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 handler_slot, static_chain, save_area;
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 static_chain = copy_to_reg (lookup_static_chain (label));
821 /* Get addr of containing function's current nonlocal goto handler,
822 which will do any cleanups and then jump to the label. */
823 handler_slot = copy_to_reg (replace_rtx (copy_rtx (handler_slot),
824 virtual_stack_vars_rtx,
827 /* Get addr of containing function's nonlocal save area. */
828 save_area = p->x_nonlocal_goto_stack_level;
830 save_area = replace_rtx (copy_rtx (save_area),
831 virtual_stack_vars_rtx, static_chain);
833 #if HAVE_nonlocal_goto
834 if (HAVE_nonlocal_goto)
835 emit_insn (gen_nonlocal_goto (static_chain, handler_slot,
836 save_area, label_ref));
840 /* Restore frame pointer for containing function.
841 This sets the actual hard register used for the frame pointer
842 to the location of the function's incoming static chain info.
843 The non-local goto handler will then adjust it to contain the
844 proper value and reload the argument pointer, if needed. */
845 emit_move_insn (hard_frame_pointer_rtx, static_chain);
846 emit_stack_restore (SAVE_NONLOCAL, save_area, NULL_RTX);
848 /* USE of hard_frame_pointer_rtx added for consistency;
849 not clear if really needed. */
850 emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx));
851 emit_insn (gen_rtx_USE (VOIDmode, stack_pointer_rtx));
852 emit_indirect_jump (handler_slot);
856 expand_goto_internal (label, label_rtx (label), NULL_RTX);
859 /* Generate RTL code for a `goto' statement with target label BODY.
860 LABEL should be a LABEL_REF.
861 LAST_INSN, if non-0, is the rtx we should consider as the last
862 insn emitted (for the purposes of cleaning up a return). */
865 expand_goto_internal (body, label, last_insn)
870 struct nesting *block;
873 if (GET_CODE (label) != CODE_LABEL)
876 /* If label has already been defined, we can tell now
877 whether and how we must alter the stack level. */
879 if (PREV_INSN (label) != 0)
881 /* Find the innermost pending block that contains the label.
882 (Check containment by comparing insn-uids.)
883 Then restore the outermost stack level within that block,
884 and do cleanups of all blocks contained in it. */
885 for (block = block_stack; block; block = block->next)
887 if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
889 if (block->data.block.stack_level != 0)
890 stack_level = block->data.block.stack_level;
891 /* Execute the cleanups for blocks we are exiting. */
892 if (block->data.block.cleanups != 0)
894 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
895 do_pending_stack_adjust ();
901 /* Ensure stack adjust isn't done by emit_jump, as this
902 would clobber the stack pointer. This one should be
903 deleted as dead by flow. */
904 clear_pending_stack_adjust ();
905 do_pending_stack_adjust ();
906 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
909 if (body != 0 && DECL_TOO_LATE (body))
910 error ("jump to `%s' invalidly jumps into binding contour",
911 IDENTIFIER_POINTER (DECL_NAME (body)));
913 /* Label not yet defined: may need to put this goto
914 on the fixup list. */
915 else if (! expand_fixup (body, label, last_insn))
917 /* No fixup needed. Record that the label is the target
918 of at least one goto that has no fixup. */
920 TREE_ADDRESSABLE (body) = 1;
926 /* Generate if necessary a fixup for a goto
927 whose target label in tree structure (if any) is TREE_LABEL
928 and whose target in rtl is RTL_LABEL.
930 If LAST_INSN is nonzero, we pretend that the jump appears
931 after insn LAST_INSN instead of at the current point in the insn stream.
933 The fixup will be used later to insert insns just before the goto.
934 Those insns will restore the stack level as appropriate for the
935 target label, and will (in the case of C++) also invoke any object
936 destructors which have to be invoked when we exit the scopes which
937 are exited by the goto.
939 Value is nonzero if a fixup is made. */
942 expand_fixup (tree_label, rtl_label, last_insn)
947 struct nesting *block, *end_block;
949 /* See if we can recognize which block the label will be output in.
