1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
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. */
38 #include "coretypes.h"
47 #include "insn-config.h"
50 #include "hard-reg-set.h"
57 #include "langhooks.h"
60 /* Assume that case vectors are not pc-relative. */
61 #ifndef CASE_VECTOR_PC_RELATIVE
62 #define CASE_VECTOR_PC_RELATIVE 0
65 /* Functions and data structures for expanding case statements. */
67 /* Case label structure, used to hold info on labels within case
68 statements. We handle "range" labels; for a single-value label
69 as in C, the high and low limits are the same.
71 An AVL tree of case nodes is initially created, and later transformed
72 to a list linked via the RIGHT fields in the nodes. Nodes with
73 higher case values are later in the list.
75 Switch statements can be output in one of two forms. A branch table
76 is used if there are more than a few labels and the labels are dense
77 within the range between the smallest and largest case value. If a
78 branch table is used, no further manipulations are done with the case
81 The alternative to the use of a branch table is to generate a series
82 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
83 and PARENT fields to hold a binary tree. Initially the tree is
84 totally unbalanced, with everything on the right. We balance the tree
85 with nodes on the left having lower case values than the parent
86 and nodes on the right having higher values. We then output the tree
89 struct case_node
GTY(())
91 struct case_node
*left
; /* Left son in binary tree */
92 struct case_node
*right
; /* Right son in binary tree; also node chain */
93 struct case_node
*parent
; /* Parent of node in binary tree */
94 tree low
; /* Lowest index value for this label */
95 tree high
; /* Highest index value for this label */
96 tree code_label
; /* Label to jump to when node matches */
100 typedef struct case_node case_node
;
101 typedef struct case_node
*case_node_ptr
;
103 /* These are used by estimate_case_costs and balance_case_nodes. */
105 /* This must be a signed type, and non-ANSI compilers lack signed char. */
106 static short cost_table_
[129];
107 static int use_cost_table
;
108 static int cost_table_initialized
;
110 /* Special care is needed because we allow -1, but TREE_INT_CST_LOW
112 #define COST_TABLE(I) cost_table_[(unsigned HOST_WIDE_INT) ((I) + 1)]
114 /* Stack of control and binding constructs we are currently inside.
116 These constructs begin when you call `expand_start_WHATEVER'
117 and end when you call `expand_end_WHATEVER'. This stack records
118 info about how the construct began that tells the end-function
119 what to do. It also may provide information about the construct
120 to alter the behavior of other constructs within the body.
121 For example, they may affect the behavior of C `break' and `continue'.
123 Each construct gets one `struct nesting' object.
124 All of these objects are chained through the `all' field.
125 `nesting_stack' points to the first object (innermost construct).
126 The position of an entry on `nesting_stack' is in its `depth' field.
128 Each type of construct has its own individual stack.
129 For example, loops have `loop_stack'. Each object points to the
130 next object of the same type through the `next' field.
132 Some constructs are visible to `break' exit-statements and others
133 are not. Which constructs are visible depends on the language.
134 Therefore, the data structure allows each construct to be visible
135 or not, according to the args given when the construct is started.
136 The construct is visible if the `exit_label' field is non-null.
137 In that case, the value should be a CODE_LABEL rtx. */
139 struct nesting
GTY(())
142 struct nesting
*next
;
153 /* For conds (if-then and if-then-else statements). */
156 /* Label for the end of the if construct.
157 There is none if EXITFLAG was not set
158 and no `else' has been seen yet. */
160 /* Label for the end of this alternative.
161 This may be the end of the if or the next else/elseif. */
163 } GTY ((tag ("COND_NESTING"))) cond
;
167 /* Label at the top of the loop; place to loop back to. */
169 /* Label at the end of the whole construct. */
171 /* Label for `continue' statement to jump to;
172 this is in front of the stepper of the loop. */
174 } GTY ((tag ("LOOP_NESTING"))) loop
;
175 /* For variable binding contours. */
178 /* Sequence number of this binding contour within the function,
179 in order of entry. */
180 int block_start_count
;
181 /* Nonzero => value to restore stack to on exit. */
183 /* The NOTE that starts this contour.
184 Used by expand_goto to check whether the destination
185 is within each contour or not. */
187 /* Innermost containing binding contour that has a stack level. */
188 struct nesting
*innermost_stack_block
;
189 /* List of cleanups to be run on exit from this contour.
190 This is a list of expressions to be evaluated.
191 The TREE_PURPOSE of each link is the ..._DECL node
192 which the cleanup pertains to. */
194 /* List of cleanup-lists of blocks containing this block,
195 as they were at the locus where this block appears.
196 There is an element for each containing block,
197 ordered innermost containing block first.
198 The tail of this list can be 0,
199 if all remaining elements would be empty lists.
200 The element's TREE_VALUE is the cleanup-list of that block,
201 which may be null. */
203 /* Chain of labels defined inside this binding contour.
204 For contours that have stack levels or cleanups. */
205 struct label_chain
*label_chain
;
206 /* Number of function calls seen, as of start of this block. */
207 int n_function_calls
;
208 /* Nonzero if this is associated with an EH region. */
209 int exception_region
;
210 /* The saved target_temp_slot_level from our outer block.
211 We may reset target_temp_slot_level to be the level of
212 this block, if that is done, target_temp_slot_level
213 reverts to the saved target_temp_slot_level at the very
215 int block_target_temp_slot_level
;
216 /* True if we are currently emitting insns in an area of
217 output code that is controlled by a conditional
218 expression. This is used by the cleanup handling code to
219 generate conditional cleanup actions. */
220 int conditional_code
;
221 /* A place to move the start of the exception region for any
222 of the conditional cleanups, must be at the end or after
223 the start of the last unconditional cleanup, and before any
224 conditional branch points. */
225 rtx last_unconditional_cleanup
;
226 } GTY ((tag ("BLOCK_NESTING"))) block
;
227 /* For switch (C) or case (Pascal) statements,
228 and also for dummies (see `expand_start_case_dummy'). */
231 /* The insn after which the case dispatch should finally
232 be emitted. Zero for a dummy. */
234 /* A list of case labels; it is first built as an AVL tree.
235 During expand_end_case, this is converted to a list, and may be
236 rearranged into a nearly balanced binary tree. */
237 struct case_node
*case_list
;
238 /* Label to jump to if no case matches. */
240 /* The expression to be dispatched on. */
242 /* Type that INDEX_EXPR should be converted to. */
244 /* Name of this kind of statement, for warnings. */
245 const char *printname
;
246 /* Used to save no_line_numbers till we see the first case label.
247 We set this to -1 when we see the first case label in this
249 int line_number_status
;
250 } GTY ((tag ("CASE_NESTING"))) case_stmt
;
251 } GTY ((desc ("%1.desc"))) data
;
254 /* Allocate and return a new `struct nesting'. */
256 #define ALLOC_NESTING() \
257 (struct nesting *) ggc_alloc (sizeof (struct nesting))
259 /* Pop the nesting stack element by element until we pop off
260 the element which is at the top of STACK.
261 Update all the other stacks, popping off elements from them
262 as we pop them from nesting_stack. */
264 #define POPSTACK(STACK) \
265 do { struct nesting *target = STACK; \
266 struct nesting *this; \
267 do { this = nesting_stack; \
268 if (loop_stack == this) \
269 loop_stack = loop_stack->next; \
270 if (cond_stack == this) \
271 cond_stack = cond_stack->next; \
272 if (block_stack == this) \
273 block_stack = block_stack->next; \
274 if (stack_block_stack == this) \
275 stack_block_stack = stack_block_stack->next; \
276 if (case_stack == this) \
277 case_stack = case_stack->next; \
278 nesting_depth = nesting_stack->depth - 1; \
279 nesting_stack = this->all; } \
280 while (this != target); } while (0)
282 /* In some cases it is impossible to generate code for a forward goto
283 until the label definition is seen. This happens when it may be necessary
284 for the goto to reset the stack pointer: we don't yet know how to do that.
285 So expand_goto puts an entry on this fixup list.
286 Each time a binding contour that resets the stack is exited,
288 If the target label has now been defined, we can insert the proper code. */
290 struct goto_fixup
GTY(())
292 /* Points to following fixup. */
293 struct goto_fixup
*next
;
294 /* Points to the insn before the jump insn.
295 If more code must be inserted, it goes after this insn. */
297 /* The LABEL_DECL that this jump is jumping to, or 0
298 for break, continue or return. */
300 /* The BLOCK for the place where this goto was found. */
302 /* The CODE_LABEL rtx that this is jumping to. */
304 /* Number of binding contours started in current function
305 before the label reference. */
306 int block_start_count
;
307 /* The outermost stack level that should be restored for this jump.
308 Each time a binding contour that resets the stack is exited,
309 if the target label is *not* yet defined, this slot is updated. */
311 /* List of lists of cleanup expressions to be run by this goto.
312 There is one element for each block that this goto is within.
313 The tail of this list can be 0,
314 if all remaining elements would be empty.
315 The TREE_VALUE contains the cleanup list of that block as of the
316 time this goto was seen.
317 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
318 tree cleanup_list_list
;
321 /* Within any binding contour that must restore a stack level,
322 all labels are recorded with a chain of these structures. */
324 struct label_chain
GTY(())
326 /* Points to following fixup. */
327 struct label_chain
*next
;
331 struct stmt_status
GTY(())
333 /* Chain of all pending binding contours. */
334 struct nesting
* x_block_stack
;
336 /* If any new stacks are added here, add them to POPSTACKS too. */
338 /* Chain of all pending binding contours that restore stack levels
340 struct nesting
* x_stack_block_stack
;
342 /* Chain of all pending conditional statements. */
343 struct nesting
* x_cond_stack
;
345 /* Chain of all pending loops. */
346 struct nesting
* x_loop_stack
;
348 /* Chain of all pending case or switch statements. */
349 struct nesting
* x_case_stack
;
351 /* Separate chain including all of the above,
352 chained through the `all' field. */
353 struct nesting
* x_nesting_stack
;
355 /* Number of entries on nesting_stack now. */
358 /* Number of binding contours started so far in this function. */
359 int x_block_start_count
;
361 /* Each time we expand an expression-statement,
362 record the expr's type and its RTL value here. */
363 tree x_last_expr_type
;
364 rtx x_last_expr_value
;
366 /* Nonzero if within a ({...}) grouping, in which case we must
367 always compute a value for each expr-stmt in case it is the last one. */
368 int x_expr_stmts_for_value
;
370 /* Filename and line number of last line-number note,
371 whether we actually emitted it or not. */
372 const char *x_emit_filename
;
375 struct goto_fixup
*x_goto_fixup_chain
;
378 #define block_stack (cfun->stmt->x_block_stack)
379 #define stack_block_stack (cfun->stmt->x_stack_block_stack)
380 #define cond_stack (cfun->stmt->x_cond_stack)
381 #define loop_stack (cfun->stmt->x_loop_stack)
382 #define case_stack (cfun->stmt->x_case_stack)
383 #define nesting_stack (cfun->stmt->x_nesting_stack)
384 #define nesting_depth (cfun->stmt->x_nesting_depth)
385 #define current_block_start_count (cfun->stmt->x_block_start_count)
386 #define last_expr_type (cfun->stmt->x_last_expr_type)
387 #define last_expr_value (cfun->stmt->x_last_expr_value)
388 #define expr_stmts_for_value (cfun->stmt->x_expr_stmts_for_value)
389 #define emit_filename (cfun->stmt->x_emit_filename)
390 #define emit_lineno (cfun->stmt->x_emit_lineno)
391 #define goto_fixup_chain (cfun->stmt->x_goto_fixup_chain)
393 /* Non-zero if we are using EH to handle cleanups. */
394 static int using_eh_for_cleanups_p
= 0;
396 static int n_occurrences
PARAMS ((int, const char *));
397 static bool parse_input_constraint
PARAMS ((const char **, int, int, int,
398 int, const char * const *,
400 static bool decl_conflicts_with_clobbers_p
PARAMS ((tree
, const HARD_REG_SET
));
401 static void expand_goto_internal
PARAMS ((tree
, rtx
, rtx
));
402 static int expand_fixup
PARAMS ((tree
, rtx
, rtx
));
403 static rtx expand_nl_handler_label
PARAMS ((rtx
, rtx
));
404 static void expand_nl_goto_receiver
PARAMS ((void));
405 static void expand_nl_goto_receivers
PARAMS ((struct nesting
*));
406 static void fixup_gotos
PARAMS ((struct nesting
*, rtx
, tree
,
408 static bool check_operand_nalternatives
PARAMS ((tree
, tree
));
409 static bool check_unique_operand_names
PARAMS ((tree
, tree
));
410 static tree resolve_operand_names
PARAMS ((tree
, tree
, tree
,
412 static char *resolve_operand_name_1
PARAMS ((char *, tree
, tree
));
413 static void expand_null_return_1
PARAMS ((rtx
));
414 static enum br_predictor return_prediction
PARAMS ((rtx
));
415 static void expand_value_return
PARAMS ((rtx
));
416 static int tail_recursion_args
PARAMS ((tree
, tree
));
417 static void expand_cleanups
PARAMS ((tree
, tree
, int, int));
418 static void check_seenlabel
PARAMS ((void));
419 static void do_jump_if_equal
PARAMS ((rtx
, rtx
, rtx
, int));
420 static int estimate_case_costs
PARAMS ((case_node_ptr
));
421 static void group_case_nodes
PARAMS ((case_node_ptr
));
422 static void balance_case_nodes
PARAMS ((case_node_ptr
*,
424 static int node_has_low_bound
PARAMS ((case_node_ptr
, tree
));
425 static int node_has_high_bound
PARAMS ((case_node_ptr
, tree
));
426 static int node_is_bounded
PARAMS ((case_node_ptr
, tree
));
427 static void emit_jump_if_reachable
PARAMS ((rtx
));
428 static void emit_case_nodes
PARAMS ((rtx
, case_node_ptr
, rtx
, tree
));
429 static struct case_node
*case_tree2list
PARAMS ((case_node
*, case_node
*));
432 using_eh_for_cleanups ()
434 using_eh_for_cleanups_p
= 1;
438 init_stmt_for_function ()
440 cfun
->stmt
= ((struct stmt_status
*)ggc_alloc (sizeof (struct stmt_status
)));
442 /* We are not currently within any block, conditional, loop or case. */
444 stack_block_stack
= 0;
451 current_block_start_count
= 0;
453 /* No gotos have been expanded yet. */
454 goto_fixup_chain
= 0;
456 /* We are not processing a ({...}) grouping. */
457 expr_stmts_for_value
= 0;
461 /* Record the current file and line. Called from emit_line_note. */
463 set_file_and_line_for_stmt (file
, line
)
467 /* If we're outputting an inline function, and we add a line note,
468 there may be no CFUN->STMT information. So, there's no need to
472 emit_filename
= file
;
477 /* Emit a no-op instruction. */
484 last_insn
= get_last_insn ();
486 && (GET_CODE (last_insn
) == CODE_LABEL
487 || (GET_CODE (last_insn
) == NOTE
488 && prev_real_insn (last_insn
) == 0)))
489 emit_insn (gen_nop ());
492 /* Return the rtx-label that corresponds to a LABEL_DECL,
493 creating it if necessary. */
499 if (TREE_CODE (label
) != LABEL_DECL
)
502 if (!DECL_RTL_SET_P (label
))
503 SET_DECL_RTL (label
, gen_label_rtx ());
505 return DECL_RTL (label
);
509 /* Add an unconditional jump to LABEL as the next sequential instruction. */
515 do_pending_stack_adjust ();
516 emit_jump_insn (gen_jump (label
));
520 /* Emit code to jump to the address
521 specified by the pointer expression EXP. */
524 expand_computed_goto (exp
)
527 rtx x
= expand_expr (exp
, NULL_RTX
, VOIDmode
, 0);
529 #ifdef POINTERS_EXTEND_UNSIGNED
530 if (GET_MODE (x
) != Pmode
)
531 x
= convert_memory_address (Pmode
, x
);
535 do_pending_stack_adjust ();
536 emit_indirect_jump (x
);
538 current_function_has_computed_jump
= 1;
541 /* Handle goto statements and the labels that they can go to. */
543 /* Specify the location in the RTL code of a label LABEL,
544 which is a LABEL_DECL tree node.
546 This is used for the kind of label that the user can jump to with a
547 goto statement, and for alternatives of a switch or case statement.
548 RTL labels generated for loops and conditionals don't go through here;
549 they are generated directly at the RTL level, by other functions below.
551 Note that this has nothing to do with defining label *names*.
552 Languages vary in how they do that and what that even means. */
558 struct label_chain
*p
;
560 do_pending_stack_adjust ();
561 emit_label (label_rtx (label
));
562 if (DECL_NAME (label
))
563 LABEL_NAME (DECL_RTL (label
)) = IDENTIFIER_POINTER (DECL_NAME (label
));
565 if (stack_block_stack
!= 0)
567 p
= (struct label_chain
*) ggc_alloc (sizeof (struct label_chain
));
568 p
->next
= stack_block_stack
->data
.block
.label_chain
;
569 stack_block_stack
->data
.block
.label_chain
= p
;
574 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
575 from nested functions. */
578 declare_nonlocal_label (label
)
581 rtx slot
= assign_stack_local (Pmode
, GET_MODE_SIZE (Pmode
), 0);
583 nonlocal_labels
= tree_cons (NULL_TREE
, label
, nonlocal_labels
);
584 LABEL_PRESERVE_P (label_rtx (label
)) = 1;
585 if (nonlocal_goto_handler_slots
== 0)
587 emit_stack_save (SAVE_NONLOCAL
,
588 &nonlocal_goto_stack_level
,
589 PREV_INSN (tail_recursion_reentry
));
591 nonlocal_goto_handler_slots
592 = gen_rtx_EXPR_LIST (VOIDmode
, slot
, nonlocal_goto_handler_slots
);
595 /* Generate RTL code for a `goto' statement with target label LABEL.
596 LABEL should be a LABEL_DECL tree node that was or will later be
597 defined with `expand_label'. */
605 /* Check for a nonlocal goto to a containing function. */
606 context
= decl_function_context (label
);
607 if (context
!= 0 && context
!= current_function_decl
)
609 struct function
*p
= find_function_data (context
);
610 rtx label_ref
= gen_rtx_LABEL_REF (Pmode
, label_rtx (label
));
611 rtx handler_slot
, static_chain
, save_area
, insn
;
614 /* Find the corresponding handler slot for this label. */
615 handler_slot
= p
->x_nonlocal_goto_handler_slots
;
616 for (link
= p
->x_nonlocal_labels
; TREE_VALUE (link
) != label
;
617 link
= TREE_CHAIN (link
))
618 handler_slot
= XEXP (handler_slot
, 1);
619 handler_slot
= XEXP (handler_slot
, 0);
621 p
->has_nonlocal_label
= 1;
622 current_function_has_nonlocal_goto
= 1;
623 LABEL_REF_NONLOCAL_P (label_ref
) = 1;
625 /* Copy the rtl for the slots so that they won't be shared in
626 case the virtual stack vars register gets instantiated differently
627 in the parent than in the child. */
629 static_chain
= copy_to_reg (lookup_static_chain (label
));
631 /* Get addr of containing function's current nonlocal goto handler,
632 which will do any cleanups and then jump to the label. */
633 handler_slot
= copy_to_reg (replace_rtx (copy_rtx (handler_slot
),
634 virtual_stack_vars_rtx
,
637 /* Get addr of containing function's nonlocal save area. */
638 save_area
= p
->x_nonlocal_goto_stack_level
;
640 save_area
= replace_rtx (copy_rtx (save_area
),
641 virtual_stack_vars_rtx
, static_chain
);
643 #if HAVE_nonlocal_goto
644 if (HAVE_nonlocal_goto
)
645 emit_insn (gen_nonlocal_goto (static_chain
, handler_slot
,
646 save_area
, label_ref
));
650 /* Restore frame pointer for containing function.
651 This sets the actual hard register used for the frame pointer
652 to the location of the function's incoming static chain info.
653 The non-local goto handler will then adjust it to contain the
654 proper value and reload the argument pointer, if needed. */
655 emit_move_insn (hard_frame_pointer_rtx
, static_chain
);
656 emit_stack_restore (SAVE_NONLOCAL
, save_area
, NULL_RTX
);
658 /* USE of hard_frame_pointer_rtx added for consistency;
659 not clear if really needed. */
660 emit_insn (gen_rtx_USE (VOIDmode
, hard_frame_pointer_rtx
));
661 emit_insn (gen_rtx_USE (VOIDmode
, stack_pointer_rtx
));
662 emit_indirect_jump (handler_slot
);
665 /* Search backwards to the jump insn and mark it as a
667 for (insn
= get_last_insn (); insn
; insn
= PREV_INSN (insn
))
669 if (GET_CODE (insn
) == JUMP_INSN
)
671 REG_NOTES (insn
) = alloc_EXPR_LIST (REG_NON_LOCAL_GOTO
,
672 const0_rtx
, REG_NOTES (insn
));
675 else if (GET_CODE (insn
) == CALL_INSN
)
680 expand_goto_internal (label
, label_rtx (label
), NULL_RTX
);
683 /* Generate RTL code for a `goto' statement with target label BODY.
684 LABEL should be a LABEL_REF.
685 LAST_INSN, if non-0, is the rtx we should consider as the last
686 insn emitted (for the purposes of cleaning up a return). */
689 expand_goto_internal (body
, label
, last_insn
)
694 struct nesting
*block
;
697 if (GET_CODE (label
) != CODE_LABEL
)
700 /* If label has already been defined, we can tell now
701 whether and how we must alter the stack level. */
703 if (PREV_INSN (label
) != 0)
705 /* Find the innermost pending block that contains the label.
706 (Check containment by comparing insn-uids.)
707 Then restore the outermost stack level within that block,
708 and do cleanups of all blocks contained in it. */
709 for (block
= block_stack
; block
; block
= block
->next
)
711 if (INSN_UID (block
->data
.block
.first_insn
) < INSN_UID (label
))
713 if (block
->data
.block
.stack_level
!= 0)
714 stack_level
= block
->data
.block
.stack_level
;
715 /* Execute the cleanups for blocks we are exiting. */
716 if (block
->data
.block
.cleanups
!= 0)
718 expand_cleanups (block
->data
.block
.cleanups
, NULL_TREE
, 1, 1);
719 do_pending_stack_adjust ();
725 /* Ensure stack adjust isn't done by emit_jump, as this
726 would clobber the stack pointer. This one should be
727 deleted as dead by flow. */
728 clear_pending_stack_adjust ();
729 do_pending_stack_adjust ();
731 /* Don't do this adjust if it's to the end label and this function
732 is to return with a depressed stack pointer. */
733 if (label
== return_label
734 && (((TREE_CODE (TREE_TYPE (current_function_decl
))
736 && (TYPE_RETURNS_STACK_DEPRESSED
737 (TREE_TYPE (current_function_decl
))))))
740 emit_stack_restore (SAVE_BLOCK
, stack_level
, NULL_RTX
);
743 if (body
!= 0 && DECL_TOO_LATE (body
))
744 error ("jump to `%s' invalidly jumps into binding contour",
745 IDENTIFIER_POINTER (DECL_NAME (body
)));
747 /* Label not yet defined: may need to put this goto
748 on the fixup list. */
749 else if (! expand_fixup (body
, label
, last_insn
))
751 /* No fixup needed. Record that the label is the target
752 of at least one goto that has no fixup. */
754 TREE_ADDRESSABLE (body
) = 1;
760 /* Generate if necessary a fixup for a goto
761 whose target label in tree structure (if any) is TREE_LABEL
762 and whose target in rtl is RTL_LABEL.
