes in their original
2133 location. That means, however, that we can't debug
2134 the exit test itself. So, we refuse to move code
2135 containing BLOCK notes at low optimization levels. */
2138 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_EH_REGION_BEG
)
2140 else if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_EH_REGION_END
)
2144 /* We've come to the end of an EH region, but
2145 never saw the beginning of that region. That
2146 means that an EH region begins before the top
2147 of the loop, and ends in the middle of it. The
2148 existence of such a situation violates a basic
2149 assumption in this code, since that would imply
2150 that even when EH_REGIONS is zero, we might
2151 move code out of an exception region. */
2155 /* We already know this INSN is a NOTE, so there's no
2156 point in looking at it to see if it's a JUMP. */
2160 if (GET_CODE (insn
) == JUMP_INSN
|| GET_CODE (insn
) == INSN
)
2163 if (last_test_insn
&& num_insns
> 30)
2167 /* We don't want to move a partial EH region. Consider:
2181 This isn't legal C++, but here's what it's supposed to
2182 mean: if cond() is true, stop looping. Otherwise,
2183 call bar, and keep looping. In addition, if cond
2184 throws an exception, catch it and keep looping. Such
2185 constructs are certainy legal in LISP.
2187 We should not move the `if (cond()) 0' test since then
2188 the EH-region for the try-block would be broken up.
2189 (In this case we would the EH_BEG note for the `try'
2190 and `if cond()' but not the call to bar() or the
2193 So we don't look for tests within an EH region. */
2196 if (GET_CODE (insn
) == JUMP_INSN
2197 && GET_CODE (PATTERN (insn
)) == SET
2198 && SET_DEST (PATTERN (insn
)) == pc_rtx
)
2200 /* This is indeed a jump. */
2201 rtx dest1
= NULL_RTX
;
2202 rtx dest2
= NULL_RTX
;
2203 rtx potential_last_test
;
2204 if (GET_CODE (SET_SRC (PATTERN (insn
))) == IF_THEN_ELSE
)
2206 /* A conditional jump. */
2207 dest1
= XEXP (SET_SRC (PATTERN (insn
)), 1);
2208 dest2
= XEXP (SET_SRC (PATTERN (insn
)), 2);
2209 potential_last_test
= insn
;
2213 /* An unconditional jump. */
2214 dest1
= SET_SRC (PATTERN (insn
));
2215 /* Include the BARRIER after the JUMP. */
2216 potential_last_test
= NEXT_INSN (insn
);
2220 if (dest1
&& GET_CODE (dest1
) == LABEL_REF
2221 && ((XEXP (dest1
, 0)
2222 == loop_stack
->data
.loop
.alt_end_label
)
2224 == loop_stack
->data
.loop
.end_label
)))
2226 last_test_insn
= potential_last_test
;
2230 /* If this was a conditional jump, there may be
2231 another label at which we should look. */
2238 if (last_test_insn
!= 0 && last_test_insn
!= get_last_insn ())
2240 /* We found one. Move everything from there up
2241 to the end of the loop, and add a jump into the loop
2242 to jump to there. */
2243 register rtx newstart_label
= gen_label_rtx ();
2244 register rtx start_move
= start_label
;
2247 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2248 then we want to move this note also. */
2249 if (GET_CODE (PREV_INSN (start_move
)) == NOTE
2250 && (NOTE_LINE_NUMBER (PREV_INSN (start_move
))
2251 == NOTE_INSN_LOOP_CONT
))
2252 start_move
= PREV_INSN (start_move
);
2254 emit_label_after (newstart_label
, PREV_INSN (start_move
));
2256 /* Actually move the insns. Start at the beginning, and
2257 keep copying insns until we've copied the
2259 for (insn
= start_move
; insn
; insn
= next_insn
)
2261 /* Figure out which insn comes after this one. We have
2262 to do this before we move INSN. */
2263 if (insn
== last_test_insn
)
2264 /* We've moved all the insns. */
2265 next_insn
= NULL_RTX
;
2267 next_insn
= NEXT_INSN (insn
);
2269 if (GET_CODE (insn
) == NOTE
2270 && (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_BEG
2271 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_END
))
2272 /* We don't want to move NOTE_INSN_BLOCK_BEGs or
2273 NOTE_INSN_BLOCK_ENDs because the correct generation
2274 of debugging information depends on these appearing
2275 in the same order in the RTL and in the tree
2276 structure, where they are represented as BLOCKs.
2277 So, we don't move block notes. Of course, moving
2278 the code inside the block is likely to make it
2279 impossible to debug the instructions in the exit
2280 test, but such is the price of optimization. */
2283 /* Move the INSN. */
2284 reorder_insns (insn
, insn
, get_last_insn ());
2287 emit_jump_insn_after (gen_jump (start_label
),
2288 PREV_INSN (newstart_label
));
2289 emit_barrier_after (PREV_INSN (newstart_label
));
2290 start_label
= newstart_label
;
2294 emit_jump (start_label
);
2295 emit_note (NULL_PTR
, NOTE_INSN_LOOP_END
);
2296 emit_label (loop_stack
->data
.loop
.end_label
);
2298 POPSTACK (loop_stack
);
2303 /* Generate a jump to the current loop's continue-point.
2304 This is usually the top of the loop, but may be specified
2305 explicitly elsewhere. If not currently inside a loop,
2306 return 0 and do nothing; caller will print an error message. */
2309 expand_continue_loop (whichloop
)
2310 struct nesting
*whichloop
;
2314 whichloop
= loop_stack
;
2317 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.continue_label
,
2322 /* Generate a jump to exit the current loop. If not currently inside a loop,
2323 return 0 and do nothing; caller will print an error message. */
2326 expand_exit_loop (whichloop
)
2327 struct nesting
*whichloop
;
2331 whichloop
= loop_stack
;
2334 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.end_label
, NULL_RTX
);
2338 /* Generate a conditional jump to exit the current loop if COND
2339 evaluates to zero. If not currently inside a loop,
2340 return 0 and do nothing; caller will print an error message. */
2343 expand_exit_loop_if_false (whichloop
, cond
)
2344 struct nesting
*whichloop
;
2347 rtx label
= gen_label_rtx ();
2352 whichloop
= loop_stack
;
2355 /* In order to handle fixups, we actually create a conditional jump
2356 around a unconditional branch to exit the loop. If fixups are
2357 necessary, they go before the unconditional branch. */
2360 do_jump (cond
, NULL_RTX
, label
);
2361 last_insn
= get_last_insn ();
2362 if (GET_CODE (last_insn
) == CODE_LABEL
)
2363 whichloop
->data
.loop
.alt_end_label
= last_insn
;
2364 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.end_label
,
2371 /* Return nonzero if the loop nest is empty. Else return zero. */
2374 stmt_loop_nest_empty ()
2376 return (loop_stack
== NULL
);
2379 /* Return non-zero if we should preserve sub-expressions as separate
2380 pseudos. We never do so if we aren't optimizing. We always do so
2381 if -fexpensive-optimizations.
2383 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2384 the loop may still be a small one. */
2387 preserve_subexpressions_p ()
2391 if (flag_expensive_optimizations
)
2394 if (optimize
== 0 || loop_stack
== 0)
2397 insn
= get_last_insn_anywhere ();
2400 && (INSN_UID (insn
) - INSN_UID (loop_stack
->data
.loop
.start_label
)
2401 < n_non_fixed_regs
* 3));
2405 /* Generate a jump to exit the current loop, conditional, binding contour
2406 or case statement. Not all such constructs are visible to this function,
2407 only those started with EXIT_FLAG nonzero. Individual languages use
2408 the EXIT_FLAG parameter to control which kinds of constructs you can
2411 If not currently inside anything that can be exited,
2412 return 0 and do nothing; caller will print an error message. */
2415 expand_exit_something ()
2419 for (n
= nesting_stack
; n
; n
= n
->all
)
2420 if (n
->exit_label
!= 0)
2422 expand_goto_internal (NULL_TREE
, n
->exit_label
, NULL_RTX
);
2429 /* Generate RTL to return from the current function, with no value.
2430 (That is, we do not do anything about returning any value.) */
2433 expand_null_return ()
2435 struct nesting
*block
= block_stack
;
2438 /* Does any pending block have cleanups? */
2440 while (block
&& block
->data
.block
.cleanups
== 0)
2441 block
= block
->next
;
2443 /* If yes, use a goto to return, since that runs cleanups. */
2445 expand_null_return_1 (last_insn
, block
!= 0);
2448 /* Generate RTL to return from the current function, with value VAL. */
2451 expand_value_return (val
)
2454 struct nesting
*block
= block_stack
;
2455 rtx last_insn
= get_last_insn ();
2456 rtx return_reg
= DECL_RTL (DECL_RESULT (current_function_decl
));
2458 /* Copy the value to the return location
2459 unless it's already there. */
2461 if (return_reg
!= val
)
2463 #ifdef PROMOTE_FUNCTION_RETURN
2464 tree type
= TREE_TYPE (DECL_RESULT (current_function_decl
));
2465 int unsignedp
= TREE_UNSIGNED (type
);
2466 enum machine_mode mode
2467 = promote_mode (type
, DECL_MODE (DECL_RESULT (current_function_decl
)),
2470 if (GET_MODE (val
) != VOIDmode
&& GET_MODE (val
) != mode
)
2471 convert_move (return_reg
, val
, unsignedp
);
2474 emit_move_insn (return_reg
, val
);
2476 if (GET_CODE (return_reg
) == REG
2477 && REGNO (return_reg
) < FIRST_PSEUDO_REGISTER
)
2478 emit_insn (gen_rtx_USE (VOIDmode
, return_reg
));
2479 /* Handle calls that return values in multiple non-contiguous locations.
2480 The Irix 6 ABI has examples of this. */
2481 else if (GET_CODE (return_reg
) == PARALLEL
)
2485 for (i
= 0; i
< XVECLEN (return_reg
, 0); i
++)
2487 rtx x
= XEXP (XVECEXP (return_reg
, 0, i
), 0);
2489 if (GET_CODE (x
) == REG
2490 && REGNO (x
) < FIRST_PSEUDO_REGISTER
)
2491 emit_insn (gen_rtx_USE (VOIDmode
, x
));
2495 /* Does any pending block have cleanups? */
2497 while (block
&& block
->data
.block
.cleanups
== 0)
2498 block
= block
->next
;
2500 /* If yes, use a goto to return, since that runs cleanups.
2501 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2503 expand_null_return_1 (last_insn
, block
!= 0);
2506 /* Output a return with no value. If LAST_INSN is nonzero,
2507 pretend that the return takes place after LAST_INSN.
2508 If USE_GOTO is nonzero then don't use a return instruction;
2509 go to the return label instead. This causes any cleanups
2510 of pending blocks to be executed normally. */
2513 expand_null_return_1 (last_insn
, use_goto
)
2517 rtx end_label
= cleanup_label
? cleanup_label
: return_label
;
2519 clear_pending_stack_adjust ();
2520 do_pending_stack_adjust ();
2523 /* PCC-struct return always uses an epilogue. */
2524 if (current_function_returns_pcc_struct
|| use_goto
)
2527 end_label
= return_label
= gen_label_rtx ();
2528 expand_goto_internal (NULL_TREE
, end_label
, last_insn
);
2532 /* Otherwise output a simple return-insn if one is available,
2533 unless it won't do the job. */
2535 if (HAVE_return
&& use_goto
== 0 && cleanup_label
== 0)
2537 emit_jump_insn (gen_return ());
2543 /* Otherwise jump to the epilogue. */
2544 expand_goto_internal (NULL_TREE
, end_label
, last_insn
);
2547 /* Generate RTL to evaluate the expression RETVAL and return it
2548 from the current function. */
2551 expand_return (retval
)
2554 /* If there are any cleanups to be performed, then they will
2555 be inserted following LAST_INSN. It is desirable
2556 that the last_insn, for such purposes, should be the
2557 last insn before computing the return value. Otherwise, cleanups
2558 which call functions can clobber the return value. */
2559 /* ??? rms: I think that is erroneous, because in C++ it would
2560 run destructors on variables that might be used in the subsequent
2561 computation of the return value. */
2563 register rtx val
= 0;
2568 /* If function wants no value, give it none. */
2569 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl
))) == VOID_TYPE
)
2571 expand_expr (retval
, NULL_RTX
, VOIDmode
, 0);
2573 expand_null_return ();
2577 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2578 /* This is not sufficient. We also need to watch for cleanups of the
2579 expression we are about to expand. Unfortunately, we cannot know
2580 if it has cleanups until we expand it, and we want to change how we
2581 expand it depending upon if we need cleanups. We can't win. */
2583 cleanups
= any_pending_cleanups (1);
2588 if (TREE_CODE (retval
) == RESULT_DECL
)
2589 retval_rhs
= retval
;
2590 else if ((TREE_CODE (retval
) == MODIFY_EXPR
|| TREE_CODE (retval
) == INIT_EXPR
)
2591 && TREE_CODE (TREE_OPERAND (retval
, 0)) == RESULT_DECL
)
2592 retval_rhs
= TREE_OPERAND (retval
, 1);
2593 else if (TREE_TYPE (retval
) == void_type_node
)
2594 /* Recognize tail-recursive call to void function. */
2595 retval_rhs
= retval
;
2597 retval_rhs
= NULL_TREE
;
2599 /* Only use `last_insn' if there are cleanups which must be run. */
2600 if (cleanups
|| cleanup_label
!= 0)
2601 last_insn
= get_last_insn ();
2603 /* Distribute return down conditional expr if either of the sides
2604 may involve tail recursion (see test below). This enhances the number
2605 of tail recursions we see. Don't do this always since it can produce
2606 sub-optimal code in some cases and we distribute assignments into
2607 conditional expressions when it would help. */
2609 if (optimize
&& retval_rhs
!= 0
2610 && frame_offset
== 0
2611 && TREE_CODE (retval_rhs
) == COND_EXPR
2612 && (TREE_CODE (TREE_OPERAND (retval_rhs
, 1)) == CALL_EXPR
2613 || TREE_CODE (TREE_OPERAND (retval_rhs
, 2)) == CALL_EXPR
))
2615 rtx label
= gen_label_rtx ();
2618 do_jump (TREE_OPERAND (retval_rhs
, 0), label
, NULL_RTX
);
2619 expr
= build (MODIFY_EXPR
, TREE_TYPE (TREE_TYPE (current_function_decl
)),
2620 DECL_RESULT (current_function_decl
),
2621 TREE_OPERAND (retval_rhs
, 1));
2622 TREE_SIDE_EFFECTS (expr
) = 1;
2623 expand_return (expr
);
2626 expr
= build (MODIFY_EXPR
, TREE_TYPE (TREE_TYPE (current_function_decl
)),
2627 DECL_RESULT (current_function_decl
),
2628 TREE_OPERAND (retval_rhs
, 2));
2629 TREE_SIDE_EFFECTS (expr
) = 1;
2630 expand_return (expr
);
2634 /* Attempt to optimize the call if it is tail recursive. */
2635 if (optimize_tail_recursion (retval_rhs
, last_insn
))
2639 /* This optimization is safe if there are local cleanups
2640 because expand_null_return takes care of them.