950 This is possible in some very common cases.
951 If we succeed, set END_BLOCK to that block.
952 Otherwise, set it to 0. */
955 && (rtl_label == cond_stack->data.cond.endif_label
956 || rtl_label == cond_stack->data.cond.next_label))
957 end_block = cond_stack;
958 /* If we are in a loop, recognize certain labels which
959 are likely targets. This reduces the number of fixups
960 we need to create. */
962 && (rtl_label == loop_stack->data.loop.start_label
963 || rtl_label == loop_stack->data.loop.end_label
964 || rtl_label == loop_stack->data.loop.continue_label))
965 end_block = loop_stack;
969 /* Now set END_BLOCK to the binding level to which we will return. */
973 struct nesting *next_block = end_block->all;
976 /* First see if the END_BLOCK is inside the innermost binding level.
977 If so, then no cleanups or stack levels are relevant. */
978 while (next_block && next_block != block)
979 next_block = next_block->all;
984 /* Otherwise, set END_BLOCK to the innermost binding level
985 which is outside the relevant control-structure nesting. */
986 next_block = block_stack->next;
987 for (block = block_stack; block != end_block; block = block->all)
988 if (block == next_block)
989 next_block = next_block->next;
990 end_block = next_block;
993 /* Does any containing block have a stack level or cleanups?
994 If not, no fixup is needed, and that is the normal case
995 (the only case, for standard C). */
996 for (block = block_stack; block != end_block; block = block->next)
997 if (block->data.block.stack_level != 0
998 || block->data.block.cleanups != 0)
1001 if (block != end_block)
1003 /* Ok, a fixup is needed. Add a fixup to the list of such. */
1004 struct goto_fixup *fixup
1005 = (struct goto_fixup *) ggc_alloc (sizeof (struct goto_fixup));
1006 /* In case an old stack level is restored, make sure that comes
1007 after any pending stack adjust. */
1008 /* ?? If the fixup isn't to come at the present position,
1009 doing the stack adjust here isn't useful. Doing it with our
1010 settings at that location isn't useful either. Let's hope
1013 do_pending_stack_adjust ();
1014 fixup->target = tree_label;
1015 fixup->target_rtl = rtl_label;
1017 /* Create a BLOCK node and a corresponding matched set of
1018 NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes at
1019 this point. The notes will encapsulate any and all fixup
1020 code which we might later insert at this point in the insn
1021 stream. Also, the BLOCK node will be the parent (i.e. the
1022 `SUPERBLOCK') of any other BLOCK nodes which we might create
1023 later on when we are expanding the fixup code.
1025 Note that optimization passes (including expand_end_loop)
1026 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
1027 as a placeholder. */
1030 register rtx original_before_jump
1031 = last_insn ? last_insn : get_last_insn ();
1036 block = make_node (BLOCK);
1037 TREE_USED (block) = 1;
1039 if (!cfun->x_whole_function_mode_p)
1040 insert_block (block);
1044 = BLOCK_CHAIN (DECL_INITIAL (current_function_decl));
1045 BLOCK_CHAIN (DECL_INITIAL (current_function_decl))
1050 start = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
1051 if (cfun->x_whole_function_mode_p)
1052 NOTE_BLOCK (start) = block;
1053 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_DELETED);
1054 end = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
1055 if (cfun->x_whole_function_mode_p)
1056 NOTE_BLOCK (end) = block;
1057 fixup->context = block;
1059 emit_insns_after (start, original_before_jump);
1062 fixup->block_start_count = current_block_start_count;
1063 fixup->stack_level = 0;
1064 fixup->cleanup_list_list
1065 = ((block->data.block.outer_cleanups
1066 || block->data.block.cleanups)
1067 ? tree_cons (NULL_TREE, block->data.block.cleanups,
1068 block->data.block.outer_cleanups)
1070 fixup->next = goto_fixup_chain;
1071 goto_fixup_chain = fixup;
1079 /* Expand any needed fixups in the outputmost binding level of the
1080 function. FIRST_INSN is the first insn in the function. */
1083 expand_fixups (first_insn)
1086 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0);
1089 /* When exiting a binding contour, process all pending gotos requiring fixups.
