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, 2003 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"
61 /* Assume that case vectors are not pc-relative. */
62 #ifndef CASE_VECTOR_PC_RELATIVE
63 #define CASE_VECTOR_PC_RELATIVE 0
66 /* Functions and data structures for expanding case statements. */
68 /* Case label structure, used to hold info on labels within case
69 statements. We handle "range" labels; for a single-value label
70 as in C, the high and low limits are the same.
72 An AVL tree of case nodes is initially created, and later transformed
73 to a list linked via the RIGHT fields in the nodes. Nodes with
74 higher case values are later in the list.
76 Switch statements can be output in one of two forms. A branch table
77 is used if there are more than a few labels and the labels are dense
78 within the range between the smallest and largest case value. If a
79 branch table is used, no further manipulations are done with the case
82 The alternative to the use of a branch table is to generate a series
83 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
84 and PARENT fields to hold a binary tree. Initially the tree is
85 totally unbalanced, with everything on the right. We balance the tree
86 with nodes on the left having lower case values than the parent
87 and nodes on the right having higher values. We then output the tree
90 struct case_node
GTY(())
92 struct case_node
*left
; /* Left son in binary tree */
93 struct case_node
*right
; /* Right son in binary tree; also node chain */
94 struct case_node
*parent
; /* Parent of node in binary tree */
95 tree low
; /* Lowest index value for this label */
96 tree high
; /* Highest index value for this label */
97 tree code_label
; /* Label to jump to when node matches */
101 typedef struct case_node case_node
;
102 typedef struct case_node
*case_node_ptr
;
104 /* These are used by estimate_case_costs and balance_case_nodes. */
106 /* This must be a signed type, and non-ANSI compilers lack signed char. */
107 static short cost_table_
[129];
108 static int use_cost_table
;
109 static int cost_table_initialized
;
111 /* Special care is needed because we allow -1, but TREE_INT_CST_LOW
113 #define COST_TABLE(I) cost_table_[(unsigned HOST_WIDE_INT) ((I) + 1)]
115 /* Stack of control and binding constructs we are currently inside.
117 These constructs begin when you call `expand_start_WHATEVER'
118 and end when you call `expand_end_WHATEVER'. This stack records
119 info about how the construct began that tells the end-function
120 what to do. It also may provide information about the construct
121 to alter the behavior of other constructs within the body.
122 For example, they may affect the behavior of C `break' and `continue'.
124 Each construct gets one `struct nesting' object.
125 All of these objects are chained through the `all' field.
126 `nesting_stack' points to the first object (innermost construct).
127 The position of an entry on `nesting_stack' is in its `depth' field.
129 Each type of construct has its own individual stack.
130 For example, loops have `loop_stack'. Each object points to the
131 next object of the same type through the `next' field.
133 Some constructs are visible to `break' exit-statements and others
134 are not. Which constructs are visible depends on the language.
135 Therefore, the data structure allows each construct to be visible
136 or not, according to the args given when the construct is started.
137 The construct is visible if the `exit_label' field is non-null.
138 In that case, the value should be a CODE_LABEL rtx. */
140 struct nesting
GTY(())
143 struct nesting
*next
;
154 /* For conds (if-then and if-then-else statements). */
157 /* Label for the end of the if construct.
158 There is none if EXITFLAG was not set
159 and no `else' has been seen yet. */
161 /* Label for the end of this alternative.
162 This may be the end of the if or the next else/elseif. */
164 } GTY ((tag ("COND_NESTING"))) cond
;
168 /* Label at the top of the loop; place to loop back to. */
170 /* Label at the end of the whole construct. */
172 /* Label for `continue' statement to jump to;
173 this is in front of the stepper of the loop. */
175 } GTY ((tag ("LOOP_NESTING"))) loop
;
176 /* For variable binding contours. */
179 /* Sequence number of this binding contour within the function,
180 in order of entry. */
181 int block_start_count
;
182 /* Nonzero => value to restore stack to on exit. */
184 /* The NOTE that starts this contour.
185 Used by expand_goto to check whether the destination
186 is within each contour or not. */
188 /* Innermost containing binding contour that has a stack level. */
189 struct nesting
*innermost_stack_block
;
190 /* List of cleanups to be run on exit from this contour.
191 This is a list of expressions to be evaluated.
192 The TREE_PURPOSE of each link is the ..._DECL node
193 which the cleanup pertains to. */
195 /* List of cleanup-lists of blocks containing this block,
196 as they were at the locus where this block appears.
197 There is an element for each containing block,
198 ordered innermost containing block first.
199 The tail of this list can be 0,
200 if all remaining elements would be empty lists.
201 The element's TREE_VALUE is the cleanup-list of that block,
202 which may be null. */
204 /* Chain of labels defined inside this binding contour.
205 For contours that have stack levels or cleanups. */
206 struct label_chain
*label_chain
;
207 /* Nonzero if this is associated with an EH region. */
208 int exception_region
;
209 /* The saved target_temp_slot_level from our outer block.
210 We may reset target_temp_slot_level to be the level of
211 this block, if that is done, target_temp_slot_level
212 reverts to the saved target_temp_slot_level at the very
214 int block_target_temp_slot_level
;
215 /* True if we are currently emitting insns in an area of
216 output code that is controlled by a conditional
217 expression. This is used by the cleanup handling code to
218 generate conditional cleanup actions. */
219 int conditional_code
;
220 /* A place to move the start of the exception region for any
221 of the conditional cleanups, must be at the end or after
222 the start of the last unconditional cleanup, and before any
223 conditional branch points. */
224 rtx last_unconditional_cleanup
;
225 } GTY ((tag ("BLOCK_NESTING"))) block
;
226 /* For switch (C) or case (Pascal) statements,
227 and also for dummies (see `expand_start_case_dummy'). */
230 /* The insn after which the case dispatch should finally
231 be emitted. Zero for a dummy. */
233 /* A list of case labels; it is first built as an AVL tree.
234 During expand_end_case, this is converted to a list, and may be
235 rearranged into a nearly balanced binary tree. */
236 struct case_node
*case_list
;
237 /* Label to jump to if no case matches. */
239 /* The expression to be dispatched on. */
241 /* Type that INDEX_EXPR should be converted to. */
243 /* Name of this kind of statement, for warnings. */
244 const char *printname
;
245 /* Used to save no_line_numbers till we see the first case label.
246 We set this to -1 when we see the first case label in this
248 int line_number_status
;
249 } GTY ((tag ("CASE_NESTING"))) case_stmt
;
250 } GTY ((desc ("%1.desc"))) data
;
253 /* Allocate and return a new `struct nesting'. */
255 #define ALLOC_NESTING() \
256 (struct nesting *) ggc_alloc (sizeof (struct nesting))
258 /* Pop the nesting stack element by element until we pop off
259 the element which is at the top of STACK.
260 Update all the other stacks, popping off elements from them
261 as we pop them from nesting_stack. */
263 #define POPSTACK(STACK) \
264 do { struct nesting *target = STACK; \
265 struct nesting *this; \
266 do { this = nesting_stack; \
267 if (loop_stack == this) \
268 loop_stack = loop_stack->next; \
269 if (cond_stack == this) \
270 cond_stack = cond_stack->next; \
271 if (block_stack == this) \
272 block_stack = block_stack->next; \
273 if (stack_block_stack == this) \
274 stack_block_stack = stack_block_stack->next; \
275 if (case_stack == this) \
276 case_stack = case_stack->next; \
277 nesting_depth = nesting_stack->depth - 1; \
278 nesting_stack = this->all; } \
279 while (this != target); } while (0)
281 /* In some cases it is impossible to generate code for a forward goto
282 until the label definition is seen. This happens when it may be necessary
283 for the goto to reset the stack pointer: we don't yet know how to do that.
284 So expand_goto puts an entry on this fixup list.
285 Each time a binding contour that resets the stack is exited,
287 If the target label has now been defined, we can insert the proper code. */
289 struct goto_fixup
GTY(())
291 /* Points to following fixup. */
292 struct goto_fixup
*next
;
293 /* Points to the insn before the jump insn.
294 If more code must be inserted, it goes after this insn. */
296 /* The LABEL_DECL that this jump is jumping to, or 0
297 for break, continue or return. */
299 /* The BLOCK for the place where this goto was found. */
301 /* The CODE_LABEL rtx that this is jumping to. */
303 /* Number of binding contours started in current function
304 before the label reference. */
305 int block_start_count
;
306 /* The outermost stack level that should be restored for this jump.
307 Each time a binding contour that resets the stack is exited,
308 if the target label is *not* yet defined, this slot is updated. */
310 /* List of lists of cleanup expressions to be run by this goto.
311 There is one element for each block that this goto is within.
312 The tail of this list can be 0,
313 if all remaining elements would be empty.
314 The TREE_VALUE contains the cleanup list of that block as of the
315 time this goto was seen.
316 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
317 tree cleanup_list_list
;
320 /* Within any binding contour that must restore a stack level,
321 all labels are recorded with a chain of these structures. */
323 struct label_chain
GTY(())
325 /* Points to following fixup. */
326 struct label_chain
*next
;
330 struct stmt_status
GTY(())
332 /* Chain of all pending binding contours. */
333 struct nesting
* x_block_stack
;
335 /* If any new stacks are added here, add them to POPSTACKS too. */
337 /* Chain of all pending binding contours that restore stack levels
339 struct nesting
* x_stack_block_stack
;
341 /* Chain of all pending conditional statements. */
342 struct nesting
* x_cond_stack
;
344 /* Chain of all pending loops. */
345 struct nesting
* x_loop_stack
;
347 /* Chain of all pending case or switch statements. */
348 struct nesting
* x_case_stack
;
350 /* Separate chain including all of the above,
351 chained through the `all' field. */
352 struct nesting
* x_nesting_stack
;
354 /* Number of entries on nesting_stack now. */
357 /* Number of binding contours started so far in this function. */
358 int x_block_start_count
;
360 /* Each time we expand an expression-statement,
361 record the expr's type and its RTL value here. */
362 tree x_last_expr_type
;
363 rtx x_last_expr_value
;
365 /* Nonzero if within a ({...}) grouping, in which case we must
366 always compute a value for each expr-stmt in case it is the last one. */
367 int x_expr_stmts_for_value
;
369 /* Location of last line-number note, whether we actually
370 emitted it or not. */
371 location_t x_emit_locus
;
373 struct goto_fixup
*x_goto_fixup_chain
;
376 #define block_stack (cfun->stmt->x_block_stack)
377 #define stack_block_stack (cfun->stmt->x_stack_block_stack)
378 #define cond_stack (cfun->stmt->x_cond_stack)
379 #define loop_stack (cfun->stmt->x_loop_stack)
380 #define case_stack (cfun->stmt->x_case_stack)
381 #define nesting_stack (cfun->stmt->x_nesting_stack)
382 #define nesting_depth (cfun->stmt->x_nesting_depth)
383 #define current_block_start_count (cfun->stmt->x_block_start_count)
384 #define last_expr_type (cfun->stmt->x_last_expr_type)
385 #define last_expr_value (cfun->stmt->x_last_expr_value)
386 #define expr_stmts_for_value (cfun->stmt->x_expr_stmts_for_value)
387 #define emit_locus (cfun->stmt->x_emit_locus)
388 #define goto_fixup_chain (cfun->stmt->x_goto_fixup_chain)
390 /* Nonzero if we are using EH to handle cleanups. */
391 static int using_eh_for_cleanups_p
= 0;
393 static int n_occurrences
PARAMS ((int, const char *));
394 static bool parse_input_constraint
PARAMS ((const char **, int, int, int,
395 int, const char * const *,
397 static bool decl_conflicts_with_clobbers_p
PARAMS ((tree
, const HARD_REG_SET
));
398 static void expand_goto_internal
PARAMS ((tree
, rtx
, rtx
));
399 static int expand_fixup
PARAMS ((tree
, rtx
, rtx
));
400 static rtx expand_nl_handler_label
PARAMS ((rtx
, rtx
));
401 static void expand_nl_goto_receiver
PARAMS ((void));
402 static void expand_nl_goto_receivers
PARAMS ((struct nesting
*));
403 static void fixup_gotos
PARAMS ((struct nesting
*, rtx
, tree
,
405 static bool check_operand_nalternatives
PARAMS ((tree
, tree
));
406 static bool check_unique_operand_names
PARAMS ((tree
, tree
));
407 static tree resolve_operand_names
PARAMS ((tree
, tree
, tree
,
409 static char *resolve_operand_name_1
PARAMS ((char *, tree
, tree
));
410 static void expand_null_return_1
PARAMS ((rtx
));
411 static enum br_predictor return_prediction
PARAMS ((rtx
));
412 static void expand_value_return
PARAMS ((rtx
));
413 static int tail_recursion_args
PARAMS ((tree
, tree
));
414 static void expand_cleanups
PARAMS ((tree
, int, int));
415 static void check_seenlabel
PARAMS ((void));
416 static void do_jump_if_equal
PARAMS ((rtx
, rtx
, rtx
, int));
417 static int estimate_case_costs
PARAMS ((case_node_ptr
));
418 static bool same_case_target_p
PARAMS ((rtx
, rtx
));
419 static void strip_default_case_nodes
PARAMS ((case_node_ptr
*, rtx
));
420 static bool lshift_cheap_p
PARAMS ((void));
421 static int case_bit_test_cmp
PARAMS ((const void *, const void *));
422 static void emit_case_bit_tests
PARAMS ((tree
, tree
, tree
, tree
,
423 case_node_ptr
, rtx
));
424 static void group_case_nodes
PARAMS ((case_node_ptr
));
425 static void balance_case_nodes
PARAMS ((case_node_ptr
*,
427 static int node_has_low_bound
PARAMS ((case_node_ptr
, tree
));
428 static int node_has_high_bound
PARAMS ((case_node_ptr
, tree
));
429 static int node_is_bounded
PARAMS ((case_node_ptr
, tree
));
430 static void emit_jump_if_reachable
PARAMS ((rtx
));
431 static void emit_case_nodes
PARAMS ((rtx
, case_node_ptr
, rtx
, tree
));
432 static struct case_node
*case_tree2list
PARAMS ((case_node
*, case_node
*));
435 using_eh_for_cleanups ()
437 using_eh_for_cleanups_p
= 1;
441 init_stmt_for_function ()
443 cfun
->stmt
= ((struct stmt_status
*)ggc_alloc (sizeof (struct stmt_status
)));
445 /* We are not currently within any block, conditional, loop or case. */
447 stack_block_stack
= 0;
454 current_block_start_count
= 0;
456 /* No gotos have been expanded yet. */
457 goto_fixup_chain
= 0;
459 /* We are not processing a ({...}) grouping. */
460 expr_stmts_for_value
= 0;
464 /* Record the current file and line. Called from emit_line_note. */
466 set_file_and_line_for_stmt (file
, line
)
470 /* If we're outputting an inline function, and we add a line note,
471 there may be no CFUN->STMT information. So, there's no need to
475 emit_locus
.file
= file
;
476 emit_locus
.line
= line
;
480 /* Emit a no-op instruction. */
487 last_insn
= get_last_insn ();
489 && (GET_CODE (last_insn
) == CODE_LABEL
490 || (GET_CODE (last_insn
) == NOTE
491 && prev_real_insn (last_insn
) == 0)))
492 emit_insn (gen_nop ());
495 /* Return the rtx-label that corresponds to a LABEL_DECL,
496 creating it if necessary. */
502 if (TREE_CODE (label
) != LABEL_DECL
)
505 if (!DECL_RTL_SET_P (label
))
506 SET_DECL_RTL (label
, gen_label_rtx ());
508 return DECL_RTL (label
);
511 /* As above, but also put it on the forced-reference list of the
512 function that contains it. */
514 force_label_rtx (label
)
517 rtx ref
= label_rtx (label
);
518 tree function
= decl_function_context (label
);
524 if (function
!= current_function_decl
525 && function
!= inline_function_decl
)
526 p
= find_function_data (function
);
530 p
->expr
->x_forced_labels
= gen_rtx_EXPR_LIST (VOIDmode
, ref
,
531 p
->expr
->x_forced_labels
);
535 /* Add an unconditional jump to LABEL as the next sequential instruction. */
541 do_pending_stack_adjust ();
542 emit_jump_insn (gen_jump (label
));
546 /* Emit code to jump to the address
547 specified by the pointer expression EXP. */
550 expand_computed_goto (exp
)
553 rtx x
= expand_expr (exp
, NULL_RTX
, VOIDmode
, 0);
555 #ifdef POINTERS_EXTEND_UNSIGNED
556 if (GET_MODE (x
) != Pmode
)
557 x
= convert_memory_address (Pmode
, x
);
562 if (! cfun
->computed_goto_common_label
)
564 cfun
->computed_goto_common_reg
= copy_to_mode_reg (Pmode
, x
);
565 cfun
->computed_goto_common_label
= gen_label_rtx ();
566 emit_label (cfun
->computed_goto_common_label
);
568 do_pending_stack_adjust ();
569 emit_indirect_jump (cfun
->computed_goto_common_reg
);
571 current_function_has_computed_jump
= 1;
575 emit_move_insn (cfun
->computed_goto_common_reg
, x
);
576 emit_jump (cfun
->computed_goto_common_label
);
580 /* Handle goto statements and the labels that they can go to. */
582 /* Specify the location in the RTL code of a label LABEL,
583 which is a LABEL_DECL tree node.
585 This is used for the kind of label that the user can jump to with a
586 goto statement, and for alternatives of a switch or case statement.
587 RTL labels generated for loops and conditionals don't go through here;
588 they are generated directly at the RTL level, by other functions below.
590 Note that this has nothing to do with defining label *names*.
591 Languages vary in how they do that and what that even means. */
597 struct label_chain
*p
;
599 do_pending_stack_adjust ();
600 emit_label (label_rtx (label
));
601 if (DECL_NAME (label
))
602 LABEL_NAME (DECL_RTL (label
)) = IDENTIFIER_POINTER (DECL_NAME (label
));
604 if (stack_block_stack
!= 0)
606 p
= (struct label_chain
*) ggc_alloc (sizeof (struct label_chain
));
607 p
->next
= stack_block_stack
->data
.block
.label_chain
;
608 stack_block_stack
->data
.block
.label_chain
= p
;
613 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
614 from nested functions. */
617 declare_nonlocal_label (label
)
620 rtx slot
= assign_stack_local (Pmode
, GET_MODE_SIZE (Pmode
), 0);
622 nonlocal_labels
= tree_cons (NULL_TREE
, label
, nonlocal_labels
);
623 LABEL_PRESERVE_P (label_rtx (label
)) = 1;
624 if (nonlocal_goto_handler_slots
== 0)
626 emit_stack_save (SAVE_NONLOCAL
,
627 &nonlocal_goto_stack_level
,
628 PREV_INSN (tail_recursion_reentry
));
630 nonlocal_goto_handler_slots
631 = gen_rtx_EXPR_LIST (VOIDmode
, slot
, nonlocal_goto_handler_slots
);
634 /* Generate RTL code for a `goto' statement with target label LABEL.
635 LABEL should be a LABEL_DECL tree node that was or will later be
636 defined with `expand_label'. */
644 /* Check for a nonlocal goto to a containing function. */
645 context
= decl_function_context (label
);
646 if (context
!= 0 && context
!= current_function_decl
)
648 struct function
*p
= find_function_data (context
);
649 rtx label_ref
= gen_rtx_LABEL_REF (Pmode
, label_rtx (label
));
650 rtx handler_slot
, static_chain
, save_area
, insn
;
653 /* Find the corresponding handler slot for this label. */
654 handler_slot
= p
->x_nonlocal_goto_handler_slots
;
655 for (link
= p
->x_nonlocal_labels
; TREE_VALUE (link
) != label
;
656 link
= TREE_CHAIN (link
))
657 handler_slot
= XEXP (handler_slot
, 1);
658 handler_slot
= XEXP (handler_slot
, 0);
660 p
->has_nonlocal_label
= 1;
661 current_function_has_nonlocal_goto
= 1;
662 LABEL_REF_NONLOCAL_P (label_ref
) = 1;
664 /* Copy the rtl for the slots so that they won't be shared in
665 case the virtual stack vars register gets instantiated differently
666 in the parent than in the child. */
668 static_chain
= copy_to_reg (lookup_static_chain (label
));
670 /* Get addr of containing function's current nonlocal goto handler,
671 which will do any cleanups and then jump to the label. */
672 handler_slot
= copy_to_reg (replace_rtx (copy_rtx (handler_slot
),
673 virtual_stack_vars_rtx
,
676 /* Get addr of containing function's nonlocal save area. */
677 save_area
= p
->x_nonlocal_goto_stack_level
;
679 save_area
= replace_rtx (copy_rtx (save_area
),
680 virtual_stack_vars_rtx
, static_chain
);
682 #if HAVE_nonlocal_goto
683 if (HAVE_nonlocal_goto
)
684 emit_insn (gen_nonlocal_goto (static_chain
, handler_slot
,
685 save_area
, label_ref
));
689 /* Restore frame pointer for containing function.
690 This sets the actual hard register used for the frame pointer
691 to the location of the function's incoming static chain info.
692 The non-local goto handler will then adjust it to contain the
693 proper value and reload the argument pointer, if needed. */
694 emit_move_insn (hard_frame_pointer_rtx
, static_chain
);
695 emit_stack_restore (SAVE_NONLOCAL
, save_area
, NULL_RTX
);
697 /* USE of hard_frame_pointer_rtx added for consistency;
698 not clear if really needed. */
699 emit_insn (gen_rtx_USE (VOIDmode
, hard_frame_pointer_rtx
));
700 emit_insn (gen_rtx_USE (VOIDmode
, stack_pointer_rtx
));
701 emit_indirect_jump (handler_slot
);
704 /* Search backwards to the jump insn and mark it as a
706 for (insn
= get_last_insn (); insn
; insn
= PREV_INSN (insn
))
708 if (GET_CODE (insn
) == JUMP_INSN
)
710 REG_NOTES (insn
) = alloc_EXPR_LIST (REG_NON_LOCAL_GOTO
,
711 const0_rtx
, REG_NOTES (insn
));
714 else if (GET_CODE (insn
) == CALL_INSN
)
719 expand_goto_internal (label
, label_rtx (label
), NULL_RTX
);
722 /* Generate RTL code for a `goto' statement with target label BODY.
723 LABEL should be a LABEL_REF.
724 LAST_INSN, if non-0, is the rtx we should consider as the last
725 insn emitted (for the purposes of cleaning up a return). */
728 expand_goto_internal (body
, label
, last_insn
)
733 struct nesting
*block
;
736 if (GET_CODE (label
) != CODE_LABEL
)
739 /* If label has already been defined, we can tell now
740 whether and how we must alter the stack level. */
742 if (PREV_INSN (label
) != 0)
744 /* Find the innermost pending block that contains the label.
745 (Check containment by comparing insn-uids.)
746 Then restore the outermost stack level within that block,
747 and do cleanups of all blocks contained in it. */
748 for (block
= block_stack
; block
; block
= block
->next
)
750 if (INSN_UID (block
->data
.block
.first_insn
) < INSN_UID (label
))
752 if (block
->data
.block
.stack_level
!= 0)
753 stack_level
= block
->data
.block
.stack_level
;
754 /* Execute the cleanups for blocks we are exiting. */
755 if (block
->data
.block
.cleanups
!= 0)
757 expand_cleanups (block
->data
.block
.cleanups
, 1, 1);
758 do_pending_stack_adjust ();
764 /* Ensure stack adjust isn't done by emit_jump, as this
765 would clobber the stack pointer. This one should be
766 deleted as dead by flow. */
767 clear_pending_stack_adjust ();
768 do_pending_stack_adjust ();
770 /* Don't do this adjust if it's to the end label and this function
771 is to return with a depressed stack pointer. */
772 if (label
== return_label
773 && (((TREE_CODE (TREE_TYPE (current_function_decl
))
775 && (TYPE_RETURNS_STACK_DEPRESSED
776 (TREE_TYPE (current_function_decl
))))))
779 emit_stack_restore (SAVE_BLOCK
, stack_level
, NULL_RTX
);
782 if (body
!= 0 && DECL_TOO_LATE (body
))
783 error ("jump to `%s' invalidly jumps into binding contour",
784 IDENTIFIER_POINTER (DECL_NAME (body
)));
786 /* Label not yet defined: may need to put this goto
787 on the fixup list. */
788 else if (! expand_fixup (body
, label
, last_insn
))
790 /* No fixup needed. Record that the label is the target
791 of at least one goto that has no fixup. */
793 TREE_ADDRESSABLE (body
) = 1;
799 /* Generate if necessary a fixup for a goto
800 whose target label in tree structure (if any) is TREE_LABEL
801 and whose target in rtl is RTL_LABEL.
