1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 88, 89, 92-98, 1999 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
22 /* This file handles the generation of rtl code from tree structure
23 above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
24 It also creates the rtl expressions for parameters and auto variables
25 and has full responsibility for allocating stack slots.
27 The functions whose names start with `expand_' are called by the
28 parser to generate RTL instructions for various kinds of constructs.
30 Some control and binding constructs require calling several such
31 functions at different times. For example, a simple if-then
32 is expanded by calling `expand_start_cond' (with the condition-expression
33 as argument) before parsing the then-clause and calling `expand_end_cond'
34 after parsing the then-clause. */
44 #include "insn-flags.h"
45 #include "insn-config.h"
46 #include "insn-codes.h"
48 #include "hard-reg-set.h"
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 /* Each time we expand the end of a binding contour (in `expand_end_bindings')
67 and we emit a new NOTE_INSN_BLOCK_END note, we save a pointer to it here.
68 This is used by the `remember_end_note' function to record the endpoint
69 of each generated block in its associated BLOCK node. */
71 static rtx last_block_end_note;
73 /* Functions and data structures for expanding case statements. */
75 /* Case label structure, used to hold info on labels within case
76 statements. We handle "range" labels; for a single-value label
77 as in C, the high and low limits are the same.
79 An AVL tree of case nodes is initially created, and later transformed
80 to a list linked via the RIGHT fields in the nodes. Nodes with
81 higher case values are later in the list.
83 Switch statements can be output in one of two forms. A branch table
84 is used if there are more than a few labels and the labels are dense
85 within the range between the smallest and largest case value. If a
86 branch table is used, no further manipulations are done with the case
89 The alternative to the use of a branch table is to generate a series
90 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
91 and PARENT fields to hold a binary tree. Initially the tree is
92 totally unbalanced, with everything on the right. We balance the tree
93 with nodes on the left having lower case values than the parent
94 and nodes on the right having higher values. We then output the tree
99 struct case_node *left; /* Left son in binary tree */
100 struct case_node *right; /* Right son in binary tree; also node chain */
101 struct case_node *parent; /* Parent of node in binary tree */
102 tree low; /* Lowest index value for this label */
103 tree high; /* Highest index value for this label */
104 tree code_label; /* Label to jump to when node matches */
108 typedef struct case_node case_node;
109 typedef struct case_node *case_node_ptr;
111 /* These are used by estimate_case_costs and balance_case_nodes. */
113 /* This must be a signed type, and non-ANSI compilers lack signed char. */
114 static short *cost_table;
115 static int use_cost_table;
117 /* Stack of control and binding constructs we are currently inside.
119 These constructs begin when you call `expand_start_WHATEVER'
120 and end when you call `expand_end_WHATEVER'. This stack records
121 info about how the construct began that tells the end-function
122 what to do. It also may provide information about the construct
123 to alter the behavior of other constructs within the body.
124 For example, they may affect the behavior of C `break' and `continue'.
126 Each construct gets one `struct nesting' object.
127 All of these objects are chained through the `all' field.
128 `nesting_stack' points to the first object (innermost construct).
129 The position of an entry on `nesting_stack' is in its `depth' field.
131 Each type of construct has its own individual stack.
132 For example, loops have `loop_stack'. Each object points to the
133 next object of the same type through the `next' field.
135 Some constructs are visible to `break' exit-statements and others
136 are not. Which constructs are visible depends on the language.
137 Therefore, the data structure allows each construct to be visible
138 or not, according to the args given when the construct is started.
139 The construct is visible if the `exit_label' field is non-null.
140 In that case, the value should be a CODE_LABEL rtx. */
145 struct nesting *next;
150 /* For conds (if-then and if-then-else statements). */
153 /* Label for the end of the if construct.
154 There is none if EXITFLAG was not set
155 and no `else' has been seen yet. */
157 /* Label for the end of this alternative.
158 This may be the end of the if or the next else/elseif. */
164 /* Label at the top of the loop; place to loop back to. */
166 /* Label at the end of the whole construct. */
168 /* Label before a jump that branches to the end of the whole
169 construct. This is where destructors go if any. */
171 /* Label for `continue' statement to jump to;
172 this is in front of the stepper of the loop. */
175 /* For variable binding contours. */
178 /* Sequence number of this binding contour within the function,
179 in order of entry. */
180 int block_start_count;
181 /* Nonzero => value to restore stack to on exit. */
183 /* The NOTE that starts this contour.
184 Used by expand_goto to check whether the destination
185 is within each contour or not. */
187 /* Innermost containing binding contour that has a stack level. */
188 struct nesting *innermost_stack_block;
189 /* List of cleanups to be run on exit from this contour.
190 This is a list of expressions to be evaluated.
191 The TREE_PURPOSE of each link is the ..._DECL node
192 which the cleanup pertains to. */
194 /* List of cleanup-lists of blocks containing this block,
195 as they were at the locus where this block appears.
196 There is an element for each containing block,
197 ordered innermost containing block first.
198 The tail of this list can be 0,
199 if all remaining elements would be empty lists.
200 The element's TREE_VALUE is the cleanup-list of that block,
201 which may be null. */
203 /* Chain of labels defined inside this binding contour.
204 For contours that have stack levels or cleanups. */
205 struct label_chain *label_chain;
206 /* Number of function calls seen, as of start of this block. */
207 int n_function_calls;
208 /* Nonzero if this is associated with a EH region. */
209 int exception_region;
210 /* The saved target_temp_slot_level from our outer block.
211 We may reset target_temp_slot_level to be the level of
212 this block, if that is done, target_temp_slot_level
213 reverts to the saved target_temp_slot_level at the very
215 int block_target_temp_slot_level;
216 /* True if we are currently emitting insns in an area of
217 output code that is controlled by a conditional
218 expression. This is used by the cleanup handling code to
219 generate conditional cleanup actions. */
220 int conditional_code;
221 /* A place to move the start of the exception region for any
222 of the conditional cleanups, must be at the end or after
223 the start of the last unconditional cleanup, and before any
224 conditional branch points. */
225 rtx last_unconditional_cleanup;
226 /* When in a conditional context, this is the specific
227 cleanup list associated with last_unconditional_cleanup,
228 where we place the conditionalized cleanups. */
231 /* For switch (C) or case (Pascal) statements,
232 and also for dummies (see `expand_start_case_dummy'). */
235 /* The insn after which the case dispatch should finally
236 be emitted. Zero for a dummy. */
238 /* A list of case labels; it is first built as an AVL tree.
239 During expand_end_case, this is converted to a list, and may be
240 rearranged into a nearly balanced binary tree. */
241 struct case_node *case_list;
242 /* Label to jump to if no case matches. */
244 /* The expression to be dispatched on. */
246 /* Type that INDEX_EXPR should be converted to. */
248 /* Number of range exprs in case statement. */
250 /* Name of this kind of statement, for warnings. */
251 const char *printname;
252 /* Used to save no_line_numbers till we see the first case label.
253 We set this to -1 when we see the first case label in this
255 int line_number_status;
260 /* Allocate and return a new `struct nesting'. */
262 #define ALLOC_NESTING() \
263 (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
265 /* Pop the nesting stack element by element until we pop off
266 the element which is at the top of STACK.
267 Update all the other stacks, popping off elements from them
268 as we pop them from nesting_stack. */
270 #define POPSTACK(STACK) \
271 do { struct nesting *target = STACK; \
272 struct nesting *this; \
273 do { this = nesting_stack; \
274 if (loop_stack == this) \
275 loop_stack = loop_stack->next; \
276 if (cond_stack == this) \
277 cond_stack = cond_stack->next; \
278 if (block_stack == this) \
279 block_stack = block_stack->next; \
280 if (stack_block_stack == this) \
281 stack_block_stack = stack_block_stack->next; \
282 if (case_stack == this) \
283 case_stack = case_stack->next; \
284 nesting_depth = nesting_stack->depth - 1; \
285 nesting_stack = this->all; \
286 obstack_free (&stmt_obstack, this); } \
287 while (this != target); } while (0)
289 /* In some cases it is impossible to generate code for a forward goto
290 until the label definition is seen. This happens when it may be necessary
291 for the goto to reset the stack pointer: we don't yet know how to do that.
292 So expand_goto puts an entry on this fixup list.
293 Each time a binding contour that resets the stack is exited,
295 If the target label has now been defined, we can insert the proper code. */
299 /* Points to following fixup. */
300 struct goto_fixup *next;
301 /* Points to the insn before the jump insn.
302 If more code must be inserted, it goes after this insn. */
304 /* The LABEL_DECL that this jump is jumping to, or 0
305 for break, continue or return. */
307 /* The BLOCK for the place where this goto was found. */
309 /* The CODE_LABEL rtx that this is jumping to. */
311 /* Number of binding contours started in current function
312 before the label reference. */
313 int block_start_count;
314 /* The outermost stack level that should be restored for this jump.
315 Each time a binding contour that resets the stack is exited,
316 if the target label is *not* yet defined, this slot is updated. */
318 /* List of lists of cleanup expressions to be run by this goto.
319 There is one element for each block that this goto is within.
320 The tail of this list can be 0,
321 if all remaining elements would be empty.
322 The TREE_VALUE contains the cleanup list of that block as of the
323 time this goto was seen.
324 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
325 tree cleanup_list_list;
328 /* Within any binding contour that must restore a stack level,
329 all labels are recorded with a chain of these structures. */
333 /* Points to following fixup. */
334 struct label_chain *next;
340 /* Chain of all pending binding contours. */
341 struct nesting *x_block_stack;
343 /* If any new stacks are added here, add them to POPSTACKS too. */
345 /* Chain of all pending binding contours that restore stack levels
347 struct nesting *x_stack_block_stack;
349 /* Chain of all pending conditional statements. */
350 struct nesting *x_cond_stack;
352 /* Chain of all pending loops. */
353 struct nesting *x_loop_stack;
355 /* Chain of all pending case or switch statements. */
356 struct nesting *x_case_stack;
358 /* Separate chain including all of the above,
359 chained through the `all' field. */
360 struct nesting *x_nesting_stack;
362 /* Number of entries on nesting_stack now. */
365 /* Number of binding contours started so far in this function. */
366 int x_block_start_count;
368 /* Each time we expand an expression-statement,
369 record the expr's type and its RTL value here. */
370 tree x_last_expr_type;
371 rtx x_last_expr_value;
373 /* Nonzero if within a ({...}) grouping, in which case we must
374 always compute a value for each expr-stmt in case it is the last one. */
375 int x_expr_stmts_for_value;
377 /* Filename and line number of last line-number note,
378 whether we actually emitted it or not. */
379 char *x_emit_filename;
382 struct goto_fixup *x_goto_fixup_chain;
385 #define block_stack (current_function->stmt->x_block_stack)
386 #define stack_block_stack (current_function->stmt->x_stack_block_stack)
387 #define cond_stack (current_function->stmt->x_cond_stack)
388 #define loop_stack (current_function->stmt->x_loop_stack)
389 #define case_stack (current_function->stmt->x_case_stack)
390 #define nesting_stack (current_function->stmt->x_nesting_stack)
391 #define nesting_depth (current_function->stmt->x_nesting_depth)
392 #define current_block_start_count (current_function->stmt->x_block_start_count)
393 #define last_expr_type (current_function->stmt->x_last_expr_type)
394 #define last_expr_value (current_function->stmt->x_last_expr_value)
395 #define expr_stmts_for_value (current_function->stmt->x_expr_stmts_for_value)
396 #define emit_filename (current_function->stmt->x_emit_filename)
397 #define emit_lineno (current_function->stmt->x_emit_lineno)
398 #define goto_fixup_chain (current_function->stmt->x_goto_fixup_chain)
400 /* Non-zero if we are using EH to handle cleanus. */
401 static int using_eh_for_cleanups_p = 0;
404 static int n_occurrences PROTO((int, const char *));
405 static void expand_goto_internal PROTO((tree, rtx, rtx));
406 static int expand_fixup PROTO((tree, rtx, rtx));
407 static rtx expand_nl_handler_label PROTO((rtx, rtx));
408 static void expand_nl_goto_receiver PROTO((void));
409 static void expand_nl_goto_receivers PROTO((struct nesting *));
410 static void fixup_gotos PROTO((struct nesting *, rtx, tree,
412 static void expand_null_return_1 PROTO((rtx, int));
413 static void expand_value_return PROTO((rtx));
414 static int tail_recursion_args PROTO((tree, tree));
415 static void expand_cleanups PROTO((tree, tree, int, int));
416 static void check_seenlabel PROTO((void));
417 static void do_jump_if_equal PROTO((rtx, rtx, rtx, int));
418 static int estimate_case_costs PROTO((case_node_ptr));
419 static void group_case_nodes PROTO((case_node_ptr));
420 static void balance_case_nodes PROTO((case_node_ptr *,
422 static int node_has_low_bound PROTO((case_node_ptr, tree));
423 static int node_has_high_bound PROTO((case_node_ptr, tree));
424 static int node_is_bounded PROTO((case_node_ptr, tree));
425 static void emit_jump_if_reachable PROTO((rtx));
426 static void emit_case_nodes PROTO((rtx, case_node_ptr, rtx, tree));
427 static int add_case_node PROTO((tree, tree, tree, tree *));
428 static struct case_node *case_tree2list PROTO((case_node *, case_node *));
429 static void mark_cond_nesting PROTO((struct nesting *));
430 static void mark_loop_nesting PROTO((struct nesting *));
431 static void mark_block_nesting PROTO((struct nesting *));
432 static void mark_case_nesting PROTO((struct nesting *));
433 static void mark_goto_fixup PROTO((struct goto_fixup *));
437 using_eh_for_cleanups ()
439 using_eh_for_cleanups_p = 1;
442 /* Mark N (known to be a cond-nesting) for GC. */
445 mark_cond_nesting (n)
450 ggc_mark_rtx (n->exit_label);
451 ggc_mark_rtx (n->data.cond.endif_label);
452 ggc_mark_rtx (n->data.cond.next_label);
458 /* Mark N (known to be a loop-nesting) for GC. */
461 mark_loop_nesting (n)
467 ggc_mark_rtx (n->exit_label);
468 ggc_mark_rtx (n->data.loop.start_label);
469 ggc_mark_rtx (n->data.loop.end_label);
470 ggc_mark_rtx (n->data.loop.alt_end_label);
471 ggc_mark_rtx (n->data.loop.continue_label);
477 /* Mark N (known to be a block-nesting) for GC. */
480 mark_block_nesting (n)
485 struct label_chain *l;
487 ggc_mark_rtx (n->exit_label);
488 ggc_mark_rtx (n->data.block.stack_level);
489 ggc_mark_rtx (n->data.block.first_insn);
490 ggc_mark_tree (n->data.block.cleanups);
491 ggc_mark_tree (n->data.block.outer_cleanups);
493 for (l = n->data.block.label_chain; l != NULL; l = l->next)
494 ggc_mark_tree (l->label);
496 ggc_mark_rtx (n->data.block.last_unconditional_cleanup);
498 /* ??? cleanup_ptr never points outside the stack, does it? */
504 /* Mark N (known to be a case-nesting) for GC. */
507 mark_case_nesting (n)
512 struct case_node *node;
514 ggc_mark_rtx (n->exit_label);
515 ggc_mark_rtx (n->data.case_stmt.start);
517 node = n->data.case_stmt.case_list;
520 ggc_mark_tree (node->low);
521 ggc_mark_tree (node->high);
522 ggc_mark_tree (node->code_label);
526 ggc_mark_tree (n->data.case_stmt.default_label);
527 ggc_mark_tree (n->data.case_stmt.index_expr);
528 ggc_mark_tree (n->data.case_stmt.nominal_type);
538 struct goto_fixup *g;
542 ggc_mark_rtx (g->before_jump);
543 ggc_mark_tree (g->target);
544 ggc_mark_tree (g->context);
545 ggc_mark_rtx (g->target_rtl);
546 ggc_mark_rtx (g->stack_level);
547 ggc_mark_tree (g->cleanup_list_list);
553 /* Clear out all parts of the state in F that can safely be discarded
554 after the function has been compiled, to let garbage collection
555 reclaim the memory. */
561 /* We're about to free the function obstack. If we hold pointers to
562 things allocated there, then we'll try to mark them when we do
563 GC. So, we clear them out here explicitly. */
564 f->stmt->x_goto_fixup_chain = 0;
571 struct stmt_status *p;
576 mark_block_nesting (p->x_block_stack);
577 mark_cond_nesting (p->x_cond_stack);
578 mark_loop_nesting (p->x_loop_stack);
579 mark_case_nesting (p->x_case_stack);
581 ggc_mark_tree (p->x_last_expr_type);
582 /* last_epxr_value is only valid if last_expr_type is nonzero. */
583 if (p->x_last_expr_type)
584 ggc_mark_rtx (p->x_last_expr_value);
586 mark_goto_fixup (p->x_goto_fixup_chain);
592 gcc_obstack_init (&stmt_obstack);
597 init_stmt_for_function ()
599 current_function->stmt
600 = (struct stmt_status *) xmalloc (sizeof (struct stmt_status));
602 /* We are not currently within any block, conditional, loop or case. */
604 stack_block_stack = 0;
611 current_block_start_count = 0;
613 /* No gotos have been expanded yet. */
614 goto_fixup_chain = 0;
616 /* We are not processing a ({...}) grouping. */
617 expr_stmts_for_value = 0;
619 last_expr_value = NULL_RTX;
621 init_eh_for_function ();
624 /* Return nonzero if anything is pushed on the loop, condition, or case
629 return cond_stack || loop_stack || case_stack;
632 /* Record the current file and line. Called from emit_line_note. */
634 set_file_and_line_for_stmt (file, line)
638 emit_filename = file;
642 /* Emit a no-op instruction. */
649 last_insn = get_last_insn ();
651 && (GET_CODE (last_insn) == CODE_LABEL
652 || (GET_CODE (last_insn) == NOTE
653 && prev_real_insn (last_insn) == 0)))
654 emit_insn (gen_nop ());
657 /* Return the rtx-label that corresponds to a LABEL_DECL,
658 creating it if necessary. */
664 if (TREE_CODE (label) != LABEL_DECL)
667 if (DECL_RTL (label))
668 return DECL_RTL (label);
670 return DECL_RTL (label) = gen_label_rtx ();
673 /* Add an unconditional jump to LABEL as the next sequential instruction. */
679 do_pending_stack_adjust ();
680 emit_jump_insn (gen_jump (label));
684 /* Emit code to jump to the address
685 specified by the pointer expression EXP. */
688 expand_computed_goto (exp)
691 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
693 #ifdef POINTERS_EXTEND_UNSIGNED
694 x = convert_memory_address (Pmode, x);
698 /* Be sure the function is executable. */
699 if (current_function_check_memory_usage)
700 emit_library_call (chkr_check_exec_libfunc, 1,
701 VOIDmode, 1, x, ptr_mode);
703 do_pending_stack_adjust ();
704 emit_indirect_jump (x);
706 current_function_has_computed_jump = 1;
709 /* Handle goto statements and the labels that they can go to. */
711 /* Specify the location in the RTL code of a label LABEL,
712 which is a LABEL_DECL tree node.
714 This is used for the kind of label that the user can jump to with a
715 goto statement, and for alternatives of a switch or case statement.
716 RTL labels generated for loops and conditionals don't go through here;
717 they are generated directly at the RTL level, by other functions below.