1090 THISBLOCK is the structure that describes the block being exited.
1091 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1092 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1093 FIRST_INSN is the insn that began this contour.
1095 Gotos that jump out of this contour must restore the
1096 stack level and do the cleanups before actually jumping.
1098 DONT_JUMP_IN nonzero means report error there is a jump into this
1099 contour from before the beginning of the contour.
1100 This is also done if STACK_LEVEL is nonzero. */
1103 fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1104 struct nesting *thisblock;
1110 register struct goto_fixup *f, *prev;
1112 /* F is the fixup we are considering; PREV is the previous one. */
1113 /* We run this loop in two passes so that cleanups of exited blocks
1114 are run first, and blocks that are exited are marked so
1117 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1119 /* Test for a fixup that is inactive because it is already handled. */
1120 if (f->before_jump == 0)
1122 /* Delete inactive fixup from the chain, if that is easy to do. */
1124 prev->next = f->next;
1126 /* Has this fixup's target label been defined?
1127 If so, we can finalize it. */
1128 else if (PREV_INSN (f->target_rtl) != 0)
1130 register rtx cleanup_insns;
1132 /* If this fixup jumped into this contour from before the beginning
1133 of this contour, report an error. This code used to use
1134 the first non-label insn after f->target_rtl, but that's
1135 wrong since such can be added, by things like put_var_into_stack
1136 and have INSN_UIDs that are out of the range of the block. */
1137 /* ??? Bug: this does not detect jumping in through intermediate
1138 blocks that have stack levels or cleanups.
1139 It detects only a problem with the innermost block
1140 around the label. */
1142 && (dont_jump_in || stack_level || cleanup_list)
1143 && INSN_UID (first_insn) < INSN_UID (f->target_rtl)
1144 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1145 && ! DECL_ERROR_ISSUED (f->target))
1147 error_with_decl (f->target,
1148 "label `%s' used before containing binding contour");
1149 /* Prevent multiple errors for one label. */
1150 DECL_ERROR_ISSUED (f->target) = 1;
1153 /* We will expand the cleanups into a sequence of their own and
1154 then later on we will attach this new sequence to the insn
1155 stream just ahead of the actual jump insn. */
1159 /* Temporarily restore the lexical context where we will
1160 logically be inserting the fixup code. We do this for the
1161 sake of getting the debugging information right. */
1164 set_block (f->context);
1166 /* Expand the cleanups for blocks this jump exits. */
1167 if (f->cleanup_list_list)
1170 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1171 /* Marked elements correspond to blocks that have been closed.
1172 Do their cleanups. */
1173 if (TREE_ADDRESSABLE (lists)
1174 && TREE_VALUE (lists) != 0)
1176 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1177 /* Pop any pushes done in the cleanups,
1178 in case function is about to return. */
1179 do_pending_stack_adjust ();
1183 /* Restore stack level for the biggest contour that this
1184 jump jumps out of. */
1186 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1188 /* Finish up the sequence containing the insns which implement the
1189 necessary cleanups, and then attach that whole sequence to the
1190 insn stream just ahead of the actual jump insn. Attaching it
1191 at that point insures that any cleanups which are in fact
1192 implicit C++ object destructions (which must be executed upon
1193 leaving the block) appear (to the debugger) to be taking place
1194 in an area of the generated code where the object(s) being
1195 destructed are still "in scope". */
1197 cleanup_insns = get_insns ();
1201 emit_insns_after (cleanup_insns, f->before_jump);
1208 /* For any still-undefined labels, do the cleanups for this block now.
1209 We must do this now since items in the cleanup list may go out
1210 of scope when the block ends. */
1211 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1212 if (f->before_jump != 0
1213 && PREV_INSN (f->target_rtl) == 0
1214 /* Label has still not appeared. If we are exiting a block with
1215 a stack level to restore, that started before the fixup,
1216 mark this stack level as needing restoration
1217 when the fixup is later finalized. */
1219 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1220 means the label is undefined. That's erroneous, but possible. */
1221 && (thisblock->data.block.block_start_count
1222 <= f->block_start_count))
1224 tree lists = f->cleanup_list_list;
1227 for (; lists; lists = TREE_CHAIN (lists))
1228 /* If the following elt. corresponds to our containing block
1229 then the elt. must be for this block. */
1230 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
1234 set_block (f->context);
1235 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1236 do_pending_stack_adjust ();
1237 cleanup_insns = get_insns ();
1240 if (cleanup_insns != 0)
1242 = emit_insns_after (cleanup_insns, f->before_jump);
1244 f->cleanup_list_list = TREE_CHAIN (lists);
1248 f->stack_level = stack_level;
1252 /* Return the number of times character C occurs in string S. */
1254 n_occurrences (c, s)
1264 /* Generate RTL for an asm statement (explicit assembler code).