803 If LAST_INSN is nonzero, we pretend that the jump appears
804 after insn LAST_INSN instead of at the current point in the insn stream.
806 The fixup will be used later to insert insns just before the goto.
807 Those insns will restore the stack level as appropriate for the
808 target label, and will (in the case of C++) also invoke any object
809 destructors which have to be invoked when we exit the scopes which
810 are exited by the goto.
812 Value is nonzero if a fixup is made. */
815 expand_fixup (tree_label
, rtl_label
, last_insn
)
820 struct nesting
*block
, *end_block
;
822 /* See if we can recognize which block the label will be output in.
823 This is possible in some very common cases.
824 If we succeed, set END_BLOCK to that block.
825 Otherwise, set it to 0. */
828 && (rtl_label
== cond_stack
->data
.cond
.endif_label
829 || rtl_label
== cond_stack
->data
.cond
.next_label
))
830 end_block
= cond_stack
;
831 /* If we are in a loop, recognize certain labels which
832 are likely targets. This reduces the number of fixups
833 we need to create. */
835 && (rtl_label
== loop_stack
->data
.loop
.start_label
836 || rtl_label
== loop_stack
->data
.loop
.end_label
837 || rtl_label
== loop_stack
->data
.loop
.continue_label
))
838 end_block
= loop_stack
;
842 /* Now set END_BLOCK to the binding level to which we will return. */
846 struct nesting
*next_block
= end_block
->all
;
849 /* First see if the END_BLOCK is inside the innermost binding level.
850 If so, then no cleanups or stack levels are relevant. */
851 while (next_block
&& next_block
!= block
)
852 next_block
= next_block
->all
;
857 /* Otherwise, set END_BLOCK to the innermost binding level
858 which is outside the relevant control-structure nesting. */
859 next_block
= block_stack
->next
;
860 for (block
= block_stack
; block
!= end_block
; block
= block
->all
)
861 if (block
== next_block
)
862 next_block
= next_block
->next
;
863 end_block
= next_block
;
866 /* Does any containing block have a stack level or cleanups?
867 If not, no fixup is needed, and that is the normal case
868 (the only case, for standard C). */
869 for (block
= block_stack
; block
!= end_block
; block
= block
->next
)
870 if (block
->data
.block
.stack_level
!= 0
871 || block
->data
.block
.cleanups
!= 0)
874 if (block
!= end_block
)
876 /* Ok, a fixup is needed. Add a fixup to the list of such. */
877 struct goto_fixup
*fixup
878 = (struct goto_fixup
*) ggc_alloc (sizeof (struct goto_fixup
));
879 /* In case an old stack level is restored, make sure that comes
880 after any pending stack adjust. */
881 /* ?? If the fixup isn't to come at the present position,
882 doing the stack adjust here isn't useful. Doing it with our
883 settings at that location isn't useful either. Let's hope
886 do_pending_stack_adjust ();
887 fixup
->target
= tree_label
;
888 fixup
->target_rtl
= rtl_label
;
890 /* Create a BLOCK node and a corresponding matched set of
891 NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes at
892 this point. The notes will encapsulate any and all fixup
893 code which we might later insert at this point in the insn
894 stream. Also, the BLOCK node will be the parent (i.e. the
895 `SUPERBLOCK') of any other BLOCK nodes which we might create
896 later on when we are expanding the fixup code.
898 Note that optimization passes (including expand_end_loop)
899 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
903 rtx original_before_jump
904 = last_insn
? last_insn
: get_last_insn ();
909 block
= make_node (BLOCK
);
910 TREE_USED (block
) = 1;
912 if (!cfun
->x_whole_function_mode_p
)
913 (*lang_hooks
.decls
.insert_block
) (block
);
917 = BLOCK_CHAIN (DECL_INITIAL (current_function_decl
));
918 BLOCK_CHAIN (DECL_INITIAL (current_function_decl
))
923 start
= emit_note (NULL
, NOTE_INSN_BLOCK_BEG
);
924 if (cfun
->x_whole_function_mode_p
)
925 NOTE_BLOCK (start
) = block
;
926 fixup
->before_jump
= emit_note (NULL
, NOTE_INSN_DELETED
);
927 end
= emit_note (NULL
, NOTE_INSN_BLOCK_END
);
928 if (cfun
->x_whole_function_mode_p
)
929 NOTE_BLOCK (end
) = block
;
930 fixup
->context
= block
;
932 emit_insn_after (start
, original_before_jump
);
935 fixup
->block_start_count
= current_block_start_count
;
936 fixup
->stack_level
= 0;
937 fixup
->cleanup_list_list
938 = ((block
->data
.block
.outer_cleanups
939 || block
->data
.block
.cleanups
)
940 ? tree_cons (NULL_TREE
, block
->data
.block
.cleanups
,
941 block
->data
.block
.outer_cleanups
)
943 fixup
->next
= goto_fixup_chain
;
944 goto_fixup_chain
= fixup
;
950 /* Expand any needed fixups in the outputmost binding level of the
951 function. FIRST_INSN is the first insn in the function. */
954 expand_fixups (first_insn
)
957 fixup_gotos (NULL
, NULL_RTX
, NULL_TREE
, first_insn
, 0);
960 /* When exiting a binding contour, process all pending gotos requiring fixups.
961 THISBLOCK is the structure that describes the block being exited.
962 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
963 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
964 FIRST_INSN is the insn that began this contour.
966 Gotos that jump out of this contour must restore the
967 stack level and do the cleanups before actually jumping.
969 DONT_JUMP_IN positive means report error if there is a jump into this
970 contour from before the beginning of the contour. This is also done if
971 STACK_LEVEL is nonzero unless DONT_JUMP_IN is negative. */
974 fixup_gotos (thisblock
, stack_level
, cleanup_list
, first_insn
, dont_jump_in
)
975 struct nesting
*thisblock
;
981 struct goto_fixup
*f
, *prev
;
983 /* F is the fixup we are considering; PREV is the previous one. */
984 /* We run this loop in two passes so that cleanups of exited blocks
985 are run first, and blocks that are exited are marked so
988 for (prev
= 0, f
= goto_fixup_chain
; f
; prev
= f
, f
= f
->next
)
990 /* Test for a fixup that is inactive because it is already handled. */
991 if (f
->before_jump
== 0)
993 /* Delete inactive fixup from the chain, if that is easy to do. */
995 prev
->next
= f
->next
;
997 /* Has this fixup's target label been defined?
998 If so, we can finalize it. */
999 else if (PREV_INSN (f
->target_rtl
) != 0)
1003 /* If this fixup jumped into this contour from before the beginning
1004 of this contour, report an error. This code used to use
1005 the first non-label insn after f->target_rtl, but that's
1006 wrong since such can be added, by things like put_var_into_stack
1007 and have INSN_UIDs that are out of the range of the block. */
1008 /* ??? Bug: this does not detect jumping in through intermediate
1009 blocks that have stack levels or cleanups.
1010 It detects only a problem with the innermost block
1011 around the label. */
1013 && (dont_jump_in
> 0 || (dont_jump_in
== 0 && stack_level
)
1015 && INSN_UID (first_insn
) < INSN_UID (f
->target_rtl
)
1016 && INSN_UID (first_insn
) > INSN_UID (f
->before_jump
)
1017 && ! DECL_ERROR_ISSUED (f
->target
))
1019 error_with_decl (f
->target
,
1020 "label `%s' used before containing binding contour");
1021 /* Prevent multiple errors for one label. */
1022 DECL_ERROR_ISSUED (f
->target
) = 1;
1025 /* We will expand the cleanups into a sequence of their own and
1026 then later on we will attach this new sequence to the insn
1027 stream just ahead of the actual jump insn. */
1031 /* Temporarily restore the lexical context where we will
1032 logically be inserting the fixup code. We do this for the
1033 sake of getting the debugging information right. */
1035 (*lang_hooks
.decls
.pushlevel
) (0);
1036 (*lang_hooks
.decls
.set_block
) (f
->context
);
1038 /* Expand the cleanups for blocks this jump exits. */
1039 if (f
->cleanup_list_list
)
1042 for (lists
= f
->cleanup_list_list
; lists
; lists
= TREE_CHAIN (lists
))
1043 /* Marked elements correspond to blocks that have been closed.
1044 Do their cleanups. */
1045 if (TREE_ADDRESSABLE (lists
)
1046 && TREE_VALUE (lists
) != 0)
1048 expand_cleanups (TREE_VALUE (lists
), 1, 1);
1049 /* Pop any pushes done in the cleanups,
1050 in case function is about to return. */
1051 do_pending_stack_adjust ();
1055 /* Restore stack level for the biggest contour that this
1056 jump jumps out of. */
1058 && ! (f
->target_rtl
== return_label
1059 && ((TREE_CODE (TREE_TYPE (current_function_decl
))
1061 && (TYPE_RETURNS_STACK_DEPRESSED
1062 (TREE_TYPE (current_function_decl
))))))
1063 emit_stack_restore (SAVE_BLOCK
, f
->stack_level
, f
->before_jump
);
1065 /* Finish up the sequence containing the insns which implement the
1066 necessary cleanups, and then attach that whole sequence to the
1067 insn stream just ahead of the actual jump insn. Attaching it
1068 at that point insures that any cleanups which are in fact
1069 implicit C++ object destructions (which must be executed upon
1070 leaving the block) appear (to the debugger) to be taking place
1071 in an area of the generated code where the object(s) being
1072 destructed are still "in scope". */
1074 cleanup_insns
= get_insns ();
1075 (*lang_hooks
.decls
.poplevel
) (1, 0, 0);
1078 emit_insn_after (cleanup_insns
, f
->before_jump
);
1084 /* For any still-undefined labels, do the cleanups for this block now.
1085 We must do this now since items in the cleanup list may go out
1086 of scope when the block ends. */
1087 for (prev
= 0, f
= goto_fixup_chain
; f
; prev
= f
, f
= f
->next
)
1088 if (f
->before_jump
!= 0
1089 && PREV_INSN (f
->target_rtl
) == 0
1090 /* Label has still not appeared. If we are exiting a block with
1091 a stack level to restore, that started before the fixup,
1092 mark this stack level as needing restoration
1093 when the fixup is later finalized. */
1095 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1096 means the label is undefined. That's erroneous, but possible. */
1097 && (thisblock
->data
.block
.block_start_count
1098 <= f
->block_start_count
))
1100 tree lists
= f
->cleanup_list_list
;
1103 for (; lists
; lists
= TREE_CHAIN (lists
))
1104 /* If the following elt. corresponds to our containing block
1105 then the elt. must be for this block. */
1106 if (TREE_CHAIN (lists
) == thisblock
->data
.block
.outer_cleanups
)
1109 (*lang_hooks
.decls
.pushlevel
) (0);
1110 (*lang_hooks
.decls
.set_block
) (f
->context
);
1111 expand_cleanups (TREE_VALUE (lists
), 1, 1);
1112 do_pending_stack_adjust ();
1113 cleanup_insns
= get_insns ();
1114 (*lang_hooks
.decls
.poplevel
) (1, 0, 0);
1116 if (cleanup_insns
!= 0)
1118 = emit_insn_after (cleanup_insns
, f
->before_jump
);
1120 f
->cleanup_list_list
= TREE_CHAIN (lists
);
1124 f
->stack_level
= stack_level
;
1128 /* Return the number of times character C occurs in string S. */
1130 n_occurrences (c
, s
)
1140 /* Generate RTL for an asm statement (explicit assembler code).
1141 STRING is a STRING_CST node containing the assembler code text,
1142 or an ADDR_EXPR containing a STRING_CST. VOL nonzero means the
1143 insn is volatile; don't optimize it. */
1146 expand_asm (string
, vol
)
1152 if (TREE_CODE (string
) == ADDR_EXPR
)
1153 string
= TREE_OPERAND (string
, 0);
1155 body
= gen_rtx_ASM_INPUT (VOIDmode
, TREE_STRING_POINTER (string
));
1157 MEM_VOLATILE_P (body
) = vol
;
1164 /* Parse the output constraint pointed to by *CONSTRAINT_P. It is the
1165 OPERAND_NUMth output operand, indexed from zero. There are NINPUTS
1166 inputs and NOUTPUTS outputs to this extended-asm. Upon return,
1167 *ALLOWS_MEM will be TRUE iff the constraint allows the use of a
1168 memory operand. Similarly, *ALLOWS_REG will be TRUE iff the
1169 constraint allows the use of a register operand. And, *IS_INOUT
1170 will be true if the operand is read-write, i.e., if it is used as
1171 an input as well as an output. If *CONSTRAINT_P is not in
1172 canonical form, it will be made canonical. (Note that `+' will be
1173 replaced with `=' as part of this process.)
1175 Returns TRUE if all went well; FALSE if an error occurred. */
1178 parse_output_constraint (constraint_p
, operand_num
, ninputs
, noutputs
,
1179 allows_mem
, allows_reg
, is_inout
)
1180 const char **constraint_p
;
1188 const char *constraint
= *constraint_p
;
1191 /* Assume the constraint doesn't allow the use of either a register
1193 *allows_mem
= false;
1194 *allows_reg
= false;
1196 /* Allow the `=' or `+' to not be at the beginning of the string,
1197 since it wasn't explicitly documented that way, and there is a
1198 large body of code that puts it last. Swap the character to
1199 the front, so as not to uglify any place else. */
1200 p
= strchr (constraint
, '=');
1202 p
= strchr (constraint
, '+');
1204 /* If the string doesn't contain an `=', issue an error
1208 error ("output operand constraint lacks `='");
1212 /* If the constraint begins with `+', then the operand is both read
1213 from and written to. */
1214 *is_inout
= (*p
== '+');
1216 /* Canonicalize the output constraint so that it begins with `='. */
1217 if (p
!= constraint
|| is_inout
)
1220 size_t c_len
= strlen (constraint
);
1222 if (p
!= constraint
)
1223 warning ("output constraint `%c' for operand %d is not at the beginning",
1226 /* Make a copy of the constraint. */
1227 buf
= alloca (c_len
+ 1);
1228 strcpy (buf
, constraint
);
1229 /* Swap the first character and the `=' or `+'. */
1230 buf
[p
- constraint
] = buf
[0];
1231 /* Make sure the first character is an `='. (Until we do this,
1232 it might be a `+'.) */
1234 /* Replace the constraint with the canonicalized string. */
1235 *constraint_p
= ggc_alloc_string (buf
, c_len
);
1236 constraint
= *constraint_p
;
1239 /* Loop through the constraint string. */
1240 for (p
= constraint
+ 1; *p
; p
+= CONSTRAINT_LEN (*p
, p
))
1245 error ("operand constraint contains incorrectly positioned '+' or '='");
1249 if (operand_num
+ 1 == ninputs
+ noutputs
)
1251 error ("`%%' constraint used with last operand");
1256 case 'V': case 'm': case 'o':
1260 case '?': case '!': case '*': case '&': case '#':
1261 case 'E': case 'F': case 'G': case 'H':
1262 case 's': case 'i': case 'n':
1263 case 'I': case 'J': case 'K': case 'L': case 'M':
1264 case 'N': case 'O': case 'P': case ',':
1267 case '0': case '1': case '2': case '3': case '4':
1268 case '5': case '6': case '7': case '8': case '9':
1270 error ("matching constraint not valid in output operand");
1274 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1275 excepting those that expand_call created. So match memory
1292 if (REG_CLASS_FROM_CONSTRAINT (*p
, p
) != NO_REGS
)
1294 #ifdef EXTRA_CONSTRAINT_STR
1295 else if (EXTRA_ADDRESS_CONSTRAINT (*p
, p
))
1297 else if (EXTRA_MEMORY_CONSTRAINT (*p
, p
))
1301 /* Otherwise we can't assume anything about the nature of
1302 the constraint except that it isn't purely registers.
1303 Treat it like "g" and hope for the best. */
1314 /* Similar, but for input constraints. */
1317 parse_input_constraint (constraint_p
, input_num
, ninputs
, noutputs
, ninout
,
1318 constraints
, allows_mem
, allows_reg
)
1319 const char **constraint_p
;
1324 const char * const * constraints
;
1328 const char *constraint
= *constraint_p
;
1329 const char *orig_constraint
= constraint
;
1330 size_t c_len
= strlen (constraint
);
1333 /* Assume the constraint doesn't allow the use of either
1334 a register or memory. */
1335 *allows_mem
= false;
1336 *allows_reg
= false;
1338 /* Make sure constraint has neither `=', `+', nor '&'. */
1340 for (j
= 0; j
< c_len
; j
+= CONSTRAINT_LEN (constraint
[j
], constraint
+j
))
1341 switch (constraint
[j
])
1343 case '+': case '=': case '&':
1344 if (constraint
== orig_constraint
)
1346 error ("input operand constraint contains `%c'", constraint
[j
]);
1352 if (constraint
== orig_constraint
1353 && input_num
+ 1 == ninputs
- ninout
)
1355 error ("`%%' constraint used with last operand");
1360 case 'V': case 'm': case 'o':
1365 case '?': case '!': case '*': case '#':
1366 case 'E': case 'F': case 'G': case 'H':
1367 case 's': case 'i': case 'n':
1368 case 'I': case 'J': case 'K': case 'L': case 'M':
1369 case 'N': case 'O': case 'P': case ',':
1372 /* Whether or not a numeric constraint allows a register is
1373 decided by the matching constraint, and so there is no need
1374 to do anything special with them. We must handle them in
1375 the default case, so that we don't unnecessarily force
1376 operands to memory. */
1377 case '0': case '1': case '2': case '3': case '4':
1378 case '5': case '6': case '7': case '8': case '9':
1381 unsigned long match
;
1383 match
= strtoul (constraint
+ j
, &end
, 10);
1384 if (match
>= (unsigned long) noutputs
)
1386 error ("matching constraint references invalid operand number");
1390 /* Try and find the real constraint for this dup. Only do this
1391 if the matching constraint is the only alternative. */
1393 && (j
== 0 || (j
== 1 && constraint
[0] == '%')))
1395 constraint
= constraints
[match
];
1396 *constraint_p
= constraint
;
1397 c_len
= strlen (constraint
);
1399 /* ??? At the end of the loop, we will skip the first part of
1400 the matched constraint. This assumes not only that the
1401 other constraint is an output constraint, but also that
1402 the '=' or '+' come first. */
1406 j
= end
- constraint
;
1407 /* Anticipate increment at end of loop. */
1422 if (! ISALPHA (constraint
[j
]))
1424 error ("invalid punctuation `%c' in constraint", constraint
[j
]);
1427 if (REG_CLASS_FROM_CONSTRAINT (constraint
[j
], constraint
+ j
)
1430 #ifdef EXTRA_CONSTRAINT_STR
1431 else if (EXTRA_ADDRESS_CONSTRAINT (constraint
[j
], constraint
+ j
))
1433 else if (EXTRA_MEMORY_CONSTRAINT (constraint
[j
], constraint
+ j
))
1437 /* Otherwise we can't assume anything about the nature of
1438 the constraint except that it isn't purely registers.
1439 Treat it like "g" and hope for the best. */
1450 /* Check for overlap between registers marked in CLOBBERED_REGS and
1451 anything inappropriate in DECL. Emit error and return TRUE for error,
1455 decl_conflicts_with_clobbers_p (decl
, clobbered_regs
)
1457 const HARD_REG_SET clobbered_regs
;
1459 /* Conflicts between asm-declared register variables and the clobber
1460 list are not allowed. */
1461 if ((TREE_CODE (decl
) == VAR_DECL
|| TREE_CODE (decl
) == PARM_DECL
)
1462 && DECL_REGISTER (decl
)
1463 && REG_P (DECL_RTL (decl
))
1464 && REGNO (DECL_RTL (decl
)) < FIRST_PSEUDO_REGISTER
)
1466 rtx reg
= DECL_RTL (decl
);
1469 for (regno
= REGNO (reg
);
1470 regno
< (REGNO (reg
)
1471 + HARD_REGNO_NREGS (REGNO (reg
), GET_MODE (reg
)));
1473 if (TEST_HARD_REG_BIT (clobbered_regs
, regno
))
1475 error ("asm-specifier for variable `%s' conflicts with asm clobber list",
1476 IDENTIFIER_POINTER (DECL_NAME (decl
)));
1478 /* Reset registerness to stop multiple errors emitted for a
1480 DECL_REGISTER (decl
) = 0;
1487 /* Generate RTL for an asm statement with arguments.
1488 STRING is the instruction template.
1489 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1490 Each output or input has an expression in the TREE_VALUE and
1491 and a tree list in TREE_PURPOSE which in turn contains a constraint
1492 name in TREE_VALUE (or NULL_TREE) and a constraint string
1494 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1495 that is clobbered by this insn.
1497 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1498 Some elements of OUTPUTS may be replaced with trees representing temporary
1499 values. The caller should copy those temporary values to the originally
1502 VOL nonzero means the insn is volatile; don't optimize it. */
1505 expand_asm_operands (string
, outputs
, inputs
, clobbers
, vol
, filename
, line
)
1506 tree string
, outputs
, inputs
, clobbers
;
1508 const char *filename
;
1511 rtvec argvec
, constraintvec
;
1513 int ninputs
= list_length (inputs
);
1514 int noutputs
= list_length (outputs
);
1517 HARD_REG_SET clobbered_regs
;
1518 int clobber_conflict_found
= 0;
1521 /* Vector of RTX's of evaluated output operands. */
1522 rtx
*output_rtx
= (rtx
*) alloca (noutputs
* sizeof (rtx
));
1523 int *inout_opnum
= (int *) alloca (noutputs
* sizeof (int));
1524 rtx
*real_output_rtx
= (rtx
*) alloca (noutputs
* sizeof (rtx
));
1525 enum machine_mode
*inout_mode
1526 = (enum machine_mode
*) alloca (noutputs
* sizeof (enum machine_mode
));
1527 const char **constraints
1528 = (const char **) alloca ((noutputs
+ ninputs
) * sizeof (const char *));
1529 int old_generating_concat_p
= generating_concat_p
;
1531 /* An ASM with no outputs needs to be treated as volatile, for now. */
1535 if (! check_operand_nalternatives (outputs
, inputs
))
1538 if (! check_unique_operand_names (outputs
, inputs
))
1541 string
= resolve_operand_names (string
, outputs
, inputs
, constraints
);
1543 #ifdef MD_ASM_CLOBBERS
1544 /* Sometimes we wish to automatically clobber registers across an asm.
1545 Case in point is when the i386 backend moved from cc0 to a hard reg --
1546 maintaining source-level compatibility means automatically clobbering
1547 the flags register. */
1548 MD_ASM_CLOBBERS (clobbers
);
1551 /* Count the number of meaningful clobbered registers, ignoring what
1552 we would ignore later. */
1554 CLEAR_HARD_REG_SET (clobbered_regs
);
1555 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
))
1557 const char *regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
1559 i
= decode_reg_name (regname
);
1560 if (i
>= 0 || i
== -4)
1563 error ("unknown register name `%s' in `asm'", regname
);
1565 /* Mark clobbered registers. */
1568 /* Clobbering the PIC register is an error */
1569 if (i
== (int) PIC_OFFSET_TABLE_REGNUM
)
1571 error ("PIC register `%s' clobbered in `asm'", regname
);
1575 SET_HARD_REG_BIT (clobbered_regs
, i
);
1581 /* First pass over inputs and outputs checks validity and sets
1582 mark_addressable if needed. */
1585 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1587 tree val
= TREE_VALUE (tail
);
1588 tree type
= TREE_TYPE (val
);
1589 const char *constraint
;
1594 /* If there's an erroneous arg, emit no insn. */
1595 if (type
== error_mark_node
)
1598 /* Try to parse the output constraint. If that fails, there's
1599 no point in going further. */
1600 constraint
= constraints
[i
];
1601 if (!parse_output_constraint (&constraint
, i
, ninputs
, noutputs
,
1602 &allows_mem
, &allows_reg
, &is_inout
))
1609 && GET_CODE (DECL_RTL (val
)) == REG
1610 && GET_MODE (DECL_RTL (val
)) != TYPE_MODE (type
))))
1611 (*lang_hooks
.mark_addressable
) (val
);
1618 if (ninputs
+ noutputs
> MAX_RECOG_OPERANDS
)
1620 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS
);
1624 for (i
= 0, tail
= inputs
; tail
; i
++, tail
= TREE_CHAIN (tail
))
1626 bool allows_reg
, allows_mem
;
1627 const char *constraint
;
1629 /* If there's an erroneous arg, emit no insn, because the ASM_INPUT
1630 would get VOIDmode and that could cause a crash in reload. */
1631 if (TREE_TYPE (TREE_VALUE (tail
)) == error_mark_node
)
1634 constraint
= constraints
[i
+ noutputs
];
1635 if (! parse_input_constraint (&constraint
, i
, ninputs
, noutputs
, ninout
,
1636 constraints
, &allows_mem
, &allows_reg
))
1639 if (! allows_reg
&& allows_mem
)
1640 (*lang_hooks
.mark_addressable
) (TREE_VALUE (tail
));
1643 /* Second pass evaluates arguments. */
1646 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1648 tree val
= TREE_VALUE (tail
);
1649 tree type
= TREE_TYPE (val
);
1655 if (!parse_output_constraint (&constraints
[i
], i
, ninputs
,
1656 noutputs
, &allows_mem
, &allows_reg
,
1660 /* If an output operand is not a decl or indirect ref and our constraint
1661 allows a register, make a temporary to act as an intermediate.
