1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
22 /* This file handles the generation of rtl code from tree structure
23 above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
24 It also creates the rtl expressions for parameters and auto variables
25 and has full responsibility for allocating stack slots.
27 The functions whose names start with `expand_' are called by the
28 parser to generate RTL instructions for various kinds of constructs.
30 Some control and binding constructs require calling several such
31 functions at different times. For example, a simple if-then
32 is expanded by calling `expand_start_cond' (with the condition-expression
33 as argument) before parsing the then-clause and calling `expand_end_cond'
34 after parsing the then-clause. */
45 #include "insn-config.h"
48 #include "hard-reg-set.h"
57 #define obstack_chunk_alloc xmalloc
58 #define obstack_chunk_free free
59 struct obstack stmt_obstack
;
61 /* Assume that case vectors are not pc-relative. */
62 #ifndef CASE_VECTOR_PC_RELATIVE
63 #define CASE_VECTOR_PC_RELATIVE 0
66 /* Functions and data structures for expanding case statements. */
68 /* Case label structure, used to hold info on labels within case
69 statements. We handle "range" labels; for a single-value label
70 as in C, the high and low limits are the same.
72 An AVL tree of case nodes is initially created, and later transformed
73 to a list linked via the RIGHT fields in the nodes. Nodes with
74 higher case values are later in the list.
76 Switch statements can be output in one of two forms. A branch table
77 is used if there are more than a few labels and the labels are dense
78 within the range between the smallest and largest case value. If a
79 branch table is used, no further manipulations are done with the case
82 The alternative to the use of a branch table is to generate a series
83 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
84 and PARENT fields to hold a binary tree. Initially the tree is
85 totally unbalanced, with everything on the right. We balance the tree
86 with nodes on the left having lower case values than the parent
87 and nodes on the right having higher values. We then output the tree
92 struct case_node
*left
; /* Left son in binary tree */
93 struct case_node
*right
; /* Right son in binary tree; also node chain */
94 struct case_node
*parent
; /* Parent of node in binary tree */
95 tree low
; /* Lowest index value for this label */
96 tree high
; /* Highest index value for this label */
97 tree code_label
; /* Label to jump to when node matches */
101 typedef struct case_node case_node
;
102 typedef struct case_node
*case_node_ptr
;
104 /* These are used by estimate_case_costs and balance_case_nodes. */
106 /* This must be a signed type, and non-ANSI compilers lack signed char. */
107 static short cost_table_
[129];
108 static int use_cost_table
;
109 static int cost_table_initialized
;
111 /* Special care is needed because we allow -1, but TREE_INT_CST_LOW
113 #define COST_TABLE(I) cost_table_[(unsigned HOST_WIDE_INT) ((I) + 1)]
115 /* Stack of control and binding constructs we are currently inside.
117 These constructs begin when you call `expand_start_WHATEVER'
118 and end when you call `expand_end_WHATEVER'. This stack records
119 info about how the construct began that tells the end-function
120 what to do. It also may provide information about the construct
121 to alter the behavior of other constructs within the body.
122 For example, they may affect the behavior of C `break' and `continue'.
124 Each construct gets one `struct nesting' object.
125 All of these objects are chained through the `all' field.
126 `nesting_stack' points to the first object (innermost construct).
127 The position of an entry on `nesting_stack' is in its `depth' field.
129 Each type of construct has its own individual stack.
130 For example, loops have `loop_stack'. Each object points to the
131 next object of the same type through the `next' field.
133 Some constructs are visible to `break' exit-statements and others
134 are not. Which constructs are visible depends on the language.
135 Therefore, the data structure allows each construct to be visible
136 or not, according to the args given when the construct is started.
137 The construct is visible if the `exit_label' field is non-null.
138 In that case, the value should be a CODE_LABEL rtx. */
143 struct nesting
*next
;
148 /* For conds (if-then and if-then-else statements). */
151 /* Label for the end of the if construct.
152 There is none if EXITFLAG was not set
153 and no `else' has been seen yet. */
155 /* Label for the end of this alternative.
156 This may be the end of the if or the next else/elseif. */
162 /* Label at the top of the loop; place to loop back to. */
164 /* Label at the end of the whole construct. */
166 /* Label before a jump that branches to the end of the whole
167 construct. This is where destructors go if any. */
169 /* Label for `continue' statement to jump to;
170 this is in front of the stepper of the loop. */
173 /* For variable binding contours. */
176 /* Sequence number of this binding contour within the function,
177 in order of entry. */
178 int block_start_count
;
179 /* Nonzero => value to restore stack to on exit. */
181 /* The NOTE that starts this contour.
182 Used by expand_goto to check whether the destination
183 is within each contour or not. */
185 /* Innermost containing binding contour that has a stack level. */
186 struct nesting
*innermost_stack_block
;
187 /* List of cleanups to be run on exit from this contour.
188 This is a list of expressions to be evaluated.
189 The TREE_PURPOSE of each link is the ..._DECL node
190 which the cleanup pertains to. */
192 /* List of cleanup-lists of blocks containing this block,
193 as they were at the locus where this block appears.
194 There is an element for each containing block,
195 ordered innermost containing block first.
196 The tail of this list can be 0,
197 if all remaining elements would be empty lists.
198 The element's TREE_VALUE is the cleanup-list of that block,
199 which may be null. */
201 /* Chain of labels defined inside this binding contour.
202 For contours that have stack levels or cleanups. */
203 struct label_chain
*label_chain
;
204 /* Number of function calls seen, as of start of this block. */
205 int n_function_calls
;
206 /* Nonzero if this is associated with a EH region. */
207 int exception_region
;
208 /* The saved target_temp_slot_level from our outer block.
209 We may reset target_temp_slot_level to be the level of
210 this block, if that is done, target_temp_slot_level
211 reverts to the saved target_temp_slot_level at the very
213 int block_target_temp_slot_level
;
214 /* True if we are currently emitting insns in an area of
215 output code that is controlled by a conditional
216 expression. This is used by the cleanup handling code to
217 generate conditional cleanup actions. */
218 int conditional_code
;
219 /* A place to move the start of the exception region for any
220 of the conditional cleanups, must be at the end or after
221 the start of the last unconditional cleanup, and before any
222 conditional branch points. */
223 rtx last_unconditional_cleanup
;
224 /* When in a conditional context, this is the specific
225 cleanup list associated with last_unconditional_cleanup,
226 where we place the conditionalized cleanups. */
229 /* For switch (C) or case (Pascal) statements,
230 and also for dummies (see `expand_start_case_dummy'). */
233 /* The insn after which the case dispatch should finally
234 be emitted. Zero for a dummy. */
236 /* A list of case labels; it is first built as an AVL tree.
237 During expand_end_case, this is converted to a list, and may be
238 rearranged into a nearly balanced binary tree. */
239 struct case_node
*case_list
;
240 /* Label to jump to if no case matches. */
242 /* The expression to be dispatched on. */
244 /* Type that INDEX_EXPR should be converted to. */
246 /* Name of this kind of statement, for warnings. */
247 const char *printname
;
248 /* Used to save no_line_numbers till we see the first case label.
249 We set this to -1 when we see the first case label in this
251 int line_number_status
;
256 /* Allocate and return a new `struct nesting'. */
258 #define ALLOC_NESTING() \
259 (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
261 /* Pop the nesting stack element by element until we pop off
262 the element which is at the top of STACK.
263 Update all the other stacks, popping off elements from them
264 as we pop them from nesting_stack. */
266 #define POPSTACK(STACK) \
267 do { struct nesting *target = STACK; \
268 struct nesting *this; \
269 do { this = nesting_stack; \
270 if (loop_stack == this) \
271 loop_stack = loop_stack->next; \
272 if (cond_stack == this) \
273 cond_stack = cond_stack->next; \
274 if (block_stack == this) \
275 block_stack = block_stack->next; \
276 if (stack_block_stack == this) \
277 stack_block_stack = stack_block_stack->next; \
278 if (case_stack == this) \
279 case_stack = case_stack->next; \
280 nesting_depth = nesting_stack->depth - 1; \
281 nesting_stack = this->all; \
282 obstack_free (&stmt_obstack, this); } \
283 while (this != target); } while (0)
285 /* In some cases it is impossible to generate code for a forward goto
286 until the label definition is seen. This happens when it may be necessary
287 for the goto to reset the stack pointer: we don't yet know how to do that.
288 So expand_goto puts an entry on this fixup list.
289 Each time a binding contour that resets the stack is exited,
291 If the target label has now been defined, we can insert the proper code. */
295 /* Points to following fixup. */
296 struct goto_fixup
*next
;
297 /* Points to the insn before the jump insn.
298 If more code must be inserted, it goes after this insn. */
300 /* The LABEL_DECL that this jump is jumping to, or 0
301 for break, continue or return. */
303 /* The BLOCK for the place where this goto was found. */
305 /* The CODE_LABEL rtx that this is jumping to. */
307 /* Number of binding contours started in current function
308 before the label reference. */
309 int block_start_count
;
310 /* The outermost stack level that should be restored for this jump.
311 Each time a binding contour that resets the stack is exited,
312 if the target label is *not* yet defined, this slot is updated. */
314 /* List of lists of cleanup expressions to be run by this goto.
315 There is one element for each block that this goto is within.
316 The tail of this list can be 0,
317 if all remaining elements would be empty.
318 The TREE_VALUE contains the cleanup list of that block as of the
319 time this goto was seen.
320 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
321 tree cleanup_list_list
;
324 /* Within any binding contour that must restore a stack level,
325 all labels are recorded with a chain of these structures. */
329 /* Points to following fixup. */
330 struct label_chain
*next
;
336 /* Chain of all pending binding contours. */
337 struct nesting
*x_block_stack
;
339 /* If any new stacks are added here, add them to POPSTACKS too. */
341 /* Chain of all pending binding contours that restore stack levels
343 struct nesting
*x_stack_block_stack
;
345 /* Chain of all pending conditional statements. */
346 struct nesting
*x_cond_stack
;
348 /* Chain of all pending loops. */
349 struct nesting
*x_loop_stack
;
351 /* Chain of all pending case or switch statements. */
352 struct nesting
*x_case_stack
;
354 /* Separate chain including all of the above,
355 chained through the `all' field. */
356 struct nesting
*x_nesting_stack
;
358 /* Number of entries on nesting_stack now. */
361 /* Number of binding contours started so far in this function. */
362 int x_block_start_count
;
364 /* Each time we expand an expression-statement,
365 record the expr's type and its RTL value here. */
366 tree x_last_expr_type
;
367 rtx x_last_expr_value
;
369 /* Nonzero if within a ({...}) grouping, in which case we must
370 always compute a value for each expr-stmt in case it is the last one. */
371 int x_expr_stmts_for_value
;
373 /* Filename and line number of last line-number note,
374 whether we actually emitted it or not. */
375 const char *x_emit_filename
;
378 struct goto_fixup
*x_goto_fixup_chain
;
381 #define block_stack (cfun->stmt->x_block_stack)
382 #define stack_block_stack (cfun->stmt->x_stack_block_stack)
383 #define cond_stack (cfun->stmt->x_cond_stack)
384 #define loop_stack (cfun->stmt->x_loop_stack)
385 #define case_stack (cfun->stmt->x_case_stack)
386 #define nesting_stack (cfun->stmt->x_nesting_stack)
387 #define nesting_depth (cfun->stmt->x_nesting_depth)
388 #define current_block_start_count (cfun->stmt->x_block_start_count)
389 #define last_expr_type (cfun->stmt->x_last_expr_type)
390 #define last_expr_value (cfun->stmt->x_last_expr_value)
391 #define expr_stmts_for_value (cfun->stmt->x_expr_stmts_for_value)
392 #define emit_filename (cfun->stmt->x_emit_filename)
393 #define emit_lineno (cfun->stmt->x_emit_lineno)
394 #define goto_fixup_chain (cfun->stmt->x_goto_fixup_chain)
396 /* Non-zero if we are using EH to handle cleanus. */
397 static int using_eh_for_cleanups_p
= 0;
399 static int n_occurrences
PARAMS ((int, const char *));
400 static bool parse_input_constraint
PARAMS ((const char **, int, int, int,
401 int, const char * const *,
403 static void expand_goto_internal
PARAMS ((tree
, rtx
, rtx
));
404 static int expand_fixup
PARAMS ((tree
, rtx
, rtx
));
405 static rtx expand_nl_handler_label
PARAMS ((rtx
, rtx
));
406 static void expand_nl_goto_receiver
PARAMS ((void));
407 static void expand_nl_goto_receivers
PARAMS ((struct nesting
*));
408 static void fixup_gotos
PARAMS ((struct nesting
*, rtx
, tree
,
410 static bool check_operand_nalternatives
PARAMS ((tree
, tree
));
411 static bool check_unique_operand_names
PARAMS ((tree
, tree
));
412 static tree resolve_operand_names
PARAMS ((tree
, tree
, tree
,
414 static char *resolve_operand_name_1
PARAMS ((char *, tree
, tree
));
415 static void expand_null_return_1
PARAMS ((rtx
));
416 static void expand_value_return
PARAMS ((rtx
));
417 static int tail_recursion_args
PARAMS ((tree
, tree
));
418 static void expand_cleanups
PARAMS ((tree
, tree
, int, int));
419 static void check_seenlabel
PARAMS ((void));
420 static void do_jump_if_equal
PARAMS ((rtx
, rtx
, rtx
, int));
421 static int estimate_case_costs
PARAMS ((case_node_ptr
));
422 static void group_case_nodes
PARAMS ((case_node_ptr
));
423 static void balance_case_nodes
PARAMS ((case_node_ptr
*,
425 static int node_has_low_bound
PARAMS ((case_node_ptr
, tree
));
426 static int node_has_high_bound
PARAMS ((case_node_ptr
, tree
));
427 static int node_is_bounded
PARAMS ((case_node_ptr
, tree
));
428 static void emit_jump_if_reachable
PARAMS ((rtx
));
429 static void emit_case_nodes
PARAMS ((rtx
, case_node_ptr
, rtx
, tree
));
430 static struct case_node
*case_tree2list
PARAMS ((case_node
*, case_node
*));
431 static void mark_cond_nesting
PARAMS ((struct nesting
*));
432 static void mark_loop_nesting
PARAMS ((struct nesting
*));
433 static void mark_block_nesting
PARAMS ((struct nesting
*));
434 static void mark_case_nesting
PARAMS ((struct nesting
*));
435 static void mark_case_node
PARAMS ((struct case_node
*));
436 static void mark_goto_fixup
PARAMS ((struct goto_fixup
*));
437 static void free_case_nodes
PARAMS ((case_node_ptr
));
440 using_eh_for_cleanups ()
442 using_eh_for_cleanups_p
= 1;
445 /* Mark N (known to be a cond-nesting) for GC. */
448 mark_cond_nesting (n
)
453 ggc_mark_rtx (n
->exit_label
);
454 ggc_mark_rtx (n
->data
.cond
.endif_label
);
455 ggc_mark_rtx (n
->data
.cond
.next_label
);
461 /* Mark N (known to be a loop-nesting) for GC. */
464 mark_loop_nesting (n
)
470 ggc_mark_rtx (n
->exit_label
);
471 ggc_mark_rtx (n
->data
.loop
.start_label
);
472 ggc_mark_rtx (n
->data
.loop
.end_label
);
473 ggc_mark_rtx (n
->data
.loop
.alt_end_label
);
474 ggc_mark_rtx (n
->data
.loop
.continue_label
);
480 /* Mark N (known to be a block-nesting) for GC. */
483 mark_block_nesting (n
)
488 struct label_chain
*l
;
490 ggc_mark_rtx (n
->exit_label
);
491 ggc_mark_rtx (n
->data
.block
.stack_level
);
492 ggc_mark_rtx (n
->data
.block
.first_insn
);
493 ggc_mark_tree (n
->data
.block
.cleanups
);
494 ggc_mark_tree (n
->data
.block
.outer_cleanups
);
496 for (l
= n
->data
.block
.label_chain
; l
!= NULL
; l
= l
->next
)
499 ggc_mark_tree (l
->label
);
502 ggc_mark_rtx (n
->data
.block
.last_unconditional_cleanup
);
504 /* ??? cleanup_ptr never points outside the stack, does it? */
510 /* Mark N (known to be a case-nesting) for GC. */
513 mark_case_nesting (n
)
518 ggc_mark_rtx (n
->exit_label
);
519 ggc_mark_rtx (n
->data
.case_stmt
.start
);
521 ggc_mark_tree (n
->data
.case_stmt
.default_label
);
522 ggc_mark_tree (n
->data
.case_stmt
.index_expr
);
523 ggc_mark_tree (n
->data
.case_stmt
.nominal_type
);
525 mark_case_node (n
->data
.case_stmt
.case_list
);
538 ggc_mark_tree (c
->low
);
539 ggc_mark_tree (c
->high
);
540 ggc_mark_tree (c
->code_label
);
542 mark_case_node (c
->right
);
543 mark_case_node (c
->left
);
551 struct goto_fixup
*g
;
556 ggc_mark_rtx (g
->before_jump
);
557 ggc_mark_tree (g
->target
);
558 ggc_mark_tree (g
->context
);
559 ggc_mark_rtx (g
->target_rtl
);
560 ggc_mark_rtx (g
->stack_level
);
561 ggc_mark_tree (g
->cleanup_list_list
);
567 /* Clear out all parts of the state in F that can safely be discarded
568 after the function has been compiled, to let garbage collection
569 reclaim the memory. */
575 /* We're about to free the function obstack. If we hold pointers to
576 things allocated there, then we'll try to mark them when we do
577 GC. So, we clear them out here explicitly. */
587 struct stmt_status
*p
;
592 mark_block_nesting (p
->x_block_stack
);
593 mark_cond_nesting (p
->x_cond_stack
);
594 mark_loop_nesting (p
->x_loop_stack
);
595 mark_case_nesting (p
->x_case_stack
);
597 ggc_mark_tree (p
->x_last_expr_type
);
598 /* last_epxr_value is only valid if last_expr_type is nonzero. */
599 if (p
->x_last_expr_type
)
600 ggc_mark_rtx (p
->x_last_expr_value
);
602 mark_goto_fixup (p
->x_goto_fixup_chain
);
608 gcc_obstack_init (&stmt_obstack
);
612 init_stmt_for_function ()
614 cfun
->stmt
= (struct stmt_status
*) xmalloc (sizeof (struct stmt_status
));
616 /* We are not currently within any block, conditional, loop or case. */
618 stack_block_stack
= 0;
625 current_block_start_count
= 0;
627 /* No gotos have been expanded yet. */
628 goto_fixup_chain
= 0;
630 /* We are not processing a ({...}) grouping. */
631 expr_stmts_for_value
= 0;
633 last_expr_value
= NULL_RTX
;
636 /* Return nonzero if anything is pushed on the loop, condition, or case
641 return cond_stack
|| loop_stack
|| case_stack
;
644 /* Record the current file and line. Called from emit_line_note. */
646 set_file_and_line_for_stmt (file
, line
)
650 /* If we're outputting an inline function, and we add a line note,
651 there may be no CFUN->STMT information. So, there's no need to
655 emit_filename
= file
;
660 /* Emit a no-op instruction. */
667 last_insn
= get_last_insn ();
669 && (GET_CODE (last_insn
) == CODE_LABEL
670 || (GET_CODE (last_insn
) == NOTE
671 && prev_real_insn (last_insn
) == 0)))
672 emit_insn (gen_nop ());
675 /* Return the rtx-label that corresponds to a LABEL_DECL,
676 creating it if necessary. */
682 if (TREE_CODE (label
) != LABEL_DECL
)
685 if (!DECL_RTL_SET_P (label
))
686 SET_DECL_RTL (label
, gen_label_rtx ());
688 return DECL_RTL (label
);
692 /* Add an unconditional jump to LABEL as the next sequential instruction. */
698 do_pending_stack_adjust ();
699 emit_jump_insn (gen_jump (label
));
703 /* Emit code to jump to the address
704 specified by the pointer expression EXP. */
707 expand_computed_goto (exp
)
710 rtx x
= expand_expr (exp
, NULL_RTX
, VOIDmode
, 0);
712 #ifdef POINTERS_EXTEND_UNSIGNED
713 if (GET_MODE (x
) != Pmode
)
714 x
= convert_memory_address (Pmode
, x
);
718 do_pending_stack_adjust ();
719 emit_indirect_jump (x
);
721 current_function_has_computed_jump
= 1;
724 /* Handle goto statements and the labels that they can go to. */
726 /* Specify the location in the RTL code of a label LABEL,
727 which is a LABEL_DECL tree node.
729 This is used for the kind of label that the user can jump to with a
730 goto statement, and for alternatives of a switch or case statement.
731 RTL labels generated for loops and conditionals don't go through here;
732 they are generated directly at the RTL level, by other functions below.
734 Note that this has nothing to do with defining label *names*.
735 Languages vary in how they do that and what that even means. */
741 struct label_chain
*p
;
743 do_pending_stack_adjust ();
744 emit_label (label_rtx (label
));
745 if (DECL_NAME (label
))
746 LABEL_NAME (DECL_RTL (label
)) = IDENTIFIER_POINTER (DECL_NAME (label
));
748 if (stack_block_stack
!= 0)
750 p
= (struct label_chain
*) ggc_alloc (sizeof (struct label_chain
));
751 p
->next
= stack_block_stack
->data
.block
.label_chain
;
752 stack_block_stack
->data
.block
.label_chain
= p
;
757 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
758 from nested functions. */
761 declare_nonlocal_label (label
)
764 rtx slot
= assign_stack_local (Pmode
, GET_MODE_SIZE (Pmode
), 0);
766 nonlocal_labels
= tree_cons (NULL_TREE
, label
, nonlocal_labels
);
767 LABEL_PRESERVE_P (label_rtx (label
)) = 1;
768 if (nonlocal_goto_handler_slots
== 0)
770 emit_stack_save (SAVE_NONLOCAL
,
771 &nonlocal_goto_stack_level
,
772 PREV_INSN (tail_recursion_reentry
));
774 nonlocal_goto_handler_slots
775 = gen_rtx_EXPR_LIST (VOIDmode
, slot
, nonlocal_goto_handler_slots
);
778 /* Generate RTL code for a `goto' statement with target label LABEL.
779 LABEL should be a LABEL_DECL tree node that was or will later be
780 defined with `expand_label'. */
788 /* Check for a nonlocal goto to a containing function. */
789 context
= decl_function_context (label
);
790 if (context
!= 0 && context
!= current_function_decl
)
792 struct function
*p
= find_function_data (context
);
793 rtx label_ref
= gen_rtx_LABEL_REF (Pmode
, label_rtx (label
));
794 rtx handler_slot
, static_chain
, save_area
, insn
;
797 /* Find the corresponding handler slot for this label. */
798 handler_slot
= p
->x_nonlocal_goto_handler_slots
;
799 for (link
= p
->x_nonlocal_labels
; TREE_VALUE (link
) != label
;
800 link
= TREE_CHAIN (link
))
801 handler_slot
= XEXP (handler_slot
, 1);
802 handler_slot
= XEXP (handler_slot
, 0);
804 p
->has_nonlocal_label
= 1;
805 current_function_has_nonlocal_goto
= 1;
806 LABEL_REF_NONLOCAL_P (label_ref
) = 1;
808 /* Copy the rtl for the slots so that they won't be shared in
809 case the virtual stack vars register gets instantiated differently
810 in the parent than in the child. */
812 static_chain
= copy_to_reg (lookup_static_chain (label
));
814 /* Get addr of containing function's current nonlocal goto handler,
815 which will do any cleanups and then jump to the label. */
816 handler_slot
= copy_to_reg (replace_rtx (copy_rtx (handler_slot
),
817 virtual_stack_vars_rtx
,
820 /* Get addr of containing function's nonlocal save area. */
821 save_area
= p
->x_nonlocal_goto_stack_level
;
823 save_area
= replace_rtx (copy_rtx (save_area
),
824 virtual_stack_vars_rtx
, static_chain
);
826 #if HAVE_nonlocal_goto
827 if (HAVE_nonlocal_goto
)
828 emit_insn (gen_nonlocal_goto (static_chain
, handler_slot
,
829 save_area
, label_ref
));
833 /* Restore frame pointer for containing function.
