1 /* Expands front end tree to back end RTL for GCC
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"
62 /* Assume that case vectors are not pc-relative. */
63 #ifndef CASE_VECTOR_PC_RELATIVE
64 #define CASE_VECTOR_PC_RELATIVE 0
67 /* Functions and data structures for expanding case statements. */
69 /* Case label structure, used to hold info on labels within case
70 statements. We handle "range" labels; for a single-value label
71 as in C, the high and low limits are the same.
73 An AVL tree of case nodes is initially created, and later transformed
74 to a list linked via the RIGHT fields in the nodes. Nodes with
75 higher case values are later in the list.
77 Switch statements can be output in one of two forms. A branch table
78 is used if there are more than a few labels and the labels are dense
79 within the range between the smallest and largest case value. If a
80 branch table is used, no further manipulations are done with the case
83 The alternative to the use of a branch table is to generate a series
84 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
85 and PARENT fields to hold a binary tree. Initially the tree is
86 totally unbalanced, with everything on the right. We balance the tree
87 with nodes on the left having lower case values than the parent
88 and nodes on the right having higher values. We then output the tree
91 struct case_node
GTY(())
93 struct case_node
*left
; /* Left son in binary tree */
94 struct case_node
*right
; /* Right son in binary tree; also node chain */
95 struct case_node
*parent
; /* Parent of node in binary tree */
96 tree low
; /* Lowest index value for this label */
97 tree high
; /* Highest index value for this label */
98 tree code_label
; /* Label to jump to when node matches */
102 typedef struct case_node case_node
;
103 typedef struct case_node
*case_node_ptr
;
105 /* These are used by estimate_case_costs and balance_case_nodes. */
107 /* This must be a signed type, and non-ANSI compilers lack signed char. */
108 static short cost_table_
[129];
109 static int use_cost_table
;
110 static int cost_table_initialized
;
112 /* Special care is needed because we allow -1, but TREE_INT_CST_LOW
114 #define COST_TABLE(I) cost_table_[(unsigned HOST_WIDE_INT) ((I) + 1)]
116 /* Stack of control and binding constructs we are currently inside.
118 These constructs begin when you call `expand_start_WHATEVER'
119 and end when you call `expand_end_WHATEVER'. This stack records
120 info about how the construct began that tells the end-function
121 what to do. It also may provide information about the construct
122 to alter the behavior of other constructs within the body.
123 For example, they may affect the behavior of C `break' and `continue'.
125 Each construct gets one `struct nesting' object.
126 All of these objects are chained through the `all' field.
127 `nesting_stack' points to the first object (innermost construct).
128 The position of an entry on `nesting_stack' is in its `depth' field.
130 Each type of construct has its own individual stack.
131 For example, loops have `loop_stack'. Each object points to the
132 next object of the same type through the `next' field.
134 Some constructs are visible to `break' exit-statements and others
135 are not. Which constructs are visible depends on the language.
136 Therefore, the data structure allows each construct to be visible
137 or not, according to the args given when the construct is started.
138 The construct is visible if the `exit_label' field is non-null.
139 In that case, the value should be a CODE_LABEL rtx. */
141 struct nesting
GTY(())
144 struct nesting
*next
;
155 /* For conds (if-then and if-then-else statements). */
158 /* Label for the end of the if construct.
159 There is none if EXITFLAG was not set
160 and no `else' has been seen yet. */
162 /* Label for the end of this alternative.
163 This may be the end of the if or the next else/elseif. */
165 } GTY ((tag ("COND_NESTING"))) cond
;
169 /* Label at the top of the loop; place to loop back to. */
171 /* Label at the end of the whole construct. */
173 /* Label for `continue' statement to jump to;
174 this is in front of the stepper of the loop. */
176 } GTY ((tag ("LOOP_NESTING"))) loop
;
177 /* For variable binding contours. */
180 /* Sequence number of this binding contour within the function,
181 in order of entry. */
182 int block_start_count
;
183 /* Nonzero => value to restore stack to on exit. */
185 /* The NOTE that starts this contour.
186 Used by expand_goto to check whether the destination
187 is within each contour or not. */
189 /* Innermost containing binding contour that has a stack level. */
190 struct nesting
*innermost_stack_block
;
191 /* List of cleanups to be run on exit from this contour.
192 This is a list of expressions to be evaluated.
193 The TREE_PURPOSE of each link is the ..._DECL node
194 which the cleanup pertains to. */
196 /* List of cleanup-lists of blocks containing this block,
197 as they were at the locus where this block appears.
198 There is an element for each containing block,
199 ordered innermost containing block first.
200 The tail of this list can be 0,
201 if all remaining elements would be empty lists.
202 The element's TREE_VALUE is the cleanup-list of that block,
203 which may be null. */
205 /* Chain of labels defined inside this binding contour.
206 For contours that have stack levels or cleanups. */
207 struct label_chain
*label_chain
;
208 /* Nonzero if this is associated with an EH region. */
209 int exception_region
;
210 /* The saved target_temp_slot_level from our outer block.
211 We may reset target_temp_slot_level to be the level of
212 this block, if that is done, target_temp_slot_level
213 reverts to the saved target_temp_slot_level at the very
215 int block_target_temp_slot_level
;
216 /* True if we are currently emitting insns in an area of
217 output code that is controlled by a conditional
218 expression. This is used by the cleanup handling code to
219 generate conditional cleanup actions. */
220 int conditional_code
;
221 /* A place to move the start of the exception region for any
222 of the conditional cleanups, must be at the end or after
223 the start of the last unconditional cleanup, and before any
224 conditional branch points. */
225 rtx last_unconditional_cleanup
;
226 } GTY ((tag ("BLOCK_NESTING"))) block
;
227 /* For switch (C) or case (Pascal) statements,
228 and also for dummies (see `expand_start_case_dummy'). */
231 /* The insn after which the case dispatch should finally
232 be emitted. Zero for a dummy. */
234 /* A list of case labels; it is first built as an AVL tree.
235 During expand_end_case, this is converted to a list, and may be
236 rearranged into a nearly balanced binary tree. */
237 struct case_node
*case_list
;
238 /* Label to jump to if no case matches. */
240 /* The expression to be dispatched on. */
242 /* Type that INDEX_EXPR should be converted to. */
244 /* Name of this kind of statement, for warnings. */
245 const char *printname
;
246 /* Used to save no_line_numbers till we see the first case label.
247 We set this to -1 when we see the first case label in this
249 int line_number_status
;
250 } GTY ((tag ("CASE_NESTING"))) case_stmt
;
251 } GTY ((desc ("%1.desc"))) data
;
254 /* Allocate and return a new `struct nesting'. */
256 #define ALLOC_NESTING() 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 (int, const char *);
394 static bool decl_conflicts_with_clobbers_p (tree
, const HARD_REG_SET
);
395 static void expand_goto_internal (tree
, rtx
, rtx
);
396 static int expand_fixup (tree
, rtx
, rtx
);
397 static rtx
expand_nl_handler_label (rtx
, rtx
);
398 static void expand_nl_goto_receiver (void);
399 static void expand_nl_goto_receivers (struct nesting
*);
400 static void fixup_gotos (struct nesting
*, rtx
, tree
, rtx
, int);
401 static bool check_operand_nalternatives (tree
, tree
);
402 static bool check_unique_operand_names (tree
, tree
);
403 static char *resolve_operand_name_1 (char *, tree
, tree
);
404 static void expand_null_return_1 (rtx
);
405 static enum br_predictor
return_prediction (rtx
);
406 static rtx
shift_return_value (rtx
);
407 static void expand_value_return (rtx
);
408 static int tail_recursion_args (tree
, tree
);
409 static void expand_cleanups (tree
, int, int);
410 static void check_seenlabel (void);
411 static void do_jump_if_equal (rtx
, rtx
, rtx
, int);
412 static int estimate_case_costs (case_node_ptr
);
413 static bool same_case_target_p (rtx
, rtx
);
414 static void strip_default_case_nodes (case_node_ptr
*, rtx
);
415 static bool lshift_cheap_p (void);
416 static int case_bit_test_cmp (const void *, const void *);
417 static void emit_case_bit_tests (tree
, tree
, tree
, tree
, case_node_ptr
, rtx
);
418 static void group_case_nodes (case_node_ptr
);
419 static void balance_case_nodes (case_node_ptr
*, case_node_ptr
);
420 static int node_has_low_bound (case_node_ptr
, tree
);
421 static int node_has_high_bound (case_node_ptr
, tree
);
422 static int node_is_bounded (case_node_ptr
, tree
);
423 static void emit_jump_if_reachable (rtx
);
424 static void emit_case_nodes (rtx
, case_node_ptr
, rtx
, tree
);
425 static struct case_node
*case_tree2list (case_node
*, case_node
*);
428 using_eh_for_cleanups (void)
430 using_eh_for_cleanups_p
= 1;
434 init_stmt_for_function (void)
436 cfun
->stmt
= ggc_alloc_cleared (sizeof (struct stmt_status
));
439 /* Record the current file and line. Called from emit_line_note. */
442 set_file_and_line_for_stmt (location_t location
)
444 /* If we're outputting an inline function, and we add a line note,
445 there may be no CFUN->STMT information. So, there's no need to
448 emit_locus
= location
;
451 /* Emit a no-op instruction. */
458 last_insn
= get_last_insn ();
460 && (GET_CODE (last_insn
) == CODE_LABEL
461 || (GET_CODE (last_insn
) == NOTE
462 && prev_real_insn (last_insn
) == 0)))
463 emit_insn (gen_nop ());
466 /* Return the rtx-label that corresponds to a LABEL_DECL,
467 creating it if necessary. */
470 label_rtx (tree label
)
472 if (TREE_CODE (label
) != LABEL_DECL
)
475 if (!DECL_RTL_SET_P (label
))
476 SET_DECL_RTL (label
, gen_label_rtx ());
478 return DECL_RTL (label
);
481 /* As above, but also put it on the forced-reference list of the
482 function that contains it. */
484 force_label_rtx (tree label
)
486 rtx ref
= label_rtx (label
);
487 tree function
= decl_function_context (label
);
493 if (function
!= current_function_decl
494 && function
!= inline_function_decl
)
495 p
= find_function_data (function
);
499 p
->expr
->x_forced_labels
= gen_rtx_EXPR_LIST (VOIDmode
, ref
,
500 p
->expr
->x_forced_labels
);
504 /* Add an unconditional jump to LABEL as the next sequential instruction. */
507 emit_jump (rtx label
)
509 do_pending_stack_adjust ();
510 emit_jump_insn (gen_jump (label
));
514 /* Emit code to jump to the address
515 specified by the pointer expression EXP. */
518 expand_computed_goto (tree exp
)
520 rtx x
= expand_expr (exp
, NULL_RTX
, VOIDmode
, 0);
522 x
= convert_memory_address (Pmode
, x
);
526 if (! cfun
->computed_goto_common_label
)
528 cfun
->computed_goto_common_reg
= copy_to_mode_reg (Pmode
, x
);
529 cfun
->computed_goto_common_label
= gen_label_rtx ();
530 emit_label (cfun
->computed_goto_common_label
);
532 do_pending_stack_adjust ();
533 emit_indirect_jump (cfun
->computed_goto_common_reg
);
535 current_function_has_computed_jump
= 1;
539 emit_move_insn (cfun
->computed_goto_common_reg
, x
);
540 emit_jump (cfun
->computed_goto_common_label
);
544 /* Handle goto statements and the labels that they can go to. */
546 /* Specify the location in the RTL code of a label LABEL,
547 which is a LABEL_DECL tree node.
549 This is used for the kind of label that the user can jump to with a
550 goto statement, and for alternatives of a switch or case statement.
551 RTL labels generated for loops and conditionals don't go through here;
552 they are generated directly at the RTL level, by other functions below.
554 Note that this has nothing to do with defining label *names*.
555 Languages vary in how they do that and what that even means. */
558 expand_label (tree label
)
560 struct label_chain
*p
;
562 do_pending_stack_adjust ();
563 emit_label (label_rtx (label
));
564 if (DECL_NAME (label
))
565 LABEL_NAME (DECL_RTL (label
)) = IDENTIFIER_POINTER (DECL_NAME (label
));
567 if (stack_block_stack
!= 0)
569 p
= ggc_alloc (sizeof (struct label_chain
));
570 p
->next
= stack_block_stack
->data
.block
.label_chain
;
571 stack_block_stack
->data
.block
.label_chain
= p
;
576 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
577 from nested functions. */
580 declare_nonlocal_label (tree label
)
582 rtx slot
= assign_stack_local (Pmode
, GET_MODE_SIZE (Pmode
), 0);
584 nonlocal_labels
= tree_cons (NULL_TREE
, label
, nonlocal_labels
);
585 LABEL_PRESERVE_P (label_rtx (label
)) = 1;
586 if (nonlocal_goto_handler_slots
== 0)
588 emit_stack_save (SAVE_NONLOCAL
,
589 &nonlocal_goto_stack_level
,
590 PREV_INSN (tail_recursion_reentry
));
592 nonlocal_goto_handler_slots
593 = gen_rtx_EXPR_LIST (VOIDmode
, slot
, nonlocal_goto_handler_slots
);
596 /* Generate RTL code for a `goto' statement with target label LABEL.
597 LABEL should be a LABEL_DECL tree node that was or will later be
598 defined with `expand_label'. */
601 expand_goto (tree label
)
605 /* Check for a nonlocal goto to a containing function. */
606 context
= decl_function_context (label
);
607 if (context
!= 0 && context
!= current_function_decl
)
609 struct function
*p
= find_function_data (context
);
610 rtx label_ref
= gen_rtx_LABEL_REF (Pmode
, label_rtx (label
));
611 rtx handler_slot
, static_chain
, save_area
, insn
;
614 /* Find the corresponding handler slot for this label. */
615 handler_slot
= p
->x_nonlocal_goto_handler_slots
;
616 for (link
= p
->x_nonlocal_labels
; TREE_VALUE (link
) != label
;
617 link
= TREE_CHAIN (link
))
618 handler_slot
= XEXP (handler_slot
, 1);
619 handler_slot
= XEXP (handler_slot
, 0);
621 p
->has_nonlocal_label
= 1;
622 current_function_has_nonlocal_goto
= 1;
623 LABEL_REF_NONLOCAL_P (label_ref
) = 1;
625 /* Copy the rtl for the slots so that they won't be shared in
626 case the virtual stack vars register gets instantiated differently
627 in the parent than in the child. */
629 static_chain
= copy_to_reg (lookup_static_chain (label
));
631 /* Get addr of containing function's current nonlocal goto handler,
632 which will do any cleanups and then jump to the label. */
633 handler_slot
= copy_to_reg (replace_rtx (copy_rtx (handler_slot
),
634 virtual_stack_vars_rtx
,
637 /* Get addr of containing function's nonlocal save area. */
638 save_area
= p
->x_nonlocal_goto_stack_level
;
640 save_area
= replace_rtx (copy_rtx (save_area
),
641 virtual_stack_vars_rtx
, static_chain
);
643 #if HAVE_nonlocal_goto
644 if (HAVE_nonlocal_goto
)
645 emit_insn (gen_nonlocal_goto (static_chain
, handler_slot
,
646 save_area
, label_ref
));
650 emit_insn (gen_rtx_CLOBBER (VOIDmode
,
651 gen_rtx_MEM (BLKmode
,
652 gen_rtx_SCRATCH (VOIDmode
))));
653 emit_insn (gen_rtx_CLOBBER (VOIDmode
,
654 gen_rtx_MEM (BLKmode
,
655 hard_frame_pointer_rtx
)));
657 /* Restore frame pointer for containing function.
658 This sets the actual hard register used for the frame pointer
659 to the location of the function's incoming static chain info.
660 The non-local goto handler will then adjust it to contain the
661 proper value and reload the argument pointer, if needed. */
662 emit_move_insn (hard_frame_pointer_rtx
, static_chain
);
663 emit_stack_restore (SAVE_NONLOCAL
, save_area
, NULL_RTX
);
665 /* USE of hard_frame_pointer_rtx added for consistency;
666 not clear if really needed. */
667 emit_insn (gen_rtx_USE (VOIDmode
, hard_frame_pointer_rtx
));
668 emit_insn (gen_rtx_USE (VOIDmode
, stack_pointer_rtx
));
669 emit_indirect_jump (handler_slot
);
672 /* Search backwards to the jump insn and mark it as a
674 for (insn
= get_last_insn (); insn
; insn
= PREV_INSN (insn
))
676 if (GET_CODE (insn
) == JUMP_INSN
)
678 REG_NOTES (insn
) = alloc_EXPR_LIST (REG_NON_LOCAL_GOTO
,
679 const0_rtx
, REG_NOTES (insn
));
682 else if (GET_CODE (insn
) == CALL_INSN
)
687 expand_goto_internal (label
, label_rtx (label
), NULL_RTX
);
690 /* Generate RTL code for a `goto' statement with target label BODY.
691 LABEL should be a LABEL_REF.
692 LAST_INSN, if non-0, is the rtx we should consider as the last
693 insn emitted (for the purposes of cleaning up a return). */
696 expand_goto_internal (tree body
, rtx label
, rtx last_insn
)
698 struct nesting
*block
;
701 if (GET_CODE (label
) != CODE_LABEL
)
704 /* If label has already been defined, we can tell now
705 whether and how we must alter the stack level. */
707 if (PREV_INSN (label
) != 0)
709 /* Find the innermost pending block that contains the label.
710 (Check containment by comparing insn-uids.)
711 Then restore the outermost stack level within that block,
712 and do cleanups of all blocks contained in it. */
713 for (block
= block_stack
; block
; block
= block
->next
)
715 if (INSN_UID (block
->data
.block
.first_insn
) < INSN_UID (label
))
717 if (block
->data
.block
.stack_level
!= 0)
718 stack_level
= block
->data
.block
.stack_level
;
719 /* Execute the cleanups for blocks we are exiting. */
720 if (block
->data
.block
.cleanups
!= 0)
722 expand_cleanups (block
->data
.block
.cleanups
, 1, 1);
723 do_pending_stack_adjust ();
729 /* Ensure stack adjust isn't done by emit_jump, as this
730 would clobber the stack pointer. This one should be
731 deleted as dead by flow. */
732 clear_pending_stack_adjust ();
733 do_pending_stack_adjust ();
735 /* Don't do this adjust if it's to the end label and this function
736 is to return with a depressed stack pointer. */
737 if (label
== return_label
738 && (((TREE_CODE (TREE_TYPE (current_function_decl
))
740 && (TYPE_RETURNS_STACK_DEPRESSED
741 (TREE_TYPE (current_function_decl
))))))
744 emit_stack_restore (SAVE_BLOCK
, stack_level
, NULL_RTX
);
747 if (body
!= 0 && DECL_TOO_LATE (body
))
748 error ("jump to `%s' invalidly jumps into binding contour",
749 IDENTIFIER_POINTER (DECL_NAME (body
)));
751 /* Label not yet defined: may need to put this goto
752 on the fixup list. */
753 else if (! expand_fixup (body
, label
, last_insn
))
755 /* No fixup needed. Record that the label is the target
756 of at least one goto that has no fixup. */
758 TREE_ADDRESSABLE (body
) = 1;
764 /* Generate if necessary a fixup for a goto
765 whose target label in tree structure (if any) is TREE_LABEL
766 and whose target in rtl is RTL_LABEL.
768 If LAST_INSN is nonzero, we pretend that the jump appears
769 after insn LAST_INSN instead of at the current point in the insn stream.
771 The fixup will be used later to insert insns just before the goto.
772 Those insns will restore the stack level as appropriate for the
773 target label, and will (in the case of C++) also invoke any object
774 destructors which have to be invoked when we exit the scopes which
775 are exited by the goto.
777 Value is nonzero if a fixup is made. */
780 expand_fixup (tree tree_label
, rtx rtl_label
, rtx last_insn
)
782 struct nesting
*block
, *end_block
;
784 /* See if we can recognize which block the label will be output in.
785 This is possible in some very common cases.
786 If we succeed, set END_BLOCK to that block.
787 Otherwise, set it to 0. */
790 && (rtl_label
== cond_stack
->data
.cond
.endif_label
791 || rtl_label
== cond_stack
->data
.cond
.next_label
))
792 end_block
= cond_stack
;
793 /* If we are in a loop, recognize certain labels which
794 are likely targets. This reduces the number of fixups
795 we need to create. */
797 && (rtl_label
== loop_stack
->data
.loop
.start_label
798 || rtl_label
== loop_stack
->data
.loop
.end_label
799 || rtl_label
== loop_stack
->data
.loop
.continue_label
))
800 end_block
= loop_stack
;
804 /* Now set END_BLOCK to the binding level to which we will return. */
808 struct nesting
*next_block
= end_block
->all
;
811 /* First see if the END_BLOCK is inside the innermost binding level.
812 If so, then no cleanups or stack levels are relevant. */
813 while (next_block
&& next_block
!= block
)
814 next_block
= next_block
->all
;
819 /* Otherwise, set END_BLOCK to the innermost binding level
820 which is outside the relevant control-structure nesting. */
821 next_block
= block_stack
->next
;
822 for (block
= block_stack
; block
!= end_block
; block
= block
->all
)
823 if (block
== next_block
)
824 next_block
= next_block
->next
;
825 end_block
= next_block
;
828 /* Does any containing block have a stack level or cleanups?
829 If not, no fixup is needed, and that is the normal case
830 (the only case, for standard C). */
831 for (block
= block_stack
; block
!= end_block
; block
= block
->next
)
832 if (block
->data
.block
.stack_level
!= 0
833 || block
->data
.block
.cleanups
!= 0)
836 if (block
!= end_block
)
838 /* Ok, a fixup is needed. Add a fixup to the list of such. */
839 struct goto_fixup
*fixup
= ggc_alloc (sizeof (struct goto_fixup
));
840 /* In case an old stack level is restored, make sure that comes
841 after any pending stack adjust. */
842 /* ?? If the fixup isn't to come at the present position,
843 doing the stack adjust here isn't useful. Doing it with our
844 settings at that location isn't useful either. Let's hope
847 do_pending_stack_adjust ();
848 fixup
->target
= tree_label
;
849 fixup
->target_rtl
= rtl_label
;
851 /* Create a BLOCK node and a corresponding matched set of
852 NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes at
853 this point. The notes will encapsulate any and all fixup
854 code which we might later insert at this point in the insn
855 stream. Also, the BLOCK node will be the parent (i.e. the
856 `SUPERBLOCK') of any other BLOCK nodes which we might create
857 later on when we are expanding the fixup code.
859 Note that optimization passes (including expand_end_loop)
860 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
864 rtx original_before_jump
865 = last_insn
? last_insn
: get_last_insn ();
870 block
= make_node (BLOCK
);
871 TREE_USED (block
) = 1;
873 if (!cfun
->x_whole_function_mode_p
)
874 (*lang_hooks
.decls
.insert_block
) (block
);
878 = BLOCK_CHAIN (DECL_INITIAL (current_function_decl
));
879 BLOCK_CHAIN (DECL_INITIAL (current_function_decl
))
884 start
= emit_note (NOTE_INSN_BLOCK_BEG
);
885 if (cfun
->x_whole_function_mode_p
)
886 NOTE_BLOCK (start
) = block
;
887 fixup
->before_jump
= emit_note (NOTE_INSN_DELETED
);
888 end
= emit_note (NOTE_INSN_BLOCK_END
);
889 if (cfun
->x_whole_function_mode_p
)
890 NOTE_BLOCK (end
) = block
;
891 fixup
->context
= block
;
893 emit_insn_after (start
, original_before_jump
);
896 fixup
->block_start_count
= current_block_start_count
;
897 fixup
->stack_level
= 0;
898 fixup
->cleanup_list_list
899 = ((block
->data
.block
.outer_cleanups
900 || block
->data
.block
.cleanups
)
901 ? tree_cons (NULL_TREE
, block
->data
.block
.cleanups
,
902 block
->data
.block
.outer_cleanups
)
904 fixup
->next
= goto_fixup_chain
;
905 goto_fixup_chain
= fixup
;
911 /* Expand any needed fixups in the outputmost binding level of the
912 function. FIRST_INSN is the first insn in the function. */
915 expand_fixups (rtx first_insn
)
917 fixup_gotos (NULL
, NULL_RTX
, NULL_TREE
, first_insn
, 0);
920 /* When exiting a binding contour, process all pending gotos requiring fixups.