719 Note that this has nothing to do with defining label *names*.
720 Languages vary in how they do that and what that even means. */
726 struct label_chain *p;
728 do_pending_stack_adjust ();
729 emit_label (label_rtx (label));
730 if (DECL_NAME (label))
731 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
733 if (stack_block_stack != 0)
735 p = (struct label_chain *) oballoc (sizeof (struct label_chain));
736 p->next = stack_block_stack->data.block.label_chain;
737 stack_block_stack->data.block.label_chain = p;
742 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
743 from nested functions. */
746 declare_nonlocal_label (label)
749 rtx slot = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
751 nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
752 LABEL_PRESERVE_P (label_rtx (label)) = 1;
753 if (nonlocal_goto_handler_slots == 0)
755 emit_stack_save (SAVE_NONLOCAL,
756 &nonlocal_goto_stack_level,
757 PREV_INSN (tail_recursion_reentry));
759 nonlocal_goto_handler_slots
760 = gen_rtx_EXPR_LIST (VOIDmode, slot, nonlocal_goto_handler_slots);
763 /* Generate RTL code for a `goto' statement with target label LABEL.
764 LABEL should be a LABEL_DECL tree node that was or will later be
765 defined with `expand_label'. */
773 /* Check for a nonlocal goto to a containing function. */
774 context = decl_function_context (label);
775 if (context != 0 && context != current_function_decl)
777 struct function *p = find_function_data (context);
778 rtx label_ref = gen_rtx_LABEL_REF (Pmode, label_rtx (label));
779 rtx temp, handler_slot;
782 /* Find the corresponding handler slot for this label. */
783 handler_slot = p->x_nonlocal_goto_handler_slots;
784 for (link = p->x_nonlocal_labels; TREE_VALUE (link) != label;
785 link = TREE_CHAIN (link))
786 handler_slot = XEXP (handler_slot, 1);
787 handler_slot = XEXP (handler_slot, 0);
789 p->has_nonlocal_label = 1;
790 current_function_has_nonlocal_goto = 1;
791 LABEL_REF_NONLOCAL_P (label_ref) = 1;
793 /* Copy the rtl for the slots so that they won't be shared in
794 case the virtual stack vars register gets instantiated differently
795 in the parent than in the child. */
797 #if HAVE_nonlocal_goto
798 if (HAVE_nonlocal_goto)
799 emit_insn (gen_nonlocal_goto (lookup_static_chain (label),
800 copy_rtx (handler_slot),
801 copy_rtx (p->x_nonlocal_goto_stack_level),
808 /* Restore frame pointer for containing function.
809 This sets the actual hard register used for the frame pointer
810 to the location of the function's incoming static chain info.
811 The non-local goto handler will then adjust it to contain the
812 proper value and reload the argument pointer, if needed. */
813 emit_move_insn (hard_frame_pointer_rtx, lookup_static_chain (label));
815 /* We have now loaded the frame pointer hardware register with
816 the address of that corresponds to the start of the virtual
817 stack vars. So replace virtual_stack_vars_rtx in all
818 addresses we use with stack_pointer_rtx. */
820 /* Get addr of containing function's current nonlocal goto handler,
821 which will do any cleanups and then jump to the label. */
822 addr = copy_rtx (handler_slot);
823 temp = copy_to_reg (replace_rtx (addr, virtual_stack_vars_rtx,
824 hard_frame_pointer_rtx));
826 /* Restore the stack pointer. Note this uses fp just restored. */
827 addr = p->x_nonlocal_goto_stack_level;
829 addr = replace_rtx (copy_rtx (addr),
830 virtual_stack_vars_rtx,
831 hard_frame_pointer_rtx);
833 emit_stack_restore (SAVE_NONLOCAL, addr, NULL_RTX);
835 /* USE of hard_frame_pointer_rtx added for consistency; not clear if
837 emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx));
838 emit_insn (gen_rtx_USE (VOIDmode, stack_pointer_rtx));
839 emit_indirect_jump (temp);
843 expand_goto_internal (label, label_rtx (label), NULL_RTX);
846 /* Generate RTL code for a `goto' statement with target label BODY.
847 LABEL should be a LABEL_REF.
848 LAST_INSN, if non-0, is the rtx we should consider as the last
849 insn emitted (for the purposes of cleaning up a return). */
852 expand_goto_internal (body, label, last_insn)
857 struct nesting *block;
860 if (GET_CODE (label) != CODE_LABEL)
863 /* If label has already been defined, we can tell now
864 whether and how we must alter the stack level. */
866 if (PREV_INSN (label) != 0)
868 /* Find the innermost pending block that contains the label.
869 (Check containment by comparing insn-uids.)
870 Then restore the outermost stack level within that block,
871 and do cleanups of all blocks contained in it. */
872 for (block = block_stack; block; block = block->next)
874 if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
876 if (block->data.block.stack_level != 0)
877 stack_level = block->data.block.stack_level;
878 /* Execute the cleanups for blocks we are exiting. */
879 if (block->data.block.cleanups != 0)
881 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
882 do_pending_stack_adjust ();
888 /* Ensure stack adjust isn't done by emit_jump, as this
889 would clobber the stack pointer. This one should be
890 deleted as dead by flow. */
891 clear_pending_stack_adjust ();
892 do_pending_stack_adjust ();
893 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
896 if (body != 0 && DECL_TOO_LATE (body))
897 error ("jump to `%s' invalidly jumps into binding contour",
898 IDENTIFIER_POINTER (DECL_NAME (body)));
900 /* Label not yet defined: may need to put this goto
901 on the fixup list. */
902 else if (! expand_fixup (body, label, last_insn))
904 /* No fixup needed. Record that the label is the target
905 of at least one goto that has no fixup. */
907 TREE_ADDRESSABLE (body) = 1;
913 /* Generate if necessary a fixup for a goto
914 whose target label in tree structure (if any) is TREE_LABEL
915 and whose target in rtl is RTL_LABEL.
917 If LAST_INSN is nonzero, we pretend that the jump appears
918 after insn LAST_INSN instead of at the current point in the insn stream.
920 The fixup will be used later to insert insns just before the goto.
921 Those insns will restore the stack level as appropriate for the
922 target label, and will (in the case of C++) also invoke any object
923 destructors which have to be invoked when we exit the scopes which
924 are exited by the goto.
926 Value is nonzero if a fixup is made. */
929 expand_fixup (tree_label, rtl_label, last_insn)
934 struct nesting *block, *end_block;
936 /* See if we can recognize which block the label will be output in.
937 This is possible in some very common cases.
938 If we succeed, set END_BLOCK to that block.
939 Otherwise, set it to 0. */
942 && (rtl_label == cond_stack->data.cond.endif_label
943 || rtl_label == cond_stack->data.cond.next_label))
944 end_block = cond_stack;
945 /* If we are in a loop, recognize certain labels which
946 are likely targets. This reduces the number of fixups
947 we need to create. */
949 && (rtl_label == loop_stack->data.loop.start_label
950 || rtl_label == loop_stack->data.loop.end_label
951 || rtl_label == loop_stack->data.loop.continue_label))
952 end_block = loop_stack;
956 /* Now set END_BLOCK to the binding level to which we will return. */
960 struct nesting *next_block = end_block->all;
963 /* First see if the END_BLOCK is inside the innermost binding level.
964 If so, then no cleanups or stack levels are relevant. */
965 while (next_block && next_block != block)
966 next_block = next_block->all;
971 /* Otherwise, set END_BLOCK to the innermost binding level
972 which is outside the relevant control-structure nesting. */
973 next_block = block_stack->next;
974 for (block = block_stack; block != end_block; block = block->all)
975 if (block == next_block)
976 next_block = next_block->next;
977 end_block = next_block;
980 /* Does any containing block have a stack level or cleanups?
981 If not, no fixup is needed, and that is the normal case
982 (the only case, for standard C). */
983 for (block = block_stack; block != end_block; block = block->next)
984 if (block->data.block.stack_level != 0
985 || block->data.block.cleanups != 0)
988 if (block != end_block)
990 /* Ok, a fixup is needed. Add a fixup to the list of such. */
991 struct goto_fixup *fixup
992 = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup));
993 /* In case an old stack level is restored, make sure that comes
994 after any pending stack adjust. */
995 /* ?? If the fixup isn't to come at the present position,
996 doing the stack adjust here isn't useful. Doing it with our
997 settings at that location isn't useful either. Let's hope
1000 do_pending_stack_adjust ();
1001 fixup->target = tree_label;
1002 fixup->target_rtl = rtl_label;
1004 /* Create a BLOCK node and a corresponding matched set of
1005 NOTE_INSN_BEGIN_BLOCK and NOTE_INSN_END_BLOCK notes at
1006 this point. The notes will encapsulate any and all fixup
1007 code which we might later insert at this point in the insn
1008 stream. Also, the BLOCK node will be the parent (i.e. the
1009 `SUPERBLOCK') of any other BLOCK nodes which we might create
1010 later on when we are expanding the fixup code.
1012 Note that optimization passes (including expand_end_loop)
1013 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
1014 as a placeholder. */
1017 register rtx original_before_jump
1018 = last_insn ? last_insn : get_last_insn ();
1023 start = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
1024 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_DELETED);
1025 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
1026 fixup->context = poplevel (1, 0, 0); /* Create the BLOCK node now! */
1028 emit_insns_after (start, original_before_jump);
1031 fixup->block_start_count = current_block_start_count;
1032 fixup->stack_level = 0;
1033 fixup->cleanup_list_list
1034 = ((block->data.block.outer_cleanups
1035 || block->data.block.cleanups)
1036 ? tree_cons (NULL_TREE, block->data.block.cleanups,
1037 block->data.block.outer_cleanups)
1039 fixup->next = goto_fixup_chain;
1040 goto_fixup_chain = fixup;
1048 /* Expand any needed fixups in the outputmost binding level of the
1049 function. FIRST_INSN is the first insn in the function. */
1052 expand_fixups (first_insn)
1055 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0);
1058 /* When exiting a binding contour, process all pending gotos requiring fixups.
1059 THISBLOCK is the structure that describes the block being exited.
1060 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1061 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1062 FIRST_INSN is the insn that began this contour.
1064 Gotos that jump out of this contour must restore the
1065 stack level and do the cleanups before actually jumping.
1067 DONT_JUMP_IN nonzero means report error there is a jump into this
1068 contour from before the beginning of the contour.
1069 This is also done if STACK_LEVEL is nonzero. */
1072 fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1073 struct nesting *thisblock;
1079 register struct goto_fixup *f, *prev;
1081 /* F is the fixup we are considering; PREV is the previous one. */
1082 /* We run this loop in two passes so that cleanups of exited blocks
1083 are run first, and blocks that are exited are marked so
1086 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1088 /* Test for a fixup that is inactive because it is already handled. */
1089 if (f->before_jump == 0)
1091 /* Delete inactive fixup from the chain, if that is easy to do. */
1093 prev->next = f->next;
1095 /* Has this fixup's target label been defined?
1096 If so, we can finalize it. */
1097 else if (PREV_INSN (f->target_rtl) != 0)
1099 register rtx cleanup_insns;
1101 /* Get the first non-label after the label
1102 this goto jumps to. If that's before this scope begins,
1103 we don't have a jump into the scope. */
1104 rtx after_label = f->target_rtl;
1105 while (after_label != 0 && GET_CODE (after_label) == CODE_LABEL)
1106 after_label = NEXT_INSN (after_label);
1108 /* If this fixup jumped into this contour from before the beginning
1109 of this contour, report an error. */
1110 /* ??? Bug: this does not detect jumping in through intermediate
1111 blocks that have stack levels or cleanups.
1112 It detects only a problem with the innermost block
1113 around the label. */
1115 && (dont_jump_in || stack_level || cleanup_list)
1116 /* If AFTER_LABEL is 0, it means the jump goes to the end
1117 of the rtl, which means it jumps into this scope. */
1118 && (after_label == 0
1119 || INSN_UID (first_insn) < INSN_UID (after_label))
1120 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1121 && ! DECL_ERROR_ISSUED (f->target))
1123 error_with_decl (f->target,
1124 "label `%s' used before containing binding contour");
1125 /* Prevent multiple errors for one label. */
1126 DECL_ERROR_ISSUED (f->target) = 1;
1129 /* We will expand the cleanups into a sequence of their own and
1130 then later on we will attach this new sequence to the insn
1131 stream just ahead of the actual jump insn. */
1135 /* Temporarily restore the lexical context where we will
1136 logically be inserting the fixup code. We do this for the
1137 sake of getting the debugging information right. */
1140 set_block (f->context);
1142 /* Expand the cleanups for blocks this jump exits. */
1143 if (f->cleanup_list_list)
1146 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1147 /* Marked elements correspond to blocks that have been closed.
1148 Do their cleanups. */
1149 if (TREE_ADDRESSABLE (lists)
1150 && TREE_VALUE (lists) != 0)
1152 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1153 /* Pop any pushes done in the cleanups,
1154 in case function is about to return. */
1155 do_pending_stack_adjust ();
1159 /* Restore stack level for the biggest contour that this
1160 jump jumps out of. */
1162 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1164 /* Finish up the sequence containing the insns which implement the
1165 necessary cleanups, and then attach that whole sequence to the
1166 insn stream just ahead of the actual jump insn. Attaching it
1167 at that point insures that any cleanups which are in fact
1168 implicit C++ object destructions (which must be executed upon
1169 leaving the block) appear (to the debugger) to be taking place
1170 in an area of the generated code where the object(s) being
1171 destructed are still "in scope". */
1173 cleanup_insns = get_insns ();
1177 emit_insns_after (cleanup_insns, f->before_jump);
1184 /* For any still-undefined labels, do the cleanups for this block now.
1185 We must do this now since items in the cleanup list may go out
1186 of scope when the block ends. */
1187 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1188 if (f->before_jump != 0
1189 && PREV_INSN (f->target_rtl) == 0
1190 /* Label has still not appeared. If we are exiting a block with
1191 a stack level to restore, that started before the fixup,
1192 mark this stack level as needing restoration
1193 when the fixup is later finalized. */
1195 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1196 means the label is undefined. That's erroneous, but possible. */
1197 && (thisblock->data.block.block_start_count
1198 <= f->block_start_count))
1200 tree lists = f->cleanup_list_list;
1203 for (; lists; lists = TREE_CHAIN (lists))
1204 /* If the following elt. corresponds to our containing block
1205 then the elt. must be for this block. */
1206 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
1210 set_block (f->context);
1211 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1212 do_pending_stack_adjust ();
1213 cleanup_insns = get_insns ();
1216 if (cleanup_insns != 0)
1218 = emit_insns_after (cleanup_insns, f->before_jump);
1220 f->cleanup_list_list = TREE_CHAIN (lists);
1224 f->stack_level = stack_level;
1228 /* Return the number of times character C occurs in string S. */
1230 n_occurrences (c, s)
1240 /* Generate RTL for an asm statement (explicit assembler code).
1241 BODY is a STRING_CST node containing the assembler code text,
1242 or an ADDR_EXPR containing a STRING_CST. */
1248 if (current_function_check_memory_usage)
1250 error ("`asm' cannot be used in function where memory usage is checked");
1254 if (TREE_CODE (body) == ADDR_EXPR)
1255 body = TREE_OPERAND (body, 0);
1257 emit_insn (gen_rtx_ASM_INPUT (VOIDmode,
1258 TREE_STRING_POINTER (body)));
1262 /* Generate RTL for an asm statement with arguments.
1263 STRING is the instruction template.
1264 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1265 Each output or input has an expression in the TREE_VALUE and
1266 a constraint-string in the TREE_PURPOSE.
1267 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1268 that is clobbered by this insn.
1270 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1271 Some elements of OUTPUTS may be replaced with trees representing temporary
1272 values. The caller should copy those temporary values to the originally
1275 VOL nonzero means the insn is volatile; don't optimize it. */
1278 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1279 tree string, outputs, inputs, clobbers;
1284 rtvec argvec, constraints;
1286 int ninputs = list_length (inputs);
1287 int noutputs = list_length (outputs);
1292 /* Vector of RTX's of evaluated output operands. */
1293 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1294 int *inout_opnum = (int *) alloca (noutputs * sizeof (int));
1295 rtx *real_output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1296 enum machine_mode *inout_mode
1297 = (enum machine_mode *) alloca (noutputs * sizeof (enum machine_mode));
1298 /* The insn we have emitted. */
1301 /* An ASM with no outputs needs to be treated as volatile, for now. */
1305 if (current_function_check_memory_usage)
1307 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1311 #ifdef MD_ASM_CLOBBERS
1312 /* Sometimes we wish to automatically clobber registers across an asm.
1313 Case in point is when the i386 backend moved from cc0 to a hard reg --
1314 maintaining source-level compatability means automatically clobbering
1315 the flags register. */
1316 MD_ASM_CLOBBERS (clobbers);
1319 if (current_function_check_memory_usage)
1321 error ("`asm' cannot be used in function where memory usage is checked");
1325 /* Count the number of meaningful clobbered registers, ignoring what
1326 we would ignore later. */
1328 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1330 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1331 i = decode_reg_name (regname);
1332 if (i >= 0 || i == -4)
1335 error ("unknown register name `%s' in `asm'", regname);
1340 /* Check that the number of alternatives is constant across all
1342 if (outputs || inputs)
1344 tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
1345 int nalternatives = n_occurrences (',', TREE_STRING_POINTER (tmp));
1348 if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
1350 error ("too many alternatives in `asm'");
1357 char *constraint = TREE_STRING_POINTER (TREE_PURPOSE (tmp));
1358 if (n_occurrences (',', constraint) != nalternatives)
1360 error ("operand constraints for `asm' differ in number of alternatives");
1363 if (TREE_CHAIN (tmp))
1364 tmp = TREE_CHAIN (tmp);
1366 tmp = next, next = 0;
1370 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1372 tree val = TREE_VALUE (tail);
1373 tree type = TREE_TYPE (val);
1382 /* If there's an erroneous arg, emit no insn. */
1383 if (TREE_TYPE (val) == error_mark_node)
1386 /* Make sure constraint has `=' and does not have `+'. Also, see
1387 if it allows any register. Be liberal on the latter test, since
1388 the worst that happens if we get it wrong is we issue an error
1391 c_len = TREE_STRING_LENGTH (TREE_PURPOSE (tail)) - 1;
1392 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1394 /* Allow the `=' or `+' to not be at the beginning of the string,
1395 since it wasn't explicitly documented that way, and there is a
1396 large body of code that puts it last. Swap the character to
1397 the front, so as not to uglify any place else. */
1401 if ((p = strchr (constraint, '=')) != NULL)
1403 if ((p = strchr (constraint, '+')) != NULL)
1406 error ("output operand constraint lacks `='");
1410 if (p != constraint)
1413 bcopy (constraint, constraint+1, p-constraint);
1416 warning ("output constraint `%c' for operand %d is not at the beginning", j, i);
1419 is_inout = constraint[0] == '+';
1420 /* Replace '+' with '='. */
1421 constraint[0] = '=';
1422 /* Make sure we can specify the matching operand. */
1423 if (is_inout && i > 9)
1425 error ("output operand constraint %d contains `+'", i);
1429 for (j = 1; j < c_len; j++)
1430 switch (constraint[j])
1434 error ("operand constraint contains '+' or '=' at illegal position.");
1438 if (i + 1 == ninputs + noutputs)
1440 error ("`%%' constraint used with last operand");
1445 case '?': case '!': case '*': case '&':
1446 case 'E': case 'F': case 'G': case 'H':
1447 case 's': case 'i': case 'n':
1448 case 'I': case 'J': case 'K': case 'L': case 'M':
1449 case 'N': case 'O': case 'P': case ',':
1450 #ifdef EXTRA_CONSTRAINT
1451 case 'Q': case 'R': case 'S': case 'T': case 'U':
1455 case '0': case '1': case '2': case '3': case '4':
1456 case '5': case '6': case '7': case '8': case '9':
1457 error ("matching constraint not valid in output operand");
1460 case 'V': case 'm': case 'o':
1465 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1466 excepting those that expand_call created. So match memory
1482 /* If an output operand is not a decl or indirect ref and our constraint
1483 allows a register, make a temporary to act as an intermediate.