764 If LAST_INSN is nonzero, we pretend that the jump appears
765 after insn LAST_INSN instead of at the current point in the insn stream.
767 The fixup will be used later to insert insns just before the goto.
768 Those insns will restore the stack level as appropriate for the
769 target label, and will (in the case of C++) also invoke any object
770 destructors which have to be invoked when we exit the scopes which
771 are exited by the goto.
773 Value is nonzero if a fixup is made. */
776 expand_fixup (tree_label
, rtl_label
, last_insn
)
781 struct nesting
*block
, *end_block
;
783 /* See if we can recognize which block the label will be output in.
784 This is possible in some very common cases.
785 If we succeed, set END_BLOCK to that block.
786 Otherwise, set it to 0. */
789 && (rtl_label
== cond_stack
->data
.cond
.endif_label
790 || rtl_label
== cond_stack
->data
.cond
.next_label
))
791 end_block
= cond_stack
;
792 /* If we are in a loop, recognize certain labels which
793 are likely targets. This reduces the number of fixups
794 we need to create. */
796 && (rtl_label
== loop_stack
->data
.loop
.start_label
797 || rtl_label
== loop_stack
->data
.loop
.end_label
798 || rtl_label
== loop_stack
->data
.loop
.continue_label
))
799 end_block
= loop_stack
;
803 /* Now set END_BLOCK to the binding level to which we will return. */
807 struct nesting
*next_block
= end_block
->all
;
810 /* First see if the END_BLOCK is inside the innermost binding level.
811 If so, then no cleanups or stack levels are relevant. */
812 while (next_block
&& next_block
!= block
)
813 next_block
= next_block
->all
;
818 /* Otherwise, set END_BLOCK to the innermost binding level
819 which is outside the relevant control-structure nesting. */
820 next_block
= block_stack
->next
;
821 for (block
= block_stack
; block
!= end_block
; block
= block
->all
)
822 if (block
== next_block
)
823 next_block
= next_block
->next
;
824 end_block
= next_block
;
827 /* Does any containing block have a stack level or cleanups?
828 If not, no fixup is needed, and that is the normal case
829 (the only case, for standard C). */
830 for (block
= block_stack
; block
!= end_block
; block
= block
->next
)
831 if (block
->data
.block
.stack_level
!= 0
832 || block
->data
.block
.cleanups
!= 0)
835 if (block
!= end_block
)
837 /* Ok, a fixup is needed. Add a fixup to the list of such. */
838 struct goto_fixup
*fixup
839 = (struct goto_fixup
*) ggc_alloc (sizeof (struct goto_fixup
));
840 /* In case an old stack level is restored, make sure that comes
841 after any pending stack adjust. */
842 /* ?? If the fixup isn't to come at the present position,
843 doing the stack adjust here isn't useful. Doing it with our
844 settings at that location isn't useful either. Let's hope
847 do_pending_stack_adjust ();
848 fixup
->target
= tree_label
;
849 fixup
->target_rtl
= rtl_label
;
851 /* Create a BLOCK node and a corresponding matched set of
852 NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes at
853 this point. The notes will encapsulate any and all fixup
854 code which we might later insert at this point in the insn
855 stream. Also, the BLOCK node will be the parent (i.e. the
856 `SUPERBLOCK') of any other BLOCK nodes which we might create
857 later on when we are expanding the fixup code.
859 Note that optimization passes (including expand_end_loop)
860 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
864 rtx original_before_jump
865 = last_insn
? last_insn
: get_last_insn ();
870 block
= make_node (BLOCK
);
871 TREE_USED (block
) = 1;
873 if (!cfun
->x_whole_function_mode_p
)
874 (*lang_hooks
.decls
.insert_block
) (block
);
878 = BLOCK_CHAIN (DECL_INITIAL (current_function_decl
));
879 BLOCK_CHAIN (DECL_INITIAL (current_function_decl
))
884 start
= emit_note (NULL
, NOTE_INSN_BLOCK_BEG
);
885 if (cfun
->x_whole_function_mode_p
)
886 NOTE_BLOCK (start
) = block
;
887 fixup
->before_jump
= emit_note (NULL
, NOTE_INSN_DELETED
);
888 end
= emit_note (NULL
, NOTE_INSN_BLOCK_END
);
889 if (cfun
->x_whole_function_mode_p
)
890 NOTE_BLOCK (end
) = block
;
891 fixup
->context
= block
;
893 emit_insn_after (start
, original_before_jump
);
896 fixup
->block_start_count
= current_block_start_count
;
897 fixup
->stack_level
= 0;
898 fixup
->cleanup_list_list
899 = ((block
->data
.block
.outer_cleanups
900 || block
->data
.block
.cleanups
)
901 ? tree_cons (NULL_TREE
, block
->data
.block
.cleanups
,
902 block
->data
.block
.outer_cleanups
)
904 fixup
->next
= goto_fixup_chain
;
905 goto_fixup_chain
= fixup
;
911 /* Expand any needed fixups in the outputmost binding level of the
912 function. FIRST_INSN is the first insn in the function. */
915 expand_fixups (first_insn
)
918 fixup_gotos (NULL
, NULL_RTX
, NULL_TREE
, first_insn
, 0);
921 /* When exiting a binding contour, process all pending gotos requiring fixups.
922 THISBLOCK is the structure that describes the block being exited.
923 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
924 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
925 FIRST_INSN is the insn that began this contour.
927 Gotos that jump out of this contour must restore the
928 stack level and do the cleanups before actually jumping.
930 DONT_JUMP_IN nonzero means report error there is a jump into this
931 contour from before the beginning of the contour.
932 This is also done if STACK_LEVEL is nonzero. */
935 fixup_gotos (thisblock
, stack_level
, cleanup_list
, first_insn
, dont_jump_in
)
936 struct nesting
*thisblock
;
942 struct goto_fixup
*f
, *prev
;
944 /* F is the fixup we are considering; PREV is the previous one. */
945 /* We run this loop in two passes so that cleanups of exited blocks
946 are run first, and blocks that are exited are marked so
949 for (prev
= 0, f
= goto_fixup_chain
; f
; prev
= f
, f
= f
->next
)
951 /* Test for a fixup that is inactive because it is already handled. */
952 if (f
->before_jump
== 0)
954 /* Delete inactive fixup from the chain, if that is easy to do. */
956 prev
->next
= f
->next
;
958 /* Has this fixup's target label been defined?
959 If so, we can finalize it. */
960 else if (PREV_INSN (f
->target_rtl
) != 0)
964 /* If this fixup jumped into this contour from before the beginning
965 of this contour, report an error. This code used to use
966 the first non-label insn after f->target_rtl, but that's
967 wrong since such can be added, by things like put_var_into_stack
968 and have INSN_UIDs that are out of the range of the block. */
969 /* ??? Bug: this does not detect jumping in through intermediate
970 blocks that have stack levels or cleanups.
971 It detects only a problem with the innermost block
974 && (dont_jump_in
|| stack_level
|| cleanup_list
)
975 && INSN_UID (first_insn
) < INSN_UID (f
->target_rtl
)
976 && INSN_UID (first_insn
) > INSN_UID (f
->before_jump
)
977 && ! DECL_ERROR_ISSUED (f
->target
))
979 error_with_decl (f
->target
,
980 "label `%s' used before containing binding contour");
981 /* Prevent multiple errors for one label. */
982 DECL_ERROR_ISSUED (f
->target
) = 1;
985 /* We will expand the cleanups into a sequence of their own and
986 then later on we will attach this new sequence to the insn
987 stream just ahead of the actual jump insn. */
991 /* Temporarily restore the lexical context where we will
992 logically be inserting the fixup code. We do this for the
993 sake of getting the debugging information right. */
995 (*lang_hooks
.decls
.pushlevel
) (0);
996 (*lang_hooks
.decls
.set_block
) (f
->context
);
998 /* Expand the cleanups for blocks this jump exits. */
999 if (f
->cleanup_list_list
)
1002 for (lists
= f
->cleanup_list_list
; lists
; lists
= TREE_CHAIN (lists
))
1003 /* Marked elements correspond to blocks that have been closed.
1004 Do their cleanups. */
1005 if (TREE_ADDRESSABLE (lists
)
1006 && TREE_VALUE (lists
) != 0)
1008 expand_cleanups (TREE_VALUE (lists
), NULL_TREE
, 1, 1);
1009 /* Pop any pushes done in the cleanups,
1010 in case function is about to return. */
1011 do_pending_stack_adjust ();
1015 /* Restore stack level for the biggest contour that this
1016 jump jumps out of. */
1018 && ! (f
->target_rtl
== return_label
1019 && ((TREE_CODE (TREE_TYPE (current_function_decl
))
1021 && (TYPE_RETURNS_STACK_DEPRESSED
1022 (TREE_TYPE (current_function_decl
))))))
1023 emit_stack_restore (SAVE_BLOCK
, f
->stack_level
, f
->before_jump
);
1025 /* Finish up the sequence containing the insns which implement the
1026 necessary cleanups, and then attach that whole sequence to the
1027 insn stream just ahead of the actual jump insn. Attaching it
1028 at that point insures that any cleanups which are in fact
1029 implicit C++ object destructions (which must be executed upon
1030 leaving the block) appear (to the debugger) to be taking place
1031 in an area of the generated code where the object(s) being
1032 destructed are still "in scope". */
1034 cleanup_insns
= get_insns ();
1035 (*lang_hooks
.decls
.poplevel
) (1, 0, 0);
1038 emit_insn_after (cleanup_insns
, f
->before_jump
);
1044 /* For any still-undefined labels, do the cleanups for this block now.
1045 We must do this now since items in the cleanup list may go out
1046 of scope when the block ends. */
1047 for (prev
= 0, f
= goto_fixup_chain
; f
; prev
= f
, f
= f
->next
)
1048 if (f
->before_jump
!= 0
1049 && PREV_INSN (f
->target_rtl
) == 0
1050 /* Label has still not appeared. If we are exiting a block with
1051 a stack level to restore, that started before the fixup,
1052 mark this stack level as needing restoration
1053 when the fixup is later finalized. */
1055 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1056 means the label is undefined. That's erroneous, but possible. */
1057 && (thisblock
->data
.block
.block_start_count
1058 <= f
->block_start_count
))
1060 tree lists
= f
->cleanup_list_list
;
1063 for (; lists
; lists
= TREE_CHAIN (lists
))
1064 /* If the following elt. corresponds to our containing block
1065 then the elt. must be for this block. */
1066 if (TREE_CHAIN (lists
) == thisblock
->data
.block
.outer_cleanups
)
1069 (*lang_hooks
.decls
.pushlevel
) (0);
1070 (*lang_hooks
.decls
.set_block
) (f
->context
);
1071 expand_cleanups (TREE_VALUE (lists
), NULL_TREE
, 1, 1);
1072 do_pending_stack_adjust ();
1073 cleanup_insns
= get_insns ();
1074 (*lang_hooks
.decls
.poplevel
) (1, 0, 0);
1076 if (cleanup_insns
!= 0)
1078 = emit_insn_after (cleanup_insns
, f
->before_jump
);
1080 f
->cleanup_list_list
= TREE_CHAIN (lists
);
1084 f
->stack_level
= stack_level
;
1088 /* Return the number of times character C occurs in string S. */
1090 n_occurrences (c
, s
)
1100 /* Generate RTL for an asm statement (explicit assembler code).
1101 BODY is a STRING_CST node containing the assembler code text,
1102 or an ADDR_EXPR containing a STRING_CST. */
1108 if (TREE_CODE (body
) == ADDR_EXPR
)
1109 body
= TREE_OPERAND (body
, 0);
1111 emit_insn (gen_rtx_ASM_INPUT (VOIDmode
,
1112 TREE_STRING_POINTER (body
)));
1116 /* Parse the output constraint pointed to by *CONSTRAINT_P. It is the
1117 OPERAND_NUMth output operand, indexed from zero. There are NINPUTS
1118 inputs and NOUTPUTS outputs to this extended-asm. Upon return,
1119 *ALLOWS_MEM will be TRUE iff the constraint allows the use of a
1120 memory operand. Similarly, *ALLOWS_REG will be TRUE iff the
1121 constraint allows the use of a register operand. And, *IS_INOUT
1122 will be true if the operand is read-write, i.e., if it is used as
1123 an input as well as an output. If *CONSTRAINT_P is not in
1124 canonical form, it will be made canonical. (Note that `+' will be
1125 rpelaced with `=' as part of this process.)
1127 Returns TRUE if all went well; FALSE if an error occurred. */
1130 parse_output_constraint (constraint_p
, operand_num
, ninputs
, noutputs
,
1131 allows_mem
, allows_reg
, is_inout
)
1132 const char **constraint_p
;
1140 const char *constraint
= *constraint_p
;
1143 /* Assume the constraint doesn't allow the use of either a register
1145 *allows_mem
= false;
1146 *allows_reg
= false;
1148 /* Allow the `=' or `+' to not be at the beginning of the string,
1149 since it wasn't explicitly documented that way, and there is a
1150 large body of code that puts it last. Swap the character to
1151 the front, so as not to uglify any place else. */
1152 p
= strchr (constraint
, '=');
1154 p
= strchr (constraint
, '+');
1156 /* If the string doesn't contain an `=', issue an error
1160 error ("output operand constraint lacks `='");
1164 /* If the constraint begins with `+', then the operand is both read
1165 from and written to. */
1166 *is_inout
= (*p
== '+');
1168 /* Canonicalize the output constraint so that it begins with `='. */
1169 if (p
!= constraint
|| is_inout
)
1172 size_t c_len
= strlen (constraint
);
1174 if (p
!= constraint
)
1175 warning ("output constraint `%c' for operand %d is not at the beginning",
1178 /* Make a copy of the constraint. */
1179 buf
= alloca (c_len
+ 1);
1180 strcpy (buf
, constraint
);
1181 /* Swap the first character and the `=' or `+'. */
1182 buf
[p
- constraint
] = buf
[0];
1183 /* Make sure the first character is an `='. (Until we do this,
1184 it might be a `+'.) */
1186 /* Replace the constraint with the canonicalized string. */
1187 *constraint_p
= ggc_alloc_string (buf
, c_len
);
1188 constraint
= *constraint_p
;
1191 /* Loop through the constraint string. */
1192 for (p
= constraint
+ 1; *p
; ++p
)
1197 error ("operand constraint contains incorrectly positioned '+' or '='");
1201 if (operand_num
+ 1 == ninputs
+ noutputs
)
1203 error ("`%%' constraint used with last operand");
1208 case 'V': case 'm': case 'o':
1212 case '?': case '!': case '*': case '&': case '#':
1213 case 'E': case 'F': case 'G': case 'H':
1214 case 's': case 'i': case 'n':
1215 case 'I': case 'J': case 'K': case 'L': case 'M':
1216 case 'N': case 'O': case 'P': case ',':
1219 case '0': case '1': case '2': case '3': case '4':
1220 case '5': case '6': case '7': case '8': case '9':
1222 error ("matching constraint not valid in output operand");
1226 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1227 excepting those that expand_call created. So match memory
1244 if (REG_CLASS_FROM_LETTER (*p
) != NO_REGS
)
1246 #ifdef EXTRA_CONSTRAINT
1247 else if (EXTRA_ADDRESS_CONSTRAINT (*p
))
1249 else if (EXTRA_MEMORY_CONSTRAINT (*p
))
1253 /* Otherwise we can't assume anything about the nature of
1254 the constraint except that it isn't purely registers.
1255 Treat it like "g" and hope for the best. */
1266 /* Similar, but for input constraints. */
1269 parse_input_constraint (constraint_p
, input_num
, ninputs
, noutputs
, ninout
,
1270 constraints
, allows_mem
, allows_reg
)
1271 const char **constraint_p
;
1276 const char * const * constraints
;
1280 const char *constraint
= *constraint_p
;
1281 const char *orig_constraint
= constraint
;
1282 size_t c_len
= strlen (constraint
);
1285 /* Assume the constraint doesn't allow the use of either
1286 a register or memory. */
1287 *allows_mem
= false;
1288 *allows_reg
= false;
1290 /* Make sure constraint has neither `=', `+', nor '&'. */
1292 for (j
= 0; j
< c_len
; j
++)
1293 switch (constraint
[j
])
1295 case '+': case '=': case '&':
1296 if (constraint
== orig_constraint
)
1298 error ("input operand constraint contains `%c'", constraint
[j
]);
1304 if (constraint
== orig_constraint
1305 && input_num
+ 1 == ninputs
- ninout
)
1307 error ("`%%' constraint used with last operand");
1312 case 'V': case 'm': case 'o':
1317 case '?': case '!': case '*': case '#':
1318 case 'E': case 'F': case 'G': case 'H':
1319 case 's': case 'i': case 'n':
1320 case 'I': case 'J': case 'K': case 'L': case 'M':
1321 case 'N': case 'O': case 'P': case ',':
1324 /* Whether or not a numeric constraint allows a register is
1325 decided by the matching constraint, and so there is no need
1326 to do anything special with them. We must handle them in
1327 the default case, so that we don't unnecessarily force
1328 operands to memory. */
1329 case '0': case '1': case '2': case '3': case '4':
1330 case '5': case '6': case '7': case '8': case '9':
1333 unsigned long match
;
1335 match
= strtoul (constraint
+ j
, &end
, 10);
1336 if (match
>= (unsigned long) noutputs
)
1338 error ("matching constraint references invalid operand number");
1342 /* Try and find the real constraint for this dup. Only do this
1343 if the matching constraint is the only alternative. */
1345 && (j
== 0 || (j
== 1 && constraint
[0] == '%')))
1347 constraint
= constraints
[match
];
1348 *constraint_p
= constraint
;
1349 c_len
= strlen (constraint
);
1354 j
= end
- constraint
;
1368 if (! ISALPHA (constraint
[j
]))
1370 error ("invalid punctuation `%c' in constraint", constraint
[j
]);
1373 if (REG_CLASS_FROM_LETTER (constraint
[j
]) != NO_REGS
)
1375 #ifdef EXTRA_CONSTRAINT
1376 else if (EXTRA_ADDRESS_CONSTRAINT (constraint
[j
]))
1378 else if (EXTRA_MEMORY_CONSTRAINT (constraint
[j
]))
1382 /* Otherwise we can't assume anything about the nature of
1383 the constraint except that it isn't purely registers.
1384 Treat it like "g" and hope for the best. */
1395 /* Check for overlap between registers marked in CLOBBERED_REGS and
1396 anything inappropriate in DECL. Emit error and return TRUE for error,
1400 decl_conflicts_with_clobbers_p (decl
, clobbered_regs
)
1402 const HARD_REG_SET clobbered_regs
;
1404 /* Conflicts between asm-declared register variables and the clobber
1405 list are not allowed. */
1406 if ((TREE_CODE (decl
) == VAR_DECL
|| TREE_CODE (decl
) == PARM_DECL
)
1407 && DECL_REGISTER (decl
)
1408 && REG_P (DECL_RTL (decl
))
1409 && REGNO (DECL_RTL (decl
)) < FIRST_PSEUDO_REGISTER
)
1411 rtx reg
= DECL_RTL (decl
);
1414 for (regno
= REGNO (reg
);
1415 regno
< (REGNO (reg
)
1416 + HARD_REGNO_NREGS (REGNO (reg
), GET_MODE (reg
)));
1418 if (TEST_HARD_REG_BIT (clobbered_regs
, regno
))
1420 error ("asm-specifier for variable `%s' conflicts with asm clobber list",
1421 IDENTIFIER_POINTER (DECL_NAME (decl
)));
1423 /* Reset registerness to stop multiple errors emitted for a
1425 DECL_REGISTER (decl
) = 0;
1432 /* Generate RTL for an asm statement with arguments.
1433 STRING is the instruction template.
1434 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1435 Each output or input has an expression in the TREE_VALUE and
1436 and a tree list in TREE_PURPOSE which in turn contains a constraint
1437 name in TREE_VALUE (or NULL_TREE) and a constraint string
1439 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1440 that is clobbered by this insn.
1442 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1443 Some elements of OUTPUTS may be replaced with trees representing temporary
1444 values. The caller should copy those temporary values to the originally
1447 VOL nonzero means the insn is volatile; don't optimize it. */
1450 expand_asm_operands (string
, outputs
, inputs
, clobbers
, vol
, filename
, line
)
1451 tree string
, outputs
, inputs
, clobbers
;
1453 const char *filename
;
1456 rtvec argvec
, constraintvec
;
1458 int ninputs
= list_length (inputs
);
1459 int noutputs
= list_length (outputs
);
1462 HARD_REG_SET clobbered_regs
;
1463 int clobber_conflict_found
= 0;
1466 /* Vector of RTX's of evaluated output operands. */
1467 rtx
*output_rtx
= (rtx
*) alloca (noutputs
* sizeof (rtx
));
1468 int *inout_opnum
= (int *) alloca (noutputs
* sizeof (int));
1469 rtx
*real_output_rtx
= (rtx
*) alloca (noutputs
* sizeof (rtx
));
1470 enum machine_mode
*inout_mode
1471 = (enum machine_mode
*) alloca (noutputs
* sizeof (enum machine_mode
));
1472 const char **constraints
1473 = (const char **) alloca ((noutputs
+ ninputs
) * sizeof (const char *));
1474 int old_generating_concat_p
= generating_concat_p
;
1476 /* An ASM with no outputs needs to be treated as volatile, for now. */
1480 if (! check_operand_nalternatives (outputs
, inputs
))
1483 if (! check_unique_operand_names (outputs
, inputs
))
1486 string
= resolve_operand_names (string
, outputs
, inputs
, constraints
);
1488 #ifdef MD_ASM_CLOBBERS
1489 /* Sometimes we wish to automatically clobber registers across an asm.
1490 Case in point is when the i386 backend moved from cc0 to a hard reg --
1491 maintaining source-level compatibility means automatically clobbering
1492 the flags register. */
1493 MD_ASM_CLOBBERS (clobbers
);
1496 /* Count the number of meaningful clobbered registers, ignoring what
1497 we would ignore later. */
1499 CLEAR_HARD_REG_SET (clobbered_regs
);
1500 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
))
1502 const char *regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
1504 i
= decode_reg_name (regname
);
1505 if (i
>= 0 || i
== -4)
1508 error ("unknown register name `%s' in `asm'", regname
);
1510 /* Mark clobbered registers. */
1512 SET_HARD_REG_BIT (clobbered_regs
, i
);
1517 /* First pass over inputs and outputs checks validity and sets
1518 mark_addressable if needed. */
1521 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1523 tree val
= TREE_VALUE (tail
);
1524 tree type
= TREE_TYPE (val
);
1525 const char *constraint
;
1530 /* If there's an erroneous arg, emit no insn. */
1531 if (type
== error_mark_node
)
1534 /* Try to parse the output constraint. If that fails, there's
1535 no point in going further. */
1536 constraint
= constraints
[i
];
1537 if (!parse_output_constraint (&constraint
, i
, ninputs
, noutputs
,
1538 &allows_mem
, &allows_reg
, &is_inout
))
1545 && GET_CODE (DECL_RTL (val
)) == REG
1546 && GET_MODE (DECL_RTL (val
)) != TYPE_MODE (type
))))
1547 (*lang_hooks
.mark_addressable
) (val
);
1554 if (ninputs
+ noutputs
> MAX_RECOG_OPERANDS
)
1556 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS
);
1560 for (i
= 0, tail
= inputs
; tail
; i
++, tail
= TREE_CHAIN (tail
))
1562 bool allows_reg
, allows_mem
;
1563 const char *constraint
;
1565 /* If there's an erroneous arg, emit no insn, because the ASM_INPUT
1566 would get VOIDmode and that could cause a crash in reload. */
1567 if (TREE_TYPE (TREE_VALUE (tail
)) == error_mark_node
)
1570 constraint
= constraints
[i
+ noutputs
];
1571 if (! parse_input_constraint (&constraint
, i
, ninputs
, noutputs
, ninout
,
1572 constraints
, &allows_mem
, &allows_reg
))
1575 if (! allows_reg
&& allows_mem
)
1576 (*lang_hooks
.mark_addressable
) (TREE_VALUE (tail
));
1579 /* Second pass evaluates arguments. */
1582 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1584 tree val
= TREE_VALUE (tail
);
1585 tree type
= TREE_TYPE (val
);
1590 if (!parse_output_constraint (&constraints
[i
], i
, ninputs
,
1591 noutputs
, &allows_mem
, &allows_reg
,
1595 /* If an output operand is not a decl or indirect ref and our constraint
1596 allows a register, make a temporary to act as an intermediate.
