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 ();
1022 start = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
1023 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_DELETED);
1024 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
1025 fixup->context = poplevel (1, 0, 0); /* Create the BLOCK node now! */
1027 emit_insns_after (start, original_before_jump);
1030 fixup->block_start_count = current_block_start_count;
1031 fixup->stack_level = 0;
1032 fixup->cleanup_list_list
1033 = ((block->data.block.outer_cleanups
1034 || block->data.block.cleanups)
1035 ? tree_cons (NULL_TREE, block->data.block.cleanups,
1036 block->data.block.outer_cleanups)
1038 fixup->next = goto_fixup_chain;
1039 goto_fixup_chain = fixup;
1047 /* Expand any needed fixups in the outputmost binding level of the
1048 function. FIRST_INSN is the first insn in the function. */
1051 expand_fixups (first_insn)
1054 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0);
1057 /* When exiting a binding contour, process all pending gotos requiring fixups.
1058 THISBLOCK is the structure that describes the block being exited.
1059 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1060 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1061 FIRST_INSN is the insn that began this contour.
1063 Gotos that jump out of this contour must restore the
1064 stack level and do the cleanups before actually jumping.
1066 DONT_JUMP_IN nonzero means report error there is a jump into this
1067 contour from before the beginning of the contour.
1068 This is also done if STACK_LEVEL is nonzero. */
1071 fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1072 struct nesting *thisblock;
1078 register struct goto_fixup *f, *prev;
1080 /* F is the fixup we are considering; PREV is the previous one. */
1081 /* We run this loop in two passes so that cleanups of exited blocks
1082 are run first, and blocks that are exited are marked so
1085 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1087 /* Test for a fixup that is inactive because it is already handled. */
1088 if (f->before_jump == 0)
1090 /* Delete inactive fixup from the chain, if that is easy to do. */
1092 prev->next = f->next;
1094 /* Has this fixup's target label been defined?
1095 If so, we can finalize it. */
1096 else if (PREV_INSN (f->target_rtl) != 0)
1098 register rtx cleanup_insns;
1100 /* Get the first non-label after the label
1101 this goto jumps to. If that's before this scope begins,
1102 we don't have a jump into the scope. */
1103 rtx after_label = f->target_rtl;
1104 while (after_label != 0 && GET_CODE (after_label) == CODE_LABEL)
1105 after_label = NEXT_INSN (after_label);
1107 /* If this fixup jumped into this contour from before the beginning
1108 of this contour, report an error. */
1109 /* ??? Bug: this does not detect jumping in through intermediate
1110 blocks that have stack levels or cleanups.
1111 It detects only a problem with the innermost block
1112 around the label. */
1114 && (dont_jump_in || stack_level || cleanup_list)
1115 /* If AFTER_LABEL is 0, it means the jump goes to the end
1116 of the rtl, which means it jumps into this scope. */
1117 && (after_label == 0
1118 || INSN_UID (first_insn) < INSN_UID (after_label))
1119 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1120 && ! DECL_ERROR_ISSUED (f->target))
1122 error_with_decl (f->target,
1123 "label `%s' used before containing binding contour");
1124 /* Prevent multiple errors for one label. */
1125 DECL_ERROR_ISSUED (f->target) = 1;
1128 /* We will expand the cleanups into a sequence of their own and
1129 then later on we will attach this new sequence to the insn
1130 stream just ahead of the actual jump insn. */
1134 /* Temporarily restore the lexical context where we will
1135 logically be inserting the fixup code. We do this for the
1136 sake of getting the debugging information right. */
1139 set_block (f->context);
1141 /* Expand the cleanups for blocks this jump exits. */
1142 if (f->cleanup_list_list)
1145 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1146 /* Marked elements correspond to blocks that have been closed.
1147 Do their cleanups. */
1148 if (TREE_ADDRESSABLE (lists)
1149 && TREE_VALUE (lists) != 0)
1151 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1152 /* Pop any pushes done in the cleanups,
1153 in case function is about to return. */
1154 do_pending_stack_adjust ();
1158 /* Restore stack level for the biggest contour that this
1159 jump jumps out of. */
1161 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1163 /* Finish up the sequence containing the insns which implement the
1164 necessary cleanups, and then attach that whole sequence to the
1165 insn stream just ahead of the actual jump insn. Attaching it
1166 at that point insures that any cleanups which are in fact
1167 implicit C++ object destructions (which must be executed upon
1168 leaving the block) appear (to the debugger) to be taking place
1169 in an area of the generated code where the object(s) being
1170 destructed are still "in scope". */
1172 cleanup_insns = get_insns ();
1176 emit_insns_after (cleanup_insns, f->before_jump);
1183 /* For any still-undefined labels, do the cleanups for this block now.
1184 We must do this now since items in the cleanup list may go out
1185 of scope when the block ends. */
1186 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1187 if (f->before_jump != 0
1188 && PREV_INSN (f->target_rtl) == 0
1189 /* Label has still not appeared. If we are exiting a block with
1190 a stack level to restore, that started before the fixup,
1191 mark this stack level as needing restoration
1192 when the fixup is later finalized. */
1194 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1195 means the label is undefined. That's erroneous, but possible. */
1196 && (thisblock->data.block.block_start_count
1197 <= f->block_start_count))
1199 tree lists = f->cleanup_list_list;
1202 for (; lists; lists = TREE_CHAIN (lists))
1203 /* If the following elt. corresponds to our containing block
1204 then the elt. must be for this block. */
1205 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
1209 set_block (f->context);
1210 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1211 do_pending_stack_adjust ();
1212 cleanup_insns = get_insns ();
1215 if (cleanup_insns != 0)
1217 = emit_insns_after (cleanup_insns, f->before_jump);
1219 f->cleanup_list_list = TREE_CHAIN (lists);
1223 f->stack_level = stack_level;
1227 /* Return the number of times character C occurs in string S. */
1229 n_occurrences (c, s)
1239 /* Generate RTL for an asm statement (explicit assembler code).
1240 BODY is a STRING_CST node containing the assembler code text,
1241 or an ADDR_EXPR containing a STRING_CST. */
1247 if (current_function_check_memory_usage)
1249 error ("`asm' cannot be used in function where memory usage is checked");
1253 if (TREE_CODE (body) == ADDR_EXPR)
1254 body = TREE_OPERAND (body, 0);
1256 emit_insn (gen_rtx_ASM_INPUT (VOIDmode,
1257 TREE_STRING_POINTER (body)));
1261 /* Generate RTL for an asm statement with arguments.
1262 STRING is the instruction template.
1263 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1264 Each output or input has an expression in the TREE_VALUE and
1265 a constraint-string in the TREE_PURPOSE.
1266 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1267 that is clobbered by this insn.
1269 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1270 Some elements of OUTPUTS may be replaced with trees representing temporary
1271 values. The caller should copy those temporary values to the originally
1274 VOL nonzero means the insn is volatile; don't optimize it. */
1277 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1278 tree string, outputs, inputs, clobbers;
1283 rtvec argvec, constraints;
1285 int ninputs = list_length (inputs);
1286 int noutputs = list_length (outputs);
1291 /* Vector of RTX's of evaluated output operands. */
1292 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1293 int *inout_opnum = (int *) alloca (noutputs * sizeof (int));
1294 rtx *real_output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1295 enum machine_mode *inout_mode
1296 = (enum machine_mode *) alloca (noutputs * sizeof (enum machine_mode));
1297 /* The insn we have emitted. */
1300 /* An ASM with no outputs needs to be treated as volatile, for now. */
1304 if (current_function_check_memory_usage)
1306 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1310 #ifdef MD_ASM_CLOBBERS
1311 /* Sometimes we wish to automatically clobber registers across an asm.
1312 Case in point is when the i386 backend moved from cc0 to a hard reg --
1313 maintaining source-level compatability means automatically clobbering
1314 the flags register. */
1315 MD_ASM_CLOBBERS (clobbers);
1318 if (current_function_check_memory_usage)
1320 error ("`asm' cannot be used in function where memory usage is checked");
1324 /* Count the number of meaningful clobbered registers, ignoring what
1325 we would ignore later. */
1327 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1329 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1330 i = decode_reg_name (regname);
1331 if (i >= 0 || i == -4)
1334 error ("unknown register name `%s' in `asm'", regname);
1339 /* Check that the number of alternatives is constant across all
1341 if (outputs || inputs)
1343 tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
1344 int nalternatives = n_occurrences (',', TREE_STRING_POINTER (tmp));
1347 if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
1349 error ("too many alternatives in `asm'");
1356 char *constraint = TREE_STRING_POINTER (TREE_PURPOSE (tmp));
1357 if (n_occurrences (',', constraint) != nalternatives)
1359 error ("operand constraints for `asm' differ in number of alternatives");
1362 if (TREE_CHAIN (tmp))
1363 tmp = TREE_CHAIN (tmp);
1365 tmp = next, next = 0;
1369 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1371 tree val = TREE_VALUE (tail);
1372 tree type = TREE_TYPE (val);
1381 /* If there's an erroneous arg, emit no insn. */
1382 if (TREE_TYPE (val) == error_mark_node)
1385 /* Make sure constraint has `=' and does not have `+'. Also, see
1386 if it allows any register. Be liberal on the latter test, since
1387 the worst that happens if we get it wrong is we issue an error
1390 c_len = TREE_STRING_LENGTH (TREE_PURPOSE (tail)) - 1;
1391 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1393 /* Allow the `=' or `+' to not be at the beginning of the string,
1394 since it wasn't explicitly documented that way, and there is a
1395 large body of code that puts it last. Swap the character to
1396 the front, so as not to uglify any place else. */
1400 if ((p = strchr (constraint, '=')) != NULL)
1402 if ((p = strchr (constraint, '+')) != NULL)
1405 error ("output operand constraint lacks `='");
1409 if (p != constraint)
1412 bcopy (constraint, constraint+1, p-constraint);
1415 warning ("output constraint `%c' for operand %d is not at the beginning", j, i);
1418 is_inout = constraint[0] == '+';
1419 /* Replace '+' with '='. */
1420 constraint[0] = '=';
1421 /* Make sure we can specify the matching operand. */
1422 if (is_inout && i > 9)
1424 error ("output operand constraint %d contains `+'", i);
1428 for (j = 1; j < c_len; j++)
1429 switch (constraint[j])
1433 error ("operand constraint contains '+' or '=' at illegal position.");
1437 if (i + 1 == ninputs + noutputs)
1439 error ("`%%' constraint used with last operand");
1444 case '?': case '!': case '*': case '&':
1445 case 'E': case 'F': case 'G': case 'H':
1446 case 's': case 'i': case 'n':
1447 case 'I': case 'J': case 'K': case 'L': case 'M':
1448 case 'N': case 'O': case 'P': case ',':
1449 #ifdef EXTRA_CONSTRAINT
1450 case 'Q': case 'R': case 'S': case 'T': case 'U':
1454 case '0': case '1': case '2': case '3': case '4':
1455 case '5': case '6': case '7': case '8': case '9':
1456 error ("matching constraint not valid in output operand");
1459 case 'V': case 'm': case 'o':
1464 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1465 excepting those that expand_call created. So match memory
1481 /* If an output operand is not a decl or indirect ref and our constraint
1482 allows a register, make a temporary to act as an intermediate.
1483 Make the asm insn write into that, then our caller will copy it to
1484 the real output operand. Likewise for promoted variables. */
1486 real_output_rtx[i] = NULL_RTX;
1487 if ((TREE_CODE (val) == INDIRECT_REF
1489 || (TREE_CODE_CLASS (TREE_CODE (val)) == 'd'
1490 && (allows_mem || GET_CODE (DECL_RTL (val)) == REG)
1491 && ! (GET_CODE (DECL_RTL (val)) == REG
1492 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
1497 mark_addressable (TREE_VALUE (tail));
1500 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode,
1501 EXPAND_MEMORY_USE_WO);
1503 if (! allows_reg && GET_CODE (output_rtx[i]) != MEM)
1504 error ("output number %d not directly addressable", i);
1505 if (! allows_mem && GET_CODE (output_rtx[i]) == MEM)
1507 real_output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1508 output_rtx[i] = gen_reg_rtx (GET_MODE (output_rtx[i]));
1510 emit_move_insn (output_rtx[i], real_output_rtx[i]);
1515 output_rtx[i] = assign_temp (type, 0, 0, 0);
1516 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1521 inout_mode[ninout] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)));
1522 inout_opnum[ninout++] = i;
1527 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1529 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1533 /* Make vectors for the expression-rtx and constraint strings. */
1535 argvec = rtvec_alloc (ninputs);
1536 constraints = rtvec_alloc (ninputs);
1538 body = gen_rtx_ASM_OPERANDS (VOIDmode,
1539 TREE_STRING_POINTER (string), "", 0, argvec,
1540 constraints, filename, line);
1542 MEM_VOLATILE_P (body) = vol;
1544 /* Eval the inputs and put them into ARGVEC.
