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. */
573 struct stmt_status *p;
578 mark_block_nesting (p->x_block_stack);
579 mark_cond_nesting (p->x_cond_stack);
580 mark_loop_nesting (p->x_loop_stack);
581 mark_case_nesting (p->x_case_stack);
583 ggc_mark_tree (p->x_last_expr_type);
584 /* last_epxr_value is only valid if last_expr_type is nonzero. */
585 if (p->x_last_expr_type)
586 ggc_mark_rtx (p->x_last_expr_value);
588 mark_goto_fixup (p->x_goto_fixup_chain);
594 gcc_obstack_init (&stmt_obstack);
598 init_stmt_for_function ()
600 current_function->stmt
601 = (struct stmt_status *) xmalloc (sizeof (struct stmt_status));
603 /* We are not currently within any block, conditional, loop or case. */
605 stack_block_stack = 0;
612 current_block_start_count = 0;
614 /* No gotos have been expanded yet. */
615 goto_fixup_chain = 0;
617 /* We are not processing a ({...}) grouping. */
618 expr_stmts_for_value = 0;
620 last_expr_value = NULL_RTX;
623 /* Return nonzero if anything is pushed on the loop, condition, or case
628 return cond_stack || loop_stack || case_stack;
631 /* Record the current file and line. Called from emit_line_note. */
633 set_file_and_line_for_stmt (file, line)
637 emit_filename = file;
641 /* Emit a no-op instruction. */
648 last_insn = get_last_insn ();
650 && (GET_CODE (last_insn) == CODE_LABEL
651 || (GET_CODE (last_insn) == NOTE
652 && prev_real_insn (last_insn) == 0)))
653 emit_insn (gen_nop ());
656 /* Return the rtx-label that corresponds to a LABEL_DECL,
657 creating it if necessary. */
663 if (TREE_CODE (label) != LABEL_DECL)
666 if (DECL_RTL (label))
667 return DECL_RTL (label);
669 return DECL_RTL (label) = gen_label_rtx ();
672 /* Add an unconditional jump to LABEL as the next sequential instruction. */
678 do_pending_stack_adjust ();
679 emit_jump_insn (gen_jump (label));
683 /* Emit code to jump to the address
684 specified by the pointer expression EXP. */
687 expand_computed_goto (exp)
690 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
692 #ifdef POINTERS_EXTEND_UNSIGNED
693 x = convert_memory_address (Pmode, x);
697 /* Be sure the function is executable. */
698 if (current_function_check_memory_usage)
699 emit_library_call (chkr_check_exec_libfunc, 1,
700 VOIDmode, 1, x, ptr_mode);
702 do_pending_stack_adjust ();
703 emit_indirect_jump (x);
705 current_function_has_computed_jump = 1;
708 /* Handle goto statements and the labels that they can go to. */
710 /* Specify the location in the RTL code of a label LABEL,
711 which is a LABEL_DECL tree node.
713 This is used for the kind of label that the user can jump to with a
714 goto statement, and for alternatives of a switch or case statement.
715 RTL labels generated for loops and conditionals don't go through here;
716 they are generated directly at the RTL level, by other functions below.
718 Note that this has nothing to do with defining label *names*.
719 Languages vary in how they do that and what that even means. */
725 struct label_chain *p;
727 do_pending_stack_adjust ();
728 emit_label (label_rtx (label));
729 if (DECL_NAME (label))
730 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
732 if (stack_block_stack != 0)
734 p = (struct label_chain *) oballoc (sizeof (struct label_chain));
735 p->next = stack_block_stack->data.block.label_chain;
736 stack_block_stack->data.block.label_chain = p;
741 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
742 from nested functions. */
745 declare_nonlocal_label (label)
748 rtx slot = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
750 nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
751 LABEL_PRESERVE_P (label_rtx (label)) = 1;
752 if (nonlocal_goto_handler_slots == 0)
754 emit_stack_save (SAVE_NONLOCAL,
755 &nonlocal_goto_stack_level,
756 PREV_INSN (tail_recursion_reentry));
758 nonlocal_goto_handler_slots
759 = gen_rtx_EXPR_LIST (VOIDmode, slot, nonlocal_goto_handler_slots);
762 /* Generate RTL code for a `goto' statement with target label LABEL.
763 LABEL should be a LABEL_DECL tree node that was or will later be
764 defined with `expand_label'. */
772 /* Check for a nonlocal goto to a containing function. */
773 context = decl_function_context (label);
774 if (context != 0 && context != current_function_decl)
776 struct function *p = find_function_data (context);
777 rtx label_ref = gen_rtx_LABEL_REF (Pmode, label_rtx (label));
778 rtx temp, handler_slot;
781 /* Find the corresponding handler slot for this label. */
782 handler_slot = p->x_nonlocal_goto_handler_slots;
783 for (link = p->x_nonlocal_labels; TREE_VALUE (link) != label;
784 link = TREE_CHAIN (link))
785 handler_slot = XEXP (handler_slot, 1);
786 handler_slot = XEXP (handler_slot, 0);
788 p->has_nonlocal_label = 1;
789 current_function_has_nonlocal_goto = 1;
790 LABEL_REF_NONLOCAL_P (label_ref) = 1;
792 /* Copy the rtl for the slots so that they won't be shared in
793 case the virtual stack vars register gets instantiated differently
794 in the parent than in the child. */
796 #if HAVE_nonlocal_goto
797 if (HAVE_nonlocal_goto)
798 emit_insn (gen_nonlocal_goto (lookup_static_chain (label),
799 copy_rtx (handler_slot),
800 copy_rtx (p->x_nonlocal_goto_stack_level),
807 /* Restore frame pointer for containing function.
808 This sets the actual hard register used for the frame pointer
809 to the location of the function's incoming static chain info.
810 The non-local goto handler will then adjust it to contain the
811 proper value and reload the argument pointer, if needed. */
812 emit_move_insn (hard_frame_pointer_rtx, lookup_static_chain (label));
814 /* We have now loaded the frame pointer hardware register with
815 the address of that corresponds to the start of the virtual
816 stack vars. So replace virtual_stack_vars_rtx in all
817 addresses we use with stack_pointer_rtx. */
819 /* Get addr of containing function's current nonlocal goto handler,
820 which will do any cleanups and then jump to the label. */
821 addr = copy_rtx (handler_slot);
822 temp = copy_to_reg (replace_rtx (addr, virtual_stack_vars_rtx,
823 hard_frame_pointer_rtx));
825 /* Restore the stack pointer. Note this uses fp just restored. */
826 addr = p->x_nonlocal_goto_stack_level;
828 addr = replace_rtx (copy_rtx (addr),
829 virtual_stack_vars_rtx,
830 hard_frame_pointer_rtx);
832 emit_stack_restore (SAVE_NONLOCAL, addr, NULL_RTX);
834 /* USE of hard_frame_pointer_rtx added for consistency; not clear if
836 emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx));
837 emit_insn (gen_rtx_USE (VOIDmode, stack_pointer_rtx));
838 emit_indirect_jump (temp);
842 expand_goto_internal (label, label_rtx (label), NULL_RTX);
845 /* Generate RTL code for a `goto' statement with target label BODY.
846 LABEL should be a LABEL_REF.
847 LAST_INSN, if non-0, is the rtx we should consider as the last
848 insn emitted (for the purposes of cleaning up a return). */
851 expand_goto_internal (body, label, last_insn)
856 struct nesting *block;
859 if (GET_CODE (label) != CODE_LABEL)
862 /* If label has already been defined, we can tell now
863 whether and how we must alter the stack level. */
865 if (PREV_INSN (label) != 0)
867 /* Find the innermost pending block that contains the label.
868 (Check containment by comparing insn-uids.)
869 Then restore the outermost stack level within that block,
870 and do cleanups of all blocks contained in it. */
871 for (block = block_stack; block; block = block->next)
873 if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
875 if (block->data.block.stack_level != 0)
876 stack_level = block->data.block.stack_level;
877 /* Execute the cleanups for blocks we are exiting. */
878 if (block->data.block.cleanups != 0)
880 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
881 do_pending_stack_adjust ();
887 /* Ensure stack adjust isn't done by emit_jump, as this
888 would clobber the stack pointer. This one should be
889 deleted as dead by flow. */
890 clear_pending_stack_adjust ();
891 do_pending_stack_adjust ();
892 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
895 if (body != 0 && DECL_TOO_LATE (body))
896 error ("jump to `%s' invalidly jumps into binding contour",
897 IDENTIFIER_POINTER (DECL_NAME (body)));
899 /* Label not yet defined: may need to put this goto
900 on the fixup list. */
901 else if (! expand_fixup (body, label, last_insn))
903 /* No fixup needed. Record that the label is the target
904 of at least one goto that has no fixup. */
906 TREE_ADDRESSABLE (body) = 1;
912 /* Generate if necessary a fixup for a goto
913 whose target label in tree structure (if any) is TREE_LABEL
914 and whose target in rtl is RTL_LABEL.
916 If LAST_INSN is nonzero, we pretend that the jump appears
917 after insn LAST_INSN instead of at the current point in the insn stream.
919 The fixup will be used later to insert insns just before the goto.
920 Those insns will restore the stack level as appropriate for the
921 target label, and will (in the case of C++) also invoke any object
922 destructors which have to be invoked when we exit the scopes which
923 are exited by the goto.
925 Value is nonzero if a fixup is made. */
928 expand_fixup (tree_label, rtl_label, last_insn)
933 struct nesting *block, *end_block;
935 /* See if we can recognize which block the label will be output in.
936 This is possible in some very common cases.
937 If we succeed, set END_BLOCK to that block.
938 Otherwise, set it to 0. */
941 && (rtl_label == cond_stack->data.cond.endif_label
942 || rtl_label == cond_stack->data.cond.next_label))
943 end_block = cond_stack;
944 /* If we are in a loop, recognize certain labels which
945 are likely targets. This reduces the number of fixups
946 we need to create. */
948 && (rtl_label == loop_stack->data.loop.start_label
949 || rtl_label == loop_stack->data.loop.end_label
950 || rtl_label == loop_stack->data.loop.continue_label))
951 end_block = loop_stack;
955 /* Now set END_BLOCK to the binding level to which we will return. */
959 struct nesting *next_block = end_block->all;
962 /* First see if the END_BLOCK is inside the innermost binding level.
963 If so, then no cleanups or stack levels are relevant. */
964 while (next_block && next_block != block)
965 next_block = next_block->all;
970 /* Otherwise, set END_BLOCK to the innermost binding level
971 which is outside the relevant control-structure nesting. */
972 next_block = block_stack->next;
973 for (block = block_stack; block != end_block; block = block->all)
974 if (block == next_block)
975 next_block = next_block->next;
976 end_block = next_block;
979 /* Does any containing block have a stack level or cleanups?
980 If not, no fixup is needed, and that is the normal case
981 (the only case, for standard C). */
982 for (block = block_stack; block != end_block; block = block->next)
983 if (block->data.block.stack_level != 0
984 || block->data.block.cleanups != 0)
987 if (block != end_block)
989 /* Ok, a fixup is needed. Add a fixup to the list of such. */
990 struct goto_fixup *fixup
991 = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup));
992 /* In case an old stack level is restored, make sure that comes
993 after any pending stack adjust. */
994 /* ?? If the fixup isn't to come at the present position,
995 doing the stack adjust here isn't useful. Doing it with our
996 settings at that location isn't useful either. Let's hope
999 do_pending_stack_adjust ();
1000 fixup->target = tree_label;
1001 fixup->target_rtl = rtl_label;
1003 /* Create a BLOCK node and a corresponding matched set of
1004 NOTE_INSN_BEGIN_BLOCK and NOTE_INSN_END_BLOCK notes at
1005 this point. The notes will encapsulate any and all fixup
1006 code which we might later insert at this point in the insn
1007 stream. Also, the BLOCK node will be the parent (i.e. the
1008 `SUPERBLOCK') of any other BLOCK nodes which we might create
1009 later on when we are expanding the fixup code.
1011 Note that optimization passes (including expand_end_loop)
1012 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
1013 as a placeholder. */
1016 register rtx original_before_jump
1017 = last_insn ? last_insn : get_last_insn ();
1021 block = make_node (BLOCK);
1022 TREE_USED (block) = 1;
1024 if (current_function->x_whole_function_mode_p)
1026 find_loop_tree_blocks ();
1027 retrofit_block (block, original_before_jump);
1030 insert_block (block);
1033 start = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
1034 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_DELETED);
1035 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
1036 fixup->context = block;
1038 emit_insns_after (start, original_before_jump);
1041 fixup->block_start_count = current_block_start_count;
1042 fixup->stack_level = 0;
1043 fixup->cleanup_list_list
1044 = ((block->data.block.outer_cleanups
1045 || block->data.block.cleanups)
1046 ? tree_cons (NULL_TREE, block->data.block.cleanups,
1047 block->data.block.outer_cleanups)
1049 fixup->next = goto_fixup_chain;
1050 goto_fixup_chain = fixup;
1058 /* Expand any needed fixups in the outputmost binding level of the
1059 function. FIRST_INSN is the first insn in the function. */
1062 expand_fixups (first_insn)
1065 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0);
1068 /* When exiting a binding contour, process all pending gotos requiring fixups.
1069 THISBLOCK is the structure that describes the block being exited.
1070 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1071 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1072 FIRST_INSN is the insn that began this contour.
1074 Gotos that jump out of this contour must restore the
1075 stack level and do the cleanups before actually jumping.
1077 DONT_JUMP_IN nonzero means report error there is a jump into this
1078 contour from before the beginning of the contour.
1079 This is also done if STACK_LEVEL is nonzero. */
1082 fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1083 struct nesting *thisblock;
1089 register struct goto_fixup *f, *prev;
1091 /* F is the fixup we are considering; PREV is the previous one. */
1092 /* We run this loop in two passes so that cleanups of exited blocks
1093 are run first, and blocks that are exited are marked so
1096 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1098 /* Test for a fixup that is inactive because it is already handled. */
1099 if (f->before_jump == 0)
1101 /* Delete inactive fixup from the chain, if that is easy to do. */
1103 prev->next = f->next;
1105 /* Has this fixup's target label been defined?
1106 If so, we can finalize it. */
1107 else if (PREV_INSN (f->target_rtl) != 0)
1109 register rtx cleanup_insns;
1111 /* Get the first non-label after the label
1112 this goto jumps to. If that's before this scope begins,
1113 we don't have a jump into the scope. */
1114 rtx after_label = f->target_rtl;
1115 while (after_label != 0 && GET_CODE (after_label) == CODE_LABEL)
1116 after_label = NEXT_INSN (after_label);
1118 /* If this fixup jumped into this contour from before the beginning
1119 of this contour, report an error. */
1120 /* ??? Bug: this does not detect jumping in through intermediate
1121 blocks that have stack levels or cleanups.
1122 It detects only a problem with the innermost block
1123 around the label. */
1125 && (dont_jump_in || stack_level || cleanup_list)
1126 /* If AFTER_LABEL is 0, it means the jump goes to the end
1127 of the rtl, which means it jumps into this scope. */
1128 && (after_label == 0
1129 || INSN_UID (first_insn) < INSN_UID (after_label))
1130 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1131 && ! DECL_ERROR_ISSUED (f->target))
1133 error_with_decl (f->target,
1134 "label `%s' used before containing binding contour");
1135 /* Prevent multiple errors for one label. */
1136 DECL_ERROR_ISSUED (f->target) = 1;
1139 /* We will expand the cleanups into a sequence of their own and
1140 then later on we will attach this new sequence to the insn
1141 stream just ahead of the actual jump insn. */
1145 /* Temporarily restore the lexical context where we will
1146 logically be inserting the fixup code. We do this for the
1147 sake of getting the debugging information right. */
1150 set_block (f->context);
1152 /* Expand the cleanups for blocks this jump exits. */
1153 if (f->cleanup_list_list)
1156 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1157 /* Marked elements correspond to blocks that have been closed.
1158 Do their cleanups. */
1159 if (TREE_ADDRESSABLE (lists)
1160 && TREE_VALUE (lists) != 0)
1162 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1163 /* Pop any pushes done in the cleanups,
1164 in case function is about to return. */
1165 do_pending_stack_adjust ();
1169 /* Restore stack level for the biggest contour that this
1170 jump jumps out of. */
1172 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1174 /* Finish up the sequence containing the insns which implement the
1175 necessary cleanups, and then attach that whole sequence to the
1176 insn stream just ahead of the actual jump insn. Attaching it
1177 at that point insures that any cleanups which are in fact
1178 implicit C++ object destructions (which must be executed upon
1179 leaving the block) appear (to the debugger) to be taking place
1180 in an area of the generated code where the object(s) being
1181 destructed are still "in scope". */
1183 cleanup_insns = get_insns ();
1187 emit_insns_after (cleanup_insns, f->before_jump);
1194 /* For any still-undefined labels, do the cleanups for this block now.
1195 We must do this now since items in the cleanup list may go out
1196 of scope when the block ends. */
1197 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1198 if (f->before_jump != 0
1199 && PREV_INSN (f->target_rtl) == 0
1200 /* Label has still not appeared. If we are exiting a block with
1201 a stack level to restore, that started before the fixup,
1202 mark this stack level as needing restoration
1203 when the fixup is later finalized. */
1205 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1206 means the label is undefined. That's erroneous, but possible. */
1207 && (thisblock->data.block.block_start_count
1208 <= f->block_start_count))
1210 tree lists = f->cleanup_list_list;
1213 for (; lists; lists = TREE_CHAIN (lists))
1214 /* If the following elt. corresponds to our containing block
1215 then the elt. must be for this block. */
1216 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
1220 set_block (f->context);
1221 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1222 do_pending_stack_adjust ();
1223 cleanup_insns = get_insns ();
1226 if (cleanup_insns != 0)
1228 = emit_insns_after (cleanup_insns, f->before_jump);
1230 f->cleanup_list_list = TREE_CHAIN (lists);
1234 f->stack_level = stack_level;
1238 /* Return the number of times character C occurs in string S. */
1240 n_occurrences (c, s)
1250 /* Generate RTL for an asm statement (explicit assembler code).