1597 Make the asm insn write into that, then our caller will copy it to
1598 the real output operand. Likewise for promoted variables. */
1600 generating_concat_p
= 0;
1602 real_output_rtx
[i
] = NULL_RTX
;
1603 if ((TREE_CODE (val
) == INDIRECT_REF
1606 && (allows_mem
|| GET_CODE (DECL_RTL (val
)) == REG
)
1607 && ! (GET_CODE (DECL_RTL (val
)) == REG
1608 && GET_MODE (DECL_RTL (val
)) != TYPE_MODE (type
)))
1612 output_rtx
[i
] = expand_expr (val
, NULL_RTX
, VOIDmode
, EXPAND_WRITE
);
1614 if (! allows_reg
&& GET_CODE (output_rtx
[i
]) != MEM
)
1615 error ("output number %d not directly addressable", i
);
1616 if ((! allows_mem
&& GET_CODE (output_rtx
[i
]) == MEM
)
1617 || GET_CODE (output_rtx
[i
]) == CONCAT
)
1619 real_output_rtx
[i
] = protect_from_queue (output_rtx
[i
], 1);
1620 output_rtx
[i
] = gen_reg_rtx (GET_MODE (output_rtx
[i
]));
1622 emit_move_insn (output_rtx
[i
], real_output_rtx
[i
]);
1627 output_rtx
[i
] = assign_temp (type
, 0, 0, 1);
1628 TREE_VALUE (tail
) = make_tree (type
, output_rtx
[i
]);
1631 generating_concat_p
= old_generating_concat_p
;
1635 inout_mode
[ninout
] = TYPE_MODE (type
);
1636 inout_opnum
[ninout
++] = i
;
1639 if (decl_conflicts_with_clobbers_p (val
, clobbered_regs
))
1640 clobber_conflict_found
= 1;
1643 /* Make vectors for the expression-rtx, constraint strings,
1644 and named operands. */
1646 argvec
= rtvec_alloc (ninputs
);
1647 constraintvec
= rtvec_alloc (ninputs
);
1649 body
= gen_rtx_ASM_OPERANDS ((noutputs
== 0 ? VOIDmode
1650 : GET_MODE (output_rtx
[0])),
1651 TREE_STRING_POINTER (string
),
1652 empty_string
, 0, argvec
, constraintvec
,
1655 MEM_VOLATILE_P (body
) = vol
;
1657 /* Eval the inputs and put them into ARGVEC.
1658 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1660 for (i
= 0, tail
= inputs
; tail
; tail
= TREE_CHAIN (tail
), ++i
)
1662 bool allows_reg
, allows_mem
;
1663 const char *constraint
;
1667 constraint
= constraints
[i
+ noutputs
];
1668 if (! parse_input_constraint (&constraint
, i
, ninputs
, noutputs
, ninout
,
1669 constraints
, &allows_mem
, &allows_reg
))
1672 generating_concat_p
= 0;
1674 val
= TREE_VALUE (tail
);
1675 type
= TREE_TYPE (val
);
1676 op
= expand_expr (val
, NULL_RTX
, VOIDmode
, 0);
1678 /* Never pass a CONCAT to an ASM. */
1679 if (GET_CODE (op
) == CONCAT
)
1680 op
= force_reg (GET_MODE (op
), op
);
1682 if (asm_operand_ok (op
, constraint
) <= 0)
1685 op
= force_reg (TYPE_MODE (type
), op
);
1686 else if (!allows_mem
)
1687 warning ("asm operand %d probably doesn't match constraints",
1689 else if (CONSTANT_P (op
))
1690 op
= force_const_mem (TYPE_MODE (type
), op
);
1691 else if (GET_CODE (op
) == REG
1692 || GET_CODE (op
) == SUBREG
1693 || GET_CODE (op
) == ADDRESSOF
1694 || GET_CODE (op
) == CONCAT
)
1696 tree qual_type
= build_qualified_type (type
,
1698 | TYPE_QUAL_CONST
));
1699 rtx memloc
= assign_temp (qual_type
, 1, 1, 1);
1701 emit_move_insn (memloc
, op
);
1705 else if (GET_CODE (op
) == MEM
&& MEM_VOLATILE_P (op
))
1707 /* We won't recognize volatile memory as available a
1708 memory_operand at this point. Ignore it. */
1710 else if (queued_subexp_p (op
))
1713 /* ??? Leave this only until we have experience with what
1714 happens in combine and elsewhere when constraints are
1716 warning ("asm operand %d probably doesn't match constraints",
1720 generating_concat_p
= old_generating_concat_p
;
1721 ASM_OPERANDS_INPUT (body
, i
) = op
;
1723 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body
, i
)
1724 = gen_rtx_ASM_INPUT (TYPE_MODE (type
), constraints
[i
+ noutputs
]);
1726 if (decl_conflicts_with_clobbers_p (val
, clobbered_regs
))
1727 clobber_conflict_found
= 1;
1730 /* Protect all the operands from the queue now that they have all been
1733 generating_concat_p
= 0;
1735 for (i
= 0; i
< ninputs
- ninout
; i
++)
1736 ASM_OPERANDS_INPUT (body
, i
)
1737 = protect_from_queue (ASM_OPERANDS_INPUT (body
, i
), 0);
1739 for (i
= 0; i
< noutputs
; i
++)
1740 output_rtx
[i
] = protect_from_queue (output_rtx
[i
], 1);
1742 /* For in-out operands, copy output rtx to input rtx. */
1743 for (i
= 0; i
< ninout
; i
++)
1745 int j
= inout_opnum
[i
];
1748 ASM_OPERANDS_INPUT (body
, ninputs
- ninout
+ i
)
1751 sprintf (buffer
, "%d", j
);
1752 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body
, ninputs
- ninout
+ i
)
1753 = gen_rtx_ASM_INPUT (inout_mode
[i
], ggc_alloc_string (buffer
, -1));
1756 generating_concat_p
= old_generating_concat_p
;
1758 /* Now, for each output, construct an rtx
1759 (set OUTPUT (asm_operands INSN OUTPUTCONSTRAINT OUTPUTNUMBER
1760 ARGVEC CONSTRAINTS OPNAMES))
1761 If there is more than one, put them inside a PARALLEL. */
1763 if (noutputs
== 1 && nclobbers
== 0)
1765 ASM_OPERANDS_OUTPUT_CONSTRAINT (body
) = constraints
[0];
1766 emit_insn (gen_rtx_SET (VOIDmode
, output_rtx
[0], body
));
1769 else if (noutputs
== 0 && nclobbers
== 0)
1771 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1783 body
= gen_rtx_PARALLEL (VOIDmode
, rtvec_alloc (num
+ nclobbers
));
1785 /* For each output operand, store a SET. */
1786 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1788 XVECEXP (body
, 0, i
)
1789 = gen_rtx_SET (VOIDmode
,
1791 gen_rtx_ASM_OPERANDS
1792 (GET_MODE (output_rtx
[i
]),
1793 TREE_STRING_POINTER (string
),
1794 constraints
[i
], i
, argvec
, constraintvec
,
1797 MEM_VOLATILE_P (SET_SRC (XVECEXP (body
, 0, i
))) = vol
;
1800 /* If there are no outputs (but there are some clobbers)
1801 store the bare ASM_OPERANDS into the PARALLEL. */
1804 XVECEXP (body
, 0, i
++) = obody
;
1806 /* Store (clobber REG) for each clobbered register specified. */
1808 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
))
1810 const char *regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
1811 int j
= decode_reg_name (regname
);
1816 if (j
== -3) /* `cc', which is not a register */
1819 if (j
== -4) /* `memory', don't cache memory across asm */
1821 XVECEXP (body
, 0, i
++)
1822 = gen_rtx_CLOBBER (VOIDmode
,
1825 gen_rtx_SCRATCH (VOIDmode
)));
1829 /* Ignore unknown register, error already signaled. */
1833 /* Use QImode since that's guaranteed to clobber just one reg. */
1834 clobbered_reg
= gen_rtx_REG (QImode
, j
);
1836 /* Do sanity check for overlap between clobbers and respectively
1837 input and outputs that hasn't been handled. Such overlap
1838 should have been detected and reported above. */
1839 if (!clobber_conflict_found
)
1843 /* We test the old body (obody) contents to avoid tripping
1844 over the under-construction body. */
1845 for (opno
= 0; opno
< noutputs
; opno
++)
1846 if (reg_overlap_mentioned_p (clobbered_reg
, output_rtx
[opno
]))
1847 internal_error ("asm clobber conflict with output operand");
1849 for (opno
= 0; opno
< ninputs
- ninout
; opno
++)
1850 if (reg_overlap_mentioned_p (clobbered_reg
,
1851 ASM_OPERANDS_INPUT (obody
, opno
)))
1852 internal_error ("asm clobber conflict with input operand");
1855 XVECEXP (body
, 0, i
++)
1856 = gen_rtx_CLOBBER (VOIDmode
, clobbered_reg
);
1862 /* For any outputs that needed reloading into registers, spill them
1863 back to where they belong. */
1864 for (i
= 0; i
< noutputs
; ++i
)
1865 if (real_output_rtx
[i
])
1866 emit_move_insn (real_output_rtx
[i
], output_rtx
[i
]);
1871 /* A subroutine of expand_asm_operands. Check that all operands have
1872 the same number of alternatives. Return true if so. */
1875 check_operand_nalternatives (outputs
, inputs
)
1876 tree outputs
, inputs
;
1878 if (outputs
|| inputs
)
1880 tree tmp
= TREE_PURPOSE (outputs
? outputs
: inputs
);
1882 = n_occurrences (',', TREE_STRING_POINTER (TREE_VALUE (tmp
)));
1885 if (nalternatives
+ 1 > MAX_RECOG_ALTERNATIVES
)
1887 error ("too many alternatives in `asm'");
1894 const char *constraint
1895 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tmp
)));
1897 if (n_occurrences (',', constraint
) != nalternatives
)
1899 error ("operand constraints for `asm' differ in number of alternatives");
1903 if (TREE_CHAIN (tmp
))
1904 tmp
= TREE_CHAIN (tmp
);
1906 tmp
= next
, next
= 0;
1913 /* A subroutine of expand_asm_operands. Check that all operand names
1914 are unique. Return true if so. We rely on the fact that these names
1915 are identifiers, and so have been canonicalized by get_identifier,
1916 so all we need are pointer comparisons. */
1919 check_unique_operand_names (outputs
, inputs
)
1920 tree outputs
, inputs
;
1924 for (i
= outputs
; i
; i
= TREE_CHAIN (i
))
1926 tree i_name
= TREE_PURPOSE (TREE_PURPOSE (i
));
1930 for (j
= TREE_CHAIN (i
); j
; j
= TREE_CHAIN (j
))
1931 if (simple_cst_equal (i_name
, TREE_PURPOSE (TREE_PURPOSE (j
))))
1935 for (i
= inputs
; i
; i
= TREE_CHAIN (i
))
1937 tree i_name
= TREE_PURPOSE (TREE_PURPOSE (i
));
1941 for (j
= TREE_CHAIN (i
); j
; j
= TREE_CHAIN (j
))
1942 if (simple_cst_equal (i_name
, TREE_PURPOSE (TREE_PURPOSE (j
))))
1944 for (j
= outputs
; j
; j
= TREE_CHAIN (j
))
1945 if (simple_cst_equal (i_name
, TREE_PURPOSE (TREE_PURPOSE (j
))))
1952 error ("duplicate asm operand name '%s'",
1953 TREE_STRING_POINTER (TREE_PURPOSE (TREE_PURPOSE (i
))));
1957 /* A subroutine of expand_asm_operands. Resolve the names of the operands
1958 in *POUTPUTS and *PINPUTS to numbers, and replace the name expansions in
1959 STRING and in the constraints to those numbers. */
1962 resolve_operand_names (string
, outputs
, inputs
, pconstraints
)
1964 tree outputs
, inputs
;
1965 const char **pconstraints
;
1967 char *buffer
= xstrdup (TREE_STRING_POINTER (string
));
1971 /* Assume that we will not need extra space to perform the substitution.
1972 This because we get to remove '[' and ']', which means we cannot have
1973 a problem until we have more than 999 operands. */
1976 while ((p
= strchr (p
, '%')) != NULL
)
1980 else if (ISALPHA (p
[1]) && p
[2] == '[')
1988 p
= resolve_operand_name_1 (p
, outputs
, inputs
);
1991 string
= build_string (strlen (buffer
), buffer
);
1994 /* Collect output constraints here because it's convenient.
1995 There should be no named operands here; this is verified
1996 in expand_asm_operand. */
1997 for (t
= outputs
; t
; t
= TREE_CHAIN (t
), pconstraints
++)
1998 *pconstraints
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t
)));
2000 /* Substitute [<name>] in input constraint strings. */
2001 for (t
= inputs
; t
; t
= TREE_CHAIN (t
), pconstraints
++)
2003 const char *c
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t
)));
2004 if (strchr (c
, '[') == NULL
)
2008 p
= buffer
= xstrdup (c
);
2009 while ((p
= strchr (p
, '[')) != NULL
)
2010 p
= resolve_operand_name_1 (p
, outputs
, inputs
);
2012 *pconstraints
= ggc_alloc_string (buffer
, -1);
2020 /* A subroutine of resolve_operand_names. P points to the '[' for a
2021 potential named operand of the form [<name>]. In place, replace
2022 the name and brackets with a number. Return a pointer to the
2023 balance of the string after substitution. */
2026 resolve_operand_name_1 (p
, outputs
, inputs
)
2028 tree outputs
, inputs
;
2035 /* Collect the operand name. */
2036 q
= strchr (p
, ']');
2039 error ("missing close brace for named operand");
2040 return strchr (p
, '\0');
2044 /* Resolve the name to a number. */
2045 for (op
= 0, t
= outputs
; t
; t
= TREE_CHAIN (t
), op
++)
2047 tree name
= TREE_PURPOSE (TREE_PURPOSE (t
));
2050 const char *c
= TREE_STRING_POINTER (name
);
2051 if (strncmp (c
, p
+ 1, len
) == 0 && c
[len
] == '\0')
2055 for (t
= inputs
; t
; t
= TREE_CHAIN (t
), op
++)
2057 tree name
= TREE_PURPOSE (TREE_PURPOSE (t
));
2060 const char *c
= TREE_STRING_POINTER (name
);
2061 if (strncmp (c
, p
+ 1, len
) == 0 && c
[len
] == '\0')
2067 error ("undefined named operand '%s'", p
+ 1);
2071 /* Replace the name with the number. Unfortunately, not all libraries
2072 get the return value of sprintf correct, so search for the end of the
2073 generated string by hand. */
2074 sprintf (p
, "%d", op
);
2075 p
= strchr (p
, '\0');
2077 /* Verify the no extra buffer space assumption. */
2081 /* Shift the rest of the buffer down to fill the gap. */
2082 memmove (p
, q
+ 1, strlen (q
+ 1) + 1);
2087 /* Generate RTL to evaluate the expression EXP
2088 and remember it in case this is the VALUE in a ({... VALUE; }) constr.
2089 Provided just for backward-compatibility. expand_expr_stmt_value()
2090 should be used for new code. */
2093 expand_expr_stmt (exp
)
2096 expand_expr_stmt_value (exp
, -1, 1);
2099 /* Generate RTL to evaluate the expression EXP. WANT_VALUE tells
2100 whether to (1) save the value of the expression, (0) discard it or
2101 (-1) use expr_stmts_for_value to tell. The use of -1 is
2102 deprecated, and retained only for backward compatibility. */
2105 expand_expr_stmt_value (exp
, want_value
, maybe_last
)
2107 int want_value
, maybe_last
;
2112 if (want_value
== -1)
2113 want_value
= expr_stmts_for_value
!= 0;
2115 /* If -W, warn about statements with no side effects,
2116 except for an explicit cast to void (e.g. for assert()), and
2117 except for last statement in ({...}) where they may be useful. */
2119 && (expr_stmts_for_value
== 0 || ! maybe_last
)
2120 && exp
!= error_mark_node
)
2122 if (! TREE_SIDE_EFFECTS (exp
))
2124 if ((extra_warnings
|| warn_unused_value
)
2125 && !(TREE_CODE (exp
) == CONVERT_EXPR
2126 && VOID_TYPE_P (TREE_TYPE (exp
))))
2127 warning_with_file_and_line (emit_filename
, emit_lineno
,
2128 "statement with no effect");
2130 else if (warn_unused_value
)
2131 warn_if_unused_value (exp
);
2134 /* If EXP is of function type and we are expanding statements for
2135 value, convert it to pointer-to-function. */
2136 if (want_value
&& TREE_CODE (TREE_TYPE (exp
)) == FUNCTION_TYPE
)
2137 exp
= build1 (ADDR_EXPR
, build_pointer_type (TREE_TYPE (exp
)), exp
);
2139 /* The call to `expand_expr' could cause last_expr_type and
2140 last_expr_value to get reset. Therefore, we set last_expr_value
2141 and last_expr_type *after* calling expand_expr. */
2142 value
= expand_expr (exp
, want_value
? NULL_RTX
: const0_rtx
,
2144 type
= TREE_TYPE (exp
);
2146 /* If all we do is reference a volatile value in memory,
2147 copy it to a register to be sure it is actually touched. */
2148 if (value
&& GET_CODE (value
) == MEM
&& TREE_THIS_VOLATILE (exp
))
2150 if (TYPE_MODE (type
) == VOIDmode
)
2152 else if (TYPE_MODE (type
) != BLKmode
)
2153 value
= copy_to_reg (value
);
2156 rtx lab
= gen_label_rtx ();
2158 /* Compare the value with itself to reference it. */
2159 emit_cmp_and_jump_insns (value
, value
, EQ
,
2160 expand_expr (TYPE_SIZE (type
),
2161 NULL_RTX
, VOIDmode
, 0),
2167 /* If this expression is part of a ({...}) and is in memory, we may have
2168 to preserve temporaries. */
2169 preserve_temp_slots (value
);
2171 /* Free any temporaries used to evaluate this expression. Any temporary
2172 used as a result of this expression will already have been preserved
2178 last_expr_value
= value
;
2179 last_expr_type
= type
;
2185 /* Warn if EXP contains any computations whose results are not used.
2186 Return 1 if a warning is printed; 0 otherwise. */
2189 warn_if_unused_value (exp
)
2192 if (TREE_USED (exp
))
2195 /* Don't warn about void constructs. This includes casting to void,
2196 void function calls, and statement expressions with a final cast
2198 if (VOID_TYPE_P (TREE_TYPE (exp
)))
2201 switch (TREE_CODE (exp
))
2203 case PREINCREMENT_EXPR
:
2204 case POSTINCREMENT_EXPR
:
2205 case PREDECREMENT_EXPR
:
2206 case POSTDECREMENT_EXPR
:
2211 case METHOD_CALL_EXPR
:
2213 case TRY_CATCH_EXPR
:
2214 case WITH_CLEANUP_EXPR
:
2219 /* For a binding, warn if no side effect within it. */
2220 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2223 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2225 case TRUTH_ORIF_EXPR
:
2226 case TRUTH_ANDIF_EXPR
:
2227 /* In && or ||, warn if 2nd operand has no side effect. */
2228 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2231 if (TREE_NO_UNUSED_WARNING (exp
))
2233 if (warn_if_unused_value (TREE_OPERAND (exp
, 0)))
2235 /* Let people do `(foo (), 0)' without a warning. */
2236 if (TREE_CONSTANT (TREE_OPERAND (exp
, 1)))
2238 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2242 case NON_LVALUE_EXPR
:
2243 /* Don't warn about conversions not explicit in the user's program. */
2244 if (TREE_NO_UNUSED_WARNING (exp
))
2246 /* Assignment to a cast usually results in a cast of a modify.
2247 Don't complain about that. There can be an arbitrary number of
2248 casts before the modify, so we must loop until we find the first
2249 non-cast expression and then test to see if that is a modify. */
2251 tree tem
= TREE_OPERAND (exp
, 0);
2253 while (TREE_CODE (tem
) == CONVERT_EXPR
|| TREE_CODE (tem
) == NOP_EXPR
)
2254 tem
= TREE_OPERAND (tem
, 0);
2256 if (TREE_CODE (tem
) == MODIFY_EXPR
|| TREE_CODE (tem
) == INIT_EXPR
2257 || TREE_CODE (tem
) == CALL_EXPR
)
2263 /* Don't warn about automatic dereferencing of references, since
2264 the user cannot control it. */
2265 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp
, 0))) == REFERENCE_TYPE
)
2266 return warn_if_unused_value (TREE_OPERAND (exp
, 0));
2270 /* Referencing a volatile value is a side effect, so don't warn. */
2272 || TREE_CODE_CLASS (TREE_CODE (exp
)) == 'r')
2273 && TREE_THIS_VOLATILE (exp
))
2276 /* If this is an expression which has no operands, there is no value
2277 to be unused. There are no such language-independent codes,
2278 but front ends may define such. */
2279 if (TREE_CODE_CLASS (TREE_CODE (exp
)) == 'e'
2280 && TREE_CODE_LENGTH (TREE_CODE (exp
)) == 0)
2284 /* If this is an expression with side effects, don't warn. */
2285 if (TREE_SIDE_EFFECTS (exp
))
2288 warning_with_file_and_line (emit_filename
, emit_lineno
,
2289 "value computed is not used");
2294 /* Clear out the memory of the last expression evaluated. */
2299 last_expr_type
= NULL_TREE
;
2300 last_expr_value
= NULL_RTX
;
2303 /* Begin a statement-expression, i.e., a series of statements which
2304 may return a value. Return the RTL_EXPR for this statement expr.
2305 The caller must save that value and pass it to
2306 expand_end_stmt_expr. If HAS_SCOPE is nonzero, temporaries created
2307 in the statement-expression are deallocated at the end of the
2311 expand_start_stmt_expr (has_scope
)
2316 /* Make the RTL_EXPR node temporary, not momentary,
2317 so that rtl_expr_chain doesn't become garbage. */
2318 t
= make_node (RTL_EXPR
);
2319 do_pending_stack_adjust ();
2321 start_sequence_for_rtl_expr (t
);
2325 expr_stmts_for_value
++;
2329 /* Restore the previous state at the end of a statement that returns a value.