2641 ??? I think it should also be safe when there is a cleanup label,
2642 because expand_null_return takes care of them, too.
2643 Any reason why not? */
2644 if (HAVE_return
&& cleanup_label
== 0
2645 && ! current_function_returns_pcc_struct
2646 && BRANCH_COST
<= 1)
2648 /* If this is return x == y; then generate
2649 if (x == y) return 1; else return 0;
2650 if we can do it with explicit return insns and branches are cheap,
2651 but not if we have the corresponding scc insn. */
2654 switch (TREE_CODE (retval_rhs
))
2680 case TRUTH_ANDIF_EXPR
:
2681 case TRUTH_ORIF_EXPR
:
2682 case TRUTH_AND_EXPR
:
2684 case TRUTH_NOT_EXPR
:
2685 case TRUTH_XOR_EXPR
:
2688 op0
= gen_label_rtx ();
2689 jumpifnot (retval_rhs
, op0
);
2690 expand_value_return (const1_rtx
);
2692 expand_value_return (const0_rtx
);
2701 #endif /* HAVE_return */
2703 /* If the result is an aggregate that is being returned in one (or more)
2704 registers, load the registers here. The compiler currently can't handle
2705 copying a BLKmode value into registers. We could put this code in a
2706 more general area (for use by everyone instead of just function
2707 call/return), but until this feature is generally usable it is kept here
2708 (and in expand_call). The value must go into a pseudo in case there
2709 are cleanups that will clobber the real return register. */
2712 && TYPE_MODE (TREE_TYPE (retval_rhs
)) == BLKmode
2713 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl
))) == REG
)
2715 int i
, bitpos
, xbitpos
;
2716 int big_endian_correction
= 0;
2717 int bytes
= int_size_in_bytes (TREE_TYPE (retval_rhs
));
2718 int n_regs
= (bytes
+ UNITS_PER_WORD
- 1) / UNITS_PER_WORD
;
2719 int bitsize
= MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs
)),
2720 (unsigned int)BITS_PER_WORD
);
2721 rtx
*result_pseudos
= (rtx
*) alloca (sizeof (rtx
) * n_regs
);
2722 rtx result_reg
, src
= NULL_RTX
, dst
= NULL_RTX
;
2723 rtx result_val
= expand_expr (retval_rhs
, NULL_RTX
, VOIDmode
, 0);
2724 enum machine_mode tmpmode
, result_reg_mode
;
2726 /* Structures whose size is not a multiple of a word are aligned
2727 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
2728 machine, this means we must skip the empty high order bytes when
2729 calculating the bit offset. */
2730 if (BYTES_BIG_ENDIAN
&& bytes
% UNITS_PER_WORD
)
2731 big_endian_correction
= (BITS_PER_WORD
- ((bytes
% UNITS_PER_WORD
)
2734 /* Copy the structure BITSIZE bits at a time. */
2735 for (bitpos
= 0, xbitpos
= big_endian_correction
;
2736 bitpos
< bytes
* BITS_PER_UNIT
;
2737 bitpos
+= bitsize
, xbitpos
+= bitsize
)
2739 /* We need a new destination pseudo each time xbitpos is
2740 on a word boundary and when xbitpos == big_endian_correction
2741 (the first time through). */
2742 if (xbitpos
% BITS_PER_WORD
== 0
2743 || xbitpos
== big_endian_correction
)
2745 /* Generate an appropriate register. */
2746 dst
= gen_reg_rtx (word_mode
);
2747 result_pseudos
[xbitpos
/ BITS_PER_WORD
] = dst
;
2749 /* Clobber the destination before we move anything into it. */
2750 emit_insn (gen_rtx_CLOBBER (VOIDmode
, dst
));
2753 /* We need a new source operand each time bitpos is on a word
2755 if (bitpos
% BITS_PER_WORD
== 0)
2756 src
= operand_subword_force (result_val
,
2757 bitpos
/ BITS_PER_WORD
,
2760 /* Use bitpos for the source extraction (left justified) and
2761 xbitpos for the destination store (right justified). */
2762 store_bit_field (dst
, bitsize
, xbitpos
% BITS_PER_WORD
, word_mode
,
2763 extract_bit_field (src
, bitsize
,
2764 bitpos
% BITS_PER_WORD
, 1,
2765 NULL_RTX
, word_mode
,
2767 bitsize
/ BITS_PER_UNIT
,
2769 bitsize
/ BITS_PER_UNIT
, BITS_PER_WORD
);
2772 /* Find the smallest integer mode large enough to hold the
2773 entire structure and use that mode instead of BLKmode
2774 on the USE insn for the return register. */
2775 bytes
= int_size_in_bytes (TREE_TYPE (retval_rhs
));
2776 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
2777 tmpmode
!= MAX_MACHINE_MODE
;
2778 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
2780 /* Have we found a large enough mode? */
2781 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
2785 /* No suitable mode found. */
2786 if (tmpmode
== MAX_MACHINE_MODE
)
2789 PUT_MODE (DECL_RTL (DECL_RESULT (current_function_decl
)), tmpmode
);
2791 if (GET_MODE_SIZE (tmpmode
) < GET_MODE_SIZE (word_mode
))
2792 result_reg_mode
= word_mode
;
2794 result_reg_mode
= tmpmode
;
2795 result_reg
= gen_reg_rtx (result_reg_mode
);
2798 for (i
= 0; i
< n_regs
; i
++)
2799 emit_move_insn (operand_subword (result_reg
, i
, 0, result_reg_mode
),
2802 if (tmpmode
!= result_reg_mode
)
2803 result_reg
= gen_lowpart (tmpmode
, result_reg
);
2805 expand_value_return (result_reg
);
2809 && TREE_TYPE (retval_rhs
) != void_type_node
2810 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl
))) == REG
)
2812 /* Calculate the return value into a pseudo reg. */
2813 val
= gen_reg_rtx (DECL_MODE (DECL_RESULT (current_function_decl
)));
2814 val
= expand_expr (retval_rhs
, val
, GET_MODE (val
), 0);
2815 val
= force_not_mem (val
);
2817 /* Return the calculated value, doing cleanups first. */
2818 expand_value_return (val
);
2822 /* No cleanups or no hard reg used;
2823 calculate value into hard return reg. */
2824 expand_expr (retval
, const0_rtx
, VOIDmode
, 0);
2826 expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl
)));
2830 /* Return 1 if the end of the generated RTX is not a barrier.
2831 This means code already compiled can drop through. */
2834 drop_through_at_end_p ()
2836 rtx insn
= get_last_insn ();
2837 while (insn
&& GET_CODE (insn
) == NOTE
)
2838 insn
= PREV_INSN (insn
);
2839 return insn
&& GET_CODE (insn
) != BARRIER
;
2842 /* Test CALL_EXPR to determine if it is a potential tail recursion call
2843 and emit code to optimize the tail recursion. LAST_INSN indicates where
2844 to place the jump to the tail recursion label. Return TRUE if the
2845 call was optimized into a goto.
2847 This is only used by expand_return, but expand_call is expected to
2851 optimize_tail_recursion (call_expr
, last_insn
)
2855 /* For tail-recursive call to current function,
2856 just jump back to the beginning.
2857 It's unsafe if any auto variable in this function
2858 has its address taken; for simplicity,
2859 require stack frame to be empty. */
2860 if (optimize
&& call_expr
!= 0
2861 && frame_offset
== 0
2862 && TREE_CODE (call_expr
) == CALL_EXPR
2863 && TREE_CODE (TREE_OPERAND (call_expr
, 0)) == ADDR_EXPR
2864 && TREE_OPERAND (TREE_OPERAND (call_expr
, 0), 0) == current_function_decl
2865 /* Finish checking validity, and if valid emit code
2866 to set the argument variables for the new call. */
2867 && tail_recursion_args (TREE_OPERAND (call_expr
, 1),
2868 DECL_ARGUMENTS (current_function_decl
)))
2870 if (tail_recursion_label
== 0)
2872 tail_recursion_label
= gen_label_rtx ();
2873 emit_label_after (tail_recursion_label
,
2874 tail_recursion_reentry
);
2877 expand_goto_internal (NULL_TREE
, tail_recursion_label
, last_insn
);
2885 /* Emit code to alter this function's formal parms for a tail-recursive call.
2886 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
2887 FORMALS is the chain of decls of formals.
2888 Return 1 if this can be done;
2889 otherwise return 0 and do not emit any code. */
2892 tail_recursion_args (actuals
, formals
)
2893 tree actuals
, formals
;
2895 register tree a
= actuals
, f
= formals
;
2897 register rtx
*argvec
;
2899 /* Check that number and types of actuals are compatible
2900 with the formals. This is not always true in valid C code.
2901 Also check that no formal needs to be addressable
2902 and that all formals are scalars. */
2904 /* Also count the args. */
2906 for (a
= actuals
, f
= formals
, i
= 0; a
&& f
; a
= TREE_CHAIN (a
), f
= TREE_CHAIN (f
), i
++)
2908 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a
)))
2909 != TYPE_MAIN_VARIANT (TREE_TYPE (f
)))
2911 if (GET_CODE (DECL_RTL (f
)) != REG
|| DECL_MODE (f
) == BLKmode
)
2914 if (a
!= 0 || f
!= 0)
2917 /* Compute all the actuals. */
2919 argvec
= (rtx
*) alloca (i
* sizeof (rtx
));
2921 for (a
= actuals
, i
= 0; a
; a
= TREE_CHAIN (a
), i
++)
2922 argvec
[i
] = expand_expr (TREE_VALUE (a
), NULL_RTX
, VOIDmode
, 0);
2924 /* Find which actual values refer to current values of previous formals.
2925 Copy each of them now, before any formal is changed. */
2927 for (a
= actuals
, i
= 0; a
; a
= TREE_CHAIN (a
), i
++)
2931 for (f
= formals
, j
= 0; j
< i
; f
= TREE_CHAIN (f
), j
++)
2932 if (reg_mentioned_p (DECL_RTL (f
), argvec
[i
]))
2933 { copy
= 1; break; }
2935 argvec
[i
] = copy_to_reg (argvec
[i
]);
2938 /* Store the values of the actuals into the formals. */
2940 for (f
= formals
, a
= actuals
, i
= 0; f
;
2941 f
= TREE_CHAIN (f
), a
= TREE_CHAIN (a
), i
++)
2943 if (GET_MODE (DECL_RTL (f
)) == GET_MODE (argvec
[i
]))
2944 emit_move_insn (DECL_RTL (f
), argvec
[i
]);
2946 convert_move (DECL_RTL (f
), argvec
[i
],
2947 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a
))));
2954 /* Generate the RTL code for entering a binding contour.
2955 The variables are declared one by one, by calls to `expand_decl'.
2957 EXIT_FLAG is nonzero if this construct should be visible to
2958 `exit_something'. */
2961 expand_start_bindings (exit_flag
)
2964 struct nesting
*thisblock
= ALLOC_NESTING ();
2965 rtx note
= emit_note (NULL_PTR
, NOTE_INSN_BLOCK_BEG
);
2967 /* Make an entry on block_stack for the block we are entering. */
2969 thisblock
->next
= block_stack
;
2970 thisblock
->all
= nesting_stack
;
2971 thisblock
->depth
= ++nesting_depth
;
2972 thisblock
->data
.block
.stack_level
= 0;
2973 thisblock
->data
.block
.cleanups
= 0;
2974 thisblock
->data
.block
.function_call_count
= 0;
2975 thisblock
->data
.block
.exception_region
= 0;
2976 thisblock
->data
.block
.target_temp_slot_level
= target_temp_slot_level
;
2978 thisblock
->data
.block
.conditional_code
= 0;
2979 thisblock
->data
.block
.last_unconditional_cleanup
= note
;
2980 thisblock
->data
.block
.cleanup_ptr
= &thisblock
->data
.block
.cleanups
;
2983 && !(block_stack
->data
.block
.cleanups
== NULL_TREE
2984 && block_stack
->data
.block
.outer_cleanups
== NULL_TREE
))
2985 thisblock
->data
.block
.outer_cleanups
2986 = tree_cons (NULL_TREE
, block_stack
->data
.block
.cleanups
,
2987 block_stack
->data
.block
.outer_cleanups
);
2989 thisblock
->data
.block
.outer_cleanups
= 0;
2990 thisblock
->data
.block
.label_chain
= 0;
2991 thisblock
->data
.block
.innermost_stack_block
= stack_block_stack
;
2992 thisblock
->data
.block
.first_insn
= note
;
2993 thisblock
->data
.block
.block_start_count
= ++block_start_count
;
2994 thisblock
->exit_label
= exit_flag
? gen_label_rtx () : 0;
2995 block_stack
= thisblock
;
2996 nesting_stack
= thisblock
;
2998 /* Make a new level for allocating stack slots. */
3002 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3003 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3004 expand_expr are made. After we end the region, we know that all
3005 space for all temporaries that were created by TARGET_EXPRs will be
3006 destroyed and their space freed for reuse. */
3009 expand_start_target_temps ()
3011 /* This is so that even if the result is preserved, the space
3012 allocated will be freed, as we know that it is no longer in use. */
3015 /* Start a new binding layer that will keep track of all cleanup
3016 actions to be performed. */
3017 expand_start_bindings (0);
3019 target_temp_slot_level
= temp_slot_level
;
3023 expand_end_target_temps ()
3025 expand_end_bindings (NULL_TREE
, 0, 0);
3027 /* This is so that even if the result is preserved, the space
3028 allocated will be freed, as we know that it is no longer in use. */
3032 /* Mark top block of block_stack as an implicit binding for an
3033 exception region. This is used to prevent infinite recursion when
3034 ending a binding with expand_end_bindings. It is only ever called
3035 by expand_eh_region_start, as that it the only way to create a
3036 block stack for a exception region. */
3039 mark_block_as_eh_region ()
3041 block_stack
->data
.block
.exception_region
= 1;
3042 if (block_stack
->next
3043 && block_stack
->next
->data
.block
.conditional_code
)
3045 block_stack
->data
.block
.conditional_code
3046 = block_stack
->next
->data
.block
.conditional_code
;
3047 block_stack
->data
.block
.last_unconditional_cleanup
3048 = block_stack
->next
->data
.block
.last_unconditional_cleanup
;
3049 block_stack
->data
.block
.cleanup_ptr
3050 = block_stack
->next
->data
.block
.cleanup_ptr
;
3054 /* True if we are currently emitting insns in an area of output code
3055 that is controlled by a conditional expression. This is used by
3056 the cleanup handling code to generate conditional cleanup actions. */
3059 conditional_context ()
3061 return block_stack
&& block_stack
->data
.block
.conditional_code
;
3064 /* Mark top block of block_stack as not for an implicit binding for an
3065 exception region. This is only ever done by expand_eh_region_end
3066 to let expand_end_bindings know that it is being called explicitly
3067 to end the binding layer for just the binding layer associated with
3068 the exception region, otherwise expand_end_bindings would try and
3069 end all implicit binding layers for exceptions regions, and then
3070 one normal binding layer. */
3073 mark_block_as_not_eh_region ()
3075 block_stack
->data
.block
.exception_region
= 0;
3078 /* True if the top block of block_stack was marked as for an exception
3079 region by mark_block_as_eh_region. */
3084 return block_stack
&& block_stack
->data
.block
.exception_region
;
3087 /* Given a pointer to a BLOCK node, save a pointer to the most recently
3088 generated NOTE_INSN_BLOCK_END in the BLOCK_END_NOTE field of the given
3092 remember_end_note (block
)
3093 register tree block
;
3095 BLOCK_END_NOTE (block
) = last_block_end_note
;
3096 last_block_end_note
= NULL_RTX
;
3099 /* Emit a handler label for a nonlocal goto handler.