1484 Make the asm insn write into that, then our caller will copy it to
1485 the real output operand. Likewise for promoted variables. */
1487 real_output_rtx[i] = NULL_RTX;
1488 if ((TREE_CODE (val) == INDIRECT_REF
1490 || (TREE_CODE_CLASS (TREE_CODE (val)) == 'd'
1491 && (allows_mem || GET_CODE (DECL_RTL (val)) == REG)
1492 && ! (GET_CODE (DECL_RTL (val)) == REG
1493 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
1498 mark_addressable (TREE_VALUE (tail));
1501 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode,
1502 EXPAND_MEMORY_USE_WO);
1504 if (! allows_reg && GET_CODE (output_rtx[i]) != MEM)
1505 error ("output number %d not directly addressable", i);
1506 if (! allows_mem && GET_CODE (output_rtx[i]) == MEM)
1508 real_output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1509 output_rtx[i] = gen_reg_rtx (GET_MODE (output_rtx[i]));
1511 emit_move_insn (output_rtx[i], real_output_rtx[i]);
1516 output_rtx[i] = assign_temp (type, 0, 0, 0);
1517 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1522 inout_mode[ninout] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)));
1523 inout_opnum[ninout++] = i;
1528 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1530 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1534 /* Make vectors for the expression-rtx and constraint strings. */
1536 argvec = rtvec_alloc (ninputs);
1537 constraints = rtvec_alloc (ninputs);
1539 body = gen_rtx_ASM_OPERANDS (VOIDmode,
1540 TREE_STRING_POINTER (string), "", 0, argvec,
1541 constraints, filename, line);
1543 MEM_VOLATILE_P (body) = vol;
1545 /* Eval the inputs and put them into ARGVEC.
1546 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1549 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1552 int allows_reg = 0, allows_mem = 0;
1553 char *constraint, *orig_constraint;
1557 /* If there's an erroneous arg, emit no insn,
1558 because the ASM_INPUT would get VOIDmode
1559 and that could cause a crash in reload. */
1560 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1563 /* ??? Can this happen, and does the error message make any sense? */
1564 if (TREE_PURPOSE (tail) == NULL_TREE)
1566 error ("hard register `%s' listed as input operand to `asm'",
1567 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1571 c_len = TREE_STRING_LENGTH (TREE_PURPOSE (tail)) - 1;
1572 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1573 orig_constraint = constraint;
1575 /* Make sure constraint has neither `=', `+', nor '&'. */
1577 for (j = 0; j < c_len; j++)
1578 switch (constraint[j])
1580 case '+': case '=': case '&':
1581 if (constraint == orig_constraint)
1583 error ("input operand constraint contains `%c'", constraint[j]);
1589 if (constraint == orig_constraint
1590 && i + 1 == ninputs - ninout)
1592 error ("`%%' constraint used with last operand");
1597 case 'V': case 'm': case 'o':
1602 case '?': case '!': case '*':
1603 case 'E': case 'F': case 'G': case 'H': case 'X':
1604 case 's': case 'i': case 'n':
1605 case 'I': case 'J': case 'K': case 'L': case 'M':
1606 case 'N': case 'O': case 'P': case ',':
1607 #ifdef EXTRA_CONSTRAINT
1608 case 'Q': case 'R': case 'S': case 'T': case 'U':
1612 /* Whether or not a numeric constraint allows a register is
1613 decided by the matching constraint, and so there is no need
1614 to do anything special with them. We must handle them in
1615 the default case, so that we don't unnecessarily force
1616 operands to memory. */
1617 case '0': case '1': case '2': case '3': case '4':
1618 case '5': case '6': case '7': case '8': case '9':
1619 if (constraint[j] >= '0' + noutputs)
1622 ("matching constraint references invalid operand number");
1626 /* Try and find the real constraint for this dup. */
1627 if ((j == 0 && c_len == 1)
1628 || (j == 1 && c_len == 2 && constraint[0] == '%'))
1631 for (j = constraint[j] - '0'; j > 0; --j)
1634 c_len = TREE_STRING_LENGTH (TREE_PURPOSE (o)) - 1;
1635 constraint = TREE_STRING_POINTER (TREE_PURPOSE (o));
1640 /* ... fall through ... */
1653 if (! allows_reg && allows_mem)
1654 mark_addressable (TREE_VALUE (tail));
1656 op = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1658 if (asm_operand_ok (op, constraint) <= 0)
1661 op = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), op);
1662 else if (!allows_mem)
1663 warning ("asm operand %d probably doesn't match constraints", i);
1664 else if (CONSTANT_P (op))
1665 op = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1667 else if (GET_CODE (op) == REG
1668 || GET_CODE (op) == SUBREG
1669 || GET_CODE (op) == CONCAT)
1671 tree type = TREE_TYPE (TREE_VALUE (tail));
1672 rtx memloc = assign_temp (type, 1, 1, 1);
1674 emit_move_insn (memloc, op);
1677 else if (GET_CODE (op) == MEM && MEM_VOLATILE_P (op))
1678 /* We won't recognize volatile memory as available a
1679 memory_operand at this point. Ignore it. */
1681 else if (queued_subexp_p (op))
1684 /* ??? Leave this only until we have experience with what
1685 happens in combine and elsewhere when constraints are
1687 warning ("asm operand %d probably doesn't match constraints", i);
1689 XVECEXP (body, 3, i) = op;
1691 XVECEXP (body, 4, i) /* constraints */
1692 = gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1697 /* Protect all the operands from the queue,
1698 now that they have all been evaluated. */
1700 for (i = 0; i < ninputs - ninout; i++)
1701 XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0);
1703 for (i = 0; i < noutputs; i++)
1704 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1706 /* For in-out operands, copy output rtx to input rtx. */
1707 for (i = 0; i < ninout; i++)
1709 static char match[9+1][2]
1710 = {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9"};
1711 int j = inout_opnum[i];
1713 XVECEXP (body, 3, ninputs - ninout + i) /* argvec */
1715 XVECEXP (body, 4, ninputs - ninout + i) /* constraints */
1716 = gen_rtx_ASM_INPUT (inout_mode[i], match[j]);
1719 /* Now, for each output, construct an rtx
1720 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1721 ARGVEC CONSTRAINTS))
1722 If there is more than one, put them inside a PARALLEL. */
1724 if (noutputs == 1 && nclobbers == 0)
1726 XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1727 insn = emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
1729 else if (noutputs == 0 && nclobbers == 0)
1731 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1732 insn = emit_insn (body);
1738 if (num == 0) num = 1;
1739 body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
1741 /* For each output operand, store a SET. */
1743 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1745 XVECEXP (body, 0, i)
1746 = gen_rtx_SET (VOIDmode,
1748 gen_rtx_ASM_OPERANDS
1750 TREE_STRING_POINTER (string),
1751 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1752 i, argvec, constraints,
1755 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1758 /* If there are no outputs (but there are some clobbers)
1759 store the bare ASM_OPERANDS into the PARALLEL. */
1762 XVECEXP (body, 0, i++) = obody;
1764 /* Store (clobber REG) for each clobbered register specified. */
1766 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1768 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1769 int j = decode_reg_name (regname);
1773 if (j == -3) /* `cc', which is not a register */
1776 if (j == -4) /* `memory', don't cache memory across asm */
1778 XVECEXP (body, 0, i++)
1779 = gen_rtx_CLOBBER (VOIDmode,
1782 gen_rtx_SCRATCH (VOIDmode)));
1786 /* Ignore unknown register, error already signaled. */
1790 /* Use QImode since that's guaranteed to clobber just one reg. */
1791 XVECEXP (body, 0, i++)
1792 = gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (QImode, j));
1795 insn = emit_insn (body);
1798 /* For any outputs that needed reloading into registers, spill them
1799 back to where they belong. */
1800 for (i = 0; i < noutputs; ++i)
1801 if (real_output_rtx[i])
1802 emit_move_insn (real_output_rtx[i], output_rtx[i]);
1807 /* Generate RTL to evaluate the expression EXP
1808 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1811 expand_expr_stmt (exp)
1814 /* If -W, warn about statements with no side effects,
1815 except for an explicit cast to void (e.g. for assert()), and
1816 except inside a ({...}) where they may be useful. */
1817 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1819 if (! TREE_SIDE_EFFECTS (exp) && (extra_warnings || warn_unused)
1820 && !(TREE_CODE (exp) == CONVERT_EXPR
1821 && TREE_TYPE (exp) == void_type_node))
1822 warning_with_file_and_line (emit_filename, emit_lineno,
1823 "statement with no effect");
1824 else if (warn_unused)
1825 warn_if_unused_value (exp);
1828 /* If EXP is of function type and we are expanding statements for
1829 value, convert it to pointer-to-function. */
1830 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1831 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1833 last_expr_type = TREE_TYPE (exp);
1834 last_expr_value = expand_expr (exp,
1835 (expr_stmts_for_value
1836 ? NULL_RTX : const0_rtx),
1839 /* If all we do is reference a volatile value in memory,
1840 copy it to a register to be sure it is actually touched. */
1841 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1842 && TREE_THIS_VOLATILE (exp))
1844 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1846 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1847 copy_to_reg (last_expr_value);
1850 rtx lab = gen_label_rtx ();
1852 /* Compare the value with itself to reference it. */
1853 emit_cmp_and_jump_insns (last_expr_value, last_expr_value, EQ,
1854 expand_expr (TYPE_SIZE (last_expr_type),
1855 NULL_RTX, VOIDmode, 0),
1857 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT,
1863 /* If this expression is part of a ({...}) and is in memory, we may have
1864 to preserve temporaries. */
1865 preserve_temp_slots (last_expr_value);
1867 /* Free any temporaries used to evaluate this expression. Any temporary
1868 used as a result of this expression will already have been preserved
1875 /* Warn if EXP contains any computations whose results are not used.
1876 Return 1 if a warning is printed; 0 otherwise. */
1879 warn_if_unused_value (exp)
1882 if (TREE_USED (exp))
1885 switch (TREE_CODE (exp))
1887 case PREINCREMENT_EXPR:
1888 case POSTINCREMENT_EXPR:
1889 case PREDECREMENT_EXPR:
1890 case POSTDECREMENT_EXPR:
1895 case METHOD_CALL_EXPR:
1897 case TRY_CATCH_EXPR:
1898 case WITH_CLEANUP_EXPR:
1900 /* We don't warn about COND_EXPR because it may be a useful
1901 construct if either arm contains a side effect. */
1906 /* For a binding, warn if no side effect within it. */
1907 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1910 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1912 case TRUTH_ORIF_EXPR:
1913 case TRUTH_ANDIF_EXPR:
1914 /* In && or ||, warn if 2nd operand has no side effect. */
1915 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1918 if (TREE_NO_UNUSED_WARNING (exp))
1920 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
1922 /* Let people do `(foo (), 0)' without a warning. */
1923 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1925 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1929 case NON_LVALUE_EXPR:
1930 /* Don't warn about values cast to void. */
1931 if (TREE_TYPE (exp) == void_type_node)
1933 /* Don't warn about conversions not explicit in the user's program. */
1934 if (TREE_NO_UNUSED_WARNING (exp))
1936 /* Assignment to a cast usually results in a cast of a modify.
1937 Don't complain about that. There can be an arbitrary number of
1938 casts before the modify, so we must loop until we find the first
1939 non-cast expression and then test to see if that is a modify. */
1941 tree tem = TREE_OPERAND (exp, 0);
1943 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1944 tem = TREE_OPERAND (tem, 0);
1946 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
1947 || TREE_CODE (tem) == CALL_EXPR)
1953 /* Don't warn about automatic dereferencing of references, since
1954 the user cannot control it. */
1955 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
1956 return warn_if_unused_value (TREE_OPERAND (exp, 0));
1957 /* ... fall through ... */
1960 /* Referencing a volatile value is a side effect, so don't warn. */
1961 if ((TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
1962 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
1963 && TREE_THIS_VOLATILE (exp))
1966 warning_with_file_and_line (emit_filename, emit_lineno,
1967 "value computed is not used");
1972 /* Clear out the memory of the last expression evaluated. */
1980 /* Begin a statement which will return a value.
1981 Return the RTL_EXPR for this statement expr.
1982 The caller must save that value and pass it to expand_end_stmt_expr. */
1985 expand_start_stmt_expr ()
1990 /* Make the RTL_EXPR node temporary, not momentary,
1991 so that rtl_expr_chain doesn't become garbage. */
1992 momentary = suspend_momentary ();
1993 t = make_node (RTL_EXPR);
1994 resume_momentary (momentary);
1995 do_pending_stack_adjust ();
1996 start_sequence_for_rtl_expr (t);
1998 expr_stmts_for_value++;
2002 /* Restore the previous state at the end of a statement that returns a value.
2003 Returns a tree node representing the statement's value and the
2004 insns to compute the value.
2006 The nodes of that expression have been freed by now, so we cannot use them.
2007 But we don't want to do that anyway; the expression has already been
2008 evaluated and now we just want to use the value. So generate a RTL_EXPR
2009 with the proper type and RTL value.
2011 If the last substatement was not an expression,
2012 return something with type `void'. */
2015 expand_end_stmt_expr (t)
2020 if (last_expr_type == 0)
2022 last_expr_type = void_type_node;
2023 last_expr_value = const0_rtx;
2025 else if (last_expr_value == 0)
2026 /* There are some cases where this can happen, such as when the
2027 statement is void type. */
2028 last_expr_value = const0_rtx;
2029 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
2030 /* Remove any possible QUEUED. */
2031 last_expr_value = protect_from_queue (last_expr_value, 0);
2035 TREE_TYPE (t) = last_expr_type;
2036 RTL_EXPR_RTL (t) = last_expr_value;
2037 RTL_EXPR_SEQUENCE (t) = get_insns ();
2039 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
2043 /* Don't consider deleting this expr or containing exprs at tree level. */
2044 TREE_SIDE_EFFECTS (t) = 1;
2045 /* Propagate volatility of the actual RTL expr. */
2046 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
2049 expr_stmts_for_value--;
2054 /* Generate RTL for the start of an if-then. COND is the expression
2055 whose truth should be tested.
2057 If EXITFLAG is nonzero, this conditional is visible to
2058 `exit_something'. */
2061 expand_start_cond (cond, exitflag)
2065 struct nesting *thiscond = ALLOC_NESTING ();
2067 /* Make an entry on cond_stack for the cond we are entering. */
2069 thiscond->next = cond_stack;
2070 thiscond->all = nesting_stack;
2071 thiscond->depth = ++nesting_depth;
2072 thiscond->data.cond.next_label = gen_label_rtx ();
2073 /* Before we encounter an `else', we don't need a separate exit label
2074 unless there are supposed to be exit statements
2075 to exit this conditional. */
2076 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
2077 thiscond->data.cond.endif_label = thiscond->exit_label;
2078 cond_stack = thiscond;
2079 nesting_stack = thiscond;
2081 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
2084 /* Generate RTL between then-clause and the elseif-clause
2085 of an if-then-elseif-.... */
2088 expand_start_elseif (cond)
2091 if (cond_stack->data.cond.endif_label == 0)
2092 cond_stack->data.cond.endif_label = gen_label_rtx ();
2093 emit_jump (cond_stack->data.cond.endif_label);
2094 emit_label (cond_stack->data.cond.next_label);
2095 cond_stack->data.cond.next_label = gen_label_rtx ();
2096 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2099 /* Generate RTL between the then-clause and the else-clause
2100 of an if-then-else. */
2103 expand_start_else ()
2105 if (cond_stack->data.cond.endif_label == 0)
2106 cond_stack->data.cond.endif_label = gen_label_rtx ();
2108 emit_jump (cond_stack->data.cond.endif_label);
2109 emit_label (cond_stack->data.cond.next_label);
2110 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
2113 /* After calling expand_start_else, turn this "else" into an "else if"
2114 by providing another condition. */
2117 expand_elseif (cond)
2120 cond_stack->data.cond.next_label = gen_label_rtx ();
2121 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2124 /* Generate RTL for the end of an if-then.
2125 Pop the record for it off of cond_stack. */
2130 struct nesting *thiscond = cond_stack;
2132 do_pending_stack_adjust ();
2133 if (thiscond->data.cond.next_label)
2134 emit_label (thiscond->data.cond.next_label);
2135 if (thiscond->data.cond.endif_label)
2136 emit_label (thiscond->data.cond.endif_label);
2138 POPSTACK (cond_stack);
2144 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2145 loop should be exited by `exit_something'. This is a loop for which
2146 `expand_continue' will jump to the top of the loop.
2148 Make an entry on loop_stack to record the labels associated with
2152 expand_start_loop (exit_flag)
2155 register struct nesting *thisloop = ALLOC_NESTING ();
2157 /* Make an entry on loop_stack for the loop we are entering. */
2159 thisloop->next = loop_stack;
2160 thisloop->all = nesting_stack;
2161 thisloop->depth = ++nesting_depth;
2162 thisloop->data.loop.start_label = gen_label_rtx ();
2163 thisloop->data.loop.end_label = gen_label_rtx ();
2164 thisloop->data.loop.alt_end_label = 0;
2165 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2166 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2167 loop_stack = thisloop;
2168 nesting_stack = thisloop;
2170 do_pending_stack_adjust ();
2172 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2173 emit_label (thisloop->data.loop.start_label);
2178 /* Like expand_start_loop but for a loop where the continuation point
2179 (for expand_continue_loop) will be specified explicitly. */
2182 expand_start_loop_continue_elsewhere (exit_flag)
2185 struct nesting *thisloop = expand_start_loop (exit_flag);
2186 loop_stack->data.loop.continue_label = gen_label_rtx ();
2190 /* Specify the continuation point for a loop started with
2191 expand_start_loop_continue_elsewhere.
2192 Use this at the point in the code to which a continue statement
2196 expand_loop_continue_here ()
2198 do_pending_stack_adjust ();
2199 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2200 emit_label (loop_stack->data.loop.continue_label);
2203 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2204 Pop the block off of loop_stack. */
2209 rtx start_label = loop_stack->data.loop.start_label;
2210 rtx insn = get_last_insn ();
2211 int needs_end_jump = 1;
2213 /* Mark the continue-point at the top of the loop if none elsewhere. */
2214 if (start_label == loop_stack->data.loop.continue_label)
2215 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2217 do_pending_stack_adjust ();
2219 /* If optimizing, perhaps reorder the loop.
2220 First, try to use a condjump near the end.
2221 expand_exit_loop_if_false ends loops with unconditional jumps,
2224 if (test) goto label;
2226 goto loop_stack->data.loop.end_label
2230 If we find such a pattern, we can end the loop earlier. */
2233 && GET_CODE (insn) == CODE_LABEL
2234 && LABEL_NAME (insn) == NULL
2235 && GET_CODE (PREV_INSN (insn)) == BARRIER)
2238 rtx jump = PREV_INSN (PREV_INSN (label));
2240 if (GET_CODE (jump) == JUMP_INSN
2241 && GET_CODE (PATTERN (jump)) == SET
2242 && SET_DEST (PATTERN (jump)) == pc_rtx
2243 && GET_CODE (SET_SRC (PATTERN (jump))) == LABEL_REF
2244 && (XEXP (SET_SRC (PATTERN (jump)), 0)
2245 == loop_stack->data.loop.end_label))
2249 /* The test might be complex and reference LABEL multiple times,
2250 like the loop in loop_iterations to set vtop. To handle this,
2252 insn = PREV_INSN (label);
2253 reorder_insns (label, label, start_label);
2255 for (prev = PREV_INSN (jump); ; prev = PREV_INSN (prev))
2257 /* We ignore line number notes, but if we see any other note,
2258 in particular NOTE_INSN_BLOCK_*, NOTE_INSN_EH_REGION_*,
2259 NOTE_INSN_LOOP_*, we disable this optimization. */
2260 if (GET_CODE (prev) == NOTE)
2262 if (NOTE_LINE_NUMBER (prev) < 0)
2266 if (GET_CODE (prev) == CODE_LABEL)
2268 if (GET_CODE (prev) == JUMP_INSN)
2270 if (GET_CODE (PATTERN (prev)) == SET
2271 && SET_DEST (PATTERN (prev)) == pc_rtx
2272 && GET_CODE (SET_SRC (PATTERN (prev))) == IF_THEN_ELSE
2273 && (GET_CODE (XEXP (SET_SRC (PATTERN (prev)), 1))
2275 && XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0) == label)
2277 XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0)
2279 emit_note_after (NOTE_INSN_LOOP_END, prev);
2288 /* If the loop starts with a loop exit, roll that to the end where
2289 it will optimize together with the jump back.