1662 Make the asm insn write into that, then our caller will copy it to
1663 the real output operand. Likewise for promoted variables. */
1665 generating_concat_p
= 0;
1667 real_output_rtx
[i
] = NULL_RTX
;
1668 if ((TREE_CODE (val
) == INDIRECT_REF
1671 && (allows_mem
|| GET_CODE (DECL_RTL (val
)) == REG
)
1672 && ! (GET_CODE (DECL_RTL (val
)) == REG
1673 && GET_MODE (DECL_RTL (val
)) != TYPE_MODE (type
)))
1677 op
= expand_expr (val
, NULL_RTX
, VOIDmode
, EXPAND_WRITE
);
1678 if (GET_CODE (op
) == MEM
)
1679 op
= validize_mem (op
);
1681 if (! allows_reg
&& GET_CODE (op
) != MEM
)
1682 error ("output number %d not directly addressable", i
);
1683 if ((! allows_mem
&& GET_CODE (op
) == MEM
)
1684 || GET_CODE (op
) == CONCAT
)
1686 real_output_rtx
[i
] = protect_from_queue (op
, 1);
1687 op
= gen_reg_rtx (GET_MODE (op
));
1689 emit_move_insn (op
, real_output_rtx
[i
]);
1694 op
= assign_temp (type
, 0, 0, 1);
1695 op
= validize_mem (op
);
1696 TREE_VALUE (tail
) = make_tree (type
, op
);
1700 generating_concat_p
= old_generating_concat_p
;
1704 inout_mode
[ninout
] = TYPE_MODE (type
);
1705 inout_opnum
[ninout
++] = i
;
1708 if (decl_conflicts_with_clobbers_p (val
, clobbered_regs
))
1709 clobber_conflict_found
= 1;
1712 /* Make vectors for the expression-rtx, constraint strings,
1713 and named operands. */
1715 argvec
= rtvec_alloc (ninputs
);
1716 constraintvec
= rtvec_alloc (ninputs
);
1718 body
= gen_rtx_ASM_OPERANDS ((noutputs
== 0 ? VOIDmode
1719 : GET_MODE (output_rtx
[0])),
1720 TREE_STRING_POINTER (string
),
1721 empty_string
, 0, argvec
, constraintvec
,
1724 MEM_VOLATILE_P (body
) = vol
;
1726 /* Eval the inputs and put them into ARGVEC.
1727 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1729 for (i
= 0, tail
= inputs
; tail
; tail
= TREE_CHAIN (tail
), ++i
)
1731 bool allows_reg
, allows_mem
;
1732 const char *constraint
;
1736 constraint
= constraints
[i
+ noutputs
];
1737 if (! parse_input_constraint (&constraint
, i
, ninputs
, noutputs
, ninout
,
1738 constraints
, &allows_mem
, &allows_reg
))
1741 generating_concat_p
= 0;
1743 val
= TREE_VALUE (tail
);
1744 type
= TREE_TYPE (val
);
1745 op
= expand_expr (val
, NULL_RTX
, VOIDmode
, 0);
1747 /* Never pass a CONCAT to an ASM. */
1748 if (GET_CODE (op
) == CONCAT
)
1749 op
= force_reg (GET_MODE (op
), op
);
1750 else if (GET_CODE (op
) == MEM
)
1751 op
= validize_mem (op
);
1753 if (asm_operand_ok (op
, constraint
) <= 0)
1756 op
= force_reg (TYPE_MODE (type
), op
);
1757 else if (!allows_mem
)
1758 warning ("asm operand %d probably doesn't match constraints",
1760 else if (CONSTANT_P (op
))
1762 op
= force_const_mem (TYPE_MODE (type
), op
);
1763 op
= validize_mem (op
);
1765 else if (GET_CODE (op
) == REG
1766 || GET_CODE (op
) == SUBREG
1767 || GET_CODE (op
) == ADDRESSOF
1768 || GET_CODE (op
) == CONCAT
)
1770 tree qual_type
= build_qualified_type (type
,
1772 | TYPE_QUAL_CONST
));
1773 rtx memloc
= assign_temp (qual_type
, 1, 1, 1);
1774 memloc
= validize_mem (memloc
);
1775 emit_move_insn (memloc
, op
);
1779 else if (GET_CODE (op
) == MEM
&& MEM_VOLATILE_P (op
))
1781 /* We won't recognize volatile memory as available a
1782 memory_operand at this point. Ignore it. */
1784 else if (queued_subexp_p (op
))
1787 /* ??? Leave this only until we have experience with what
1788 happens in combine and elsewhere when constraints are
1790 warning ("asm operand %d probably doesn't match constraints",
1794 generating_concat_p
= old_generating_concat_p
;
1795 ASM_OPERANDS_INPUT (body
, i
) = op
;
1797 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body
, i
)
1798 = gen_rtx_ASM_INPUT (TYPE_MODE (type
), constraints
[i
+ noutputs
]);
1800 if (decl_conflicts_with_clobbers_p (val
, clobbered_regs
))
1801 clobber_conflict_found
= 1;
1804 /* Protect all the operands from the queue now that they have all been
1807 generating_concat_p
= 0;
1809 for (i
= 0; i
< ninputs
- ninout
; i
++)
1810 ASM_OPERANDS_INPUT (body
, i
)
1811 = protect_from_queue (ASM_OPERANDS_INPUT (body
, i
), 0);
1813 for (i
= 0; i
< noutputs
; i
++)
1814 output_rtx
[i
] = protect_from_queue (output_rtx
[i
], 1);
1816 /* For in-out operands, copy output rtx to input rtx. */
1817 for (i
= 0; i
< ninout
; i
++)
1819 int j
= inout_opnum
[i
];
1822 ASM_OPERANDS_INPUT (body
, ninputs
- ninout
+ i
)
1825 sprintf (buffer
, "%d", j
);
1826 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body
, ninputs
- ninout
+ i
)
1827 = gen_rtx_ASM_INPUT (inout_mode
[i
], ggc_alloc_string (buffer
, -1));
1830 generating_concat_p
= old_generating_concat_p
;
1832 /* Now, for each output, construct an rtx
1833 (set OUTPUT (asm_operands INSN OUTPUTCONSTRAINT OUTPUTNUMBER
1834 ARGVEC CONSTRAINTS OPNAMES))
1835 If there is more than one, put them inside a PARALLEL. */
1837 if (noutputs
== 1 && nclobbers
== 0)
1839 ASM_OPERANDS_OUTPUT_CONSTRAINT (body
) = constraints
[0];
1840 emit_insn (gen_rtx_SET (VOIDmode
, output_rtx
[0], body
));
1843 else if (noutputs
== 0 && nclobbers
== 0)
1845 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1857 body
= gen_rtx_PARALLEL (VOIDmode
, rtvec_alloc (num
+ nclobbers
));
1859 /* For each output operand, store a SET. */
1860 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1862 XVECEXP (body
, 0, i
)
1863 = gen_rtx_SET (VOIDmode
,
1865 gen_rtx_ASM_OPERANDS
1866 (GET_MODE (output_rtx
[i
]),
1867 TREE_STRING_POINTER (string
),
1868 constraints
[i
], i
, argvec
, constraintvec
,
1871 MEM_VOLATILE_P (SET_SRC (XVECEXP (body
, 0, i
))) = vol
;
1874 /* If there are no outputs (but there are some clobbers)
1875 store the bare ASM_OPERANDS into the PARALLEL. */
1878 XVECEXP (body
, 0, i
++) = obody
;
1880 /* Store (clobber REG) for each clobbered register specified. */
1882 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
))
1884 const char *regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
1885 int j
= decode_reg_name (regname
);
1890 if (j
== -3) /* `cc', which is not a register */
1893 if (j
== -4) /* `memory', don't cache memory across asm */
1895 XVECEXP (body
, 0, i
++)
1896 = gen_rtx_CLOBBER (VOIDmode
,
1899 gen_rtx_SCRATCH (VOIDmode
)));
1903 /* Ignore unknown register, error already signaled. */
1907 /* Use QImode since that's guaranteed to clobber just one reg. */
1908 clobbered_reg
= gen_rtx_REG (QImode
, j
);
1910 /* Do sanity check for overlap between clobbers and respectively
1911 input and outputs that hasn't been handled. Such overlap
1912 should have been detected and reported above. */
1913 if (!clobber_conflict_found
)
1917 /* We test the old body (obody) contents to avoid tripping
1918 over the under-construction body. */
1919 for (opno
= 0; opno
< noutputs
; opno
++)
1920 if (reg_overlap_mentioned_p (clobbered_reg
, output_rtx
[opno
]))
1921 internal_error ("asm clobber conflict with output operand");
1923 for (opno
= 0; opno
< ninputs
- ninout
; opno
++)
1924 if (reg_overlap_mentioned_p (clobbered_reg
,
1925 ASM_OPERANDS_INPUT (obody
, opno
)))
1926 internal_error ("asm clobber conflict with input operand");
1929 XVECEXP (body
, 0, i
++)
1930 = gen_rtx_CLOBBER (VOIDmode
, clobbered_reg
);
1936 /* For any outputs that needed reloading into registers, spill them
1937 back to where they belong. */
1938 for (i
= 0; i
< noutputs
; ++i
)
1939 if (real_output_rtx
[i
])
1940 emit_move_insn (real_output_rtx
[i
], output_rtx
[i
]);
1945 /* A subroutine of expand_asm_operands. Check that all operands have
1946 the same number of alternatives. Return true if so. */
1949 check_operand_nalternatives (outputs
, inputs
)
1950 tree outputs
, inputs
;
1952 if (outputs
|| inputs
)
1954 tree tmp
= TREE_PURPOSE (outputs
? outputs
: inputs
);
1956 = n_occurrences (',', TREE_STRING_POINTER (TREE_VALUE (tmp
)));
1959 if (nalternatives
+ 1 > MAX_RECOG_ALTERNATIVES
)
1961 error ("too many alternatives in `asm'");
1968 const char *constraint
1969 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tmp
)));
1971 if (n_occurrences (',', constraint
) != nalternatives
)
1973 error ("operand constraints for `asm' differ in number of alternatives");
1977 if (TREE_CHAIN (tmp
))
1978 tmp
= TREE_CHAIN (tmp
);
1980 tmp
= next
, next
= 0;
1987 /* A subroutine of expand_asm_operands. Check that all operand names
1988 are unique. Return true if so. We rely on the fact that these names
1989 are identifiers, and so have been canonicalized by get_identifier,
1990 so all we need are pointer comparisons. */
1993 check_unique_operand_names (outputs
, inputs
)
1994 tree outputs
, inputs
;
1998 for (i
= outputs
; i
; i
= TREE_CHAIN (i
))
2000 tree i_name
= TREE_PURPOSE (TREE_PURPOSE (i
));
2004 for (j
= TREE_CHAIN (i
); j
; j
= TREE_CHAIN (j
))
2005 if (simple_cst_equal (i_name
, TREE_PURPOSE (TREE_PURPOSE (j
))))
2009 for (i
= inputs
; i
; i
= TREE_CHAIN (i
))
2011 tree i_name
= TREE_PURPOSE (TREE_PURPOSE (i
));
2015 for (j
= TREE_CHAIN (i
); j
; j
= TREE_CHAIN (j
))
2016 if (simple_cst_equal (i_name
, TREE_PURPOSE (TREE_PURPOSE (j
))))
2018 for (j
= outputs
; j
; j
= TREE_CHAIN (j
))
2019 if (simple_cst_equal (i_name
, TREE_PURPOSE (TREE_PURPOSE (j
))))
2026 error ("duplicate asm operand name '%s'",
2027 TREE_STRING_POINTER (TREE_PURPOSE (TREE_PURPOSE (i
))));
2031 /* A subroutine of expand_asm_operands. Resolve the names of the operands
2032 in *POUTPUTS and *PINPUTS to numbers, and replace the name expansions in
2033 STRING and in the constraints to those numbers. */
2036 resolve_operand_names (string
, outputs
, inputs
, pconstraints
)
2038 tree outputs
, inputs
;
2039 const char **pconstraints
;
2041 char *buffer
= xstrdup (TREE_STRING_POINTER (string
));
2045 /* Assume that we will not need extra space to perform the substitution.
2046 This because we get to remove '[' and ']', which means we cannot have
2047 a problem until we have more than 999 operands. */
2050 while ((p
= strchr (p
, '%')) != NULL
)
2054 else if (ISALPHA (p
[1]) && p
[2] == '[')
2062 p
= resolve_operand_name_1 (p
, outputs
, inputs
);
2065 string
= build_string (strlen (buffer
), buffer
);
2068 /* Collect output constraints here because it's convenient.
2069 There should be no named operands here; this is verified
2070 in expand_asm_operand. */
2071 for (t
= outputs
; t
; t
= TREE_CHAIN (t
), pconstraints
++)
2072 *pconstraints
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t
)));
2074 /* Substitute [<name>] in input constraint strings. */
2075 for (t
= inputs
; t
; t
= TREE_CHAIN (t
), pconstraints
++)
2077 const char *c
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t
)));
2078 if (strchr (c
, '[') == NULL
)
2082 p
= buffer
= xstrdup (c
);
2083 while ((p
= strchr (p
, '[')) != NULL
)
2084 p
= resolve_operand_name_1 (p
, outputs
, inputs
);
2086 *pconstraints
= ggc_alloc_string (buffer
, -1);
2094 /* A subroutine of resolve_operand_names. P points to the '[' for a
2095 potential named operand of the form [<name>]. In place, replace
2096 the name and brackets with a number. Return a pointer to the
2097 balance of the string after substitution. */
2100 resolve_operand_name_1 (p
, outputs
, inputs
)
2102 tree outputs
, inputs
;
2109 /* Collect the operand name. */
2110 q
= strchr (p
, ']');
2113 error ("missing close brace for named operand");
2114 return strchr (p
, '\0');
2118 /* Resolve the name to a number. */
2119 for (op
= 0, t
= outputs
; t
; t
= TREE_CHAIN (t
), op
++)
2121 tree name
= TREE_PURPOSE (TREE_PURPOSE (t
));
2124 const char *c
= TREE_STRING_POINTER (name
);
2125 if (strncmp (c
, p
+ 1, len
) == 0 && c
[len
] == '\0')
2129 for (t
= inputs
; t
; t
= TREE_CHAIN (t
), op
++)
2131 tree name
= TREE_PURPOSE (TREE_PURPOSE (t
));
2134 const char *c
= TREE_STRING_POINTER (name
);
2135 if (strncmp (c
, p
+ 1, len
) == 0 && c
[len
] == '\0')
2141 error ("undefined named operand '%s'", p
+ 1);
2145 /* Replace the name with the number. Unfortunately, not all libraries
2146 get the return value of sprintf correct, so search for the end of the
2147 generated string by hand. */
2148 sprintf (p
, "%d", op
);
2149 p
= strchr (p
, '\0');
2151 /* Verify the no extra buffer space assumption. */
2155 /* Shift the rest of the buffer down to fill the gap. */
2156 memmove (p
, q
+ 1, strlen (q
+ 1) + 1);
2161 /* Generate RTL to evaluate the expression EXP
2162 and remember it in case this is the VALUE in a ({... VALUE; }) constr.
2163 Provided just for backward-compatibility. expand_expr_stmt_value()
2164 should be used for new code. */
2167 expand_expr_stmt (exp
)
2170 expand_expr_stmt_value (exp
, -1, 1);
2173 /* Generate RTL to evaluate the expression EXP. WANT_VALUE tells
2174 whether to (1) save the value of the expression, (0) discard it or
2175 (-1) use expr_stmts_for_value to tell. The use of -1 is
2176 deprecated, and retained only for backward compatibility. */
2179 expand_expr_stmt_value (exp
, want_value
, maybe_last
)
2181 int want_value
, maybe_last
;
2186 if (want_value
== -1)
2187 want_value
= expr_stmts_for_value
!= 0;
2189 /* If -Wextra, warn about statements with no side effects,
2190 except for an explicit cast to void (e.g. for assert()), and
2191 except for last statement in ({...}) where they may be useful. */
2193 && (expr_stmts_for_value
== 0 || ! maybe_last
)
2194 && exp
!= error_mark_node
)
2196 if (! TREE_SIDE_EFFECTS (exp
))
2198 if (warn_unused_value
2199 && !(TREE_CODE (exp
) == CONVERT_EXPR
2200 && VOID_TYPE_P (TREE_TYPE (exp
))))
2201 warning ("%Hstatement with no effect", &emit_locus
);
2203 else if (warn_unused_value
)
2204 warn_if_unused_value (exp
);
2207 /* If EXP is of function type and we are expanding statements for
2208 value, convert it to pointer-to-function. */
2209 if (want_value
&& TREE_CODE (TREE_TYPE (exp
)) == FUNCTION_TYPE
)
2210 exp
= build1 (ADDR_EXPR
, build_pointer_type (TREE_TYPE (exp
)), exp
);
2212 /* The call to `expand_expr' could cause last_expr_type and
2213 last_expr_value to get reset. Therefore, we set last_expr_value
2214 and last_expr_type *after* calling expand_expr. */
2215 value
= expand_expr (exp
, want_value
? NULL_RTX
: const0_rtx
,
2217 type
= TREE_TYPE (exp
);
2219 /* If all we do is reference a volatile value in memory,
2220 copy it to a register to be sure it is actually touched. */
2221 if (value
&& GET_CODE (value
) == MEM
&& TREE_THIS_VOLATILE (exp
))
2223 if (TYPE_MODE (type
) == VOIDmode
)
2225 else if (TYPE_MODE (type
) != BLKmode
)
2226 value
= copy_to_reg (value
);
2229 rtx lab
= gen_label_rtx ();
2231 /* Compare the value with itself to reference it. */
2232 emit_cmp_and_jump_insns (value
, value
, EQ
,
2233 expand_expr (TYPE_SIZE (type
),
2234 NULL_RTX
, VOIDmode
, 0),
2240 /* If this expression is part of a ({...}) and is in memory, we may have
2241 to preserve temporaries. */
2242 preserve_temp_slots (value
);
2244 /* Free any temporaries used to evaluate this expression. Any temporary
2245 used as a result of this expression will already have been preserved
2251 last_expr_value
= value
;
2252 last_expr_type
= type
;
2258 /* Warn if EXP contains any computations whose results are not used.
2259 Return 1 if a warning is printed; 0 otherwise. */
2262 warn_if_unused_value (exp
)
2265 if (TREE_USED (exp
))
2268 /* Don't warn about void constructs. This includes casting to void,
2269 void function calls, and statement expressions with a final cast
2271 if (VOID_TYPE_P (TREE_TYPE (exp
)))
2274 switch (TREE_CODE (exp
))
2276 case PREINCREMENT_EXPR
:
2277 case POSTINCREMENT_EXPR
:
2278 case PREDECREMENT_EXPR
:
2279 case POSTDECREMENT_EXPR
:
2284 case METHOD_CALL_EXPR
:
2286 case TRY_CATCH_EXPR
:
2287 case WITH_CLEANUP_EXPR
:
2292 /* For a binding, warn if no side effect within it. */
2293 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2296 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2298 case TRUTH_ORIF_EXPR
:
2299 case TRUTH_ANDIF_EXPR
:
2300 /* In && or ||, warn if 2nd operand has no side effect. */
2301 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2304 if (TREE_NO_UNUSED_WARNING (exp
))
2306 if (warn_if_unused_value (TREE_OPERAND (exp
, 0)))
2308 /* Let people do `(foo (), 0)' without a warning. */
2309 if (TREE_CONSTANT (TREE_OPERAND (exp
, 1)))
2311 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2315 case NON_LVALUE_EXPR
:
2316 /* Don't warn about conversions not explicit in the user's program. */
2317 if (TREE_NO_UNUSED_WARNING (exp
))
2319 /* Assignment to a cast usually results in a cast of a modify.
2320 Don't complain about that. There can be an arbitrary number of
2321 casts before the modify, so we must loop until we find the first
2322 non-cast expression and then test to see if that is a modify. */
2324 tree tem
= TREE_OPERAND (exp
, 0);
2326 while (TREE_CODE (tem
) == CONVERT_EXPR
|| TREE_CODE (tem
) == NOP_EXPR
)
2327 tem
= TREE_OPERAND (tem
, 0);
2329 if (TREE_CODE (tem
) == MODIFY_EXPR
|| TREE_CODE (tem
) == INIT_EXPR
2330 || TREE_CODE (tem
) == CALL_EXPR
)
2336 /* Don't warn about automatic dereferencing of references, since
2337 the user cannot control it. */
2338 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp
, 0))) == REFERENCE_TYPE
)
2339 return warn_if_unused_value (TREE_OPERAND (exp
, 0));
2343 /* Referencing a volatile value is a side effect, so don't warn. */
2345 || TREE_CODE_CLASS (TREE_CODE (exp
)) == 'r')
2346 && TREE_THIS_VOLATILE (exp
))
2349 /* If this is an expression which has no operands, there is no value
2350 to be unused. There are no such language-independent codes,
2351 but front ends may define such. */
2352 if (TREE_CODE_CLASS (TREE_CODE (exp
)) == 'e'
2353 && TREE_CODE_LENGTH (TREE_CODE (exp
)) == 0)
2357 /* If this is an expression with side effects, don't warn. */
2358 if (TREE_SIDE_EFFECTS (exp
))
2361 warning ("%Hvalue computed is not used", &emit_locus
);
2366 /* Clear out the memory of the last expression evaluated. */
2371 last_expr_type
= NULL_TREE
;
2372 last_expr_value
= NULL_RTX
;
2375 /* Begin a statement-expression, i.e., a series of statements which
2376 may return a value. Return the RTL_EXPR for this statement expr.
2377 The caller must save that value and pass it to
2378 expand_end_stmt_expr. If HAS_SCOPE is nonzero, temporaries created
2379 in the statement-expression are deallocated at the end of the
2383 expand_start_stmt_expr (has_scope
)
2388 /* Make the RTL_EXPR node temporary, not momentary,
2389 so that rtl_expr_chain doesn't become garbage. */
2390 t
= make_node (RTL_EXPR
);
2391 do_pending_stack_adjust ();
2393 start_sequence_for_rtl_expr (t
);
2397 expr_stmts_for_value
++;
2401 /* Restore the previous state at the end of a statement that returns a value.
2402 Returns a tree node representing the statement's value and the
2403 insns to compute the value.
2405 The nodes of that expression have been freed by now, so we cannot use them.
2406 But we don't want to do that anyway; the expression has already been
2407 evaluated and now we just want to use the value. So generate a RTL_EXPR
2408 with the proper type and RTL value.
2410 If the last substatement was not an expression,
2411 return something with type `void'. */
2414 expand_end_stmt_expr (t
)
2419 if (! last_expr_value
|| ! last_expr_type
)
2421 last_expr_value
= const0_rtx
;
2422 last_expr_type
= void_type_node
;
2424 else if (GET_CODE (last_expr_value
) != REG
&& ! CONSTANT_P (last_expr_value
))
2425 /* Remove any possible QUEUED. */
2426 last_expr_value
= protect_from_queue (last_expr_value
, 0);
2430 TREE_TYPE (t
) = last_expr_type
;
2431 RTL_EXPR_RTL (t
) = last_expr_value
;
2432 RTL_EXPR_SEQUENCE (t
) = get_insns ();
2434 rtl_expr_chain
= tree_cons (NULL_TREE
, t
, rtl_expr_chain
);
2438 /* Don't consider deleting this expr or containing exprs at tree level. */
2439 TREE_SIDE_EFFECTS (t
) = 1;
2440 /* Propagate volatility of the actual RTL expr. */
2441 TREE_THIS_VOLATILE (t
) = volatile_refs_p (last_expr_value
);
2444 expr_stmts_for_value
--;
2449 /* Generate RTL for the start of an if-then. COND is the expression
2450 whose truth should be tested.