3100 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3103 expand_nl_handler_label (slot
, before_insn
)
3104 rtx slot
, before_insn
;
3107 rtx handler_label
= gen_label_rtx ();
3109 /* Don't let jump_optimize delete the handler. */
3110 LABEL_PRESERVE_P (handler_label
) = 1;
3113 emit_move_insn (slot
, gen_rtx_LABEL_REF (Pmode
, handler_label
));
3114 insns
= get_insns ();
3116 emit_insns_before (insns
, before_insn
);
3118 emit_label (handler_label
);
3121 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3124 expand_nl_goto_receiver ()
3126 #ifdef HAVE_nonlocal_goto
3127 if (! HAVE_nonlocal_goto
)
3129 /* First adjust our frame pointer to its actual value. It was
3130 previously set to the start of the virtual area corresponding to
3131 the stacked variables when we branched here and now needs to be
3132 adjusted to the actual hardware fp value.
3134 Assignments are to virtual registers are converted by
3135 instantiate_virtual_regs into the corresponding assignment
3136 to the underlying register (fp in this case) that makes
3137 the original assignment true.
3138 So the following insn will actually be
3139 decrementing fp by STARTING_FRAME_OFFSET. */
3140 emit_move_insn (virtual_stack_vars_rtx
, hard_frame_pointer_rtx
);
3142 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3143 if (fixed_regs
[ARG_POINTER_REGNUM
])
3145 #ifdef ELIMINABLE_REGS
3146 /* If the argument pointer can be eliminated in favor of the
3147 frame pointer, we don't need to restore it. We assume here
3148 that if such an elimination is present, it can always be used.
3149 This is the case on all known machines; if we don't make this
3150 assumption, we do unnecessary saving on many machines. */
3151 static struct elims
{int from
, to
;} elim_regs
[] = ELIMINABLE_REGS
;
3154 for (i
= 0; i
< sizeof elim_regs
/ sizeof elim_regs
[0]; i
++)
3155 if (elim_regs
[i
].from
== ARG_POINTER_REGNUM
3156 && elim_regs
[i
].to
== HARD_FRAME_POINTER_REGNUM
)
3159 if (i
== sizeof elim_regs
/ sizeof elim_regs
[0])
3162 /* Now restore our arg pointer from the address at which it
3163 was saved in our stack frame.
3164 If there hasn't be space allocated for it yet, make
3166 if (arg_pointer_save_area
== 0)
3167 arg_pointer_save_area
3168 = assign_stack_local (Pmode
, GET_MODE_SIZE (Pmode
), 0);
3169 emit_move_insn (virtual_incoming_args_rtx
,
3170 /* We need a pseudo here, or else
3171 instantiate_virtual_regs_1 complains. */
3172 copy_to_reg (arg_pointer_save_area
));
3177 #ifdef HAVE_nonlocal_goto_receiver
3178 if (HAVE_nonlocal_goto_receiver
)
3179 emit_insn (gen_nonlocal_goto_receiver ());
3183 /* Make handlers for nonlocal gotos taking place in the function calls in
3187 expand_nl_goto_receivers (thisblock
)
3188 struct nesting
*thisblock
;
3191 rtx afterward
= gen_label_rtx ();
3195 /* Record the handler address in the stack slot for that purpose,
3196 during this block, saving and restoring the outer value. */
3197 if (thisblock
->next
!= 0)
3198 for (slot
= nonlocal_goto_handler_slots
; slot
; slot
= XEXP (slot
, 1))
3200 rtx save_receiver
= gen_reg_rtx (Pmode
);
3201 emit_move_insn (XEXP (slot
, 0), save_receiver
);
3204 emit_move_insn (save_receiver
, XEXP (slot
, 0));
3205 insns
= get_insns ();
3207 emit_insns_before (insns
, thisblock
->data
.block
.first_insn
);
3210 /* Jump around the handlers; they run only when specially invoked. */
3211 emit_jump (afterward
);
3213 /* Make a separate handler for each label. */
3214 link
= nonlocal_labels
;
3215 slot
= nonlocal_goto_handler_slots
;
3216 for (; link
; link
= TREE_CHAIN (link
), slot
= XEXP (slot
, 1))
3217 /* Skip any labels we shouldn't be able to jump to from here,
3218 we generate one special handler for all of them below which just calls
3220 if (! DECL_TOO_LATE (TREE_VALUE (link
)))
3222 expand_nl_handler_label (XEXP (slot
, 0),
3223 thisblock
->data
.block
.first_insn
);
3224 expand_nl_goto_receiver ();
3226 /* Jump to the "real" nonlocal label. */
3227 expand_goto (TREE_VALUE (link
));
3230 /* A second pass over all nonlocal labels; this time we handle those
3231 we should not be able to jump to at this point. */
3232 link
= nonlocal_labels
;
3233 slot
= nonlocal_goto_handler_slots
;
3235 for (; link
; link
= TREE_CHAIN (link
), slot
= XEXP (slot
, 1))
3236 if (DECL_TOO_LATE (TREE_VALUE (link
)))
3238 expand_nl_handler_label (XEXP (slot
, 0),
3239 thisblock
->data
.block
.first_insn
);
3245 expand_nl_goto_receiver ();
3246 emit_library_call (gen_rtx_SYMBOL_REF (Pmode
, "abort"), 0,
3251 emit_label (afterward
);
3254 /* Generate RTL code to terminate a binding contour.
3255 VARS is the chain of VAR_DECL nodes
3256 for the variables bound in this contour.
3257 MARK_ENDS is nonzero if we should put a note at the beginning
3258 and end of this binding contour.
3260 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3261 (That is true automatically if the contour has a saved stack level.) */
3264 expand_end_bindings (vars
, mark_ends
, dont_jump_in
)
3269 register struct nesting
*thisblock
;
3272 while (block_stack
->data
.block
.exception_region
)
3274 /* Because we don't need or want a new temporary level and
3275 because we didn't create one in expand_eh_region_start,
3276 create a fake one now to avoid removing one in
3277 expand_end_bindings. */
3280 block_stack
->data
.block
.exception_region
= 0;
3282 expand_end_bindings (NULL_TREE
, 0, 0);
3285 /* Since expand_eh_region_start does an expand_start_bindings, we
3286 have to first end all the bindings that were created by
3287 expand_eh_region_start. */
3289 thisblock
= block_stack
;
3292 for (decl
= vars
; decl
; decl
= TREE_CHAIN (decl
))
3293 if (! TREE_USED (decl
) && TREE_CODE (decl
) == VAR_DECL
3294 && ! DECL_IN_SYSTEM_HEADER (decl
)
3295 && DECL_NAME (decl
) && ! DECL_ARTIFICIAL (decl
))
3296 warning_with_decl (decl
, "unused variable `%s'");
3298 if (thisblock
->exit_label
)
3300 do_pending_stack_adjust ();
3301 emit_label (thisblock
->exit_label
);
3304 /* If necessary, make handlers for nonlocal gotos taking
3305 place in the function calls in this block. */
3306 if (function_call_count
!= thisblock
->data
.block
.function_call_count
3308 /* Make handler for outermost block
3309 if there were any nonlocal gotos to this function. */
3310 && (thisblock
->next
== 0 ? current_function_has_nonlocal_label
3311 /* Make handler for inner block if it has something
3312 special to do when you jump out of it. */
3313 : (thisblock
->data
.block
.cleanups
!= 0
3314 || thisblock
->data
.block
.stack_level
!= 0)))
3315 expand_nl_goto_receivers (thisblock
);
3317 /* Don't allow jumping into a block that has a stack level.
3318 Cleanups are allowed, though. */
3320 || thisblock
->data
.block
.stack_level
!= 0)
3322 struct label_chain
*chain
;
3324 /* Any labels in this block are no longer valid to go to.
3325 Mark them to cause an error message. */
3326 for (chain
= thisblock
->data
.block
.label_chain
; chain
; chain
= chain
->next
)
3328 DECL_TOO_LATE (chain
->label
) = 1;
3329 /* If any goto without a fixup came to this label,
3330 that must be an error, because gotos without fixups
3331 come from outside all saved stack-levels. */
3332 if (TREE_ADDRESSABLE (chain
->label
))
3333 error_with_decl (chain
->label
,
3334 "label `%s' used before containing binding contour");
3338 /* Restore stack level in effect before the block
3339 (only if variable-size objects allocated). */
3340 /* Perform any cleanups associated with the block. */
3342 if (thisblock
->data
.block
.stack_level
!= 0
3343 || thisblock
->data
.block
.cleanups
!= 0)
3345 /* Only clean up here if this point can actually be reached. */
3346 int reachable
= GET_CODE (get_last_insn ()) != BARRIER
;
3348 /* Don't let cleanups affect ({...}) constructs. */
3349 int old_expr_stmts_for_value
= expr_stmts_for_value
;
3350 rtx old_last_expr_value
= last_expr_value
;
3351 tree old_last_expr_type
= last_expr_type
;
3352 expr_stmts_for_value
= 0;
3354 /* Do the cleanups. */
3355 expand_cleanups (thisblock
->data
.block
.cleanups
, NULL_TREE
, 0, reachable
);
3357 do_pending_stack_adjust ();
3359 expr_stmts_for_value
= old_expr_stmts_for_value
;
3360 last_expr_value
= old_last_expr_value
;
3361 last_expr_type
= old_last_expr_type
;
3363 /* Restore the stack level. */
3365 if (reachable
&& thisblock
->data
.block
.stack_level
!= 0)
3367 emit_stack_restore (thisblock
->next
? SAVE_BLOCK
: SAVE_FUNCTION
,
3368 thisblock
->data
.block
.stack_level
, NULL_RTX
);
3369 if (nonlocal_goto_handler_slots
!= 0)
3370 emit_stack_save (SAVE_NONLOCAL
, &nonlocal_goto_stack_level
,
3374 /* Any gotos out of this block must also do these things.
3375 Also report any gotos with fixups that came to labels in this
3377 fixup_gotos (thisblock
,
3378 thisblock
->data
.block
.stack_level
,
3379 thisblock
->data
.block
.cleanups
,
3380 thisblock
->data
.block
.first_insn
,
3384 /* Mark the beginning and end of the scope if requested.
3385 We do this now, after running cleanups on the variables
3386 just going out of scope, so they are in scope for their cleanups. */
3389 last_block_end_note
= emit_note (NULL_PTR
, NOTE_INSN_BLOCK_END
);
3391 /* Get rid of the beginning-mark if we don't make an end-mark. */
3392 NOTE_LINE_NUMBER (thisblock
->data
.block
.first_insn
) = NOTE_INSN_DELETED
;
3394 /* If doing stupid register allocation, make sure lives of all
3395 register variables declared here extend thru end of scope. */
3398 for (decl
= vars
; decl
; decl
= TREE_CHAIN (decl
))
3400 rtx rtl
= DECL_RTL (decl
);
3401 if (TREE_CODE (decl
) == VAR_DECL
&& rtl
!= 0)
3405 /* Restore the temporary level of TARGET_EXPRs. */
3406 target_temp_slot_level
= thisblock
->data
.block
.target_temp_slot_level
;
3408 /* Restore block_stack level for containing block. */
3410 stack_block_stack
= thisblock
->data
.block
.innermost_stack_block
;
3411 POPSTACK (block_stack
);
3413 /* Pop the stack slot nesting and free any slots at this level. */
3417 /* Generate RTL for the automatic variable declaration DECL.
3418 (Other kinds of declarations are simply ignored if seen here.) */
3424 struct nesting
*thisblock
= block_stack
;
3427 type
= TREE_TYPE (decl
);
3429 /* Only automatic variables need any expansion done.
3430 Static and external variables, and external functions,
3431 will be handled by `assemble_variable' (called from finish_decl).
3432 TYPE_DECL and CONST_DECL require nothing.
3433 PARM_DECLs are handled in `assign_parms'. */
3435 if (TREE_CODE (decl
) != VAR_DECL
)
3437 if (TREE_STATIC (decl
) || DECL_EXTERNAL (decl
))
3440 /* Create the RTL representation for the variable. */
3442 if (type
== error_mark_node
)
3443 DECL_RTL (decl
) = gen_rtx_MEM (BLKmode
, const0_rtx
);
3444 else if (DECL_SIZE (decl
) == 0)
3445 /* Variable with incomplete type. */
3447 if (DECL_INITIAL (decl
) == 0)
3448 /* Error message was already done; now avoid a crash. */
3449 DECL_RTL (decl
) = assign_stack_temp (DECL_MODE (decl
), 0, 1);
3451 /* An initializer is going to decide the size of this array.
3452 Until we know the size, represent its address with a reg. */
3453 DECL_RTL (decl
) = gen_rtx_MEM (BLKmode
, gen_reg_rtx (Pmode
));
3454 MEM_SET_IN_STRUCT_P (DECL_RTL (decl
), AGGREGATE_TYPE_P (type
));
3456 else if (DECL_MODE (decl
) != BLKmode
3457 /* If -ffloat-store, don't put explicit float vars
3459 && !(flag_float_store
3460 && TREE_CODE (type
) == REAL_TYPE
)
3461 && ! TREE_THIS_VOLATILE (decl
)
3462 && ! TREE_ADDRESSABLE (decl
)
3463 && (DECL_REGISTER (decl
) || ! obey_regdecls
)
3464 /* if -fcheck-memory-usage, check all variables. */
3465 && ! current_function_check_memory_usage
)
3467 /* Automatic variable that can go in a register. */
3468 int unsignedp
= TREE_UNSIGNED (type
);
3469 enum machine_mode reg_mode
3470 = promote_mode (type
, DECL_MODE (decl
), &unsignedp
, 0);
3472 DECL_RTL (decl
) = gen_reg_rtx (reg_mode
);
3473 mark_user_reg (DECL_RTL (decl
));
3475 if (POINTER_TYPE_P (type
))
3476 mark_reg_pointer (DECL_RTL (decl
),
3477 (TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl
)))
3481 else if (TREE_CODE (DECL_SIZE (decl
)) == INTEGER_CST
3482 && ! (flag_stack_check
&& ! STACK_CHECK_BUILTIN
3483 && (TREE_INT_CST_HIGH (DECL_SIZE (decl
)) != 0
3484 || (TREE_INT_CST_LOW (DECL_SIZE (decl
))
3485 > STACK_CHECK_MAX_VAR_SIZE
* BITS_PER_UNIT
))))
3487 /* Variable of fixed size that goes on the stack. */
3491 /* If we previously made RTL for this decl, it must be an array
3492 whose size was determined by the initializer.