1545 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1548 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1551 int allows_reg = 0, allows_mem = 0;
1552 char *constraint, *orig_constraint;
1556 /* If there's an erroneous arg, emit no insn,
1557 because the ASM_INPUT would get VOIDmode
1558 and that could cause a crash in reload. */
1559 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1562 /* ??? Can this happen, and does the error message make any sense? */
1563 if (TREE_PURPOSE (tail) == NULL_TREE)
1565 error ("hard register `%s' listed as input operand to `asm'",
1566 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1570 c_len = TREE_STRING_LENGTH (TREE_PURPOSE (tail)) - 1;
1571 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1572 orig_constraint = constraint;
1574 /* Make sure constraint has neither `=', `+', nor '&'. */
1576 for (j = 0; j < c_len; j++)
1577 switch (constraint[j])
1579 case '+': case '=': case '&':
1580 if (constraint == orig_constraint)
1582 error ("input operand constraint contains `%c'", constraint[j]);
1588 if (constraint == orig_constraint
1589 && i + 1 == ninputs - ninout)
1591 error ("`%%' constraint used with last operand");
1596 case 'V': case 'm': case 'o':
1601 case '?': case '!': case '*':
1602 case 'E': case 'F': case 'G': case 'H': case 'X':
1603 case 's': case 'i': case 'n':
1604 case 'I': case 'J': case 'K': case 'L': case 'M':
1605 case 'N': case 'O': case 'P': case ',':
1606 #ifdef EXTRA_CONSTRAINT
1607 case 'Q': case 'R': case 'S': case 'T': case 'U':
1611 /* Whether or not a numeric constraint allows a register is
1612 decided by the matching constraint, and so there is no need
1613 to do anything special with them. We must handle them in
1614 the default case, so that we don't unnecessarily force
1615 operands to memory. */
1616 case '0': case '1': case '2': case '3': case '4':
1617 case '5': case '6': case '7': case '8': case '9':
1618 if (constraint[j] >= '0' + noutputs)
1621 ("matching constraint references invalid operand number");
1625 /* Try and find the real constraint for this dup. */
1626 if ((j == 0 && c_len == 1)
1627 || (j == 1 && c_len == 2 && constraint[0] == '%'))
1630 for (j = constraint[j] - '0'; j > 0; --j)
1633 c_len = TREE_STRING_LENGTH (TREE_PURPOSE (o)) - 1;
1634 constraint = TREE_STRING_POINTER (TREE_PURPOSE (o));
1639 /* ... fall through ... */
1652 if (! allows_reg && allows_mem)
1653 mark_addressable (TREE_VALUE (tail));
1655 op = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1657 if (asm_operand_ok (op, constraint) <= 0)
1660 op = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), op);
1661 else if (!allows_mem)
1662 warning ("asm operand %d probably doesn't match constraints", i);
1663 else if (CONSTANT_P (op))
1664 op = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1666 else if (GET_CODE (op) == REG
1667 || GET_CODE (op) == SUBREG
1668 || GET_CODE (op) == CONCAT)
1670 tree type = TREE_TYPE (TREE_VALUE (tail));
1671 rtx memloc = assign_temp (type, 1, 1, 1);
1673 emit_move_insn (memloc, op);
1676 else if (GET_CODE (op) == MEM && MEM_VOLATILE_P (op))
1677 /* We won't recognize volatile memory as available a
1678 memory_operand at this point. Ignore it. */
1680 else if (queued_subexp_p (op))
1683 /* ??? Leave this only until we have experience with what
1684 happens in combine and elsewhere when constraints are
1686 warning ("asm operand %d probably doesn't match constraints", i);
1688 XVECEXP (body, 3, i) = op;
1690 XVECEXP (body, 4, i) /* constraints */
1691 = gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1696 /* Protect all the operands from the queue,
1697 now that they have all been evaluated. */
1699 for (i = 0; i < ninputs - ninout; i++)
1700 XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0);
1702 for (i = 0; i < noutputs; i++)
1703 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1705 /* For in-out operands, copy output rtx to input rtx. */
1706 for (i = 0; i < ninout; i++)
1708 static char match[9+1][2]
1709 = {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9"};
1710 int j = inout_opnum[i];
1712 XVECEXP (body, 3, ninputs - ninout + i) /* argvec */
1714 XVECEXP (body, 4, ninputs - ninout + i) /* constraints */
1715 = gen_rtx_ASM_INPUT (inout_mode[i], match[j]);
1718 /* Now, for each output, construct an rtx
1719 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1720 ARGVEC CONSTRAINTS))
1721 If there is more than one, put them inside a PARALLEL. */
1723 if (noutputs == 1 && nclobbers == 0)
1725 XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1726 insn = emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
1728 else if (noutputs == 0 && nclobbers == 0)
1730 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1731 insn = emit_insn (body);
1737 if (num == 0) num = 1;
1738 body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
1740 /* For each output operand, store a SET. */
1742 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1744 XVECEXP (body, 0, i)
1745 = gen_rtx_SET (VOIDmode,
1747 gen_rtx_ASM_OPERANDS
1749 TREE_STRING_POINTER (string),
1750 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1751 i, argvec, constraints,
1754 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1757 /* If there are no outputs (but there are some clobbers)
1758 store the bare ASM_OPERANDS into the PARALLEL. */
1761 XVECEXP (body, 0, i++) = obody;
1763 /* Store (clobber REG) for each clobbered register specified. */
1765 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1767 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1768 int j = decode_reg_name (regname);
1772 if (j == -3) /* `cc', which is not a register */
1775 if (j == -4) /* `memory', don't cache memory across asm */
1777 XVECEXP (body, 0, i++)
1778 = gen_rtx_CLOBBER (VOIDmode,
1781 gen_rtx_SCRATCH (VOIDmode)));
1785 /* Ignore unknown register, error already signaled. */
1789 /* Use QImode since that's guaranteed to clobber just one reg. */
1790 XVECEXP (body, 0, i++)
1791 = gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (QImode, j));
1794 insn = emit_insn (body);
1797 /* For any outputs that needed reloading into registers, spill them
1798 back to where they belong. */
1799 for (i = 0; i < noutputs; ++i)
1800 if (real_output_rtx[i])
1801 emit_move_insn (real_output_rtx[i], output_rtx[i]);
1806 /* Generate RTL to evaluate the expression EXP
1807 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1810 expand_expr_stmt (exp)
1813 /* If -W, warn about statements with no side effects,
1814 except for an explicit cast to void (e.g. for assert()), and
1815 except inside a ({...}) where they may be useful. */
1816 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1818 if (! TREE_SIDE_EFFECTS (exp) && (extra_warnings || warn_unused)
1819 && !(TREE_CODE (exp) == CONVERT_EXPR
1820 && TREE_TYPE (exp) == void_type_node))
1821 warning_with_file_and_line (emit_filename, emit_lineno,
1822 "statement with no effect");
1823 else if (warn_unused)
1824 warn_if_unused_value (exp);
1827 /* If EXP is of function type and we are expanding statements for
1828 value, convert it to pointer-to-function. */
1829 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1830 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1832 last_expr_type = TREE_TYPE (exp);
1833 last_expr_value = expand_expr (exp,
1834 (expr_stmts_for_value
1835 ? NULL_RTX : const0_rtx),
1838 /* If all we do is reference a volatile value in memory,
1839 copy it to a register to be sure it is actually touched. */
1840 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1841 && TREE_THIS_VOLATILE (exp))
1843 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1845 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1846 copy_to_reg (last_expr_value);
1849 rtx lab = gen_label_rtx ();
1851 /* Compare the value with itself to reference it. */
1852 emit_cmp_and_jump_insns (last_expr_value, last_expr_value, EQ,
1853 expand_expr (TYPE_SIZE (last_expr_type),
1854 NULL_RTX, VOIDmode, 0),
1856 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT,
1862 /* If this expression is part of a ({...}) and is in memory, we may have
1863 to preserve temporaries. */
1864 preserve_temp_slots (last_expr_value);
1866 /* Free any temporaries used to evaluate this expression. Any temporary
1867 used as a result of this expression will already have been preserved
1874 /* Warn if EXP contains any computations whose results are not used.
1875 Return 1 if a warning is printed; 0 otherwise. */
1878 warn_if_unused_value (exp)
1881 if (TREE_USED (exp))
1884 switch (TREE_CODE (exp))
1886 case PREINCREMENT_EXPR:
1887 case POSTINCREMENT_EXPR:
1888 case PREDECREMENT_EXPR:
1889 case POSTDECREMENT_EXPR:
1894 case METHOD_CALL_EXPR:
1896 case TRY_CATCH_EXPR:
1897 case WITH_CLEANUP_EXPR:
1899 /* We don't warn about COND_EXPR because it may be a useful
1900 construct if either arm contains a side effect. */
1905 /* For a binding, warn if no side effect within it. */
1906 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1909 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1911 case TRUTH_ORIF_EXPR:
1912 case TRUTH_ANDIF_EXPR:
1913 /* In && or ||, warn if 2nd operand has no side effect. */
1914 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1917 if (TREE_NO_UNUSED_WARNING (exp))
1919 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
1921 /* Let people do `(foo (), 0)' without a warning. */
1922 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1924 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1928 case NON_LVALUE_EXPR:
1929 /* Don't warn about values cast to void. */
1930 if (TREE_TYPE (exp) == void_type_node)
1932 /* Don't warn about conversions not explicit in the user's program. */
1933 if (TREE_NO_UNUSED_WARNING (exp))
1935 /* Assignment to a cast usually results in a cast of a modify.
1936 Don't complain about that. There can be an arbitrary number of
1937 casts before the modify, so we must loop until we find the first
1938 non-cast expression and then test to see if that is a modify. */
1940 tree tem = TREE_OPERAND (exp, 0);
1942 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1943 tem = TREE_OPERAND (tem, 0);
1945 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
1946 || TREE_CODE (tem) == CALL_EXPR)
1952 /* Don't warn about automatic dereferencing of references, since
1953 the user cannot control it. */
1954 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
1955 return warn_if_unused_value (TREE_OPERAND (exp, 0));
1956 /* ... fall through ... */
1959 /* Referencing a volatile value is a side effect, so don't warn. */
1960 if ((TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
1961 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
1962 && TREE_THIS_VOLATILE (exp))
1965 warning_with_file_and_line (emit_filename, emit_lineno,
1966 "value computed is not used");
1971 /* Clear out the memory of the last expression evaluated. */
1979 /* Begin a statement which will return a value.
1980 Return the RTL_EXPR for this statement expr.
1981 The caller must save that value and pass it to expand_end_stmt_expr. */
1984 expand_start_stmt_expr ()
1989 /* Make the RTL_EXPR node temporary, not momentary,
1990 so that rtl_expr_chain doesn't become garbage. */
1991 momentary = suspend_momentary ();
1992 t = make_node (RTL_EXPR);
1993 resume_momentary (momentary);
1994 do_pending_stack_adjust ();
1995 start_sequence_for_rtl_expr (t);
1997 expr_stmts_for_value++;
2001 /* Restore the previous state at the end of a statement that returns a value.
2002 Returns a tree node representing the statement's value and the
2003 insns to compute the value.
2005 The nodes of that expression have been freed by now, so we cannot use them.
2006 But we don't want to do that anyway; the expression has already been
2007 evaluated and now we just want to use the value. So generate a RTL_EXPR
2008 with the proper type and RTL value.
2010 If the last substatement was not an expression,
2011 return something with type `void'. */
2014 expand_end_stmt_expr (t)
2019 if (last_expr_type == 0)
2021 last_expr_type = void_type_node;
2022 last_expr_value = const0_rtx;
2024 else if (last_expr_value == 0)
2025 /* There are some cases where this can happen, such as when the
2026 statement is void type. */
2027 last_expr_value = const0_rtx;
2028 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
2029 /* Remove any possible QUEUED. */
2030 last_expr_value = protect_from_queue (last_expr_value, 0);
2034 TREE_TYPE (t) = last_expr_type;
2035 RTL_EXPR_RTL (t) = last_expr_value;
2036 RTL_EXPR_SEQUENCE (t) = get_insns ();
2038 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
2042 /* Don't consider deleting this expr or containing exprs at tree level. */
2043 TREE_SIDE_EFFECTS (t) = 1;
2044 /* Propagate volatility of the actual RTL expr. */
2045 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
2048 expr_stmts_for_value--;
2053 /* Generate RTL for the start of an if-then. COND is the expression
2054 whose truth should be tested.
2056 If EXITFLAG is nonzero, this conditional is visible to
2057 `exit_something'. */
2060 expand_start_cond (cond, exitflag)
2064 struct nesting *thiscond = ALLOC_NESTING ();
2066 /* Make an entry on cond_stack for the cond we are entering. */
2068 thiscond->next = cond_stack;
2069 thiscond->all = nesting_stack;
2070 thiscond->depth = ++nesting_depth;
2071 thiscond->data.cond.next_label = gen_label_rtx ();
2072 /* Before we encounter an `else', we don't need a separate exit label
2073 unless there are supposed to be exit statements
2074 to exit this conditional. */
2075 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
2076 thiscond->data.cond.endif_label = thiscond->exit_label;
2077 cond_stack = thiscond;
2078 nesting_stack = thiscond;
2080 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
2083 /* Generate RTL between then-clause and the elseif-clause
2084 of an if-then-elseif-.... */
2087 expand_start_elseif (cond)
2090 if (cond_stack->data.cond.endif_label == 0)
2091 cond_stack->data.cond.endif_label = gen_label_rtx ();
2092 emit_jump (cond_stack->data.cond.endif_label);
2093 emit_label (cond_stack->data.cond.next_label);
2094 cond_stack->data.cond.next_label = gen_label_rtx ();
2095 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2098 /* Generate RTL between the then-clause and the else-clause
2099 of an if-then-else. */
2102 expand_start_else ()
2104 if (cond_stack->data.cond.endif_label == 0)
2105 cond_stack->data.cond.endif_label = gen_label_rtx ();
2107 emit_jump (cond_stack->data.cond.endif_label);
2108 emit_label (cond_stack->data.cond.next_label);
2109 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
2112 /* After calling expand_start_else, turn this "else" into an "else if"
2113 by providing another condition. */
2116 expand_elseif (cond)
2119 cond_stack->data.cond.next_label = gen_label_rtx ();
2120 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2123 /* Generate RTL for the end of an if-then.
2124 Pop the record for it off of cond_stack. */
2129 struct nesting *thiscond = cond_stack;
2131 do_pending_stack_adjust ();
2132 if (thiscond->data.cond.next_label)
2133 emit_label (thiscond->data.cond.next_label);
2134 if (thiscond->data.cond.endif_label)
2135 emit_label (thiscond->data.cond.endif_label);
2137 POPSTACK (cond_stack);
2143 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2144 loop should be exited by `exit_something'. This is a loop for which
2145 `expand_continue' will jump to the top of the loop.
2147 Make an entry on loop_stack to record the labels associated with
2151 expand_start_loop (exit_flag)
2154 register struct nesting *thisloop = ALLOC_NESTING ();
2156 /* Make an entry on loop_stack for the loop we are entering. */
2158 thisloop->next = loop_stack;
2159 thisloop->all = nesting_stack;
2160 thisloop->depth = ++nesting_depth;
2161 thisloop->data.loop.start_label = gen_label_rtx ();
2162 thisloop->data.loop.end_label = gen_label_rtx ();
2163 thisloop->data.loop.alt_end_label = 0;
2164 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2165 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2166 loop_stack = thisloop;
2167 nesting_stack = thisloop;
2169 do_pending_stack_adjust ();
2171 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2172 emit_label (thisloop->data.loop.start_label);
2177 /* Like expand_start_loop but for a loop where the continuation point
2178 (for expand_continue_loop) will be specified explicitly. */
2181 expand_start_loop_continue_elsewhere (exit_flag)
2184 struct nesting *thisloop = expand_start_loop (exit_flag);
2185 loop_stack->data.loop.continue_label = gen_label_rtx ();
2189 /* Specify the continuation point for a loop started with
2190 expand_start_loop_continue_elsewhere.
2191 Use this at the point in the code to which a continue statement
2195 expand_loop_continue_here ()
2197 do_pending_stack_adjust ();
2198 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2199 emit_label (loop_stack->data.loop.continue_label);
2202 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2203 Pop the block off of loop_stack. */
2208 rtx start_label = loop_stack->data.loop.start_label;
2209 rtx insn = get_last_insn ();
2210 int needs_end_jump = 1;
2212 /* Mark the continue-point at the top of the loop if none elsewhere. */
2213 if (start_label == loop_stack->data.loop.continue_label)
2214 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2216 do_pending_stack_adjust ();
2218 /* If optimizing, perhaps reorder the loop.
2219 First, try to use a condjump near the end.
2220 expand_exit_loop_if_false ends loops with unconditional jumps,
2223 if (test) goto label;
2225 goto loop_stack->data.loop.end_label
2229 If we find such a pattern, we can end the loop earlier. */
2232 && GET_CODE (insn) == CODE_LABEL
2233 && LABEL_NAME (insn) == NULL
2234 && GET_CODE (PREV_INSN (insn)) == BARRIER)
2237 rtx jump = PREV_INSN (PREV_INSN (label));
2239 if (GET_CODE (jump) == JUMP_INSN
2240 && GET_CODE (PATTERN (jump)) == SET
2241 && SET_DEST (PATTERN (jump)) == pc_rtx
2242 && GET_CODE (SET_SRC (PATTERN (jump))) == LABEL_REF
2243 && (XEXP (SET_SRC (PATTERN (jump)), 0)
2244 == loop_stack->data.loop.end_label))
2248 /* The test might be complex and reference LABEL multiple times,
2249 like the loop in loop_iterations to set vtop. To handle this,
2251 insn = PREV_INSN (label);
2252 reorder_insns (label, label, start_label);
2254 for (prev = PREV_INSN (jump); ; prev = PREV_INSN (prev))
2256 /* We ignore line number notes, but if we see any other note,
2257 in particular NOTE_INSN_BLOCK_*, NOTE_INSN_EH_REGION_*,
2258 NOTE_INSN_LOOP_*, we disable this optimization. */
2259 if (GET_CODE (prev) == NOTE)
2261 if (NOTE_LINE_NUMBER (prev) < 0)
2265 if (GET_CODE (prev) == CODE_LABEL)
2267 if (GET_CODE (prev) == JUMP_INSN)
2269 if (GET_CODE (PATTERN (prev)) == SET
2270 && SET_DEST (PATTERN (prev)) == pc_rtx
2271 && GET_CODE (SET_SRC (PATTERN (prev))) == IF_THEN_ELSE
2272 && (GET_CODE (XEXP (SET_SRC (PATTERN (prev)), 1))
2274 && XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0) == label)
2276 XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0)
2278 emit_note_after (NOTE_INSN_LOOP_END, prev);
2287 /* If the loop starts with a loop exit, roll that to the end where
2288 it will optimize together with the jump back.
2290 We look for the conditional branch to the exit, except that once
2291 we find such a branch, we don't look past 30 instructions.
2293 In more detail, if the loop presently looks like this (in pseudo-C):
2296 if (test) goto end_label;
2301 transform it to look like:
2307 if (test) goto end_label;
2308 goto newstart_label;
2311 Here, the `test' may actually consist of some reasonably complex
2312 code, terminating in a test. */
2317 ! (GET_CODE (insn) == JUMP_INSN
2318 && GET_CODE (PATTERN (insn)) == SET
2319 && SET_DEST (PATTERN (insn)) == pc_rtx
2320 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2324 rtx last_test_insn = NULL_RTX;
2326 /* Scan insns from the top of the loop looking for a qualified
2327 conditional exit. */
2328 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2329 insn = NEXT_INSN (insn))
2331 if (GET_CODE (insn) == NOTE)
2334 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2335 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2336 /* The code that actually moves the exit test will
2337 carefully leave BLOCK notes in their original
2338 location. That means, however, that we can't debug
2339 the exit test itself. So, we refuse to move code
2340 containing BLOCK notes at low optimization levels. */
2343 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG)
2345 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)
2349 /* We've come to the end of an EH region, but
2350 never saw the beginning of that region. That
2351 means that an EH region begins before the top
2352 of the loop, and ends in the middle of it. The
2353 existence of such a situation violates a basic
2354 assumption in this code, since that would imply
2355 that even when EH_REGIONS is zero, we might
2356 move code out of an exception region. */
2360 /* We must not walk into a nested loop. */
2361 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
2364 /* We already know this INSN is a NOTE, so there's no
2365 point in looking at it to see if it's a JUMP. */
2369 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2372 if (last_test_insn && num_insns > 30)
2376 /* We don't want to move a partial EH region. Consider:
2390 This isn't legal C++, but here's what it's supposed to
2391 mean: if cond() is true, stop looping. Otherwise,
2392 call bar, and keep looping. In addition, if cond
2393 throws an exception, catch it and keep looping. Such
2394 constructs are certainy legal in LISP.