2291 We look for the conditional branch to the exit, except that once
2292 we find such a branch, we don't look past 30 instructions.
2294 In more detail, if the loop presently looks like this (in pseudo-C):
2297 if (test) goto end_label;
2302 transform it to look like:
2308 if (test) goto end_label;
2309 goto newstart_label;
2312 Here, the `test' may actually consist of some reasonably complex
2313 code, terminating in a test. */
2318 ! (GET_CODE (insn) == JUMP_INSN
2319 && GET_CODE (PATTERN (insn)) == SET
2320 && SET_DEST (PATTERN (insn)) == pc_rtx
2321 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2325 rtx last_test_insn = NULL_RTX;
2327 /* Scan insns from the top of the loop looking for a qualified
2328 conditional exit. */
2329 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2330 insn = NEXT_INSN (insn))
2332 if (GET_CODE (insn) == NOTE)
2335 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2336 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2337 /* The code that actually moves the exit test will
2338 carefully leave BLOCK notes in their original
2339 location. That means, however, that we can't debug
2340 the exit test itself. So, we refuse to move code
2341 containing BLOCK notes at low optimization levels. */
2344 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG)
2346 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)
2350 /* We've come to the end of an EH region, but
2351 never saw the beginning of that region. That
2352 means that an EH region begins before the top
2353 of the loop, and ends in the middle of it. The
2354 existence of such a situation violates a basic
2355 assumption in this code, since that would imply
2356 that even when EH_REGIONS is zero, we might
2357 move code out of an exception region. */
2361 /* We must not walk into a nested loop. */
2362 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
2365 /* We already know this INSN is a NOTE, so there's no
2366 point in looking at it to see if it's a JUMP. */
2370 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2373 if (last_test_insn && num_insns > 30)
2377 /* We don't want to move a partial EH region. Consider:
2391 This isn't legal C++, but here's what it's supposed to
2392 mean: if cond() is true, stop looping. Otherwise,
2393 call bar, and keep looping. In addition, if cond
2394 throws an exception, catch it and keep looping. Such
2395 constructs are certainy legal in LISP.
2397 We should not move the `if (cond()) 0' test since then
2398 the EH-region for the try-block would be broken up.
2399 (In this case we would the EH_BEG note for the `try'
2400 and `if cond()' but not the call to bar() or the
2403 So we don't look for tests within an EH region. */
2406 if (GET_CODE (insn) == JUMP_INSN
2407 && GET_CODE (PATTERN (insn)) == SET
2408 && SET_DEST (PATTERN (insn)) == pc_rtx)
2410 /* This is indeed a jump. */
2411 rtx dest1 = NULL_RTX;
2412 rtx dest2 = NULL_RTX;
2413 rtx potential_last_test;
2414 if (GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE)
2416 /* A conditional jump. */
2417 dest1 = XEXP (SET_SRC (PATTERN (insn)), 1);
2418 dest2 = XEXP (SET_SRC (PATTERN (insn)), 2);
2419 potential_last_test = insn;
2423 /* An unconditional jump. */
2424 dest1 = SET_SRC (PATTERN (insn));
2425 /* Include the BARRIER after the JUMP. */
2426 potential_last_test = NEXT_INSN (insn);
2430 if (dest1 && GET_CODE (dest1) == LABEL_REF
2431 && ((XEXP (dest1, 0)
2432 == loop_stack->data.loop.alt_end_label)
2434 == loop_stack->data.loop.end_label)))
2436 last_test_insn = potential_last_test;
2440 /* If this was a conditional jump, there may be
2441 another label at which we should look. */
2448 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2450 /* We found one. Move everything from there up
2451 to the end of the loop, and add a jump into the loop
2452 to jump to there. */
2453 register rtx newstart_label = gen_label_rtx ();
2454 register rtx start_move = start_label;
2457 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2458 then we want to move this note also. */
2459 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2460 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2461 == NOTE_INSN_LOOP_CONT))
2462 start_move = PREV_INSN (start_move);
2464 emit_label_after (newstart_label, PREV_INSN (start_move));
2466 /* Actually move the insns. Start at the beginning, and
2467 keep copying insns until we've copied the
2469 for (insn = start_move; insn; insn = next_insn)
2471 /* Figure out which insn comes after this one. We have
2472 to do this before we move INSN. */
2473 if (insn == last_test_insn)
2474 /* We've moved all the insns. */
2475 next_insn = NULL_RTX;
2477 next_insn = NEXT_INSN (insn);
2479 if (GET_CODE (insn) == NOTE
2480 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2481 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2482 /* We don't want to move NOTE_INSN_BLOCK_BEGs or
2483 NOTE_INSN_BLOCK_ENDs because the correct generation
2484 of debugging information depends on these appearing
2485 in the same order in the RTL and in the tree
2486 structure, where they are represented as BLOCKs.
2487 So, we don't move block notes. Of course, moving
2488 the code inside the block is likely to make it
2489 impossible to debug the instructions in the exit
2490 test, but such is the price of optimization. */
2493 /* Move the INSN. */
2494 reorder_insns (insn, insn, get_last_insn ());
2497 emit_jump_insn_after (gen_jump (start_label),
2498 PREV_INSN (newstart_label));
2499 emit_barrier_after (PREV_INSN (newstart_label));
2500 start_label = newstart_label;
2506 emit_jump (start_label);
2507 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2509 emit_label (loop_stack->data.loop.end_label);
2511 POPSTACK (loop_stack);
2516 /* Generate a jump to the current loop's continue-point.
2517 This is usually the top of the loop, but may be specified
2518 explicitly elsewhere. If not currently inside a loop,
2519 return 0 and do nothing; caller will print an error message. */
2522 expand_continue_loop (whichloop)
2523 struct nesting *whichloop;
2527 whichloop = loop_stack;
2530 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2535 /* Generate a jump to exit the current loop. If not currently inside a loop,
2536 return 0 and do nothing; caller will print an error message. */
2539 expand_exit_loop (whichloop)
2540 struct nesting *whichloop;
2544 whichloop = loop_stack;
2547 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2551 /* Generate a conditional jump to exit the current loop if COND
2552 evaluates to zero. If not currently inside a loop,
2553 return 0 and do nothing; caller will print an error message. */
2556 expand_exit_loop_if_false (whichloop, cond)
2557 struct nesting *whichloop;
2560 rtx label = gen_label_rtx ();
2565 whichloop = loop_stack;
2568 /* In order to handle fixups, we actually create a conditional jump
2569 around a unconditional branch to exit the loop. If fixups are
2570 necessary, they go before the unconditional branch. */
2573 do_jump (cond, NULL_RTX, label);
2574 last_insn = get_last_insn ();
2575 if (GET_CODE (last_insn) == CODE_LABEL)
2576 whichloop->data.loop.alt_end_label = last_insn;
2577 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2584 /* Return nonzero if the loop nest is empty. Else return zero. */
2587 stmt_loop_nest_empty ()
2589 return (loop_stack == NULL);
2592 /* Return non-zero if we should preserve sub-expressions as separate
2593 pseudos. We never do so if we aren't optimizing. We always do so
2594 if -fexpensive-optimizations.
2596 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2597 the loop may still be a small one. */
2600 preserve_subexpressions_p ()
2604 if (flag_expensive_optimizations)
2607 if (optimize == 0 || current_function == 0 || loop_stack == 0)
2610 insn = get_last_insn_anywhere ();
2613 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2614 < n_non_fixed_regs * 3));
2618 /* Generate a jump to exit the current loop, conditional, binding contour
2619 or case statement. Not all such constructs are visible to this function,
2620 only those started with EXIT_FLAG nonzero. Individual languages use
2621 the EXIT_FLAG parameter to control which kinds of constructs you can
2624 If not currently inside anything that can be exited,
2625 return 0 and do nothing; caller will print an error message. */
2628 expand_exit_something ()
2632 for (n = nesting_stack; n; n = n->all)
2633 if (n->exit_label != 0)
2635 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2642 /* Generate RTL to return from the current function, with no value.
2643 (That is, we do not do anything about returning any value.) */
2646 expand_null_return ()
2648 struct nesting *block = block_stack;
2651 /* Does any pending block have cleanups? */
2653 while (block && block->data.block.cleanups == 0)
2654 block = block->next;
2656 /* If yes, use a goto to return, since that runs cleanups. */
2658 expand_null_return_1 (last_insn, block != 0);
2661 /* Generate RTL to return from the current function, with value VAL. */
2664 expand_value_return (val)
2667 struct nesting *block = block_stack;
2668 rtx last_insn = get_last_insn ();
2669 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2671 /* Copy the value to the return location
2672 unless it's already there. */
2674 if (return_reg != val)
2676 #ifdef PROMOTE_FUNCTION_RETURN
2677 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2678 int unsignedp = TREE_UNSIGNED (type);
2679 enum machine_mode mode
2680 = promote_mode (type, DECL_MODE (DECL_RESULT (current_function_decl)),
2683 if (GET_MODE (val) != VOIDmode && GET_MODE (val) != mode)
2684 convert_move (return_reg, val, unsignedp);
2687 emit_move_insn (return_reg, val);
2689 if (GET_CODE (return_reg) == REG
2690 && REGNO (return_reg) < FIRST_PSEUDO_REGISTER)
2691 emit_insn (gen_rtx_USE (VOIDmode, return_reg));
2692 /* Handle calls that return values in multiple non-contiguous locations.
2693 The Irix 6 ABI has examples of this. */
2694 else if (GET_CODE (return_reg) == PARALLEL)
2698 for (i = 0; i < XVECLEN (return_reg, 0); i++)
2700 rtx x = XEXP (XVECEXP (return_reg, 0, i), 0);
2702 if (GET_CODE (x) == REG
2703 && REGNO (x) < FIRST_PSEUDO_REGISTER)
2704 emit_insn (gen_rtx_USE (VOIDmode, x));
2708 /* Does any pending block have cleanups? */
2710 while (block && block->data.block.cleanups == 0)
2711 block = block->next;
2713 /* If yes, use a goto to return, since that runs cleanups.
2714 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2716 expand_null_return_1 (last_insn, block != 0);
2719 /* Output a return with no value. If LAST_INSN is nonzero,
2720 pretend that the return takes place after LAST_INSN.
2721 If USE_GOTO is nonzero then don't use a return instruction;
2722 go to the return label instead. This causes any cleanups
2723 of pending blocks to be executed normally. */
2726 expand_null_return_1 (last_insn, use_goto)
2730 rtx end_label = cleanup_label ? cleanup_label : return_label;
2732 clear_pending_stack_adjust ();
2733 do_pending_stack_adjust ();
2736 /* PCC-struct return always uses an epilogue. */
2737 if (current_function_returns_pcc_struct || use_goto)
2740 end_label = return_label = gen_label_rtx ();
2741 expand_goto_internal (NULL_TREE, end_label, last_insn);
2745 /* Otherwise output a simple return-insn if one is available,
2746 unless it won't do the job. */
2748 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2750 emit_jump_insn (gen_return ());
2756 /* Otherwise jump to the epilogue. */
2757 expand_goto_internal (NULL_TREE, end_label, last_insn);
2760 /* Generate RTL to evaluate the expression RETVAL and return it
2761 from the current function. */
2764 expand_return (retval)
2767 /* If there are any cleanups to be performed, then they will
2768 be inserted following LAST_INSN. It is desirable
2769 that the last_insn, for such purposes, should be the
2770 last insn before computing the return value. Otherwise, cleanups
2771 which call functions can clobber the return value. */
2772 /* ??? rms: I think that is erroneous, because in C++ it would
2773 run destructors on variables that might be used in the subsequent
2774 computation of the return value. */
2776 register rtx val = 0;
2781 /* If function wants no value, give it none. */
2782 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2784 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2786 expand_null_return ();
2790 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2791 /* This is not sufficient. We also need to watch for cleanups of the
2792 expression we are about to expand. Unfortunately, we cannot know
2793 if it has cleanups until we expand it, and we want to change how we
2794 expand it depending upon if we need cleanups. We can't win. */
2796 cleanups = any_pending_cleanups (1);
2801 if (TREE_CODE (retval) == RESULT_DECL)
2802 retval_rhs = retval;
2803 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2804 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2805 retval_rhs = TREE_OPERAND (retval, 1);
2806 else if (TREE_TYPE (retval) == void_type_node)
2807 /* Recognize tail-recursive call to void function. */
2808 retval_rhs = retval;
2810 retval_rhs = NULL_TREE;
2812 /* Only use `last_insn' if there are cleanups which must be run. */
2813 if (cleanups || cleanup_label != 0)
2814 last_insn = get_last_insn ();
2816 /* Distribute return down conditional expr if either of the sides
2817 may involve tail recursion (see test below). This enhances the number
2818 of tail recursions we see. Don't do this always since it can produce
2819 sub-optimal code in some cases and we distribute assignments into
2820 conditional expressions when it would help. */
2822 if (optimize && retval_rhs != 0
2823 && frame_offset == 0
2824 && TREE_CODE (retval_rhs) == COND_EXPR
2825 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2826 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2828 rtx label = gen_label_rtx ();
2831 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2832 start_cleanup_deferral ();
2833 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2834 DECL_RESULT (current_function_decl),
2835 TREE_OPERAND (retval_rhs, 1));
2836 TREE_SIDE_EFFECTS (expr) = 1;
2837 expand_return (expr);
2840 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2841 DECL_RESULT (current_function_decl),
2842 TREE_OPERAND (retval_rhs, 2));
2843 TREE_SIDE_EFFECTS (expr) = 1;
2844 expand_return (expr);
2845 end_cleanup_deferral ();
2849 /* Attempt to optimize the call if it is tail recursive. */
2850 if (optimize_tail_recursion (retval_rhs, last_insn))
2854 /* This optimization is safe if there are local cleanups
2855 because expand_null_return takes care of them.
2856 ??? I think it should also be safe when there is a cleanup label,
2857 because expand_null_return takes care of them, too.
2858 Any reason why not? */
2859 if (HAVE_return && cleanup_label == 0
2860 && ! current_function_returns_pcc_struct
2861 && BRANCH_COST <= 1)
2863 /* If this is return x == y; then generate
2864 if (x == y) return 1; else return 0;
2865 if we can do it with explicit return insns and branches are cheap,
2866 but not if we have the corresponding scc insn. */
2869 switch (TREE_CODE (retval_rhs))
2895 case TRUTH_ANDIF_EXPR:
2896 case TRUTH_ORIF_EXPR:
2897 case TRUTH_AND_EXPR:
2899 case TRUTH_NOT_EXPR:
2900 case TRUTH_XOR_EXPR:
2903 op0 = gen_label_rtx ();
2904 jumpifnot (retval_rhs, op0);
2905 expand_value_return (const1_rtx);
2907 expand_value_return (const0_rtx);
2916 #endif /* HAVE_return */
2918 /* If the result is an aggregate that is being returned in one (or more)
2919 registers, load the registers here. The compiler currently can't handle
2920 copying a BLKmode value into registers. We could put this code in a
2921 more general area (for use by everyone instead of just function
2922 call/return), but until this feature is generally usable it is kept here
2923 (and in expand_call). The value must go into a pseudo in case there
2924 are cleanups that will clobber the real return register. */
2927 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2928 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2930 int i, bitpos, xbitpos;
2931 int big_endian_correction = 0;
2932 int bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2933 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2934 int bitsize = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)),
2935 (unsigned int)BITS_PER_WORD);
2936 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2937 rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
2938 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2939 enum machine_mode tmpmode, result_reg_mode;
2941 /* Structures whose size is not a multiple of a word are aligned
2942 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
2943 machine, this means we must skip the empty high order bytes when
2944 calculating the bit offset. */
2945 if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD)
2946 big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
2949 /* Copy the structure BITSIZE bits at a time. */
2950 for (bitpos = 0, xbitpos = big_endian_correction;
2951 bitpos < bytes * BITS_PER_UNIT;
2952 bitpos += bitsize, xbitpos += bitsize)
2954 /* We need a new destination pseudo each time xbitpos is
2955 on a word boundary and when xbitpos == big_endian_correction
2956 (the first time through). */
2957 if (xbitpos % BITS_PER_WORD == 0
2958 || xbitpos == big_endian_correction)
2960 /* Generate an appropriate register. */
2961 dst = gen_reg_rtx (word_mode);
2962 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
2964 /* Clobber the destination before we move anything into it. */
2965 emit_insn (gen_rtx_CLOBBER (VOIDmode, dst));
2968 /* We need a new source operand each time bitpos is on a word
2970 if (bitpos % BITS_PER_WORD == 0)
2971 src = operand_subword_force (result_val,
2972 bitpos / BITS_PER_WORD,
2975 /* Use bitpos for the source extraction (left justified) and
2976 xbitpos for the destination store (right justified). */
2977 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
2978 extract_bit_field (src, bitsize,
2979 bitpos % BITS_PER_WORD, 1,
2980 NULL_RTX, word_mode,
2982 bitsize / BITS_PER_UNIT,
2984 bitsize / BITS_PER_UNIT, BITS_PER_WORD);
2987 /* Find the smallest integer mode large enough to hold the
2988 entire structure and use that mode instead of BLKmode
2989 on the USE insn for the return register. */
2990 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2991 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
2992 tmpmode != VOIDmode;
2993 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
2995 /* Have we found a large enough mode? */
2996 if (GET_MODE_SIZE (tmpmode) >= bytes)
3000 /* No suitable mode found. */
3001 if (tmpmode == VOIDmode)
3004 PUT_MODE (DECL_RTL (DECL_RESULT (current_function_decl)), tmpmode);
3006 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
3007 result_reg_mode = word_mode;
3009 result_reg_mode = tmpmode;
3010 result_reg = gen_reg_rtx (result_reg_mode);
3013 for (i = 0; i < n_regs; i++)
3014 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
3017 if (tmpmode != result_reg_mode)
3018 result_reg = gen_lowpart (tmpmode, result_reg);
3020 expand_value_return (result_reg);
3024 && TREE_TYPE (retval_rhs) != void_type_node
3025 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
3027 /* Calculate the return value into a pseudo reg. */
3028 val = gen_reg_rtx (DECL_MODE (DECL_RESULT (current_function_decl)));
3029 val = expand_expr (retval_rhs, val, GET_MODE (val), 0);
3030 val = force_not_mem (val);
3032 /* Return the calculated value, doing cleanups first. */
3033 expand_value_return (val);
3037 /* No cleanups or no hard reg used;
3038 calculate value into hard return reg. */
3039 expand_expr (retval, const0_rtx, VOIDmode, 0);
3041 expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl)));
3045 /* Return 1 if the end of the generated RTX is not a barrier.
3046 This means code already compiled can drop through. */
3049 drop_through_at_end_p ()
3051 rtx insn = get_last_insn ();
3052 while (insn && GET_CODE (insn) == NOTE)
3053 insn = PREV_INSN (insn);
3054 return insn && GET_CODE (insn) != BARRIER;
3057 /* Test CALL_EXPR to determine if it is a potential tail recursion call
3058 and emit code to optimize the tail recursion. LAST_INSN indicates where
3059 to place the jump to the tail recursion label. Return TRUE if the
3060 call was optimized into a goto.
3062 This is only used by expand_return, but expand_call is expected to
3066 optimize_tail_recursion (call_expr, last_insn)
3070 /* For tail-recursive call to current function,
3071 just jump back to the beginning.