3493 The old address was a register; set that register now
3494 to the proper address. */
3495 if (DECL_RTL (decl
) != 0)
3497 if (GET_CODE (DECL_RTL (decl
)) != MEM
3498 || GET_CODE (XEXP (DECL_RTL (decl
), 0)) != REG
)
3500 oldaddr
= XEXP (DECL_RTL (decl
), 0);
3503 DECL_RTL (decl
) = assign_temp (TREE_TYPE (decl
), 1, 1, 1);
3504 MEM_SET_IN_STRUCT_P (DECL_RTL (decl
),
3505 AGGREGATE_TYPE_P (TREE_TYPE (decl
)));
3507 /* Set alignment we actually gave this decl. */
3508 DECL_ALIGN (decl
) = (DECL_MODE (decl
) == BLKmode
? BIGGEST_ALIGNMENT
3509 : GET_MODE_BITSIZE (DECL_MODE (decl
)));
3513 addr
= force_operand (XEXP (DECL_RTL (decl
), 0), oldaddr
);
3514 if (addr
!= oldaddr
)
3515 emit_move_insn (oldaddr
, addr
);
3518 /* If this is a memory ref that contains aggregate components,
3519 mark it as such for cse and loop optimize. */
3520 MEM_SET_IN_STRUCT_P (DECL_RTL (decl
),
3521 AGGREGATE_TYPE_P (TREE_TYPE (decl
)));
3523 /* If this is in memory because of -ffloat-store,
3524 set the volatile bit, to prevent optimizations from
3525 undoing the effects. */
3526 if (flag_float_store
&& TREE_CODE (type
) == REAL_TYPE
)
3527 MEM_VOLATILE_P (DECL_RTL (decl
)) = 1;
3530 MEM_ALIAS_SET (DECL_RTL (decl
)) = get_alias_set (decl
);
3533 /* Dynamic-size object: must push space on the stack. */
3537 /* Record the stack pointer on entry to block, if have
3538 not already done so. */
3539 if (thisblock
->data
.block
.stack_level
== 0)
3541 do_pending_stack_adjust ();
3542 emit_stack_save (thisblock
->next
? SAVE_BLOCK
: SAVE_FUNCTION
,
3543 &thisblock
->data
.block
.stack_level
,
3544 thisblock
->data
.block
.first_insn
);
3545 stack_block_stack
= thisblock
;
3548 /* Compute the variable's size, in bytes. */
3549 size
= expand_expr (size_binop (CEIL_DIV_EXPR
,
3551 size_int (BITS_PER_UNIT
)),
3552 NULL_RTX
, VOIDmode
, 0);
3555 /* Allocate space on the stack for the variable. Note that
3556 DECL_ALIGN says how the variable is to be aligned and we
3557 cannot use it to conclude anything about the alignment of
3559 address
= allocate_dynamic_stack_space (size
, NULL_RTX
,
3560 TYPE_ALIGN (TREE_TYPE (decl
)));
3562 /* Reference the variable indirect through that rtx. */
3563 DECL_RTL (decl
) = gen_rtx_MEM (DECL_MODE (decl
), address
);
3565 /* If this is a memory ref that contains aggregate components,
3566 mark it as such for cse and loop optimize. */
3567 MEM_SET_IN_STRUCT_P (DECL_RTL (decl
),
3568 AGGREGATE_TYPE_P (TREE_TYPE (decl
)));
3570 /* Indicate the alignment we actually gave this variable. */
3571 #ifdef STACK_BOUNDARY
3572 DECL_ALIGN (decl
) = STACK_BOUNDARY
;
3574 DECL_ALIGN (decl
) = BIGGEST_ALIGNMENT
;
3578 if (TREE_THIS_VOLATILE (decl
))
3579 MEM_VOLATILE_P (DECL_RTL (decl
)) = 1;
3580 #if 0 /* A variable is not necessarily unchanging
3581 just because it is const. RTX_UNCHANGING_P
3582 means no change in the function,
3583 not merely no change in the variable's scope.
3584 It is correct to set RTX_UNCHANGING_P if the variable's scope
3585 is the whole function. There's no convenient way to test that. */
3586 if (TREE_READONLY (decl
))
3587 RTX_UNCHANGING_P (DECL_RTL (decl
)) = 1;
3590 /* If doing stupid register allocation, make sure life of any
3591 register variable starts here, at the start of its scope. */
3594 use_variable (DECL_RTL (decl
));
3599 /* Emit code to perform the initialization of a declaration DECL. */
3602 expand_decl_init (decl
)
3605 int was_used
= TREE_USED (decl
);
3607 /* If this is a CONST_DECL, we don't have to generate any code, but
3608 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3609 to be set while in the obstack containing the constant. If we don't
3610 do this, we can lose if we have functions nested three deep and the middle
3611 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3612 the innermost function is the first to expand that STRING_CST. */
3613 if (TREE_CODE (decl
) == CONST_DECL
)
3615 if (DECL_INITIAL (decl
) && TREE_CONSTANT (DECL_INITIAL (decl
)))
3616 expand_expr (DECL_INITIAL (decl
), NULL_RTX
, VOIDmode
,
3617 EXPAND_INITIALIZER
);
3621 if (TREE_STATIC (decl
))
3624 /* Compute and store the initial value now. */
3626 if (DECL_INITIAL (decl
) == error_mark_node
)
3628 enum tree_code code
= TREE_CODE (TREE_TYPE (decl
));
3630 if (code
== INTEGER_TYPE
|| code
== REAL_TYPE
|| code
== ENUMERAL_TYPE
3631 || code
== POINTER_TYPE
|| code
== REFERENCE_TYPE
)
3632 expand_assignment (decl
, convert (TREE_TYPE (decl
), integer_zero_node
),
3636 else if (DECL_INITIAL (decl
) && TREE_CODE (DECL_INITIAL (decl
)) != TREE_LIST
)
3638 emit_line_note (DECL_SOURCE_FILE (decl
), DECL_SOURCE_LINE (decl
));
3639 expand_assignment (decl
, DECL_INITIAL (decl
), 0, 0);
3643 /* Don't let the initialization count as "using" the variable. */
3644 TREE_USED (decl
) = was_used
;
3646 /* Free any temporaries we made while initializing the decl. */
3647 preserve_temp_slots (NULL_RTX
);
3651 /* CLEANUP is an expression to be executed at exit from this binding contour;
3652 for example, in C++, it might call the destructor for this variable.
3654 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
3655 CLEANUP multiple times, and have the correct semantics. This
3656 happens in exception handling, for gotos, returns, breaks that
3657 leave the current scope.
3659 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3660 that is not associated with any particular variable. */
3663 expand_decl_cleanup (decl
, cleanup
)
3666 struct nesting
*thisblock
= block_stack
;
3668 /* Error if we are not in any block. */
3672 /* Record the cleanup if there is one. */
3678 tree
*cleanups
= &thisblock
->data
.block
.cleanups
;
3679 int cond_context
= conditional_context ();
3683 rtx flag
= gen_reg_rtx (word_mode
);
3688 emit_move_insn (flag
, const0_rtx
);
3689 set_flag_0
= get_insns ();
3692 thisblock
->data
.block
.last_unconditional_cleanup
3693 = emit_insns_after (set_flag_0
,
3694 thisblock
->data
.block
.last_unconditional_cleanup
);
3696 emit_move_insn (flag
, const1_rtx
);
3698 /* All cleanups must be on the function_obstack. */
3699 push_obstacks_nochange ();
3700 resume_temporary_allocation ();
3702 cond
= build_decl (VAR_DECL
, NULL_TREE
, type_for_mode (word_mode
, 1));
3703 DECL_RTL (cond
) = flag
;
3705 /* Conditionalize the cleanup. */
3706 cleanup
= build (COND_EXPR
, void_type_node
,
3707 truthvalue_conversion (cond
),
3708 cleanup
, integer_zero_node
);
3709 cleanup
= fold (cleanup
);
3713 cleanups
= thisblock
->data
.block
.cleanup_ptr
;
3716 /* All cleanups must be on the function_obstack. */
3717 push_obstacks_nochange ();
3718 resume_temporary_allocation ();
3719 cleanup
= unsave_expr (cleanup
);
3722 t
= *cleanups
= temp_tree_cons (decl
, cleanup
, *cleanups
);
3725 /* If this block has a cleanup, it belongs in stack_block_stack. */
3726 stack_block_stack
= thisblock
;
3733 /* If this was optimized so that there is no exception region for the
3734 cleanup, then mark the TREE_LIST node, so that we can later tell
3735 if we need to call expand_eh_region_end. */
3736 if (! using_eh_for_cleanups_p
3737 || expand_eh_region_start_tree (decl
, cleanup
))
3738 TREE_ADDRESSABLE (t
) = 1;
3739 /* If that started a new EH region, we're in a new block. */
3740 thisblock
= block_stack
;
3747 thisblock
->data
.block
.last_unconditional_cleanup
3748 = emit_insns_after (seq
,
3749 thisblock
->data
.block
.last_unconditional_cleanup
);
3753 thisblock
->data
.block
.last_unconditional_cleanup
3755 thisblock
->data
.block
.cleanup_ptr
= &thisblock
->data
.block
.cleanups
;
3761 /* Like expand_decl_cleanup, but suppress generating an exception handler
3762 to perform the cleanup. */
3765 expand_decl_cleanup_no_eh (decl
, cleanup
)
3768 int save_eh
= using_eh_for_cleanups_p
;
3771 using_eh_for_cleanups_p
= 0;
3772 result
= expand_decl_cleanup (decl
, cleanup
);
3773 using_eh_for_cleanups_p
= save_eh
;
3778 /* Arrange for the top element of the dynamic cleanup chain to be
3779 popped if we exit the current binding contour. DECL is the
3780 associated declaration, if any, otherwise NULL_TREE. If the
3781 current contour is left via an exception, then __sjthrow will pop
3782 the top element off the dynamic cleanup chain. The code that
3783 avoids doing the action we push into the cleanup chain in the
3784 exceptional case is contained in expand_cleanups.
3786 This routine is only used by expand_eh_region_start, and that is
3787 the only way in which an exception region should be started. This
3788 routine is only used when using the setjmp/longjmp codegen method
3789 for exception handling. */
3792 expand_dcc_cleanup (decl
)
3795 struct nesting
*thisblock
= block_stack
;
3798 /* Error if we are not in any block. */
3802 /* Record the cleanup for the dynamic handler chain. */
3804 /* All cleanups must be on the function_obstack. */
3805 push_obstacks_nochange ();
3806 resume_temporary_allocation ();
3807 cleanup
= make_node (POPDCC_EXPR
);
3810 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
3811 thisblock
->data
.block
.cleanups
3812 = temp_tree_cons (decl
, cleanup
, thisblock
->data
.block
.cleanups
);
3814 /* If this block has a cleanup, it belongs in stack_block_stack. */
3815 stack_block_stack
= thisblock
;
3819 /* Arrange for the top element of the dynamic handler chain to be
3820 popped if we exit the current binding contour. DECL is the
3821 associated declaration, if any, otherwise NULL_TREE. If the current
3822 contour is left via an exception, then __sjthrow will pop the top
3823 element off the dynamic handler chain. The code that avoids doing
3824 the action we push into the handler chain in the exceptional case
3825 is contained in expand_cleanups.
3827 This routine is only used by expand_eh_region_start, and that is
3828 the only way in which an exception region should be started. This
3829 routine is only used when using the setjmp/longjmp codegen method
3830 for exception handling. */
3833 expand_dhc_cleanup (decl
)
3836 struct nesting
*thisblock
= block_stack
;
3839 /* Error if we are not in any block. */
3843 /* Record the cleanup for the dynamic handler chain. */
3845 /* All cleanups must be on the function_obstack. */
3846 push_obstacks_nochange ();
3847 resume_temporary_allocation ();
3848 cleanup
= make_node (POPDHC_EXPR
);
3851 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
3852 thisblock
->data
.block
.cleanups
3853 = temp_tree_cons (decl
, cleanup
, thisblock
->data
.block
.cleanups
);
3855 /* If this block has a cleanup, it belongs in stack_block_stack. */
3856 stack_block_stack
= thisblock
;
3860 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
3861 DECL_ELTS is the list of elements that belong to DECL's type.
3862 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
3865 expand_anon_union_decl (decl
, cleanup
, decl_elts
)
3866 tree decl
, cleanup
, decl_elts
;
3868 struct nesting
*thisblock
= block_stack
;
3872 expand_decl_cleanup (decl
, cleanup
);
3873 x
= DECL_RTL (decl
);
3877 tree decl_elt
= TREE_VALUE (decl_elts
);
3878 tree cleanup_elt
= TREE_PURPOSE (decl_elts
);
3879 enum machine_mode mode
= TYPE_MODE (TREE_TYPE (decl_elt
));
3881 /* Propagate the union's alignment to the elements. */
3882 DECL_ALIGN (decl_elt
) = DECL_ALIGN (decl
);
3884 /* If the element has BLKmode and the union doesn't, the union is
3885 aligned such that the element doesn't need to have BLKmode, so
3886 change the element's mode to the appropriate one for its size. */
3887 if (mode
== BLKmode
&& DECL_MODE (decl
) != BLKmode
)
3888 DECL_MODE (decl_elt
) = mode
3889 = mode_for_size (TREE_INT_CST_LOW (DECL_SIZE (decl_elt
)),
3892 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
3893 instead create a new MEM rtx with the proper mode. */
3894 if (GET_CODE (x
) == MEM
)
3896 if (mode
== GET_MODE (x
))
3897 DECL_RTL (decl_elt
) = x
;
3900 DECL_RTL (decl_elt
) = gen_rtx_MEM (mode
, copy_rtx (XEXP (x
, 0)));
3901 MEM_COPY_ATTRIBUTES (DECL_RTL (decl_elt
), x
);
3902 RTX_UNCHANGING_P (DECL_RTL (decl_elt
)) = RTX_UNCHANGING_P (x
);
3905 else if (GET_CODE (x
) == REG
)
3907 if (mode
== GET_MODE (x
))
3908 DECL_RTL (decl_elt
) = x
;
3910 DECL_RTL (decl_elt
) = gen_rtx_SUBREG (mode
, x
, 0);
3915 /* Record the cleanup if there is one. */
3918 thisblock
->data
.block
.cleanups
3919 = temp_tree_cons (decl_elt
, cleanup_elt
,
3920 thisblock
->data
.block
.cleanups
);
3922 decl_elts
= TREE_CHAIN (decl_elts
);
3926 /* Expand a list of cleanups LIST.