2396 We should not move the `if (cond()) 0' test since then
2397 the EH-region for the try-block would be broken up.
2398 (In this case we would the EH_BEG note for the `try'
2399 and `if cond()' but not the call to bar() or the
2402 So we don't look for tests within an EH region. */
2405 if (GET_CODE (insn) == JUMP_INSN
2406 && GET_CODE (PATTERN (insn)) == SET
2407 && SET_DEST (PATTERN (insn)) == pc_rtx)
2409 /* This is indeed a jump. */
2410 rtx dest1 = NULL_RTX;
2411 rtx dest2 = NULL_RTX;
2412 rtx potential_last_test;
2413 if (GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE)
2415 /* A conditional jump. */
2416 dest1 = XEXP (SET_SRC (PATTERN (insn)), 1);
2417 dest2 = XEXP (SET_SRC (PATTERN (insn)), 2);
2418 potential_last_test = insn;
2422 /* An unconditional jump. */
2423 dest1 = SET_SRC (PATTERN (insn));
2424 /* Include the BARRIER after the JUMP. */
2425 potential_last_test = NEXT_INSN (insn);
2429 if (dest1 && GET_CODE (dest1) == LABEL_REF
2430 && ((XEXP (dest1, 0)
2431 == loop_stack->data.loop.alt_end_label)
2433 == loop_stack->data.loop.end_label)))
2435 last_test_insn = potential_last_test;
2439 /* If this was a conditional jump, there may be
2440 another label at which we should look. */
2447 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2449 /* We found one. Move everything from there up
2450 to the end of the loop, and add a jump into the loop
2451 to jump to there. */
2452 register rtx newstart_label = gen_label_rtx ();
2453 register rtx start_move = start_label;
2456 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2457 then we want to move this note also. */
2458 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2459 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2460 == NOTE_INSN_LOOP_CONT))
2461 start_move = PREV_INSN (start_move);
2463 emit_label_after (newstart_label, PREV_INSN (start_move));
2465 /* Actually move the insns. Start at the beginning, and
2466 keep copying insns until we've copied the
2468 for (insn = start_move; insn; insn = next_insn)
2470 /* Figure out which insn comes after this one. We have
2471 to do this before we move INSN. */
2472 if (insn == last_test_insn)
2473 /* We've moved all the insns. */
2474 next_insn = NULL_RTX;
2476 next_insn = NEXT_INSN (insn);
2478 if (GET_CODE (insn) == NOTE
2479 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2480 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2481 /* We don't want to move NOTE_INSN_BLOCK_BEGs or
2482 NOTE_INSN_BLOCK_ENDs because the correct generation
2483 of debugging information depends on these appearing
2484 in the same order in the RTL and in the tree
2485 structure, where they are represented as BLOCKs.
2486 So, we don't move block notes. Of course, moving
2487 the code inside the block is likely to make it
2488 impossible to debug the instructions in the exit
2489 test, but such is the price of optimization. */
2492 /* Move the INSN. */
2493 reorder_insns (insn, insn, get_last_insn ());
2496 emit_jump_insn_after (gen_jump (start_label),
2497 PREV_INSN (newstart_label));
2498 emit_barrier_after (PREV_INSN (newstart_label));
2499 start_label = newstart_label;
2505 emit_jump (start_label);
2506 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2508 emit_label (loop_stack->data.loop.end_label);
2510 POPSTACK (loop_stack);
2515 /* Generate a jump to the current loop's continue-point.
2516 This is usually the top of the loop, but may be specified
2517 explicitly elsewhere. If not currently inside a loop,
2518 return 0 and do nothing; caller will print an error message. */
2521 expand_continue_loop (whichloop)
2522 struct nesting *whichloop;
2526 whichloop = loop_stack;
2529 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2534 /* Generate a jump to exit the current loop. If not currently inside a loop,
2535 return 0 and do nothing; caller will print an error message. */
2538 expand_exit_loop (whichloop)
2539 struct nesting *whichloop;
2543 whichloop = loop_stack;
2546 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2550 /* Generate a conditional jump to exit the current loop if COND
2551 evaluates to zero. If not currently inside a loop,
2552 return 0 and do nothing; caller will print an error message. */
2555 expand_exit_loop_if_false (whichloop, cond)
2556 struct nesting *whichloop;
2559 rtx label = gen_label_rtx ();
2564 whichloop = loop_stack;
2567 /* In order to handle fixups, we actually create a conditional jump
2568 around a unconditional branch to exit the loop. If fixups are
2569 necessary, they go before the unconditional branch. */
2572 do_jump (cond, NULL_RTX, label);
2573 last_insn = get_last_insn ();
2574 if (GET_CODE (last_insn) == CODE_LABEL)
2575 whichloop->data.loop.alt_end_label = last_insn;
2576 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2583 /* Return nonzero if the loop nest is empty. Else return zero. */
2586 stmt_loop_nest_empty ()
2588 return (loop_stack == NULL);
2591 /* Return non-zero if we should preserve sub-expressions as separate
2592 pseudos. We never do so if we aren't optimizing. We always do so
2593 if -fexpensive-optimizations.
2595 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2596 the loop may still be a small one. */
2599 preserve_subexpressions_p ()
2603 if (flag_expensive_optimizations)
2606 if (optimize == 0 || current_function == 0
2607 || current_function->stmt == 0 || loop_stack == 0)
2610 insn = get_last_insn_anywhere ();
2613 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2614 < n_non_fixed_regs * 3));
2618 /* Generate a jump to exit the current loop, conditional, binding contour
2619 or case statement. Not all such constructs are visible to this function,
2620 only those started with EXIT_FLAG nonzero. Individual languages use
2621 the EXIT_FLAG parameter to control which kinds of constructs you can
2624 If not currently inside anything that can be exited,
2625 return 0 and do nothing; caller will print an error message. */
2628 expand_exit_something ()
2632 for (n = nesting_stack; n; n = n->all)
2633 if (n->exit_label != 0)
2635 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2642 /* Generate RTL to return from the current function, with no value.
2643 (That is, we do not do anything about returning any value.) */
2646 expand_null_return ()
2648 struct nesting *block = block_stack;
2651 /* Does any pending block have cleanups? */
2653 while (block && block->data.block.cleanups == 0)
2654 block = block->next;
2656 /* If yes, use a goto to return, since that runs cleanups. */
2658 expand_null_return_1 (last_insn, block != 0);
2661 /* Generate RTL to return from the current function, with value VAL. */
2664 expand_value_return (val)
2667 struct nesting *block = block_stack;
2668 rtx last_insn = get_last_insn ();
2669 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2671 /* Copy the value to the return location
2672 unless it's already there. */
2674 if (return_reg != val)
2676 #ifdef PROMOTE_FUNCTION_RETURN
2677 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2678 int unsignedp = TREE_UNSIGNED (type);
2679 enum machine_mode mode
2680 = promote_mode (type, DECL_MODE (DECL_RESULT (current_function_decl)),
2683 if (GET_MODE (val) != VOIDmode && GET_MODE (val) != mode)
2684 convert_move (return_reg, val, unsignedp);
2687 emit_move_insn (return_reg, val);
2689 if (GET_CODE (return_reg) == REG
2690 && REGNO (return_reg) < FIRST_PSEUDO_REGISTER)
2691 emit_insn (gen_rtx_USE (VOIDmode, return_reg));
2692 /* Handle calls that return values in multiple non-contiguous locations.
2693 The Irix 6 ABI has examples of this. */
2694 else if (GET_CODE (return_reg) == PARALLEL)
2698 for (i = 0; i < XVECLEN (return_reg, 0); i++)
2700 rtx x = XEXP (XVECEXP (return_reg, 0, i), 0);
2702 if (GET_CODE (x) == REG
2703 && REGNO (x) < FIRST_PSEUDO_REGISTER)
2704 emit_insn (gen_rtx_USE (VOIDmode, x));
2708 /* Does any pending block have cleanups? */
2710 while (block && block->data.block.cleanups == 0)
2711 block = block->next;
2713 /* If yes, use a goto to return, since that runs cleanups.
2714 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2716 expand_null_return_1 (last_insn, block != 0);
2719 /* Output a return with no value. If LAST_INSN is nonzero,
2720 pretend that the return takes place after LAST_INSN.
2721 If USE_GOTO is nonzero then don't use a return instruction;
2722 go to the return label instead. This causes any cleanups
2723 of pending blocks to be executed normally. */
2726 expand_null_return_1 (last_insn, use_goto)
2730 rtx end_label = cleanup_label ? cleanup_label : return_label;
2732 clear_pending_stack_adjust ();
2733 do_pending_stack_adjust ();
2736 /* PCC-struct return always uses an epilogue. */
2737 if (current_function_returns_pcc_struct || use_goto)
2740 end_label = return_label = gen_label_rtx ();
2741 expand_goto_internal (NULL_TREE, end_label, last_insn);
2745 /* Otherwise output a simple return-insn if one is available,
2746 unless it won't do the job. */
2748 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2750 emit_jump_insn (gen_return ());
2756 /* Otherwise jump to the epilogue. */
2757 expand_goto_internal (NULL_TREE, end_label, last_insn);
2760 /* Generate RTL to evaluate the expression RETVAL and return it
2761 from the current function. */
2764 expand_return (retval)
2767 /* If there are any cleanups to be performed, then they will
2768 be inserted following LAST_INSN. It is desirable
2769 that the last_insn, for such purposes, should be the
2770 last insn before computing the return value. Otherwise, cleanups
2771 which call functions can clobber the return value. */
2772 /* ??? rms: I think that is erroneous, because in C++ it would
2773 run destructors on variables that might be used in the subsequent
2774 computation of the return value. */
2776 register rtx val = 0;
2781 /* If function wants no value, give it none. */
2782 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2784 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2786 expand_null_return ();
2790 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2791 /* This is not sufficient. We also need to watch for cleanups of the
2792 expression we are about to expand. Unfortunately, we cannot know
2793 if it has cleanups until we expand it, and we want to change how we
2794 expand it depending upon if we need cleanups. We can't win. */
2796 cleanups = any_pending_cleanups (1);
2801 if (TREE_CODE (retval) == RESULT_DECL)
2802 retval_rhs = retval;
2803 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2804 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2805 retval_rhs = TREE_OPERAND (retval, 1);
2806 else if (TREE_TYPE (retval) == void_type_node)
2807 /* Recognize tail-recursive call to void function. */
2808 retval_rhs = retval;
2810 retval_rhs = NULL_TREE;
2812 /* Only use `last_insn' if there are cleanups which must be run. */
2813 if (cleanups || cleanup_label != 0)
2814 last_insn = get_last_insn ();
2816 /* Distribute return down conditional expr if either of the sides
2817 may involve tail recursion (see test below). This enhances the number
2818 of tail recursions we see. Don't do this always since it can produce
2819 sub-optimal code in some cases and we distribute assignments into
2820 conditional expressions when it would help. */
2822 if (optimize && retval_rhs != 0
2823 && frame_offset == 0
2824 && TREE_CODE (retval_rhs) == COND_EXPR
2825 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2826 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2828 rtx label = gen_label_rtx ();
2831 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2832 start_cleanup_deferral ();
2833 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2834 DECL_RESULT (current_function_decl),
2835 TREE_OPERAND (retval_rhs, 1));
2836 TREE_SIDE_EFFECTS (expr) = 1;
2837 expand_return (expr);
2840 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2841 DECL_RESULT (current_function_decl),
2842 TREE_OPERAND (retval_rhs, 2));
2843 TREE_SIDE_EFFECTS (expr) = 1;
2844 expand_return (expr);
2845 end_cleanup_deferral ();
2849 /* Attempt to optimize the call if it is tail recursive. */
2850 if (optimize_tail_recursion (retval_rhs, last_insn))
2854 /* This optimization is safe if there are local cleanups
2855 because expand_null_return takes care of them.
2856 ??? I think it should also be safe when there is a cleanup label,
2857 because expand_null_return takes care of them, too.
2858 Any reason why not? */
2859 if (HAVE_return && cleanup_label == 0
2860 && ! current_function_returns_pcc_struct
2861 && BRANCH_COST <= 1)
2863 /* If this is return x == y; then generate
2864 if (x == y) return 1; else return 0;
2865 if we can do it with explicit return insns and branches are cheap,
2866 but not if we have the corresponding scc insn. */
2869 switch (TREE_CODE (retval_rhs))
2895 case TRUTH_ANDIF_EXPR:
2896 case TRUTH_ORIF_EXPR:
2897 case TRUTH_AND_EXPR:
2899 case TRUTH_NOT_EXPR:
2900 case TRUTH_XOR_EXPR:
2903 op0 = gen_label_rtx ();
2904 jumpifnot (retval_rhs, op0);
2905 expand_value_return (const1_rtx);
2907 expand_value_return (const0_rtx);
2916 #endif /* HAVE_return */
2918 /* If the result is an aggregate that is being returned in one (or more)
2919 registers, load the registers here. The compiler currently can't handle
2920 copying a BLKmode value into registers. We could put this code in a
2921 more general area (for use by everyone instead of just function
2922 call/return), but until this feature is generally usable it is kept here
2923 (and in expand_call). The value must go into a pseudo in case there
2924 are cleanups that will clobber the real return register. */
2927 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2928 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2930 int i, bitpos, xbitpos;
2931 int big_endian_correction = 0;
2932 int bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2933 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2934 int bitsize = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)),
2935 (unsigned int)BITS_PER_WORD);
2936 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2937 rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
2938 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2939 enum machine_mode tmpmode, result_reg_mode;
2941 /* Structures whose size is not a multiple of a word are aligned
2942 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
2943 machine, this means we must skip the empty high order bytes when
2944 calculating the bit offset. */
2945 if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD)
2946 big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
2949 /* Copy the structure BITSIZE bits at a time. */
2950 for (bitpos = 0, xbitpos = big_endian_correction;
2951 bitpos < bytes * BITS_PER_UNIT;
2952 bitpos += bitsize, xbitpos += bitsize)
2954 /* We need a new destination pseudo each time xbitpos is
2955 on a word boundary and when xbitpos == big_endian_correction
2956 (the first time through). */
2957 if (xbitpos % BITS_PER_WORD == 0
2958 || xbitpos == big_endian_correction)
2960 /* Generate an appropriate register. */
2961 dst = gen_reg_rtx (word_mode);
2962 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
2964 /* Clobber the destination before we move anything into it. */
2965 emit_insn (gen_rtx_CLOBBER (VOIDmode, dst));
2968 /* We need a new source operand each time bitpos is on a word
2970 if (bitpos % BITS_PER_WORD == 0)
2971 src = operand_subword_force (result_val,
2972 bitpos / BITS_PER_WORD,
2975 /* Use bitpos for the source extraction (left justified) and
2976 xbitpos for the destination store (right justified). */
2977 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
2978 extract_bit_field (src, bitsize,
2979 bitpos % BITS_PER_WORD, 1,
2980 NULL_RTX, word_mode,
2982 bitsize / BITS_PER_UNIT,
2984 bitsize / BITS_PER_UNIT, BITS_PER_WORD);
2987 /* Find the smallest integer mode large enough to hold the
2988 entire structure and use that mode instead of BLKmode
2989 on the USE insn for the return register. */
2990 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2991 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
2992 tmpmode != VOIDmode;
2993 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
2995 /* Have we found a large enough mode? */
2996 if (GET_MODE_SIZE (tmpmode) >= bytes)
3000 /* No suitable mode found. */
3001 if (tmpmode == VOIDmode)
3004 PUT_MODE (DECL_RTL (DECL_RESULT (current_function_decl)), tmpmode);
3006 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
3007 result_reg_mode = word_mode;
3009 result_reg_mode = tmpmode;
3010 result_reg = gen_reg_rtx (result_reg_mode);
3013 for (i = 0; i < n_regs; i++)
3014 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
3017 if (tmpmode != result_reg_mode)
3018 result_reg = gen_lowpart (tmpmode, result_reg);
3020 expand_value_return (result_reg);
3024 && TREE_TYPE (retval_rhs) != void_type_node
3025 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
3027 /* Calculate the return value into a pseudo reg. */
3028 val = gen_reg_rtx (DECL_MODE (DECL_RESULT (current_function_decl)));
3029 val = expand_expr (retval_rhs, val, GET_MODE (val), 0);
3030 val = force_not_mem (val);
3032 /* Return the calculated value, doing cleanups first. */
3033 expand_value_return (val);
3037 /* No cleanups or no hard reg used;
3038 calculate value into hard return reg. */
3039 expand_expr (retval, const0_rtx, VOIDmode, 0);
3041 expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl)));
3045 /* Return 1 if the end of the generated RTX is not a barrier.