834 This sets the actual hard register used for the frame pointer
835 to the location of the function's incoming static chain info.
836 The non-local goto handler will then adjust it to contain the
837 proper value and reload the argument pointer, if needed. */
838 emit_move_insn (hard_frame_pointer_rtx
, static_chain
);
839 emit_stack_restore (SAVE_NONLOCAL
, save_area
, NULL_RTX
);
841 /* USE of hard_frame_pointer_rtx added for consistency;
842 not clear if really needed. */
843 emit_insn (gen_rtx_USE (VOIDmode
, hard_frame_pointer_rtx
));
844 emit_insn (gen_rtx_USE (VOIDmode
, stack_pointer_rtx
));
845 emit_indirect_jump (handler_slot
);
848 /* Search backwards to the jump insn and mark it as a
850 for (insn
= get_last_insn (); insn
; insn
= PREV_INSN (insn
))
852 if (GET_CODE (insn
) == JUMP_INSN
)
854 REG_NOTES (insn
) = alloc_EXPR_LIST (REG_NON_LOCAL_GOTO
,
855 const0_rtx
, REG_NOTES (insn
));
858 else if (GET_CODE (insn
) == CALL_INSN
)
863 expand_goto_internal (label
, label_rtx (label
), NULL_RTX
);
866 /* Generate RTL code for a `goto' statement with target label BODY.
867 LABEL should be a LABEL_REF.
868 LAST_INSN, if non-0, is the rtx we should consider as the last
869 insn emitted (for the purposes of cleaning up a return). */
872 expand_goto_internal (body
, label
, last_insn
)
877 struct nesting
*block
;
880 if (GET_CODE (label
) != CODE_LABEL
)
883 /* If label has already been defined, we can tell now
884 whether and how we must alter the stack level. */
886 if (PREV_INSN (label
) != 0)
888 /* Find the innermost pending block that contains the label.
889 (Check containment by comparing insn-uids.)
890 Then restore the outermost stack level within that block,
891 and do cleanups of all blocks contained in it. */
892 for (block
= block_stack
; block
; block
= block
->next
)
894 if (INSN_UID (block
->data
.block
.first_insn
) < INSN_UID (label
))
896 if (block
->data
.block
.stack_level
!= 0)
897 stack_level
= block
->data
.block
.stack_level
;
898 /* Execute the cleanups for blocks we are exiting. */
899 if (block
->data
.block
.cleanups
!= 0)
901 expand_cleanups (block
->data
.block
.cleanups
, NULL_TREE
, 1, 1);
902 do_pending_stack_adjust ();
908 /* Ensure stack adjust isn't done by emit_jump, as this
909 would clobber the stack pointer. This one should be
910 deleted as dead by flow. */
911 clear_pending_stack_adjust ();
912 do_pending_stack_adjust ();
914 /* Don't do this adjust if it's to the end label and this function
915 is to return with a depressed stack pointer. */
916 if (label
== return_label
917 && (((TREE_CODE (TREE_TYPE (current_function_decl
))
919 && (TYPE_RETURNS_STACK_DEPRESSED
920 (TREE_TYPE (current_function_decl
))))))
923 emit_stack_restore (SAVE_BLOCK
, stack_level
, NULL_RTX
);
926 if (body
!= 0 && DECL_TOO_LATE (body
))
927 error ("jump to `%s' invalidly jumps into binding contour",
928 IDENTIFIER_POINTER (DECL_NAME (body
)));
930 /* Label not yet defined: may need to put this goto
931 on the fixup list. */
932 else if (! expand_fixup (body
, label
, last_insn
))
934 /* No fixup needed. Record that the label is the target
935 of at least one goto that has no fixup. */
937 TREE_ADDRESSABLE (body
) = 1;
943 /* Generate if necessary a fixup for a goto
944 whose target label in tree structure (if any) is TREE_LABEL
945 and whose target in rtl is RTL_LABEL.
947 If LAST_INSN is nonzero, we pretend that the jump appears
948 after insn LAST_INSN instead of at the current point in the insn stream.
950 The fixup will be used later to insert insns just before the goto.
951 Those insns will restore the stack level as appropriate for the
952 target label, and will (in the case of C++) also invoke any object
953 destructors which have to be invoked when we exit the scopes which
954 are exited by the goto.
956 Value is nonzero if a fixup is made. */
959 expand_fixup (tree_label
, rtl_label
, last_insn
)
964 struct nesting
*block
, *end_block
;
966 /* See if we can recognize which block the label will be output in.
967 This is possible in some very common cases.
968 If we succeed, set END_BLOCK to that block.
969 Otherwise, set it to 0. */
972 && (rtl_label
== cond_stack
->data
.cond
.endif_label
973 || rtl_label
== cond_stack
->data
.cond
.next_label
))
974 end_block
= cond_stack
;
975 /* If we are in a loop, recognize certain labels which
976 are likely targets. This reduces the number of fixups
977 we need to create. */
979 && (rtl_label
== loop_stack
->data
.loop
.start_label
980 || rtl_label
== loop_stack
->data
.loop
.end_label
981 || rtl_label
== loop_stack
->data
.loop
.continue_label
))
982 end_block
= loop_stack
;
986 /* Now set END_BLOCK to the binding level to which we will return. */
990 struct nesting
*next_block
= end_block
->all
;
993 /* First see if the END_BLOCK is inside the innermost binding level.
994 If so, then no cleanups or stack levels are relevant. */
995 while (next_block
&& next_block
!= block
)
996 next_block
= next_block
->all
;
1001 /* Otherwise, set END_BLOCK to the innermost binding level
1002 which is outside the relevant control-structure nesting. */
1003 next_block
= block_stack
->next
;
1004 for (block
= block_stack
; block
!= end_block
; block
= block
->all
)
1005 if (block
== next_block
)
1006 next_block
= next_block
->next
;
1007 end_block
= next_block
;
1010 /* Does any containing block have a stack level or cleanups?
1011 If not, no fixup is needed, and that is the normal case
1012 (the only case, for standard C). */
1013 for (block
= block_stack
; block
!= end_block
; block
= block
->next
)
1014 if (block
->data
.block
.stack_level
!= 0
1015 || block
->data
.block
.cleanups
!= 0)
1018 if (block
!= end_block
)
1020 /* Ok, a fixup is needed. Add a fixup to the list of such. */
1021 struct goto_fixup
*fixup
1022 = (struct goto_fixup
*) ggc_alloc (sizeof (struct goto_fixup
));
1023 /* In case an old stack level is restored, make sure that comes
1024 after any pending stack adjust. */
1025 /* ?? If the fixup isn't to come at the present position,
1026 doing the stack adjust here isn't useful. Doing it with our
1027 settings at that location isn't useful either. Let's hope
1030 do_pending_stack_adjust ();
1031 fixup
->target
= tree_label
;
1032 fixup
->target_rtl
= rtl_label
;
1034 /* Create a BLOCK node and a corresponding matched set of
1035 NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes at
1036 this point. The notes will encapsulate any and all fixup
1037 code which we might later insert at this point in the insn
1038 stream. Also, the BLOCK node will be the parent (i.e. the
1039 `SUPERBLOCK') of any other BLOCK nodes which we might create
1040 later on when we are expanding the fixup code.
1042 Note that optimization passes (including expand_end_loop)
1043 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
1044 as a placeholder. */
1047 rtx original_before_jump
1048 = last_insn
? last_insn
: get_last_insn ();
1053 block
= make_node (BLOCK
);
1054 TREE_USED (block
) = 1;
1056 if (!cfun
->x_whole_function_mode_p
)
1057 insert_block (block
);
1061 = BLOCK_CHAIN (DECL_INITIAL (current_function_decl
));
1062 BLOCK_CHAIN (DECL_INITIAL (current_function_decl
))
1067 start
= emit_note (NULL
, NOTE_INSN_BLOCK_BEG
);
1068 if (cfun
->x_whole_function_mode_p
)
1069 NOTE_BLOCK (start
) = block
;
1070 fixup
->before_jump
= emit_note (NULL
, NOTE_INSN_DELETED
);
1071 end
= emit_note (NULL
, NOTE_INSN_BLOCK_END
);
1072 if (cfun
->x_whole_function_mode_p
)
1073 NOTE_BLOCK (end
) = block
;
1074 fixup
->context
= block
;
1076 emit_insns_after (start
, original_before_jump
);
1079 fixup
->block_start_count
= current_block_start_count
;
1080 fixup
->stack_level
= 0;
1081 fixup
->cleanup_list_list
1082 = ((block
->data
.block
.outer_cleanups
1083 || block
->data
.block
.cleanups
)
1084 ? tree_cons (NULL_TREE
, block
->data
.block
.cleanups
,
1085 block
->data
.block
.outer_cleanups
)
1087 fixup
->next
= goto_fixup_chain
;
1088 goto_fixup_chain
= fixup
;
1094 /* Expand any needed fixups in the outputmost binding level of the
1095 function. FIRST_INSN is the first insn in the function. */
1098 expand_fixups (first_insn
)
1101 fixup_gotos (NULL
, NULL_RTX
, NULL_TREE
, first_insn
, 0);
1104 /* When exiting a binding contour, process all pending gotos requiring fixups.
1105 THISBLOCK is the structure that describes the block being exited.
1106 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1107 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1108 FIRST_INSN is the insn that began this contour.
1110 Gotos that jump out of this contour must restore the
1111 stack level and do the cleanups before actually jumping.
1113 DONT_JUMP_IN nonzero means report error there is a jump into this
1114 contour from before the beginning of the contour.
1115 This is also done if STACK_LEVEL is nonzero. */
1118 fixup_gotos (thisblock
, stack_level
, cleanup_list
, first_insn
, dont_jump_in
)
1119 struct nesting
*thisblock
;
1125 struct goto_fixup
*f
, *prev
;
1127 /* F is the fixup we are considering; PREV is the previous one. */
1128 /* We run this loop in two passes so that cleanups of exited blocks
1129 are run first, and blocks that are exited are marked so
1132 for (prev
= 0, f
= goto_fixup_chain
; f
; prev
= f
, f
= f
->next
)
1134 /* Test for a fixup that is inactive because it is already handled. */
1135 if (f
->before_jump
== 0)
1137 /* Delete inactive fixup from the chain, if that is easy to do. */
1139 prev
->next
= f
->next
;
1141 /* Has this fixup's target label been defined?
1142 If so, we can finalize it. */
1143 else if (PREV_INSN (f
->target_rtl
) != 0)
1147 /* If this fixup jumped into this contour from before the beginning
1148 of this contour, report an error. This code used to use
1149 the first non-label insn after f->target_rtl, but that's
1150 wrong since such can be added, by things like put_var_into_stack
1151 and have INSN_UIDs that are out of the range of the block. */
1152 /* ??? Bug: this does not detect jumping in through intermediate
1153 blocks that have stack levels or cleanups.
1154 It detects only a problem with the innermost block
1155 around the label. */
1157 && (dont_jump_in
|| stack_level
|| cleanup_list
)
1158 && INSN_UID (first_insn
) < INSN_UID (f
->target_rtl
)
1159 && INSN_UID (first_insn
) > INSN_UID (f
->before_jump
)
1160 && ! DECL_ERROR_ISSUED (f
->target
))
1162 error_with_decl (f
->target
,
1163 "label `%s' used before containing binding contour");
1164 /* Prevent multiple errors for one label. */
1165 DECL_ERROR_ISSUED (f
->target
) = 1;
1168 /* We will expand the cleanups into a sequence of their own and
1169 then later on we will attach this new sequence to the insn
1170 stream just ahead of the actual jump insn. */
1174 /* Temporarily restore the lexical context where we will
1175 logically be inserting the fixup code. We do this for the
1176 sake of getting the debugging information right. */
1179 set_block (f
->context
);
1181 /* Expand the cleanups for blocks this jump exits. */
1182 if (f
->cleanup_list_list
)
1185 for (lists
= f
->cleanup_list_list
; lists
; lists
= TREE_CHAIN (lists
))
1186 /* Marked elements correspond to blocks that have been closed.
1187 Do their cleanups. */
1188 if (TREE_ADDRESSABLE (lists
)
1189 && TREE_VALUE (lists
) != 0)
1191 expand_cleanups (TREE_VALUE (lists
), NULL_TREE
, 1, 1);
1192 /* Pop any pushes done in the cleanups,
1193 in case function is about to return. */
1194 do_pending_stack_adjust ();
1198 /* Restore stack level for the biggest contour that this
1199 jump jumps out of. */
1201 && ! (f
->target_rtl
== return_label
1202 && ((TREE_CODE (TREE_TYPE (current_function_decl
))
1204 && (TYPE_RETURNS_STACK_DEPRESSED
1205 (TREE_TYPE (current_function_decl
))))))
1206 emit_stack_restore (SAVE_BLOCK
, f
->stack_level
, f
->before_jump
);
1208 /* Finish up the sequence containing the insns which implement the
1209 necessary cleanups, and then attach that whole sequence to the
1210 insn stream just ahead of the actual jump insn. Attaching it
1211 at that point insures that any cleanups which are in fact
1212 implicit C++ object destructions (which must be executed upon
1213 leaving the block) appear (to the debugger) to be taking place
1214 in an area of the generated code where the object(s) being
1215 destructed are still "in scope". */
1217 cleanup_insns
= get_insns ();
1221 emit_insns_after (cleanup_insns
, f
->before_jump
);
1227 /* For any still-undefined labels, do the cleanups for this block now.
1228 We must do this now since items in the cleanup list may go out
1229 of scope when the block ends. */
1230 for (prev
= 0, f
= goto_fixup_chain
; f
; prev
= f
, f
= f
->next
)
1231 if (f
->before_jump
!= 0
1232 && PREV_INSN (f
->target_rtl
) == 0
1233 /* Label has still not appeared. If we are exiting a block with
1234 a stack level to restore, that started before the fixup,
1235 mark this stack level as needing restoration
1236 when the fixup is later finalized. */
1238 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1239 means the label is undefined. That's erroneous, but possible. */
1240 && (thisblock
->data
.block
.block_start_count
1241 <= f
->block_start_count
))
1243 tree lists
= f
->cleanup_list_list
;
1246 for (; lists
; lists
= TREE_CHAIN (lists
))
1247 /* If the following elt. corresponds to our containing block
1248 then the elt. must be for this block. */
1249 if (TREE_CHAIN (lists
) == thisblock
->data
.block
.outer_cleanups
)
1253 set_block (f
->context
);
1254 expand_cleanups (TREE_VALUE (lists
), NULL_TREE
, 1, 1);
1255 do_pending_stack_adjust ();
1256 cleanup_insns
= get_insns ();
1259 if (cleanup_insns
!= 0)
1261 = emit_insns_after (cleanup_insns
, f
->before_jump
);
1263 f
->cleanup_list_list
= TREE_CHAIN (lists
);
1267 f
->stack_level
= stack_level
;
1271 /* Return the number of times character C occurs in string S. */
1273 n_occurrences (c
, s
)
1283 /* Generate RTL for an asm statement (explicit assembler code).
1284 BODY is a STRING_CST node containing the assembler code text,
1285 or an ADDR_EXPR containing a STRING_CST. */
1291 if (TREE_CODE (body
) == ADDR_EXPR
)
1292 body
= TREE_OPERAND (body
, 0);
1294 emit_insn (gen_rtx_ASM_INPUT (VOIDmode
,
1295 TREE_STRING_POINTER (body
)));
1299 /* Parse the output constraint pointed to by *CONSTRAINT_P. It is the
1300 OPERAND_NUMth output operand, indexed from zero. There are NINPUTS
1301 inputs and NOUTPUTS outputs to this extended-asm. Upon return,
1302 *ALLOWS_MEM will be TRUE iff the constraint allows the use of a
1303 memory operand. Similarly, *ALLOWS_REG will be TRUE iff the
1304 constraint allows the use of a register operand. And, *IS_INOUT
1305 will be true if the operand is read-write, i.e., if it is used as
1306 an input as well as an output. If *CONSTRAINT_P is not in
1307 canonical form, it will be made canonical. (Note that `+' will be
1308 rpelaced with `=' as part of this process.)
1310 Returns TRUE if all went well; FALSE if an error occurred. */
1313 parse_output_constraint (constraint_p
, operand_num
, ninputs
, noutputs
,
1314 allows_mem
, allows_reg
, is_inout
)
1315 const char **constraint_p
;
1323 const char *constraint
= *constraint_p
;
1326 /* Assume the constraint doesn't allow the use of either a register
1328 *allows_mem
= false;
1329 *allows_reg
= false;
1331 /* Allow the `=' or `+' to not be at the beginning of the string,
1332 since it wasn't explicitly documented that way, and there is a
1333 large body of code that puts it last. Swap the character to
1334 the front, so as not to uglify any place else. */
1335 p
= strchr (constraint
, '=');
1337 p
= strchr (constraint
, '+');
1339 /* If the string doesn't contain an `=', issue an error
1343 error ("output operand constraint lacks `='");
1347 /* If the constraint begins with `+', then the operand is both read
1348 from and written to. */
1349 *is_inout
= (*p
== '+');
1351 /* Canonicalize the output constraint so that it begins with `='. */
1352 if (p
!= constraint
|| is_inout
)
1355 size_t c_len
= strlen (constraint
);
1357 if (p
!= constraint
)
1358 warning ("output constraint `%c' for operand %d is not at the beginning",
1361 /* Make a copy of the constraint. */
1362 buf
= alloca (c_len
+ 1);
1363 strcpy (buf
, constraint
);
1364 /* Swap the first character and the `=' or `+'. */
1365 buf
[p
- constraint
] = buf
[0];
1366 /* Make sure the first character is an `='. (Until we do this,
1367 it might be a `+'.) */
1369 /* Replace the constraint with the canonicalized string. */
1370 *constraint_p
= ggc_alloc_string (buf
, c_len
);
1371 constraint
= *constraint_p
;
1374 /* Loop through the constraint string. */
1375 for (p
= constraint
+ 1; *p
; ++p
)
1380 error ("operand constraint contains incorrectly positioned '+' or '='");
1384 if (operand_num
+ 1 == ninputs
+ noutputs
)
1386 error ("`%%' constraint used with last operand");
1391 case 'V': case 'm': case 'o':
1395 case '?': case '!': case '*': case '&': case '#':
1396 case 'E': case 'F': case 'G': case 'H':
1397 case 's': case 'i': case 'n':
1398 case 'I': case 'J': case 'K': case 'L': case 'M':
1399 case 'N': case 'O': case 'P': case ',':
1402 case '0': case '1': case '2': case '3': case '4':
1403 case '5': case '6': case '7': case '8': case '9':
1405 error ("matching constraint not valid in output operand");
1409 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1410 excepting those that expand_call created. So match memory
1427 if (REG_CLASS_FROM_LETTER (*p
) != NO_REGS
)
1429 #ifdef EXTRA_CONSTRAINT
1432 /* Otherwise we can't assume anything about the nature of
1433 the constraint except that it isn't purely registers.
1434 Treat it like "g" and hope for the best. */
1445 /* Similar, but for input constraints. */
1448 parse_input_constraint (constraint_p
, input_num
, ninputs
, noutputs
, ninout
,
1449 constraints
, allows_mem
, allows_reg
)
1450 const char **constraint_p
;
1455 const char * const * constraints
;
1459 const char *constraint
= *constraint_p
;
1460 const char *orig_constraint
= constraint
;
1461 size_t c_len
= strlen (constraint
);
1464 /* Assume the constraint doesn't allow the use of either
1465 a register or memory. */
1466 *allows_mem
= false;
1467 *allows_reg
= false;
1469 /* Make sure constraint has neither `=', `+', nor '&'. */
1471 for (j
= 0; j
< c_len
; j
++)
1472 switch (constraint
[j
])
1474 case '+': case '=': case '&':
1475 if (constraint
== orig_constraint
)
1477 error ("input operand constraint contains `%c'", constraint
[j
]);
1483 if (constraint
== orig_constraint
1484 && input_num
+ 1 == ninputs
- ninout
)
1486 error ("`%%' constraint used with last operand");
1491 case 'V': case 'm': case 'o':
1496 case '?': case '!': case '*': case '#':
1497 case 'E': case 'F': case 'G': case 'H':
1498 case 's': case 'i': case 'n':
1499 case 'I': case 'J': case 'K': case 'L': case 'M':
1500 case 'N': case 'O': case 'P': case ',':
1503 /* Whether or not a numeric constraint allows a register is
1504 decided by the matching constraint, and so there is no need
1505 to do anything special with them. We must handle them in
1506 the default case, so that we don't unnecessarily force
1507 operands to memory. */
1508 case '0': case '1': case '2': case '3': case '4':
1509 case '5': case '6': case '7': case '8': case '9':
1512 unsigned long match
;
1514 match
= strtoul (constraint
+ j
, &end
, 10);
1515 if (match
>= (unsigned long) noutputs
)
1517 error ("matching constraint references invalid operand number");
1521 /* Try and find the real constraint for this dup. Only do this
1522 if the matching constraint is the only alternative. */
1524 && (j
== 0 || (j
== 1 && constraint
[0] == '%')))
1526 constraint
= constraints
[match
];
1527 *constraint_p
= constraint
;
1528 c_len
= strlen (constraint
);
1533 j
= end
- constraint
;
1547 if (! ISALPHA (constraint
[j
]))
1549 error ("invalid punctuation `%c' in constraint", constraint
[j
]);
1552 if (REG_CLASS_FROM_LETTER (constraint
[j
]) != NO_REGS
)
1554 #ifdef EXTRA_CONSTRAINT
1557 /* Otherwise we can't assume anything about the nature of
1558 the constraint except that it isn't purely registers.
1559 Treat it like "g" and hope for the best. */
1570 /* Generate RTL for an asm statement with arguments.
1571 STRING is the instruction template.
1572 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1573 Each output or input has an expression in the TREE_VALUE and
1574 and a tree list in TREE_PURPOSE which in turn contains a constraint
1575 name in TREE_VALUE (or NULL_TREE) and a constraint string
1577 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1578 that is clobbered by this insn.