1265 BODY is a STRING_CST node containing the assembler code text,
1266 or an ADDR_EXPR containing a STRING_CST. */
1272 if (current_function_check_memory_usage)
1274 error ("`asm' cannot be used in function where memory usage is checked");
1278 if (TREE_CODE (body) == ADDR_EXPR)
1279 body = TREE_OPERAND (body, 0);
1281 emit_insn (gen_rtx_ASM_INPUT (VOIDmode,
1282 TREE_STRING_POINTER (body)));
1286 /* Generate RTL for an asm statement with arguments.
1287 STRING is the instruction template.
1288 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1289 Each output or input has an expression in the TREE_VALUE and
1290 a constraint-string in the TREE_PURPOSE.
1291 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1292 that is clobbered by this insn.
1294 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1295 Some elements of OUTPUTS may be replaced with trees representing temporary
1296 values. The caller should copy those temporary values to the originally
1299 VOL nonzero means the insn is volatile; don't optimize it. */
1302 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1303 tree string, outputs, inputs, clobbers;
1305 const char *filename;
1308 rtvec argvec, constraints;
1310 int ninputs = list_length (inputs);
1311 int noutputs = list_length (outputs);
1316 /* Vector of RTX's of evaluated output operands. */
1317 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1318 int *inout_opnum = (int *) alloca (noutputs * sizeof (int));
1319 rtx *real_output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1320 enum machine_mode *inout_mode
1321 = (enum machine_mode *) alloca (noutputs * sizeof (enum machine_mode));
1322 /* The insn we have emitted. */
1325 /* An ASM with no outputs needs to be treated as volatile, for now. */
1329 if (current_function_check_memory_usage)
1331 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1335 #ifdef MD_ASM_CLOBBERS
1336 /* Sometimes we wish to automatically clobber registers across an asm.
1337 Case in point is when the i386 backend moved from cc0 to a hard reg --
1338 maintaining source-level compatability means automatically clobbering
1339 the flags register. */
1340 MD_ASM_CLOBBERS (clobbers);
1343 if (current_function_check_memory_usage)
1345 error ("`asm' cannot be used in function where memory usage is checked");
1349 /* Count the number of meaningful clobbered registers, ignoring what
1350 we would ignore later. */
1352 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1354 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1356 i = decode_reg_name (regname);
1357 if (i >= 0 || i == -4)
1360 error ("unknown register name `%s' in `asm'", regname);
1365 /* Check that the number of alternatives is constant across all
1367 if (outputs || inputs)
1369 tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
1370 int nalternatives = n_occurrences (',', TREE_STRING_POINTER (tmp));
1373 if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
1375 error ("too many alternatives in `asm'");
1382 const char *constraint = TREE_STRING_POINTER (TREE_PURPOSE (tmp));
1384 if (n_occurrences (',', constraint) != nalternatives)
1386 error ("operand constraints for `asm' differ in number of alternatives");
1390 if (TREE_CHAIN (tmp))
1391 tmp = TREE_CHAIN (tmp);
1393 tmp = next, next = 0;
1397 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1399 tree val = TREE_VALUE (tail);
1400 tree type = TREE_TYPE (val);
1409 /* If there's an erroneous arg, emit no insn. */
1410 if (TREE_TYPE (val) == error_mark_node)
1413 /* Make sure constraint has `=' and does not have `+'. Also, see