3046 This means code already compiled can drop through. */
3049 drop_through_at_end_p ()
3051 rtx insn = get_last_insn ();
3052 while (insn && GET_CODE (insn) == NOTE)
3053 insn = PREV_INSN (insn);
3054 return insn && GET_CODE (insn) != BARRIER;
3057 /* Test CALL_EXPR to determine if it is a potential tail recursion call
3058 and emit code to optimize the tail recursion. LAST_INSN indicates where
3059 to place the jump to the tail recursion label. Return TRUE if the
3060 call was optimized into a goto.
3062 This is only used by expand_return, but expand_call is expected to
3066 optimize_tail_recursion (call_expr, last_insn)
3070 /* For tail-recursive call to current function,
3071 just jump back to the beginning.
3072 It's unsafe if any auto variable in this function
3073 has its address taken; for simplicity,
3074 require stack frame to be empty. */
3075 if (optimize && call_expr != 0
3076 && frame_offset == 0
3077 && TREE_CODE (call_expr) == CALL_EXPR
3078 && TREE_CODE (TREE_OPERAND (call_expr, 0)) == ADDR_EXPR
3079 && TREE_OPERAND (TREE_OPERAND (call_expr, 0), 0) == current_function_decl
3080 /* Finish checking validity, and if valid emit code
3081 to set the argument variables for the new call. */
3082 && tail_recursion_args (TREE_OPERAND (call_expr, 1),
3083 DECL_ARGUMENTS (current_function_decl)))
3085 if (tail_recursion_label == 0)
3087 tail_recursion_label = gen_label_rtx ();
3088 emit_label_after (tail_recursion_label,
3089 tail_recursion_reentry);
3092 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
3100 /* Emit code to alter this function's formal parms for a tail-recursive call.
3101 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3102 FORMALS is the chain of decls of formals.
3103 Return 1 if this can be done;
3104 otherwise return 0 and do not emit any code. */
3107 tail_recursion_args (actuals, formals)
3108 tree actuals, formals;
3110 register tree a = actuals, f = formals;
3112 register rtx *argvec;
3114 /* Check that number and types of actuals are compatible
3115 with the formals. This is not always true in valid C code.
3116 Also check that no formal needs to be addressable
3117 and that all formals are scalars. */
3119 /* Also count the args. */
3121 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
3123 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a)))
3124 != TYPE_MAIN_VARIANT (TREE_TYPE (f)))
3126 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
3129 if (a != 0 || f != 0)
3132 /* Compute all the actuals. */
3134 argvec = (rtx *) alloca (i * sizeof (rtx));
3136 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3137 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
3139 /* Find which actual values refer to current values of previous formals.
3140 Copy each of them now, before any formal is changed. */
3142 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3146 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
3147 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
3148 { copy = 1; break; }
3150 argvec[i] = copy_to_reg (argvec[i]);
3153 /* Store the values of the actuals into the formals. */
3155 for (f = formals, a = actuals, i = 0; f;
3156 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
3158 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
3159 emit_move_insn (DECL_RTL (f), argvec[i]);
3161 convert_move (DECL_RTL (f), argvec[i],
3162 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
3169 /* Generate the RTL code for entering a binding contour.
3170 The variables are declared one by one, by calls to `expand_decl'.
3172 FLAGS is a bitwise or of the following flags:
3174 1 - Nonzero if this construct should be visible to
3177 2 - Nonzero if this contour does not require a
3178 NOTE_INSN_BLOCK_BEG note. Virtually all calls from
3179 language-independent code should set this flag because they
3180 will not create corresponding BLOCK nodes. (There should be
3181 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
3182 and BLOCKs.) If this flag is set, MARK_ENDS should be zero
3183 when expand_end_bindings is called. */
3186 expand_start_bindings (flags)
3189 struct nesting *thisblock = ALLOC_NESTING ();
3191 int exit_flag = ((flags & 1) != 0);
3192 int block_flag = ((flags & 2) == 0);
3194 note = emit_note (NULL_PTR,
3195 block_flag ? NOTE_INSN_BLOCK_BEG : NOTE_INSN_DELETED);
3197 /* Make an entry on block_stack for the block we are entering. */
3199 thisblock->next = block_stack;
3200 thisblock->all = nesting_stack;
3201 thisblock->depth = ++nesting_depth;
3202 thisblock->data.block.stack_level = 0;
3203 thisblock->data.block.cleanups = 0;
3204 thisblock->data.block.n_function_calls = 0;
3205 thisblock->data.block.exception_region = 0;
3206 thisblock->data.block.block_target_temp_slot_level = target_temp_slot_level;
3208 thisblock->data.block.conditional_code = 0;
3209 thisblock->data.block.last_unconditional_cleanup = note;
3210 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
3213 && !(block_stack->data.block.cleanups == NULL_TREE
3214 && block_stack->data.block.outer_cleanups == NULL_TREE))
3215 thisblock->data.block.outer_cleanups
3216 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
3217 block_stack->data.block.outer_cleanups);
3219 thisblock->data.block.outer_cleanups = 0;
3220 thisblock->data.block.label_chain = 0;
3221 thisblock->data.block.innermost_stack_block = stack_block_stack;
3222 thisblock->data.block.first_insn = note;
3223 thisblock->data.block.block_start_count = ++current_block_start_count;
3224 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
3225 block_stack = thisblock;
3226 nesting_stack = thisblock;
3228 /* Make a new level for allocating stack slots. */
3232 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3233 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3234 expand_expr are made. After we end the region, we know that all
3235 space for all temporaries that were created by TARGET_EXPRs will be
3236 destroyed and their space freed for reuse. */
3239 expand_start_target_temps ()
3241 /* This is so that even if the result is preserved, the space
3242 allocated will be freed, as we know that it is no longer in use. */
3245 /* Start a new binding layer that will keep track of all cleanup
3246 actions to be performed. */
3247 expand_start_bindings (2);
3249 target_temp_slot_level = temp_slot_level;
3253 expand_end_target_temps ()
3255 expand_end_bindings (NULL_TREE, 0, 0);
3257 /* This is so that even if the result is preserved, the space
3258 allocated will be freed, as we know that it is no longer in use. */
3262 /* Mark top block of block_stack as an implicit binding for an
3263 exception region. This is used to prevent infinite recursion when
3264 ending a binding with expand_end_bindings. It is only ever called
3265 by expand_eh_region_start, as that it the only way to create a
3266 block stack for a exception region. */
3269 mark_block_as_eh_region ()
3271 block_stack->data.block.exception_region = 1;
3272 if (block_stack->next
3273 && block_stack->next->data.block.conditional_code)
3275 block_stack->data.block.conditional_code
3276 = block_stack->next->data.block.conditional_code;
3277 block_stack->data.block.last_unconditional_cleanup
3278 = block_stack->next->data.block.last_unconditional_cleanup;
3279 block_stack->data.block.cleanup_ptr
3280 = block_stack->next->data.block.cleanup_ptr;
3284 /* True if we are currently emitting insns in an area of output code
3285 that is controlled by a conditional expression. This is used by
3286 the cleanup handling code to generate conditional cleanup actions. */
3289 conditional_context ()
3291 return block_stack && block_stack->data.block.conditional_code;
3294 /* Mark top block of block_stack as not for an implicit binding for an
3295 exception region. This is only ever done by expand_eh_region_end
3296 to let expand_end_bindings know that it is being called explicitly
3297 to end the binding layer for just the binding layer associated with
3298 the exception region, otherwise expand_end_bindings would try and
3299 end all implicit binding layers for exceptions regions, and then
3300 one normal binding layer. */
3303 mark_block_as_not_eh_region ()
3305 block_stack->data.block.exception_region = 0;
3308 /* True if the top block of block_stack was marked as for an exception
3309 region by mark_block_as_eh_region. */
3314 return (current_function && block_stack
3315 && block_stack->data.block.exception_region);
3318 /* Given a pointer to a BLOCK node, save a pointer to the most recently
3319 generated NOTE_INSN_BLOCK_END in the BLOCK_END_NOTE field of the given
3323 remember_end_note (block)
3324 register tree block;
3326 BLOCK_END_NOTE (block) = last_block_end_note;
3327 last_block_end_note = NULL_RTX;
3330 /* Emit a handler label for a nonlocal goto handler.
3331 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3334 expand_nl_handler_label (slot, before_insn)
3335 rtx slot, before_insn;
3338 rtx handler_label = gen_label_rtx ();
3340 /* Don't let jump_optimize delete the handler. */
3341 LABEL_PRESERVE_P (handler_label) = 1;
3344 emit_move_insn (slot, gen_rtx_LABEL_REF (Pmode, handler_label));
3345 insns = get_insns ();
3347 emit_insns_before (insns, before_insn);
3349 emit_label (handler_label);
3351 return handler_label;
3354 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3357 expand_nl_goto_receiver ()
3359 #ifdef HAVE_nonlocal_goto
3360 if (! HAVE_nonlocal_goto)
3362 /* First adjust our frame pointer to its actual value. It was
3363 previously set to the start of the virtual area corresponding to
3364 the stacked variables when we branched here and now needs to be
3365 adjusted to the actual hardware fp value.
3367 Assignments are to virtual registers are converted by
3368 instantiate_virtual_regs into the corresponding assignment
3369 to the underlying register (fp in this case) that makes
3370 the original assignment true.
3371 So the following insn will actually be
3372 decrementing fp by STARTING_FRAME_OFFSET. */
3373 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3375 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3376 if (fixed_regs[ARG_POINTER_REGNUM])
3378 #ifdef ELIMINABLE_REGS
3379 /* If the argument pointer can be eliminated in favor of the
3380 frame pointer, we don't need to restore it. We assume here
3381 that if such an elimination is present, it can always be used.
3382 This is the case on all known machines; if we don't make this
3383 assumption, we do unnecessary saving on many machines. */
3384 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3387 for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
3388 if (elim_regs[i].from == ARG_POINTER_REGNUM
3389 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3392 if (i == sizeof elim_regs / sizeof elim_regs [0])
3395 /* Now restore our arg pointer from the address at which it
3396 was saved in our stack frame.
3397 If there hasn't be space allocated for it yet, make
3399 if (arg_pointer_save_area == 0)
3400 arg_pointer_save_area
3401 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3402 emit_move_insn (virtual_incoming_args_rtx,
3403 /* We need a pseudo here, or else
3404 instantiate_virtual_regs_1 complains. */
3405 copy_to_reg (arg_pointer_save_area));
3410 #ifdef HAVE_nonlocal_goto_receiver
3411 if (HAVE_nonlocal_goto_receiver)
3412 emit_insn (gen_nonlocal_goto_receiver ());
3416 /* Make handlers for nonlocal gotos taking place in the function calls in
3420 expand_nl_goto_receivers (thisblock)
3421 struct nesting *thisblock;
3424 rtx afterward = gen_label_rtx ();
3429 /* Record the handler address in the stack slot for that purpose,
3430 during this block, saving and restoring the outer value. */
3431 if (thisblock->next != 0)
3432 for (slot = nonlocal_goto_handler_slots; slot; slot = XEXP (slot, 1))
3434 rtx save_receiver = gen_reg_rtx (Pmode);
3435 emit_move_insn (XEXP (slot, 0), save_receiver);
3438 emit_move_insn (save_receiver, XEXP (slot, 0));
3439 insns = get_insns ();
3441 emit_insns_before (insns, thisblock->data.block.first_insn);
3444 /* Jump around the handlers; they run only when specially invoked. */
3445 emit_jump (afterward);
3447 /* Make a separate handler for each label. */
3448 link = nonlocal_labels;
3449 slot = nonlocal_goto_handler_slots;
3450 label_list = NULL_RTX;
3451 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3452 /* Skip any labels we shouldn't be able to jump to from here,
3453 we generate one special handler for all of them below which just calls
3455 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3458 lab = expand_nl_handler_label (XEXP (slot, 0),
3459 thisblock->data.block.first_insn);
3460 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3462 expand_nl_goto_receiver ();
3464 /* Jump to the "real" nonlocal label. */
3465 expand_goto (TREE_VALUE (link));
3468 /* A second pass over all nonlocal labels; this time we handle those
3469 we should not be able to jump to at this point. */
3470 link = nonlocal_labels;
3471 slot = nonlocal_goto_handler_slots;
3473 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3474 if (DECL_TOO_LATE (TREE_VALUE (link)))
3477 lab = expand_nl_handler_label (XEXP (slot, 0),
3478 thisblock->data.block.first_insn);
3479 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3485 expand_nl_goto_receiver ();
3486 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "abort"), 0,
3491 nonlocal_goto_handler_labels = label_list;
3492 emit_label (afterward);
3495 /* Warn about any unused VARS (which may contain nodes other than
3496 VAR_DECLs, but such nodes are ignored). The nodes are connected
3497 via the TREE_CHAIN field. */
3500 warn_about_unused_variables (vars)
3506 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3507 if (TREE_CODE (decl) == VAR_DECL
3508 && ! TREE_USED (decl)
3509 && ! DECL_IN_SYSTEM_HEADER (decl)
3510 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
3511 warning_with_decl (decl, "unused variable `%s'");
3514 /* Generate RTL code to terminate a binding contour.
3516 VARS is the chain of VAR_DECL nodes for the variables bound in this
3517 contour. There may actually be other nodes in this chain, but any
3518 nodes other than VAR_DECLS are ignored.
3520 MARK_ENDS is nonzero if we should put a note at the beginning
3521 and end of this binding contour.
3523 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3524 (That is true automatically if the contour has a saved stack level.) */
3527 expand_end_bindings (vars, mark_ends, dont_jump_in)
3532 register struct nesting *thisblock;
3535 while (block_stack->data.block.exception_region)
3537 /* Because we don't need or want a new temporary level and
3538 because we didn't create one in expand_eh_region_start,
3539 create a fake one now to avoid removing one in
3540 expand_end_bindings. */
3543 block_stack->data.block.exception_region = 0;
3545 expand_end_bindings (NULL_TREE, 0, 0);
3548 /* Since expand_eh_region_start does an expand_start_bindings, we
3549 have to first end all the bindings that were created by
3550 expand_eh_region_start. */
3552 thisblock = block_stack;
3554 /* If any of the variables in this scope were not used, warn the
3556 warn_about_unused_variables (vars);
3558 if (thisblock->exit_label)
3560 do_pending_stack_adjust ();
3561 emit_label (thisblock->exit_label);
3564 /* If necessary, make handlers for nonlocal gotos taking
3565 place in the function calls in this block. */
3566 if (function_call_count != thisblock->data.block.n_function_calls
3568 /* Make handler for outermost block
3569 if there were any nonlocal gotos to this function. */
3570 && (thisblock->next == 0 ? current_function_has_nonlocal_label
3571 /* Make handler for inner block if it has something
3572 special to do when you jump out of it. */
3573 : (thisblock->data.block.cleanups != 0
3574 || thisblock->data.block.stack_level != 0)))
3575 expand_nl_goto_receivers (thisblock);
3577 /* Don't allow jumping into a block that has a stack level.
3578 Cleanups are allowed, though. */
3580 || thisblock->data.block.stack_level != 0)
3582 struct label_chain *chain;
3584 /* Any labels in this block are no longer valid to go to.