3072 It's unsafe if any auto variable in this function
3073 has its address taken; for simplicity,
3074 require stack frame to be empty. */
3075 if (optimize && call_expr != 0
3076 && frame_offset == 0
3077 && TREE_CODE (call_expr) == CALL_EXPR
3078 && TREE_CODE (TREE_OPERAND (call_expr, 0)) == ADDR_EXPR
3079 && TREE_OPERAND (TREE_OPERAND (call_expr, 0), 0) == current_function_decl
3080 /* Finish checking validity, and if valid emit code
3081 to set the argument variables for the new call. */
3082 && tail_recursion_args (TREE_OPERAND (call_expr, 1),
3083 DECL_ARGUMENTS (current_function_decl)))
3085 if (tail_recursion_label == 0)
3087 tail_recursion_label = gen_label_rtx ();
3088 emit_label_after (tail_recursion_label,
3089 tail_recursion_reentry);
3092 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
3100 /* Emit code to alter this function's formal parms for a tail-recursive call.
3101 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3102 FORMALS is the chain of decls of formals.
3103 Return 1 if this can be done;
3104 otherwise return 0 and do not emit any code. */
3107 tail_recursion_args (actuals, formals)
3108 tree actuals, formals;
3110 register tree a = actuals, f = formals;
3112 register rtx *argvec;
3114 /* Check that number and types of actuals are compatible
3115 with the formals. This is not always true in valid C code.
3116 Also check that no formal needs to be addressable
3117 and that all formals are scalars. */
3119 /* Also count the args. */
3121 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
3123 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a)))
3124 != TYPE_MAIN_VARIANT (TREE_TYPE (f)))
3126 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
3129 if (a != 0 || f != 0)
3132 /* Compute all the actuals. */
3134 argvec = (rtx *) alloca (i * sizeof (rtx));
3136 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3137 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
3139 /* Find which actual values refer to current values of previous formals.
3140 Copy each of them now, before any formal is changed. */
3142 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3146 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
3147 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
3148 { copy = 1; break; }
3150 argvec[i] = copy_to_reg (argvec[i]);
3153 /* Store the values of the actuals into the formals. */
3155 for (f = formals, a = actuals, i = 0; f;
3156 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
3158 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
3159 emit_move_insn (DECL_RTL (f), argvec[i]);
3161 convert_move (DECL_RTL (f), argvec[i],
3162 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
3169 /* Generate the RTL code for entering a binding contour.
3170 The variables are declared one by one, by calls to `expand_decl'.
3172 EXIT_FLAG is nonzero if this construct should be visible to
3173 `exit_something'. */
3176 expand_start_bindings (exit_flag)
3179 struct nesting *thisblock = ALLOC_NESTING ();
3180 rtx note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
3182 /* Make an entry on block_stack for the block we are entering. */
3184 thisblock->next = block_stack;
3185 thisblock->all = nesting_stack;
3186 thisblock->depth = ++nesting_depth;
3187 thisblock->data.block.stack_level = 0;
3188 thisblock->data.block.cleanups = 0;
3189 thisblock->data.block.n_function_calls = 0;
3190 thisblock->data.block.exception_region = 0;
3191 thisblock->data.block.block_target_temp_slot_level = target_temp_slot_level;
3193 thisblock->data.block.conditional_code = 0;
3194 thisblock->data.block.last_unconditional_cleanup = note;
3195 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
3198 && !(block_stack->data.block.cleanups == NULL_TREE
3199 && block_stack->data.block.outer_cleanups == NULL_TREE))
3200 thisblock->data.block.outer_cleanups
3201 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
3202 block_stack->data.block.outer_cleanups);
3204 thisblock->data.block.outer_cleanups = 0;
3205 thisblock->data.block.label_chain = 0;
3206 thisblock->data.block.innermost_stack_block = stack_block_stack;
3207 thisblock->data.block.first_insn = note;
3208 thisblock->data.block.block_start_count = ++current_block_start_count;
3209 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
3210 block_stack = thisblock;
3211 nesting_stack = thisblock;
3213 /* Make a new level for allocating stack slots. */
3217 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3218 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3219 expand_expr are made. After we end the region, we know that all
3220 space for all temporaries that were created by TARGET_EXPRs will be
3221 destroyed and their space freed for reuse. */
3224 expand_start_target_temps ()
3226 /* This is so that even if the result is preserved, the space
3227 allocated will be freed, as we know that it is no longer in use. */
3230 /* Start a new binding layer that will keep track of all cleanup
3231 actions to be performed. */
3232 expand_start_bindings (0);
3234 target_temp_slot_level = temp_slot_level;
3238 expand_end_target_temps ()
3240 expand_end_bindings (NULL_TREE, 0, 0);
3242 /* This is so that even if the result is preserved, the space
3243 allocated will be freed, as we know that it is no longer in use. */
3247 /* Mark top block of block_stack as an implicit binding for an
3248 exception region. This is used to prevent infinite recursion when
3249 ending a binding with expand_end_bindings. It is only ever called
3250 by expand_eh_region_start, as that it the only way to create a
3251 block stack for a exception region. */
3254 mark_block_as_eh_region ()
3256 block_stack->data.block.exception_region = 1;
3257 if (block_stack->next
3258 && block_stack->next->data.block.conditional_code)
3260 block_stack->data.block.conditional_code
3261 = block_stack->next->data.block.conditional_code;
3262 block_stack->data.block.last_unconditional_cleanup
3263 = block_stack->next->data.block.last_unconditional_cleanup;
3264 block_stack->data.block.cleanup_ptr
3265 = block_stack->next->data.block.cleanup_ptr;
3269 /* True if we are currently emitting insns in an area of output code
3270 that is controlled by a conditional expression. This is used by
3271 the cleanup handling code to generate conditional cleanup actions. */
3274 conditional_context ()
3276 return block_stack && block_stack->data.block.conditional_code;
3279 /* Mark top block of block_stack as not for an implicit binding for an
3280 exception region. This is only ever done by expand_eh_region_end
3281 to let expand_end_bindings know that it is being called explicitly
3282 to end the binding layer for just the binding layer associated with
3283 the exception region, otherwise expand_end_bindings would try and
3284 end all implicit binding layers for exceptions regions, and then
3285 one normal binding layer. */
3288 mark_block_as_not_eh_region ()
3290 block_stack->data.block.exception_region = 0;
3293 /* True if the top block of block_stack was marked as for an exception
3294 region by mark_block_as_eh_region. */
3299 return (current_function && block_stack
3300 && block_stack->data.block.exception_region);
3303 /* Given a pointer to a BLOCK node, save a pointer to the most recently
3304 generated NOTE_INSN_BLOCK_END in the BLOCK_END_NOTE field of the given
3308 remember_end_note (block)
3309 register tree block;
3311 BLOCK_END_NOTE (block) = last_block_end_note;
3312 last_block_end_note = NULL_RTX;
3315 /* Emit a handler label for a nonlocal goto handler.
3316 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3319 expand_nl_handler_label (slot, before_insn)
3320 rtx slot, before_insn;
3323 rtx handler_label = gen_label_rtx ();
3325 /* Don't let jump_optimize delete the handler. */
3326 LABEL_PRESERVE_P (handler_label) = 1;
3329 emit_move_insn (slot, gen_rtx_LABEL_REF (Pmode, handler_label));
3330 insns = get_insns ();
3332 emit_insns_before (insns, before_insn);
3334 emit_label (handler_label);
3336 return handler_label;
3339 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3342 expand_nl_goto_receiver ()
3344 #ifdef HAVE_nonlocal_goto
3345 if (! HAVE_nonlocal_goto)
3347 /* First adjust our frame pointer to its actual value. It was
3348 previously set to the start of the virtual area corresponding to
3349 the stacked variables when we branched here and now needs to be
3350 adjusted to the actual hardware fp value.
3352 Assignments are to virtual registers are converted by
3353 instantiate_virtual_regs into the corresponding assignment
3354 to the underlying register (fp in this case) that makes
3355 the original assignment true.
3356 So the following insn will actually be
3357 decrementing fp by STARTING_FRAME_OFFSET. */
3358 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3360 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3361 if (fixed_regs[ARG_POINTER_REGNUM])
3363 #ifdef ELIMINABLE_REGS
3364 /* If the argument pointer can be eliminated in favor of the
3365 frame pointer, we don't need to restore it. We assume here
3366 that if such an elimination is present, it can always be used.
3367 This is the case on all known machines; if we don't make this
3368 assumption, we do unnecessary saving on many machines. */
3369 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3372 for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
3373 if (elim_regs[i].from == ARG_POINTER_REGNUM
3374 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3377 if (i == sizeof elim_regs / sizeof elim_regs [0])
3380 /* Now restore our arg pointer from the address at which it
3381 was saved in our stack frame.
3382 If there hasn't be space allocated for it yet, make
3384 if (arg_pointer_save_area == 0)
3385 arg_pointer_save_area
3386 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3387 emit_move_insn (virtual_incoming_args_rtx,
3388 /* We need a pseudo here, or else
3389 instantiate_virtual_regs_1 complains. */
3390 copy_to_reg (arg_pointer_save_area));
3395 #ifdef HAVE_nonlocal_goto_receiver
3396 if (HAVE_nonlocal_goto_receiver)
3397 emit_insn (gen_nonlocal_goto_receiver ());
3401 /* Make handlers for nonlocal gotos taking place in the function calls in
3405 expand_nl_goto_receivers (thisblock)
3406 struct nesting *thisblock;
3409 rtx afterward = gen_label_rtx ();
3414 /* Record the handler address in the stack slot for that purpose,
3415 during this block, saving and restoring the outer value. */
3416 if (thisblock->next != 0)
3417 for (slot = nonlocal_goto_handler_slots; slot; slot = XEXP (slot, 1))
3419 rtx save_receiver = gen_reg_rtx (Pmode);
3420 emit_move_insn (XEXP (slot, 0), save_receiver);
3423 emit_move_insn (save_receiver, XEXP (slot, 0));
3424 insns = get_insns ();
3426 emit_insns_before (insns, thisblock->data.block.first_insn);
3429 /* Jump around the handlers; they run only when specially invoked. */
3430 emit_jump (afterward);
3432 /* Make a separate handler for each label. */
3433 link = nonlocal_labels;
3434 slot = nonlocal_goto_handler_slots;
3435 label_list = NULL_RTX;
3436 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3437 /* Skip any labels we shouldn't be able to jump to from here,
3438 we generate one special handler for all of them below which just calls
3440 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3443 lab = expand_nl_handler_label (XEXP (slot, 0),
3444 thisblock->data.block.first_insn);
3445 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3447 expand_nl_goto_receiver ();
3449 /* Jump to the "real" nonlocal label. */
3450 expand_goto (TREE_VALUE (link));
3453 /* A second pass over all nonlocal labels; this time we handle those
3454 we should not be able to jump to at this point. */
3455 link = nonlocal_labels;
3456 slot = nonlocal_goto_handler_slots;
3458 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3459 if (DECL_TOO_LATE (TREE_VALUE (link)))
3462 lab = expand_nl_handler_label (XEXP (slot, 0),
3463 thisblock->data.block.first_insn);
3464 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3470 expand_nl_goto_receiver ();
3471 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "abort"), 0,
3476 nonlocal_goto_handler_labels = label_list;
3477 emit_label (afterward);
3480 /* Generate RTL code to terminate a binding contour.
3482 VARS is the chain of VAR_DECL nodes for the variables bound in this
3483 contour. There may actually be other nodes in this chain, but any
3484 nodes other than VAR_DECLS are ignored.
3486 MARK_ENDS is nonzero if we should put a note at the beginning
3487 and end of this binding contour.
3489 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3490 (That is true automatically if the contour has a saved stack level.) */
3493 expand_end_bindings (vars, mark_ends, dont_jump_in)
3498 register struct nesting *thisblock;
3501 while (block_stack->data.block.exception_region)
3503 /* Because we don't need or want a new temporary level and
3504 because we didn't create one in expand_eh_region_start,
3505 create a fake one now to avoid removing one in
3506 expand_end_bindings. */
3509 block_stack->data.block.exception_region = 0;
3511 expand_end_bindings (NULL_TREE, 0, 0);
3514 /* Since expand_eh_region_start does an expand_start_bindings, we
3515 have to first end all the bindings that were created by
3516 expand_eh_region_start. */
3518 thisblock = block_stack;
3521 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3522 if (TREE_CODE (decl) == VAR_DECL
3523 && ! TREE_USED (decl)
3524 && ! DECL_IN_SYSTEM_HEADER (decl)
3525 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
3526 warning_with_decl (decl, "unused variable `%s'");
3528 if (thisblock->exit_label)
3530 do_pending_stack_adjust ();
3531 emit_label (thisblock->exit_label);
3534 /* If necessary, make handlers for nonlocal gotos taking
3535 place in the function calls in this block. */
3536 if (function_call_count != thisblock->data.block.n_function_calls
3538 /* Make handler for outermost block
3539 if there were any nonlocal gotos to this function. */
3540 && (thisblock->next == 0 ? current_function_has_nonlocal_label
3541 /* Make handler for inner block if it has something
3542 special to do when you jump out of it. */
3543 : (thisblock->data.block.cleanups != 0
3544 || thisblock->data.block.stack_level != 0)))
3545 expand_nl_goto_receivers (thisblock);
3547 /* Don't allow jumping into a block that has a stack level.
3548 Cleanups are allowed, though. */
3550 || thisblock->data.block.stack_level != 0)
3552 struct label_chain *chain;
3554 /* Any labels in this block are no longer valid to go to.
3555 Mark them to cause an error message. */
3556 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3558 DECL_TOO_LATE (chain->label) = 1;
3559 /* If any goto without a fixup came to this label,
3560 that must be an error, because gotos without fixups
3561 come from outside all saved stack-levels. */
3562 if (TREE_ADDRESSABLE (chain->label))
3563 error_with_decl (chain->label,
3564 "label `%s' used before containing binding contour");
3568 /* Restore stack level in effect before the block
3569 (only if variable-size objects allocated). */
3570 /* Perform any cleanups associated with the block. */
3572 if (thisblock->data.block.stack_level != 0
3573 || thisblock->data.block.cleanups != 0)
3575 /* Only clean up here if this point can actually be reached. */
3576 int reachable = GET_CODE (get_last_insn ()) != BARRIER;
3578 /* Don't let cleanups affect ({...}) constructs. */
3579 int old_expr_stmts_for_value = expr_stmts_for_value;
3580 rtx old_last_expr_value = last_expr_value;
3581 tree old_last_expr_type = last_expr_type;
3582 expr_stmts_for_value = 0;
3584 /* Do the cleanups. */
3585 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3587 do_pending_stack_adjust ();
3589 expr_stmts_for_value = old_expr_stmts_for_value;
3590 last_expr_value = old_last_expr_value;
3591 last_expr_type = old_last_expr_type;
3593 /* Restore the stack level. */
3595 if (reachable && thisblock->data.block.stack_level != 0)
3597 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3598 thisblock->data.block.stack_level, NULL_RTX);
3599 if (nonlocal_goto_handler_slots != 0)
3600 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3604 /* Any gotos out of this block must also do these things.
3605 Also report any gotos with fixups that came to labels in this
3607 fixup_gotos (thisblock,
3608 thisblock->data.block.stack_level,
3609 thisblock->data.block.cleanups,
3610 thisblock->data.block.first_insn,
3614 /* Mark the beginning and end of the scope if requested.
3615 We do this now, after running cleanups on the variables
3616 just going out of scope, so they are in scope for their cleanups. */
3619 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3621 /* Get rid of the beginning-mark if we don't make an end-mark. */
3622 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3624 /* If doing stupid register allocation, make sure lives of all
3625 register variables declared here extend thru end of scope. */
3628 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3629 if (TREE_CODE (decl) == VAR_DECL && DECL_RTL (decl))
3630 use_variable (DECL_RTL (decl));
3632 /* Restore the temporary level of TARGET_EXPRs. */
3633 target_temp_slot_level = thisblock->data.block.block_target_temp_slot_level;
3635 /* Restore block_stack level for containing block. */
3637 stack_block_stack = thisblock->data.block.innermost_stack_block;
3638 POPSTACK (block_stack);
3640 /* Pop the stack slot nesting and free any slots at this level. */
3644 /* Generate RTL for the automatic variable declaration DECL.
3645 (Other kinds of declarations are simply ignored if seen here.) */
3651 struct nesting *thisblock;
3654 type = TREE_TYPE (decl);
3656 /* Only automatic variables need any expansion done.
3657 Static and external variables, and external functions,
3658 will be handled by `assemble_variable' (called from finish_decl).
3659 TYPE_DECL and CONST_DECL require nothing.
3660 PARM_DECLs are handled in `assign_parms'. */
3662 if (TREE_CODE (decl) != VAR_DECL)
3664 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3667 thisblock = block_stack;
3669 /* Create the RTL representation for the variable. */
3671 if (type == error_mark_node)
3672 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, const0_rtx);
3673 else if (DECL_SIZE (decl) == 0)
3674 /* Variable with incomplete type. */
3676 if (DECL_INITIAL (decl) == 0)
3677 /* Error message was already done; now avoid a crash. */
3678 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3680 /* An initializer is going to decide the size of this array.
3681 Until we know the size, represent its address with a reg. */
3682 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode));
3683 MEM_SET_IN_STRUCT_P (DECL_RTL (decl), AGGREGATE_TYPE_P (type));
3685 else if (DECL_MODE (decl) != BLKmode
3686 /* If -ffloat-store, don't put explicit float vars
3688 && !(flag_float_store
3689 && TREE_CODE (type) == REAL_TYPE)
3690 && ! TREE_THIS_VOLATILE (decl)
3691 && ! TREE_ADDRESSABLE (decl)
3692 && (DECL_REGISTER (decl) || ! obey_regdecls)
3693 /* if -fcheck-memory-usage, check all variables. */
3694 && ! current_function_check_memory_usage)
3696 /* Automatic variable that can go in a register. */
3697 int unsignedp = TREE_UNSIGNED (type);
3698 enum machine_mode reg_mode
3699 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3701 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3702 mark_user_reg (DECL_RTL (decl));
3704 if (POINTER_TYPE_P (type))
3705 mark_reg_pointer (DECL_RTL (decl),
3706 (TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl)))
3710 else if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST
3711 && ! (flag_stack_check && ! STACK_CHECK_BUILTIN
3712 && (TREE_INT_CST_HIGH (DECL_SIZE (decl)) != 0
3713 || (TREE_INT_CST_LOW (DECL_SIZE (decl))
3714 > STACK_CHECK_MAX_VAR_SIZE * BITS_PER_UNIT))))
3716 /* Variable of fixed size that goes on the stack. */
3720 /* If we previously made RTL for this decl, it must be an array
3721 whose size was determined by the initializer.