3927 Elements may be expressions or may be nested lists.
3929 If DONT_DO is nonnull, then any list-element
3930 whose TREE_PURPOSE matches DONT_DO is omitted.
3931 This is sometimes used to avoid a cleanup associated with
3932 a value that is being returned out of the scope.
3934 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
3935 goto and handle protection regions specially in that case.
3937 If REACHABLE, we emit code, otherwise just inform the exception handling
3938 code about this finalization. */
3941 expand_cleanups (list
, dont_do
, in_fixup
, reachable
)
3948 for (tail
= list
; tail
; tail
= TREE_CHAIN (tail
))
3949 if (dont_do
== 0 || TREE_PURPOSE (tail
) != dont_do
)
3951 if (TREE_CODE (TREE_VALUE (tail
)) == TREE_LIST
)
3952 expand_cleanups (TREE_VALUE (tail
), dont_do
, in_fixup
, reachable
);
3957 tree cleanup
= TREE_VALUE (tail
);
3959 /* See expand_d{h,c}c_cleanup for why we avoid this. */
3960 if (TREE_CODE (cleanup
) != POPDHC_EXPR
3961 && TREE_CODE (cleanup
) != POPDCC_EXPR
3962 /* See expand_eh_region_start_tree for this case. */
3963 && ! TREE_ADDRESSABLE (tail
))
3965 cleanup
= protect_with_terminate (cleanup
);
3966 expand_eh_region_end (cleanup
);
3972 /* Cleanups may be run multiple times. For example,
3973 when exiting a binding contour, we expand the
3974 cleanups associated with that contour. When a goto
3975 within that binding contour has a target outside that
3976 contour, it will expand all cleanups from its scope to
3977 the target. Though the cleanups are expanded multiple
3978 times, the control paths are non-overlapping so the
3979 cleanups will not be executed twice. */
3981 /* We may need to protect fixups with rethrow regions. */
3982 int protect
= (in_fixup
&& ! TREE_ADDRESSABLE (tail
));
3985 expand_fixup_region_start ();
3987 expand_expr (TREE_VALUE (tail
), const0_rtx
, VOIDmode
, 0);
3989 expand_fixup_region_end (TREE_VALUE (tail
));
3996 /* Mark when the context we are emitting RTL for as a conditional
3997 context, so that any cleanup actions we register with
3998 expand_decl_init will be properly conditionalized when those
3999 cleanup actions are later performed. Must be called before any
4000 expression (tree) is expanded that is within a conditional context. */
4003 start_cleanup_deferral ()
4005 /* block_stack can be NULL if we are inside the parameter list. It is
4006 OK to do nothing, because cleanups aren't possible here. */
4008 ++block_stack
->data
.block
.conditional_code
;
4011 /* Mark the end of a conditional region of code. Because cleanup
4012 deferrals may be nested, we may still be in a conditional region
4013 after we end the currently deferred cleanups, only after we end all
4014 deferred cleanups, are we back in unconditional code. */
4017 end_cleanup_deferral ()
4019 /* block_stack can be NULL if we are inside the parameter list. It is
4020 OK to do nothing, because cleanups aren't possible here. */
4022 --block_stack
->data
.block
.conditional_code
;
4025 /* Move all cleanups from the current block_stack
4026 to the containing block_stack, where they are assumed to
4027 have been created. If anything can cause a temporary to
4028 be created, but not expanded for more than one level of
4029 block_stacks, then this code will have to change. */
4034 struct nesting
*block
= block_stack
;
4035 struct nesting
*outer
= block
->next
;
4037 outer
->data
.block
.cleanups
4038 = chainon (block
->data
.block
.cleanups
,
4039 outer
->data
.block
.cleanups
);
4040 block
->data
.block
.cleanups
= 0;
4044 last_cleanup_this_contour ()
4046 if (block_stack
== 0)
4049 return block_stack
->data
.block
.cleanups
;
4052 /* Return 1 if there are any pending cleanups at this point.
4053 If THIS_CONTOUR is nonzero, check the current contour as well.
4054 Otherwise, look only at the contours that enclose this one. */
4057 any_pending_cleanups (this_contour
)
4060 struct nesting
*block
;
4062 if (block_stack
== 0)
4065 if (this_contour
&& block_stack
->data
.block
.cleanups
!= NULL
)
4067 if (block_stack
->data
.block
.cleanups
== 0
4068 && block_stack
->data
.block
.outer_cleanups
== 0)
4071 for (block
= block_stack
->next
; block
; block
= block
->next
)
4072 if (block
->data
.block
.cleanups
!= 0)
4078 /* Enter a case (Pascal) or switch (C) statement.
4079 Push a block onto case_stack and nesting_stack
4080 to accumulate the case-labels that are seen
4081 and to record the labels generated for the statement.
4083 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4084 Otherwise, this construct is transparent for `exit_something'.
4086 EXPR is the index-expression to be dispatched on.
4087 TYPE is its nominal type. We could simply convert EXPR to this type,
4088 but instead we take short cuts. */
4091 expand_start_case (exit_flag
, expr
, type
, printname
)
4097 register struct nesting
*thiscase
= ALLOC_NESTING ();
4099 /* Make an entry on case_stack for the case we are entering. */
4101 thiscase
->next
= case_stack
;
4102 thiscase
->all
= nesting_stack
;
4103 thiscase
->depth
= ++nesting_depth
;
4104 thiscase
->exit_label
= exit_flag
? gen_label_rtx () : 0;
4105 thiscase
->data
.case_stmt
.case_list
= 0;
4106 thiscase
->data
.case_stmt
.index_expr
= expr
;
4107 thiscase
->data
.case_stmt
.nominal_type
= type
;
4108 thiscase
->data
.case_stmt
.default_label
= 0;
4109 thiscase
->data
.case_stmt
.num_ranges
= 0;
4110 thiscase
->data
.case_stmt
.printname
= printname
;
4111 thiscase
->data
.case_stmt
.line_number_status
= force_line_numbers ();
4112 case_stack
= thiscase
;
4113 nesting_stack
= thiscase
;
4115 do_pending_stack_adjust ();
4117 /* Make sure case_stmt.start points to something that won't
4118 need any transformation before expand_end_case. */
4119 if (GET_CODE (get_last_insn ()) != NOTE
)
4120 emit_note (NULL_PTR
, NOTE_INSN_DELETED
);
4122 thiscase
->data
.case_stmt
.start
= get_last_insn ();
4124 start_cleanup_deferral ();
4128 /* Start a "dummy case statement" within which case labels are invalid
4129 and are not connected to any larger real case statement.
4130 This can be used if you don't want to let a case statement jump
4131 into the middle of certain kinds of constructs. */
4134 expand_start_case_dummy ()
4136 register struct nesting
*thiscase
= ALLOC_NESTING ();
4138 /* Make an entry on case_stack for the dummy. */
4140 thiscase
->next
= case_stack
;
4141 thiscase
->all
= nesting_stack
;
4142 thiscase
->depth
= ++nesting_depth
;
4143 thiscase
->exit_label
= 0;
4144 thiscase
->data
.case_stmt
.case_list
= 0;
4145 thiscase
->data
.case_stmt
.start
= 0;
4146 thiscase
->data
.case_stmt
.nominal_type
= 0;
4147 thiscase
->data
.case_stmt
.default_label
= 0;
4148 thiscase
->data
.case_stmt
.num_ranges
= 0;
4149 case_stack
= thiscase
;
4150 nesting_stack
= thiscase
;
4151 start_cleanup_deferral ();
4154 /* End a dummy case statement. */
4157 expand_end_case_dummy ()
4159 end_cleanup_deferral ();
4160 POPSTACK (case_stack
);
4163 /* Return the data type of the index-expression
4164 of the innermost case statement, or null if none. */
4167 case_index_expr_type ()
4170 return TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4177 /* If this is the first label, warn if any insns have been emitted. */
4178 if (case_stack
->data
.case_stmt
.line_number_status
>= 0)
4182 restore_line_number_status
4183 (case_stack
->data
.case_stmt
.line_number_status
);
4184 case_stack
->data
.case_stmt
.line_number_status
= -1;
4186 for (insn
= case_stack
->data
.case_stmt
.start
;
4188 insn
= NEXT_INSN (insn
))
4190 if (GET_CODE (insn
) == CODE_LABEL
)
4192 if (GET_CODE (insn
) != NOTE
4193 && (GET_CODE (insn
) != INSN
|| GET_CODE (PATTERN (insn
)) != USE
))
4196 insn
= PREV_INSN (insn
);
4197 while (insn
&& (GET_CODE (insn
) != NOTE
|| NOTE_LINE_NUMBER (insn
) < 0));
4199 /* If insn is zero, then there must have been a syntax error. */
4201 warning_with_file_and_line (NOTE_SOURCE_FILE(insn
),
4202 NOTE_LINE_NUMBER(insn
),
4203 "unreachable code at beginning of %s",
4204 case_stack
->data
.case_stmt
.printname
);
4211 /* Accumulate one case or default label inside a case or switch statement.
4212 VALUE is the value of the case (a null pointer, for a default label).
4213 The function CONVERTER, when applied to arguments T and V,
4214 converts the value V to the type T.
4216 If not currently inside a case or switch statement, return 1 and do
4217 nothing. The caller will print a language-specific error message.
4218 If VALUE is a duplicate or overlaps, return 2 and do nothing
4219 except store the (first) duplicate node in *DUPLICATE.
4220 If VALUE is out of range, return 3 and do nothing.
4221 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4222 Return 0 on success.
4224 Extended to handle range statements. */
4227 pushcase (value
, converter
, label
, duplicate
)
4228 register tree value
;
4229 tree (*converter
) PROTO((tree
, tree
));
4230 register tree label
;
4236 /* Fail if not inside a real case statement. */
4237 if (! (case_stack
&& case_stack
->data
.case_stmt
.start
))
4240 if (stack_block_stack
4241 && stack_block_stack
->depth
> case_stack
->depth
)
4244 index_type
= TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4245 nominal_type
= case_stack
->data
.case_stmt
.nominal_type
;
4247 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4248 if (index_type
== error_mark_node
)
4251 /* Convert VALUE to the type in which the comparisons are nominally done. */
4253 value
= (*converter
) (nominal_type
, value
);
4257 /* Fail if this value is out of range for the actual type of the index
4258 (which may be narrower than NOMINAL_TYPE). */
4259 if (value
!= 0 && ! int_fits_type_p (value
, index_type
))
4262 /* Fail if this is a duplicate or overlaps another entry. */
4265 if (case_stack
->data
.case_stmt
.default_label
!= 0)
4267 *duplicate
= case_stack
->data
.case_stmt
.default_label
;
4270 case_stack
->data
.case_stmt
.default_label
= label
;
4273 return add_case_node (value
, value
, label
, duplicate
);
4275 expand_label (label
);
4279 /* Like pushcase but this case applies to all values between VALUE1 and
4280 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4281 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4282 starts at VALUE1 and ends at the highest value of the index type.
4283 If both are NULL, this case applies to all values.
4285 The return value is the same as that of pushcase but there is one
4286 additional error code: 4 means the specified range was empty. */
4289 pushcase_range (value1
, value2
, converter
, label
, duplicate
)
4290 register tree value1
, value2
;
4291 tree (*converter
) PROTO((tree
, tree
));
4292 register tree label
;
4298 /* Fail if not inside a real case statement. */
4299 if (! (case_stack
&& case_stack
->data
.case_stmt
.start
))
4302 if (stack_block_stack
4303 && stack_block_stack
->depth
> case_stack
->depth
)
4306 index_type
= TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4307 nominal_type
= case_stack
->data
.case_stmt
.nominal_type
;
4309 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4310 if (index_type
== error_mark_node
)
4315 /* Convert VALUEs to type in which the comparisons are nominally done
4316 and replace any unspecified value with the corresponding bound. */
4318 value1
= TYPE_MIN_VALUE (index_type
);
4320 value2
= TYPE_MAX_VALUE (index_type
);
4322 /* Fail if the range is empty. Do this before any conversion since
4323 we want to allow out-of-range empty ranges. */
4324 if (value2
&& tree_int_cst_lt (value2
, value1
))
4327 value1
= (*converter
) (nominal_type
, value1
);
4329 /* If the max was unbounded, use the max of the nominal_type we are
4330 converting to. Do this after the < check above to suppress false
4333 value2
= TYPE_MAX_VALUE (nominal_type
);
4334 value2
= (*converter
) (nominal_type
, value2
);
4336 /* Fail if these values are out of range. */
4337 if (TREE_CONSTANT_OVERFLOW (value1
)
4338 || ! int_fits_type_p (value1
, index_type
))
4341 if (TREE_CONSTANT_OVERFLOW (value2
)
4342 || ! int_fits_type_p (value2
, index_type
))
4345 return add_case_node (value1
, value2
, label
, duplicate
);
4348 /* Do the actual insertion of a case label for pushcase and pushcase_range
4349 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4350 slowdown for large switch statements. */
4353 add_case_node (low
, high
, label
, duplicate
)
4358 struct case_node
*p
, **q
, *r
;
4360 q
= &case_stack
->data
.case_stmt
.case_list
;
4367 /* Keep going past elements distinctly greater than HIGH. */
4368 if (tree_int_cst_lt (high
, p
->low
))
4371 /* or distinctly less than LOW. */
4372 else if (tree_int_cst_lt (p
->high
, low
))
4377 /* We have an overlap; this is an error. */
4378 *duplicate
= p
->code_label
;
4383 /* Add this label to the chain, and succeed.
4384 Copy LOW, HIGH so they are on temporary rather than momentary
4385 obstack and will thus survive till the end of the case statement. */
4387 r
= (struct case_node
*) oballoc (sizeof (struct case_node
));
4388 r
->low
= copy_node (low
);
4390 /* If the bounds are equal, turn this into the one-value case. */
4392 if (tree_int_cst_equal (low
, high
))
4396 r
->high
= copy_node (high
);
4397 case_stack
->data
.case_stmt
.num_ranges
++;
4400 r
->code_label
= label
;
4401 expand_label (label
);
4411 struct case_node
*s
;
4417 if (! (b
= p
->balance
))
4418 /* Growth propagation from left side. */
4425 if ((p
->left
= s
= r
->right
))
4434 if ((r
->parent
= s
))
4442 case_stack
->data
.case_stmt
.case_list
= r
;
4445 /* r->balance == +1 */
4450 struct case_node
*t
= r
->right
;
4452 if ((p
->left
= s
= t
->right
))
4456 if ((r
->right
= s
= t
->left
))
4470 if ((t
->parent
= s
))
4478 case_stack
->data
.case_stmt
.case_list
= t
;
4485 /* p->balance == +1; growth of left side balances the node. */
4495 if (! (b
= p
->balance
))
4496 /* Growth propagation from right side. */
4504 if ((p
->right
= s
= r
->left
))
4512 if ((r
->parent
= s
))
4521 case_stack
->data
.case_stmt
.case_list
= r
;
4525 /* r->balance == -1 */
4529 struct case_node
*t
= r
->left
;
4531 if ((p
->right
= s
= t
->left
))
4536 if ((r
->left
= s
= t
->right
))
4550 if ((t
->parent
= s
))
4559 case_stack
->data
.case_stmt
.case_list
= t
;
4565 /* p->balance == -1; growth of right side balances the node. */
4579 /* Returns the number of possible values of TYPE.