2330 Returns a tree node representing the statement's value and the
2331 insns to compute the value.
2333 The nodes of that expression have been freed by now, so we cannot use them.
2334 But we don't want to do that anyway; the expression has already been
2335 evaluated and now we just want to use the value. So generate a RTL_EXPR
2336 with the proper type and RTL value.
2338 If the last substatement was not an expression,
2339 return something with type `void'. */
2342 expand_end_stmt_expr (t
)
2347 if (! last_expr_value
|| ! last_expr_type
)
2349 last_expr_value
= const0_rtx
;
2350 last_expr_type
= void_type_node
;
2352 else if (GET_CODE (last_expr_value
) != REG
&& ! CONSTANT_P (last_expr_value
))
2353 /* Remove any possible QUEUED. */
2354 last_expr_value
= protect_from_queue (last_expr_value
, 0);
2358 TREE_TYPE (t
) = last_expr_type
;
2359 RTL_EXPR_RTL (t
) = last_expr_value
;
2360 RTL_EXPR_SEQUENCE (t
) = get_insns ();
2362 rtl_expr_chain
= tree_cons (NULL_TREE
, t
, rtl_expr_chain
);
2366 /* Don't consider deleting this expr or containing exprs at tree level. */
2367 TREE_SIDE_EFFECTS (t
) = 1;
2368 /* Propagate volatility of the actual RTL expr. */
2369 TREE_THIS_VOLATILE (t
) = volatile_refs_p (last_expr_value
);
2372 expr_stmts_for_value
--;
2377 /* Generate RTL for the start of an if-then. COND is the expression
2378 whose truth should be tested.
2380 If EXITFLAG is nonzero, this conditional is visible to
2381 `exit_something'. */
2384 expand_start_cond (cond
, exitflag
)
2388 struct nesting
*thiscond
= ALLOC_NESTING ();
2390 /* Make an entry on cond_stack for the cond we are entering. */
2392 thiscond
->desc
= COND_NESTING
;
2393 thiscond
->next
= cond_stack
;
2394 thiscond
->all
= nesting_stack
;
2395 thiscond
->depth
= ++nesting_depth
;
2396 thiscond
->data
.cond
.next_label
= gen_label_rtx ();
2397 /* Before we encounter an `else', we don't need a separate exit label
2398 unless there are supposed to be exit statements
2399 to exit this conditional. */
2400 thiscond
->exit_label
= exitflag
? gen_label_rtx () : 0;
2401 thiscond
->data
.cond
.endif_label
= thiscond
->exit_label
;
2402 cond_stack
= thiscond
;
2403 nesting_stack
= thiscond
;
2405 do_jump (cond
, thiscond
->data
.cond
.next_label
, NULL_RTX
);
2408 /* Generate RTL between then-clause and the elseif-clause
2409 of an if-then-elseif-.... */
2412 expand_start_elseif (cond
)
2415 if (cond_stack
->data
.cond
.endif_label
== 0)
2416 cond_stack
->data
.cond
.endif_label
= gen_label_rtx ();
2417 emit_jump (cond_stack
->data
.cond
.endif_label
);
2418 emit_label (cond_stack
->data
.cond
.next_label
);
2419 cond_stack
->data
.cond
.next_label
= gen_label_rtx ();
2420 do_jump (cond
, cond_stack
->data
.cond
.next_label
, NULL_RTX
);
2423 /* Generate RTL between the then-clause and the else-clause
2424 of an if-then-else. */
2427 expand_start_else ()
2429 if (cond_stack
->data
.cond
.endif_label
== 0)
2430 cond_stack
->data
.cond
.endif_label
= gen_label_rtx ();
2432 emit_jump (cond_stack
->data
.cond
.endif_label
);
2433 emit_label (cond_stack
->data
.cond
.next_label
);
2434 cond_stack
->data
.cond
.next_label
= 0; /* No more _else or _elseif calls. */
2437 /* After calling expand_start_else, turn this "else" into an "else if"
2438 by providing another condition. */
2441 expand_elseif (cond
)
2444 cond_stack
->data
.cond
.next_label
= gen_label_rtx ();
2445 do_jump (cond
, cond_stack
->data
.cond
.next_label
, NULL_RTX
);
2448 /* Generate RTL for the end of an if-then.
2449 Pop the record for it off of cond_stack. */
2454 struct nesting
*thiscond
= cond_stack
;
2456 do_pending_stack_adjust ();
2457 if (thiscond
->data
.cond
.next_label
)
2458 emit_label (thiscond
->data
.cond
.next_label
);
2459 if (thiscond
->data
.cond
.endif_label
)
2460 emit_label (thiscond
->data
.cond
.endif_label
);
2462 POPSTACK (cond_stack
);
2466 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2467 loop should be exited by `exit_something'. This is a loop for which
2468 `expand_continue' will jump to the top of the loop.
2470 Make an entry on loop_stack to record the labels associated with
2474 expand_start_loop (exit_flag
)
2477 struct nesting
*thisloop
= ALLOC_NESTING ();
2479 /* Make an entry on loop_stack for the loop we are entering. */
2481 thisloop
->desc
= LOOP_NESTING
;
2482 thisloop
->next
= loop_stack
;
2483 thisloop
->all
= nesting_stack
;
2484 thisloop
->depth
= ++nesting_depth
;
2485 thisloop
->data
.loop
.start_label
= gen_label_rtx ();
2486 thisloop
->data
.loop
.end_label
= gen_label_rtx ();
2487 thisloop
->data
.loop
.continue_label
= thisloop
->data
.loop
.start_label
;
2488 thisloop
->exit_label
= exit_flag
? thisloop
->data
.loop
.end_label
: 0;
2489 loop_stack
= thisloop
;
2490 nesting_stack
= thisloop
;
2492 do_pending_stack_adjust ();
2494 emit_note (NULL
, NOTE_INSN_LOOP_BEG
);
2495 emit_label (thisloop
->data
.loop
.start_label
);
2500 /* Like expand_start_loop but for a loop where the continuation point
2501 (for expand_continue_loop) will be specified explicitly. */
2504 expand_start_loop_continue_elsewhere (exit_flag
)
2507 struct nesting
*thisloop
= expand_start_loop (exit_flag
);
2508 loop_stack
->data
.loop
.continue_label
= gen_label_rtx ();
2512 /* Begin a null, aka do { } while (0) "loop". But since the contents
2513 of said loop can still contain a break, we must frob the loop nest. */
2516 expand_start_null_loop ()
2518 struct nesting
*thisloop
= ALLOC_NESTING ();
2520 /* Make an entry on loop_stack for the loop we are entering. */
2522 thisloop
->desc
= LOOP_NESTING
;
2523 thisloop
->next
= loop_stack
;
2524 thisloop
->all
= nesting_stack
;
2525 thisloop
->depth
= ++nesting_depth
;
2526 thisloop
->data
.loop
.start_label
= emit_note (NULL
, NOTE_INSN_DELETED
);
2527 thisloop
->data
.loop
.end_label
= gen_label_rtx ();
2528 thisloop
->data
.loop
.continue_label
= thisloop
->data
.loop
.end_label
;
2529 thisloop
->exit_label
= thisloop
->data
.loop
.end_label
;
2530 loop_stack
= thisloop
;
2531 nesting_stack
= thisloop
;
2536 /* Specify the continuation point for a loop started with
2537 expand_start_loop_continue_elsewhere.
2538 Use this at the point in the code to which a continue statement
2542 expand_loop_continue_here ()
2544 do_pending_stack_adjust ();
2545 emit_note (NULL
, NOTE_INSN_LOOP_CONT
);
2546 emit_label (loop_stack
->data
.loop
.continue_label
);
2549 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2550 Pop the block off of loop_stack. */
2555 rtx start_label
= loop_stack
->data
.loop
.start_label
;
2557 int eh_regions
, debug_blocks
;
2560 /* Mark the continue-point at the top of the loop if none elsewhere. */
2561 if (start_label
== loop_stack
->data
.loop
.continue_label
)
2562 emit_note_before (NOTE_INSN_LOOP_CONT
, start_label
);
2564 do_pending_stack_adjust ();
2566 /* If the loop starts with a loop exit, roll that to the end where
2567 it will optimize together with the jump back.
2569 If the loop presently looks like this (in pseudo-C):
2573 if (test) goto end_label;
2579 transform it to look like:
2586 if (test) goto end_label;
2590 We rely on the presence of NOTE_INSN_LOOP_END_TOP_COND to mark
2591 the end of the entry condtional. Without this, our lexical scan
2592 can't tell the difference between an entry conditional and a
2593 body conditional that exits the loop. Mistaking the two means
2594 that we can misplace the NOTE_INSN_LOOP_CONT note, which can
2595 screw up loop unrolling.
2597 Things will be oh so much better when loop optimization is done
2598 off of a proper control flow graph... */
2600 /* Scan insns from the top of the loop looking for the END_TOP_COND note. */
2603 eh_regions
= debug_blocks
= 0;
2604 for (etc_note
= start_label
; etc_note
; etc_note
= NEXT_INSN (etc_note
))
2605 if (GET_CODE (etc_note
) == NOTE
)
2607 if (NOTE_LINE_NUMBER (etc_note
) == NOTE_INSN_LOOP_END_TOP_COND
)
2610 /* We must not walk into a nested loop. */
2611 else if (NOTE_LINE_NUMBER (etc_note
) == NOTE_INSN_LOOP_BEG
)
2613 etc_note
= NULL_RTX
;
2617 /* At the same time, scan for EH region notes, as we don't want
2618 to scrog region nesting. This shouldn't happen, but... */
2619 else if (NOTE_LINE_NUMBER (etc_note
) == NOTE_INSN_EH_REGION_BEG
)
2621 else if (NOTE_LINE_NUMBER (etc_note
) == NOTE_INSN_EH_REGION_END
)
2623 if (--eh_regions
< 0)
2624 /* We've come to the end of an EH region, but never saw the
2625 beginning of that region. That means that an EH region
2626 begins before the top of the loop, and ends in the middle
2627 of it. The existence of such a situation violates a basic
2628 assumption in this code, since that would imply that even
2629 when EH_REGIONS is zero, we might move code out of an
2630 exception region. */
2634 /* Likewise for debug scopes. In this case we'll either (1) move
2635 all of the notes if they are properly nested or (2) leave the
2636 notes alone and only rotate the loop at high optimization
2637 levels when we expect to scrog debug info. */
2638 else if (NOTE_LINE_NUMBER (etc_note
) == NOTE_INSN_BLOCK_BEG
)
2640 else if (NOTE_LINE_NUMBER (etc_note
) == NOTE_INSN_BLOCK_END
)
2643 else if (INSN_P (etc_note
))
2650 && (debug_blocks
== 0 || optimize
>= 2)
2651 && NEXT_INSN (etc_note
) != NULL_RTX
2652 && ! any_condjump_p (get_last_insn ()))
2654 /* We found one. Move everything from START to ETC to the end
2655 of the loop, and add a jump from the top of the loop. */
2656 rtx top_label
= gen_label_rtx ();
2657 rtx start_move
= start_label
;
2659 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2660 then we want to move this note also. */
2661 if (GET_CODE (PREV_INSN (start_move
)) == NOTE
2662 && NOTE_LINE_NUMBER (PREV_INSN (start_move
)) == NOTE_INSN_LOOP_CONT
)
2663 start_move
= PREV_INSN (start_move
);
2665 emit_label_before (top_label
, start_move
);
2667 /* Actually move the insns. If the debug scopes are nested, we
2668 can move everything at once. Otherwise we have to move them
2669 one by one and squeeze out the block notes. */
2670 if (debug_blocks
== 0)
2671 reorder_insns (start_move
, etc_note
, get_last_insn ());
2674 rtx insn
, next_insn
;
2675 for (insn
= start_move
; insn
; insn
= next_insn
)
2677 /* Figure out which insn comes after this one. We have
2678 to do this before we move INSN. */
2679 next_insn
= (insn
== etc_note
? NULL
: NEXT_INSN (insn
));
2681 if (GET_CODE (insn
) == NOTE
2682 && (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_BEG
2683 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_END
))
2686 reorder_insns (insn
, insn
, get_last_insn ());
2690 /* Add the jump from the top of the loop. */
2691 emit_jump_insn_before (gen_jump (start_label
), top_label
);
2692 emit_barrier_before (top_label
);
2693 start_label
= top_label
;
2696 emit_jump (start_label
);
2697 emit_note (NULL
, NOTE_INSN_LOOP_END
);
2698 emit_label (loop_stack
->data
.loop
.end_label
);
2700 POPSTACK (loop_stack
);
2705 /* Finish a null loop, aka do { } while (0). */
2708 expand_end_null_loop ()
2710 do_pending_stack_adjust ();
2711 emit_label (loop_stack
->data
.loop
.end_label
);
2713 POPSTACK (loop_stack
);
2718 /* Generate a jump to the current loop's continue-point.
2719 This is usually the top of the loop, but may be specified
2720 explicitly elsewhere. If not currently inside a loop,
2721 return 0 and do nothing; caller will print an error message. */
2724 expand_continue_loop (whichloop
)
2725 struct nesting
*whichloop
;
2727 /* Emit information for branch prediction. */
2730 note
= emit_note (NULL
, NOTE_INSN_PREDICTION
);
2731 NOTE_PREDICTION (note
) = NOTE_PREDICT (PRED_CONTINUE
, IS_TAKEN
);
2734 whichloop
= loop_stack
;
2737 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.continue_label
,
2742 /* Generate a jump to exit the current loop. If not currently inside a loop,
2743 return 0 and do nothing; caller will print an error message. */
2746 expand_exit_loop (whichloop
)
2747 struct nesting
*whichloop
;
2751 whichloop
= loop_stack
;
2754 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.end_label
, NULL_RTX
);
2758 /* Generate a conditional jump to exit the current loop if COND
2759 evaluates to zero. If not currently inside a loop,
2760 return 0 and do nothing; caller will print an error message. */
2763 expand_exit_loop_if_false (whichloop
, cond
)
2764 struct nesting
*whichloop
;
2771 whichloop
= loop_stack
;
2775 if (integer_nonzerop (cond
))
2777 if (integer_zerop (cond
))
2778 return expand_exit_loop (whichloop
);
2780 /* Check if we definitely won't need a fixup. */
2781 if (whichloop
== nesting_stack
)
2783 jumpifnot (cond
, whichloop
->data
.loop
.end_label
);
2787 /* In order to handle fixups, we actually create a conditional jump
2788 around an unconditional branch to exit the loop. If fixups are
2789 necessary, they go before the unconditional branch. */
2791 label
= gen_label_rtx ();
2792 jumpif (cond
, label
);
2793 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.end_label
,
2800 /* Like expand_exit_loop_if_false except also emit a note marking
2801 the end of the conditional. Should only be used immediately
2802 after expand_loop_start. */
2805 expand_exit_loop_top_cond (whichloop
, cond
)
2806 struct nesting
*whichloop
;
2809 if (! expand_exit_loop_if_false (whichloop
, cond
))
2812 emit_note (NULL
, NOTE_INSN_LOOP_END_TOP_COND
);
2816 /* Return nonzero if we should preserve sub-expressions as separate
2817 pseudos. We never do so if we aren't optimizing. We always do so
2818 if -fexpensive-optimizations.
2820 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2821 the loop may still be a small one. */
2824 preserve_subexpressions_p ()
2828 if (flag_expensive_optimizations
)
2831 if (optimize
== 0 || cfun
== 0 || cfun
->stmt
== 0 || loop_stack
== 0)
2834 insn
= get_last_insn_anywhere ();
2837 && (INSN_UID (insn
) - INSN_UID (loop_stack
->data
.loop
.start_label
)
2838 < n_non_fixed_regs
* 3));
2842 /* Generate a jump to exit the current loop, conditional, binding contour
2843 or case statement. Not all such constructs are visible to this function,
2844 only those started with EXIT_FLAG nonzero. Individual languages use
2845 the EXIT_FLAG parameter to control which kinds of constructs you can
2848 If not currently inside anything that can be exited,
2849 return 0 and do nothing; caller will print an error message. */
2852 expand_exit_something ()
2856 for (n
= nesting_stack
; n
; n
= n
->all
)
2857 if (n
->exit_label
!= 0)
2859 expand_goto_internal (NULL_TREE
, n
->exit_label
, NULL_RTX
);
2866 /* Generate RTL to return from the current function, with no value.
2867 (That is, we do not do anything about returning any value.) */
2870 expand_null_return ()
2874 last_insn
= get_last_insn ();
2876 /* If this function was declared to return a value, but we
2877 didn't, clobber the return registers so that they are not
2878 propagated live to the rest of the function. */
2879 clobber_return_register ();
2881 expand_null_return_1 (last_insn
);
2884 /* Try to guess whether the value of return means error code. */
2885 static enum br_predictor
2886 return_prediction (val
)
2889 /* Different heuristics for pointers and scalars. */
2890 if (POINTER_TYPE_P (TREE_TYPE (DECL_RESULT (current_function_decl
))))
2892 /* NULL is usually not returned. */
2893 if (val
== const0_rtx
)
2894 return PRED_NULL_RETURN
;
2898 /* Negative return values are often used to indicate
2900 if (GET_CODE (val
) == CONST_INT
2901 && INTVAL (val
) < 0)
2902 return PRED_NEGATIVE_RETURN
;
2903 /* Constant return values are also usually erors,
2904 zero/one often mean booleans so exclude them from the
2906 if (CONSTANT_P (val
)
2907 && (val
!= const0_rtx
&& val
!= const1_rtx
))
2908 return PRED_CONST_RETURN
;
2910 return PRED_NO_PREDICTION
;
2913 /* Generate RTL to return from the current function, with value VAL. */
2916 expand_value_return (val
)
2921 enum br_predictor pred
;
2923 if ((pred
= return_prediction (val
)) != PRED_NO_PREDICTION
)
2925 /* Emit information for branch prediction. */
2928 note
= emit_note (NULL
, NOTE_INSN_PREDICTION
);
2930 NOTE_PREDICTION (note
) = NOTE_PREDICT (pred
, NOT_TAKEN
);
2934 last_insn
= get_last_insn ();
2935 return_reg
= DECL_RTL (DECL_RESULT (current_function_decl
));
2937 /* Copy the value to the return location
2938 unless it's already there. */
2940 if (return_reg
!= val
)
2942 tree type
= TREE_TYPE (DECL_RESULT (current_function_decl
));
2943 #ifdef PROMOTE_FUNCTION_RETURN
2944 int unsignedp
= TREE_UNSIGNED (type
);
2945 enum machine_mode old_mode
2946 = DECL_MODE (DECL_RESULT (current_function_decl
));
2947 enum machine_mode mode
2948 = promote_mode (type
, old_mode
, &unsignedp
, 1);
2950 if (mode
!= old_mode
)
2951 val
= convert_modes (mode
, old_mode
, val
, unsignedp
);
2953 if (GET_CODE (return_reg
) == PARALLEL
)
2954 emit_group_load (return_reg
, val
, int_size_in_bytes (type
));
2956 emit_move_insn (return_reg
, val
);
2959 expand_null_return_1 (last_insn
);
2962 /* Output a return with no value. If LAST_INSN is nonzero,
2963 pretend that the return takes place after LAST_INSN. */
2966 expand_null_return_1 (last_insn
)
2969 rtx end_label
= cleanup_label
? cleanup_label
: return_label
;
2971 clear_pending_stack_adjust ();
2972 do_pending_stack_adjust ();
2976 end_label
= return_label
= gen_label_rtx ();
2977 expand_goto_internal (NULL_TREE
, end_label
, last_insn
);
2980 /* Generate RTL to evaluate the expression RETVAL and return it
2981 from the current function. */
2984 expand_return (retval
)
2987 /* If there are any cleanups to be performed, then they will
2988 be inserted following LAST_INSN. It is desirable
2989 that the last_insn, for such purposes, should be the
2990 last insn before computing the return value. Otherwise, cleanups
2991 which call functions can clobber the return value. */
2992 /* ??? rms: I think that is erroneous, because in C++ it would
2993 run destructors on variables that might be used in the subsequent
2994 computation of the return value. */
3000 /* If function wants no value, give it none. */
3001 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl
))) == VOID_TYPE
)
3003 expand_expr (retval
, NULL_RTX
, VOIDmode
, 0);
3005 expand_null_return ();
3009 if (retval
== error_mark_node
)
3011 /* Treat this like a return of no value from a function that
3013 expand_null_return ();
3016 else if (TREE_CODE (retval
) == RESULT_DECL
)
3017 retval_rhs
= retval
;
3018 else if ((TREE_CODE (retval
) == MODIFY_EXPR
|| TREE_CODE (retval
) == INIT_EXPR
)
3019 && TREE_CODE (TREE_OPERAND (retval
, 0)) == RESULT_DECL
)
3020 retval_rhs
= TREE_OPERAND (retval
, 1);
3021 else if (VOID_TYPE_P (TREE_TYPE (retval
)))
3022 /* Recognize tail-recursive call to void function. */
3023 retval_rhs
= retval
;
3025 retval_rhs
= NULL_TREE
;
3027 last_insn
= get_last_insn ();
3029 /* Distribute return down conditional expr if either of the sides
3030 may involve tail recursion (see test below). This enhances the number
3031 of tail recursions we see. Don't do this always since it can produce
3032 sub-optimal code in some cases and we distribute assignments into
3033 conditional expressions when it would help. */
3035 if (optimize
&& retval_rhs
!= 0
3036 && frame_offset
== 0
3037 && TREE_CODE (retval_rhs
) == COND_EXPR
3038 && (TREE_CODE (TREE_OPERAND (retval_rhs
, 1)) == CALL_EXPR
3039 || TREE_CODE (TREE_OPERAND (retval_rhs
, 2)) == CALL_EXPR
))
3041 rtx label
= gen_label_rtx ();
3044 do_jump (TREE_OPERAND (retval_rhs
, 0), label
, NULL_RTX
);
3045 start_cleanup_deferral ();
3046 expr
= build (MODIFY_EXPR
, TREE_TYPE (TREE_TYPE (current_function_decl
)),
3047 DECL_RESULT (current_function_decl
),
3048 TREE_OPERAND (retval_rhs
, 1));
3049 TREE_SIDE_EFFECTS (expr
) = 1;
3050 expand_return (expr
);
3053 expr
= build (MODIFY_EXPR
, TREE_TYPE (TREE_TYPE (current_function_decl
)),
3054 DECL_RESULT (current_function_decl
),
3055 TREE_OPERAND (retval_rhs
, 2));
3056 TREE_SIDE_EFFECTS (expr
) = 1;
3057 expand_return (expr
);
3058 end_cleanup_deferral ();
3062 result_rtl
= DECL_RTL (DECL_RESULT (current_function_decl
));
3064 /* If the result is an aggregate that is being returned in one (or more)
3065 registers, load the registers here. The compiler currently can't handle
3066 copying a BLKmode value into registers. We could put this code in a
3067 more general area (for use by everyone instead of just function
3068 call/return), but until this feature is generally usable it is kept here
3069 (and in expand_call). The value must go into a pseudo in case there
3070 are cleanups that will clobber the real return register. */
3073 && TYPE_MODE (TREE_TYPE (retval_rhs
)) == BLKmode
3074 && GET_CODE (result_rtl
) == REG
)
3077 unsigned HOST_WIDE_INT bitpos
, xbitpos
;
3078 unsigned HOST_WIDE_INT big_endian_correction
= 0;
3079 unsigned HOST_WIDE_INT bytes
3080 = int_size_in_bytes (TREE_TYPE (retval_rhs
));
3081 int n_regs
= (bytes
+ UNITS_PER_WORD
- 1) / UNITS_PER_WORD
;
3082 unsigned int bitsize
3083 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs
)), BITS_PER_WORD
);
3084 rtx
*result_pseudos
= (rtx
*) alloca (sizeof (rtx
) * n_regs
);
3085 rtx result_reg
, src
= NULL_RTX
, dst
= NULL_RTX
;
3086 rtx result_val
= expand_expr (retval_rhs
, NULL_RTX
, VOIDmode
, 0);
3087 enum machine_mode tmpmode
, result_reg_mode
;
3091 expand_null_return ();
3095 /* Structures whose size is not a multiple of a word are aligned
3096 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
3097 machine, this means we must skip the empty high order bytes when
3098 calculating the bit offset. */
3099 if (BYTES_BIG_ENDIAN
3100 && bytes
% UNITS_PER_WORD
)
3101 big_endian_correction
= (BITS_PER_WORD
- ((bytes
% UNITS_PER_WORD
)
3104 /* Copy the structure BITSIZE bits at a time. */
3105 for (bitpos
= 0, xbitpos
= big_endian_correction
;
3106 bitpos
< bytes
* BITS_PER_UNIT
;
3107 bitpos
+= bitsize
, xbitpos
+= bitsize
)
3109 /* We need a new destination pseudo each time xbitpos is
3110 on a word boundary and when xbitpos == big_endian_correction
3111 (the first time through). */
3112 if (xbitpos
% BITS_PER_WORD
== 0
3113 || xbitpos
== big_endian_correction
)
3115 /* Generate an appropriate register. */
3116 dst
= gen_reg_rtx (word_mode
);
3117 result_pseudos
[xbitpos
/ BITS_PER_WORD
] = dst
;
3119 /* Clear the destination before we move anything into it. */
3120 emit_move_insn (dst
, CONST0_RTX (GET_MODE (dst
)));
3123 /* We need a new source operand each time bitpos is on a word
3125 if (bitpos
% BITS_PER_WORD
== 0)
3126 src
= operand_subword_force (result_val
,
3127 bitpos
/ BITS_PER_WORD
,
3130 /* Use bitpos for the source extraction (left justified) and
3131 xbitpos for the destination store (right justified). */
3132 store_bit_field (dst
, bitsize
, xbitpos
% BITS_PER_WORD
, word_mode
,
3133 extract_bit_field (src
, bitsize
,
3134 bitpos
% BITS_PER_WORD
, 1,
3135 NULL_RTX
, word_mode
, word_mode
,
3140 /* Find the smallest integer mode large enough to hold the
3141 entire structure and use that mode instead of BLKmode
3142 on the USE insn for the return register. */
3143 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
3144 tmpmode
!= VOIDmode
;
3145 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
3146 /* Have we found a large enough mode? */
3147 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
3150 /* No suitable mode found. */
3151 if (tmpmode
== VOIDmode
)
3154 PUT_MODE (result_rtl
, tmpmode
);
3156 if (GET_MODE_SIZE (tmpmode
) < GET_MODE_SIZE (word_mode
))
3157 result_reg_mode
= word_mode
;
3159 result_reg_mode
= tmpmode
;
3160 result_reg
= gen_reg_rtx (result_reg_mode
);
3163 for (i
= 0; i
< n_regs
; i
++)
3164 emit_move_insn (operand_subword (result_reg
, i
, 0, result_reg_mode
),
3167 if (tmpmode
!= result_reg_mode
)
3168 result_reg
= gen_lowpart (tmpmode
, result_reg
);
3170 expand_value_return (result_reg
);
3172 else if (retval_rhs
!= 0
3173 && !VOID_TYPE_P (TREE_TYPE (retval_rhs
))
3174 && (GET_CODE (result_rtl
) == REG
3175 || (GET_CODE (result_rtl
) == PARALLEL
)))
3177 /* Calculate the return value into a temporary (usually a pseudo
3179 tree ot
= TREE_TYPE (DECL_RESULT (current_function_decl
));
3180 tree nt
= build_qualified_type (ot
, TYPE_QUALS (ot
) | TYPE_QUAL_CONST
);
3182 val
= assign_temp (nt
, 0, 0, 1);
3183 val
= expand_expr (retval_rhs
, val
, GET_MODE (val
), 0);
3184 val
= force_not_mem (val
);
3186 /* Return the calculated value, doing cleanups first. */
3187 expand_value_return (val
);
3191 /* No cleanups or no hard reg used;
3192 calculate value into hard return reg. */
3193 expand_expr (retval
, const0_rtx
, VOIDmode
, 0);
3195 expand_value_return (result_rtl
);
3199 /* Attempt to optimize a potential tail recursion call into a goto.