921 THISBLOCK is the structure that describes the block being exited.
922 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
923 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
924 FIRST_INSN is the insn that began this contour.
926 Gotos that jump out of this contour must restore the
927 stack level and do the cleanups before actually jumping.
929 DONT_JUMP_IN positive means report error if there is a jump into this
930 contour from before the beginning of the contour. This is also done if
931 STACK_LEVEL is nonzero unless DONT_JUMP_IN is negative. */
934 fixup_gotos (struct nesting
*thisblock
, rtx stack_level
,
935 tree cleanup_list
, rtx first_insn
, int dont_jump_in
)
937 struct goto_fixup
*f
, *prev
;
939 /* F is the fixup we are considering; PREV is the previous one. */
940 /* We run this loop in two passes so that cleanups of exited blocks
941 are run first, and blocks that are exited are marked so
944 for (prev
= 0, f
= goto_fixup_chain
; f
; prev
= f
, f
= f
->next
)
946 /* Test for a fixup that is inactive because it is already handled. */
947 if (f
->before_jump
== 0)
949 /* Delete inactive fixup from the chain, if that is easy to do. */
951 prev
->next
= f
->next
;
953 /* Has this fixup's target label been defined?
954 If so, we can finalize it. */
955 else if (PREV_INSN (f
->target_rtl
) != 0)
959 /* If this fixup jumped into this contour from before the beginning
960 of this contour, report an error. This code used to use
961 the first non-label insn after f->target_rtl, but that's
962 wrong since such can be added, by things like put_var_into_stack
963 and have INSN_UIDs that are out of the range of the block. */
964 /* ??? Bug: this does not detect jumping in through intermediate
965 blocks that have stack levels or cleanups.
966 It detects only a problem with the innermost block
969 && (dont_jump_in
> 0 || (dont_jump_in
== 0 && stack_level
)
971 && INSN_UID (first_insn
) < INSN_UID (f
->target_rtl
)
972 && INSN_UID (first_insn
) > INSN_UID (f
->before_jump
)
973 && ! DECL_ERROR_ISSUED (f
->target
))
975 error ("%Jlabel '%D' used before containing binding contour",
976 f
->target
, f
->target
);
977 /* Prevent multiple errors for one label. */
978 DECL_ERROR_ISSUED (f
->target
) = 1;
981 /* We will expand the cleanups into a sequence of their own and
982 then later on we will attach this new sequence to the insn
983 stream just ahead of the actual jump insn. */
987 /* Temporarily restore the lexical context where we will
988 logically be inserting the fixup code. We do this for the
989 sake of getting the debugging information right. */
991 (*lang_hooks
.decls
.pushlevel
) (0);
992 (*lang_hooks
.decls
.set_block
) (f
->context
);
994 /* Expand the cleanups for blocks this jump exits. */
995 if (f
->cleanup_list_list
)
998 for (lists
= f
->cleanup_list_list
; lists
; lists
= TREE_CHAIN (lists
))
999 /* Marked elements correspond to blocks that have been closed.
1000 Do their cleanups. */
1001 if (TREE_ADDRESSABLE (lists
)
1002 && TREE_VALUE (lists
) != 0)
1004 expand_cleanups (TREE_VALUE (lists
), 1, 1);
1005 /* Pop any pushes done in the cleanups,
1006 in case function is about to return. */
1007 do_pending_stack_adjust ();
1011 /* Restore stack level for the biggest contour that this
1012 jump jumps out of. */
1014 && ! (f
->target_rtl
== return_label
1015 && ((TREE_CODE (TREE_TYPE (current_function_decl
))
1017 && (TYPE_RETURNS_STACK_DEPRESSED
1018 (TREE_TYPE (current_function_decl
))))))
1019 emit_stack_restore (SAVE_BLOCK
, f
->stack_level
, f
->before_jump
);
1021 /* Finish up the sequence containing the insns which implement the
1022 necessary cleanups, and then attach that whole sequence to the
1023 insn stream just ahead of the actual jump insn. Attaching it
1024 at that point insures that any cleanups which are in fact
1025 implicit C++ object destructions (which must be executed upon
1026 leaving the block) appear (to the debugger) to be taking place
1027 in an area of the generated code where the object(s) being
1028 destructed are still "in scope". */
1030 cleanup_insns
= get_insns ();
1031 (*lang_hooks
.decls
.poplevel
) (1, 0, 0);
1034 emit_insn_after (cleanup_insns
, f
->before_jump
);
1040 /* For any still-undefined labels, do the cleanups for this block now.
1041 We must do this now since items in the cleanup list may go out
1042 of scope when the block ends. */
1043 for (prev
= 0, f
= goto_fixup_chain
; f
; prev
= f
, f
= f
->next
)
1044 if (f
->before_jump
!= 0
1045 && PREV_INSN (f
->target_rtl
) == 0
1046 /* Label has still not appeared. If we are exiting a block with
1047 a stack level to restore, that started before the fixup,
1048 mark this stack level as needing restoration
1049 when the fixup is later finalized. */
1051 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1052 means the label is undefined. That's erroneous, but possible. */
1053 && (thisblock
->data
.block
.block_start_count
1054 <= f
->block_start_count
))
1056 tree lists
= f
->cleanup_list_list
;
1059 for (; lists
; lists
= TREE_CHAIN (lists
))
1060 /* If the following elt. corresponds to our containing block
1061 then the elt. must be for this block. */
1062 if (TREE_CHAIN (lists
) == thisblock
->data
.block
.outer_cleanups
)
1065 (*lang_hooks
.decls
.pushlevel
) (0);
1066 (*lang_hooks
.decls
.set_block
) (f
->context
);
1067 expand_cleanups (TREE_VALUE (lists
), 1, 1);
1068 do_pending_stack_adjust ();
1069 cleanup_insns
= get_insns ();
1070 (*lang_hooks
.decls
.poplevel
) (1, 0, 0);
1072 if (cleanup_insns
!= 0)
1074 = emit_insn_after (cleanup_insns
, f
->before_jump
);
1076 f
->cleanup_list_list
= TREE_CHAIN (lists
);
1080 f
->stack_level
= stack_level
;
1084 /* Return the number of times character C occurs in string S. */
1086 n_occurrences (int c
, const char *s
)
1094 /* Generate RTL for an asm statement (explicit assembler code).
1095 STRING is a STRING_CST node containing the assembler code text,
1096 or an ADDR_EXPR containing a STRING_CST. VOL nonzero means the
1097 insn is volatile; don't optimize it. */
1100 expand_asm (tree string
, int vol
)
1104 if (TREE_CODE (string
) == ADDR_EXPR
)
1105 string
= TREE_OPERAND (string
, 0);
1107 body
= gen_rtx_ASM_INPUT (VOIDmode
, TREE_STRING_POINTER (string
));
1109 MEM_VOLATILE_P (body
) = vol
;
1116 /* Parse the output constraint pointed to by *CONSTRAINT_P. It is the
1117 OPERAND_NUMth output operand, indexed from zero. There are NINPUTS
1118 inputs and NOUTPUTS outputs to this extended-asm. Upon return,
1119 *ALLOWS_MEM will be TRUE iff the constraint allows the use of a
1120 memory operand. Similarly, *ALLOWS_REG will be TRUE iff the
1121 constraint allows the use of a register operand. And, *IS_INOUT
1122 will be true if the operand is read-write, i.e., if it is used as
1123 an input as well as an output. If *CONSTRAINT_P is not in
1124 canonical form, it will be made canonical. (Note that `+' will be
1125 replaced with `=' as part of this process.)
1127 Returns TRUE if all went well; FALSE if an error occurred. */
1130 parse_output_constraint (const char **constraint_p
, int operand_num
,
1131 int ninputs
, int noutputs
, bool *allows_mem
,
1132 bool *allows_reg
, bool *is_inout
)
1134 const char *constraint
= *constraint_p
;
1137 /* Assume the constraint doesn't allow the use of either a register
1139 *allows_mem
= false;
1140 *allows_reg
= false;
1142 /* Allow the `=' or `+' to not be at the beginning of the string,
1143 since it wasn't explicitly documented that way, and there is a
1144 large body of code that puts it last. Swap the character to
1145 the front, so as not to uglify any place else. */
1146 p
= strchr (constraint
, '=');
1148 p
= strchr (constraint
, '+');
1150 /* If the string doesn't contain an `=', issue an error
1154 error ("output operand constraint lacks `='");
1158 /* If the constraint begins with `+', then the operand is both read
1159 from and written to. */
1160 *is_inout
= (*p
== '+');
1162 /* Canonicalize the output constraint so that it begins with `='. */
1163 if (p
!= constraint
|| is_inout
)
1166 size_t c_len
= strlen (constraint
);
1168 if (p
!= constraint
)
1169 warning ("output constraint `%c' for operand %d is not at the beginning",
1172 /* Make a copy of the constraint. */
1173 buf
= alloca (c_len
+ 1);
1174 strcpy (buf
, constraint
);
1175 /* Swap the first character and the `=' or `+'. */
1176 buf
[p
- constraint
] = buf
[0];
1177 /* Make sure the first character is an `='. (Until we do this,
1178 it might be a `+'.) */
1180 /* Replace the constraint with the canonicalized string. */
1181 *constraint_p
= ggc_alloc_string (buf
, c_len
);
1182 constraint
= *constraint_p
;
1185 /* Loop through the constraint string. */
1186 for (p
= constraint
+ 1; *p
; p
+= CONSTRAINT_LEN (*p
, p
))
1191 error ("operand constraint contains incorrectly positioned '+' or '='");
1195 if (operand_num
+ 1 == ninputs
+ noutputs
)
1197 error ("`%%' constraint used with last operand");
1202 case 'V': case 'm': case 'o':
1206 case '?': case '!': case '*': case '&': case '#':
1207 case 'E': case 'F': case 'G': case 'H':
1208 case 's': case 'i': case 'n':
1209 case 'I': case 'J': case 'K': case 'L': case 'M':
1210 case 'N': case 'O': case 'P': case ',':
1213 case '0': case '1': case '2': case '3': case '4':
1214 case '5': case '6': case '7': case '8': case '9':
1216 error ("matching constraint not valid in output operand");
1220 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1221 excepting those that expand_call created. So match memory
1238 if (REG_CLASS_FROM_CONSTRAINT (*p
, p
) != NO_REGS
)
1240 #ifdef EXTRA_CONSTRAINT_STR
1241 else if (EXTRA_ADDRESS_CONSTRAINT (*p
, p
))
1243 else if (EXTRA_MEMORY_CONSTRAINT (*p
, p
))
1247 /* Otherwise we can't assume anything about the nature of
1248 the constraint except that it isn't purely registers.
1249 Treat it like "g" and hope for the best. */
1260 /* Similar, but for input constraints. */
1263 parse_input_constraint (const char **constraint_p
, int input_num
,
1264 int ninputs
, int noutputs
, int ninout
,
1265 const char * const * constraints
,
1266 bool *allows_mem
, bool *allows_reg
)
1268 const char *constraint
= *constraint_p
;
1269 const char *orig_constraint
= constraint
;
1270 size_t c_len
= strlen (constraint
);
1273 /* Assume the constraint doesn't allow the use of either
1274 a register or memory. */
1275 *allows_mem
= false;
1276 *allows_reg
= false;
1278 /* Make sure constraint has neither `=', `+', nor '&'. */
1280 for (j
= 0; j
< c_len
; j
+= CONSTRAINT_LEN (constraint
[j
], constraint
+j
))
1281 switch (constraint
[j
])
1283 case '+': case '=': case '&':
1284 if (constraint
== orig_constraint
)
1286 error ("input operand constraint contains `%c'", constraint
[j
]);
1292 if (constraint
== orig_constraint
1293 && input_num
+ 1 == ninputs
- ninout
)
1295 error ("`%%' constraint used with last operand");
1300 case 'V': case 'm': case 'o':
1305 case '?': case '!': case '*': case '#':
1306 case 'E': case 'F': case 'G': case 'H':
1307 case 's': case 'i': case 'n':
1308 case 'I': case 'J': case 'K': case 'L': case 'M':
1309 case 'N': case 'O': case 'P': case ',':
1312 /* Whether or not a numeric constraint allows a register is
1313 decided by the matching constraint, and so there is no need
1314 to do anything special with them. We must handle them in
1315 the default case, so that we don't unnecessarily force
1316 operands to memory. */
1317 case '0': case '1': case '2': case '3': case '4':
1318 case '5': case '6': case '7': case '8': case '9':
1321 unsigned long match
;
1323 match
= strtoul (constraint
+ j
, &end
, 10);
1324 if (match
>= (unsigned long) noutputs
)
1326 error ("matching constraint references invalid operand number");
1330 /* Try and find the real constraint for this dup. Only do this
1331 if the matching constraint is the only alternative. */
1333 && (j
== 0 || (j
== 1 && constraint
[0] == '%')))
1335 constraint
= constraints
[match
];
1336 *constraint_p
= constraint
;
1337 c_len
= strlen (constraint
);
1339 /* ??? At the end of the loop, we will skip the first part of
1340 the matched constraint. This assumes not only that the
1341 other constraint is an output constraint, but also that
1342 the '=' or '+' come first. */
1346 j
= end
- constraint
;
1347 /* Anticipate increment at end of loop. */
1362 if (! ISALPHA (constraint
[j
]))
1364 error ("invalid punctuation `%c' in constraint", constraint
[j
]);
1367 if (REG_CLASS_FROM_CONSTRAINT (constraint
[j
], constraint
+ j
)
1370 #ifdef EXTRA_CONSTRAINT_STR
1371 else if (EXTRA_ADDRESS_CONSTRAINT (constraint
[j
], constraint
+ j
))
1373 else if (EXTRA_MEMORY_CONSTRAINT (constraint
[j
], constraint
+ j
))
1377 /* Otherwise we can't assume anything about the nature of
1378 the constraint except that it isn't purely registers.
1379 Treat it like "g" and hope for the best. */
1390 /* Check for overlap between registers marked in CLOBBERED_REGS and
1391 anything inappropriate in DECL. Emit error and return TRUE for error,
1395 decl_conflicts_with_clobbers_p (tree decl
, const HARD_REG_SET clobbered_regs
)
1397 /* Conflicts between asm-declared register variables and the clobber
1398 list are not allowed. */
1399 if ((TREE_CODE (decl
) == VAR_DECL
|| TREE_CODE (decl
) == PARM_DECL
)
1400 && DECL_REGISTER (decl
)
1401 && REG_P (DECL_RTL (decl
))
1402 && REGNO (DECL_RTL (decl
)) < FIRST_PSEUDO_REGISTER
)
1404 rtx reg
= DECL_RTL (decl
);
1407 for (regno
= REGNO (reg
);
1408 regno
< (REGNO (reg
)
1409 + HARD_REGNO_NREGS (REGNO (reg
), GET_MODE (reg
)));
1411 if (TEST_HARD_REG_BIT (clobbered_regs
, regno
))
1413 error ("asm-specifier for variable `%s' conflicts with asm clobber list",
1414 IDENTIFIER_POINTER (DECL_NAME (decl
)));
1416 /* Reset registerness to stop multiple errors emitted for a
1418 DECL_REGISTER (decl
) = 0;
1425 /* Generate RTL for an asm statement with arguments.
1426 STRING is the instruction template.
1427 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1428 Each output or input has an expression in the TREE_VALUE and
1429 and a tree list in TREE_PURPOSE which in turn contains a constraint
1430 name in TREE_VALUE (or NULL_TREE) and a constraint string
1432 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1433 that is clobbered by this insn.
1435 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1436 Some elements of OUTPUTS may be replaced with trees representing temporary
1437 values. The caller should copy those temporary values to the originally
1440 VOL nonzero means the insn is volatile; don't optimize it. */
1443 expand_asm_operands (tree string
, tree outputs
, tree inputs
,
1444 tree clobbers
, int vol
, location_t locus
)
1446 rtvec argvec
, constraintvec
;
1448 int ninputs
= list_length (inputs
);
1449 int noutputs
= list_length (outputs
);
1452 HARD_REG_SET clobbered_regs
;
1453 int clobber_conflict_found
= 0;
1457 /* Vector of RTX's of evaluated output operands. */
1458 rtx
*output_rtx
= alloca (noutputs
* sizeof (rtx
));
1459 int *inout_opnum
= alloca (noutputs
* sizeof (int));
1460 rtx
*real_output_rtx
= alloca (noutputs
* sizeof (rtx
));
1461 enum machine_mode
*inout_mode
1462 = alloca (noutputs
* sizeof (enum machine_mode
));
1463 const char **constraints
1464 = alloca ((noutputs
+ ninputs
) * sizeof (const char *));
1465 int old_generating_concat_p
= generating_concat_p
;
1467 /* An ASM with no outputs needs to be treated as volatile, for now. */
1471 if (! check_operand_nalternatives (outputs
, inputs
))
1474 string
= resolve_asm_operand_names (string
, outputs
, inputs
);
1476 /* Collect constraints. */
1478 for (t
= outputs
; t
; t
= TREE_CHAIN (t
), i
++)
1479 constraints
[i
] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t
)));
1480 for (t
= inputs
; t
; t
= TREE_CHAIN (t
), i
++)
1481 constraints
[i
] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t
)));
1483 #ifdef MD_ASM_CLOBBERS
1484 /* Sometimes we wish to automatically clobber registers across an asm.
1485 Case in point is when the i386 backend moved from cc0 to a hard reg --
1486 maintaining source-level compatibility means automatically clobbering
1487 the flags register. */
1488 MD_ASM_CLOBBERS (clobbers
);
1491 /* Count the number of meaningful clobbered registers, ignoring what
1492 we would ignore later. */
1494 CLEAR_HARD_REG_SET (clobbered_regs
);
1495 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
))
1497 const char *regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
1499 i
= decode_reg_name (regname
);
1500 if (i
>= 0 || i
== -4)
1503 error ("unknown register name `%s' in `asm'", regname
);
1505 /* Mark clobbered registers. */
1508 /* Clobbering the PIC register is an error */
1509 if (i
== (int) PIC_OFFSET_TABLE_REGNUM
)
1511 error ("PIC register `%s' clobbered in `asm'", regname
);
1515 SET_HARD_REG_BIT (clobbered_regs
, i
);
1521 /* First pass over inputs and outputs checks validity and sets
1522 mark_addressable if needed. */
1525 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1527 tree val
= TREE_VALUE (tail
);
1528 tree type
= TREE_TYPE (val
);
1529 const char *constraint
;
1534 /* If there's an erroneous arg, emit no insn. */
1535 if (type
== error_mark_node
)
1538 /* Try to parse the output constraint. If that fails, there's
1539 no point in going further. */
1540 constraint
= constraints
[i
];
1541 if (!parse_output_constraint (&constraint
, i
, ninputs
, noutputs
,
1542 &allows_mem
, &allows_reg
, &is_inout
))
1549 && GET_CODE (DECL_RTL (val
)) == REG
1550 && GET_MODE (DECL_RTL (val
)) != TYPE_MODE (type
))))
1551 (*lang_hooks
.mark_addressable
) (val
);
1558 if (ninputs
+ noutputs
> MAX_RECOG_OPERANDS
)
1560 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS
);
1564 for (i
= 0, tail
= inputs
; tail
; i
++, tail
= TREE_CHAIN (tail
))
1566 bool allows_reg
, allows_mem
;
1567 const char *constraint
;
1569 /* If there's an erroneous arg, emit no insn, because the ASM_INPUT
1570 would get VOIDmode and that could cause a crash in reload. */
1571 if (TREE_TYPE (TREE_VALUE (tail
)) == error_mark_node
)
1574 constraint
= constraints
[i
+ noutputs
];
1575 if (! parse_input_constraint (&constraint
, i
, ninputs
, noutputs
, ninout
,
1576 constraints
, &allows_mem
, &allows_reg
))
1579 if (! allows_reg
&& allows_mem
)
1580 (*lang_hooks
.mark_addressable
) (TREE_VALUE (tail
));
1583 /* Second pass evaluates arguments. */
1586 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1588 tree val
= TREE_VALUE (tail
);
1589 tree type
= TREE_TYPE (val
);
1595 if (!parse_output_constraint (&constraints
[i
], i
, ninputs
,
1596 noutputs
, &allows_mem
, &allows_reg
,
1600 /* If an output operand is not a decl or indirect ref and our constraint
1601 allows a register, make a temporary to act as an intermediate.
1602 Make the asm insn write into that, then our caller will copy it to
1603 the real output operand. Likewise for promoted variables. */
1605 generating_concat_p
= 0;
1607 real_output_rtx
[i
] = NULL_RTX
;
1608 if ((TREE_CODE (val
) == INDIRECT_REF
1611 && (allows_mem
|| GET_CODE (DECL_RTL (val
)) == REG
)
1612 && ! (GET_CODE (DECL_RTL (val
)) == REG
1613 && GET_MODE (DECL_RTL (val
)) != TYPE_MODE (type
)))
1617 op
= expand_expr (val
, NULL_RTX
, VOIDmode
, EXPAND_WRITE
);
1618 if (GET_CODE (op
) == MEM
)
1619 op
= validize_mem (op
);
1621 if (! allows_reg
&& GET_CODE (op
) != MEM
)
1622 error ("output number %d not directly addressable", i
);
1623 if ((! allows_mem
&& GET_CODE (op
) == MEM
)
1624 || GET_CODE (op
) == CONCAT
)
1626 real_output_rtx
[i
] = protect_from_queue (op
, 1);
1627 op
= gen_reg_rtx (GET_MODE (op
));
1629 emit_move_insn (op
, real_output_rtx
[i
]);
1634 op
= assign_temp (type
, 0, 0, 1);
1635 op
= validize_mem (op
);
1636 TREE_VALUE (tail
) = make_tree (type
, op
);
1640 generating_concat_p
= old_generating_concat_p
;
1644 inout_mode
[ninout
] = TYPE_MODE (type
);
1645 inout_opnum
[ninout
++] = i
;
1648 if (decl_conflicts_with_clobbers_p (val
, clobbered_regs
))
1649 clobber_conflict_found
= 1;
1652 /* Make vectors for the expression-rtx, constraint strings,
1653 and named operands. */
1655 argvec
= rtvec_alloc (ninputs
);
1656 constraintvec
= rtvec_alloc (ninputs
);
1658 body
= gen_rtx_ASM_OPERANDS ((noutputs
== 0 ? VOIDmode
1659 : GET_MODE (output_rtx
[0])),
1660 TREE_STRING_POINTER (string
),
1661 empty_string
, 0, argvec
, constraintvec
,
1662 locus
.file
, locus
.line
);
1664 MEM_VOLATILE_P (body
) = vol
;
1666 /* Eval the inputs and put them into ARGVEC.