2452 If EXITFLAG is nonzero, this conditional is visible to
2453 `exit_something'. */
2456 expand_start_cond (cond
, exitflag
)
2460 struct nesting
*thiscond
= ALLOC_NESTING ();
2462 /* Make an entry on cond_stack for the cond we are entering. */
2464 thiscond
->desc
= COND_NESTING
;
2465 thiscond
->next
= cond_stack
;
2466 thiscond
->all
= nesting_stack
;
2467 thiscond
->depth
= ++nesting_depth
;
2468 thiscond
->data
.cond
.next_label
= gen_label_rtx ();
2469 /* Before we encounter an `else', we don't need a separate exit label
2470 unless there are supposed to be exit statements
2471 to exit this conditional. */
2472 thiscond
->exit_label
= exitflag
? gen_label_rtx () : 0;
2473 thiscond
->data
.cond
.endif_label
= thiscond
->exit_label
;
2474 cond_stack
= thiscond
;
2475 nesting_stack
= thiscond
;
2477 do_jump (cond
, thiscond
->data
.cond
.next_label
, NULL_RTX
);
2480 /* Generate RTL between then-clause and the elseif-clause
2481 of an if-then-elseif-.... */
2484 expand_start_elseif (cond
)
2487 if (cond_stack
->data
.cond
.endif_label
== 0)
2488 cond_stack
->data
.cond
.endif_label
= gen_label_rtx ();
2489 emit_jump (cond_stack
->data
.cond
.endif_label
);
2490 emit_label (cond_stack
->data
.cond
.next_label
);
2491 cond_stack
->data
.cond
.next_label
= gen_label_rtx ();
2492 do_jump (cond
, cond_stack
->data
.cond
.next_label
, NULL_RTX
);
2495 /* Generate RTL between the then-clause and the else-clause
2496 of an if-then-else. */
2499 expand_start_else ()
2501 if (cond_stack
->data
.cond
.endif_label
== 0)
2502 cond_stack
->data
.cond
.endif_label
= gen_label_rtx ();
2504 emit_jump (cond_stack
->data
.cond
.endif_label
);
2505 emit_label (cond_stack
->data
.cond
.next_label
);
2506 cond_stack
->data
.cond
.next_label
= 0; /* No more _else or _elseif calls. */
2509 /* After calling expand_start_else, turn this "else" into an "else if"
2510 by providing another condition. */
2513 expand_elseif (cond
)
2516 cond_stack
->data
.cond
.next_label
= gen_label_rtx ();
2517 do_jump (cond
, cond_stack
->data
.cond
.next_label
, NULL_RTX
);
2520 /* Generate RTL for the end of an if-then.
2521 Pop the record for it off of cond_stack. */
2526 struct nesting
*thiscond
= cond_stack
;
2528 do_pending_stack_adjust ();
2529 if (thiscond
->data
.cond
.next_label
)
2530 emit_label (thiscond
->data
.cond
.next_label
);
2531 if (thiscond
->data
.cond
.endif_label
)
2532 emit_label (thiscond
->data
.cond
.endif_label
);
2534 POPSTACK (cond_stack
);
2538 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2539 loop should be exited by `exit_something'. This is a loop for which
2540 `expand_continue' will jump to the top of the loop.
2542 Make an entry on loop_stack to record the labels associated with
2546 expand_start_loop (exit_flag
)
2549 struct nesting
*thisloop
= ALLOC_NESTING ();
2551 /* Make an entry on loop_stack for the loop we are entering. */
2553 thisloop
->desc
= LOOP_NESTING
;
2554 thisloop
->next
= loop_stack
;
2555 thisloop
->all
= nesting_stack
;
2556 thisloop
->depth
= ++nesting_depth
;
2557 thisloop
->data
.loop
.start_label
= gen_label_rtx ();
2558 thisloop
->data
.loop
.end_label
= gen_label_rtx ();
2559 thisloop
->data
.loop
.continue_label
= thisloop
->data
.loop
.start_label
;
2560 thisloop
->exit_label
= exit_flag
? thisloop
->data
.loop
.end_label
: 0;
2561 loop_stack
= thisloop
;
2562 nesting_stack
= thisloop
;
2564 do_pending_stack_adjust ();
2566 emit_note (NULL
, NOTE_INSN_LOOP_BEG
);
2567 emit_label (thisloop
->data
.loop
.start_label
);
2572 /* Like expand_start_loop but for a loop where the continuation point
2573 (for expand_continue_loop) will be specified explicitly. */
2576 expand_start_loop_continue_elsewhere (exit_flag
)
2579 struct nesting
*thisloop
= expand_start_loop (exit_flag
);
2580 loop_stack
->data
.loop
.continue_label
= gen_label_rtx ();
2584 /* Begin a null, aka do { } while (0) "loop". But since the contents
2585 of said loop can still contain a break, we must frob the loop nest. */
2588 expand_start_null_loop ()
2590 struct nesting
*thisloop
= ALLOC_NESTING ();
2592 /* Make an entry on loop_stack for the loop we are entering. */
2594 thisloop
->desc
= LOOP_NESTING
;
2595 thisloop
->next
= loop_stack
;
2596 thisloop
->all
= nesting_stack
;
2597 thisloop
->depth
= ++nesting_depth
;
2598 thisloop
->data
.loop
.start_label
= emit_note (NULL
, NOTE_INSN_DELETED
);
2599 thisloop
->data
.loop
.end_label
= gen_label_rtx ();
2600 thisloop
->data
.loop
.continue_label
= thisloop
->data
.loop
.end_label
;
2601 thisloop
->exit_label
= thisloop
->data
.loop
.end_label
;
2602 loop_stack
= thisloop
;
2603 nesting_stack
= thisloop
;
2608 /* Specify the continuation point for a loop started with
2609 expand_start_loop_continue_elsewhere.
2610 Use this at the point in the code to which a continue statement
2614 expand_loop_continue_here ()
2616 do_pending_stack_adjust ();
2617 emit_note (NULL
, NOTE_INSN_LOOP_CONT
);
2618 emit_label (loop_stack
->data
.loop
.continue_label
);
2621 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2622 Pop the block off of loop_stack. */
2627 rtx start_label
= loop_stack
->data
.loop
.start_label
;
2629 int eh_regions
, debug_blocks
;
2632 /* Mark the continue-point at the top of the loop if none elsewhere. */
2633 if (start_label
== loop_stack
->data
.loop
.continue_label
)
2634 emit_note_before (NOTE_INSN_LOOP_CONT
, start_label
);
2636 do_pending_stack_adjust ();
2638 /* If the loop starts with a loop exit, roll that to the end where
2639 it will optimize together with the jump back.
2641 If the loop presently looks like this (in pseudo-C):
2645 if (test) goto end_label;
2651 transform it to look like:
2658 if (test) goto end_label;
2662 We rely on the presence of NOTE_INSN_LOOP_END_TOP_COND to mark
2663 the end of the entry conditional. Without this, our lexical scan
2664 can't tell the difference between an entry conditional and a
2665 body conditional that exits the loop. Mistaking the two means
2666 that we can misplace the NOTE_INSN_LOOP_CONT note, which can
2667 screw up loop unrolling.
2669 Things will be oh so much better when loop optimization is done
2670 off of a proper control flow graph... */
2672 /* Scan insns from the top of the loop looking for the END_TOP_COND note. */
2675 eh_regions
= debug_blocks
= 0;
2676 for (etc_note
= start_label
; etc_note
; etc_note
= NEXT_INSN (etc_note
))
2677 if (GET_CODE (etc_note
) == NOTE
)
2679 if (NOTE_LINE_NUMBER (etc_note
) == NOTE_INSN_LOOP_END_TOP_COND
)
2682 /* We must not walk into a nested loop. */
2683 else if (NOTE_LINE_NUMBER (etc_note
) == NOTE_INSN_LOOP_BEG
)
2685 etc_note
= NULL_RTX
;
2689 /* At the same time, scan for EH region notes, as we don't want
2690 to scrog region nesting. This shouldn't happen, but... */
2691 else if (NOTE_LINE_NUMBER (etc_note
) == NOTE_INSN_EH_REGION_BEG
)
2693 else if (NOTE_LINE_NUMBER (etc_note
) == NOTE_INSN_EH_REGION_END
)
2695 if (--eh_regions
< 0)
2696 /* We've come to the end of an EH region, but never saw the
2697 beginning of that region. That means that an EH region
2698 begins before the top of the loop, and ends in the middle
2699 of it. The existence of such a situation violates a basic
2700 assumption in this code, since that would imply that even
2701 when EH_REGIONS is zero, we might move code out of an
2702 exception region. */
2706 /* Likewise for debug scopes. In this case we'll either (1) move
2707 all of the notes if they are properly nested or (2) leave the
2708 notes alone and only rotate the loop at high optimization
2709 levels when we expect to scrog debug info. */
2710 else if (NOTE_LINE_NUMBER (etc_note
) == NOTE_INSN_BLOCK_BEG
)
2712 else if (NOTE_LINE_NUMBER (etc_note
) == NOTE_INSN_BLOCK_END
)
2715 else if (INSN_P (etc_note
))
2722 && (debug_blocks
== 0 || optimize
>= 2)
2723 && NEXT_INSN (etc_note
) != NULL_RTX
2724 && ! any_condjump_p (get_last_insn ()))
2726 /* We found one. Move everything from START to ETC to the end
2727 of the loop, and add a jump from the top of the loop. */
2728 rtx top_label
= gen_label_rtx ();
2729 rtx start_move
= start_label
;
2731 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2732 then we want to move this note also. */
2733 if (GET_CODE (PREV_INSN (start_move
)) == NOTE
2734 && NOTE_LINE_NUMBER (PREV_INSN (start_move
)) == NOTE_INSN_LOOP_CONT
)
2735 start_move
= PREV_INSN (start_move
);
2737 emit_label_before (top_label
, start_move
);
2739 /* Actually move the insns. If the debug scopes are nested, we
2740 can move everything at once. Otherwise we have to move them
2741 one by one and squeeze out the block notes. */
2742 if (debug_blocks
== 0)
2743 reorder_insns (start_move
, etc_note
, get_last_insn ());
2746 rtx insn
, next_insn
;
2747 for (insn
= start_move
; insn
; insn
= next_insn
)
2749 /* Figure out which insn comes after this one. We have
2750 to do this before we move INSN. */
2751 next_insn
= (insn
== etc_note
? NULL
: NEXT_INSN (insn
));
2753 if (GET_CODE (insn
) == NOTE
2754 && (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_BEG
2755 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_END
))
2758 reorder_insns (insn
, insn
, get_last_insn ());
2762 /* Add the jump from the top of the loop. */
2763 emit_jump_insn_before (gen_jump (start_label
), top_label
);
2764 emit_barrier_before (top_label
);
2765 start_label
= top_label
;
2768 emit_jump (start_label
);
2769 emit_note (NULL
, NOTE_INSN_LOOP_END
);
2770 emit_label (loop_stack
->data
.loop
.end_label
);
2772 POPSTACK (loop_stack
);
2777 /* Finish a null loop, aka do { } while (0). */
2780 expand_end_null_loop ()
2782 do_pending_stack_adjust ();
2783 emit_label (loop_stack
->data
.loop
.end_label
);
2785 POPSTACK (loop_stack
);
2790 /* Generate a jump to the current loop's continue-point.
2791 This is usually the top of the loop, but may be specified
2792 explicitly elsewhere. If not currently inside a loop,
2793 return 0 and do nothing; caller will print an error message. */
2796 expand_continue_loop (whichloop
)
2797 struct nesting
*whichloop
;
2799 /* Emit information for branch prediction. */
2802 if (flag_guess_branch_prob
)
2804 note
= emit_note (NULL
, NOTE_INSN_PREDICTION
);
2805 NOTE_PREDICTION (note
) = NOTE_PREDICT (PRED_CONTINUE
, IS_TAKEN
);
2809 whichloop
= loop_stack
;
2812 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.continue_label
,
2817 /* Generate a jump to exit the current loop. If not currently inside a loop,
2818 return 0 and do nothing; caller will print an error message. */
2821 expand_exit_loop (whichloop
)
2822 struct nesting
*whichloop
;
2826 whichloop
= loop_stack
;
2829 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.end_label
, NULL_RTX
);
2833 /* Generate a conditional jump to exit the current loop if COND
2834 evaluates to zero. If not currently inside a loop,
2835 return 0 and do nothing; caller will print an error message. */
2838 expand_exit_loop_if_false (whichloop
, cond
)
2839 struct nesting
*whichloop
;
2846 whichloop
= loop_stack
;
2850 if (integer_nonzerop (cond
))
2852 if (integer_zerop (cond
))
2853 return expand_exit_loop (whichloop
);
2855 /* Check if we definitely won't need a fixup. */
2856 if (whichloop
== nesting_stack
)
2858 jumpifnot (cond
, whichloop
->data
.loop
.end_label
);
2862 /* In order to handle fixups, we actually create a conditional jump
2863 around an unconditional branch to exit the loop. If fixups are
2864 necessary, they go before the unconditional branch. */
2866 label
= gen_label_rtx ();
2867 jumpif (cond
, label
);
2868 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.end_label
,
2875 /* Like expand_exit_loop_if_false except also emit a note marking
2876 the end of the conditional. Should only be used immediately
2877 after expand_loop_start. */
2880 expand_exit_loop_top_cond (whichloop
, cond
)
2881 struct nesting
*whichloop
;
2884 if (! expand_exit_loop_if_false (whichloop
, cond
))
2887 emit_note (NULL
, NOTE_INSN_LOOP_END_TOP_COND
);
2891 /* Return nonzero if we should preserve sub-expressions as separate
2892 pseudos. We never do so if we aren't optimizing. We always do so
2893 if -fexpensive-optimizations.
2895 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2896 the loop may still be a small one. */
2899 preserve_subexpressions_p ()
2903 if (flag_expensive_optimizations
)
2906 if (optimize
== 0 || cfun
== 0 || cfun
->stmt
== 0 || loop_stack
== 0)
2909 insn
= get_last_insn_anywhere ();
2912 && (INSN_UID (insn
) - INSN_UID (loop_stack
->data
.loop
.start_label
)
2913 < n_non_fixed_regs
* 3));
2917 /* Generate a jump to exit the current loop, conditional, binding contour
2918 or case statement. Not all such constructs are visible to this function,
2919 only those started with EXIT_FLAG nonzero. Individual languages use
2920 the EXIT_FLAG parameter to control which kinds of constructs you can
2923 If not currently inside anything that can be exited,
2924 return 0 and do nothing; caller will print an error message. */
2927 expand_exit_something ()
2931 for (n
= nesting_stack
; n
; n
= n
->all
)
2932 if (n
->exit_label
!= 0)
2934 expand_goto_internal (NULL_TREE
, n
->exit_label
, NULL_RTX
);
2941 /* Generate RTL to return from the current function, with no value.
2942 (That is, we do not do anything about returning any value.) */
2945 expand_null_return ()
2949 last_insn
= get_last_insn ();
2951 /* If this function was declared to return a value, but we
2952 didn't, clobber the return registers so that they are not
2953 propagated live to the rest of the function. */
2954 clobber_return_register ();
2956 expand_null_return_1 (last_insn
);
2959 /* Try to guess whether the value of return means error code. */
2960 static enum br_predictor
2961 return_prediction (val
)
2964 /* Different heuristics for pointers and scalars. */
2965 if (POINTER_TYPE_P (TREE_TYPE (DECL_RESULT (current_function_decl
))))
2967 /* NULL is usually not returned. */
2968 if (val
== const0_rtx
)
2969 return PRED_NULL_RETURN
;
2973 /* Negative return values are often used to indicate
2975 if (GET_CODE (val
) == CONST_INT
2976 && INTVAL (val
) < 0)
2977 return PRED_NEGATIVE_RETURN
;
2978 /* Constant return values are also usually erors,
2979 zero/one often mean booleans so exclude them from the
2981 if (CONSTANT_P (val
)
2982 && (val
!= const0_rtx
&& val
!= const1_rtx
))
2983 return PRED_CONST_RETURN
;
2985 return PRED_NO_PREDICTION
;
2988 /* Generate RTL to return from the current function, with value VAL. */
2991 expand_value_return (val
)
2996 enum br_predictor pred
;
2998 if (flag_guess_branch_prob
2999 && (pred
= return_prediction (val
)) != PRED_NO_PREDICTION
)
3001 /* Emit information for branch prediction. */
3004 note
= emit_note (NULL
, NOTE_INSN_PREDICTION
);
3006 NOTE_PREDICTION (note
) = NOTE_PREDICT (pred
, NOT_TAKEN
);
3010 last_insn
= get_last_insn ();
3011 return_reg
= DECL_RTL (DECL_RESULT (current_function_decl
));
3013 /* Copy the value to the return location
3014 unless it's already there. */
3016 if (return_reg
!= val
)
3018 tree type
= TREE_TYPE (DECL_RESULT (current_function_decl
));
3019 #ifdef PROMOTE_FUNCTION_RETURN
3020 int unsignedp
= TREE_UNSIGNED (type
);
3021 enum machine_mode old_mode
3022 = DECL_MODE (DECL_RESULT (current_function_decl
));
3023 enum machine_mode mode
3024 = promote_mode (type
, old_mode
, &unsignedp
, 1);
3026 if (mode
!= old_mode
)
3027 val
= convert_modes (mode
, old_mode
, val
, unsignedp
);
3029 if (GET_CODE (return_reg
) == PARALLEL
)
3030 emit_group_load (return_reg
, val
, int_size_in_bytes (type
));
3032 emit_move_insn (return_reg
, val
);
3035 expand_null_return_1 (last_insn
);
3038 /* Output a return with no value. If LAST_INSN is nonzero,
3039 pretend that the return takes place after LAST_INSN. */
3042 expand_null_return_1 (last_insn
)
3045 rtx end_label
= cleanup_label
? cleanup_label
: return_label
;
3047 clear_pending_stack_adjust ();
3048 do_pending_stack_adjust ();
3052 end_label
= return_label
= gen_label_rtx ();
3053 expand_goto_internal (NULL_TREE
, end_label
, last_insn
);
3056 /* Generate RTL to evaluate the expression RETVAL and return it
3057 from the current function. */
3060 expand_return (retval
)
3063 /* If there are any cleanups to be performed, then they will
3064 be inserted following LAST_INSN. It is desirable
3065 that the last_insn, for such purposes, should be the
3066 last insn before computing the return value. Otherwise, cleanups
3067 which call functions can clobber the return value. */
3068 /* ??? rms: I think that is erroneous, because in C++ it would
3069 run destructors on variables that might be used in the subsequent
3070 computation of the return value. */
3076 /* If function wants no value, give it none. */
3077 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl
))) == VOID_TYPE
)
3079 expand_expr (retval
, NULL_RTX
, VOIDmode
, 0);
3081 expand_null_return ();
3085 if (retval
== error_mark_node
)
3087 /* Treat this like a return of no value from a function that
3089 expand_null_return ();
3092 else if (TREE_CODE (retval
) == RESULT_DECL
)
3093 retval_rhs
= retval
;
3094 else if ((TREE_CODE (retval
) == MODIFY_EXPR
|| TREE_CODE (retval
) == INIT_EXPR
)
3095 && TREE_CODE (TREE_OPERAND (retval
, 0)) == RESULT_DECL
)
3096 retval_rhs
= TREE_OPERAND (retval
, 1);
3097 else if (VOID_TYPE_P (TREE_TYPE (retval
)))
3098 /* Recognize tail-recursive call to void function. */
3099 retval_rhs
= retval
;
3101 retval_rhs
= NULL_TREE
;
3103 last_insn
= get_last_insn ();
3105 /* Distribute return down conditional expr if either of the sides
3106 may involve tail recursion (see test below). This enhances the number
3107 of tail recursions we see. Don't do this always since it can produce
3108 sub-optimal code in some cases and we distribute assignments into
3109 conditional expressions when it would help. */
3111 if (optimize
&& retval_rhs
!= 0
3112 && frame_offset
== 0
3113 && TREE_CODE (retval_rhs
) == COND_EXPR
3114 && (TREE_CODE (TREE_OPERAND (retval_rhs
, 1)) == CALL_EXPR
3115 || TREE_CODE (TREE_OPERAND (retval_rhs
, 2)) == CALL_EXPR
))
3117 rtx label
= gen_label_rtx ();
3120 do_jump (TREE_OPERAND (retval_rhs
, 0), label
, NULL_RTX
);
3121 start_cleanup_deferral ();
3122 expr
= build (MODIFY_EXPR
, TREE_TYPE (TREE_TYPE (current_function_decl
)),
3123 DECL_RESULT (current_function_decl
),
3124 TREE_OPERAND (retval_rhs
, 1));
3125 TREE_SIDE_EFFECTS (expr
) = 1;
3126 expand_return (expr
);
3129 expr
= build (MODIFY_EXPR
, TREE_TYPE (TREE_TYPE (current_function_decl
)),
3130 DECL_RESULT (current_function_decl
),
3131 TREE_OPERAND (retval_rhs
, 2));
3132 TREE_SIDE_EFFECTS (expr
) = 1;
3133 expand_return (expr
);
3134 end_cleanup_deferral ();
3138 result_rtl
= DECL_RTL (DECL_RESULT (current_function_decl
));
3140 /* If the result is an aggregate that is being returned in one (or more)
3141 registers, load the registers here. The compiler currently can't handle
3142 copying a BLKmode value into registers. We could put this code in a
3143 more general area (for use by everyone instead of just function
3144 call/return), but until this feature is generally usable it is kept here
3145 (and in expand_call). The value must go into a pseudo in case there
3146 are cleanups that will clobber the real return register. */
3149 && TYPE_MODE (TREE_TYPE (retval_rhs
)) == BLKmode
3150 && GET_CODE (result_rtl
) == REG
)
3153 unsigned HOST_WIDE_INT bitpos
, xbitpos
;
3154 unsigned HOST_WIDE_INT big_endian_correction
= 0;
3155 unsigned HOST_WIDE_INT bytes
3156 = int_size_in_bytes (TREE_TYPE (retval_rhs
));
3157 int n_regs
= (bytes
+ UNITS_PER_WORD
- 1) / UNITS_PER_WORD
;
3158 unsigned int bitsize
3159 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs
)), BITS_PER_WORD
);
3160 rtx
*result_pseudos
= (rtx
*) alloca (sizeof (rtx
) * n_regs
);
3161 rtx result_reg
, src
= NULL_RTX
, dst
= NULL_RTX
;
3162 rtx result_val
= expand_expr (retval_rhs
, NULL_RTX
, VOIDmode
, 0);
3163 enum machine_mode tmpmode
, result_reg_mode
;
3167 expand_null_return ();
3171 /* Structures whose size is not a multiple of a word are aligned
3172 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
3173 machine, this means we must skip the empty high order bytes when
3174 calculating the bit offset. */
3175 if (BYTES_BIG_ENDIAN
3176 && bytes
% UNITS_PER_WORD
)
3177 big_endian_correction
= (BITS_PER_WORD
- ((bytes
% UNITS_PER_WORD
)
3180 /* Copy the structure BITSIZE bits at a time. */
3181 for (bitpos
= 0, xbitpos
= big_endian_correction
;
3182 bitpos
< bytes
* BITS_PER_UNIT
;
3183 bitpos
+= bitsize
, xbitpos
+= bitsize
)
3185 /* We need a new destination pseudo each time xbitpos is
3186 on a word boundary and when xbitpos == big_endian_correction
3187 (the first time through). */
3188 if (xbitpos
% BITS_PER_WORD
== 0
3189 || xbitpos
== big_endian_correction
)
3191 /* Generate an appropriate register. */
3192 dst
= gen_reg_rtx (word_mode
);
3193 result_pseudos
[xbitpos
/ BITS_PER_WORD
] = dst
;
3195 /* Clear the destination before we move anything into it. */
3196 emit_move_insn (dst
, CONST0_RTX (GET_MODE (dst
)));
3199 /* We need a new source operand each time bitpos is on a word
3201 if (bitpos
% BITS_PER_WORD
== 0)
3202 src
= operand_subword_force (result_val
,
3203 bitpos
/ BITS_PER_WORD
,
3206 /* Use bitpos for the source extraction (left justified) and
3207 xbitpos for the destination store (right justified). */
3208 store_bit_field (dst
, bitsize
, xbitpos
% BITS_PER_WORD
, word_mode
,
3209 extract_bit_field (src
, bitsize
,
3210 bitpos
% BITS_PER_WORD
, 1,
3211 NULL_RTX
, word_mode
, word_mode
,
3216 /* Find the smallest integer mode large enough to hold the
3217 entire structure and use that mode instead of BLKmode
3218 on the USE insn for the return register. */
3219 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
3220 tmpmode
!= VOIDmode
;
3221 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
3222 /* Have we found a large enough mode? */
3223 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
3226 /* No suitable mode found. */
3227 if (tmpmode
== VOIDmode
)
3230 PUT_MODE (result_rtl
, tmpmode
);
3232 if (GET_MODE_SIZE (tmpmode
) < GET_MODE_SIZE (word_mode
))
3233 result_reg_mode
= word_mode
;
3235 result_reg_mode
= tmpmode
;
3236 result_reg
= gen_reg_rtx (result_reg_mode
);
3239 for (i
= 0; i
< n_regs
; i
++)
3240 emit_move_insn (operand_subword (result_reg
, i
, 0, result_reg_mode
),
3243 if (tmpmode
!= result_reg_mode
)
3244 result_reg
= gen_lowpart (tmpmode
, result_reg
);
3246 expand_value_return (result_reg
);
3248 else if (retval_rhs
!= 0
3249 && !VOID_TYPE_P (TREE_TYPE (retval_rhs
))
3250 && (GET_CODE (result_rtl
) == REG
3251 || (GET_CODE (result_rtl
) == PARALLEL
)))
3253 /* Calculate the return value into a temporary (usually a pseudo
3255 tree ot
= TREE_TYPE (DECL_RESULT (current_function_decl
));
3256 tree nt
= build_qualified_type (ot
, TYPE_QUALS (ot
) | TYPE_QUAL_CONST
);
3258 val
= assign_temp (nt
, 0, 0, 1);
3259 val
= expand_expr (retval_rhs
, val
, GET_MODE (val
), 0);
3260 val
= force_not_mem (val
);
3262 /* Return the calculated value, doing cleanups first. */
3263 expand_value_return (val
);
3267 /* No cleanups or no hard reg used;
3268 calculate value into hard return reg. */
3269 expand_expr (retval
, const0_rtx
, VOIDmode
, 0);
3271 expand_value_return (result_rtl
);
3275 /* Attempt to optimize a potential tail recursion call into a goto.