3200 ARGUMENTS are the arguments to a CALL_EXPR; LAST_INSN indicates
3201 where to place the jump to the tail recursion label.
3203 Return TRUE if the call was optimized into a goto. */
3206 optimize_tail_recursion (arguments
, last_insn
)
3210 /* Finish checking validity, and if valid emit code to set the
3211 argument variables for the new call. */
3212 if (tail_recursion_args (arguments
, DECL_ARGUMENTS (current_function_decl
)))
3214 if (tail_recursion_label
== 0)
3216 tail_recursion_label
= gen_label_rtx ();
3217 emit_label_after (tail_recursion_label
,
3218 tail_recursion_reentry
);
3221 expand_goto_internal (NULL_TREE
, tail_recursion_label
, last_insn
);
3228 /* Emit code to alter this function's formal parms for a tail-recursive call.
3229 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3230 FORMALS is the chain of decls of formals.
3231 Return 1 if this can be done;
3232 otherwise return 0 and do not emit any code. */
3235 tail_recursion_args (actuals
, formals
)
3236 tree actuals
, formals
;
3238 tree a
= actuals
, f
= formals
;
3242 /* Check that number and types of actuals are compatible
3243 with the formals. This is not always true in valid C code.
3244 Also check that no formal needs to be addressable
3245 and that all formals are scalars. */
3247 /* Also count the args. */
3249 for (a
= actuals
, f
= formals
, i
= 0; a
&& f
; a
= TREE_CHAIN (a
), f
= TREE_CHAIN (f
), i
++)
3251 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a
)))
3252 != TYPE_MAIN_VARIANT (TREE_TYPE (f
)))
3254 if (GET_CODE (DECL_RTL (f
)) != REG
|| DECL_MODE (f
) == BLKmode
)
3257 if (a
!= 0 || f
!= 0)
3260 /* Compute all the actuals. */
3262 argvec
= (rtx
*) alloca (i
* sizeof (rtx
));
3264 for (a
= actuals
, i
= 0; a
; a
= TREE_CHAIN (a
), i
++)
3265 argvec
[i
] = expand_expr (TREE_VALUE (a
), NULL_RTX
, VOIDmode
, 0);
3267 /* Find which actual values refer to current values of previous formals.
3268 Copy each of them now, before any formal is changed. */
3270 for (a
= actuals
, i
= 0; a
; a
= TREE_CHAIN (a
), i
++)
3274 for (f
= formals
, j
= 0; j
< i
; f
= TREE_CHAIN (f
), j
++)
3275 if (reg_mentioned_p (DECL_RTL (f
), argvec
[i
]))
3281 argvec
[i
] = copy_to_reg (argvec
[i
]);
3284 /* Store the values of the actuals into the formals. */
3286 for (f
= formals
, a
= actuals
, i
= 0; f
;
3287 f
= TREE_CHAIN (f
), a
= TREE_CHAIN (a
), i
++)
3289 if (GET_MODE (DECL_RTL (f
)) == GET_MODE (argvec
[i
]))
3290 emit_move_insn (DECL_RTL (f
), argvec
[i
]);
3293 rtx tmp
= argvec
[i
];
3295 if (DECL_MODE (f
) != GET_MODE (DECL_RTL (f
)))
3297 tmp
= gen_reg_rtx (DECL_MODE (f
));
3298 convert_move (tmp
, argvec
[i
],
3299 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a
))));
3301 convert_move (DECL_RTL (f
), tmp
,
3302 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a
))));
3310 /* Generate the RTL code for entering a binding contour.
3311 The variables are declared one by one, by calls to `expand_decl'.
3313 FLAGS is a bitwise or of the following flags:
3315 1 - Nonzero if this construct should be visible to
3318 2 - Nonzero if this contour does not require a
3319 NOTE_INSN_BLOCK_BEG note. Virtually all calls from
3320 language-independent code should set this flag because they
3321 will not create corresponding BLOCK nodes. (There should be
3322 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
3323 and BLOCKs.) If this flag is set, MARK_ENDS should be zero
3324 when expand_end_bindings is called.
3326 If we are creating a NOTE_INSN_BLOCK_BEG note, a BLOCK may
3327 optionally be supplied. If so, it becomes the NOTE_BLOCK for the
3331 expand_start_bindings_and_block (flags
, block
)
3335 struct nesting
*thisblock
= ALLOC_NESTING ();
3337 int exit_flag
= ((flags
& 1) != 0);
3338 int block_flag
= ((flags
& 2) == 0);
3340 /* If a BLOCK is supplied, then the caller should be requesting a
3341 NOTE_INSN_BLOCK_BEG note. */
3342 if (!block_flag
&& block
)
3345 /* Create a note to mark the beginning of the block. */
3348 note
= emit_note (NULL
, NOTE_INSN_BLOCK_BEG
);
3349 NOTE_BLOCK (note
) = block
;
3352 note
= emit_note (NULL
, NOTE_INSN_DELETED
);
3354 /* Make an entry on block_stack for the block we are entering. */
3356 thisblock
->desc
= BLOCK_NESTING
;
3357 thisblock
->next
= block_stack
;
3358 thisblock
->all
= nesting_stack
;
3359 thisblock
->depth
= ++nesting_depth
;
3360 thisblock
->data
.block
.stack_level
= 0;
3361 thisblock
->data
.block
.cleanups
= 0;
3362 thisblock
->data
.block
.n_function_calls
= 0;
3363 thisblock
->data
.block
.exception_region
= 0;
3364 thisblock
->data
.block
.block_target_temp_slot_level
= target_temp_slot_level
;
3366 thisblock
->data
.block
.conditional_code
= 0;
3367 thisblock
->data
.block
.last_unconditional_cleanup
= note
;
3368 /* When we insert instructions after the last unconditional cleanup,
3369 we don't adjust last_insn. That means that a later add_insn will
3370 clobber the instructions we've just added. The easiest way to
3371 fix this is to just insert another instruction here, so that the
3372 instructions inserted after the last unconditional cleanup are
3373 never the last instruction. */
3374 emit_note (NULL
, NOTE_INSN_DELETED
);
3377 && !(block_stack
->data
.block
.cleanups
== NULL_TREE
3378 && block_stack
->data
.block
.outer_cleanups
== NULL_TREE
))
3379 thisblock
->data
.block
.outer_cleanups
3380 = tree_cons (NULL_TREE
, block_stack
->data
.block
.cleanups
,
3381 block_stack
->data
.block
.outer_cleanups
);
3383 thisblock
->data
.block
.outer_cleanups
= 0;
3384 thisblock
->data
.block
.label_chain
= 0;
3385 thisblock
->data
.block
.innermost_stack_block
= stack_block_stack
;
3386 thisblock
->data
.block
.first_insn
= note
;
3387 thisblock
->data
.block
.block_start_count
= ++current_block_start_count
;
3388 thisblock
->exit_label
= exit_flag
? gen_label_rtx () : 0;
3389 block_stack
= thisblock
;
3390 nesting_stack
= thisblock
;
3392 /* Make a new level for allocating stack slots. */
3396 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3397 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3398 expand_expr are made. After we end the region, we know that all
3399 space for all temporaries that were created by TARGET_EXPRs will be
3400 destroyed and their space freed for reuse. */
3403 expand_start_target_temps ()
3405 /* This is so that even if the result is preserved, the space
3406 allocated will be freed, as we know that it is no longer in use. */
3409 /* Start a new binding layer that will keep track of all cleanup
3410 actions to be performed. */
3411 expand_start_bindings (2);
3413 target_temp_slot_level
= temp_slot_level
;
3417 expand_end_target_temps ()
3419 expand_end_bindings (NULL_TREE
, 0, 0);
3421 /* This is so that even if the result is preserved, the space
3422 allocated will be freed, as we know that it is no longer in use. */
3426 /* Given a pointer to a BLOCK node return nonzero if (and only if) the node
3427 in question represents the outermost pair of curly braces (i.e. the "body
3428 block") of a function or method.
3430 For any BLOCK node representing a "body block" of a function or method, the
3431 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
3432 represents the outermost (function) scope for the function or method (i.e.
3433 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
3434 *that* node in turn will point to the relevant FUNCTION_DECL node. */
3437 is_body_block (stmt
)
3440 if (TREE_CODE (stmt
) == BLOCK
)
3442 tree parent
= BLOCK_SUPERCONTEXT (stmt
);
3444 if (parent
&& TREE_CODE (parent
) == BLOCK
)
3446 tree grandparent
= BLOCK_SUPERCONTEXT (parent
);
3448 if (grandparent
&& TREE_CODE (grandparent
) == FUNCTION_DECL
)
3456 /* True if we are currently emitting insns in an area of output code
3457 that is controlled by a conditional expression. This is used by
3458 the cleanup handling code to generate conditional cleanup actions. */
3461 conditional_context ()
3463 return block_stack
&& block_stack
->data
.block
.conditional_code
;
3466 /* Return an opaque pointer to the current nesting level, so frontend code
3467 can check its own sanity. */
3470 current_nesting_level ()
3472 return cfun
? block_stack
: 0;
3475 /* Emit a handler label for a nonlocal goto handler.
3476 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3479 expand_nl_handler_label (slot
, before_insn
)
3480 rtx slot
, before_insn
;
3483 rtx handler_label
= gen_label_rtx ();
3485 /* Don't let cleanup_cfg delete the handler. */
3486 LABEL_PRESERVE_P (handler_label
) = 1;
3489 emit_move_insn (slot
, gen_rtx_LABEL_REF (Pmode
, handler_label
));
3490 insns
= get_insns ();
3492 emit_insn_before (insns
, before_insn
);
3494 emit_label (handler_label
);
3496 return handler_label
;
3499 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3502 expand_nl_goto_receiver ()
3504 #ifdef HAVE_nonlocal_goto
3505 if (! HAVE_nonlocal_goto
)
3507 /* First adjust our frame pointer to its actual value. It was
3508 previously set to the start of the virtual area corresponding to
3509 the stacked variables when we branched here and now needs to be
3510 adjusted to the actual hardware fp value.
3512 Assignments are to virtual registers are converted by
3513 instantiate_virtual_regs into the corresponding assignment
3514 to the underlying register (fp in this case) that makes
3515 the original assignment true.
3516 So the following insn will actually be
3517 decrementing fp by STARTING_FRAME_OFFSET. */
3518 emit_move_insn (virtual_stack_vars_rtx
, hard_frame_pointer_rtx
);
3520 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3521 if (fixed_regs
[ARG_POINTER_REGNUM
])
3523 #ifdef ELIMINABLE_REGS
3524 /* If the argument pointer can be eliminated in favor of the
3525 frame pointer, we don't need to restore it. We assume here
3526 that if such an elimination is present, it can always be used.
3527 This is the case on all known machines; if we don't make this
3528 assumption, we do unnecessary saving on many machines. */
3529 static const struct elims
{const int from
, to
;} elim_regs
[] = ELIMINABLE_REGS
;
3532 for (i
= 0; i
< ARRAY_SIZE (elim_regs
); i
++)
3533 if (elim_regs
[i
].from
== ARG_POINTER_REGNUM
3534 && elim_regs
[i
].to
== HARD_FRAME_POINTER_REGNUM
)
3537 if (i
== ARRAY_SIZE (elim_regs
))
3540 /* Now restore our arg pointer from the address at which it
3541 was saved in our stack frame. */
3542 emit_move_insn (virtual_incoming_args_rtx
,
3543 copy_to_reg (get_arg_pointer_save_area (cfun
)));
3548 #ifdef HAVE_nonlocal_goto_receiver
3549 if (HAVE_nonlocal_goto_receiver
)
3550 emit_insn (gen_nonlocal_goto_receiver ());
3554 /* Make handlers for nonlocal gotos taking place in the function calls in
3558 expand_nl_goto_receivers (thisblock
)
3559 struct nesting
*thisblock
;
3562 rtx afterward
= gen_label_rtx ();
3567 /* Record the handler address in the stack slot for that purpose,
3568 during this block, saving and restoring the outer value. */
3569 if (thisblock
->next
!= 0)
3570 for (slot
= nonlocal_goto_handler_slots
; slot
; slot
= XEXP (slot
, 1))
3572 rtx save_receiver
= gen_reg_rtx (Pmode
);
3573 emit_move_insn (XEXP (slot
, 0), save_receiver
);
3576 emit_move_insn (save_receiver
, XEXP (slot
, 0));
3577 insns
= get_insns ();
3579 emit_insn_before (insns
, thisblock
->data
.block
.first_insn
);
3582 /* Jump around the handlers; they run only when specially invoked. */
3583 emit_jump (afterward
);
3585 /* Make a separate handler for each label. */
3586 link
= nonlocal_labels
;
3587 slot
= nonlocal_goto_handler_slots
;
3588 label_list
= NULL_RTX
;
3589 for (; link
; link
= TREE_CHAIN (link
), slot
= XEXP (slot
, 1))
3590 /* Skip any labels we shouldn't be able to jump to from here,
3591 we generate one special handler for all of them below which just calls
3593 if (! DECL_TOO_LATE (TREE_VALUE (link
)))
3596 lab
= expand_nl_handler_label (XEXP (slot
, 0),
3597 thisblock
->data
.block
.first_insn
);
3598 label_list
= gen_rtx_EXPR_LIST (VOIDmode
, lab
, label_list
);
3600 expand_nl_goto_receiver ();
3602 /* Jump to the "real" nonlocal label. */
3603 expand_goto (TREE_VALUE (link
));
3606 /* A second pass over all nonlocal labels; this time we handle those
3607 we should not be able to jump to at this point. */
3608 link
= nonlocal_labels
;
3609 slot
= nonlocal_goto_handler_slots
;
3611 for (; link
; link
= TREE_CHAIN (link
), slot
= XEXP (slot
, 1))
3612 if (DECL_TOO_LATE (TREE_VALUE (link
)))
3615 lab
= expand_nl_handler_label (XEXP (slot
, 0),
3616 thisblock
->data
.block
.first_insn
);
3617 label_list
= gen_rtx_EXPR_LIST (VOIDmode
, lab
, label_list
);
3623 expand_nl_goto_receiver ();
3624 expand_builtin_trap ();
3627 nonlocal_goto_handler_labels
= label_list
;
3628 emit_label (afterward
);
3631 /* Warn about any unused VARS (which may contain nodes other than
3632 VAR_DECLs, but such nodes are ignored). The nodes are connected
3633 via the TREE_CHAIN field. */
3636 warn_about_unused_variables (vars
)
3641 if (warn_unused_variable
)
3642 for (decl
= vars
; decl
; decl
= TREE_CHAIN (decl
))
3643 if (TREE_CODE (decl
) == VAR_DECL
3644 && ! TREE_USED (decl
)
3645 && ! DECL_IN_SYSTEM_HEADER (decl
)
3646 && DECL_NAME (decl
) && ! DECL_ARTIFICIAL (decl
))
3647 warning_with_decl (decl
, "unused variable `%s'");
3650 /* Generate RTL code to terminate a binding contour.
3652 VARS is the chain of VAR_DECL nodes for the variables bound in this
3653 contour. There may actually be other nodes in this chain, but any
3654 nodes other than VAR_DECLS are ignored.
3656 MARK_ENDS is nonzero if we should put a note at the beginning
3657 and end of this binding contour.
3659 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3660 (That is true automatically if the contour has a saved stack level.) */
3663 expand_end_bindings (vars
, mark_ends
, dont_jump_in
)
3668 struct nesting
*thisblock
= block_stack
;
3670 /* If any of the variables in this scope were not used, warn the
3672 warn_about_unused_variables (vars
);
3674 if (thisblock
->exit_label
)
3676 do_pending_stack_adjust ();
3677 emit_label (thisblock
->exit_label
);
3680 /* If necessary, make handlers for nonlocal gotos taking
3681 place in the function calls in this block. */
3682 if (function_call_count
!= thisblock
->data
.block
.n_function_calls
3684 /* Make handler for outermost block
3685 if there were any nonlocal gotos to this function. */
3686 && (thisblock
->next
== 0 ? current_function_has_nonlocal_label
3687 /* Make handler for inner block if it has something
3688 special to do when you jump out of it. */
3689 : (thisblock
->data
.block
.cleanups
!= 0
3690 || thisblock
->data
.block
.stack_level
!= 0)))
3691 expand_nl_goto_receivers (thisblock
);
3693 /* Don't allow jumping into a block that has a stack level.
3694 Cleanups are allowed, though. */
3696 || thisblock
->data
.block
.stack_level
!= 0)
3698 struct label_chain
*chain
;
3700 /* Any labels in this block are no longer valid to go to.
3701 Mark them to cause an error message. */
3702 for (chain
= thisblock
->data
.block
.label_chain
; chain
; chain
= chain
->next
)
3704 DECL_TOO_LATE (chain
->label
) = 1;
3705 /* If any goto without a fixup came to this label,
3706 that must be an error, because gotos without fixups
3707 come from outside all saved stack-levels. */
3708 if (TREE_ADDRESSABLE (chain
->label
))
3709 error_with_decl (chain
->label
,
3710 "label `%s' used before containing binding contour");
3714 /* Restore stack level in effect before the block
3715 (only if variable-size objects allocated). */
3716 /* Perform any cleanups associated with the block. */
3718 if (thisblock
->data
.block
.stack_level
!= 0
3719 || thisblock
->data
.block
.cleanups
!= 0)
3724 /* Don't let cleanups affect ({...}) constructs. */
3725 int old_expr_stmts_for_value
= expr_stmts_for_value
;
3726 rtx old_last_expr_value
= last_expr_value
;
3727 tree old_last_expr_type
= last_expr_type
;
3728 expr_stmts_for_value
= 0;
3730 /* Only clean up here if this point can actually be reached. */
3731 insn
= get_last_insn ();
3732 if (GET_CODE (insn
) == NOTE
)
3733 insn
= prev_nonnote_insn (insn
);
3734 reachable
= (! insn
|| GET_CODE (insn
) != BARRIER
);
3736 /* Do the cleanups. */
3737 expand_cleanups (thisblock
->data
.block
.cleanups
, NULL_TREE
, 0, reachable
);
3739 do_pending_stack_adjust ();
3741 expr_stmts_for_value
= old_expr_stmts_for_value
;
3742 last_expr_value
= old_last_expr_value
;
3743 last_expr_type
= old_last_expr_type
;
3745 /* Restore the stack level. */
3747 if (reachable
&& thisblock
->data
.block
.stack_level
!= 0)
3749 emit_stack_restore (thisblock
->next
? SAVE_BLOCK
: SAVE_FUNCTION
,
3750 thisblock
->data
.block
.stack_level
, NULL_RTX
);
3751 if (nonlocal_goto_handler_slots
!= 0)
3752 emit_stack_save (SAVE_NONLOCAL
, &nonlocal_goto_stack_level
,
3756 /* Any gotos out of this block must also do these things.