1667 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1669 for (i
= 0, tail
= inputs
; tail
; tail
= TREE_CHAIN (tail
), ++i
)
1671 bool allows_reg
, allows_mem
;
1672 const char *constraint
;
1676 constraint
= constraints
[i
+ noutputs
];
1677 if (! parse_input_constraint (&constraint
, i
, ninputs
, noutputs
, ninout
,
1678 constraints
, &allows_mem
, &allows_reg
))
1681 generating_concat_p
= 0;
1683 val
= TREE_VALUE (tail
);
1684 type
= TREE_TYPE (val
);
1685 op
= expand_expr (val
, NULL_RTX
, VOIDmode
,
1686 (allows_mem
&& !allows_reg
1687 ? EXPAND_MEMORY
: EXPAND_NORMAL
));
1689 /* Never pass a CONCAT to an ASM. */
1690 if (GET_CODE (op
) == CONCAT
)
1691 op
= force_reg (GET_MODE (op
), op
);
1692 else if (GET_CODE (op
) == MEM
)
1693 op
= validize_mem (op
);
1695 if (asm_operand_ok (op
, constraint
) <= 0)
1698 op
= force_reg (TYPE_MODE (type
), op
);
1699 else if (!allows_mem
)
1700 warning ("asm operand %d probably doesn't match constraints",
1702 else if (GET_CODE (op
) == MEM
)
1704 /* We won't recognize either volatile memory or memory
1705 with a queued address as available a memory_operand
1706 at this point. Ignore it: clearly this *is* a memory. */
1710 warning ("use of memory input without lvalue in "
1711 "asm operand %d is deprecated", i
+ noutputs
);
1713 if (CONSTANT_P (op
))
1715 op
= force_const_mem (TYPE_MODE (type
), op
);
1716 op
= validize_mem (op
);
1718 else if (GET_CODE (op
) == REG
1719 || GET_CODE (op
) == SUBREG
1720 || GET_CODE (op
) == ADDRESSOF
1721 || GET_CODE (op
) == CONCAT
)
1723 tree qual_type
= build_qualified_type (type
,
1725 | TYPE_QUAL_CONST
));
1726 rtx memloc
= assign_temp (qual_type
, 1, 1, 1);
1727 memloc
= validize_mem (memloc
);
1728 emit_move_insn (memloc
, op
);
1734 generating_concat_p
= old_generating_concat_p
;
1735 ASM_OPERANDS_INPUT (body
, i
) = op
;
1737 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body
, i
)
1738 = gen_rtx_ASM_INPUT (TYPE_MODE (type
), constraints
[i
+ noutputs
]);
1740 if (decl_conflicts_with_clobbers_p (val
, clobbered_regs
))
1741 clobber_conflict_found
= 1;
1744 /* Protect all the operands from the queue now that they have all been
1747 generating_concat_p
= 0;
1749 for (i
= 0; i
< ninputs
- ninout
; i
++)
1750 ASM_OPERANDS_INPUT (body
, i
)
1751 = protect_from_queue (ASM_OPERANDS_INPUT (body
, i
), 0);
1753 for (i
= 0; i
< noutputs
; i
++)
1754 output_rtx
[i
] = protect_from_queue (output_rtx
[i
], 1);
1756 /* For in-out operands, copy output rtx to input rtx. */
1757 for (i
= 0; i
< ninout
; i
++)
1759 int j
= inout_opnum
[i
];
1762 ASM_OPERANDS_INPUT (body
, ninputs
- ninout
+ i
)
1765 sprintf (buffer
, "%d", j
);
1766 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body
, ninputs
- ninout
+ i
)
1767 = gen_rtx_ASM_INPUT (inout_mode
[i
], ggc_strdup (buffer
));
1770 generating_concat_p
= old_generating_concat_p
;
1772 /* Now, for each output, construct an rtx
1773 (set OUTPUT (asm_operands INSN OUTPUTCONSTRAINT OUTPUTNUMBER
1774 ARGVEC CONSTRAINTS OPNAMES))
1775 If there is more than one, put them inside a PARALLEL. */
1777 if (noutputs
== 1 && nclobbers
== 0)
1779 ASM_OPERANDS_OUTPUT_CONSTRAINT (body
) = constraints
[0];
1780 emit_insn (gen_rtx_SET (VOIDmode
, output_rtx
[0], body
));
1783 else if (noutputs
== 0 && nclobbers
== 0)
1785 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1797 body
= gen_rtx_PARALLEL (VOIDmode
, rtvec_alloc (num
+ nclobbers
));
1799 /* For each output operand, store a SET. */
1800 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1802 XVECEXP (body
, 0, i
)
1803 = gen_rtx_SET (VOIDmode
,
1805 gen_rtx_ASM_OPERANDS
1806 (GET_MODE (output_rtx
[i
]),
1807 TREE_STRING_POINTER (string
),
1808 constraints
[i
], i
, argvec
, constraintvec
,
1809 locus
.file
, locus
.line
));
1811 MEM_VOLATILE_P (SET_SRC (XVECEXP (body
, 0, i
))) = vol
;
1814 /* If there are no outputs (but there are some clobbers)
1815 store the bare ASM_OPERANDS into the PARALLEL. */
1818 XVECEXP (body
, 0, i
++) = obody
;
1820 /* Store (clobber REG) for each clobbered register specified. */
1822 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
))
1824 const char *regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
1825 int j
= decode_reg_name (regname
);
1830 if (j
== -3) /* `cc', which is not a register */
1833 if (j
== -4) /* `memory', don't cache memory across asm */
1835 XVECEXP (body
, 0, i
++)
1836 = gen_rtx_CLOBBER (VOIDmode
,
1839 gen_rtx_SCRATCH (VOIDmode
)));
1843 /* Ignore unknown register, error already signaled. */
1847 /* Use QImode since that's guaranteed to clobber just one reg. */
1848 clobbered_reg
= gen_rtx_REG (QImode
, j
);
1850 /* Do sanity check for overlap between clobbers and respectively
1851 input and outputs that hasn't been handled. Such overlap
1852 should have been detected and reported above. */
1853 if (!clobber_conflict_found
)
1857 /* We test the old body (obody) contents to avoid tripping
1858 over the under-construction body. */
1859 for (opno
= 0; opno
< noutputs
; opno
++)
1860 if (reg_overlap_mentioned_p (clobbered_reg
, output_rtx
[opno
]))
1861 internal_error ("asm clobber conflict with output operand");
1863 for (opno
= 0; opno
< ninputs
- ninout
; opno
++)
1864 if (reg_overlap_mentioned_p (clobbered_reg
,
1865 ASM_OPERANDS_INPUT (obody
, opno
)))
1866 internal_error ("asm clobber conflict with input operand");
1869 XVECEXP (body
, 0, i
++)
1870 = gen_rtx_CLOBBER (VOIDmode
, clobbered_reg
);
1876 /* For any outputs that needed reloading into registers, spill them
1877 back to where they belong. */
1878 for (i
= 0; i
< noutputs
; ++i
)
1879 if (real_output_rtx
[i
])
1880 emit_move_insn (real_output_rtx
[i
], output_rtx
[i
]);
1885 /* A subroutine of expand_asm_operands. Check that all operands have
1886 the same number of alternatives. Return true if so. */
1889 check_operand_nalternatives (tree outputs
, tree inputs
)
1891 if (outputs
|| inputs
)
1893 tree tmp
= TREE_PURPOSE (outputs
? outputs
: inputs
);
1895 = n_occurrences (',', TREE_STRING_POINTER (TREE_VALUE (tmp
)));
1898 if (nalternatives
+ 1 > MAX_RECOG_ALTERNATIVES
)
1900 error ("too many alternatives in `asm'");
1907 const char *constraint
1908 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tmp
)));
1910 if (n_occurrences (',', constraint
) != nalternatives
)
1912 error ("operand constraints for `asm' differ in number of alternatives");
1916 if (TREE_CHAIN (tmp
))
1917 tmp
= TREE_CHAIN (tmp
);
1919 tmp
= next
, next
= 0;
1926 /* A subroutine of expand_asm_operands. Check that all operand names
1927 are unique. Return true if so. We rely on the fact that these names
1928 are identifiers, and so have been canonicalized by get_identifier,
1929 so all we need are pointer comparisons. */
1932 check_unique_operand_names (tree outputs
, tree inputs
)
1936 for (i
= outputs
; i
; i
= TREE_CHAIN (i
))
1938 tree i_name
= TREE_PURPOSE (TREE_PURPOSE (i
));
1942 for (j
= TREE_CHAIN (i
); j
; j
= TREE_CHAIN (j
))
1943 if (simple_cst_equal (i_name
, TREE_PURPOSE (TREE_PURPOSE (j
))))
1947 for (i
= inputs
; i
; i
= TREE_CHAIN (i
))
1949 tree i_name
= TREE_PURPOSE (TREE_PURPOSE (i
));
1953 for (j
= TREE_CHAIN (i
); j
; j
= TREE_CHAIN (j
))
1954 if (simple_cst_equal (i_name
, TREE_PURPOSE (TREE_PURPOSE (j
))))
1956 for (j
= outputs
; j
; j
= TREE_CHAIN (j
))
1957 if (simple_cst_equal (i_name
, TREE_PURPOSE (TREE_PURPOSE (j
))))
1964 error ("duplicate asm operand name '%s'",
1965 TREE_STRING_POINTER (TREE_PURPOSE (TREE_PURPOSE (i
))));
1969 /* A subroutine of expand_asm_operands. Resolve the names of the operands
1970 in *POUTPUTS and *PINPUTS to numbers, and replace the name expansions in
1971 STRING and in the constraints to those numbers. */
1974 resolve_asm_operand_names (tree string
, tree outputs
, tree inputs
)
1981 check_unique_operand_names (outputs
, inputs
);
1983 /* Substitute [<name>] in input constraint strings. There should be no
1984 named operands in output constraints. */
1985 for (t
= inputs
; t
; t
= TREE_CHAIN (t
))
1987 c
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t
)));
1988 if (strchr (c
, '[') != NULL
)
1990 p
= buffer
= xstrdup (c
);
1991 while ((p
= strchr (p
, '[')) != NULL
)
1992 p
= resolve_operand_name_1 (p
, outputs
, inputs
);
1993 TREE_VALUE (TREE_PURPOSE (t
))
1994 = build_string (strlen (buffer
), buffer
);
1999 /* Now check for any needed substitutions in the template. */
2000 c
= TREE_STRING_POINTER (string
);
2001 while ((c
= strchr (c
, '%')) != NULL
)
2005 else if (ISALPHA (c
[1]) && c
[2] == '[')
2016 /* OK, we need to make a copy so we can perform the substitutions.
2017 Assume that we will not need extra space--we get to remove '['
2018 and ']', which means we cannot have a problem until we have more
2019 than 999 operands. */
2020 buffer
= xstrdup (TREE_STRING_POINTER (string
));
2021 p
= buffer
+ (c
- TREE_STRING_POINTER (string
));
2023 while ((p
= strchr (p
, '%')) != NULL
)
2027 else if (ISALPHA (p
[1]) && p
[2] == '[')
2035 p
= resolve_operand_name_1 (p
, outputs
, inputs
);
2038 string
= build_string (strlen (buffer
), buffer
);
2045 /* A subroutine of resolve_operand_names. P points to the '[' for a
2046 potential named operand of the form [<name>]. In place, replace
2047 the name and brackets with a number. Return a pointer to the
2048 balance of the string after substitution. */
2051 resolve_operand_name_1 (char *p
, tree outputs
, tree inputs
)
2058 /* Collect the operand name. */
2059 q
= strchr (p
, ']');
2062 error ("missing close brace for named operand");
2063 return strchr (p
, '\0');
2067 /* Resolve the name to a number. */
2068 for (op
= 0, t
= outputs
; t
; t
= TREE_CHAIN (t
), op
++)
2070 tree name
= TREE_PURPOSE (TREE_PURPOSE (t
));
2073 const char *c
= TREE_STRING_POINTER (name
);
2074 if (strncmp (c
, p
+ 1, len
) == 0 && c
[len
] == '\0')
2078 for (t
= inputs
; t
; t
= TREE_CHAIN (t
), op
++)
2080 tree name
= TREE_PURPOSE (TREE_PURPOSE (t
));
2083 const char *c
= TREE_STRING_POINTER (name
);
2084 if (strncmp (c
, p
+ 1, len
) == 0 && c
[len
] == '\0')
2090 error ("undefined named operand '%s'", p
+ 1);
2094 /* Replace the name with the number. Unfortunately, not all libraries
2095 get the return value of sprintf correct, so search for the end of the
2096 generated string by hand. */
2097 sprintf (p
, "%d", op
);
2098 p
= strchr (p
, '\0');
2100 /* Verify the no extra buffer space assumption. */
2104 /* Shift the rest of the buffer down to fill the gap. */
2105 memmove (p
, q
+ 1, strlen (q
+ 1) + 1);
2110 /* Generate RTL to evaluate the expression EXP
2111 and remember it in case this is the VALUE in a ({... VALUE; }) constr.
2112 Provided just for backward-compatibility. expand_expr_stmt_value()
2113 should be used for new code. */
2116 expand_expr_stmt (tree exp
)
2118 expand_expr_stmt_value (exp
, -1, 1);
2121 /* Generate RTL to evaluate the expression EXP. WANT_VALUE tells
2122 whether to (1) save the value of the expression, (0) discard it or
2123 (-1) use expr_stmts_for_value to tell. The use of -1 is
2124 deprecated, and retained only for backward compatibility. */
2127 expand_expr_stmt_value (tree exp
, int want_value
, int maybe_last
)
2132 if (want_value
== -1)
2133 want_value
= expr_stmts_for_value
!= 0;
2135 /* If -Wextra, warn about statements with no side effects,
2136 except for an explicit cast to void (e.g. for assert()), and
2137 except for last statement in ({...}) where they may be useful. */
2139 && (expr_stmts_for_value
== 0 || ! maybe_last
)
2140 && exp
!= error_mark_node
2141 && warn_unused_value
)
2143 if (TREE_SIDE_EFFECTS (exp
))
2144 warn_if_unused_value (exp
);
2145 else if (!VOID_TYPE_P (TREE_TYPE (exp
)))
2146 warning ("%Hstatement with no effect", &emit_locus
);
2149 /* If EXP is of function type and we are expanding statements for
2150 value, convert it to pointer-to-function. */
2151 if (want_value
&& TREE_CODE (TREE_TYPE (exp
)) == FUNCTION_TYPE
)
2152 exp
= build1 (ADDR_EXPR
, build_pointer_type (TREE_TYPE (exp
)), exp
);
2154 /* The call to `expand_expr' could cause last_expr_type and
2155 last_expr_value to get reset. Therefore, we set last_expr_value
2156 and last_expr_type *after* calling expand_expr. */
2157 value
= expand_expr (exp
, want_value
? NULL_RTX
: const0_rtx
,
2159 type
= TREE_TYPE (exp
);
2161 /* If all we do is reference a volatile value in memory,
2162 copy it to a register to be sure it is actually touched. */
2163 if (value
&& GET_CODE (value
) == MEM
&& TREE_THIS_VOLATILE (exp
))
2165 if (TYPE_MODE (type
) == VOIDmode
)
2167 else if (TYPE_MODE (type
) != BLKmode
)
2168 value
= copy_to_reg (value
);
2171 rtx lab
= gen_label_rtx ();
2173 /* Compare the value with itself to reference it. */
2174 emit_cmp_and_jump_insns (value
, value
, EQ
,
2175 expand_expr (TYPE_SIZE (type
),
2176 NULL_RTX
, VOIDmode
, 0),
2182 /* If this expression is part of a ({...}) and is in memory, we may have
2183 to preserve temporaries. */
2184 preserve_temp_slots (value
);
2186 /* Free any temporaries used to evaluate this expression. Any temporary
2187 used as a result of this expression will already have been preserved
2193 last_expr_value
= value
;
2194 last_expr_type
= type
;
2200 /* Warn if EXP contains any computations whose results are not used.
2201 Return 1 if a warning is printed; 0 otherwise. */
2204 warn_if_unused_value (tree exp
)
2206 if (TREE_USED (exp
))
2209 /* Don't warn about void constructs. This includes casting to void,
2210 void function calls, and statement expressions with a final cast
2212 if (VOID_TYPE_P (TREE_TYPE (exp
)))
2215 switch (TREE_CODE (exp
))
2217 case PREINCREMENT_EXPR
:
2218 case POSTINCREMENT_EXPR
:
2219 case PREDECREMENT_EXPR
:
2220 case POSTDECREMENT_EXPR
:
2226 case TRY_CATCH_EXPR
:
2227 case WITH_CLEANUP_EXPR
:
2232 /* For a binding, warn if no side effect within it. */
2233 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2236 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2238 case TRUTH_ORIF_EXPR
:
2239 case TRUTH_ANDIF_EXPR
:
2240 /* In && or ||, warn if 2nd operand has no side effect. */
2241 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2244 if (TREE_NO_UNUSED_WARNING (exp
))
2246 if (warn_if_unused_value (TREE_OPERAND (exp
, 0)))
2248 /* Let people do `(foo (), 0)' without a warning. */
2249 if (TREE_CONSTANT (TREE_OPERAND (exp
, 1)))
2251 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2255 case NON_LVALUE_EXPR
:
2256 /* Don't warn about conversions not explicit in the user's program. */
2257 if (TREE_NO_UNUSED_WARNING (exp
))
2259 /* Assignment to a cast usually results in a cast of a modify.
2260 Don't complain about that. There can be an arbitrary number of
2261 casts before the modify, so we must loop until we find the first
2262 non-cast expression and then test to see if that is a modify. */
2264 tree tem
= TREE_OPERAND (exp
, 0);
2266 while (TREE_CODE (tem
) == CONVERT_EXPR
|| TREE_CODE (tem
) == NOP_EXPR
)
2267 tem
= TREE_OPERAND (tem
, 0);
2269 if (TREE_CODE (tem
) == MODIFY_EXPR
|| TREE_CODE (tem
) == INIT_EXPR
2270 || TREE_CODE (tem
) == CALL_EXPR
)
2276 /* Don't warn about automatic dereferencing of references, since
2277 the user cannot control it. */
2278 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp
, 0))) == REFERENCE_TYPE
)
2279 return warn_if_unused_value (TREE_OPERAND (exp
, 0));
2283 /* Referencing a volatile value is a side effect, so don't warn. */
2285 || TREE_CODE_CLASS (TREE_CODE (exp
)) == 'r')
2286 && TREE_THIS_VOLATILE (exp
))
2289 /* If this is an expression which has no operands, there is no value
2290 to be unused. There are no such language-independent codes,
2291 but front ends may define such. */
2292 if (TREE_CODE_CLASS (TREE_CODE (exp
)) == 'e'
2293 && TREE_CODE_LENGTH (TREE_CODE (exp
)) == 0)
2297 /* If this is an expression with side effects, don't warn. */
2298 if (TREE_SIDE_EFFECTS (exp
))
2301 warning ("%Hvalue computed is not used", &emit_locus
);
2306 /* Clear out the memory of the last expression evaluated. */
2309 clear_last_expr (void)
2311 last_expr_type
= NULL_TREE
;
2312 last_expr_value
= NULL_RTX
;
2315 /* Begin a statement-expression, i.e., a series of statements which
2316 may return a value. Return the RTL_EXPR for this statement expr.
2317 The caller must save that value and pass it to
2318 expand_end_stmt_expr. If HAS_SCOPE is nonzero, temporaries created
2319 in the statement-expression are deallocated at the end of the
2323 expand_start_stmt_expr (int has_scope
)
2327 /* Make the RTL_EXPR node temporary, not momentary,
2328 so that rtl_expr_chain doesn't become garbage. */
2329 t
= make_node (RTL_EXPR
);
2330 do_pending_stack_adjust ();
2332 start_sequence_for_rtl_expr (t
);
2336 expr_stmts_for_value
++;
2340 /* Restore the previous state at the end of a statement that returns a value.
2341 Returns a tree node representing the statement's value and the
2342 insns to compute the value.
2344 The nodes of that expression have been freed by now, so we cannot use them.
2345 But we don't want to do that anyway; the expression has already been
2346 evaluated and now we just want to use the value. So generate a RTL_EXPR
2347 with the proper type and RTL value.
2349 If the last substatement was not an expression,
2350 return something with type `void'. */
2353 expand_end_stmt_expr (tree t
)
2357 if (! last_expr_value
|| ! last_expr_type
)
2359 last_expr_value
= const0_rtx
;
2360 last_expr_type
= void_type_node
;
2362 else if (GET_CODE (last_expr_value
) != REG
&& ! CONSTANT_P (last_expr_value
))
2363 /* Remove any possible QUEUED. */
2364 last_expr_value
= protect_from_queue (last_expr_value
, 0);
2368 TREE_TYPE (t
) = last_expr_type
;
2369 RTL_EXPR_RTL (t
) = last_expr_value
;
2370 RTL_EXPR_SEQUENCE (t
) = get_insns ();
2372 rtl_expr_chain
= tree_cons (NULL_TREE
, t
, rtl_expr_chain
);
2376 /* Don't consider deleting this expr or containing exprs at tree level. */
2377 TREE_SIDE_EFFECTS (t
) = 1;
2378 /* Propagate volatility of the actual RTL expr. */
2379 TREE_THIS_VOLATILE (t
) = volatile_refs_p (last_expr_value
);
2382 expr_stmts_for_value
--;
2387 /* Generate RTL for the start of an if-then. COND is the expression
2388 whose truth should be tested.
2390 If EXITFLAG is nonzero, this conditional is visible to
2391 `exit_something'. */
2394 expand_start_cond (tree cond
, int exitflag
)
2396 struct nesting
*thiscond
= ALLOC_NESTING ();
2398 /* Make an entry on cond_stack for the cond we are entering. */
2400 thiscond
->desc
= COND_NESTING
;
2401 thiscond
->next
= cond_stack
;
2402 thiscond
->all
= nesting_stack
;
2403 thiscond
->depth
= ++nesting_depth
;
2404 thiscond
->data
.cond
.next_label
= gen_label_rtx ();
2405 /* Before we encounter an `else', we don't need a separate exit label
2406 unless there are supposed to be exit statements
2407 to exit this conditional. */
2408 thiscond
->exit_label
= exitflag
? gen_label_rtx () : 0;
2409 thiscond
->data
.cond
.endif_label
= thiscond
->exit_label
;
2410 cond_stack
= thiscond
;
2411 nesting_stack
= thiscond
;
2413 do_jump (cond
, thiscond
->data
.cond
.next_label
, NULL_RTX
);
2416 /* Generate RTL between then-clause and the elseif-clause
2417 of an if-then-elseif-.... */
2420 expand_start_elseif (tree cond
)
2422 if (cond_stack
->data
.cond
.endif_label
== 0)
2423 cond_stack
->data
.cond
.endif_label
= gen_label_rtx ();
2424 emit_jump (cond_stack
->data
.cond
.endif_label
);
2425 emit_label (cond_stack
->data
.cond
.next_label
);
2426 cond_stack
->data
.cond
.next_label
= gen_label_rtx ();
2427 do_jump (cond
, cond_stack
->data
.cond
.next_label
, NULL_RTX
);
2430 /* Generate RTL between the then-clause and the else-clause
2431 of an if-then-else. */
2434 expand_start_else (void)
2436 if (cond_stack
->data
.cond
.endif_label
== 0)
2437 cond_stack
->data
.cond
.endif_label
= gen_label_rtx ();
2439 emit_jump (cond_stack
->data
.cond
.endif_label
);
2440 emit_label (cond_stack
->data
.cond
.next_label
);
2441 cond_stack
->data
.cond
.next_label
= 0; /* No more _else or _elseif calls. */
2444 /* After calling expand_start_else, turn this "else" into an "else if"
2445 by providing another condition. */
2448 expand_elseif (tree cond
)
2450 cond_stack
->data
.cond
.next_label
= gen_label_rtx ();
2451 do_jump (cond
, cond_stack
->data
.cond
.next_label
, NULL_RTX
);
2454 /* Generate RTL for the end of an if-then.
2455 Pop the record for it off of cond_stack. */
2458 expand_end_cond (void)
2460 struct nesting
*thiscond
= cond_stack
;
2462 do_pending_stack_adjust ();
2463 if (thiscond
->data
.cond
.next_label
)
2464 emit_label (thiscond
->data
.cond
.next_label
);
2465 if (thiscond
->data
.cond
.endif_label
)
2466 emit_label (thiscond
->data
.cond
.endif_label
);
2468 POPSTACK (cond_stack
);
2472 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2473 loop should be exited by `exit_something'. This is a loop for which
2474 `expand_continue' will jump to the top of the loop.
