1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000 Free Software Foundation, Inc.
5 This file is part of GNU CC.
7 GNU CC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GNU CC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNU CC; see the file COPYING. If not, write to
19 the Free Software Foundation, 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
23 /* This file handles the generation of rtl code from tree structure
24 above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
25 It also creates the rtl expressions for parameters and auto variables
26 and has full responsibility for allocating stack slots.
28 The functions whose names start with `expand_' are called by the
29 parser to generate RTL instructions for various kinds of constructs.
31 Some control and binding constructs require calling several such
32 functions at different times. For example, a simple if-then
33 is expanded by calling `expand_start_cond' (with the condition-expression
34 as argument) before parsing the then-clause and calling `expand_end_cond'
35 after parsing the then-clause. */
46 #include "insn-flags.h"
47 #include "insn-config.h"
48 #include "insn-codes.h"
50 #include "hard-reg-set.h"
59 #define obstack_chunk_alloc xmalloc
60 #define obstack_chunk_free free
61 struct obstack stmt_obstack;
63 /* Assume that case vectors are not pc-relative. */
64 #ifndef CASE_VECTOR_PC_RELATIVE
65 #define CASE_VECTOR_PC_RELATIVE 0
69 /* Functions and data structures for expanding case statements. */
71 /* Case label structure, used to hold info on labels within case
72 statements. We handle "range" labels; for a single-value label
73 as in C, the high and low limits are the same.
75 An AVL tree of case nodes is initially created, and later transformed
76 to a list linked via the RIGHT fields in the nodes. Nodes with
77 higher case values are later in the list.
79 Switch statements can be output in one of two forms. A branch table
80 is used if there are more than a few labels and the labels are dense
81 within the range between the smallest and largest case value. If a
82 branch table is used, no further manipulations are done with the case
85 The alternative to the use of a branch table is to generate a series
86 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
87 and PARENT fields to hold a binary tree. Initially the tree is
88 totally unbalanced, with everything on the right. We balance the tree
89 with nodes on the left having lower case values than the parent
90 and nodes on the right having higher values. We then output the tree
95 struct case_node *left; /* Left son in binary tree */
96 struct case_node *right; /* Right son in binary tree; also node chain */
97 struct case_node *parent; /* Parent of node in binary tree */
98 tree low; /* Lowest index value for this label */
99 tree high; /* Highest index value for this label */
100 tree code_label; /* Label to jump to when node matches */
104 typedef struct case_node case_node;
105 typedef struct case_node *case_node_ptr;
107 /* These are used by estimate_case_costs and balance_case_nodes. */
109 /* This must be a signed type, and non-ANSI compilers lack signed char. */
110 static short cost_table_[129];
111 static short *cost_table;
112 static int use_cost_table;
114 /* Stack of control and binding constructs we are currently inside.
116 These constructs begin when you call `expand_start_WHATEVER'
117 and end when you call `expand_end_WHATEVER'. This stack records
118 info about how the construct began that tells the end-function
119 what to do. It also may provide information about the construct
120 to alter the behavior of other constructs within the body.
121 For example, they may affect the behavior of C `break' and `continue'.
123 Each construct gets one `struct nesting' object.
124 All of these objects are chained through the `all' field.
125 `nesting_stack' points to the first object (innermost construct).
126 The position of an entry on `nesting_stack' is in its `depth' field.
128 Each type of construct has its own individual stack.
129 For example, loops have `loop_stack'. Each object points to the
130 next object of the same type through the `next' field.
132 Some constructs are visible to `break' exit-statements and others
133 are not. Which constructs are visible depends on the language.
134 Therefore, the data structure allows each construct to be visible
135 or not, according to the args given when the construct is started.
136 The construct is visible if the `exit_label' field is non-null.
137 In that case, the value should be a CODE_LABEL rtx. */
142 struct nesting *next;
147 /* For conds (if-then and if-then-else statements). */
150 /* Label for the end of the if construct.
151 There is none if EXITFLAG was not set
152 and no `else' has been seen yet. */
154 /* Label for the end of this alternative.
155 This may be the end of the if or the next else/elseif. */
161 /* Label at the top of the loop; place to loop back to. */
163 /* Label at the end of the whole construct. */
165 /* Label before a jump that branches to the end of the whole
166 construct. This is where destructors go if any. */
168 /* Label for `continue' statement to jump to;
169 this is in front of the stepper of the loop. */
172 /* For variable binding contours. */
175 /* Sequence number of this binding contour within the function,
176 in order of entry. */
177 int block_start_count;
178 /* Nonzero => value to restore stack to on exit. */
180 /* The NOTE that starts this contour.
181 Used by expand_goto to check whether the destination
182 is within each contour or not. */
184 /* Innermost containing binding contour that has a stack level. */
185 struct nesting *innermost_stack_block;
186 /* List of cleanups to be run on exit from this contour.
187 This is a list of expressions to be evaluated.
188 The TREE_PURPOSE of each link is the ..._DECL node
189 which the cleanup pertains to. */
191 /* List of cleanup-lists of blocks containing this block,
192 as they were at the locus where this block appears.
193 There is an element for each containing block,
194 ordered innermost containing block first.
195 The tail of this list can be 0,
196 if all remaining elements would be empty lists.
197 The element's TREE_VALUE is the cleanup-list of that block,
198 which may be null. */
200 /* Chain of labels defined inside this binding contour.
201 For contours that have stack levels or cleanups. */
202 struct label_chain *label_chain;
203 /* Number of function calls seen, as of start of this block. */
204 int n_function_calls;
205 /* Nonzero if this is associated with a EH region. */
206 int exception_region;
207 /* The saved target_temp_slot_level from our outer block.
208 We may reset target_temp_slot_level to be the level of
209 this block, if that is done, target_temp_slot_level
210 reverts to the saved target_temp_slot_level at the very
212 int block_target_temp_slot_level;
213 /* True if we are currently emitting insns in an area of
214 output code that is controlled by a conditional
215 expression. This is used by the cleanup handling code to
216 generate conditional cleanup actions. */
217 int conditional_code;
218 /* A place to move the start of the exception region for any
219 of the conditional cleanups, must be at the end or after
220 the start of the last unconditional cleanup, and before any
221 conditional branch points. */
222 rtx last_unconditional_cleanup;
223 /* When in a conditional context, this is the specific
224 cleanup list associated with last_unconditional_cleanup,
225 where we place the conditionalized cleanups. */
228 /* For switch (C) or case (Pascal) statements,
229 and also for dummies (see `expand_start_case_dummy'). */
232 /* The insn after which the case dispatch should finally
233 be emitted. Zero for a dummy. */
235 /* A list of case labels; it is first built as an AVL tree.
236 During expand_end_case, this is converted to a list, and may be
237 rearranged into a nearly balanced binary tree. */
238 struct case_node *case_list;
239 /* Label to jump to if no case matches. */
241 /* The expression to be dispatched on. */
243 /* Type that INDEX_EXPR should be converted to. */
245 /* Number of range exprs in case statement. */
247 /* Name of this kind of statement, for warnings. */
248 const char *printname;
249 /* Used to save no_line_numbers till we see the first case label.
250 We set this to -1 when we see the first case label in this
252 int line_number_status;
257 /* Allocate and return a new `struct nesting'. */
259 #define ALLOC_NESTING() \
260 (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
262 /* Pop the nesting stack element by element until we pop off
263 the element which is at the top of STACK.
264 Update all the other stacks, popping off elements from them
265 as we pop them from nesting_stack. */
267 #define POPSTACK(STACK) \
268 do { struct nesting *target = STACK; \
269 struct nesting *this; \
270 do { this = nesting_stack; \
271 if (loop_stack == this) \
272 loop_stack = loop_stack->next; \
273 if (cond_stack == this) \
274 cond_stack = cond_stack->next; \
275 if (block_stack == this) \
276 block_stack = block_stack->next; \
277 if (stack_block_stack == this) \
278 stack_block_stack = stack_block_stack->next; \
279 if (case_stack == this) \
280 case_stack = case_stack->next; \
281 nesting_depth = nesting_stack->depth - 1; \
282 nesting_stack = this->all; \
283 obstack_free (&stmt_obstack, this); } \
284 while (this != target); } while (0)
286 /* In some cases it is impossible to generate code for a forward goto
287 until the label definition is seen. This happens when it may be necessary
288 for the goto to reset the stack pointer: we don't yet know how to do that.
289 So expand_goto puts an entry on this fixup list.
290 Each time a binding contour that resets the stack is exited,
292 If the target label has now been defined, we can insert the proper code. */
296 /* Points to following fixup. */
297 struct goto_fixup *next;
298 /* Points to the insn before the jump insn.
299 If more code must be inserted, it goes after this insn. */
301 /* The LABEL_DECL that this jump is jumping to, or 0
302 for break, continue or return. */
304 /* The BLOCK for the place where this goto was found. */
306 /* The CODE_LABEL rtx that this is jumping to. */
308 /* Number of binding contours started in current function
309 before the label reference. */
310 int block_start_count;
311 /* The outermost stack level that should be restored for this jump.
312 Each time a binding contour that resets the stack is exited,
313 if the target label is *not* yet defined, this slot is updated. */
315 /* List of lists of cleanup expressions to be run by this goto.
316 There is one element for each block that this goto is within.
317 The tail of this list can be 0,
318 if all remaining elements would be empty.
319 The TREE_VALUE contains the cleanup list of that block as of the
320 time this goto was seen.
321 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
322 tree cleanup_list_list;
325 /* Within any binding contour that must restore a stack level,
326 all labels are recorded with a chain of these structures. */
330 /* Points to following fixup. */
331 struct label_chain *next;
337 /* Chain of all pending binding contours. */
338 struct nesting *x_block_stack;
340 /* If any new stacks are added here, add them to POPSTACKS too. */
342 /* Chain of all pending binding contours that restore stack levels
344 struct nesting *x_stack_block_stack;
346 /* Chain of all pending conditional statements. */
347 struct nesting *x_cond_stack;
349 /* Chain of all pending loops. */
350 struct nesting *x_loop_stack;
352 /* Chain of all pending case or switch statements. */
353 struct nesting *x_case_stack;
355 /* Separate chain including all of the above,
356 chained through the `all' field. */
357 struct nesting *x_nesting_stack;
359 /* Number of entries on nesting_stack now. */
362 /* Number of binding contours started so far in this function. */
363 int x_block_start_count;
365 /* Each time we expand an expression-statement,
366 record the expr's type and its RTL value here. */
367 tree x_last_expr_type;
368 rtx x_last_expr_value;
370 /* Nonzero if within a ({...}) grouping, in which case we must
371 always compute a value for each expr-stmt in case it is the last one. */
372 int x_expr_stmts_for_value;
374 /* Filename and line number of last line-number note,
375 whether we actually emitted it or not. */
376 const char *x_emit_filename;
379 struct goto_fixup *x_goto_fixup_chain;
382 #define block_stack (cfun->stmt->x_block_stack)
383 #define stack_block_stack (cfun->stmt->x_stack_block_stack)
384 #define cond_stack (cfun->stmt->x_cond_stack)
385 #define loop_stack (cfun->stmt->x_loop_stack)
386 #define case_stack (cfun->stmt->x_case_stack)
387 #define nesting_stack (cfun->stmt->x_nesting_stack)
388 #define nesting_depth (cfun->stmt->x_nesting_depth)
389 #define current_block_start_count (cfun->stmt->x_block_start_count)
390 #define last_expr_type (cfun->stmt->x_last_expr_type)
391 #define last_expr_value (cfun->stmt->x_last_expr_value)
392 #define expr_stmts_for_value (cfun->stmt->x_expr_stmts_for_value)
393 #define emit_filename (cfun->stmt->x_emit_filename)
394 #define emit_lineno (cfun->stmt->x_emit_lineno)
395 #define goto_fixup_chain (cfun->stmt->x_goto_fixup_chain)
397 /* Non-zero if we are using EH to handle cleanus. */
398 static int using_eh_for_cleanups_p = 0;
400 /* Character strings, each containing a single decimal digit. */
401 static char *digit_strings[10];
404 static int n_occurrences PARAMS ((int, const char *));
405 static void expand_goto_internal PARAMS ((tree, rtx, rtx));
406 static int expand_fixup PARAMS ((tree, rtx, rtx));
407 static rtx expand_nl_handler_label PARAMS ((rtx, rtx));
408 static void expand_nl_goto_receiver PARAMS ((void));
409 static void expand_nl_goto_receivers PARAMS ((struct nesting *));
410 static void fixup_gotos PARAMS ((struct nesting *, rtx, tree,
412 static void expand_null_return_1 PARAMS ((rtx, int));
413 static void expand_value_return PARAMS ((rtx));
414 static int tail_recursion_args PARAMS ((tree, tree));
415 static void expand_cleanups PARAMS ((tree, tree, int, int));
416 static void check_seenlabel PARAMS ((void));
417 static void do_jump_if_equal PARAMS ((rtx, rtx, rtx, int));
418 static int estimate_case_costs PARAMS ((case_node_ptr));
419 static void group_case_nodes PARAMS ((case_node_ptr));
420 static void balance_case_nodes PARAMS ((case_node_ptr *,
422 static int node_has_low_bound PARAMS ((case_node_ptr, tree));
423 static int node_has_high_bound PARAMS ((case_node_ptr, tree));
424 static int node_is_bounded PARAMS ((case_node_ptr, tree));
425 static void emit_jump_if_reachable PARAMS ((rtx));
426 static void emit_case_nodes PARAMS ((rtx, case_node_ptr, rtx, tree));
427 static int add_case_node PARAMS ((tree, tree, tree, tree *));
428 static struct case_node *case_tree2list PARAMS ((case_node *, case_node *));
429 static void mark_cond_nesting PARAMS ((struct nesting *));
430 static void mark_loop_nesting PARAMS ((struct nesting *));
431 static void mark_block_nesting PARAMS ((struct nesting *));
432 static void mark_case_nesting PARAMS ((struct nesting *));
433 static void mark_case_node PARAMS ((struct case_node *));
434 static void mark_goto_fixup PARAMS ((struct goto_fixup *));
438 using_eh_for_cleanups ()
440 using_eh_for_cleanups_p = 1;
443 /* Mark N (known to be a cond-nesting) for GC. */
446 mark_cond_nesting (n)
451 ggc_mark_rtx (n->exit_label);
452 ggc_mark_rtx (n->data.cond.endif_label);
453 ggc_mark_rtx (n->data.cond.next_label);
459 /* Mark N (known to be a loop-nesting) for GC. */
462 mark_loop_nesting (n)
468 ggc_mark_rtx (n->exit_label);
469 ggc_mark_rtx (n->data.loop.start_label);
470 ggc_mark_rtx (n->data.loop.end_label);
471 ggc_mark_rtx (n->data.loop.alt_end_label);
472 ggc_mark_rtx (n->data.loop.continue_label);
478 /* Mark N (known to be a block-nesting) for GC. */
481 mark_block_nesting (n)
486 struct label_chain *l;
488 ggc_mark_rtx (n->exit_label);
489 ggc_mark_rtx (n->data.block.stack_level);
490 ggc_mark_rtx (n->data.block.first_insn);
491 ggc_mark_tree (n->data.block.cleanups);
492 ggc_mark_tree (n->data.block.outer_cleanups);
494 for (l = n->data.block.label_chain; l != NULL; l = l->next)
495 ggc_mark_tree (l->label);
497 ggc_mark_rtx (n->data.block.last_unconditional_cleanup);
499 /* ??? cleanup_ptr never points outside the stack, does it? */
505 /* Mark N (known to be a case-nesting) for GC. */
508 mark_case_nesting (n)
513 ggc_mark_rtx (n->exit_label);
514 ggc_mark_rtx (n->data.case_stmt.start);
516 ggc_mark_tree (n->data.case_stmt.default_label);
517 ggc_mark_tree (n->data.case_stmt.index_expr);
518 ggc_mark_tree (n->data.case_stmt.nominal_type);
520 mark_case_node (n->data.case_stmt.case_list);
533 ggc_mark_tree (c->low);
534 ggc_mark_tree (c->high);
535 ggc_mark_tree (c->code_label);
537 mark_case_node (c->right);
538 mark_case_node (c->left);
546 struct goto_fixup *g;
551 ggc_mark_rtx (g->before_jump);
552 ggc_mark_tree (g->target);
553 ggc_mark_tree (g->context);
554 ggc_mark_rtx (g->target_rtl);
555 ggc_mark_rtx (g->stack_level);
556 ggc_mark_tree (g->cleanup_list_list);
562 /* Clear out all parts of the state in F that can safely be discarded
563 after the function has been compiled, to let garbage collection
564 reclaim the memory. */
570 /* We're about to free the function obstack. If we hold pointers to
571 things allocated there, then we'll try to mark them when we do
572 GC. So, we clear them out here explicitly. */
582 struct stmt_status *p;
587 mark_block_nesting (p->x_block_stack);
588 mark_cond_nesting (p->x_cond_stack);
589 mark_loop_nesting (p->x_loop_stack);
590 mark_case_nesting (p->x_case_stack);
592 ggc_mark_tree (p->x_last_expr_type);
593 /* last_epxr_value is only valid if last_expr_type is nonzero. */
594 if (p->x_last_expr_type)
595 ggc_mark_rtx (p->x_last_expr_value);
597 mark_goto_fixup (p->x_goto_fixup_chain);
605 gcc_obstack_init (&stmt_obstack);
607 for (i = 0; i < 10; i++)
609 digit_strings[i] = ggc_alloc_string (NULL, 1);
610 digit_strings[i][0] = '0' + i;
612 ggc_add_string_root (digit_strings, 10);
616 init_stmt_for_function ()
618 cfun->stmt = (struct stmt_status *) xmalloc (sizeof (struct stmt_status));
620 /* We are not currently within any block, conditional, loop or case. */
622 stack_block_stack = 0;
629 current_block_start_count = 0;
631 /* No gotos have been expanded yet. */
632 goto_fixup_chain = 0;
634 /* We are not processing a ({...}) grouping. */
635 expr_stmts_for_value = 0;
637 last_expr_value = NULL_RTX;
640 /* Return nonzero if anything is pushed on the loop, condition, or case
645 return cond_stack || loop_stack || case_stack;
648 /* Record the current file and line. Called from emit_line_note. */
650 set_file_and_line_for_stmt (file, line)
654 /* If we're outputting an inline function, and we add a line note,
655 there may be no CFUN->STMT information. So, there's no need to
659 emit_filename = file;
664 /* Emit a no-op instruction. */
671 last_insn = get_last_insn ();
673 && (GET_CODE (last_insn) == CODE_LABEL
674 || (GET_CODE (last_insn) == NOTE
675 && prev_real_insn (last_insn) == 0)))
676 emit_insn (gen_nop ());
679 /* Return the rtx-label that corresponds to a LABEL_DECL,
680 creating it if necessary. */
686 if (TREE_CODE (label) != LABEL_DECL)
689 if (DECL_RTL (label))
690 return DECL_RTL (label);
692 return DECL_RTL (label) = gen_label_rtx ();
695 /* Add an unconditional jump to LABEL as the next sequential instruction. */
701 do_pending_stack_adjust ();
702 emit_jump_insn (gen_jump (label));
706 /* Emit code to jump to the address
707 specified by the pointer expression EXP. */
710 expand_computed_goto (exp)
713 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
715 #ifdef POINTERS_EXTEND_UNSIGNED
716 x = convert_memory_address (Pmode, x);
720 /* Be sure the function is executable. */
721 if (current_function_check_memory_usage)
722 emit_library_call (chkr_check_exec_libfunc, 1,
723 VOIDmode, 1, x, ptr_mode);
725 do_pending_stack_adjust ();
726 emit_indirect_jump (x);
728 current_function_has_computed_jump = 1;
731 /* Handle goto statements and the labels that they can go to. */
733 /* Specify the location in the RTL code of a label LABEL,
734 which is a LABEL_DECL tree node.
736 This is used for the kind of label that the user can jump to with a
737 goto statement, and for alternatives of a switch or case statement.
738 RTL labels generated for loops and conditionals don't go through here;
739 they are generated directly at the RTL level, by other functions below.