3585 Mark them to cause an error message. */
3586 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3588 DECL_TOO_LATE (chain->label) = 1;
3589 /* If any goto without a fixup came to this label,
3590 that must be an error, because gotos without fixups
3591 come from outside all saved stack-levels. */
3592 if (TREE_ADDRESSABLE (chain->label))
3593 error_with_decl (chain->label,
3594 "label `%s' used before containing binding contour");
3598 /* Restore stack level in effect before the block
3599 (only if variable-size objects allocated). */
3600 /* Perform any cleanups associated with the block. */
3602 if (thisblock->data.block.stack_level != 0
3603 || thisblock->data.block.cleanups != 0)
3605 /* Only clean up here if this point can actually be reached. */
3606 int reachable = GET_CODE (get_last_insn ()) != BARRIER;
3608 /* Don't let cleanups affect ({...}) constructs. */
3609 int old_expr_stmts_for_value = expr_stmts_for_value;
3610 rtx old_last_expr_value = last_expr_value;
3611 tree old_last_expr_type = last_expr_type;
3612 expr_stmts_for_value = 0;
3614 /* Do the cleanups. */
3615 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3617 do_pending_stack_adjust ();
3619 expr_stmts_for_value = old_expr_stmts_for_value;
3620 last_expr_value = old_last_expr_value;
3621 last_expr_type = old_last_expr_type;
3623 /* Restore the stack level. */
3625 if (reachable && thisblock->data.block.stack_level != 0)
3627 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3628 thisblock->data.block.stack_level, NULL_RTX);
3629 if (nonlocal_goto_handler_slots != 0)
3630 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3634 /* Any gotos out of this block must also do these things.
3635 Also report any gotos with fixups that came to labels in this
3637 fixup_gotos (thisblock,
3638 thisblock->data.block.stack_level,
3639 thisblock->data.block.cleanups,
3640 thisblock->data.block.first_insn,
3644 /* Mark the beginning and end of the scope if requested.
3645 We do this now, after running cleanups on the variables
3646 just going out of scope, so they are in scope for their cleanups. */
3649 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3651 /* Get rid of the beginning-mark if we don't make an end-mark. */
3652 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3654 /* If doing stupid register allocation, make sure lives of all
3655 register variables declared here extend thru end of scope. */
3658 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3659 if (TREE_CODE (decl) == VAR_DECL && DECL_RTL (decl))
3660 use_variable (DECL_RTL (decl));
3662 /* Restore the temporary level of TARGET_EXPRs. */
3663 target_temp_slot_level = thisblock->data.block.block_target_temp_slot_level;
3665 /* Restore block_stack level for containing block. */
3667 stack_block_stack = thisblock->data.block.innermost_stack_block;
3668 POPSTACK (block_stack);
3670 /* Pop the stack slot nesting and free any slots at this level. */
3674 /* Generate RTL for the automatic variable declaration DECL.
3675 (Other kinds of declarations are simply ignored if seen here.) */
3681 struct nesting *thisblock;
3684 type = TREE_TYPE (decl);
3686 /* Only automatic variables need any expansion done.
3687 Static and external variables, and external functions,
3688 will be handled by `assemble_variable' (called from finish_decl).
3689 TYPE_DECL and CONST_DECL require nothing.
3690 PARM_DECLs are handled in `assign_parms'. */
3692 if (TREE_CODE (decl) != VAR_DECL)
3694 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3697 thisblock = block_stack;
3699 /* Create the RTL representation for the variable. */
3701 if (type == error_mark_node)
3702 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, const0_rtx);
3703 else if (DECL_SIZE (decl) == 0)
3704 /* Variable with incomplete type. */
3706 if (DECL_INITIAL (decl) == 0)
3707 /* Error message was already done; now avoid a crash. */
3708 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3710 /* An initializer is going to decide the size of this array.
3711 Until we know the size, represent its address with a reg. */
3712 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode));
3713 MEM_SET_IN_STRUCT_P (DECL_RTL (decl), AGGREGATE_TYPE_P (type));
3715 else if (DECL_MODE (decl) != BLKmode
3716 /* If -ffloat-store, don't put explicit float vars
3718 && !(flag_float_store
3719 && TREE_CODE (type) == REAL_TYPE)
3720 && ! TREE_THIS_VOLATILE (decl)
3721 && ! TREE_ADDRESSABLE (decl)
3722 && (DECL_REGISTER (decl) || ! obey_regdecls)
3723 /* if -fcheck-memory-usage, check all variables. */
3724 && ! current_function_check_memory_usage)
3726 /* Automatic variable that can go in a register. */
3727 int unsignedp = TREE_UNSIGNED (type);
3728 enum machine_mode reg_mode
3729 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3731 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3732 mark_user_reg (DECL_RTL (decl));
3734 if (POINTER_TYPE_P (type))
3735 mark_reg_pointer (DECL_RTL (decl),
3736 (TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl)))
3740 else if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST
3741 && ! (flag_stack_check && ! STACK_CHECK_BUILTIN
3742 && (TREE_INT_CST_HIGH (DECL_SIZE (decl)) != 0
3743 || (TREE_INT_CST_LOW (DECL_SIZE (decl))
3744 > STACK_CHECK_MAX_VAR_SIZE * BITS_PER_UNIT))))
3746 /* Variable of fixed size that goes on the stack. */
3750 /* If we previously made RTL for this decl, it must be an array
3751 whose size was determined by the initializer.
3752 The old address was a register; set that register now
3753 to the proper address. */
3754 if (DECL_RTL (decl) != 0)
3756 if (GET_CODE (DECL_RTL (decl)) != MEM
3757 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3759 oldaddr = XEXP (DECL_RTL (decl), 0);
3762 DECL_RTL (decl) = assign_temp (TREE_TYPE (decl), 1, 1, 1);
3763 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3764 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3766 /* Set alignment we actually gave this decl. */
3767 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3768 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3772 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3773 if (addr != oldaddr)
3774 emit_move_insn (oldaddr, addr);
3777 /* If this is a memory ref that contains aggregate components,
3778 mark it as such for cse and loop optimize. */
3779 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3780 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3782 /* If this is in memory because of -ffloat-store,
3783 set the volatile bit, to prevent optimizations from
3784 undoing the effects. */
3785 if (flag_float_store && TREE_CODE (type) == REAL_TYPE)
3786 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3789 MEM_ALIAS_SET (DECL_RTL (decl)) = get_alias_set (decl);
3792 /* Dynamic-size object: must push space on the stack. */
3796 /* Record the stack pointer on entry to block, if have
3797 not already done so. */
3798 if (thisblock->data.block.stack_level == 0)
3800 do_pending_stack_adjust ();
3801 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3802 &thisblock->data.block.stack_level,
3803 thisblock->data.block.first_insn);
3804 stack_block_stack = thisblock;
3807 /* Compute the variable's size, in bytes. */
3808 size = expand_expr (size_binop (CEIL_DIV_EXPR,
3810 size_int (BITS_PER_UNIT)),
3811 NULL_RTX, VOIDmode, 0);
3814 /* Allocate space on the stack for the variable. Note that
3815 DECL_ALIGN says how the variable is to be aligned and we
3816 cannot use it to conclude anything about the alignment of
3818 address = allocate_dynamic_stack_space (size, NULL_RTX,
3819 TYPE_ALIGN (TREE_TYPE (decl)));
3821 /* Reference the variable indirect through that rtx. */
3822 DECL_RTL (decl) = gen_rtx_MEM (DECL_MODE (decl), address);
3824 /* If this is a memory ref that contains aggregate components,
3825 mark it as such for cse and loop optimize. */
3826 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3827 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3829 /* Indicate the alignment we actually gave this variable. */
3830 #ifdef STACK_BOUNDARY
3831 DECL_ALIGN (decl) = STACK_BOUNDARY;
3833 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3837 if (TREE_THIS_VOLATILE (decl))
3838 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3839 #if 0 /* A variable is not necessarily unchanging
3840 just because it is const. RTX_UNCHANGING_P
3841 means no change in the function,
3842 not merely no change in the variable's scope.
3843 It is correct to set RTX_UNCHANGING_P if the variable's scope
3844 is the whole function. There's no convenient way to test that. */
3845 if (TREE_READONLY (decl))
3846 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
3849 /* If doing stupid register allocation, make sure life of any
3850 register variable starts here, at the start of its scope. */
3853 use_variable (DECL_RTL (decl));
3858 /* Emit code to perform the initialization of a declaration DECL. */
3861 expand_decl_init (decl)
3864 int was_used = TREE_USED (decl);
3866 /* If this is a CONST_DECL, we don't have to generate any code, but
3867 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3868 to be set while in the obstack containing the constant. If we don't
3869 do this, we can lose if we have functions nested three deep and the middle
3870 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3871 the innermost function is the first to expand that STRING_CST. */
3872 if (TREE_CODE (decl) == CONST_DECL)
3874 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3875 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3876 EXPAND_INITIALIZER);
3880 if (TREE_STATIC (decl))
3883 /* Compute and store the initial value now. */
3885 if (DECL_INITIAL (decl) == error_mark_node)
3887 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3889 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3890 || code == POINTER_TYPE || code == REFERENCE_TYPE)
3891 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3895 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3897 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3898 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3902 /* Don't let the initialization count as "using" the variable. */
3903 TREE_USED (decl) = was_used;
3905 /* Free any temporaries we made while initializing the decl. */
3906 preserve_temp_slots (NULL_RTX);
3910 /* CLEANUP is an expression to be executed at exit from this binding contour;
3911 for example, in C++, it might call the destructor for this variable.
3913 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
3914 CLEANUP multiple times, and have the correct semantics. This
3915 happens in exception handling, for gotos, returns, breaks that
3916 leave the current scope.
3918 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3919 that is not associated with any particular variable. */
3922 expand_decl_cleanup (decl, cleanup)
3925 struct nesting *thisblock;
3927 /* Error if we are not in any block. */
3928 if (current_function == 0 || block_stack == 0)
3931 thisblock = block_stack;
3933 /* Record the cleanup if there is one. */
3939 tree *cleanups = &thisblock->data.block.cleanups;
3940 int cond_context = conditional_context ();
3944 rtx flag = gen_reg_rtx (word_mode);
3949 emit_move_insn (flag, const0_rtx);
3950 set_flag_0 = get_insns ();
3953 thisblock->data.block.last_unconditional_cleanup
3954 = emit_insns_after (set_flag_0,
3955 thisblock->data.block.last_unconditional_cleanup);
3957 emit_move_insn (flag, const1_rtx);
3959 /* All cleanups must be on the function_obstack. */
3960 push_obstacks_nochange ();
3961 resume_temporary_allocation ();
3963 cond = build_decl (VAR_DECL, NULL_TREE, type_for_mode (word_mode, 1));
3964 DECL_RTL (cond) = flag;
3966 /* Conditionalize the cleanup. */
3967 cleanup = build (COND_EXPR, void_type_node,
3968 truthvalue_conversion (cond),
3969 cleanup, integer_zero_node);
3970 cleanup = fold (cleanup);
3974 cleanups = thisblock->data.block.cleanup_ptr;
3977 /* All cleanups must be on the function_obstack. */
3978 push_obstacks_nochange ();
3979 resume_temporary_allocation ();
3980 cleanup = unsave_expr (cleanup);
3983 t = *cleanups = temp_tree_cons (decl, cleanup, *cleanups);
3986 /* If this block has a cleanup, it belongs in stack_block_stack. */
3987 stack_block_stack = thisblock;
3994 /* If this was optimized so that there is no exception region for the
3995 cleanup, then mark the TREE_LIST node, so that we can later tell
3996 if we need to call expand_eh_region_end. */
3997 if (! using_eh_for_cleanups_p
3998 || expand_eh_region_start_tree (decl, cleanup))
3999 TREE_ADDRESSABLE (t) = 1;
4000 /* If that started a new EH region, we're in a new block. */
4001 thisblock = block_stack;
4008 thisblock->data.block.last_unconditional_cleanup
4009 = emit_insns_after (seq,
4010 thisblock->data.block.last_unconditional_cleanup);
4014 thisblock->data.block.last_unconditional_cleanup
4016 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
4022 /* Like expand_decl_cleanup, but suppress generating an exception handler
4023 to perform the cleanup. */
4026 expand_decl_cleanup_no_eh (decl, cleanup)
4029 int save_eh = using_eh_for_cleanups_p;
4032 using_eh_for_cleanups_p = 0;
4033 result = expand_decl_cleanup (decl, cleanup);
4034 using_eh_for_cleanups_p = save_eh;
4039 /* Arrange for the top element of the dynamic cleanup chain to be
4040 popped if we exit the current binding contour. DECL is the
4041 associated declaration, if any, otherwise NULL_TREE. If the
4042 current contour is left via an exception, then __sjthrow will pop
4043 the top element off the dynamic cleanup chain. The code that
4044 avoids doing the action we push into the cleanup chain in the
4045 exceptional case is contained in expand_cleanups.
4047 This routine is only used by expand_eh_region_start, and that is
4048 the only way in which an exception region should be started. This
4049 routine is only used when using the setjmp/longjmp codegen method
4050 for exception handling. */
4053 expand_dcc_cleanup (decl)
4056 struct nesting *thisblock;
4059 /* Error if we are not in any block. */
4060 if (current_function == 0 || block_stack == 0)
4062 thisblock = block_stack;
4064 /* Record the cleanup for the dynamic handler chain. */
4066 /* All cleanups must be on the function_obstack. */
4067 push_obstacks_nochange ();
4068 resume_temporary_allocation ();
4069 cleanup = make_node (POPDCC_EXPR);
4072 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4073 thisblock->data.block.cleanups
4074 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4076 /* If this block has a cleanup, it belongs in stack_block_stack. */
4077 stack_block_stack = thisblock;
4081 /* Arrange for the top element of the dynamic handler chain to be
4082 popped if we exit the current binding contour. DECL is the
4083 associated declaration, if any, otherwise NULL_TREE. If the current
4084 contour is left via an exception, then __sjthrow will pop the top
4085 element off the dynamic handler chain. The code that avoids doing
4086 the action we push into the handler chain in the exceptional case
4087 is contained in expand_cleanups.
4089 This routine is only used by expand_eh_region_start, and that is
4090 the only way in which an exception region should be started. This
4091 routine is only used when using the setjmp/longjmp codegen method
4092 for exception handling. */
4095 expand_dhc_cleanup (decl)
4098 struct nesting *thisblock;
4101 /* Error if we are not in any block. */
4102 if (current_function == 0 || block_stack == 0)
4104 thisblock = block_stack;
4106 /* Record the cleanup for the dynamic handler chain. */
4108 /* All cleanups must be on the function_obstack. */
4109 push_obstacks_nochange ();
4110 resume_temporary_allocation ();
4111 cleanup = make_node (POPDHC_EXPR);
4114 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4115 thisblock->data.block.cleanups
4116 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4118 /* If this block has a cleanup, it belongs in stack_block_stack. */
4119 stack_block_stack = thisblock;
4123 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4124 DECL_ELTS is the list of elements that belong to DECL's type.
4125 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4128 expand_anon_union_decl (decl, cleanup, decl_elts)
4129 tree decl, cleanup, decl_elts;
4131 struct nesting *thisblock = current_function == 0 ? 0 : block_stack;
4135 expand_decl_cleanup (decl, cleanup);
4136 x = DECL_RTL (decl);
4140 tree decl_elt = TREE_VALUE (decl_elts);
4141 tree cleanup_elt = TREE_PURPOSE (decl_elts);
4142 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
4144 /* Propagate the union's alignment to the elements. */
4145 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
4147 /* If the element has BLKmode and the union doesn't, the union is
4148 aligned such that the element doesn't need to have BLKmode, so
4149 change the element's mode to the appropriate one for its size. */
4150 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
4151 DECL_MODE (decl_elt) = mode
4152 = mode_for_size (TREE_INT_CST_LOW (DECL_SIZE (decl_elt)),
4155 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4156 instead create a new MEM rtx with the proper mode. */
4157 if (GET_CODE (x) == MEM)
4159 if (mode == GET_MODE (x))
4160 DECL_RTL (decl_elt) = x;
4163 DECL_RTL (decl_elt) = gen_rtx_MEM (mode, copy_rtx (XEXP (x, 0)));
4164 MEM_COPY_ATTRIBUTES (DECL_RTL (decl_elt), x);
4165 RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x);
4168 else if (GET_CODE (x) == REG)
4170 if (mode == GET_MODE (x))
4171 DECL_RTL (decl_elt) = x;
4173 DECL_RTL (decl_elt) = gen_rtx_SUBREG (mode, x, 0);
4178 /* Record the cleanup if there is one. */
4181 thisblock->data.block.cleanups
4182 = temp_tree_cons (decl_elt, cleanup_elt,
4183 thisblock->data.block.cleanups);
4185 decl_elts = TREE_CHAIN (decl_elts);
4189 /* Expand a list of cleanups LIST.