2476 Make an entry on loop_stack to record the labels associated with
2480 expand_start_loop (int exit_flag
)
2482 struct nesting
*thisloop
= ALLOC_NESTING ();
2484 /* Make an entry on loop_stack for the loop we are entering. */
2486 thisloop
->desc
= LOOP_NESTING
;
2487 thisloop
->next
= loop_stack
;
2488 thisloop
->all
= nesting_stack
;
2489 thisloop
->depth
= ++nesting_depth
;
2490 thisloop
->data
.loop
.start_label
= gen_label_rtx ();
2491 thisloop
->data
.loop
.end_label
= gen_label_rtx ();
2492 thisloop
->data
.loop
.continue_label
= thisloop
->data
.loop
.start_label
;
2493 thisloop
->exit_label
= exit_flag
? thisloop
->data
.loop
.end_label
: 0;
2494 loop_stack
= thisloop
;
2495 nesting_stack
= thisloop
;
2497 do_pending_stack_adjust ();
2499 emit_note (NOTE_INSN_LOOP_BEG
);
2500 emit_label (thisloop
->data
.loop
.start_label
);
2505 /* Like expand_start_loop but for a loop where the continuation point
2506 (for expand_continue_loop) will be specified explicitly. */
2509 expand_start_loop_continue_elsewhere (int exit_flag
)
2511 struct nesting
*thisloop
= expand_start_loop (exit_flag
);
2512 loop_stack
->data
.loop
.continue_label
= gen_label_rtx ();
2516 /* Begin a null, aka do { } while (0) "loop". But since the contents
2517 of said loop can still contain a break, we must frob the loop nest. */
2520 expand_start_null_loop (void)
2522 struct nesting
*thisloop
= ALLOC_NESTING ();
2524 /* Make an entry on loop_stack for the loop we are entering. */
2526 thisloop
->desc
= LOOP_NESTING
;
2527 thisloop
->next
= loop_stack
;
2528 thisloop
->all
= nesting_stack
;
2529 thisloop
->depth
= ++nesting_depth
;
2530 thisloop
->data
.loop
.start_label
= emit_note (NOTE_INSN_DELETED
);
2531 thisloop
->data
.loop
.end_label
= gen_label_rtx ();
2532 thisloop
->data
.loop
.continue_label
= thisloop
->data
.loop
.end_label
;
2533 thisloop
->exit_label
= thisloop
->data
.loop
.end_label
;
2534 loop_stack
= thisloop
;
2535 nesting_stack
= thisloop
;
2540 /* Specify the continuation point for a loop started with
2541 expand_start_loop_continue_elsewhere.
2542 Use this at the point in the code to which a continue statement
2546 expand_loop_continue_here (void)
2548 do_pending_stack_adjust ();
2549 emit_note (NOTE_INSN_LOOP_CONT
);
2550 emit_label (loop_stack
->data
.loop
.continue_label
);
2553 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2554 Pop the block off of loop_stack. */
2557 expand_end_loop (void)
2559 rtx start_label
= loop_stack
->data
.loop
.start_label
;
2561 int eh_regions
, debug_blocks
;
2564 /* Mark the continue-point at the top of the loop if none elsewhere. */
2565 if (start_label
== loop_stack
->data
.loop
.continue_label
)
2566 emit_note_before (NOTE_INSN_LOOP_CONT
, start_label
);
2568 do_pending_stack_adjust ();
2570 /* If the loop starts with a loop exit, roll that to the end where
2571 it will optimize together with the jump back.
2573 If the loop presently looks like this (in pseudo-C):
2577 if (test) goto end_label;
2583 transform it to look like:
2590 if (test) goto end_label;
2594 We rely on the presence of NOTE_INSN_LOOP_END_TOP_COND to mark
2595 the end of the entry conditional. Without this, our lexical scan
2596 can't tell the difference between an entry conditional and a
2597 body conditional that exits the loop. Mistaking the two means
2598 that we can misplace the NOTE_INSN_LOOP_CONT note, which can
2599 screw up loop unrolling.
2601 Things will be oh so much better when loop optimization is done
2602 off of a proper control flow graph... */
2604 /* Scan insns from the top of the loop looking for the END_TOP_COND note. */
2607 eh_regions
= debug_blocks
= 0;
2608 for (etc_note
= start_label
; etc_note
; etc_note
= NEXT_INSN (etc_note
))
2609 if (GET_CODE (etc_note
) == NOTE
)
2611 if (NOTE_LINE_NUMBER (etc_note
) == NOTE_INSN_LOOP_END_TOP_COND
)
2614 /* We must not walk into a nested loop. */
2615 else if (NOTE_LINE_NUMBER (etc_note
) == NOTE_INSN_LOOP_BEG
)
2617 etc_note
= NULL_RTX
;
2621 /* At the same time, scan for EH region notes, as we don't want
2622 to scrog region nesting. This shouldn't happen, but... */
2623 else if (NOTE_LINE_NUMBER (etc_note
) == NOTE_INSN_EH_REGION_BEG
)
2625 else if (NOTE_LINE_NUMBER (etc_note
) == NOTE_INSN_EH_REGION_END
)
2627 if (--eh_regions
< 0)
2628 /* We've come to the end of an EH region, but never saw the
2629 beginning of that region. That means that an EH region
2630 begins before the top of the loop, and ends in the middle
2631 of it. The existence of such a situation violates a basic
2632 assumption in this code, since that would imply that even
2633 when EH_REGIONS is zero, we might move code out of an
2634 exception region. */
2638 /* Likewise for debug scopes. In this case we'll either (1) move
2639 all of the notes if they are properly nested or (2) leave the
2640 notes alone and only rotate the loop at high optimization
2641 levels when we expect to scrog debug info. */
2642 else if (NOTE_LINE_NUMBER (etc_note
) == NOTE_INSN_BLOCK_BEG
)
2644 else if (NOTE_LINE_NUMBER (etc_note
) == NOTE_INSN_BLOCK_END
)
2647 else if (INSN_P (etc_note
))
2654 && (debug_blocks
== 0 || optimize
>= 2)
2655 && NEXT_INSN (etc_note
) != NULL_RTX
2656 && ! any_condjump_p (get_last_insn ()))
2658 /* We found one. Move everything from START to ETC to the end
2659 of the loop, and add a jump from the top of the loop. */
2660 rtx top_label
= gen_label_rtx ();
2661 rtx start_move
= start_label
;
2663 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2664 then we want to move this note also. */
2665 if (GET_CODE (PREV_INSN (start_move
)) == NOTE
2666 && NOTE_LINE_NUMBER (PREV_INSN (start_move
)) == NOTE_INSN_LOOP_CONT
)
2667 start_move
= PREV_INSN (start_move
);
2669 emit_label_before (top_label
, start_move
);
2671 /* Actually move the insns. If the debug scopes are nested, we
2672 can move everything at once. Otherwise we have to move them
2673 one by one and squeeze out the block notes. */
2674 if (debug_blocks
== 0)
2675 reorder_insns (start_move
, etc_note
, get_last_insn ());
2678 rtx insn
, next_insn
;
2679 for (insn
= start_move
; insn
; insn
= next_insn
)
2681 /* Figure out which insn comes after this one. We have
2682 to do this before we move INSN. */
2683 next_insn
= (insn
== etc_note
? NULL
: NEXT_INSN (insn
));
2685 if (GET_CODE (insn
) == NOTE
2686 && (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_BEG
2687 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_END
))
2690 reorder_insns (insn
, insn
, get_last_insn ());
2694 /* Add the jump from the top of the loop. */
2695 emit_jump_insn_before (gen_jump (start_label
), top_label
);
2696 emit_barrier_before (top_label
);
2697 start_label
= top_label
;
2700 emit_jump (start_label
);
2701 emit_note (NOTE_INSN_LOOP_END
);
2702 emit_label (loop_stack
->data
.loop
.end_label
);
2704 POPSTACK (loop_stack
);
2709 /* Finish a null loop, aka do { } while (0). */
2712 expand_end_null_loop (void)
2714 do_pending_stack_adjust ();
2715 emit_label (loop_stack
->data
.loop
.end_label
);
2717 POPSTACK (loop_stack
);
2722 /* Generate a jump to the current loop's continue-point.
2723 This is usually the top of the loop, but may be specified
2724 explicitly elsewhere. If not currently inside a loop,
2725 return 0 and do nothing; caller will print an error message. */
2728 expand_continue_loop (struct nesting
*whichloop
)
2730 /* Emit information for branch prediction. */
2733 if (flag_guess_branch_prob
)
2735 note
= emit_note (NOTE_INSN_PREDICTION
);
2736 NOTE_PREDICTION (note
) = NOTE_PREDICT (PRED_CONTINUE
, IS_TAKEN
);
2740 whichloop
= loop_stack
;
2743 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.continue_label
,
2748 /* Generate a jump to exit the current loop. If not currently inside a loop,
2749 return 0 and do nothing; caller will print an error message. */
2752 expand_exit_loop (struct nesting
*whichloop
)
2756 whichloop
= loop_stack
;
2759 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.end_label
, NULL_RTX
);
2763 /* Generate a conditional jump to exit the current loop if COND
2764 evaluates to zero. If not currently inside a loop,
2765 return 0 and do nothing; caller will print an error message. */
2768 expand_exit_loop_if_false (struct nesting
*whichloop
, tree cond
)
2774 whichloop
= loop_stack
;
2778 if (integer_nonzerop (cond
))
2780 if (integer_zerop (cond
))
2781 return expand_exit_loop (whichloop
);
2783 /* Check if we definitely won't need a fixup. */
2784 if (whichloop
== nesting_stack
)
2786 jumpifnot (cond
, whichloop
->data
.loop
.end_label
);
2790 /* In order to handle fixups, we actually create a conditional jump
2791 around an unconditional branch to exit the loop. If fixups are
2792 necessary, they go before the unconditional branch. */
2794 label
= gen_label_rtx ();
2795 jumpif (cond
, label
);
2796 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.end_label
,
2803 /* Like expand_exit_loop_if_false except also emit a note marking
2804 the end of the conditional. Should only be used immediately
2805 after expand_loop_start. */
2808 expand_exit_loop_top_cond (struct nesting
*whichloop
, tree cond
)
2810 if (! expand_exit_loop_if_false (whichloop
, cond
))
2813 emit_note (NOTE_INSN_LOOP_END_TOP_COND
);
2817 /* Return nonzero if we should preserve sub-expressions as separate
2818 pseudos. We never do so if we aren't optimizing. We always do so
2819 if -fexpensive-optimizations.
2821 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2822 the loop may still be a small one. */
2825 preserve_subexpressions_p (void)
2829 if (flag_expensive_optimizations
)
2832 if (optimize
== 0 || cfun
== 0 || cfun
->stmt
== 0 || loop_stack
== 0)
2835 insn
= get_last_insn_anywhere ();
2838 && (INSN_UID (insn
) - INSN_UID (loop_stack
->data
.loop
.start_label
)
2839 < n_non_fixed_regs
* 3));
2843 /* Generate a jump to exit the current loop, conditional, binding contour
2844 or case statement. Not all such constructs are visible to this function,
2845 only those started with EXIT_FLAG nonzero. Individual languages use
2846 the EXIT_FLAG parameter to control which kinds of constructs you can
2849 If not currently inside anything that can be exited,
2850 return 0 and do nothing; caller will print an error message. */
2853 expand_exit_something (void)
2857 for (n
= nesting_stack
; n
; n
= n
->all
)
2858 if (n
->exit_label
!= 0)
2860 expand_goto_internal (NULL_TREE
, n
->exit_label
, NULL_RTX
);
2867 /* Generate RTL to return from the current function, with no value.
2868 (That is, we do not do anything about returning any value.) */
2871 expand_null_return (void)
2875 last_insn
= get_last_insn ();
2877 /* If this function was declared to return a value, but we
2878 didn't, clobber the return registers so that they are not
2879 propagated live to the rest of the function. */
2880 clobber_return_register ();
2882 expand_null_return_1 (last_insn
);
2885 /* Try to guess whether the value of return means error code. */
2886 static enum br_predictor
2887 return_prediction (rtx val
)
2889 /* Different heuristics for pointers and scalars. */
2890 if (POINTER_TYPE_P (TREE_TYPE (DECL_RESULT (current_function_decl
))))
2892 /* NULL is usually not returned. */
2893 if (val
== const0_rtx
)
2894 return PRED_NULL_RETURN
;
2898 /* Negative return values are often used to indicate
2900 if (GET_CODE (val
) == CONST_INT
2901 && INTVAL (val
) < 0)
2902 return PRED_NEGATIVE_RETURN
;
2903 /* Constant return values are also usually erors,
2904 zero/one often mean booleans so exclude them from the
2906 if (CONSTANT_P (val
)
2907 && (val
!= const0_rtx
&& val
!= const1_rtx
))
2908 return PRED_CONST_RETURN
;
2910 return PRED_NO_PREDICTION
;
2914 /* If the current function returns values in the most significant part
2915 of a register, shift return value VAL appropriately. The mode of
2916 the function's return type is known not to be BLKmode. */
2919 shift_return_value (rtx val
)
2923 type
= TREE_TYPE (DECL_RESULT (current_function_decl
));
2924 if (targetm
.calls
.return_in_msb (type
))
2927 HOST_WIDE_INT shift
;
2929 target
= DECL_RTL (DECL_RESULT (current_function_decl
));
2930 shift
= (GET_MODE_BITSIZE (GET_MODE (target
))
2931 - BITS_PER_UNIT
* int_size_in_bytes (type
));
2933 val
= expand_binop (GET_MODE (target
), ashl_optab
,
2934 gen_lowpart (GET_MODE (target
), val
),
2935 GEN_INT (shift
), target
, 1, OPTAB_WIDEN
);
2941 /* Generate RTL to return from the current function, with value VAL. */
2944 expand_value_return (rtx val
)
2948 enum br_predictor pred
;
2950 if (flag_guess_branch_prob
2951 && (pred
= return_prediction (val
)) != PRED_NO_PREDICTION
)
2953 /* Emit information for branch prediction. */
2956 note
= emit_note (NOTE_INSN_PREDICTION
);
2958 NOTE_PREDICTION (note
) = NOTE_PREDICT (pred
, NOT_TAKEN
);
2962 last_insn
= get_last_insn ();
2963 return_reg
= DECL_RTL (DECL_RESULT (current_function_decl
));
2965 /* Copy the value to the return location
2966 unless it's already there. */
2968 if (return_reg
!= val
)
2970 tree type
= TREE_TYPE (DECL_RESULT (current_function_decl
));
2971 if (targetm
.calls
.promote_function_return (TREE_TYPE (current_function_decl
)))
2973 int unsignedp
= TREE_UNSIGNED (type
);
2974 enum machine_mode old_mode
2975 = DECL_MODE (DECL_RESULT (current_function_decl
));
2976 enum machine_mode mode
2977 = promote_mode (type
, old_mode
, &unsignedp
, 1);
2979 if (mode
!= old_mode
)
2980 val
= convert_modes (mode
, old_mode
, val
, unsignedp
);
2982 if (GET_CODE (return_reg
) == PARALLEL
)
2983 emit_group_load (return_reg
, val
, type
, int_size_in_bytes (type
));
2985 emit_move_insn (return_reg
, val
);
2988 expand_null_return_1 (last_insn
);
2991 /* Output a return with no value. If LAST_INSN is nonzero,
2992 pretend that the return takes place after LAST_INSN. */
2995 expand_null_return_1 (rtx last_insn
)
2997 rtx end_label
= cleanup_label
? cleanup_label
: return_label
;
2999 clear_pending_stack_adjust ();
3000 do_pending_stack_adjust ();
3004 end_label
= return_label
= gen_label_rtx ();
3005 expand_goto_internal (NULL_TREE
, end_label
, last_insn
);
3008 /* Generate RTL to evaluate the expression RETVAL and return it
3009 from the current function. */
3012 expand_return (tree retval
)
3014 /* If there are any cleanups to be performed, then they will
3015 be inserted following LAST_INSN. It is desirable
3016 that the last_insn, for such purposes, should be the
3017 last insn before computing the return value. Otherwise, cleanups
3018 which call functions can clobber the return value. */
3019 /* ??? rms: I think that is erroneous, because in C++ it would
3020 run destructors on variables that might be used in the subsequent
3021 computation of the return value. */
3027 /* If function wants no value, give it none. */
3028 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl
))) == VOID_TYPE
)
3030 expand_expr (retval
, NULL_RTX
, VOIDmode
, 0);
3032 expand_null_return ();
3036 if (retval
== error_mark_node
)
3038 /* Treat this like a return of no value from a function that
3040 expand_null_return ();
3043 else if (TREE_CODE (retval
) == RESULT_DECL
)
3044 retval_rhs
= retval
;
3045 else if ((TREE_CODE (retval
) == MODIFY_EXPR
|| TREE_CODE (retval
) == INIT_EXPR
)
3046 && TREE_CODE (TREE_OPERAND (retval
, 0)) == RESULT_DECL
)
3047 retval_rhs
= TREE_OPERAND (retval
, 1);
3048 else if (VOID_TYPE_P (TREE_TYPE (retval
)))
3049 /* Recognize tail-recursive call to void function. */
3050 retval_rhs
= retval
;
3052 retval_rhs
= NULL_TREE
;
3054 last_insn
= get_last_insn ();
3056 /* Distribute return down conditional expr if either of the sides
3057 may involve tail recursion (see test below). This enhances the number
3058 of tail recursions we see. Don't do this always since it can produce
3059 sub-optimal code in some cases and we distribute assignments into
3060 conditional expressions when it would help. */
3062 if (optimize
&& retval_rhs
!= 0
3063 && frame_offset
== 0
3064 && TREE_CODE (retval_rhs
) == COND_EXPR
3065 && (TREE_CODE (TREE_OPERAND (retval_rhs
, 1)) == CALL_EXPR
3066 || TREE_CODE (TREE_OPERAND (retval_rhs
, 2)) == CALL_EXPR
))
3068 rtx label
= gen_label_rtx ();
3071 do_jump (TREE_OPERAND (retval_rhs
, 0), label
, NULL_RTX
);
3072 start_cleanup_deferral ();
3073 expr
= build (MODIFY_EXPR
, TREE_TYPE (TREE_TYPE (current_function_decl
)),
3074 DECL_RESULT (current_function_decl
),
3075 TREE_OPERAND (retval_rhs
, 1));
3076 TREE_SIDE_EFFECTS (expr
) = 1;
3077 expand_return (expr
);
3080 expr
= build (MODIFY_EXPR
, TREE_TYPE (TREE_TYPE (current_function_decl
)),
3081 DECL_RESULT (current_function_decl
),
3082 TREE_OPERAND (retval_rhs
, 2));
3083 TREE_SIDE_EFFECTS (expr
) = 1;
3084 expand_return (expr
);
3085 end_cleanup_deferral ();
3089 result_rtl
= DECL_RTL (DECL_RESULT (current_function_decl
));
3091 /* If the result is an aggregate that is being returned in one (or more)
3092 registers, load the registers here. The compiler currently can't handle
3093 copying a BLKmode value into registers. We could put this code in a
3094 more general area (for use by everyone instead of just function
3095 call/return), but until this feature is generally usable it is kept here
3096 (and in expand_call). The value must go into a pseudo in case there
3097 are cleanups that will clobber the real return register. */
3100 && TYPE_MODE (TREE_TYPE (retval_rhs
)) == BLKmode
3101 && GET_CODE (result_rtl
) == REG
)
3104 unsigned HOST_WIDE_INT bitpos
, xbitpos
;
3105 unsigned HOST_WIDE_INT padding_correction
= 0;
3106 unsigned HOST_WIDE_INT bytes
3107 = int_size_in_bytes (TREE_TYPE (retval_rhs
));
3108 int n_regs
= (bytes
+ UNITS_PER_WORD
- 1) / UNITS_PER_WORD
;
3109 unsigned int bitsize
3110 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs
)), BITS_PER_WORD
);
3111 rtx
*result_pseudos
= alloca (sizeof (rtx
) * n_regs
);
3112 rtx result_reg
, src
= NULL_RTX
, dst
= NULL_RTX
;
3113 rtx result_val
= expand_expr (retval_rhs
, NULL_RTX
, VOIDmode
, 0);
3114 enum machine_mode tmpmode
, result_reg_mode
;
3118 expand_null_return ();
3122 /* If the structure doesn't take up a whole number of words, see
3123 whether the register value should be padded on the left or on
3124 the right. Set PADDING_CORRECTION to the number of padding
3125 bits needed on the left side.
3127 In most ABIs, the structure will be returned at the least end of
3128 the register, which translates to right padding on little-endian
3129 targets and left padding on big-endian targets. The opposite
3130 holds if the structure is returned at the most significant
3131 end of the register. */
3132 if (bytes
% UNITS_PER_WORD
!= 0
3133 && (targetm
.calls
.return_in_msb (TREE_TYPE (retval_rhs
))
3135 : BYTES_BIG_ENDIAN
))
3136 padding_correction
= (BITS_PER_WORD
- ((bytes
% UNITS_PER_WORD
)
3139 /* Copy the structure BITSIZE bits at a time. */
3140 for (bitpos
= 0, xbitpos
= padding_correction
;
3141 bitpos
< bytes
* BITS_PER_UNIT
;
3142 bitpos
+= bitsize
, xbitpos
+= bitsize
)
3144 /* We need a new destination pseudo each time xbitpos is
3145 on a word boundary and when xbitpos == padding_correction
3146 (the first time through). */
3147 if (xbitpos
% BITS_PER_WORD
== 0
3148 || xbitpos
== padding_correction
)
3150 /* Generate an appropriate register. */
3151 dst
= gen_reg_rtx (word_mode
);
3152 result_pseudos
[xbitpos
/ BITS_PER_WORD
] = dst
;
3154 /* Clear the destination before we move anything into it. */
3155 emit_move_insn (dst
, CONST0_RTX (GET_MODE (dst
)));
3158 /* We need a new source operand each time bitpos is on a word
3160 if (bitpos
% BITS_PER_WORD
== 0)
3161 src
= operand_subword_force (result_val
,
3162 bitpos
/ BITS_PER_WORD
,
3165 /* Use bitpos for the source extraction (left justified) and
3166 xbitpos for the destination store (right justified). */
3167 store_bit_field (dst
, bitsize
, xbitpos
% BITS_PER_WORD
, word_mode
,
3168 extract_bit_field (src
, bitsize
,
3169 bitpos
% BITS_PER_WORD
, 1,
3170 NULL_RTX
, word_mode
, word_mode
,
3175 tmpmode
= GET_MODE (result_rtl
);
3176 if (tmpmode
== BLKmode
)
3178 /* Find the smallest integer mode large enough to hold the
3179 entire structure and use that mode instead of BLKmode
3180 on the USE insn for the return register. */
3181 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
3182 tmpmode
!= VOIDmode
;
3183 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
3184 /* Have we found a large enough mode? */
3185 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
3188 /* No suitable mode found. */
3189 if (tmpmode
== VOIDmode
)
3192 PUT_MODE (result_rtl
, tmpmode
);
3195 if (GET_MODE_SIZE (tmpmode
) < GET_MODE_SIZE (word_mode
))
3196 result_reg_mode
= word_mode
;
3198 result_reg_mode
= tmpmode
;
3199 result_reg
= gen_reg_rtx (result_reg_mode
);
3202 for (i
= 0; i
< n_regs
; i
++)
3203 emit_move_insn (operand_subword (result_reg
, i
, 0, result_reg_mode
),
3206 if (tmpmode
!= result_reg_mode
)
3207 result_reg
= gen_lowpart (tmpmode
, result_reg
);
3209 expand_value_return (result_reg
);
3211 else if (retval_rhs
!= 0
3212 && !VOID_TYPE_P (TREE_TYPE (retval_rhs
))
3213 && (GET_CODE (result_rtl
) == REG
3214 || (GET_CODE (result_rtl
) == PARALLEL
)))
3216 /* Calculate the return value into a temporary (usually a pseudo
3218 tree ot
= TREE_TYPE (DECL_RESULT (current_function_decl
));
3219 tree nt
= build_qualified_type (ot
, TYPE_QUALS (ot
) | TYPE_QUAL_CONST
);
3221 val
= assign_temp (nt
, 0, 0, 1);
3222 val
= expand_expr (retval_rhs
, val
, GET_MODE (val
), 0);
3223 val
= force_not_mem (val
);
3225 /* Return the calculated value, doing cleanups first. */
3226 expand_value_return (shift_return_value (val
));
3230 /* No cleanups or no hard reg used;
3231 calculate value into hard return reg. */
3232 expand_expr (retval
, const0_rtx
, VOIDmode
, 0);
3234 expand_value_return (result_rtl
);
3238 /* Attempt to optimize a potential tail recursion call into a goto.