1251 BODY is a STRING_CST node containing the assembler code text,
1252 or an ADDR_EXPR containing a STRING_CST. */
1258 if (current_function_check_memory_usage)
1260 error ("`asm' cannot be used in function where memory usage is checked");
1264 if (TREE_CODE (body) == ADDR_EXPR)
1265 body = TREE_OPERAND (body, 0);
1267 emit_insn (gen_rtx_ASM_INPUT (VOIDmode,
1268 TREE_STRING_POINTER (body)));
1272 /* Generate RTL for an asm statement with arguments.
1273 STRING is the instruction template.
1274 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1275 Each output or input has an expression in the TREE_VALUE and
1276 a constraint-string in the TREE_PURPOSE.
1277 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1278 that is clobbered by this insn.
1280 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1281 Some elements of OUTPUTS may be replaced with trees representing temporary
1282 values. The caller should copy those temporary values to the originally
1285 VOL nonzero means the insn is volatile; don't optimize it. */
1288 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1289 tree string, outputs, inputs, clobbers;
1294 rtvec argvec, constraints;
1296 int ninputs = list_length (inputs);
1297 int noutputs = list_length (outputs);
1302 /* Vector of RTX's of evaluated output operands. */
1303 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1304 int *inout_opnum = (int *) alloca (noutputs * sizeof (int));
1305 rtx *real_output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1306 enum machine_mode *inout_mode
1307 = (enum machine_mode *) alloca (noutputs * sizeof (enum machine_mode));
1308 /* The insn we have emitted. */
1311 /* An ASM with no outputs needs to be treated as volatile, for now. */
1315 if (current_function_check_memory_usage)
1317 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1321 #ifdef MD_ASM_CLOBBERS
1322 /* Sometimes we wish to automatically clobber registers across an asm.
1323 Case in point is when the i386 backend moved from cc0 to a hard reg --
1324 maintaining source-level compatability means automatically clobbering
1325 the flags register. */
1326 MD_ASM_CLOBBERS (clobbers);
1329 if (current_function_check_memory_usage)
1331 error ("`asm' cannot be used in function where memory usage is checked");
1335 /* Count the number of meaningful clobbered registers, ignoring what
1336 we would ignore later. */
1338 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1340 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1341 i = decode_reg_name (regname);
1342 if (i >= 0 || i == -4)
1345 error ("unknown register name `%s' in `asm'", regname);
1350 /* Check that the number of alternatives is constant across all
1352 if (outputs || inputs)
1354 tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
1355 int nalternatives = n_occurrences (',', TREE_STRING_POINTER (tmp));
1358 if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
1360 error ("too many alternatives in `asm'");
1367 char *constraint = TREE_STRING_POINTER (TREE_PURPOSE (tmp));
1368 if (n_occurrences (',', constraint) != nalternatives)
1370 error ("operand constraints for `asm' differ in number of alternatives");
1373 if (TREE_CHAIN (tmp))
1374 tmp = TREE_CHAIN (tmp);
1376 tmp = next, next = 0;
1380 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1382 tree val = TREE_VALUE (tail);
1383 tree type = TREE_TYPE (val);
1392 /* If there's an erroneous arg, emit no insn. */
1393 if (TREE_TYPE (val) == error_mark_node)
1396 /* Make sure constraint has `=' and does not have `+'. Also, see
1397 if it allows any register. Be liberal on the latter test, since
1398 the worst that happens if we get it wrong is we issue an error
1401 c_len = TREE_STRING_LENGTH (TREE_PURPOSE (tail)) - 1;
1402 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1404 /* Allow the `=' or `+' to not be at the beginning of the string,
1405 since it wasn't explicitly documented that way, and there is a
1406 large body of code that puts it last. Swap the character to
1407 the front, so as not to uglify any place else. */
1411 if ((p = strchr (constraint, '=')) != NULL)
1413 if ((p = strchr (constraint, '+')) != NULL)
1416 error ("output operand constraint lacks `='");
1420 if (p != constraint)
1423 bcopy (constraint, constraint+1, p-constraint);
1426 warning ("output constraint `%c' for operand %d is not at the beginning", j, i);
1429 is_inout = constraint[0] == '+';
1430 /* Replace '+' with '='. */
1431 constraint[0] = '=';
1432 /* Make sure we can specify the matching operand. */
1433 if (is_inout && i > 9)
1435 error ("output operand constraint %d contains `+'", i);
1439 for (j = 1; j < c_len; j++)
1440 switch (constraint[j])
1444 error ("operand constraint contains '+' or '=' at illegal position.");
1448 if (i + 1 == ninputs + noutputs)
1450 error ("`%%' constraint used with last operand");
1455 case '?': case '!': case '*': case '&':
1456 case 'E': case 'F': case 'G': case 'H':
1457 case 's': case 'i': case 'n':
1458 case 'I': case 'J': case 'K': case 'L': case 'M':
1459 case 'N': case 'O': case 'P': case ',':
1460 #ifdef EXTRA_CONSTRAINT
1461 case 'Q': case 'R': case 'S': case 'T': case 'U':
1465 case '0': case '1': case '2': case '3': case '4':
1466 case '5': case '6': case '7': case '8': case '9':
1467 error ("matching constraint not valid in output operand");
1470 case 'V': case 'm': case 'o':
1475 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1476 excepting those that expand_call created. So match memory
1492 /* If an output operand is not a decl or indirect ref and our constraint
1493 allows a register, make a temporary to act as an intermediate.
1494 Make the asm insn write into that, then our caller will copy it to
1495 the real output operand. Likewise for promoted variables. */
1497 real_output_rtx[i] = NULL_RTX;
1498 if ((TREE_CODE (val) == INDIRECT_REF
1500 || (TREE_CODE_CLASS (TREE_CODE (val)) == 'd'
1501 && (allows_mem || GET_CODE (DECL_RTL (val)) == REG)
1502 && ! (GET_CODE (DECL_RTL (val)) == REG
1503 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
1508 mark_addressable (TREE_VALUE (tail));
1511 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode,
1512 EXPAND_MEMORY_USE_WO);
1514 if (! allows_reg && GET_CODE (output_rtx[i]) != MEM)
1515 error ("output number %d not directly addressable", i);
1516 if (! allows_mem && GET_CODE (output_rtx[i]) == MEM)
1518 real_output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1519 output_rtx[i] = gen_reg_rtx (GET_MODE (output_rtx[i]));
1521 emit_move_insn (output_rtx[i], real_output_rtx[i]);
1526 output_rtx[i] = assign_temp (type, 0, 0, 0);
1527 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1532 inout_mode[ninout] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)));
1533 inout_opnum[ninout++] = i;
1538 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1540 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1544 /* Make vectors for the expression-rtx and constraint strings. */
1546 argvec = rtvec_alloc (ninputs);
1547 constraints = rtvec_alloc (ninputs);
1549 body = gen_rtx_ASM_OPERANDS (VOIDmode,
1550 TREE_STRING_POINTER (string), "", 0, argvec,
1551 constraints, filename, line);
1553 MEM_VOLATILE_P (body) = vol;
1555 /* Eval the inputs and put them into ARGVEC.
1556 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1559 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1562 int allows_reg = 0, allows_mem = 0;
1563 char *constraint, *orig_constraint;
1567 /* If there's an erroneous arg, emit no insn,
1568 because the ASM_INPUT would get VOIDmode
1569 and that could cause a crash in reload. */
1570 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1573 /* ??? Can this happen, and does the error message make any sense? */
1574 if (TREE_PURPOSE (tail) == NULL_TREE)
1576 error ("hard register `%s' listed as input operand to `asm'",
1577 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1581 c_len = TREE_STRING_LENGTH (TREE_PURPOSE (tail)) - 1;
1582 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1583 orig_constraint = constraint;
1585 /* Make sure constraint has neither `=', `+', nor '&'. */
1587 for (j = 0; j < c_len; j++)
1588 switch (constraint[j])
1590 case '+': case '=': case '&':
1591 if (constraint == orig_constraint)
1593 error ("input operand constraint contains `%c'", constraint[j]);
1599 if (constraint == orig_constraint
1600 && i + 1 == ninputs - ninout)
1602 error ("`%%' constraint used with last operand");
1607 case 'V': case 'm': case 'o':
1612 case '?': case '!': case '*':
1613 case 'E': case 'F': case 'G': case 'H': case 'X':
1614 case 's': case 'i': case 'n':
1615 case 'I': case 'J': case 'K': case 'L': case 'M':
1616 case 'N': case 'O': case 'P': case ',':
1617 #ifdef EXTRA_CONSTRAINT
1618 case 'Q': case 'R': case 'S': case 'T': case 'U':
1622 /* Whether or not a numeric constraint allows a register is
1623 decided by the matching constraint, and so there is no need
1624 to do anything special with them. We must handle them in
1625 the default case, so that we don't unnecessarily force
1626 operands to memory. */
1627 case '0': case '1': case '2': case '3': case '4':
1628 case '5': case '6': case '7': case '8': case '9':
1629 if (constraint[j] >= '0' + noutputs)
1632 ("matching constraint references invalid operand number");
1636 /* Try and find the real constraint for this dup. */
1637 if ((j == 0 && c_len == 1)
1638 || (j == 1 && c_len == 2 && constraint[0] == '%'))
1641 for (j = constraint[j] - '0'; j > 0; --j)
1644 c_len = TREE_STRING_LENGTH (TREE_PURPOSE (o)) - 1;
1645 constraint = TREE_STRING_POINTER (TREE_PURPOSE (o));
1650 /* ... fall through ... */
1663 if (! allows_reg && allows_mem)
1664 mark_addressable (TREE_VALUE (tail));
1666 op = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1668 if (asm_operand_ok (op, constraint) <= 0)
1671 op = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), op);
1672 else if (!allows_mem)
1673 warning ("asm operand %d probably doesn't match constraints", i);
1674 else if (CONSTANT_P (op))
1675 op = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1677 else if (GET_CODE (op) == REG
1678 || GET_CODE (op) == SUBREG
1679 || GET_CODE (op) == CONCAT)
1681 tree type = TREE_TYPE (TREE_VALUE (tail));
1682 rtx memloc = assign_temp (type, 1, 1, 1);
1684 emit_move_insn (memloc, op);
1687 else if (GET_CODE (op) == MEM && MEM_VOLATILE_P (op))
1688 /* We won't recognize volatile memory as available a
1689 memory_operand at this point. Ignore it. */
1691 else if (queued_subexp_p (op))
1694 /* ??? Leave this only until we have experience with what
1695 happens in combine and elsewhere when constraints are
1697 warning ("asm operand %d probably doesn't match constraints", i);
1699 XVECEXP (body, 3, i) = op;
1701 XVECEXP (body, 4, i) /* constraints */
1702 = gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1707 /* Protect all the operands from the queue,
1708 now that they have all been evaluated. */
1710 for (i = 0; i < ninputs - ninout; i++)
1711 XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0);
1713 for (i = 0; i < noutputs; i++)
1714 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1716 /* For in-out operands, copy output rtx to input rtx. */
1717 for (i = 0; i < ninout; i++)
1719 static char match[9+1][2]
1720 = {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9"};
1721 int j = inout_opnum[i];
1723 XVECEXP (body, 3, ninputs - ninout + i) /* argvec */
1725 XVECEXP (body, 4, ninputs - ninout + i) /* constraints */
1726 = gen_rtx_ASM_INPUT (inout_mode[i], match[j]);
1729 /* Now, for each output, construct an rtx
1730 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1731 ARGVEC CONSTRAINTS))
1732 If there is more than one, put them inside a PARALLEL. */
1734 if (noutputs == 1 && nclobbers == 0)
1736 XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1737 insn = emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
1739 else if (noutputs == 0 && nclobbers == 0)
1741 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1742 insn = emit_insn (body);
1748 if (num == 0) num = 1;
1749 body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
1751 /* For each output operand, store a SET. */
1753 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1755 XVECEXP (body, 0, i)
1756 = gen_rtx_SET (VOIDmode,
1758 gen_rtx_ASM_OPERANDS
1760 TREE_STRING_POINTER (string),
1761 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1762 i, argvec, constraints,
1765 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1768 /* If there are no outputs (but there are some clobbers)
1769 store the bare ASM_OPERANDS into the PARALLEL. */
1772 XVECEXP (body, 0, i++) = obody;
1774 /* Store (clobber REG) for each clobbered register specified. */
1776 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1778 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1779 int j = decode_reg_name (regname);
1783 if (j == -3) /* `cc', which is not a register */
1786 if (j == -4) /* `memory', don't cache memory across asm */
1788 XVECEXP (body, 0, i++)
1789 = gen_rtx_CLOBBER (VOIDmode,
1792 gen_rtx_SCRATCH (VOIDmode)));
1796 /* Ignore unknown register, error already signaled. */
1800 /* Use QImode since that's guaranteed to clobber just one reg. */
1801 XVECEXP (body, 0, i++)
1802 = gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (QImode, j));
1805 insn = emit_insn (body);
1808 /* For any outputs that needed reloading into registers, spill them
1809 back to where they belong. */
1810 for (i = 0; i < noutputs; ++i)
1811 if (real_output_rtx[i])
1812 emit_move_insn (real_output_rtx[i], output_rtx[i]);
1817 /* Generate RTL to evaluate the expression EXP
1818 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1821 expand_expr_stmt (exp)
1824 /* If -W, warn about statements with no side effects,
1825 except for an explicit cast to void (e.g. for assert()), and
1826 except inside a ({...}) where they may be useful. */
1827 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1829 if (! TREE_SIDE_EFFECTS (exp) && (extra_warnings || warn_unused)
1830 && !(TREE_CODE (exp) == CONVERT_EXPR
1831 && TREE_TYPE (exp) == void_type_node))
1832 warning_with_file_and_line (emit_filename, emit_lineno,
1833 "statement with no effect");
1834 else if (warn_unused)
1835 warn_if_unused_value (exp);
1838 /* If EXP is of function type and we are expanding statements for
1839 value, convert it to pointer-to-function. */
1840 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1841 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1843 last_expr_type = TREE_TYPE (exp);
1844 last_expr_value = expand_expr (exp,
1845 (expr_stmts_for_value
1846 ? NULL_RTX : const0_rtx),
1849 /* If all we do is reference a volatile value in memory,
1850 copy it to a register to be sure it is actually touched. */
1851 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1852 && TREE_THIS_VOLATILE (exp))
1854 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1856 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1857 copy_to_reg (last_expr_value);
1860 rtx lab = gen_label_rtx ();
1862 /* Compare the value with itself to reference it. */
1863 emit_cmp_and_jump_insns (last_expr_value, last_expr_value, EQ,
1864 expand_expr (TYPE_SIZE (last_expr_type),
1865 NULL_RTX, VOIDmode, 0),
1867 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT,
1873 /* If this expression is part of a ({...}) and is in memory, we may have
1874 to preserve temporaries. */
1875 preserve_temp_slots (last_expr_value);
1877 /* Free any temporaries used to evaluate this expression. Any temporary
1878 used as a result of this expression will already have been preserved
1885 /* Warn if EXP contains any computations whose results are not used.
1886 Return 1 if a warning is printed; 0 otherwise. */
1889 warn_if_unused_value (exp)
1892 if (TREE_USED (exp))
1895 switch (TREE_CODE (exp))
1897 case PREINCREMENT_EXPR:
1898 case POSTINCREMENT_EXPR:
1899 case PREDECREMENT_EXPR:
1900 case POSTDECREMENT_EXPR:
1905 case METHOD_CALL_EXPR:
1907 case TRY_CATCH_EXPR:
1908 case WITH_CLEANUP_EXPR:
1910 /* We don't warn about COND_EXPR because it may be a useful
1911 construct if either arm contains a side effect. */
1916 /* For a binding, warn if no side effect within it. */
1917 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1920 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1922 case TRUTH_ORIF_EXPR:
1923 case TRUTH_ANDIF_EXPR:
1924 /* In && or ||, warn if 2nd operand has no side effect. */
1925 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1928 if (TREE_NO_UNUSED_WARNING (exp))
1930 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
1932 /* Let people do `(foo (), 0)' without a warning. */
1933 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1935 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1939 case NON_LVALUE_EXPR:
1940 /* Don't warn about values cast to void. */
1941 if (TREE_TYPE (exp) == void_type_node)
1943 /* Don't warn about conversions not explicit in the user's program. */
1944 if (TREE_NO_UNUSED_WARNING (exp))
1946 /* Assignment to a cast usually results in a cast of a modify.
1947 Don't complain about that. There can be an arbitrary number of
1948 casts before the modify, so we must loop until we find the first
1949 non-cast expression and then test to see if that is a modify. */
1951 tree tem = TREE_OPERAND (exp, 0);
1953 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1954 tem = TREE_OPERAND (tem, 0);
1956 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
1957 || TREE_CODE (tem) == CALL_EXPR)
1963 /* Don't warn about automatic dereferencing of references, since
1964 the user cannot control it. */
1965 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
1966 return warn_if_unused_value (TREE_OPERAND (exp, 0));
1967 /* ... fall through ... */
1970 /* Referencing a volatile value is a side effect, so don't warn. */
1971 if ((TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
1972 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
1973 && TREE_THIS_VOLATILE (exp))
1976 warning_with_file_and_line (emit_filename, emit_lineno,
1977 "value computed is not used");
1982 /* Clear out the memory of the last expression evaluated. */
1990 /* Begin a statement which will return a value.
1991 Return the RTL_EXPR for this statement expr.
1992 The caller must save that value and pass it to expand_end_stmt_expr. */
1995 expand_start_stmt_expr ()
2000 /* Make the RTL_EXPR node temporary, not momentary,
2001 so that rtl_expr_chain doesn't become garbage. */
2002 momentary = suspend_momentary ();
2003 t = make_node (RTL_EXPR);
2004 resume_momentary (momentary);
2005 do_pending_stack_adjust ();
2006 start_sequence_for_rtl_expr (t);
2008 expr_stmts_for_value++;
2012 /* Restore the previous state at the end of a statement that returns a value.