1580 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1581 Some elements of OUTPUTS may be replaced with trees representing temporary
1582 values. The caller should copy those temporary values to the originally
1585 VOL nonzero means the insn is volatile; don't optimize it. */
1588 expand_asm_operands (string
, outputs
, inputs
, clobbers
, vol
, filename
, line
)
1589 tree string
, outputs
, inputs
, clobbers
;
1591 const char *filename
;
1594 rtvec argvec
, constraintvec
;
1596 int ninputs
= list_length (inputs
);
1597 int noutputs
= list_length (outputs
);
1602 /* Vector of RTX's of evaluated output operands. */
1603 rtx
*output_rtx
= (rtx
*) alloca (noutputs
* sizeof (rtx
));
1604 int *inout_opnum
= (int *) alloca (noutputs
* sizeof (int));
1605 rtx
*real_output_rtx
= (rtx
*) alloca (noutputs
* sizeof (rtx
));
1606 enum machine_mode
*inout_mode
1607 = (enum machine_mode
*) alloca (noutputs
* sizeof (enum machine_mode
));
1608 const char **constraints
1609 = (const char **) alloca ((noutputs
+ ninputs
) * sizeof (const char *));
1610 /* The insn we have emitted. */
1612 int old_generating_concat_p
= generating_concat_p
;
1614 /* An ASM with no outputs needs to be treated as volatile, for now. */
1618 if (! check_operand_nalternatives (outputs
, inputs
))
1621 if (! check_unique_operand_names (outputs
, inputs
))
1624 string
= resolve_operand_names (string
, outputs
, inputs
, constraints
);
1626 #ifdef MD_ASM_CLOBBERS
1627 /* Sometimes we wish to automatically clobber registers across an asm.
1628 Case in point is when the i386 backend moved from cc0 to a hard reg --
1629 maintaining source-level compatibility means automatically clobbering
1630 the flags register. */
1631 MD_ASM_CLOBBERS (clobbers
);
1634 /* Count the number of meaningful clobbered registers, ignoring what
1635 we would ignore later. */
1637 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
))
1639 const char *regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
1641 i
= decode_reg_name (regname
);
1642 if (i
>= 0 || i
== -4)
1645 error ("unknown register name `%s' in `asm'", regname
);
1650 /* First pass over inputs and outputs checks validity and sets
1651 mark_addressable if needed. */
1654 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1656 tree val
= TREE_VALUE (tail
);
1657 tree type
= TREE_TYPE (val
);
1658 const char *constraint
;
1663 /* If there's an erroneous arg, emit no insn. */
1664 if (type
== error_mark_node
)
1667 /* Try to parse the output constraint. If that fails, there's
1668 no point in going further. */
1669 constraint
= constraints
[i
];
1670 if (!parse_output_constraint (&constraint
, i
, ninputs
, noutputs
,
1671 &allows_mem
, &allows_reg
, &is_inout
))
1678 && GET_CODE (DECL_RTL (val
)) == REG
1679 && GET_MODE (DECL_RTL (val
)) != TYPE_MODE (type
))))
1680 mark_addressable (val
);
1687 if (ninputs
+ noutputs
> MAX_RECOG_OPERANDS
)
1689 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS
);
1693 for (i
= 0, tail
= inputs
; tail
; i
++, tail
= TREE_CHAIN (tail
))
1695 bool allows_reg
, allows_mem
;
1696 const char *constraint
;
1698 /* If there's an erroneous arg, emit no insn, because the ASM_INPUT
1699 would get VOIDmode and that could cause a crash in reload. */
1700 if (TREE_TYPE (TREE_VALUE (tail
)) == error_mark_node
)
1703 constraint
= constraints
[i
+ noutputs
];
1704 if (! parse_input_constraint (&constraint
, i
, ninputs
, noutputs
, ninout
,
1705 constraints
, &allows_mem
, &allows_reg
))
1708 if (! allows_reg
&& allows_mem
)
1709 mark_addressable (TREE_VALUE (tail
));
1712 /* Second pass evaluates arguments. */
1715 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1717 tree val
= TREE_VALUE (tail
);
1718 tree type
= TREE_TYPE (val
);
1723 if (!parse_output_constraint (&constraints
[i
], i
, ninputs
,
1724 noutputs
, &allows_mem
, &allows_reg
,
1728 /* If an output operand is not a decl or indirect ref and our constraint
1729 allows a register, make a temporary to act as an intermediate.
1730 Make the asm insn write into that, then our caller will copy it to
1731 the real output operand. Likewise for promoted variables. */
1733 generating_concat_p
= 0;
1735 real_output_rtx
[i
] = NULL_RTX
;
1736 if ((TREE_CODE (val
) == INDIRECT_REF
1739 && (allows_mem
|| GET_CODE (DECL_RTL (val
)) == REG
)
1740 && ! (GET_CODE (DECL_RTL (val
)) == REG
1741 && GET_MODE (DECL_RTL (val
)) != TYPE_MODE (type
)))
1745 output_rtx
[i
] = expand_expr (val
, NULL_RTX
, VOIDmode
, EXPAND_WRITE
);
1747 if (! allows_reg
&& GET_CODE (output_rtx
[i
]) != MEM
)
1748 error ("output number %d not directly addressable", i
);
1749 if ((! allows_mem
&& GET_CODE (output_rtx
[i
]) == MEM
)
1750 || GET_CODE (output_rtx
[i
]) == CONCAT
)
1752 real_output_rtx
[i
] = protect_from_queue (output_rtx
[i
], 1);
1753 output_rtx
[i
] = gen_reg_rtx (GET_MODE (output_rtx
[i
]));
1755 emit_move_insn (output_rtx
[i
], real_output_rtx
[i
]);
1760 output_rtx
[i
] = assign_temp (type
, 0, 0, 1);
1761 TREE_VALUE (tail
) = make_tree (type
, output_rtx
[i
]);
1764 generating_concat_p
= old_generating_concat_p
;
1768 inout_mode
[ninout
] = TYPE_MODE (type
);
1769 inout_opnum
[ninout
++] = i
;
1773 /* Make vectors for the expression-rtx, constraint strings,
1774 and named operands. */
1776 argvec
= rtvec_alloc (ninputs
);
1777 constraintvec
= rtvec_alloc (ninputs
);
1779 body
= gen_rtx_ASM_OPERANDS ((noutputs
== 0 ? VOIDmode
1780 : GET_MODE (output_rtx
[0])),
1781 TREE_STRING_POINTER (string
),
1782 empty_string
, 0, argvec
, constraintvec
,
1785 MEM_VOLATILE_P (body
) = vol
;
1787 /* Eval the inputs and put them into ARGVEC.
1788 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1790 for (i
= 0, tail
= inputs
; tail
; tail
= TREE_CHAIN (tail
), ++i
)
1792 bool allows_reg
, allows_mem
;
1793 const char *constraint
;
1797 constraint
= constraints
[i
+ noutputs
];
1798 if (! parse_input_constraint (&constraint
, i
, ninputs
, noutputs
, ninout
,
1799 constraints
, &allows_mem
, &allows_reg
))
1802 generating_concat_p
= 0;
1804 val
= TREE_VALUE (tail
);
1805 type
= TREE_TYPE (val
);
1806 op
= expand_expr (val
, NULL_RTX
, VOIDmode
, 0);
1808 /* Never pass a CONCAT to an ASM. */
1809 if (GET_CODE (op
) == CONCAT
)
1810 op
= force_reg (GET_MODE (op
), op
);
1812 if (asm_operand_ok (op
, constraint
) <= 0)
1815 op
= force_reg (TYPE_MODE (type
), op
);
1816 else if (!allows_mem
)
1817 warning ("asm operand %d probably doesn't match constraints",
1819 else if (CONSTANT_P (op
))
1820 op
= force_const_mem (TYPE_MODE (type
), op
);
1821 else if (GET_CODE (op
) == REG
1822 || GET_CODE (op
) == SUBREG
1823 || GET_CODE (op
) == ADDRESSOF
1824 || GET_CODE (op
) == CONCAT
)
1826 tree qual_type
= build_qualified_type (type
,
1828 | TYPE_QUAL_CONST
));
1829 rtx memloc
= assign_temp (qual_type
, 1, 1, 1);
1831 emit_move_insn (memloc
, op
);
1835 else if (GET_CODE (op
) == MEM
&& MEM_VOLATILE_P (op
))
1837 /* We won't recognize volatile memory as available a
1838 memory_operand at this point. Ignore it. */
1840 else if (queued_subexp_p (op
))
1843 /* ??? Leave this only until we have experience with what
1844 happens in combine and elsewhere when constraints are
1846 warning ("asm operand %d probably doesn't match constraints",
1850 generating_concat_p
= old_generating_concat_p
;
1851 ASM_OPERANDS_INPUT (body
, i
) = op
;
1853 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body
, i
)
1854 = gen_rtx_ASM_INPUT (TYPE_MODE (type
), constraints
[i
+ noutputs
]);
1857 /* Protect all the operands from the queue now that they have all been
1860 generating_concat_p
= 0;
1862 for (i
= 0; i
< ninputs
- ninout
; i
++)
1863 ASM_OPERANDS_INPUT (body
, i
)
1864 = protect_from_queue (ASM_OPERANDS_INPUT (body
, i
), 0);
1866 for (i
= 0; i
< noutputs
; i
++)
1867 output_rtx
[i
] = protect_from_queue (output_rtx
[i
], 1);
1869 /* For in-out operands, copy output rtx to input rtx. */
1870 for (i
= 0; i
< ninout
; i
++)
1872 int j
= inout_opnum
[i
];
1875 ASM_OPERANDS_INPUT (body
, ninputs
- ninout
+ i
)
1878 sprintf (buffer
, "%d", j
);
1879 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body
, ninputs
- ninout
+ i
)
1880 = gen_rtx_ASM_INPUT (inout_mode
[i
], ggc_alloc_string (buffer
, -1));
1883 generating_concat_p
= old_generating_concat_p
;
1885 /* Now, for each output, construct an rtx
1886 (set OUTPUT (asm_operands INSN OUTPUTCONSTRAINT OUTPUTNUMBER
1887 ARGVEC CONSTRAINTS OPNAMES))
1888 If there is more than one, put them inside a PARALLEL. */
1890 if (noutputs
== 1 && nclobbers
== 0)
1892 ASM_OPERANDS_OUTPUT_CONSTRAINT (body
) = constraints
[0];
1893 insn
= emit_insn (gen_rtx_SET (VOIDmode
, output_rtx
[0], body
));
1896 else if (noutputs
== 0 && nclobbers
== 0)
1898 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1899 insn
= emit_insn (body
);
1910 body
= gen_rtx_PARALLEL (VOIDmode
, rtvec_alloc (num
+ nclobbers
));
1912 /* For each output operand, store a SET. */
1913 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1915 XVECEXP (body
, 0, i
)
1916 = gen_rtx_SET (VOIDmode
,
1918 gen_rtx_ASM_OPERANDS
1919 (GET_MODE (output_rtx
[i
]),
1920 TREE_STRING_POINTER (string
),
1921 constraints
[i
], i
, argvec
, constraintvec
,
1924 MEM_VOLATILE_P (SET_SRC (XVECEXP (body
, 0, i
))) = vol
;
1927 /* If there are no outputs (but there are some clobbers)
1928 store the bare ASM_OPERANDS into the PARALLEL. */
1931 XVECEXP (body
, 0, i
++) = obody
;
1933 /* Store (clobber REG) for each clobbered register specified. */
1935 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
))
1937 const char *regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
1938 int j
= decode_reg_name (regname
);
1942 if (j
== -3) /* `cc', which is not a register */
1945 if (j
== -4) /* `memory', don't cache memory across asm */
1947 XVECEXP (body
, 0, i
++)
1948 = gen_rtx_CLOBBER (VOIDmode
,
1951 gen_rtx_SCRATCH (VOIDmode
)));
1955 /* Ignore unknown register, error already signaled. */
1959 /* Use QImode since that's guaranteed to clobber just one reg. */
1960 XVECEXP (body
, 0, i
++)
1961 = gen_rtx_CLOBBER (VOIDmode
, gen_rtx_REG (QImode
, j
));
1964 insn
= emit_insn (body
);
1967 /* For any outputs that needed reloading into registers, spill them
1968 back to where they belong. */
1969 for (i
= 0; i
< noutputs
; ++i
)
1970 if (real_output_rtx
[i
])
1971 emit_move_insn (real_output_rtx
[i
], output_rtx
[i
]);
1976 /* A subroutine of expand_asm_operands. Check that all operands have
1977 the same number of alternatives. Return true if so. */
1980 check_operand_nalternatives (outputs
, inputs
)
1981 tree outputs
, inputs
;
1983 if (outputs
|| inputs
)
1985 tree tmp
= TREE_PURPOSE (outputs
? outputs
: inputs
);
1987 = n_occurrences (',', TREE_STRING_POINTER (TREE_VALUE (tmp
)));
1990 if (nalternatives
+ 1 > MAX_RECOG_ALTERNATIVES
)
1992 error ("too many alternatives in `asm'");
1999 const char *constraint
2000 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tmp
)));
2002 if (n_occurrences (',', constraint
) != nalternatives
)
2004 error ("operand constraints for `asm' differ in number of alternatives");
2008 if (TREE_CHAIN (tmp
))
2009 tmp
= TREE_CHAIN (tmp
);
2011 tmp
= next
, next
= 0;
2018 /* A subroutine of expand_asm_operands. Check that all operand names
2019 are unique. Return true if so. We rely on the fact that these names
2020 are identifiers, and so have been canonicalized by get_identifier,
2021 so all we need are pointer comparisons. */
2024 check_unique_operand_names (outputs
, inputs
)
2025 tree outputs
, inputs
;
2029 for (i
= outputs
; i
; i
= TREE_CHAIN (i
))
2031 tree i_name
= TREE_PURPOSE (TREE_PURPOSE (i
));
2035 for (j
= TREE_CHAIN (i
); j
; j
= TREE_CHAIN (j
))
2036 if (i_name
== TREE_PURPOSE (TREE_PURPOSE (j
)))
2040 for (i
= inputs
; i
; i
= TREE_CHAIN (i
))
2042 tree i_name
= TREE_PURPOSE (TREE_PURPOSE (i
));
2046 for (j
= TREE_CHAIN (i
); j
; j
= TREE_CHAIN (j
))
2047 if (i_name
== TREE_PURPOSE (TREE_PURPOSE (j
)))
2049 for (j
= outputs
; j
; j
= TREE_CHAIN (j
))
2050 if (i_name
== TREE_PURPOSE (TREE_PURPOSE (j
)))
2057 error ("duplicate asm operand name '%s'",
2058 IDENTIFIER_POINTER (TREE_PURPOSE (TREE_PURPOSE (i
))));
2062 /* A subroutine of expand_asm_operands. Resolve the names of the operands
2063 in *POUTPUTS and *PINPUTS to numbers, and replace the name expansions in
2064 STRING and in the constraints to those numbers. */
2067 resolve_operand_names (string
, outputs
, inputs
, pconstraints
)
2069 tree outputs
, inputs
;
2070 const char **pconstraints
;
2072 char *buffer
= xstrdup (TREE_STRING_POINTER (string
));
2076 /* Assume that we will not need extra space to perform the substitution.
2077 This because we get to remove '[' and ']', which means we cannot have
2078 a problem until we have more than 999 operands. */
2081 while ((p
= strchr (p
, '%')) != NULL
)
2085 else if (ISALPHA (p
[1]) && p
[2] == '[')
2093 p
= resolve_operand_name_1 (p
, outputs
, inputs
);
2096 string
= build_string (strlen (buffer
), buffer
);
2099 /* Collect output constraints here because it's convenient.
2100 There should be no named operands here; this is verified
2101 in expand_asm_operand. */
2102 for (t
= outputs
; t
; t
= TREE_CHAIN (t
), pconstraints
++)
2103 *pconstraints
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t
)));
2105 /* Substitute [<name>] in input constraint strings. */
2106 for (t
= inputs
; t
; t
= TREE_CHAIN (t
), pconstraints
++)
2108 const char *c
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t
)));
2109 if (strchr (c
, '[') == NULL
)
2113 p
= buffer
= xstrdup (c
);
2114 while ((p
= strchr (p
, '[')) != NULL
)
2115 p
= resolve_operand_name_1 (p
, outputs
, inputs
);
2117 *pconstraints
= ggc_alloc_string (buffer
, -1);
2125 /* A subroutine of resolve_operand_names. P points to the '[' for a
2126 potential named operand of the form [<name>]. In place, replace
2127 the name and brackets with a number. Return a pointer to the
2128 balance of the string after substitution. */
2131 resolve_operand_name_1 (p
, outputs
, inputs
)
2133 tree outputs
, inputs
;
2140 /* Collect the operand name. */
2141 q
= strchr (p
, ']');
2144 error ("missing close brace for named operand");
2145 return strchr (p
, '\0');
2149 /* Resolve the name to a number. */
2150 for (op
= 0, t
= outputs
; t
; t
= TREE_CHAIN (t
), op
++)
2152 const char *c
= IDENTIFIER_POINTER (TREE_PURPOSE (TREE_PURPOSE (t
)));
2153 if (strncmp (c
, p
+ 1, len
) == 0 && c
[len
] == '\0')
2156 for (t
= inputs
; t
; t
= TREE_CHAIN (t
), op
++)
2158 const char *c
= IDENTIFIER_POINTER (TREE_PURPOSE (TREE_PURPOSE (t
)));
2159 if (strncmp (c
, p
+ 1, len
) == 0 && c
[len
] == '\0')
2164 error ("undefined named operand '%s'", p
+ 1);
2168 /* Replace the name with the number. Unfortunately, not all libraries
2169 get the return value of sprintf correct, so search for the end of the
2170 generated string by hand. */
2171 sprintf (p
, "%d", op
);
2172 p
= strchr (p
, '\0');
2174 /* Verify the no extra buffer space assumption. */
2178 /* Shift the rest of the buffer down to fill the gap. */
2179 memmove (p
, q
+ 1, strlen (q
+ 1) + 1);
2184 /* Generate RTL to evaluate the expression EXP
2185 and remember it in case this is the VALUE in a ({... VALUE; }) constr.
2186 Provided just for backward-compatibility. expand_expr_stmt_value()
2187 should be used for new code. */
2190 expand_expr_stmt (exp
)
2193 expand_expr_stmt_value (exp
, -1, 1);
2196 /* Generate RTL to evaluate the expression EXP. WANT_VALUE tells
2197 whether to (1) save the value of the expression, (0) discard it or
2198 (-1) use expr_stmts_for_value to tell. The use of -1 is
2199 deprecated, and retained only for backward compatibility. */
2202 expand_expr_stmt_value (exp
, want_value
, maybe_last
)
2204 int want_value
, maybe_last
;
2209 if (want_value
== -1)
2210 want_value
= expr_stmts_for_value
!= 0;
2212 /* If -W, warn about statements with no side effects,
2213 except for an explicit cast to void (e.g. for assert()), and
2214 except for last statement in ({...}) where they may be useful. */
2216 && (expr_stmts_for_value
== 0 || ! maybe_last
)
2217 && exp
!= error_mark_node
)
2219 if (! TREE_SIDE_EFFECTS (exp
))
2221 if ((extra_warnings
|| warn_unused_value
)
2222 && !(TREE_CODE (exp
) == CONVERT_EXPR
2223 && VOID_TYPE_P (TREE_TYPE (exp
))))
2224 warning_with_file_and_line (emit_filename
, emit_lineno
,
2225 "statement with no effect");
2227 else if (warn_unused_value
)
2228 warn_if_unused_value (exp
);
2231 /* If EXP is of function type and we are expanding statements for
2232 value, convert it to pointer-to-function. */
2233 if (want_value
&& TREE_CODE (TREE_TYPE (exp
)) == FUNCTION_TYPE
)
2234 exp
= build1 (ADDR_EXPR
, build_pointer_type (TREE_TYPE (exp
)), exp
);
2236 /* The call to `expand_expr' could cause last_expr_type and
2237 last_expr_value to get reset. Therefore, we set last_expr_value
2238 and last_expr_type *after* calling expand_expr. */
2239 value
= expand_expr (exp
, want_value
? NULL_RTX
: const0_rtx
,
2241 type
= TREE_TYPE (exp
);
2243 /* If all we do is reference a volatile value in memory,
2244 copy it to a register to be sure it is actually touched. */
2245 if (value
&& GET_CODE (value
) == MEM
&& TREE_THIS_VOLATILE (exp
))
2247 if (TYPE_MODE (type
) == VOIDmode
)
2249 else if (TYPE_MODE (type
) != BLKmode
)
2250 value
= copy_to_reg (value
);
2253 rtx lab
= gen_label_rtx ();
2255 /* Compare the value with itself to reference it. */
2256 emit_cmp_and_jump_insns (value
, value
, EQ
,
2257 expand_expr (TYPE_SIZE (type
),
2258 NULL_RTX
, VOIDmode
, 0),
2264 /* If this expression is part of a ({...}) and is in memory, we may have
2265 to preserve temporaries. */
2266 preserve_temp_slots (value
);
2268 /* Free any temporaries used to evaluate this expression. Any temporary
2269 used as a result of this expression will already have been preserved
2275 last_expr_value
= value
;
2276 last_expr_type
= type
;
2282 /* Warn if EXP contains any computations whose results are not used.
2283 Return 1 if a warning is printed; 0 otherwise. */
2286 warn_if_unused_value (exp
)
2289 if (TREE_USED (exp
))
2292 /* Don't warn about void constructs. This includes casting to void,
2293 void function calls, and statement expressions with a final cast
2295 if (VOID_TYPE_P (TREE_TYPE (exp
)))
2298 /* If this is an expression with side effects, don't warn. */
2299 if (TREE_SIDE_EFFECTS (exp
))
2302 switch (TREE_CODE (exp
))
2304 case PREINCREMENT_EXPR
:
2305 case POSTINCREMENT_EXPR
:
2306 case PREDECREMENT_EXPR
:
2307 case POSTDECREMENT_EXPR
:
2312 case METHOD_CALL_EXPR
:
2314 case TRY_CATCH_EXPR
:
2315 case WITH_CLEANUP_EXPR
:
2320 /* For a binding, warn if no side effect within it. */
2321 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2324 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2326 case TRUTH_ORIF_EXPR
:
2327 case TRUTH_ANDIF_EXPR
:
2328 /* In && or ||, warn if 2nd operand has no side effect. */
2329 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2332 if (TREE_NO_UNUSED_WARNING (exp
))
2334 if (warn_if_unused_value (TREE_OPERAND (exp
, 0)))
2336 /* Let people do `(foo (), 0)' without a warning. */
2337 if (TREE_CONSTANT (TREE_OPERAND (exp
, 1)))
2339 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
2343 case NON_LVALUE_EXPR
:
2344 /* Don't warn about conversions not explicit in the user's program. */
2345 if (TREE_NO_UNUSED_WARNING (exp
))
2347 /* Assignment to a cast usually results in a cast of a modify.