3239 ARGUMENTS are the arguments to a CALL_EXPR; LAST_INSN indicates
3240 where to place the jump to the tail recursion label.
3242 Return TRUE if the call was optimized into a goto. */
3245 optimize_tail_recursion (tree arguments
, rtx last_insn
)
3247 /* Finish checking validity, and if valid emit code to set the
3248 argument variables for the new call. */
3249 if (tail_recursion_args (arguments
, DECL_ARGUMENTS (current_function_decl
)))
3251 if (tail_recursion_label
== 0)
3253 tail_recursion_label
= gen_label_rtx ();
3254 emit_label_after (tail_recursion_label
,
3255 tail_recursion_reentry
);
3258 expand_goto_internal (NULL_TREE
, tail_recursion_label
, last_insn
);
3265 /* Emit code to alter this function's formal parms for a tail-recursive call.
3266 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3267 FORMALS is the chain of decls of formals.
3268 Return 1 if this can be done;
3269 otherwise return 0 and do not emit any code. */
3272 tail_recursion_args (tree actuals
, tree formals
)
3274 tree a
= actuals
, f
= formals
;
3278 /* Check that number and types of actuals are compatible
3279 with the formals. This is not always true in valid C code.
3280 Also check that no formal needs to be addressable
3281 and that all formals are scalars. */
3283 /* Also count the args. */
3285 for (a
= actuals
, f
= formals
, i
= 0; a
&& f
; a
= TREE_CHAIN (a
), f
= TREE_CHAIN (f
), i
++)
3287 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a
)))
3288 != TYPE_MAIN_VARIANT (TREE_TYPE (f
)))
3290 if (GET_CODE (DECL_RTL (f
)) != REG
|| DECL_MODE (f
) == BLKmode
)
3293 if (a
!= 0 || f
!= 0)
3296 /* Compute all the actuals. */
3298 argvec
= alloca (i
* sizeof (rtx
));
3300 for (a
= actuals
, i
= 0; a
; a
= TREE_CHAIN (a
), i
++)
3301 argvec
[i
] = expand_expr (TREE_VALUE (a
), NULL_RTX
, VOIDmode
, 0);
3303 /* Find which actual values refer to current values of previous formals.
3304 Copy each of them now, before any formal is changed. */
3306 for (a
= actuals
, i
= 0; a
; a
= TREE_CHAIN (a
), i
++)
3310 for (f
= formals
, j
= 0; j
< i
; f
= TREE_CHAIN (f
), j
++)
3311 if (reg_mentioned_p (DECL_RTL (f
), argvec
[i
]))
3317 argvec
[i
] = copy_to_reg (argvec
[i
]);
3320 /* Store the values of the actuals into the formals. */
3322 for (f
= formals
, a
= actuals
, i
= 0; f
;
3323 f
= TREE_CHAIN (f
), a
= TREE_CHAIN (a
), i
++)
3325 if (GET_MODE (DECL_RTL (f
)) == GET_MODE (argvec
[i
]))
3326 emit_move_insn (DECL_RTL (f
), argvec
[i
]);
3329 rtx tmp
= argvec
[i
];
3330 int unsignedp
= TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a
)));
3331 promote_mode(TREE_TYPE (TREE_VALUE (a
)), GET_MODE (tmp
),
3333 if (DECL_MODE (f
) != GET_MODE (DECL_RTL (f
)))
3335 tmp
= gen_reg_rtx (DECL_MODE (f
));
3336 convert_move (tmp
, argvec
[i
], unsignedp
);
3338 convert_move (DECL_RTL (f
), tmp
, unsignedp
);
3346 /* Generate the RTL code for entering a binding contour.
3347 The variables are declared one by one, by calls to `expand_decl'.
3349 FLAGS is a bitwise or of the following flags:
3351 1 - Nonzero if this construct should be visible to
3354 2 - Nonzero if this contour does not require a
3355 NOTE_INSN_BLOCK_BEG note. Virtually all calls from
3356 language-independent code should set this flag because they
3357 will not create corresponding BLOCK nodes. (There should be
3358 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
3359 and BLOCKs.) If this flag is set, MARK_ENDS should be zero
3360 when expand_end_bindings is called.
3362 If we are creating a NOTE_INSN_BLOCK_BEG note, a BLOCK may
3363 optionally be supplied. If so, it becomes the NOTE_BLOCK for the
3367 expand_start_bindings_and_block (int flags
, tree block
)
3369 struct nesting
*thisblock
= ALLOC_NESTING ();
3371 int exit_flag
= ((flags
& 1) != 0);
3372 int block_flag
= ((flags
& 2) == 0);
3374 /* If a BLOCK is supplied, then the caller should be requesting a
3375 NOTE_INSN_BLOCK_BEG note. */
3376 if (!block_flag
&& block
)
3379 /* Create a note to mark the beginning of the block. */
3382 note
= emit_note (NOTE_INSN_BLOCK_BEG
);
3383 NOTE_BLOCK (note
) = block
;
3386 note
= emit_note (NOTE_INSN_DELETED
);
3388 /* Make an entry on block_stack for the block we are entering. */
3390 thisblock
->desc
= BLOCK_NESTING
;
3391 thisblock
->next
= block_stack
;
3392 thisblock
->all
= nesting_stack
;
3393 thisblock
->depth
= ++nesting_depth
;
3394 thisblock
->data
.block
.stack_level
= 0;
3395 thisblock
->data
.block
.cleanups
= 0;
3396 thisblock
->data
.block
.exception_region
= 0;
3397 thisblock
->data
.block
.block_target_temp_slot_level
= target_temp_slot_level
;
3399 thisblock
->data
.block
.conditional_code
= 0;
3400 thisblock
->data
.block
.last_unconditional_cleanup
= note
;
3401 /* When we insert instructions after the last unconditional cleanup,
3402 we don't adjust last_insn. That means that a later add_insn will
3403 clobber the instructions we've just added. The easiest way to
3404 fix this is to just insert another instruction here, so that the
3405 instructions inserted after the last unconditional cleanup are
3406 never the last instruction. */
3407 emit_note (NOTE_INSN_DELETED
);
3410 && !(block_stack
->data
.block
.cleanups
== NULL_TREE
3411 && block_stack
->data
.block
.outer_cleanups
== NULL_TREE
))
3412 thisblock
->data
.block
.outer_cleanups
3413 = tree_cons (NULL_TREE
, block_stack
->data
.block
.cleanups
,
3414 block_stack
->data
.block
.outer_cleanups
);
3416 thisblock
->data
.block
.outer_cleanups
= 0;
3417 thisblock
->data
.block
.label_chain
= 0;
3418 thisblock
->data
.block
.innermost_stack_block
= stack_block_stack
;
3419 thisblock
->data
.block
.first_insn
= note
;
3420 thisblock
->data
.block
.block_start_count
= ++current_block_start_count
;
3421 thisblock
->exit_label
= exit_flag
? gen_label_rtx () : 0;
3422 block_stack
= thisblock
;
3423 nesting_stack
= thisblock
;
3425 /* Make a new level for allocating stack slots. */
3429 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3430 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3431 expand_expr are made. After we end the region, we know that all
3432 space for all temporaries that were created by TARGET_EXPRs will be
3433 destroyed and their space freed for reuse. */
3436 expand_start_target_temps (void)
3438 /* This is so that even if the result is preserved, the space
3439 allocated will be freed, as we know that it is no longer in use. */
3442 /* Start a new binding layer that will keep track of all cleanup
3443 actions to be performed. */
3444 expand_start_bindings (2);
3446 target_temp_slot_level
= temp_slot_level
;
3450 expand_end_target_temps (void)
3452 expand_end_bindings (NULL_TREE
, 0, 0);
3454 /* This is so that even if the result is preserved, the space
3455 allocated will be freed, as we know that it is no longer in use. */
3459 /* Given a pointer to a BLOCK node return nonzero if (and only if) the node
3460 in question represents the outermost pair of curly braces (i.e. the "body
3461 block") of a function or method.
3463 For any BLOCK node representing a "body block" of a function or method, the
3464 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
3465 represents the outermost (function) scope for the function or method (i.e.
3466 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
3467 *that* node in turn will point to the relevant FUNCTION_DECL node. */
3470 is_body_block (tree stmt
)
3472 if (lang_hooks
.no_body_blocks
)
3475 if (TREE_CODE (stmt
) == BLOCK
)
3477 tree parent
= BLOCK_SUPERCONTEXT (stmt
);
3479 if (parent
&& TREE_CODE (parent
) == BLOCK
)
3481 tree grandparent
= BLOCK_SUPERCONTEXT (parent
);
3483 if (grandparent
&& TREE_CODE (grandparent
) == FUNCTION_DECL
)
3491 /* True if we are currently emitting insns in an area of output code
3492 that is controlled by a conditional expression. This is used by
3493 the cleanup handling code to generate conditional cleanup actions. */
3496 conditional_context (void)
3498 return block_stack
&& block_stack
->data
.block
.conditional_code
;
3501 /* Return an opaque pointer to the current nesting level, so frontend code
3502 can check its own sanity. */
3505 current_nesting_level (void)
3507 return cfun
? block_stack
: 0;
3510 /* Emit a handler label for a nonlocal goto handler.
3511 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3514 expand_nl_handler_label (rtx slot
, rtx before_insn
)
3517 rtx handler_label
= gen_label_rtx ();
3519 /* Don't let cleanup_cfg delete the handler. */
3520 LABEL_PRESERVE_P (handler_label
) = 1;
3523 emit_move_insn (slot
, gen_rtx_LABEL_REF (Pmode
, handler_label
));
3524 insns
= get_insns ();
3526 emit_insn_before (insns
, before_insn
);
3528 emit_label (handler_label
);
3530 return handler_label
;
3533 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3536 expand_nl_goto_receiver (void)
3538 #ifdef HAVE_nonlocal_goto
3539 if (! HAVE_nonlocal_goto
)
3541 /* First adjust our frame pointer to its actual value. It was
3542 previously set to the start of the virtual area corresponding to
3543 the stacked variables when we branched here and now needs to be
3544 adjusted to the actual hardware fp value.
3546 Assignments are to virtual registers are converted by
3547 instantiate_virtual_regs into the corresponding assignment
3548 to the underlying register (fp in this case) that makes
3549 the original assignment true.
3550 So the following insn will actually be
3551 decrementing fp by STARTING_FRAME_OFFSET. */
3552 emit_move_insn (virtual_stack_vars_rtx
, hard_frame_pointer_rtx
);
3554 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3555 if (fixed_regs
[ARG_POINTER_REGNUM
])
3557 #ifdef ELIMINABLE_REGS
3558 /* If the argument pointer can be eliminated in favor of the
3559 frame pointer, we don't need to restore it. We assume here
3560 that if such an elimination is present, it can always be used.
3561 This is the case on all known machines; if we don't make this
3562 assumption, we do unnecessary saving on many machines. */
3563 static const struct elims
{const int from
, to
;} elim_regs
[] = ELIMINABLE_REGS
;
3566 for (i
= 0; i
< ARRAY_SIZE (elim_regs
); i
++)
3567 if (elim_regs
[i
].from
== ARG_POINTER_REGNUM
3568 && elim_regs
[i
].to
== HARD_FRAME_POINTER_REGNUM
)
3571 if (i
== ARRAY_SIZE (elim_regs
))
3574 /* Now restore our arg pointer from the address at which it
3575 was saved in our stack frame. */
3576 emit_move_insn (virtual_incoming_args_rtx
,
3577 copy_to_reg (get_arg_pointer_save_area (cfun
)));
3582 #ifdef HAVE_nonlocal_goto_receiver
3583 if (HAVE_nonlocal_goto_receiver
)
3584 emit_insn (gen_nonlocal_goto_receiver ());
3588 /* Make handlers for nonlocal gotos taking place in the function calls in
3592 expand_nl_goto_receivers (struct nesting
*thisblock
)
3595 rtx afterward
= gen_label_rtx ();
3600 /* Record the handler address in the stack slot for that purpose,
3601 during this block, saving and restoring the outer value. */
3602 if (thisblock
->next
!= 0)
3603 for (slot
= nonlocal_goto_handler_slots
; slot
; slot
= XEXP (slot
, 1))
3605 rtx save_receiver
= gen_reg_rtx (Pmode
);
3606 emit_move_insn (XEXP (slot
, 0), save_receiver
);
3609 emit_move_insn (save_receiver
, XEXP (slot
, 0));
3610 insns
= get_insns ();
3612 emit_insn_before (insns
, thisblock
->data
.block
.first_insn
);
3615 /* Jump around the handlers; they run only when specially invoked. */
3616 emit_jump (afterward
);
3618 /* Make a separate handler for each label. */
3619 link
= nonlocal_labels
;
3620 slot
= nonlocal_goto_handler_slots
;
3621 label_list
= NULL_RTX
;
3622 for (; link
; link
= TREE_CHAIN (link
), slot
= XEXP (slot
, 1))
3623 /* Skip any labels we shouldn't be able to jump to from here,
3624 we generate one special handler for all of them below which just calls
3626 if (! DECL_TOO_LATE (TREE_VALUE (link
)))
3629 lab
= expand_nl_handler_label (XEXP (slot
, 0),
3630 thisblock
->data
.block
.first_insn
);
3631 label_list
= gen_rtx_EXPR_LIST (VOIDmode
, lab
, label_list
);
3633 expand_nl_goto_receiver ();
3635 /* Jump to the "real" nonlocal label. */
3636 expand_goto (TREE_VALUE (link
));
3639 /* A second pass over all nonlocal labels; this time we handle those
3640 we should not be able to jump to at this point. */
3641 link
= nonlocal_labels
;
3642 slot
= nonlocal_goto_handler_slots
;
3644 for (; link
; link
= TREE_CHAIN (link
), slot
= XEXP (slot
, 1))
3645 if (DECL_TOO_LATE (TREE_VALUE (link
)))
3648 lab
= expand_nl_handler_label (XEXP (slot
, 0),
3649 thisblock
->data
.block
.first_insn
);
3650 label_list
= gen_rtx_EXPR_LIST (VOIDmode
, lab
, label_list
);
3656 expand_nl_goto_receiver ();
3657 expand_builtin_trap ();
3660 nonlocal_goto_handler_labels
= label_list
;
3661 emit_label (afterward
);
3664 /* Warn about any unused VARS (which may contain nodes other than
3665 VAR_DECLs, but such nodes are ignored). The nodes are connected
3666 via the TREE_CHAIN field. */
3669 warn_about_unused_variables (tree vars
)
3673 if (warn_unused_variable
)
3674 for (decl
= vars
; decl
; decl
= TREE_CHAIN (decl
))
3675 if (TREE_CODE (decl
) == VAR_DECL
3676 && ! TREE_USED (decl
)
3677 && ! DECL_IN_SYSTEM_HEADER (decl
)
3678 && DECL_NAME (decl
) && ! DECL_ARTIFICIAL (decl
))
3679 warning ("%Junused variable '%D'", decl
, decl
);
3682 /* Generate RTL code to terminate a binding contour.
3684 VARS is the chain of VAR_DECL nodes for the variables bound in this
3685 contour. There may actually be other nodes in this chain, but any
3686 nodes other than VAR_DECLS are ignored.
3688 MARK_ENDS is nonzero if we should put a note at the beginning
3689 and end of this binding contour.
3691 DONT_JUMP_IN is positive if it is not valid to jump into this contour,
3692 zero if we can jump into this contour only if it does not have a saved
3693 stack level, and negative if we are not to check for invalid use of
3694 labels (because the front end does that). */
3697 expand_end_bindings (tree vars
, int mark_ends
, int dont_jump_in
)
3699 struct nesting
*thisblock
= block_stack
;
3701 /* If any of the variables in this scope were not used, warn the
3703 warn_about_unused_variables (vars
);
3705 if (thisblock
->exit_label
)
3707 do_pending_stack_adjust ();
3708 emit_label (thisblock
->exit_label
);
3711 /* If necessary, make handlers for nonlocal gotos taking
3712 place in the function calls in this block. */
3713 if (function_call_count
!= 0 && nonlocal_labels
3714 /* Make handler for outermost block
3715 if there were any nonlocal gotos to this function. */
3716 && (thisblock
->next
== 0 ? current_function_has_nonlocal_label
3717 /* Make handler for inner block if it has something
3718 special to do when you jump out of it. */
3719 : (thisblock
->data
.block
.cleanups
!= 0
3720 || thisblock
->data
.block
.stack_level
!= 0)))
3721 expand_nl_goto_receivers (thisblock
);
3723 /* Don't allow jumping into a block that has a stack level.
3724 Cleanups are allowed, though. */
3725 if (dont_jump_in
> 0
3726 || (dont_jump_in
== 0 && thisblock
->data
.block
.stack_level
!= 0))
3728 struct label_chain
*chain
;
3730 /* Any labels in this block are no longer valid to go to.
3731 Mark them to cause an error message. */
3732 for (chain
= thisblock
->data
.block
.label_chain
; chain
; chain
= chain
->next
)
3734 DECL_TOO_LATE (chain
->label
) = 1;
3735 /* If any goto without a fixup came to this label,
3736 that must be an error, because gotos without fixups
3737 come from outside all saved stack-levels. */
3738 if (TREE_ADDRESSABLE (chain
->label
))
3739 error ("%Jlabel '%D' used before containing binding contour",
3740 chain
->label
, chain
->label
);
3744 /* Restore stack level in effect before the block
3745 (only if variable-size objects allocated). */
3746 /* Perform any cleanups associated with the block. */
3748 if (thisblock
->data
.block
.stack_level
!= 0
3749 || thisblock
->data
.block
.cleanups
!= 0)
3754 /* Don't let cleanups affect ({...}) constructs. */
3755 int old_expr_stmts_for_value
= expr_stmts_for_value
;
3756 rtx old_last_expr_value
= last_expr_value
;
3757 tree old_last_expr_type
= last_expr_type
;
3758 expr_stmts_for_value
= 0;
3760 /* Only clean up here if this point can actually be reached. */
3761 insn
= get_last_insn ();
3762 if (GET_CODE (insn
) == NOTE
)
3763 insn
= prev_nonnote_insn (insn
);
3764 reachable
= (! insn
|| GET_CODE (insn
) != BARRIER
);
3766 /* Do the cleanups. */
3767 expand_cleanups (thisblock
->data
.block
.cleanups
, 0, reachable
);
3769 do_pending_stack_adjust ();
3771 expr_stmts_for_value
= old_expr_stmts_for_value
;
3772 last_expr_value
= old_last_expr_value
;
3773 last_expr_type
= old_last_expr_type
;
3775 /* Restore the stack level. */
3777 if (reachable
&& thisblock
->data
.block
.stack_level
!= 0)
3779 emit_stack_restore (thisblock
->next
? SAVE_BLOCK
: SAVE_FUNCTION
,
3780 thisblock
->data
.block
.stack_level
, NULL_RTX
);
3781 if (nonlocal_goto_handler_slots
!= 0)
3782 emit_stack_save (SAVE_NONLOCAL
, &nonlocal_goto_stack_level
,
3786 /* Any gotos out of this block must also do these things.
3787 Also report any gotos with fixups that came to labels in this
3789 fixup_gotos (thisblock
,
3790 thisblock
->data
.block
.stack_level
,
3791 thisblock
->data
.block
.cleanups
,
3792 thisblock
->data
.block
.first_insn
,
3796 /* Mark the beginning and end of the scope if requested.
3797 We do this now, after running cleanups on the variables
3798 just going out of scope, so they are in scope for their cleanups. */
3802 rtx note
= emit_note (NOTE_INSN_BLOCK_END
);
3803 NOTE_BLOCK (note
) = NOTE_BLOCK (thisblock
->data
.block
.first_insn
);
3806 /* Get rid of the beginning-mark if we don't make an end-mark. */
3807 NOTE_LINE_NUMBER (thisblock
->data
.block
.first_insn
) = NOTE_INSN_DELETED
;
3809 /* Restore the temporary level of TARGET_EXPRs. */
3810 target_temp_slot_level
= thisblock
->data
.block
.block_target_temp_slot_level
;
3812 /* Restore block_stack level for containing block. */
3814 stack_block_stack
= thisblock
->data
.block
.innermost_stack_block
;
3815 POPSTACK (block_stack
);
3817 /* Pop the stack slot nesting and free any slots at this level. */
3821 /* Generate code to save the stack pointer at the start of the current block
3822 and set up to restore it on exit. */
3825 save_stack_pointer (void)
3827 struct nesting
*thisblock
= block_stack
;
3829 if (thisblock
->data
.block
.stack_level
== 0)
3831 emit_stack_save (thisblock
->next
? SAVE_BLOCK
: SAVE_FUNCTION
,
3832 &thisblock
->data
.block
.stack_level
,
3833 thisblock
->data
.block
.first_insn
);
3834 stack_block_stack
= thisblock
;
3838 /* Generate RTL for the automatic variable declaration DECL.
3839 (Other kinds of declarations are simply ignored if seen here.) */
3842 expand_decl (tree decl
)
3846 type
= TREE_TYPE (decl
);
3848 /* For a CONST_DECL, set mode, alignment, and sizes from those of the
3849 type in case this node is used in a reference. */
3850 if (TREE_CODE (decl
) == CONST_DECL
)
3852 DECL_MODE (decl
) = TYPE_MODE (type
);
3853 DECL_ALIGN (decl
) = TYPE_ALIGN (type
);
3854 DECL_SIZE (decl
) = TYPE_SIZE (type
);
3855 DECL_SIZE_UNIT (decl
) = TYPE_SIZE_UNIT (type
);
3859 /* Otherwise, only automatic variables need any expansion done. Static and
3860 external variables, and external functions, will be handled by
3861 `assemble_variable' (called from finish_decl). TYPE_DECL requires
3862 nothing. PARM_DECLs are handled in `assign_parms'. */
3863 if (TREE_CODE (decl
) != VAR_DECL
)
3866 if (TREE_STATIC (decl
) || DECL_EXTERNAL (decl
))
3869 /* Create the RTL representation for the variable. */
3871 if (type
== error_mark_node
)
3872 SET_DECL_RTL (decl
, gen_rtx_MEM (BLKmode
, const0_rtx
));
3874 else if (DECL_SIZE (decl
) == 0)
3875 /* Variable with incomplete type. */
3878 if (DECL_INITIAL (decl
) == 0)
3879 /* Error message was already done; now avoid a crash. */
3880 x
= gen_rtx_MEM (BLKmode
, const0_rtx
);
3882 /* An initializer is going to decide the size of this array.
3883 Until we know the size, represent its address with a reg. */
3884 x
= gen_rtx_MEM (BLKmode
, gen_reg_rtx (Pmode
));
3886 set_mem_attributes (x
, decl
, 1);
3887 SET_DECL_RTL (decl
, x
);
3889 else if (DECL_MODE (decl
) != BLKmode
3890 /* If -ffloat-store, don't put explicit float vars
3892 && !(flag_float_store
3893 && TREE_CODE (type
) == REAL_TYPE
)
3894 && ! TREE_THIS_VOLATILE (decl
)
3895 && ! DECL_NONLOCAL (decl
)
3896 && (DECL_REGISTER (decl
) || DECL_ARTIFICIAL (decl
) || optimize
))
3898 /* Automatic variable that can go in a register. */
3899 int unsignedp
= TREE_UNSIGNED (type
);
3900 enum machine_mode reg_mode
3901 = promote_mode (type
, DECL_MODE (decl
), &unsignedp
, 0);
3903 SET_DECL_RTL (decl
, gen_reg_rtx (reg_mode
));
3905 if (!DECL_ARTIFICIAL (decl
))
3906 mark_user_reg (DECL_RTL (decl
));
3908 if (POINTER_TYPE_P (type
))
3909 mark_reg_pointer (DECL_RTL (decl
),
3910 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl
))));
3912 maybe_set_unchanging (DECL_RTL (decl
), decl
);
3914 /* If something wants our address, try to use ADDRESSOF. */
3915 if (TREE_ADDRESSABLE (decl
))
3916 put_var_into_stack (decl
, /*rescan=*/false);
3919 else if (TREE_CODE (DECL_SIZE_UNIT (decl
)) == INTEGER_CST
3920 && ! (flag_stack_check
&& ! STACK_CHECK_BUILTIN
3921 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl
),
3922 STACK_CHECK_MAX_VAR_SIZE
)))
3924 /* Variable of fixed size that goes on the stack. */
3929 /* If we previously made RTL for this decl, it must be an array
3930 whose size was determined by the initializer.