2013 Returns a tree node representing the statement's value and the
2014 insns to compute the value.
2016 The nodes of that expression have been freed by now, so we cannot use them.
2017 But we don't want to do that anyway; the expression has already been
2018 evaluated and now we just want to use the value. So generate a RTL_EXPR
2019 with the proper type and RTL value.
2021 If the last substatement was not an expression,
2022 return something with type `void'. */
2025 expand_end_stmt_expr (t)
2030 if (last_expr_type == 0)
2032 last_expr_type = void_type_node;
2033 last_expr_value = const0_rtx;
2035 else if (last_expr_value == 0)
2036 /* There are some cases where this can happen, such as when the
2037 statement is void type. */
2038 last_expr_value = const0_rtx;
2039 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
2040 /* Remove any possible QUEUED. */
2041 last_expr_value = protect_from_queue (last_expr_value, 0);
2045 TREE_TYPE (t) = last_expr_type;
2046 RTL_EXPR_RTL (t) = last_expr_value;
2047 RTL_EXPR_SEQUENCE (t) = get_insns ();
2049 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
2053 /* Don't consider deleting this expr or containing exprs at tree level. */
2054 TREE_SIDE_EFFECTS (t) = 1;
2055 /* Propagate volatility of the actual RTL expr. */
2056 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
2059 expr_stmts_for_value--;
2064 /* Generate RTL for the start of an if-then. COND is the expression
2065 whose truth should be tested.
2067 If EXITFLAG is nonzero, this conditional is visible to
2068 `exit_something'. */
2071 expand_start_cond (cond, exitflag)
2075 struct nesting *thiscond = ALLOC_NESTING ();
2077 /* Make an entry on cond_stack for the cond we are entering. */
2079 thiscond->next = cond_stack;
2080 thiscond->all = nesting_stack;
2081 thiscond->depth = ++nesting_depth;
2082 thiscond->data.cond.next_label = gen_label_rtx ();
2083 /* Before we encounter an `else', we don't need a separate exit label
2084 unless there are supposed to be exit statements
2085 to exit this conditional. */
2086 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
2087 thiscond->data.cond.endif_label = thiscond->exit_label;
2088 cond_stack = thiscond;
2089 nesting_stack = thiscond;
2091 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
2094 /* Generate RTL between then-clause and the elseif-clause
2095 of an if-then-elseif-.... */
2098 expand_start_elseif (cond)
2101 if (cond_stack->data.cond.endif_label == 0)
2102 cond_stack->data.cond.endif_label = gen_label_rtx ();
2103 emit_jump (cond_stack->data.cond.endif_label);
2104 emit_label (cond_stack->data.cond.next_label);
2105 cond_stack->data.cond.next_label = gen_label_rtx ();
2106 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2109 /* Generate RTL between the then-clause and the else-clause
2110 of an if-then-else. */
2113 expand_start_else ()
2115 if (cond_stack->data.cond.endif_label == 0)
2116 cond_stack->data.cond.endif_label = gen_label_rtx ();
2118 emit_jump (cond_stack->data.cond.endif_label);
2119 emit_label (cond_stack->data.cond.next_label);
2120 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
2123 /* After calling expand_start_else, turn this "else" into an "else if"
2124 by providing another condition. */
2127 expand_elseif (cond)
2130 cond_stack->data.cond.next_label = gen_label_rtx ();
2131 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2134 /* Generate RTL for the end of an if-then.
2135 Pop the record for it off of cond_stack. */
2140 struct nesting *thiscond = cond_stack;
2142 do_pending_stack_adjust ();
2143 if (thiscond->data.cond.next_label)
2144 emit_label (thiscond->data.cond.next_label);
2145 if (thiscond->data.cond.endif_label)
2146 emit_label (thiscond->data.cond.endif_label);
2148 POPSTACK (cond_stack);
2154 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2155 loop should be exited by `exit_something'. This is a loop for which
2156 `expand_continue' will jump to the top of the loop.
2158 Make an entry on loop_stack to record the labels associated with
2162 expand_start_loop (exit_flag)
2165 register struct nesting *thisloop = ALLOC_NESTING ();
2167 /* Make an entry on loop_stack for the loop we are entering. */
2169 thisloop->next = loop_stack;
2170 thisloop->all = nesting_stack;
2171 thisloop->depth = ++nesting_depth;
2172 thisloop->data.loop.start_label = gen_label_rtx ();
2173 thisloop->data.loop.end_label = gen_label_rtx ();
2174 thisloop->data.loop.alt_end_label = 0;
2175 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2176 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2177 loop_stack = thisloop;
2178 nesting_stack = thisloop;
2180 do_pending_stack_adjust ();
2182 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2183 emit_label (thisloop->data.loop.start_label);
2188 /* Like expand_start_loop but for a loop where the continuation point
2189 (for expand_continue_loop) will be specified explicitly. */
2192 expand_start_loop_continue_elsewhere (exit_flag)
2195 struct nesting *thisloop = expand_start_loop (exit_flag);
2196 loop_stack->data.loop.continue_label = gen_label_rtx ();
2200 /* Specify the continuation point for a loop started with
2201 expand_start_loop_continue_elsewhere.
2202 Use this at the point in the code to which a continue statement
2206 expand_loop_continue_here ()
2208 do_pending_stack_adjust ();
2209 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2210 emit_label (loop_stack->data.loop.continue_label);
2213 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2214 Pop the block off of loop_stack. */
2219 rtx start_label = loop_stack->data.loop.start_label;
2220 rtx insn = get_last_insn ();
2221 int needs_end_jump = 1;
2223 /* Mark the continue-point at the top of the loop if none elsewhere. */
2224 if (start_label == loop_stack->data.loop.continue_label)
2225 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2227 do_pending_stack_adjust ();
2229 /* If optimizing, perhaps reorder the loop.
2230 First, try to use a condjump near the end.
2231 expand_exit_loop_if_false ends loops with unconditional jumps,
2234 if (test) goto label;
2236 goto loop_stack->data.loop.end_label
2240 If we find such a pattern, we can end the loop earlier. */
2243 && GET_CODE (insn) == CODE_LABEL
2244 && LABEL_NAME (insn) == NULL
2245 && GET_CODE (PREV_INSN (insn)) == BARRIER)
2248 rtx jump = PREV_INSN (PREV_INSN (label));
2250 if (GET_CODE (jump) == JUMP_INSN
2251 && GET_CODE (PATTERN (jump)) == SET
2252 && SET_DEST (PATTERN (jump)) == pc_rtx
2253 && GET_CODE (SET_SRC (PATTERN (jump))) == LABEL_REF
2254 && (XEXP (SET_SRC (PATTERN (jump)), 0)
2255 == loop_stack->data.loop.end_label))
2259 /* The test might be complex and reference LABEL multiple times,
2260 like the loop in loop_iterations to set vtop. To handle this,
2262 insn = PREV_INSN (label);
2263 reorder_insns (label, label, start_label);
2265 for (prev = PREV_INSN (jump); ; prev = PREV_INSN (prev))
2267 /* We ignore line number notes, but if we see any other note,
2268 in particular NOTE_INSN_BLOCK_*, NOTE_INSN_EH_REGION_*,
2269 NOTE_INSN_LOOP_*, we disable this optimization. */
2270 if (GET_CODE (prev) == NOTE)
2272 if (NOTE_LINE_NUMBER (prev) < 0)
2276 if (GET_CODE (prev) == CODE_LABEL)
2278 if (GET_CODE (prev) == JUMP_INSN)
2280 if (GET_CODE (PATTERN (prev)) == SET
2281 && SET_DEST (PATTERN (prev)) == pc_rtx
2282 && GET_CODE (SET_SRC (PATTERN (prev))) == IF_THEN_ELSE
2283 && (GET_CODE (XEXP (SET_SRC (PATTERN (prev)), 1))
2285 && XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0) == label)
2287 XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0)
2289 emit_note_after (NOTE_INSN_LOOP_END, prev);
2298 /* If the loop starts with a loop exit, roll that to the end where
2299 it will optimize together with the jump back.
2301 We look for the conditional branch to the exit, except that once
2302 we find such a branch, we don't look past 30 instructions.
2304 In more detail, if the loop presently looks like this (in pseudo-C):
2307 if (test) goto end_label;
2312 transform it to look like:
2318 if (test) goto end_label;
2319 goto newstart_label;
2322 Here, the `test' may actually consist of some reasonably complex
2323 code, terminating in a test. */
2328 ! (GET_CODE (insn) == JUMP_INSN
2329 && GET_CODE (PATTERN (insn)) == SET
2330 && SET_DEST (PATTERN (insn)) == pc_rtx
2331 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2335 rtx last_test_insn = NULL_RTX;
2337 /* Scan insns from the top of the loop looking for a qualified
2338 conditional exit. */
2339 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2340 insn = NEXT_INSN (insn))
2342 if (GET_CODE (insn) == NOTE)
2345 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2346 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2347 /* The code that actually moves the exit test will
2348 carefully leave BLOCK notes in their original
2349 location. That means, however, that we can't debug
2350 the exit test itself. So, we refuse to move code
2351 containing BLOCK notes at low optimization levels. */
2354 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG)
2356 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)
2360 /* We've come to the end of an EH region, but
2361 never saw the beginning of that region. That
2362 means that an EH region begins before the top
2363 of the loop, and ends in the middle of it. The
2364 existence of such a situation violates a basic
2365 assumption in this code, since that would imply
2366 that even when EH_REGIONS is zero, we might
2367 move code out of an exception region. */
2371 /* We must not walk into a nested loop. */
2372 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
2375 /* We already know this INSN is a NOTE, so there's no
2376 point in looking at it to see if it's a JUMP. */
2380 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2383 if (last_test_insn && num_insns > 30)
2387 /* We don't want to move a partial EH region. Consider:
2401 This isn't legal C++, but here's what it's supposed to
2402 mean: if cond() is true, stop looping. Otherwise,
2403 call bar, and keep looping. In addition, if cond
2404 throws an exception, catch it and keep looping. Such
2405 constructs are certainy legal in LISP.
2407 We should not move the `if (cond()) 0' test since then
2408 the EH-region for the try-block would be broken up.
2409 (In this case we would the EH_BEG note for the `try'
2410 and `if cond()' but not the call to bar() or the
2413 So we don't look for tests within an EH region. */
2416 if (GET_CODE (insn) == JUMP_INSN
2417 && GET_CODE (PATTERN (insn)) == SET
2418 && SET_DEST (PATTERN (insn)) == pc_rtx)
2420 /* This is indeed a jump. */
2421 rtx dest1 = NULL_RTX;
2422 rtx dest2 = NULL_RTX;
2423 rtx potential_last_test;
2424 if (GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE)
2426 /* A conditional jump. */
2427 dest1 = XEXP (SET_SRC (PATTERN (insn)), 1);
2428 dest2 = XEXP (SET_SRC (PATTERN (insn)), 2);
2429 potential_last_test = insn;
2433 /* An unconditional jump. */
2434 dest1 = SET_SRC (PATTERN (insn));
2435 /* Include the BARRIER after the JUMP. */
2436 potential_last_test = NEXT_INSN (insn);
2440 if (dest1 && GET_CODE (dest1) == LABEL_REF
2441 && ((XEXP (dest1, 0)
2442 == loop_stack->data.loop.alt_end_label)
2444 == loop_stack->data.loop.end_label)))
2446 last_test_insn = potential_last_test;
2450 /* If this was a conditional jump, there may be
2451 another label at which we should look. */
2458 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2460 /* We found one. Move everything from there up
2461 to the end of the loop, and add a jump into the loop
2462 to jump to there. */
2463 register rtx newstart_label = gen_label_rtx ();
2464 register rtx start_move = start_label;
2467 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2468 then we want to move this note also. */
2469 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2470 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2471 == NOTE_INSN_LOOP_CONT))
2472 start_move = PREV_INSN (start_move);
2474 emit_label_after (newstart_label, PREV_INSN (start_move));
2476 /* Actually move the insns. Start at the beginning, and
2477 keep copying insns until we've copied the
2479 for (insn = start_move; insn; insn = next_insn)
2481 /* Figure out which insn comes after this one. We have
2482 to do this before we move INSN. */
2483 if (insn == last_test_insn)
2484 /* We've moved all the insns. */
2485 next_insn = NULL_RTX;
2487 next_insn = NEXT_INSN (insn);
2489 if (GET_CODE (insn) == NOTE
2490 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2491 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2492 /* We don't want to move NOTE_INSN_BLOCK_BEGs or
2493 NOTE_INSN_BLOCK_ENDs because the correct generation
2494 of debugging information depends on these appearing
2495 in the same order in the RTL and in the tree
2496 structure, where they are represented as BLOCKs.
2497 So, we don't move block notes. Of course, moving
2498 the code inside the block is likely to make it
2499 impossible to debug the instructions in the exit
2500 test, but such is the price of optimization. */
2503 /* Move the INSN. */
2504 reorder_insns (insn, insn, get_last_insn ());
2507 emit_jump_insn_after (gen_jump (start_label),
2508 PREV_INSN (newstart_label));
2509 emit_barrier_after (PREV_INSN (newstart_label));
2510 start_label = newstart_label;
2516 emit_jump (start_label);
2517 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2519 emit_label (loop_stack->data.loop.end_label);
2521 POPSTACK (loop_stack);
2526 /* Generate a jump to the current loop's continue-point.
2527 This is usually the top of the loop, but may be specified
2528 explicitly elsewhere. If not currently inside a loop,
2529 return 0 and do nothing; caller will print an error message. */
2532 expand_continue_loop (whichloop)
2533 struct nesting *whichloop;
2537 whichloop = loop_stack;
2540 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2545 /* Generate a jump to exit the current loop. If not currently inside a loop,
2546 return 0 and do nothing; caller will print an error message. */
2549 expand_exit_loop (whichloop)
2550 struct nesting *whichloop;
2554 whichloop = loop_stack;
2557 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2561 /* Generate a conditional jump to exit the current loop if COND
2562 evaluates to zero. If not currently inside a loop,
2563 return 0 and do nothing; caller will print an error message. */
2566 expand_exit_loop_if_false (whichloop, cond)
2567 struct nesting *whichloop;
2570 rtx label = gen_label_rtx ();
2575 whichloop = loop_stack;
2578 /* In order to handle fixups, we actually create a conditional jump
2579 around a unconditional branch to exit the loop. If fixups are
2580 necessary, they go before the unconditional branch. */
2583 do_jump (cond, NULL_RTX, label);
2584 last_insn = get_last_insn ();
2585 if (GET_CODE (last_insn) == CODE_LABEL)
2586 whichloop->data.loop.alt_end_label = last_insn;
2587 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2594 /* Return nonzero if the loop nest is empty. Else return zero. */
2597 stmt_loop_nest_empty ()
2599 return (loop_stack == NULL);
2602 /* Return non-zero if we should preserve sub-expressions as separate
2603 pseudos. We never do so if we aren't optimizing. We always do so
2604 if -fexpensive-optimizations.
2606 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2607 the loop may still be a small one. */
2610 preserve_subexpressions_p ()
2614 if (flag_expensive_optimizations)
2617 if (optimize == 0 || current_function == 0
2618 || current_function->stmt == 0 || loop_stack == 0)
2621 insn = get_last_insn_anywhere ();
2624 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2625 < n_non_fixed_regs * 3));
2629 /* Generate a jump to exit the current loop, conditional, binding contour
2630 or case statement. Not all such constructs are visible to this function,
2631 only those started with EXIT_FLAG nonzero. Individual languages use
2632 the EXIT_FLAG parameter to control which kinds of constructs you can
2635 If not currently inside anything that can be exited,
2636 return 0 and do nothing; caller will print an error message. */
2639 expand_exit_something ()
2643 for (n = nesting_stack; n; n = n->all)
2644 if (n->exit_label != 0)
2646 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2653 /* Generate RTL to return from the current function, with no value.
2654 (That is, we do not do anything about returning any value.) */
2657 expand_null_return ()
2659 struct nesting *block = block_stack;
2662 /* Does any pending block have cleanups? */
2664 while (block && block->data.block.cleanups == 0)
2665 block = block->next;
2667 /* If yes, use a goto to return, since that runs cleanups. */
2669 expand_null_return_1 (last_insn, block != 0);
2672 /* Generate RTL to return from the current function, with value VAL. */
2675 expand_value_return (val)
2678 struct nesting *block = block_stack;
2679 rtx last_insn = get_last_insn ();
2680 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2682 /* Copy the value to the return location
2683 unless it's already there. */
2685 if (return_reg != val)
2687 #ifdef PROMOTE_FUNCTION_RETURN
2688 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2689 int unsignedp = TREE_UNSIGNED (type);
2690 enum machine_mode mode
2691 = promote_mode (type, DECL_MODE (DECL_RESULT (current_function_decl)),
2694 if (GET_MODE (val) != VOIDmode && GET_MODE (val) != mode)
2695 convert_move (return_reg, val, unsignedp);
2698 emit_move_insn (return_reg, val);
2700 if (GET_CODE (return_reg) == REG
2701 && REGNO (return_reg) < FIRST_PSEUDO_REGISTER)
2702 emit_insn (gen_rtx_USE (VOIDmode, return_reg));
2703 /* Handle calls that return values in multiple non-contiguous locations.
2704 The Irix 6 ABI has examples of this. */
2705 else if (GET_CODE (return_reg) == PARALLEL)
2709 for (i = 0; i < XVECLEN (return_reg, 0); i++)
2711 rtx x = XEXP (XVECEXP (return_reg, 0, i), 0);
2713 if (GET_CODE (x) == REG
2714 && REGNO (x) < FIRST_PSEUDO_REGISTER)
2715 emit_insn (gen_rtx_USE (VOIDmode, x));
2719 /* Does any pending block have cleanups? */
2721 while (block && block->data.block.cleanups == 0)
2722 block = block->next;
2724 /* If yes, use a goto to return, since that runs cleanups.