741 Note that this has nothing to do with defining label *names*.
742 Languages vary in how they do that and what that even means. */
748 struct label_chain *p;
750 do_pending_stack_adjust ();
751 emit_label (label_rtx (label));
752 if (DECL_NAME (label))
753 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
755 if (stack_block_stack != 0)
757 p = (struct label_chain *) oballoc (sizeof (struct label_chain));
758 p->next = stack_block_stack->data.block.label_chain;
759 stack_block_stack->data.block.label_chain = p;
764 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
765 from nested functions. */
768 declare_nonlocal_label (label)
771 rtx slot = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
773 nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
774 LABEL_PRESERVE_P (label_rtx (label)) = 1;
775 if (nonlocal_goto_handler_slots == 0)
777 emit_stack_save (SAVE_NONLOCAL,
778 &nonlocal_goto_stack_level,
779 PREV_INSN (tail_recursion_reentry));
781 nonlocal_goto_handler_slots
782 = gen_rtx_EXPR_LIST (VOIDmode, slot, nonlocal_goto_handler_slots);
785 /* Generate RTL code for a `goto' statement with target label LABEL.
786 LABEL should be a LABEL_DECL tree node that was or will later be
787 defined with `expand_label'. */
795 /* Check for a nonlocal goto to a containing function. */
796 context = decl_function_context (label);
797 if (context != 0 && context != current_function_decl)
799 struct function *p = find_function_data (context);
800 rtx label_ref = gen_rtx_LABEL_REF (Pmode, label_rtx (label));
801 rtx temp, handler_slot;
804 /* Find the corresponding handler slot for this label. */
805 handler_slot = p->x_nonlocal_goto_handler_slots;
806 for (link = p->x_nonlocal_labels; TREE_VALUE (link) != label;
807 link = TREE_CHAIN (link))
808 handler_slot = XEXP (handler_slot, 1);
809 handler_slot = XEXP (handler_slot, 0);
811 p->has_nonlocal_label = 1;
812 current_function_has_nonlocal_goto = 1;
813 LABEL_REF_NONLOCAL_P (label_ref) = 1;
815 /* Copy the rtl for the slots so that they won't be shared in
816 case the virtual stack vars register gets instantiated differently
817 in the parent than in the child. */
819 #if HAVE_nonlocal_goto
820 if (HAVE_nonlocal_goto)
821 emit_insn (gen_nonlocal_goto (lookup_static_chain (label),
822 copy_rtx (handler_slot),
823 copy_rtx (p->x_nonlocal_goto_stack_level),
830 /* Restore frame pointer for containing function.
831 This sets the actual hard register used for the frame pointer
832 to the location of the function's incoming static chain info.
833 The non-local goto handler will then adjust it to contain the
834 proper value and reload the argument pointer, if needed. */
835 emit_move_insn (hard_frame_pointer_rtx, lookup_static_chain (label));
837 /* We have now loaded the frame pointer hardware register with
838 the address of that corresponds to the start of the virtual
839 stack vars. So replace virtual_stack_vars_rtx in all
840 addresses we use with stack_pointer_rtx. */
842 /* Get addr of containing function's current nonlocal goto handler,
843 which will do any cleanups and then jump to the label. */
844 addr = copy_rtx (handler_slot);
845 temp = copy_to_reg (replace_rtx (addr, virtual_stack_vars_rtx,
846 hard_frame_pointer_rtx));
848 /* Restore the stack pointer. Note this uses fp just restored. */
849 addr = p->x_nonlocal_goto_stack_level;
851 addr = replace_rtx (copy_rtx (addr),
852 virtual_stack_vars_rtx,
853 hard_frame_pointer_rtx);
855 emit_stack_restore (SAVE_NONLOCAL, addr, NULL_RTX);
857 /* USE of hard_frame_pointer_rtx added for consistency; not clear if
859 emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx));
860 emit_insn (gen_rtx_USE (VOIDmode, stack_pointer_rtx));
861 emit_indirect_jump (temp);
865 expand_goto_internal (label, label_rtx (label), NULL_RTX);
868 /* Generate RTL code for a `goto' statement with target label BODY.
869 LABEL should be a LABEL_REF.
870 LAST_INSN, if non-0, is the rtx we should consider as the last
871 insn emitted (for the purposes of cleaning up a return). */
874 expand_goto_internal (body, label, last_insn)
879 struct nesting *block;
882 if (GET_CODE (label) != CODE_LABEL)
885 /* If label has already been defined, we can tell now
886 whether and how we must alter the stack level. */
888 if (PREV_INSN (label) != 0)
890 /* Find the innermost pending block that contains the label.
891 (Check containment by comparing insn-uids.)
892 Then restore the outermost stack level within that block,
893 and do cleanups of all blocks contained in it. */
894 for (block = block_stack; block; block = block->next)
896 if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
898 if (block->data.block.stack_level != 0)
899 stack_level = block->data.block.stack_level;
900 /* Execute the cleanups for blocks we are exiting. */
901 if (block->data.block.cleanups != 0)
903 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
904 do_pending_stack_adjust ();
910 /* Ensure stack adjust isn't done by emit_jump, as this
911 would clobber the stack pointer. This one should be
912 deleted as dead by flow. */
913 clear_pending_stack_adjust ();
914 do_pending_stack_adjust ();
915 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
918 if (body != 0 && DECL_TOO_LATE (body))
919 error ("jump to `%s' invalidly jumps into binding contour",
920 IDENTIFIER_POINTER (DECL_NAME (body)));
922 /* Label not yet defined: may need to put this goto
923 on the fixup list. */
924 else if (! expand_fixup (body, label, last_insn))
926 /* No fixup needed. Record that the label is the target
927 of at least one goto that has no fixup. */
929 TREE_ADDRESSABLE (body) = 1;
935 /* Generate if necessary a fixup for a goto
936 whose target label in tree structure (if any) is TREE_LABEL
937 and whose target in rtl is RTL_LABEL.
939 If LAST_INSN is nonzero, we pretend that the jump appears
940 after insn LAST_INSN instead of at the current point in the insn stream.
942 The fixup will be used later to insert insns just before the goto.
943 Those insns will restore the stack level as appropriate for the
944 target label, and will (in the case of C++) also invoke any object
945 destructors which have to be invoked when we exit the scopes which
946 are exited by the goto.
948 Value is nonzero if a fixup is made. */
951 expand_fixup (tree_label, rtl_label, last_insn)
956 struct nesting *block, *end_block;
958 /* See if we can recognize which block the label will be output in.
959 This is possible in some very common cases.
960 If we succeed, set END_BLOCK to that block.
961 Otherwise, set it to 0. */
964 && (rtl_label == cond_stack->data.cond.endif_label
965 || rtl_label == cond_stack->data.cond.next_label))
966 end_block = cond_stack;
967 /* If we are in a loop, recognize certain labels which
968 are likely targets. This reduces the number of fixups
969 we need to create. */
971 && (rtl_label == loop_stack->data.loop.start_label
972 || rtl_label == loop_stack->data.loop.end_label
973 || rtl_label == loop_stack->data.loop.continue_label))
974 end_block = loop_stack;
978 /* Now set END_BLOCK to the binding level to which we will return. */
982 struct nesting *next_block = end_block->all;
985 /* First see if the END_BLOCK is inside the innermost binding level.
986 If so, then no cleanups or stack levels are relevant. */
987 while (next_block && next_block != block)
988 next_block = next_block->all;
993 /* Otherwise, set END_BLOCK to the innermost binding level
994 which is outside the relevant control-structure nesting. */
995 next_block = block_stack->next;
996 for (block = block_stack; block != end_block; block = block->all)
997 if (block == next_block)
998 next_block = next_block->next;
999 end_block = next_block;
1002 /* Does any containing block have a stack level or cleanups?
1003 If not, no fixup is needed, and that is the normal case
1004 (the only case, for standard C). */
1005 for (block = block_stack; block != end_block; block = block->next)
1006 if (block->data.block.stack_level != 0
1007 || block->data.block.cleanups != 0)
1010 if (block != end_block)
1012 /* Ok, a fixup is needed. Add a fixup to the list of such. */
1013 struct goto_fixup *fixup
1014 = (struct goto_fixup *) ggc_alloc (sizeof (struct goto_fixup));
1015 /* In case an old stack level is restored, make sure that comes
1016 after any pending stack adjust. */
1017 /* ?? If the fixup isn't to come at the present position,
1018 doing the stack adjust here isn't useful. Doing it with our
1019 settings at that location isn't useful either. Let's hope
1022 do_pending_stack_adjust ();
1023 fixup->target = tree_label;
1024 fixup->target_rtl = rtl_label;
1026 /* Create a BLOCK node and a corresponding matched set of
1027 NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes at
1028 this point. The notes will encapsulate any and all fixup
1029 code which we might later insert at this point in the insn
1030 stream. Also, the BLOCK node will be the parent (i.e. the
1031 `SUPERBLOCK') of any other BLOCK nodes which we might create
1032 later on when we are expanding the fixup code.
1034 Note that optimization passes (including expand_end_loop)
1035 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
1036 as a placeholder. */
1039 register rtx original_before_jump
1040 = last_insn ? last_insn : get_last_insn ();
1045 block = make_node (BLOCK);
1046 TREE_USED (block) = 1;
1048 if (!cfun->x_whole_function_mode_p)
1049 insert_block (block);
1053 = BLOCK_CHAIN (DECL_INITIAL (current_function_decl));
1054 BLOCK_CHAIN (DECL_INITIAL (current_function_decl))
1059 start = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
1060 if (cfun->x_whole_function_mode_p)
1061 NOTE_BLOCK (start) = block;
1062 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_DELETED);
1063 end = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
1064 if (cfun->x_whole_function_mode_p)
1065 NOTE_BLOCK (end) = block;
1066 fixup->context = block;
1068 emit_insns_after (start, original_before_jump);
1071 fixup->block_start_count = current_block_start_count;
1072 fixup->stack_level = 0;
1073 fixup->cleanup_list_list
1074 = ((block->data.block.outer_cleanups
1075 || block->data.block.cleanups)
1076 ? tree_cons (NULL_TREE, block->data.block.cleanups,
1077 block->data.block.outer_cleanups)
1079 fixup->next = goto_fixup_chain;
1080 goto_fixup_chain = fixup;
1088 /* Expand any needed fixups in the outputmost binding level of the
1089 function. FIRST_INSN is the first insn in the function. */
1092 expand_fixups (first_insn)
1095 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0);
1098 /* When exiting a binding contour, process all pending gotos requiring fixups.
1099 THISBLOCK is the structure that describes the block being exited.
1100 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1101 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1102 FIRST_INSN is the insn that began this contour.
1104 Gotos that jump out of this contour must restore the
1105 stack level and do the cleanups before actually jumping.
1107 DONT_JUMP_IN nonzero means report error there is a jump into this
1108 contour from before the beginning of the contour.
1109 This is also done if STACK_LEVEL is nonzero. */
1112 fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1113 struct nesting *thisblock;
1119 register struct goto_fixup *f, *prev;
1121 /* F is the fixup we are considering; PREV is the previous one. */
1122 /* We run this loop in two passes so that cleanups of exited blocks
1123 are run first, and blocks that are exited are marked so
1126 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1128 /* Test for a fixup that is inactive because it is already handled. */
1129 if (f->before_jump == 0)
1131 /* Delete inactive fixup from the chain, if that is easy to do. */
1133 prev->next = f->next;
1135 /* Has this fixup's target label been defined?
1136 If so, we can finalize it. */
1137 else if (PREV_INSN (f->target_rtl) != 0)
1139 register rtx cleanup_insns;
1141 /* If this fixup jumped into this contour from before the beginning
1142 of this contour, report an error. This code used to use
1143 the first non-label insn after f->target_rtl, but that's
1144 wrong since such can be added, by things like put_var_into_stack
1145 and have INSN_UIDs that are out of the range of the block. */
1146 /* ??? Bug: this does not detect jumping in through intermediate
1147 blocks that have stack levels or cleanups.
1148 It detects only a problem with the innermost block
1149 around the label. */
1151 && (dont_jump_in || stack_level || cleanup_list)
1152 && INSN_UID (first_insn) < INSN_UID (f->target_rtl)
1153 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1154 && ! DECL_ERROR_ISSUED (f->target))
1156 error_with_decl (f->target,
1157 "label `%s' used before containing binding contour");
1158 /* Prevent multiple errors for one label. */
1159 DECL_ERROR_ISSUED (f->target) = 1;
1162 /* We will expand the cleanups into a sequence of their own and
1163 then later on we will attach this new sequence to the insn
1164 stream just ahead of the actual jump insn. */
1168 /* Temporarily restore the lexical context where we will
1169 logically be inserting the fixup code. We do this for the
1170 sake of getting the debugging information right. */
1173 set_block (f->context);
1175 /* Expand the cleanups for blocks this jump exits. */
1176 if (f->cleanup_list_list)
1179 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1180 /* Marked elements correspond to blocks that have been closed.
1181 Do their cleanups. */
1182 if (TREE_ADDRESSABLE (lists)
1183 && TREE_VALUE (lists) != 0)
1185 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1186 /* Pop any pushes done in the cleanups,
1187 in case function is about to return. */
1188 do_pending_stack_adjust ();
1192 /* Restore stack level for the biggest contour that this
1193 jump jumps out of. */
1195 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1197 /* Finish up the sequence containing the insns which implement the
1198 necessary cleanups, and then attach that whole sequence to the
1199 insn stream just ahead of the actual jump insn. Attaching it
1200 at that point insures that any cleanups which are in fact
1201 implicit C++ object destructions (which must be executed upon
1202 leaving the block) appear (to the debugger) to be taking place
1203 in an area of the generated code where the object(s) being
1204 destructed are still "in scope". */
1206 cleanup_insns = get_insns ();
1210 emit_insns_after (cleanup_insns, f->before_jump);
1217 /* For any still-undefined labels, do the cleanups for this block now.
1218 We must do this now since items in the cleanup list may go out
1219 of scope when the block ends. */
1220 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1221 if (f->before_jump != 0
1222 && PREV_INSN (f->target_rtl) == 0
1223 /* Label has still not appeared. If we are exiting a block with
1224 a stack level to restore, that started before the fixup,
1225 mark this stack level as needing restoration
1226 when the fixup is later finalized. */
1228 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1229 means the label is undefined. That's erroneous, but possible. */
1230 && (thisblock->data.block.block_start_count
1231 <= f->block_start_count))
1233 tree lists = f->cleanup_list_list;
1236 for (; lists; lists = TREE_CHAIN (lists))
1237 /* If the following elt. corresponds to our containing block
1238 then the elt. must be for this block. */
1239 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
1243 set_block (f->context);
1244 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1245 do_pending_stack_adjust ();
1246 cleanup_insns = get_insns ();
1249 if (cleanup_insns != 0)
1251 = emit_insns_after (cleanup_insns, f->before_jump);
1253 f->cleanup_list_list = TREE_CHAIN (lists);
1257 f->stack_level = stack_level;
1261 /* Return the number of times character C occurs in string S. */
1263 n_occurrences (c, s)
1273 /* Generate RTL for an asm statement (explicit assembler code).
1274 BODY is a STRING_CST node containing the assembler code text,
1275 or an ADDR_EXPR containing a STRING_CST. */
1281 if (current_function_check_memory_usage)
1283 error ("`asm' cannot be used in function where memory usage is checked");
1287 if (TREE_CODE (body) == ADDR_EXPR)
1288 body = TREE_OPERAND (body, 0);
1290 emit_insn (gen_rtx_ASM_INPUT (VOIDmode,
1291 TREE_STRING_POINTER (body)));
1295 /* Generate RTL for an asm statement with arguments.
1296 STRING is the instruction template.
1297 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1298 Each output or input has an expression in the TREE_VALUE and
1299 a constraint-string in the TREE_PURPOSE.
1300 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1301 that is clobbered by this insn.
1303 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1304 Some elements of OUTPUTS may be replaced with trees representing temporary
1305 values. The caller should copy those temporary values to the originally
1308 VOL nonzero means the insn is volatile; don't optimize it. */
1311 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1312 tree string, outputs, inputs, clobbers;
1314 const char *filename;
1317 rtvec argvec, constraints;
1319 int ninputs = list_length (inputs);
1320 int noutputs = list_length (outputs);
1325 /* Vector of RTX's of evaluated output operands. */
1326 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1327 int *inout_opnum = (int *) alloca (noutputs * sizeof (int));
1328 rtx *real_output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1329 enum machine_mode *inout_mode
1330 = (enum machine_mode *) alloca (noutputs * sizeof (enum machine_mode));
1331 /* The insn we have emitted. */
1334 /* An ASM with no outputs needs to be treated as volatile, for now. */
1338 if (current_function_check_memory_usage)
1340 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1344 #ifdef MD_ASM_CLOBBERS
1345 /* Sometimes we wish to automatically clobber registers across an asm.
1346 Case in point is when the i386 backend moved from cc0 to a hard reg --
1347 maintaining source-level compatability means automatically clobbering
1348 the flags register. */
1349 MD_ASM_CLOBBERS (clobbers);
1352 if (current_function_check_memory_usage)
1354 error ("`asm' cannot be used in function where memory usage is checked");
1358 /* Count the number of meaningful clobbered registers, ignoring what
1359 we would ignore later. */
1361 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1363 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1365 i = decode_reg_name (regname);
1366 if (i >= 0 || i == -4)
1369 error ("unknown register name `%s' in `asm'", regname);
1374 /* Check that the number of alternatives is constant across all
1376 if (outputs || inputs)
1378 tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
1379 int nalternatives = n_occurrences (',', TREE_STRING_POINTER (tmp));
1382 if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
1384 error ("too many alternatives in `asm'");
1391 const char *constraint = TREE_STRING_POINTER (TREE_PURPOSE (tmp));
1393 if (n_occurrences (',', constraint) != nalternatives)
1395 error ("operand constraints for `asm' differ in number of alternatives");
1399 if (TREE_CHAIN (tmp))
1400 tmp = TREE_CHAIN (tmp);
1402 tmp = next, next = 0;
1406 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1408 tree val = TREE_VALUE (tail);
1409 tree type = TREE_TYPE (val);
1418 /* If there's an erroneous arg, emit no insn. */
1419 if (TREE_TYPE (val) == error_mark_node)
1422 /* Make sure constraint has `=' and does not have `+'. Also, see
1423 if it allows any register. Be liberal on the latter test, since
1424 the worst that happens if we get it wrong is we issue an error
1427 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1428 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1430 /* Allow the `=' or `+' to not be at the beginning of the string,
1431 since it wasn't explicitly documented that way, and there is a
1432 large body of code that puts it last. Swap the character to
1433 the front, so as not to uglify any place else. */
1437 if ((p = strchr (constraint, '=')) != NULL)
1439 if ((p = strchr (constraint, '+')) != NULL)
1442 error ("output operand constraint lacks `='");
1446 if (p != constraint)
1449 bcopy (constraint, constraint+1, p-constraint);
1452 warning ("output constraint `%c' for operand %d is not at the beginning", j, i);
1455 is_inout = constraint[0] == '+';
1456 /* Replace '+' with '='. */
1457 constraint[0] = '=';
1458 /* Make sure we can specify the matching operand. */
1459 if (is_inout && i > 9)
1461 error ("output operand constraint %d contains `+'", i);
1465 for (j = 1; j < c_len; j++)
1466 switch (constraint[j])
1470 error ("operand constraint contains '+' or '=' at illegal position.");
1474 if (i + 1 == ninputs + noutputs)
1476 error ("`%%' constraint used with last operand");
1481 case '?': case '!': case '*': case '&':
1482 case 'E': case 'F': case 'G': case 'H':
1483 case 's': case 'i': case 'n':
1484 case 'I': case 'J': case 'K': case 'L': case 'M':
1485 case 'N': case 'O': case 'P': case ',':
1486 #ifdef EXTRA_CONSTRAINT
1487 case 'Q': case 'R': case 'S': case 'T': case 'U':
1491 case '0': case '1': case '2': case '3': case '4':
1492 case '5': case '6': case '7': case '8': case '9':
1493 error ("matching constraint not valid in output operand");
1496 case 'V': case 'm': case 'o':
1501 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1502 excepting those that expand_call created. So match memory
1518 /* If an output operand is not a decl or indirect ref and our constraint
1519 allows a register, make a temporary to act as an intermediate.