2348 Don't complain about that. There can be an arbitrary number of
2349 casts before the modify, so we must loop until we find the first
2350 non-cast expression and then test to see if that is a modify. */
2352 tree tem
= TREE_OPERAND (exp
, 0);
2354 while (TREE_CODE (tem
) == CONVERT_EXPR
|| TREE_CODE (tem
) == NOP_EXPR
)
2355 tem
= TREE_OPERAND (tem
, 0);
2357 if (TREE_CODE (tem
) == MODIFY_EXPR
|| TREE_CODE (tem
) == INIT_EXPR
2358 || TREE_CODE (tem
) == CALL_EXPR
)
2364 /* Don't warn about automatic dereferencing of references, since
2365 the user cannot control it. */
2366 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp
, 0))) == REFERENCE_TYPE
)
2367 return warn_if_unused_value (TREE_OPERAND (exp
, 0));
2371 /* Referencing a volatile value is a side effect, so don't warn. */
2373 || TREE_CODE_CLASS (TREE_CODE (exp
)) == 'r')
2374 && TREE_THIS_VOLATILE (exp
))
2377 /* If this is an expression which has no operands, there is no value
2378 to be unused. There are no such language-independent codes,
2379 but front ends may define such. */
2380 if (TREE_CODE_CLASS (TREE_CODE (exp
)) == 'e'
2381 && TREE_CODE_LENGTH (TREE_CODE (exp
)) == 0)
2385 warning_with_file_and_line (emit_filename
, emit_lineno
,
2386 "value computed is not used");
2391 /* Clear out the memory of the last expression evaluated. */
2399 /* Begin a statement which will return a value.
2400 Return the RTL_EXPR for this statement expr.
2401 The caller must save that value and pass it to expand_end_stmt_expr. */
2404 expand_start_stmt_expr ()
2408 /* Make the RTL_EXPR node temporary, not momentary,
2409 so that rtl_expr_chain doesn't become garbage. */
2410 t
= make_node (RTL_EXPR
);
2411 do_pending_stack_adjust ();
2412 start_sequence_for_rtl_expr (t
);
2414 expr_stmts_for_value
++;
2415 last_expr_value
= NULL_RTX
;
2419 /* Restore the previous state at the end of a statement that returns a value.
2420 Returns a tree node representing the statement's value and the
2421 insns to compute the value.
2423 The nodes of that expression have been freed by now, so we cannot use them.
2424 But we don't want to do that anyway; the expression has already been
2425 evaluated and now we just want to use the value. So generate a RTL_EXPR
2426 with the proper type and RTL value.
2428 If the last substatement was not an expression,
2429 return something with type `void'. */
2432 expand_end_stmt_expr (t
)
2437 if (! last_expr_value
|| ! last_expr_type
)
2439 last_expr_value
= const0_rtx
;
2440 last_expr_type
= void_type_node
;
2442 else if (GET_CODE (last_expr_value
) != REG
&& ! CONSTANT_P (last_expr_value
))
2443 /* Remove any possible QUEUED. */
2444 last_expr_value
= protect_from_queue (last_expr_value
, 0);
2448 TREE_TYPE (t
) = last_expr_type
;
2449 RTL_EXPR_RTL (t
) = last_expr_value
;
2450 RTL_EXPR_SEQUENCE (t
) = get_insns ();
2452 rtl_expr_chain
= tree_cons (NULL_TREE
, t
, rtl_expr_chain
);
2456 /* Don't consider deleting this expr or containing exprs at tree level. */
2457 TREE_SIDE_EFFECTS (t
) = 1;
2458 /* Propagate volatility of the actual RTL expr. */
2459 TREE_THIS_VOLATILE (t
) = volatile_refs_p (last_expr_value
);
2462 expr_stmts_for_value
--;
2467 /* Generate RTL for the start of an if-then. COND is the expression
2468 whose truth should be tested.
2470 If EXITFLAG is nonzero, this conditional is visible to
2471 `exit_something'. */
2474 expand_start_cond (cond
, exitflag
)
2478 struct nesting
*thiscond
= ALLOC_NESTING ();
2480 /* Make an entry on cond_stack for the cond we are entering. */
2482 thiscond
->next
= cond_stack
;
2483 thiscond
->all
= nesting_stack
;
2484 thiscond
->depth
= ++nesting_depth
;
2485 thiscond
->data
.cond
.next_label
= gen_label_rtx ();
2486 /* Before we encounter an `else', we don't need a separate exit label
2487 unless there are supposed to be exit statements
2488 to exit this conditional. */
2489 thiscond
->exit_label
= exitflag
? gen_label_rtx () : 0;
2490 thiscond
->data
.cond
.endif_label
= thiscond
->exit_label
;
2491 cond_stack
= thiscond
;
2492 nesting_stack
= thiscond
;
2494 do_jump (cond
, thiscond
->data
.cond
.next_label
, NULL_RTX
);
2497 /* Generate RTL between then-clause and the elseif-clause
2498 of an if-then-elseif-.... */
2501 expand_start_elseif (cond
)
2504 if (cond_stack
->data
.cond
.endif_label
== 0)
2505 cond_stack
->data
.cond
.endif_label
= gen_label_rtx ();
2506 emit_jump (cond_stack
->data
.cond
.endif_label
);
2507 emit_label (cond_stack
->data
.cond
.next_label
);
2508 cond_stack
->data
.cond
.next_label
= gen_label_rtx ();
2509 do_jump (cond
, cond_stack
->data
.cond
.next_label
, NULL_RTX
);
2512 /* Generate RTL between the then-clause and the else-clause
2513 of an if-then-else. */
2516 expand_start_else ()
2518 if (cond_stack
->data
.cond
.endif_label
== 0)
2519 cond_stack
->data
.cond
.endif_label
= gen_label_rtx ();
2521 emit_jump (cond_stack
->data
.cond
.endif_label
);
2522 emit_label (cond_stack
->data
.cond
.next_label
);
2523 cond_stack
->data
.cond
.next_label
= 0; /* No more _else or _elseif calls. */
2526 /* After calling expand_start_else, turn this "else" into an "else if"
2527 by providing another condition. */
2530 expand_elseif (cond
)
2533 cond_stack
->data
.cond
.next_label
= gen_label_rtx ();
2534 do_jump (cond
, cond_stack
->data
.cond
.next_label
, NULL_RTX
);
2537 /* Generate RTL for the end of an if-then.
2538 Pop the record for it off of cond_stack. */
2543 struct nesting
*thiscond
= cond_stack
;
2545 do_pending_stack_adjust ();
2546 if (thiscond
->data
.cond
.next_label
)
2547 emit_label (thiscond
->data
.cond
.next_label
);
2548 if (thiscond
->data
.cond
.endif_label
)
2549 emit_label (thiscond
->data
.cond
.endif_label
);
2551 POPSTACK (cond_stack
);
2555 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2556 loop should be exited by `exit_something'. This is a loop for which
2557 `expand_continue' will jump to the top of the loop.
2559 Make an entry on loop_stack to record the labels associated with
2563 expand_start_loop (exit_flag
)
2566 struct nesting
*thisloop
= ALLOC_NESTING ();
2568 /* Make an entry on loop_stack for the loop we are entering. */
2570 thisloop
->next
= loop_stack
;
2571 thisloop
->all
= nesting_stack
;
2572 thisloop
->depth
= ++nesting_depth
;
2573 thisloop
->data
.loop
.start_label
= gen_label_rtx ();
2574 thisloop
->data
.loop
.end_label
= gen_label_rtx ();
2575 thisloop
->data
.loop
.alt_end_label
= 0;
2576 thisloop
->data
.loop
.continue_label
= thisloop
->data
.loop
.start_label
;
2577 thisloop
->exit_label
= exit_flag
? thisloop
->data
.loop
.end_label
: 0;
2578 loop_stack
= thisloop
;
2579 nesting_stack
= thisloop
;
2581 do_pending_stack_adjust ();
2583 emit_note (NULL
, NOTE_INSN_LOOP_BEG
);
2584 emit_label (thisloop
->data
.loop
.start_label
);
2589 /* Like expand_start_loop but for a loop where the continuation point
2590 (for expand_continue_loop) will be specified explicitly. */
2593 expand_start_loop_continue_elsewhere (exit_flag
)
2596 struct nesting
*thisloop
= expand_start_loop (exit_flag
);
2597 loop_stack
->data
.loop
.continue_label
= gen_label_rtx ();
2601 /* Begin a null, aka do { } while (0) "loop". But since the contents
2602 of said loop can still contain a break, we must frob the loop nest. */
2605 expand_start_null_loop ()
2607 struct nesting
*thisloop
= ALLOC_NESTING ();
2609 /* Make an entry on loop_stack for the loop we are entering. */
2611 thisloop
->next
= loop_stack
;
2612 thisloop
->all
= nesting_stack
;
2613 thisloop
->depth
= ++nesting_depth
;
2614 thisloop
->data
.loop
.start_label
= emit_note (NULL
, NOTE_INSN_DELETED
);
2615 thisloop
->data
.loop
.end_label
= gen_label_rtx ();
2616 thisloop
->data
.loop
.alt_end_label
= NULL_RTX
;
2617 thisloop
->data
.loop
.continue_label
= thisloop
->data
.loop
.end_label
;
2618 thisloop
->exit_label
= thisloop
->data
.loop
.end_label
;
2619 loop_stack
= thisloop
;
2620 nesting_stack
= thisloop
;
2625 /* Specify the continuation point for a loop started with
2626 expand_start_loop_continue_elsewhere.
2627 Use this at the point in the code to which a continue statement
2631 expand_loop_continue_here ()
2633 do_pending_stack_adjust ();
2634 emit_note (NULL
, NOTE_INSN_LOOP_CONT
);
2635 emit_label (loop_stack
->data
.loop
.continue_label
);
2638 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2639 Pop the block off of loop_stack. */
2644 rtx start_label
= loop_stack
->data
.loop
.start_label
;
2646 int eh_regions
, debug_blocks
;
2648 /* Mark the continue-point at the top of the loop if none elsewhere. */
2649 if (start_label
== loop_stack
->data
.loop
.continue_label
)
2650 emit_note_before (NOTE_INSN_LOOP_CONT
, start_label
);
2652 do_pending_stack_adjust ();
2654 /* If the loop starts with a loop exit, roll that to the end where
2655 it will optimize together with the jump back.
2657 If the loop presently looks like this (in pseudo-C):
2661 if (test) goto end_label;
2667 transform it to look like:
2674 if (test) goto end_label;
2678 We rely on the presence of NOTE_INSN_LOOP_END_TOP_COND to mark
2679 the end of the entry condtional. Without this, our lexical scan
2680 can't tell the difference between an entry conditional and a
2681 body conditional that exits the loop. Mistaking the two means
2682 that we can misplace the NOTE_INSN_LOOP_CONT note, which can
2683 screw up loop unrolling.
2685 Things will be oh so much better when loop optimization is done
2686 off of a proper control flow graph... */
2688 /* Scan insns from the top of the loop looking for the END_TOP_COND note. */
2690 eh_regions
= debug_blocks
= 0;
2691 for (etc_note
= start_label
; etc_note
; etc_note
= NEXT_INSN (etc_note
))
2692 if (GET_CODE (etc_note
) == NOTE
)
2694 if (NOTE_LINE_NUMBER (etc_note
) == NOTE_INSN_LOOP_END_TOP_COND
)
2697 /* We must not walk into a nested loop. */
2698 else if (NOTE_LINE_NUMBER (etc_note
) == NOTE_INSN_LOOP_BEG
)
2700 etc_note
= NULL_RTX
;
2704 /* At the same time, scan for EH region notes, as we don't want
2705 to scrog region nesting. This shouldn't happen, but... */
2706 else if (NOTE_LINE_NUMBER (etc_note
) == NOTE_INSN_EH_REGION_BEG
)
2708 else if (NOTE_LINE_NUMBER (etc_note
) == NOTE_INSN_EH_REGION_END
)
2710 if (--eh_regions
< 0)
2711 /* We've come to the end of an EH region, but never saw the
2712 beginning of that region. That means that an EH region
2713 begins before the top of the loop, and ends in the middle
2714 of it. The existence of such a situation violates a basic
2715 assumption in this code, since that would imply that even
2716 when EH_REGIONS is zero, we might move code out of an
2717 exception region. */
2721 /* Likewise for debug scopes. In this case we'll either (1) move
2722 all of the notes if they are properly nested or (2) leave the
2723 notes alone and only rotate the loop at high optimization
2724 levels when we expect to scrog debug info. */
2725 else if (NOTE_LINE_NUMBER (etc_note
) == NOTE_INSN_BLOCK_BEG
)
2727 else if (NOTE_LINE_NUMBER (etc_note
) == NOTE_INSN_BLOCK_END
)
2734 && (debug_blocks
== 0 || optimize
>= 2)
2735 && NEXT_INSN (etc_note
) != NULL_RTX
2736 && ! any_condjump_p (get_last_insn ()))
2738 /* We found one. Move everything from START to ETC to the end
2739 of the loop, and add a jump from the top of the loop. */
2740 rtx top_label
= gen_label_rtx ();
2741 rtx start_move
= start_label
;
2743 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2744 then we want to move this note also. */
2745 if (GET_CODE (PREV_INSN (start_move
)) == NOTE
2746 && NOTE_LINE_NUMBER (PREV_INSN (start_move
)) == NOTE_INSN_LOOP_CONT
)
2747 start_move
= PREV_INSN (start_move
);
2749 emit_label_before (top_label
, start_move
);
2751 /* Actually move the insns. If the debug scopes are nested, we
2752 can move everything at once. Otherwise we have to move them
2753 one by one and squeeze out the block notes. */
2754 if (debug_blocks
== 0)
2755 reorder_insns (start_move
, etc_note
, get_last_insn ());
2758 rtx insn
, next_insn
;
2759 for (insn
= start_move
; insn
; insn
= next_insn
)
2761 /* Figure out which insn comes after this one. We have
2762 to do this before we move INSN. */
2763 next_insn
= (insn
== etc_note
? NULL
: NEXT_INSN (insn
));
2765 if (GET_CODE (insn
) == NOTE
2766 && (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_BEG
2767 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_END
))
2770 reorder_insns (insn
, insn
, get_last_insn ());
2774 /* Add the jump from the top of the loop. */
2775 emit_jump_insn_before (gen_jump (start_label
), top_label
);
2776 emit_barrier_before (top_label
);
2777 start_label
= top_label
;
2780 emit_jump (start_label
);
2781 emit_note (NULL
, NOTE_INSN_LOOP_END
);
2782 emit_label (loop_stack
->data
.loop
.end_label
);
2784 POPSTACK (loop_stack
);
2789 /* Finish a null loop, aka do { } while (0). */
2792 expand_end_null_loop ()
2794 do_pending_stack_adjust ();
2795 emit_label (loop_stack
->data
.loop
.end_label
);
2797 POPSTACK (loop_stack
);
2802 /* Generate a jump to the current loop's continue-point.
2803 This is usually the top of the loop, but may be specified
2804 explicitly elsewhere. If not currently inside a loop,
2805 return 0 and do nothing; caller will print an error message. */
2808 expand_continue_loop (whichloop
)
2809 struct nesting
*whichloop
;
2813 whichloop
= loop_stack
;
2816 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.continue_label
,
2821 /* Generate a jump to exit the current loop. If not currently inside a loop,
2822 return 0 and do nothing; caller will print an error message. */
2825 expand_exit_loop (whichloop
)
2826 struct nesting
*whichloop
;
2830 whichloop
= loop_stack
;
2833 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.end_label
, NULL_RTX
);
2837 /* Generate a conditional jump to exit the current loop if COND
2838 evaluates to zero. If not currently inside a loop,
2839 return 0 and do nothing; caller will print an error message. */
2842 expand_exit_loop_if_false (whichloop
, cond
)
2843 struct nesting
*whichloop
;
2846 rtx label
= gen_label_rtx ();
2851 whichloop
= loop_stack
;
2854 /* In order to handle fixups, we actually create a conditional jump
2855 around an unconditional branch to exit the loop. If fixups are
2856 necessary, they go before the unconditional branch. */
2858 do_jump (cond
, NULL_RTX
, label
);
2859 last_insn
= get_last_insn ();
2860 if (GET_CODE (last_insn
) == CODE_LABEL
)
2861 whichloop
->data
.loop
.alt_end_label
= last_insn
;
2862 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.end_label
,
2869 /* Like expand_exit_loop_if_false except also emit a note marking
2870 the end of the conditional. Should only be used immediately
2871 after expand_loop_start. */
2874 expand_exit_loop_top_cond (whichloop
, cond
)
2875 struct nesting
*whichloop
;
2878 if (! expand_exit_loop_if_false (whichloop
, cond
))
2881 emit_note (NULL
, NOTE_INSN_LOOP_END_TOP_COND
);
2885 /* Return nonzero if the loop nest is empty. Else return zero. */
2888 stmt_loop_nest_empty ()
2890 /* cfun->stmt can be NULL if we are building a call to get the
2891 EH context for a setjmp/longjmp EH target and the current
2892 function was a deferred inline function. */
2893 return (cfun
->stmt
== NULL
|| loop_stack
== NULL
);
2896 /* Return non-zero if we should preserve sub-expressions as separate
2897 pseudos. We never do so if we aren't optimizing. We always do so
2898 if -fexpensive-optimizations.
2900 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2901 the loop may still be a small one. */
2904 preserve_subexpressions_p ()
2908 if (flag_expensive_optimizations
)
2911 if (optimize
== 0 || cfun
== 0 || cfun
->stmt
== 0 || loop_stack
== 0)
2914 insn
= get_last_insn_anywhere ();
2917 && (INSN_UID (insn
) - INSN_UID (loop_stack
->data
.loop
.start_label
)
2918 < n_non_fixed_regs
* 3));
2922 /* Generate a jump to exit the current loop, conditional, binding contour
2923 or case statement. Not all such constructs are visible to this function,
2924 only those started with EXIT_FLAG nonzero. Individual languages use
2925 the EXIT_FLAG parameter to control which kinds of constructs you can
2928 If not currently inside anything that can be exited,
2929 return 0 and do nothing; caller will print an error message. */
2932 expand_exit_something ()
2936 for (n
= nesting_stack
; n
; n
= n
->all
)
2937 if (n
->exit_label
!= 0)
2939 expand_goto_internal (NULL_TREE
, n
->exit_label
, NULL_RTX
);
2946 /* Generate RTL to return from the current function, with no value.
2947 (That is, we do not do anything about returning any value.) */
2950 expand_null_return ()
2952 rtx last_insn
= get_last_insn ();
2954 /* If this function was declared to return a value, but we
2955 didn't, clobber the return registers so that they are not
2956 propagated live to the rest of the function. */
2957 clobber_return_register ();
2959 expand_null_return_1 (last_insn
);
2962 /* Generate RTL to return from the current function, with value VAL. */
2965 expand_value_return (val
)
2968 rtx last_insn
= get_last_insn ();
2969 rtx return_reg
= DECL_RTL (DECL_RESULT (current_function_decl
));
2971 /* Copy the value to the return location
2972 unless it's already there. */
2974 if (return_reg
!= val
)
2976 tree type
= TREE_TYPE (DECL_RESULT (current_function_decl
));
2977 #ifdef PROMOTE_FUNCTION_RETURN
2978 int unsignedp
= TREE_UNSIGNED (type
);
2979 enum machine_mode old_mode
2980 = DECL_MODE (DECL_RESULT (current_function_decl
));
2981 enum machine_mode mode
2982 = promote_mode (type
, old_mode
, &unsignedp
, 1);
2984 if (mode
!= old_mode
)
2985 val
= convert_modes (mode
, old_mode
, val
, unsignedp
);
2987 if (GET_CODE (return_reg
) == PARALLEL
)
2988 emit_group_load (return_reg
, val
, int_size_in_bytes (type
));
2990 emit_move_insn (return_reg
, val
);
2993 expand_null_return_1 (last_insn
);
2996 /* Output a return with no value. If LAST_INSN is nonzero,
2997 pretend that the return takes place after LAST_INSN. */
3000 expand_null_return_1 (last_insn
)
3003 rtx end_label
= cleanup_label
? cleanup_label
: return_label
;
3005 clear_pending_stack_adjust ();
3006 do_pending_stack_adjust ();
3010 end_label
= return_label
= gen_label_rtx ();
3011 expand_goto_internal (NULL_TREE
, end_label
, last_insn
);
3014 /* Generate RTL to evaluate the expression RETVAL and return it
3015 from the current function. */
3018 expand_return (retval
)
3021 /* If there are any cleanups to be performed, then they will
3022 be inserted following LAST_INSN. It is desirable
3023 that the last_insn, for such purposes, should be the
3024 last insn before computing the return value. Otherwise, cleanups
3025 which call functions can clobber the return value. */
3026 /* ??? rms: I think that is erroneous, because in C++ it would
3027 run destructors on variables that might be used in the subsequent
3028 computation of the return value. */
3034 /* If function wants no value, give it none. */
3035 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl
))) == VOID_TYPE
)
3037 expand_expr (retval
, NULL_RTX
, VOIDmode
, 0);
3039 expand_null_return ();
3043 if (retval
== error_mark_node
)
3045 /* Treat this like a return of no value from a function that
3047 expand_null_return ();
3050 else if (TREE_CODE (retval
) == RESULT_DECL
)
3051 retval_rhs
= retval
;
3052 else if ((TREE_CODE (retval
) == MODIFY_EXPR
|| TREE_CODE (retval
) == INIT_EXPR
)
3053 && TREE_CODE (TREE_OPERAND (retval
, 0)) == RESULT_DECL
)
3054 retval_rhs
= TREE_OPERAND (retval
, 1);
3055 else if (VOID_TYPE_P (TREE_TYPE (retval
)))
3056 /* Recognize tail-recursive call to void function. */
3057 retval_rhs
= retval
;
3059 retval_rhs
= NULL_TREE
;
3061 last_insn
= get_last_insn ();
3063 /* Distribute return down conditional expr if either of the sides
3064 may involve tail recursion (see test below). This enhances the number
3065 of tail recursions we see. Don't do this always since it can produce
3066 sub-optimal code in some cases and we distribute assignments into
3067 conditional expressions when it would help. */
3069 if (optimize
&& retval_rhs
!= 0
3070 && frame_offset
== 0
3071 && TREE_CODE (retval_rhs
) == COND_EXPR
3072 && (TREE_CODE (TREE_OPERAND (retval_rhs
, 1)) == CALL_EXPR
3073 || TREE_CODE (TREE_OPERAND (retval_rhs
, 2)) == CALL_EXPR
))
3075 rtx label
= gen_label_rtx ();
3078 do_jump (TREE_OPERAND (retval_rhs
, 0), label
, NULL_RTX
);
3079 start_cleanup_deferral ();
3080 expr
= build (MODIFY_EXPR
, TREE_TYPE (TREE_TYPE (current_function_decl
)),
3081 DECL_RESULT (current_function_decl
),
3082 TREE_OPERAND (retval_rhs
, 1));
3083 TREE_SIDE_EFFECTS (expr
) = 1;
3084 expand_return (expr
);
3087 expr
= build (MODIFY_EXPR
, TREE_TYPE (TREE_TYPE (current_function_decl
)),
3088 DECL_RESULT (current_function_decl
),
3089 TREE_OPERAND (retval_rhs
, 2));
3090 TREE_SIDE_EFFECTS (expr
) = 1;
3091 expand_return (expr
);
3092 end_cleanup_deferral ();
3096 result_rtl
= DECL_RTL (DECL_RESULT (current_function_decl
));
3098 /* If the result is an aggregate that is being returned in one (or more)
3099 registers, load the registers here. The compiler currently can't handle
3100 copying a BLKmode value into registers. We could put this code in a
3101 more general area (for use by everyone instead of just function
3102 call/return), but until this feature is generally usable it is kept here
3103 (and in expand_call). The value must go into a pseudo in case there
3104 are cleanups that will clobber the real return register. */
3107 && TYPE_MODE (TREE_TYPE (retval_rhs
)) == BLKmode
3108 && GET_CODE (result_rtl
) == REG
)
3111 unsigned HOST_WIDE_INT bitpos
, xbitpos
;
3112 unsigned HOST_WIDE_INT big_endian_correction
= 0;
3113 unsigned HOST_WIDE_INT bytes
3114 = int_size_in_bytes (TREE_TYPE (retval_rhs
));
3115 int n_regs
= (bytes
+ UNITS_PER_WORD
- 1) / UNITS_PER_WORD
;
3116 unsigned int bitsize
3117 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs
)), BITS_PER_WORD
);
3118 rtx
*result_pseudos
= (rtx
*) alloca (sizeof (rtx
) * n_regs
);
3119 rtx result_reg
, src
= NULL_RTX
, dst
= NULL_RTX
;
3120 rtx result_val
= expand_expr (retval_rhs
, NULL_RTX
, VOIDmode
, 0);
3121 enum machine_mode tmpmode
, result_reg_mode
;
3125 expand_null_return ();
3129 /* Structures whose size is not a multiple of a word are aligned
3130 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
3131 machine, this means we must skip the empty high order bytes when
3132 calculating the bit offset. */
3133 if (BYTES_BIG_ENDIAN
3134 && !FUNCTION_ARG_REG_LITTLE_ENDIAN
3135 && bytes
% UNITS_PER_WORD
)
3136 big_endian_correction
= (BITS_PER_WORD
- ((bytes
% UNITS_PER_WORD
)
3139 /* Copy the structure BITSIZE bits at a time. */
3140 for (bitpos
= 0, xbitpos
= big_endian_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 == big_endian_correction
3146 (the first time through). */
3147 if (xbitpos
% BITS_PER_WORD
== 0
3148 || xbitpos
== big_endian_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 /* Find the smallest integer mode large enough to hold the
3176 entire structure and use that mode instead of BLKmode
3177 on the USE insn for the return register. */
3178 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
3179 tmpmode
!= VOIDmode
;
3180 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
3181 /* Have we found a large enough mode? */
3182 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
3185 /* No suitable mode found. */
3186 if (tmpmode
== VOIDmode
)
3189 PUT_MODE (result_rtl
, tmpmode
);
3191 if (GET_MODE_SIZE (tmpmode
) < GET_MODE_SIZE (word_mode
))
3192 result_reg_mode
= word_mode
;
3194 result_reg_mode
= tmpmode
;
3195 result_reg
= gen_reg_rtx (result_reg_mode
);
3198 for (i
= 0; i
< n_regs
; i
++)
3199 emit_move_insn (operand_subword (result_reg
, i
, 0, result_reg_mode
),
3202 if (tmpmode
!= result_reg_mode
)
3203 result_reg
= gen_lowpart (tmpmode
, result_reg
);
3205 expand_value_return (result_reg
);
3207 else if (retval_rhs
!= 0
3208 && !VOID_TYPE_P (TREE_TYPE (retval_rhs
))
3209 && (GET_CODE (result_rtl
) == REG
3210 || (GET_CODE (result_rtl
) == PARALLEL
)))
3212 /* Calculate the return value into a temporary (usually a pseudo
3214 tree ot
= TREE_TYPE (DECL_RESULT (current_function_decl
));
3215 tree nt
= build_qualified_type (ot
, TYPE_QUALS (ot
) | TYPE_QUAL_CONST
);
3217 val
= assign_temp (nt
, 0, 0, 1);
3218 val
= expand_expr (retval_rhs
, val
, GET_MODE (val
), 0);
3219 val
= force_not_mem (val
);
3221 /* Return the calculated value, doing cleanups first. */
3222 expand_value_return (val
);
3226 /* No cleanups or no hard reg used;
3227 calculate value into hard return reg. */
3228 expand_expr (retval
, const0_rtx
, VOIDmode
, 0);
3230 expand_value_return (result_rtl
);
3234 /* Return 1 if the end of the generated RTX is not a barrier.