3722 The old address was a register; set that register now
3723 to the proper address. */
3724 if (DECL_RTL (decl) != 0)
3726 if (GET_CODE (DECL_RTL (decl)) != MEM
3727 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3729 oldaddr = XEXP (DECL_RTL (decl), 0);
3732 DECL_RTL (decl) = assign_temp (TREE_TYPE (decl), 1, 1, 1);
3733 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3734 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3736 /* Set alignment we actually gave this decl. */
3737 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3738 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3742 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3743 if (addr != oldaddr)
3744 emit_move_insn (oldaddr, addr);
3747 /* If this is a memory ref that contains aggregate components,
3748 mark it as such for cse and loop optimize. */
3749 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3750 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3752 /* If this is in memory because of -ffloat-store,
3753 set the volatile bit, to prevent optimizations from
3754 undoing the effects. */
3755 if (flag_float_store && TREE_CODE (type) == REAL_TYPE)
3756 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3759 MEM_ALIAS_SET (DECL_RTL (decl)) = get_alias_set (decl);
3762 /* Dynamic-size object: must push space on the stack. */
3766 /* Record the stack pointer on entry to block, if have
3767 not already done so. */
3768 if (thisblock->data.block.stack_level == 0)
3770 do_pending_stack_adjust ();
3771 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3772 &thisblock->data.block.stack_level,
3773 thisblock->data.block.first_insn);
3774 stack_block_stack = thisblock;
3777 /* Compute the variable's size, in bytes. */
3778 size = expand_expr (size_binop (CEIL_DIV_EXPR,
3780 size_int (BITS_PER_UNIT)),
3781 NULL_RTX, VOIDmode, 0);
3784 /* Allocate space on the stack for the variable. Note that
3785 DECL_ALIGN says how the variable is to be aligned and we
3786 cannot use it to conclude anything about the alignment of
3788 address = allocate_dynamic_stack_space (size, NULL_RTX,
3789 TYPE_ALIGN (TREE_TYPE (decl)));
3791 /* Reference the variable indirect through that rtx. */
3792 DECL_RTL (decl) = gen_rtx_MEM (DECL_MODE (decl), address);
3794 /* If this is a memory ref that contains aggregate components,
3795 mark it as such for cse and loop optimize. */
3796 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3797 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3799 /* Indicate the alignment we actually gave this variable. */
3800 #ifdef STACK_BOUNDARY
3801 DECL_ALIGN (decl) = STACK_BOUNDARY;
3803 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3807 if (TREE_THIS_VOLATILE (decl))
3808 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3809 #if 0 /* A variable is not necessarily unchanging
3810 just because it is const. RTX_UNCHANGING_P
3811 means no change in the function,
3812 not merely no change in the variable's scope.
3813 It is correct to set RTX_UNCHANGING_P if the variable's scope
3814 is the whole function. There's no convenient way to test that. */
3815 if (TREE_READONLY (decl))
3816 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
3819 /* If doing stupid register allocation, make sure life of any
3820 register variable starts here, at the start of its scope. */
3823 use_variable (DECL_RTL (decl));
3828 /* Emit code to perform the initialization of a declaration DECL. */
3831 expand_decl_init (decl)
3834 int was_used = TREE_USED (decl);
3836 /* If this is a CONST_DECL, we don't have to generate any code, but
3837 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3838 to be set while in the obstack containing the constant. If we don't
3839 do this, we can lose if we have functions nested three deep and the middle
3840 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3841 the innermost function is the first to expand that STRING_CST. */
3842 if (TREE_CODE (decl) == CONST_DECL)
3844 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3845 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3846 EXPAND_INITIALIZER);
3850 if (TREE_STATIC (decl))
3853 /* Compute and store the initial value now. */
3855 if (DECL_INITIAL (decl) == error_mark_node)
3857 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3859 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3860 || code == POINTER_TYPE || code == REFERENCE_TYPE)
3861 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3865 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3867 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3868 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3872 /* Don't let the initialization count as "using" the variable. */
3873 TREE_USED (decl) = was_used;
3875 /* Free any temporaries we made while initializing the decl. */
3876 preserve_temp_slots (NULL_RTX);
3880 /* CLEANUP is an expression to be executed at exit from this binding contour;
3881 for example, in C++, it might call the destructor for this variable.
3883 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
3884 CLEANUP multiple times, and have the correct semantics. This
3885 happens in exception handling, for gotos, returns, breaks that
3886 leave the current scope.
3888 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3889 that is not associated with any particular variable. */
3892 expand_decl_cleanup (decl, cleanup)
3895 struct nesting *thisblock;
3897 /* Error if we are not in any block. */
3898 if (current_function == 0 || block_stack == 0)
3901 thisblock = block_stack;
3903 /* Record the cleanup if there is one. */
3909 tree *cleanups = &thisblock->data.block.cleanups;
3910 int cond_context = conditional_context ();
3914 rtx flag = gen_reg_rtx (word_mode);
3919 emit_move_insn (flag, const0_rtx);
3920 set_flag_0 = get_insns ();
3923 thisblock->data.block.last_unconditional_cleanup
3924 = emit_insns_after (set_flag_0,
3925 thisblock->data.block.last_unconditional_cleanup);
3927 emit_move_insn (flag, const1_rtx);
3929 /* All cleanups must be on the function_obstack. */
3930 push_obstacks_nochange ();
3931 resume_temporary_allocation ();
3933 cond = build_decl (VAR_DECL, NULL_TREE, type_for_mode (word_mode, 1));
3934 DECL_RTL (cond) = flag;
3936 /* Conditionalize the cleanup. */
3937 cleanup = build (COND_EXPR, void_type_node,
3938 truthvalue_conversion (cond),
3939 cleanup, integer_zero_node);
3940 cleanup = fold (cleanup);
3944 cleanups = thisblock->data.block.cleanup_ptr;
3947 /* All cleanups must be on the function_obstack. */
3948 push_obstacks_nochange ();
3949 resume_temporary_allocation ();
3950 cleanup = unsave_expr (cleanup);
3953 t = *cleanups = temp_tree_cons (decl, cleanup, *cleanups);
3956 /* If this block has a cleanup, it belongs in stack_block_stack. */
3957 stack_block_stack = thisblock;
3964 /* If this was optimized so that there is no exception region for the
3965 cleanup, then mark the TREE_LIST node, so that we can later tell
3966 if we need to call expand_eh_region_end. */
3967 if (! using_eh_for_cleanups_p
3968 || expand_eh_region_start_tree (decl, cleanup))
3969 TREE_ADDRESSABLE (t) = 1;
3970 /* If that started a new EH region, we're in a new block. */
3971 thisblock = block_stack;
3978 thisblock->data.block.last_unconditional_cleanup
3979 = emit_insns_after (seq,
3980 thisblock->data.block.last_unconditional_cleanup);
3984 thisblock->data.block.last_unconditional_cleanup
3986 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
3992 /* Like expand_decl_cleanup, but suppress generating an exception handler
3993 to perform the cleanup. */
3996 expand_decl_cleanup_no_eh (decl, cleanup)
3999 int save_eh = using_eh_for_cleanups_p;
4002 using_eh_for_cleanups_p = 0;
4003 result = expand_decl_cleanup (decl, cleanup);
4004 using_eh_for_cleanups_p = save_eh;
4009 /* Arrange for the top element of the dynamic cleanup chain to be
4010 popped if we exit the current binding contour. DECL is the
4011 associated declaration, if any, otherwise NULL_TREE. If the
4012 current contour is left via an exception, then __sjthrow will pop
4013 the top element off the dynamic cleanup chain. The code that
4014 avoids doing the action we push into the cleanup chain in the
4015 exceptional case is contained in expand_cleanups.
4017 This routine is only used by expand_eh_region_start, and that is
4018 the only way in which an exception region should be started. This
4019 routine is only used when using the setjmp/longjmp codegen method
4020 for exception handling. */
4023 expand_dcc_cleanup (decl)
4026 struct nesting *thisblock;
4029 /* Error if we are not in any block. */
4030 if (current_function == 0 || block_stack == 0)
4032 thisblock = block_stack;
4034 /* Record the cleanup for the dynamic handler chain. */
4036 /* All cleanups must be on the function_obstack. */
4037 push_obstacks_nochange ();
4038 resume_temporary_allocation ();
4039 cleanup = make_node (POPDCC_EXPR);
4042 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4043 thisblock->data.block.cleanups
4044 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4046 /* If this block has a cleanup, it belongs in stack_block_stack. */
4047 stack_block_stack = thisblock;
4051 /* Arrange for the top element of the dynamic handler chain to be
4052 popped if we exit the current binding contour. DECL is the
4053 associated declaration, if any, otherwise NULL_TREE. If the current
4054 contour is left via an exception, then __sjthrow will pop the top
4055 element off the dynamic handler chain. The code that avoids doing
4056 the action we push into the handler chain in the exceptional case
4057 is contained in expand_cleanups.
4059 This routine is only used by expand_eh_region_start, and that is
4060 the only way in which an exception region should be started. This
4061 routine is only used when using the setjmp/longjmp codegen method
4062 for exception handling. */
4065 expand_dhc_cleanup (decl)
4068 struct nesting *thisblock;
4071 /* Error if we are not in any block. */
4072 if (current_function == 0 || block_stack == 0)
4074 thisblock = block_stack;
4076 /* Record the cleanup for the dynamic handler chain. */
4078 /* All cleanups must be on the function_obstack. */
4079 push_obstacks_nochange ();
4080 resume_temporary_allocation ();
4081 cleanup = make_node (POPDHC_EXPR);
4084 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4085 thisblock->data.block.cleanups
4086 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4088 /* If this block has a cleanup, it belongs in stack_block_stack. */
4089 stack_block_stack = thisblock;
4093 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4094 DECL_ELTS is the list of elements that belong to DECL's type.
4095 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4098 expand_anon_union_decl (decl, cleanup, decl_elts)
4099 tree decl, cleanup, decl_elts;
4101 struct nesting *thisblock = current_function == 0 ? 0 : block_stack;
4105 expand_decl_cleanup (decl, cleanup);
4106 x = DECL_RTL (decl);
4110 tree decl_elt = TREE_VALUE (decl_elts);
4111 tree cleanup_elt = TREE_PURPOSE (decl_elts);
4112 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
4114 /* Propagate the union's alignment to the elements. */
4115 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
4117 /* If the element has BLKmode and the union doesn't, the union is
4118 aligned such that the element doesn't need to have BLKmode, so
4119 change the element's mode to the appropriate one for its size. */
4120 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
4121 DECL_MODE (decl_elt) = mode
4122 = mode_for_size (TREE_INT_CST_LOW (DECL_SIZE (decl_elt)),
4125 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4126 instead create a new MEM rtx with the proper mode. */
4127 if (GET_CODE (x) == MEM)
4129 if (mode == GET_MODE (x))
4130 DECL_RTL (decl_elt) = x;
4133 DECL_RTL (decl_elt) = gen_rtx_MEM (mode, copy_rtx (XEXP (x, 0)));
4134 MEM_COPY_ATTRIBUTES (DECL_RTL (decl_elt), x);
4135 RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x);
4138 else if (GET_CODE (x) == REG)
4140 if (mode == GET_MODE (x))
4141 DECL_RTL (decl_elt) = x;
4143 DECL_RTL (decl_elt) = gen_rtx_SUBREG (mode, x, 0);
4148 /* Record the cleanup if there is one. */
4151 thisblock->data.block.cleanups
4152 = temp_tree_cons (decl_elt, cleanup_elt,
4153 thisblock->data.block.cleanups);
4155 decl_elts = TREE_CHAIN (decl_elts);
4159 /* Expand a list of cleanups LIST.
4160 Elements may be expressions or may be nested lists.
4162 If DONT_DO is nonnull, then any list-element
4163 whose TREE_PURPOSE matches DONT_DO is omitted.
4164 This is sometimes used to avoid a cleanup associated with
4165 a value that is being returned out of the scope.
4167 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
4168 goto and handle protection regions specially in that case.
4170 If REACHABLE, we emit code, otherwise just inform the exception handling
4171 code about this finalization. */
4174 expand_cleanups (list, dont_do, in_fixup, reachable)
4181 for (tail = list; tail; tail = TREE_CHAIN (tail))
4182 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
4184 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
4185 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
4190 tree cleanup = TREE_VALUE (tail);
4192 /* See expand_d{h,c}c_cleanup for why we avoid this. */
4193 if (TREE_CODE (cleanup) != POPDHC_EXPR
4194 && TREE_CODE (cleanup) != POPDCC_EXPR
4195 /* See expand_eh_region_start_tree for this case. */
4196 && ! TREE_ADDRESSABLE (tail))
4198 cleanup = protect_with_terminate (cleanup);
4199 expand_eh_region_end (cleanup);
4205 /* Cleanups may be run multiple times. For example,
4206 when exiting a binding contour, we expand the
4207 cleanups associated with that contour. When a goto
4208 within that binding contour has a target outside that
4209 contour, it will expand all cleanups from its scope to
4210 the target. Though the cleanups are expanded multiple
4211 times, the control paths are non-overlapping so the
4212 cleanups will not be executed twice. */
4214 /* We may need to protect fixups with rethrow regions. */
4215 int protect = (in_fixup && ! TREE_ADDRESSABLE (tail));
4218 expand_fixup_region_start ();
4220 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
4222 expand_fixup_region_end (TREE_VALUE (tail));
4229 /* Mark when the context we are emitting RTL for as a conditional
4230 context, so that any cleanup actions we register with
4231 expand_decl_init will be properly conditionalized when those
4232 cleanup actions are later performed. Must be called before any
4233 expression (tree) is expanded that is within a conditional context. */
4236 start_cleanup_deferral ()
4238 /* block_stack can be NULL if we are inside the parameter list. It is
4239 OK to do nothing, because cleanups aren't possible here. */
4241 ++block_stack->data.block.conditional_code;
4244 /* Mark the end of a conditional region of code. Because cleanup
4245 deferrals may be nested, we may still be in a conditional region
4246 after we end the currently deferred cleanups, only after we end all
4247 deferred cleanups, are we back in unconditional code. */
4250 end_cleanup_deferral ()
4252 /* block_stack can be NULL if we are inside the parameter list. It is
4253 OK to do nothing, because cleanups aren't possible here. */
4255 --block_stack->data.block.conditional_code;
4258 /* Move all cleanups from the current block_stack
4259 to the containing block_stack, where they are assumed to
4260 have been created. If anything can cause a temporary to
4261 be created, but not expanded for more than one level of
4262 block_stacks, then this code will have to change. */
4267 struct nesting *block = block_stack;
4268 struct nesting *outer = block->next;
4270 outer->data.block.cleanups
4271 = chainon (block->data.block.cleanups,
4272 outer->data.block.cleanups);
4273 block->data.block.cleanups = 0;
4277 last_cleanup_this_contour ()
4279 if (block_stack == 0)
4282 return block_stack->data.block.cleanups;
4285 /* Return 1 if there are any pending cleanups at this point.
4286 If THIS_CONTOUR is nonzero, check the current contour as well.
4287 Otherwise, look only at the contours that enclose this one. */
4290 any_pending_cleanups (this_contour)
4293 struct nesting *block;
4295 if (block_stack == 0)
4298 if (this_contour && block_stack->data.block.cleanups != NULL)
4300 if (block_stack->data.block.cleanups == 0
4301 && block_stack->data.block.outer_cleanups == 0)
4304 for (block = block_stack->next; block; block = block->next)
4305 if (block->data.block.cleanups != 0)
4311 /* Enter a case (Pascal) or switch (C) statement.
4312 Push a block onto case_stack and nesting_stack
4313 to accumulate the case-labels that are seen
4314 and to record the labels generated for the statement.
4316 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4317 Otherwise, this construct is transparent for `exit_something'.
4319 EXPR is the index-expression to be dispatched on.
4320 TYPE is its nominal type. We could simply convert EXPR to this type,
4321 but instead we take short cuts. */
4324 expand_start_case (exit_flag, expr, type, printname)
4328 const char *printname;
4330 register struct nesting *thiscase = ALLOC_NESTING ();
4332 /* Make an entry on case_stack for the case we are entering. */
4334 thiscase->next = case_stack;
4335 thiscase->all = nesting_stack;
4336 thiscase->depth = ++nesting_depth;
4337 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
4338 thiscase->data.case_stmt.case_list = 0;
4339 thiscase->data.case_stmt.index_expr = expr;
4340 thiscase->data.case_stmt.nominal_type = type;
4341 thiscase->data.case_stmt.default_label = 0;
4342 thiscase->data.case_stmt.num_ranges = 0;
4343 thiscase->data.case_stmt.printname = printname;
4344 thiscase->data.case_stmt.line_number_status = force_line_numbers ();
4345 case_stack = thiscase;
4346 nesting_stack = thiscase;
4348 do_pending_stack_adjust ();
4350 /* Make sure case_stmt.start points to something that won't
4351 need any transformation before expand_end_case. */
4352 if (GET_CODE (get_last_insn ()) != NOTE)
4353 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4355 thiscase->data.case_stmt.start = get_last_insn ();
4357 start_cleanup_deferral ();
4361 /* Start a "dummy case statement" within which case labels are invalid
4362 and are not connected to any larger real case statement.
4363 This can be used if you don't want to let a case statement jump
4364 into the middle of certain kinds of constructs. */
4367 expand_start_case_dummy ()
4369 register struct nesting *thiscase = ALLOC_NESTING ();
4371 /* Make an entry on case_stack for the dummy. */
4373 thiscase->next = case_stack;
4374 thiscase->all = nesting_stack;
4375 thiscase->depth = ++nesting_depth;
4376 thiscase->exit_label = 0;
4377 thiscase->data.case_stmt.case_list = 0;
4378 thiscase->data.case_stmt.start = 0;
4379 thiscase->data.case_stmt.nominal_type = 0;
4380 thiscase->data.case_stmt.default_label = 0;
4381 thiscase->data.case_stmt.num_ranges = 0;
4382 case_stack = thiscase;
4383 nesting_stack = thiscase;
4384 start_cleanup_deferral ();
4387 /* End a dummy case statement. */
4390 expand_end_case_dummy ()
4392 end_cleanup_deferral ();
4393 POPSTACK (case_stack);
4396 /* Return the data type of the index-expression
4397 of the innermost case statement, or null if none. */
4400 case_index_expr_type ()
4403 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
4410 /* If this is the first label, warn if any insns have been emitted. */
4411 if (case_stack->data.case_stmt.line_number_status >= 0)
4415 restore_line_number_status
4416 (case_stack->data.case_stmt.line_number_status);
4417 case_stack->data.case_stmt.line_number_status = -1;
4419 for (insn = case_stack->data.case_stmt.start;
4421 insn = NEXT_INSN (insn))
4423 if (GET_CODE (insn) == CODE_LABEL)
4425 if (GET_CODE (insn) != NOTE
4426 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4429 insn = PREV_INSN (insn);
4430 while (insn && (GET_CODE (insn) != NOTE || NOTE_LINE_NUMBER (insn) < 0));
4432 /* If insn is zero, then there must have been a syntax error. */
4434 warning_with_file_and_line (NOTE_SOURCE_FILE(insn),
4435 NOTE_LINE_NUMBER(insn),
4436 "unreachable code at beginning of %s",
4437 case_stack->data.case_stmt.printname);
4444 /* Accumulate one case or default label inside a case or switch statement.
4445 VALUE is the value of the case (a null pointer, for a default label).
4446 The function CONVERTER, when applied to arguments T and V,
4447 converts the value V to the type T.
4449 If not currently inside a case or switch statement, return 1 and do
4450 nothing. The caller will print a language-specific error message.
4451 If VALUE is a duplicate or overlaps, return 2 and do nothing
4452 except store the (first) duplicate node in *DUPLICATE.
4453 If VALUE is out of range, return 3 and do nothing.
4454 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4455 Return 0 on success.
4457 Extended to handle range statements. */
4460 pushcase (value, converter, label, duplicate)
4461 register tree value;
4462 tree (*converter) PROTO((tree, tree));
4463 register tree label;
4469 /* Fail if not inside a real case statement. */
4470 if (! (case_stack && case_stack->data.case_stmt.start))
4473 if (stack_block_stack
4474 && stack_block_stack->depth > case_stack->depth)
4477 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4478 nominal_type = case_stack->data.case_stmt.nominal_type;
4480 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4481 if (index_type == error_mark_node)
4484 /* Convert VALUE to the type in which the comparisons are nominally done. */
4486 value = (*converter) (nominal_type, value);
4490 /* Fail if this value is out of range for the actual type of the index
4491 (which may be narrower than NOMINAL_TYPE). */
4492 if (value != 0 && ! int_fits_type_p (value, index_type))
4495 /* Fail if this is a duplicate or overlaps another entry. */
4498 if (case_stack->data.case_stmt.default_label != 0)
4500 *duplicate = case_stack->data.case_stmt.default_label;
4503 case_stack->data.case_stmt.default_label = label;
4506 return add_case_node (value, value, label, duplicate);
4508 expand_label (label);
4512 /* Like pushcase but this case applies to all values between VALUE1 and
4513 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4514 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4515 starts at VALUE1 and ends at the highest value of the index type.