1520 Make the asm insn write into that, then our caller will copy it to
1521 the real output operand. Likewise for promoted variables. */
1523 real_output_rtx[i] = NULL_RTX;
1524 if ((TREE_CODE (val) == INDIRECT_REF
1527 && (allows_mem || GET_CODE (DECL_RTL (val)) == REG)
1528 && ! (GET_CODE (DECL_RTL (val)) == REG
1529 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
1534 mark_addressable (TREE_VALUE (tail));
1537 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode,
1538 EXPAND_MEMORY_USE_WO);
1540 if (! allows_reg && GET_CODE (output_rtx[i]) != MEM)
1541 error ("output number %d not directly addressable", i);
1542 if (! allows_mem && GET_CODE (output_rtx[i]) == MEM)
1544 real_output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1545 output_rtx[i] = gen_reg_rtx (GET_MODE (output_rtx[i]));
1547 emit_move_insn (output_rtx[i], real_output_rtx[i]);
1552 output_rtx[i] = assign_temp (type, 0, 0, 1);
1553 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1558 inout_mode[ninout] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)));
1559 inout_opnum[ninout++] = i;
1564 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1566 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1570 /* Make vectors for the expression-rtx and constraint strings. */
1572 argvec = rtvec_alloc (ninputs);
1573 constraints = rtvec_alloc (ninputs);
1575 body = gen_rtx_ASM_OPERANDS (VOIDmode, TREE_STRING_POINTER (string),
1576 empty_string, 0, argvec, constraints,
1579 MEM_VOLATILE_P (body) = vol;
1581 /* Eval the inputs and put them into ARGVEC.
1582 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1585 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1588 int allows_reg = 0, allows_mem = 0;
1589 char *constraint, *orig_constraint;
1593 /* If there's an erroneous arg, emit no insn,
1594 because the ASM_INPUT would get VOIDmode
1595 and that could cause a crash in reload. */
1596 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1599 /* ??? Can this happen, and does the error message make any sense? */
1600 if (TREE_PURPOSE (tail) == NULL_TREE)
1602 error ("hard register `%s' listed as input operand to `asm'",
1603 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1607 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1608 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1609 orig_constraint = constraint;
1611 /* Make sure constraint has neither `=', `+', nor '&'. */
1613 for (j = 0; j < c_len; j++)
1614 switch (constraint[j])
1616 case '+': case '=': case '&':
1617 if (constraint == orig_constraint)
1619 error ("input operand constraint contains `%c'",
1626 if (constraint == orig_constraint
1627 && i + 1 == ninputs - ninout)
1629 error ("`%%' constraint used with last operand");
1634 case 'V': case 'm': case 'o':
1639 case '?': case '!': case '*':
1640 case 'E': case 'F': case 'G': case 'H': case 'X':
1641 case 's': case 'i': case 'n':
1642 case 'I': case 'J': case 'K': case 'L': case 'M':
1643 case 'N': case 'O': case 'P': case ',':
1644 #ifdef EXTRA_CONSTRAINT
1645 case 'Q': case 'R': case 'S': case 'T': case 'U':
1649 /* Whether or not a numeric constraint allows a register is
1650 decided by the matching constraint, and so there is no need
1651 to do anything special with them. We must handle them in
1652 the default case, so that we don't unnecessarily force
1653 operands to memory. */
1654 case '0': case '1': case '2': case '3': case '4':
1655 case '5': case '6': case '7': case '8': case '9':
1656 if (constraint[j] >= '0' + noutputs)
1659 ("matching constraint references invalid operand number");
1663 /* Try and find the real constraint for this dup. */
1664 if ((j == 0 && c_len == 1)
1665 || (j == 1 && c_len == 2 && constraint[0] == '%'))
1669 for (j = constraint[j] - '0'; j > 0; --j)
1672 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (o)));
1673 constraint = TREE_STRING_POINTER (TREE_PURPOSE (o));
1678 /* ... fall through ... */
1691 if (! allows_reg && allows_mem)
1692 mark_addressable (TREE_VALUE (tail));
1694 op = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1696 if (asm_operand_ok (op, constraint) <= 0)
1699 op = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), op);
1700 else if (!allows_mem)
1701 warning ("asm operand %d probably doesn't match constraints", i);
1702 else if (CONSTANT_P (op))
1703 op = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1705 else if (GET_CODE (op) == REG
1706 || GET_CODE (op) == SUBREG
1707 || GET_CODE (op) == CONCAT)
1709 tree type = TREE_TYPE (TREE_VALUE (tail));
1710 rtx memloc = assign_temp (type, 1, 1, 1);
1712 emit_move_insn (memloc, op);
1716 else if (GET_CODE (op) == MEM && MEM_VOLATILE_P (op))
1717 /* We won't recognize volatile memory as available a
1718 memory_operand at this point. Ignore it. */
1720 else if (queued_subexp_p (op))
1723 /* ??? Leave this only until we have experience with what
1724 happens in combine and elsewhere when constraints are
1726 warning ("asm operand %d probably doesn't match constraints", i);
1728 XVECEXP (body, 3, i) = op;
1730 XVECEXP (body, 4, i) /* constraints */
1731 = gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1736 /* Protect all the operands from the queue now that they have all been
1739 for (i = 0; i < ninputs - ninout; i++)
1740 XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0);
1742 for (i = 0; i < noutputs; i++)
1743 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1745 /* For in-out operands, copy output rtx to input rtx. */
1746 for (i = 0; i < ninout; i++)
1748 int j = inout_opnum[i];
1750 XVECEXP (body, 3, ninputs - ninout + i) /* argvec */
1752 XVECEXP (body, 4, ninputs - ninout + i) /* constraints */
1753 = gen_rtx_ASM_INPUT (inout_mode[i], digit_strings[j]);
1756 /* Now, for each output, construct an rtx
1757 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1758 ARGVEC CONSTRAINTS))
1759 If there is more than one, put them inside a PARALLEL. */
1761 if (noutputs == 1 && nclobbers == 0)
1763 XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1764 insn = emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
1767 else if (noutputs == 0 && nclobbers == 0)
1769 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1770 insn = emit_insn (body);
1781 body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
1783 /* For each output operand, store a SET. */
1784 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1786 XVECEXP (body, 0, i)
1787 = gen_rtx_SET (VOIDmode,
1789 gen_rtx_ASM_OPERANDS
1791 TREE_STRING_POINTER (string),
1792 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1793 i, argvec, constraints,
1796 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1799 /* If there are no outputs (but there are some clobbers)
1800 store the bare ASM_OPERANDS into the PARALLEL. */
1803 XVECEXP (body, 0, i++) = obody;
1805 /* Store (clobber REG) for each clobbered register specified. */
1807 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1809 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1810 int j = decode_reg_name (regname);
1814 if (j == -3) /* `cc', which is not a register */
1817 if (j == -4) /* `memory', don't cache memory across asm */
1819 XVECEXP (body, 0, i++)
1820 = gen_rtx_CLOBBER (VOIDmode,
1823 gen_rtx_SCRATCH (VOIDmode)));
1827 /* Ignore unknown register, error already signaled. */
1831 /* Use QImode since that's guaranteed to clobber just one reg. */
1832 XVECEXP (body, 0, i++)
1833 = gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (QImode, j));
1836 insn = emit_insn (body);
1839 /* For any outputs that needed reloading into registers, spill them
1840 back to where they belong. */
1841 for (i = 0; i < noutputs; ++i)
1842 if (real_output_rtx[i])
1843 emit_move_insn (real_output_rtx[i], output_rtx[i]);
1848 /* Generate RTL to evaluate the expression EXP
1849 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1852 expand_expr_stmt (exp)
1855 /* If -W, warn about statements with no side effects,
1856 except for an explicit cast to void (e.g. for assert()), and
1857 except inside a ({...}) where they may be useful. */
1858 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1860 if (! TREE_SIDE_EFFECTS (exp)
1861 && (extra_warnings || warn_unused_value)
1862 && !(TREE_CODE (exp) == CONVERT_EXPR
1863 && VOID_TYPE_P (TREE_TYPE (exp))))
1864 warning_with_file_and_line (emit_filename, emit_lineno,
1865 "statement with no effect");
1866 else if (warn_unused_value)
1867 warn_if_unused_value (exp);
1870 /* If EXP is of function type and we are expanding statements for
1871 value, convert it to pointer-to-function. */
1872 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1873 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1875 last_expr_type = TREE_TYPE (exp);
1876 last_expr_value = expand_expr (exp,
1877 (expr_stmts_for_value
1878 ? NULL_RTX : const0_rtx),
1881 /* If all we do is reference a volatile value in memory,
1882 copy it to a register to be sure it is actually touched. */
1883 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1884 && TREE_THIS_VOLATILE (exp))
1886 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1888 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1889 copy_to_reg (last_expr_value);
1892 rtx lab = gen_label_rtx ();
1894 /* Compare the value with itself to reference it. */
1895 emit_cmp_and_jump_insns (last_expr_value, last_expr_value, EQ,
1896 expand_expr (TYPE_SIZE (last_expr_type),
1897 NULL_RTX, VOIDmode, 0),
1899 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT,
1905 /* If this expression is part of a ({...}) and is in memory, we may have
1906 to preserve temporaries. */
1907 preserve_temp_slots (last_expr_value);
1909 /* Free any temporaries used to evaluate this expression. Any temporary
1910 used as a result of this expression will already have been preserved
1917 /* Warn if EXP contains any computations whose results are not used.
1918 Return 1 if a warning is printed; 0 otherwise. */
1921 warn_if_unused_value (exp)
1924 if (TREE_USED (exp))
1927 switch (TREE_CODE (exp))
1929 case PREINCREMENT_EXPR:
1930 case POSTINCREMENT_EXPR:
1931 case PREDECREMENT_EXPR:
1932 case POSTDECREMENT_EXPR:
1937 case METHOD_CALL_EXPR:
1939 case TRY_CATCH_EXPR:
1940 case WITH_CLEANUP_EXPR:
1942 /* We don't warn about COND_EXPR because it may be a useful
1943 construct if either arm contains a side effect. */
1948 /* For a binding, warn if no side effect within it. */
1949 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1952 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1954 case TRUTH_ORIF_EXPR:
1955 case TRUTH_ANDIF_EXPR:
1956 /* In && or ||, warn if 2nd operand has no side effect. */
1957 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1960 if (TREE_NO_UNUSED_WARNING (exp))
1962 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
1964 /* Let people do `(foo (), 0)' without a warning. */
1965 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1967 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1971 case NON_LVALUE_EXPR:
1972 /* Don't warn about values cast to void. */
1973 if (VOID_TYPE_P (TREE_TYPE (exp)))
1975 /* Don't warn about conversions not explicit in the user's program. */
1976 if (TREE_NO_UNUSED_WARNING (exp))
1978 /* Assignment to a cast usually results in a cast of a modify.
1979 Don't complain about that. There can be an arbitrary number of
1980 casts before the modify, so we must loop until we find the first
1981 non-cast expression and then test to see if that is a modify. */
1983 tree tem = TREE_OPERAND (exp, 0);
1985 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1986 tem = TREE_OPERAND (tem, 0);
1988 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
1989 || TREE_CODE (tem) == CALL_EXPR)
1995 /* Don't warn about automatic dereferencing of references, since
1996 the user cannot control it. */
1997 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
1998 return warn_if_unused_value (TREE_OPERAND (exp, 0));
1999 /* ... fall through ... */
2002 /* Referencing a volatile value is a side effect, so don't warn. */
2004 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
2005 && TREE_THIS_VOLATILE (exp))
2008 /* If this is an expression which has no operands, there is no value
2009 to be unused. There are no such language-independent codes,
2010 but front ends may define such. */
2011 if (TREE_CODE_CLASS (TREE_CODE (exp)) == 'e'
2012 && TREE_CODE_LENGTH (TREE_CODE (exp)) == 0)
2016 warning_with_file_and_line (emit_filename, emit_lineno,
2017 "value computed is not used");
2022 /* Clear out the memory of the last expression evaluated. */
2030 /* Begin a statement which will return a value.
2031 Return the RTL_EXPR for this statement expr.
2032 The caller must save that value and pass it to expand_end_stmt_expr. */
2035 expand_start_stmt_expr ()
2040 /* Make the RTL_EXPR node temporary, not momentary,
2041 so that rtl_expr_chain doesn't become garbage. */
2042 momentary = suspend_momentary ();
2043 t = make_node (RTL_EXPR);
2044 resume_momentary (momentary);
2045 do_pending_stack_adjust ();
2046 start_sequence_for_rtl_expr (t);
2048 expr_stmts_for_value++;
2052 /* Restore the previous state at the end of a statement that returns a value.
2053 Returns a tree node representing the statement's value and the
2054 insns to compute the value.
2056 The nodes of that expression have been freed by now, so we cannot use them.
2057 But we don't want to do that anyway; the expression has already been
2058 evaluated and now we just want to use the value. So generate a RTL_EXPR
2059 with the proper type and RTL value.
2061 If the last substatement was not an expression,
2062 return something with type `void'. */
2065 expand_end_stmt_expr (t)
2070 if (last_expr_type == 0)
2072 last_expr_type = void_type_node;
2073 last_expr_value = const0_rtx;
2075 else if (last_expr_value == 0)
2076 /* There are some cases where this can happen, such as when the
2077 statement is void type. */
2078 last_expr_value = const0_rtx;
2079 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
2080 /* Remove any possible QUEUED. */
2081 last_expr_value = protect_from_queue (last_expr_value, 0);
2085 TREE_TYPE (t) = last_expr_type;
2086 RTL_EXPR_RTL (t) = last_expr_value;
2087 RTL_EXPR_SEQUENCE (t) = get_insns ();
2089 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
2093 /* Don't consider deleting this expr or containing exprs at tree level. */
2094 TREE_SIDE_EFFECTS (t) = 1;
2095 /* Propagate volatility of the actual RTL expr. */
2096 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
2099 expr_stmts_for_value--;
2104 /* Generate RTL for the start of an if-then. COND is the expression
2105 whose truth should be tested.
2107 If EXITFLAG is nonzero, this conditional is visible to
2108 `exit_something'. */
2111 expand_start_cond (cond, exitflag)
2115 struct nesting *thiscond = ALLOC_NESTING ();
2117 /* Make an entry on cond_stack for the cond we are entering. */
2119 thiscond->next = cond_stack;
2120 thiscond->all = nesting_stack;
2121 thiscond->depth = ++nesting_depth;
2122 thiscond->data.cond.next_label = gen_label_rtx ();
2123 /* Before we encounter an `else', we don't need a separate exit label
2124 unless there are supposed to be exit statements
2125 to exit this conditional. */
2126 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
2127 thiscond->data.cond.endif_label = thiscond->exit_label;
2128 cond_stack = thiscond;
2129 nesting_stack = thiscond;
2131 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
2134 /* Generate RTL between then-clause and the elseif-clause
2135 of an if-then-elseif-.... */
2138 expand_start_elseif (cond)
2141 if (cond_stack->data.cond.endif_label == 0)
2142 cond_stack->data.cond.endif_label = gen_label_rtx ();
2143 emit_jump (cond_stack->data.cond.endif_label);
2144 emit_label (cond_stack->data.cond.next_label);
2145 cond_stack->data.cond.next_label = gen_label_rtx ();
2146 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2149 /* Generate RTL between the then-clause and the else-clause
2150 of an if-then-else. */
2153 expand_start_else ()
2155 if (cond_stack->data.cond.endif_label == 0)
2156 cond_stack->data.cond.endif_label = gen_label_rtx ();
2158 emit_jump (cond_stack->data.cond.endif_label);
2159 emit_label (cond_stack->data.cond.next_label);
2160 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
2163 /* After calling expand_start_else, turn this "else" into an "else if"
2164 by providing another condition. */
2167 expand_elseif (cond)
2170 cond_stack->data.cond.next_label = gen_label_rtx ();
2171 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2174 /* Generate RTL for the end of an if-then.
2175 Pop the record for it off of cond_stack. */
2180 struct nesting *thiscond = cond_stack;
2182 do_pending_stack_adjust ();
2183 if (thiscond->data.cond.next_label)
2184 emit_label (thiscond->data.cond.next_label);
2185 if (thiscond->data.cond.endif_label)
2186 emit_label (thiscond->data.cond.endif_label);
2188 POPSTACK (cond_stack);
2194 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2195 loop should be exited by `exit_something'. This is a loop for which
2196 `expand_continue' will jump to the top of the loop.
2198 Make an entry on loop_stack to record the labels associated with
2202 expand_start_loop (exit_flag)
2205 register struct nesting *thisloop = ALLOC_NESTING ();
2207 /* Make an entry on loop_stack for the loop we are entering. */
2209 thisloop->next = loop_stack;
2210 thisloop->all = nesting_stack;
2211 thisloop->depth = ++nesting_depth;
2212 thisloop->data.loop.start_label = gen_label_rtx ();
2213 thisloop->data.loop.end_label = gen_label_rtx ();
2214 thisloop->data.loop.alt_end_label = 0;
2215 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2216 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2217 loop_stack = thisloop;
2218 nesting_stack = thisloop;
2220 do_pending_stack_adjust ();
2222 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2223 emit_label (thisloop->data.loop.start_label);
2228 /* Like expand_start_loop but for a loop where the continuation point
2229 (for expand_continue_loop) will be specified explicitly. */
2232 expand_start_loop_continue_elsewhere (exit_flag)
2235 struct nesting *thisloop = expand_start_loop (exit_flag);
2236 loop_stack->data.loop.continue_label = gen_label_rtx ();
2240 /* Specify the continuation point for a loop started with
2241 expand_start_loop_continue_elsewhere.
2242 Use this at the point in the code to which a continue statement
2246 expand_loop_continue_here ()
2248 do_pending_stack_adjust ();
2249 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2250 emit_label (loop_stack->data.loop.continue_label);
2253 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2254 Pop the block off of loop_stack. */
2259 rtx start_label = loop_stack->data.loop.start_label;
2260 rtx insn = get_last_insn ();
2261 int needs_end_jump = 1;
2263 /* Mark the continue-point at the top of the loop if none elsewhere. */
2264 if (start_label == loop_stack->data.loop.continue_label)
2265 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2267 do_pending_stack_adjust ();
2269 /* If optimizing, perhaps reorder the loop.
2270 First, try to use a condjump near the end.
2271 expand_exit_loop_if_false ends loops with unconditional jumps,
2274 if (test) goto label;
2276 goto loop_stack->data.loop.end_label
2280 If we find such a pattern, we can end the loop earlier. */
2283 && GET_CODE (insn) == CODE_LABEL
2284 && LABEL_NAME (insn) == NULL
2285 && GET_CODE (PREV_INSN (insn)) == BARRIER)
2288 rtx jump = PREV_INSN (PREV_INSN (label));
2290 if (GET_CODE (jump) == JUMP_INSN
2291 && GET_CODE (PATTERN (jump)) == SET
2292 && SET_DEST (PATTERN (jump)) == pc_rtx
2293 && GET_CODE (SET_SRC (PATTERN (jump))) == LABEL_REF
2294 && (XEXP (SET_SRC (PATTERN (jump)), 0)
2295 == loop_stack->data.loop.end_label))
2299 /* The test might be complex and reference LABEL multiple times,
2300 like the loop in loop_iterations to set vtop. To handle this,
2302 insn = PREV_INSN (label);
2303 reorder_insns (label, label, start_label);
2305 for (prev = PREV_INSN (jump); ; prev = PREV_INSN (prev))
2307 /* We ignore line number notes, but if we see any other note,
2308 in particular NOTE_INSN_BLOCK_*, NOTE_INSN_EH_REGION_*,
2309 NOTE_INSN_LOOP_*, we disable this optimization. */
2310 if (GET_CODE (prev) == NOTE)
2312 if (NOTE_LINE_NUMBER (prev) < 0)
2316 if (GET_CODE (prev) == CODE_LABEL)
2318 if (GET_CODE (prev) == JUMP_INSN)
2320 if (GET_CODE (PATTERN (prev)) == SET
2321 && SET_DEST (PATTERN (prev)) == pc_rtx
2322 && GET_CODE (SET_SRC (PATTERN (prev))) == IF_THEN_ELSE
2323 && (GET_CODE (XEXP (SET_SRC (PATTERN (prev)), 1))
2325 && XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0) == label)
2327 XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0)
2329 emit_note_after (NOTE_INSN_LOOP_END, prev);
2338 /* If the loop starts with a loop exit, roll that to the end where
2339 it will optimize together with the jump back.