4580 Returns -1 if the number is unknown or variable.
4581 Returns -2 if the number does not fit in a HOST_WIDE_INT.
4582 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4583 do not increase monotonically (there may be duplicates);
4584 to 1 if the values increase monotonically, but not always by 1;
4585 otherwise sets it to 0. */
4588 all_cases_count (type
, spareness
)
4592 HOST_WIDE_INT count
;
4595 switch (TREE_CODE (type
))
4602 count
= 1 << BITS_PER_UNIT
;
4606 if (TREE_CODE (TYPE_MIN_VALUE (type
)) != INTEGER_CST
4607 || TYPE_MAX_VALUE (type
) == NULL
4608 || TREE_CODE (TYPE_MAX_VALUE (type
)) != INTEGER_CST
)
4613 = TREE_INT_CST_LOW (TYPE_MAX_VALUE (type))
4614 - TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + 1
4615 but with overflow checking. */
4616 tree mint
= TYPE_MIN_VALUE (type
);
4617 tree maxt
= TYPE_MAX_VALUE (type
);
4618 HOST_WIDE_INT lo
, hi
;
4619 neg_double(TREE_INT_CST_LOW (mint
), TREE_INT_CST_HIGH (mint
),
4621 add_double(TREE_INT_CST_LOW (maxt
), TREE_INT_CST_HIGH (maxt
),
4623 add_double (lo
, hi
, 1, 0, &lo
, &hi
);
4624 if (hi
!= 0 || lo
< 0)
4631 for (t
= TYPE_VALUES (type
); t
!= NULL_TREE
; t
= TREE_CHAIN (t
))
4633 if (TREE_CODE (TYPE_MIN_VALUE (type
)) != INTEGER_CST
4634 || TREE_CODE (TREE_VALUE (t
)) != INTEGER_CST
4635 || TREE_INT_CST_LOW (TYPE_MIN_VALUE (type
)) + count
4636 != TREE_INT_CST_LOW (TREE_VALUE (t
)))
4640 if (*spareness
== 1)
4642 tree prev
= TREE_VALUE (TYPE_VALUES (type
));
4643 for (t
= TYPE_VALUES (type
); t
= TREE_CHAIN (t
), t
!= NULL_TREE
; )
4645 if (! tree_int_cst_lt (prev
, TREE_VALUE (t
)))
4650 prev
= TREE_VALUE (t
);
4659 #define BITARRAY_TEST(ARRAY, INDEX) \
4660 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4661 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4662 #define BITARRAY_SET(ARRAY, INDEX) \
4663 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4664 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4666 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4667 with the case values we have seen, assuming the case expression
4669 SPARSENESS is as determined by all_cases_count.
4671 The time needed is proportional to COUNT, unless
4672 SPARSENESS is 2, in which case quadratic time is needed. */
4675 mark_seen_cases (type
, cases_seen
, count
, sparseness
)
4677 unsigned char *cases_seen
;
4681 tree next_node_to_try
= NULL_TREE
;
4682 long next_node_offset
= 0;
4684 register struct case_node
*n
, *root
= case_stack
->data
.case_stmt
.case_list
;
4685 tree val
= make_node (INTEGER_CST
);
4686 TREE_TYPE (val
) = type
;
4689 else if (sparseness
== 2)
4694 /* This less efficient loop is only needed to handle
4695 duplicate case values (multiple enum constants
4696 with the same value). */
4697 TREE_TYPE (val
) = TREE_TYPE (root
->low
);
4698 for (t
= TYPE_VALUES (type
), xlo
= 0; t
!= NULL_TREE
;
4699 t
= TREE_CHAIN (t
), xlo
++)
4701 TREE_INT_CST_LOW (val
) = TREE_INT_CST_LOW (TREE_VALUE (t
));
4702 TREE_INT_CST_HIGH (val
) = TREE_INT_CST_HIGH (TREE_VALUE (t
));
4706 /* Keep going past elements distinctly greater than VAL. */
4707 if (tree_int_cst_lt (val
, n
->low
))
4710 /* or distinctly less than VAL. */
4711 else if (tree_int_cst_lt (n
->high
, val
))
4716 /* We have found a matching range. */
4717 BITARRAY_SET (cases_seen
, xlo
);
4727 case_stack
->data
.case_stmt
.case_list
= root
= case_tree2list (root
, 0);
4728 for (n
= root
; n
; n
= n
->right
)
4730 TREE_INT_CST_LOW (val
) = TREE_INT_CST_LOW (n
->low
);
4731 TREE_INT_CST_HIGH (val
) = TREE_INT_CST_HIGH (n
->low
);
4732 while ( ! tree_int_cst_lt (n
->high
, val
))
4734 /* Calculate (into xlo) the "offset" of the integer (val).
4735 The element with lowest value has offset 0, the next smallest
4736 element has offset 1, etc. */
4738 HOST_WIDE_INT xlo
, xhi
;
4740 if (sparseness
&& TYPE_VALUES (type
) != NULL_TREE
)
4742 /* The TYPE_VALUES will be in increasing order, so
4743 starting searching where we last ended. */
4744 t
= next_node_to_try
;
4745 xlo
= next_node_offset
;
4751 t
= TYPE_VALUES (type
);
4754 if (tree_int_cst_equal (val
, TREE_VALUE (t
)))
4756 next_node_to_try
= TREE_CHAIN (t
);
4757 next_node_offset
= xlo
+ 1;
4762 if (t
== next_node_to_try
)
4771 t
= TYPE_MIN_VALUE (type
);
4773 neg_double (TREE_INT_CST_LOW (t
), TREE_INT_CST_HIGH (t
),
4777 add_double (xlo
, xhi
,
4778 TREE_INT_CST_LOW (val
), TREE_INT_CST_HIGH (val
),
4782 if (xhi
== 0 && xlo
>= 0 && xlo
< count
)
4783 BITARRAY_SET (cases_seen
, xlo
);
4784 add_double (TREE_INT_CST_LOW (val
), TREE_INT_CST_HIGH (val
),
4786 &TREE_INT_CST_LOW (val
), &TREE_INT_CST_HIGH (val
));
4792 /* Called when the index of a switch statement is an enumerated type
4793 and there is no default label.
4795 Checks that all enumeration literals are covered by the case
4796 expressions of a switch. Also, warn if there are any extra
4797 switch cases that are *not* elements of the enumerated type.
4799 If all enumeration literals were covered by the case expressions,
4800 turn one of the expressions into the default expression since it should
4801 not be possible to fall through such a switch. */
4804 check_for_full_enumeration_handling (type
)
4807 register struct case_node
*n
;
4808 register tree chain
;
4809 #if 0 /* variable used by 'if 0'ed code below. */
4810 register struct case_node
**l
;
4814 /* True iff the selector type is a numbered set mode. */
4817 /* The number of possible selector values. */
4820 /* For each possible selector value. a one iff it has been matched
4821 by a case value alternative. */
4822 unsigned char *cases_seen
;
4824 /* The allocated size of cases_seen, in chars. */
4830 size
= all_cases_count (type
, &sparseness
);
4831 bytes_needed
= (size
+ HOST_BITS_PER_CHAR
) / HOST_BITS_PER_CHAR
;
4833 if (size
> 0 && size
< 600000
4834 /* We deliberately use malloc here - not xmalloc. */
4835 && (cases_seen
= (unsigned char *) malloc (bytes_needed
)) != NULL
)
4838 tree v
= TYPE_VALUES (type
);
4839 bzero (cases_seen
, bytes_needed
);
4841 /* The time complexity of this code is normally O(N), where
4842 N being the number of members in the enumerated type.
4843 However, if type is a ENUMERAL_TYPE whose values do not
4844 increase monotonically, O(N*log(N)) time may be needed. */
4846 mark_seen_cases (type
, cases_seen
, size
, sparseness
);
4848 for (i
= 0; v
!= NULL_TREE
&& i
< size
; i
++, v
= TREE_CHAIN (v
))
4850 if (BITARRAY_TEST(cases_seen
, i
) == 0)
4851 warning ("enumeration value `%s' not handled in switch",
4852 IDENTIFIER_POINTER (TREE_PURPOSE (v
)));
4858 /* Now we go the other way around; we warn if there are case
4859 expressions that don't correspond to enumerators. This can
4860 occur since C and C++ don't enforce type-checking of
4861 assignments to enumeration variables. */
4863 if (case_stack
->data
.case_stmt
.case_list
4864 && case_stack
->data
.case_stmt
.case_list
->left
)
4865 case_stack
->data
.case_stmt
.case_list
4866 = case_tree2list (case_stack
->data
.case_stmt
.case_list
, 0);
4868 for (n
= case_stack
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
4870 for (chain
= TYPE_VALUES (type
);
4871 chain
&& !tree_int_cst_equal (n
->low
, TREE_VALUE (chain
));
4872 chain
= TREE_CHAIN (chain
))
4877 if (TYPE_NAME (type
) == 0)
4878 warning ("case value `%ld' not in enumerated type",
4879 (long) TREE_INT_CST_LOW (n
->low
));
4881 warning ("case value `%ld' not in enumerated type `%s'",
4882 (long) TREE_INT_CST_LOW (n
->low
),
4883 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type
))
4886 : DECL_NAME (TYPE_NAME (type
))));
4888 if (!tree_int_cst_equal (n
->low
, n
->high
))
4890 for (chain
= TYPE_VALUES (type
);
4891 chain
&& !tree_int_cst_equal (n
->high
, TREE_VALUE (chain
));
4892 chain
= TREE_CHAIN (chain
))
4897 if (TYPE_NAME (type
) == 0)
4898 warning ("case value `%ld' not in enumerated type",
4899 (long) TREE_INT_CST_LOW (n
->high
));
4901 warning ("case value `%ld' not in enumerated type `%s'",
4902 (long) TREE_INT_CST_LOW (n
->high
),
4903 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type
))
4906 : DECL_NAME (TYPE_NAME (type
))));
4912 /* ??? This optimization is disabled because it causes valid programs to
4913 fail. ANSI C does not guarantee that an expression with enum type
4914 will have a value that is the same as one of the enumeration literals. */
4916 /* If all values were found as case labels, make one of them the default
4917 label. Thus, this switch will never fall through. We arbitrarily pick
4918 the last one to make the default since this is likely the most
4919 efficient choice. */
4923 for (l
= &case_stack
->data
.case_stmt
.case_list
;
4928 case_stack
->data
.case_stmt
.default_label
= (*l
)->code_label
;
4935 /* Terminate a case (Pascal) or switch (C) statement
4936 in which ORIG_INDEX is the expression to be tested.
4937 Generate the code to test it and jump to the right place. */
4940 expand_end_case (orig_index
)
4943 tree minval
, maxval
, range
, orig_minval
;
4944 rtx default_label
= 0;
4945 register struct case_node
*n
;
4953 register struct nesting
*thiscase
= case_stack
;
4954 tree index_expr
, index_type
;
4957 table_label
= gen_label_rtx ();
4958 index_expr
= thiscase
->data
.case_stmt
.index_expr
;
4959 index_type
= TREE_TYPE (index_expr
);
4960 unsignedp
= TREE_UNSIGNED (index_type
);
4962 do_pending_stack_adjust ();
4964 /* This might get an spurious warning in the presence of a syntax error;
4965 it could be fixed by moving the call to check_seenlabel after the
4966 check for error_mark_node, and copying the code of check_seenlabel that
4967 deals with case_stack->data.case_stmt.line_number_status /
4968 restore_line_number_status in front of the call to end_cleanup_deferral;
4969 However, this might miss some useful warnings in the presence of
4970 non-syntax errors. */
4973 /* An ERROR_MARK occurs for various reasons including invalid data type. */
4974 if (index_type
!= error_mark_node
)
4976 /* If switch expression was an enumerated type, check that all
4977 enumeration literals are covered by the cases.
4978 No sense trying this if there's a default case, however. */
4980 if (!thiscase
->data
.case_stmt
.default_label
4981 && TREE_CODE (TREE_TYPE (orig_index
)) == ENUMERAL_TYPE
4982 && TREE_CODE (index_expr
) != INTEGER_CST
)
4983 check_for_full_enumeration_handling (TREE_TYPE (orig_index
));
4985 /* If we don't have a default-label, create one here,
4986 after the body of the switch. */
4987 if (thiscase
->data
.case_stmt
.default_label
== 0)
4989 thiscase
->data
.case_stmt
.default_label
4990 = build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
4991 expand_label (thiscase
->data
.case_stmt
.default_label
);
4993 default_label
= label_rtx (thiscase
->data
.case_stmt
.default_label
);
4995 before_case
= get_last_insn ();
4997 if (thiscase
->data
.case_stmt
.case_list
4998 && thiscase
->data
.case_stmt
.case_list
->left
)
4999 thiscase
->data
.case_stmt
.case_list
5000 = case_tree2list(thiscase
->data
.case_stmt
.case_list
, 0);
5002 /* Simplify the case-list before we count it. */
5003 group_case_nodes (thiscase
->data
.case_stmt
.case_list
);
5005 /* Get upper and lower bounds of case values.
5006 Also convert all the case values to the index expr's data type. */
5009 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5011 /* Check low and high label values are integers. */
5012 if (TREE_CODE (n
->low
) != INTEGER_CST
)
5014 if (TREE_CODE (n
->high
) != INTEGER_CST
)
5017 n
->low
= convert (index_type
, n
->low
);
5018 n
->high
= convert (index_type
, n
->high
);
5020 /* Count the elements and track the largest and smallest
5021 of them (treating them as signed even if they are not). */
5029 if (INT_CST_LT (n
->low
, minval
))
5031 if (INT_CST_LT (maxval
, n
->high
))
5034 /* A range counts double, since it requires two compares. */
5035 if (! tree_int_cst_equal (n
->low
, n
->high
))
5039 orig_minval
= minval
;
5041 /* Compute span of values. */
5043 range
= fold (build (MINUS_EXPR
, index_type
, maxval
, minval
));
5045 end_cleanup_deferral ();
5049 expand_expr (index_expr
, const0_rtx
, VOIDmode
, 0);
5051 emit_jump (default_label
);
5054 /* If range of values is much bigger than number of values,
5055 make a sequence of conditional branches instead of a dispatch.