4516 If both are NULL, this case applies to all values.
4518 The return value is the same as that of pushcase but there is one
4519 additional error code: 4 means the specified range was empty. */
4522 pushcase_range (value1, value2, converter, label, duplicate)
4523 register tree value1, value2;
4524 tree (*converter) PROTO((tree, tree));
4525 register tree label;
4531 /* Fail if not inside a real case statement. */
4532 if (! (case_stack && case_stack->data.case_stmt.start))
4535 if (stack_block_stack
4536 && stack_block_stack->depth > case_stack->depth)
4539 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4540 nominal_type = case_stack->data.case_stmt.nominal_type;
4542 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4543 if (index_type == error_mark_node)
4548 /* Convert VALUEs to type in which the comparisons are nominally done
4549 and replace any unspecified value with the corresponding bound. */
4551 value1 = TYPE_MIN_VALUE (index_type);
4553 value2 = TYPE_MAX_VALUE (index_type);
4555 /* Fail if the range is empty. Do this before any conversion since
4556 we want to allow out-of-range empty ranges. */
4557 if (value2 && tree_int_cst_lt (value2, value1))
4560 value1 = (*converter) (nominal_type, value1);
4562 /* If the max was unbounded, use the max of the nominal_type we are
4563 converting to. Do this after the < check above to suppress false
4566 value2 = TYPE_MAX_VALUE (nominal_type);
4567 value2 = (*converter) (nominal_type, value2);
4569 /* Fail if these values are out of range. */
4570 if (TREE_CONSTANT_OVERFLOW (value1)
4571 || ! int_fits_type_p (value1, index_type))
4574 if (TREE_CONSTANT_OVERFLOW (value2)
4575 || ! int_fits_type_p (value2, index_type))
4578 return add_case_node (value1, value2, label, duplicate);
4581 /* Do the actual insertion of a case label for pushcase and pushcase_range
4582 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4583 slowdown for large switch statements. */
4586 add_case_node (low, high, label, duplicate)
4591 struct case_node *p, **q, *r;
4593 q = &case_stack->data.case_stmt.case_list;
4600 /* Keep going past elements distinctly greater than HIGH. */
4601 if (tree_int_cst_lt (high, p->low))
4604 /* or distinctly less than LOW. */
4605 else if (tree_int_cst_lt (p->high, low))
4610 /* We have an overlap; this is an error. */
4611 *duplicate = p->code_label;
4616 /* Add this label to the chain, and succeed.
4617 Copy LOW, HIGH so they are on temporary rather than momentary
4618 obstack and will thus survive till the end of the case statement. */
4620 r = (struct case_node *) oballoc (sizeof (struct case_node));
4621 r->low = copy_node (low);
4623 /* If the bounds are equal, turn this into the one-value case. */
4625 if (tree_int_cst_equal (low, high))
4629 r->high = copy_node (high);
4630 case_stack->data.case_stmt.num_ranges++;
4633 r->code_label = label;
4634 expand_label (label);
4644 struct case_node *s;
4650 if (! (b = p->balance))
4651 /* Growth propagation from left side. */
4658 if ((p->left = s = r->right))
4667 if ((r->parent = s))
4675 case_stack->data.case_stmt.case_list = r;
4678 /* r->balance == +1 */
4683 struct case_node *t = r->right;
4685 if ((p->left = s = t->right))
4689 if ((r->right = s = t->left))
4703 if ((t->parent = s))
4711 case_stack->data.case_stmt.case_list = t;
4718 /* p->balance == +1; growth of left side balances the node. */
4728 if (! (b = p->balance))
4729 /* Growth propagation from right side. */
4737 if ((p->right = s = r->left))
4745 if ((r->parent = s))
4754 case_stack->data.case_stmt.case_list = r;
4758 /* r->balance == -1 */
4762 struct case_node *t = r->left;
4764 if ((p->right = s = t->left))
4769 if ((r->left = s = t->right))
4783 if ((t->parent = s))
4792 case_stack->data.case_stmt.case_list = t;
4798 /* p->balance == -1; growth of right side balances the node. */
4812 /* Returns the number of possible values of TYPE.
4813 Returns -1 if the number is unknown or variable.
4814 Returns -2 if the number does not fit in a HOST_WIDE_INT.
4815 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4816 do not increase monotonically (there may be duplicates);
4817 to 1 if the values increase monotonically, but not always by 1;
4818 otherwise sets it to 0. */
4821 all_cases_count (type, spareness)
4825 HOST_WIDE_INT count;
4828 switch (TREE_CODE (type))
4835 count = 1 << BITS_PER_UNIT;
4839 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4840 || TYPE_MAX_VALUE (type) == NULL
4841 || TREE_CODE (TYPE_MAX_VALUE (type)) != INTEGER_CST)
4846 = TREE_INT_CST_LOW (TYPE_MAX_VALUE (type))
4847 - TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + 1
4848 but with overflow checking. */
4849 tree mint = TYPE_MIN_VALUE (type);
4850 tree maxt = TYPE_MAX_VALUE (type);
4851 HOST_WIDE_INT lo, hi;
4852 neg_double(TREE_INT_CST_LOW (mint), TREE_INT_CST_HIGH (mint),
4854 add_double(TREE_INT_CST_LOW (maxt), TREE_INT_CST_HIGH (maxt),
4856 add_double (lo, hi, 1, 0, &lo, &hi);
4857 if (hi != 0 || lo < 0)
4864 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4866 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4867 || TREE_CODE (TREE_VALUE (t)) != INTEGER_CST
4868 || TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + count
4869 != TREE_INT_CST_LOW (TREE_VALUE (t)))
4873 if (*spareness == 1)
4875 tree prev = TREE_VALUE (TYPE_VALUES (type));
4876 for (t = TYPE_VALUES (type); t = TREE_CHAIN (t), t != NULL_TREE; )
4878 if (! tree_int_cst_lt (prev, TREE_VALUE (t)))
4883 prev = TREE_VALUE (t);
4892 #define BITARRAY_TEST(ARRAY, INDEX) \
4893 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4894 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4895 #define BITARRAY_SET(ARRAY, INDEX) \
4896 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4897 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4899 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4900 with the case values we have seen, assuming the case expression
4902 SPARSENESS is as determined by all_cases_count.
4904 The time needed is proportional to COUNT, unless
4905 SPARSENESS is 2, in which case quadratic time is needed. */
4908 mark_seen_cases (type, cases_seen, count, sparseness)
4910 unsigned char *cases_seen;
4914 tree next_node_to_try = NULL_TREE;
4915 long next_node_offset = 0;
4917 register struct case_node *n, *root = case_stack->data.case_stmt.case_list;
4918 tree val = make_node (INTEGER_CST);
4919 TREE_TYPE (val) = type;
4922 else if (sparseness == 2)
4927 /* This less efficient loop is only needed to handle
4928 duplicate case values (multiple enum constants
4929 with the same value). */
4930 TREE_TYPE (val) = TREE_TYPE (root->low);
4931 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
4932 t = TREE_CHAIN (t), xlo++)
4934 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (TREE_VALUE (t));
4935 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (TREE_VALUE (t));
4939 /* Keep going past elements distinctly greater than VAL. */
4940 if (tree_int_cst_lt (val, n->low))
4943 /* or distinctly less than VAL. */
4944 else if (tree_int_cst_lt (n->high, val))
4949 /* We have found a matching range. */
4950 BITARRAY_SET (cases_seen, xlo);
4960 case_stack->data.case_stmt.case_list = root = case_tree2list (root, 0);
4961 for (n = root; n; n = n->right)
4963 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
4964 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
4965 while ( ! tree_int_cst_lt (n->high, val))
4967 /* Calculate (into xlo) the "offset" of the integer (val).
4968 The element with lowest value has offset 0, the next smallest
4969 element has offset 1, etc. */
4971 HOST_WIDE_INT xlo, xhi;
4973 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
4975 /* The TYPE_VALUES will be in increasing order, so
4976 starting searching where we last ended. */
4977 t = next_node_to_try;
4978 xlo = next_node_offset;
4984 t = TYPE_VALUES (type);
4987 if (tree_int_cst_equal (val, TREE_VALUE (t)))
4989 next_node_to_try = TREE_CHAIN (t);
4990 next_node_offset = xlo + 1;
4995 if (t == next_node_to_try)
5004 t = TYPE_MIN_VALUE (type);
5006 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
5010 add_double (xlo, xhi,
5011 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5015 if (xhi == 0 && xlo >= 0 && xlo < count)
5016 BITARRAY_SET (cases_seen, xlo);
5017 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5019 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
5025 /* Called when the index of a switch statement is an enumerated type
5026 and there is no default label.
5028 Checks that all enumeration literals are covered by the case
5029 expressions of a switch. Also, warn if there are any extra
5030 switch cases that are *not* elements of the enumerated type.
5032 If all enumeration literals were covered by the case expressions,
5033 turn one of the expressions into the default expression since it should
5034 not be possible to fall through such a switch. */
5037 check_for_full_enumeration_handling (type)
5040 register struct case_node *n;
5041 register tree chain;
5042 #if 0 /* variable used by 'if 0'ed code below. */
5043 register struct case_node **l;
5047 /* True iff the selector type is a numbered set mode. */
5050 /* The number of possible selector values. */
5053 /* For each possible selector value. a one iff it has been matched
5054 by a case value alternative. */
5055 unsigned char *cases_seen;
5057 /* The allocated size of cases_seen, in chars. */
5063 size = all_cases_count (type, &sparseness);
5064 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
5066 if (size > 0 && size < 600000
5067 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5068 this optimization if we don't have enough memory rather than
5069 aborting, as xmalloc would do. */
5070 && (cases_seen = (unsigned char *) calloc (bytes_needed, 1)) != NULL)
5073 tree v = TYPE_VALUES (type);
5075 /* The time complexity of this code is normally O(N), where
5076 N being the number of members in the enumerated type.
5077 However, if type is a ENUMERAL_TYPE whose values do not
5078 increase monotonically, O(N*log(N)) time may be needed. */
5080 mark_seen_cases (type, cases_seen, size, sparseness);
5082 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
5084 if (BITARRAY_TEST(cases_seen, i) == 0)
5085 warning ("enumeration value `%s' not handled in switch",
5086 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
5092 /* Now we go the other way around; we warn if there are case
5093 expressions that don't correspond to enumerators. This can
5094 occur since C and C++ don't enforce type-checking of
5095 assignments to enumeration variables. */
5097 if (case_stack->data.case_stmt.case_list
5098 && case_stack->data.case_stmt.case_list->left)
5099 case_stack->data.case_stmt.case_list
5100 = case_tree2list (case_stack->data.case_stmt.case_list, 0);
5102 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
5104 for (chain = TYPE_VALUES (type);
5105 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
5106 chain = TREE_CHAIN (chain))
5111 if (TYPE_NAME (type) == 0)
5112 warning ("case value `%ld' not in enumerated type",
5113 (long) TREE_INT_CST_LOW (n->low));
5115 warning ("case value `%ld' not in enumerated type `%s'",
5116 (long) TREE_INT_CST_LOW (n->low),
5117 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5120 : DECL_NAME (TYPE_NAME (type))));
5122 if (!tree_int_cst_equal (n->low, n->high))
5124 for (chain = TYPE_VALUES (type);
5125 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
5126 chain = TREE_CHAIN (chain))
5131 if (TYPE_NAME (type) == 0)
5132 warning ("case value `%ld' not in enumerated type",
5133 (long) TREE_INT_CST_LOW (n->high));
5135 warning ("case value `%ld' not in enumerated type `%s'",
5136 (long) TREE_INT_CST_LOW (n->high),
5137 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5140 : DECL_NAME (TYPE_NAME (type))));
5146 /* ??? This optimization is disabled because it causes valid programs to
5147 fail. ANSI C does not guarantee that an expression with enum type
5148 will have a value that is the same as one of the enumeration literals. */
5150 /* If all values were found as case labels, make one of them the default
5151 label. Thus, this switch will never fall through. We arbitrarily pick
5152 the last one to make the default since this is likely the most
5153 efficient choice. */
5157 for (l = &case_stack->data.case_stmt.case_list;
5162 case_stack->data.case_stmt.default_label = (*l)->code_label;
5169 /* Terminate a case (Pascal) or switch (C) statement
5170 in which ORIG_INDEX is the expression to be tested.
5171 Generate the code to test it and jump to the right place. */
5174 expand_end_case (orig_index)
5177 tree minval = NULL_TREE, maxval = NULL_TREE, range, orig_minval;
5178 rtx default_label = 0;
5179 register struct case_node *n;
5187 register struct nesting *thiscase = case_stack;
5188 tree index_expr, index_type;
5191 /* Don't crash due to previous errors. */
5192 if (thiscase == NULL)
5195 table_label = gen_label_rtx ();
5196 index_expr = thiscase->data.case_stmt.index_expr;
5197 index_type = TREE_TYPE (index_expr);
5198 unsignedp = TREE_UNSIGNED (index_type);
5200 do_pending_stack_adjust ();
5202 /* This might get an spurious warning in the presence of a syntax error;
5203 it could be fixed by moving the call to check_seenlabel after the
5204 check for error_mark_node, and copying the code of check_seenlabel that
5205 deals with case_stack->data.case_stmt.line_number_status /
5206 restore_line_number_status in front of the call to end_cleanup_deferral;
5207 However, this might miss some useful warnings in the presence of
5208 non-syntax errors. */
5211 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5212 if (index_type != error_mark_node)
5214 /* If switch expression was an enumerated type, check that all
5215 enumeration literals are covered by the cases.
5216 No sense trying this if there's a default case, however. */
5218 if (!thiscase->data.case_stmt.default_label
5219 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
5220 && TREE_CODE (index_expr) != INTEGER_CST)
5221 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
5223 /* If we don't have a default-label, create one here,
5224 after the body of the switch. */
5225 if (thiscase->data.case_stmt.default_label == 0)
5227 thiscase->data.case_stmt.default_label
5228 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5229 expand_label (thiscase->data.case_stmt.default_label);
5231 default_label = label_rtx (thiscase->data.case_stmt.default_label);
5233 before_case = get_last_insn ();
5235 if (thiscase->data.case_stmt.case_list
5236 && thiscase->data.case_stmt.case_list->left)
5237 thiscase->data.case_stmt.case_list
5238 = case_tree2list(thiscase->data.case_stmt.case_list, 0);
5240 /* Simplify the case-list before we count it. */
5241 group_case_nodes (thiscase->data.case_stmt.case_list);
5243 /* Get upper and lower bounds of case values.
5244 Also convert all the case values to the index expr's data type. */
5247 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5249 /* Check low and high label values are integers. */
5250 if (TREE_CODE (n->low) != INTEGER_CST)
5252 if (TREE_CODE (n->high) != INTEGER_CST)
5255 n->low = convert (index_type, n->low);
5256 n->high = convert (index_type, n->high);
5258 /* Count the elements and track the largest and smallest
5259 of them (treating them as signed even if they are not). */
5267 if (INT_CST_LT (n->low, minval))
5269 if (INT_CST_LT (maxval, n->high))
5272 /* A range counts double, since it requires two compares. */
5273 if (! tree_int_cst_equal (n->low, n->high))
5277 orig_minval = minval;
5279 /* Compute span of values. */
5281 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
5283 end_cleanup_deferral ();
5287 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
5289 emit_jump (default_label);
5292 /* If range of values is much bigger than number of values,
5293 make a sequence of conditional branches instead of a dispatch.
5294 If the switch-index is a constant, do it this way
5295 because we can optimize it. */
5297 #ifndef CASE_VALUES_THRESHOLD
5299 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
5301 /* If machine does not have a case insn that compares the
5302 bounds, this means extra overhead for dispatch tables
5303 which raises the threshold for using them. */
5304 #define CASE_VALUES_THRESHOLD 5
5305 #endif /* HAVE_casesi */
5306 #endif /* CASE_VALUES_THRESHOLD */
5308 else if (TREE_INT_CST_HIGH (range) != 0
5309 || count < (unsigned int) CASE_VALUES_THRESHOLD
5310 || ((unsigned HOST_WIDE_INT) (TREE_INT_CST_LOW (range))
5312 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5315 || TREE_CODE (index_expr) == INTEGER_CST
5316 /* These will reduce to a constant. */
5317 || (TREE_CODE (index_expr) == CALL_EXPR
5318 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
5319 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
5320 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
5321 || (TREE_CODE (index_expr) == COMPOUND_EXPR
5322 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
5324 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5326 /* If the index is a short or char that we do not have
5327 an insn to handle comparisons directly, convert it to
5328 a full integer now, rather than letting each comparison
5329 generate the conversion. */
5331 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
5332 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
5333 == CODE_FOR_nothing))
5335 enum machine_mode wider_mode;
5336 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
5337 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
5338 if (cmp_optab->handlers[(int) wider_mode].insn_code
5339 != CODE_FOR_nothing)
5341 index = convert_to_mode (wider_mode, index, unsignedp);
5347 do_pending_stack_adjust ();
5349 index = protect_from_queue (index, 0);
5350 if (GET_CODE (index) == MEM)
5351 index = copy_to_reg (index);
5352 if (GET_CODE (index) == CONST_INT
5353 || TREE_CODE (index_expr) == INTEGER_CST)
5355 /* Make a tree node with the proper constant value
5356 if we don't already have one. */
5357 if (TREE_CODE (index_expr) != INTEGER_CST)
5360 = build_int_2 (INTVAL (index),
5361 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
5362 index_expr = convert (index_type, index_expr);
5365 /* For constant index expressions we need only
5366 issue a unconditional branch to the appropriate
5367 target code. The job of removing any unreachable
5368 code is left to the optimisation phase if the
5369 "-O" option is specified. */
5370 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5371 if (! tree_int_cst_lt (index_expr, n->low)
5372 && ! tree_int_cst_lt (n->high, index_expr))
5376 emit_jump (label_rtx (n->code_label));
5378 emit_jump (default_label);
5382 /* If the index expression is not constant we generate
5383 a binary decision tree to select the appropriate
5384 target code. This is done as follows:
5386 The list of cases is rearranged into a binary tree,
5387 nearly optimal assuming equal probability for each case.
5389 The tree is transformed into RTL, eliminating
5390 redundant test conditions at the same time.