1414 if it allows any register. Be liberal on the latter test, since
1415 the worst that happens if we get it wrong is we issue an error
1418 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1419 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1421 /* Allow the `=' or `+' to not be at the beginning of the string,
1422 since it wasn't explicitly documented that way, and there is a
1423 large body of code that puts it last. Swap the character to
1424 the front, so as not to uglify any place else. */
1428 if ((p = strchr (constraint, '=')) != NULL)
1430 if ((p = strchr (constraint, '+')) != NULL)
1433 error ("output operand constraint lacks `='");
1437 if (p != constraint)
1440 bcopy (constraint, constraint+1, p-constraint);
1443 warning ("output constraint `%c' for operand %d is not at the beginning", j, i);
1446 is_inout = constraint[0] == '+';
1447 /* Replace '+' with '='. */
1448 constraint[0] = '=';
1449 /* Make sure we can specify the matching operand. */
1450 if (is_inout && i > 9)
1452 error ("output operand constraint %d contains `+'", i);
1456 for (j = 1; j < c_len; j++)
1457 switch (constraint[j])
1461 error ("operand constraint contains '+' or '=' at illegal position.");
1465 if (i + 1 == ninputs + noutputs)
1467 error ("`%%' constraint used with last operand");
1472 case '?': case '!': case '*': case '&':
1473 case 'E': case 'F': case 'G': case 'H':
1474 case 's': case 'i': case 'n':
1475 case 'I': case 'J': case 'K': case 'L': case 'M':
1476 case 'N': case 'O': case 'P': case ',':
1477 #ifdef EXTRA_CONSTRAINT
1478 case 'Q': case 'R': case 'S': case 'T': case 'U':
1482 case '0': case '1': case '2': case '3': case '4':
1483 case '5': case '6': case '7': case '8': case '9':
1484 error ("matching constraint not valid in output operand");
1487 case 'V': case 'm': case 'o':
1492 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1493 excepting those that expand_call created. So match memory
1509 /* If an output operand is not a decl or indirect ref and our constraint
1510 allows a register, make a temporary to act as an intermediate.
1511 Make the asm insn write into that, then our caller will copy it to
1512 the real output operand. Likewise for promoted variables. */
1514 real_output_rtx[i] = NULL_RTX;
1515 if ((TREE_CODE (val) == INDIRECT_REF
1518 && (allows_mem || GET_CODE (DECL_RTL (val)) == REG)
1519 && ! (GET_CODE (DECL_RTL (val)) == REG
1520 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
1525 mark_addressable (TREE_VALUE (tail));
1528 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode,
1529 EXPAND_MEMORY_USE_WO);
1531 if (! allows_reg && GET_CODE (output_rtx[i]) != MEM)
1532 error ("output number %d not directly addressable", i);
1533 if (! allows_mem && GET_CODE (output_rtx[i]) == MEM)
1535 real_output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1536 output_rtx[i] = gen_reg_rtx (GET_MODE (output_rtx[i]));
1538 emit_move_insn (output_rtx[i], real_output_rtx[i]);
1543 output_rtx[i] = assign_temp (type, 0, 0, 1);
1544 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1549 inout_mode[ninout] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)));
1550 inout_opnum[ninout++] = i;
1555 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1557 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1561 /* Make vectors for the expression-rtx and constraint strings. */
1563 argvec = rtvec_alloc (ninputs);
1564 constraints = rtvec_alloc (ninputs);
1566 body = gen_rtx_ASM_OPERANDS (VOIDmode, TREE_STRING_POINTER (string),
1567 empty_string, 0, argvec, constraints,
1570 MEM_VOLATILE_P (body) = vol;
1572 /* Eval the inputs and put them into ARGVEC.