4190 Elements may be expressions or may be nested lists.
4192 If DONT_DO is nonnull, then any list-element
4193 whose TREE_PURPOSE matches DONT_DO is omitted.
4194 This is sometimes used to avoid a cleanup associated with
4195 a value that is being returned out of the scope.
4197 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
4198 goto and handle protection regions specially in that case.
4200 If REACHABLE, we emit code, otherwise just inform the exception handling
4201 code about this finalization. */
4204 expand_cleanups (list, dont_do, in_fixup, reachable)
4211 for (tail = list; tail; tail = TREE_CHAIN (tail))
4212 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
4214 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
4215 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
4220 tree cleanup = TREE_VALUE (tail);
4222 /* See expand_d{h,c}c_cleanup for why we avoid this. */
4223 if (TREE_CODE (cleanup) != POPDHC_EXPR
4224 && TREE_CODE (cleanup) != POPDCC_EXPR
4225 /* See expand_eh_region_start_tree for this case. */
4226 && ! TREE_ADDRESSABLE (tail))
4228 cleanup = protect_with_terminate (cleanup);
4229 expand_eh_region_end (cleanup);
4235 /* Cleanups may be run multiple times. For example,
4236 when exiting a binding contour, we expand the
4237 cleanups associated with that contour. When a goto
4238 within that binding contour has a target outside that
4239 contour, it will expand all cleanups from its scope to
4240 the target. Though the cleanups are expanded multiple
4241 times, the control paths are non-overlapping so the
4242 cleanups will not be executed twice. */
4244 /* We may need to protect fixups with rethrow regions. */
4245 int protect = (in_fixup && ! TREE_ADDRESSABLE (tail));
4248 expand_fixup_region_start ();
4250 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
4252 expand_fixup_region_end (TREE_VALUE (tail));
4259 /* Mark when the context we are emitting RTL for as a conditional
4260 context, so that any cleanup actions we register with
4261 expand_decl_init will be properly conditionalized when those
4262 cleanup actions are later performed. Must be called before any
4263 expression (tree) is expanded that is within a conditional context. */
4266 start_cleanup_deferral ()
4268 /* block_stack can be NULL if we are inside the parameter list. It is
4269 OK to do nothing, because cleanups aren't possible here. */
4271 ++block_stack->data.block.conditional_code;
4274 /* Mark the end of a conditional region of code. Because cleanup
4275 deferrals may be nested, we may still be in a conditional region
4276 after we end the currently deferred cleanups, only after we end all
4277 deferred cleanups, are we back in unconditional code. */
4280 end_cleanup_deferral ()
4282 /* block_stack can be NULL if we are inside the parameter list. It is
4283 OK to do nothing, because cleanups aren't possible here. */
4285 --block_stack->data.block.conditional_code;
4288 /* Move all cleanups from the current block_stack
4289 to the containing block_stack, where they are assumed to
4290 have been created. If anything can cause a temporary to
4291 be created, but not expanded for more than one level of
4292 block_stacks, then this code will have to change. */
4297 struct nesting *block = block_stack;
4298 struct nesting *outer = block->next;
4300 outer->data.block.cleanups
4301 = chainon (block->data.block.cleanups,
4302 outer->data.block.cleanups);
4303 block->data.block.cleanups = 0;
4307 last_cleanup_this_contour ()
4309 if (block_stack == 0)
4312 return block_stack->data.block.cleanups;
4315 /* Return 1 if there are any pending cleanups at this point.
4316 If THIS_CONTOUR is nonzero, check the current contour as well.
4317 Otherwise, look only at the contours that enclose this one. */
4320 any_pending_cleanups (this_contour)
4323 struct nesting *block;
4325 if (block_stack == 0)
4328 if (this_contour && block_stack->data.block.cleanups != NULL)
4330 if (block_stack->data.block.cleanups == 0
4331 && block_stack->data.block.outer_cleanups == 0)
4334 for (block = block_stack->next; block; block = block->next)
4335 if (block->data.block.cleanups != 0)
4341 /* Enter a case (Pascal) or switch (C) statement.
4342 Push a block onto case_stack and nesting_stack
4343 to accumulate the case-labels that are seen
4344 and to record the labels generated for the statement.
4346 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4347 Otherwise, this construct is transparent for `exit_something'.
4349 EXPR is the index-expression to be dispatched on.
4350 TYPE is its nominal type. We could simply convert EXPR to this type,
4351 but instead we take short cuts. */
4354 expand_start_case (exit_flag, expr, type, printname)
4358 const char *printname;
4360 register struct nesting *thiscase = ALLOC_NESTING ();
4362 /* Make an entry on case_stack for the case we are entering. */
4364 thiscase->next = case_stack;
4365 thiscase->all = nesting_stack;
4366 thiscase->depth = ++nesting_depth;
4367 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
4368 thiscase->data.case_stmt.case_list = 0;
4369 thiscase->data.case_stmt.index_expr = expr;
4370 thiscase->data.case_stmt.nominal_type = type;
4371 thiscase->data.case_stmt.default_label = 0;
4372 thiscase->data.case_stmt.num_ranges = 0;
4373 thiscase->data.case_stmt.printname = printname;
4374 thiscase->data.case_stmt.line_number_status = force_line_numbers ();
4375 case_stack = thiscase;
4376 nesting_stack = thiscase;
4378 do_pending_stack_adjust ();
4380 /* Make sure case_stmt.start points to something that won't
4381 need any transformation before expand_end_case. */
4382 if (GET_CODE (get_last_insn ()) != NOTE)
4383 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4385 thiscase->data.case_stmt.start = get_last_insn ();
4387 start_cleanup_deferral ();
4391 /* Start a "dummy case statement" within which case labels are invalid
4392 and are not connected to any larger real case statement.
4393 This can be used if you don't want to let a case statement jump
4394 into the middle of certain kinds of constructs. */
4397 expand_start_case_dummy ()
4399 register struct nesting *thiscase = ALLOC_NESTING ();
4401 /* Make an entry on case_stack for the dummy. */
4403 thiscase->next = case_stack;
4404 thiscase->all = nesting_stack;
4405 thiscase->depth = ++nesting_depth;
4406 thiscase->exit_label = 0;
4407 thiscase->data.case_stmt.case_list = 0;
4408 thiscase->data.case_stmt.start = 0;
4409 thiscase->data.case_stmt.nominal_type = 0;
4410 thiscase->data.case_stmt.default_label = 0;
4411 thiscase->data.case_stmt.num_ranges = 0;
4412 case_stack = thiscase;
4413 nesting_stack = thiscase;
4414 start_cleanup_deferral ();
4417 /* End a dummy case statement. */
4420 expand_end_case_dummy ()
4422 end_cleanup_deferral ();
4423 POPSTACK (case_stack);
4426 /* Return the data type of the index-expression
4427 of the innermost case statement, or null if none. */
4430 case_index_expr_type ()
4433 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
4440 /* If this is the first label, warn if any insns have been emitted. */
4441 if (case_stack->data.case_stmt.line_number_status >= 0)
4445 restore_line_number_status
4446 (case_stack->data.case_stmt.line_number_status);
4447 case_stack->data.case_stmt.line_number_status = -1;
4449 for (insn = case_stack->data.case_stmt.start;
4451 insn = NEXT_INSN (insn))
4453 if (GET_CODE (insn) == CODE_LABEL)
4455 if (GET_CODE (insn) != NOTE
4456 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4459 insn = PREV_INSN (insn);
4460 while (insn && (GET_CODE (insn) != NOTE || NOTE_LINE_NUMBER (insn) < 0));
4462 /* If insn is zero, then there must have been a syntax error. */
4464 warning_with_file_and_line (NOTE_SOURCE_FILE(insn),
4465 NOTE_LINE_NUMBER(insn),
4466 "unreachable code at beginning of %s",
4467 case_stack->data.case_stmt.printname);
4474 /* Accumulate one case or default label inside a case or switch statement.
4475 VALUE is the value of the case (a null pointer, for a default label).
4476 The function CONVERTER, when applied to arguments T and V,
4477 converts the value V to the type T.
4479 If not currently inside a case or switch statement, return 1 and do
4480 nothing. The caller will print a language-specific error message.
4481 If VALUE is a duplicate or overlaps, return 2 and do nothing
4482 except store the (first) duplicate node in *DUPLICATE.
4483 If VALUE is out of range, return 3 and do nothing.
4484 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4485 Return 0 on success.
4487 Extended to handle range statements. */
4490 pushcase (value, converter, label, duplicate)
4491 register tree value;
4492 tree (*converter) PROTO((tree, tree));
4493 register tree label;
4499 /* Fail if not inside a real case statement. */
4500 if (! (case_stack && case_stack->data.case_stmt.start))
4503 if (stack_block_stack
4504 && stack_block_stack->depth > case_stack->depth)
4507 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4508 nominal_type = case_stack->data.case_stmt.nominal_type;
4510 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4511 if (index_type == error_mark_node)
4514 /* Convert VALUE to the type in which the comparisons are nominally done. */
4516 value = (*converter) (nominal_type, value);
4520 /* Fail if this value is out of range for the actual type of the index
4521 (which may be narrower than NOMINAL_TYPE). */
4522 if (value != 0 && ! int_fits_type_p (value, index_type))
4525 /* Fail if this is a duplicate or overlaps another entry. */
4528 if (case_stack->data.case_stmt.default_label != 0)
4530 *duplicate = case_stack->data.case_stmt.default_label;
4533 case_stack->data.case_stmt.default_label = label;
4536 return add_case_node (value, value, label, duplicate);
4538 expand_label (label);
4542 /* Like pushcase but this case applies to all values between VALUE1 and
4543 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4544 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4545 starts at VALUE1 and ends at the highest value of the index type.
4546 If both are NULL, this case applies to all values.
4548 The return value is the same as that of pushcase but there is one
4549 additional error code: 4 means the specified range was empty. */
4552 pushcase_range (value1, value2, converter, label, duplicate)
4553 register tree value1, value2;
4554 tree (*converter) PROTO((tree, tree));
4555 register tree label;
4561 /* Fail if not inside a real case statement. */
4562 if (! (case_stack && case_stack->data.case_stmt.start))
4565 if (stack_block_stack
4566 && stack_block_stack->depth > case_stack->depth)
4569 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4570 nominal_type = case_stack->data.case_stmt.nominal_type;
4572 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4573 if (index_type == error_mark_node)
4578 /* Convert VALUEs to type in which the comparisons are nominally done
4579 and replace any unspecified value with the corresponding bound. */
4581 value1 = TYPE_MIN_VALUE (index_type);
4583 value2 = TYPE_MAX_VALUE (index_type);
4585 /* Fail if the range is empty. Do this before any conversion since
4586 we want to allow out-of-range empty ranges. */
4587 if (value2 && tree_int_cst_lt (value2, value1))
4590 value1 = (*converter) (nominal_type, value1);
4592 /* If the max was unbounded, use the max of the nominal_type we are
4593 converting to. Do this after the < check above to suppress false
4596 value2 = TYPE_MAX_VALUE (nominal_type);
4597 value2 = (*converter) (nominal_type, value2);
4599 /* Fail if these values are out of range. */
4600 if (TREE_CONSTANT_OVERFLOW (value1)
4601 || ! int_fits_type_p (value1, index_type))
4604 if (TREE_CONSTANT_OVERFLOW (value2)
4605 || ! int_fits_type_p (value2, index_type))
4608 return add_case_node (value1, value2, label, duplicate);
4611 /* Do the actual insertion of a case label for pushcase and pushcase_range
4612 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4613 slowdown for large switch statements. */
4616 add_case_node (low, high, label, duplicate)
4621 struct case_node *p, **q, *r;
4623 q = &case_stack->data.case_stmt.case_list;
4630 /* Keep going past elements distinctly greater than HIGH. */
4631 if (tree_int_cst_lt (high, p->low))
4634 /* or distinctly less than LOW. */
4635 else if (tree_int_cst_lt (p->high, low))
4640 /* We have an overlap; this is an error. */
4641 *duplicate = p->code_label;
4646 /* Add this label to the chain, and succeed.
4647 Copy LOW, HIGH so they are on temporary rather than momentary
4648 obstack and will thus survive till the end of the case statement. */
4650 r = (struct case_node *) oballoc (sizeof (struct case_node));
4651 r->low = copy_node (low);
4653 /* If the bounds are equal, turn this into the one-value case. */
4655 if (tree_int_cst_equal (low, high))
4659 r->high = copy_node (high);
4660 case_stack->data.case_stmt.num_ranges++;
4663 r->code_label = label;
4664 expand_label (label);
4674 struct case_node *s;
4680 if (! (b = p->balance))
4681 /* Growth propagation from left side. */
4688 if ((p->left = s = r->right))
4697 if ((r->parent = s))
4705 case_stack->data.case_stmt.case_list = r;
4708 /* r->balance == +1 */
4713 struct case_node *t = r->right;
4715 if ((p->left = s = t->right))
4719 if ((r->right = s = t->left))
4733 if ((t->parent = s))
4741 case_stack->data.case_stmt.case_list = t;
4748 /* p->balance == +1; growth of left side balances the node. */
4758 if (! (b = p->balance))
4759 /* Growth propagation from right side. */
4767 if ((p->right = s = r->left))
4775 if ((r->parent = s))
4784 case_stack->data.case_stmt.case_list = r;
4788 /* r->balance == -1 */
4792 struct case_node *t = r->left;
4794 if ((p->right = s = t->left))
4799 if ((r->left = s = t->right))
4813 if ((t->parent = s))
4822 case_stack->data.case_stmt.case_list = t;
4828 /* p->balance == -1; growth of right side balances the node. */
4842 /* Returns the number of possible values of TYPE.
4843 Returns -1 if the number is unknown or variable.
4844 Returns -2 if the number does not fit in a HOST_WIDE_INT.
4845 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4846 do not increase monotonically (there may be duplicates);
4847 to 1 if the values increase monotonically, but not always by 1;
4848 otherwise sets it to 0. */
4851 all_cases_count (type, spareness)
4855 HOST_WIDE_INT count;
4858 switch (TREE_CODE (type))
4865 count = 1 << BITS_PER_UNIT;
4869 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4870 || TYPE_MAX_VALUE (type) == NULL
4871 || TREE_CODE (TYPE_MAX_VALUE (type)) != INTEGER_CST)
4876 = TREE_INT_CST_LOW (TYPE_MAX_VALUE (type))
4877 - TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + 1
4878 but with overflow checking. */
4879 tree mint = TYPE_MIN_VALUE (type);
4880 tree maxt = TYPE_MAX_VALUE (type);
4881 HOST_WIDE_INT lo, hi;
4882 neg_double(TREE_INT_CST_LOW (mint), TREE_INT_CST_HIGH (mint),
4884 add_double(TREE_INT_CST_LOW (maxt), TREE_INT_CST_HIGH (maxt),
4886 add_double (lo, hi, 1, 0, &lo, &hi);
4887 if (hi != 0 || lo < 0)
4894 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4896 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4897 || TREE_CODE (TREE_VALUE (t)) != INTEGER_CST
4898 || TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + count
4899 != TREE_INT_CST_LOW (TREE_VALUE (t)))
4903 if (*spareness == 1)
4905 tree prev = TREE_VALUE (TYPE_VALUES (type));
4906 for (t = TYPE_VALUES (type); t = TREE_CHAIN (t), t != NULL_TREE; )
4908 if (! tree_int_cst_lt (prev, TREE_VALUE (t)))
4913 prev = TREE_VALUE (t);
4922 #define BITARRAY_TEST(ARRAY, INDEX) \
4923 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4924 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4925 #define BITARRAY_SET(ARRAY, INDEX) \
4926 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4927 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4929 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4930 with the case values we have seen, assuming the case expression
4932 SPARSENESS is as determined by all_cases_count.
4934 The time needed is proportional to COUNT, unless
4935 SPARSENESS is 2, in which case quadratic time is needed. */
4938 mark_seen_cases (type, cases_seen, count, sparseness)
4940 unsigned char *cases_seen;
4944 tree next_node_to_try = NULL_TREE;
4945 long next_node_offset = 0;
4947 register struct case_node *n, *root = case_stack->data.case_stmt.case_list;
4948 tree val = make_node (INTEGER_CST);
4949 TREE_TYPE (val) = type;
4952 else if (sparseness == 2)
4957 /* This less efficient loop is only needed to handle
4958 duplicate case values (multiple enum constants
4959 with the same value). */
4960 TREE_TYPE (val) = TREE_TYPE (root->low);
4961 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
4962 t = TREE_CHAIN (t), xlo++)
4964 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (TREE_VALUE (t));
4965 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (TREE_VALUE (t));
4969 /* Keep going past elements distinctly greater than VAL. */
4970 if (tree_int_cst_lt (val, n->low))
4973 /* or distinctly less than VAL. */
4974 else if (tree_int_cst_lt (n->high, val))
4979 /* We have found a matching range. */
4980 BITARRAY_SET (cases_seen, xlo);
4990 case_stack->data.case_stmt.case_list = root = case_tree2list (root, 0);
4991 for (n = root; n; n = n->right)
4993 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
4994 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
4995 while ( ! tree_int_cst_lt (n->high, val))
4997 /* Calculate (into xlo) the "offset" of the integer (val).