3757 Also report any gotos with fixups that came to labels in this
3759 fixup_gotos (thisblock
,
3760 thisblock
->data
.block
.stack_level
,
3761 thisblock
->data
.block
.cleanups
,
3762 thisblock
->data
.block
.first_insn
,
3766 /* Mark the beginning and end of the scope if requested.
3767 We do this now, after running cleanups on the variables
3768 just going out of scope, so they are in scope for their cleanups. */
3772 rtx note
= emit_note (NULL
, NOTE_INSN_BLOCK_END
);
3773 NOTE_BLOCK (note
) = NOTE_BLOCK (thisblock
->data
.block
.first_insn
);
3776 /* Get rid of the beginning-mark if we don't make an end-mark. */
3777 NOTE_LINE_NUMBER (thisblock
->data
.block
.first_insn
) = NOTE_INSN_DELETED
;
3779 /* Restore the temporary level of TARGET_EXPRs. */
3780 target_temp_slot_level
= thisblock
->data
.block
.block_target_temp_slot_level
;
3782 /* Restore block_stack level for containing block. */
3784 stack_block_stack
= thisblock
->data
.block
.innermost_stack_block
;
3785 POPSTACK (block_stack
);
3787 /* Pop the stack slot nesting and free any slots at this level. */
3791 /* Generate code to save the stack pointer at the start of the current block
3792 and set up to restore it on exit. */
3795 save_stack_pointer ()
3797 struct nesting
*thisblock
= block_stack
;
3799 if (thisblock
->data
.block
.stack_level
== 0)
3801 emit_stack_save (thisblock
->next
? SAVE_BLOCK
: SAVE_FUNCTION
,
3802 &thisblock
->data
.block
.stack_level
,
3803 thisblock
->data
.block
.first_insn
);
3804 stack_block_stack
= thisblock
;
3808 /* Generate RTL for the automatic variable declaration DECL.
3809 (Other kinds of declarations are simply ignored if seen here.) */
3817 type
= TREE_TYPE (decl
);
3819 /* For a CONST_DECL, set mode, alignment, and sizes from those of the
3820 type in case this node is used in a reference. */
3821 if (TREE_CODE (decl
) == CONST_DECL
)
3823 DECL_MODE (decl
) = TYPE_MODE (type
);
3824 DECL_ALIGN (decl
) = TYPE_ALIGN (type
);
3825 DECL_SIZE (decl
) = TYPE_SIZE (type
);
3826 DECL_SIZE_UNIT (decl
) = TYPE_SIZE_UNIT (type
);
3830 /* Otherwise, only automatic variables need any expansion done. Static and
3831 external variables, and external functions, will be handled by
3832 `assemble_variable' (called from finish_decl). TYPE_DECL requires
3833 nothing. PARM_DECLs are handled in `assign_parms'. */
3834 if (TREE_CODE (decl
) != VAR_DECL
)
3837 if (TREE_STATIC (decl
) || DECL_EXTERNAL (decl
))
3840 /* Create the RTL representation for the variable. */
3842 if (type
== error_mark_node
)
3843 SET_DECL_RTL (decl
, gen_rtx_MEM (BLKmode
, const0_rtx
));
3845 else if (DECL_SIZE (decl
) == 0)
3846 /* Variable with incomplete type. */
3849 if (DECL_INITIAL (decl
) == 0)
3850 /* Error message was already done; now avoid a crash. */
3851 x
= gen_rtx_MEM (BLKmode
, const0_rtx
);
3853 /* An initializer is going to decide the size of this array.
3854 Until we know the size, represent its address with a reg. */
3855 x
= gen_rtx_MEM (BLKmode
, gen_reg_rtx (Pmode
));
3857 set_mem_attributes (x
, decl
, 1);
3858 SET_DECL_RTL (decl
, x
);
3860 else if (DECL_MODE (decl
) != BLKmode
3861 /* If -ffloat-store, don't put explicit float vars
3863 && !(flag_float_store
3864 && TREE_CODE (type
) == REAL_TYPE
)
3865 && ! TREE_THIS_VOLATILE (decl
)
3866 && (DECL_REGISTER (decl
) || optimize
))
3868 /* Automatic variable that can go in a register. */
3869 int unsignedp
= TREE_UNSIGNED (type
);
3870 enum machine_mode reg_mode
3871 = promote_mode (type
, DECL_MODE (decl
), &unsignedp
, 0);
3873 SET_DECL_RTL (decl
, gen_reg_rtx (reg_mode
));
3875 if (GET_CODE (DECL_RTL (decl
)) == REG
)
3876 REGNO_DECL (REGNO (DECL_RTL (decl
))) = decl
;
3877 else if (GET_CODE (DECL_RTL (decl
)) == CONCAT
)
3879 REGNO_DECL (REGNO (XEXP (DECL_RTL (decl
), 0))) = decl
;
3880 REGNO_DECL (REGNO (XEXP (DECL_RTL (decl
), 1))) = decl
;
3883 mark_user_reg (DECL_RTL (decl
));
3885 if (POINTER_TYPE_P (type
))
3886 mark_reg_pointer (DECL_RTL (decl
),
3887 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl
))));
3889 maybe_set_unchanging (DECL_RTL (decl
), decl
);
3891 /* If something wants our address, try to use ADDRESSOF. */
3892 if (TREE_ADDRESSABLE (decl
))
3893 put_var_into_stack (decl
);
3896 else if (TREE_CODE (DECL_SIZE_UNIT (decl
)) == INTEGER_CST
3897 && ! (flag_stack_check
&& ! STACK_CHECK_BUILTIN
3898 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl
),
3899 STACK_CHECK_MAX_VAR_SIZE
)))
3901 /* Variable of fixed size that goes on the stack. */
3906 /* If we previously made RTL for this decl, it must be an array
3907 whose size was determined by the initializer.
3908 The old address was a register; set that register now
3909 to the proper address. */
3910 if (DECL_RTL_SET_P (decl
))
3912 if (GET_CODE (DECL_RTL (decl
)) != MEM
3913 || GET_CODE (XEXP (DECL_RTL (decl
), 0)) != REG
)
3915 oldaddr
= XEXP (DECL_RTL (decl
), 0);
3918 /* Set alignment we actually gave this decl. */
3919 DECL_ALIGN (decl
) = (DECL_MODE (decl
) == BLKmode
? BIGGEST_ALIGNMENT
3920 : GET_MODE_BITSIZE (DECL_MODE (decl
)));
3921 DECL_USER_ALIGN (decl
) = 0;
3923 x
= assign_temp (decl
, 1, 1, 1);
3924 set_mem_attributes (x
, decl
, 1);
3925 SET_DECL_RTL (decl
, x
);
3929 addr
= force_operand (XEXP (DECL_RTL (decl
), 0), oldaddr
);
3930 if (addr
!= oldaddr
)
3931 emit_move_insn (oldaddr
, addr
);
3935 /* Dynamic-size object: must push space on the stack. */
3937 rtx address
, size
, x
;
3939 /* Record the stack pointer on entry to block, if have
3940 not already done so. */
3941 do_pending_stack_adjust ();
3942 save_stack_pointer ();
3944 /* In function-at-a-time mode, variable_size doesn't expand this,
3946 if (TREE_CODE (type
) == ARRAY_TYPE
&& TYPE_DOMAIN (type
))
3947 expand_expr (TYPE_MAX_VALUE (TYPE_DOMAIN (type
)),
3948 const0_rtx
, VOIDmode
, 0);
3950 /* Compute the variable's size, in bytes. */
3951 size
= expand_expr (DECL_SIZE_UNIT (decl
), NULL_RTX
, VOIDmode
, 0);
3954 /* Allocate space on the stack for the variable. Note that
3955 DECL_ALIGN says how the variable is to be aligned and we
3956 cannot use it to conclude anything about the alignment of
3958 address
= allocate_dynamic_stack_space (size
, NULL_RTX
,
3959 TYPE_ALIGN (TREE_TYPE (decl
)));
3961 /* Reference the variable indirect through that rtx. */
3962 x
= gen_rtx_MEM (DECL_MODE (decl
), address
);
3963 set_mem_attributes (x
, decl
, 1);
3964 SET_DECL_RTL (decl
, x
);
3967 /* Indicate the alignment we actually gave this variable. */
3968 #ifdef STACK_BOUNDARY
3969 DECL_ALIGN (decl
) = STACK_BOUNDARY
;
3971 DECL_ALIGN (decl
) = BIGGEST_ALIGNMENT
;
3973 DECL_USER_ALIGN (decl
) = 0;
3977 /* Emit code to perform the initialization of a declaration DECL. */
3980 expand_decl_init (decl
)
3983 int was_used
= TREE_USED (decl
);
3985 /* If this is a CONST_DECL, we don't have to generate any code. Likewise
3986 for static decls. */
3987 if (TREE_CODE (decl
) == CONST_DECL
3988 || TREE_STATIC (decl
))
3991 /* Compute and store the initial value now. */
3993 if (DECL_INITIAL (decl
) == error_mark_node
)
3995 enum tree_code code
= TREE_CODE (TREE_TYPE (decl
));
3997 if (code
== INTEGER_TYPE
|| code
== REAL_TYPE
|| code
== ENUMERAL_TYPE
3998 || code
== POINTER_TYPE
|| code
== REFERENCE_TYPE
)
3999 expand_assignment (decl
, convert (TREE_TYPE (decl
), integer_zero_node
),
4003 else if (DECL_INITIAL (decl
) && TREE_CODE (DECL_INITIAL (decl
)) != TREE_LIST
)
4005 emit_line_note (DECL_SOURCE_FILE (decl
), DECL_SOURCE_LINE (decl
));
4006 expand_assignment (decl
, DECL_INITIAL (decl
), 0, 0);
4010 /* Don't let the initialization count as "using" the variable. */
4011 TREE_USED (decl
) = was_used
;
4013 /* Free any temporaries we made while initializing the decl. */
4014 preserve_temp_slots (NULL_RTX
);
4018 /* CLEANUP is an expression to be executed at exit from this binding contour;
4019 for example, in C++, it might call the destructor for this variable.
4021 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
4022 CLEANUP multiple times, and have the correct semantics. This
4023 happens in exception handling, for gotos, returns, breaks that
4024 leave the current scope.
4026 If CLEANUP is nonzero and DECL is zero, we record a cleanup
4027 that is not associated with any particular variable. */
4030 expand_decl_cleanup (decl
, cleanup
)
4033 struct nesting
*thisblock
;
4035 /* Error if we are not in any block. */
4036 if (cfun
== 0 || block_stack
== 0)
4039 thisblock
= block_stack
;
4041 /* Record the cleanup if there is one. */
4047 tree
*cleanups
= &thisblock
->data
.block
.cleanups
;
4048 int cond_context
= conditional_context ();
4052 rtx flag
= gen_reg_rtx (word_mode
);
4057 emit_move_insn (flag
, const0_rtx
);
4058 set_flag_0
= get_insns ();
4061 thisblock
->data
.block
.last_unconditional_cleanup
4062 = emit_insn_after (set_flag_0
,
4063 thisblock
->data
.block
.last_unconditional_cleanup
);
4065 emit_move_insn (flag
, const1_rtx
);
4067 cond
= build_decl (VAR_DECL
, NULL_TREE
,
4068 (*lang_hooks
.types
.type_for_mode
) (word_mode
, 1));
4069 SET_DECL_RTL (cond
, flag
);
4071 /* Conditionalize the cleanup. */
4072 cleanup
= build (COND_EXPR
, void_type_node
,
4073 (*lang_hooks
.truthvalue_conversion
) (cond
),
4074 cleanup
, integer_zero_node
);
4075 cleanup
= fold (cleanup
);
4077 cleanups
= &thisblock
->data
.block
.cleanups
;
4080 cleanup
= unsave_expr (cleanup
);
4082 t
= *cleanups
= tree_cons (decl
, cleanup
, *cleanups
);
4085 /* If this block has a cleanup, it belongs in stack_block_stack. */
4086 stack_block_stack
= thisblock
;
4093 if (! using_eh_for_cleanups_p
)
4094 TREE_ADDRESSABLE (t
) = 1;
4096 expand_eh_region_start ();
4103 thisblock
->data
.block
.last_unconditional_cleanup
4104 = emit_insn_after (seq
,
4105 thisblock
->data
.block
.last_unconditional_cleanup
);
4109 thisblock
->data
.block
.last_unconditional_cleanup
4111 /* When we insert instructions after the last unconditional cleanup,
4112 we don't adjust last_insn. That means that a later add_insn will
4113 clobber the instructions we've just added. The easiest way to
4114 fix this is to just insert another instruction here, so that the
4115 instructions inserted after the last unconditional cleanup are
4116 never the last instruction. */
4117 emit_note (NULL
, NOTE_INSN_DELETED
);
4123 /* Like expand_decl_cleanup, but maybe only run the cleanup if an exception
4127 expand_decl_cleanup_eh (decl
, cleanup
, eh_only
)
4131 int ret
= expand_decl_cleanup (decl
, cleanup
);
4134 tree node
= block_stack
->data
.block
.cleanups
;
4135 CLEANUP_EH_ONLY (node
) = eh_only
;
4140 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4141 DECL_ELTS is the list of elements that belong to DECL's type.
4142 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4145 expand_anon_union_decl (decl
, cleanup
, decl_elts
)
4146 tree decl
, cleanup
, decl_elts
;
4148 struct nesting
*thisblock
= cfun
== 0 ? 0 : block_stack
;
4152 /* If any of the elements are addressable, so is the entire union. */
4153 for (t
= decl_elts
; t
; t
= TREE_CHAIN (t
))
4154 if (TREE_ADDRESSABLE (TREE_VALUE (t
)))
4156 TREE_ADDRESSABLE (decl
) = 1;
4161 expand_decl_cleanup (decl
, cleanup
);
4162 x
= DECL_RTL (decl
);
4164 /* Go through the elements, assigning RTL to each. */
4165 for (t
= decl_elts
; t
; t
= TREE_CHAIN (t
))
4167 tree decl_elt
= TREE_VALUE (t
);
4168 tree cleanup_elt
= TREE_PURPOSE (t
);
4169 enum machine_mode mode
= TYPE_MODE (TREE_TYPE (decl_elt
));
4171 /* If any of the elements are addressable, so is the entire
4173 if (TREE_USED (decl_elt
))
4174 TREE_USED (decl
) = 1;
4176 /* Propagate the union's alignment to the elements. */
4177 DECL_ALIGN (decl_elt
) = DECL_ALIGN (decl
);
4178 DECL_USER_ALIGN (decl_elt
) = DECL_USER_ALIGN (decl
);
4180 /* If the element has BLKmode and the union doesn't, the union is
4181 aligned such that the element doesn't need to have BLKmode, so
4182 change the element's mode to the appropriate one for its size. */
4183 if (mode
== BLKmode
&& DECL_MODE (decl
) != BLKmode
)
4184 DECL_MODE (decl_elt
) = mode
4185 = mode_for_size_tree (DECL_SIZE (decl_elt
), MODE_INT
, 1);
4187 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4188 instead create a new MEM rtx with the proper mode. */
4189 if (GET_CODE (x
) == MEM
)
4191 if (mode
== GET_MODE (x
))
4192 SET_DECL_RTL (decl_elt
, x
);
4194 SET_DECL_RTL (decl_elt
, adjust_address_nv (x
, mode
, 0));
4196 else if (GET_CODE (x
) == REG
)
4198 if (mode
== GET_MODE (x
))
4199 SET_DECL_RTL (decl_elt
, x
);
4201 SET_DECL_RTL (decl_elt
, gen_lowpart_SUBREG (mode
, x
));
4206 /* Record the cleanup if there is one. */
4209 thisblock
->data
.block
.cleanups
4210 = tree_cons (decl_elt
, cleanup_elt
,
4211 thisblock
->data
.block
.cleanups
);
4215 /* Expand a list of cleanups LIST.
4216 Elements may be expressions or may be nested lists.
4218 If DONT_DO is nonnull, then any list-element
4219 whose TREE_PURPOSE matches DONT_DO is omitted.
4220 This is sometimes used to avoid a cleanup associated with
4221 a value that is being returned out of the scope.
4223 If IN_FIXUP is nonzero, we are generating this cleanup for a fixup
4224 goto and handle protection regions specially in that case.
4226 If REACHABLE, we emit code, otherwise just inform the exception handling
4227 code about this finalization. */
4230 expand_cleanups (list
, dont_do
, in_fixup
, reachable
)
4237 for (tail
= list
; tail
; tail
= TREE_CHAIN (tail
))
4238 if (dont_do
== 0 || TREE_PURPOSE (tail
) != dont_do
)
4240 if (TREE_CODE (TREE_VALUE (tail
)) == TREE_LIST
)
4241 expand_cleanups (TREE_VALUE (tail
), dont_do
, in_fixup
, reachable
);
4244 if (! in_fixup
&& using_eh_for_cleanups_p
)
4245 expand_eh_region_end_cleanup (TREE_VALUE (tail
));
4247 if (reachable
&& !CLEANUP_EH_ONLY (tail
))
4249 /* Cleanups may be run multiple times. For example,
4250 when exiting a binding contour, we expand the
4251 cleanups associated with that contour. When a goto
4252 within that binding contour has a target outside that
4253 contour, it will expand all cleanups from its scope to
4254 the target. Though the cleanups are expanded multiple
4255 times, the control paths are non-overlapping so the
4256 cleanups will not be executed twice. */
4258 /* We may need to protect from outer cleanups. */
4259 if (in_fixup
&& using_eh_for_cleanups_p
)
4261 expand_eh_region_start ();
4263 expand_expr (TREE_VALUE (tail
), const0_rtx
, VOIDmode
, 0);
4265 expand_eh_region_end_fixup (TREE_VALUE (tail
));
4268 expand_expr (TREE_VALUE (tail
), const0_rtx
, VOIDmode
, 0);
4276 /* Mark when the context we are emitting RTL for as a conditional
4277 context, so that any cleanup actions we register with
4278 expand_decl_init will be properly conditionalized when those
4279 cleanup actions are later performed. Must be called before any
4280 expression (tree) is expanded that is within a conditional context. */
4283 start_cleanup_deferral ()
4285 /* block_stack can be NULL if we are inside the parameter list. It is
4286 OK to do nothing, because cleanups aren't possible here. */
4288 ++block_stack
->data
.block
.conditional_code
;
4291 /* Mark the end of a conditional region of code. Because cleanup
4292 deferrals may be nested, we may still be in a conditional region
4293 after we end the currently deferred cleanups, only after we end all
4294 deferred cleanups, are we back in unconditional code. */
4297 end_cleanup_deferral ()
4299 /* block_stack can be NULL if we are inside the parameter list. It is
4300 OK to do nothing, because cleanups aren't possible here. */
4302 --block_stack
->data
.block
.conditional_code
;
4306 last_cleanup_this_contour ()
4308 if (block_stack
== 0)
4311 return block_stack
->data
.block
.cleanups
;
4314 /* Return 1 if there are any pending cleanups at this point.
4315 If THIS_CONTOUR is nonzero, check the current contour as well.
4316 Otherwise, look only at the contours that enclose this one. */
4319 any_pending_cleanups (this_contour
)
4322 struct nesting
*block
;
4324 if (cfun
== NULL
|| cfun
->stmt
== NULL
|| block_stack
== 0)
4327 if (this_contour
&& block_stack
->data
.block
.cleanups
!= NULL
)
4329 if (block_stack
->data
.block
.cleanups
== 0
4330 && block_stack
->data
.block
.outer_cleanups
== 0)
4333 for (block
= block_stack
->next
; block
; block
= block
->next
)
4334 if (block
->data
.block
.cleanups
!= 0)
4340 /* Enter a case (Pascal) or switch (C) statement.
4341 Push a block onto case_stack and nesting_stack
4342 to accumulate the case-labels that are seen
4343 and to record the labels generated for the statement.
4345 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4346 Otherwise, this construct is transparent for `exit_something'.
4348 EXPR is the index-expression to be dispatched on.
4349 TYPE is its nominal type. We could simply convert EXPR to this type,
4350 but instead we take short cuts. */
4353 expand_start_case (exit_flag
, expr
, type
, printname
)
4357 const char *printname
;
4359 struct nesting
*thiscase
= ALLOC_NESTING ();
4361 /* Make an entry on case_stack for the case we are entering. */
4363 thiscase
->desc
= CASE_NESTING
;
4364 thiscase
->next
= case_stack
;
4365 thiscase
->all
= nesting_stack
;
4366 thiscase
->depth
= ++nesting_depth
;
4367 thiscase
->exit_label
= exit_flag
? gen_label_rtx () : 0;
4368 thiscase
->data
.case_stmt
.case_list
= 0;
4369 thiscase
->data
.case_stmt
.index_expr
= expr
;
4370 thiscase
->data
.case_stmt
.nominal_type
= type
;
4371 thiscase
->data
.case_stmt
.default_label
= 0;
4372 thiscase
->data
.case_stmt
.printname
= printname
;
4373 thiscase
->data
.case_stmt
.line_number_status
= force_line_numbers ();
4374 case_stack
= thiscase
;
4375 nesting_stack
= thiscase
;
4377 do_pending_stack_adjust ();
4379 /* Make sure case_stmt.start points to something that won't
4380 need any transformation before expand_end_case. */
4381 if (GET_CODE (get_last_insn ()) != NOTE
)
4382 emit_note (NULL
, NOTE_INSN_DELETED
);
4384 thiscase
->data
.case_stmt
.start
= get_last_insn ();
4386 start_cleanup_deferral ();
4389 /* Start a "dummy case statement" within which case labels are invalid
4390 and are not connected to any larger real case statement.
4391 This can be used if you don't want to let a case statement jump
4392 into the middle of certain kinds of constructs. */
4395 expand_start_case_dummy ()
4397 struct nesting
*thiscase
= ALLOC_NESTING ();
4399 /* Make an entry on case_stack for the dummy. */
4401 thiscase
->desc
= CASE_NESTING
;
4402 thiscase
->next
= case_stack
;
4403 thiscase
->all
= nesting_stack
;
4404 thiscase
->depth
= ++nesting_depth
;
4405 thiscase
->exit_label
= 0;
4406 thiscase
->data
.case_stmt
.case_list
= 0;
4407 thiscase
->data
.case_stmt
.start
= 0;
4408 thiscase
->data
.case_stmt
.nominal_type
= 0;
4409 thiscase
->data
.case_stmt
.default_label
= 0;
4410 case_stack
= thiscase
;
4411 nesting_stack
= thiscase
;
4412 start_cleanup_deferral ();
4418 /* If this is the first label, warn if any insns have been emitted. */
4419 if (case_stack
->data
.case_stmt
.line_number_status
>= 0)
4423 restore_line_number_status
4424 (case_stack
->data
.case_stmt
.line_number_status
);
4425 case_stack
->data
.case_stmt
.line_number_status
= -1;
4427 for (insn
= case_stack
->data
.case_stmt
.start
;
4429 insn
= NEXT_INSN (insn
))
4431 if (GET_CODE (insn
) == CODE_LABEL
)
4433 if (GET_CODE (insn
) != NOTE
4434 && (GET_CODE (insn
) != INSN
|| GET_CODE (PATTERN (insn
)) != USE
))
4437 insn
= PREV_INSN (insn
);
4438 while (insn
&& (GET_CODE (insn
) != NOTE
|| NOTE_LINE_NUMBER (insn
) < 0));
4440 /* If insn is zero, then there must have been a syntax error. */
4442 warning_with_file_and_line (NOTE_SOURCE_FILE (insn
),
4443 NOTE_LINE_NUMBER (insn
),
4444 "unreachable code at beginning of %s",
4445 case_stack
->data
.case_stmt
.printname
);
4452 /* Accumulate one case or default label inside a case or switch statement.