1573 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1576 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1579 int allows_reg = 0, allows_mem = 0;
1580 char *constraint, *orig_constraint;
1584 /* If there's an erroneous arg, emit no insn,
1585 because the ASM_INPUT would get VOIDmode
1586 and that could cause a crash in reload. */
1587 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1590 /* ??? Can this happen, and does the error message make any sense? */
1591 if (TREE_PURPOSE (tail) == NULL_TREE)
1593 error ("hard register `%s' listed as input operand to `asm'",
1594 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1598 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1599 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1600 orig_constraint = constraint;
1602 /* Make sure constraint has neither `=', `+', nor '&'. */
1604 for (j = 0; j < c_len; j++)
1605 switch (constraint[j])
1607 case '+': case '=': case '&':
1608 if (constraint == orig_constraint)
1610 error ("input operand constraint contains `%c'",
1617 if (constraint == orig_constraint
1618 && i + 1 == ninputs - ninout)
1620 error ("`%%' constraint used with last operand");
1625 case 'V': case 'm': case 'o':
1630 case '?': case '!': case '*':
1631 case 'E': case 'F': case 'G': case 'H': case 'X':
1632 case 's': case 'i': case 'n':
1633 case 'I': case 'J': case 'K': case 'L': case 'M':
1634 case 'N': case 'O': case 'P': case ',':
1635 #ifdef EXTRA_CONSTRAINT
1636 case 'Q': case 'R': case 'S': case 'T': case 'U':
1640 /* Whether or not a numeric constraint allows a register is
1641 decided by the matching constraint, and so there is no need
1642 to do anything special with them. We must handle them in
1643 the default case, so that we don't unnecessarily force
1644 operands to memory. */
1645 case '0': case '1': case '2': case '3': case '4':
1646 case '5': case '6': case '7': case '8': case '9':
1647 if (constraint[j] >= '0' + noutputs)
1650 ("matching constraint references invalid operand number");
1654 /* Try and find the real constraint for this dup. */
1655 if ((j == 0 && c_len == 1)
1656 || (j == 1 && c_len == 2 && constraint[0] == '%'))
1660 for (j = constraint[j] - '0'; j > 0; --j)
1663 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (o)));
1664 constraint = TREE_STRING_POINTER (TREE_PURPOSE (o));
1669 /* ... fall through ... */
1682 if (! allows_reg && allows_mem)
1683 mark_addressable (TREE_VALUE (tail));
1685 op = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1687 if (asm_operand_ok (op, constraint) <= 0)
1690 op = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), op);
1691 else if (!allows_mem)
1692 warning ("asm operand %d probably doesn't match constraints", i);
1693 else if (CONSTANT_P (op))
1694 op = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1696 else if (GET_CODE (op) == REG
1697 || GET_CODE (op) == SUBREG
1698 || GET_CODE (op) == CONCAT)
1700 tree type = TREE_TYPE (TREE_VALUE (tail));
1701 rtx memloc = assign_temp (type, 1, 1, 1);
1703 emit_move_insn (memloc, op);
1707 else if (GET_CODE (op) == MEM && MEM_VOLATILE_P (op))
1708 /* We won't recognize volatile memory as available a
1709 memory_operand at this point. Ignore it. */
1711 else if (queued_subexp_p (op))
1714 /* ??? Leave this only until we have experience with what
1715 happens in combine and elsewhere when constraints are
1717 warning ("asm operand %d probably doesn't match constraints", i);
1719 XVECEXP (body, 3, i) = op;
1721 XVECEXP (body, 4, i) /* constraints */
1722 = gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1727 /* Protect all the operands from the queue now that they have all been
1730 for (i = 0; i < ninputs - ninout; i++)
1731 XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0);
1733 for (i = 0; i < noutputs; i++)
1734 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1736 /* For in-out operands, copy output rtx to input rtx. */
1737 for (i = 0; i < ninout; i++)
1739 int j = inout_opnum[i];
1741 XVECEXP (body, 3, ninputs - ninout + i) /* argvec */
1743 XVECEXP (body, 4, ninputs - ninout + i) /* constraints */
1744 = gen_rtx_ASM_INPUT (inout_mode[i], digit_strings[j]);
1747 /* Now, for each output, construct an rtx
1748 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1749 ARGVEC CONSTRAINTS))
1750 If there is more than one, put them inside a PARALLEL. */
1752 if (noutputs == 1 && nclobbers == 0)
1754 XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1755 insn = emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
1758 else if (noutputs == 0 && nclobbers == 0)
1760 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1761 insn = emit_insn (body);
1772 body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
1774 /* For each output operand, store a SET. */
1775 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1777 XVECEXP (body, 0, i)