3235 This means code already compiled can drop through. */
3238 drop_through_at_end_p ()
3240 rtx insn
= get_last_insn ();
3241 while (insn
&& GET_CODE (insn
) == NOTE
)
3242 insn
= PREV_INSN (insn
);
3243 return insn
&& GET_CODE (insn
) != BARRIER
;
3246 /* Attempt to optimize a potential tail recursion call into a goto.
3247 ARGUMENTS are the arguments to a CALL_EXPR; LAST_INSN indicates
3248 where to place the jump to the tail recursion label.
3250 Return TRUE if the call was optimized into a goto. */
3253 optimize_tail_recursion (arguments
, last_insn
)
3257 /* Finish checking validity, and if valid emit code to set the
3258 argument variables for the new call. */
3259 if (tail_recursion_args (arguments
, DECL_ARGUMENTS (current_function_decl
)))
3261 if (tail_recursion_label
== 0)
3263 tail_recursion_label
= gen_label_rtx ();
3264 emit_label_after (tail_recursion_label
,
3265 tail_recursion_reentry
);
3268 expand_goto_internal (NULL_TREE
, tail_recursion_label
, last_insn
);
3275 /* Emit code to alter this function's formal parms for a tail-recursive call.
3276 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3277 FORMALS is the chain of decls of formals.
3278 Return 1 if this can be done;
3279 otherwise return 0 and do not emit any code. */
3282 tail_recursion_args (actuals
, formals
)
3283 tree actuals
, formals
;
3285 tree a
= actuals
, f
= formals
;
3289 /* Check that number and types of actuals are compatible
3290 with the formals. This is not always true in valid C code.
3291 Also check that no formal needs to be addressable
3292 and that all formals are scalars. */
3294 /* Also count the args. */
3296 for (a
= actuals
, f
= formals
, i
= 0; a
&& f
; a
= TREE_CHAIN (a
), f
= TREE_CHAIN (f
), i
++)
3298 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a
)))
3299 != TYPE_MAIN_VARIANT (TREE_TYPE (f
)))
3301 if (GET_CODE (DECL_RTL (f
)) != REG
|| DECL_MODE (f
) == BLKmode
)
3304 if (a
!= 0 || f
!= 0)
3307 /* Compute all the actuals. */
3309 argvec
= (rtx
*) alloca (i
* sizeof (rtx
));
3311 for (a
= actuals
, i
= 0; a
; a
= TREE_CHAIN (a
), i
++)
3312 argvec
[i
] = expand_expr (TREE_VALUE (a
), NULL_RTX
, VOIDmode
, 0);
3314 /* Find which actual values refer to current values of previous formals.
3315 Copy each of them now, before any formal is changed. */
3317 for (a
= actuals
, i
= 0; a
; a
= TREE_CHAIN (a
), i
++)
3321 for (f
= formals
, j
= 0; j
< i
; f
= TREE_CHAIN (f
), j
++)
3322 if (reg_mentioned_p (DECL_RTL (f
), argvec
[i
]))
3328 argvec
[i
] = copy_to_reg (argvec
[i
]);
3331 /* Store the values of the actuals into the formals. */
3333 for (f
= formals
, a
= actuals
, i
= 0; f
;
3334 f
= TREE_CHAIN (f
), a
= TREE_CHAIN (a
), i
++)
3336 if (GET_MODE (DECL_RTL (f
)) == GET_MODE (argvec
[i
]))
3337 emit_move_insn (DECL_RTL (f
), argvec
[i
]);
3339 convert_move (DECL_RTL (f
), argvec
[i
],
3340 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a
))));
3347 /* Generate the RTL code for entering a binding contour.
3348 The variables are declared one by one, by calls to `expand_decl'.
3350 FLAGS is a bitwise or of the following flags:
3352 1 - Nonzero if this construct should be visible to
3355 2 - Nonzero if this contour does not require a
3356 NOTE_INSN_BLOCK_BEG note. Virtually all calls from
3357 language-independent code should set this flag because they
3358 will not create corresponding BLOCK nodes. (There should be
3359 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
3360 and BLOCKs.) If this flag is set, MARK_ENDS should be zero
3361 when expand_end_bindings is called.
3363 If we are creating a NOTE_INSN_BLOCK_BEG note, a BLOCK may
3364 optionally be supplied. If so, it becomes the NOTE_BLOCK for the
3368 expand_start_bindings_and_block (flags
, block
)
3372 struct nesting
*thisblock
= ALLOC_NESTING ();
3374 int exit_flag
= ((flags
& 1) != 0);
3375 int block_flag
= ((flags
& 2) == 0);
3377 /* If a BLOCK is supplied, then the caller should be requesting a
3378 NOTE_INSN_BLOCK_BEG note. */
3379 if (!block_flag
&& block
)
3382 /* Create a note to mark the beginning of the block. */
3385 note
= emit_note (NULL
, NOTE_INSN_BLOCK_BEG
);
3386 NOTE_BLOCK (note
) = block
;
3389 note
= emit_note (NULL
, NOTE_INSN_DELETED
);
3391 /* Make an entry on block_stack for the block we are entering. */
3393 thisblock
->next
= block_stack
;
3394 thisblock
->all
= nesting_stack
;
3395 thisblock
->depth
= ++nesting_depth
;
3396 thisblock
->data
.block
.stack_level
= 0;
3397 thisblock
->data
.block
.cleanups
= 0;
3398 thisblock
->data
.block
.n_function_calls
= 0;
3399 thisblock
->data
.block
.exception_region
= 0;
3400 thisblock
->data
.block
.block_target_temp_slot_level
= target_temp_slot_level
;
3402 thisblock
->data
.block
.conditional_code
= 0;
3403 thisblock
->data
.block
.last_unconditional_cleanup
= note
;
3404 /* When we insert instructions after the last unconditional cleanup,
3405 we don't adjust last_insn. That means that a later add_insn will
3406 clobber the instructions we've just added. The easiest way to
3407 fix this is to just insert another instruction here, so that the
3408 instructions inserted after the last unconditional cleanup are
3409 never the last instruction. */
3410 emit_note (NULL
, NOTE_INSN_DELETED
);
3411 thisblock
->data
.block
.cleanup_ptr
= &thisblock
->data
.block
.cleanups
;
3414 && !(block_stack
->data
.block
.cleanups
== NULL_TREE
3415 && block_stack
->data
.block
.outer_cleanups
== NULL_TREE
))
3416 thisblock
->data
.block
.outer_cleanups
3417 = tree_cons (NULL_TREE
, block_stack
->data
.block
.cleanups
,
3418 block_stack
->data
.block
.outer_cleanups
);
3420 thisblock
->data
.block
.outer_cleanups
= 0;
3421 thisblock
->data
.block
.label_chain
= 0;
3422 thisblock
->data
.block
.innermost_stack_block
= stack_block_stack
;
3423 thisblock
->data
.block
.first_insn
= note
;
3424 thisblock
->data
.block
.block_start_count
= ++current_block_start_count
;
3425 thisblock
->exit_label
= exit_flag
? gen_label_rtx () : 0;
3426 block_stack
= thisblock
;
3427 nesting_stack
= thisblock
;
3429 /* Make a new level for allocating stack slots. */
3433 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3434 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3435 expand_expr are made. After we end the region, we know that all
3436 space for all temporaries that were created by TARGET_EXPRs will be
3437 destroyed and their space freed for reuse. */
3440 expand_start_target_temps ()
3442 /* This is so that even if the result is preserved, the space
3443 allocated will be freed, as we know that it is no longer in use. */
3446 /* Start a new binding layer that will keep track of all cleanup
3447 actions to be performed. */
3448 expand_start_bindings (2);
3450 target_temp_slot_level
= temp_slot_level
;
3454 expand_end_target_temps ()
3456 expand_end_bindings (NULL_TREE
, 0, 0);
3458 /* This is so that even if the result is preserved, the space
3459 allocated will be freed, as we know that it is no longer in use. */
3463 /* Given a pointer to a BLOCK node return non-zero if (and only if) the node
3464 in question represents the outermost pair of curly braces (i.e. the "body
3465 block") of a function or method.
3467 For any BLOCK node representing a "body block" of a function or method, the
3468 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
3469 represents the outermost (function) scope for the function or method (i.e.
3470 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
3471 *that* node in turn will point to the relevant FUNCTION_DECL node. */
3474 is_body_block (stmt
)
3477 if (TREE_CODE (stmt
) == BLOCK
)
3479 tree parent
= BLOCK_SUPERCONTEXT (stmt
);
3481 if (parent
&& TREE_CODE (parent
) == BLOCK
)
3483 tree grandparent
= BLOCK_SUPERCONTEXT (parent
);
3485 if (grandparent
&& TREE_CODE (grandparent
) == FUNCTION_DECL
)
3493 /* True if we are currently emitting insns in an area of output code
3494 that is controlled by a conditional expression. This is used by
3495 the cleanup handling code to generate conditional cleanup actions. */
3498 conditional_context ()
3500 return block_stack
&& block_stack
->data
.block
.conditional_code
;
3503 /* Return an opaque pointer to the current nesting level, so frontend code
3504 can check its own sanity. */
3507 current_nesting_level ()
3509 return cfun
? block_stack
: 0;
3512 /* Emit a handler label for a nonlocal goto handler.
3513 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3516 expand_nl_handler_label (slot
, before_insn
)
3517 rtx slot
, before_insn
;
3520 rtx handler_label
= gen_label_rtx ();
3522 /* Don't let cleanup_cfg delete the handler. */
3523 LABEL_PRESERVE_P (handler_label
) = 1;
3526 emit_move_insn (slot
, gen_rtx_LABEL_REF (Pmode
, handler_label
));
3527 insns
= get_insns ();
3529 emit_insns_before (insns
, before_insn
);
3531 emit_label (handler_label
);
3533 return handler_label
;
3536 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3539 expand_nl_goto_receiver ()
3541 #ifdef HAVE_nonlocal_goto
3542 if (! HAVE_nonlocal_goto
)
3544 /* First adjust our frame pointer to its actual value. It was
3545 previously set to the start of the virtual area corresponding to
3546 the stacked variables when we branched here and now needs to be
3547 adjusted to the actual hardware fp value.
3549 Assignments are to virtual registers are converted by
3550 instantiate_virtual_regs into the corresponding assignment
3551 to the underlying register (fp in this case) that makes
3552 the original assignment true.
3553 So the following insn will actually be
3554 decrementing fp by STARTING_FRAME_OFFSET. */
3555 emit_move_insn (virtual_stack_vars_rtx
, hard_frame_pointer_rtx
);
3557 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3558 if (fixed_regs
[ARG_POINTER_REGNUM
])
3560 #ifdef ELIMINABLE_REGS
3561 /* If the argument pointer can be eliminated in favor of the
3562 frame pointer, we don't need to restore it. We assume here
3563 that if such an elimination is present, it can always be used.
3564 This is the case on all known machines; if we don't make this
3565 assumption, we do unnecessary saving on many machines. */
3566 static const struct elims
{const int from
, to
;} elim_regs
[] = ELIMINABLE_REGS
;
3569 for (i
= 0; i
< ARRAY_SIZE (elim_regs
); i
++)
3570 if (elim_regs
[i
].from
== ARG_POINTER_REGNUM
3571 && elim_regs
[i
].to
== HARD_FRAME_POINTER_REGNUM
)
3574 if (i
== ARRAY_SIZE (elim_regs
))
3577 /* Now restore our arg pointer from the address at which it
3578 was saved in our stack frame. */
3579 emit_move_insn (virtual_incoming_args_rtx
,
3580 copy_to_reg (get_arg_pointer_save_area (cfun
)));
3585 #ifdef HAVE_nonlocal_goto_receiver
3586 if (HAVE_nonlocal_goto_receiver
)
3587 emit_insn (gen_nonlocal_goto_receiver ());
3591 /* Make handlers for nonlocal gotos taking place in the function calls in
3595 expand_nl_goto_receivers (thisblock
)
3596 struct nesting
*thisblock
;
3599 rtx afterward
= gen_label_rtx ();
3604 /* Record the handler address in the stack slot for that purpose,
3605 during this block, saving and restoring the outer value. */
3606 if (thisblock
->next
!= 0)
3607 for (slot
= nonlocal_goto_handler_slots
; slot
; slot
= XEXP (slot
, 1))
3609 rtx save_receiver
= gen_reg_rtx (Pmode
);
3610 emit_move_insn (XEXP (slot
, 0), save_receiver
);
3613 emit_move_insn (save_receiver
, XEXP (slot
, 0));
3614 insns
= get_insns ();
3616 emit_insns_before (insns
, thisblock
->data
.block
.first_insn
);
3619 /* Jump around the handlers; they run only when specially invoked. */
3620 emit_jump (afterward
);
3622 /* Make a separate handler for each label. */
3623 link
= nonlocal_labels
;
3624 slot
= nonlocal_goto_handler_slots
;
3625 label_list
= NULL_RTX
;
3626 for (; link
; link
= TREE_CHAIN (link
), slot
= XEXP (slot
, 1))
3627 /* Skip any labels we shouldn't be able to jump to from here,
3628 we generate one special handler for all of them below which just calls
3630 if (! DECL_TOO_LATE (TREE_VALUE (link
)))
3633 lab
= expand_nl_handler_label (XEXP (slot
, 0),
3634 thisblock
->data
.block
.first_insn
);
3635 label_list
= gen_rtx_EXPR_LIST (VOIDmode
, lab
, label_list
);
3637 expand_nl_goto_receiver ();
3639 /* Jump to the "real" nonlocal label. */
3640 expand_goto (TREE_VALUE (link
));
3643 /* A second pass over all nonlocal labels; this time we handle those
3644 we should not be able to jump to at this point. */
3645 link
= nonlocal_labels
;
3646 slot
= nonlocal_goto_handler_slots
;
3648 for (; link
; link
= TREE_CHAIN (link
), slot
= XEXP (slot
, 1))
3649 if (DECL_TOO_LATE (TREE_VALUE (link
)))
3652 lab
= expand_nl_handler_label (XEXP (slot
, 0),
3653 thisblock
->data
.block
.first_insn
);
3654 label_list
= gen_rtx_EXPR_LIST (VOIDmode
, lab
, label_list
);
3660 expand_nl_goto_receiver ();
3661 emit_library_call (gen_rtx_SYMBOL_REF (Pmode
, "abort"), LCT_NORETURN
,
3666 nonlocal_goto_handler_labels
= label_list
;
3667 emit_label (afterward
);
3670 /* Warn about any unused VARS (which may contain nodes other than
3671 VAR_DECLs, but such nodes are ignored). The nodes are connected
3672 via the TREE_CHAIN field. */
3675 warn_about_unused_variables (vars
)
3680 if (warn_unused_variable
)
3681 for (decl
= vars
; decl
; decl
= TREE_CHAIN (decl
))
3682 if (TREE_CODE (decl
) == VAR_DECL
3683 && ! TREE_USED (decl
)
3684 && ! DECL_IN_SYSTEM_HEADER (decl
)
3685 && DECL_NAME (decl
) && ! DECL_ARTIFICIAL (decl
))
3686 warning_with_decl (decl
, "unused variable `%s'");
3689 /* Generate RTL code to terminate a binding contour.
3691 VARS is the chain of VAR_DECL nodes for the variables bound in this
3692 contour. There may actually be other nodes in this chain, but any
3693 nodes other than VAR_DECLS are ignored.
3695 MARK_ENDS is nonzero if we should put a note at the beginning
3696 and end of this binding contour.
3698 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3699 (That is true automatically if the contour has a saved stack level.) */
3702 expand_end_bindings (vars
, mark_ends
, dont_jump_in
)
3707 struct nesting
*thisblock
= block_stack
;
3709 /* If any of the variables in this scope were not used, warn the
3711 warn_about_unused_variables (vars
);
3713 if (thisblock
->exit_label
)
3715 do_pending_stack_adjust ();
3716 emit_label (thisblock
->exit_label
);
3719 /* If necessary, make handlers for nonlocal gotos taking
3720 place in the function calls in this block. */
3721 if (function_call_count
!= thisblock
->data
.block
.n_function_calls
3723 /* Make handler for outermost block
3724 if there were any nonlocal gotos to this function. */
3725 && (thisblock
->next
== 0 ? current_function_has_nonlocal_label
3726 /* Make handler for inner block if it has something
3727 special to do when you jump out of it. */
3728 : (thisblock
->data
.block
.cleanups
!= 0
3729 || thisblock
->data
.block
.stack_level
!= 0)))
3730 expand_nl_goto_receivers (thisblock
);
3732 /* Don't allow jumping into a block that has a stack level.
3733 Cleanups are allowed, though. */
3735 || thisblock
->data
.block
.stack_level
!= 0)
3737 struct label_chain
*chain
;
3739 /* Any labels in this block are no longer valid to go to.
3740 Mark them to cause an error message. */
3741 for (chain
= thisblock
->data
.block
.label_chain
; chain
; chain
= chain
->next
)
3743 DECL_TOO_LATE (chain
->label
) = 1;
3744 /* If any goto without a fixup came to this label,
3745 that must be an error, because gotos without fixups
3746 come from outside all saved stack-levels. */
3747 if (TREE_ADDRESSABLE (chain
->label
))
3748 error_with_decl (chain
->label
,
3749 "label `%s' used before containing binding contour");
3753 /* Restore stack level in effect before the block
3754 (only if variable-size objects allocated). */
3755 /* Perform any cleanups associated with the block. */
3757 if (thisblock
->data
.block
.stack_level
!= 0
3758 || thisblock
->data
.block
.cleanups
!= 0)
3763 /* Don't let cleanups affect ({...}) constructs. */
3764 int old_expr_stmts_for_value
= expr_stmts_for_value
;
3765 rtx old_last_expr_value
= last_expr_value
;
3766 tree old_last_expr_type
= last_expr_type
;
3767 expr_stmts_for_value
= 0;
3769 /* Only clean up here if this point can actually be reached. */
3770 insn
= get_last_insn ();
3771 if (GET_CODE (insn
) == NOTE
)
3772 insn
= prev_nonnote_insn (insn
);
3773 reachable
= (! insn
|| GET_CODE (insn
) != BARRIER
);
3775 /* Do the cleanups. */
3776 expand_cleanups (thisblock
->data
.block
.cleanups
, NULL_TREE
, 0, reachable
);
3778 do_pending_stack_adjust ();
3780 expr_stmts_for_value
= old_expr_stmts_for_value
;
3781 last_expr_value
= old_last_expr_value
;
3782 last_expr_type
= old_last_expr_type
;
3784 /* Restore the stack level. */
3786 if (reachable
&& thisblock
->data
.block
.stack_level
!= 0)
3788 emit_stack_restore (thisblock
->next
? SAVE_BLOCK
: SAVE_FUNCTION
,
3789 thisblock
->data
.block
.stack_level
, NULL_RTX
);
3790 if (nonlocal_goto_handler_slots
!= 0)
3791 emit_stack_save (SAVE_NONLOCAL
, &nonlocal_goto_stack_level
,
3795 /* Any gotos out of this block must also do these things.
3796 Also report any gotos with fixups that came to labels in this
3798 fixup_gotos (thisblock
,
3799 thisblock
->data
.block
.stack_level
,
3800 thisblock
->data
.block
.cleanups
,
3801 thisblock
->data
.block
.first_insn
,
3805 /* Mark the beginning and end of the scope if requested.