2341 We look for the conditional branch to the exit, except that once
2342 we find such a branch, we don't look past 30 instructions.
2344 In more detail, if the loop presently looks like this (in pseudo-C):
2347 if (test) goto end_label;
2352 transform it to look like:
2358 if (test) goto end_label;
2359 goto newstart_label;
2362 Here, the `test' may actually consist of some reasonably complex
2363 code, terminating in a test. */
2368 ! (GET_CODE (insn) == JUMP_INSN
2369 && GET_CODE (PATTERN (insn)) == SET
2370 && SET_DEST (PATTERN (insn)) == pc_rtx
2371 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2375 rtx last_test_insn = NULL_RTX;
2377 /* Scan insns from the top of the loop looking for a qualified
2378 conditional exit. */
2379 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2380 insn = NEXT_INSN (insn))
2382 if (GET_CODE (insn) == NOTE)
2385 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2386 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2387 /* The code that actually moves the exit test will
2388 carefully leave BLOCK notes in their original
2389 location. That means, however, that we can't debug
2390 the exit test itself. So, we refuse to move code
2391 containing BLOCK notes at low optimization levels. */
2394 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG)
2396 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)
2400 /* We've come to the end of an EH region, but
2401 never saw the beginning of that region. That
2402 means that an EH region begins before the top
2403 of the loop, and ends in the middle of it. The
2404 existence of such a situation violates a basic
2405 assumption in this code, since that would imply
2406 that even when EH_REGIONS is zero, we might
2407 move code out of an exception region. */
2411 /* We must not walk into a nested loop. */
2412 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
2415 /* We already know this INSN is a NOTE, so there's no
2416 point in looking at it to see if it's a JUMP. */
2420 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2423 if (last_test_insn && num_insns > 30)
2427 /* We don't want to move a partial EH region. Consider:
2441 This isn't legal C++, but here's what it's supposed to
2442 mean: if cond() is true, stop looping. Otherwise,
2443 call bar, and keep looping. In addition, if cond
2444 throws an exception, catch it and keep looping. Such
2445 constructs are certainy legal in LISP.
2447 We should not move the `if (cond()) 0' test since then
2448 the EH-region for the try-block would be broken up.
2449 (In this case we would the EH_BEG note for the `try'
2450 and `if cond()' but not the call to bar() or the
2453 So we don't look for tests within an EH region. */
2456 if (GET_CODE (insn) == JUMP_INSN
2457 && GET_CODE (PATTERN (insn)) == SET
2458 && SET_DEST (PATTERN (insn)) == pc_rtx)
2460 /* This is indeed a jump. */
2461 rtx dest1 = NULL_RTX;
2462 rtx dest2 = NULL_RTX;
2463 rtx potential_last_test;
2464 if (GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE)
2466 /* A conditional jump. */
2467 dest1 = XEXP (SET_SRC (PATTERN (insn)), 1);
2468 dest2 = XEXP (SET_SRC (PATTERN (insn)), 2);
2469 potential_last_test = insn;
2473 /* An unconditional jump. */
2474 dest1 = SET_SRC (PATTERN (insn));
2475 /* Include the BARRIER after the JUMP. */
2476 potential_last_test = NEXT_INSN (insn);
2480 if (dest1 && GET_CODE (dest1) == LABEL_REF
2481 && ((XEXP (dest1, 0)
2482 == loop_stack->data.loop.alt_end_label)
2484 == loop_stack->data.loop.end_label)))
2486 last_test_insn = potential_last_test;
2490 /* If this was a conditional jump, there may be
2491 another label at which we should look. */
2498 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2500 /* We found one. Move everything from there up
2501 to the end of the loop, and add a jump into the loop
2502 to jump to there. */
2503 register rtx newstart_label = gen_label_rtx ();
2504 register rtx start_move = start_label;
2507 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2508 then we want to move this note also. */
2509 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2510 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2511 == NOTE_INSN_LOOP_CONT))
2512 start_move = PREV_INSN (start_move);
2514 emit_label_after (newstart_label, PREV_INSN (start_move));
2516 /* Actually move the insns. Start at the beginning, and
2517 keep copying insns until we've copied the
2519 for (insn = start_move; insn; insn = next_insn)
2521 /* Figure out which insn comes after this one. We have
2522 to do this before we move INSN. */
2523 if (insn == last_test_insn)
2524 /* We've moved all the insns. */
2525 next_insn = NULL_RTX;
2527 next_insn = NEXT_INSN (insn);
2529 if (GET_CODE (insn) == NOTE
2530 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2531 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2532 /* We don't want to move NOTE_INSN_BLOCK_BEGs or
2533 NOTE_INSN_BLOCK_ENDs because the correct generation
2534 of debugging information depends on these appearing
2535 in the same order in the RTL and in the tree
2536 structure, where they are represented as BLOCKs.
2537 So, we don't move block notes. Of course, moving
2538 the code inside the block is likely to make it
2539 impossible to debug the instructions in the exit
2540 test, but such is the price of optimization. */
2543 /* Move the INSN. */
2544 reorder_insns (insn, insn, get_last_insn ());
2547 emit_jump_insn_after (gen_jump (start_label),
2548 PREV_INSN (newstart_label));
2549 emit_barrier_after (PREV_INSN (newstart_label));
2550 start_label = newstart_label;
2556 emit_jump (start_label);
2557 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2559 emit_label (loop_stack->data.loop.end_label);
2561 POPSTACK (loop_stack);
2566 /* Generate a jump to the current loop's continue-point.
2567 This is usually the top of the loop, but may be specified
2568 explicitly elsewhere. If not currently inside a loop,
2569 return 0 and do nothing; caller will print an error message. */
2572 expand_continue_loop (whichloop)
2573 struct nesting *whichloop;
2577 whichloop = loop_stack;
2580 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2585 /* Generate a jump to exit the current loop. If not currently inside a loop,
2586 return 0 and do nothing; caller will print an error message. */
2589 expand_exit_loop (whichloop)
2590 struct nesting *whichloop;
2594 whichloop = loop_stack;
2597 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2601 /* Generate a conditional jump to exit the current loop if COND
2602 evaluates to zero. If not currently inside a loop,
2603 return 0 and do nothing; caller will print an error message. */
2606 expand_exit_loop_if_false (whichloop, cond)
2607 struct nesting *whichloop;
2610 rtx label = gen_label_rtx ();
2615 whichloop = loop_stack;
2618 /* In order to handle fixups, we actually create a conditional jump
2619 around a unconditional branch to exit the loop. If fixups are
2620 necessary, they go before the unconditional branch. */
2623 do_jump (cond, NULL_RTX, label);
2624 last_insn = get_last_insn ();
2625 if (GET_CODE (last_insn) == CODE_LABEL)
2626 whichloop->data.loop.alt_end_label = last_insn;
2627 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2634 /* Return nonzero if the loop nest is empty. Else return zero. */
2637 stmt_loop_nest_empty ()
2639 /* cfun->stmt can be NULL if we are building a call to get the
2640 EH context for a setjmp/longjmp EH target and the current
2641 function was a deferred inline function. */
2642 return (cfun->stmt == NULL || loop_stack == NULL);
2645 /* Return non-zero if we should preserve sub-expressions as separate
2646 pseudos. We never do so if we aren't optimizing. We always do so
2647 if -fexpensive-optimizations.
2649 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2650 the loop may still be a small one. */
2653 preserve_subexpressions_p ()
2657 if (flag_expensive_optimizations)
2660 if (optimize == 0 || cfun == 0 || cfun->stmt == 0 || loop_stack == 0)
2663 insn = get_last_insn_anywhere ();
2666 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2667 < n_non_fixed_regs * 3));
2671 /* Generate a jump to exit the current loop, conditional, binding contour
2672 or case statement. Not all such constructs are visible to this function,
2673 only those started with EXIT_FLAG nonzero. Individual languages use
2674 the EXIT_FLAG parameter to control which kinds of constructs you can
2677 If not currently inside anything that can be exited,
2678 return 0 and do nothing; caller will print an error message. */
2681 expand_exit_something ()
2685 for (n = nesting_stack; n; n = n->all)
2686 if (n->exit_label != 0)
2688 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2695 /* Generate RTL to return from the current function, with no value.
2696 (That is, we do not do anything about returning any value.) */
2699 expand_null_return ()
2701 struct nesting *block = block_stack;
2702 rtx last_insn = get_last_insn ();
2704 /* If this function was declared to return a value, but we
2705 didn't, clobber the return registers so that they are not
2706 propogated live to the rest of the function. */
2707 clobber_return_register ();
2709 /* 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. */
2715 expand_null_return_1 (last_insn, block != 0);
2718 /* Generate RTL to return from the current function, with value VAL. */
2721 expand_value_return (val)
2724 struct nesting *block = block_stack;
2725 rtx last_insn = get_last_insn ();
2726 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2728 /* Copy the value to the return location
2729 unless it's already there. */
2731 if (return_reg != val)
2733 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2734 #ifdef PROMOTE_FUNCTION_RETURN
2735 int unsignedp = TREE_UNSIGNED (type);
2736 enum machine_mode old_mode
2737 = DECL_MODE (DECL_RESULT (current_function_decl));
2738 enum machine_mode mode
2739 = promote_mode (type, old_mode, &unsignedp, 1);
2741 if (mode != old_mode)
2742 val = convert_modes (mode, old_mode, val, unsignedp);
2744 if (GET_CODE (return_reg) == PARALLEL)
2745 emit_group_load (return_reg, val, int_size_in_bytes (type),
2748 emit_move_insn (return_reg, val);
2751 /* Does any pending block have cleanups? */
2753 while (block && block->data.block.cleanups == 0)
2754 block = block->next;
2756 /* If yes, use a goto to return, since that runs cleanups.
2757 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2759 expand_null_return_1 (last_insn, block != 0);
2762 /* Output a return with no value. If LAST_INSN is nonzero,
2763 pretend that the return takes place after LAST_INSN.
2764 If USE_GOTO is nonzero then don't use a return instruction;
2765 go to the return label instead. This causes any cleanups
2766 of pending blocks to be executed normally. */
2769 expand_null_return_1 (last_insn, use_goto)
2773 rtx end_label = cleanup_label ? cleanup_label : return_label;
2775 clear_pending_stack_adjust ();
2776 do_pending_stack_adjust ();
2779 /* PCC-struct return always uses an epilogue. */
2780 if (current_function_returns_pcc_struct || use_goto)
2783 end_label = return_label = gen_label_rtx ();
2784 expand_goto_internal (NULL_TREE, end_label, last_insn);
2788 /* Otherwise output a simple return-insn if one is available,
2789 unless it won't do the job. */
2791 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2793 emit_jump_insn (gen_return ());
2799 /* Otherwise jump to the epilogue. */
2800 expand_goto_internal (NULL_TREE, end_label, last_insn);
2803 /* Generate RTL to evaluate the expression RETVAL and return it
2804 from the current function. */
2807 expand_return (retval)
2810 /* If there are any cleanups to be performed, then they will
2811 be inserted following LAST_INSN. It is desirable
2812 that the last_insn, for such purposes, should be the
2813 last insn before computing the return value. Otherwise, cleanups
2814 which call functions can clobber the return value. */
2815 /* ??? rms: I think that is erroneous, because in C++ it would
2816 run destructors on variables that might be used in the subsequent
2817 computation of the return value. */
2819 rtx result_rtl = DECL_RTL (DECL_RESULT (current_function_decl));
2820 register rtx val = 0;
2827 /* If function wants no value, give it none. */
2828 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2830 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2832 expand_null_return ();
2836 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2837 /* This is not sufficient. We also need to watch for cleanups of the
2838 expression we are about to expand. Unfortunately, we cannot know
2839 if it has cleanups until we expand it, and we want to change how we
2840 expand it depending upon if we need cleanups. We can't win. */
2842 cleanups = any_pending_cleanups (1);
2847 if (retval == error_mark_node)
2848 retval_rhs = NULL_TREE;
2849 else if (TREE_CODE (retval) == RESULT_DECL)
2850 retval_rhs = retval;
2851 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2852 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2853 retval_rhs = TREE_OPERAND (retval, 1);
2854 else if (VOID_TYPE_P (TREE_TYPE (retval)))
2855 /* Recognize tail-recursive call to void function. */
2856 retval_rhs = retval;
2858 retval_rhs = NULL_TREE;
2860 /* Only use `last_insn' if there are cleanups which must be run. */
2861 if (cleanups || cleanup_label != 0)
2862 last_insn = get_last_insn ();
2864 /* Distribute return down conditional expr if either of the sides
2865 may involve tail recursion (see test below). This enhances the number
2866 of tail recursions we see. Don't do this always since it can produce
2867 sub-optimal code in some cases and we distribute assignments into
2868 conditional expressions when it would help. */
2870 if (optimize && retval_rhs != 0
2871 && frame_offset == 0
2872 && TREE_CODE (retval_rhs) == COND_EXPR
2873 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2874 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2876 rtx label = gen_label_rtx ();
2879 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2880 start_cleanup_deferral ();
2881 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2882 DECL_RESULT (current_function_decl),
2883 TREE_OPERAND (retval_rhs, 1));
2884 TREE_SIDE_EFFECTS (expr) = 1;
2885 expand_return (expr);
2888 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2889 DECL_RESULT (current_function_decl),
2890 TREE_OPERAND (retval_rhs, 2));
2891 TREE_SIDE_EFFECTS (expr) = 1;
2892 expand_return (expr);
2893 end_cleanup_deferral ();
2897 /* Attempt to optimize the call if it is tail recursive. */
2898 if (flag_optimize_sibling_calls
2899 && retval_rhs != NULL_TREE
2900 && frame_offset == 0
2901 && TREE_CODE (retval_rhs) == CALL_EXPR
2902 && TREE_CODE (TREE_OPERAND (retval_rhs, 0)) == ADDR_EXPR
2903 && (TREE_OPERAND (TREE_OPERAND (retval_rhs, 0), 0)
2904 == current_function_decl)
2905 && optimize_tail_recursion (TREE_OPERAND (retval_rhs, 1), last_insn))
2909 /* This optimization is safe if there are local cleanups
2910 because expand_null_return takes care of them.
2911 ??? I think it should also be safe when there is a cleanup label,
2912 because expand_null_return takes care of them, too.
2913 Any reason why not? */
2914 if (HAVE_return && cleanup_label == 0
2915 && ! current_function_returns_pcc_struct
2916 && BRANCH_COST <= 1)
2918 /* If this is return x == y; then generate
2919 if (x == y) return 1; else return 0;
2920 if we can do it with explicit return insns and branches are cheap,
2921 but not if we have the corresponding scc insn. */
2924 switch (TREE_CODE (retval_rhs))
2950 case TRUTH_ANDIF_EXPR:
2951 case TRUTH_ORIF_EXPR:
2952 case TRUTH_AND_EXPR:
2954 case TRUTH_NOT_EXPR:
2955 case TRUTH_XOR_EXPR:
2958 op0 = gen_label_rtx ();
2959 jumpifnot (retval_rhs, op0);
2960 expand_value_return (const1_rtx);
2962 expand_value_return (const0_rtx);
2971 #endif /* HAVE_return */
2973 /* If the result is an aggregate that is being returned in one (or more)
2974 registers, load the registers here. The compiler currently can't handle
2975 copying a BLKmode value into registers. We could put this code in a
2976 more general area (for use by everyone instead of just function
2977 call/return), but until this feature is generally usable it is kept here
2978 (and in expand_call). The value must go into a pseudo in case there
2979 are cleanups that will clobber the real return register. */
2982 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2983 && GET_CODE (result_rtl) == REG)
2986 unsigned HOST_WIDE_INT bitpos, xbitpos;
2987 unsigned HOST_WIDE_INT big_endian_correction = 0;
2988 unsigned HOST_WIDE_INT bytes
2989 = int_size_in_bytes (TREE_TYPE (retval_rhs));
2990 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2991 unsigned int bitsize
2992 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)), BITS_PER_WORD);
2993 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2994 rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
2995 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2996 enum machine_mode tmpmode, result_reg_mode;
2998 /* Structures whose size is not a multiple of a word are aligned
2999 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
3000 machine, this means we must skip the empty high order bytes when
3001 calculating the bit offset. */
3002 if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD)
3003 big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
3006 /* Copy the structure BITSIZE bits at a time. */
3007 for (bitpos = 0, xbitpos = big_endian_correction;
3008 bitpos < bytes * BITS_PER_UNIT;
3009 bitpos += bitsize, xbitpos += bitsize)
3011 /* We need a new destination pseudo each time xbitpos is
3012 on a word boundary and when xbitpos == big_endian_correction
3013 (the first time through). */
3014 if (xbitpos % BITS_PER_WORD == 0
3015 || xbitpos == big_endian_correction)
3017 /* Generate an appropriate register. */
3018 dst = gen_reg_rtx (word_mode);
3019 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
3021 /* Clobber the destination before we move anything into it. */
3022 emit_insn (gen_rtx_CLOBBER (VOIDmode, dst));
3025 /* We need a new source operand each time bitpos is on a word
3027 if (bitpos % BITS_PER_WORD == 0)
3028 src = operand_subword_force (result_val,
3029 bitpos / BITS_PER_WORD,
3032 /* Use bitpos for the source extraction (left justified) and
3033 xbitpos for the destination store (right justified). */
3034 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
3035 extract_bit_field (src, bitsize,
3036 bitpos % BITS_PER_WORD, 1,
3037 NULL_RTX, word_mode, word_mode,
3038 bitsize, BITS_PER_WORD),
3039 bitsize, BITS_PER_WORD);
3042 /* Find the smallest integer mode large enough to hold the
3043 entire structure and use that mode instead of BLKmode
3044 on the USE insn for the return register. */
3045 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
3046 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
3047 tmpmode != VOIDmode;
3048 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
3050 /* Have we found a large enough mode? */
3051 if (GET_MODE_SIZE (tmpmode) >= bytes)
3055 /* No suitable mode found. */
3056 if (tmpmode == VOIDmode)
3059 PUT_MODE (result_rtl, tmpmode);
3061 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
3062 result_reg_mode = word_mode;
3064 result_reg_mode = tmpmode;
3065 result_reg = gen_reg_rtx (result_reg_mode);
3068 for (i = 0; i < n_regs; i++)
3069 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
3072 if (tmpmode != result_reg_mode)
3073 result_reg = gen_lowpart (tmpmode, result_reg);
3075 expand_value_return (result_reg);
3079 && !VOID_TYPE_P (TREE_TYPE (retval_rhs))
3080 && (GET_CODE (result_rtl) == REG
3081 || (GET_CODE (result_rtl) == PARALLEL)))
3083 /* Calculate the return value into a temporary (usually a pseudo
3085 val = assign_temp (TREE_TYPE (DECL_RESULT (current_function_decl)),
3087 val = expand_expr (retval_rhs, val, GET_MODE (val), 0);
3088 val = force_not_mem (val);
3090 /* Return the calculated value, doing cleanups first. */
3091 expand_value_return (val);
3095 /* No cleanups or no hard reg used;
3096 calculate value into hard return reg. */
3097 expand_expr (retval, const0_rtx, VOIDmode, 0);
3099 expand_value_return (result_rtl);
3103 /* Return 1 if the end of the generated RTX is not a barrier.
3104 This means code already compiled can drop through. */
3107 drop_through_at_end_p ()
3109 rtx insn = get_last_insn ();
3110 while (insn && GET_CODE (insn) == NOTE)
3111 insn = PREV_INSN (insn);
3112 return insn && GET_CODE (insn) != BARRIER;
3115 /* Attempt to optimize a potential tail recursion call into a goto.
3116 ARGUMENTS are the arguments to a CALL_EXPR; LAST_INSN indicates
3117 where to place the jump to the tail recursion label.