1778 = gen_rtx_SET (VOIDmode,
1780 gen_rtx_ASM_OPERANDS
1782 TREE_STRING_POINTER (string),
1783 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1784 i, argvec, constraints,
1787 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1790 /* If there are no outputs (but there are some clobbers)
1791 store the bare ASM_OPERANDS into the PARALLEL. */
1794 XVECEXP (body, 0, i++) = obody;
1796 /* Store (clobber REG) for each clobbered register specified. */
1798 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1800 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1801 int j = decode_reg_name (regname);
1805 if (j == -3) /* `cc', which is not a register */
1808 if (j == -4) /* `memory', don't cache memory across asm */
1810 XVECEXP (body, 0, i++)
1811 = gen_rtx_CLOBBER (VOIDmode,
1814 gen_rtx_SCRATCH (VOIDmode)));
1818 /* Ignore unknown register, error already signaled. */
1822 /* Use QImode since that's guaranteed to clobber just one reg. */
1823 XVECEXP (body, 0, i++)
1824 = gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (QImode, j));
1827 insn = emit_insn (body);
1830 /* For any outputs that needed reloading into registers, spill them
1831 back to where they belong. */
1832 for (i = 0; i < noutputs; ++i)
1833 if (real_output_rtx[i])
1834 emit_move_insn (real_output_rtx[i], output_rtx[i]);
1839 /* Generate RTL to evaluate the expression EXP
1840 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1843 expand_expr_stmt (exp)
1846 /* If -W, warn about statements with no side effects,
1847 except for an explicit cast to void (e.g. for assert()), and
1848 except inside a ({...}) where they may be useful. */
1849 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1851 if (! TREE_SIDE_EFFECTS (exp)
1852 && (extra_warnings || warn_unused_value)
1853 && !(TREE_CODE (exp) == CONVERT_EXPR
1854 && VOID_TYPE_P (TREE_TYPE (exp))))
1855 warning_with_file_and_line (emit_filename, emit_lineno,
1856 "statement with no effect");
1857 else if (warn_unused_value)
1858 warn_if_unused_value (exp);
1861 /* If EXP is of function type and we are expanding statements for
1862 value, convert it to pointer-to-function. */
1863 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1864 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1866 last_expr_type = TREE_TYPE (exp);
1867 last_expr_value = expand_expr (exp,
1868 (expr_stmts_for_value
1869 ? NULL_RTX : const0_rtx),
1872 /* If all we do is reference a volatile value in memory,
1873 copy it to a register to be sure it is actually touched. */
1874 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1875 && TREE_THIS_VOLATILE (exp))
1877 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1879 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1880 copy_to_reg (last_expr_value);
1883 rtx lab = gen_label_rtx ();
1885 /* Compare the value with itself to reference it. */
1886 emit_cmp_and_jump_insns (last_expr_value, last_expr_value, EQ,
1887 expand_expr (TYPE_SIZE (last_expr_type),
1888 NULL_RTX, VOIDmode, 0),
1890 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT,
1896 /* If this expression is part of a ({...}) and is in memory, we may have
1897 to preserve temporaries. */
1898 preserve_temp_slots (last_expr_value);
1900 /* Free any temporaries used to evaluate this expression. Any temporary
1901 used as a result of this expression will already have been preserved
1908 /* Warn if EXP contains any computations whose results are not used.
1909 Return 1 if a warning is printed; 0 otherwise. */
1912 warn_if_unused_value (exp)
1915 if (TREE_USED (exp))
1918 switch (TREE_CODE (exp))
1920 case PREINCREMENT_EXPR:
1921 case POSTINCREMENT_EXPR:
1922 case PREDECREMENT_EXPR:
1923 case POSTDECREMENT_EXPR:
1928 case METHOD_CALL_EXPR:
1930 case TRY_CATCH_EXPR:
1931 case WITH_CLEANUP_EXPR:
1933 /* We don't warn about COND_EXPR because it may be a useful
1934 construct if either arm contains a side effect. */
1939 /* For a binding, warn if no side effect within it. */
1940 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1943 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1945 case TRUTH_ORIF_EXPR:
1946 case TRUTH_ANDIF_EXPR:
1947 /* In && or ||, warn if 2nd operand has no side effect. */
1948 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1951 if (TREE_NO_UNUSED_WARNING (exp))
1953 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
1955 /* Let people do `(foo (), 0)' without a warning. */
1956 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1958 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1962 case NON_LVALUE_EXPR:
1963 /* Don't warn about values cast to void. */
1964 if (VOID_TYPE_P (TREE_TYPE (exp)))
1966 /* Don't warn about conversions not explicit in the user's program. */
1967 if (TREE_NO_UNUSED_WARNING (exp))
1969 /* Assignment to a cast usually results in a cast of a modify.