4998 The element with lowest value has offset 0, the next smallest
4999 element has offset 1, etc. */
5001 HOST_WIDE_INT xlo, xhi;
5003 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
5005 /* The TYPE_VALUES will be in increasing order, so
5006 starting searching where we last ended. */
5007 t = next_node_to_try;
5008 xlo = next_node_offset;
5014 t = TYPE_VALUES (type);
5017 if (tree_int_cst_equal (val, TREE_VALUE (t)))
5019 next_node_to_try = TREE_CHAIN (t);
5020 next_node_offset = xlo + 1;
5025 if (t == next_node_to_try)
5034 t = TYPE_MIN_VALUE (type);
5036 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
5040 add_double (xlo, xhi,
5041 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5045 if (xhi == 0 && xlo >= 0 && xlo < count)
5046 BITARRAY_SET (cases_seen, xlo);
5047 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5049 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
5055 /* Called when the index of a switch statement is an enumerated type
5056 and there is no default label.
5058 Checks that all enumeration literals are covered by the case
5059 expressions of a switch. Also, warn if there are any extra
5060 switch cases that are *not* elements of the enumerated type.
5062 If all enumeration literals were covered by the case expressions,
5063 turn one of the expressions into the default expression since it should
5064 not be possible to fall through such a switch. */
5067 check_for_full_enumeration_handling (type)
5070 register struct case_node *n;
5071 register tree chain;
5072 #if 0 /* variable used by 'if 0'ed code below. */
5073 register struct case_node **l;
5077 /* True iff the selector type is a numbered set mode. */
5080 /* The number of possible selector values. */
5083 /* For each possible selector value. a one iff it has been matched
5084 by a case value alternative. */
5085 unsigned char *cases_seen;
5087 /* The allocated size of cases_seen, in chars. */
5093 size = all_cases_count (type, &sparseness);
5094 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
5096 if (size > 0 && size < 600000
5097 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5098 this optimization if we don't have enough memory rather than
5099 aborting, as xmalloc would do. */
5100 && (cases_seen = (unsigned char *) calloc (bytes_needed, 1)) != NULL)
5103 tree v = TYPE_VALUES (type);
5105 /* The time complexity of this code is normally O(N), where
5106 N being the number of members in the enumerated type.
5107 However, if type is a ENUMERAL_TYPE whose values do not
5108 increase monotonically, O(N*log(N)) time may be needed. */
5110 mark_seen_cases (type, cases_seen, size, sparseness);
5112 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
5114 if (BITARRAY_TEST(cases_seen, i) == 0)
5115 warning ("enumeration value `%s' not handled in switch",
5116 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
5122 /* Now we go the other way around; we warn if there are case
5123 expressions that don't correspond to enumerators. This can
5124 occur since C and C++ don't enforce type-checking of
5125 assignments to enumeration variables. */
5127 if (case_stack->data.case_stmt.case_list
5128 && case_stack->data.case_stmt.case_list->left)
5129 case_stack->data.case_stmt.case_list
5130 = case_tree2list (case_stack->data.case_stmt.case_list, 0);
5132 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
5134 for (chain = TYPE_VALUES (type);
5135 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
5136 chain = TREE_CHAIN (chain))
5141 if (TYPE_NAME (type) == 0)
5142 warning ("case value `%ld' not in enumerated type",
5143 (long) TREE_INT_CST_LOW (n->low));
5145 warning ("case value `%ld' not in enumerated type `%s'",
5146 (long) TREE_INT_CST_LOW (n->low),
5147 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5150 : DECL_NAME (TYPE_NAME (type))));
5152 if (!tree_int_cst_equal (n->low, n->high))
5154 for (chain = TYPE_VALUES (type);
5155 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
5156 chain = TREE_CHAIN (chain))
5161 if (TYPE_NAME (type) == 0)
5162 warning ("case value `%ld' not in enumerated type",
5163 (long) TREE_INT_CST_LOW (n->high));
5165 warning ("case value `%ld' not in enumerated type `%s'",
5166 (long) TREE_INT_CST_LOW (n->high),
5167 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5170 : DECL_NAME (TYPE_NAME (type))));
5176 /* ??? This optimization is disabled because it causes valid programs to
5177 fail. ANSI C does not guarantee that an expression with enum type
5178 will have a value that is the same as one of the enumeration literals. */
5180 /* If all values were found as case labels, make one of them the default
5181 label. Thus, this switch will never fall through. We arbitrarily pick
5182 the last one to make the default since this is likely the most
5183 efficient choice. */
5187 for (l = &case_stack->data.case_stmt.case_list;
5192 case_stack->data.case_stmt.default_label = (*l)->code_label;
5199 /* Terminate a case (Pascal) or switch (C) statement
5200 in which ORIG_INDEX is the expression to be tested.
5201 Generate the code to test it and jump to the right place. */
5204 expand_end_case (orig_index)
5207 tree minval = NULL_TREE, maxval = NULL_TREE, range, orig_minval;
5208 rtx default_label = 0;
5209 register struct case_node *n;
5217 register struct nesting *thiscase = case_stack;
5218 tree index_expr, index_type;
5221 /* Don't crash due to previous errors. */
5222 if (thiscase == NULL)
5225 table_label = gen_label_rtx ();
5226 index_expr = thiscase->data.case_stmt.index_expr;
5227 index_type = TREE_TYPE (index_expr);
5228 unsignedp = TREE_UNSIGNED (index_type);
5230 do_pending_stack_adjust ();
5232 /* This might get an spurious warning in the presence of a syntax error;
5233 it could be fixed by moving the call to check_seenlabel after the
5234 check for error_mark_node, and copying the code of check_seenlabel that
5235 deals with case_stack->data.case_stmt.line_number_status /
5236 restore_line_number_status in front of the call to end_cleanup_deferral;
5237 However, this might miss some useful warnings in the presence of
5238 non-syntax errors. */
5241 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5242 if (index_type != error_mark_node)
5244 /* If switch expression was an enumerated type, check that all
5245 enumeration literals are covered by the cases.
5246 No sense trying this if there's a default case, however. */
5248 if (!thiscase->data.case_stmt.default_label
5249 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
5250 && TREE_CODE (index_expr) != INTEGER_CST)
5251 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
5253 /* If we don't have a default-label, create one here,
5254 after the body of the switch. */
5255 if (thiscase->data.case_stmt.default_label == 0)
5257 thiscase->data.case_stmt.default_label
5258 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5259 expand_label (thiscase->data.case_stmt.default_label);
5261 default_label = label_rtx (thiscase->data.case_stmt.default_label);
5263 before_case = get_last_insn ();
5265 if (thiscase->data.case_stmt.case_list
5266 && thiscase->data.case_stmt.case_list->left)
5267 thiscase->data.case_stmt.case_list
5268 = case_tree2list(thiscase->data.case_stmt.case_list, 0);
5270 /* Simplify the case-list before we count it. */
5271 group_case_nodes (thiscase->data.case_stmt.case_list);
5273 /* Get upper and lower bounds of case values.
5274 Also convert all the case values to the index expr's data type. */
5277 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5279 /* Check low and high label values are integers. */
5280 if (TREE_CODE (n->low) != INTEGER_CST)
5282 if (TREE_CODE (n->high) != INTEGER_CST)
5285 n->low = convert (index_type, n->low);
5286 n->high = convert (index_type, n->high);
5288 /* Count the elements and track the largest and smallest
5289 of them (treating them as signed even if they are not). */
5297 if (INT_CST_LT (n->low, minval))
5299 if (INT_CST_LT (maxval, n->high))
5302 /* A range counts double, since it requires two compares. */
5303 if (! tree_int_cst_equal (n->low, n->high))
5307 orig_minval = minval;
5309 /* Compute span of values. */
5311 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
5313 end_cleanup_deferral ();
5317 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
5319 emit_jump (default_label);
5322 /* If range of values is much bigger than number of values,
5323 make a sequence of conditional branches instead of a dispatch.
5324 If the switch-index is a constant, do it this way
5325 because we can optimize it. */
5327 #ifndef CASE_VALUES_THRESHOLD
5329 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
5331 /* If machine does not have a case insn that compares the
5332 bounds, this means extra overhead for dispatch tables
5333 which raises the threshold for using them. */
5334 #define CASE_VALUES_THRESHOLD 5
5335 #endif /* HAVE_casesi */
5336 #endif /* CASE_VALUES_THRESHOLD */
5338 else if (TREE_INT_CST_HIGH (range) != 0
5339 || count < (unsigned int) CASE_VALUES_THRESHOLD
5340 || ((unsigned HOST_WIDE_INT) (TREE_INT_CST_LOW (range))
5342 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5345 || TREE_CODE (index_expr) == INTEGER_CST
5346 /* These will reduce to a constant. */
5347 || (TREE_CODE (index_expr) == CALL_EXPR
5348 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
5349 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
5350 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
5351 || (TREE_CODE (index_expr) == COMPOUND_EXPR
5352 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
5354 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5356 /* If the index is a short or char that we do not have
5357 an insn to handle comparisons directly, convert it to
5358 a full integer now, rather than letting each comparison
5359 generate the conversion. */
5361 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
5362 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
5363 == CODE_FOR_nothing))
5365 enum machine_mode wider_mode;
5366 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
5367 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
5368 if (cmp_optab->handlers[(int) wider_mode].insn_code
5369 != CODE_FOR_nothing)
5371 index = convert_to_mode (wider_mode, index, unsignedp);
5377 do_pending_stack_adjust ();
5379 index = protect_from_queue (index, 0);
5380 if (GET_CODE (index) == MEM)
5381 index = copy_to_reg (index);
5382 if (GET_CODE (index) == CONST_INT
5383 || TREE_CODE (index_expr) == INTEGER_CST)
5385 /* Make a tree node with the proper constant value
5386 if we don't already have one. */
5387 if (TREE_CODE (index_expr) != INTEGER_CST)
5390 = build_int_2 (INTVAL (index),
5391 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
5392 index_expr = convert (index_type, index_expr);
5395 /* For constant index expressions we need only
5396 issue a unconditional branch to the appropriate
5397 target code. The job of removing any unreachable
5398 code is left to the optimisation phase if the
5399 "-O" option is specified. */
5400 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5401 if (! tree_int_cst_lt (index_expr, n->low)
5402 && ! tree_int_cst_lt (n->high, index_expr))
5406 emit_jump (label_rtx (n->code_label));
5408 emit_jump (default_label);
5412 /* If the index expression is not constant we generate
5413 a binary decision tree to select the appropriate
5414 target code. This is done as follows:
5416 The list of cases is rearranged into a binary tree,
5417 nearly optimal assuming equal probability for each case.
5419 The tree is transformed into RTL, eliminating
5420 redundant test conditions at the same time.
5422 If program flow could reach the end of the
5423 decision tree an unconditional jump to the
5424 default code is emitted. */
5427 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
5428 && estimate_case_costs (thiscase->data.case_stmt.case_list));
5429 balance_case_nodes (&thiscase->data.case_stmt.case_list,
5431 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
5432 default_label, index_type);
5433 emit_jump_if_reachable (default_label);
5442 enum machine_mode index_mode = SImode;
5443 int index_bits = GET_MODE_BITSIZE (index_mode);
5445 enum machine_mode op_mode;
5447 /* Convert the index to SImode. */
5448 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
5449 > GET_MODE_BITSIZE (index_mode))
5451 enum machine_mode omode = TYPE_MODE (index_type);
5452 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
5454 /* We must handle the endpoints in the original mode. */
5455 index_expr = build (MINUS_EXPR, index_type,
5456 index_expr, minval);
5457 minval = integer_zero_node;
5458 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5459 emit_cmp_and_jump_insns (rangertx, index, LTU, NULL_RTX,
5460 omode, 1, 0, default_label);
5461 /* Now we can safely truncate. */
5462 index = convert_to_mode (index_mode, index, 0);
5466 if (TYPE_MODE (index_type) != index_mode)
5468 index_expr = convert (type_for_size (index_bits, 0),
5470 index_type = TREE_TYPE (index_expr);
5473 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5476 index = protect_from_queue (index, 0);
5477 do_pending_stack_adjust ();
5479 op_mode = insn_data[(int)CODE_FOR_casesi].operand[0].mode;
5480 if (! (*insn_data[(int)CODE_FOR_casesi].operand[0].predicate)
5482 index = copy_to_mode_reg (op_mode, index);
5484 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
5486 op_mode = insn_data[(int)CODE_FOR_casesi].operand[1].mode;
5487 if (! (*insn_data[(int)CODE_FOR_casesi].operand[1].predicate)
5489 op1 = copy_to_mode_reg (op_mode, op1);
5491 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
5493 op_mode = insn_data[(int)CODE_FOR_casesi].operand[2].mode;
5494 if (! (*insn_data[(int)CODE_FOR_casesi].operand[2].predicate)
5496 op2 = copy_to_mode_reg (op_mode, op2);
5498 emit_jump_insn (gen_casesi (index, op1, op2,
5499 table_label, default_label));
5503 #ifdef HAVE_tablejump
5504 if (! win && HAVE_tablejump)
5506 index_expr = convert (thiscase->data.case_stmt.nominal_type,
5507 fold (build (MINUS_EXPR, index_type,
5508 index_expr, minval)));
5509 index_type = TREE_TYPE (index_expr);
5510 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5512 index = protect_from_queue (index, 0);
5513 do_pending_stack_adjust ();
5515 do_tablejump (index, TYPE_MODE (index_type),
5516 expand_expr (range, NULL_RTX, VOIDmode, 0),
5517 table_label, default_label);
5524 /* Get table of labels to jump to, in order of case index. */
5526 ncases = TREE_INT_CST_LOW (range) + 1;
5527 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
5528 bzero ((char *) labelvec, ncases * sizeof (rtx));
5530 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5532 register HOST_WIDE_INT i
5533 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
5538 = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
5539 if (i + TREE_INT_CST_LOW (orig_minval)
5540 == TREE_INT_CST_LOW (n->high))
5546 /* Fill in the gaps with the default. */
5547 for (i = 0; i < ncases; i++)
5548 if (labelvec[i] == 0)
5549 labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
5551 /* Output the table */
5552 emit_label (table_label);
5554 if (CASE_VECTOR_PC_RELATIVE || flag_pic)
5555 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
5556 gen_rtx_LABEL_REF (Pmode, table_label),
5557 gen_rtvec_v (ncases, labelvec),
5558 const0_rtx, const0_rtx));
5560 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
5561 gen_rtvec_v (ncases, labelvec)));
5563 /* If the case insn drops through the table,
5564 after the table we must jump to the default-label.
5565 Otherwise record no drop-through after the table. */
5566 #ifdef CASE_DROPS_THROUGH
5567 emit_jump (default_label);
5573 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
5574 reorder_insns (before_case, get_last_insn (),
5575 thiscase->data.case_stmt.start);
5578 end_cleanup_deferral ();
5580 if (thiscase->exit_label)
5581 emit_label (thiscase->exit_label);
5583 POPSTACK (case_stack);
5588 /* Convert the tree NODE into a list linked by the right field, with the left
5589 field zeroed. RIGHT is used for recursion; it is a list to be placed
5590 rightmost in the resulting list. */
5592 static struct case_node *
5593 case_tree2list (node, right)
5594 struct case_node *node, *right;
5596 struct case_node *left;
5599 right = case_tree2list (node->right, right);
5601 node->right = right;
5602 if ((left = node->left))
5605 return case_tree2list (left, node);
5611 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5614 do_jump_if_equal (op1, op2, label, unsignedp)
5615 rtx op1, op2, label;
5618 if (GET_CODE (op1) == CONST_INT
5619 && GET_CODE (op2) == CONST_INT)
5621 if (INTVAL (op1) == INTVAL (op2))
5626 enum machine_mode mode = GET_MODE (op1);
5627 if (mode == VOIDmode)
5628 mode = GET_MODE (op2);
5629 emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX, mode, unsignedp,
5634 /* Not all case values are encountered equally. This function
5635 uses a heuristic to weight case labels, in cases where that
5636 looks like a reasonable thing to do.