3276 ARGUMENTS are the arguments to a CALL_EXPR; LAST_INSN indicates
3277 where to place the jump to the tail recursion label.
3279 Return TRUE if the call was optimized into a goto. */
3282 optimize_tail_recursion (arguments
, last_insn
)
3286 /* Finish checking validity, and if valid emit code to set the
3287 argument variables for the new call. */
3288 if (tail_recursion_args (arguments
, DECL_ARGUMENTS (current_function_decl
)))
3290 if (tail_recursion_label
== 0)
3292 tail_recursion_label
= gen_label_rtx ();
3293 emit_label_after (tail_recursion_label
,
3294 tail_recursion_reentry
);
3297 expand_goto_internal (NULL_TREE
, tail_recursion_label
, last_insn
);
3304 /* Emit code to alter this function's formal parms for a tail-recursive call.
3305 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3306 FORMALS is the chain of decls of formals.
3307 Return 1 if this can be done;
3308 otherwise return 0 and do not emit any code. */
3311 tail_recursion_args (actuals
, formals
)
3312 tree actuals
, formals
;
3314 tree a
= actuals
, f
= formals
;
3318 /* Check that number and types of actuals are compatible
3319 with the formals. This is not always true in valid C code.
3320 Also check that no formal needs to be addressable
3321 and that all formals are scalars. */
3323 /* Also count the args. */
3325 for (a
= actuals
, f
= formals
, i
= 0; a
&& f
; a
= TREE_CHAIN (a
), f
= TREE_CHAIN (f
), i
++)
3327 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a
)))
3328 != TYPE_MAIN_VARIANT (TREE_TYPE (f
)))
3330 if (GET_CODE (DECL_RTL (f
)) != REG
|| DECL_MODE (f
) == BLKmode
)
3333 if (a
!= 0 || f
!= 0)
3336 /* Compute all the actuals. */
3338 argvec
= (rtx
*) alloca (i
* sizeof (rtx
));
3340 for (a
= actuals
, i
= 0; a
; a
= TREE_CHAIN (a
), i
++)
3341 argvec
[i
] = expand_expr (TREE_VALUE (a
), NULL_RTX
, VOIDmode
, 0);
3343 /* Find which actual values refer to current values of previous formals.
3344 Copy each of them now, before any formal is changed. */
3346 for (a
= actuals
, i
= 0; a
; a
= TREE_CHAIN (a
), i
++)
3350 for (f
= formals
, j
= 0; j
< i
; f
= TREE_CHAIN (f
), j
++)
3351 if (reg_mentioned_p (DECL_RTL (f
), argvec
[i
]))
3357 argvec
[i
] = copy_to_reg (argvec
[i
]);
3360 /* Store the values of the actuals into the formals. */
3362 for (f
= formals
, a
= actuals
, i
= 0; f
;
3363 f
= TREE_CHAIN (f
), a
= TREE_CHAIN (a
), i
++)
3365 if (GET_MODE (DECL_RTL (f
)) == GET_MODE (argvec
[i
]))
3366 emit_move_insn (DECL_RTL (f
), argvec
[i
]);
3369 rtx tmp
= argvec
[i
];
3370 int unsignedp
= TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a
)));
3371 promote_mode(TREE_TYPE (TREE_VALUE (a
)), GET_MODE (tmp
),
3373 if (DECL_MODE (f
) != GET_MODE (DECL_RTL (f
)))
3375 tmp
= gen_reg_rtx (DECL_MODE (f
));
3376 convert_move (tmp
, argvec
[i
], unsignedp
);
3378 convert_move (DECL_RTL (f
), tmp
, unsignedp
);
3386 /* Generate the RTL code for entering a binding contour.
3387 The variables are declared one by one, by calls to `expand_decl'.
3389 FLAGS is a bitwise or of the following flags:
3391 1 - Nonzero if this construct should be visible to
3394 2 - Nonzero if this contour does not require a
3395 NOTE_INSN_BLOCK_BEG note. Virtually all calls from
3396 language-independent code should set this flag because they
3397 will not create corresponding BLOCK nodes. (There should be
3398 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
3399 and BLOCKs.) If this flag is set, MARK_ENDS should be zero
3400 when expand_end_bindings is called.
3402 If we are creating a NOTE_INSN_BLOCK_BEG note, a BLOCK may
3403 optionally be supplied. If so, it becomes the NOTE_BLOCK for the
3407 expand_start_bindings_and_block (flags
, block
)
3411 struct nesting
*thisblock
= ALLOC_NESTING ();
3413 int exit_flag
= ((flags
& 1) != 0);
3414 int block_flag
= ((flags
& 2) == 0);
3416 /* If a BLOCK is supplied, then the caller should be requesting a
3417 NOTE_INSN_BLOCK_BEG note. */
3418 if (!block_flag
&& block
)
3421 /* Create a note to mark the beginning of the block. */
3424 note
= emit_note (NULL
, NOTE_INSN_BLOCK_BEG
);
3425 NOTE_BLOCK (note
) = block
;
3428 note
= emit_note (NULL
, NOTE_INSN_DELETED
);
3430 /* Make an entry on block_stack for the block we are entering. */
3432 thisblock
->desc
= BLOCK_NESTING
;
3433 thisblock
->next
= block_stack
;
3434 thisblock
->all
= nesting_stack
;
3435 thisblock
->depth
= ++nesting_depth
;
3436 thisblock
->data
.block
.stack_level
= 0;
3437 thisblock
->data
.block
.cleanups
= 0;
3438 thisblock
->data
.block
.exception_region
= 0;
3439 thisblock
->data
.block
.block_target_temp_slot_level
= target_temp_slot_level
;
3441 thisblock
->data
.block
.conditional_code
= 0;
3442 thisblock
->data
.block
.last_unconditional_cleanup
= note
;
3443 /* When we insert instructions after the last unconditional cleanup,
3444 we don't adjust last_insn. That means that a later add_insn will
3445 clobber the instructions we've just added. The easiest way to
3446 fix this is to just insert another instruction here, so that the
3447 instructions inserted after the last unconditional cleanup are
3448 never the last instruction. */
3449 emit_note (NULL
, NOTE_INSN_DELETED
);
3452 && !(block_stack
->data
.block
.cleanups
== NULL_TREE
3453 && block_stack
->data
.block
.outer_cleanups
== NULL_TREE
))
3454 thisblock
->data
.block
.outer_cleanups
3455 = tree_cons (NULL_TREE
, block_stack
->data
.block
.cleanups
,
3456 block_stack
->data
.block
.outer_cleanups
);
3458 thisblock
->data
.block
.outer_cleanups
= 0;
3459 thisblock
->data
.block
.label_chain
= 0;
3460 thisblock
->data
.block
.innermost_stack_block
= stack_block_stack
;
3461 thisblock
->data
.block
.first_insn
= note
;
3462 thisblock
->data
.block
.block_start_count
= ++current_block_start_count
;
3463 thisblock
->exit_label
= exit_flag
? gen_label_rtx () : 0;
3464 block_stack
= thisblock
;
3465 nesting_stack
= thisblock
;
3467 /* Make a new level for allocating stack slots. */
3471 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3472 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3473 expand_expr are made. After we end the region, we know that all
3474 space for all temporaries that were created by TARGET_EXPRs will be
3475 destroyed and their space freed for reuse. */
3478 expand_start_target_temps ()
3480 /* This is so that even if the result is preserved, the space
3481 allocated will be freed, as we know that it is no longer in use. */
3484 /* Start a new binding layer that will keep track of all cleanup
3485 actions to be performed. */
3486 expand_start_bindings (2);
3488 target_temp_slot_level
= temp_slot_level
;
3492 expand_end_target_temps ()
3494 expand_end_bindings (NULL_TREE
, 0, 0);
3496 /* This is so that even if the result is preserved, the space
3497 allocated will be freed, as we know that it is no longer in use. */
3501 /* Given a pointer to a BLOCK node return nonzero if (and only if) the node
3502 in question represents the outermost pair of curly braces (i.e. the "body
3503 block") of a function or method.
3505 For any BLOCK node representing a "body block" of a function or method, the
3506 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
3507 represents the outermost (function) scope for the function or method (i.e.
3508 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
3509 *that* node in turn will point to the relevant FUNCTION_DECL node. */
3512 is_body_block (stmt
)
3515 if (TREE_CODE (stmt
) == BLOCK
)
3517 tree parent
= BLOCK_SUPERCONTEXT (stmt
);
3519 if (parent
&& TREE_CODE (parent
) == BLOCK
)
3521 tree grandparent
= BLOCK_SUPERCONTEXT (parent
);
3523 if (grandparent
&& TREE_CODE (grandparent
) == FUNCTION_DECL
)
3531 /* True if we are currently emitting insns in an area of output code
3532 that is controlled by a conditional expression. This is used by
3533 the cleanup handling code to generate conditional cleanup actions. */
3536 conditional_context ()
3538 return block_stack
&& block_stack
->data
.block
.conditional_code
;
3541 /* Return an opaque pointer to the current nesting level, so frontend code
3542 can check its own sanity. */
3545 current_nesting_level ()
3547 return cfun
? block_stack
: 0;
3550 /* Emit a handler label for a nonlocal goto handler.
3551 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3554 expand_nl_handler_label (slot
, before_insn
)
3555 rtx slot
, before_insn
;
3558 rtx handler_label
= gen_label_rtx ();
3560 /* Don't let cleanup_cfg delete the handler. */
3561 LABEL_PRESERVE_P (handler_label
) = 1;
3564 emit_move_insn (slot
, gen_rtx_LABEL_REF (Pmode
, handler_label
));
3565 insns
= get_insns ();
3567 emit_insn_before (insns
, before_insn
);
3569 emit_label (handler_label
);
3571 return handler_label
;
3574 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3577 expand_nl_goto_receiver ()
3579 #ifdef HAVE_nonlocal_goto
3580 if (! HAVE_nonlocal_goto
)
3582 /* First adjust our frame pointer to its actual value. It was
3583 previously set to the start of the virtual area corresponding to
3584 the stacked variables when we branched here and now needs to be
3585 adjusted to the actual hardware fp value.
3587 Assignments are to virtual registers are converted by
3588 instantiate_virtual_regs into the corresponding assignment
3589 to the underlying register (fp in this case) that makes
3590 the original assignment true.
3591 So the following insn will actually be
3592 decrementing fp by STARTING_FRAME_OFFSET. */
3593 emit_move_insn (virtual_stack_vars_rtx
, hard_frame_pointer_rtx
);
3595 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3596 if (fixed_regs
[ARG_POINTER_REGNUM
])
3598 #ifdef ELIMINABLE_REGS
3599 /* If the argument pointer can be eliminated in favor of the
3600 frame pointer, we don't need to restore it. We assume here
3601 that if such an elimination is present, it can always be used.
3602 This is the case on all known machines; if we don't make this
3603 assumption, we do unnecessary saving on many machines. */
3604 static const struct elims
{const int from
, to
;} elim_regs
[] = ELIMINABLE_REGS
;
3607 for (i
= 0; i
< ARRAY_SIZE (elim_regs
); i
++)
3608 if (elim_regs
[i
].from
== ARG_POINTER_REGNUM
3609 && elim_regs
[i
].to
== HARD_FRAME_POINTER_REGNUM
)
3612 if (i
== ARRAY_SIZE (elim_regs
))
3615 /* Now restore our arg pointer from the address at which it
3616 was saved in our stack frame. */
3617 emit_move_insn (virtual_incoming_args_rtx
,
3618 copy_to_reg (get_arg_pointer_save_area (cfun
)));
3623 #ifdef HAVE_nonlocal_goto_receiver
3624 if (HAVE_nonlocal_goto_receiver
)
3625 emit_insn (gen_nonlocal_goto_receiver ());
3629 /* Make handlers for nonlocal gotos taking place in the function calls in
3633 expand_nl_goto_receivers (thisblock
)
3634 struct nesting
*thisblock
;
3637 rtx afterward
= gen_label_rtx ();
3642 /* Record the handler address in the stack slot for that purpose,
3643 during this block, saving and restoring the outer value. */
3644 if (thisblock
->next
!= 0)
3645 for (slot
= nonlocal_goto_handler_slots
; slot
; slot
= XEXP (slot
, 1))
3647 rtx save_receiver
= gen_reg_rtx (Pmode
);
3648 emit_move_insn (XEXP (slot
, 0), save_receiver
);
3651 emit_move_insn (save_receiver
, XEXP (slot
, 0));
3652 insns
= get_insns ();
3654 emit_insn_before (insns
, thisblock
->data
.block
.first_insn
);
3657 /* Jump around the handlers; they run only when specially invoked. */
3658 emit_jump (afterward
);
3660 /* Make a separate handler for each label. */
3661 link
= nonlocal_labels
;
3662 slot
= nonlocal_goto_handler_slots
;
3663 label_list
= NULL_RTX
;
3664 for (; link
; link
= TREE_CHAIN (link
), slot
= XEXP (slot
, 1))
3665 /* Skip any labels we shouldn't be able to jump to from here,
3666 we generate one special handler for all of them below which just calls
3668 if (! DECL_TOO_LATE (TREE_VALUE (link
)))
3671 lab
= expand_nl_handler_label (XEXP (slot
, 0),
3672 thisblock
->data
.block
.first_insn
);
3673 label_list
= gen_rtx_EXPR_LIST (VOIDmode
, lab
, label_list
);
3675 expand_nl_goto_receiver ();
3677 /* Jump to the "real" nonlocal label. */
3678 expand_goto (TREE_VALUE (link
));
3681 /* A second pass over all nonlocal labels; this time we handle those
3682 we should not be able to jump to at this point. */
3683 link
= nonlocal_labels
;
3684 slot
= nonlocal_goto_handler_slots
;
3686 for (; link
; link
= TREE_CHAIN (link
), slot
= XEXP (slot
, 1))
3687 if (DECL_TOO_LATE (TREE_VALUE (link
)))
3690 lab
= expand_nl_handler_label (XEXP (slot
, 0),
3691 thisblock
->data
.block
.first_insn
);
3692 label_list
= gen_rtx_EXPR_LIST (VOIDmode
, lab
, label_list
);
3698 expand_nl_goto_receiver ();
3699 expand_builtin_trap ();
3702 nonlocal_goto_handler_labels
= label_list
;
3703 emit_label (afterward
);
3706 /* Warn about any unused VARS (which may contain nodes other than
3707 VAR_DECLs, but such nodes are ignored). The nodes are connected
3708 via the TREE_CHAIN field. */
3711 warn_about_unused_variables (vars
)
3716 if (warn_unused_variable
)
3717 for (decl
= vars
; decl
; decl
= TREE_CHAIN (decl
))
3718 if (TREE_CODE (decl
) == VAR_DECL
3719 && ! TREE_USED (decl
)
3720 && ! DECL_IN_SYSTEM_HEADER (decl
)
3721 && DECL_NAME (decl
) && ! DECL_ARTIFICIAL (decl
))
3722 warning_with_decl (decl
, "unused variable `%s'");
3725 /* Generate RTL code to terminate a binding contour.
3727 VARS is the chain of VAR_DECL nodes for the variables bound in this
3728 contour. There may actually be other nodes in this chain, but any
3729 nodes other than VAR_DECLS are ignored.
3731 MARK_ENDS is nonzero if we should put a note at the beginning
3732 and end of this binding contour.
3734 DONT_JUMP_IN is positive if it is not valid to jump into this contour,
3735 zero if we can jump into this contour only if it does not have a saved
3736 stack level, and negative if we are not to check for invalid use of
3737 labels (because the front end does that). */
3740 expand_end_bindings (vars
, mark_ends
, dont_jump_in
)
3745 struct nesting
*thisblock
= block_stack
;
3747 /* If any of the variables in this scope were not used, warn the
3749 warn_about_unused_variables (vars
);
3751 if (thisblock
->exit_label
)
3753 do_pending_stack_adjust ();
3754 emit_label (thisblock
->exit_label
);
3757 /* If necessary, make handlers for nonlocal gotos taking
3758 place in the function calls in this block. */
3759 if (function_call_count
!= 0 && nonlocal_labels
3760 /* Make handler for outermost block
3761 if there were any nonlocal gotos to this function. */
3762 && (thisblock
->next
== 0 ? current_function_has_nonlocal_label
3763 /* Make handler for inner block if it has something
3764 special to do when you jump out of it. */
3765 : (thisblock
->data
.block
.cleanups
!= 0
3766 || thisblock
->data
.block
.stack_level
!= 0)))
3767 expand_nl_goto_receivers (thisblock
);
3769 /* Don't allow jumping into a block that has a stack level.
3770 Cleanups are allowed, though. */
3771 if (dont_jump_in
> 0
3772 || (dont_jump_in
== 0 && thisblock
->data
.block
.stack_level
!= 0))
3774 struct label_chain
*chain
;
3776 /* Any labels in this block are no longer valid to go to.
3777 Mark them to cause an error message. */
3778 for (chain
= thisblock
->data
.block
.label_chain
; chain
; chain
= chain
->next
)
3780 DECL_TOO_LATE (chain
->label
) = 1;
3781 /* If any goto without a fixup came to this label,
3782 that must be an error, because gotos without fixups
3783 come from outside all saved stack-levels. */
3784 if (TREE_ADDRESSABLE (chain
->label
))
3785 error_with_decl (chain
->label
,
3786 "label `%s' used before containing binding contour");
3790 /* Restore stack level in effect before the block
3791 (only if variable-size objects allocated). */
3792 /* Perform any cleanups associated with the block. */
3794 if (thisblock
->data
.block
.stack_level
!= 0
3795 || thisblock
->data
.block
.cleanups
!= 0)
3800 /* Don't let cleanups affect ({...}) constructs. */
3801 int old_expr_stmts_for_value
= expr_stmts_for_value
;
3802 rtx old_last_expr_value
= last_expr_value
;
3803 tree old_last_expr_type
= last_expr_type
;
3804 expr_stmts_for_value
= 0;
3806 /* Only clean up here if this point can actually be reached. */
3807 insn
= get_last_insn ();
3808 if (GET_CODE (insn
) == NOTE
)
3809 insn
= prev_nonnote_insn (insn
);
3810 reachable
= (! insn
|| GET_CODE (insn
) != BARRIER
);
3812 /* Do the cleanups. */
3813 expand_cleanups (thisblock
->data
.block
.cleanups
, 0, reachable
);
3815 do_pending_stack_adjust ();
3817 expr_stmts_for_value
= old_expr_stmts_for_value
;
3818 last_expr_value
= old_last_expr_value
;
3819 last_expr_type
= old_last_expr_type
;
3821 /* Restore the stack level. */
3823 if (reachable
&& thisblock
->data
.block
.stack_level
!= 0)
3825 emit_stack_restore (thisblock
->next
? SAVE_BLOCK
: SAVE_FUNCTION
,
3826 thisblock
->data
.block
.stack_level
, NULL_RTX
);
3827 if (nonlocal_goto_handler_slots
!= 0)
3828 emit_stack_save (SAVE_NONLOCAL
, &nonlocal_goto_stack_level
,
3832 /* Any gotos out of this block must also do these things.
3833 Also report any gotos with fixups that came to labels in this
3835 fixup_gotos (thisblock
,
3836 thisblock
->data
.block
.stack_level
,
3837 thisblock
->data
.block
.cleanups
,
3838 thisblock
->data
.block
.first_insn
,
3842 /* Mark the beginning and end of the scope if requested.
3843 We do this now, after running cleanups on the variables
3844 just going out of scope, so they are in scope for their cleanups. */
3848 rtx note
= emit_note (NULL
, NOTE_INSN_BLOCK_END
);
3849 NOTE_BLOCK (note
) = NOTE_BLOCK (thisblock
->data
.block
.first_insn
);
3852 /* Get rid of the beginning-mark if we don't make an end-mark. */
3853 NOTE_LINE_NUMBER (thisblock
->data
.block
.first_insn
) = NOTE_INSN_DELETED
;
3855 /* Restore the temporary level of TARGET_EXPRs. */
3856 target_temp_slot_level
= thisblock
->data
.block
.block_target_temp_slot_level
;
3858 /* Restore block_stack level for containing block. */
3860 stack_block_stack
= thisblock
->data
.block
.innermost_stack_block
;
3861 POPSTACK (block_stack
);
3863 /* Pop the stack slot nesting and free any slots at this level. */
3867 /* Generate code to save the stack pointer at the start of the current block
3868 and set up to restore it on exit. */
3871 save_stack_pointer ()
3873 struct nesting
*thisblock
= block_stack
;
3875 if (thisblock
->data
.block
.stack_level
== 0)
3877 emit_stack_save (thisblock
->next
? SAVE_BLOCK
: SAVE_FUNCTION
,
3878 &thisblock
->data
.block
.stack_level
,
3879 thisblock
->data
.block
.first_insn
);
3880 stack_block_stack
= thisblock
;
3884 /* Generate RTL for the automatic variable declaration DECL.
3885 (Other kinds of declarations are simply ignored if seen here.) */
3893 type
= TREE_TYPE (decl
);
3895 /* For a CONST_DECL, set mode, alignment, and sizes from those of the
3896 type in case this node is used in a reference. */
3897 if (TREE_CODE (decl
) == CONST_DECL
)
3899 DECL_MODE (decl
) = TYPE_MODE (type
);
3900 DECL_ALIGN (decl
) = TYPE_ALIGN (type
);
3901 DECL_SIZE (decl
) = TYPE_SIZE (type
);
3902 DECL_SIZE_UNIT (decl
) = TYPE_SIZE_UNIT (type
);
3906 /* Otherwise, only automatic variables need any expansion done. Static and
3907 external variables, and external functions, will be handled by
3908 `assemble_variable' (called from finish_decl). TYPE_DECL requires
3909 nothing. PARM_DECLs are handled in `assign_parms'. */
3910 if (TREE_CODE (decl
) != VAR_DECL
)
3913 if (TREE_STATIC (decl
) || DECL_EXTERNAL (decl
))
3916 /* Create the RTL representation for the variable. */
3918 if (type
== error_mark_node
)
3919 SET_DECL_RTL (decl
, gen_rtx_MEM (BLKmode
, const0_rtx
));
3921 else if (DECL_SIZE (decl
) == 0)
3922 /* Variable with incomplete type. */
3925 if (DECL_INITIAL (decl
) == 0)
3926 /* Error message was already done; now avoid a crash. */
3927 x
= gen_rtx_MEM (BLKmode
, const0_rtx
);
3929 /* An initializer is going to decide the size of this array.