3806 We do this now, after running cleanups on the variables
3807 just going out of scope, so they are in scope for their cleanups. */
3811 rtx note
= emit_note (NULL
, NOTE_INSN_BLOCK_END
);
3812 NOTE_BLOCK (note
) = NOTE_BLOCK (thisblock
->data
.block
.first_insn
);
3815 /* Get rid of the beginning-mark if we don't make an end-mark. */
3816 NOTE_LINE_NUMBER (thisblock
->data
.block
.first_insn
) = NOTE_INSN_DELETED
;
3818 /* Restore the temporary level of TARGET_EXPRs. */
3819 target_temp_slot_level
= thisblock
->data
.block
.block_target_temp_slot_level
;
3821 /* Restore block_stack level for containing block. */
3823 stack_block_stack
= thisblock
->data
.block
.innermost_stack_block
;
3824 POPSTACK (block_stack
);
3826 /* Pop the stack slot nesting and free any slots at this level. */
3830 /* Generate code to save the stack pointer at the start of the current block
3831 and set up to restore it on exit. */
3834 save_stack_pointer ()
3836 struct nesting
*thisblock
= block_stack
;
3838 if (thisblock
->data
.block
.stack_level
== 0)
3840 emit_stack_save (thisblock
->next
? SAVE_BLOCK
: SAVE_FUNCTION
,
3841 &thisblock
->data
.block
.stack_level
,
3842 thisblock
->data
.block
.first_insn
);
3843 stack_block_stack
= thisblock
;
3847 /* Generate RTL for the automatic variable declaration DECL.
3848 (Other kinds of declarations are simply ignored if seen here.) */
3854 struct nesting
*thisblock
;
3857 type
= TREE_TYPE (decl
);
3859 /* For a CONST_DECL, set mode, alignment, and sizes from those of the
3860 type in case this node is used in a reference. */
3861 if (TREE_CODE (decl
) == CONST_DECL
)
3863 DECL_MODE (decl
) = TYPE_MODE (type
);
3864 DECL_ALIGN (decl
) = TYPE_ALIGN (type
);
3865 DECL_SIZE (decl
) = TYPE_SIZE (type
);
3866 DECL_SIZE_UNIT (decl
) = TYPE_SIZE_UNIT (type
);
3870 /* Otherwise, only automatic variables need any expansion done. Static and
3871 external variables, and external functions, will be handled by
3872 `assemble_variable' (called from finish_decl). TYPE_DECL requires
3873 nothing. PARM_DECLs are handled in `assign_parms'. */
3874 if (TREE_CODE (decl
) != VAR_DECL
)
3877 if (TREE_STATIC (decl
) || DECL_EXTERNAL (decl
))
3880 thisblock
= block_stack
;
3882 /* Create the RTL representation for the variable. */
3884 if (type
== error_mark_node
)
3885 SET_DECL_RTL (decl
, gen_rtx_MEM (BLKmode
, const0_rtx
));
3887 else if (DECL_SIZE (decl
) == 0)
3888 /* Variable with incomplete type. */
3891 if (DECL_INITIAL (decl
) == 0)
3892 /* Error message was already done; now avoid a crash. */
3893 x
= gen_rtx_MEM (BLKmode
, const0_rtx
);
3895 /* An initializer is going to decide the size of this array.
3896 Until we know the size, represent its address with a reg. */
3897 x
= gen_rtx_MEM (BLKmode
, gen_reg_rtx (Pmode
));
3899 set_mem_attributes (x
, decl
, 1);
3900 SET_DECL_RTL (decl
, x
);
3902 else if (DECL_MODE (decl
) != BLKmode
3903 /* If -ffloat-store, don't put explicit float vars
3905 && !(flag_float_store
3906 && TREE_CODE (type
) == REAL_TYPE
)
3907 && ! TREE_THIS_VOLATILE (decl
)
3908 && (DECL_REGISTER (decl
) || optimize
))
3910 /* Automatic variable that can go in a register. */
3911 int unsignedp
= TREE_UNSIGNED (type
);
3912 enum machine_mode reg_mode
3913 = promote_mode (type
, DECL_MODE (decl
), &unsignedp
, 0);
3915 SET_DECL_RTL (decl
, gen_reg_rtx (reg_mode
));
3917 if (GET_CODE (DECL_RTL (decl
)) == REG
)
3918 REGNO_DECL (REGNO (DECL_RTL (decl
))) = decl
;
3919 else if (GET_CODE (DECL_RTL (decl
)) == CONCAT
)
3921 REGNO_DECL (REGNO (XEXP (DECL_RTL (decl
), 0))) = decl
;
3922 REGNO_DECL (REGNO (XEXP (DECL_RTL (decl
), 1))) = decl
;
3925 mark_user_reg (DECL_RTL (decl
));
3927 if (POINTER_TYPE_P (type
))
3928 mark_reg_pointer (DECL_RTL (decl
),
3929 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl
))));
3931 maybe_set_unchanging (DECL_RTL (decl
), decl
);
3933 /* If something wants our address, try to use ADDRESSOF. */
3934 if (TREE_ADDRESSABLE (decl
))
3935 put_var_into_stack (decl
);
3938 else if (TREE_CODE (DECL_SIZE_UNIT (decl
)) == INTEGER_CST
3939 && ! (flag_stack_check
&& ! STACK_CHECK_BUILTIN
3940 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl
),
3941 STACK_CHECK_MAX_VAR_SIZE
)))
3943 /* Variable of fixed size that goes on the stack. */
3948 /* If we previously made RTL for this decl, it must be an array
3949 whose size was determined by the initializer.
3950 The old address was a register; set that register now
3951 to the proper address. */
3952 if (DECL_RTL_SET_P (decl
))
3954 if (GET_CODE (DECL_RTL (decl
)) != MEM
3955 || GET_CODE (XEXP (DECL_RTL (decl
), 0)) != REG
)
3957 oldaddr
= XEXP (DECL_RTL (decl
), 0);
3960 /* Set alignment we actually gave this decl. */
3961 DECL_ALIGN (decl
) = (DECL_MODE (decl
) == BLKmode
? BIGGEST_ALIGNMENT
3962 : GET_MODE_BITSIZE (DECL_MODE (decl
)));
3963 DECL_USER_ALIGN (decl
) = 0;
3965 x
= assign_temp (TREE_TYPE (decl
), 1, 1, 1);
3966 set_mem_attributes (x
, decl
, 1);
3967 SET_DECL_RTL (decl
, x
);
3971 addr
= force_operand (XEXP (DECL_RTL (decl
), 0), oldaddr
);
3972 if (addr
!= oldaddr
)
3973 emit_move_insn (oldaddr
, addr
);
3977 /* Dynamic-size object: must push space on the stack. */
3979 rtx address
, size
, x
;
3981 /* Record the stack pointer on entry to block, if have
3982 not already done so. */
3983 do_pending_stack_adjust ();
3984 save_stack_pointer ();
3986 /* In function-at-a-time mode, variable_size doesn't expand this,
3988 if (TREE_CODE (type
) == ARRAY_TYPE
&& TYPE_DOMAIN (type
))
3989 expand_expr (TYPE_MAX_VALUE (TYPE_DOMAIN (type
)),
3990 const0_rtx
, VOIDmode
, 0);
3992 /* Compute the variable's size, in bytes. */
3993 size
= expand_expr (DECL_SIZE_UNIT (decl
), NULL_RTX
, VOIDmode
, 0);
3996 /* Allocate space on the stack for the variable. Note that
3997 DECL_ALIGN says how the variable is to be aligned and we
3998 cannot use it to conclude anything about the alignment of
4000 address
= allocate_dynamic_stack_space (size
, NULL_RTX
,
4001 TYPE_ALIGN (TREE_TYPE (decl
)));
4003 /* Reference the variable indirect through that rtx. */
4004 x
= gen_rtx_MEM (DECL_MODE (decl
), address
);
4005 set_mem_attributes (x
, decl
, 1);
4006 SET_DECL_RTL (decl
, x
);
4009 /* Indicate the alignment we actually gave this variable. */
4010 #ifdef STACK_BOUNDARY
4011 DECL_ALIGN (decl
) = STACK_BOUNDARY
;
4013 DECL_ALIGN (decl
) = BIGGEST_ALIGNMENT
;
4015 DECL_USER_ALIGN (decl
) = 0;
4019 /* Emit code to perform the initialization of a declaration DECL. */
4022 expand_decl_init (decl
)
4025 int was_used
= TREE_USED (decl
);
4027 /* If this is a CONST_DECL, we don't have to generate any code. Likewise
4028 for static decls. */
4029 if (TREE_CODE (decl
) == CONST_DECL
4030 || TREE_STATIC (decl
))
4033 /* Compute and store the initial value now. */
4035 if (DECL_INITIAL (decl
) == error_mark_node
)
4037 enum tree_code code
= TREE_CODE (TREE_TYPE (decl
));
4039 if (code
== INTEGER_TYPE
|| code
== REAL_TYPE
|| code
== ENUMERAL_TYPE
4040 || code
== POINTER_TYPE
|| code
== REFERENCE_TYPE
)
4041 expand_assignment (decl
, convert (TREE_TYPE (decl
), integer_zero_node
),
4045 else if (DECL_INITIAL (decl
) && TREE_CODE (DECL_INITIAL (decl
)) != TREE_LIST
)
4047 emit_line_note (DECL_SOURCE_FILE (decl
), DECL_SOURCE_LINE (decl
));
4048 expand_assignment (decl
, DECL_INITIAL (decl
), 0, 0);
4052 /* Don't let the initialization count as "using" the variable. */
4053 TREE_USED (decl
) = was_used
;
4055 /* Free any temporaries we made while initializing the decl. */
4056 preserve_temp_slots (NULL_RTX
);
4060 /* CLEANUP is an expression to be executed at exit from this binding contour;
4061 for example, in C++, it might call the destructor for this variable.
4063 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
4064 CLEANUP multiple times, and have the correct semantics. This
4065 happens in exception handling, for gotos, returns, breaks that
4066 leave the current scope.
4068 If CLEANUP is nonzero and DECL is zero, we record a cleanup
4069 that is not associated with any particular variable. */
4072 expand_decl_cleanup (decl
, cleanup
)
4075 struct nesting
*thisblock
;
4077 /* Error if we are not in any block. */
4078 if (cfun
== 0 || block_stack
== 0)
4081 thisblock
= block_stack
;
4083 /* Record the cleanup if there is one. */
4089 tree
*cleanups
= &thisblock
->data
.block
.cleanups
;
4090 int cond_context
= conditional_context ();
4094 rtx flag
= gen_reg_rtx (word_mode
);
4099 emit_move_insn (flag
, const0_rtx
);
4100 set_flag_0
= get_insns ();
4103 thisblock
->data
.block
.last_unconditional_cleanup
4104 = emit_insns_after (set_flag_0
,
4105 thisblock
->data
.block
.last_unconditional_cleanup
);
4107 emit_move_insn (flag
, const1_rtx
);
4109 cond
= build_decl (VAR_DECL
, NULL_TREE
, type_for_mode (word_mode
, 1));
4110 SET_DECL_RTL (cond
, flag
);
4112 /* Conditionalize the cleanup. */
4113 cleanup
= build (COND_EXPR
, void_type_node
,
4114 truthvalue_conversion (cond
),
4115 cleanup
, integer_zero_node
);
4116 cleanup
= fold (cleanup
);
4118 cleanups
= thisblock
->data
.block
.cleanup_ptr
;
4121 cleanup
= unsave_expr (cleanup
);
4123 t
= *cleanups
= tree_cons (decl
, cleanup
, *cleanups
);
4126 /* If this block has a cleanup, it belongs in stack_block_stack. */
4127 stack_block_stack
= thisblock
;
4134 if (! using_eh_for_cleanups_p
)
4135 TREE_ADDRESSABLE (t
) = 1;
4137 expand_eh_region_start ();
4144 thisblock
->data
.block
.last_unconditional_cleanup
4145 = emit_insns_after (seq
,
4146 thisblock
->data
.block
.last_unconditional_cleanup
);
4150 thisblock
->data
.block
.last_unconditional_cleanup
4152 /* When we insert instructions after the last unconditional cleanup,
4153 we don't adjust last_insn. That means that a later add_insn will
4154 clobber the instructions we've just added. The easiest way to
4155 fix this is to just insert another instruction here, so that the
4156 instructions inserted after the last unconditional cleanup are
4157 never the last instruction. */
4158 emit_note (NULL
, NOTE_INSN_DELETED
);
4159 thisblock
->data
.block
.cleanup_ptr
= &thisblock
->data
.block
.cleanups
;
4165 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4166 DECL_ELTS is the list of elements that belong to DECL's type.
4167 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4170 expand_anon_union_decl (decl
, cleanup
, decl_elts
)
4171 tree decl
, cleanup
, decl_elts
;
4173 struct nesting
*thisblock
= cfun
== 0 ? 0 : block_stack
;
4177 /* If any of the elements are addressable, so is the entire union. */
4178 for (t
= decl_elts
; t
; t
= TREE_CHAIN (t
))
4179 if (TREE_ADDRESSABLE (TREE_VALUE (t
)))
4181 TREE_ADDRESSABLE (decl
) = 1;
4186 expand_decl_cleanup (decl
, cleanup
);
4187 x
= DECL_RTL (decl
);
4189 /* Go through the elements, assigning RTL to each. */
4190 for (t
= decl_elts
; t
; t
= TREE_CHAIN (t
))
4192 tree decl_elt
= TREE_VALUE (t
);
4193 tree cleanup_elt
= TREE_PURPOSE (t
);
4194 enum machine_mode mode
= TYPE_MODE (TREE_TYPE (decl_elt
));
4196 /* Propagate the union's alignment to the elements. */
4197 DECL_ALIGN (decl_elt
) = DECL_ALIGN (decl
);
4198 DECL_USER_ALIGN (decl_elt
) = DECL_USER_ALIGN (decl
);
4200 /* If the element has BLKmode and the union doesn't, the union is
4201 aligned such that the element doesn't need to have BLKmode, so
4202 change the element's mode to the appropriate one for its size. */
4203 if (mode
== BLKmode
&& DECL_MODE (decl
) != BLKmode
)
4204 DECL_MODE (decl_elt
) = mode
4205 = mode_for_size_tree (DECL_SIZE (decl_elt
), MODE_INT
, 1);
4207 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4208 instead create a new MEM rtx with the proper mode. */
4209 if (GET_CODE (x
) == MEM
)
4211 if (mode
== GET_MODE (x
))
4212 SET_DECL_RTL (decl_elt
, x
);
4214 SET_DECL_RTL (decl_elt
, adjust_address_nv (x
, mode
, 0));
4216 else if (GET_CODE (x
) == REG
)
4218 if (mode
== GET_MODE (x
))
4219 SET_DECL_RTL (decl_elt
, x
);
4221 SET_DECL_RTL (decl_elt
, gen_lowpart_SUBREG (mode
, x
));
4226 /* Record the cleanup if there is one. */
4229 thisblock
->data
.block
.cleanups
4230 = tree_cons (decl_elt
, cleanup_elt
,
4231 thisblock
->data
.block
.cleanups
);
4235 /* Expand a list of cleanups LIST.
4236 Elements may be expressions or may be nested lists.
4238 If DONT_DO is nonnull, then any list-element
4239 whose TREE_PURPOSE matches DONT_DO is omitted.
4240 This is sometimes used to avoid a cleanup associated with
4241 a value that is being returned out of the scope.
4243 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
4244 goto and handle protection regions specially in that case.
4246 If REACHABLE, we emit code, otherwise just inform the exception handling
4247 code about this finalization. */
4250 expand_cleanups (list
, dont_do
, in_fixup
, reachable
)
4257 for (tail
= list
; tail
; tail
= TREE_CHAIN (tail
))
4258 if (dont_do
== 0 || TREE_PURPOSE (tail
) != dont_do
)
4260 if (TREE_CODE (TREE_VALUE (tail
)) == TREE_LIST
)
4261 expand_cleanups (TREE_VALUE (tail
), dont_do
, in_fixup
, reachable
);
4264 if (! in_fixup
&& using_eh_for_cleanups_p
)
4265 expand_eh_region_end_cleanup (TREE_VALUE (tail
));
4269 /* Cleanups may be run multiple times. For example,
4270 when exiting a binding contour, we expand the
4271 cleanups associated with that contour. When a goto
4272 within that binding contour has a target outside that
4273 contour, it will expand all cleanups from its scope to
4274 the target. Though the cleanups are expanded multiple
4275 times, the control paths are non-overlapping so the
4276 cleanups will not be executed twice. */
4278 /* We may need to protect from outer cleanups. */
4279 if (in_fixup
&& using_eh_for_cleanups_p
)
4281 expand_eh_region_start ();
4283 expand_expr (TREE_VALUE (tail
), const0_rtx
, VOIDmode
, 0);
4285 expand_eh_region_end_fixup (TREE_VALUE (tail
));
4288 expand_expr (TREE_VALUE (tail
), const0_rtx
, VOIDmode
, 0);
4296 /* Mark when the context we are emitting RTL for as a conditional
4297 context, so that any cleanup actions we register with
4298 expand_decl_init will be properly conditionalized when those
4299 cleanup actions are later performed. Must be called before any
4300 expression (tree) is expanded that is within a conditional context. */
4303 start_cleanup_deferral ()
4305 /* block_stack can be NULL if we are inside the parameter list. It is
4306 OK to do nothing, because cleanups aren't possible here. */
4308 ++block_stack
->data
.block
.conditional_code
;
4311 /* Mark the end of a conditional region of code. Because cleanup
4312 deferrals may be nested, we may still be in a conditional region
4313 after we end the currently deferred cleanups, only after we end all
4314 deferred cleanups, are we back in unconditional code. */
4317 end_cleanup_deferral ()
4319 /* block_stack can be NULL if we are inside the parameter list. It is
4320 OK to do nothing, because cleanups aren't possible here. */
4322 --block_stack
->data
.block
.conditional_code
;
4325 /* Move all cleanups from the current block_stack
4326 to the containing block_stack, where they are assumed to
4327 have been created. If anything can cause a temporary to
4328 be created, but not expanded for more than one level of
4329 block_stacks, then this code will have to change. */
4334 struct nesting
*block
= block_stack
;
4335 struct nesting
*outer
= block
->next
;
4337 outer
->data
.block
.cleanups
4338 = chainon (block
->data
.block
.cleanups
,
4339 outer
->data
.block
.cleanups
);
4340 block
->data
.block
.cleanups
= 0;
4344 last_cleanup_this_contour ()
4346 if (block_stack
== 0)
4349 return block_stack
->data
.block
.cleanups
;
4352 /* Return 1 if there are any pending cleanups at this point.
4353 If THIS_CONTOUR is nonzero, check the current contour as well.
4354 Otherwise, look only at the contours that enclose this one. */
4357 any_pending_cleanups (this_contour
)
4360 struct nesting
*block
;
4362 if (cfun
== NULL
|| cfun
->stmt
== NULL
|| block_stack
== 0)
4365 if (this_contour
&& block_stack
->data
.block
.cleanups
!= NULL
)
4367 if (block_stack
->data
.block
.cleanups
== 0
4368 && block_stack
->data
.block
.outer_cleanups
== 0)
4371 for (block
= block_stack
->next
; block
; block
= block
->next
)
4372 if (block
->data
.block
.cleanups
!= 0)
4378 /* Enter a case (Pascal) or switch (C) statement.
4379 Push a block onto case_stack and nesting_stack
4380 to accumulate the case-labels that are seen
4381 and to record the labels generated for the statement.
4383 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4384 Otherwise, this construct is transparent for `exit_something'.
4386 EXPR is the index-expression to be dispatched on.
4387 TYPE is its nominal type. We could simply convert EXPR to this type,
4388 but instead we take short cuts. */
4391 expand_start_case (exit_flag
, expr
, type
, printname
)
4395 const char *printname
;
4397 struct nesting
*thiscase
= ALLOC_NESTING ();
4399 /* Make an entry on case_stack for the case we are entering. */
4401 thiscase
->next
= case_stack
;
4402 thiscase
->all
= nesting_stack
;
4403 thiscase
->depth
= ++nesting_depth
;
4404 thiscase
->exit_label
= exit_flag
? gen_label_rtx () : 0;
4405 thiscase
->data
.case_stmt
.case_list
= 0;
4406 thiscase
->data
.case_stmt
.index_expr
= expr
;
4407 thiscase
->data
.case_stmt
.nominal_type
= type
;
4408 thiscase
->data
.case_stmt
.default_label
= 0;
4409 thiscase
->data
.case_stmt
.printname
= printname
;
4410 thiscase
->data
.case_stmt
.line_number_status
= force_line_numbers ();
4411 case_stack
= thiscase
;
4412 nesting_stack
= thiscase
;
4414 do_pending_stack_adjust ();
4416 /* Make sure case_stmt.start points to something that won't
4417 need any transformation before expand_end_case. */
4418 if (GET_CODE (get_last_insn ()) != NOTE
)
4419 emit_note (NULL
, NOTE_INSN_DELETED
);
4421 thiscase
->data
.case_stmt
.start
= get_last_insn ();
4423 start_cleanup_deferral ();
4426 /* Start a "dummy case statement" within which case labels are invalid
4427 and are not connected to any larger real case statement.
4428 This can be used if you don't want to let a case statement jump
4429 into the middle of certain kinds of constructs. */
4432 expand_start_case_dummy ()
4434 struct nesting
*thiscase
= ALLOC_NESTING ();
4436 /* Make an entry on case_stack for the dummy. */
4438 thiscase
->next
= case_stack
;
4439 thiscase
->all
= nesting_stack
;
4440 thiscase
->depth
= ++nesting_depth
;
4441 thiscase
->exit_label
= 0;
4442 thiscase
->data
.case_stmt
.case_list
= 0;
4443 thiscase
->data
.case_stmt
.start
= 0;
4444 thiscase
->data
.case_stmt
.nominal_type
= 0;
4445 thiscase
->data
.case_stmt
.default_label
= 0;
4446 case_stack
= thiscase
;
4447 nesting_stack
= thiscase
;
4448 start_cleanup_deferral ();
4451 /* End a dummy case statement. */
4454 expand_end_case_dummy ()
4456 end_cleanup_deferral ();
4457 POPSTACK (case_stack
);
4460 /* Return the data type of the index-expression
4461 of the innermost case statement, or null if none. */
4464 case_index_expr_type ()
4467 return TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4474 /* If this is the first label, warn if any insns have been emitted. */
4475 if (case_stack
->data
.case_stmt
.line_number_status
>= 0)
4479 restore_line_number_status
4480 (case_stack
->data
.case_stmt
.line_number_status
);
4481 case_stack
->data
.case_stmt
.line_number_status
= -1;
4483 for (insn
= case_stack
->data
.case_stmt
.start
;
4485 insn
= NEXT_INSN (insn
))
4487 if (GET_CODE (insn
) == CODE_LABEL
)
4489 if (GET_CODE (insn
) != NOTE
4490 && (GET_CODE (insn
) != INSN
|| GET_CODE (PATTERN (insn
)) != USE
))
4493 insn
= PREV_INSN (insn
);
4494 while (insn
&& (GET_CODE (insn
) != NOTE
|| NOTE_LINE_NUMBER (insn
) < 0));
4496 /* If insn is zero, then there must have been a syntax error. */
4498 warning_with_file_and_line (NOTE_SOURCE_FILE (insn
),
4499 NOTE_LINE_NUMBER (insn
),
4500 "unreachable code at beginning of %s",
4501 case_stack
->data
.case_stmt
.printname
);
4508 /* Accumulate one case or default label inside a case or switch statement.