3931 The old address was a register; set that register now
3932 to the proper address. */
3933 if (DECL_RTL_SET_P (decl
))
3935 if (GET_CODE (DECL_RTL (decl
)) != MEM
3936 || GET_CODE (XEXP (DECL_RTL (decl
), 0)) != REG
)
3938 oldaddr
= XEXP (DECL_RTL (decl
), 0);
3941 /* Set alignment we actually gave this decl. */
3942 DECL_ALIGN (decl
) = (DECL_MODE (decl
) == BLKmode
? BIGGEST_ALIGNMENT
3943 : GET_MODE_BITSIZE (DECL_MODE (decl
)));
3944 DECL_USER_ALIGN (decl
) = 0;
3946 x
= assign_temp (decl
, 1, 1, 1);
3947 set_mem_attributes (x
, decl
, 1);
3948 SET_DECL_RTL (decl
, x
);
3952 addr
= force_operand (XEXP (DECL_RTL (decl
), 0), oldaddr
);
3953 if (addr
!= oldaddr
)
3954 emit_move_insn (oldaddr
, addr
);
3958 /* Dynamic-size object: must push space on the stack. */
3960 rtx address
, size
, x
;
3962 /* Record the stack pointer on entry to block, if have
3963 not already done so. */
3964 do_pending_stack_adjust ();
3965 save_stack_pointer ();
3967 /* In function-at-a-time mode, variable_size doesn't expand this,
3969 if (TREE_CODE (type
) == ARRAY_TYPE
&& TYPE_DOMAIN (type
))
3970 expand_expr (TYPE_MAX_VALUE (TYPE_DOMAIN (type
)),
3971 const0_rtx
, VOIDmode
, 0);
3973 /* Compute the variable's size, in bytes. */
3974 size
= expand_expr (DECL_SIZE_UNIT (decl
), NULL_RTX
, VOIDmode
, 0);
3977 /* Allocate space on the stack for the variable. Note that
3978 DECL_ALIGN says how the variable is to be aligned and we
3979 cannot use it to conclude anything about the alignment of
3981 address
= allocate_dynamic_stack_space (size
, NULL_RTX
,
3982 TYPE_ALIGN (TREE_TYPE (decl
)));
3984 /* Reference the variable indirect through that rtx. */
3985 x
= gen_rtx_MEM (DECL_MODE (decl
), address
);
3986 set_mem_attributes (x
, decl
, 1);
3987 SET_DECL_RTL (decl
, x
);
3990 /* Indicate the alignment we actually gave this variable. */
3991 #ifdef STACK_BOUNDARY
3992 DECL_ALIGN (decl
) = STACK_BOUNDARY
;
3994 DECL_ALIGN (decl
) = BIGGEST_ALIGNMENT
;
3996 DECL_USER_ALIGN (decl
) = 0;
4000 /* Emit code to perform the initialization of a declaration DECL. */
4003 expand_decl_init (tree decl
)
4005 int was_used
= TREE_USED (decl
);
4007 /* If this is a CONST_DECL, we don't have to generate any code. Likewise
4008 for static decls. */
4009 if (TREE_CODE (decl
) == CONST_DECL
4010 || TREE_STATIC (decl
))
4013 /* Compute and store the initial value now. */
4017 if (DECL_INITIAL (decl
) == error_mark_node
)
4019 enum tree_code code
= TREE_CODE (TREE_TYPE (decl
));
4021 if (code
== INTEGER_TYPE
|| code
== REAL_TYPE
|| code
== ENUMERAL_TYPE
4022 || code
== POINTER_TYPE
|| code
== REFERENCE_TYPE
)
4023 expand_assignment (decl
, convert (TREE_TYPE (decl
), integer_zero_node
),
4027 else if (DECL_INITIAL (decl
) && TREE_CODE (DECL_INITIAL (decl
)) != TREE_LIST
)
4029 emit_line_note (DECL_SOURCE_LOCATION (decl
));
4030 expand_assignment (decl
, DECL_INITIAL (decl
), 0);
4034 /* Don't let the initialization count as "using" the variable. */
4035 TREE_USED (decl
) = was_used
;
4037 /* Free any temporaries we made while initializing the decl. */
4038 preserve_temp_slots (NULL_RTX
);
4043 /* CLEANUP is an expression to be executed at exit from this binding contour;
4044 for example, in C++, it might call the destructor for this variable.
4046 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
4047 CLEANUP multiple times, and have the correct semantics. This
4048 happens in exception handling, for gotos, returns, breaks that
4049 leave the current scope.
4051 If CLEANUP is nonzero and DECL is zero, we record a cleanup
4052 that is not associated with any particular variable. */
4055 expand_decl_cleanup (tree decl
, tree cleanup
)
4057 struct nesting
*thisblock
;
4059 /* Error if we are not in any block. */
4060 if (cfun
== 0 || block_stack
== 0)
4063 thisblock
= block_stack
;
4065 /* Record the cleanup if there is one. */
4071 tree
*cleanups
= &thisblock
->data
.block
.cleanups
;
4072 int cond_context
= conditional_context ();
4076 rtx flag
= gen_reg_rtx (word_mode
);
4081 emit_move_insn (flag
, const0_rtx
);
4082 set_flag_0
= get_insns ();
4085 thisblock
->data
.block
.last_unconditional_cleanup
4086 = emit_insn_after (set_flag_0
,
4087 thisblock
->data
.block
.last_unconditional_cleanup
);
4089 emit_move_insn (flag
, const1_rtx
);
4091 cond
= build_decl (VAR_DECL
, NULL_TREE
,
4092 (*lang_hooks
.types
.type_for_mode
) (word_mode
, 1));
4093 SET_DECL_RTL (cond
, flag
);
4095 /* Conditionalize the cleanup. */
4096 cleanup
= build (COND_EXPR
, void_type_node
,
4097 (*lang_hooks
.truthvalue_conversion
) (cond
),
4098 cleanup
, integer_zero_node
);
4099 cleanup
= fold (cleanup
);
4101 cleanups
= &thisblock
->data
.block
.cleanups
;
4104 cleanup
= unsave_expr (cleanup
);
4106 t
= *cleanups
= tree_cons (decl
, cleanup
, *cleanups
);
4109 /* If this block has a cleanup, it belongs in stack_block_stack. */
4110 stack_block_stack
= thisblock
;
4117 if (! using_eh_for_cleanups_p
)
4118 TREE_ADDRESSABLE (t
) = 1;
4120 expand_eh_region_start ();
4127 thisblock
->data
.block
.last_unconditional_cleanup
4128 = emit_insn_after (seq
,
4129 thisblock
->data
.block
.last_unconditional_cleanup
);
4133 thisblock
->data
.block
.last_unconditional_cleanup
4135 /* When we insert instructions after the last unconditional cleanup,
4136 we don't adjust last_insn. That means that a later add_insn will
4137 clobber the instructions we've just added. The easiest way to
4138 fix this is to just insert another instruction here, so that the
4139 instructions inserted after the last unconditional cleanup are
4140 never the last instruction. */
4141 emit_note (NOTE_INSN_DELETED
);
4147 /* Like expand_decl_cleanup, but maybe only run the cleanup if an exception
4151 expand_decl_cleanup_eh (tree decl
, tree cleanup
, int eh_only
)
4153 int ret
= expand_decl_cleanup (decl
, cleanup
);
4156 tree node
= block_stack
->data
.block
.cleanups
;
4157 CLEANUP_EH_ONLY (node
) = eh_only
;
4162 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4163 DECL_ELTS is the list of elements that belong to DECL's type.
4164 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4167 expand_anon_union_decl (tree decl
, tree cleanup
, tree decl_elts
)
4169 struct nesting
*thisblock
= cfun
== 0 ? 0 : block_stack
;
4173 /* If any of the elements are addressable, so is the entire union. */
4174 for (t
= decl_elts
; t
; t
= TREE_CHAIN (t
))
4175 if (TREE_ADDRESSABLE (TREE_VALUE (t
)))
4177 TREE_ADDRESSABLE (decl
) = 1;
4182 expand_decl_cleanup (decl
, cleanup
);
4183 x
= DECL_RTL (decl
);
4185 /* Go through the elements, assigning RTL to each. */
4186 for (t
= decl_elts
; t
; t
= TREE_CHAIN (t
))
4188 tree decl_elt
= TREE_VALUE (t
);
4189 tree cleanup_elt
= TREE_PURPOSE (t
);
4190 enum machine_mode mode
= TYPE_MODE (TREE_TYPE (decl_elt
));
4192 /* If any of the elements are addressable, so is the entire
4194 if (TREE_USED (decl_elt
))
4195 TREE_USED (decl
) = 1;
4197 /* Propagate the union's alignment to the elements. */
4198 DECL_ALIGN (decl_elt
) = DECL_ALIGN (decl
);
4199 DECL_USER_ALIGN (decl_elt
) = DECL_USER_ALIGN (decl
);
4201 /* If the element has BLKmode and the union doesn't, the union is
4202 aligned such that the element doesn't need to have BLKmode, so
4203 change the element's mode to the appropriate one for its size. */
4204 if (mode
== BLKmode
&& DECL_MODE (decl
) != BLKmode
)
4205 DECL_MODE (decl_elt
) = mode
4206 = mode_for_size_tree (DECL_SIZE (decl_elt
), MODE_INT
, 1);
4208 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4209 instead create a new MEM rtx with the proper mode. */
4210 if (GET_CODE (x
) == MEM
)
4212 if (mode
== GET_MODE (x
))
4213 SET_DECL_RTL (decl_elt
, x
);
4215 SET_DECL_RTL (decl_elt
, adjust_address_nv (x
, mode
, 0));
4217 else if (GET_CODE (x
) == REG
)
4219 if (mode
== GET_MODE (x
))
4220 SET_DECL_RTL (decl_elt
, x
);
4222 SET_DECL_RTL (decl_elt
, gen_lowpart_SUBREG (mode
, x
));
4227 /* Record the cleanup if there is one. */
4230 thisblock
->data
.block
.cleanups
4231 = tree_cons (decl_elt
, cleanup_elt
,
4232 thisblock
->data
.block
.cleanups
);
4236 /* Expand a list of cleanups LIST.
4237 Elements may be expressions or may be nested lists.
4239 If IN_FIXUP is nonzero, we are generating this cleanup for a fixup
4240 goto and handle protection regions specially in that case.
4242 If REACHABLE, we emit code, otherwise just inform the exception handling
4243 code about this finalization. */
4246 expand_cleanups (tree list
, int in_fixup
, int reachable
)
4249 for (tail
= list
; tail
; tail
= TREE_CHAIN (tail
))
4250 if (TREE_CODE (TREE_VALUE (tail
)) == TREE_LIST
)
4251 expand_cleanups (TREE_VALUE (tail
), in_fixup
, reachable
);
4254 if (! in_fixup
&& using_eh_for_cleanups_p
)
4255 expand_eh_region_end_cleanup (TREE_VALUE (tail
));
4257 if (reachable
&& !CLEANUP_EH_ONLY (tail
))
4259 /* Cleanups may be run multiple times. For example,
4260 when exiting a binding contour, we expand the
4261 cleanups associated with that contour. When a goto
4262 within that binding contour has a target outside that
4263 contour, it will expand all cleanups from its scope to
4264 the target. Though the cleanups are expanded multiple
4265 times, the control paths are non-overlapping so the
4266 cleanups will not be executed twice. */
4268 /* We may need to protect from outer cleanups. */
4269 if (in_fixup
&& using_eh_for_cleanups_p
)
4271 expand_eh_region_start ();
4273 expand_expr (TREE_VALUE (tail
), const0_rtx
, VOIDmode
, 0);
4275 expand_eh_region_end_fixup (TREE_VALUE (tail
));
4278 expand_expr (TREE_VALUE (tail
), const0_rtx
, VOIDmode
, 0);
4285 /* Mark when the context we are emitting RTL for as a conditional
4286 context, so that any cleanup actions we register with
4287 expand_decl_init will be properly conditionalized when those
4288 cleanup actions are later performed. Must be called before any
4289 expression (tree) is expanded that is within a conditional context. */
4292 start_cleanup_deferral (void)
4294 /* block_stack can be NULL if we are inside the parameter list. It is
4295 OK to do nothing, because cleanups aren't possible here. */
4297 ++block_stack
->data
.block
.conditional_code
;
4300 /* Mark the end of a conditional region of code. Because cleanup
4301 deferrals may be nested, we may still be in a conditional region
4302 after we end the currently deferred cleanups, only after we end all
4303 deferred cleanups, are we back in unconditional code. */
4306 end_cleanup_deferral (void)
4308 /* block_stack can be NULL if we are inside the parameter list. It is
4309 OK to do nothing, because cleanups aren't possible here. */
4311 --block_stack
->data
.block
.conditional_code
;
4315 last_cleanup_this_contour (void)
4317 if (block_stack
== 0)
4320 return block_stack
->data
.block
.cleanups
;
4323 /* Return 1 if there are any pending cleanups at this point.
4324 Check the current contour as well as contours that enclose
4325 the current contour. */
4328 any_pending_cleanups (void)
4330 struct nesting
*block
;
4332 if (cfun
== NULL
|| cfun
->stmt
== NULL
|| block_stack
== 0)
4335 if (block_stack
->data
.block
.cleanups
!= NULL
)
4338 if (block_stack
->data
.block
.outer_cleanups
== 0)
4341 for (block
= block_stack
->next
; block
; block
= block
->next
)
4342 if (block
->data
.block
.cleanups
!= 0)
4348 /* Enter a case (Pascal) or switch (C) statement.
4349 Push a block onto case_stack and nesting_stack
4350 to accumulate the case-labels that are seen
4351 and to record the labels generated for the statement.
4353 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4354 Otherwise, this construct is transparent for `exit_something'.
4356 EXPR is the index-expression to be dispatched on.
4357 TYPE is its nominal type. We could simply convert EXPR to this type,
4358 but instead we take short cuts. */
4361 expand_start_case (int exit_flag
, tree expr
, tree type
,
4362 const char *printname
)
4364 struct nesting
*thiscase
= ALLOC_NESTING ();
4366 /* Make an entry on case_stack for the case we are entering. */
4368 thiscase
->desc
= CASE_NESTING
;
4369 thiscase
->next
= case_stack
;
4370 thiscase
->all
= nesting_stack
;
4371 thiscase
->depth
= ++nesting_depth
;
4372 thiscase
->exit_label
= exit_flag
? gen_label_rtx () : 0;
4373 thiscase
->data
.case_stmt
.case_list
= 0;
4374 thiscase
->data
.case_stmt
.index_expr
= expr
;
4375 thiscase
->data
.case_stmt
.nominal_type
= type
;
4376 thiscase
->data
.case_stmt
.default_label
= 0;
4377 thiscase
->data
.case_stmt
.printname
= printname
;
4378 thiscase
->data
.case_stmt
.line_number_status
= force_line_numbers ();
4379 case_stack
= thiscase
;
4380 nesting_stack
= thiscase
;
4382 do_pending_stack_adjust ();
4385 /* Make sure case_stmt.start points to something that won't
4386 need any transformation before expand_end_case. */
4387 if (GET_CODE (get_last_insn ()) != NOTE
)
4388 emit_note (NOTE_INSN_DELETED
);
4390 thiscase
->data
.case_stmt
.start
= get_last_insn ();
4392 start_cleanup_deferral ();
4395 /* Start a "dummy case statement" within which case labels are invalid
4396 and are not connected to any larger real case statement.
4397 This can be used if you don't want to let a case statement jump
4398 into the middle of certain kinds of constructs. */
4401 expand_start_case_dummy (void)
4403 struct nesting
*thiscase
= ALLOC_NESTING ();
4405 /* Make an entry on case_stack for the dummy. */
4407 thiscase
->desc
= CASE_NESTING
;
4408 thiscase
->next
= case_stack
;
4409 thiscase
->all
= nesting_stack
;
4410 thiscase
->depth
= ++nesting_depth
;
4411 thiscase
->exit_label
= 0;
4412 thiscase
->data
.case_stmt
.case_list
= 0;
4413 thiscase
->data
.case_stmt
.start
= 0;
4414 thiscase
->data
.case_stmt
.nominal_type
= 0;
4415 thiscase
->data
.case_stmt
.default_label
= 0;
4416 case_stack
= thiscase
;
4417 nesting_stack
= thiscase
;
4418 start_cleanup_deferral ();
4422 check_seenlabel (void)
4424 /* If this is the first label, warn if any insns have been emitted. */
4425 if (case_stack
->data
.case_stmt
.line_number_status
>= 0)
4429 restore_line_number_status
4430 (case_stack
->data
.case_stmt
.line_number_status
);
4431 case_stack
->data
.case_stmt
.line_number_status
= -1;
4433 for (insn
= case_stack
->data
.case_stmt
.start
;
4435 insn
= NEXT_INSN (insn
))
4437 if (GET_CODE (insn
) == CODE_LABEL
)
4439 if (GET_CODE (insn
) != NOTE
4440 && (GET_CODE (insn
) != INSN
|| GET_CODE (PATTERN (insn
)) != USE
))
4443 insn
= PREV_INSN (insn
);
4444 while (insn
&& (GET_CODE (insn
) != NOTE
|| NOTE_LINE_NUMBER (insn
) < 0));
4446 /* If insn is zero, then there must have been a syntax error. */
4450 locus
.file
= NOTE_SOURCE_FILE (insn
);
4451 locus
.line
= NOTE_LINE_NUMBER (insn
);
4452 warning ("%Hunreachable code at beginning of %s", &locus
,
4453 case_stack
->data
.case_stmt
.printname
);
4461 /* Accumulate one case or default label inside a case or switch statement.
4462 VALUE is the value of the case (a null pointer, for a default label).
4463 The function CONVERTER, when applied to arguments T and V,
4464 converts the value V to the type T.
4466 If not currently inside a case or switch statement, return 1 and do
4467 nothing. The caller will print a language-specific error message.
4468 If VALUE is a duplicate or overlaps, return 2 and do nothing
4469 except store the (first) duplicate node in *DUPLICATE.
4470 If VALUE is out of range, return 3 and do nothing.
4471 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4472 Return 0 on success.
4474 Extended to handle range statements. */
4477 pushcase (tree value
, tree (*converter
) (tree
, tree
), tree label
,
4483 /* Fail if not inside a real case statement. */
4484 if (! (case_stack
&& case_stack
->data
.case_stmt
.start
))
4487 if (stack_block_stack
4488 && stack_block_stack
->depth
> case_stack
->depth
)
4491 index_type
= TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4492 nominal_type
= case_stack
->data
.case_stmt
.nominal_type
;
4494 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4495 if (index_type
== error_mark_node
)
4498 /* Convert VALUE to the type in which the comparisons are nominally done. */
4500 value
= (*converter
) (nominal_type
, value
);
4504 /* Fail if this value is out of range for the actual type of the index
4505 (which may be narrower than NOMINAL_TYPE). */
4507 && (TREE_CONSTANT_OVERFLOW (value
)
4508 || ! int_fits_type_p (value
, index_type
)))
4511 return add_case_node (value
, value
, label
, duplicate
);
4514 /* Like pushcase but this case applies to all values between VALUE1 and
4515 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4516 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4517 starts at VALUE1 and ends at the highest value of the index type.
4518 If both are NULL, this case applies to all values.
4520 The return value is the same as that of pushcase but there is one
4521 additional error code: 4 means the specified range was empty. */
4524 pushcase_range (tree value1
, tree value2
, tree (*converter
) (tree
, tree
),
4525 tree label
, tree
*duplicate
)
4530 /* Fail if not inside a real case statement. */
4531 if (! (case_stack
&& case_stack
->data
.case_stmt
.start
))
4534 if (stack_block_stack
4535 && stack_block_stack
->depth
> case_stack
->depth
)
4538 index_type
= TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4539 nominal_type
= case_stack
->data
.case_stmt
.nominal_type
;
4541 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4542 if (index_type
== error_mark_node
)
4547 /* Convert VALUEs to type in which the comparisons are nominally done
4548 and replace any unspecified value with the corresponding bound. */
4550 value1
= TYPE_MIN_VALUE (index_type
);
4552 value2
= TYPE_MAX_VALUE (index_type
);
4554 /* Fail if the range is empty. Do this before any conversion since
4555 we want to allow out-of-range empty ranges. */
4556 if (value2
!= 0 && tree_int_cst_lt (value2
, value1
))
4559 /* If the max was unbounded, use the max of the nominal_type we are
4560 converting to. Do this after the < check above to suppress false
4563 value2
= TYPE_MAX_VALUE (nominal_type
);
4565 value1
= (*converter
) (nominal_type
, value1
);
4566 value2
= (*converter
) (nominal_type
, value2
);
4568 /* Fail if these values are out of range. */
4569 if (TREE_CONSTANT_OVERFLOW (value1
)
4570 || ! int_fits_type_p (value1
, index_type
))
4573 if (TREE_CONSTANT_OVERFLOW (value2
)
4574 || ! int_fits_type_p (value2
, index_type
))
4577 return add_case_node (value1
, value2
, label
, duplicate
);
4580 /* Do the actual insertion of a case label for pushcase and pushcase_range
4581 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4582 slowdown for large switch statements. */
4585 add_case_node (tree low
, tree high
, tree label
, tree
*duplicate
)
4587 struct case_node
*p
, **q
, *r
;
4589 /* If there's no HIGH value, then this is not a case range; it's
4590 just a simple case label. But that's just a degenerate case
4595 /* Handle default labels specially. */
4598 if (case_stack
->data
.case_stmt
.default_label
!= 0)
4600 *duplicate
= case_stack
->data
.case_stmt
.default_label
;
4603 case_stack
->data
.case_stmt
.default_label
= label
;
4604 expand_label (label
);
4608 q
= &case_stack
->data
.case_stmt
.case_list
;
4615 /* Keep going past elements distinctly greater than HIGH. */
4616 if (tree_int_cst_lt (high
, p
->low
))
4619 /* or distinctly less than LOW. */
4620 else if (tree_int_cst_lt (p
->high
, low
))
4625 /* We have an overlap; this is an error. */
4626 *duplicate
= p
->code_label
;
4631 /* Add this label to the chain, and succeed. */
4633 r
= ggc_alloc (sizeof (struct case_node
));
4636 /* If the bounds are equal, turn this into the one-value case. */
4637 if (tree_int_cst_equal (low
, high
))
4642 r
->code_label
= label
;
4643 expand_label (label
);
4653 struct case_node
*s
;
4659 if (! (b
= p
->balance
))
4660 /* Growth propagation from left side. */
4667 if ((p
->left
= s
= r
->right
))
4676 if ((r
->parent
= s
))
4684 case_stack
->data
.case_stmt
.case_list
= r
;
4687 /* r->balance == +1 */
4692 struct case_node
*t
= r
->right
;
4694 if ((p
->left
= s
= t
->right
))
4698 if ((r
->right
= s
= t
->left
))
4712 if ((t
->parent
= s
))
4720 case_stack
->data
.case_stmt
.case_list
= t
;
4727 /* p->balance == +1; growth of left side balances the node. */
4737 if (! (b
= p
->balance
))
4738 /* Growth propagation from right side. */
4746 if ((p
->right
= s
= r
->left
))
4754 if ((r
->parent
= s
))
4763 case_stack
->data
.case_stmt
.case_list
= r
;
4767 /* r->balance == -1 */
4771 struct case_node
*t
= r
->left
;
4773 if ((p
->right
= s
= t
->left
))
4778 if ((r
->left
= s
= t
->right
))
4792 if ((t
->parent
= s
))
4801 case_stack
->data
.case_stmt
.case_list
= t
;
4807 /* p->balance == -1; growth of right side balances the node. */
4820 /* Returns the number of possible values of TYPE.