3930 Until we know the size, represent its address with a reg. */
3931 x
= gen_rtx_MEM (BLKmode
, gen_reg_rtx (Pmode
));
3933 set_mem_attributes (x
, decl
, 1);
3934 SET_DECL_RTL (decl
, x
);
3936 else if (DECL_MODE (decl
) != BLKmode
3937 /* If -ffloat-store, don't put explicit float vars
3939 && !(flag_float_store
3940 && TREE_CODE (type
) == REAL_TYPE
)
3941 && ! TREE_THIS_VOLATILE (decl
)
3942 && ! DECL_NONLOCAL (decl
)
3943 && (DECL_REGISTER (decl
) || optimize
))
3945 /* Automatic variable that can go in a register. */
3946 int unsignedp
= TREE_UNSIGNED (type
);
3947 enum machine_mode reg_mode
3948 = promote_mode (type
, DECL_MODE (decl
), &unsignedp
, 0);
3950 SET_DECL_RTL (decl
, gen_reg_rtx (reg_mode
));
3952 mark_user_reg (DECL_RTL (decl
));
3954 if (POINTER_TYPE_P (type
))
3955 mark_reg_pointer (DECL_RTL (decl
),
3956 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl
))));
3958 maybe_set_unchanging (DECL_RTL (decl
), decl
);
3960 /* If something wants our address, try to use ADDRESSOF. */
3961 if (TREE_ADDRESSABLE (decl
))
3962 put_var_into_stack (decl
, /*rescan=*/false);
3965 else if (TREE_CODE (DECL_SIZE_UNIT (decl
)) == INTEGER_CST
3966 && ! (flag_stack_check
&& ! STACK_CHECK_BUILTIN
3967 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl
),
3968 STACK_CHECK_MAX_VAR_SIZE
)))
3970 /* Variable of fixed size that goes on the stack. */
3975 /* If we previously made RTL for this decl, it must be an array
3976 whose size was determined by the initializer.
3977 The old address was a register; set that register now
3978 to the proper address. */
3979 if (DECL_RTL_SET_P (decl
))
3981 if (GET_CODE (DECL_RTL (decl
)) != MEM
3982 || GET_CODE (XEXP (DECL_RTL (decl
), 0)) != REG
)
3984 oldaddr
= XEXP (DECL_RTL (decl
), 0);
3987 /* Set alignment we actually gave this decl. */
3988 DECL_ALIGN (decl
) = (DECL_MODE (decl
) == BLKmode
? BIGGEST_ALIGNMENT
3989 : GET_MODE_BITSIZE (DECL_MODE (decl
)));
3990 DECL_USER_ALIGN (decl
) = 0;
3992 x
= assign_temp (decl
, 1, 1, 1);
3993 set_mem_attributes (x
, decl
, 1);
3994 SET_DECL_RTL (decl
, x
);
3998 addr
= force_operand (XEXP (DECL_RTL (decl
), 0), oldaddr
);
3999 if (addr
!= oldaddr
)
4000 emit_move_insn (oldaddr
, addr
);
4004 /* Dynamic-size object: must push space on the stack. */
4006 rtx address
, size
, x
;
4008 /* Record the stack pointer on entry to block, if have
4009 not already done so. */
4010 do_pending_stack_adjust ();
4011 save_stack_pointer ();
4013 /* In function-at-a-time mode, variable_size doesn't expand this,
4015 if (TREE_CODE (type
) == ARRAY_TYPE
&& TYPE_DOMAIN (type
))
4016 expand_expr (TYPE_MAX_VALUE (TYPE_DOMAIN (type
)),
4017 const0_rtx
, VOIDmode
, 0);
4019 /* Compute the variable's size, in bytes. */
4020 size
= expand_expr (DECL_SIZE_UNIT (decl
), NULL_RTX
, VOIDmode
, 0);
4023 /* Allocate space on the stack for the variable. Note that
4024 DECL_ALIGN says how the variable is to be aligned and we
4025 cannot use it to conclude anything about the alignment of
4027 address
= allocate_dynamic_stack_space (size
, NULL_RTX
,
4028 TYPE_ALIGN (TREE_TYPE (decl
)));
4030 /* Reference the variable indirect through that rtx. */
4031 x
= gen_rtx_MEM (DECL_MODE (decl
), address
);
4032 set_mem_attributes (x
, decl
, 1);
4033 SET_DECL_RTL (decl
, x
);
4036 /* Indicate the alignment we actually gave this variable. */
4037 #ifdef STACK_BOUNDARY
4038 DECL_ALIGN (decl
) = STACK_BOUNDARY
;
4040 DECL_ALIGN (decl
) = BIGGEST_ALIGNMENT
;
4042 DECL_USER_ALIGN (decl
) = 0;
4046 /* Emit code to perform the initialization of a declaration DECL. */
4049 expand_decl_init (decl
)
4052 int was_used
= TREE_USED (decl
);
4054 /* If this is a CONST_DECL, we don't have to generate any code. Likewise
4055 for static decls. */
4056 if (TREE_CODE (decl
) == CONST_DECL
4057 || TREE_STATIC (decl
))
4060 /* Compute and store the initial value now. */
4064 if (DECL_INITIAL (decl
) == error_mark_node
)
4066 enum tree_code code
= TREE_CODE (TREE_TYPE (decl
));
4068 if (code
== INTEGER_TYPE
|| code
== REAL_TYPE
|| code
== ENUMERAL_TYPE
4069 || code
== POINTER_TYPE
|| code
== REFERENCE_TYPE
)
4070 expand_assignment (decl
, convert (TREE_TYPE (decl
), integer_zero_node
),
4074 else if (DECL_INITIAL (decl
) && TREE_CODE (DECL_INITIAL (decl
)) != TREE_LIST
)
4076 emit_line_note (DECL_SOURCE_FILE (decl
), DECL_SOURCE_LINE (decl
));
4077 expand_assignment (decl
, DECL_INITIAL (decl
), 0, 0);
4081 /* Don't let the initialization count as "using" the variable. */
4082 TREE_USED (decl
) = was_used
;
4084 /* Free any temporaries we made while initializing the decl. */
4085 preserve_temp_slots (NULL_RTX
);
4090 /* CLEANUP is an expression to be executed at exit from this binding contour;
4091 for example, in C++, it might call the destructor for this variable.
4093 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
4094 CLEANUP multiple times, and have the correct semantics. This
4095 happens in exception handling, for gotos, returns, breaks that
4096 leave the current scope.
4098 If CLEANUP is nonzero and DECL is zero, we record a cleanup
4099 that is not associated with any particular variable. */
4102 expand_decl_cleanup (decl
, cleanup
)
4105 struct nesting
*thisblock
;
4107 /* Error if we are not in any block. */
4108 if (cfun
== 0 || block_stack
== 0)
4111 thisblock
= block_stack
;
4113 /* Record the cleanup if there is one. */
4119 tree
*cleanups
= &thisblock
->data
.block
.cleanups
;
4120 int cond_context
= conditional_context ();
4124 rtx flag
= gen_reg_rtx (word_mode
);
4129 emit_move_insn (flag
, const0_rtx
);
4130 set_flag_0
= get_insns ();
4133 thisblock
->data
.block
.last_unconditional_cleanup
4134 = emit_insn_after (set_flag_0
,
4135 thisblock
->data
.block
.last_unconditional_cleanup
);
4137 emit_move_insn (flag
, const1_rtx
);
4139 cond
= build_decl (VAR_DECL
, NULL_TREE
,
4140 (*lang_hooks
.types
.type_for_mode
) (word_mode
, 1));
4141 SET_DECL_RTL (cond
, flag
);
4143 /* Conditionalize the cleanup. */
4144 cleanup
= build (COND_EXPR
, void_type_node
,
4145 (*lang_hooks
.truthvalue_conversion
) (cond
),
4146 cleanup
, integer_zero_node
);
4147 cleanup
= fold (cleanup
);
4149 cleanups
= &thisblock
->data
.block
.cleanups
;
4152 cleanup
= unsave_expr (cleanup
);
4154 t
= *cleanups
= tree_cons (decl
, cleanup
, *cleanups
);
4157 /* If this block has a cleanup, it belongs in stack_block_stack. */
4158 stack_block_stack
= thisblock
;
4165 if (! using_eh_for_cleanups_p
)
4166 TREE_ADDRESSABLE (t
) = 1;
4168 expand_eh_region_start ();
4175 thisblock
->data
.block
.last_unconditional_cleanup
4176 = emit_insn_after (seq
,
4177 thisblock
->data
.block
.last_unconditional_cleanup
);
4181 thisblock
->data
.block
.last_unconditional_cleanup
4183 /* When we insert instructions after the last unconditional cleanup,
4184 we don't adjust last_insn. That means that a later add_insn will
4185 clobber the instructions we've just added. The easiest way to
4186 fix this is to just insert another instruction here, so that the
4187 instructions inserted after the last unconditional cleanup are
4188 never the last instruction. */
4189 emit_note (NULL
, NOTE_INSN_DELETED
);
4195 /* Like expand_decl_cleanup, but maybe only run the cleanup if an exception
4199 expand_decl_cleanup_eh (decl
, cleanup
, eh_only
)
4203 int ret
= expand_decl_cleanup (decl
, cleanup
);
4206 tree node
= block_stack
->data
.block
.cleanups
;
4207 CLEANUP_EH_ONLY (node
) = eh_only
;
4212 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4213 DECL_ELTS is the list of elements that belong to DECL's type.
4214 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4217 expand_anon_union_decl (decl
, cleanup
, decl_elts
)
4218 tree decl
, cleanup
, decl_elts
;
4220 struct nesting
*thisblock
= cfun
== 0 ? 0 : block_stack
;
4224 /* If any of the elements are addressable, so is the entire union. */
4225 for (t
= decl_elts
; t
; t
= TREE_CHAIN (t
))
4226 if (TREE_ADDRESSABLE (TREE_VALUE (t
)))
4228 TREE_ADDRESSABLE (decl
) = 1;
4233 expand_decl_cleanup (decl
, cleanup
);
4234 x
= DECL_RTL (decl
);
4236 /* Go through the elements, assigning RTL to each. */
4237 for (t
= decl_elts
; t
; t
= TREE_CHAIN (t
))
4239 tree decl_elt
= TREE_VALUE (t
);
4240 tree cleanup_elt
= TREE_PURPOSE (t
);
4241 enum machine_mode mode
= TYPE_MODE (TREE_TYPE (decl_elt
));
4243 /* If any of the elements are addressable, so is the entire
4245 if (TREE_USED (decl_elt
))
4246 TREE_USED (decl
) = 1;
4248 /* Propagate the union's alignment to the elements. */
4249 DECL_ALIGN (decl_elt
) = DECL_ALIGN (decl
);
4250 DECL_USER_ALIGN (decl_elt
) = DECL_USER_ALIGN (decl
);
4252 /* If the element has BLKmode and the union doesn't, the union is
4253 aligned such that the element doesn't need to have BLKmode, so
4254 change the element's mode to the appropriate one for its size. */
4255 if (mode
== BLKmode
&& DECL_MODE (decl
) != BLKmode
)
4256 DECL_MODE (decl_elt
) = mode
4257 = mode_for_size_tree (DECL_SIZE (decl_elt
), MODE_INT
, 1);
4259 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4260 instead create a new MEM rtx with the proper mode. */
4261 if (GET_CODE (x
) == MEM
)
4263 if (mode
== GET_MODE (x
))
4264 SET_DECL_RTL (decl_elt
, x
);
4266 SET_DECL_RTL (decl_elt
, adjust_address_nv (x
, mode
, 0));
4268 else if (GET_CODE (x
) == REG
)
4270 if (mode
== GET_MODE (x
))
4271 SET_DECL_RTL (decl_elt
, x
);
4273 SET_DECL_RTL (decl_elt
, gen_lowpart_SUBREG (mode
, x
));
4278 /* Record the cleanup if there is one. */
4281 thisblock
->data
.block
.cleanups
4282 = tree_cons (decl_elt
, cleanup_elt
,
4283 thisblock
->data
.block
.cleanups
);
4287 /* Expand a list of cleanups LIST.
4288 Elements may be expressions or may be nested lists.
4290 If IN_FIXUP is nonzero, we are generating this cleanup for a fixup
4291 goto and handle protection regions specially in that case.
4293 If REACHABLE, we emit code, otherwise just inform the exception handling
4294 code about this finalization. */
4297 expand_cleanups (list
, in_fixup
, reachable
)
4303 for (tail
= list
; tail
; tail
= TREE_CHAIN (tail
))
4304 if (TREE_CODE (TREE_VALUE (tail
)) == TREE_LIST
)
4305 expand_cleanups (TREE_VALUE (tail
), in_fixup
, reachable
);
4308 if (! in_fixup
&& using_eh_for_cleanups_p
)
4309 expand_eh_region_end_cleanup (TREE_VALUE (tail
));
4311 if (reachable
&& !CLEANUP_EH_ONLY (tail
))
4313 /* Cleanups may be run multiple times. For example,
4314 when exiting a binding contour, we expand the
4315 cleanups associated with that contour. When a goto
4316 within that binding contour has a target outside that
4317 contour, it will expand all cleanups from its scope to
4318 the target. Though the cleanups are expanded multiple
4319 times, the control paths are non-overlapping so the
4320 cleanups will not be executed twice. */
4322 /* We may need to protect from outer cleanups. */
4323 if (in_fixup
&& using_eh_for_cleanups_p
)
4325 expand_eh_region_start ();
4327 expand_expr (TREE_VALUE (tail
), const0_rtx
, VOIDmode
, 0);
4329 expand_eh_region_end_fixup (TREE_VALUE (tail
));
4332 expand_expr (TREE_VALUE (tail
), const0_rtx
, VOIDmode
, 0);
4339 /* Mark when the context we are emitting RTL for as a conditional
4340 context, so that any cleanup actions we register with
4341 expand_decl_init will be properly conditionalized when those
4342 cleanup actions are later performed. Must be called before any
4343 expression (tree) is expanded that is within a conditional context. */
4346 start_cleanup_deferral ()
4348 /* block_stack can be NULL if we are inside the parameter list. It is
4349 OK to do nothing, because cleanups aren't possible here. */
4351 ++block_stack
->data
.block
.conditional_code
;
4354 /* Mark the end of a conditional region of code. Because cleanup
4355 deferrals may be nested, we may still be in a conditional region
4356 after we end the currently deferred cleanups, only after we end all
4357 deferred cleanups, are we back in unconditional code. */
4360 end_cleanup_deferral ()
4362 /* block_stack can be NULL if we are inside the parameter list. It is
4363 OK to do nothing, because cleanups aren't possible here. */
4365 --block_stack
->data
.block
.conditional_code
;
4369 last_cleanup_this_contour ()
4371 if (block_stack
== 0)
4374 return block_stack
->data
.block
.cleanups
;
4377 /* Return 1 if there are any pending cleanups at this point.
4378 If THIS_CONTOUR is nonzero, check the current contour as well.
4379 Otherwise, look only at the contours that enclose this one. */
4382 any_pending_cleanups (this_contour
)
4385 struct nesting
*block
;
4387 if (cfun
== NULL
|| cfun
->stmt
== NULL
|| block_stack
== 0)
4390 if (this_contour
&& block_stack
->data
.block
.cleanups
!= NULL
)
4392 if (block_stack
->data
.block
.cleanups
== 0
4393 && block_stack
->data
.block
.outer_cleanups
== 0)
4396 for (block
= block_stack
->next
; block
; block
= block
->next
)
4397 if (block
->data
.block
.cleanups
!= 0)
4403 /* Enter a case (Pascal) or switch (C) statement.
4404 Push a block onto case_stack and nesting_stack
4405 to accumulate the case-labels that are seen
4406 and to record the labels generated for the statement.
4408 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4409 Otherwise, this construct is transparent for `exit_something'.
4411 EXPR is the index-expression to be dispatched on.
4412 TYPE is its nominal type. We could simply convert EXPR to this type,
4413 but instead we take short cuts. */
4416 expand_start_case (exit_flag
, expr
, type
, printname
)
4420 const char *printname
;
4422 struct nesting
*thiscase
= ALLOC_NESTING ();
4424 /* Make an entry on case_stack for the case we are entering. */
4426 thiscase
->desc
= CASE_NESTING
;
4427 thiscase
->next
= case_stack
;
4428 thiscase
->all
= nesting_stack
;
4429 thiscase
->depth
= ++nesting_depth
;
4430 thiscase
->exit_label
= exit_flag
? gen_label_rtx () : 0;
4431 thiscase
->data
.case_stmt
.case_list
= 0;
4432 thiscase
->data
.case_stmt
.index_expr
= expr
;
4433 thiscase
->data
.case_stmt
.nominal_type
= type
;
4434 thiscase
->data
.case_stmt
.default_label
= 0;
4435 thiscase
->data
.case_stmt
.printname
= printname
;
4436 thiscase
->data
.case_stmt
.line_number_status
= force_line_numbers ();
4437 case_stack
= thiscase
;
4438 nesting_stack
= thiscase
;
4440 do_pending_stack_adjust ();
4443 /* Make sure case_stmt.start points to something that won't
4444 need any transformation before expand_end_case. */
4445 if (GET_CODE (get_last_insn ()) != NOTE
)
4446 emit_note (NULL
, NOTE_INSN_DELETED
);
4448 thiscase
->data
.case_stmt
.start
= get_last_insn ();
4450 start_cleanup_deferral ();
4453 /* Start a "dummy case statement" within which case labels are invalid
4454 and are not connected to any larger real case statement.
4455 This can be used if you don't want to let a case statement jump
4456 into the middle of certain kinds of constructs. */
4459 expand_start_case_dummy ()
4461 struct nesting
*thiscase
= ALLOC_NESTING ();
4463 /* Make an entry on case_stack for the dummy. */
4465 thiscase
->desc
= CASE_NESTING
;
4466 thiscase
->next
= case_stack
;
4467 thiscase
->all
= nesting_stack
;
4468 thiscase
->depth
= ++nesting_depth
;
4469 thiscase
->exit_label
= 0;
4470 thiscase
->data
.case_stmt
.case_list
= 0;
4471 thiscase
->data
.case_stmt
.start
= 0;
4472 thiscase
->data
.case_stmt
.nominal_type
= 0;
4473 thiscase
->data
.case_stmt
.default_label
= 0;
4474 case_stack
= thiscase
;
4475 nesting_stack
= thiscase
;
4476 start_cleanup_deferral ();
4482 /* If this is the first label, warn if any insns have been emitted. */
4483 if (case_stack
->data
.case_stmt
.line_number_status
>= 0)
4487 restore_line_number_status
4488 (case_stack
->data
.case_stmt
.line_number_status
);
4489 case_stack
->data
.case_stmt
.line_number_status
= -1;
4491 for (insn
= case_stack
->data
.case_stmt
.start
;
4493 insn
= NEXT_INSN (insn
))
4495 if (GET_CODE (insn
) == CODE_LABEL
)
4497 if (GET_CODE (insn
) != NOTE
4498 && (GET_CODE (insn
) != INSN
|| GET_CODE (PATTERN (insn
)) != USE
))
4501 insn
= PREV_INSN (insn
);
4502 while (insn
&& (GET_CODE (insn
) != NOTE
|| NOTE_LINE_NUMBER (insn
) < 0));
4504 /* If insn is zero, then there must have been a syntax error. */
4508 locus
.file
= NOTE_SOURCE_FILE (insn
);
4509 locus
.line
= NOTE_LINE_NUMBER (insn
);
4510 warning ("%Hunreachable code at beginning of %s", &locus
,
4511 case_stack
->data
.case_stmt
.printname
);
4519 /* Accumulate one case or default label inside a case or switch statement.
4520 VALUE is the value of the case (a null pointer, for a default label).
4521 The function CONVERTER, when applied to arguments T and V,
4522 converts the value V to the type T.
4524 If not currently inside a case or switch statement, return 1 and do
4525 nothing. The caller will print a language-specific error message.
4526 If VALUE is a duplicate or overlaps, return 2 and do nothing
4527 except store the (first) duplicate node in *DUPLICATE.
4528 If VALUE is out of range, return 3 and do nothing.
4529 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4530 Return 0 on success.
4532 Extended to handle range statements. */
4535 pushcase (value
, converter
, label
, duplicate
)
4537 tree (*converter
) PARAMS ((tree
, tree
));
4544 /* Fail if not inside a real case statement. */
4545 if (! (case_stack
&& case_stack
->data
.case_stmt
.start
))
4548 if (stack_block_stack
4549 && stack_block_stack
->depth
> case_stack
->depth
)
4552 index_type
= TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4553 nominal_type
= case_stack
->data
.case_stmt
.nominal_type
;
4555 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4556 if (index_type
== error_mark_node
)
4559 /* Convert VALUE to the type in which the comparisons are nominally done. */
4561 value
= (*converter
) (nominal_type
, value
);
4565 /* Fail if this value is out of range for the actual type of the index
4566 (which may be narrower than NOMINAL_TYPE). */
4568 && (TREE_CONSTANT_OVERFLOW (value
)
4569 || ! int_fits_type_p (value
, index_type
)))
4572 return add_case_node (value
, value
, label
, duplicate
);
4575 /* Like pushcase but this case applies to all values between VALUE1 and
4576 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4577 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4578 starts at VALUE1 and ends at the highest value of the index type.
4579 If both are NULL, this case applies to all values.
4581 The return value is the same as that of pushcase but there is one
4582 additional error code: 4 means the specified range was empty. */
4585 pushcase_range (value1
, value2
, converter
, label
, duplicate
)
4586 tree value1
, value2
;
4587 tree (*converter
) PARAMS ((tree
, tree
));
4594 /* Fail if not inside a real case statement. */
4595 if (! (case_stack
&& case_stack
->data
.case_stmt
.start
))
4598 if (stack_block_stack
4599 && stack_block_stack
->depth
> case_stack
->depth
)
4602 index_type
= TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4603 nominal_type
= case_stack
->data
.case_stmt
.nominal_type
;
4605 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4606 if (index_type
== error_mark_node
)
4611 /* Convert VALUEs to type in which the comparisons are nominally done
4612 and replace any unspecified value with the corresponding bound. */
4614 value1
= TYPE_MIN_VALUE (index_type
);
4616 value2
= TYPE_MAX_VALUE (index_type
);
4618 /* Fail if the range is empty. Do this before any conversion since
4619 we want to allow out-of-range empty ranges. */
4620 if (value2
!= 0 && tree_int_cst_lt (value2
, value1
))
4623 /* If the max was unbounded, use the max of the nominal_type we are
4624 converting to. Do this after the < check above to suppress false
4627 value2
= TYPE_MAX_VALUE (nominal_type
);
4629 value1
= (*converter
) (nominal_type
, value1
);
4630 value2
= (*converter
) (nominal_type
, value2
);
4632 /* Fail if these values are out of range. */
4633 if (TREE_CONSTANT_OVERFLOW (value1
)
4634 || ! int_fits_type_p (value1
, index_type
))
4637 if (TREE_CONSTANT_OVERFLOW (value2
)
4638 || ! int_fits_type_p (value2
, index_type
))
4641 return add_case_node (value1
, value2
, label
, duplicate
);
4644 /* Do the actual insertion of a case label for pushcase and pushcase_range
4645 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4646 slowdown for large switch statements. */
4649 add_case_node (low
, high
, label
, duplicate
)
4654 struct case_node
*p
, **q
, *r
;
4656 /* If there's no HIGH value, then this is not a case range; it's
4657 just a simple case label. But that's just a degenerate case
4662 /* Handle default labels specially. */
4665 if (case_stack
->data
.case_stmt
.default_label
!= 0)
4667 *duplicate
= case_stack
->data
.case_stmt
.default_label
;
4670 case_stack
->data
.case_stmt
.default_label
= label
;
4671 expand_label (label
);
4675 q
= &case_stack
->data
.case_stmt
.case_list
;
4682 /* Keep going past elements distinctly greater than HIGH. */
4683 if (tree_int_cst_lt (high
, p
->low
))
4686 /* or distinctly less than LOW. */
4687 else if (tree_int_cst_lt (p
->high
, low
))
4692 /* We have an overlap; this is an error. */
4693 *duplicate
= p
->code_label
;
4698 /* Add this label to the chain, and succeed. */
4700 r
= (struct case_node
*) ggc_alloc (sizeof (struct case_node
));
4703 /* If the bounds are equal, turn this into the one-value case. */
4704 if (tree_int_cst_equal (low
, high
))
4709 r
->code_label
= label
;
4710 expand_label (label
);
4720 struct case_node
*s
;
4726 if (! (b
= p
->balance
))
4727 /* Growth propagation from left side. */
4734 if ((p
->left
= s
= r
->right
))
4743 if ((r
->parent
= s
))
4751 case_stack
->data
.case_stmt
.case_list
= r
;
4754 /* r->balance == +1 */
4759 struct case_node
*t
= r
->right
;
4761 if ((p
->left
= s
= t
->right
))
4765 if ((r
->right
= s
= t
->left
))
4779 if ((t
->parent
= s
))
4787 case_stack
->data
.case_stmt
.case_list
= t
;
4794 /* p->balance == +1; growth of left side balances the node. */
4804 if (! (b
= p
->balance
))
4805 /* Growth propagation from right side. */
4813 if ((p
->right
= s
= r
->left
))
4821 if ((r
->parent
= s
))
4830 case_stack
->data
.case_stmt
.case_list
= r
;
4834 /* r->balance == -1 */
4838 struct case_node
*t
= r
->left
;
4840 if ((p
->right
= s
= t
->left
))
4845 if ((r
->left
= s
= t
->right
))
4859 if ((t
->parent
= s
))
4868 case_stack
->data
.case_stmt
.case_list
= t
;
4874 /* p->balance == -1; growth of right side balances the node. */
4887 /* Returns the number of possible values of TYPE.