2725 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2727 expand_null_return_1 (last_insn, block != 0);
2730 /* Output a return with no value. If LAST_INSN is nonzero,
2731 pretend that the return takes place after LAST_INSN.
2732 If USE_GOTO is nonzero then don't use a return instruction;
2733 go to the return label instead. This causes any cleanups
2734 of pending blocks to be executed normally. */
2737 expand_null_return_1 (last_insn, use_goto)
2741 rtx end_label = cleanup_label ? cleanup_label : return_label;
2743 clear_pending_stack_adjust ();
2744 do_pending_stack_adjust ();
2747 /* PCC-struct return always uses an epilogue. */
2748 if (current_function_returns_pcc_struct || use_goto)
2751 end_label = return_label = gen_label_rtx ();
2752 expand_goto_internal (NULL_TREE, end_label, last_insn);
2756 /* Otherwise output a simple return-insn if one is available,
2757 unless it won't do the job. */
2759 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2761 emit_jump_insn (gen_return ());
2767 /* Otherwise jump to the epilogue. */
2768 expand_goto_internal (NULL_TREE, end_label, last_insn);
2771 /* Generate RTL to evaluate the expression RETVAL and return it
2772 from the current function. */
2775 expand_return (retval)
2778 /* If there are any cleanups to be performed, then they will
2779 be inserted following LAST_INSN. It is desirable
2780 that the last_insn, for such purposes, should be the
2781 last insn before computing the return value. Otherwise, cleanups
2782 which call functions can clobber the return value. */
2783 /* ??? rms: I think that is erroneous, because in C++ it would
2784 run destructors on variables that might be used in the subsequent
2785 computation of the return value. */
2787 register rtx val = 0;
2792 /* If function wants no value, give it none. */
2793 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2795 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2797 expand_null_return ();
2801 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2802 /* This is not sufficient. We also need to watch for cleanups of the
2803 expression we are about to expand. Unfortunately, we cannot know
2804 if it has cleanups until we expand it, and we want to change how we
2805 expand it depending upon if we need cleanups. We can't win. */
2807 cleanups = any_pending_cleanups (1);
2812 if (TREE_CODE (retval) == RESULT_DECL)
2813 retval_rhs = retval;
2814 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2815 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2816 retval_rhs = TREE_OPERAND (retval, 1);
2817 else if (TREE_TYPE (retval) == void_type_node)
2818 /* Recognize tail-recursive call to void function. */
2819 retval_rhs = retval;
2821 retval_rhs = NULL_TREE;
2823 /* Only use `last_insn' if there are cleanups which must be run. */
2824 if (cleanups || cleanup_label != 0)
2825 last_insn = get_last_insn ();
2827 /* Distribute return down conditional expr if either of the sides
2828 may involve tail recursion (see test below). This enhances the number
2829 of tail recursions we see. Don't do this always since it can produce
2830 sub-optimal code in some cases and we distribute assignments into
2831 conditional expressions when it would help. */
2833 if (optimize && retval_rhs != 0
2834 && frame_offset == 0
2835 && TREE_CODE (retval_rhs) == COND_EXPR
2836 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2837 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2839 rtx label = gen_label_rtx ();
2842 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2843 start_cleanup_deferral ();
2844 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2845 DECL_RESULT (current_function_decl),
2846 TREE_OPERAND (retval_rhs, 1));
2847 TREE_SIDE_EFFECTS (expr) = 1;
2848 expand_return (expr);
2851 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2852 DECL_RESULT (current_function_decl),
2853 TREE_OPERAND (retval_rhs, 2));
2854 TREE_SIDE_EFFECTS (expr) = 1;
2855 expand_return (expr);
2856 end_cleanup_deferral ();
2860 /* Attempt to optimize the call if it is tail recursive. */
2861 if (optimize_tail_recursion (retval_rhs, last_insn))
2865 /* This optimization is safe if there are local cleanups
2866 because expand_null_return takes care of them.
2867 ??? I think it should also be safe when there is a cleanup label,
2868 because expand_null_return takes care of them, too.
2869 Any reason why not? */
2870 if (HAVE_return && cleanup_label == 0
2871 && ! current_function_returns_pcc_struct
2872 && BRANCH_COST <= 1)
2874 /* If this is return x == y; then generate
2875 if (x == y) return 1; else return 0;
2876 if we can do it with explicit return insns and branches are cheap,
2877 but not if we have the corresponding scc insn. */
2880 switch (TREE_CODE (retval_rhs))
2906 case TRUTH_ANDIF_EXPR:
2907 case TRUTH_ORIF_EXPR:
2908 case TRUTH_AND_EXPR:
2910 case TRUTH_NOT_EXPR:
2911 case TRUTH_XOR_EXPR:
2914 op0 = gen_label_rtx ();
2915 jumpifnot (retval_rhs, op0);
2916 expand_value_return (const1_rtx);
2918 expand_value_return (const0_rtx);
2927 #endif /* HAVE_return */
2929 /* If the result is an aggregate that is being returned in one (or more)
2930 registers, load the registers here. The compiler currently can't handle
2931 copying a BLKmode value into registers. We could put this code in a
2932 more general area (for use by everyone instead of just function
2933 call/return), but until this feature is generally usable it is kept here
2934 (and in expand_call). The value must go into a pseudo in case there
2935 are cleanups that will clobber the real return register. */
2938 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2939 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2941 int i, bitpos, xbitpos;
2942 int big_endian_correction = 0;
2943 int bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2944 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2945 int bitsize = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)),
2946 (unsigned int)BITS_PER_WORD);
2947 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2948 rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
2949 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2950 enum machine_mode tmpmode, result_reg_mode;
2952 /* Structures whose size is not a multiple of a word are aligned
2953 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
2954 machine, this means we must skip the empty high order bytes when
2955 calculating the bit offset. */
2956 if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD)
2957 big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
2960 /* Copy the structure BITSIZE bits at a time. */
2961 for (bitpos = 0, xbitpos = big_endian_correction;
2962 bitpos < bytes * BITS_PER_UNIT;
2963 bitpos += bitsize, xbitpos += bitsize)
2965 /* We need a new destination pseudo each time xbitpos is
2966 on a word boundary and when xbitpos == big_endian_correction
2967 (the first time through). */
2968 if (xbitpos % BITS_PER_WORD == 0
2969 || xbitpos == big_endian_correction)
2971 /* Generate an appropriate register. */
2972 dst = gen_reg_rtx (word_mode);
2973 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
2975 /* Clobber the destination before we move anything into it. */
2976 emit_insn (gen_rtx_CLOBBER (VOIDmode, dst));
2979 /* We need a new source operand each time bitpos is on a word
2981 if (bitpos % BITS_PER_WORD == 0)
2982 src = operand_subword_force (result_val,
2983 bitpos / BITS_PER_WORD,
2986 /* Use bitpos for the source extraction (left justified) and
2987 xbitpos for the destination store (right justified). */
2988 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
2989 extract_bit_field (src, bitsize,
2990 bitpos % BITS_PER_WORD, 1,
2991 NULL_RTX, word_mode,
2993 bitsize / BITS_PER_UNIT,
2995 bitsize / BITS_PER_UNIT, BITS_PER_WORD);
2998 /* Find the smallest integer mode large enough to hold the
2999 entire structure and use that mode instead of BLKmode
3000 on the USE insn for the return register. */
3001 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
3002 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
3003 tmpmode != VOIDmode;
3004 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
3006 /* Have we found a large enough mode? */
3007 if (GET_MODE_SIZE (tmpmode) >= bytes)
3011 /* No suitable mode found. */
3012 if (tmpmode == VOIDmode)
3015 PUT_MODE (DECL_RTL (DECL_RESULT (current_function_decl)), tmpmode);
3017 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
3018 result_reg_mode = word_mode;
3020 result_reg_mode = tmpmode;
3021 result_reg = gen_reg_rtx (result_reg_mode);
3024 for (i = 0; i < n_regs; i++)
3025 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
3028 if (tmpmode != result_reg_mode)
3029 result_reg = gen_lowpart (tmpmode, result_reg);
3031 expand_value_return (result_reg);
3035 && TREE_TYPE (retval_rhs) != void_type_node
3036 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
3038 /* Calculate the return value into a pseudo reg. */
3039 val = gen_reg_rtx (DECL_MODE (DECL_RESULT (current_function_decl)));
3040 val = expand_expr (retval_rhs, val, GET_MODE (val), 0);
3041 val = force_not_mem (val);
3043 /* Return the calculated value, doing cleanups first. */
3044 expand_value_return (val);
3048 /* No cleanups or no hard reg used;
3049 calculate value into hard return reg. */
3050 expand_expr (retval, const0_rtx, VOIDmode, 0);
3052 expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl)));
3056 /* Return 1 if the end of the generated RTX is not a barrier.
3057 This means code already compiled can drop through. */
3060 drop_through_at_end_p ()
3062 rtx insn = get_last_insn ();
3063 while (insn && GET_CODE (insn) == NOTE)
3064 insn = PREV_INSN (insn);
3065 return insn && GET_CODE (insn) != BARRIER;
3068 /* Test CALL_EXPR to determine if it is a potential tail recursion call
3069 and emit code to optimize the tail recursion. LAST_INSN indicates where
3070 to place the jump to the tail recursion label. Return TRUE if the
3071 call was optimized into a goto.
3073 This is only used by expand_return, but expand_call is expected to
3077 optimize_tail_recursion (call_expr, last_insn)
3081 /* For tail-recursive call to current function,
3082 just jump back to the beginning.
3083 It's unsafe if any auto variable in this function
3084 has its address taken; for simplicity,
3085 require stack frame to be empty. */
3086 if (optimize && call_expr != 0
3087 && frame_offset == 0
3088 && TREE_CODE (call_expr) == CALL_EXPR
3089 && TREE_CODE (TREE_OPERAND (call_expr, 0)) == ADDR_EXPR
3090 && TREE_OPERAND (TREE_OPERAND (call_expr, 0), 0) == current_function_decl
3091 /* Finish checking validity, and if valid emit code
3092 to set the argument variables for the new call. */
3093 && tail_recursion_args (TREE_OPERAND (call_expr, 1),
3094 DECL_ARGUMENTS (current_function_decl)))
3096 if (tail_recursion_label == 0)
3098 tail_recursion_label = gen_label_rtx ();
3099 emit_label_after (tail_recursion_label,
3100 tail_recursion_reentry);
3103 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
3111 /* Emit code to alter this function's formal parms for a tail-recursive call.
3112 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3113 FORMALS is the chain of decls of formals.
3114 Return 1 if this can be done;
3115 otherwise return 0 and do not emit any code. */
3118 tail_recursion_args (actuals, formals)
3119 tree actuals, formals;
3121 register tree a = actuals, f = formals;
3123 register rtx *argvec;
3125 /* Check that number and types of actuals are compatible
3126 with the formals. This is not always true in valid C code.
3127 Also check that no formal needs to be addressable
3128 and that all formals are scalars. */
3130 /* Also count the args. */
3132 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
3134 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a)))
3135 != TYPE_MAIN_VARIANT (TREE_TYPE (f)))
3137 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
3140 if (a != 0 || f != 0)
3143 /* Compute all the actuals. */
3145 argvec = (rtx *) alloca (i * sizeof (rtx));
3147 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3148 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
3150 /* Find which actual values refer to current values of previous formals.
3151 Copy each of them now, before any formal is changed. */
3153 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3157 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
3158 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
3159 { copy = 1; break; }
3161 argvec[i] = copy_to_reg (argvec[i]);
3164 /* Store the values of the actuals into the formals. */
3166 for (f = formals, a = actuals, i = 0; f;
3167 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
3169 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
3170 emit_move_insn (DECL_RTL (f), argvec[i]);
3172 convert_move (DECL_RTL (f), argvec[i],
3173 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
3180 /* Generate the RTL code for entering a binding contour.
3181 The variables are declared one by one, by calls to `expand_decl'.
3183 FLAGS is a bitwise or of the following flags:
3185 1 - Nonzero if this construct should be visible to
3188 2 - Nonzero if this contour does not require a
3189 NOTE_INSN_BLOCK_BEG note. Virtually all calls from
3190 language-independent code should set this flag because they
3191 will not create corresponding BLOCK nodes. (There should be
3192 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
3193 and BLOCKs.) If this flag is set, MARK_ENDS should be zero
3194 when expand_end_bindings is called. */
3197 expand_start_bindings (flags)
3200 struct nesting *thisblock = ALLOC_NESTING ();
3202 int exit_flag = ((flags & 1) != 0);
3203 int block_flag = ((flags & 2) == 0);
3205 note = emit_note (NULL_PTR,
3206 block_flag ? NOTE_INSN_BLOCK_BEG : NOTE_INSN_DELETED);
3208 /* Make an entry on block_stack for the block we are entering. */
3210 thisblock->next = block_stack;
3211 thisblock->all = nesting_stack;
3212 thisblock->depth = ++nesting_depth;
3213 thisblock->data.block.stack_level = 0;
3214 thisblock->data.block.cleanups = 0;
3215 thisblock->data.block.n_function_calls = 0;
3216 thisblock->data.block.exception_region = 0;
3217 thisblock->data.block.block_target_temp_slot_level = target_temp_slot_level;
3219 thisblock->data.block.conditional_code = 0;
3220 thisblock->data.block.last_unconditional_cleanup = note;
3221 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
3224 && !(block_stack->data.block.cleanups == NULL_TREE
3225 && block_stack->data.block.outer_cleanups == NULL_TREE))
3226 thisblock->data.block.outer_cleanups
3227 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
3228 block_stack->data.block.outer_cleanups);
3230 thisblock->data.block.outer_cleanups = 0;
3231 thisblock->data.block.label_chain = 0;
3232 thisblock->data.block.innermost_stack_block = stack_block_stack;
3233 thisblock->data.block.first_insn = note;
3234 thisblock->data.block.block_start_count = ++current_block_start_count;
3235 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
3236 block_stack = thisblock;
3237 nesting_stack = thisblock;
3239 /* Make a new level for allocating stack slots. */
3243 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3244 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3245 expand_expr are made. After we end the region, we know that all
3246 space for all temporaries that were created by TARGET_EXPRs will be
3247 destroyed and their space freed for reuse. */
3250 expand_start_target_temps ()
3252 /* This is so that even if the result is preserved, the space
3253 allocated will be freed, as we know that it is no longer in use. */
3256 /* Start a new binding layer that will keep track of all cleanup
3257 actions to be performed. */
3258 expand_start_bindings (2);
3260 target_temp_slot_level = temp_slot_level;
3264 expand_end_target_temps ()
3266 expand_end_bindings (NULL_TREE, 0, 0);
3268 /* This is so that even if the result is preserved, the space
3269 allocated will be freed, as we know that it is no longer in use. */
3273 /* Mark top block of block_stack as an implicit binding for an
3274 exception region. This is used to prevent infinite recursion when
3275 ending a binding with expand_end_bindings. It is only ever called
3276 by expand_eh_region_start, as that it the only way to create a
3277 block stack for a exception region. */
3280 mark_block_as_eh_region ()
3282 block_stack->data.block.exception_region = 1;
3283 if (block_stack->next
3284 && block_stack->next->data.block.conditional_code)
3286 block_stack->data.block.conditional_code
3287 = block_stack->next->data.block.conditional_code;
3288 block_stack->data.block.last_unconditional_cleanup
3289 = block_stack->next->data.block.last_unconditional_cleanup;
3290 block_stack->data.block.cleanup_ptr
3291 = block_stack->next->data.block.cleanup_ptr;
3295 /* True if we are currently emitting insns in an area of output code
3296 that is controlled by a conditional expression. This is used by
3297 the cleanup handling code to generate conditional cleanup actions. */
3300 conditional_context ()
3302 return block_stack && block_stack->data.block.conditional_code;
3305 /* Mark top block of block_stack as not for an implicit binding for an
3306 exception region. This is only ever done by expand_eh_region_end
3307 to let expand_end_bindings know that it is being called explicitly
3308 to end the binding layer for just the binding layer associated with
3309 the exception region, otherwise expand_end_bindings would try and
3310 end all implicit binding layers for exceptions regions, and then
3311 one normal binding layer. */
3314 mark_block_as_not_eh_region ()
3316 block_stack->data.block.exception_region = 0;
3319 /* True if the top block of block_stack was marked as for an exception
3320 region by mark_block_as_eh_region. */
3325 return (current_function && block_stack
3326 && block_stack->data.block.exception_region);
3329 /* Given a pointer to a BLOCK node, save a pointer to the most recently
3330 generated NOTE_INSN_BLOCK_END in the BLOCK_END_NOTE field of the given
3334 remember_end_note (block)
3335 register tree block;
3337 BLOCK_END_NOTE (block) = last_block_end_note;
3338 last_block_end_note = NULL_RTX;
3341 /* Emit a handler label for a nonlocal goto handler.
3342 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3345 expand_nl_handler_label (slot, before_insn)
3346 rtx slot, before_insn;
3349 rtx handler_label = gen_label_rtx ();
3351 /* Don't let jump_optimize delete the handler. */
3352 LABEL_PRESERVE_P (handler_label) = 1;
3355 emit_move_insn (slot, gen_rtx_LABEL_REF (Pmode, handler_label));
3356 insns = get_insns ();
3358 emit_insns_before (insns, before_insn);
3360 emit_label (handler_label);
3362 return handler_label;
3365 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3368 expand_nl_goto_receiver ()
3370 #ifdef HAVE_nonlocal_goto
3371 if (! HAVE_nonlocal_goto)
3373 /* First adjust our frame pointer to its actual value. It was
3374 previously set to the start of the virtual area corresponding to
3375 the stacked variables when we branched here and now needs to be
3376 adjusted to the actual hardware fp value.
3378 Assignments are to virtual registers are converted by
3379 instantiate_virtual_regs into the corresponding assignment
3380 to the underlying register (fp in this case) that makes
3381 the original assignment true.
3382 So the following insn will actually be
3383 decrementing fp by STARTING_FRAME_OFFSET. */
3384 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3386 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3387 if (fixed_regs[ARG_POINTER_REGNUM])
3389 #ifdef ELIMINABLE_REGS
3390 /* If the argument pointer can be eliminated in favor of the
3391 frame pointer, we don't need to restore it. We assume here
3392 that if such an elimination is present, it can always be used.