4509 VALUE is the value of the case (a null pointer, for a default label).
4510 The function CONVERTER, when applied to arguments T and V,
4511 converts the value V to the type T.
4513 If not currently inside a case or switch statement, return 1 and do
4514 nothing. The caller will print a language-specific error message.
4515 If VALUE is a duplicate or overlaps, return 2 and do nothing
4516 except store the (first) duplicate node in *DUPLICATE.
4517 If VALUE is out of range, return 3 and do nothing.
4518 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4519 Return 0 on success.
4521 Extended to handle range statements. */
4524 pushcase (value
, converter
, label
, duplicate
)
4526 tree (*converter
) PARAMS ((tree
, tree
));
4533 /* Fail if not inside a real case statement. */
4534 if (! (case_stack
&& case_stack
->data
.case_stmt
.start
))
4537 if (stack_block_stack
4538 && stack_block_stack
->depth
> case_stack
->depth
)
4541 index_type
= TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4542 nominal_type
= case_stack
->data
.case_stmt
.nominal_type
;
4544 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4545 if (index_type
== error_mark_node
)
4548 /* Convert VALUE to the type in which the comparisons are nominally done. */
4550 value
= (*converter
) (nominal_type
, value
);
4554 /* Fail if this value is out of range for the actual type of the index
4555 (which may be narrower than NOMINAL_TYPE). */
4557 && (TREE_CONSTANT_OVERFLOW (value
)
4558 || ! int_fits_type_p (value
, index_type
)))
4561 return add_case_node (value
, value
, label
, duplicate
);
4564 /* Like pushcase but this case applies to all values between VALUE1 and
4565 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4566 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4567 starts at VALUE1 and ends at the highest value of the index type.
4568 If both are NULL, this case applies to all values.
4570 The return value is the same as that of pushcase but there is one
4571 additional error code: 4 means the specified range was empty. */
4574 pushcase_range (value1
, value2
, converter
, label
, duplicate
)
4575 tree value1
, value2
;
4576 tree (*converter
) PARAMS ((tree
, tree
));
4583 /* Fail if not inside a real case statement. */
4584 if (! (case_stack
&& case_stack
->data
.case_stmt
.start
))
4587 if (stack_block_stack
4588 && stack_block_stack
->depth
> case_stack
->depth
)
4591 index_type
= TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4592 nominal_type
= case_stack
->data
.case_stmt
.nominal_type
;
4594 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4595 if (index_type
== error_mark_node
)
4600 /* Convert VALUEs to type in which the comparisons are nominally done
4601 and replace any unspecified value with the corresponding bound. */
4603 value1
= TYPE_MIN_VALUE (index_type
);
4605 value2
= TYPE_MAX_VALUE (index_type
);
4607 /* Fail if the range is empty. Do this before any conversion since
4608 we want to allow out-of-range empty ranges. */
4609 if (value2
!= 0 && tree_int_cst_lt (value2
, value1
))
4612 /* If the max was unbounded, use the max of the nominal_type we are
4613 converting to. Do this after the < check above to suppress false
4616 value2
= TYPE_MAX_VALUE (nominal_type
);
4618 value1
= (*converter
) (nominal_type
, value1
);
4619 value2
= (*converter
) (nominal_type
, value2
);
4621 /* Fail if these values are out of range. */
4622 if (TREE_CONSTANT_OVERFLOW (value1
)
4623 || ! int_fits_type_p (value1
, index_type
))
4626 if (TREE_CONSTANT_OVERFLOW (value2
)
4627 || ! int_fits_type_p (value2
, index_type
))
4630 return add_case_node (value1
, value2
, label
, duplicate
);
4633 /* Do the actual insertion of a case label for pushcase and pushcase_range
4634 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4635 slowdown for large switch statements. */
4638 add_case_node (low
, high
, label
, duplicate
)
4643 struct case_node
*p
, **q
, *r
;
4645 /* If there's no HIGH value, then this is not a case range; it's
4646 just a simple case label. But that's just a degenerate case
4651 /* Handle default labels specially. */
4654 if (case_stack
->data
.case_stmt
.default_label
!= 0)
4656 *duplicate
= case_stack
->data
.case_stmt
.default_label
;
4659 case_stack
->data
.case_stmt
.default_label
= label
;
4660 expand_label (label
);
4664 q
= &case_stack
->data
.case_stmt
.case_list
;
4671 /* Keep going past elements distinctly greater than HIGH. */
4672 if (tree_int_cst_lt (high
, p
->low
))
4675 /* or distinctly less than LOW. */
4676 else if (tree_int_cst_lt (p
->high
, low
))
4681 /* We have an overlap; this is an error. */
4682 *duplicate
= p
->code_label
;
4687 /* Add this label to the chain, and succeed. */
4689 r
= (struct case_node
*) xmalloc (sizeof (struct case_node
));
4692 /* If the bounds are equal, turn this into the one-value case. */
4693 if (tree_int_cst_equal (low
, high
))
4698 r
->code_label
= label
;
4699 expand_label (label
);
4709 struct case_node
*s
;
4715 if (! (b
= p
->balance
))
4716 /* Growth propagation from left side. */
4723 if ((p
->left
= s
= r
->right
))
4732 if ((r
->parent
= s
))
4740 case_stack
->data
.case_stmt
.case_list
= r
;
4743 /* r->balance == +1 */
4748 struct case_node
*t
= r
->right
;
4750 if ((p
->left
= s
= t
->right
))
4754 if ((r
->right
= s
= t
->left
))
4768 if ((t
->parent
= s
))
4776 case_stack
->data
.case_stmt
.case_list
= t
;
4783 /* p->balance == +1; growth of left side balances the node. */
4793 if (! (b
= p
->balance
))
4794 /* Growth propagation from right side. */
4802 if ((p
->right
= s
= r
->left
))
4810 if ((r
->parent
= s
))
4819 case_stack
->data
.case_stmt
.case_list
= r
;
4823 /* r->balance == -1 */
4827 struct case_node
*t
= r
->left
;
4829 if ((p
->right
= s
= t
->left
))
4834 if ((r
->left
= s
= t
->right
))
4848 if ((t
->parent
= s
))
4857 case_stack
->data
.case_stmt
.case_list
= t
;
4863 /* p->balance == -1; growth of right side balances the node. */
4876 /* Returns the number of possible values of TYPE.
4877 Returns -1 if the number is unknown, variable, or if the number does not
4878 fit in a HOST_WIDE_INT.
4879 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4880 do not increase monotonically (there may be duplicates);
4881 to 1 if the values increase monotonically, but not always by 1;
4882 otherwise sets it to 0. */
4885 all_cases_count (type
, spareness
)
4890 HOST_WIDE_INT count
, minval
, lastval
;
4894 switch (TREE_CODE (type
))
4901 count
= 1 << BITS_PER_UNIT
;
4906 if (TYPE_MAX_VALUE (type
) != 0
4907 && 0 != (t
= fold (build (MINUS_EXPR
, type
, TYPE_MAX_VALUE (type
),
4908 TYPE_MIN_VALUE (type
))))
4909 && 0 != (t
= fold (build (PLUS_EXPR
, type
, t
,
4910 convert (type
, integer_zero_node
))))
4911 && host_integerp (t
, 1))
4912 count
= tree_low_cst (t
, 1);
4918 /* Don't waste time with enumeral types with huge values. */
4919 if (! host_integerp (TYPE_MIN_VALUE (type
), 0)
4920 || TYPE_MAX_VALUE (type
) == 0
4921 || ! host_integerp (TYPE_MAX_VALUE (type
), 0))
4924 lastval
= minval
= tree_low_cst (TYPE_MIN_VALUE (type
), 0);
4927 for (t
= TYPE_VALUES (type
); t
!= NULL_TREE
; t
= TREE_CHAIN (t
))
4929 HOST_WIDE_INT thisval
= tree_low_cst (TREE_VALUE (t
), 0);
4931 if (*spareness
== 2 || thisval
< lastval
)
4933 else if (thisval
!= minval
+ count
)
4943 #define BITARRAY_TEST(ARRAY, INDEX) \
4944 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4945 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4946 #define BITARRAY_SET(ARRAY, INDEX) \
4947 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4948 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4950 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4951 with the case values we have seen, assuming the case expression
4953 SPARSENESS is as determined by all_cases_count.
4955 The time needed is proportional to COUNT, unless
4956 SPARSENESS is 2, in which case quadratic time is needed. */
4959 mark_seen_cases (type
, cases_seen
, count
, sparseness
)
4961 unsigned char *cases_seen
;
4962 HOST_WIDE_INT count
;
4965 tree next_node_to_try
= NULL_TREE
;
4966 HOST_WIDE_INT next_node_offset
= 0;
4968 struct case_node
*n
, *root
= case_stack
->data
.case_stmt
.case_list
;
4969 tree val
= make_node (INTEGER_CST
);
4971 TREE_TYPE (val
) = type
;
4975 else if (sparseness
== 2)
4978 unsigned HOST_WIDE_INT xlo
;
4980 /* This less efficient loop is only needed to handle
4981 duplicate case values (multiple enum constants
4982 with the same value). */
4983 TREE_TYPE (val
) = TREE_TYPE (root
->low
);
4984 for (t
= TYPE_VALUES (type
), xlo
= 0; t
!= NULL_TREE
;
4985 t
= TREE_CHAIN (t
), xlo
++)
4987 TREE_INT_CST_LOW (val
) = TREE_INT_CST_LOW (TREE_VALUE (t
));
4988 TREE_INT_CST_HIGH (val
) = TREE_INT_CST_HIGH (TREE_VALUE (t
));
4992 /* Keep going past elements distinctly greater than VAL. */
4993 if (tree_int_cst_lt (val
, n
->low
))
4996 /* or distinctly less than VAL. */
4997 else if (tree_int_cst_lt (n
->high
, val
))
5002 /* We have found a matching range. */
5003 BITARRAY_SET (cases_seen
, xlo
);
5013 case_stack
->data
.case_stmt
.case_list
= root
= case_tree2list (root
, 0);
5015 for (n
= root
; n
; n
= n
->right
)
5017 TREE_INT_CST_LOW (val
) = TREE_INT_CST_LOW (n
->low
);
5018 TREE_INT_CST_HIGH (val
) = TREE_INT_CST_HIGH (n
->low
);
5019 while (! tree_int_cst_lt (n
->high
, val
))
5021 /* Calculate (into xlo) the "offset" of the integer (val).
5022 The element with lowest value has offset 0, the next smallest
5023 element has offset 1, etc. */
5025 unsigned HOST_WIDE_INT xlo
;
5029 if (sparseness
&& TYPE_VALUES (type
) != NULL_TREE
)
5031 /* The TYPE_VALUES will be in increasing order, so
5032 starting searching where we last ended. */
5033 t
= next_node_to_try
;
5034 xlo
= next_node_offset
;
5040 t
= TYPE_VALUES (type
);
5043 if (tree_int_cst_equal (val
, TREE_VALUE (t
)))
5045 next_node_to_try
= TREE_CHAIN (t
);
5046 next_node_offset
= xlo
+ 1;
5051 if (t
== next_node_to_try
)
5060 t
= TYPE_MIN_VALUE (type
);
5062 neg_double (TREE_INT_CST_LOW (t
), TREE_INT_CST_HIGH (t
),
5066 add_double (xlo
, xhi
,
5067 TREE_INT_CST_LOW (val
), TREE_INT_CST_HIGH (val
),
5071 if (xhi
== 0 && xlo
< (unsigned HOST_WIDE_INT
) count
)
5072 BITARRAY_SET (cases_seen
, xlo
);
5074 add_double (TREE_INT_CST_LOW (val
), TREE_INT_CST_HIGH (val
),
5076 &TREE_INT_CST_LOW (val
), &TREE_INT_CST_HIGH (val
));
5082 /* Called when the index of a switch statement is an enumerated type
5083 and there is no default label.
5085 Checks that all enumeration literals are covered by the case
5086 expressions of a switch. Also, warn if there are any extra
5087 switch cases that are *not* elements of the enumerated type.
5089 If all enumeration literals were covered by the case expressions,
5090 turn one of the expressions into the default expression since it should
5091 not be possible to fall through such a switch. */
5094 check_for_full_enumeration_handling (type
)
5097 struct case_node
*n
;
5100 /* True iff the selector type is a numbered set mode. */
5103 /* The number of possible selector values. */
5106 /* For each possible selector value. a one iff it has been matched
5107 by a case value alternative. */
5108 unsigned char *cases_seen
;
5110 /* The allocated size of cases_seen, in chars. */
5111 HOST_WIDE_INT bytes_needed
;
5116 size
= all_cases_count (type
, &sparseness
);
5117 bytes_needed
= (size
+ HOST_BITS_PER_CHAR
) / HOST_BITS_PER_CHAR
;
5119 if (size
> 0 && size
< 600000
5120 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5121 this optimization if we don't have enough memory rather than
5122 aborting, as xmalloc would do. */
5124 (unsigned char *) really_call_calloc (bytes_needed
, 1)) != NULL
)
5127 tree v
= TYPE_VALUES (type
);
5129 /* The time complexity of this code is normally O(N), where
5130 N being the number of members in the enumerated type.
5131 However, if type is a ENUMERAL_TYPE whose values do not
5132 increase monotonically, O(N*log(N)) time may be needed. */
5134 mark_seen_cases (type
, cases_seen
, size
, sparseness
);
5136 for (i
= 0; v
!= NULL_TREE
&& i
< size
; i
++, v
= TREE_CHAIN (v
))
5137 if (BITARRAY_TEST (cases_seen
, i
) == 0)
5138 warning ("enumeration value `%s' not handled in switch",
5139 IDENTIFIER_POINTER (TREE_PURPOSE (v
)));
5144 /* Now we go the other way around; we warn if there are case
5145 expressions that don't correspond to enumerators. This can
5146 occur since C and C++ don't enforce type-checking of
5147 assignments to enumeration variables. */
5149 if (case_stack
->data
.case_stmt
.case_list
5150 && case_stack
->data
.case_stmt
.case_list
->left
)
5151 case_stack
->data
.case_stmt
.case_list
5152 = case_tree2list (case_stack
->data
.case_stmt
.case_list
, 0);
5154 for (n
= case_stack
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5156 for (chain
= TYPE_VALUES (type
);
5157 chain
&& !tree_int_cst_equal (n
->low
, TREE_VALUE (chain
));
5158 chain
= TREE_CHAIN (chain
))
5163 if (TYPE_NAME (type
) == 0)
5164 warning ("case value `%ld' not in enumerated type",
5165 (long) TREE_INT_CST_LOW (n
->low
));
5167 warning ("case value `%ld' not in enumerated type `%s'",
5168 (long) TREE_INT_CST_LOW (n
->low
),
5169 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type
))
5172 : DECL_NAME (TYPE_NAME (type
))));
5174 if (!tree_int_cst_equal (n
->low
, n
->high
))
5176 for (chain
= TYPE_VALUES (type
);
5177 chain
&& !tree_int_cst_equal (n
->high
, TREE_VALUE (chain
));
5178 chain
= TREE_CHAIN (chain
))
5183 if (TYPE_NAME (type
) == 0)
5184 warning ("case value `%ld' not in enumerated type",
5185 (long) TREE_INT_CST_LOW (n
->high
));
5187 warning ("case value `%ld' not in enumerated type `%s'",
5188 (long) TREE_INT_CST_LOW (n
->high
),
5189 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type
))
5192 : DECL_NAME (TYPE_NAME (type
))));
5198 /* Free CN, and its children. */
5201 free_case_nodes (cn
)
5206 free_case_nodes (cn
->left
);
5207 free_case_nodes (cn
->right
);
5214 /* Terminate a case (Pascal) or switch (C) statement
5215 in which ORIG_INDEX is the expression to be tested.
5216 Generate the code to test it and jump to the right place. */
5219 expand_end_case (orig_index
)
5222 tree minval
= NULL_TREE
, maxval
= NULL_TREE
, range
= NULL_TREE
;
5223 rtx default_label
= 0;
5224 struct case_node
*n
;
5231 rtx before_case
, end
;
5232 struct nesting
*thiscase
= case_stack
;
5233 tree index_expr
, index_type
;
5236 /* Don't crash due to previous errors. */
5237 if (thiscase
== NULL
)
5240 table_label
= gen_label_rtx ();
5241 index_expr
= thiscase
->data
.case_stmt
.index_expr
;
5242 index_type
= TREE_TYPE (index_expr
);
5243 unsignedp
= TREE_UNSIGNED (index_type
);
5245 do_pending_stack_adjust ();
5247 /* This might get an spurious warning in the presence of a syntax error;
5248 it could be fixed by moving the call to check_seenlabel after the
5249 check for error_mark_node, and copying the code of check_seenlabel that
5250 deals with case_stack->data.case_stmt.line_number_status /
5251 restore_line_number_status in front of the call to end_cleanup_deferral;
5252 However, this might miss some useful warnings in the presence of
5253 non-syntax errors. */
5256 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5257 if (index_type
!= error_mark_node
)
5259 /* If switch expression was an enumerated type, check that all
5260 enumeration literals are covered by the cases.
5261 No sense trying this if there's a default case, however. */
5263 if (!thiscase
->data
.case_stmt
.default_label
5264 && TREE_CODE (TREE_TYPE (orig_index
)) == ENUMERAL_TYPE
5265 && TREE_CODE (index_expr
) != INTEGER_CST
)
5266 check_for_full_enumeration_handling (TREE_TYPE (orig_index
));
5268 /* If we don't have a default-label, create one here,
5269 after the body of the switch. */
5270 if (thiscase
->data
.case_stmt
.default_label
== 0)
5272 thiscase
->data
.case_stmt
.default_label
5273 = build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
5274 expand_label (thiscase
->data
.case_stmt
.default_label
);
5276 default_label
= label_rtx (thiscase
->data
.case_stmt
.default_label
);
5278 before_case
= get_last_insn ();
5280 if (thiscase
->data
.case_stmt
.case_list
5281 && thiscase
->data
.case_stmt
.case_list
->left
)
5282 thiscase
->data
.case_stmt
.case_list
5283 = case_tree2list (thiscase
->data
.case_stmt
.case_list
, 0);
5285 /* Simplify the case-list before we count it. */
5286 group_case_nodes (thiscase
->data
.case_stmt
.case_list
);
5288 /* Get upper and lower bounds of case values.
5289 Also convert all the case values to the index expr's data type. */
5292 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5294 /* Check low and high label values are integers. */
5295 if (TREE_CODE (n
->low
) != INTEGER_CST
)
5297 if (TREE_CODE (n
->high
) != INTEGER_CST
)
5300 n
->low
= convert (index_type
, n
->low
);
5301 n
->high
= convert (index_type
, n
->high
);
5303 /* Count the elements and track the largest and smallest
5304 of them (treating them as signed even if they are not). */
5312 if (INT_CST_LT (n
->low
, minval
))
5314 if (INT_CST_LT (maxval
, n
->high
))
5317 /* A range counts double, since it requires two compares. */
5318 if (! tree_int_cst_equal (n
->low
, n
->high
))
5322 /* Compute span of values. */
5324 range
= fold (build (MINUS_EXPR
, index_type
, maxval
, minval
));
5326 end_cleanup_deferral ();
5330 expand_expr (index_expr
, const0_rtx
, VOIDmode
, 0);
5332 emit_jump (default_label
);
5335 /* If range of values is much bigger than number of values,
5336 make a sequence of conditional branches instead of a dispatch.
5337 If the switch-index is a constant, do it this way
5338 because we can optimize it. */
5340 else if (count
< case_values_threshold ()
5341 || compare_tree_int (range
, 10 * count
) > 0
5342 /* RANGE may be signed, and really large ranges will show up
5343 as negative numbers. */
5344 || compare_tree_int (range
, 0) < 0
5345 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5348 || TREE_CODE (index_expr
) == INTEGER_CST
5349 || (TREE_CODE (index_expr
) == COMPOUND_EXPR
5350 && TREE_CODE (TREE_OPERAND (index_expr
, 1)) == INTEGER_CST
))
5352 index
= expand_expr (index_expr
, NULL_RTX
, VOIDmode
, 0);
5354 /* If the index is a short or char that we do not have
5355 an insn to handle comparisons directly, convert it to
5356 a full integer now, rather than letting each comparison
5357 generate the conversion. */
5359 if (GET_MODE_CLASS (GET_MODE (index
)) == MODE_INT
5360 && ! have_insn_for (COMPARE
, GET_MODE (index
)))
5362 enum machine_mode wider_mode
;
5363 for (wider_mode
= GET_MODE (index
); wider_mode
!= VOIDmode
;
5364 wider_mode
= GET_MODE_WIDER_MODE (wider_mode
))
5365 if (have_insn_for (COMPARE
, wider_mode
))
5367 index
= convert_to_mode (wider_mode
, index
, unsignedp
);
5373 do_pending_stack_adjust ();
5375 index
= protect_from_queue (index
, 0);
5376 if (GET_CODE (index
) == MEM
)
5377 index
= copy_to_reg (index
);
5378 if (GET_CODE (index
) == CONST_INT
5379 || TREE_CODE (index_expr
) == INTEGER_CST
)
5381 /* Make a tree node with the proper constant value
5382 if we don't already have one. */
5383 if (TREE_CODE (index_expr
) != INTEGER_CST
)
5386 = build_int_2 (INTVAL (index
),
5387 unsignedp
|| INTVAL (index
) >= 0 ? 0 : -1);
5388 index_expr
= convert (index_type
, index_expr
);
5391 /* For constant index expressions we need only
5392 issue an unconditional branch to the appropriate
5393 target code. The job of removing any unreachable
5394 code is left to the optimisation phase if the
5395 "-O" option is specified. */
5396 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5397 if (! tree_int_cst_lt (index_expr
, n
->low
)
5398 && ! tree_int_cst_lt (n
->high
, index_expr
))
5402 emit_jump (label_rtx (n
->code_label
));
5404 emit_jump (default_label
);
5408 /* If the index expression is not constant we generate
5409 a binary decision tree to select the appropriate
5410 target code. This is done as follows:
5412 The list of cases is rearranged into a binary tree,
5413 nearly optimal assuming equal probability for each case.
5415 The tree is transformed into RTL, eliminating
5416 redundant test conditions at the same time.