5392 If program flow could reach the end of the
5393 decision tree an unconditional jump to the
5394 default code is emitted. */
5397 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
5398 && estimate_case_costs (thiscase->data.case_stmt.case_list));
5399 balance_case_nodes (&thiscase->data.case_stmt.case_list,
5401 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
5402 default_label, index_type);
5403 emit_jump_if_reachable (default_label);
5412 enum machine_mode index_mode = SImode;
5413 int index_bits = GET_MODE_BITSIZE (index_mode);
5415 enum machine_mode op_mode;
5417 /* Convert the index to SImode. */
5418 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
5419 > GET_MODE_BITSIZE (index_mode))
5421 enum machine_mode omode = TYPE_MODE (index_type);
5422 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
5424 /* We must handle the endpoints in the original mode. */
5425 index_expr = build (MINUS_EXPR, index_type,
5426 index_expr, minval);
5427 minval = integer_zero_node;
5428 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5429 emit_cmp_and_jump_insns (rangertx, index, LTU, NULL_RTX,
5430 omode, 1, 0, default_label);
5431 /* Now we can safely truncate. */
5432 index = convert_to_mode (index_mode, index, 0);
5436 if (TYPE_MODE (index_type) != index_mode)
5438 index_expr = convert (type_for_size (index_bits, 0),
5440 index_type = TREE_TYPE (index_expr);
5443 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5446 index = protect_from_queue (index, 0);
5447 do_pending_stack_adjust ();
5449 op_mode = insn_data[(int)CODE_FOR_casesi].operand[0].mode;
5450 if (! (*insn_data[(int)CODE_FOR_casesi].operand[0].predicate)
5452 index = copy_to_mode_reg (op_mode, index);
5454 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
5456 op_mode = insn_data[(int)CODE_FOR_casesi].operand[1].mode;
5457 if (! (*insn_data[(int)CODE_FOR_casesi].operand[1].predicate)
5459 op1 = copy_to_mode_reg (op_mode, op1);
5461 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
5463 op_mode = insn_data[(int)CODE_FOR_casesi].operand[2].mode;
5464 if (! (*insn_data[(int)CODE_FOR_casesi].operand[2].predicate)
5466 op2 = copy_to_mode_reg (op_mode, op2);
5468 emit_jump_insn (gen_casesi (index, op1, op2,
5469 table_label, default_label));
5473 #ifdef HAVE_tablejump
5474 if (! win && HAVE_tablejump)
5476 index_expr = convert (thiscase->data.case_stmt.nominal_type,
5477 fold (build (MINUS_EXPR, index_type,
5478 index_expr, minval)));
5479 index_type = TREE_TYPE (index_expr);
5480 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5482 index = protect_from_queue (index, 0);
5483 do_pending_stack_adjust ();
5485 do_tablejump (index, TYPE_MODE (index_type),
5486 expand_expr (range, NULL_RTX, VOIDmode, 0),
5487 table_label, default_label);
5494 /* Get table of labels to jump to, in order of case index. */
5496 ncases = TREE_INT_CST_LOW (range) + 1;
5497 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
5498 bzero ((char *) labelvec, ncases * sizeof (rtx));
5500 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5502 register HOST_WIDE_INT i
5503 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
5508 = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
5509 if (i + TREE_INT_CST_LOW (orig_minval)
5510 == TREE_INT_CST_LOW (n->high))
5516 /* Fill in the gaps with the default. */
5517 for (i = 0; i < ncases; i++)
5518 if (labelvec[i] == 0)
5519 labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
5521 /* Output the table */
5522 emit_label (table_label);
5524 if (CASE_VECTOR_PC_RELATIVE || flag_pic)
5525 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
5526 gen_rtx_LABEL_REF (Pmode, table_label),
5527 gen_rtvec_v (ncases, labelvec),
5528 const0_rtx, const0_rtx));
5530 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
5531 gen_rtvec_v (ncases, labelvec)));
5533 /* If the case insn drops through the table,
5534 after the table we must jump to the default-label.
5535 Otherwise record no drop-through after the table. */
5536 #ifdef CASE_DROPS_THROUGH
5537 emit_jump (default_label);
5543 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
5544 reorder_insns (before_case, get_last_insn (),
5545 thiscase->data.case_stmt.start);
5548 end_cleanup_deferral ();
5550 if (thiscase->exit_label)
5551 emit_label (thiscase->exit_label);
5553 POPSTACK (case_stack);
5558 /* Convert the tree NODE into a list linked by the right field, with the left
5559 field zeroed. RIGHT is used for recursion; it is a list to be placed
5560 rightmost in the resulting list. */
5562 static struct case_node *
5563 case_tree2list (node, right)
5564 struct case_node *node, *right;
5566 struct case_node *left;
5569 right = case_tree2list (node->right, right);
5571 node->right = right;
5572 if ((left = node->left))
5575 return case_tree2list (left, node);
5581 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5584 do_jump_if_equal (op1, op2, label, unsignedp)
5585 rtx op1, op2, label;
5588 if (GET_CODE (op1) == CONST_INT
5589 && GET_CODE (op2) == CONST_INT)
5591 if (INTVAL (op1) == INTVAL (op2))
5596 enum machine_mode mode = GET_MODE (op1);
5597 if (mode == VOIDmode)
5598 mode = GET_MODE (op2);
5599 emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX, mode, unsignedp,
5604 /* Not all case values are encountered equally. This function
5605 uses a heuristic to weight case labels, in cases where that
5606 looks like a reasonable thing to do.
5608 Right now, all we try to guess is text, and we establish the
5611 chars above space: 16
5620 If we find any cases in the switch that are not either -1 or in the range
5621 of valid ASCII characters, or are control characters other than those
5622 commonly used with "\", don't treat this switch scanning text.
5624 Return 1 if these nodes are suitable for cost estimation, otherwise
5628 estimate_case_costs (node)
5631 tree min_ascii = build_int_2 (-1, -1);
5632 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5636 /* If we haven't already made the cost table, make it now. Note that the
5637 lower bound of the table is -1, not zero. */
5639 if (cost_table == NULL)
5641 cost_table = ((short *) xcalloc (129, sizeof (short))) + 1;
5643 for (i = 0; i < 128; i++)
5647 else if (ISPUNCT (i))
5649 else if (ISCNTRL (i))
5653 cost_table[' '] = 8;
5654 cost_table['\t'] = 4;
5655 cost_table['\0'] = 4;
5656 cost_table['\n'] = 2;
5657 cost_table['\f'] = 1;
5658 cost_table['\v'] = 1;
5659 cost_table['\b'] = 1;
5662 /* See if all the case expressions look like text. It is text if the
5663 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5664 as signed arithmetic since we don't want to ever access cost_table with a
5665 value less than -1. Also check that none of the constants in a range
5666 are strange control characters. */
5668 for (n = node; n; n = n->right)
5670 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5673 for (i = TREE_INT_CST_LOW (n->low); i <= TREE_INT_CST_LOW (n->high); i++)
5674 if (cost_table[i] < 0)
5678 /* All interesting values are within the range of interesting
5679 ASCII characters. */
5683 /* Scan an ordered list of case nodes
5684 combining those with consecutive values or ranges.
5686 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5689 group_case_nodes (head)
5692 case_node_ptr node = head;
5696 rtx lb = next_real_insn (label_rtx (node->code_label));
5698 case_node_ptr np = node;
5700 /* Try to group the successors of NODE with NODE. */
5701 while (((np = np->right) != 0)
5702 /* Do they jump to the same place? */
5703 && ((lb2 = next_real_insn (label_rtx (np->code_label))) == lb
5704 || (lb != 0 && lb2 != 0
5705 && simplejump_p (lb)
5706 && simplejump_p (lb2)
5707 && rtx_equal_p (SET_SRC (PATTERN (lb)),
5708 SET_SRC (PATTERN (lb2)))))
5709 /* Are their ranges consecutive? */
5710 && tree_int_cst_equal (np->low,
5711 fold (build (PLUS_EXPR,
5712 TREE_TYPE (node->high),
5715 /* An overflow is not consecutive. */
5716 && tree_int_cst_lt (node->high,
5717 fold (build (PLUS_EXPR,
5718 TREE_TYPE (node->high),
5720 integer_one_node))))
5722 node->high = np->high;
5724 /* NP is the first node after NODE which can't be grouped with it.
5725 Delete the nodes in between, and move on to that node. */
5731 /* Take an ordered list of case nodes
5732 and transform them into a near optimal binary tree,
5733 on the assumption that any target code selection value is as
5734 likely as any other.
5736 The transformation is performed by splitting the ordered
5737 list into two equal sections plus a pivot. The parts are
5738 then attached to the pivot as left and right branches. Each
5739 branch is then transformed recursively. */
5742 balance_case_nodes (head, parent)
5743 case_node_ptr *head;
5744 case_node_ptr parent;
5746 register case_node_ptr np;
5754 register case_node_ptr *npp;
5757 /* Count the number of entries on branch. Also count the ranges. */
5761 if (!tree_int_cst_equal (np->low, np->high))
5765 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5769 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5777 /* Split this list if it is long enough for that to help. */
5782 /* Find the place in the list that bisects the list's total cost,
5783 Here I gets half the total cost. */
5788 /* Skip nodes while their cost does not reach that amount. */
5789 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5790 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5791 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5794 npp = &(*npp)->right;
5799 /* Leave this branch lopsided, but optimize left-hand
5800 side and fill in `parent' fields for right-hand side. */
5802 np->parent = parent;
5803 balance_case_nodes (&np->left, np);
5804 for (; np->right; np = np->right)
5805 np->right->parent = np;
5809 /* If there are just three nodes, split at the middle one. */
5811 npp = &(*npp)->right;
5814 /* Find the place in the list that bisects the list's total cost,
5815 where ranges count as 2.
5816 Here I gets half the total cost. */
5817 i = (i + ranges + 1) / 2;
5820 /* Skip nodes while their cost does not reach that amount. */
5821 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5826 npp = &(*npp)->right;
5831 np->parent = parent;
5834 /* Optimize each of the two split parts. */
5835 balance_case_nodes (&np->left, np);
5836 balance_case_nodes (&np->right, np);
5840 /* Else leave this branch as one level,
5841 but fill in `parent' fields. */
5843 np->parent = parent;
5844 for (; np->right; np = np->right)
5845 np->right->parent = np;
5850 /* Search the parent sections of the case node tree
5851 to see if a test for the lower bound of NODE would be redundant.
5852 INDEX_TYPE is the type of the index expression.
5854 The instructions to generate the case decision tree are
5855 output in the same order as nodes are processed so it is
5856 known that if a parent node checks the range of the current
5857 node minus one that the current node is bounded at its lower
5858 span. Thus the test would be redundant. */
5861 node_has_low_bound (node, index_type)
5866 case_node_ptr pnode;
5868 /* If the lower bound of this node is the lowest value in the index type,
5869 we need not test it. */
5871 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5874 /* If this node has a left branch, the value at the left must be less
5875 than that at this node, so it cannot be bounded at the bottom and
5876 we need not bother testing any further. */
5881 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5882 node->low, integer_one_node));
5884 /* If the subtraction above overflowed, we can't verify anything.
5885 Otherwise, look for a parent that tests our value - 1. */
5887 if (! tree_int_cst_lt (low_minus_one, node->low))
5890 for (pnode = node->parent; pnode; pnode = pnode->parent)
5891 if (tree_int_cst_equal (low_minus_one, pnode->high))
5897 /* Search the parent sections of the case node tree
5898 to see if a test for the upper bound of NODE would be redundant.
5899 INDEX_TYPE is the type of the index expression.
5901 The instructions to generate the case decision tree are
5902 output in the same order as nodes are processed so it is
5903 known that if a parent node checks the range of the current
5904 node plus one that the current node is bounded at its upper
5905 span. Thus the test would be redundant. */
5908 node_has_high_bound (node, index_type)
5913 case_node_ptr pnode;
5915 /* If there is no upper bound, obviously no test is needed. */
5917 if (TYPE_MAX_VALUE (index_type) == NULL)
5920 /* If the upper bound of this node is the highest value in the type
5921 of the index expression, we need not test against it. */
5923 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
5926 /* If this node has a right branch, the value at the right must be greater
5927 than that at this node, so it cannot be bounded at the top and
5928 we need not bother testing any further. */
5933 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
5934 node->high, integer_one_node));
5936 /* If the addition above overflowed, we can't verify anything.
5937 Otherwise, look for a parent that tests our value + 1. */
5939 if (! tree_int_cst_lt (node->high, high_plus_one))
5942 for (pnode = node->parent; pnode; pnode = pnode->parent)
5943 if (tree_int_cst_equal (high_plus_one, pnode->low))
5949 /* Search the parent sections of the
5950 case node tree to see if both tests for the upper and lower
5951 bounds of NODE would be redundant. */
5954 node_is_bounded (node, index_type)
5958 return (node_has_low_bound (node, index_type)
5959 && node_has_high_bound (node, index_type));
5962 /* Emit an unconditional jump to LABEL unless it would be dead code. */
5965 emit_jump_if_reachable (label)
5968 if (GET_CODE (get_last_insn ()) != BARRIER)
5972 /* Emit step-by-step code to select a case for the value of INDEX.
5973 The thus generated decision tree follows the form of the
5974 case-node binary tree NODE, whose nodes represent test conditions.
5975 INDEX_TYPE is the type of the index of the switch.
5977 Care is taken to prune redundant tests from the decision tree
5978 by detecting any boundary conditions already checked by
5979 emitted rtx. (See node_has_high_bound, node_has_low_bound
5980 and node_is_bounded, above.)
5982 Where the test conditions can be shown to be redundant we emit
5983 an unconditional jump to the target code. As a further
5984 optimization, the subordinates of a tree node are examined to
5985 check for bounded nodes. In this case conditional and/or
5986 unconditional jumps as a result of the boundary check for the
5987 current node are arranged to target the subordinates associated
5988 code for out of bound conditions on the current node.
5990 We can assume that when control reaches the code generated here,
5991 the index value has already been compared with the parents
5992 of this node, and determined to be on the same side of each parent
5993 as this node is. Thus, if this node tests for the value 51,
5994 and a parent tested for 52, we don't need to consider
5995 the possibility of a value greater than 51. If another parent
5996 tests for the value 50, then this node need not test anything. */
5999 emit_case_nodes (index, node, default_label, index_type)
6005 /* If INDEX has an unsigned type, we must make unsigned branches. */
6006 int unsignedp = TREE_UNSIGNED (index_type);
6007 typedef rtx rtx_fn ();
6008 enum machine_mode mode = GET_MODE (index);
6010 /* See if our parents have already tested everything for us.
6011 If they have, emit an unconditional jump for this node. */
6012 if (node_is_bounded (node, index_type))
6013 emit_jump (label_rtx (node->code_label));
6015 else if (tree_int_cst_equal (node->low, node->high))
6017 /* Node is single valued. First see if the index expression matches
6018 this node and then check our children, if any. */
6020 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
6021 label_rtx (node->code_label), unsignedp);
6023 if (node->right != 0 && node->left != 0)
6025 /* This node has children on both sides.
6026 Dispatch to one side or the other
6027 by comparing the index value with this node's value.
6028 If one subtree is bounded, check that one first,
6029 so we can avoid real branches in the tree. */
6031 if (node_is_bounded (node->right, index_type))
6033 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6035 GT, NULL_RTX, mode, unsignedp, 0,
6036 label_rtx (node->right->code_label));
6037 emit_case_nodes (index, node->left, default_label, index_type);
6040 else if (node_is_bounded (node->left, index_type))
6042 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6044 LT, NULL_RTX, mode, unsignedp, 0,
6045 label_rtx (node->left->code_label));
6046 emit_case_nodes (index, node->right, default_label, index_type);
6051 /* Neither node is bounded. First distinguish the two sides;
6052 then emit the code for one side at a time. */
6055 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6057 /* See if the value is on the right. */
6058 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6060 GT, NULL_RTX, mode, unsignedp, 0,
6061 label_rtx (test_label));
6063 /* Value must be on the left.
6064 Handle the left-hand subtree. */
6065 emit_case_nodes (index, node->left, default_label, index_type);
6066 /* If left-hand subtree does nothing,
6068 emit_jump_if_reachable (default_label);
6070 /* Code branches here for the right-hand subtree. */
6071 expand_label (test_label);
6072 emit_case_nodes (index, node->right, default_label, index_type);
6076 else if (node->right != 0 && node->left == 0)
6078 /* Here we have a right child but no left so we issue conditional
6079 branch to default and process the right child.
6081 Omit the conditional branch to default if we it avoid only one
6082 right child; it costs too much space to save so little time. */
6084 if (node->right->right || node->right->left
6085 || !tree_int_cst_equal (node->right->low, node->right->high))
6087 if (!node_has_low_bound (node, index_type))
6089 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6092 LT, NULL_RTX, mode, unsignedp, 0,
6096 emit_case_nodes (index, node->right, default_label, index_type);
6099 /* We cannot process node->right normally
6100 since we haven't ruled out the numbers less than
6101 this node's value. So handle node->right explicitly. */
6102 do_jump_if_equal (index,
6103 expand_expr (node->right->low, NULL_RTX,
6105 label_rtx (node->right->code_label), unsignedp);
6108 else if (node->right == 0 && node->left != 0)
6110 /* Just one subtree, on the left. */
6112 #if 0 /* The following code and comment were formerly part
6113 of the condition here, but they didn't work
6114 and I don't understand what the idea was. -- rms. */
6115 /* If our "most probable entry" is less probable
6116 than the default label, emit a jump to
6117 the default label using condition codes
6118 already lying around. With no right branch,
6119 a branch-greater-than will get us to the default
6122 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
6125 if (node->left->left || node->left->right
6126 || !tree_int_cst_equal (node->left->low, node->left->high))
6128 if (!node_has_high_bound (node, index_type))
6130 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6133 GT, NULL_RTX, mode, unsignedp, 0,
6137 emit_case_nodes (index, node->left, default_label, index_type);
6140 /* We cannot process node->left normally
6141 since we haven't ruled out the numbers less than
6142 this node's value. So handle node->left explicitly. */
6143 do_jump_if_equal (index,
6144 expand_expr (node->left->low, NULL_RTX,
6146 label_rtx (node->left->code_label), unsignedp);
6151 /* Node is a range. These cases are very similar to those for a single
6152 value, except that we do not start by testing whether this node
6153 is the one to branch to. */
6155 if (node->right != 0 && node->left != 0)
6157 /* Node has subtrees on both sides.
6158 If the right-hand subtree is bounded,
6159 test for it first, since we can go straight there.
6160 Otherwise, we need to make a branch in the control structure,
6161 then handle the two subtrees. */
6162 tree test_label = 0;
6165 if (node_is_bounded (node->right, index_type))
6166 /* Right hand node is fully bounded so we can eliminate any
6167 testing and branch directly to the target code. */
6168 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6170 GT, NULL_RTX, mode, unsignedp, 0,
6171 label_rtx (node->right->code_label));
6174 /* Right hand node requires testing.
6175 Branch to a label where we will handle it later. */
6177 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6178 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6180 GT, NULL_RTX, mode, unsignedp, 0,
6181 label_rtx (test_label));
6184 /* Value belongs to this node or to the left-hand subtree. */
6186 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6188 GE, NULL_RTX, mode, unsignedp, 0,
6189 label_rtx (node->code_label));
6191 /* Handle the left-hand subtree. */
6192 emit_case_nodes (index, node->left, default_label, index_type);
6194 /* If right node had to be handled later, do that now. */
6198 /* If the left-hand subtree fell through,
6199 don't let it fall into the right-hand subtree. */
6200 emit_jump_if_reachable (default_label);
6202 expand_label (test_label);
6203 emit_case_nodes (index, node->right, default_label, index_type);
6207 else if (node->right != 0 && node->left == 0)
6209 /* Deal with values to the left of this node,
6210 if they are possible. */
6211 if (!node_has_low_bound (node, index_type))
6213 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6215 LT, NULL_RTX, mode, unsignedp, 0,
6219 /* Value belongs to this node or to the right-hand subtree. */
6221 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6223 LE, NULL_RTX, mode, unsignedp, 0,
6224 label_rtx (node->code_label));
6226 emit_case_nodes (index, node->right, default_label, index_type);
6229 else if (node->right == 0 && node->left != 0)
6231 /* Deal with values to the right of this node,
6232 if they are possible. */
6233 if (!node_has_high_bound (node, index_type))
6235 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6237 GT, NULL_RTX, mode, unsignedp, 0,
6241 /* Value belongs to this node or to the left-hand subtree. */
6243 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6245 GE, NULL_RTX, mode, unsignedp, 0,
6246 label_rtx (node->code_label));
6248 emit_case_nodes (index, node->left, default_label, index_type);
6253 /* Node has no children so we check low and high bounds to remove
6254 redundant tests. Only one of the bounds can exist,
6255 since otherwise this node is bounded--a case tested already. */
6257 if (!node_has_high_bound (node, index_type))
6259 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6261 GT, NULL_RTX, mode, unsignedp, 0,
6265 if (!node_has_low_bound (node, index_type))
6267 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6269 LT, NULL_RTX, mode, unsignedp, 0,
6273 emit_jump (label_rtx (node->code_label));
6278 /* These routines are used by the loop unrolling code. They copy BLOCK trees
6279 so that the debugging info will be correct for the unrolled loop. */
6282 find_loop_tree_blocks ()
6284 identify_blocks (DECL_INITIAL (current_function_decl), get_insns ());
6288 unroll_block_trees ()
6290 tree block = DECL_INITIAL (current_function_decl);
6292 reorder_blocks (block, get_insns ());