4453 VALUE is the value of the case (a null pointer, for a default label).
4454 The function CONVERTER, when applied to arguments T and V,
4455 converts the value V to the type T.
4457 If not currently inside a case or switch statement, return 1 and do
4458 nothing. The caller will print a language-specific error message.
4459 If VALUE is a duplicate or overlaps, return 2 and do nothing
4460 except store the (first) duplicate node in *DUPLICATE.
4461 If VALUE is out of range, return 3 and do nothing.
4462 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4463 Return 0 on success.
4465 Extended to handle range statements. */
4468 pushcase (value
, converter
, label
, duplicate
)
4470 tree (*converter
) PARAMS ((tree
, tree
));
4477 /* Fail if not inside a real case statement. */
4478 if (! (case_stack
&& case_stack
->data
.case_stmt
.start
))
4481 if (stack_block_stack
4482 && stack_block_stack
->depth
> case_stack
->depth
)
4485 index_type
= TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4486 nominal_type
= case_stack
->data
.case_stmt
.nominal_type
;
4488 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4489 if (index_type
== error_mark_node
)
4492 /* Convert VALUE to the type in which the comparisons are nominally done. */
4494 value
= (*converter
) (nominal_type
, value
);
4498 /* Fail if this value is out of range for the actual type of the index
4499 (which may be narrower than NOMINAL_TYPE). */
4501 && (TREE_CONSTANT_OVERFLOW (value
)
4502 || ! int_fits_type_p (value
, index_type
)))
4505 return add_case_node (value
, value
, label
, duplicate
);
4508 /* Like pushcase but this case applies to all values between VALUE1 and
4509 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4510 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4511 starts at VALUE1 and ends at the highest value of the index type.
4512 If both are NULL, this case applies to all values.
4514 The return value is the same as that of pushcase but there is one
4515 additional error code: 4 means the specified range was empty. */
4518 pushcase_range (value1
, value2
, converter
, label
, duplicate
)
4519 tree value1
, value2
;
4520 tree (*converter
) PARAMS ((tree
, tree
));
4527 /* Fail if not inside a real case statement. */
4528 if (! (case_stack
&& case_stack
->data
.case_stmt
.start
))
4531 if (stack_block_stack
4532 && stack_block_stack
->depth
> case_stack
->depth
)
4535 index_type
= TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4536 nominal_type
= case_stack
->data
.case_stmt
.nominal_type
;
4538 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4539 if (index_type
== error_mark_node
)
4544 /* Convert VALUEs to type in which the comparisons are nominally done
4545 and replace any unspecified value with the corresponding bound. */
4547 value1
= TYPE_MIN_VALUE (index_type
);
4549 value2
= TYPE_MAX_VALUE (index_type
);
4551 /* Fail if the range is empty. Do this before any conversion since
4552 we want to allow out-of-range empty ranges. */
4553 if (value2
!= 0 && tree_int_cst_lt (value2
, value1
))
4556 /* If the max was unbounded, use the max of the nominal_type we are
4557 converting to. Do this after the < check above to suppress false
4560 value2
= TYPE_MAX_VALUE (nominal_type
);
4562 value1
= (*converter
) (nominal_type
, value1
);
4563 value2
= (*converter
) (nominal_type
, value2
);
4565 /* Fail if these values are out of range. */
4566 if (TREE_CONSTANT_OVERFLOW (value1
)
4567 || ! int_fits_type_p (value1
, index_type
))
4570 if (TREE_CONSTANT_OVERFLOW (value2
)
4571 || ! int_fits_type_p (value2
, index_type
))
4574 return add_case_node (value1
, value2
, label
, duplicate
);
4577 /* Do the actual insertion of a case label for pushcase and pushcase_range
4578 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4579 slowdown for large switch statements. */
4582 add_case_node (low
, high
, label
, duplicate
)
4587 struct case_node
*p
, **q
, *r
;
4589 /* If there's no HIGH value, then this is not a case range; it's
4590 just a simple case label. But that's just a degenerate case
4595 /* Handle default labels specially. */
4598 if (case_stack
->data
.case_stmt
.default_label
!= 0)
4600 *duplicate
= case_stack
->data
.case_stmt
.default_label
;
4603 case_stack
->data
.case_stmt
.default_label
= label
;
4604 expand_label (label
);
4608 q
= &case_stack
->data
.case_stmt
.case_list
;
4615 /* Keep going past elements distinctly greater than HIGH. */
4616 if (tree_int_cst_lt (high
, p
->low
))
4619 /* or distinctly less than LOW. */
4620 else if (tree_int_cst_lt (p
->high
, low
))
4625 /* We have an overlap; this is an error. */
4626 *duplicate
= p
->code_label
;
4631 /* Add this label to the chain, and succeed. */
4633 r
= (struct case_node
*) ggc_alloc (sizeof (struct case_node
));
4636 /* If the bounds are equal, turn this into the one-value case. */
4637 if (tree_int_cst_equal (low
, high
))
4642 r
->code_label
= label
;
4643 expand_label (label
);
4653 struct case_node
*s
;
4659 if (! (b
= p
->balance
))
4660 /* Growth propagation from left side. */
4667 if ((p
->left
= s
= r
->right
))
4676 if ((r
->parent
= s
))
4684 case_stack
->data
.case_stmt
.case_list
= r
;
4687 /* r->balance == +1 */
4692 struct case_node
*t
= r
->right
;
4694 if ((p
->left
= s
= t
->right
))
4698 if ((r
->right
= s
= t
->left
))
4712 if ((t
->parent
= s
))
4720 case_stack
->data
.case_stmt
.case_list
= t
;
4727 /* p->balance == +1; growth of left side balances the node. */
4737 if (! (b
= p
->balance
))
4738 /* Growth propagation from right side. */
4746 if ((p
->right
= s
= r
->left
))
4754 if ((r
->parent
= s
))
4763 case_stack
->data
.case_stmt
.case_list
= r
;
4767 /* r->balance == -1 */
4771 struct case_node
*t
= r
->left
;
4773 if ((p
->right
= s
= t
->left
))
4778 if ((r
->left
= s
= t
->right
))
4792 if ((t
->parent
= s
))
4801 case_stack
->data
.case_stmt
.case_list
= t
;
4807 /* p->balance == -1; growth of right side balances the node. */
4820 /* Returns the number of possible values of TYPE.
4821 Returns -1 if the number is unknown, variable, or if the number does not
4822 fit in a HOST_WIDE_INT.
4823 Sets *SPARSENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4824 do not increase monotonically (there may be duplicates);
4825 to 1 if the values increase monotonically, but not always by 1;
4826 otherwise sets it to 0. */
4829 all_cases_count (type
, sparseness
)
4834 HOST_WIDE_INT count
, minval
, lastval
;
4838 switch (TREE_CODE (type
))
4845 count
= 1 << BITS_PER_UNIT
;
4850 if (TYPE_MAX_VALUE (type
) != 0
4851 && 0 != (t
= fold (build (MINUS_EXPR
, type
, TYPE_MAX_VALUE (type
),
4852 TYPE_MIN_VALUE (type
))))
4853 && 0 != (t
= fold (build (PLUS_EXPR
, type
, t
,
4854 convert (type
, integer_zero_node
))))
4855 && host_integerp (t
, 1))
4856 count
= tree_low_cst (t
, 1);
4862 /* Don't waste time with enumeral types with huge values. */
4863 if (! host_integerp (TYPE_MIN_VALUE (type
), 0)
4864 || TYPE_MAX_VALUE (type
) == 0
4865 || ! host_integerp (TYPE_MAX_VALUE (type
), 0))
4868 lastval
= minval
= tree_low_cst (TYPE_MIN_VALUE (type
), 0);
4871 for (t
= TYPE_VALUES (type
); t
!= NULL_TREE
; t
= TREE_CHAIN (t
))
4873 HOST_WIDE_INT thisval
= tree_low_cst (TREE_VALUE (t
), 0);
4875 if (*sparseness
== 2 || thisval
<= lastval
)
4877 else if (thisval
!= minval
+ count
)
4888 #define BITARRAY_TEST(ARRAY, INDEX) \
4889 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4890 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4891 #define BITARRAY_SET(ARRAY, INDEX) \
4892 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4893 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4895 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4896 with the case values we have seen, assuming the case expression
4898 SPARSENESS is as determined by all_cases_count.
4900 The time needed is proportional to COUNT, unless
4901 SPARSENESS is 2, in which case quadratic time is needed. */
4904 mark_seen_cases (type
, cases_seen
, count
, sparseness
)
4906 unsigned char *cases_seen
;
4907 HOST_WIDE_INT count
;
4910 tree next_node_to_try
= NULL_TREE
;
4911 HOST_WIDE_INT next_node_offset
= 0;
4913 struct case_node
*n
, *root
= case_stack
->data
.case_stmt
.case_list
;
4914 tree val
= make_node (INTEGER_CST
);
4916 TREE_TYPE (val
) = type
;
4920 else if (sparseness
== 2)
4923 unsigned HOST_WIDE_INT xlo
;
4925 /* This less efficient loop is only needed to handle
4926 duplicate case values (multiple enum constants
4927 with the same value). */
4928 TREE_TYPE (val
) = TREE_TYPE (root
->low
);
4929 for (t
= TYPE_VALUES (type
), xlo
= 0; t
!= NULL_TREE
;
4930 t
= TREE_CHAIN (t
), xlo
++)
4932 TREE_INT_CST_LOW (val
) = TREE_INT_CST_LOW (TREE_VALUE (t
));
4933 TREE_INT_CST_HIGH (val
) = TREE_INT_CST_HIGH (TREE_VALUE (t
));
4937 /* Keep going past elements distinctly greater than VAL. */
4938 if (tree_int_cst_lt (val
, n
->low
))
4941 /* or distinctly less than VAL. */
4942 else if (tree_int_cst_lt (n
->high
, val
))
4947 /* We have found a matching range. */
4948 BITARRAY_SET (cases_seen
, xlo
);
4958 case_stack
->data
.case_stmt
.case_list
= root
= case_tree2list (root
, 0);
4960 for (n
= root
; n
; n
= n
->right
)
4962 TREE_INT_CST_LOW (val
) = TREE_INT_CST_LOW (n
->low
);
4963 TREE_INT_CST_HIGH (val
) = TREE_INT_CST_HIGH (n
->low
);
4964 while (! tree_int_cst_lt (n
->high
, val
))
4966 /* Calculate (into xlo) the "offset" of the integer (val).
4967 The element with lowest value has offset 0, the next smallest
4968 element has offset 1, etc. */
4970 unsigned HOST_WIDE_INT xlo
;
4974 if (sparseness
&& TYPE_VALUES (type
) != NULL_TREE
)
4976 /* The TYPE_VALUES will be in increasing order, so
4977 starting searching where we last ended. */
4978 t
= next_node_to_try
;
4979 xlo
= next_node_offset
;
4985 t
= TYPE_VALUES (type
);
4988 if (tree_int_cst_equal (val
, TREE_VALUE (t
)))
4990 next_node_to_try
= TREE_CHAIN (t
);
4991 next_node_offset
= xlo
+ 1;
4996 if (t
== next_node_to_try
)
5005 t
= TYPE_MIN_VALUE (type
);
5007 neg_double (TREE_INT_CST_LOW (t
), TREE_INT_CST_HIGH (t
),
5011 add_double (xlo
, xhi
,
5012 TREE_INT_CST_LOW (val
), TREE_INT_CST_HIGH (val
),
5016 if (xhi
== 0 && xlo
< (unsigned HOST_WIDE_INT
) count
)
5017 BITARRAY_SET (cases_seen
, xlo
);
5019 add_double (TREE_INT_CST_LOW (val
), TREE_INT_CST_HIGH (val
),
5021 &TREE_INT_CST_LOW (val
), &TREE_INT_CST_HIGH (val
));
5027 /* Given a switch statement with an expression that is an enumeration
5028 type, warn if any of the enumeration type's literals are not
5029 covered by the case expressions of the switch. Also, warn if there
5030 are any extra switch cases that are *not* elements of the
5035 At one stage this function would: ``If all enumeration literals
5036 were covered by the case expressions, turn one of the expressions
5037 into the default expression since it should not be possible to fall
5038 through such a switch.''
5040 That code has since been removed as: ``This optimization is
5041 disabled because it causes valid programs to fail. ANSI C does not
5042 guarantee that an expression with enum type will have a value that
5043 is the same as one of the enumeration literals.'' */
5046 check_for_full_enumeration_handling (type
)
5049 struct case_node
*n
;
5052 /* True iff the selector type is a numbered set mode. */
5055 /* The number of possible selector values. */
5058 /* For each possible selector value. a one iff it has been matched
5059 by a case value alternative. */
5060 unsigned char *cases_seen
;
5062 /* The allocated size of cases_seen, in chars. */
5063 HOST_WIDE_INT bytes_needed
;
5065 size
= all_cases_count (type
, &sparseness
);
5066 bytes_needed
= (size
+ HOST_BITS_PER_CHAR
) / HOST_BITS_PER_CHAR
;
5068 if (size
> 0 && size
< 600000
5069 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5070 this optimization if we don't have enough memory rather than
5071 aborting, as xmalloc would do. */
5073 (unsigned char *) really_call_calloc (bytes_needed
, 1)) != NULL
)
5076 tree v
= TYPE_VALUES (type
);
5078 /* The time complexity of this code is normally O(N), where
5079 N being the number of members in the enumerated type.
5080 However, if type is an ENUMERAL_TYPE whose values do not
5081 increase monotonically, O(N*log(N)) time may be needed. */
5083 mark_seen_cases (type
, cases_seen
, size
, sparseness
);
5085 for (i
= 0; v
!= NULL_TREE
&& i
< size
; i
++, v
= TREE_CHAIN (v
))
5086 if (BITARRAY_TEST (cases_seen
, i
) == 0)
5087 warning ("enumeration value `%s' not handled in switch",
5088 IDENTIFIER_POINTER (TREE_PURPOSE (v
)));
5093 /* Now we go the other way around; we warn if there are case
5094 expressions that don't correspond to enumerators. This can
5095 occur since C and C++ don't enforce type-checking of
5096 assignments to enumeration variables. */
5098 if (case_stack
->data
.case_stmt
.case_list
5099 && case_stack
->data
.case_stmt
.case_list
->left
)
5100 case_stack
->data
.case_stmt
.case_list
5101 = case_tree2list (case_stack
->data
.case_stmt
.case_list
, 0);
5102 for (n
= case_stack
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5104 for (chain
= TYPE_VALUES (type
);
5105 chain
&& !tree_int_cst_equal (n
->low
, TREE_VALUE (chain
));
5106 chain
= TREE_CHAIN (chain
))
5111 if (TYPE_NAME (type
) == 0)
5112 warning ("case value `%ld' not in enumerated type",
5113 (long) TREE_INT_CST_LOW (n
->low
));
5115 warning ("case value `%ld' not in enumerated type `%s'",
5116 (long) TREE_INT_CST_LOW (n
->low
),
5117 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type
))
5120 : DECL_NAME (TYPE_NAME (type
))));
5122 if (!tree_int_cst_equal (n
->low
, n
->high
))
5124 for (chain
= TYPE_VALUES (type
);
5125 chain
&& !tree_int_cst_equal (n
->high
, TREE_VALUE (chain
));
5126 chain
= TREE_CHAIN (chain
))
5131 if (TYPE_NAME (type
) == 0)
5132 warning ("case value `%ld' not in enumerated type",
5133 (long) TREE_INT_CST_LOW (n
->high
));
5135 warning ("case value `%ld' not in enumerated type `%s'",
5136 (long) TREE_INT_CST_LOW (n
->high
),
5137 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type
))
5140 : DECL_NAME (TYPE_NAME (type
))));
5148 /* Terminate a case (Pascal) or switch (C) statement
5149 in which ORIG_INDEX is the expression to be tested.
5150 If ORIG_TYPE is not NULL, it is the original ORIG_INDEX
5151 type as given in the source before any compiler conversions.
5152 Generate the code to test it and jump to the right place. */
5155 expand_end_case_type (orig_index
, orig_type
)
5156 tree orig_index
, orig_type
;
5158 tree minval
= NULL_TREE
, maxval
= NULL_TREE
, range
= NULL_TREE
;
5159 rtx default_label
= 0;
5160 struct case_node
*n
;
5167 rtx before_case
, end
;
5168 struct nesting
*thiscase
= case_stack
;
5169 tree index_expr
, index_type
;
5172 /* Don't crash due to previous errors. */
5173 if (thiscase
== NULL
)
5176 table_label
= gen_label_rtx ();
5177 index_expr
= thiscase
->data
.case_stmt
.index_expr
;
5178 index_type
= TREE_TYPE (index_expr
);
5179 unsignedp
= TREE_UNSIGNED (index_type
);
5180 if (orig_type
== NULL
)
5181 orig_type
= TREE_TYPE (orig_index
);
5183 do_pending_stack_adjust ();
5185 /* This might get a spurious warning in the presence of a syntax error;
5186 it could be fixed by moving the call to check_seenlabel after the
5187 check for error_mark_node, and copying the code of check_seenlabel that
5188 deals with case_stack->data.case_stmt.line_number_status /
5189 restore_line_number_status in front of the call to end_cleanup_deferral;
5190 However, this might miss some useful warnings in the presence of
5191 non-syntax errors. */
5194 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5195 if (index_type
!= error_mark_node
)
5197 /* If the switch expression was an enumerated type, check that
5198 exactly all enumeration literals are covered by the cases.
5199 The check is made when -Wswitch was specified and there is no
5200 default case, or when -Wswitch-enum was specified. */
5201 if (((warn_switch
&& !thiscase
->data
.case_stmt
.default_label
)
5202 || warn_switch_enum
)
5203 && TREE_CODE (orig_type
) == ENUMERAL_TYPE
5204 && TREE_CODE (index_expr
) != INTEGER_CST
)
5205 check_for_full_enumeration_handling (orig_type
);
5207 if (warn_switch_default
&& !thiscase
->data
.case_stmt
.default_label
)
5208 warning ("switch missing default case");
5210 /* If we don't have a default-label, create one here,
5211 after the body of the switch. */
5212 if (thiscase
->data
.case_stmt
.default_label
== 0)
5214 thiscase
->data
.case_stmt
.default_label
5215 = build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
5216 expand_label (thiscase
->data
.case_stmt
.default_label
);
5218 default_label
= label_rtx (thiscase
->data
.case_stmt
.default_label
);
5220 before_case
= get_last_insn ();
5222 if (thiscase
->data
.case_stmt
.case_list
5223 && thiscase
->data
.case_stmt
.case_list
->left
)
5224 thiscase
->data
.case_stmt
.case_list
5225 = case_tree2list (thiscase
->data
.case_stmt
.case_list
, 0);
5227 /* Simplify the case-list before we count it. */
5228 group_case_nodes (thiscase
->data
.case_stmt
.case_list
);
5230 /* Get upper and lower bounds of case values.
5231 Also convert all the case values to the index expr's data type. */
5234 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5236 /* Check low and high label values are integers. */
5237 if (TREE_CODE (n
->low
) != INTEGER_CST
)
5239 if (TREE_CODE (n
->high
) != INTEGER_CST
)
5242 n
->low
= convert (index_type
, n
->low
);
5243 n
->high
= convert (index_type
, n
->high
);
5245 /* Count the elements and track the largest and smallest
5246 of them (treating them as signed even if they are not). */
5254 if (INT_CST_LT (n
->low
, minval
))
5256 if (INT_CST_LT (maxval
, n
->high
))
5259 /* A range counts double, since it requires two compares. */
5260 if (! tree_int_cst_equal (n
->low
, n
->high
))
5264 /* Compute span of values. */
5266 range
= fold (build (MINUS_EXPR
, index_type
, maxval
, minval
));
5268 end_cleanup_deferral ();
5272 expand_expr (index_expr
, const0_rtx
, VOIDmode
, 0);
5274 emit_jump (default_label
);
5277 /* If range of values is much bigger than number of values,
5278 make a sequence of conditional branches instead of a dispatch.
5279 If the switch-index is a constant, do it this way
5280 because we can optimize it. */
5282 else if (count
< case_values_threshold ()
5283 || compare_tree_int (range
, 10 * count
) > 0
5284 /* RANGE may be signed, and really large ranges will show up
5285 as negative numbers. */
5286 || compare_tree_int (range
, 0) < 0
5287 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5290 || TREE_CODE (index_expr
) == INTEGER_CST
5291 || (TREE_CODE (index_expr
) == COMPOUND_EXPR
5292 && TREE_CODE (TREE_OPERAND (index_expr
, 1)) == INTEGER_CST
))
5294 index
= expand_expr (index_expr
, NULL_RTX
, VOIDmode
, 0);
5296 /* If the index is a short or char that we do not have
5297 an insn to handle comparisons directly, convert it to
5298 a full integer now, rather than letting each comparison
5299 generate the conversion. */
5301 if (GET_MODE_CLASS (GET_MODE (index
)) == MODE_INT
5302 && ! have_insn_for (COMPARE
, GET_MODE (index
)))
5304 enum machine_mode wider_mode
;
5305 for (wider_mode
= GET_MODE (index
); wider_mode
!= VOIDmode
;
5306 wider_mode
= GET_MODE_WIDER_MODE (wider_mode
))
5307 if (have_insn_for (COMPARE
, wider_mode
))
5309 index
= convert_to_mode (wider_mode
, index
, unsignedp
);
5315 do_pending_stack_adjust ();
5317 index
= protect_from_queue (index
, 0);
5318 if (GET_CODE (index
) == MEM
)
5319 index
= copy_to_reg (index
);
5320 if (GET_CODE (index
) == CONST_INT
5321 || TREE_CODE (index_expr
) == INTEGER_CST
)
5323 /* Make a tree node with the proper constant value
5324 if we don't already have one. */
5325 if (TREE_CODE (index_expr
) != INTEGER_CST
)
5328 = build_int_2 (INTVAL (index
),
5329 unsignedp
|| INTVAL (index
) >= 0 ? 0 : -1);
5330 index_expr
= convert (index_type
, index_expr
);
5333 /* For constant index expressions we need only
5334 issue an unconditional branch to the appropriate
5335 target code. The job of removing any unreachable
5336 code is left to the optimisation phase if the
5337 "-O" option is specified. */
5338 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5339 if (! tree_int_cst_lt (index_expr
, n
->low
)
5340 && ! tree_int_cst_lt (n
->high
, index_expr
))
5344 emit_jump (label_rtx (n
->code_label
));
5346 emit_jump (default_label
);
5350 /* If the index expression is not constant we generate
5351 a binary decision tree to select the appropriate
5352 target code. This is done as follows:
5354 The list of cases is rearranged into a binary tree,
5355 nearly optimal assuming equal probability for each case.
5357 The tree is transformed into RTL, eliminating
5358 redundant test conditions at the same time.