5638 Right now, all we try to guess is text, and we establish the
5641 chars above space: 16
5650 If we find any cases in the switch that are not either -1 or in the range
5651 of valid ASCII characters, or are control characters other than those
5652 commonly used with "\", don't treat this switch scanning text.
5654 Return 1 if these nodes are suitable for cost estimation, otherwise
5658 estimate_case_costs (node)
5661 tree min_ascii = build_int_2 (-1, -1);
5662 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5666 /* If we haven't already made the cost table, make it now. Note that the
5667 lower bound of the table is -1, not zero. */
5669 if (cost_table == NULL)
5671 cost_table = ((short *) xcalloc (129, sizeof (short))) + 1;
5673 for (i = 0; i < 128; i++)
5677 else if (ISPUNCT (i))
5679 else if (ISCNTRL (i))
5683 cost_table[' '] = 8;
5684 cost_table['\t'] = 4;
5685 cost_table['\0'] = 4;
5686 cost_table['\n'] = 2;
5687 cost_table['\f'] = 1;
5688 cost_table['\v'] = 1;
5689 cost_table['\b'] = 1;
5692 /* See if all the case expressions look like text. It is text if the
5693 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5694 as signed arithmetic since we don't want to ever access cost_table with a
5695 value less than -1. Also check that none of the constants in a range
5696 are strange control characters. */
5698 for (n = node; n; n = n->right)
5700 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5703 for (i = TREE_INT_CST_LOW (n->low); i <= TREE_INT_CST_LOW (n->high); i++)
5704 if (cost_table[i] < 0)
5708 /* All interesting values are within the range of interesting
5709 ASCII characters. */
5713 /* Scan an ordered list of case nodes
5714 combining those with consecutive values or ranges.
5716 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5719 group_case_nodes (head)
5722 case_node_ptr node = head;
5726 rtx lb = next_real_insn (label_rtx (node->code_label));
5728 case_node_ptr np = node;
5730 /* Try to group the successors of NODE with NODE. */
5731 while (((np = np->right) != 0)
5732 /* Do they jump to the same place? */
5733 && ((lb2 = next_real_insn (label_rtx (np->code_label))) == lb
5734 || (lb != 0 && lb2 != 0
5735 && simplejump_p (lb)
5736 && simplejump_p (lb2)
5737 && rtx_equal_p (SET_SRC (PATTERN (lb)),
5738 SET_SRC (PATTERN (lb2)))))
5739 /* Are their ranges consecutive? */
5740 && tree_int_cst_equal (np->low,
5741 fold (build (PLUS_EXPR,
5742 TREE_TYPE (node->high),
5745 /* An overflow is not consecutive. */
5746 && tree_int_cst_lt (node->high,
5747 fold (build (PLUS_EXPR,
5748 TREE_TYPE (node->high),
5750 integer_one_node))))
5752 node->high = np->high;
5754 /* NP is the first node after NODE which can't be grouped with it.
5755 Delete the nodes in between, and move on to that node. */
5761 /* Take an ordered list of case nodes
5762 and transform them into a near optimal binary tree,
5763 on the assumption that any target code selection value is as
5764 likely as any other.
5766 The transformation is performed by splitting the ordered
5767 list into two equal sections plus a pivot. The parts are
5768 then attached to the pivot as left and right branches. Each
5769 branch is then transformed recursively. */
5772 balance_case_nodes (head, parent)
5773 case_node_ptr *head;
5774 case_node_ptr parent;
5776 register case_node_ptr np;
5784 register case_node_ptr *npp;
5787 /* Count the number of entries on branch. Also count the ranges. */
5791 if (!tree_int_cst_equal (np->low, np->high))
5795 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5799 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5807 /* Split this list if it is long enough for that to help. */
5812 /* Find the place in the list that bisects the list's total cost,
5813 Here I gets half the total cost. */
5818 /* Skip nodes while their cost does not reach that amount. */
5819 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5820 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5821 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5824 npp = &(*npp)->right;
5829 /* Leave this branch lopsided, but optimize left-hand
5830 side and fill in `parent' fields for right-hand side. */
5832 np->parent = parent;
5833 balance_case_nodes (&np->left, np);
5834 for (; np->right; np = np->right)
5835 np->right->parent = np;
5839 /* If there are just three nodes, split at the middle one. */
5841 npp = &(*npp)->right;
5844 /* Find the place in the list that bisects the list's total cost,
5845 where ranges count as 2.
5846 Here I gets half the total cost. */
5847 i = (i + ranges + 1) / 2;
5850 /* Skip nodes while their cost does not reach that amount. */
5851 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5856 npp = &(*npp)->right;
5861 np->parent = parent;
5864 /* Optimize each of the two split parts. */
5865 balance_case_nodes (&np->left, np);
5866 balance_case_nodes (&np->right, np);
5870 /* Else leave this branch as one level,
5871 but fill in `parent' fields. */
5873 np->parent = parent;
5874 for (; np->right; np = np->right)
5875 np->right->parent = np;
5880 /* Search the parent sections of the case node tree
5881 to see if a test for the lower bound of NODE would be redundant.
5882 INDEX_TYPE is the type of the index expression.
5884 The instructions to generate the case decision tree are
5885 output in the same order as nodes are processed so it is
5886 known that if a parent node checks the range of the current
5887 node minus one that the current node is bounded at its lower
5888 span. Thus the test would be redundant. */
5891 node_has_low_bound (node, index_type)
5896 case_node_ptr pnode;
5898 /* If the lower bound of this node is the lowest value in the index type,
5899 we need not test it. */
5901 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5904 /* If this node has a left branch, the value at the left must be less
5905 than that at this node, so it cannot be bounded at the bottom and
5906 we need not bother testing any further. */
5911 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5912 node->low, integer_one_node));
5914 /* If the subtraction above overflowed, we can't verify anything.
5915 Otherwise, look for a parent that tests our value - 1. */
5917 if (! tree_int_cst_lt (low_minus_one, node->low))
5920 for (pnode = node->parent; pnode; pnode = pnode->parent)
5921 if (tree_int_cst_equal (low_minus_one, pnode->high))
5927 /* Search the parent sections of the case node tree
5928 to see if a test for the upper bound of NODE would be redundant.
5929 INDEX_TYPE is the type of the index expression.
5931 The instructions to generate the case decision tree are
5932 output in the same order as nodes are processed so it is
5933 known that if a parent node checks the range of the current
5934 node plus one that the current node is bounded at its upper
5935 span. Thus the test would be redundant. */
5938 node_has_high_bound (node, index_type)
5943 case_node_ptr pnode;
5945 /* If there is no upper bound, obviously no test is needed. */
5947 if (TYPE_MAX_VALUE (index_type) == NULL)
5950 /* If the upper bound of this node is the highest value in the type
5951 of the index expression, we need not test against it. */
5953 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
5956 /* If this node has a right branch, the value at the right must be greater
5957 than that at this node, so it cannot be bounded at the top and
5958 we need not bother testing any further. */
5963 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
5964 node->high, integer_one_node));
5966 /* If the addition above overflowed, we can't verify anything.
5967 Otherwise, look for a parent that tests our value + 1. */
5969 if (! tree_int_cst_lt (node->high, high_plus_one))
5972 for (pnode = node->parent; pnode; pnode = pnode->parent)
5973 if (tree_int_cst_equal (high_plus_one, pnode->low))
5979 /* Search the parent sections of the
5980 case node tree to see if both tests for the upper and lower
5981 bounds of NODE would be redundant. */
5984 node_is_bounded (node, index_type)
5988 return (node_has_low_bound (node, index_type)
5989 && node_has_high_bound (node, index_type));
5992 /* Emit an unconditional jump to LABEL unless it would be dead code. */
5995 emit_jump_if_reachable (label)
5998 if (GET_CODE (get_last_insn ()) != BARRIER)
6002 /* Emit step-by-step code to select a case for the value of INDEX.
6003 The thus generated decision tree follows the form of the
6004 case-node binary tree NODE, whose nodes represent test conditions.
6005 INDEX_TYPE is the type of the index of the switch.
6007 Care is taken to prune redundant tests from the decision tree
6008 by detecting any boundary conditions already checked by
6009 emitted rtx. (See node_has_high_bound, node_has_low_bound
6010 and node_is_bounded, above.)
6012 Where the test conditions can be shown to be redundant we emit
6013 an unconditional jump to the target code. As a further
6014 optimization, the subordinates of a tree node are examined to
6015 check for bounded nodes. In this case conditional and/or
6016 unconditional jumps as a result of the boundary check for the
6017 current node are arranged to target the subordinates associated
6018 code for out of bound conditions on the current node.
6020 We can assume that when control reaches the code generated here,
6021 the index value has already been compared with the parents
6022 of this node, and determined to be on the same side of each parent
6023 as this node is. Thus, if this node tests for the value 51,
6024 and a parent tested for 52, we don't need to consider
6025 the possibility of a value greater than 51. If another parent
6026 tests for the value 50, then this node need not test anything. */
6029 emit_case_nodes (index, node, default_label, index_type)
6035 /* If INDEX has an unsigned type, we must make unsigned branches. */
6036 int unsignedp = TREE_UNSIGNED (index_type);
6037 typedef rtx rtx_fn ();
6038 enum machine_mode mode = GET_MODE (index);
6040 /* See if our parents have already tested everything for us.
6041 If they have, emit an unconditional jump for this node. */
6042 if (node_is_bounded (node, index_type))
6043 emit_jump (label_rtx (node->code_label));
6045 else if (tree_int_cst_equal (node->low, node->high))
6047 /* Node is single valued. First see if the index expression matches
6048 this node and then check our children, if any. */
6050 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
6051 label_rtx (node->code_label), unsignedp);
6053 if (node->right != 0 && node->left != 0)
6055 /* This node has children on both sides.
6056 Dispatch to one side or the other
6057 by comparing the index value with this node's value.
6058 If one subtree is bounded, check that one first,
6059 so we can avoid real branches in the tree. */
6061 if (node_is_bounded (node->right, index_type))
6063 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6065 GT, NULL_RTX, mode, unsignedp, 0,
6066 label_rtx (node->right->code_label));
6067 emit_case_nodes (index, node->left, default_label, index_type);
6070 else if (node_is_bounded (node->left, index_type))
6072 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6074 LT, NULL_RTX, mode, unsignedp, 0,
6075 label_rtx (node->left->code_label));
6076 emit_case_nodes (index, node->right, default_label, index_type);
6081 /* Neither node is bounded. First distinguish the two sides;
6082 then emit the code for one side at a time. */
6085 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6087 /* See if the value is on the right. */
6088 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6090 GT, NULL_RTX, mode, unsignedp, 0,
6091 label_rtx (test_label));
6093 /* Value must be on the left.
6094 Handle the left-hand subtree. */
6095 emit_case_nodes (index, node->left, default_label, index_type);
6096 /* If left-hand subtree does nothing,
6098 emit_jump_if_reachable (default_label);
6100 /* Code branches here for the right-hand subtree. */
6101 expand_label (test_label);
6102 emit_case_nodes (index, node->right, default_label, index_type);
6106 else if (node->right != 0 && node->left == 0)
6108 /* Here we have a right child but no left so we issue conditional
6109 branch to default and process the right child.
6111 Omit the conditional branch to default if we it avoid only one
6112 right child; it costs too much space to save so little time. */
6114 if (node->right->right || node->right->left
6115 || !tree_int_cst_equal (node->right->low, node->right->high))
6117 if (!node_has_low_bound (node, index_type))
6119 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6122 LT, NULL_RTX, mode, unsignedp, 0,
6126 emit_case_nodes (index, node->right, default_label, index_type);
6129 /* We cannot process node->right normally
6130 since we haven't ruled out the numbers less than
6131 this node's value. So handle node->right explicitly. */
6132 do_jump_if_equal (index,
6133 expand_expr (node->right->low, NULL_RTX,
6135 label_rtx (node->right->code_label), unsignedp);
6138 else if (node->right == 0 && node->left != 0)
6140 /* Just one subtree, on the left. */
6142 #if 0 /* The following code and comment were formerly part
6143 of the condition here, but they didn't work
6144 and I don't understand what the idea was. -- rms. */
6145 /* If our "most probable entry" is less probable
6146 than the default label, emit a jump to
6147 the default label using condition codes
6148 already lying around. With no right branch,
6149 a branch-greater-than will get us to the default
6152 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
6155 if (node->left->left || node->left->right
6156 || !tree_int_cst_equal (node->left->low, node->left->high))
6158 if (!node_has_high_bound (node, index_type))
6160 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6163 GT, NULL_RTX, mode, unsignedp, 0,
6167 emit_case_nodes (index, node->left, default_label, index_type);
6170 /* We cannot process node->left normally
6171 since we haven't ruled out the numbers less than
6172 this node's value. So handle node->left explicitly. */
6173 do_jump_if_equal (index,
6174 expand_expr (node->left->low, NULL_RTX,
6176 label_rtx (node->left->code_label), unsignedp);
6181 /* Node is a range. These cases are very similar to those for a single
6182 value, except that we do not start by testing whether this node
6183 is the one to branch to. */
6185 if (node->right != 0 && node->left != 0)
6187 /* Node has subtrees on both sides.
6188 If the right-hand subtree is bounded,
6189 test for it first, since we can go straight there.
6190 Otherwise, we need to make a branch in the control structure,
6191 then handle the two subtrees. */
6192 tree test_label = 0;
6195 if (node_is_bounded (node->right, index_type))
6196 /* Right hand node is fully bounded so we can eliminate any
6197 testing and branch directly to the target code. */
6198 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6200 GT, NULL_RTX, mode, unsignedp, 0,
6201 label_rtx (node->right->code_label));
6204 /* Right hand node requires testing.
6205 Branch to a label where we will handle it later. */
6207 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6208 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6210 GT, NULL_RTX, mode, unsignedp, 0,
6211 label_rtx (test_label));
6214 /* Value belongs to this node or to the left-hand subtree. */
6216 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6218 GE, NULL_RTX, mode, unsignedp, 0,
6219 label_rtx (node->code_label));
6221 /* Handle the left-hand subtree. */
6222 emit_case_nodes (index, node->left, default_label, index_type);
6224 /* If right node had to be handled later, do that now. */
6228 /* If the left-hand subtree fell through,
6229 don't let it fall into the right-hand subtree. */
6230 emit_jump_if_reachable (default_label);
6232 expand_label (test_label);
6233 emit_case_nodes (index, node->right, default_label, index_type);
6237 else if (node->right != 0 && node->left == 0)
6239 /* Deal with values to the left of this node,
6240 if they are possible. */
6241 if (!node_has_low_bound (node, index_type))
6243 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6245 LT, NULL_RTX, mode, unsignedp, 0,
6249 /* Value belongs to this node or to the right-hand subtree. */
6251 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6253 LE, NULL_RTX, mode, unsignedp, 0,
6254 label_rtx (node->code_label));
6256 emit_case_nodes (index, node->right, default_label, index_type);
6259 else if (node->right == 0 && node->left != 0)
6261 /* Deal with values to the right of this node,
6262 if they are possible. */
6263 if (!node_has_high_bound (node, index_type))
6265 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6267 GT, NULL_RTX, mode, unsignedp, 0,
6271 /* Value belongs to this node or to the left-hand subtree. */
6273 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6275 GE, NULL_RTX, mode, unsignedp, 0,
6276 label_rtx (node->code_label));
6278 emit_case_nodes (index, node->left, default_label, index_type);
6283 /* Node has no children so we check low and high bounds to remove
6284 redundant tests. Only one of the bounds can exist,
6285 since otherwise this node is bounded--a case tested already. */
6287 if (!node_has_high_bound (node, index_type))
6289 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6291 GT, NULL_RTX, mode, unsignedp, 0,
6295 if (!node_has_low_bound (node, index_type))
6297 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6299 LT, NULL_RTX, mode, unsignedp, 0,
6303 emit_jump (label_rtx (node->code_label));
6308 /* These routines are used by the loop unrolling code. They copy BLOCK trees
6309 so that the debugging info will be correct for the unrolled loop. */
6312 find_loop_tree_blocks ()
6314 identify_blocks (DECL_INITIAL (current_function_decl), get_insns ());
6318 unroll_block_trees ()
6320 tree block = DECL_INITIAL (current_function_decl);
6322 reorder_blocks (block, get_insns ());