3119 Return TRUE if the call was optimized into a goto. */
3122 optimize_tail_recursion (arguments, last_insn)
3126 /* Finish checking validity, and if valid emit code to set the
3127 argument variables for the new call. */
3128 if (tail_recursion_args (arguments, DECL_ARGUMENTS (current_function_decl)))
3130 if (tail_recursion_label == 0)
3132 tail_recursion_label = gen_label_rtx ();
3133 emit_label_after (tail_recursion_label,
3134 tail_recursion_reentry);
3137 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
3144 /* Emit code to alter this function's formal parms for a tail-recursive call.
3145 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3146 FORMALS is the chain of decls of formals.
3147 Return 1 if this can be done;
3148 otherwise return 0 and do not emit any code. */
3151 tail_recursion_args (actuals, formals)
3152 tree actuals, formals;
3154 register tree a = actuals, f = formals;
3156 register rtx *argvec;
3158 /* Check that number and types of actuals are compatible
3159 with the formals. This is not always true in valid C code.
3160 Also check that no formal needs to be addressable
3161 and that all formals are scalars. */
3163 /* Also count the args. */
3165 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
3167 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a)))
3168 != TYPE_MAIN_VARIANT (TREE_TYPE (f)))
3170 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
3173 if (a != 0 || f != 0)
3176 /* Compute all the actuals. */
3178 argvec = (rtx *) alloca (i * sizeof (rtx));
3180 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3181 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
3183 /* Find which actual values refer to current values of previous formals.
3184 Copy each of them now, before any formal is changed. */
3186 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3190 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
3191 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
3192 { copy = 1; break; }
3194 argvec[i] = copy_to_reg (argvec[i]);
3197 /* Store the values of the actuals into the formals. */
3199 for (f = formals, a = actuals, i = 0; f;
3200 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
3202 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
3203 emit_move_insn (DECL_RTL (f), argvec[i]);
3205 convert_move (DECL_RTL (f), argvec[i],
3206 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
3213 /* Generate the RTL code for entering a binding contour.
3214 The variables are declared one by one, by calls to `expand_decl'.
3216 FLAGS is a bitwise or of the following flags:
3218 1 - Nonzero if this construct should be visible to
3221 2 - Nonzero if this contour does not require a
3222 NOTE_INSN_BLOCK_BEG note. Virtually all calls from
3223 language-independent code should set this flag because they
3224 will not create corresponding BLOCK nodes. (There should be
3225 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
3226 and BLOCKs.) If this flag is set, MARK_ENDS should be zero
3227 when expand_end_bindings is called.
3229 If we are creating a NOTE_INSN_BLOCK_BEG note, a BLOCK may
3230 optionally be supplied. If so, it becomes the NOTE_BLOCK for the
3234 expand_start_bindings_and_block (flags, block)
3238 struct nesting *thisblock = ALLOC_NESTING ();
3240 int exit_flag = ((flags & 1) != 0);
3241 int block_flag = ((flags & 2) == 0);
3243 /* If a BLOCK is supplied, then the caller should be requesting a
3244 NOTE_INSN_BLOCK_BEG note. */
3245 if (!block_flag && block)
3248 /* Create a note to mark the beginning of the block. */
3251 note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
3252 NOTE_BLOCK (note) = block;
3255 note = emit_note (NULL_PTR, NOTE_INSN_DELETED);
3257 /* Make an entry on block_stack for the block we are entering. */
3259 thisblock->next = block_stack;
3260 thisblock->all = nesting_stack;
3261 thisblock->depth = ++nesting_depth;
3262 thisblock->data.block.stack_level = 0;
3263 thisblock->data.block.cleanups = 0;
3264 thisblock->data.block.n_function_calls = 0;
3265 thisblock->data.block.exception_region = 0;
3266 thisblock->data.block.block_target_temp_slot_level = target_temp_slot_level;
3268 thisblock->data.block.conditional_code = 0;
3269 thisblock->data.block.last_unconditional_cleanup = note;
3270 /* When we insert instructions after the last unconditional cleanup,
3271 we don't adjust last_insn. That means that a later add_insn will
3272 clobber the instructions we've just added. The easiest way to
3273 fix this is to just insert another instruction here, so that the
3274 instructions inserted after the last unconditional cleanup are
3275 never the last instruction. */
3276 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3277 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
3280 && !(block_stack->data.block.cleanups == NULL_TREE
3281 && block_stack->data.block.outer_cleanups == NULL_TREE))
3282 thisblock->data.block.outer_cleanups
3283 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
3284 block_stack->data.block.outer_cleanups);
3286 thisblock->data.block.outer_cleanups = 0;
3287 thisblock->data.block.label_chain = 0;
3288 thisblock->data.block.innermost_stack_block = stack_block_stack;
3289 thisblock->data.block.first_insn = note;
3290 thisblock->data.block.block_start_count = ++current_block_start_count;
3291 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
3292 block_stack = thisblock;
3293 nesting_stack = thisblock;
3295 /* Make a new level for allocating stack slots. */
3299 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3300 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3301 expand_expr are made. After we end the region, we know that all
3302 space for all temporaries that were created by TARGET_EXPRs will be
3303 destroyed and their space freed for reuse. */
3306 expand_start_target_temps ()
3308 /* This is so that even if the result is preserved, the space
3309 allocated will be freed, as we know that it is no longer in use. */
3312 /* Start a new binding layer that will keep track of all cleanup
3313 actions to be performed. */
3314 expand_start_bindings (2);
3316 target_temp_slot_level = temp_slot_level;
3320 expand_end_target_temps ()
3322 expand_end_bindings (NULL_TREE, 0, 0);
3324 /* This is so that even if the result is preserved, the space
3325 allocated will be freed, as we know that it is no longer in use. */
3329 /* Given a pointer to a BLOCK node return non-zero if (and only if) the node
3330 in question represents the outermost pair of curly braces (i.e. the "body
3331 block") of a function or method.
3333 For any BLOCK node representing a "body block" of a function or method, the
3334 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
3335 represents the outermost (function) scope for the function or method (i.e.
3336 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
3337 *that* node in turn will point to the relevant FUNCTION_DECL node. */
3340 is_body_block (stmt)
3343 if (TREE_CODE (stmt) == BLOCK)
3345 tree parent = BLOCK_SUPERCONTEXT (stmt);
3347 if (parent && TREE_CODE (parent) == BLOCK)
3349 tree grandparent = BLOCK_SUPERCONTEXT (parent);
3351 if (grandparent && TREE_CODE (grandparent) == FUNCTION_DECL)
3359 /* Mark top block of block_stack as an implicit binding for an
3360 exception region. This is used to prevent infinite recursion when
3361 ending a binding with expand_end_bindings. It is only ever called
3362 by expand_eh_region_start, as that it the only way to create a
3363 block stack for a exception region. */
3366 mark_block_as_eh_region ()
3368 block_stack->data.block.exception_region = 1;
3369 if (block_stack->next
3370 && block_stack->next->data.block.conditional_code)
3372 block_stack->data.block.conditional_code
3373 = block_stack->next->data.block.conditional_code;
3374 block_stack->data.block.last_unconditional_cleanup
3375 = block_stack->next->data.block.last_unconditional_cleanup;
3376 block_stack->data.block.cleanup_ptr
3377 = block_stack->next->data.block.cleanup_ptr;
3381 /* True if we are currently emitting insns in an area of output code
3382 that is controlled by a conditional expression. This is used by
3383 the cleanup handling code to generate conditional cleanup actions. */
3386 conditional_context ()
3388 return block_stack && block_stack->data.block.conditional_code;
3391 /* Mark top block of block_stack as not for an implicit binding for an
3392 exception region. This is only ever done by expand_eh_region_end
3393 to let expand_end_bindings know that it is being called explicitly
3394 to end the binding layer for just the binding layer associated with
3395 the exception region, otherwise expand_end_bindings would try and
3396 end all implicit binding layers for exceptions regions, and then
3397 one normal binding layer. */
3400 mark_block_as_not_eh_region ()
3402 block_stack->data.block.exception_region = 0;
3405 /* True if the top block of block_stack was marked as for an exception
3406 region by mark_block_as_eh_region. */
3411 return cfun && block_stack && block_stack->data.block.exception_region;
3414 /* Emit a handler label for a nonlocal goto handler.
3415 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3418 expand_nl_handler_label (slot, before_insn)
3419 rtx slot, before_insn;
3422 rtx handler_label = gen_label_rtx ();
3424 /* Don't let jump_optimize delete the handler. */
3425 LABEL_PRESERVE_P (handler_label) = 1;
3428 emit_move_insn (slot, gen_rtx_LABEL_REF (Pmode, handler_label));
3429 insns = get_insns ();
3431 emit_insns_before (insns, before_insn);
3433 emit_label (handler_label);
3435 return handler_label;
3438 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3441 expand_nl_goto_receiver ()
3443 #ifdef HAVE_nonlocal_goto
3444 if (! HAVE_nonlocal_goto)
3446 /* First adjust our frame pointer to its actual value. It was
3447 previously set to the start of the virtual area corresponding to
3448 the stacked variables when we branched here and now needs to be
3449 adjusted to the actual hardware fp value.
3451 Assignments are to virtual registers are converted by
3452 instantiate_virtual_regs into the corresponding assignment
3453 to the underlying register (fp in this case) that makes
3454 the original assignment true.
3455 So the following insn will actually be
3456 decrementing fp by STARTING_FRAME_OFFSET. */
3457 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3459 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3460 if (fixed_regs[ARG_POINTER_REGNUM])
3462 #ifdef ELIMINABLE_REGS
3463 /* If the argument pointer can be eliminated in favor of the
3464 frame pointer, we don't need to restore it. We assume here
3465 that if such an elimination is present, it can always be used.
3466 This is the case on all known machines; if we don't make this
3467 assumption, we do unnecessary saving on many machines. */
3468 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3471 for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
3472 if (elim_regs[i].from == ARG_POINTER_REGNUM
3473 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3476 if (i == sizeof elim_regs / sizeof elim_regs [0])
3479 /* Now restore our arg pointer from the address at which it
3480 was saved in our stack frame.
3481 If there hasn't be space allocated for it yet, make
3483 if (arg_pointer_save_area == 0)
3484 arg_pointer_save_area
3485 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3486 emit_move_insn (virtual_incoming_args_rtx,
3487 /* We need a pseudo here, or else
3488 instantiate_virtual_regs_1 complains. */
3489 copy_to_reg (arg_pointer_save_area));
3494 #ifdef HAVE_nonlocal_goto_receiver
3495 if (HAVE_nonlocal_goto_receiver)
3496 emit_insn (gen_nonlocal_goto_receiver ());
3500 /* Make handlers for nonlocal gotos taking place in the function calls in
3504 expand_nl_goto_receivers (thisblock)
3505 struct nesting *thisblock;
3508 rtx afterward = gen_label_rtx ();
3513 /* Record the handler address in the stack slot for that purpose,
3514 during this block, saving and restoring the outer value. */
3515 if (thisblock->next != 0)
3516 for (slot = nonlocal_goto_handler_slots; slot; slot = XEXP (slot, 1))
3518 rtx save_receiver = gen_reg_rtx (Pmode);
3519 emit_move_insn (XEXP (slot, 0), save_receiver);
3522 emit_move_insn (save_receiver, XEXP (slot, 0));
3523 insns = get_insns ();
3525 emit_insns_before (insns, thisblock->data.block.first_insn);
3528 /* Jump around the handlers; they run only when specially invoked. */
3529 emit_jump (afterward);
3531 /* Make a separate handler for each label. */
3532 link = nonlocal_labels;
3533 slot = nonlocal_goto_handler_slots;
3534 label_list = NULL_RTX;
3535 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3536 /* Skip any labels we shouldn't be able to jump to from here,
3537 we generate one special handler for all of them below which just calls
3539 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3542 lab = expand_nl_handler_label (XEXP (slot, 0),
3543 thisblock->data.block.first_insn);
3544 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3546 expand_nl_goto_receiver ();
3548 /* Jump to the "real" nonlocal label. */
3549 expand_goto (TREE_VALUE (link));
3552 /* A second pass over all nonlocal labels; this time we handle those
3553 we should not be able to jump to at this point. */
3554 link = nonlocal_labels;
3555 slot = nonlocal_goto_handler_slots;
3557 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3558 if (DECL_TOO_LATE (TREE_VALUE (link)))
3561 lab = expand_nl_handler_label (XEXP (slot, 0),
3562 thisblock->data.block.first_insn);
3563 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3569 expand_nl_goto_receiver ();
3570 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "abort"), 0,
3575 nonlocal_goto_handler_labels = label_list;
3576 emit_label (afterward);
3579 /* Warn about any unused VARS (which may contain nodes other than
3580 VAR_DECLs, but such nodes are ignored). The nodes are connected
3581 via the TREE_CHAIN field. */
3584 warn_about_unused_variables (vars)
3589 if (warn_unused_variable)
3590 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3591 if (TREE_CODE (decl) == VAR_DECL
3592 && ! TREE_USED (decl)
3593 && ! DECL_IN_SYSTEM_HEADER (decl)
3594 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
3595 warning_with_decl (decl, "unused variable `%s'");
3598 /* Generate RTL code to terminate a binding contour.
3600 VARS is the chain of VAR_DECL nodes for the variables bound in this
3601 contour. There may actually be other nodes in this chain, but any
3602 nodes other than VAR_DECLS are ignored.
3604 MARK_ENDS is nonzero if we should put a note at the beginning
3605 and end of this binding contour.
3607 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3608 (That is true automatically if the contour has a saved stack level.) */
3611 expand_end_bindings (vars, mark_ends, dont_jump_in)
3616 register struct nesting *thisblock;
3618 while (block_stack->data.block.exception_region)
3620 /* Because we don't need or want a new temporary level and
3621 because we didn't create one in expand_eh_region_start,
3622 create a fake one now to avoid removing one in
3623 expand_end_bindings. */
3626 block_stack->data.block.exception_region = 0;
3628 expand_end_bindings (NULL_TREE, 0, 0);
3631 /* Since expand_eh_region_start does an expand_start_bindings, we
3632 have to first end all the bindings that were created by
3633 expand_eh_region_start. */
3635 thisblock = block_stack;
3637 /* If any of the variables in this scope were not used, warn the
3639 warn_about_unused_variables (vars);
3641 if (thisblock->exit_label)
3643 do_pending_stack_adjust ();
3644 emit_label (thisblock->exit_label);
3647 /* If necessary, make handlers for nonlocal gotos taking
3648 place in the function calls in this block. */
3649 if (function_call_count != thisblock->data.block.n_function_calls
3651 /* Make handler for outermost block
3652 if there were any nonlocal gotos to this function. */
3653 && (thisblock->next == 0 ? current_function_has_nonlocal_label
3654 /* Make handler for inner block if it has something
3655 special to do when you jump out of it. */
3656 : (thisblock->data.block.cleanups != 0
3657 || thisblock->data.block.stack_level != 0)))
3658 expand_nl_goto_receivers (thisblock);
3660 /* Don't allow jumping into a block that has a stack level.
3661 Cleanups are allowed, though. */
3663 || thisblock->data.block.stack_level != 0)
3665 struct label_chain *chain;
3667 /* Any labels in this block are no longer valid to go to.
3668 Mark them to cause an error message. */
3669 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3671 DECL_TOO_LATE (chain->label) = 1;
3672 /* If any goto without a fixup came to this label,
3673 that must be an error, because gotos without fixups
3674 come from outside all saved stack-levels. */
3675 if (TREE_ADDRESSABLE (chain->label))
3676 error_with_decl (chain->label,
3677 "label `%s' used before containing binding contour");
3681 /* Restore stack level in effect before the block
3682 (only if variable-size objects allocated). */
3683 /* Perform any cleanups associated with the block. */
3685 if (thisblock->data.block.stack_level != 0
3686 || thisblock->data.block.cleanups != 0)
3691 /* Don't let cleanups affect ({...}) constructs. */
3692 int old_expr_stmts_for_value = expr_stmts_for_value;
3693 rtx old_last_expr_value = last_expr_value;
3694 tree old_last_expr_type = last_expr_type;
3695 expr_stmts_for_value = 0;
3697 /* Only clean up here if this point can actually be reached. */
3698 insn = get_last_insn ();
3699 if (GET_CODE (insn) == NOTE)
3700 insn = prev_nonnote_insn (insn);
3701 reachable = (! insn || GET_CODE (insn) != BARRIER);
3703 /* Do the cleanups. */
3704 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3706 do_pending_stack_adjust ();
3708 expr_stmts_for_value = old_expr_stmts_for_value;
3709 last_expr_value = old_last_expr_value;
3710 last_expr_type = old_last_expr_type;
3712 /* Restore the stack level. */
3714 if (reachable && thisblock->data.block.stack_level != 0)
3716 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3717 thisblock->data.block.stack_level, NULL_RTX);
3718 if (nonlocal_goto_handler_slots != 0)
3719 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3723 /* Any gotos out of this block must also do these things.
3724 Also report any gotos with fixups that came to labels in this
3726 fixup_gotos (thisblock,
3727 thisblock->data.block.stack_level,
3728 thisblock->data.block.cleanups,
3729 thisblock->data.block.first_insn,
3733 /* Mark the beginning and end of the scope if requested.
3734 We do this now, after running cleanups on the variables
3735 just going out of scope, so they are in scope for their cleanups. */
3739 rtx note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3740 NOTE_BLOCK (note) = NOTE_BLOCK (thisblock->data.block.first_insn);
3743 /* Get rid of the beginning-mark if we don't make an end-mark. */
3744 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3746 /* Restore the temporary level of TARGET_EXPRs. */
3747 target_temp_slot_level = thisblock->data.block.block_target_temp_slot_level;
3749 /* Restore block_stack level for containing block. */
3751 stack_block_stack = thisblock->data.block.innermost_stack_block;
3752 POPSTACK (block_stack);
3754 /* Pop the stack slot nesting and free any slots at this level. */
3758 /* Generate RTL for the automatic variable declaration DECL.
3759 (Other kinds of declarations are simply ignored if seen here.) */
3765 struct nesting *thisblock;
3768 type = TREE_TYPE (decl);
3770 /* Only automatic variables need any expansion done.
3771 Static and external variables, and external functions,
3772 will be handled by `assemble_variable' (called from finish_decl).
3773 TYPE_DECL and CONST_DECL require nothing.
3774 PARM_DECLs are handled in `assign_parms'. */
3776 if (TREE_CODE (decl) != VAR_DECL)
3778 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3781 thisblock = block_stack;
3783 /* Create the RTL representation for the variable. */
3785 if (type == error_mark_node)
3786 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, const0_rtx);
3787 else if (DECL_SIZE (decl) == 0)
3788 /* Variable with incomplete type. */
3790 if (DECL_INITIAL (decl) == 0)
3791 /* Error message was already done; now avoid a crash. */
3792 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3794 /* An initializer is going to decide the size of this array.
3795 Until we know the size, represent its address with a reg. */
3796 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode));
3798 set_mem_attributes (DECL_RTL (decl), decl, 1);
3800 else if (DECL_MODE (decl) != BLKmode
3801 /* If -ffloat-store, don't put explicit float vars
3803 && !(flag_float_store
3804 && TREE_CODE (type) == REAL_TYPE)
3805 && ! TREE_THIS_VOLATILE (decl)
3806 && ! TREE_ADDRESSABLE (decl)
3807 && (DECL_REGISTER (decl) || optimize)
3808 /* if -fcheck-memory-usage, check all variables. */
3809 && ! current_function_check_memory_usage)
3811 /* Automatic variable that can go in a register. */
3812 int unsignedp = TREE_UNSIGNED (type);
3813 enum machine_mode reg_mode
3814 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3816 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3817 mark_user_reg (DECL_RTL (decl));
3819 if (POINTER_TYPE_P (type))
3820 mark_reg_pointer (DECL_RTL (decl),
3821 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
3823 maybe_set_unchanging (DECL_RTL (decl), decl);
3826 else if (TREE_CODE (DECL_SIZE_UNIT (decl)) == INTEGER_CST
3827 && ! (flag_stack_check && ! STACK_CHECK_BUILTIN
3828 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl),
3829 STACK_CHECK_MAX_VAR_SIZE)))
3831 /* Variable of fixed size that goes on the stack. */
3835 /* If we previously made RTL for this decl, it must be an array
3836 whose size was determined by the initializer.