5418 If program flow could reach the end of the
5419 decision tree an unconditional jump to the
5420 default code is emitted. */
5423 = (TREE_CODE (TREE_TYPE (orig_index
)) != ENUMERAL_TYPE
5424 && estimate_case_costs (thiscase
->data
.case_stmt
.case_list
));
5425 balance_case_nodes (&thiscase
->data
.case_stmt
.case_list
, NULL
);
5426 emit_case_nodes (index
, thiscase
->data
.case_stmt
.case_list
,
5427 default_label
, index_type
);
5428 emit_jump_if_reachable (default_label
);
5433 if (! try_casesi (index_type
, index_expr
, minval
, range
,
5434 table_label
, default_label
))
5436 index_type
= thiscase
->data
.case_stmt
.nominal_type
;
5438 /* Index jumptables from zero for suitable values of
5439 minval to avoid a subtraction. */
5441 && compare_tree_int (minval
, 0) > 0
5442 && compare_tree_int (minval
, 3) < 0)
5444 minval
= integer_zero_node
;
5448 if (! try_tablejump (index_type
, index_expr
, minval
, range
,
5449 table_label
, default_label
))
5453 /* Get table of labels to jump to, in order of case index. */
5455 ncases
= tree_low_cst (range
, 0) + 1;
5456 labelvec
= (rtx
*) alloca (ncases
* sizeof (rtx
));
5457 memset ((char *) labelvec
, 0, ncases
* sizeof (rtx
));
5459 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5461 /* Compute the low and high bounds relative to the minimum
5462 value since that should fit in a HOST_WIDE_INT while the
5463 actual values may not. */
5465 = tree_low_cst (fold (build (MINUS_EXPR
, index_type
,
5466 n
->low
, minval
)), 1);
5467 HOST_WIDE_INT i_high
5468 = tree_low_cst (fold (build (MINUS_EXPR
, index_type
,
5469 n
->high
, minval
)), 1);
5472 for (i
= i_low
; i
<= i_high
; i
++)
5474 = gen_rtx_LABEL_REF (Pmode
, label_rtx (n
->code_label
));
5477 /* Fill in the gaps with the default. */
5478 for (i
= 0; i
< ncases
; i
++)
5479 if (labelvec
[i
] == 0)
5480 labelvec
[i
] = gen_rtx_LABEL_REF (Pmode
, default_label
);
5482 /* Output the table */
5483 emit_label (table_label
);
5485 if (CASE_VECTOR_PC_RELATIVE
|| flag_pic
)
5486 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE
,
5487 gen_rtx_LABEL_REF (Pmode
, table_label
),
5488 gen_rtvec_v (ncases
, labelvec
),
5489 const0_rtx
, const0_rtx
));
5491 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE
,
5492 gen_rtvec_v (ncases
, labelvec
)));
5494 /* If the case insn drops through the table,
5495 after the table we must jump to the default-label.
5496 Otherwise record no drop-through after the table. */
5497 #ifdef CASE_DROPS_THROUGH
5498 emit_jump (default_label
);
5504 before_case
= NEXT_INSN (before_case
);
5505 end
= get_last_insn ();
5506 if (squeeze_notes (&before_case
, &end
))
5508 reorder_insns (before_case
, end
,
5509 thiscase
->data
.case_stmt
.start
);
5512 end_cleanup_deferral ();
5514 if (thiscase
->exit_label
)
5515 emit_label (thiscase
->exit_label
);
5517 free_case_nodes (case_stack
->data
.case_stmt
.case_list
);
5518 POPSTACK (case_stack
);
5523 /* Convert the tree NODE into a list linked by the right field, with the left
5524 field zeroed. RIGHT is used for recursion; it is a list to be placed
5525 rightmost in the resulting list. */
5527 static struct case_node
*
5528 case_tree2list (node
, right
)
5529 struct case_node
*node
, *right
;
5531 struct case_node
*left
;
5534 right
= case_tree2list (node
->right
, right
);
5536 node
->right
= right
;
5537 if ((left
= node
->left
))
5540 return case_tree2list (left
, node
);
5546 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5549 do_jump_if_equal (op1
, op2
, label
, unsignedp
)
5550 rtx op1
, op2
, label
;
5553 if (GET_CODE (op1
) == CONST_INT
&& GET_CODE (op2
) == CONST_INT
)
5555 if (INTVAL (op1
) == INTVAL (op2
))
5559 emit_cmp_and_jump_insns (op1
, op2
, EQ
, NULL_RTX
,
5560 (GET_MODE (op1
) == VOIDmode
5561 ? GET_MODE (op2
) : GET_MODE (op1
)),
5565 /* Not all case values are encountered equally. This function
5566 uses a heuristic to weight case labels, in cases where that
5567 looks like a reasonable thing to do.
5569 Right now, all we try to guess is text, and we establish the
5572 chars above space: 16
5581 If we find any cases in the switch that are not either -1 or in the range
5582 of valid ASCII characters, or are control characters other than those
5583 commonly used with "\", don't treat this switch scanning text.
5585 Return 1 if these nodes are suitable for cost estimation, otherwise
5589 estimate_case_costs (node
)
5592 tree min_ascii
= integer_minus_one_node
;
5593 tree max_ascii
= convert (TREE_TYPE (node
->high
), build_int_2 (127, 0));
5597 /* If we haven't already made the cost table, make it now. Note that the
5598 lower bound of the table is -1, not zero. */
5600 if (! cost_table_initialized
)
5602 cost_table_initialized
= 1;
5604 for (i
= 0; i
< 128; i
++)
5607 COST_TABLE (i
) = 16;
5608 else if (ISPUNCT (i
))
5610 else if (ISCNTRL (i
))
5611 COST_TABLE (i
) = -1;
5614 COST_TABLE (' ') = 8;
5615 COST_TABLE ('\t') = 4;
5616 COST_TABLE ('\0') = 4;
5617 COST_TABLE ('\n') = 2;
5618 COST_TABLE ('\f') = 1;
5619 COST_TABLE ('\v') = 1;
5620 COST_TABLE ('\b') = 1;
5623 /* See if all the case expressions look like text. It is text if the
5624 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5625 as signed arithmetic since we don't want to ever access cost_table with a
5626 value less than -1. Also check that none of the constants in a range
5627 are strange control characters. */
5629 for (n
= node
; n
; n
= n
->right
)
5631 if ((INT_CST_LT (n
->low
, min_ascii
)) || INT_CST_LT (max_ascii
, n
->high
))
5634 for (i
= (HOST_WIDE_INT
) TREE_INT_CST_LOW (n
->low
);
5635 i
<= (HOST_WIDE_INT
) TREE_INT_CST_LOW (n
->high
); i
++)
5636 if (COST_TABLE (i
) < 0)
5640 /* All interesting values are within the range of interesting
5641 ASCII characters. */
5645 /* Scan an ordered list of case nodes
5646 combining those with consecutive values or ranges.
5648 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5651 group_case_nodes (head
)
5654 case_node_ptr node
= head
;
5658 rtx lb
= next_real_insn (label_rtx (node
->code_label
));
5660 case_node_ptr np
= node
;
5662 /* Try to group the successors of NODE with NODE. */
5663 while (((np
= np
->right
) != 0)
5664 /* Do they jump to the same place? */
5665 && ((lb2
= next_real_insn (label_rtx (np
->code_label
))) == lb
5666 || (lb
!= 0 && lb2
!= 0
5667 && simplejump_p (lb
)
5668 && simplejump_p (lb2
)
5669 && rtx_equal_p (SET_SRC (PATTERN (lb
)),
5670 SET_SRC (PATTERN (lb2
)))))
5671 /* Are their ranges consecutive? */
5672 && tree_int_cst_equal (np
->low
,
5673 fold (build (PLUS_EXPR
,
5674 TREE_TYPE (node
->high
),
5677 /* An overflow is not consecutive. */
5678 && tree_int_cst_lt (node
->high
,
5679 fold (build (PLUS_EXPR
,
5680 TREE_TYPE (node
->high
),
5682 integer_one_node
))))
5684 node
->high
= np
->high
;
5686 /* NP is the first node after NODE which can't be grouped with it.
5687 Delete the nodes in between, and move on to that node. */
5693 /* Take an ordered list of case nodes
5694 and transform them into a near optimal binary tree,
5695 on the assumption that any target code selection value is as
5696 likely as any other.
5698 The transformation is performed by splitting the ordered
5699 list into two equal sections plus a pivot. The parts are
5700 then attached to the pivot as left and right branches. Each
5701 branch is then transformed recursively. */
5704 balance_case_nodes (head
, parent
)
5705 case_node_ptr
*head
;
5706 case_node_ptr parent
;
5719 /* Count the number of entries on branch. Also count the ranges. */
5723 if (!tree_int_cst_equal (np
->low
, np
->high
))
5727 cost
+= COST_TABLE (TREE_INT_CST_LOW (np
->high
));
5731 cost
+= COST_TABLE (TREE_INT_CST_LOW (np
->low
));
5739 /* Split this list if it is long enough for that to help. */
5744 /* Find the place in the list that bisects the list's total cost,
5745 Here I gets half the total cost. */
5750 /* Skip nodes while their cost does not reach that amount. */
5751 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
5752 i
-= COST_TABLE (TREE_INT_CST_LOW ((*npp
)->high
));
5753 i
-= COST_TABLE (TREE_INT_CST_LOW ((*npp
)->low
));
5756 npp
= &(*npp
)->right
;
5761 /* Leave this branch lopsided, but optimize left-hand
5762 side and fill in `parent' fields for right-hand side. */
5764 np
->parent
= parent
;
5765 balance_case_nodes (&np
->left
, np
);
5766 for (; np
->right
; np
= np
->right
)
5767 np
->right
->parent
= np
;
5771 /* If there are just three nodes, split at the middle one. */
5773 npp
= &(*npp
)->right
;
5776 /* Find the place in the list that bisects the list's total cost,
5777 where ranges count as 2.
5778 Here I gets half the total cost. */
5779 i
= (i
+ ranges
+ 1) / 2;
5782 /* Skip nodes while their cost does not reach that amount. */
5783 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
5788 npp
= &(*npp
)->right
;
5793 np
->parent
= parent
;
5796 /* Optimize each of the two split parts. */
5797 balance_case_nodes (&np
->left
, np
);
5798 balance_case_nodes (&np
->right
, np
);
5802 /* Else leave this branch as one level,
5803 but fill in `parent' fields. */
5805 np
->parent
= parent
;
5806 for (; np
->right
; np
= np
->right
)
5807 np
->right
->parent
= np
;
5812 /* Search the parent sections of the case node tree
5813 to see if a test for the lower bound of NODE would be redundant.
5814 INDEX_TYPE is the type of the index expression.
5816 The instructions to generate the case decision tree are
5817 output in the same order as nodes are processed so it is
5818 known that if a parent node checks the range of the current
5819 node minus one that the current node is bounded at its lower
5820 span. Thus the test would be redundant. */
5823 node_has_low_bound (node
, index_type
)
5828 case_node_ptr pnode
;
5830 /* If the lower bound of this node is the lowest value in the index type,
5831 we need not test it. */
5833 if (tree_int_cst_equal (node
->low
, TYPE_MIN_VALUE (index_type
)))
5836 /* If this node has a left branch, the value at the left must be less
5837 than that at this node, so it cannot be bounded at the bottom and
5838 we need not bother testing any further. */
5843 low_minus_one
= fold (build (MINUS_EXPR
, TREE_TYPE (node
->low
),
5844 node
->low
, integer_one_node
));
5846 /* If the subtraction above overflowed, we can't verify anything.
5847 Otherwise, look for a parent that tests our value - 1. */
5849 if (! tree_int_cst_lt (low_minus_one
, node
->low
))
5852 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
5853 if (tree_int_cst_equal (low_minus_one
, pnode
->high
))
5859 /* Search the parent sections of the case node tree
5860 to see if a test for the upper bound of NODE would be redundant.
5861 INDEX_TYPE is the type of the index expression.
5863 The instructions to generate the case decision tree are
5864 output in the same order as nodes are processed so it is
5865 known that if a parent node checks the range of the current
5866 node plus one that the current node is bounded at its upper
5867 span. Thus the test would be redundant. */
5870 node_has_high_bound (node
, index_type
)
5875 case_node_ptr pnode
;
5877 /* If there is no upper bound, obviously no test is needed. */
5879 if (TYPE_MAX_VALUE (index_type
) == NULL
)
5882 /* If the upper bound of this node is the highest value in the type
5883 of the index expression, we need not test against it. */
5885 if (tree_int_cst_equal (node
->high
, TYPE_MAX_VALUE (index_type
)))
5888 /* If this node has a right branch, the value at the right must be greater
5889 than that at this node, so it cannot be bounded at the top and
5890 we need not bother testing any further. */
5895 high_plus_one
= fold (build (PLUS_EXPR
, TREE_TYPE (node
->high
),
5896 node
->high
, integer_one_node
));
5898 /* If the addition above overflowed, we can't verify anything.
5899 Otherwise, look for a parent that tests our value + 1. */
5901 if (! tree_int_cst_lt (node
->high
, high_plus_one
))
5904 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
5905 if (tree_int_cst_equal (high_plus_one
, pnode
->low
))
5911 /* Search the parent sections of the
5912 case node tree to see if both tests for the upper and lower
5913 bounds of NODE would be redundant. */
5916 node_is_bounded (node
, index_type
)
5920 return (node_has_low_bound (node
, index_type
)
5921 && node_has_high_bound (node
, index_type
));
5924 /* Emit an unconditional jump to LABEL unless it would be dead code. */
5927 emit_jump_if_reachable (label
)
5930 if (GET_CODE (get_last_insn ()) != BARRIER
)
5934 /* Emit step-by-step code to select a case for the value of INDEX.
5935 The thus generated decision tree follows the form of the
5936 case-node binary tree NODE, whose nodes represent test conditions.
5937 INDEX_TYPE is the type of the index of the switch.
5939 Care is taken to prune redundant tests from the decision tree
5940 by detecting any boundary conditions already checked by
5941 emitted rtx. (See node_has_high_bound, node_has_low_bound
5942 and node_is_bounded, above.)
5944 Where the test conditions can be shown to be redundant we emit
5945 an unconditional jump to the target code. As a further
5946 optimization, the subordinates of a tree node are examined to
5947 check for bounded nodes. In this case conditional and/or
5948 unconditional jumps as a result of the boundary check for the
5949 current node are arranged to target the subordinates associated
5950 code for out of bound conditions on the current node.
5952 We can assume that when control reaches the code generated here,
5953 the index value has already been compared with the parents
5954 of this node, and determined to be on the same side of each parent
5955 as this node is. Thus, if this node tests for the value 51,
5956 and a parent tested for 52, we don't need to consider
5957 the possibility of a value greater than 51. If another parent
5958 tests for the value 50, then this node need not test anything. */
5961 emit_case_nodes (index
, node
, default_label
, index_type
)
5967 /* If INDEX has an unsigned type, we must make unsigned branches. */
5968 int unsignedp
= TREE_UNSIGNED (index_type
);
5969 enum machine_mode mode
= GET_MODE (index
);
5970 enum machine_mode imode
= TYPE_MODE (index_type
);
5972 /* See if our parents have already tested everything for us.
5973 If they have, emit an unconditional jump for this node. */
5974 if (node_is_bounded (node
, index_type
))
5975 emit_jump (label_rtx (node
->code_label
));
5977 else if (tree_int_cst_equal (node
->low
, node
->high
))
5979 /* Node is single valued. First see if the index expression matches
5980 this node and then check our children, if any. */
5982 do_jump_if_equal (index
,
5983 convert_modes (mode
, imode
,
5984 expand_expr (node
->low
, NULL_RTX
,
5987 label_rtx (node
->code_label
), unsignedp
);
5989 if (node
->right
!= 0 && node
->left
!= 0)
5991 /* This node has children on both sides.
5992 Dispatch to one side or the other
5993 by comparing the index value with this node's value.
5994 If one subtree is bounded, check that one first,
5995 so we can avoid real branches in the tree. */
5997 if (node_is_bounded (node
->right
, index_type
))
5999 emit_cmp_and_jump_insns (index
,
6002 expand_expr (node
->high
, NULL_RTX
,
6005 GT
, NULL_RTX
, mode
, unsignedp
,
6006 label_rtx (node
->right
->code_label
));
6007 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6010 else if (node_is_bounded (node
->left
, index_type
))
6012 emit_cmp_and_jump_insns (index
,
6015 expand_expr (node
->high
, NULL_RTX
,
6018 LT
, NULL_RTX
, mode
, unsignedp
,
6019 label_rtx (node
->left
->code_label
));
6020 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6025 /* Neither node is bounded. First distinguish the two sides;
6026 then emit the code for one side at a time. */
6028 tree test_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
6030 /* See if the value is on the right. */
6031 emit_cmp_and_jump_insns (index
,
6034 expand_expr (node
->high
, NULL_RTX
,
6037 GT
, NULL_RTX
, mode
, unsignedp
,
6038 label_rtx (test_label
));
6040 /* Value must be on the left.
6041 Handle the left-hand subtree. */
6042 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6043 /* If left-hand subtree does nothing,
6045 emit_jump_if_reachable (default_label
);
6047 /* Code branches here for the right-hand subtree. */
6048 expand_label (test_label
);
6049 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6053 else if (node
->right
!= 0 && node
->left
== 0)
6055 /* Here we have a right child but no left so we issue conditional
6056 branch to default and process the right child.
6058 Omit the conditional branch to default if we it avoid only one
6059 right child; it costs too much space to save so little time. */
6061 if (node
->right
->right
|| node
->right
->left
6062 || !tree_int_cst_equal (node
->right
->low
, node
->right
->high
))
6064 if (!node_has_low_bound (node
, index_type
))
6066 emit_cmp_and_jump_insns (index
,
6069 expand_expr (node
->high
, NULL_RTX
,
6072 LT
, NULL_RTX
, mode
, unsignedp
,
6076 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6079 /* We cannot process node->right normally
6080 since we haven't ruled out the numbers less than
6081 this node's value. So handle node->right explicitly. */
6082 do_jump_if_equal (index
,
6085 expand_expr (node
->right
->low
, NULL_RTX
,
6088 label_rtx (node
->right
->code_label
), unsignedp
);
6091 else if (node
->right
== 0 && node
->left
!= 0)
6093 /* Just one subtree, on the left. */
6094 if (node
->left
->left
|| node
->left
->right
6095 || !tree_int_cst_equal (node
->left
->low
, node
->left
->high
))
6097 if (!node_has_high_bound (node
, index_type
))
6099 emit_cmp_and_jump_insns (index
,
6102 expand_expr (node
->high
, NULL_RTX
,
6105 GT
, NULL_RTX
, mode
, unsignedp
,
6109 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6112 /* We cannot process node->left normally
6113 since we haven't ruled out the numbers less than
6114 this node's value. So handle node->left explicitly. */
6115 do_jump_if_equal (index
,
6118 expand_expr (node
->left
->low
, NULL_RTX
,
6121 label_rtx (node
->left
->code_label
), unsignedp
);
6126 /* Node is a range. These cases are very similar to those for a single
6127 value, except that we do not start by testing whether this node
6128 is the one to branch to. */
6130 if (node
->right
!= 0 && node
->left
!= 0)
6132 /* Node has subtrees on both sides.
6133 If the right-hand subtree is bounded,
6134 test for it first, since we can go straight there.
6135 Otherwise, we need to make a branch in the control structure,
6136 then handle the two subtrees. */
6137 tree test_label
= 0;
6139 if (node_is_bounded (node
->right
, index_type
))
6140 /* Right hand node is fully bounded so we can eliminate any
6141 testing and branch directly to the target code. */
6142 emit_cmp_and_jump_insns (index
,
6145 expand_expr (node
->high
, NULL_RTX
,
6148 GT
, NULL_RTX
, mode
, unsignedp
,
6149 label_rtx (node
->right
->code_label
));
6152 /* Right hand node requires testing.
6153 Branch to a label where we will handle it later. */
6155 test_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
6156 emit_cmp_and_jump_insns (index
,
6159 expand_expr (node
->high
, NULL_RTX
,
6162 GT
, NULL_RTX
, mode
, unsignedp
,
6163 label_rtx (test_label
));
6166 /* Value belongs to this node or to the left-hand subtree. */
6168 emit_cmp_and_jump_insns (index
,
6171 expand_expr (node
->low
, NULL_RTX
,
6174 GE
, NULL_RTX
, mode
, unsignedp
,
6175 label_rtx (node
->code_label
));
6177 /* Handle the left-hand subtree. */
6178 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6180 /* If right node had to be handled later, do that now. */
6184 /* If the left-hand subtree fell through,
6185 don't let it fall into the right-hand subtree. */
6186 emit_jump_if_reachable (default_label
);
6188 expand_label (test_label
);
6189 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6193 else if (node
->right
!= 0 && node
->left
== 0)
6195 /* Deal with values to the left of this node,
6196 if they are possible. */
6197 if (!node_has_low_bound (node
, index_type
))
6199 emit_cmp_and_jump_insns (index
,
6202 expand_expr (node
->low
, NULL_RTX
,
6205 LT
, NULL_RTX
, mode
, unsignedp
,
6209 /* Value belongs to this node or to the right-hand subtree. */
6211 emit_cmp_and_jump_insns (index
,
6214 expand_expr (node
->high
, NULL_RTX
,
6217 LE
, NULL_RTX
, mode
, unsignedp
,
6218 label_rtx (node
->code_label
));
6220 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
6223 else if (node
->right
== 0 && node
->left
!= 0)
6225 /* Deal with values to the right of this node,
6226 if they are possible. */
6227 if (!node_has_high_bound (node
, index_type
))
6229 emit_cmp_and_jump_insns (index
,
6232 expand_expr (node
->high
, NULL_RTX
,
6235 GT
, NULL_RTX
, mode
, unsignedp
,
6239 /* Value belongs to this node or to the left-hand subtree. */
6241 emit_cmp_and_jump_insns (index
,
6244 expand_expr (node
->low
, NULL_RTX
,
6247 GE
, NULL_RTX
, mode
, unsignedp
,
6248 label_rtx (node
->code_label
));
6250 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
6255 /* Node has no children so we check low and high bounds to remove
6256 redundant tests. Only one of the bounds can exist,
6257 since otherwise this node is bounded--a case tested already. */
6258 int high_bound
= node_has_high_bound (node
, index_type
);
6259 int low_bound
= node_has_low_bound (node
, index_type
);
6261 if (!high_bound
&& low_bound
)
6263 emit_cmp_and_jump_insns (index
,
6266 expand_expr (node
->high
, NULL_RTX
,
6269 GT
, NULL_RTX
, mode
, unsignedp
,
6273 else if (!low_bound
&& high_bound
)
6275 emit_cmp_and_jump_insns (index
,
6278 expand_expr (node
->low
, NULL_RTX
,
6281 LT
, NULL_RTX
, mode
, unsignedp
,
6284 else if (!low_bound
&& !high_bound
)
6286 /* Widen LOW and HIGH to the same width as INDEX. */
6287 tree type
= type_for_mode (mode
, unsignedp
);
6288 tree low
= build1 (CONVERT_EXPR
, type
, node
->low
);
6289 tree high
= build1 (CONVERT_EXPR
, type
, node
->high
);
6290 rtx low_rtx
, new_index
, new_bound
;
6292 /* Instead of doing two branches, emit one unsigned branch for
6293 (index-low) > (high-low). */
6294 low_rtx
= expand_expr (low
, NULL_RTX
, mode
, 0);
6295 new_index
= expand_simple_binop (mode
, MINUS
, index
, low_rtx
,
6296 NULL_RTX
, unsignedp
,
6298 new_bound
= expand_expr (fold (build (MINUS_EXPR
, type
,
6302 emit_cmp_and_jump_insns (new_index
, new_bound
, GT
, NULL_RTX
,
6303 mode
, 1, default_label
);
6306 emit_jump (label_rtx (node
->code_label
));