4888 Returns -1 if the number is unknown, variable, or if the number does not
4889 fit in a HOST_WIDE_INT.
4890 Sets *SPARSENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4891 do not increase monotonically (there may be duplicates);
4892 to 1 if the values increase monotonically, but not always by 1;
4893 otherwise sets it to 0. */
4896 all_cases_count (type
, sparseness
)
4901 HOST_WIDE_INT count
, minval
, lastval
;
4905 switch (TREE_CODE (type
))
4912 count
= 1 << BITS_PER_UNIT
;
4917 if (TYPE_MAX_VALUE (type
) != 0
4918 && 0 != (t
= fold (build (MINUS_EXPR
, type
, TYPE_MAX_VALUE (type
),
4919 TYPE_MIN_VALUE (type
))))
4920 && 0 != (t
= fold (build (PLUS_EXPR
, type
, t
,
4921 convert (type
, integer_zero_node
))))
4922 && host_integerp (t
, 1))
4923 count
= tree_low_cst (t
, 1);
4929 /* Don't waste time with enumeral types with huge values. */
4930 if (! host_integerp (TYPE_MIN_VALUE (type
), 0)
4931 || TYPE_MAX_VALUE (type
) == 0
4932 || ! host_integerp (TYPE_MAX_VALUE (type
), 0))
4935 lastval
= minval
= tree_low_cst (TYPE_MIN_VALUE (type
), 0);
4938 for (t
= TYPE_VALUES (type
); t
!= NULL_TREE
; t
= TREE_CHAIN (t
))
4940 HOST_WIDE_INT thisval
= tree_low_cst (TREE_VALUE (t
), 0);
4942 if (*sparseness
== 2 || thisval
<= lastval
)
4944 else if (thisval
!= minval
+ count
)
4955 #define BITARRAY_TEST(ARRAY, INDEX) \
4956 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4957 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4958 #define BITARRAY_SET(ARRAY, INDEX) \
4959 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4960 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4962 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4963 with the case values we have seen, assuming the case expression
4965 SPARSENESS is as determined by all_cases_count.
4967 The time needed is proportional to COUNT, unless
4968 SPARSENESS is 2, in which case quadratic time is needed. */
4971 mark_seen_cases (type
, cases_seen
, count
, sparseness
)
4973 unsigned char *cases_seen
;
4974 HOST_WIDE_INT count
;
4977 tree next_node_to_try
= NULL_TREE
;
4978 HOST_WIDE_INT next_node_offset
= 0;
4980 struct case_node
*n
, *root
= case_stack
->data
.case_stmt
.case_list
;
4981 tree val
= make_node (INTEGER_CST
);
4983 TREE_TYPE (val
) = type
;
4987 else if (sparseness
== 2)
4990 unsigned HOST_WIDE_INT xlo
;
4992 /* This less efficient loop is only needed to handle
4993 duplicate case values (multiple enum constants
4994 with the same value). */
4995 TREE_TYPE (val
) = TREE_TYPE (root
->low
);
4996 for (t
= TYPE_VALUES (type
), xlo
= 0; t
!= NULL_TREE
;
4997 t
= TREE_CHAIN (t
), xlo
++)
4999 TREE_INT_CST_LOW (val
) = TREE_INT_CST_LOW (TREE_VALUE (t
));
5000 TREE_INT_CST_HIGH (val
) = TREE_INT_CST_HIGH (TREE_VALUE (t
));
5004 /* Keep going past elements distinctly greater than VAL. */
5005 if (tree_int_cst_lt (val
, n
->low
))
5008 /* or distinctly less than VAL. */
5009 else if (tree_int_cst_lt (n
->high
, val
))
5014 /* We have found a matching range. */
5015 BITARRAY_SET (cases_seen
, xlo
);
5025 case_stack
->data
.case_stmt
.case_list
= root
= case_tree2list (root
, 0);
5027 for (n
= root
; n
; n
= n
->right
)
5029 TREE_INT_CST_LOW (val
) = TREE_INT_CST_LOW (n
->low
);
5030 TREE_INT_CST_HIGH (val
) = TREE_INT_CST_HIGH (n
->low
);
5031 while (! tree_int_cst_lt (n
->high
, val
))
5033 /* Calculate (into xlo) the "offset" of the integer (val).
5034 The element with lowest value has offset 0, the next smallest
5035 element has offset 1, etc. */
5037 unsigned HOST_WIDE_INT xlo
;
5041 if (sparseness
&& TYPE_VALUES (type
) != NULL_TREE
)
5043 /* The TYPE_VALUES will be in increasing order, so
5044 starting searching where we last ended. */
5045 t
= next_node_to_try
;
5046 xlo
= next_node_offset
;
5052 t
= TYPE_VALUES (type
);
5055 if (tree_int_cst_equal (val
, TREE_VALUE (t
)))
5057 next_node_to_try
= TREE_CHAIN (t
);
5058 next_node_offset
= xlo
+ 1;
5063 if (t
== next_node_to_try
)
5072 t
= TYPE_MIN_VALUE (type
);
5074 neg_double (TREE_INT_CST_LOW (t
), TREE_INT_CST_HIGH (t
),
5078 add_double (xlo
, xhi
,
5079 TREE_INT_CST_LOW (val
), TREE_INT_CST_HIGH (val
),
5083 if (xhi
== 0 && xlo
< (unsigned HOST_WIDE_INT
) count
)
5084 BITARRAY_SET (cases_seen
, xlo
);
5086 add_double (TREE_INT_CST_LOW (val
), TREE_INT_CST_HIGH (val
),
5088 &TREE_INT_CST_LOW (val
), &TREE_INT_CST_HIGH (val
));
5094 /* Given a switch statement with an expression that is an enumeration
5095 type, warn if any of the enumeration type's literals are not
5096 covered by the case expressions of the switch. Also, warn if there
5097 are any extra switch cases that are *not* elements of the
5102 At one stage this function would: ``If all enumeration literals
5103 were covered by the case expressions, turn one of the expressions
5104 into the default expression since it should not be possible to fall
5105 through such a switch.''
5107 That code has since been removed as: ``This optimization is
5108 disabled because it causes valid programs to fail. ANSI C does not
5109 guarantee that an expression with enum type will have a value that
5110 is the same as one of the enumeration literals.'' */
5113 check_for_full_enumeration_handling (type
)
5116 struct case_node
*n
;
5119 /* True iff the selector type is a numbered set mode. */
5122 /* The number of possible selector values. */
5125 /* For each possible selector value. a one iff it has been matched
5126 by a case value alternative. */
5127 unsigned char *cases_seen
;
5129 /* The allocated size of cases_seen, in chars. */
5130 HOST_WIDE_INT bytes_needed
;
5132 size
= all_cases_count (type
, &sparseness
);
5133 bytes_needed
= (size
+ HOST_BITS_PER_CHAR
) / HOST_BITS_PER_CHAR
;
5135 if (size
> 0 && size
< 600000
5136 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5137 this optimization if we don't have enough memory rather than
5138 aborting, as xmalloc would do. */
5140 (unsigned char *) really_call_calloc (bytes_needed
, 1)) != NULL
)
5143 tree v
= TYPE_VALUES (type
);
5145 /* The time complexity of this code is normally O(N), where
5146 N being the number of members in the enumerated type.
5147 However, if type is an ENUMERAL_TYPE whose values do not
5148 increase monotonically, O(N*log(N)) time may be needed. */
5150 mark_seen_cases (type
, cases_seen
, size
, sparseness
);
5152 for (i
= 0; v
!= NULL_TREE
&& i
< size
; i
++, v
= TREE_CHAIN (v
))
5153 if (BITARRAY_TEST (cases_seen
, i
) == 0)
5154 warning ("enumeration value `%s' not handled in switch",
5155 IDENTIFIER_POINTER (TREE_PURPOSE (v
)));
5160 /* Now we go the other way around; we warn if there are case
5161 expressions that don't correspond to enumerators. This can
5162 occur since C and C++ don't enforce type-checking of
5163 assignments to enumeration variables. */
5165 if (case_stack
->data
.case_stmt
.case_list
5166 && case_stack
->data
.case_stmt
.case_list
->left
)
5167 case_stack
->data
.case_stmt
.case_list
5168 = case_tree2list (case_stack
->data
.case_stmt
.case_list
, 0);
5169 for (n
= case_stack
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5171 for (chain
= TYPE_VALUES (type
);
5172 chain
&& !tree_int_cst_equal (n
->low
, TREE_VALUE (chain
));
5173 chain
= TREE_CHAIN (chain
))
5178 if (TYPE_NAME (type
) == 0)
5179 warning ("case value `%ld' not in enumerated type",
5180 (long) TREE_INT_CST_LOW (n
->low
));
5182 warning ("case value `%ld' not in enumerated type `%s'",
5183 (long) TREE_INT_CST_LOW (n
->low
),
5184 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type
))
5187 : DECL_NAME (TYPE_NAME (type
))));
5189 if (!tree_int_cst_equal (n
->low
, n
->high
))
5191 for (chain
= TYPE_VALUES (type
);
5192 chain
&& !tree_int_cst_equal (n
->high
, TREE_VALUE (chain
));
5193 chain
= TREE_CHAIN (chain
))
5198 if (TYPE_NAME (type
) == 0)
5199 warning ("case value `%ld' not in enumerated type",
5200 (long) TREE_INT_CST_LOW (n
->high
));
5202 warning ("case value `%ld' not in enumerated type `%s'",
5203 (long) TREE_INT_CST_LOW (n
->high
),
5204 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type
))
5207 : DECL_NAME (TYPE_NAME (type
))));
5214 /* Maximum number of case bit tests. */
5215 #define MAX_CASE_BIT_TESTS 3
5217 /* By default, enable case bit tests on targets with ashlsi3. */
5218 #ifndef CASE_USE_BIT_TESTS
5219 #define CASE_USE_BIT_TESTS (ashl_optab->handlers[word_mode].insn_code \
5220 != CODE_FOR_nothing)
5224 /* A case_bit_test represents a set of case nodes that may be
5225 selected from using a bit-wise comparison. HI and LO hold
5226 the integer to be tested against, LABEL contains the label
5227 to jump to upon success and BITS counts the number of case
5228 nodes handled by this test, typically the number of bits
5231 struct case_bit_test
5239 /* Determine whether "1 << x" is relatively cheap in word_mode. */
5241 static bool lshift_cheap_p ()
5243 static bool init
= false;
5244 static bool cheap
= true;
5248 rtx reg
= gen_rtx_REG (word_mode
, 10000);
5249 int cost
= rtx_cost (gen_rtx_ASHIFT (word_mode
, const1_rtx
, reg
), SET
);
5250 cheap
= cost
< COSTS_N_INSNS (3);
5257 /* Comparison function for qsort to order bit tests by decreasing
5258 number of case nodes, i.e. the node with the most cases gets
5261 static int case_bit_test_cmp (p1
, p2
)
5265 const struct case_bit_test
*d1
= p1
;
5266 const struct case_bit_test
*d2
= p2
;
5268 return d2
->bits
- d1
->bits
;
5271 /* Expand a switch statement by a short sequence of bit-wise
5272 comparisons. "switch(x)" is effectively converted into
5273 "if ((1 << (x-MINVAL)) & CST)" where CST and MINVAL are
5276 INDEX_EXPR is the value being switched on, which is of
5277 type INDEX_TYPE. MINVAL is the lowest case value of in
5278 the case nodes, of INDEX_TYPE type, and RANGE is highest
5279 value minus MINVAL, also of type INDEX_TYPE. NODES is
5280 the set of case nodes, and DEFAULT_LABEL is the label to
5281 branch to should none of the cases match.
5283 There *MUST* be MAX_CASE_BIT_TESTS or less unique case
5287 emit_case_bit_tests (index_type
, index_expr
, minval
, range
,
5288 nodes
, default_label
)
5289 tree index_type
, index_expr
, minval
, range
;
5290 case_node_ptr nodes
;
5293 struct case_bit_test test
[MAX_CASE_BIT_TESTS
];
5294 enum machine_mode mode
;
5295 rtx expr
, index
, label
;
5296 unsigned int i
,j
,lo
,hi
;
5297 struct case_node
*n
;
5301 for (n
= nodes
; n
; n
= n
->right
)
5303 label
= label_rtx (n
->code_label
);
5304 for (i
= 0; i
< count
; i
++)
5305 if (same_case_target_p (label
, test
[i
].label
))
5310 if (count
>= MAX_CASE_BIT_TESTS
)
5314 test
[i
].label
= label
;
5321 lo
= tree_low_cst (fold (build (MINUS_EXPR
, index_type
,
5322 n
->low
, minval
)), 1);
5323 hi
= tree_low_cst (fold (build (MINUS_EXPR
, index_type
,
5324 n
->high
, minval
)), 1);
5325 for (j
= lo
; j
<= hi
; j
++)
5326 if (j
>= HOST_BITS_PER_WIDE_INT
)
5327 test
[i
].hi
|= (HOST_WIDE_INT
) 1 << (j
- HOST_BITS_PER_INT
);
5329 test
[i
].lo
|= (HOST_WIDE_INT
) 1 << j
;
5332 qsort (test
, count
, sizeof(*test
), case_bit_test_cmp
);
5334 index_expr
= fold (build (MINUS_EXPR
, index_type
,
5335 convert (index_type
, index_expr
),
5336 convert (index_type
, minval
)));
5337 index
= expand_expr (index_expr
, NULL_RTX
, VOIDmode
, 0);
5339 index
= protect_from_queue (index
, 0);
5340 do_pending_stack_adjust ();
5342 mode
= TYPE_MODE (index_type
);
5343 expr
= expand_expr (range
, NULL_RTX
, VOIDmode
, 0);
5344 emit_cmp_and_jump_insns (index
, expr
, GTU
, NULL_RTX
, mode
, 1,
5347 index
= convert_to_mode (word_mode
, index
, 0);
5348 index
= expand_binop (word_mode
, ashl_optab
, const1_rtx
,
5349 index
, NULL_RTX
, 1, OPTAB_WIDEN
);
5351 for (i
= 0; i
< count
; i
++)
5353 expr
= immed_double_const (test
[i
].lo
, test
[i
].hi
, word_mode
);
5354 expr
= expand_binop (word_mode
, and_optab
, index
, expr
,
5355 NULL_RTX
, 1, OPTAB_WIDEN
);
5356 emit_cmp_and_jump_insns (expr
, const0_rtx
, NE
, NULL_RTX
,
5357 word_mode
, 1, test
[i
].label
);
5360 emit_jump (default_label
);
5363 /* Terminate a case (Pascal) or switch (C) statement
5364 in which ORIG_INDEX is the expression to be tested.
5365 If ORIG_TYPE is not NULL, it is the original ORIG_INDEX
5366 type as given in the source before any compiler conversions.
5367 Generate the code to test it and jump to the right place. */
5370 expand_end_case_type (orig_index
, orig_type
)
5371 tree orig_index
, orig_type
;
5373 tree minval
= NULL_TREE
, maxval
= NULL_TREE
, range
= NULL_TREE
;
5374 rtx default_label
= 0;
5375 struct case_node
*n
, *m
;
5376 unsigned int count
, uniq
;
5382 rtx before_case
, end
, lab
;
5383 struct nesting
*thiscase
= case_stack
;
5384 tree index_expr
, index_type
;
5385 bool exit_done
= false;
5388 /* Don't crash due to previous errors. */
5389 if (thiscase
== NULL
)
5392 index_expr
= thiscase
->data
.case_stmt
.index_expr
;
5393 index_type
= TREE_TYPE (index_expr
);
5394 unsignedp
= TREE_UNSIGNED (index_type
);
5395 if (orig_type
== NULL
)
5396 orig_type
= TREE_TYPE (orig_index
);
5398 do_pending_stack_adjust ();
5400 /* This might get a spurious warning in the presence of a syntax error;
5401 it could be fixed by moving the call to check_seenlabel after the
5402 check for error_mark_node, and copying the code of check_seenlabel that
5403 deals with case_stack->data.case_stmt.line_number_status /
5404 restore_line_number_status in front of the call to end_cleanup_deferral;
5405 However, this might miss some useful warnings in the presence of
5406 non-syntax errors. */
5409 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5410 if (index_type
!= error_mark_node
)
5412 /* If the switch expression was an enumerated type, check that
5413 exactly all enumeration literals are covered by the cases.
5414 The check is made when -Wswitch was specified and there is no
5415 default case, or when -Wswitch-enum was specified. */
5416 if (((warn_switch
&& !thiscase
->data
.case_stmt
.default_label
)
5417 || warn_switch_enum
)
5418 && TREE_CODE (orig_type
) == ENUMERAL_TYPE
5419 && TREE_CODE (index_expr
) != INTEGER_CST
)
5420 check_for_full_enumeration_handling (orig_type
);
5422 if (warn_switch_default
&& !thiscase
->data
.case_stmt
.default_label
)
5423 warning ("switch missing default case");
5425 /* If we don't have a default-label, create one here,
5426 after the body of the switch. */
5427 if (thiscase
->data
.case_stmt
.default_label
== 0)
5429 thiscase
->data
.case_stmt
.default_label
5430 = build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
5431 /* Share the exit label if possible. */
5432 if (thiscase
->exit_label
)
5434 SET_DECL_RTL (thiscase
->data
.case_stmt
.default_label
,
5435 thiscase
->exit_label
);
5438 expand_label (thiscase
->data
.case_stmt
.default_label
);
5440 default_label
= label_rtx (thiscase
->data
.case_stmt
.default_label
);
5442 before_case
= get_last_insn ();
5444 if (thiscase
->data
.case_stmt
.case_list
5445 && thiscase
->data
.case_stmt
.case_list
->left
)
5446 thiscase
->data
.case_stmt
.case_list
5447 = case_tree2list (thiscase
->data
.case_stmt
.case_list
, 0);
5449 /* Simplify the case-list before we count it. */
5450 group_case_nodes (thiscase
->data
.case_stmt
.case_list
);
5451 strip_default_case_nodes (&thiscase
->data
.case_stmt
.case_list
,
5454 /* Get upper and lower bounds of case values.
5455 Also convert all the case values to the index expr's data type. */
5459 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5461 /* Check low and high label values are integers. */
5462 if (TREE_CODE (n
->low
) != INTEGER_CST
)
5464 if (TREE_CODE (n
->high
) != INTEGER_CST
)
5467 n
->low
= convert (index_type
, n
->low
);
5468 n
->high
= convert (index_type
, n
->high
);
5470 /* Count the elements and track the largest and smallest
5471 of them (treating them as signed even if they are not). */
5479 if (INT_CST_LT (n
->low
, minval
))
5481 if (INT_CST_LT (maxval
, n
->high
))
5484 /* A range counts double, since it requires two compares. */
5485 if (! tree_int_cst_equal (n
->low
, n
->high
))
5488 /* Count the number of unique case node targets. */
5490 lab
= label_rtx (n
->code_label
);
5491 for (m
= thiscase
->data
.case_stmt
.case_list
; m
!= n
; m
= m
->right
)
5492 if (same_case_target_p (label_rtx (m
->code_label
), lab
))
5499 /* Compute span of values. */
5501 range
= fold (build (MINUS_EXPR
, index_type
, maxval
, minval
));
5503 end_cleanup_deferral ();
5507 expand_expr (index_expr
, const0_rtx
, VOIDmode
, 0);
5509 emit_jump (default_label
);
5512 /* Try implementing this switch statement by a short sequence of
5513 bit-wise comparisons. However, we let the binary-tree case
5514 below handle constant index expressions. */
5515 else if (CASE_USE_BIT_TESTS
5516 && ! TREE_CONSTANT (index_expr
)
5517 && compare_tree_int (range
, GET_MODE_BITSIZE (word_mode
)) < 0
5518 && compare_tree_int (range
, 0) > 0
5519 && lshift_cheap_p ()
5520 && ((uniq
== 1 && count
>= 3)
5521 || (uniq
== 2 && count
>= 5)
5522 || (uniq
== 3 && count
>= 6)))
5524 /* Optimize the case where all the case values fit in a
5525 word without having to subtract MINVAL. In this case,
5526 we can optimize away the subtraction. */
5527 if (compare_tree_int (minval
, 0) > 0
5528 && compare_tree_int (maxval
, GET_MODE_BITSIZE (word_mode
)) < 0)
5530 minval
= integer_zero_node
;
5533 emit_case_bit_tests (index_type
, index_expr
, minval
, range
,
5534 thiscase
->data
.case_stmt
.case_list
,
5538 /* If range of values is much bigger than number of values,
5539 make a sequence of conditional branches instead of a dispatch.
5540 If the switch-index is a constant, do it this way
5541 because we can optimize it. */
5543 else if (count
< case_values_threshold ()
5544 || compare_tree_int (range
, 10 * count
) > 0
5545 /* RANGE may be signed, and really large ranges will show up
5546 as negative numbers. */
5547 || compare_tree_int (range
, 0) < 0
5548 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5551 || TREE_CONSTANT (index_expr
))
5553 index
= expand_expr (index_expr
, NULL_RTX
, VOIDmode
, 0);
5555 /* If the index is a short or char that we do not have
5556 an insn to handle comparisons directly, convert it to
5557 a full integer now, rather than letting each comparison
5558 generate the conversion. */
5560 if (GET_MODE_CLASS (GET_MODE (index
)) == MODE_INT
5561 && ! have_insn_for (COMPARE
, GET_MODE (index
)))
5563 enum machine_mode wider_mode
;
5564 for (wider_mode
= GET_MODE (index
); wider_mode
!= VOIDmode
;
5565 wider_mode
= GET_MODE_WIDER_MODE (wider_mode
))
5566 if (have_insn_for (COMPARE
, wider_mode
))
5568 index
= convert_to_mode (wider_mode
, index
, unsignedp
);
5574 do_pending_stack_adjust ();
5576 index
= protect_from_queue (index
, 0);
5577 if (GET_CODE (index
) == MEM
)
5578 index
= copy_to_reg (index
);
5579 if (GET_CODE (index
) == CONST_INT
5580 || TREE_CODE (index_expr
) == INTEGER_CST
)
5582 /* Make a tree node with the proper constant value
5583 if we don't already have one. */
5584 if (TREE_CODE (index_expr
) != INTEGER_CST
)
5587 = build_int_2 (INTVAL (index
),
5588 unsignedp
|| INTVAL (index
) >= 0 ? 0 : -1);
5589 index_expr
= convert (index_type
, index_expr
);
5592 /* For constant index expressions we need only
5593 issue an unconditional branch to the appropriate
5594 target code. The job of removing any unreachable
5595 code is left to the optimisation phase if the
5596 "-O" option is specified. */
5597 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5598 if (! tree_int_cst_lt (index_expr
, n
->low
)
5599 && ! tree_int_cst_lt (n
->high
, index_expr
))
5603 emit_jump (label_rtx (n
->code_label
));
5605 emit_jump (default_label
);
5609 /* If the index expression is not constant we generate
5610 a binary decision tree to select the appropriate
5611 target code. This is done as follows:
5613 The list of cases is rearranged into a binary tree,
5614 nearly optimal assuming equal probability for each case.