3837 The old address was a register; set that register now
3838 to the proper address. */
3839 if (DECL_RTL (decl) != 0)
3841 if (GET_CODE (DECL_RTL (decl)) != MEM
3842 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3844 oldaddr = XEXP (DECL_RTL (decl), 0);
3847 DECL_RTL (decl) = assign_temp (TREE_TYPE (decl), 1, 1, 1);
3849 /* Set alignment we actually gave this decl. */
3850 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3851 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3852 DECL_USER_ALIGN (decl) = 0;
3856 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3857 if (addr != oldaddr)
3858 emit_move_insn (oldaddr, addr);
3862 /* Dynamic-size object: must push space on the stack. */
3866 /* Record the stack pointer on entry to block, if have
3867 not already done so. */
3868 if (thisblock->data.block.stack_level == 0)
3870 do_pending_stack_adjust ();
3871 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3872 &thisblock->data.block.stack_level,
3873 thisblock->data.block.first_insn);
3874 stack_block_stack = thisblock;
3877 /* In function-at-a-time mode, variable_size doesn't expand this,
3879 if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
3880 expand_expr (TYPE_MAX_VALUE (TYPE_DOMAIN (type)),
3881 const0_rtx, VOIDmode, 0);
3883 /* Compute the variable's size, in bytes. */
3884 size = expand_expr (DECL_SIZE_UNIT (decl), NULL_RTX, VOIDmode, 0);
3887 /* Allocate space on the stack for the variable. Note that
3888 DECL_ALIGN says how the variable is to be aligned and we
3889 cannot use it to conclude anything about the alignment of
3891 address = allocate_dynamic_stack_space (size, NULL_RTX,
3892 TYPE_ALIGN (TREE_TYPE (decl)));
3894 /* Reference the variable indirect through that rtx. */
3895 DECL_RTL (decl) = gen_rtx_MEM (DECL_MODE (decl), address);
3897 set_mem_attributes (DECL_RTL (decl), decl, 1);
3899 /* Indicate the alignment we actually gave this variable. */
3900 #ifdef STACK_BOUNDARY
3901 DECL_ALIGN (decl) = STACK_BOUNDARY;
3903 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3905 DECL_USER_ALIGN (decl) = 0;
3909 /* Emit code to perform the initialization of a declaration DECL. */
3912 expand_decl_init (decl)
3915 int was_used = TREE_USED (decl);
3917 /* If this is a CONST_DECL, we don't have to generate any code, but
3918 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3919 to be set while in the obstack containing the constant. If we don't
3920 do this, we can lose if we have functions nested three deep and the middle
3921 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3922 the innermost function is the first to expand that STRING_CST. */
3923 if (TREE_CODE (decl) == CONST_DECL)
3925 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3926 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3927 EXPAND_INITIALIZER);
3931 if (TREE_STATIC (decl))
3934 /* Compute and store the initial value now. */
3936 if (DECL_INITIAL (decl) == error_mark_node)
3938 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3940 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3941 || code == POINTER_TYPE || code == REFERENCE_TYPE)
3942 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3946 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3948 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3949 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3953 /* Don't let the initialization count as "using" the variable. */
3954 TREE_USED (decl) = was_used;
3956 /* Free any temporaries we made while initializing the decl. */
3957 preserve_temp_slots (NULL_RTX);
3961 /* CLEANUP is an expression to be executed at exit from this binding contour;
3962 for example, in C++, it might call the destructor for this variable.
3964 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
3965 CLEANUP multiple times, and have the correct semantics. This
3966 happens in exception handling, for gotos, returns, breaks that
3967 leave the current scope.
3969 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3970 that is not associated with any particular variable. */
3973 expand_decl_cleanup (decl, cleanup)
3976 struct nesting *thisblock;
3978 /* Error if we are not in any block. */
3979 if (cfun == 0 || block_stack == 0)
3982 thisblock = block_stack;
3984 /* Record the cleanup if there is one. */
3990 tree *cleanups = &thisblock->data.block.cleanups;
3991 int cond_context = conditional_context ();
3995 rtx flag = gen_reg_rtx (word_mode);
4000 emit_move_insn (flag, const0_rtx);
4001 set_flag_0 = get_insns ();
4004 thisblock->data.block.last_unconditional_cleanup
4005 = emit_insns_after (set_flag_0,
4006 thisblock->data.block.last_unconditional_cleanup);
4008 emit_move_insn (flag, const1_rtx);
4010 /* All cleanups must be on the function_obstack. */
4011 push_obstacks_nochange ();
4012 resume_temporary_allocation ();
4014 cond = build_decl (VAR_DECL, NULL_TREE, type_for_mode (word_mode, 1));
4015 DECL_RTL (cond) = flag;
4017 /* Conditionalize the cleanup. */
4018 cleanup = build (COND_EXPR, void_type_node,
4019 truthvalue_conversion (cond),
4020 cleanup, integer_zero_node);
4021 cleanup = fold (cleanup);
4025 cleanups = thisblock->data.block.cleanup_ptr;
4028 /* All cleanups must be on the function_obstack. */
4029 push_obstacks_nochange ();
4030 resume_temporary_allocation ();
4031 cleanup = unsave_expr (cleanup);
4034 t = *cleanups = temp_tree_cons (decl, cleanup, *cleanups);
4037 /* If this block has a cleanup, it belongs in stack_block_stack. */
4038 stack_block_stack = thisblock;
4045 /* If this was optimized so that there is no exception region for the
4046 cleanup, then mark the TREE_LIST node, so that we can later tell
4047 if we need to call expand_eh_region_end. */
4048 if (! using_eh_for_cleanups_p
4049 || expand_eh_region_start_tree (decl, cleanup))
4050 TREE_ADDRESSABLE (t) = 1;
4051 /* If that started a new EH region, we're in a new block. */
4052 thisblock = block_stack;
4059 thisblock->data.block.last_unconditional_cleanup
4060 = emit_insns_after (seq,
4061 thisblock->data.block.last_unconditional_cleanup);
4065 thisblock->data.block.last_unconditional_cleanup
4067 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
4073 /* Like expand_decl_cleanup, but suppress generating an exception handler
4074 to perform the cleanup. */
4078 expand_decl_cleanup_no_eh (decl, cleanup)
4081 int save_eh = using_eh_for_cleanups_p;
4084 using_eh_for_cleanups_p = 0;
4085 result = expand_decl_cleanup (decl, cleanup);
4086 using_eh_for_cleanups_p = save_eh;
4092 /* Arrange for the top element of the dynamic cleanup chain to be
4093 popped if we exit the current binding contour. DECL is the
4094 associated declaration, if any, otherwise NULL_TREE. If the
4095 current contour is left via an exception, then __sjthrow will pop
4096 the top element off the dynamic cleanup chain. The code that
4097 avoids doing the action we push into the cleanup chain in the
4098 exceptional case is contained in expand_cleanups.
4100 This routine is only used by expand_eh_region_start, and that is
4101 the only way in which an exception region should be started. This
4102 routine is only used when using the setjmp/longjmp codegen method
4103 for exception handling. */
4106 expand_dcc_cleanup (decl)
4109 struct nesting *thisblock;
4112 /* Error if we are not in any block. */
4113 if (cfun == 0 || block_stack == 0)
4115 thisblock = block_stack;
4117 /* Record the cleanup for the dynamic handler chain. */
4119 /* All cleanups must be on the function_obstack. */
4120 push_obstacks_nochange ();
4121 resume_temporary_allocation ();
4122 cleanup = make_node (POPDCC_EXPR);
4125 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4126 thisblock->data.block.cleanups
4127 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4129 /* If this block has a cleanup, it belongs in stack_block_stack. */
4130 stack_block_stack = thisblock;
4134 /* Arrange for the top element of the dynamic handler chain to be
4135 popped if we exit the current binding contour. DECL is the
4136 associated declaration, if any, otherwise NULL_TREE. If the current
4137 contour is left via an exception, then __sjthrow will pop the top
4138 element off the dynamic handler chain. The code that avoids doing
4139 the action we push into the handler chain in the exceptional case
4140 is contained in expand_cleanups.
4142 This routine is only used by expand_eh_region_start, and that is
4143 the only way in which an exception region should be started. This
4144 routine is only used when using the setjmp/longjmp codegen method
4145 for exception handling. */
4148 expand_dhc_cleanup (decl)
4151 struct nesting *thisblock;
4154 /* Error if we are not in any block. */
4155 if (cfun == 0 || block_stack == 0)
4157 thisblock = block_stack;
4159 /* Record the cleanup for the dynamic handler chain. */
4161 /* All cleanups must be on the function_obstack. */
4162 push_obstacks_nochange ();
4163 resume_temporary_allocation ();
4164 cleanup = make_node (POPDHC_EXPR);
4167 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4168 thisblock->data.block.cleanups
4169 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4171 /* If this block has a cleanup, it belongs in stack_block_stack. */
4172 stack_block_stack = thisblock;
4176 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4177 DECL_ELTS is the list of elements that belong to DECL's type.
4178 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4181 expand_anon_union_decl (decl, cleanup, decl_elts)
4182 tree decl, cleanup, decl_elts;
4184 struct nesting *thisblock = cfun == 0 ? 0 : block_stack;
4188 /* If any of the elements are addressable, so is the entire union. */
4189 for (t = decl_elts; t; t = TREE_CHAIN (t))
4190 if (TREE_ADDRESSABLE (TREE_VALUE (t)))
4192 TREE_ADDRESSABLE (decl) = 1;
4197 expand_decl_cleanup (decl, cleanup);
4198 x = DECL_RTL (decl);
4200 /* Go through the elements, assigning RTL to each. */
4201 for (t = decl_elts; t; t = TREE_CHAIN (t))
4203 tree decl_elt = TREE_VALUE (t);
4204 tree cleanup_elt = TREE_PURPOSE (t);
4205 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
4207 /* Propagate the union's alignment to the elements. */
4208 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
4209 DECL_USER_ALIGN (decl_elt) = DECL_USER_ALIGN (decl);
4211 /* If the element has BLKmode and the union doesn't, the union is
4212 aligned such that the element doesn't need to have BLKmode, so
4213 change the element's mode to the appropriate one for its size. */
4214 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
4215 DECL_MODE (decl_elt) = mode
4216 = mode_for_size_tree (DECL_SIZE (decl_elt), MODE_INT, 1);
4218 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4219 instead create a new MEM rtx with the proper mode. */
4220 if (GET_CODE (x) == MEM)
4222 if (mode == GET_MODE (x))
4223 DECL_RTL (decl_elt) = x;
4226 DECL_RTL (decl_elt) = gen_rtx_MEM (mode, copy_rtx (XEXP (x, 0)));
4227 MEM_COPY_ATTRIBUTES (DECL_RTL (decl_elt), x);
4230 else if (GET_CODE (x) == REG)
4232 if (mode == GET_MODE (x))
4233 DECL_RTL (decl_elt) = x;
4235 DECL_RTL (decl_elt) = gen_rtx_SUBREG (mode, x, 0);
4240 /* Record the cleanup if there is one. */
4243 thisblock->data.block.cleanups
4244 = temp_tree_cons (decl_elt, cleanup_elt,
4245 thisblock->data.block.cleanups);
4249 /* Expand a list of cleanups LIST.
4250 Elements may be expressions or may be nested lists.
4252 If DONT_DO is nonnull, then any list-element
4253 whose TREE_PURPOSE matches DONT_DO is omitted.
4254 This is sometimes used to avoid a cleanup associated with
4255 a value that is being returned out of the scope.
4257 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
4258 goto and handle protection regions specially in that case.
4260 If REACHABLE, we emit code, otherwise just inform the exception handling
4261 code about this finalization. */
4264 expand_cleanups (list, dont_do, in_fixup, reachable)
4271 for (tail = list; tail; tail = TREE_CHAIN (tail))
4272 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
4274 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
4275 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
4280 tree cleanup = TREE_VALUE (tail);
4282 /* See expand_d{h,c}c_cleanup for why we avoid this. */
4283 if (TREE_CODE (cleanup) != POPDHC_EXPR
4284 && TREE_CODE (cleanup) != POPDCC_EXPR
4285 /* See expand_eh_region_start_tree for this case. */
4286 && ! TREE_ADDRESSABLE (tail))
4288 cleanup = protect_with_terminate (cleanup);
4289 expand_eh_region_end (cleanup);
4295 /* Cleanups may be run multiple times. For example,
4296 when exiting a binding contour, we expand the
4297 cleanups associated with that contour. When a goto
4298 within that binding contour has a target outside that
4299 contour, it will expand all cleanups from its scope to
4300 the target. Though the cleanups are expanded multiple
4301 times, the control paths are non-overlapping so the
4302 cleanups will not be executed twice. */
4304 /* We may need to protect fixups with rethrow regions. */
4305 int protect = (in_fixup && ! TREE_ADDRESSABLE (tail));
4308 expand_fixup_region_start ();
4310 /* The cleanup might contain try-blocks, so we have to
4311 preserve our current queue. */
4313 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
4316 expand_fixup_region_end (TREE_VALUE (tail));
4323 /* Mark when the context we are emitting RTL for as a conditional
4324 context, so that any cleanup actions we register with
4325 expand_decl_init will be properly conditionalized when those
4326 cleanup actions are later performed. Must be called before any
4327 expression (tree) is expanded that is within a conditional context. */
4330 start_cleanup_deferral ()
4332 /* block_stack can be NULL if we are inside the parameter list. It is
4333 OK to do nothing, because cleanups aren't possible here. */
4335 ++block_stack->data.block.conditional_code;
4338 /* Mark the end of a conditional region of code. Because cleanup
4339 deferrals may be nested, we may still be in a conditional region
4340 after we end the currently deferred cleanups, only after we end all
4341 deferred cleanups, are we back in unconditional code. */
4344 end_cleanup_deferral ()
4346 /* block_stack can be NULL if we are inside the parameter list. It is
4347 OK to do nothing, because cleanups aren't possible here. */
4349 --block_stack->data.block.conditional_code;
4352 /* Move all cleanups from the current block_stack
4353 to the containing block_stack, where they are assumed to
4354 have been created. If anything can cause a temporary to
4355 be created, but not expanded for more than one level of
4356 block_stacks, then this code will have to change. */
4361 struct nesting *block = block_stack;
4362 struct nesting *outer = block->next;
4364 outer->data.block.cleanups
4365 = chainon (block->data.block.cleanups,
4366 outer->data.block.cleanups);
4367 block->data.block.cleanups = 0;
4371 last_cleanup_this_contour ()
4373 if (block_stack == 0)
4376 return block_stack->data.block.cleanups;
4379 /* Return 1 if there are any pending cleanups at this point.
4380 If THIS_CONTOUR is nonzero, check the current contour as well.
4381 Otherwise, look only at the contours that enclose this one. */
4384 any_pending_cleanups (this_contour)
4387 struct nesting *block;
4389 if (cfun == NULL || cfun->stmt == NULL || block_stack == 0)
4392 if (this_contour && block_stack->data.block.cleanups != NULL)
4394 if (block_stack->data.block.cleanups == 0
4395 && block_stack->data.block.outer_cleanups == 0)
4398 for (block = block_stack->next; block; block = block->next)
4399 if (block->data.block.cleanups != 0)
4405 /* Enter a case (Pascal) or switch (C) statement.
4406 Push a block onto case_stack and nesting_stack
4407 to accumulate the case-labels that are seen
4408 and to record the labels generated for the statement.
4410 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4411 Otherwise, this construct is transparent for `exit_something'.
4413 EXPR is the index-expression to be dispatched on.
4414 TYPE is its nominal type. We could simply convert EXPR to this type,
4415 but instead we take short cuts. */
4418 expand_start_case (exit_flag, expr, type, printname)
4422 const char *printname;
4424 register struct nesting *thiscase = ALLOC_NESTING ();
4426 /* Make an entry on case_stack for the case we are entering. */
4428 thiscase->next = case_stack;
4429 thiscase->all = nesting_stack;
4430 thiscase->depth = ++nesting_depth;
4431 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
4432 thiscase->data.case_stmt.case_list = 0;
4433 thiscase->data.case_stmt.index_expr = expr;
4434 thiscase->data.case_stmt.nominal_type = type;
4435 thiscase->data.case_stmt.default_label = 0;
4436 thiscase->data.case_stmt.num_ranges = 0;
4437 thiscase->data.case_stmt.printname = printname;
4438 thiscase->data.case_stmt.line_number_status = force_line_numbers ();
4439 case_stack = thiscase;
4440 nesting_stack = thiscase;
4442 do_pending_stack_adjust ();
4444 /* Make sure case_stmt.start points to something that won't
4445 need any transformation before expand_end_case. */
4446 if (GET_CODE (get_last_insn ()) != NOTE)
4447 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4449 thiscase->data.case_stmt.start = get_last_insn ();
4451 start_cleanup_deferral ();
4455 /* Start a "dummy case statement" within which case labels are invalid
4456 and are not connected to any larger real case statement.
4457 This can be used if you don't want to let a case statement jump
4458 into the middle of certain kinds of constructs. */
4461 expand_start_case_dummy ()
4463 register struct nesting *thiscase = ALLOC_NESTING ();
4465 /* Make an entry on case_stack for the dummy. */
4467 thiscase->next = case_stack;
4468 thiscase->all = nesting_stack;
4469 thiscase->depth = ++nesting_depth;
4470 thiscase->exit_label = 0;
4471 thiscase->data.case_stmt.case_list = 0;
4472 thiscase->data.case_stmt.start = 0;
4473 thiscase->data.case_stmt.nominal_type = 0;
4474 thiscase->data.case_stmt.default_label = 0;
4475 thiscase->data.case_stmt.num_ranges = 0;
4476 case_stack = thiscase;
4477 nesting_stack = thiscase;
4478 start_cleanup_deferral ();
4481 /* End a dummy case statement. */
4484 expand_end_case_dummy ()
4486 end_cleanup_deferral ();
4487 POPSTACK (case_stack);
4490 /* Return the data type of the index-expression
4491 of the innermost case statement, or null if none. */
4494 case_index_expr_type ()
4497 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
4504 /* If this is the first label, warn if any insns have been emitted. */
4505 if (case_stack->data.case_stmt.line_number_status >= 0)
4509 restore_line_number_status
4510 (case_stack->data.case_stmt.line_number_status);
4511 case_stack->data.case_stmt.line_number_status = -1;
4513 for (insn = case_stack->data.case_stmt.start;
4515 insn = NEXT_INSN (insn))
4517 if (GET_CODE (insn) == CODE_LABEL)
4519 if (GET_CODE (insn) != NOTE
4520 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4523 insn = PREV_INSN (insn);
4524 while (insn && (GET_CODE (insn) != NOTE || NOTE_LINE_NUMBER (insn) < 0));
4526 /* If insn is zero, then there must have been a syntax error. */
4528 warning_with_file_and_line (NOTE_SOURCE_FILE(insn),
4529 NOTE_LINE_NUMBER(insn),
4530 "unreachable code at beginning of %s",
4531 case_stack->data.case_stmt.printname);
4538 /* Accumulate one case or default label inside a case or switch statement.
4539 VALUE is the value of the case (a null pointer, for a default label).
4540 The function CONVERTER, when applied to arguments T and V,
4541 converts the value V to the type T.
4543 If not currently inside a case or switch statement, return 1 and do
4544 nothing. The caller will print a language-specific error message.
4545 If VALUE is a duplicate or overlaps, return 2 and do nothing
4546 except store the (first) duplicate node in *DUPLICATE.
4547 If VALUE is out of range, return 3 and do nothing.
4548 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4549 Return 0 on success.