3393 This is the case on all known machines; if we don't make this
3394 assumption, we do unnecessary saving on many machines. */
3395 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3398 for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
3399 if (elim_regs[i].from == ARG_POINTER_REGNUM
3400 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3403 if (i == sizeof elim_regs / sizeof elim_regs [0])
3406 /* Now restore our arg pointer from the address at which it
3407 was saved in our stack frame.
3408 If there hasn't be space allocated for it yet, make
3410 if (arg_pointer_save_area == 0)
3411 arg_pointer_save_area
3412 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3413 emit_move_insn (virtual_incoming_args_rtx,
3414 /* We need a pseudo here, or else
3415 instantiate_virtual_regs_1 complains. */
3416 copy_to_reg (arg_pointer_save_area));
3421 #ifdef HAVE_nonlocal_goto_receiver
3422 if (HAVE_nonlocal_goto_receiver)
3423 emit_insn (gen_nonlocal_goto_receiver ());
3427 /* Make handlers for nonlocal gotos taking place in the function calls in
3431 expand_nl_goto_receivers (thisblock)
3432 struct nesting *thisblock;
3435 rtx afterward = gen_label_rtx ();
3440 /* Record the handler address in the stack slot for that purpose,
3441 during this block, saving and restoring the outer value. */
3442 if (thisblock->next != 0)
3443 for (slot = nonlocal_goto_handler_slots; slot; slot = XEXP (slot, 1))
3445 rtx save_receiver = gen_reg_rtx (Pmode);
3446 emit_move_insn (XEXP (slot, 0), save_receiver);
3449 emit_move_insn (save_receiver, XEXP (slot, 0));
3450 insns = get_insns ();
3452 emit_insns_before (insns, thisblock->data.block.first_insn);
3455 /* Jump around the handlers; they run only when specially invoked. */
3456 emit_jump (afterward);
3458 /* Make a separate handler for each label. */
3459 link = nonlocal_labels;
3460 slot = nonlocal_goto_handler_slots;
3461 label_list = NULL_RTX;
3462 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3463 /* Skip any labels we shouldn't be able to jump to from here,
3464 we generate one special handler for all of them below which just calls
3466 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3469 lab = expand_nl_handler_label (XEXP (slot, 0),
3470 thisblock->data.block.first_insn);
3471 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3473 expand_nl_goto_receiver ();
3475 /* Jump to the "real" nonlocal label. */
3476 expand_goto (TREE_VALUE (link));
3479 /* A second pass over all nonlocal labels; this time we handle those
3480 we should not be able to jump to at this point. */
3481 link = nonlocal_labels;
3482 slot = nonlocal_goto_handler_slots;
3484 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3485 if (DECL_TOO_LATE (TREE_VALUE (link)))
3488 lab = expand_nl_handler_label (XEXP (slot, 0),
3489 thisblock->data.block.first_insn);
3490 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3496 expand_nl_goto_receiver ();
3497 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "abort"), 0,
3502 nonlocal_goto_handler_labels = label_list;
3503 emit_label (afterward);
3506 /* Warn about any unused VARS (which may contain nodes other than
3507 VAR_DECLs, but such nodes are ignored). The nodes are connected
3508 via the TREE_CHAIN field. */
3511 warn_about_unused_variables (vars)
3517 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3518 if (TREE_CODE (decl) == VAR_DECL
3519 && ! TREE_USED (decl)
3520 && ! DECL_IN_SYSTEM_HEADER (decl)
3521 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
3522 warning_with_decl (decl, "unused variable `%s'");
3525 /* Generate RTL code to terminate a binding contour.
3527 VARS is the chain of VAR_DECL nodes for the variables bound in this
3528 contour. There may actually be other nodes in this chain, but any
3529 nodes other than VAR_DECLS are ignored.
3531 MARK_ENDS is nonzero if we should put a note at the beginning
3532 and end of this binding contour.
3534 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3535 (That is true automatically if the contour has a saved stack level.) */
3538 expand_end_bindings (vars, mark_ends, dont_jump_in)
3543 register struct nesting *thisblock;
3546 while (block_stack->data.block.exception_region)
3548 /* Because we don't need or want a new temporary level and
3549 because we didn't create one in expand_eh_region_start,
3550 create a fake one now to avoid removing one in
3551 expand_end_bindings. */
3554 block_stack->data.block.exception_region = 0;
3556 expand_end_bindings (NULL_TREE, 0, 0);
3559 /* Since expand_eh_region_start does an expand_start_bindings, we
3560 have to first end all the bindings that were created by
3561 expand_eh_region_start. */
3563 thisblock = block_stack;
3565 /* If any of the variables in this scope were not used, warn the
3567 warn_about_unused_variables (vars);
3569 if (thisblock->exit_label)
3571 do_pending_stack_adjust ();
3572 emit_label (thisblock->exit_label);
3575 /* If necessary, make handlers for nonlocal gotos taking
3576 place in the function calls in this block. */
3577 if (function_call_count != thisblock->data.block.n_function_calls
3579 /* Make handler for outermost block
3580 if there were any nonlocal gotos to this function. */
3581 && (thisblock->next == 0 ? current_function_has_nonlocal_label
3582 /* Make handler for inner block if it has something
3583 special to do when you jump out of it. */
3584 : (thisblock->data.block.cleanups != 0
3585 || thisblock->data.block.stack_level != 0)))
3586 expand_nl_goto_receivers (thisblock);
3588 /* Don't allow jumping into a block that has a stack level.
3589 Cleanups are allowed, though. */
3591 || thisblock->data.block.stack_level != 0)
3593 struct label_chain *chain;
3595 /* Any labels in this block are no longer valid to go to.
3596 Mark them to cause an error message. */
3597 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3599 DECL_TOO_LATE (chain->label) = 1;
3600 /* If any goto without a fixup came to this label,
3601 that must be an error, because gotos without fixups
3602 come from outside all saved stack-levels. */
3603 if (TREE_ADDRESSABLE (chain->label))
3604 error_with_decl (chain->label,
3605 "label `%s' used before containing binding contour");
3609 /* Restore stack level in effect before the block
3610 (only if variable-size objects allocated). */
3611 /* Perform any cleanups associated with the block. */
3613 if (thisblock->data.block.stack_level != 0
3614 || thisblock->data.block.cleanups != 0)
3616 /* Only clean up here if this point can actually be reached. */
3617 int reachable = GET_CODE (get_last_insn ()) != BARRIER;
3619 /* Don't let cleanups affect ({...}) constructs. */
3620 int old_expr_stmts_for_value = expr_stmts_for_value;
3621 rtx old_last_expr_value = last_expr_value;
3622 tree old_last_expr_type = last_expr_type;
3623 expr_stmts_for_value = 0;
3625 /* Do the cleanups. */
3626 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3628 do_pending_stack_adjust ();
3630 expr_stmts_for_value = old_expr_stmts_for_value;
3631 last_expr_value = old_last_expr_value;
3632 last_expr_type = old_last_expr_type;
3634 /* Restore the stack level. */
3636 if (reachable && thisblock->data.block.stack_level != 0)
3638 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3639 thisblock->data.block.stack_level, NULL_RTX);
3640 if (nonlocal_goto_handler_slots != 0)
3641 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3645 /* Any gotos out of this block must also do these things.
3646 Also report any gotos with fixups that came to labels in this
3648 fixup_gotos (thisblock,
3649 thisblock->data.block.stack_level,
3650 thisblock->data.block.cleanups,
3651 thisblock->data.block.first_insn,
3655 /* Mark the beginning and end of the scope if requested.
3656 We do this now, after running cleanups on the variables
3657 just going out of scope, so they are in scope for their cleanups. */
3660 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3662 /* Get rid of the beginning-mark if we don't make an end-mark. */
3663 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3665 /* If doing stupid register allocation, make sure lives of all
3666 register variables declared here extend thru end of scope. */
3669 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3670 if (TREE_CODE (decl) == VAR_DECL && DECL_RTL (decl))
3671 use_variable (DECL_RTL (decl));
3673 /* Restore the temporary level of TARGET_EXPRs. */
3674 target_temp_slot_level = thisblock->data.block.block_target_temp_slot_level;
3676 /* Restore block_stack level for containing block. */
3678 stack_block_stack = thisblock->data.block.innermost_stack_block;
3679 POPSTACK (block_stack);
3681 /* Pop the stack slot nesting and free any slots at this level. */
3685 /* Generate RTL for the automatic variable declaration DECL.
3686 (Other kinds of declarations are simply ignored if seen here.) */
3692 struct nesting *thisblock;
3695 type = TREE_TYPE (decl);
3697 /* Only automatic variables need any expansion done.
3698 Static and external variables, and external functions,
3699 will be handled by `assemble_variable' (called from finish_decl).
3700 TYPE_DECL and CONST_DECL require nothing.
3701 PARM_DECLs are handled in `assign_parms'. */
3703 if (TREE_CODE (decl) != VAR_DECL)
3705 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3708 thisblock = block_stack;
3710 /* Create the RTL representation for the variable. */
3712 if (type == error_mark_node)
3713 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, const0_rtx);
3714 else if (DECL_SIZE (decl) == 0)
3715 /* Variable with incomplete type. */
3717 if (DECL_INITIAL (decl) == 0)
3718 /* Error message was already done; now avoid a crash. */
3719 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3721 /* An initializer is going to decide the size of this array.
3722 Until we know the size, represent its address with a reg. */
3723 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode));
3724 MEM_SET_IN_STRUCT_P (DECL_RTL (decl), AGGREGATE_TYPE_P (type));
3726 else if (DECL_MODE (decl) != BLKmode
3727 /* If -ffloat-store, don't put explicit float vars
3729 && !(flag_float_store
3730 && TREE_CODE (type) == REAL_TYPE)
3731 && ! TREE_THIS_VOLATILE (decl)
3732 && ! TREE_ADDRESSABLE (decl)
3733 && (DECL_REGISTER (decl) || ! obey_regdecls)
3734 /* if -fcheck-memory-usage, check all variables. */
3735 && ! current_function_check_memory_usage)
3737 /* Automatic variable that can go in a register. */
3738 int unsignedp = TREE_UNSIGNED (type);
3739 enum machine_mode reg_mode
3740 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3742 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3743 mark_user_reg (DECL_RTL (decl));
3745 if (POINTER_TYPE_P (type))
3746 mark_reg_pointer (DECL_RTL (decl),
3747 (TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl)))
3751 else if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST
3752 && ! (flag_stack_check && ! STACK_CHECK_BUILTIN
3753 && (TREE_INT_CST_HIGH (DECL_SIZE (decl)) != 0
3754 || (TREE_INT_CST_LOW (DECL_SIZE (decl))
3755 > STACK_CHECK_MAX_VAR_SIZE * BITS_PER_UNIT))))
3757 /* Variable of fixed size that goes on the stack. */
3761 /* If we previously made RTL for this decl, it must be an array
3762 whose size was determined by the initializer.
3763 The old address was a register; set that register now
3764 to the proper address. */
3765 if (DECL_RTL (decl) != 0)
3767 if (GET_CODE (DECL_RTL (decl)) != MEM
3768 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3770 oldaddr = XEXP (DECL_RTL (decl), 0);
3773 DECL_RTL (decl) = assign_temp (TREE_TYPE (decl), 1, 1, 1);
3774 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3775 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3777 /* Set alignment we actually gave this decl. */
3778 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3779 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3783 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3784 if (addr != oldaddr)
3785 emit_move_insn (oldaddr, addr);
3788 /* If this is a memory ref that contains aggregate components,
3789 mark it as such for cse and loop optimize. */
3790 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3791 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3793 /* If this is in memory because of -ffloat-store,
3794 set the volatile bit, to prevent optimizations from
3795 undoing the effects. */
3796 if (flag_float_store && TREE_CODE (type) == REAL_TYPE)
3797 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3800 MEM_ALIAS_SET (DECL_RTL (decl)) = get_alias_set (decl);
3803 /* Dynamic-size object: must push space on the stack. */
3807 /* Record the stack pointer on entry to block, if have
3808 not already done so. */
3809 if (thisblock->data.block.stack_level == 0)
3811 do_pending_stack_adjust ();
3812 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3813 &thisblock->data.block.stack_level,
3814 thisblock->data.block.first_insn);
3815 stack_block_stack = thisblock;
3818 /* Compute the variable's size, in bytes. */
3819 size = expand_expr (size_binop (CEIL_DIV_EXPR,
3821 size_int (BITS_PER_UNIT)),
3822 NULL_RTX, VOIDmode, 0);
3825 /* Allocate space on the stack for the variable. Note that
3826 DECL_ALIGN says how the variable is to be aligned and we
3827 cannot use it to conclude anything about the alignment of
3829 address = allocate_dynamic_stack_space (size, NULL_RTX,
3830 TYPE_ALIGN (TREE_TYPE (decl)));
3832 /* Reference the variable indirect through that rtx. */
3833 DECL_RTL (decl) = gen_rtx_MEM (DECL_MODE (decl), address);
3835 /* If this is a memory ref that contains aggregate components,
3836 mark it as such for cse and loop optimize. */
3837 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3838 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3840 /* Indicate the alignment we actually gave this variable. */
3841 #ifdef STACK_BOUNDARY
3842 DECL_ALIGN (decl) = STACK_BOUNDARY;
3844 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3848 if (TREE_THIS_VOLATILE (decl))
3849 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3850 #if 0 /* A variable is not necessarily unchanging
3851 just because it is const. RTX_UNCHANGING_P
3852 means no change in the function,
3853 not merely no change in the variable's scope.
3854 It is correct to set RTX_UNCHANGING_P if the variable's scope
3855 is the whole function. There's no convenient way to test that. */
3856 if (TREE_READONLY (decl))
3857 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
3860 /* If doing stupid register allocation, make sure life of any
3861 register variable starts here, at the start of its scope. */
3864 use_variable (DECL_RTL (decl));
3869 /* Emit code to perform the initialization of a declaration DECL. */
3872 expand_decl_init (decl)
3875 int was_used = TREE_USED (decl);
3877 /* If this is a CONST_DECL, we don't have to generate any code, but
3878 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3879 to be set while in the obstack containing the constant. If we don't
3880 do this, we can lose if we have functions nested three deep and the middle
3881 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3882 the innermost function is the first to expand that STRING_CST. */
3883 if (TREE_CODE (decl) == CONST_DECL)
3885 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3886 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3887 EXPAND_INITIALIZER);
3891 if (TREE_STATIC (decl))
3894 /* Compute and store the initial value now. */
3896 if (DECL_INITIAL (decl) == error_mark_node)
3898 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3900 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3901 || code == POINTER_TYPE || code == REFERENCE_TYPE)
3902 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3906 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3908 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3909 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3913 /* Don't let the initialization count as "using" the variable. */
3914 TREE_USED (decl) = was_used;
3916 /* Free any temporaries we made while initializing the decl. */
3917 preserve_temp_slots (NULL_RTX);
3921 /* CLEANUP is an expression to be executed at exit from this binding contour;
3922 for example, in C++, it might call the destructor for this variable.
3924 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
3925 CLEANUP multiple times, and have the correct semantics. This
3926 happens in exception handling, for gotos, returns, breaks that
3927 leave the current scope.
3929 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3930 that is not associated with any particular variable. */
3933 expand_decl_cleanup (decl, cleanup)
3936 struct nesting *thisblock;
3938 /* Error if we are not in any block. */
3939 if (current_function == 0 || block_stack == 0)
3942 thisblock = block_stack;
3944 /* Record the cleanup if there is one. */
3950 tree *cleanups = &thisblock->data.block.cleanups;
3951 int cond_context = conditional_context ();
3955 rtx flag = gen_reg_rtx (word_mode);
3960 emit_move_insn (flag, const0_rtx);
3961 set_flag_0 = get_insns ();
3964 thisblock->data.block.last_unconditional_cleanup
3965 = emit_insns_after (set_flag_0,
3966 thisblock->data.block.last_unconditional_cleanup);
3968 emit_move_insn (flag, const1_rtx);
3970 /* All cleanups must be on the function_obstack. */
3971 push_obstacks_nochange ();
3972 resume_temporary_allocation ();
3974 cond = build_decl (VAR_DECL, NULL_TREE, type_for_mode (word_mode, 1));
3975 DECL_RTL (cond) = flag;
3977 /* Conditionalize the cleanup. */
3978 cleanup = build (COND_EXPR, void_type_node,
3979 truthvalue_conversion (cond),
3980 cleanup, integer_zero_node);
3981 cleanup = fold (cleanup);
3985 cleanups = thisblock->data.block.cleanup_ptr;
3988 /* All cleanups must be on the function_obstack. */
3989 push_obstacks_nochange ();
3990 resume_temporary_allocation ();
3991 cleanup = unsave_expr (cleanup);
3994 t = *cleanups = temp_tree_cons (decl, cleanup, *cleanups);
3997 /* If this block has a cleanup, it belongs in stack_block_stack. */
3998 stack_block_stack = thisblock;
4005 /* If this was optimized so that there is no exception region for the
4006 cleanup, then mark the TREE_LIST node, so that we can later tell
4007 if we need to call expand_eh_region_end. */
4008 if (! using_eh_for_cleanups_p
4009 || expand_eh_region_start_tree (decl, cleanup))
4010 TREE_ADDRESSABLE (t) = 1;
4011 /* If that started a new EH region, we're in a new block. */
4012 thisblock = block_stack;
4019 thisblock->data.block.last_unconditional_cleanup
4020 = emit_insns_after (seq,
4021 thisblock->data.block.last_unconditional_cleanup);
4025 thisblock->data.block.last_unconditional_cleanup
4027 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
4033 /* Like expand_decl_cleanup, but suppress generating an exception handler
4034 to perform the cleanup. */
4037 expand_decl_cleanup_no_eh (decl, cleanup)
4040 int save_eh = using_eh_for_cleanups_p;
4043 using_eh_for_cleanups_p = 0;
4044 result = expand_decl_cleanup (decl, cleanup);
4045 using_eh_for_cleanups_p = save_eh;
4050 /* Arrange for the top element of the dynamic cleanup chain to be
4051 popped if we exit the current binding contour. DECL is the
4052 associated declaration, if any, otherwise NULL_TREE. If the
4053 current contour is left via an exception, then __sjthrow will pop
4054 the top element off the dynamic cleanup chain. The code that
4055 avoids doing the action we push into the cleanup chain in the
4056 exceptional case is contained in expand_cleanups.