5056 If the switch-index is a constant, do it this way
5057 because we can optimize it. */
5059 #ifndef CASE_VALUES_THRESHOLD
5061 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
5063 /* If machine does not have a case insn that compares the
5064 bounds, this means extra overhead for dispatch tables
5065 which raises the threshold for using them. */
5066 #define CASE_VALUES_THRESHOLD 5
5067 #endif /* HAVE_casesi */
5068 #endif /* CASE_VALUES_THRESHOLD */
5070 else if (TREE_INT_CST_HIGH (range
) != 0
5071 || count
< (unsigned int) CASE_VALUES_THRESHOLD
5072 || ((unsigned HOST_WIDE_INT
) (TREE_INT_CST_LOW (range
))
5074 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5077 || TREE_CODE (index_expr
) == INTEGER_CST
5078 /* These will reduce to a constant. */
5079 || (TREE_CODE (index_expr
) == CALL_EXPR
5080 && TREE_CODE (TREE_OPERAND (index_expr
, 0)) == ADDR_EXPR
5081 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr
, 0), 0)) == FUNCTION_DECL
5082 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr
, 0), 0)) == BUILT_IN_CLASSIFY_TYPE
)
5083 || (TREE_CODE (index_expr
) == COMPOUND_EXPR
5084 && TREE_CODE (TREE_OPERAND (index_expr
, 1)) == INTEGER_CST
))
5086 index
= expand_expr (index_expr
, NULL_RTX
, VOIDmode
, 0);
5088 /* If the index is a short or char that we do not have
5089 an insn to handle comparisons directly, convert it to
5090 a full integer now, rather than letting each comparison
5091 generate the conversion. */
5093 if (GET_MODE_CLASS (GET_MODE (index
)) == MODE_INT
5094 && (cmp_optab
->handlers
[(int) GET_MODE(index
)].insn_code
5095 == CODE_FOR_nothing
))
5097 enum machine_mode wider_mode
;
5098 for (wider_mode
= GET_MODE (index
); wider_mode
!= VOIDmode
;
5099 wider_mode
= GET_MODE_WIDER_MODE (wider_mode
))
5100 if (cmp_optab
->handlers
[(int) wider_mode
].insn_code
5101 != CODE_FOR_nothing
)
5103 index
= convert_to_mode (wider_mode
, index
, unsignedp
);
5109 do_pending_stack_adjust ();
5111 index
= protect_from_queue (index
, 0);
5112 if (GET_CODE (index
) == MEM
)
5113 index
= copy_to_reg (index
);
5114 if (GET_CODE (index
) == CONST_INT
5115 || TREE_CODE (index_expr
) == INTEGER_CST
)
5117 /* Make a tree node with the proper constant value
5118 if we don't already have one. */
5119 if (TREE_CODE (index_expr
) != INTEGER_CST
)
5122 = build_int_2 (INTVAL (index
),
5123 unsignedp
|| INTVAL (index
) >= 0 ? 0 : -1);
5124 index_expr
= convert (index_type
, index_expr
);
5127 /* For constant index expressions we need only
5128 issue a unconditional branch to the appropriate
5129 target code. The job of removing any unreachable
5130 code is left to the optimisation phase if the
5131 "-O" option is specified. */
5132 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5133 if (! tree_int_cst_lt (index_expr
, n
->low
)
5134 && ! tree_int_cst_lt (n
->high
, index_expr
))
5138 emit_jump (label_rtx (n
->code_label
));
5140 emit_jump (default_label
);
5144 /* If the index expression is not constant we generate
5145 a binary decision tree to select the appropriate
5146 target code. This is done as follows:
5148 The list of cases is rearranged into a binary tree,
5149 nearly optimal assuming equal probability for each case.
5151 The tree is transformed into RTL, eliminating
5152 redundant test conditions at the same time.
5154 If program flow could reach the end of the
5155 decision tree an unconditional jump to the
5156 default code is emitted. */
5159 = (TREE_CODE (TREE_TYPE (orig_index
)) != ENUMERAL_TYPE
5160 && estimate_case_costs (thiscase
->data
.case_stmt
.case_list
));
5161 balance_case_nodes (&thiscase
->data
.case_stmt
.case_list
,
5163 emit_case_nodes (index
, thiscase
->data
.case_stmt
.case_list
,
5164 default_label
, index_type
);
5165 emit_jump_if_reachable (default_label
);
5174 enum machine_mode index_mode
= SImode
;
5175 int index_bits
= GET_MODE_BITSIZE (index_mode
);
5177 enum machine_mode op_mode
;
5179 /* Convert the index to SImode. */
5180 if (GET_MODE_BITSIZE (TYPE_MODE (index_type
))
5181 > GET_MODE_BITSIZE (index_mode
))
5183 enum machine_mode omode
= TYPE_MODE (index_type
);
5184 rtx rangertx
= expand_expr (range
, NULL_RTX
, VOIDmode
, 0);
5186 /* We must handle the endpoints in the original mode. */
5187 index_expr
= build (MINUS_EXPR
, index_type
,
5188 index_expr
, minval
);
5189 minval
= integer_zero_node
;
5190 index
= expand_expr (index_expr
, NULL_RTX
, VOIDmode
, 0);
5191 emit_cmp_and_jump_insns (rangertx
, index
, LTU
, NULL_RTX
,
5192 omode
, 1, 0, default_label
);
5193 /* Now we can safely truncate. */
5194 index
= convert_to_mode (index_mode
, index
, 0);
5198 if (TYPE_MODE (index_type
) != index_mode
)
5200 index_expr
= convert (type_for_size (index_bits
, 0),
5202 index_type
= TREE_TYPE (index_expr
);
5205 index
= expand_expr (index_expr
, NULL_RTX
, VOIDmode
, 0);
5208 index
= protect_from_queue (index
, 0);
5209 do_pending_stack_adjust ();
5211 op_mode
= insn_operand_mode
[(int)CODE_FOR_casesi
][0];
5212 if (! (*insn_operand_predicate
[(int)CODE_FOR_casesi
][0])
5214 index
= copy_to_mode_reg (op_mode
, index
);
5216 op1
= expand_expr (minval
, NULL_RTX
, VOIDmode
, 0);
5218 op_mode
= insn_operand_mode
[(int)CODE_FOR_casesi
][1];
5219 if (! (*insn_operand_predicate
[(int)CODE_FOR_casesi
][1])
5221 op1
= copy_to_mode_reg (op_mode
, op1
);
5223 op2
= expand_expr (range
, NULL_RTX
, VOIDmode
, 0);
5225 op_mode
= insn_operand_mode
[(int)CODE_FOR_casesi
][2];
5226 if (! (*insn_operand_predicate
[(int)CODE_FOR_casesi
][2])
5228 op2
= copy_to_mode_reg (op_mode
, op2
);
5230 emit_jump_insn (gen_casesi (index
, op1
, op2
,
5231 table_label
, default_label
));
5235 #ifdef HAVE_tablejump
5236 if (! win
&& HAVE_tablejump
)
5238 index_expr
= convert (thiscase
->data
.case_stmt
.nominal_type
,
5239 fold (build (MINUS_EXPR
, index_type
,
5240 index_expr
, minval
)));
5241 index_type
= TREE_TYPE (index_expr
);
5242 index
= expand_expr (index_expr
, NULL_RTX
, VOIDmode
, 0);
5244 index
= protect_from_queue (index
, 0);
5245 do_pending_stack_adjust ();
5247 do_tablejump (index
, TYPE_MODE (index_type
),
5248 expand_expr (range
, NULL_RTX
, VOIDmode
, 0),
5249 table_label
, default_label
);
5256 /* Get table of labels to jump to, in order of case index. */
5258 ncases
= TREE_INT_CST_LOW (range
) + 1;
5259 labelvec
= (rtx
*) alloca (ncases
* sizeof (rtx
));
5260 bzero ((char *) labelvec
, ncases
* sizeof (rtx
));
5262 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5264 register HOST_WIDE_INT i
5265 = TREE_INT_CST_LOW (n
->low
) - TREE_INT_CST_LOW (orig_minval
);
5270 = gen_rtx_LABEL_REF (Pmode
, label_rtx (n
->code_label
));
5271 if (i
+ TREE_INT_CST_LOW (orig_minval
)
5272 == TREE_INT_CST_LOW (n
->high
))
5278 /* Fill in the gaps with the default. */
5279 for (i
= 0; i
< ncases
; i
++)
5280 if (labelvec
[i
] == 0)
5281 labelvec
[i
] = gen_rtx_LABEL_REF (Pmode
, default_label
);
5283 /* Output the table */
5284 emit_label (table_label
);
5286 if (CASE_VECTOR_PC_RELATIVE
|| flag_pic
)
5287 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE
,
5288 gen_rtx_LABEL_REF (Pmode
, table_label
),
5289 gen_rtvec_v (ncases
, labelvec
),
5290 const0_rtx
, const0_rtx
, 0));
5292 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE
,
5293 gen_rtvec_v (ncases
, labelvec
)));
5295 /* If the case insn drops through the table,
5296 after the table we must jump to the default-label.
5297 Otherwise record no drop-through after the table. */
5298 #ifdef CASE_DROPS_THROUGH
5299 emit_jump (default_label
);
5305 before_case
= squeeze_notes (NEXT_INSN (before_case
), get_last_insn ());
5306 reorder_insns (before_case
, get_last_insn (),
5307 thiscase
->data
.case_stmt
.start
);
5310 end_cleanup_deferral ();
5312 if (thiscase
->exit_label
)
5313 emit_label (thiscase
->exit_label
);
5315 POPSTACK (case_stack
);
5320 /* Convert the tree NODE into a list linked by the right field, with the left
5321 field zeroed. RIGHT is used for recursion; it is a list to be placed
5322 rightmost in the resulting list. */
5324 static struct case_node
*
5325 case_tree2list (node
, right
)
5326 struct case_node
*node
, *right
;
5328 struct case_node
*left
;
5331 right
= case_tree2list (node
->right
, right
);
5333 node
->right
= right
;
5334 if ((left
= node
->left
))
5337 return case_tree2list (left
, node
);
5343 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5346 do_jump_if_equal (op1
, op2
, label
, unsignedp
)
5347 rtx op1
, op2
, label
;
5350 if (GET_CODE (op1
) == CONST_INT
5351 && GET_CODE (op2
) == CONST_INT
)
5353 if (INTVAL (op1
) == INTVAL (op2
))
5358 enum machine_mode mode
= GET_MODE (op1
);
5359 if (mode
== VOIDmode
)
5360 mode
= GET_MODE (op2
);
5361 emit_cmp_and_jump_insns (op1
, op2
, EQ
, NULL_RTX
, mode
, unsignedp
,
5366 /* Not all case values are encountered equally. This function
5367 uses a heuristic to weight case labels, in cases where that
5368 looks like a reasonable thing to do.
5370 Right now, all we try to guess is text, and we establish the
5373 chars above space: 16
5382 If we find any cases in the switch that are not either -1 or in the range
5383 of valid ASCII characters, or are control characters other than those
5384 commonly used with "\", don't treat this switch scanning text.
5386 Return 1 if these nodes are suitable for cost estimation, otherwise
5390 estimate_case_costs (node
)
5393 tree min_ascii
= build_int_2 (-1, -1);
5394 tree max_ascii
= convert (TREE_TYPE (node
->high
), build_int_2 (127, 0));
5398 /* If we haven't already made the cost table, make it now. Note that the
5399 lower bound of the table is -1, not zero. */
5401 if (cost_table
== NULL
)
5403 cost_table
= ((short *) xmalloc (129 * sizeof (short))) + 1;
5404 bzero ((char *) (cost_table
- 1), 129 * sizeof (short));
5406 for (i
= 0; i
< 128; i
++)
5410 else if (ISPUNCT (i
))
5412 else if (ISCNTRL (i
))
5416 cost_table
[' '] = 8;
5417 cost_table
['\t'] = 4;
5418 cost_table
['\0'] = 4;
5419 cost_table
['\n'] = 2;
5420 cost_table
['\f'] = 1;
5421 cost_table
['\v'] = 1;
5422 cost_table
['\b'] = 1;
5425 /* See if all the case expressions look like text. It is text if the
5426 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5427 as signed arithmetic since we don't want to ever access cost_table with a
5428 value less than -1. Also check that none of the constants in a range
5429 are strange control characters. */
5431 for (n
= node
; n
; n
= n
->right
)
5433 if ((INT_CST_LT (n
->low
, min_ascii
)) || INT_CST_LT (max_ascii
, n
->high
))
5436 for (i
= TREE_INT_CST_LOW (n
->low
); i
<= TREE_INT_CST_LOW (n
->high
); i
++)
5437 if (cost_table
[i
] < 0)
5441 /* All interesting values are within the range of interesting
5442 ASCII characters. */
5446 /* Scan an ordered list of case nodes
5447 combining those with consecutive values or ranges.
5449 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5452 group_case_nodes (head
)
5455 case_node_ptr node
= head
;
5459 rtx lb
= next_real_insn (label_rtx (node
->code_label
));
5461 case_node_ptr np
= node
;
5463 /* Try to group the successors of NODE with NODE. */
5464 while (((np
= np
->right
) != 0)
5465 /* Do they jump to the same place? */
5466 && ((lb2
= next_real_insn (label_rtx (np
->code_label
))) == lb
5467 || (lb
!= 0 && lb2
!= 0
5468 && simplejump_p (lb
)
5469 && simplejump_p (lb2
)
5470 && rtx_equal_p (SET_SRC (PATTERN (lb
)),
5471 SET_SRC (PATTERN (lb2
)))))
5472 /* Are their ranges consecutive? */
5473 && tree_int_cst_equal (np
->low
,
5474 fold (build (PLUS_EXPR
,
5475 TREE_TYPE (node
->high
),
5478 /* An overflow is not consecutive. */
5479 && tree_int_cst_lt (node
->high
,
5480 fold (build (PLUS_EXPR
,
5481 TREE_TYPE (node
->high
),
5483 integer_one_node
))))
5485 node
->high
= np
->high
;
5487 /* NP is the first node after NODE which can't be grouped with it.
5488 Delete the nodes in between, and move on to that node. */
5494 /* Take an ordered list of case nodes
5495 and transform them into a near optimal binary tree,
5496 on the assumption that any target code selection value is as
5497 likely as any other.
5499 The transformation is performed by splitting the ordered
5500 list into two equal sections plus a pivot. The parts are
5501 then attached to the pivot as left and right branches. Each
5502 branch is then transformed recursively. */
5505 balance_case_nodes (head
, parent
)
5506 case_node_ptr
*head
;
5507 case_node_ptr parent
;
5509 register case_node_ptr np
;
5517 register case_node_ptr
*npp
;
5520 /* Count the number of entries on branch. Also count the ranges. */
5524 if (!tree_int_cst_equal (np
->low
, np
->high
))
5528 cost
+= cost_table
[TREE_INT_CST_LOW (np
->high
)];
5532 cost
+= cost_table
[TREE_INT_CST_LOW (np
->low
)];
5540 /* Split this list if it is long enough for that to help. */
5545 /* Find the place in the list that bisects the list's total cost,
5546 Here I gets half the total cost. */
5551 /* Skip nodes while their cost does not reach that amount. */
5552 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
5553 i
-= cost_table
[TREE_INT_CST_LOW ((*npp
)->high
)];
5554 i
-= cost_table
[TREE_INT_CST_LOW ((*npp
)->low
)];
5557 npp
= &(*npp
)->right
;
5562 /* Leave this branch lopsided, but optimize left-hand
5563 side and fill in `parent' fields for right-hand side. */
5565 np
->parent
= parent
;
5566 balance_case_nodes (&np
->left
, np
);
5567 for (; np
->right
; np
= np
->right
)
5568 np
->right
->parent
= np
;
5572 /* If there are just three nodes, split at the middle one. */
5574 npp
= &(*npp
)->right
;
5577 /* Find the place in the list that bisects the list's total cost,
5578 where ranges count as 2.