5616 The tree is transformed into RTL, eliminating
5617 redundant test conditions at the same time.
5619 If program flow could reach the end of the
5620 decision tree an unconditional jump to the
5621 default code is emitted. */
5624 = (TREE_CODE (orig_type
) != ENUMERAL_TYPE
5625 && estimate_case_costs (thiscase
->data
.case_stmt
.case_list
));
5626 balance_case_nodes (&thiscase
->data
.case_stmt
.case_list
, NULL
);
5627 emit_case_nodes (index
, thiscase
->data
.case_stmt
.case_list
,
5628 default_label
, index_type
);
5629 emit_jump_if_reachable (default_label
);
5634 table_label
= gen_label_rtx ();
5635 if (! try_casesi (index_type
, index_expr
, minval
, range
,
5636 table_label
, default_label
))
5638 index_type
= thiscase
->data
.case_stmt
.nominal_type
;
5640 /* Index jumptables from zero for suitable values of
5641 minval to avoid a subtraction. */
5643 && compare_tree_int (minval
, 0) > 0
5644 && compare_tree_int (minval
, 3) < 0)
5646 minval
= integer_zero_node
;
5650 if (! try_tablejump (index_type
, index_expr
, minval
, range
,
5651 table_label
, default_label
))
5655 /* Get table of labels to jump to, in order of case index. */
5657 ncases
= tree_low_cst (range
, 0) + 1;
5658 labelvec
= (rtx
*) alloca (ncases
* sizeof (rtx
));
5659 memset ((char *) labelvec
, 0, ncases
* sizeof (rtx
));
5661 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5663 /* Compute the low and high bounds relative to the minimum
5664 value since that should fit in a HOST_WIDE_INT while the
5665 actual values may not. */
5667 = tree_low_cst (fold (build (MINUS_EXPR
, index_type
,
5668 n
->low
, minval
)), 1);
5669 HOST_WIDE_INT i_high
5670 = tree_low_cst (fold (build (MINUS_EXPR
, index_type
,
5671 n
->high
, minval
)), 1);
5674 for (i
= i_low
; i
<= i_high
; i
++)
5676 = gen_rtx_LABEL_REF (Pmode
, label_rtx (n
->code_label
));
5679 /* Fill in the gaps with the default. */
5680 for (i
= 0; i
< ncases
; i
++)
5681 if (labelvec
[i
] == 0)
5682 labelvec
[i
] = gen_rtx_LABEL_REF (Pmode
, default_label
);
5684 /* Output the table */
5685 emit_label (table_label
);
5687 if (CASE_VECTOR_PC_RELATIVE
|| flag_pic
)
5688 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE
,
5689 gen_rtx_LABEL_REF (Pmode
, table_label
),
5690 gen_rtvec_v (ncases
, labelvec
),
5691 const0_rtx
, const0_rtx
));
5693 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE
,
5694 gen_rtvec_v (ncases
, labelvec
)));
5696 /* If the case insn drops through the table,
5697 after the table we must jump to the default-label.
5698 Otherwise record no drop-through after the table. */
5699 #ifdef CASE_DROPS_THROUGH
5700 emit_jump (default_label
);
5706 before_case
= NEXT_INSN (before_case
);
5707 end
= get_last_insn ();
5708 if (squeeze_notes (&before_case
, &end
))
5710 reorder_insns (before_case
, end
,
5711 thiscase
->data
.case_stmt
.start
);
5714 end_cleanup_deferral ();
5716 if (thiscase
->exit_label
&& !exit_done
)
5717 emit_label (thiscase
->exit_label
);
5719 POPSTACK (case_stack
);
5724 /* Convert the tree NODE into a list linked by the right field, with the left
5725 field zeroed. RIGHT is used for recursion; it is a list to be placed
5726 rightmost in the resulting list. */
5728 static struct case_node
*
5729 case_tree2list (node
, right
)
5730 struct case_node
*node
, *right
;
5732 struct case_node
*left
;
5735 right
= case_tree2list (node
->right
, right
);
5737 node
->right
= right
;
5738 if ((left
= node
->left
))
5741 return case_tree2list (left
, node
);
5747 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5750 do_jump_if_equal (op1
, op2
, label
, unsignedp
)
5751 rtx op1
, op2
, label
;
5754 if (GET_CODE (op1
) == CONST_INT
&& GET_CODE (op2
) == CONST_INT
)
5756 if (INTVAL (op1
) == INTVAL (op2
))
5760 emit_cmp_and_jump_insns (op1
, op2
, EQ
, NULL_RTX
,
5761 (GET_MODE (op1
) == VOIDmode
5762 ? GET_MODE (op2
) : GET_MODE (op1
)),
5766 /* Not all case values are encountered equally. This function
5767 uses a heuristic to weight case labels, in cases where that
5768 looks like a reasonable thing to do.
5770 Right now, all we try to guess is text, and we establish the
5773 chars above space: 16
5782 If we find any cases in the switch that are not either -1 or in the range
5783 of valid ASCII characters, or are control characters other than those
5784 commonly used with "\", don't treat this switch scanning text.
5786 Return 1 if these nodes are suitable for cost estimation, otherwise
5790 estimate_case_costs (node
)
5793 tree min_ascii
= integer_minus_one_node
;
5794 tree max_ascii
= convert (TREE_TYPE (node
->high
), build_int_2 (127, 0));
5798 /* If we haven't already made the cost table, make it now. Note that the
5799 lower bound of the table is -1, not zero. */
5801 if (! cost_table_initialized
)
5803 cost_table_initialized
= 1;
5805 for (i
= 0; i
< 128; i
++)
5808 COST_TABLE (i
) = 16;
5809 else if (ISPUNCT (i
))
5811 else if (ISCNTRL (i
))
5812 COST_TABLE (i
) = -1;
5815 COST_TABLE (' ') = 8;
5816 COST_TABLE ('\t') = 4;
5817 COST_TABLE ('\0') = 4;
5818 COST_TABLE ('\n') = 2;
5819 COST_TABLE ('\f') = 1;
5820 COST_TABLE ('\v') = 1;
5821 COST_TABLE ('\b') = 1;
5824 /* See if all the case expressions look like text. It is text if the
5825 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5826 as signed arithmetic since we don't want to ever access cost_table with a
5827 value less than -1. Also check that none of the constants in a range
5828 are strange control characters. */
5830 for (n
= node
; n
; n
= n
->right
)
5832 if ((INT_CST_LT (n
->low
, min_ascii
)) || INT_CST_LT (max_ascii
, n
->high
))
5835 for (i
= (HOST_WIDE_INT
) TREE_INT_CST_LOW (n
->low
);
5836 i
<= (HOST_WIDE_INT
) TREE_INT_CST_LOW (n
->high
); i
++)
5837 if (COST_TABLE (i
) < 0)
5841 /* All interesting values are within the range of interesting
5842 ASCII characters. */
5846 /* Determine whether two case labels branch to the same target. */
5849 same_case_target_p (l1
, l2
)
5857 i1
= next_real_insn (l1
);
5858 i2
= next_real_insn (l2
);
5862 if (i1
&& simplejump_p (i1
))
5864 l1
= XEXP (SET_SRC (PATTERN (i1
)), 0);
5867 if (i2
&& simplejump_p (i2
))
5869 l2
= XEXP (SET_SRC (PATTERN (i2
)), 0);
5874 /* Delete nodes that branch to the default label from a list of
5875 case nodes. Eg. case 5: default: becomes just default: */
5878 strip_default_case_nodes (prev
, deflab
)
5879 case_node_ptr
*prev
;
5887 if (same_case_target_p (label_rtx (ptr
->code_label
), deflab
))
5894 /* Scan an ordered list of case nodes
5895 combining those with consecutive values or ranges.
5897 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5900 group_case_nodes (head
)
5903 case_node_ptr node
= head
;
5907 rtx lab
= label_rtx (node
->code_label
);
5908 case_node_ptr np
= node
;
5910 /* Try to group the successors of NODE with NODE. */
5911 while (((np
= np
->right
) != 0)
5912 /* Do they jump to the same place? */
5913 && same_case_target_p (label_rtx (np
->code_label
), lab
)
5914 /* Are their ranges consecutive? */
5915 && tree_int_cst_equal (np
->low
,
5916 fold (build (PLUS_EXPR
,
5917 TREE_TYPE (node
->high
),
5920 /* An overflow is not consecutive. */
5921 && tree_int_cst_lt (node
->high
,
5922 fold (build (PLUS_EXPR
,
5923 TREE_TYPE (node
->high
),
5925 integer_one_node
))))
5927 node
->high
= np
->high
;
5929 /* NP is the first node after NODE which can't be grouped with it.
5930 Delete the nodes in between, and move on to that node. */
5936 /* Take an ordered list of case nodes
5937 and transform them into a near optimal binary tree,
5938 on the assumption that any target code selection value is as
5939 likely as any other.
5941 The transformation is performed by splitting the ordered
5942 list into two equal sections plus a pivot. The parts are
5943 then attached to the pivot as left and right branches. Each
5944 branch is then transformed recursively. */
5947 balance_case_nodes (head
, parent
)
5948 case_node_ptr
*head
;
5949 case_node_ptr parent
;
5962 /* Count the number of entries on branch. Also count the ranges. */
5966 if (!tree_int_cst_equal (np
->low
, np
->high
))
5970 cost
+= COST_TABLE (TREE_INT_CST_LOW (np
->high
));
5974 cost
+= COST_TABLE (TREE_INT_CST_LOW (np
->low
));
5982 /* Split this list if it is long enough for that to help. */
5987 /* Find the place in the list that bisects the list's total cost,
5988 Here I gets half the total cost. */
5993 /* Skip nodes while their cost does not reach that amount. */
5994 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
5995 i
-= COST_TABLE (TREE_INT_CST_LOW ((*npp
)->high
));
5996 i
-= COST_TABLE (TREE_INT_CST_LOW ((*npp
)->low
));
5999 npp
= &(*npp
)->right
;
6004 /* Leave this branch lopsided, but optimize left-hand
6005 side and fill in `parent' fields for right-hand side. */
6007 np
->parent
= parent
;
6008 balance_case_nodes (&np
->left
, np
);
6009 for (; np
->right
; np
= np
->right
)
6010 np
->right
->parent
= np
;
6014 /* If there are just three nodes, split at the middle one. */
6016 npp
= &(*npp
)->right
;
6019 /* Find the place in the list that bisects the list's total cost,
6020 where ranges count as 2.
6021 Here I gets half the total cost. */
6022 i
= (i
+ ranges
+ 1) / 2;
6025 /* Skip nodes while their cost does not reach that amount. */
6026 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
6031 npp
= &(*npp
)->right
;
6036 np
->parent
= parent
;
6039 /* Optimize each of the two split parts. */
6040 balance_case_nodes (&np
->left
, np
);
6041 balance_case_nodes (&np
->right
, np
);
6045 /* Else leave this branch as one level,
6046 but fill in `parent' fields. */
6048 np
->parent
= parent
;
6049 for (; np
->right
; np
= np
->right
)
6050 np
->right
->parent
= np
;
6055 /* Search the parent sections of the case node tree
6056 to see if a test for the lower bound of NODE would be redundant.
6057 INDEX_TYPE is the type of the index expression.
6059 The instructions to generate the case decision tree are
6060 output in the same order as nodes are processed so it is
6061 known that if a parent node checks the range of the current
6062 node minus one that the current node is bounded at its lower
6063 span. Thus the test would be redundant. */
6066 node_has_low_bound (node
, index_type
)
6071 case_node_ptr pnode
;
6073 /* If the lower bound of this node is the lowest value in the index type,
6074 we need not test it. */
6076 if (tree_int_cst_equal (node
->low
, TYPE_MIN_VALUE (index_type
)))
6079 /* If this node has a left branch, the value at the left must be less
6080 than that at this node, so it cannot be bounded at the bottom and
6081 we need not bother testing any further. */
6086 low_minus_one
= fold (build (MINUS_EXPR
, TREE_TYPE (node
->low
),
6087 node
->low
, integer_one_node
));
6089 /* If the subtraction above overflowed, we can't verify anything.
6090 Otherwise, look for a parent that tests our value - 1. */
6092 if (! tree_int_cst_lt (low_minus_one
, node
->low
))
6095 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
6096 if (tree_int_cst_equal (low_minus_one
, pnode
->high
))
6102 /* Search the parent sections of the case node tree
6103 to see if a test for the upper bound of NODE would be redundant.
6104 INDEX_TYPE is the type of the index expression.
6106 The instructions to generate the case decision tree are
6107 output in the same order as nodes are processed so it is
6108 known that if a parent node checks the range of the current
6109 node plus one that the current node is bounded at its upper
6110 span. Thus the test would be redundant. */
6113 node_has_high_bound (node
, index_type
)
6118 case_node_ptr pnode
;
6120 /* If there is no upper bound, obviously no test is needed. */
6122 if (TYPE_MAX_VALUE (index_type
) == NULL
)
6125 /* If the upper bound of this node is the highest value in the type
6126 of the index expression, we need not test against it. */
6128 if (tree_int_cst_equal (node
->high
, TYPE_MAX_VALUE (index_type
)))
6131 /* If this node has a right branch, the value at the right must be greater
6132 than that at this node, so it cannot be bounded at the top and
6133 we need not bother testing any further. */
6138 high_plus_one
= fold (build (PLUS_EXPR
, TREE_TYPE (node
->high
),
6139 node
->high
, integer_one_node
));
6141 /* If the addition above overflowed, we can't verify anything.
6142 Otherwise, look for a parent that tests our value + 1. */
6144 if (! tree_int_cst_lt (node
->high
, high_plus_one
))
6147 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
6148 if (tree_int_cst_equal (high_plus_one
, pnode
->low
))
6154 /* Search the parent sections of the
6155 case node tree to see if both tests for the upper and lower
6156 bounds of NODE would be redundant. */
6159 node_is_bounded (node
, index_type
)
6163 return (node_has_low_bound (node
, index_type
)
6164 && node_has_high_bound (node
, index_type
));
6167 /* Emit an unconditional jump to LABEL unless it would be dead code. */
6170 emit_jump_if_reachable (label
)
6173 if (GET_CODE (get_last_insn ()) != BARRIER
)
6177 /* Emit step-by-step code to select a case for the value of INDEX.
6178 The thus generated decision tree follows the form of the
6179 case-node binary tree NODE, whose nodes represent test conditions.
6180 INDEX_TYPE is the type of the index of the switch.
6182 Care is taken to prune redundant tests from the decision tree
6183 by detecting any boundary conditions already checked by
6184 emitted rtx. (See node_has_high_bound, node_has_low_bound
6185 and node_is_bounded, above.)
6187 Where the test conditions can be shown to be redundant we emit
6188 an unconditional jump to the target code. As a further
6189 optimization, the subordinates of a tree node are examined to
6190 check for bounded nodes. In this case conditional and/or
6191 unconditional jumps as a result of the boundary check for the
6192 current node are arranged to target the subordinates associated
6193 code for out of bound conditions on the current node.
6195 We can assume that when control reaches the code generated here,
6196 the index value has already been compared with the parents
6197 of this node, and determined to be on the same side of each parent
6198 as this node is. Thus, if this node tests for the value 51,
6199 and a parent tested for 52, we don't need to consider
6200 the possibility of a value greater than 51. If another parent
6201 tests for the value 50, then this node need not test anything. */
6204 emit_case_nodes (index
, node
, default_label
, index_type
)
6210 /* If INDEX has an unsigned type, we must make unsigned branches. */
6211 int unsignedp
= TREE_UNSIGNED (index_type
);
6212 enum machine_mode mode
= GET_MODE (index
);
6213 enum machine_mode imode
= TYPE_MODE (index_type
);
6215 /* See if our parents have already tested everything for us.
6216 If they have, emit an unconditional jump for this node. */
6217 if (node_is_bounded (node
, index_type
))
6218 emit_jump (label_rtx (node
->code_label
));
6220 else if (tree_int_cst_equal (node
->low
, node
->high
))
6222 /* Node is single valued. First see if the index expression matches
6223 this node and then check our children, if any. */
6225 do_jump_if_equal (index
,
6226 convert_modes (mode
, imode
,
6227 expand_expr (node
->low
, NULL_RTX
,
6230 label_rtx (node
->code_label
), unsignedp
);
6232 if (node
->right
!= 0 && node
->left
!= 0)
6234 /* This node has children on both sides.
6235 Dispatch to one side or the other
6236 by comparing the index value with this node's value.
6237 If one subtree is bounded, check that one first,
6238 so we can avoid real branches in the tree. */
6240 if (node_is_bounded (node
->right
, index_type
))
6242 emit_cmp_and_jump_insns (index
,
6245 expand_expr (node
->high
, NULL_RTX
,
6248 GT
, NULL_RTX
, mode
, unsignedp
,
6249 label_rtx (node
->right
->code_label
));
6250 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6253 else if (node_is_bounded (node
->left
, index_type
))
6255 emit_cmp_and_jump_insns (index
,
6258 expand_expr (node
->high
, NULL_RTX
,
6261 LT
, NULL_RTX
, mode
, unsignedp
,
6262 label_rtx (node
->left
->code_label
));
6263 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6268 /* Neither node is bounded. First distinguish the two sides;
6269 then emit the code for one side at a time. */
6271 tree test_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
6273 /* See if the value is on the right. */
6274 emit_cmp_and_jump_insns (index
,
6277 expand_expr (node
->high
, NULL_RTX
,
6280 GT
, NULL_RTX
, mode
, unsignedp
,
6281 label_rtx (test_label
));
6283 /* Value must be on the left.
6284 Handle the left-hand subtree. */
6285 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6286 /* If left-hand subtree does nothing,
6288 emit_jump_if_reachable (default_label
);
6290 /* Code branches here for the right-hand subtree. */
6291 expand_label (test_label
);
6292 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6296 else if (node
->right
!= 0 && node
->left
== 0)
6298 /* Here we have a right child but no left so we issue conditional
6299 branch to default and process the right child.
6301 Omit the conditional branch to default if we it avoid only one
6302 right child; it costs too much space to save so little time. */
6304 if (node
->right
->right
|| node
->right
->left
6305 || !tree_int_cst_equal (node
->right
->low
, node
->right
->high
))
6307 if (!node_has_low_bound (node
, index_type
))
6309 emit_cmp_and_jump_insns (index
,
6312 expand_expr (node
->high
, NULL_RTX
,
6315 LT
, NULL_RTX
, mode
, unsignedp
,
6319 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6322 /* We cannot process node->right normally
6323 since we haven't ruled out the numbers less than
6324 this node's value. So handle node->right explicitly. */
6325 do_jump_if_equal (index
,
6328 expand_expr (node
->right
->low
, NULL_RTX
,
6331 label_rtx (node
->right
->code_label
), unsignedp
);
6334 else if (node
->right
== 0 && node
->left
!= 0)
6336 /* Just one subtree, on the left. */
6337 if (node
->left
->left
|| node
->left
->right
6338 || !tree_int_cst_equal (node
->left
->low
, node
->left
->high
))
6340 if (!node_has_high_bound (node
, index_type
))
6342 emit_cmp_and_jump_insns (index
,
6345 expand_expr (node
->high
, NULL_RTX
,
6348 GT
, NULL_RTX
, mode
, unsignedp
,
6352 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6355 /* We cannot process node->left normally
6356 since we haven't ruled out the numbers less than
6357 this node's value. So handle node->left explicitly. */
6358 do_jump_if_equal (index
,
6361 expand_expr (node
->left
->low
, NULL_RTX
,
6364 label_rtx (node
->left
->code_label
), unsignedp
);
6369 /* Node is a range. These cases are very similar to those for a single
6370 value, except that we do not start by testing whether this node
6371 is the one to branch to. */
6373 if (node
->right
!= 0 && node
->left
!= 0)
6375 /* Node has subtrees on both sides.
6376 If the right-hand subtree is bounded,
6377 test for it first, since we can go straight there.
6378 Otherwise, we need to make a branch in the control structure,
6379 then handle the two subtrees. */
6380 tree test_label
= 0;
6382 if (node_is_bounded (node
->right
, index_type
))
6383 /* Right hand node is fully bounded so we can eliminate any
6384 testing and branch directly to the target code. */
6385 emit_cmp_and_jump_insns (index
,
6388 expand_expr (node
->high
, NULL_RTX
,
6391 GT
, NULL_RTX
, mode
, unsignedp
,
6392 label_rtx (node
->right
->code_label
));
6395 /* Right hand node requires testing.
6396 Branch to a label where we will handle it later. */
6398 test_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
6399 emit_cmp_and_jump_insns (index
,
6402 expand_expr (node
->high
, NULL_RTX
,
6405 GT
, NULL_RTX
, mode
, unsignedp
,
6406 label_rtx (test_label
));
6409 /* Value belongs to this node or to the left-hand subtree. */
6411 emit_cmp_and_jump_insns (index
,
6414 expand_expr (node
->low
, NULL_RTX
,
6417 GE
, NULL_RTX
, mode
, unsignedp
,
6418 label_rtx (node
->code_label
));
6420 /* Handle the left-hand subtree. */
6421 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6423 /* If right node had to be handled later, do that now. */
6427 /* If the left-hand subtree fell through,
6428 don't let it fall into the right-hand subtree. */
6429 emit_jump_if_reachable (default_label
);
6431 expand_label (test_label
);
6432 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6436 else if (node
->right
!= 0 && node
->left
== 0)
6438 /* Deal with values to the left of this node,
6439 if they are possible. */
6440 if (!node_has_low_bound (node
, index_type
))
6442 emit_cmp_and_jump_insns (index
,
6445 expand_expr (node
->low
, NULL_RTX
,
6448 LT
, NULL_RTX
, mode
, unsignedp
,
6452 /* Value belongs to this node or to the right-hand subtree. */
6454 emit_cmp_and_jump_insns (index
,
6457 expand_expr (node
->high
, NULL_RTX
,
6460 LE
, NULL_RTX
, mode
, unsignedp
,
6461 label_rtx (node
->code_label
));
6463 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6466 else if (node
->right
== 0 && node
->left
!= 0)
6468 /* Deal with values to the right of this node,
6469 if they are possible. */
6470 if (!node_has_high_bound (node
, index_type
))
6472 emit_cmp_and_jump_insns (index
,
6475 expand_expr (node
->high
, NULL_RTX
,
6478 GT
, NULL_RTX
, mode
, unsignedp
,
6482 /* Value belongs to this node or to the left-hand subtree. */
6484 emit_cmp_and_jump_insns (index
,
6487 expand_expr (node
->low
, NULL_RTX
,
6490 GE
, NULL_RTX
, mode
, unsignedp
,
6491 label_rtx (node
->code_label
));
6493 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6498 /* Node has no children so we check low and high bounds to remove
6499 redundant tests. Only one of the bounds can exist,
6500 since otherwise this node is bounded--a case tested already. */
6501 int high_bound
= node_has_high_bound (node
, index_type
);
6502 int low_bound
= node_has_low_bound (node
, index_type
);
6504 if (!high_bound
&& low_bound
)
6506 emit_cmp_and_jump_insns (index
,
6509 expand_expr (node
->high
, NULL_RTX
,
6512 GT
, NULL_RTX
, mode
, unsignedp
,
6516 else if (!low_bound
&& high_bound
)
6518 emit_cmp_and_jump_insns (index
,
6521 expand_expr (node
->low
, NULL_RTX
,
6524 LT
, NULL_RTX
, mode
, unsignedp
,
6527 else if (!low_bound
&& !high_bound
)
6529 /* Widen LOW and HIGH to the same width as INDEX. */
6530 tree type
= (*lang_hooks
.types
.type_for_mode
) (mode
, unsignedp
);
6531 tree low
= build1 (CONVERT_EXPR
, type
, node
->low
);
6532 tree high
= build1 (CONVERT_EXPR
, type
, node
->high
);
6533 rtx low_rtx
, new_index
, new_bound
;
6535 /* Instead of doing two branches, emit one unsigned branch for
6536 (index-low) > (high-low). */
6537 low_rtx
= expand_expr (low
, NULL_RTX
, mode
, 0);
6538 new_index
= expand_simple_binop (mode
, MINUS
, index
, low_rtx
,
6539 NULL_RTX
, unsignedp
,
6541 new_bound
= expand_expr (fold (build (MINUS_EXPR
, type
,
6545 emit_cmp_and_jump_insns (new_index
, new_bound
, GT
, NULL_RTX
,
6546 mode
, 1, default_label
);
6549 emit_jump (label_rtx (node
->code_label
));
6554 #include "gt-stmt.h"