4058 This routine is only used by expand_eh_region_start, and that is
4059 the only way in which an exception region should be started. This
4060 routine is only used when using the setjmp/longjmp codegen method
4061 for exception handling. */
4064 expand_dcc_cleanup (decl)
4067 struct nesting *thisblock;
4070 /* Error if we are not in any block. */
4071 if (current_function == 0 || block_stack == 0)
4073 thisblock = block_stack;
4075 /* Record the cleanup for the dynamic handler chain. */
4077 /* All cleanups must be on the function_obstack. */
4078 push_obstacks_nochange ();
4079 resume_temporary_allocation ();
4080 cleanup = make_node (POPDCC_EXPR);
4083 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4084 thisblock->data.block.cleanups
4085 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4087 /* If this block has a cleanup, it belongs in stack_block_stack. */
4088 stack_block_stack = thisblock;
4092 /* Arrange for the top element of the dynamic handler chain to be
4093 popped if we exit the current binding contour. DECL is the
4094 associated declaration, if any, otherwise NULL_TREE. If the current
4095 contour is left via an exception, then __sjthrow will pop the top
4096 element off the dynamic handler chain. The code that avoids doing
4097 the action we push into the handler chain in the exceptional case
4098 is contained in expand_cleanups.
4100 This routine is only used by expand_eh_region_start, and that is
4101 the only way in which an exception region should be started. This
4102 routine is only used when using the setjmp/longjmp codegen method
4103 for exception handling. */
4106 expand_dhc_cleanup (decl)
4109 struct nesting *thisblock;
4112 /* Error if we are not in any block. */
4113 if (current_function == 0 || block_stack == 0)
4115 thisblock = block_stack;
4117 /* Record the cleanup for the dynamic handler chain. */
4119 /* All cleanups must be on the function_obstack. */
4120 push_obstacks_nochange ();
4121 resume_temporary_allocation ();
4122 cleanup = make_node (POPDHC_EXPR);
4125 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4126 thisblock->data.block.cleanups
4127 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4129 /* If this block has a cleanup, it belongs in stack_block_stack. */
4130 stack_block_stack = thisblock;
4134 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4135 DECL_ELTS is the list of elements that belong to DECL's type.
4136 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4139 expand_anon_union_decl (decl, cleanup, decl_elts)
4140 tree decl, cleanup, decl_elts;
4142 struct nesting *thisblock = current_function == 0 ? 0 : block_stack;
4146 expand_decl_cleanup (decl, cleanup);
4147 x = DECL_RTL (decl);
4151 tree decl_elt = TREE_VALUE (decl_elts);
4152 tree cleanup_elt = TREE_PURPOSE (decl_elts);
4153 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
4155 /* Propagate the union's alignment to the elements. */
4156 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
4158 /* If the element has BLKmode and the union doesn't, the union is
4159 aligned such that the element doesn't need to have BLKmode, so
4160 change the element's mode to the appropriate one for its size. */
4161 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
4162 DECL_MODE (decl_elt) = mode
4163 = mode_for_size (TREE_INT_CST_LOW (DECL_SIZE (decl_elt)),
4166 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4167 instead create a new MEM rtx with the proper mode. */
4168 if (GET_CODE (x) == MEM)
4170 if (mode == GET_MODE (x))
4171 DECL_RTL (decl_elt) = x;
4174 DECL_RTL (decl_elt) = gen_rtx_MEM (mode, copy_rtx (XEXP (x, 0)));
4175 MEM_COPY_ATTRIBUTES (DECL_RTL (decl_elt), x);
4176 RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x);
4179 else if (GET_CODE (x) == REG)
4181 if (mode == GET_MODE (x))
4182 DECL_RTL (decl_elt) = x;
4184 DECL_RTL (decl_elt) = gen_rtx_SUBREG (mode, x, 0);
4189 /* Record the cleanup if there is one. */
4192 thisblock->data.block.cleanups
4193 = temp_tree_cons (decl_elt, cleanup_elt,
4194 thisblock->data.block.cleanups);
4196 decl_elts = TREE_CHAIN (decl_elts);
4200 /* Expand a list of cleanups LIST.
4201 Elements may be expressions or may be nested lists.
4203 If DONT_DO is nonnull, then any list-element
4204 whose TREE_PURPOSE matches DONT_DO is omitted.
4205 This is sometimes used to avoid a cleanup associated with
4206 a value that is being returned out of the scope.
4208 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
4209 goto and handle protection regions specially in that case.
4211 If REACHABLE, we emit code, otherwise just inform the exception handling
4212 code about this finalization. */
4215 expand_cleanups (list, dont_do, in_fixup, reachable)
4222 for (tail = list; tail; tail = TREE_CHAIN (tail))
4223 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
4225 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
4226 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
4231 tree cleanup = TREE_VALUE (tail);
4233 /* See expand_d{h,c}c_cleanup for why we avoid this. */
4234 if (TREE_CODE (cleanup) != POPDHC_EXPR
4235 && TREE_CODE (cleanup) != POPDCC_EXPR
4236 /* See expand_eh_region_start_tree for this case. */
4237 && ! TREE_ADDRESSABLE (tail))
4239 cleanup = protect_with_terminate (cleanup);
4240 expand_eh_region_end (cleanup);
4246 /* Cleanups may be run multiple times. For example,
4247 when exiting a binding contour, we expand the
4248 cleanups associated with that contour. When a goto
4249 within that binding contour has a target outside that
4250 contour, it will expand all cleanups from its scope to
4251 the target. Though the cleanups are expanded multiple
4252 times, the control paths are non-overlapping so the
4253 cleanups will not be executed twice. */
4255 /* We may need to protect fixups with rethrow regions. */
4256 int protect = (in_fixup && ! TREE_ADDRESSABLE (tail));
4259 expand_fixup_region_start ();
4261 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
4263 expand_fixup_region_end (TREE_VALUE (tail));
4270 /* Mark when the context we are emitting RTL for as a conditional
4271 context, so that any cleanup actions we register with
4272 expand_decl_init will be properly conditionalized when those
4273 cleanup actions are later performed. Must be called before any
4274 expression (tree) is expanded that is within a conditional context. */
4277 start_cleanup_deferral ()
4279 /* block_stack can be NULL if we are inside the parameter list. It is
4280 OK to do nothing, because cleanups aren't possible here. */
4282 ++block_stack->data.block.conditional_code;
4285 /* Mark the end of a conditional region of code. Because cleanup
4286 deferrals may be nested, we may still be in a conditional region
4287 after we end the currently deferred cleanups, only after we end all
4288 deferred cleanups, are we back in unconditional code. */
4291 end_cleanup_deferral ()
4293 /* block_stack can be NULL if we are inside the parameter list. It is
4294 OK to do nothing, because cleanups aren't possible here. */
4296 --block_stack->data.block.conditional_code;
4299 /* Move all cleanups from the current block_stack
4300 to the containing block_stack, where they are assumed to
4301 have been created. If anything can cause a temporary to
4302 be created, but not expanded for more than one level of
4303 block_stacks, then this code will have to change. */
4308 struct nesting *block = block_stack;
4309 struct nesting *outer = block->next;
4311 outer->data.block.cleanups
4312 = chainon (block->data.block.cleanups,
4313 outer->data.block.cleanups);
4314 block->data.block.cleanups = 0;
4318 last_cleanup_this_contour ()
4320 if (block_stack == 0)
4323 return block_stack->data.block.cleanups;
4326 /* Return 1 if there are any pending cleanups at this point.
4327 If THIS_CONTOUR is nonzero, check the current contour as well.
4328 Otherwise, look only at the contours that enclose this one. */
4331 any_pending_cleanups (this_contour)
4334 struct nesting *block;
4336 if (block_stack == 0)
4339 if (this_contour && block_stack->data.block.cleanups != NULL)
4341 if (block_stack->data.block.cleanups == 0
4342 && block_stack->data.block.outer_cleanups == 0)
4345 for (block = block_stack->next; block; block = block->next)
4346 if (block->data.block.cleanups != 0)
4352 /* Enter a case (Pascal) or switch (C) statement.
4353 Push a block onto case_stack and nesting_stack
4354 to accumulate the case-labels that are seen
4355 and to record the labels generated for the statement.
4357 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4358 Otherwise, this construct is transparent for `exit_something'.
4360 EXPR is the index-expression to be dispatched on.
4361 TYPE is its nominal type. We could simply convert EXPR to this type,
4362 but instead we take short cuts. */
4365 expand_start_case (exit_flag, expr, type, printname)
4369 const char *printname;
4371 register struct nesting *thiscase = ALLOC_NESTING ();
4373 /* Make an entry on case_stack for the case we are entering. */
4375 thiscase->next = case_stack;
4376 thiscase->all = nesting_stack;
4377 thiscase->depth = ++nesting_depth;
4378 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
4379 thiscase->data.case_stmt.case_list = 0;
4380 thiscase->data.case_stmt.index_expr = expr;
4381 thiscase->data.case_stmt.nominal_type = type;
4382 thiscase->data.case_stmt.default_label = 0;
4383 thiscase->data.case_stmt.num_ranges = 0;
4384 thiscase->data.case_stmt.printname = printname;
4385 thiscase->data.case_stmt.line_number_status = force_line_numbers ();
4386 case_stack = thiscase;
4387 nesting_stack = thiscase;
4389 do_pending_stack_adjust ();
4391 /* Make sure case_stmt.start points to something that won't
4392 need any transformation before expand_end_case. */
4393 if (GET_CODE (get_last_insn ()) != NOTE)
4394 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4396 thiscase->data.case_stmt.start = get_last_insn ();
4398 start_cleanup_deferral ();
4402 /* Start a "dummy case statement" within which case labels are invalid
4403 and are not connected to any larger real case statement.
4404 This can be used if you don't want to let a case statement jump
4405 into the middle of certain kinds of constructs. */
4408 expand_start_case_dummy ()
4410 register struct nesting *thiscase = ALLOC_NESTING ();
4412 /* Make an entry on case_stack for the dummy. */
4414 thiscase->next = case_stack;
4415 thiscase->all = nesting_stack;
4416 thiscase->depth = ++nesting_depth;
4417 thiscase->exit_label = 0;
4418 thiscase->data.case_stmt.case_list = 0;
4419 thiscase->data.case_stmt.start = 0;
4420 thiscase->data.case_stmt.nominal_type = 0;
4421 thiscase->data.case_stmt.default_label = 0;
4422 thiscase->data.case_stmt.num_ranges = 0;
4423 case_stack = thiscase;
4424 nesting_stack = thiscase;
4425 start_cleanup_deferral ();
4428 /* End a dummy case statement. */
4431 expand_end_case_dummy ()
4433 end_cleanup_deferral ();
4434 POPSTACK (case_stack);
4437 /* Return the data type of the index-expression
4438 of the innermost case statement, or null if none. */
4441 case_index_expr_type ()
4444 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
4451 /* If this is the first label, warn if any insns have been emitted. */
4452 if (case_stack->data.case_stmt.line_number_status >= 0)
4456 restore_line_number_status
4457 (case_stack->data.case_stmt.line_number_status);
4458 case_stack->data.case_stmt.line_number_status = -1;
4460 for (insn = case_stack->data.case_stmt.start;
4462 insn = NEXT_INSN (insn))
4464 if (GET_CODE (insn) == CODE_LABEL)
4466 if (GET_CODE (insn) != NOTE
4467 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4470 insn = PREV_INSN (insn);
4471 while (insn && (GET_CODE (insn) != NOTE || NOTE_LINE_NUMBER (insn) < 0));
4473 /* If insn is zero, then there must have been a syntax error. */
4475 warning_with_file_and_line (NOTE_SOURCE_FILE(insn),
4476 NOTE_LINE_NUMBER(insn),
4477 "unreachable code at beginning of %s",
4478 case_stack->data.case_stmt.printname);
4485 /* Accumulate one case or default label inside a case or switch statement.
4486 VALUE is the value of the case (a null pointer, for a default label).
4487 The function CONVERTER, when applied to arguments T and V,
4488 converts the value V to the type T.
4490 If not currently inside a case or switch statement, return 1 and do
4491 nothing. The caller will print a language-specific error message.
4492 If VALUE is a duplicate or overlaps, return 2 and do nothing
4493 except store the (first) duplicate node in *DUPLICATE.
4494 If VALUE is out of range, return 3 and do nothing.
4495 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4496 Return 0 on success.
4498 Extended to handle range statements. */
4501 pushcase (value, converter, label, duplicate)
4502 register tree value;
4503 tree (*converter) PROTO((tree, tree));
4504 register tree label;
4510 /* Fail if not inside a real case statement. */
4511 if (! (case_stack && case_stack->data.case_stmt.start))
4514 if (stack_block_stack
4515 && stack_block_stack->depth > case_stack->depth)
4518 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4519 nominal_type = case_stack->data.case_stmt.nominal_type;
4521 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4522 if (index_type == error_mark_node)
4525 /* Convert VALUE to the type in which the comparisons are nominally done. */
4527 value = (*converter) (nominal_type, value);
4531 /* Fail if this value is out of range for the actual type of the index
4532 (which may be narrower than NOMINAL_TYPE). */
4533 if (value != 0 && ! int_fits_type_p (value, index_type))
4536 /* Fail if this is a duplicate or overlaps another entry. */
4539 if (case_stack->data.case_stmt.default_label != 0)
4541 *duplicate = case_stack->data.case_stmt.default_label;
4544 case_stack->data.case_stmt.default_label = label;
4547 return add_case_node (value, value, label, duplicate);
4549 expand_label (label);
4553 /* Like pushcase but this case applies to all values between VALUE1 and
4554 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4555 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4556 starts at VALUE1 and ends at the highest value of the index type.
4557 If both are NULL, this case applies to all values.
4559 The return value is the same as that of pushcase but there is one
4560 additional error code: 4 means the specified range was empty. */
4563 pushcase_range (value1, value2, converter, label, duplicate)
4564 register tree value1, value2;
4565 tree (*converter) PROTO((tree, tree));
4566 register tree label;
4572 /* Fail if not inside a real case statement. */
4573 if (! (case_stack && case_stack->data.case_stmt.start))
4576 if (stack_block_stack
4577 && stack_block_stack->depth > case_stack->depth)
4580 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4581 nominal_type = case_stack->data.case_stmt.nominal_type;
4583 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4584 if (index_type == error_mark_node)
4589 /* Convert VALUEs to type in which the comparisons are nominally done
4590 and replace any unspecified value with the corresponding bound. */
4592 value1 = TYPE_MIN_VALUE (index_type);
4594 value2 = TYPE_MAX_VALUE (index_type);
4596 /* Fail if the range is empty. Do this before any conversion since
4597 we want to allow out-of-range empty ranges. */
4598 if (value2 && tree_int_cst_lt (value2, value1))
4601 value1 = (*converter) (nominal_type, value1);
4603 /* If the max was unbounded, use the max of the nominal_type we are
4604 converting to. Do this after the < check above to suppress false
4607 value2 = TYPE_MAX_VALUE (nominal_type);
4608 value2 = (*converter) (nominal_type, value2);
4610 /* Fail if these values are out of range. */
4611 if (TREE_CONSTANT_OVERFLOW (value1)
4612 || ! int_fits_type_p (value1, index_type))
4615 if (TREE_CONSTANT_OVERFLOW (value2)
4616 || ! int_fits_type_p (value2, index_type))
4619 return add_case_node (value1, value2, label, duplicate);
4622 /* Do the actual insertion of a case label for pushcase and pushcase_range
4623 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4624 slowdown for large switch statements. */
4627 add_case_node (low, high, label, duplicate)
4632 struct case_node *p, **q, *r;
4634 q = &case_stack->data.case_stmt.case_list;
4641 /* Keep going past elements distinctly greater than HIGH. */
4642 if (tree_int_cst_lt (high, p->low))
4645 /* or distinctly less than LOW. */
4646 else if (tree_int_cst_lt (p->high, low))
4651 /* We have an overlap; this is an error. */
4652 *duplicate = p->code_label;
4657 /* Add this label to the chain, and succeed.
4658 Copy LOW, HIGH so they are on temporary rather than momentary
4659 obstack and will thus survive till the end of the case statement. */
4661 r = (struct case_node *) oballoc (sizeof (struct case_node));
4662 r->low = copy_node (low);
4664 /* If the bounds are equal, turn this into the one-value case. */
4666 if (tree_int_cst_equal (low, high))
4670 r->high = copy_node (high);
4671 case_stack->data.case_stmt.num_ranges++;
4674 r->code_label = label;
4675 expand_label (label);
4685 struct case_node *s;
4691 if (! (b = p->balance))
4692 /* Growth propagation from left side. */
4699 if ((p->left = s = r->right))
4708 if ((r->parent = s))
4716 case_stack->data.case_stmt.case_list = r;
4719 /* r->balance == +1 */
4724 struct case_node *t = r->right;
4726 if ((p->left = s = t->right))
4730 if ((r->right = s = t->left))
4744 if ((t->parent = s))
4752 case_stack->data.case_stmt.case_list = t;
4759 /* p->balance == +1; growth of left side balances the node. */
4769 if (! (b = p->balance))
4770 /* Growth propagation from right side. */
4778 if ((p->right = s = r->left))
4786 if ((r->parent = s))
4795 case_stack->data.case_stmt.case_list = r;
4799 /* r->balance == -1 */
4803 struct case_node *t = r->left;
4805 if ((p->right = s = t->left))
4810 if ((r->left = s = t->right))
4824 if ((t->parent = s))
4833 case_stack->data.case_stmt.case_list = t;
4839 /* p->balance == -1; growth of right side balances the node. */
4853 /* Returns the number of possible values of TYPE.