4821 Returns -1 if the number is unknown, variable, or if the number does not
4822 fit in a HOST_WIDE_INT.
4823 Sets *SPARSENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4824 do not increase monotonically (there may be duplicates);
4825 to 1 if the values increase monotonically, but not always by 1;
4826 otherwise sets it to 0. */
4829 all_cases_count (tree type
, int *sparseness
)
4832 HOST_WIDE_INT count
, minval
, lastval
;
4836 switch (TREE_CODE (type
))
4843 count
= 1 << BITS_PER_UNIT
;
4848 if (TYPE_MAX_VALUE (type
) != 0
4849 && 0 != (t
= fold (build (MINUS_EXPR
, type
, TYPE_MAX_VALUE (type
),
4850 TYPE_MIN_VALUE (type
))))
4851 && 0 != (t
= fold (build (PLUS_EXPR
, type
, t
,
4852 convert (type
, integer_zero_node
))))
4853 && host_integerp (t
, 1))
4854 count
= tree_low_cst (t
, 1);
4860 /* Don't waste time with enumeral types with huge values. */
4861 if (! host_integerp (TYPE_MIN_VALUE (type
), 0)
4862 || TYPE_MAX_VALUE (type
) == 0
4863 || ! host_integerp (TYPE_MAX_VALUE (type
), 0))
4866 lastval
= minval
= tree_low_cst (TYPE_MIN_VALUE (type
), 0);
4869 for (t
= TYPE_VALUES (type
); t
!= NULL_TREE
; t
= TREE_CHAIN (t
))
4871 HOST_WIDE_INT thisval
= tree_low_cst (TREE_VALUE (t
), 0);
4873 if (*sparseness
== 2 || thisval
<= lastval
)
4875 else if (thisval
!= minval
+ count
)
4886 #define BITARRAY_TEST(ARRAY, INDEX) \
4887 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4888 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4889 #define BITARRAY_SET(ARRAY, INDEX) \
4890 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4891 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4893 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4894 with the case values we have seen, assuming the case expression
4896 SPARSENESS is as determined by all_cases_count.
4898 The time needed is proportional to COUNT, unless
4899 SPARSENESS is 2, in which case quadratic time is needed. */
4902 mark_seen_cases (tree type
, unsigned char *cases_seen
, HOST_WIDE_INT count
,
4905 tree next_node_to_try
= NULL_TREE
;
4906 HOST_WIDE_INT next_node_offset
= 0;
4908 struct case_node
*n
, *root
= case_stack
->data
.case_stmt
.case_list
;
4909 tree val
= make_node (INTEGER_CST
);
4911 TREE_TYPE (val
) = type
;
4915 else if (sparseness
== 2)
4918 unsigned HOST_WIDE_INT xlo
;
4920 /* This less efficient loop is only needed to handle
4921 duplicate case values (multiple enum constants
4922 with the same value). */
4923 TREE_TYPE (val
) = TREE_TYPE (root
->low
);
4924 for (t
= TYPE_VALUES (type
), xlo
= 0; t
!= NULL_TREE
;
4925 t
= TREE_CHAIN (t
), xlo
++)
4927 TREE_INT_CST_LOW (val
) = TREE_INT_CST_LOW (TREE_VALUE (t
));
4928 TREE_INT_CST_HIGH (val
) = TREE_INT_CST_HIGH (TREE_VALUE (t
));
4932 /* Keep going past elements distinctly greater than VAL. */
4933 if (tree_int_cst_lt (val
, n
->low
))
4936 /* or distinctly less than VAL. */
4937 else if (tree_int_cst_lt (n
->high
, val
))
4942 /* We have found a matching range. */
4943 BITARRAY_SET (cases_seen
, xlo
);
4953 case_stack
->data
.case_stmt
.case_list
= root
= case_tree2list (root
, 0);
4955 for (n
= root
; n
; n
= n
->right
)
4957 TREE_INT_CST_LOW (val
) = TREE_INT_CST_LOW (n
->low
);
4958 TREE_INT_CST_HIGH (val
) = TREE_INT_CST_HIGH (n
->low
);
4959 while (! tree_int_cst_lt (n
->high
, val
))
4961 /* Calculate (into xlo) the "offset" of the integer (val).
4962 The element with lowest value has offset 0, the next smallest
4963 element has offset 1, etc. */
4965 unsigned HOST_WIDE_INT xlo
;
4969 if (sparseness
&& TYPE_VALUES (type
) != NULL_TREE
)
4971 /* The TYPE_VALUES will be in increasing order, so
4972 starting searching where we last ended. */
4973 t
= next_node_to_try
;
4974 xlo
= next_node_offset
;
4980 t
= TYPE_VALUES (type
);
4983 if (tree_int_cst_equal (val
, TREE_VALUE (t
)))
4985 next_node_to_try
= TREE_CHAIN (t
);
4986 next_node_offset
= xlo
+ 1;
4991 if (t
== next_node_to_try
)
5000 t
= TYPE_MIN_VALUE (type
);
5002 neg_double (TREE_INT_CST_LOW (t
), TREE_INT_CST_HIGH (t
),
5006 add_double (xlo
, xhi
,
5007 TREE_INT_CST_LOW (val
), TREE_INT_CST_HIGH (val
),
5011 if (xhi
== 0 && xlo
< (unsigned HOST_WIDE_INT
) count
)
5012 BITARRAY_SET (cases_seen
, xlo
);
5014 add_double (TREE_INT_CST_LOW (val
), TREE_INT_CST_HIGH (val
),
5016 &TREE_INT_CST_LOW (val
), &TREE_INT_CST_HIGH (val
));
5022 /* Given a switch statement with an expression that is an enumeration
5023 type, warn if any of the enumeration type's literals are not
5024 covered by the case expressions of the switch. Also, warn if there
5025 are any extra switch cases that are *not* elements of the
5030 At one stage this function would: ``If all enumeration literals
5031 were covered by the case expressions, turn one of the expressions
5032 into the default expression since it should not be possible to fall
5033 through such a switch.''
5035 That code has since been removed as: ``This optimization is
5036 disabled because it causes valid programs to fail. ANSI C does not
5037 guarantee that an expression with enum type will have a value that
5038 is the same as one of the enumeration literals.'' */
5041 check_for_full_enumeration_handling (tree type
)
5043 struct case_node
*n
;
5046 /* True iff the selector type is a numbered set mode. */
5049 /* The number of possible selector values. */
5052 /* For each possible selector value. a one iff it has been matched
5053 by a case value alternative. */
5054 unsigned char *cases_seen
;
5056 /* The allocated size of cases_seen, in chars. */
5057 HOST_WIDE_INT bytes_needed
;
5059 size
= all_cases_count (type
, &sparseness
);
5060 bytes_needed
= (size
+ HOST_BITS_PER_CHAR
) / HOST_BITS_PER_CHAR
;
5062 if (size
> 0 && size
< 600000
5063 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5064 this optimization if we don't have enough memory rather than
5065 aborting, as xmalloc would do. */
5066 && (cases_seen
= really_call_calloc (bytes_needed
, 1)) != NULL
)
5069 tree v
= TYPE_VALUES (type
);
5071 /* The time complexity of this code is normally O(N), where
5072 N being the number of members in the enumerated type.
5073 However, if type is an ENUMERAL_TYPE whose values do not
5074 increase monotonically, O(N*log(N)) time may be needed. */
5076 mark_seen_cases (type
, cases_seen
, size
, sparseness
);
5078 for (i
= 0; v
!= NULL_TREE
&& i
< size
; i
++, v
= TREE_CHAIN (v
))
5079 if (BITARRAY_TEST (cases_seen
, i
) == 0)
5080 warning ("enumeration value `%s' not handled in switch",
5081 IDENTIFIER_POINTER (TREE_PURPOSE (v
)));
5086 /* Now we go the other way around; we warn if there are case
5087 expressions that don't correspond to enumerators. This can
5088 occur since C and C++ don't enforce type-checking of
5089 assignments to enumeration variables. */
5091 if (case_stack
->data
.case_stmt
.case_list
5092 && case_stack
->data
.case_stmt
.case_list
->left
)
5093 case_stack
->data
.case_stmt
.case_list
5094 = case_tree2list (case_stack
->data
.case_stmt
.case_list
, 0);
5095 for (n
= case_stack
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5097 for (chain
= TYPE_VALUES (type
);
5098 chain
&& !tree_int_cst_equal (n
->low
, TREE_VALUE (chain
));
5099 chain
= TREE_CHAIN (chain
))
5104 if (TYPE_NAME (type
) == 0)
5105 warning ("case value `%ld' not in enumerated type",
5106 (long) TREE_INT_CST_LOW (n
->low
));
5108 warning ("case value `%ld' not in enumerated type `%s'",
5109 (long) TREE_INT_CST_LOW (n
->low
),
5110 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type
))
5113 : DECL_NAME (TYPE_NAME (type
))));
5115 if (!tree_int_cst_equal (n
->low
, n
->high
))
5117 for (chain
= TYPE_VALUES (type
);
5118 chain
&& !tree_int_cst_equal (n
->high
, TREE_VALUE (chain
));
5119 chain
= TREE_CHAIN (chain
))
5124 if (TYPE_NAME (type
) == 0)
5125 warning ("case value `%ld' not in enumerated type",
5126 (long) TREE_INT_CST_LOW (n
->high
));
5128 warning ("case value `%ld' not in enumerated type `%s'",
5129 (long) TREE_INT_CST_LOW (n
->high
),
5130 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type
))
5133 : DECL_NAME (TYPE_NAME (type
))));
5140 /* Maximum number of case bit tests. */
5141 #define MAX_CASE_BIT_TESTS 3
5143 /* By default, enable case bit tests on targets with ashlsi3. */
5144 #ifndef CASE_USE_BIT_TESTS
5145 #define CASE_USE_BIT_TESTS (ashl_optab->handlers[word_mode].insn_code \
5146 != CODE_FOR_nothing)
5150 /* A case_bit_test represents a set of case nodes that may be
5151 selected from using a bit-wise comparison. HI and LO hold
5152 the integer to be tested against, LABEL contains the label
5153 to jump to upon success and BITS counts the number of case
5154 nodes handled by this test, typically the number of bits
5157 struct case_bit_test
5165 /* Determine whether "1 << x" is relatively cheap in word_mode. */
5168 bool lshift_cheap_p (void)
5170 static bool init
= false;
5171 static bool cheap
= true;
5175 rtx reg
= gen_rtx_REG (word_mode
, 10000);
5176 int cost
= rtx_cost (gen_rtx_ASHIFT (word_mode
, const1_rtx
, reg
), SET
);
5177 cheap
= cost
< COSTS_N_INSNS (3);
5184 /* Comparison function for qsort to order bit tests by decreasing
5185 number of case nodes, i.e. the node with the most cases gets
5189 int case_bit_test_cmp (const void *p1
, const void *p2
)
5191 const struct case_bit_test
*d1
= p1
;
5192 const struct case_bit_test
*d2
= p2
;
5194 return d2
->bits
- d1
->bits
;
5197 /* Expand a switch statement by a short sequence of bit-wise
5198 comparisons. "switch(x)" is effectively converted into
5199 "if ((1 << (x-MINVAL)) & CST)" where CST and MINVAL are
5202 INDEX_EXPR is the value being switched on, which is of
5203 type INDEX_TYPE. MINVAL is the lowest case value of in
5204 the case nodes, of INDEX_TYPE type, and RANGE is highest
5205 value minus MINVAL, also of type INDEX_TYPE. NODES is
5206 the set of case nodes, and DEFAULT_LABEL is the label to
5207 branch to should none of the cases match.
5209 There *MUST* be MAX_CASE_BIT_TESTS or less unique case
5213 emit_case_bit_tests (tree index_type
, tree index_expr
, tree minval
,
5214 tree range
, case_node_ptr nodes
, rtx default_label
)
5216 struct case_bit_test test
[MAX_CASE_BIT_TESTS
];
5217 enum machine_mode mode
;
5218 rtx expr
, index
, label
;
5219 unsigned int i
,j
,lo
,hi
;
5220 struct case_node
*n
;
5224 for (n
= nodes
; n
; n
= n
->right
)
5226 label
= label_rtx (n
->code_label
);
5227 for (i
= 0; i
< count
; i
++)
5228 if (same_case_target_p (label
, test
[i
].label
))
5233 if (count
>= MAX_CASE_BIT_TESTS
)
5237 test
[i
].label
= label
;
5244 lo
= tree_low_cst (fold (build (MINUS_EXPR
, index_type
,
5245 n
->low
, minval
)), 1);
5246 hi
= tree_low_cst (fold (build (MINUS_EXPR
, index_type
,
5247 n
->high
, minval
)), 1);
5248 for (j
= lo
; j
<= hi
; j
++)
5249 if (j
>= HOST_BITS_PER_WIDE_INT
)
5250 test
[i
].hi
|= (HOST_WIDE_INT
) 1 << (j
- HOST_BITS_PER_INT
);
5252 test
[i
].lo
|= (HOST_WIDE_INT
) 1 << j
;
5255 qsort (test
, count
, sizeof(*test
), case_bit_test_cmp
);
5257 index_expr
= fold (build (MINUS_EXPR
, index_type
,
5258 convert (index_type
, index_expr
),
5259 convert (index_type
, minval
)));
5260 index
= expand_expr (index_expr
, NULL_RTX
, VOIDmode
, 0);
5262 index
= protect_from_queue (index
, 0);
5263 do_pending_stack_adjust ();
5265 mode
= TYPE_MODE (index_type
);
5266 expr
= expand_expr (range
, NULL_RTX
, VOIDmode
, 0);
5267 emit_cmp_and_jump_insns (index
, expr
, GTU
, NULL_RTX
, mode
, 1,
5270 index
= convert_to_mode (word_mode
, index
, 0);
5271 index
= expand_binop (word_mode
, ashl_optab
, const1_rtx
,
5272 index
, NULL_RTX
, 1, OPTAB_WIDEN
);
5274 for (i
= 0; i
< count
; i
++)
5276 expr
= immed_double_const (test
[i
].lo
, test
[i
].hi
, word_mode
);
5277 expr
= expand_binop (word_mode
, and_optab
, index
, expr
,
5278 NULL_RTX
, 1, OPTAB_WIDEN
);
5279 emit_cmp_and_jump_insns (expr
, const0_rtx
, NE
, NULL_RTX
,
5280 word_mode
, 1, test
[i
].label
);
5283 emit_jump (default_label
);
5286 /* Terminate a case (Pascal) or switch (C) statement
5287 in which ORIG_INDEX is the expression to be tested.
5288 If ORIG_TYPE is not NULL, it is the original ORIG_INDEX
5289 type as given in the source before any compiler conversions.
5290 Generate the code to test it and jump to the right place. */
5293 expand_end_case_type (tree orig_index
, tree orig_type
)
5295 tree minval
= NULL_TREE
, maxval
= NULL_TREE
, range
= NULL_TREE
;
5296 rtx default_label
= 0;
5297 struct case_node
*n
, *m
;
5298 unsigned int count
, uniq
;
5304 rtx before_case
, end
, lab
;
5305 struct nesting
*thiscase
= case_stack
;
5306 tree index_expr
, index_type
;
5307 bool exit_done
= false;
5310 /* Don't crash due to previous errors. */
5311 if (thiscase
== NULL
)
5314 index_expr
= thiscase
->data
.case_stmt
.index_expr
;
5315 index_type
= TREE_TYPE (index_expr
);
5316 unsignedp
= TREE_UNSIGNED (index_type
);
5317 if (orig_type
== NULL
)
5318 orig_type
= TREE_TYPE (orig_index
);
5320 do_pending_stack_adjust ();
5322 /* This might get a spurious warning in the presence of a syntax error;
5323 it could be fixed by moving the call to check_seenlabel after the
5324 check for error_mark_node, and copying the code of check_seenlabel that
5325 deals with case_stack->data.case_stmt.line_number_status /
5326 restore_line_number_status in front of the call to end_cleanup_deferral;
5327 However, this might miss some useful warnings in the presence of
5328 non-syntax errors. */
5331 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5332 if (index_type
!= error_mark_node
)
5334 /* If the switch expression was an enumerated type, check that
5335 exactly all enumeration literals are covered by the cases.
5336 The check is made when -Wswitch was specified and there is no
5337 default case, or when -Wswitch-enum was specified. */
5338 if (((warn_switch
&& !thiscase
->data
.case_stmt
.default_label
)
5339 || warn_switch_enum
)
5340 && TREE_CODE (orig_type
) == ENUMERAL_TYPE
5341 && TREE_CODE (index_expr
) != INTEGER_CST
)
5342 check_for_full_enumeration_handling (orig_type
);
5344 if (warn_switch_default
&& !thiscase
->data
.case_stmt
.default_label
)
5345 warning ("switch missing default case");
5347 /* If we don't have a default-label, create one here,
5348 after the body of the switch. */
5349 if (thiscase
->data
.case_stmt
.default_label
== 0)
5351 thiscase
->data
.case_stmt
.default_label
5352 = build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
5353 /* Share the exit label if possible. */
5354 if (thiscase
->exit_label
)
5356 SET_DECL_RTL (thiscase
->data
.case_stmt
.default_label
,
5357 thiscase
->exit_label
);
5360 expand_label (thiscase
->data
.case_stmt
.default_label
);
5362 default_label
= label_rtx (thiscase
->data
.case_stmt
.default_label
);
5364 before_case
= get_last_insn ();
5366 if (thiscase
->data
.case_stmt
.case_list
5367 && thiscase
->data
.case_stmt
.case_list
->left
)
5368 thiscase
->data
.case_stmt
.case_list
5369 = case_tree2list (thiscase
->data
.case_stmt
.case_list
, 0);
5371 /* Simplify the case-list before we count it. */
5372 group_case_nodes (thiscase
->data
.case_stmt
.case_list
);
5373 strip_default_case_nodes (&thiscase
->data
.case_stmt
.case_list
,
5376 /* Get upper and lower bounds of case values.
5377 Also convert all the case values to the index expr's data type. */
5381 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5383 /* Check low and high label values are integers. */
5384 if (TREE_CODE (n
->low
) != INTEGER_CST
)
5386 if (TREE_CODE (n
->high
) != INTEGER_CST
)
5389 n
->low
= convert (index_type
, n
->low
);
5390 n
->high
= convert (index_type
, n
->high
);
5392 /* Count the elements and track the largest and smallest
5393 of them (treating them as signed even if they are not). */
5401 if (INT_CST_LT (n
->low
, minval
))
5403 if (INT_CST_LT (maxval
, n
->high
))
5406 /* A range counts double, since it requires two compares. */
5407 if (! tree_int_cst_equal (n
->low
, n
->high
))
5410 /* Count the number of unique case node targets. */
5412 lab
= label_rtx (n
->code_label
);
5413 for (m
= thiscase
->data
.case_stmt
.case_list
; m
!= n
; m
= m
->right
)
5414 if (same_case_target_p (label_rtx (m
->code_label
), lab
))
5421 /* Compute span of values. */
5423 range
= fold (build (MINUS_EXPR
, index_type
, maxval
, minval
));
5425 end_cleanup_deferral ();
5429 expand_expr (index_expr
, const0_rtx
, VOIDmode
, 0);
5431 emit_jump (default_label
);
5434 /* Try implementing this switch statement by a short sequence of
5435 bit-wise comparisons. However, we let the binary-tree case
5436 below handle constant index expressions. */
5437 else if (CASE_USE_BIT_TESTS
5438 && ! TREE_CONSTANT (index_expr
)
5439 && compare_tree_int (range
, GET_MODE_BITSIZE (word_mode
)) < 0
5440 && compare_tree_int (range
, 0) > 0
5441 && lshift_cheap_p ()
5442 && ((uniq
== 1 && count
>= 3)
5443 || (uniq
== 2 && count
>= 5)
5444 || (uniq
== 3 && count
>= 6)))
5446 /* Optimize the case where all the case values fit in a
5447 word without having to subtract MINVAL. In this case,
5448 we can optimize away the subtraction. */
5449 if (compare_tree_int (minval
, 0) > 0
5450 && compare_tree_int (maxval
, GET_MODE_BITSIZE (word_mode
)) < 0)
5452 minval
= integer_zero_node
;
5455 emit_case_bit_tests (index_type
, index_expr
, minval
, range
,
5456 thiscase
->data
.case_stmt
.case_list
,
5460 /* If range of values is much bigger than number of values,
5461 make a sequence of conditional branches instead of a dispatch.
5462 If the switch-index is a constant, do it this way
5463 because we can optimize it. */
5465 else if (count
< case_values_threshold ()
5466 || compare_tree_int (range
,
5467 (optimize_size
? 3 : 10) * count
) > 0
5468 /* RANGE may be signed, and really large ranges will show up
5469 as negative numbers. */
5470 || compare_tree_int (range
, 0) < 0
5471 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5474 || TREE_CONSTANT (index_expr
))
5476 index
= expand_expr (index_expr
, NULL_RTX
, VOIDmode
, 0);
5478 /* If the index is a short or char that we do not have
5479 an insn to handle comparisons directly, convert it to
5480 a full integer now, rather than letting each comparison
5481 generate the conversion. */
5483 if (GET_MODE_CLASS (GET_MODE (index
)) == MODE_INT
5484 && ! have_insn_for (COMPARE
, GET_MODE (index
)))
5486 enum machine_mode wider_mode
;
5487 for (wider_mode
= GET_MODE (index
); wider_mode
!= VOIDmode
;
5488 wider_mode
= GET_MODE_WIDER_MODE (wider_mode
))
5489 if (have_insn_for (COMPARE
, wider_mode
))
5491 index
= convert_to_mode (wider_mode
, index
, unsignedp
);
5497 do_pending_stack_adjust ();
5499 index
= protect_from_queue (index
, 0);
5500 if (GET_CODE (index
) == MEM
)
5501 index
= copy_to_reg (index
);
5502 if (GET_CODE (index
) == CONST_INT
5503 || TREE_CODE (index_expr
) == INTEGER_CST
)
5505 /* Make a tree node with the proper constant value
5506 if we don't already have one. */
5507 if (TREE_CODE (index_expr
) != INTEGER_CST
)
5510 = build_int_2 (INTVAL (index
),
5511 unsignedp
|| INTVAL (index
) >= 0 ? 0 : -1);
5512 index_expr
= convert (index_type
, index_expr
);
5515 /* For constant index expressions we need only
5516 issue an unconditional branch to the appropriate
5517 target code. The job of removing any unreachable
5518 code is left to the optimization phase if the
5519 "-O" option is specified. */
5520 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5521 if (! tree_int_cst_lt (index_expr
, n
->low
)
5522 && ! tree_int_cst_lt (n
->high
, index_expr
))
5526 emit_jump (label_rtx (n
->code_label
));
5528 emit_jump (default_label
);
5532 /* If the index expression is not constant we generate
5533 a binary decision tree to select the appropriate
5534 target code. This is done as follows:
5536 The list of cases is rearranged into a binary tree,
5537 nearly optimal assuming equal probability for each case.
5539 The tree is transformed into RTL, eliminating
5540 redundant test conditions at the same time.