5579 Here I gets half the total cost. */
5580 i
= (i
+ ranges
+ 1) / 2;
5583 /* Skip nodes while their cost does not reach that amount. */
5584 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
5589 npp
= &(*npp
)->right
;
5594 np
->parent
= parent
;
5597 /* Optimize each of the two split parts. */
5598 balance_case_nodes (&np
->left
, np
);
5599 balance_case_nodes (&np
->right
, np
);
5603 /* Else leave this branch as one level,
5604 but fill in `parent' fields. */
5606 np
->parent
= parent
;
5607 for (; np
->right
; np
= np
->right
)
5608 np
->right
->parent
= np
;
5613 /* Search the parent sections of the case node tree
5614 to see if a test for the lower bound of NODE would be redundant.
5615 INDEX_TYPE is the type of the index expression.
5617 The instructions to generate the case decision tree are
5618 output in the same order as nodes are processed so it is
5619 known that if a parent node checks the range of the current
5620 node minus one that the current node is bounded at its lower
5621 span. Thus the test would be redundant. */
5624 node_has_low_bound (node
, index_type
)
5629 case_node_ptr pnode
;
5631 /* If the lower bound of this node is the lowest value in the index type,
5632 we need not test it. */
5634 if (tree_int_cst_equal (node
->low
, TYPE_MIN_VALUE (index_type
)))
5637 /* If this node has a left branch, the value at the left must be less
5638 than that at this node, so it cannot be bounded at the bottom and
5639 we need not bother testing any further. */
5644 low_minus_one
= fold (build (MINUS_EXPR
, TREE_TYPE (node
->low
),
5645 node
->low
, integer_one_node
));
5647 /* If the subtraction above overflowed, we can't verify anything.
5648 Otherwise, look for a parent that tests our value - 1. */
5650 if (! tree_int_cst_lt (low_minus_one
, node
->low
))
5653 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
5654 if (tree_int_cst_equal (low_minus_one
, pnode
->high
))
5660 /* Search the parent sections of the case node tree
5661 to see if a test for the upper bound of NODE would be redundant.
5662 INDEX_TYPE is the type of the index expression.
5664 The instructions to generate the case decision tree are
5665 output in the same order as nodes are processed so it is
5666 known that if a parent node checks the range of the current
5667 node plus one that the current node is bounded at its upper
5668 span. Thus the test would be redundant. */
5671 node_has_high_bound (node
, index_type
)
5676 case_node_ptr pnode
;
5678 /* If there is no upper bound, obviously no test is needed. */
5680 if (TYPE_MAX_VALUE (index_type
) == NULL
)
5683 /* If the upper bound of this node is the highest value in the type
5684 of the index expression, we need not test against it. */
5686 if (tree_int_cst_equal (node
->high
, TYPE_MAX_VALUE (index_type
)))
5689 /* If this node has a right branch, the value at the right must be greater
5690 than that at this node, so it cannot be bounded at the top and
5691 we need not bother testing any further. */
5696 high_plus_one
= fold (build (PLUS_EXPR
, TREE_TYPE (node
->high
),
5697 node
->high
, integer_one_node
));
5699 /* If the addition above overflowed, we can't verify anything.
5700 Otherwise, look for a parent that tests our value + 1. */
5702 if (! tree_int_cst_lt (node
->high
, high_plus_one
))
5705 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
5706 if (tree_int_cst_equal (high_plus_one
, pnode
->low
))
5712 /* Search the parent sections of the
5713 case node tree to see if both tests for the upper and lower
5714 bounds of NODE would be redundant. */
5717 node_is_bounded (node
, index_type
)
5721 return (node_has_low_bound (node
, index_type
)
5722 && node_has_high_bound (node
, index_type
));
5725 /* Emit an unconditional jump to LABEL unless it would be dead code. */
5728 emit_jump_if_reachable (label
)
5731 if (GET_CODE (get_last_insn ()) != BARRIER
)
5735 /* Emit step-by-step code to select a case for the value of INDEX.
5736 The thus generated decision tree follows the form of the
5737 case-node binary tree NODE, whose nodes represent test conditions.
5738 INDEX_TYPE is the type of the index of the switch.
5740 Care is taken to prune redundant tests from the decision tree
5741 by detecting any boundary conditions already checked by
5742 emitted rtx. (See node_has_high_bound, node_has_low_bound
5743 and node_is_bounded, above.)
5745 Where the test conditions can be shown to be redundant we emit
5746 an unconditional jump to the target code. As a further
5747 optimization, the subordinates of a tree node are examined to
5748 check for bounded nodes. In this case conditional and/or
5749 unconditional jumps as a result of the boundary check for the
5750 current node are arranged to target the subordinates associated
5751 code for out of bound conditions on the current node.
5753 We can assume that when control reaches the code generated here,
5754 the index value has already been compared with the parents
5755 of this node, and determined to be on the same side of each parent
5756 as this node is. Thus, if this node tests for the value 51,
5757 and a parent tested for 52, we don't need to consider
5758 the possibility of a value greater than 51. If another parent
5759 tests for the value 50, then this node need not test anything. */
5762 emit_case_nodes (index
, node
, default_label
, index_type
)
5768 /* If INDEX has an unsigned type, we must make unsigned branches. */
5769 int unsignedp
= TREE_UNSIGNED (index_type
);
5770 typedef rtx
rtx_fn ();
5771 enum machine_mode mode
= GET_MODE (index
);
5773 /* See if our parents have already tested everything for us.
5774 If they have, emit an unconditional jump for this node. */
5775 if (node_is_bounded (node
, index_type
))
5776 emit_jump (label_rtx (node
->code_label
));
5778 else if (tree_int_cst_equal (node
->low
, node
->high
))
5780 /* Node is single valued. First see if the index expression matches
5781 this node and then check our children, if any. */
5783 do_jump_if_equal (index
, expand_expr (node
->low
, NULL_RTX
, VOIDmode
, 0),
5784 label_rtx (node
->code_label
), unsignedp
);
5786 if (node
->right
!= 0 && node
->left
!= 0)
5788 /* This node has children on both sides.
5789 Dispatch to one side or the other
5790 by comparing the index value with this node's value.
5791 If one subtree is bounded, check that one first,
5792 so we can avoid real branches in the tree. */
5794 if (node_is_bounded (node
->right
, index_type
))
5796 emit_cmp_and_jump_insns (index
, expand_expr (node
->high
, NULL_RTX
,
5798 GT
, NULL_RTX
, mode
, unsignedp
, 0,
5799 label_rtx (node
->right
->code_label
));
5800 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
5803 else if (node_is_bounded (node
->left
, index_type
))
5805 emit_cmp_and_jump_insns (index
, expand_expr (node
->high
, NULL_RTX
,
5807 LT
, NULL_RTX
, mode
, unsignedp
, 0,
5808 label_rtx (node
->left
->code_label
));
5809 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
5814 /* Neither node is bounded. First distinguish the two sides;
5815 then emit the code for one side at a time. */
5818 = build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
5820 /* See if the value is on the right. */
5821 emit_cmp_and_jump_insns (index
, expand_expr (node
->high
, NULL_RTX
,
5823 GT
, NULL_RTX
, mode
, unsignedp
, 0,
5824 label_rtx (test_label
));
5826 /* Value must be on the left.
5827 Handle the left-hand subtree. */
5828 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
5829 /* If left-hand subtree does nothing,
5831 emit_jump_if_reachable (default_label
);
5833 /* Code branches here for the right-hand subtree. */
5834 expand_label (test_label
);
5835 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
5839 else if (node
->right
!= 0 && node
->left
== 0)
5841 /* Here we have a right child but no left so we issue conditional
5842 branch to default and process the right child.
5844 Omit the conditional branch to default if we it avoid only one
5845 right child; it costs too much space to save so little time. */
5847 if (node
->right
->right
|| node
->right
->left
5848 || !tree_int_cst_equal (node
->right
->low
, node
->right
->high
))
5850 if (!node_has_low_bound (node
, index_type
))
5852 emit_cmp_and_jump_insns (index
, expand_expr (node
->high
,
5855 LT
, NULL_RTX
, mode
, unsignedp
, 0,
5859 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
5862 /* We cannot process node->right normally
5863 since we haven't ruled out the numbers less than
5864 this node's value. So handle node->right explicitly. */
5865 do_jump_if_equal (index
,
5866 expand_expr (node
->right
->low
, NULL_RTX
,
5868 label_rtx (node
->right
->code_label
), unsignedp
);
5871 else if (node
->right
== 0 && node
->left
!= 0)
5873 /* Just one subtree, on the left. */
5875 #if 0 /* The following code and comment were formerly part
5876 of the condition here, but they didn't work
5877 and I don't understand what the idea was. -- rms. */
5878 /* If our "most probable entry" is less probable
5879 than the default label, emit a jump to
5880 the default label using condition codes
5881 already lying around. With no right branch,
5882 a branch-greater-than will get us to the default
5885 && cost_table
[TREE_INT_CST_LOW (node
->high
)] < 12)
5888 if (node
->left
->left
|| node
->left
->right
5889 || !tree_int_cst_equal (node
->left
->low
, node
->left
->high
))
5891 if (!node_has_high_bound (node
, index_type
))
5893 emit_cmp_and_jump_insns (index
, expand_expr (node
->high
,
5896 GT
, NULL_RTX
, mode
, unsignedp
, 0,
5900 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
5903 /* We cannot process node->left normally
5904 since we haven't ruled out the numbers less than
5905 this node's value. So handle node->left explicitly. */
5906 do_jump_if_equal (index
,
5907 expand_expr (node
->left
->low
, NULL_RTX
,
5909 label_rtx (node
->left
->code_label
), unsignedp
);
5914 /* Node is a range. These cases are very similar to those for a single
5915 value, except that we do not start by testing whether this node
5916 is the one to branch to. */
5918 if (node
->right
!= 0 && node
->left
!= 0)
5920 /* Node has subtrees on both sides.
5921 If the right-hand subtree is bounded,
5922 test for it first, since we can go straight there.
5923 Otherwise, we need to make a branch in the control structure,
5924 then handle the two subtrees. */
5925 tree test_label
= 0;
5928 if (node_is_bounded (node
->right
, index_type
))
5929 /* Right hand node is fully bounded so we can eliminate any
5930 testing and branch directly to the target code. */
5931 emit_cmp_and_jump_insns (index
, expand_expr (node
->high
, NULL_RTX
,
5933 GT
, NULL_RTX
, mode
, unsignedp
, 0,
5934 label_rtx (node
->right
->code_label
));
5937 /* Right hand node requires testing.
5938 Branch to a label where we will handle it later. */
5940 test_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
5941 emit_cmp_and_jump_insns (index
, expand_expr (node
->high
, NULL_RTX
,
5943 GT
, NULL_RTX
, mode
, unsignedp
, 0,
5944 label_rtx (test_label
));
5947 /* Value belongs to this node or to the left-hand subtree. */
5949 emit_cmp_and_jump_insns (index
, expand_expr (node
->low
, NULL_RTX
,
5951 GE
, NULL_RTX
, mode
, unsignedp
, 0,
5952 label_rtx (node
->code_label
));
5954 /* Handle the left-hand subtree. */
5955 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
5957 /* If right node had to be handled later, do that now. */
5961 /* If the left-hand subtree fell through,
5962 don't let it fall into the right-hand subtree. */
5963 emit_jump_if_reachable (default_label
);
5965 expand_label (test_label
);
5966 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
5970 else if (node
->right
!= 0 && node
->left
== 0)
5972 /* Deal with values to the left of this node,
5973 if they are possible. */
5974 if (!node_has_low_bound (node
, index_type
))
5976 emit_cmp_and_jump_insns (index
, expand_expr (node
->low
, NULL_RTX
,
5978 LT
, NULL_RTX
, mode
, unsignedp
, 0,
5982 /* Value belongs to this node or to the right-hand subtree. */
5984 emit_cmp_and_jump_insns (index
, expand_expr (node
->high
, NULL_RTX
,
5986 LE
, NULL_RTX
, mode
, unsignedp
, 0,
5987 label_rtx (node
->code_label
));
5989 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
5992 else if (node
->right
== 0 && node
->left
!= 0)
5994 /* Deal with values to the right of this node,
5995 if they are possible. */
5996 if (!node_has_high_bound (node
, index_type
))
5998 emit_cmp_and_jump_insns (index
, expand_expr (node
->high
, NULL_RTX
,
6000 GT
, NULL_RTX
, mode
, unsignedp
, 0,
6004 /* Value belongs to this node or to the left-hand subtree. */
6006 emit_cmp_and_jump_insns (index
, expand_expr (node
->low
, NULL_RTX
,
6008 GE
, NULL_RTX
, mode
, unsignedp
, 0,
6009 label_rtx (node
->code_label
));
6011 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6016 /* Node has no children so we check low and high bounds to remove
6017 redundant tests. Only one of the bounds can exist,
6018 since otherwise this node is bounded--a case tested already. */
6020 if (!node_has_high_bound (node
, index_type
))
6022 emit_cmp_and_jump_insns (index
, expand_expr (node
->high
, NULL_RTX
,
6024 GT
, NULL_RTX
, mode
, unsignedp
, 0,
6028 if (!node_has_low_bound (node
, index_type
))
6030 emit_cmp_and_jump_insns (index
, expand_expr (node
->low
, NULL_RTX
,
6032 LT
, NULL_RTX
, mode
, unsignedp
, 0,
6036 emit_jump (label_rtx (node
->code_label
));
6041 /* These routines are used by the loop unrolling code. They copy BLOCK trees
6042 so that the debugging info will be correct for the unrolled loop. */
6044 /* Indexed by block number, contains a pointer to the N'th block node.
6046 Allocated by the call to identify_blocks, then released after the call
6047 to reorder_blocks in the function unroll_block_trees. */
6049 static tree
*block_vector
;
6052 find_loop_tree_blocks ()
6054 tree block
= DECL_INITIAL (current_function_decl
);
6056 block_vector
= identify_blocks (block
, get_insns ());
6060 unroll_block_trees ()
6062 tree block
= DECL_INITIAL (current_function_decl
);
6064 reorder_blocks (block_vector
, block
, get_insns ());
6066 /* Release any memory allocated by identify_blocks. */
6068 free (block_vector
);