4854 Returns -1 if the number is unknown or variable.
4855 Returns -2 if the number does not fit in a HOST_WIDE_INT.
4856 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4857 do not increase monotonically (there may be duplicates);
4858 to 1 if the values increase monotonically, but not always by 1;
4859 otherwise sets it to 0. */
4862 all_cases_count (type, spareness)
4866 HOST_WIDE_INT count;
4869 switch (TREE_CODE (type))
4876 count = 1 << BITS_PER_UNIT;
4880 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4881 || TYPE_MAX_VALUE (type) == NULL
4882 || TREE_CODE (TYPE_MAX_VALUE (type)) != INTEGER_CST)
4887 = TREE_INT_CST_LOW (TYPE_MAX_VALUE (type))
4888 - TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + 1
4889 but with overflow checking. */
4890 tree mint = TYPE_MIN_VALUE (type);
4891 tree maxt = TYPE_MAX_VALUE (type);
4892 HOST_WIDE_INT lo, hi;
4893 neg_double(TREE_INT_CST_LOW (mint), TREE_INT_CST_HIGH (mint),
4895 add_double(TREE_INT_CST_LOW (maxt), TREE_INT_CST_HIGH (maxt),
4897 add_double (lo, hi, 1, 0, &lo, &hi);
4898 if (hi != 0 || lo < 0)
4905 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4907 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4908 || TREE_CODE (TREE_VALUE (t)) != INTEGER_CST
4909 || TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + count
4910 != TREE_INT_CST_LOW (TREE_VALUE (t)))
4914 if (*spareness == 1)
4916 tree prev = TREE_VALUE (TYPE_VALUES (type));
4917 for (t = TYPE_VALUES (type); t = TREE_CHAIN (t), t != NULL_TREE; )
4919 if (! tree_int_cst_lt (prev, TREE_VALUE (t)))
4924 prev = TREE_VALUE (t);
4933 #define BITARRAY_TEST(ARRAY, INDEX) \
4934 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4935 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4936 #define BITARRAY_SET(ARRAY, INDEX) \
4937 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4938 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4940 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4941 with the case values we have seen, assuming the case expression
4943 SPARSENESS is as determined by all_cases_count.
4945 The time needed is proportional to COUNT, unless
4946 SPARSENESS is 2, in which case quadratic time is needed. */
4949 mark_seen_cases (type, cases_seen, count, sparseness)
4951 unsigned char *cases_seen;
4955 tree next_node_to_try = NULL_TREE;
4956 long next_node_offset = 0;
4958 register struct case_node *n, *root = case_stack->data.case_stmt.case_list;
4959 tree val = make_node (INTEGER_CST);
4960 TREE_TYPE (val) = type;
4963 else if (sparseness == 2)
4968 /* This less efficient loop is only needed to handle
4969 duplicate case values (multiple enum constants
4970 with the same value). */
4971 TREE_TYPE (val) = TREE_TYPE (root->low);
4972 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
4973 t = TREE_CHAIN (t), xlo++)
4975 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (TREE_VALUE (t));
4976 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (TREE_VALUE (t));
4980 /* Keep going past elements distinctly greater than VAL. */
4981 if (tree_int_cst_lt (val, n->low))
4984 /* or distinctly less than VAL. */
4985 else if (tree_int_cst_lt (n->high, val))
4990 /* We have found a matching range. */
4991 BITARRAY_SET (cases_seen, xlo);
5001 case_stack->data.case_stmt.case_list = root = case_tree2list (root, 0);
5002 for (n = root; n; n = n->right)
5004 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
5005 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
5006 while ( ! tree_int_cst_lt (n->high, val))
5008 /* Calculate (into xlo) the "offset" of the integer (val).
5009 The element with lowest value has offset 0, the next smallest
5010 element has offset 1, etc. */
5012 HOST_WIDE_INT xlo, xhi;
5014 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
5016 /* The TYPE_VALUES will be in increasing order, so
5017 starting searching where we last ended. */
5018 t = next_node_to_try;
5019 xlo = next_node_offset;
5025 t = TYPE_VALUES (type);
5028 if (tree_int_cst_equal (val, TREE_VALUE (t)))
5030 next_node_to_try = TREE_CHAIN (t);
5031 next_node_offset = xlo + 1;
5036 if (t == next_node_to_try)
5045 t = TYPE_MIN_VALUE (type);
5047 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
5051 add_double (xlo, xhi,
5052 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5056 if (xhi == 0 && xlo >= 0 && xlo < count)
5057 BITARRAY_SET (cases_seen, xlo);
5058 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5060 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
5066 /* Called when the index of a switch statement is an enumerated type
5067 and there is no default label.
5069 Checks that all enumeration literals are covered by the case
5070 expressions of a switch. Also, warn if there are any extra
5071 switch cases that are *not* elements of the enumerated type.
5073 If all enumeration literals were covered by the case expressions,
5074 turn one of the expressions into the default expression since it should
5075 not be possible to fall through such a switch. */
5078 check_for_full_enumeration_handling (type)
5081 register struct case_node *n;
5082 register tree chain;
5083 #if 0 /* variable used by 'if 0'ed code below. */
5084 register struct case_node **l;
5088 /* True iff the selector type is a numbered set mode. */
5091 /* The number of possible selector values. */
5094 /* For each possible selector value. a one iff it has been matched
5095 by a case value alternative. */
5096 unsigned char *cases_seen;
5098 /* The allocated size of cases_seen, in chars. */
5104 size = all_cases_count (type, &sparseness);
5105 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
5107 if (size > 0 && size < 600000
5108 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5109 this optimization if we don't have enough memory rather than
5110 aborting, as xmalloc would do. */
5111 && (cases_seen = (unsigned char *) calloc (bytes_needed, 1)) != NULL)
5114 tree v = TYPE_VALUES (type);
5116 /* The time complexity of this code is normally O(N), where
5117 N being the number of members in the enumerated type.
5118 However, if type is a ENUMERAL_TYPE whose values do not
5119 increase monotonically, O(N*log(N)) time may be needed. */
5121 mark_seen_cases (type, cases_seen, size, sparseness);
5123 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
5125 if (BITARRAY_TEST(cases_seen, i) == 0)
5126 warning ("enumeration value `%s' not handled in switch",
5127 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
5133 /* Now we go the other way around; we warn if there are case
5134 expressions that don't correspond to enumerators. This can
5135 occur since C and C++ don't enforce type-checking of
5136 assignments to enumeration variables. */
5138 if (case_stack->data.case_stmt.case_list
5139 && case_stack->data.case_stmt.case_list->left)
5140 case_stack->data.case_stmt.case_list
5141 = case_tree2list (case_stack->data.case_stmt.case_list, 0);
5143 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
5145 for (chain = TYPE_VALUES (type);
5146 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
5147 chain = TREE_CHAIN (chain))
5152 if (TYPE_NAME (type) == 0)
5153 warning ("case value `%ld' not in enumerated type",
5154 (long) TREE_INT_CST_LOW (n->low));
5156 warning ("case value `%ld' not in enumerated type `%s'",
5157 (long) TREE_INT_CST_LOW (n->low),
5158 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5161 : DECL_NAME (TYPE_NAME (type))));
5163 if (!tree_int_cst_equal (n->low, n->high))
5165 for (chain = TYPE_VALUES (type);
5166 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
5167 chain = TREE_CHAIN (chain))
5172 if (TYPE_NAME (type) == 0)
5173 warning ("case value `%ld' not in enumerated type",
5174 (long) TREE_INT_CST_LOW (n->high));
5176 warning ("case value `%ld' not in enumerated type `%s'",
5177 (long) TREE_INT_CST_LOW (n->high),
5178 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5181 : DECL_NAME (TYPE_NAME (type))));
5187 /* ??? This optimization is disabled because it causes valid programs to
5188 fail. ANSI C does not guarantee that an expression with enum type
5189 will have a value that is the same as one of the enumeration literals. */
5191 /* If all values were found as case labels, make one of them the default
5192 label. Thus, this switch will never fall through. We arbitrarily pick
5193 the last one to make the default since this is likely the most
5194 efficient choice. */
5198 for (l = &case_stack->data.case_stmt.case_list;
5203 case_stack->data.case_stmt.default_label = (*l)->code_label;
5210 /* Terminate a case (Pascal) or switch (C) statement
5211 in which ORIG_INDEX is the expression to be tested.
5212 Generate the code to test it and jump to the right place. */
5215 expand_end_case (orig_index)
5218 tree minval = NULL_TREE, maxval = NULL_TREE, range, orig_minval;
5219 rtx default_label = 0;
5220 register struct case_node *n;
5228 register struct nesting *thiscase = case_stack;
5229 tree index_expr, index_type;
5232 /* Don't crash due to previous errors. */
5233 if (thiscase == NULL)
5236 table_label = gen_label_rtx ();
5237 index_expr = thiscase->data.case_stmt.index_expr;
5238 index_type = TREE_TYPE (index_expr);
5239 unsignedp = TREE_UNSIGNED (index_type);
5241 do_pending_stack_adjust ();
5243 /* This might get an spurious warning in the presence of a syntax error;
5244 it could be fixed by moving the call to check_seenlabel after the
5245 check for error_mark_node, and copying the code of check_seenlabel that
5246 deals with case_stack->data.case_stmt.line_number_status /
5247 restore_line_number_status in front of the call to end_cleanup_deferral;
5248 However, this might miss some useful warnings in the presence of
5249 non-syntax errors. */
5252 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5253 if (index_type != error_mark_node)
5255 /* If switch expression was an enumerated type, check that all
5256 enumeration literals are covered by the cases.
5257 No sense trying this if there's a default case, however. */
5259 if (!thiscase->data.case_stmt.default_label
5260 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
5261 && TREE_CODE (index_expr) != INTEGER_CST)
5262 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
5264 /* If we don't have a default-label, create one here,
5265 after the body of the switch. */
5266 if (thiscase->data.case_stmt.default_label == 0)
5268 thiscase->data.case_stmt.default_label
5269 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5270 expand_label (thiscase->data.case_stmt.default_label);
5272 default_label = label_rtx (thiscase->data.case_stmt.default_label);
5274 before_case = get_last_insn ();
5276 if (thiscase->data.case_stmt.case_list
5277 && thiscase->data.case_stmt.case_list->left)
5278 thiscase->data.case_stmt.case_list
5279 = case_tree2list(thiscase->data.case_stmt.case_list, 0);
5281 /* Simplify the case-list before we count it. */
5282 group_case_nodes (thiscase->data.case_stmt.case_list);
5284 /* Get upper and lower bounds of case values.
5285 Also convert all the case values to the index expr's data type. */
5288 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5290 /* Check low and high label values are integers. */
5291 if (TREE_CODE (n->low) != INTEGER_CST)
5293 if (TREE_CODE (n->high) != INTEGER_CST)
5296 n->low = convert (index_type, n->low);
5297 n->high = convert (index_type, n->high);
5299 /* Count the elements and track the largest and smallest
5300 of them (treating them as signed even if they are not). */
5308 if (INT_CST_LT (n->low, minval))
5310 if (INT_CST_LT (maxval, n->high))
5313 /* A range counts double, since it requires two compares. */
5314 if (! tree_int_cst_equal (n->low, n->high))
5318 orig_minval = minval;
5320 /* Compute span of values. */
5322 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
5324 end_cleanup_deferral ();
5328 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
5330 emit_jump (default_label);
5333 /* If range of values is much bigger than number of values,
5334 make a sequence of conditional branches instead of a dispatch.
5335 If the switch-index is a constant, do it this way
5336 because we can optimize it. */
5338 #ifndef CASE_VALUES_THRESHOLD
5340 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
5342 /* If machine does not have a case insn that compares the
5343 bounds, this means extra overhead for dispatch tables
5344 which raises the threshold for using them. */
5345 #define CASE_VALUES_THRESHOLD 5
5346 #endif /* HAVE_casesi */
5347 #endif /* CASE_VALUES_THRESHOLD */
5349 else if (TREE_INT_CST_HIGH (range) != 0
5350 || count < (unsigned int) CASE_VALUES_THRESHOLD
5351 || ((unsigned HOST_WIDE_INT) (TREE_INT_CST_LOW (range))
5353 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5356 || TREE_CODE (index_expr) == INTEGER_CST
5357 /* These will reduce to a constant. */
5358 || (TREE_CODE (index_expr) == CALL_EXPR
5359 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
5360 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
5361 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
5362 || (TREE_CODE (index_expr) == COMPOUND_EXPR
5363 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
5365 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5367 /* If the index is a short or char that we do not have
5368 an insn to handle comparisons directly, convert it to
5369 a full integer now, rather than letting each comparison
5370 generate the conversion. */
5372 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
5373 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
5374 == CODE_FOR_nothing))
5376 enum machine_mode wider_mode;
5377 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
5378 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
5379 if (cmp_optab->handlers[(int) wider_mode].insn_code
5380 != CODE_FOR_nothing)
5382 index = convert_to_mode (wider_mode, index, unsignedp);
5388 do_pending_stack_adjust ();
5390 index = protect_from_queue (index, 0);
5391 if (GET_CODE (index) == MEM)
5392 index = copy_to_reg (index);
5393 if (GET_CODE (index) == CONST_INT
5394 || TREE_CODE (index_expr) == INTEGER_CST)
5396 /* Make a tree node with the proper constant value
5397 if we don't already have one. */
5398 if (TREE_CODE (index_expr) != INTEGER_CST)
5401 = build_int_2 (INTVAL (index),
5402 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
5403 index_expr = convert (index_type, index_expr);
5406 /* For constant index expressions we need only
5407 issue a unconditional branch to the appropriate
5408 target code. The job of removing any unreachable
5409 code is left to the optimisation phase if the
5410 "-O" option is specified. */
5411 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5412 if (! tree_int_cst_lt (index_expr, n->low)
5413 && ! tree_int_cst_lt (n->high, index_expr))
5417 emit_jump (label_rtx (n->code_label));
5419 emit_jump (default_label);
5423 /* If the index expression is not constant we generate
5424 a binary decision tree to select the appropriate
5425 target code. This is done as follows:
5427 The list of cases is rearranged into a binary tree,
5428 nearly optimal assuming equal probability for each case.
5430 The tree is transformed into RTL, eliminating
5431 redundant test conditions at the same time.
5433 If program flow could reach the end of the
5434 decision tree an unconditional jump to the
5435 default code is emitted. */
5438 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
5439 && estimate_case_costs (thiscase->data.case_stmt.case_list));
5440 balance_case_nodes (&thiscase->data.case_stmt.case_list,
5442 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
5443 default_label, index_type);
5444 emit_jump_if_reachable (default_label);
5453 enum machine_mode index_mode = SImode;
5454 int index_bits = GET_MODE_BITSIZE (index_mode);
5456 enum machine_mode op_mode;
5458 /* Convert the index to SImode. */
5459 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
5460 > GET_MODE_BITSIZE (index_mode))
5462 enum machine_mode omode = TYPE_MODE (index_type);
5463 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
5465 /* We must handle the endpoints in the original mode. */
5466 index_expr = build (MINUS_EXPR, index_type,
5467 index_expr, minval);
5468 minval = integer_zero_node;
5469 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5470 emit_cmp_and_jump_insns (rangertx, index, LTU, NULL_RTX,
5471 omode, 1, 0, default_label);
5472 /* Now we can safely truncate. */
5473 index = convert_to_mode (index_mode, index, 0);
5477 if (TYPE_MODE (index_type) != index_mode)
5479 index_expr = convert (type_for_size (index_bits, 0),
5481 index_type = TREE_TYPE (index_expr);
5484 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5487 index = protect_from_queue (index, 0);
5488 do_pending_stack_adjust ();
5490 op_mode = insn_data[(int)CODE_FOR_casesi].operand[0].mode;
5491 if (! (*insn_data[(int)CODE_FOR_casesi].operand[0].predicate)
5493 index = copy_to_mode_reg (op_mode, index);
5495 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
5497 op_mode = insn_data[(int)CODE_FOR_casesi].operand[1].mode;
5498 if (! (*insn_data[(int)CODE_FOR_casesi].operand[1].predicate)
5500 op1 = copy_to_mode_reg (op_mode, op1);
5502 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
5504 op_mode = insn_data[(int)CODE_FOR_casesi].operand[2].mode;
5505 if (! (*insn_data[(int)CODE_FOR_casesi].operand[2].predicate)
5507 op2 = copy_to_mode_reg (op_mode, op2);
5509 emit_jump_insn (gen_casesi (index, op1, op2,
5510 table_label, default_label));
5514 #ifdef HAVE_tablejump
5515 if (! win && HAVE_tablejump)
5517 index_expr = convert (thiscase->data.case_stmt.nominal_type,
5518 fold (build (MINUS_EXPR, index_type,
5519 index_expr, minval)));
5520 index_type = TREE_TYPE (index_expr);
5521 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5523 index = protect_from_queue (index, 0);
5524 do_pending_stack_adjust ();
5526 do_tablejump (index, TYPE_MODE (index_type),
5527 expand_expr (range, NULL_RTX, VOIDmode, 0),
5528 table_label, default_label);
5535 /* Get table of labels to jump to, in order of case index. */
5537 ncases = TREE_INT_CST_LOW (range) + 1;
5538 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
5539 bzero ((char *) labelvec, ncases * sizeof (rtx));
5541 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5543 register HOST_WIDE_INT i
5544 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
5549 = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
5550 if (i + TREE_INT_CST_LOW (orig_minval)
5551 == TREE_INT_CST_LOW (n->high))
5557 /* Fill in the gaps with the default. */
5558 for (i = 0; i < ncases; i++)
5559 if (labelvec[i] == 0)
5560 labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
5562 /* Output the table */
5563 emit_label (table_label);
5565 if (CASE_VECTOR_PC_RELATIVE || flag_pic)
5566 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
5567 gen_rtx_LABEL_REF (Pmode, table_label),
5568 gen_rtvec_v (ncases, labelvec),
5569 const0_rtx, const0_rtx));
5571 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
5572 gen_rtvec_v (ncases, labelvec)));
5574 /* If the case insn drops through the table,
5575 after the table we must jump to the default-label.