5542 If program flow could reach the end of the
5543 decision tree an unconditional jump to the
5544 default code is emitted. */
5547 = (TREE_CODE (orig_type
) != ENUMERAL_TYPE
5548 && estimate_case_costs (thiscase
->data
.case_stmt
.case_list
));
5549 balance_case_nodes (&thiscase
->data
.case_stmt
.case_list
, NULL
);
5550 emit_case_nodes (index
, thiscase
->data
.case_stmt
.case_list
,
5551 default_label
, index_type
);
5552 emit_jump_if_reachable (default_label
);
5557 table_label
= gen_label_rtx ();
5558 if (! try_casesi (index_type
, index_expr
, minval
, range
,
5559 table_label
, default_label
))
5561 index_type
= thiscase
->data
.case_stmt
.nominal_type
;
5563 /* Index jumptables from zero for suitable values of
5564 minval to avoid a subtraction. */
5566 && compare_tree_int (minval
, 0) > 0
5567 && compare_tree_int (minval
, 3) < 0)
5569 minval
= integer_zero_node
;
5573 if (! try_tablejump (index_type
, index_expr
, minval
, range
,
5574 table_label
, default_label
))
5578 /* Get table of labels to jump to, in order of case index. */
5580 ncases
= tree_low_cst (range
, 0) + 1;
5581 labelvec
= alloca (ncases
* sizeof (rtx
));
5582 memset (labelvec
, 0, ncases
* sizeof (rtx
));
5584 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5586 /* Compute the low and high bounds relative to the minimum
5587 value since that should fit in a HOST_WIDE_INT while the
5588 actual values may not. */
5590 = tree_low_cst (fold (build (MINUS_EXPR
, index_type
,
5591 n
->low
, minval
)), 1);
5592 HOST_WIDE_INT i_high
5593 = tree_low_cst (fold (build (MINUS_EXPR
, index_type
,
5594 n
->high
, minval
)), 1);
5597 for (i
= i_low
; i
<= i_high
; i
++)
5599 = gen_rtx_LABEL_REF (Pmode
, label_rtx (n
->code_label
));
5602 /* Fill in the gaps with the default. */
5603 for (i
= 0; i
< ncases
; i
++)
5604 if (labelvec
[i
] == 0)
5605 labelvec
[i
] = gen_rtx_LABEL_REF (Pmode
, default_label
);
5607 /* Output the table. */
5608 emit_label (table_label
);
5610 if (CASE_VECTOR_PC_RELATIVE
|| flag_pic
)
5611 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE
,
5612 gen_rtx_LABEL_REF (Pmode
, table_label
),
5613 gen_rtvec_v (ncases
, labelvec
),
5614 const0_rtx
, const0_rtx
));
5616 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE
,
5617 gen_rtvec_v (ncases
, labelvec
)));
5619 /* If the case insn drops through the table,
5620 after the table we must jump to the default-label.
5621 Otherwise record no drop-through after the table. */
5622 #ifdef CASE_DROPS_THROUGH
5623 emit_jump (default_label
);
5629 before_case
= NEXT_INSN (before_case
);
5630 end
= get_last_insn ();
5631 if (squeeze_notes (&before_case
, &end
))
5633 reorder_insns (before_case
, end
,
5634 thiscase
->data
.case_stmt
.start
);
5637 end_cleanup_deferral ();
5639 if (thiscase
->exit_label
&& !exit_done
)
5640 emit_label (thiscase
->exit_label
);
5642 POPSTACK (case_stack
);
5647 /* Convert the tree NODE into a list linked by the right field, with the left
5648 field zeroed. RIGHT is used for recursion; it is a list to be placed
5649 rightmost in the resulting list. */
5651 static struct case_node
*
5652 case_tree2list (struct case_node
*node
, struct case_node
*right
)
5654 struct case_node
*left
;
5657 right
= case_tree2list (node
->right
, right
);
5659 node
->right
= right
;
5660 if ((left
= node
->left
))
5663 return case_tree2list (left
, node
);
5669 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5672 do_jump_if_equal (rtx op1
, rtx op2
, rtx label
, int unsignedp
)
5674 if (GET_CODE (op1
) == CONST_INT
&& GET_CODE (op2
) == CONST_INT
)
5680 emit_cmp_and_jump_insns (op1
, op2
, EQ
, NULL_RTX
,
5681 (GET_MODE (op1
) == VOIDmode
5682 ? GET_MODE (op2
) : GET_MODE (op1
)),
5686 /* Not all case values are encountered equally. This function
5687 uses a heuristic to weight case labels, in cases where that
5688 looks like a reasonable thing to do.
5690 Right now, all we try to guess is text, and we establish the
5693 chars above space: 16
5702 If we find any cases in the switch that are not either -1 or in the range
5703 of valid ASCII characters, or are control characters other than those
5704 commonly used with "\", don't treat this switch scanning text.
5706 Return 1 if these nodes are suitable for cost estimation, otherwise
5710 estimate_case_costs (case_node_ptr node
)
5712 tree min_ascii
= integer_minus_one_node
;
5713 tree max_ascii
= convert (TREE_TYPE (node
->high
), build_int_2 (127, 0));
5717 /* If we haven't already made the cost table, make it now. Note that the
5718 lower bound of the table is -1, not zero. */
5720 if (! cost_table_initialized
)
5722 cost_table_initialized
= 1;
5724 for (i
= 0; i
< 128; i
++)
5727 COST_TABLE (i
) = 16;
5728 else if (ISPUNCT (i
))
5730 else if (ISCNTRL (i
))
5731 COST_TABLE (i
) = -1;
5734 COST_TABLE (' ') = 8;
5735 COST_TABLE ('\t') = 4;
5736 COST_TABLE ('\0') = 4;
5737 COST_TABLE ('\n') = 2;
5738 COST_TABLE ('\f') = 1;
5739 COST_TABLE ('\v') = 1;
5740 COST_TABLE ('\b') = 1;
5743 /* See if all the case expressions look like text. It is text if the
5744 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5745 as signed arithmetic since we don't want to ever access cost_table with a
5746 value less than -1. Also check that none of the constants in a range
5747 are strange control characters. */
5749 for (n
= node
; n
; n
= n
->right
)
5751 if ((INT_CST_LT (n
->low
, min_ascii
)) || INT_CST_LT (max_ascii
, n
->high
))
5754 for (i
= (HOST_WIDE_INT
) TREE_INT_CST_LOW (n
->low
);
5755 i
<= (HOST_WIDE_INT
) TREE_INT_CST_LOW (n
->high
); i
++)
5756 if (COST_TABLE (i
) < 0)
5760 /* All interesting values are within the range of interesting
5761 ASCII characters. */
5765 /* Determine whether two case labels branch to the same target. */
5768 same_case_target_p (rtx l1
, rtx l2
)
5775 i1
= next_real_insn (l1
);
5776 i2
= next_real_insn (l2
);
5780 if (i1
&& simplejump_p (i1
))
5782 l1
= XEXP (SET_SRC (PATTERN (i1
)), 0);
5785 if (i2
&& simplejump_p (i2
))
5787 l2
= XEXP (SET_SRC (PATTERN (i2
)), 0);
5792 /* Delete nodes that branch to the default label from a list of
5793 case nodes. Eg. case 5: default: becomes just default: */
5796 strip_default_case_nodes (case_node_ptr
*prev
, rtx deflab
)
5803 if (same_case_target_p (label_rtx (ptr
->code_label
), deflab
))
5810 /* Scan an ordered list of case nodes
5811 combining those with consecutive values or ranges.
5813 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5816 group_case_nodes (case_node_ptr head
)
5818 case_node_ptr node
= head
;
5822 rtx lab
= label_rtx (node
->code_label
);
5823 case_node_ptr np
= node
;
5825 /* Try to group the successors of NODE with NODE. */
5826 while (((np
= np
->right
) != 0)
5827 /* Do they jump to the same place? */
5828 && same_case_target_p (label_rtx (np
->code_label
), lab
)
5829 /* Are their ranges consecutive? */
5830 && tree_int_cst_equal (np
->low
,
5831 fold (build (PLUS_EXPR
,
5832 TREE_TYPE (node
->high
),
5835 /* An overflow is not consecutive. */
5836 && tree_int_cst_lt (node
->high
,
5837 fold (build (PLUS_EXPR
,
5838 TREE_TYPE (node
->high
),
5840 integer_one_node
))))
5842 node
->high
= np
->high
;
5844 /* NP is the first node after NODE which can't be grouped with it.
5845 Delete the nodes in between, and move on to that node. */
5851 /* Take an ordered list of case nodes
5852 and transform them into a near optimal binary tree,
5853 on the assumption that any target code selection value is as
5854 likely as any other.
5856 The transformation is performed by splitting the ordered
5857 list into two equal sections plus a pivot. The parts are
5858 then attached to the pivot as left and right branches. Each
5859 branch is then transformed recursively. */
5862 balance_case_nodes (case_node_ptr
*head
, case_node_ptr parent
)
5875 /* Count the number of entries on branch. Also count the ranges. */
5879 if (!tree_int_cst_equal (np
->low
, np
->high
))
5883 cost
+= COST_TABLE (TREE_INT_CST_LOW (np
->high
));
5887 cost
+= COST_TABLE (TREE_INT_CST_LOW (np
->low
));
5895 /* Split this list if it is long enough for that to help. */
5900 /* Find the place in the list that bisects the list's total cost,
5901 Here I gets half the total cost. */
5906 /* Skip nodes while their cost does not reach that amount. */
5907 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
5908 i
-= COST_TABLE (TREE_INT_CST_LOW ((*npp
)->high
));
5909 i
-= COST_TABLE (TREE_INT_CST_LOW ((*npp
)->low
));
5912 npp
= &(*npp
)->right
;
5917 /* Leave this branch lopsided, but optimize left-hand
5918 side and fill in `parent' fields for right-hand side. */
5920 np
->parent
= parent
;
5921 balance_case_nodes (&np
->left
, np
);
5922 for (; np
->right
; np
= np
->right
)
5923 np
->right
->parent
= np
;
5927 /* If there are just three nodes, split at the middle one. */
5929 npp
= &(*npp
)->right
;
5932 /* Find the place in the list that bisects the list's total cost,
5933 where ranges count as 2.
5934 Here I gets half the total cost. */
5935 i
= (i
+ ranges
+ 1) / 2;
5938 /* Skip nodes while their cost does not reach that amount. */
5939 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
5944 npp
= &(*npp
)->right
;
5949 np
->parent
= parent
;
5952 /* Optimize each of the two split parts. */
5953 balance_case_nodes (&np
->left
, np
);
5954 balance_case_nodes (&np
->right
, np
);
5958 /* Else leave this branch as one level,
5959 but fill in `parent' fields. */
5961 np
->parent
= parent
;
5962 for (; np
->right
; np
= np
->right
)
5963 np
->right
->parent
= np
;
5968 /* Search the parent sections of the case node tree
5969 to see if a test for the lower bound of NODE would be redundant.
5970 INDEX_TYPE is the type of the index expression.
5972 The instructions to generate the case decision tree are
5973 output in the same order as nodes are processed so it is
5974 known that if a parent node checks the range of the current
5975 node minus one that the current node is bounded at its lower
5976 span. Thus the test would be redundant. */
5979 node_has_low_bound (case_node_ptr node
, tree index_type
)
5982 case_node_ptr pnode
;
5984 /* If the lower bound of this node is the lowest value in the index type,
5985 we need not test it. */
5987 if (tree_int_cst_equal (node
->low
, TYPE_MIN_VALUE (index_type
)))
5990 /* If this node has a left branch, the value at the left must be less
5991 than that at this node, so it cannot be bounded at the bottom and
5992 we need not bother testing any further. */
5997 low_minus_one
= fold (build (MINUS_EXPR
, TREE_TYPE (node
->low
),
5998 node
->low
, integer_one_node
));
6000 /* If the subtraction above overflowed, we can't verify anything.
6001 Otherwise, look for a parent that tests our value - 1. */
6003 if (! tree_int_cst_lt (low_minus_one
, node
->low
))
6006 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
6007 if (tree_int_cst_equal (low_minus_one
, pnode
->high
))
6013 /* Search the parent sections of the case node tree
6014 to see if a test for the upper bound of NODE would be redundant.
6015 INDEX_TYPE is the type of the index expression.
6017 The instructions to generate the case decision tree are
6018 output in the same order as nodes are processed so it is
6019 known that if a parent node checks the range of the current
6020 node plus one that the current node is bounded at its upper
6021 span. Thus the test would be redundant. */
6024 node_has_high_bound (case_node_ptr node
, tree index_type
)
6027 case_node_ptr pnode
;
6029 /* If there is no upper bound, obviously no test is needed. */
6031 if (TYPE_MAX_VALUE (index_type
) == NULL
)
6034 /* If the upper bound of this node is the highest value in the type
6035 of the index expression, we need not test against it. */
6037 if (tree_int_cst_equal (node
->high
, TYPE_MAX_VALUE (index_type
)))
6040 /* If this node has a right branch, the value at the right must be greater
6041 than that at this node, so it cannot be bounded at the top and
6042 we need not bother testing any further. */
6047 high_plus_one
= fold (build (PLUS_EXPR
, TREE_TYPE (node
->high
),
6048 node
->high
, integer_one_node
));
6050 /* If the addition above overflowed, we can't verify anything.
6051 Otherwise, look for a parent that tests our value + 1. */
6053 if (! tree_int_cst_lt (node
->high
, high_plus_one
))
6056 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
6057 if (tree_int_cst_equal (high_plus_one
, pnode
->low
))
6063 /* Search the parent sections of the
6064 case node tree to see if both tests for the upper and lower
6065 bounds of NODE would be redundant. */
6068 node_is_bounded (case_node_ptr node
, tree index_type
)
6070 return (node_has_low_bound (node
, index_type
)
6071 && node_has_high_bound (node
, index_type
));
6074 /* Emit an unconditional jump to LABEL unless it would be dead code. */
6077 emit_jump_if_reachable (rtx label
)
6079 if (GET_CODE (get_last_insn ()) != BARRIER
)
6083 /* Emit step-by-step code to select a case for the value of INDEX.
6084 The thus generated decision tree follows the form of the
6085 case-node binary tree NODE, whose nodes represent test conditions.
6086 INDEX_TYPE is the type of the index of the switch.
6088 Care is taken to prune redundant tests from the decision tree
6089 by detecting any boundary conditions already checked by
6090 emitted rtx. (See node_has_high_bound, node_has_low_bound
6091 and node_is_bounded, above.)
6093 Where the test conditions can be shown to be redundant we emit
6094 an unconditional jump to the target code. As a further
6095 optimization, the subordinates of a tree node are examined to
6096 check for bounded nodes. In this case conditional and/or
6097 unconditional jumps as a result of the boundary check for the
6098 current node are arranged to target the subordinates associated
6099 code for out of bound conditions on the current node.
6101 We can assume that when control reaches the code generated here,
6102 the index value has already been compared with the parents
6103 of this node, and determined to be on the same side of each parent
6104 as this node is. Thus, if this node tests for the value 51,
6105 and a parent tested for 52, we don't need to consider
6106 the possibility of a value greater than 51. If another parent
6107 tests for the value 50, then this node need not test anything. */
6110 emit_case_nodes (rtx index
, case_node_ptr node
, rtx default_label
,
6113 /* If INDEX has an unsigned type, we must make unsigned branches. */
6114 int unsignedp
= TREE_UNSIGNED (index_type
);
6115 enum machine_mode mode
= GET_MODE (index
);
6116 enum machine_mode imode
= TYPE_MODE (index_type
);
6118 /* See if our parents have already tested everything for us.
6119 If they have, emit an unconditional jump for this node. */
6120 if (node_is_bounded (node
, index_type
))
6121 emit_jump (label_rtx (node
->code_label
));
6123 else if (tree_int_cst_equal (node
->low
, node
->high
))
6125 /* Node is single valued. First see if the index expression matches
6126 this node and then check our children, if any. */
6128 do_jump_if_equal (index
,
6129 convert_modes (mode
, imode
,
6130 expand_expr (node
->low
, NULL_RTX
,
6133 label_rtx (node
->code_label
), unsignedp
);
6135 if (node
->right
!= 0 && node
->left
!= 0)
6137 /* This node has children on both sides.
6138 Dispatch to one side or the other
6139 by comparing the index value with this node's value.
6140 If one subtree is bounded, check that one first,
6141 so we can avoid real branches in the tree. */
6143 if (node_is_bounded (node
->right
, index_type
))
6145 emit_cmp_and_jump_insns (index
,
6148 expand_expr (node
->high
, NULL_RTX
,
6151 GT
, NULL_RTX
, mode
, unsignedp
,
6152 label_rtx (node
->right
->code_label
));
6153 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6156 else if (node_is_bounded (node
->left
, index_type
))
6158 emit_cmp_and_jump_insns (index
,
6161 expand_expr (node
->high
, NULL_RTX
,
6164 LT
, NULL_RTX
, mode
, unsignedp
,
6165 label_rtx (node
->left
->code_label
));
6166 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6171 /* Neither node is bounded. First distinguish the two sides;
6172 then emit the code for one side at a time. */
6174 tree test_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
6176 /* See if the value is on the right. */
6177 emit_cmp_and_jump_insns (index
,
6180 expand_expr (node
->high
, NULL_RTX
,
6183 GT
, NULL_RTX
, mode
, unsignedp
,
6184 label_rtx (test_label
));
6186 /* Value must be on the left.
6187 Handle the left-hand subtree. */
6188 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6189 /* If left-hand subtree does nothing,
6191 emit_jump_if_reachable (default_label
);
6193 /* Code branches here for the right-hand subtree. */
6194 expand_label (test_label
);
6195 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6199 else if (node
->right
!= 0 && node
->left
== 0)
6201 /* Here we have a right child but no left so we issue conditional
6202 branch to default and process the right child.
6204 Omit the conditional branch to default if we it avoid only one
6205 right child; it costs too much space to save so little time. */
6207 if (node
->right
->right
|| node
->right
->left
6208 || !tree_int_cst_equal (node
->right
->low
, node
->right
->high
))
6210 if (!node_has_low_bound (node
, index_type
))
6212 emit_cmp_and_jump_insns (index
,
6215 expand_expr (node
->high
, NULL_RTX
,
6218 LT
, NULL_RTX
, mode
, unsignedp
,
6222 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6225 /* We cannot process node->right normally
6226 since we haven't ruled out the numbers less than
6227 this node's value. So handle node->right explicitly. */
6228 do_jump_if_equal (index
,
6231 expand_expr (node
->right
->low
, NULL_RTX
,
6234 label_rtx (node
->right
->code_label
), unsignedp
);
6237 else if (node
->right
== 0 && node
->left
!= 0)
6239 /* Just one subtree, on the left. */
6240 if (node
->left
->left
|| node
->left
->right
6241 || !tree_int_cst_equal (node
->left
->low
, node
->left
->high
))
6243 if (!node_has_high_bound (node
, index_type
))
6245 emit_cmp_and_jump_insns (index
,
6248 expand_expr (node
->high
, NULL_RTX
,
6251 GT
, NULL_RTX
, mode
, unsignedp
,
6255 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6258 /* We cannot process node->left normally
6259 since we haven't ruled out the numbers less than
6260 this node's value. So handle node->left explicitly. */
6261 do_jump_if_equal (index
,
6264 expand_expr (node
->left
->low
, NULL_RTX
,
6267 label_rtx (node
->left
->code_label
), unsignedp
);
6272 /* Node is a range. These cases are very similar to those for a single
6273 value, except that we do not start by testing whether this node
6274 is the one to branch to. */
6276 if (node
->right
!= 0 && node
->left
!= 0)
6278 /* Node has subtrees on both sides.
6279 If the right-hand subtree is bounded,
6280 test for it first, since we can go straight there.
6281 Otherwise, we need to make a branch in the control structure,
6282 then handle the two subtrees. */
6283 tree test_label
= 0;
6285 if (node_is_bounded (node
->right
, index_type
))
6286 /* Right hand node is fully bounded so we can eliminate any
6287 testing and branch directly to the target code. */
6288 emit_cmp_and_jump_insns (index
,
6291 expand_expr (node
->high
, NULL_RTX
,
6294 GT
, NULL_RTX
, mode
, unsignedp
,
6295 label_rtx (node
->right
->code_label
));
6298 /* Right hand node requires testing.
6299 Branch to a label where we will handle it later. */
6301 test_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
6302 emit_cmp_and_jump_insns (index
,
6305 expand_expr (node
->high
, NULL_RTX
,
6308 GT
, NULL_RTX
, mode
, unsignedp
,
6309 label_rtx (test_label
));
6312 /* Value belongs to this node or to the left-hand subtree. */
6314 emit_cmp_and_jump_insns (index
,
6317 expand_expr (node
->low
, NULL_RTX
,
6320 GE
, NULL_RTX
, mode
, unsignedp
,
6321 label_rtx (node
->code_label
));
6323 /* Handle the left-hand subtree. */
6324 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6326 /* If right node had to be handled later, do that now. */
6330 /* If the left-hand subtree fell through,
6331 don't let it fall into the right-hand subtree. */
6332 emit_jump_if_reachable (default_label
);
6334 expand_label (test_label
);
6335 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6339 else if (node
->right
!= 0 && node
->left
== 0)
6341 /* Deal with values to the left of this node,
6342 if they are possible. */
6343 if (!node_has_low_bound (node
, index_type
))
6345 emit_cmp_and_jump_insns (index
,
6348 expand_expr (node
->low
, NULL_RTX
,
6351 LT
, NULL_RTX
, mode
, unsignedp
,
6355 /* Value belongs to this node or to the right-hand subtree. */
6357 emit_cmp_and_jump_insns (index
,
6360 expand_expr (node
->high
, NULL_RTX
,
6363 LE
, NULL_RTX
, mode
, unsignedp
,
6364 label_rtx (node
->code_label
));
6366 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6369 else if (node
->right
== 0 && node
->left
!= 0)
6371 /* Deal with values to the right of this node,
6372 if they are possible. */
6373 if (!node_has_high_bound (node
, index_type
))
6375 emit_cmp_and_jump_insns (index
,
6378 expand_expr (node
->high
, NULL_RTX
,
6381 GT
, NULL_RTX
, mode
, unsignedp
,
6385 /* Value belongs to this node or to the left-hand subtree. */
6387 emit_cmp_and_jump_insns (index
,
6390 expand_expr (node
->low
, NULL_RTX
,
6393 GE
, NULL_RTX
, mode
, unsignedp
,
6394 label_rtx (node
->code_label
));
6396 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6401 /* Node has no children so we check low and high bounds to remove
6402 redundant tests. Only one of the bounds can exist,
6403 since otherwise this node is bounded--a case tested already. */
6404 int high_bound
= node_has_high_bound (node
, index_type
);
6405 int low_bound
= node_has_low_bound (node
, index_type
);
6407 if (!high_bound
&& low_bound
)
6409 emit_cmp_and_jump_insns (index
,
6412 expand_expr (node
->high
, NULL_RTX
,
6415 GT
, NULL_RTX
, mode
, unsignedp
,
6419 else if (!low_bound
&& high_bound
)
6421 emit_cmp_and_jump_insns (index
,
6424 expand_expr (node
->low
, NULL_RTX
,
6427 LT
, NULL_RTX
, mode
, unsignedp
,
6430 else if (!low_bound
&& !high_bound
)
6432 /* Widen LOW and HIGH to the same width as INDEX. */
6433 tree type
= (*lang_hooks
.types
.type_for_mode
) (mode
, unsignedp
);
6434 tree low
= build1 (CONVERT_EXPR
, type
, node
->low
);
6435 tree high
= build1 (CONVERT_EXPR
, type
, node
->high
);
6436 rtx low_rtx
, new_index
, new_bound
;
6438 /* Instead of doing two branches, emit one unsigned branch for
6439 (index-low) > (high-low). */
6440 low_rtx
= expand_expr (low
, NULL_RTX
, mode
, 0);
6441 new_index
= expand_simple_binop (mode
, MINUS
, index
, low_rtx
,
6442 NULL_RTX
, unsignedp
,
6444 new_bound
= expand_expr (fold (build (MINUS_EXPR
, type
,
6448 emit_cmp_and_jump_insns (new_index
, new_bound
, GT
, NULL_RTX
,
6449 mode
, 1, default_label
);
6452 emit_jump (label_rtx (node
->code_label
));
6457 #include "gt-stmt.h"