4551 Extended to handle range statements. */
4554 pushcase (value, converter, label, duplicate)
4555 register tree value;
4556 tree (*converter) PARAMS ((tree, tree));
4557 register tree label;
4563 /* Fail if not inside a real case statement. */
4564 if (! (case_stack && case_stack->data.case_stmt.start))
4567 if (stack_block_stack
4568 && stack_block_stack->depth > case_stack->depth)
4571 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4572 nominal_type = case_stack->data.case_stmt.nominal_type;
4574 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4575 if (index_type == error_mark_node)
4578 /* Convert VALUE to the type in which the comparisons are nominally done. */
4580 value = (*converter) (nominal_type, value);
4584 /* Fail if this value is out of range for the actual type of the index
4585 (which may be narrower than NOMINAL_TYPE). */
4587 && (TREE_CONSTANT_OVERFLOW (value)
4588 || ! int_fits_type_p (value, index_type)))
4591 /* Fail if this is a duplicate or overlaps another entry. */
4594 if (case_stack->data.case_stmt.default_label != 0)
4596 *duplicate = case_stack->data.case_stmt.default_label;
4599 case_stack->data.case_stmt.default_label = label;
4602 return add_case_node (value, value, label, duplicate);
4604 expand_label (label);
4608 /* Like pushcase but this case applies to all values between VALUE1 and
4609 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4610 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4611 starts at VALUE1 and ends at the highest value of the index type.
4612 If both are NULL, this case applies to all values.
4614 The return value is the same as that of pushcase but there is one
4615 additional error code: 4 means the specified range was empty. */
4618 pushcase_range (value1, value2, converter, label, duplicate)
4619 register tree value1, value2;
4620 tree (*converter) PARAMS ((tree, tree));
4621 register tree label;
4627 /* Fail if not inside a real case statement. */
4628 if (! (case_stack && case_stack->data.case_stmt.start))
4631 if (stack_block_stack
4632 && stack_block_stack->depth > case_stack->depth)
4635 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4636 nominal_type = case_stack->data.case_stmt.nominal_type;
4638 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4639 if (index_type == error_mark_node)
4644 /* Convert VALUEs to type in which the comparisons are nominally done
4645 and replace any unspecified value with the corresponding bound. */
4647 value1 = TYPE_MIN_VALUE (index_type);
4649 value2 = TYPE_MAX_VALUE (index_type);
4651 /* Fail if the range is empty. Do this before any conversion since
4652 we want to allow out-of-range empty ranges. */
4653 if (value2 != 0 && tree_int_cst_lt (value2, value1))
4656 /* If the max was unbounded, use the max of the nominal_type we are
4657 converting to. Do this after the < check above to suppress false
4660 value2 = TYPE_MAX_VALUE (nominal_type);
4662 value1 = (*converter) (nominal_type, value1);
4663 value2 = (*converter) (nominal_type, value2);
4665 /* Fail if these values are out of range. */
4666 if (TREE_CONSTANT_OVERFLOW (value1)
4667 || ! int_fits_type_p (value1, index_type))
4670 if (TREE_CONSTANT_OVERFLOW (value2)
4671 || ! int_fits_type_p (value2, index_type))
4674 return add_case_node (value1, value2, label, duplicate);
4677 /* Do the actual insertion of a case label for pushcase and pushcase_range
4678 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4679 slowdown for large switch statements. */
4682 add_case_node (low, high, label, duplicate)
4687 struct case_node *p, **q, *r;
4689 q = &case_stack->data.case_stmt.case_list;
4696 /* Keep going past elements distinctly greater than HIGH. */
4697 if (tree_int_cst_lt (high, p->low))
4700 /* or distinctly less than LOW. */
4701 else if (tree_int_cst_lt (p->high, low))
4706 /* We have an overlap; this is an error. */
4707 *duplicate = p->code_label;
4712 /* Add this label to the chain, and succeed.
4713 Copy LOW, HIGH so they are on temporary rather than momentary
4714 obstack and will thus survive till the end of the case statement. */
4716 r = (struct case_node *) oballoc (sizeof (struct case_node));
4717 r->low = copy_node (low);
4719 /* If the bounds are equal, turn this into the one-value case. */
4721 if (tree_int_cst_equal (low, high))
4725 r->high = copy_node (high);
4726 case_stack->data.case_stmt.num_ranges++;
4729 r->code_label = label;
4730 expand_label (label);
4740 struct case_node *s;
4746 if (! (b = p->balance))
4747 /* Growth propagation from left side. */
4754 if ((p->left = s = r->right))
4763 if ((r->parent = s))
4771 case_stack->data.case_stmt.case_list = r;
4774 /* r->balance == +1 */
4779 struct case_node *t = r->right;
4781 if ((p->left = s = t->right))
4785 if ((r->right = s = t->left))
4799 if ((t->parent = s))
4807 case_stack->data.case_stmt.case_list = t;
4814 /* p->balance == +1; growth of left side balances the node. */
4824 if (! (b = p->balance))
4825 /* Growth propagation from right side. */
4833 if ((p->right = s = r->left))
4841 if ((r->parent = s))
4850 case_stack->data.case_stmt.case_list = r;
4854 /* r->balance == -1 */
4858 struct case_node *t = r->left;
4860 if ((p->right = s = t->left))
4865 if ((r->left = s = t->right))
4879 if ((t->parent = s))
4888 case_stack->data.case_stmt.case_list = t;
4894 /* p->balance == -1; growth of right side balances the node. */
4908 /* Returns the number of possible values of TYPE.
4909 Returns -1 if the number is unknown, variable, or if the number does not
4910 fit in a HOST_WIDE_INT.
4911 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4912 do not increase monotonically (there may be duplicates);
4913 to 1 if the values increase monotonically, but not always by 1;
4914 otherwise sets it to 0. */
4917 all_cases_count (type, spareness)
4922 HOST_WIDE_INT count, minval, lastval;
4926 switch (TREE_CODE (type))
4933 count = 1 << BITS_PER_UNIT;
4938 if (TYPE_MAX_VALUE (type) != 0
4939 && 0 != (t = fold (build (MINUS_EXPR, type, TYPE_MAX_VALUE (type),
4940 TYPE_MIN_VALUE (type))))
4941 && 0 != (t = fold (build (PLUS_EXPR, type, t,
4942 convert (type, integer_zero_node))))
4943 && host_integerp (t, 1))
4944 count = tree_low_cst (t, 1);
4950 /* Don't waste time with enumeral types with huge values. */
4951 if (! host_integerp (TYPE_MIN_VALUE (type), 0)
4952 || TYPE_MAX_VALUE (type) == 0
4953 || ! host_integerp (TYPE_MAX_VALUE (type), 0))
4956 lastval = minval = tree_low_cst (TYPE_MIN_VALUE (type), 0);
4959 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4961 HOST_WIDE_INT thisval = tree_low_cst (TREE_VALUE (t), 0);
4963 if (*spareness == 2 || thisval < lastval)
4965 else if (thisval != minval + count)
4975 #define BITARRAY_TEST(ARRAY, INDEX) \
4976 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4977 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4978 #define BITARRAY_SET(ARRAY, INDEX) \
4979 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4980 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4982 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4983 with the case values we have seen, assuming the case expression
4985 SPARSENESS is as determined by all_cases_count.
4987 The time needed is proportional to COUNT, unless
4988 SPARSENESS is 2, in which case quadratic time is needed. */
4991 mark_seen_cases (type, cases_seen, count, sparseness)
4993 unsigned char *cases_seen;
4994 HOST_WIDE_INT count;
4997 tree next_node_to_try = NULL_TREE;
4998 HOST_WIDE_INT next_node_offset = 0;
5000 register struct case_node *n, *root = case_stack->data.case_stmt.case_list;
5001 tree val = make_node (INTEGER_CST);
5003 TREE_TYPE (val) = type;
5006 else if (sparseness == 2)
5009 unsigned HOST_WIDE_INT xlo;
5011 /* This less efficient loop is only needed to handle
5012 duplicate case values (multiple enum constants
5013 with the same value). */
5014 TREE_TYPE (val) = TREE_TYPE (root->low);
5015 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
5016 t = TREE_CHAIN (t), xlo++)
5018 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (TREE_VALUE (t));
5019 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (TREE_VALUE (t));
5023 /* Keep going past elements distinctly greater than VAL. */
5024 if (tree_int_cst_lt (val, n->low))
5027 /* or distinctly less than VAL. */
5028 else if (tree_int_cst_lt (n->high, val))
5033 /* We have found a matching range. */
5034 BITARRAY_SET (cases_seen, xlo);
5044 case_stack->data.case_stmt.case_list = root = case_tree2list (root, 0);
5046 for (n = root; n; n = n->right)
5048 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
5049 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
5050 while ( ! tree_int_cst_lt (n->high, val))
5052 /* Calculate (into xlo) the "offset" of the integer (val).
5053 The element with lowest value has offset 0, the next smallest
5054 element has offset 1, etc. */
5056 unsigned HOST_WIDE_INT xlo;
5060 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
5062 /* The TYPE_VALUES will be in increasing order, so
5063 starting searching where we last ended. */
5064 t = next_node_to_try;
5065 xlo = next_node_offset;
5071 t = TYPE_VALUES (type);
5074 if (tree_int_cst_equal (val, TREE_VALUE (t)))
5076 next_node_to_try = TREE_CHAIN (t);
5077 next_node_offset = xlo + 1;
5082 if (t == next_node_to_try)
5091 t = TYPE_MIN_VALUE (type);
5093 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
5097 add_double (xlo, xhi,
5098 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5102 if (xhi == 0 && xlo < (unsigned HOST_WIDE_INT) count)
5103 BITARRAY_SET (cases_seen, xlo);
5105 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5107 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
5113 /* Called when the index of a switch statement is an enumerated type
5114 and there is no default label.
5116 Checks that all enumeration literals are covered by the case
5117 expressions of a switch. Also, warn if there are any extra
5118 switch cases that are *not* elements of the enumerated type.
5120 If all enumeration literals were covered by the case expressions,
5121 turn one of the expressions into the default expression since it should
5122 not be possible to fall through such a switch. */
5125 check_for_full_enumeration_handling (type)
5128 register struct case_node *n;
5129 register tree chain;
5130 #if 0 /* variable used by 'if 0'ed code below. */
5131 register struct case_node **l;
5135 /* True iff the selector type is a numbered set mode. */
5138 /* The number of possible selector values. */
5141 /* For each possible selector value. a one iff it has been matched
5142 by a case value alternative. */
5143 unsigned char *cases_seen;
5145 /* The allocated size of cases_seen, in chars. */
5146 HOST_WIDE_INT bytes_needed;
5151 size = all_cases_count (type, &sparseness);
5152 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
5154 if (size > 0 && size < 600000
5155 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5156 this optimization if we don't have enough memory rather than
5157 aborting, as xmalloc would do. */
5158 && (cases_seen = (unsigned char *) calloc (bytes_needed, 1)) != NULL)
5161 tree v = TYPE_VALUES (type);
5163 /* The time complexity of this code is normally O(N), where
5164 N being the number of members in the enumerated type.
5165 However, if type is a ENUMERAL_TYPE whose values do not
5166 increase monotonically, O(N*log(N)) time may be needed. */
5168 mark_seen_cases (type, cases_seen, size, sparseness);
5170 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
5171 if (BITARRAY_TEST(cases_seen, i) == 0)
5172 warning ("enumeration value `%s' not handled in switch",
5173 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
5178 /* Now we go the other way around; we warn if there are case
5179 expressions that don't correspond to enumerators. This can
5180 occur since C and C++ don't enforce type-checking of
5181 assignments to enumeration variables. */
5183 if (case_stack->data.case_stmt.case_list
5184 && case_stack->data.case_stmt.case_list->left)
5185 case_stack->data.case_stmt.case_list
5186 = case_tree2list (case_stack->data.case_stmt.case_list, 0);
5188 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
5190 for (chain = TYPE_VALUES (type);
5191 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
5192 chain = TREE_CHAIN (chain))
5197 if (TYPE_NAME (type) == 0)
5198 warning ("case value `%ld' not in enumerated type",
5199 (long) TREE_INT_CST_LOW (n->low));
5201 warning ("case value `%ld' not in enumerated type `%s'",
5202 (long) TREE_INT_CST_LOW (n->low),
5203 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5206 : DECL_NAME (TYPE_NAME (type))));
5208 if (!tree_int_cst_equal (n->low, n->high))
5210 for (chain = TYPE_VALUES (type);
5211 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
5212 chain = TREE_CHAIN (chain))
5217 if (TYPE_NAME (type) == 0)
5218 warning ("case value `%ld' not in enumerated type",
5219 (long) TREE_INT_CST_LOW (n->high));
5221 warning ("case value `%ld' not in enumerated type `%s'",
5222 (long) TREE_INT_CST_LOW (n->high),
5223 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5226 : DECL_NAME (TYPE_NAME (type))));
5232 /* ??? This optimization is disabled because it causes valid programs to
5233 fail. ANSI C does not guarantee that an expression with enum type
5234 will have a value that is the same as one of the enumeration literals. */
5236 /* If all values were found as case labels, make one of them the default
5237 label. Thus, this switch will never fall through. We arbitrarily pick
5238 the last one to make the default since this is likely the most
5239 efficient choice. */
5243 for (l = &case_stack->data.case_stmt.case_list;
5248 case_stack->data.case_stmt.default_label = (*l)->code_label;
5255 /* Terminate a case (Pascal) or switch (C) statement
5256 in which ORIG_INDEX is the expression to be tested.
5257 Generate the code to test it and jump to the right place. */
5260 expand_end_case (orig_index)
5263 tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE, orig_minval;
5264 rtx default_label = 0;
5265 register struct case_node *n;
5273 register struct nesting *thiscase = case_stack;
5274 tree index_expr, index_type;
5277 /* Don't crash due to previous errors. */
5278 if (thiscase == NULL)
5281 table_label = gen_label_rtx ();
5282 index_expr = thiscase->data.case_stmt.index_expr;
5283 index_type = TREE_TYPE (index_expr);
5284 unsignedp = TREE_UNSIGNED (index_type);
5286 do_pending_stack_adjust ();
5288 /* This might get an spurious warning in the presence of a syntax error;
5289 it could be fixed by moving the call to check_seenlabel after the
5290 check for error_mark_node, and copying the code of check_seenlabel that
5291 deals with case_stack->data.case_stmt.line_number_status /
5292 restore_line_number_status in front of the call to end_cleanup_deferral;
5293 However, this might miss some useful warnings in the presence of
5294 non-syntax errors. */
5297 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5298 if (index_type != error_mark_node)
5300 /* If switch expression was an enumerated type, check that all
5301 enumeration literals are covered by the cases.
5302 No sense trying this if there's a default case, however. */
5304 if (!thiscase->data.case_stmt.default_label
5305 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
5306 && TREE_CODE (index_expr) != INTEGER_CST)
5307 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
5309 /* If we don't have a default-label, create one here,
5310 after the body of the switch. */
5311 if (thiscase->data.case_stmt.default_label == 0)
5313 thiscase->data.case_stmt.default_label
5314 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5315 expand_label (thiscase->data.case_stmt.default_label);
5317 default_label = label_rtx (thiscase->data.case_stmt.default_label);
5319 before_case = get_last_insn ();
5321 if (thiscase->data.case_stmt.case_list
5322 && thiscase->data.case_stmt.case_list->left)
5323 thiscase->data.case_stmt.case_list
5324 = case_tree2list(thiscase->data.case_stmt.case_list, 0);
5326 /* Simplify the case-list before we count it. */
5327 group_case_nodes (thiscase->data.case_stmt.case_list);
5329 /* Get upper and lower bounds of case values.
5330 Also convert all the case values to the index expr's data type. */
5333 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5335 /* Check low and high label values are integers. */
5336 if (TREE_CODE (n->low) != INTEGER_CST)
5338 if (TREE_CODE (n->high) != INTEGER_CST)
5341 n->low = convert (index_type, n->low);
5342 n->high = convert (index_type, n->high);
5344 /* Count the elements and track the largest and smallest
5345 of them (treating them as signed even if they are not). */
5353 if (INT_CST_LT (n->low, minval))
5355 if (INT_CST_LT (maxval, n->high))
5358 /* A range counts double, since it requires two compares. */
5359 if (! tree_int_cst_equal (n->low, n->high))
5363 orig_minval = minval;
5365 /* Compute span of values. */
5367 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
5369 end_cleanup_deferral ();
5373 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
5375 emit_jump (default_label);
5378 /* If range of values is much bigger than number of values,
5379 make a sequence of conditional branches instead of a dispatch.
5380 If the switch-index is a constant, do it this way
5381 because we can optimize it. */
5383 #ifndef CASE_VALUES_THRESHOLD
5385 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
5387 /* If machine does not have a case insn that compares the
5388 bounds, this means extra overhead for dispatch tables
5389 which raises the threshold for using them. */
5390 #define CASE_VALUES_THRESHOLD 5
5391 #endif /* HAVE_casesi */
5392 #endif /* CASE_VALUES_THRESHOLD */
5394 else if (count < CASE_VALUES_THRESHOLD
5395 || compare_tree_int (range, 10 * count) > 0
5396 /* RANGE may be signed, and really large ranges will show up
5397 as negative numbers. */
5398 || compare_tree_int (range, 0) < 0
5399 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5402 || TREE_CODE (index_expr) == INTEGER_CST
5403 /* These will reduce to a constant. */
5404 || (TREE_CODE (index_expr) == CALL_EXPR
5405 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
5406 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
5407 && DECL_BUILT_IN_CLASS (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_NORMAL
5408 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
5409 || (TREE_CODE (index_expr) == COMPOUND_EXPR
5410 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
5412 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5414 /* If the index is a short or char that we do not have
5415 an insn to handle comparisons directly, convert it to
5416 a full integer now, rather than letting each comparison
5417 generate the conversion. */
5419 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
5420 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
5421 == CODE_FOR_nothing))
5423 enum machine_mode wider_mode;
5424 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
5425 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
5426 if (cmp_optab->handlers[(int) wider_mode].insn_code
5427 != CODE_FOR_nothing)
5429 index = convert_to_mode (wider_mode, index, unsignedp);
5435 do_pending_stack_adjust ();
5437 index = protect_from_queue (index, 0);
5438 if (GET_CODE (index) == MEM)
5439 index = copy_to_reg (index);
5440 if (GET_CODE (index) == CONST_INT
5441 || TREE_CODE (index_expr) == INTEGER_CST)
5443 /* Make a tree node with the proper constant value
5444 if we don't already have one. */
5445 if (TREE_CODE (index_expr) != INTEGER_CST)
5448 = build_int_2 (INTVAL (index),
5449 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
5450 index_expr = convert (index_type, index_expr);
5453 /* For constant index expressions we need only
5454 issue a unconditional branch to the appropriate
5455 target code. The job of removing any unreachable
5456 code is left to the optimisation phase if the
5457 "-O" option is specified. */
5458 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5459 if (! tree_int_cst_lt (index_expr, n->low)
5460 && ! tree_int_cst_lt (n->high, index_expr))
5464 emit_jump (label_rtx (n->code_label));
5466 emit_jump (default_label);
5470 /* If the index expression is not constant we generate
5471 a binary decision tree to select the appropriate
5472 target code. This is done as follows:
5474 The list of cases is rearranged into a binary tree,
5475 nearly optimal assuming equal probability for each case.
5477 The tree is transformed into RTL, eliminating
5478 redundant test conditions at the same time.