5576 Otherwise record no drop-through after the table. */
5577 #ifdef CASE_DROPS_THROUGH
5578 emit_jump (default_label);
5584 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
5585 reorder_insns (before_case, get_last_insn (),
5586 thiscase->data.case_stmt.start);
5589 end_cleanup_deferral ();
5591 if (thiscase->exit_label)
5592 emit_label (thiscase->exit_label);
5594 POPSTACK (case_stack);
5599 /* Convert the tree NODE into a list linked by the right field, with the left
5600 field zeroed. RIGHT is used for recursion; it is a list to be placed
5601 rightmost in the resulting list. */
5603 static struct case_node *
5604 case_tree2list (node, right)
5605 struct case_node *node, *right;
5607 struct case_node *left;
5610 right = case_tree2list (node->right, right);
5612 node->right = right;
5613 if ((left = node->left))
5616 return case_tree2list (left, node);
5622 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5625 do_jump_if_equal (op1, op2, label, unsignedp)
5626 rtx op1, op2, label;
5629 if (GET_CODE (op1) == CONST_INT
5630 && GET_CODE (op2) == CONST_INT)
5632 if (INTVAL (op1) == INTVAL (op2))
5637 enum machine_mode mode = GET_MODE (op1);
5638 if (mode == VOIDmode)
5639 mode = GET_MODE (op2);
5640 emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX, mode, unsignedp,
5645 /* Not all case values are encountered equally. This function
5646 uses a heuristic to weight case labels, in cases where that
5647 looks like a reasonable thing to do.
5649 Right now, all we try to guess is text, and we establish the
5652 chars above space: 16
5661 If we find any cases in the switch that are not either -1 or in the range
5662 of valid ASCII characters, or are control characters other than those
5663 commonly used with "\", don't treat this switch scanning text.
5665 Return 1 if these nodes are suitable for cost estimation, otherwise
5669 estimate_case_costs (node)
5672 tree min_ascii = build_int_2 (-1, -1);
5673 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5677 /* If we haven't already made the cost table, make it now. Note that the
5678 lower bound of the table is -1, not zero. */
5680 if (cost_table == NULL)
5682 cost_table = ((short *) xcalloc (129, sizeof (short))) + 1;
5684 for (i = 0; i < 128; i++)
5688 else if (ISPUNCT (i))
5690 else if (ISCNTRL (i))
5694 cost_table[' '] = 8;
5695 cost_table['\t'] = 4;
5696 cost_table['\0'] = 4;
5697 cost_table['\n'] = 2;
5698 cost_table['\f'] = 1;
5699 cost_table['\v'] = 1;
5700 cost_table['\b'] = 1;
5703 /* See if all the case expressions look like text. It is text if the
5704 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5705 as signed arithmetic since we don't want to ever access cost_table with a
5706 value less than -1. Also check that none of the constants in a range
5707 are strange control characters. */
5709 for (n = node; n; n = n->right)
5711 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5714 for (i = TREE_INT_CST_LOW (n->low); i <= TREE_INT_CST_LOW (n->high); i++)
5715 if (cost_table[i] < 0)
5719 /* All interesting values are within the range of interesting
5720 ASCII characters. */
5724 /* Scan an ordered list of case nodes
5725 combining those with consecutive values or ranges.
5727 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5730 group_case_nodes (head)
5733 case_node_ptr node = head;
5737 rtx lb = next_real_insn (label_rtx (node->code_label));
5739 case_node_ptr np = node;
5741 /* Try to group the successors of NODE with NODE. */
5742 while (((np = np->right) != 0)
5743 /* Do they jump to the same place? */
5744 && ((lb2 = next_real_insn (label_rtx (np->code_label))) == lb
5745 || (lb != 0 && lb2 != 0
5746 && simplejump_p (lb)
5747 && simplejump_p (lb2)
5748 && rtx_equal_p (SET_SRC (PATTERN (lb)),
5749 SET_SRC (PATTERN (lb2)))))
5750 /* Are their ranges consecutive? */
5751 && tree_int_cst_equal (np->low,
5752 fold (build (PLUS_EXPR,
5753 TREE_TYPE (node->high),
5756 /* An overflow is not consecutive. */
5757 && tree_int_cst_lt (node->high,
5758 fold (build (PLUS_EXPR,
5759 TREE_TYPE (node->high),
5761 integer_one_node))))
5763 node->high = np->high;
5765 /* NP is the first node after NODE which can't be grouped with it.
5766 Delete the nodes in between, and move on to that node. */
5772 /* Take an ordered list of case nodes
5773 and transform them into a near optimal binary tree,
5774 on the assumption that any target code selection value is as
5775 likely as any other.
5777 The transformation is performed by splitting the ordered
5778 list into two equal sections plus a pivot. The parts are
5779 then attached to the pivot as left and right branches. Each
5780 branch is then transformed recursively. */
5783 balance_case_nodes (head, parent)
5784 case_node_ptr *head;
5785 case_node_ptr parent;
5787 register case_node_ptr np;
5795 register case_node_ptr *npp;
5798 /* Count the number of entries on branch. Also count the ranges. */
5802 if (!tree_int_cst_equal (np->low, np->high))
5806 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5810 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5818 /* Split this list if it is long enough for that to help. */
5823 /* Find the place in the list that bisects the list's total cost,
5824 Here I gets half the total cost. */
5829 /* Skip nodes while their cost does not reach that amount. */
5830 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5831 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5832 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5835 npp = &(*npp)->right;
5840 /* Leave this branch lopsided, but optimize left-hand
5841 side and fill in `parent' fields for right-hand side. */
5843 np->parent = parent;
5844 balance_case_nodes (&np->left, np);
5845 for (; np->right; np = np->right)
5846 np->right->parent = np;
5850 /* If there are just three nodes, split at the middle one. */
5852 npp = &(*npp)->right;
5855 /* Find the place in the list that bisects the list's total cost,
5856 where ranges count as 2.
5857 Here I gets half the total cost. */
5858 i = (i + ranges + 1) / 2;
5861 /* Skip nodes while their cost does not reach that amount. */
5862 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5867 npp = &(*npp)->right;
5872 np->parent = parent;
5875 /* Optimize each of the two split parts. */
5876 balance_case_nodes (&np->left, np);
5877 balance_case_nodes (&np->right, np);
5881 /* Else leave this branch as one level,
5882 but fill in `parent' fields. */
5884 np->parent = parent;
5885 for (; np->right; np = np->right)
5886 np->right->parent = np;
5891 /* Search the parent sections of the case node tree
5892 to see if a test for the lower bound of NODE would be redundant.
5893 INDEX_TYPE is the type of the index expression.
5895 The instructions to generate the case decision tree are
5896 output in the same order as nodes are processed so it is
5897 known that if a parent node checks the range of the current
5898 node minus one that the current node is bounded at its lower
5899 span. Thus the test would be redundant. */
5902 node_has_low_bound (node, index_type)
5907 case_node_ptr pnode;
5909 /* If the lower bound of this node is the lowest value in the index type,
5910 we need not test it. */
5912 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5915 /* If this node has a left branch, the value at the left must be less
5916 than that at this node, so it cannot be bounded at the bottom and
5917 we need not bother testing any further. */
5922 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5923 node->low, integer_one_node));
5925 /* If the subtraction above overflowed, we can't verify anything.
5926 Otherwise, look for a parent that tests our value - 1. */
5928 if (! tree_int_cst_lt (low_minus_one, node->low))
5931 for (pnode = node->parent; pnode; pnode = pnode->parent)
5932 if (tree_int_cst_equal (low_minus_one, pnode->high))
5938 /* Search the parent sections of the case node tree
5939 to see if a test for the upper bound of NODE would be redundant.
5940 INDEX_TYPE is the type of the index expression.
5942 The instructions to generate the case decision tree are
5943 output in the same order as nodes are processed so it is
5944 known that if a parent node checks the range of the current
5945 node plus one that the current node is bounded at its upper
5946 span. Thus the test would be redundant. */
5949 node_has_high_bound (node, index_type)
5954 case_node_ptr pnode;
5956 /* If there is no upper bound, obviously no test is needed. */
5958 if (TYPE_MAX_VALUE (index_type) == NULL)
5961 /* If the upper bound of this node is the highest value in the type
5962 of the index expression, we need not test against it. */
5964 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
5967 /* If this node has a right branch, the value at the right must be greater
5968 than that at this node, so it cannot be bounded at the top and
5969 we need not bother testing any further. */
5974 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
5975 node->high, integer_one_node));
5977 /* If the addition above overflowed, we can't verify anything.
5978 Otherwise, look for a parent that tests our value + 1. */
5980 if (! tree_int_cst_lt (node->high, high_plus_one))
5983 for (pnode = node->parent; pnode; pnode = pnode->parent)
5984 if (tree_int_cst_equal (high_plus_one, pnode->low))
5990 /* Search the parent sections of the
5991 case node tree to see if both tests for the upper and lower
5992 bounds of NODE would be redundant. */
5995 node_is_bounded (node, index_type)
5999 return (node_has_low_bound (node, index_type)
6000 && node_has_high_bound (node, index_type));
6003 /* Emit an unconditional jump to LABEL unless it would be dead code. */
6006 emit_jump_if_reachable (label)
6009 if (GET_CODE (get_last_insn ()) != BARRIER)
6013 /* Emit step-by-step code to select a case for the value of INDEX.
6014 The thus generated decision tree follows the form of the
6015 case-node binary tree NODE, whose nodes represent test conditions.
6016 INDEX_TYPE is the type of the index of the switch.
6018 Care is taken to prune redundant tests from the decision tree
6019 by detecting any boundary conditions already checked by
6020 emitted rtx. (See node_has_high_bound, node_has_low_bound
6021 and node_is_bounded, above.)
6023 Where the test conditions can be shown to be redundant we emit
6024 an unconditional jump to the target code. As a further
6025 optimization, the subordinates of a tree node are examined to
6026 check for bounded nodes. In this case conditional and/or
6027 unconditional jumps as a result of the boundary check for the
6028 current node are arranged to target the subordinates associated
6029 code for out of bound conditions on the current node.
6031 We can assume that when control reaches the code generated here,
6032 the index value has already been compared with the parents
6033 of this node, and determined to be on the same side of each parent
6034 as this node is. Thus, if this node tests for the value 51,
6035 and a parent tested for 52, we don't need to consider
6036 the possibility of a value greater than 51. If another parent
6037 tests for the value 50, then this node need not test anything. */
6040 emit_case_nodes (index, node, default_label, index_type)
6046 /* If INDEX has an unsigned type, we must make unsigned branches. */
6047 int unsignedp = TREE_UNSIGNED (index_type);
6048 typedef rtx rtx_fn ();
6049 enum machine_mode mode = GET_MODE (index);
6051 /* See if our parents have already tested everything for us.
6052 If they have, emit an unconditional jump for this node. */
6053 if (node_is_bounded (node, index_type))
6054 emit_jump (label_rtx (node->code_label));
6056 else if (tree_int_cst_equal (node->low, node->high))
6058 /* Node is single valued. First see if the index expression matches
6059 this node and then check our children, if any. */
6061 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
6062 label_rtx (node->code_label), unsignedp);
6064 if (node->right != 0 && node->left != 0)
6066 /* This node has children on both sides.
6067 Dispatch to one side or the other
6068 by comparing the index value with this node's value.
6069 If one subtree is bounded, check that one first,
6070 so we can avoid real branches in the tree. */
6072 if (node_is_bounded (node->right, index_type))
6074 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6076 GT, NULL_RTX, mode, unsignedp, 0,
6077 label_rtx (node->right->code_label));
6078 emit_case_nodes (index, node->left, default_label, index_type);
6081 else if (node_is_bounded (node->left, index_type))
6083 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6085 LT, NULL_RTX, mode, unsignedp, 0,
6086 label_rtx (node->left->code_label));
6087 emit_case_nodes (index, node->right, default_label, index_type);
6092 /* Neither node is bounded. First distinguish the two sides;
6093 then emit the code for one side at a time. */
6096 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6098 /* See if the value is on the right. */
6099 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6101 GT, NULL_RTX, mode, unsignedp, 0,
6102 label_rtx (test_label));
6104 /* Value must be on the left.
6105 Handle the left-hand subtree. */
6106 emit_case_nodes (index, node->left, default_label, index_type);
6107 /* If left-hand subtree does nothing,
6109 emit_jump_if_reachable (default_label);
6111 /* Code branches here for the right-hand subtree. */
6112 expand_label (test_label);
6113 emit_case_nodes (index, node->right, default_label, index_type);
6117 else if (node->right != 0 && node->left == 0)
6119 /* Here we have a right child but no left so we issue conditional
6120 branch to default and process the right child.
6122 Omit the conditional branch to default if we it avoid only one
6123 right child; it costs too much space to save so little time. */
6125 if (node->right->right || node->right->left
6126 || !tree_int_cst_equal (node->right->low, node->right->high))
6128 if (!node_has_low_bound (node, index_type))
6130 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6133 LT, NULL_RTX, mode, unsignedp, 0,
6137 emit_case_nodes (index, node->right, default_label, index_type);
6140 /* We cannot process node->right normally
6141 since we haven't ruled out the numbers less than
6142 this node's value. So handle node->right explicitly. */
6143 do_jump_if_equal (index,
6144 expand_expr (node->right->low, NULL_RTX,
6146 label_rtx (node->right->code_label), unsignedp);
6149 else if (node->right == 0 && node->left != 0)
6151 /* Just one subtree, on the left. */
6153 #if 0 /* The following code and comment were formerly part
6154 of the condition here, but they didn't work
6155 and I don't understand what the idea was. -- rms. */
6156 /* If our "most probable entry" is less probable
6157 than the default label, emit a jump to
6158 the default label using condition codes
6159 already lying around. With no right branch,
6160 a branch-greater-than will get us to the default
6163 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
6166 if (node->left->left || node->left->right
6167 || !tree_int_cst_equal (node->left->low, node->left->high))
6169 if (!node_has_high_bound (node, index_type))
6171 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6174 GT, NULL_RTX, mode, unsignedp, 0,
6178 emit_case_nodes (index, node->left, default_label, index_type);
6181 /* We cannot process node->left normally
6182 since we haven't ruled out the numbers less than
6183 this node's value. So handle node->left explicitly. */
6184 do_jump_if_equal (index,
6185 expand_expr (node->left->low, NULL_RTX,
6187 label_rtx (node->left->code_label), unsignedp);
6192 /* Node is a range. These cases are very similar to those for a single
6193 value, except that we do not start by testing whether this node
6194 is the one to branch to. */
6196 if (node->right != 0 && node->left != 0)
6198 /* Node has subtrees on both sides.
6199 If the right-hand subtree is bounded,
6200 test for it first, since we can go straight there.
6201 Otherwise, we need to make a branch in the control structure,
6202 then handle the two subtrees. */
6203 tree test_label = 0;
6206 if (node_is_bounded (node->right, index_type))
6207 /* Right hand node is fully bounded so we can eliminate any
6208 testing and branch directly to the target code. */
6209 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6211 GT, NULL_RTX, mode, unsignedp, 0,
6212 label_rtx (node->right->code_label));
6215 /* Right hand node requires testing.
6216 Branch to a label where we will handle it later. */
6218 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6219 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6221 GT, NULL_RTX, mode, unsignedp, 0,
6222 label_rtx (test_label));
6225 /* Value belongs to this node or to the left-hand subtree. */
6227 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6229 GE, NULL_RTX, mode, unsignedp, 0,
6230 label_rtx (node->code_label));
6232 /* Handle the left-hand subtree. */
6233 emit_case_nodes (index, node->left, default_label, index_type);
6235 /* If right node had to be handled later, do that now. */
6239 /* If the left-hand subtree fell through,
6240 don't let it fall into the right-hand subtree. */
6241 emit_jump_if_reachable (default_label);
6243 expand_label (test_label);
6244 emit_case_nodes (index, node->right, default_label, index_type);
6248 else if (node->right != 0 && node->left == 0)
6250 /* Deal with values to the left of this node,
6251 if they are possible. */
6252 if (!node_has_low_bound (node, index_type))
6254 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6256 LT, NULL_RTX, mode, unsignedp, 0,
6260 /* Value belongs to this node or to the right-hand subtree. */
6262 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6264 LE, NULL_RTX, mode, unsignedp, 0,
6265 label_rtx (node->code_label));
6267 emit_case_nodes (index, node->right, default_label, index_type);
6270 else if (node->right == 0 && node->left != 0)
6272 /* Deal with values to the right of this node,
6273 if they are possible. */
6274 if (!node_has_high_bound (node, index_type))
6276 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6278 GT, NULL_RTX, mode, unsignedp, 0,
6282 /* Value belongs to this node or to the left-hand subtree. */
6284 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6286 GE, NULL_RTX, mode, unsignedp, 0,
6287 label_rtx (node->code_label));
6289 emit_case_nodes (index, node->left, default_label, index_type);
6294 /* Node has no children so we check low and high bounds to remove
6295 redundant tests. Only one of the bounds can exist,
6296 since otherwise this node is bounded--a case tested already. */
6298 if (!node_has_high_bound (node, index_type))
6300 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6302 GT, NULL_RTX, mode, unsignedp, 0,
6306 if (!node_has_low_bound (node, index_type))
6308 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6310 LT, NULL_RTX, mode, unsignedp, 0,
6314 emit_jump (label_rtx (node->code_label));
6319 /* These routines are used by the loop unrolling code. They copy BLOCK trees
6320 so that the debugging info will be correct for the unrolled loop. */
6323 find_loop_tree_blocks ()
6325 identify_blocks (DECL_INITIAL (current_function_decl), get_insns ());
6329 unroll_block_trees ()
6331 tree block = DECL_INITIAL (current_function_decl);
6333 reorder_blocks (block, get_insns ());