5360 If program flow could reach the end of the
5361 decision tree an unconditional jump to the
5362 default code is emitted. */
5365 = (TREE_CODE (orig_type
) != ENUMERAL_TYPE
5366 && estimate_case_costs (thiscase
->data
.case_stmt
.case_list
));
5367 balance_case_nodes (&thiscase
->data
.case_stmt
.case_list
, NULL
);
5368 emit_case_nodes (index
, thiscase
->data
.case_stmt
.case_list
,
5369 default_label
, index_type
);
5370 emit_jump_if_reachable (default_label
);
5375 if (! try_casesi (index_type
, index_expr
, minval
, range
,
5376 table_label
, default_label
))
5378 index_type
= thiscase
->data
.case_stmt
.nominal_type
;
5380 /* Index jumptables from zero for suitable values of
5381 minval to avoid a subtraction. */
5383 && compare_tree_int (minval
, 0) > 0
5384 && compare_tree_int (minval
, 3) < 0)
5386 minval
= integer_zero_node
;
5390 if (! try_tablejump (index_type
, index_expr
, minval
, range
,
5391 table_label
, default_label
))
5395 /* Get table of labels to jump to, in order of case index. */
5397 ncases
= tree_low_cst (range
, 0) + 1;
5398 labelvec
= (rtx
*) alloca (ncases
* sizeof (rtx
));
5399 memset ((char *) labelvec
, 0, ncases
* sizeof (rtx
));
5401 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5403 /* Compute the low and high bounds relative to the minimum
5404 value since that should fit in a HOST_WIDE_INT while the
5405 actual values may not. */
5407 = tree_low_cst (fold (build (MINUS_EXPR
, index_type
,
5408 n
->low
, minval
)), 1);
5409 HOST_WIDE_INT i_high
5410 = tree_low_cst (fold (build (MINUS_EXPR
, index_type
,
5411 n
->high
, minval
)), 1);
5414 for (i
= i_low
; i
<= i_high
; i
++)
5416 = gen_rtx_LABEL_REF (Pmode
, label_rtx (n
->code_label
));
5419 /* Fill in the gaps with the default. */
5420 for (i
= 0; i
< ncases
; i
++)
5421 if (labelvec
[i
] == 0)
5422 labelvec
[i
] = gen_rtx_LABEL_REF (Pmode
, default_label
);
5424 /* Output the table */
5425 emit_label (table_label
);
5427 if (CASE_VECTOR_PC_RELATIVE
|| flag_pic
)
5428 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE
,
5429 gen_rtx_LABEL_REF (Pmode
, table_label
),
5430 gen_rtvec_v (ncases
, labelvec
),
5431 const0_rtx
, const0_rtx
));
5433 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE
,
5434 gen_rtvec_v (ncases
, labelvec
)));
5436 /* If the case insn drops through the table,
5437 after the table we must jump to the default-label.
5438 Otherwise record no drop-through after the table. */
5439 #ifdef CASE_DROPS_THROUGH
5440 emit_jump (default_label
);
5446 before_case
= NEXT_INSN (before_case
);
5447 end
= get_last_insn ();
5448 if (squeeze_notes (&before_case
, &end
))
5450 reorder_insns (before_case
, end
,
5451 thiscase
->data
.case_stmt
.start
);
5454 end_cleanup_deferral ();
5456 if (thiscase
->exit_label
)
5457 emit_label (thiscase
->exit_label
);
5459 POPSTACK (case_stack
);
5464 /* Convert the tree NODE into a list linked by the right field, with the left
5465 field zeroed. RIGHT is used for recursion; it is a list to be placed
5466 rightmost in the resulting list. */
5468 static struct case_node
*
5469 case_tree2list (node
, right
)
5470 struct case_node
*node
, *right
;
5472 struct case_node
*left
;
5475 right
= case_tree2list (node
->right
, right
);
5477 node
->right
= right
;
5478 if ((left
= node
->left
))
5481 return case_tree2list (left
, node
);
5487 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5490 do_jump_if_equal (op1
, op2
, label
, unsignedp
)
5491 rtx op1
, op2
, label
;
5494 if (GET_CODE (op1
) == CONST_INT
&& GET_CODE (op2
) == CONST_INT
)
5496 if (INTVAL (op1
) == INTVAL (op2
))
5500 emit_cmp_and_jump_insns (op1
, op2
, EQ
, NULL_RTX
,
5501 (GET_MODE (op1
) == VOIDmode
5502 ? GET_MODE (op2
) : GET_MODE (op1
)),
5506 /* Not all case values are encountered equally. This function
5507 uses a heuristic to weight case labels, in cases where that
5508 looks like a reasonable thing to do.
5510 Right now, all we try to guess is text, and we establish the
5513 chars above space: 16
5522 If we find any cases in the switch that are not either -1 or in the range
5523 of valid ASCII characters, or are control characters other than those
5524 commonly used with "\", don't treat this switch scanning text.
5526 Return 1 if these nodes are suitable for cost estimation, otherwise
5530 estimate_case_costs (node
)
5533 tree min_ascii
= integer_minus_one_node
;
5534 tree max_ascii
= convert (TREE_TYPE (node
->high
), build_int_2 (127, 0));
5538 /* If we haven't already made the cost table, make it now. Note that the
5539 lower bound of the table is -1, not zero. */
5541 if (! cost_table_initialized
)
5543 cost_table_initialized
= 1;
5545 for (i
= 0; i
< 128; i
++)
5548 COST_TABLE (i
) = 16;
5549 else if (ISPUNCT (i
))
5551 else if (ISCNTRL (i
))
5552 COST_TABLE (i
) = -1;
5555 COST_TABLE (' ') = 8;
5556 COST_TABLE ('\t') = 4;
5557 COST_TABLE ('\0') = 4;
5558 COST_TABLE ('\n') = 2;
5559 COST_TABLE ('\f') = 1;
5560 COST_TABLE ('\v') = 1;
5561 COST_TABLE ('\b') = 1;
5564 /* See if all the case expressions look like text. It is text if the
5565 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5566 as signed arithmetic since we don't want to ever access cost_table with a
5567 value less than -1. Also check that none of the constants in a range
5568 are strange control characters. */
5570 for (n
= node
; n
; n
= n
->right
)
5572 if ((INT_CST_LT (n
->low
, min_ascii
)) || INT_CST_LT (max_ascii
, n
->high
))
5575 for (i
= (HOST_WIDE_INT
) TREE_INT_CST_LOW (n
->low
);
5576 i
<= (HOST_WIDE_INT
) TREE_INT_CST_LOW (n
->high
); i
++)
5577 if (COST_TABLE (i
) < 0)
5581 /* All interesting values are within the range of interesting
5582 ASCII characters. */
5586 /* Scan an ordered list of case nodes
5587 combining those with consecutive values or ranges.
5589 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5592 group_case_nodes (head
)
5595 case_node_ptr node
= head
;
5599 rtx lb
= next_real_insn (label_rtx (node
->code_label
));
5601 case_node_ptr np
= node
;
5603 /* Try to group the successors of NODE with NODE. */
5604 while (((np
= np
->right
) != 0)
5605 /* Do they jump to the same place? */
5606 && ((lb2
= next_real_insn (label_rtx (np
->code_label
))) == lb
5607 || (lb
!= 0 && lb2
!= 0
5608 && simplejump_p (lb
)
5609 && simplejump_p (lb2
)
5610 && rtx_equal_p (SET_SRC (PATTERN (lb
)),
5611 SET_SRC (PATTERN (lb2
)))))
5612 /* Are their ranges consecutive? */
5613 && tree_int_cst_equal (np
->low
,
5614 fold (build (PLUS_EXPR
,
5615 TREE_TYPE (node
->high
),
5618 /* An overflow is not consecutive. */
5619 && tree_int_cst_lt (node
->high
,
5620 fold (build (PLUS_EXPR
,
5621 TREE_TYPE (node
->high
),
5623 integer_one_node
))))
5625 node
->high
= np
->high
;
5627 /* NP is the first node after NODE which can't be grouped with it.
5628 Delete the nodes in between, and move on to that node. */
5634 /* Take an ordered list of case nodes
5635 and transform them into a near optimal binary tree,
5636 on the assumption that any target code selection value is as
5637 likely as any other.
5639 The transformation is performed by splitting the ordered
5640 list into two equal sections plus a pivot. The parts are
5641 then attached to the pivot as left and right branches. Each
5642 branch is then transformed recursively. */
5645 balance_case_nodes (head
, parent
)
5646 case_node_ptr
*head
;
5647 case_node_ptr parent
;
5660 /* Count the number of entries on branch. Also count the ranges. */
5664 if (!tree_int_cst_equal (np
->low
, np
->high
))
5668 cost
+= COST_TABLE (TREE_INT_CST_LOW (np
->high
));
5672 cost
+= COST_TABLE (TREE_INT_CST_LOW (np
->low
));
5680 /* Split this list if it is long enough for that to help. */
5685 /* Find the place in the list that bisects the list's total cost,
5686 Here I gets half the total cost. */
5691 /* Skip nodes while their cost does not reach that amount. */
5692 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
5693 i
-= COST_TABLE (TREE_INT_CST_LOW ((*npp
)->high
));
5694 i
-= COST_TABLE (TREE_INT_CST_LOW ((*npp
)->low
));
5697 npp
= &(*npp
)->right
;
5702 /* Leave this branch lopsided, but optimize left-hand
5703 side and fill in `parent' fields for right-hand side. */
5705 np
->parent
= parent
;
5706 balance_case_nodes (&np
->left
, np
);
5707 for (; np
->right
; np
= np
->right
)
5708 np
->right
->parent
= np
;
5712 /* If there are just three nodes, split at the middle one. */
5714 npp
= &(*npp
)->right
;
5717 /* Find the place in the list that bisects the list's total cost,
5718 where ranges count as 2.
5719 Here I gets half the total cost. */
5720 i
= (i
+ ranges
+ 1) / 2;
5723 /* Skip nodes while their cost does not reach that amount. */
5724 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
5729 npp
= &(*npp
)->right
;
5734 np
->parent
= parent
;
5737 /* Optimize each of the two split parts. */
5738 balance_case_nodes (&np
->left
, np
);
5739 balance_case_nodes (&np
->right
, np
);
5743 /* Else leave this branch as one level,
5744 but fill in `parent' fields. */
5746 np
->parent
= parent
;
5747 for (; np
->right
; np
= np
->right
)
5748 np
->right
->parent
= np
;
5753 /* Search the parent sections of the case node tree
5754 to see if a test for the lower bound of NODE would be redundant.
5755 INDEX_TYPE is the type of the index expression.
5757 The instructions to generate the case decision tree are
5758 output in the same order as nodes are processed so it is
5759 known that if a parent node checks the range of the current
5760 node minus one that the current node is bounded at its lower
5761 span. Thus the test would be redundant. */
5764 node_has_low_bound (node
, index_type
)
5769 case_node_ptr pnode
;
5771 /* If the lower bound of this node is the lowest value in the index type,
5772 we need not test it. */
5774 if (tree_int_cst_equal (node
->low
, TYPE_MIN_VALUE (index_type
)))
5777 /* If this node has a left branch, the value at the left must be less
5778 than that at this node, so it cannot be bounded at the bottom and
5779 we need not bother testing any further. */
5784 low_minus_one
= fold (build (MINUS_EXPR
, TREE_TYPE (node
->low
),
5785 node
->low
, integer_one_node
));
5787 /* If the subtraction above overflowed, we can't verify anything.
5788 Otherwise, look for a parent that tests our value - 1. */
5790 if (! tree_int_cst_lt (low_minus_one
, node
->low
))
5793 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
5794 if (tree_int_cst_equal (low_minus_one
, pnode
->high
))
5800 /* Search the parent sections of the case node tree
5801 to see if a test for the upper bound of NODE would be redundant.
5802 INDEX_TYPE is the type of the index expression.
5804 The instructions to generate the case decision tree are
5805 output in the same order as nodes are processed so it is
5806 known that if a parent node checks the range of the current
5807 node plus one that the current node is bounded at its upper
5808 span. Thus the test would be redundant. */
5811 node_has_high_bound (node
, index_type
)
5816 case_node_ptr pnode
;
5818 /* If there is no upper bound, obviously no test is needed. */
5820 if (TYPE_MAX_VALUE (index_type
) == NULL
)
5823 /* If the upper bound of this node is the highest value in the type
5824 of the index expression, we need not test against it. */
5826 if (tree_int_cst_equal (node
->high
, TYPE_MAX_VALUE (index_type
)))
5829 /* If this node has a right branch, the value at the right must be greater
5830 than that at this node, so it cannot be bounded at the top and
5831 we need not bother testing any further. */
5836 high_plus_one
= fold (build (PLUS_EXPR
, TREE_TYPE (node
->high
),
5837 node
->high
, integer_one_node
));
5839 /* If the addition above overflowed, we can't verify anything.
5840 Otherwise, look for a parent that tests our value + 1. */
5842 if (! tree_int_cst_lt (node
->high
, high_plus_one
))
5845 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
5846 if (tree_int_cst_equal (high_plus_one
, pnode
->low
))
5852 /* Search the parent sections of the
5853 case node tree to see if both tests for the upper and lower
5854 bounds of NODE would be redundant. */
5857 node_is_bounded (node
, index_type
)
5861 return (node_has_low_bound (node
, index_type
)
5862 && node_has_high_bound (node
, index_type
));
5865 /* Emit an unconditional jump to LABEL unless it would be dead code. */
5868 emit_jump_if_reachable (label
)
5871 if (GET_CODE (get_last_insn ()) != BARRIER
)
5875 /* Emit step-by-step code to select a case for the value of INDEX.
5876 The thus generated decision tree follows the form of the
5877 case-node binary tree NODE, whose nodes represent test conditions.
5878 INDEX_TYPE is the type of the index of the switch.
5880 Care is taken to prune redundant tests from the decision tree
5881 by detecting any boundary conditions already checked by
5882 emitted rtx. (See node_has_high_bound, node_has_low_bound
5883 and node_is_bounded, above.)
5885 Where the test conditions can be shown to be redundant we emit
5886 an unconditional jump to the target code. As a further
5887 optimization, the subordinates of a tree node are examined to
5888 check for bounded nodes. In this case conditional and/or
5889 unconditional jumps as a result of the boundary check for the
5890 current node are arranged to target the subordinates associated
5891 code for out of bound conditions on the current node.
5893 We can assume that when control reaches the code generated here,
5894 the index value has already been compared with the parents
5895 of this node, and determined to be on the same side of each parent
5896 as this node is. Thus, if this node tests for the value 51,
5897 and a parent tested for 52, we don't need to consider
5898 the possibility of a value greater than 51. If another parent
5899 tests for the value 50, then this node need not test anything. */
5902 emit_case_nodes (index
, node
, default_label
, index_type
)
5908 /* If INDEX has an unsigned type, we must make unsigned branches. */
5909 int unsignedp
= TREE_UNSIGNED (index_type
);
5910 enum machine_mode mode
= GET_MODE (index
);
5911 enum machine_mode imode
= TYPE_MODE (index_type
);
5913 /* See if our parents have already tested everything for us.
5914 If they have, emit an unconditional jump for this node. */
5915 if (node_is_bounded (node
, index_type
))
5916 emit_jump (label_rtx (node
->code_label
));
5918 else if (tree_int_cst_equal (node
->low
, node
->high
))
5920 /* Node is single valued. First see if the index expression matches
5921 this node and then check our children, if any. */
5923 do_jump_if_equal (index
,
5924 convert_modes (mode
, imode
,
5925 expand_expr (node
->low
, NULL_RTX
,
5928 label_rtx (node
->code_label
), unsignedp
);
5930 if (node
->right
!= 0 && node
->left
!= 0)
5932 /* This node has children on both sides.
5933 Dispatch to one side or the other
5934 by comparing the index value with this node's value.
5935 If one subtree is bounded, check that one first,
5936 so we can avoid real branches in the tree. */
5938 if (node_is_bounded (node
->right
, index_type
))
5940 emit_cmp_and_jump_insns (index
,
5943 expand_expr (node
->high
, NULL_RTX
,
5946 GT
, NULL_RTX
, mode
, unsignedp
,
5947 label_rtx (node
->right
->code_label
));
5948 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
5951 else if (node_is_bounded (node
->left
, index_type
))
5953 emit_cmp_and_jump_insns (index
,
5956 expand_expr (node
->high
, NULL_RTX
,
5959 LT
, NULL_RTX
, mode
, unsignedp
,
5960 label_rtx (node
->left
->code_label
));
5961 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
5966 /* Neither node is bounded. First distinguish the two sides;
5967 then emit the code for one side at a time. */
5969 tree test_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
5971 /* See if the value is on the right. */
5972 emit_cmp_and_jump_insns (index
,
5975 expand_expr (node
->high
, NULL_RTX
,
5978 GT
, NULL_RTX
, mode
, unsignedp
,
5979 label_rtx (test_label
));
5981 /* Value must be on the left.
5982 Handle the left-hand subtree. */
5983 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
5984 /* If left-hand subtree does nothing,
5986 emit_jump_if_reachable (default_label
);
5988 /* Code branches here for the right-hand subtree. */
5989 expand_label (test_label
);
5990 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
5994 else if (node
->right
!= 0 && node
->left
== 0)
5996 /* Here we have a right child but no left so we issue conditional
5997 branch to default and process the right child.
5999 Omit the conditional branch to default if we it avoid only one
6000 right child; it costs too much space to save so little time. */
6002 if (node
->right
->right
|| node
->right
->left
6003 || !tree_int_cst_equal (node
->right
->low
, node
->right
->high
))
6005 if (!node_has_low_bound (node
, index_type
))
6007 emit_cmp_and_jump_insns (index
,
6010 expand_expr (node
->high
, NULL_RTX
,
6013 LT
, NULL_RTX
, mode
, unsignedp
,
6017 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6020 /* We cannot process node->right normally
6021 since we haven't ruled out the numbers less than
6022 this node's value. So handle node->right explicitly. */
6023 do_jump_if_equal (index
,
6026 expand_expr (node
->right
->low
, NULL_RTX
,
6029 label_rtx (node
->right
->code_label
), unsignedp
);
6032 else if (node
->right
== 0 && node
->left
!= 0)
6034 /* Just one subtree, on the left. */
6035 if (node
->left
->left
|| node
->left
->right
6036 || !tree_int_cst_equal (node
->left
->low
, node
->left
->high
))
6038 if (!node_has_high_bound (node
, index_type
))
6040 emit_cmp_and_jump_insns (index
,
6043 expand_expr (node
->high
, NULL_RTX
,
6046 GT
, NULL_RTX
, mode
, unsignedp
,
6050 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6053 /* We cannot process node->left normally
6054 since we haven't ruled out the numbers less than
6055 this node's value. So handle node->left explicitly. */
6056 do_jump_if_equal (index
,
6059 expand_expr (node
->left
->low
, NULL_RTX
,
6062 label_rtx (node
->left
->code_label
), unsignedp
);
6067 /* Node is a range. These cases are very similar to those for a single
6068 value, except that we do not start by testing whether this node
6069 is the one to branch to. */
6071 if (node
->right
!= 0 && node
->left
!= 0)
6073 /* Node has subtrees on both sides.
6074 If the right-hand subtree is bounded,
6075 test for it first, since we can go straight there.
6076 Otherwise, we need to make a branch in the control structure,
6077 then handle the two subtrees. */
6078 tree test_label
= 0;
6080 if (node_is_bounded (node
->right
, index_type
))
6081 /* Right hand node is fully bounded so we can eliminate any
6082 testing and branch directly to the target code. */
6083 emit_cmp_and_jump_insns (index
,
6086 expand_expr (node
->high
, NULL_RTX
,
6089 GT
, NULL_RTX
, mode
, unsignedp
,
6090 label_rtx (node
->right
->code_label
));
6093 /* Right hand node requires testing.
6094 Branch to a label where we will handle it later. */
6096 test_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
6097 emit_cmp_and_jump_insns (index
,
6100 expand_expr (node
->high
, NULL_RTX
,
6103 GT
, NULL_RTX
, mode
, unsignedp
,
6104 label_rtx (test_label
));
6107 /* Value belongs to this node or to the left-hand subtree. */
6109 emit_cmp_and_jump_insns (index
,
6112 expand_expr (node
->low
, NULL_RTX
,
6115 GE
, NULL_RTX
, mode
, unsignedp
,
6116 label_rtx (node
->code_label
));
6118 /* Handle the left-hand subtree. */
6119 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6121 /* If right node had to be handled later, do that now. */
6125 /* If the left-hand subtree fell through,
6126 don't let it fall into the right-hand subtree. */
6127 emit_jump_if_reachable (default_label
);
6129 expand_label (test_label
);
6130 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6134 else if (node
->right
!= 0 && node
->left
== 0)
6136 /* Deal with values to the left of this node,
6137 if they are possible. */
6138 if (!node_has_low_bound (node
, index_type
))
6140 emit_cmp_and_jump_insns (index
,
6143 expand_expr (node
->low
, NULL_RTX
,
6146 LT
, NULL_RTX
, mode
, unsignedp
,
6150 /* Value belongs to this node or to the right-hand subtree. */
6152 emit_cmp_and_jump_insns (index
,
6155 expand_expr (node
->high
, NULL_RTX
,
6158 LE
, NULL_RTX
, mode
, unsignedp
,
6159 label_rtx (node
->code_label
));
6161 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6164 else if (node
->right
== 0 && node
->left
!= 0)
6166 /* Deal with values to the right of this node,
6167 if they are possible. */
6168 if (!node_has_high_bound (node
, index_type
))
6170 emit_cmp_and_jump_insns (index
,
6173 expand_expr (node
->high
, NULL_RTX
,
6176 GT
, NULL_RTX
, mode
, unsignedp
,
6180 /* Value belongs to this node or to the left-hand subtree. */
6182 emit_cmp_and_jump_insns (index
,
6185 expand_expr (node
->low
, NULL_RTX
,
6188 GE
, NULL_RTX
, mode
, unsignedp
,
6189 label_rtx (node
->code_label
));
6191 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6196 /* Node has no children so we check low and high bounds to remove
6197 redundant tests. Only one of the bounds can exist,
6198 since otherwise this node is bounded--a case tested already. */
6199 int high_bound
= node_has_high_bound (node
, index_type
);
6200 int low_bound
= node_has_low_bound (node
, index_type
);
6202 if (!high_bound
&& low_bound
)
6204 emit_cmp_and_jump_insns (index
,
6207 expand_expr (node
->high
, NULL_RTX
,
6210 GT
, NULL_RTX
, mode
, unsignedp
,
6214 else if (!low_bound
&& high_bound
)
6216 emit_cmp_and_jump_insns (index
,
6219 expand_expr (node
->low
, NULL_RTX
,
6222 LT
, NULL_RTX
, mode
, unsignedp
,
6225 else if (!low_bound
&& !high_bound
)
6227 /* Widen LOW and HIGH to the same width as INDEX. */
6228 tree type
= (*lang_hooks
.types
.type_for_mode
) (mode
, unsignedp
);
6229 tree low
= build1 (CONVERT_EXPR
, type
, node
->low
);
6230 tree high
= build1 (CONVERT_EXPR
, type
, node
->high
);
6231 rtx low_rtx
, new_index
, new_bound
;
6233 /* Instead of doing two branches, emit one unsigned branch for
6234 (index-low) > (high-low). */
6235 low_rtx
= expand_expr (low
, NULL_RTX
, mode
, 0);
6236 new_index
= expand_simple_binop (mode
, MINUS
, index
, low_rtx
,
6237 NULL_RTX
, unsignedp
,
6239 new_bound
= expand_expr (fold (build (MINUS_EXPR
, type
,
6243 emit_cmp_and_jump_insns (new_index
, new_bound
, GT
, NULL_RTX
,
6244 mode
, 1, default_label
);
6247 emit_jump (label_rtx (node
->code_label
));
6252 #include "gt-stmt.h"