5480 If program flow could reach the end of the
5481 decision tree an unconditional jump to the
5482 default code is emitted. */
5485 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
5486 && estimate_case_costs (thiscase->data.case_stmt.case_list));
5487 balance_case_nodes (&thiscase->data.case_stmt.case_list,
5489 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
5490 default_label, index_type);
5491 emit_jump_if_reachable (default_label);
5500 enum machine_mode index_mode = SImode;
5501 int index_bits = GET_MODE_BITSIZE (index_mode);
5503 enum machine_mode op_mode;
5505 /* Convert the index to SImode. */
5506 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
5507 > GET_MODE_BITSIZE (index_mode))
5509 enum machine_mode omode = TYPE_MODE (index_type);
5510 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
5512 /* We must handle the endpoints in the original mode. */
5513 index_expr = build (MINUS_EXPR, index_type,
5514 index_expr, minval);
5515 minval = integer_zero_node;
5516 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5517 emit_cmp_and_jump_insns (rangertx, index, LTU, NULL_RTX,
5518 omode, 1, 0, default_label);
5519 /* Now we can safely truncate. */
5520 index = convert_to_mode (index_mode, index, 0);
5524 if (TYPE_MODE (index_type) != index_mode)
5526 index_expr = convert (type_for_size (index_bits, 0),
5528 index_type = TREE_TYPE (index_expr);
5531 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5534 index = protect_from_queue (index, 0);
5535 do_pending_stack_adjust ();
5537 op_mode = insn_data[(int)CODE_FOR_casesi].operand[0].mode;
5538 if (! (*insn_data[(int)CODE_FOR_casesi].operand[0].predicate)
5540 index = copy_to_mode_reg (op_mode, index);
5542 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
5544 op_mode = insn_data[(int)CODE_FOR_casesi].operand[1].mode;
5545 if (! (*insn_data[(int)CODE_FOR_casesi].operand[1].predicate)
5547 op1 = copy_to_mode_reg (op_mode, op1);
5549 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
5551 op_mode = insn_data[(int)CODE_FOR_casesi].operand[2].mode;
5552 if (! (*insn_data[(int)CODE_FOR_casesi].operand[2].predicate)
5554 op2 = copy_to_mode_reg (op_mode, op2);
5556 emit_jump_insn (gen_casesi (index, op1, op2,
5557 table_label, default_label));
5561 #ifdef HAVE_tablejump
5562 if (! win && HAVE_tablejump)
5564 index_type = thiscase->data.case_stmt.nominal_type;
5565 index_expr = fold (build (MINUS_EXPR, index_type,
5566 convert (index_type, index_expr),
5567 convert (index_type, minval)));
5568 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5570 index = protect_from_queue (index, 0);
5571 do_pending_stack_adjust ();
5573 do_tablejump (index, TYPE_MODE (index_type),
5574 expand_expr (range, NULL_RTX, VOIDmode, 0),
5575 table_label, default_label);
5582 /* Get table of labels to jump to, in order of case index. */
5584 ncases = TREE_INT_CST_LOW (range) + 1;
5585 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
5586 bzero ((char *) labelvec, ncases * sizeof (rtx));
5588 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5590 register HOST_WIDE_INT i
5591 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
5596 = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
5597 if (i + TREE_INT_CST_LOW (orig_minval)
5598 == TREE_INT_CST_LOW (n->high))
5604 /* Fill in the gaps with the default. */
5605 for (i = 0; i < ncases; i++)
5606 if (labelvec[i] == 0)
5607 labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
5609 /* Output the table */
5610 emit_label (table_label);
5612 if (CASE_VECTOR_PC_RELATIVE || flag_pic)
5613 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
5614 gen_rtx_LABEL_REF (Pmode, table_label),
5615 gen_rtvec_v (ncases, labelvec),
5616 const0_rtx, const0_rtx));
5618 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
5619 gen_rtvec_v (ncases, labelvec)));
5621 /* If the case insn drops through the table,
5622 after the table we must jump to the default-label.
5623 Otherwise record no drop-through after the table. */
5624 #ifdef CASE_DROPS_THROUGH
5625 emit_jump (default_label);
5631 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
5632 reorder_insns (before_case, get_last_insn (),
5633 thiscase->data.case_stmt.start);
5636 end_cleanup_deferral ();
5638 if (thiscase->exit_label)
5639 emit_label (thiscase->exit_label);
5641 POPSTACK (case_stack);
5646 /* Convert the tree NODE into a list linked by the right field, with the left
5647 field zeroed. RIGHT is used for recursion; it is a list to be placed
5648 rightmost in the resulting list. */
5650 static struct case_node *
5651 case_tree2list (node, right)
5652 struct case_node *node, *right;
5654 struct case_node *left;
5657 right = case_tree2list (node->right, right);
5659 node->right = right;
5660 if ((left = node->left))
5663 return case_tree2list (left, node);
5669 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5672 do_jump_if_equal (op1, op2, label, unsignedp)
5673 rtx op1, op2, label;
5676 if (GET_CODE (op1) == CONST_INT
5677 && GET_CODE (op2) == CONST_INT)
5679 if (INTVAL (op1) == INTVAL (op2))
5684 enum machine_mode mode = GET_MODE (op1);
5685 if (mode == VOIDmode)
5686 mode = GET_MODE (op2);
5687 emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX, mode, unsignedp,
5692 /* Not all case values are encountered equally. This function
5693 uses a heuristic to weight case labels, in cases where that
5694 looks like a reasonable thing to do.
5696 Right now, all we try to guess is text, and we establish the
5699 chars above space: 16
5708 If we find any cases in the switch that are not either -1 or in the range
5709 of valid ASCII characters, or are control characters other than those
5710 commonly used with "\", don't treat this switch scanning text.
5712 Return 1 if these nodes are suitable for cost estimation, otherwise
5716 estimate_case_costs (node)
5719 tree min_ascii = build_int_2 (-1, -1);
5720 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5724 /* If we haven't already made the cost table, make it now. Note that the
5725 lower bound of the table is -1, not zero. */
5727 if (cost_table == NULL)
5729 cost_table = cost_table_ + 1;
5731 for (i = 0; i < 128; i++)
5735 else if (ISPUNCT (i))
5737 else if (ISCNTRL (i))
5741 cost_table[' '] = 8;
5742 cost_table['\t'] = 4;
5743 cost_table['\0'] = 4;
5744 cost_table['\n'] = 2;
5745 cost_table['\f'] = 1;
5746 cost_table['\v'] = 1;
5747 cost_table['\b'] = 1;
5750 /* See if all the case expressions look like text. It is text if the
5751 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5752 as signed arithmetic since we don't want to ever access cost_table with a
5753 value less than -1. Also check that none of the constants in a range
5754 are strange control characters. */
5756 for (n = node; n; n = n->right)
5758 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5761 for (i = (HOST_WIDE_INT) TREE_INT_CST_LOW (n->low);
5762 i <= (HOST_WIDE_INT) TREE_INT_CST_LOW (n->high); i++)
5763 if (cost_table[i] < 0)
5767 /* All interesting values are within the range of interesting
5768 ASCII characters. */
5772 /* Scan an ordered list of case nodes
5773 combining those with consecutive values or ranges.
5775 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5778 group_case_nodes (head)
5781 case_node_ptr node = head;
5785 rtx lb = next_real_insn (label_rtx (node->code_label));
5787 case_node_ptr np = node;
5789 /* Try to group the successors of NODE with NODE. */
5790 while (((np = np->right) != 0)
5791 /* Do they jump to the same place? */
5792 && ((lb2 = next_real_insn (label_rtx (np->code_label))) == lb
5793 || (lb != 0 && lb2 != 0
5794 && simplejump_p (lb)
5795 && simplejump_p (lb2)
5796 && rtx_equal_p (SET_SRC (PATTERN (lb)),
5797 SET_SRC (PATTERN (lb2)))))
5798 /* Are their ranges consecutive? */
5799 && tree_int_cst_equal (np->low,
5800 fold (build (PLUS_EXPR,
5801 TREE_TYPE (node->high),
5804 /* An overflow is not consecutive. */
5805 && tree_int_cst_lt (node->high,
5806 fold (build (PLUS_EXPR,
5807 TREE_TYPE (node->high),
5809 integer_one_node))))
5811 node->high = np->high;
5813 /* NP is the first node after NODE which can't be grouped with it.
5814 Delete the nodes in between, and move on to that node. */
5820 /* Take an ordered list of case nodes
5821 and transform them into a near optimal binary tree,
5822 on the assumption that any target code selection value is as
5823 likely as any other.
5825 The transformation is performed by splitting the ordered
5826 list into two equal sections plus a pivot. The parts are
5827 then attached to the pivot as left and right branches. Each
5828 branch is then transformed recursively. */
5831 balance_case_nodes (head, parent)
5832 case_node_ptr *head;
5833 case_node_ptr parent;
5835 register case_node_ptr np;
5843 register case_node_ptr *npp;
5846 /* Count the number of entries on branch. Also count the ranges. */
5850 if (!tree_int_cst_equal (np->low, np->high))
5854 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5858 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5866 /* Split this list if it is long enough for that to help. */
5871 /* Find the place in the list that bisects the list's total cost,
5872 Here I gets half the total cost. */
5877 /* Skip nodes while their cost does not reach that amount. */
5878 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5879 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5880 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5883 npp = &(*npp)->right;
5888 /* Leave this branch lopsided, but optimize left-hand
5889 side and fill in `parent' fields for right-hand side. */
5891 np->parent = parent;
5892 balance_case_nodes (&np->left, np);
5893 for (; np->right; np = np->right)
5894 np->right->parent = np;
5898 /* If there are just three nodes, split at the middle one. */
5900 npp = &(*npp)->right;
5903 /* Find the place in the list that bisects the list's total cost,
5904 where ranges count as 2.
5905 Here I gets half the total cost. */
5906 i = (i + ranges + 1) / 2;
5909 /* Skip nodes while their cost does not reach that amount. */
5910 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5915 npp = &(*npp)->right;
5920 np->parent = parent;
5923 /* Optimize each of the two split parts. */
5924 balance_case_nodes (&np->left, np);
5925 balance_case_nodes (&np->right, np);
5929 /* Else leave this branch as one level,
5930 but fill in `parent' fields. */
5932 np->parent = parent;
5933 for (; np->right; np = np->right)
5934 np->right->parent = np;
5939 /* Search the parent sections of the case node tree
5940 to see if a test for the lower bound of NODE would be redundant.
5941 INDEX_TYPE is the type of the index expression.
5943 The instructions to generate the case decision tree are
5944 output in the same order as nodes are processed so it is
5945 known that if a parent node checks the range of the current
5946 node minus one that the current node is bounded at its lower
5947 span. Thus the test would be redundant. */
5950 node_has_low_bound (node, index_type)
5955 case_node_ptr pnode;
5957 /* If the lower bound of this node is the lowest value in the index type,
5958 we need not test it. */
5960 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5963 /* If this node has a left branch, the value at the left must be less
5964 than that at this node, so it cannot be bounded at the bottom and
5965 we need not bother testing any further. */
5970 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5971 node->low, integer_one_node));
5973 /* If the subtraction above overflowed, we can't verify anything.
5974 Otherwise, look for a parent that tests our value - 1. */
5976 if (! tree_int_cst_lt (low_minus_one, node->low))
5979 for (pnode = node->parent; pnode; pnode = pnode->parent)
5980 if (tree_int_cst_equal (low_minus_one, pnode->high))
5986 /* Search the parent sections of the case node tree
5987 to see if a test for the upper bound of NODE would be redundant.
5988 INDEX_TYPE is the type of the index expression.
5990 The instructions to generate the case decision tree are
5991 output in the same order as nodes are processed so it is
5992 known that if a parent node checks the range of the current
5993 node plus one that the current node is bounded at its upper
5994 span. Thus the test would be redundant. */
5997 node_has_high_bound (node, index_type)
6002 case_node_ptr pnode;
6004 /* If there is no upper bound, obviously no test is needed. */
6006 if (TYPE_MAX_VALUE (index_type) == NULL)
6009 /* If the upper bound of this node is the highest value in the type
6010 of the index expression, we need not test against it. */
6012 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
6015 /* If this node has a right branch, the value at the right must be greater
6016 than that at this node, so it cannot be bounded at the top and
6017 we need not bother testing any further. */
6022 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
6023 node->high, integer_one_node));
6025 /* If the addition above overflowed, we can't verify anything.
6026 Otherwise, look for a parent that tests our value + 1. */
6028 if (! tree_int_cst_lt (node->high, high_plus_one))
6031 for (pnode = node->parent; pnode; pnode = pnode->parent)
6032 if (tree_int_cst_equal (high_plus_one, pnode->low))
6038 /* Search the parent sections of the
6039 case node tree to see if both tests for the upper and lower
6040 bounds of NODE would be redundant. */
6043 node_is_bounded (node, index_type)
6047 return (node_has_low_bound (node, index_type)
6048 && node_has_high_bound (node, index_type));
6051 /* Emit an unconditional jump to LABEL unless it would be dead code. */
6054 emit_jump_if_reachable (label)
6057 if (GET_CODE (get_last_insn ()) != BARRIER)
6061 /* Emit step-by-step code to select a case for the value of INDEX.
6062 The thus generated decision tree follows the form of the
6063 case-node binary tree NODE, whose nodes represent test conditions.
6064 INDEX_TYPE is the type of the index of the switch.
6066 Care is taken to prune redundant tests from the decision tree
6067 by detecting any boundary conditions already checked by
6068 emitted rtx. (See node_has_high_bound, node_has_low_bound
6069 and node_is_bounded, above.)
6071 Where the test conditions can be shown to be redundant we emit
6072 an unconditional jump to the target code. As a further
6073 optimization, the subordinates of a tree node are examined to
6074 check for bounded nodes. In this case conditional and/or
6075 unconditional jumps as a result of the boundary check for the
6076 current node are arranged to target the subordinates associated
6077 code for out of bound conditions on the current node.
6079 We can assume that when control reaches the code generated here,
6080 the index value has already been compared with the parents
6081 of this node, and determined to be on the same side of each parent
6082 as this node is. Thus, if this node tests for the value 51,
6083 and a parent tested for 52, we don't need to consider
6084 the possibility of a value greater than 51. If another parent
6085 tests for the value 50, then this node need not test anything. */
6088 emit_case_nodes (index, node, default_label, index_type)
6094 /* If INDEX has an unsigned type, we must make unsigned branches. */
6095 int unsignedp = TREE_UNSIGNED (index_type);
6096 enum machine_mode mode = GET_MODE (index);
6098 /* See if our parents have already tested everything for us.
6099 If they have, emit an unconditional jump for this node. */
6100 if (node_is_bounded (node, index_type))
6101 emit_jump (label_rtx (node->code_label));
6103 else if (tree_int_cst_equal (node->low, node->high))
6105 /* Node is single valued. First see if the index expression matches
6106 this node and then check our children, if any. */
6108 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
6109 label_rtx (node->code_label), unsignedp);
6111 if (node->right != 0 && node->left != 0)
6113 /* This node has children on both sides.
6114 Dispatch to one side or the other
6115 by comparing the index value with this node's value.
6116 If one subtree is bounded, check that one first,
6117 so we can avoid real branches in the tree. */
6119 if (node_is_bounded (node->right, index_type))
6121 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6123 GT, NULL_RTX, mode, unsignedp, 0,
6124 label_rtx (node->right->code_label));
6125 emit_case_nodes (index, node->left, default_label, index_type);
6128 else if (node_is_bounded (node->left, index_type))
6130 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6132 LT, NULL_RTX, mode, unsignedp, 0,
6133 label_rtx (node->left->code_label));
6134 emit_case_nodes (index, node->right, default_label, index_type);
6139 /* Neither node is bounded. First distinguish the two sides;
6140 then emit the code for one side at a time. */
6143 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6145 /* See if the value is on the right. */
6146 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6148 GT, NULL_RTX, mode, unsignedp, 0,
6149 label_rtx (test_label));
6151 /* Value must be on the left.
6152 Handle the left-hand subtree. */
6153 emit_case_nodes (index, node->left, default_label, index_type);
6154 /* If left-hand subtree does nothing,
6156 emit_jump_if_reachable (default_label);
6158 /* Code branches here for the right-hand subtree. */
6159 expand_label (test_label);
6160 emit_case_nodes (index, node->right, default_label, index_type);
6164 else if (node->right != 0 && node->left == 0)
6166 /* Here we have a right child but no left so we issue conditional
6167 branch to default and process the right child.
6169 Omit the conditional branch to default if we it avoid only one
6170 right child; it costs too much space to save so little time. */
6172 if (node->right->right || node->right->left
6173 || !tree_int_cst_equal (node->right->low, node->right->high))
6175 if (!node_has_low_bound (node, index_type))
6177 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6180 LT, NULL_RTX, mode, unsignedp, 0,
6184 emit_case_nodes (index, node->right, default_label, index_type);
6187 /* We cannot process node->right normally
6188 since we haven't ruled out the numbers less than
6189 this node's value. So handle node->right explicitly. */
6190 do_jump_if_equal (index,
6191 expand_expr (node->right->low, NULL_RTX,
6193 label_rtx (node->right->code_label), unsignedp);
6196 else if (node->right == 0 && node->left != 0)
6198 /* Just one subtree, on the left. */
6200 #if 0 /* The following code and comment were formerly part
6201 of the condition here, but they didn't work
6202 and I don't understand what the idea was. -- rms. */
6203 /* If our "most probable entry" is less probable
6204 than the default label, emit a jump to
6205 the default label using condition codes
6206 already lying around. With no right branch,
6207 a branch-greater-than will get us to the default
6210 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
6213 if (node->left->left || node->left->right
6214 || !tree_int_cst_equal (node->left->low, node->left->high))
6216 if (!node_has_high_bound (node, index_type))
6218 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6221 GT, NULL_RTX, mode, unsignedp, 0,
6225 emit_case_nodes (index, node->left, default_label, index_type);
6228 /* We cannot process node->left normally
6229 since we haven't ruled out the numbers less than
6230 this node's value. So handle node->left explicitly. */
6231 do_jump_if_equal (index,
6232 expand_expr (node->left->low, NULL_RTX,
6234 label_rtx (node->left->code_label), unsignedp);
6239 /* Node is a range. These cases are very similar to those for a single
6240 value, except that we do not start by testing whether this node
6241 is the one to branch to. */
6243 if (node->right != 0 && node->left != 0)
6245 /* Node has subtrees on both sides.
6246 If the right-hand subtree is bounded,
6247 test for it first, since we can go straight there.
6248 Otherwise, we need to make a branch in the control structure,
6249 then handle the two subtrees. */
6250 tree test_label = 0;
6253 if (node_is_bounded (node->right, index_type))
6254 /* Right hand node is fully bounded so we can eliminate any
6255 testing and branch directly to the target code. */
6256 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6258 GT, NULL_RTX, mode, unsignedp, 0,
6259 label_rtx (node->right->code_label));
6262 /* Right hand node requires testing.
6263 Branch to a label where we will handle it later. */
6265 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6266 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6268 GT, NULL_RTX, mode, unsignedp, 0,
6269 label_rtx (test_label));
6272 /* Value belongs to this node or to the left-hand subtree. */
6274 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6276 GE, NULL_RTX, mode, unsignedp, 0,
6277 label_rtx (node->code_label));
6279 /* Handle the left-hand subtree. */
6280 emit_case_nodes (index, node->left, default_label, index_type);
6282 /* If right node had to be handled later, do that now. */
6286 /* If the left-hand subtree fell through,
6287 don't let it fall into the right-hand subtree. */
6288 emit_jump_if_reachable (default_label);
6290 expand_label (test_label);
6291 emit_case_nodes (index, node->right, default_label, index_type);
6295 else if (node->right != 0 && node->left == 0)
6297 /* Deal with values to the left of this node,
6298 if they are possible. */
6299 if (!node_has_low_bound (node, index_type))
6301 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6303 LT, NULL_RTX, mode, unsignedp, 0,
6307 /* Value belongs to this node or to the right-hand subtree. */
6309 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6311 LE, NULL_RTX, mode, unsignedp, 0,
6312 label_rtx (node->code_label));
6314 emit_case_nodes (index, node->right, default_label, index_type);
6317 else if (node->right == 0 && node->left != 0)
6319 /* Deal with values to the right of this node,
6320 if they are possible. */
6321 if (!node_has_high_bound (node, index_type))
6323 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6325 GT, NULL_RTX, mode, unsignedp, 0,
6329 /* Value belongs to this node or to the left-hand subtree. */
6331 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6333 GE, NULL_RTX, mode, unsignedp, 0,
6334 label_rtx (node->code_label));
6336 emit_case_nodes (index, node->left, default_label, index_type);
6341 /* Node has no children so we check low and high bounds to remove
6342 redundant tests. Only one of the bounds can exist,
6343 since otherwise this node is bounded--a case tested already. */
6345 if (!node_has_high_bound (node, index_type))
6347 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6349 GT, NULL_RTX, mode, unsignedp, 0,
6353 if (!node_has_low_bound (node, index_type))
6355 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6357 LT, NULL_RTX, mode, unsignedp, 0,
6361 emit_jump (label_rtx (node->code_label));