1970 Don't complain about that. There can be an arbitrary number of
1971 casts before the modify, so we must loop until we find the first
1972 non-cast expression and then test to see if that is a modify. */
1974 tree tem = TREE_OPERAND (exp, 0);
1976 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1977 tem = TREE_OPERAND (tem, 0);
1979 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
1980 || TREE_CODE (tem) == CALL_EXPR)
1986 /* Don't warn about automatic dereferencing of references, since
1987 the user cannot control it. */
1988 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
1989 return warn_if_unused_value (TREE_OPERAND (exp, 0));
1990 /* ... fall through ... */
1993 /* Referencing a volatile value is a side effect, so don't warn. */
1995 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
1996 && TREE_THIS_VOLATILE (exp))
1999 /* If this is an expression which has no operands, there is no value
2000 to be unused. There are no such language-independent codes,
2001 but front ends may define such. */
2002 if (TREE_CODE_CLASS (TREE_CODE (exp)) == 'e'
2003 && TREE_CODE_LENGTH (TREE_CODE (exp)) == 0)
2007 warning_with_file_and_line (emit_filename, emit_lineno,
2008 "value computed is not used");
2013 /* Clear out the memory of the last expression evaluated. */
2021 /* Begin a statement which will return a value.
2022 Return the RTL_EXPR for this statement expr.
2023 The caller must save that value and pass it to expand_end_stmt_expr. */
2026 expand_start_stmt_expr ()
2031 /* Make the RTL_EXPR node temporary, not momentary,
2032 so that rtl_expr_chain doesn't become garbage. */
2033 momentary = suspend_momentary ();
2034 t = make_node (RTL_EXPR);
2035 resume_momentary (momentary);
2036 do_pending_stack_adjust ();
2037 start_sequence_for_rtl_expr (t);
2039 expr_stmts_for_value++;
2043 /* Restore the previous state at the end of a statement that returns a value.
2044 Returns a tree node representing the statement's value and the
2045 insns to compute the value.
2047 The nodes of that expression have been freed by now, so we cannot use them.
2048 But we don't want to do that anyway; the expression has already been
2049 evaluated and now we just want to use the value. So generate a RTL_EXPR
2050 with the proper type and RTL value.
2052 If the last substatement was not an expression,
2053 return something with type `void'. */
2056 expand_end_stmt_expr (t)
2061 if (last_expr_type == 0)
2063 last_expr_type = void_type_node;
2064 last_expr_value = const0_rtx;
2066 else if (last_expr_value == 0)
2067 /* There are some cases where this can happen, such as when the
2068 statement is void type. */
2069 last_expr_value = const0_rtx;
2070 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
2071 /* Remove any possible QUEUED. */
2072 last_expr_value = protect_from_queue (last_expr_value, 0);
2076 TREE_TYPE (t) = last_expr_type;
2077 RTL_EXPR_RTL (t) = last_expr_value;
2078 RTL_EXPR_SEQUENCE (t) = get_insns ();
2080 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
2084 /* Don't consider deleting this expr or containing exprs at tree level. */
2085 TREE_SIDE_EFFECTS (t) = 1;
2086 /* Propagate volatility of the actual RTL expr. */
2087 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
2090 expr_stmts_for_value--;
2095 /* Generate RTL for the start of an if-then. COND is the expression
2096 whose truth should be tested.
2098 If EXITFLAG is nonzero, this conditional is visible to
2099 `exit_something'. */
2102 expand_start_cond (cond, exitflag)
2106 struct nesting *thiscond = ALLOC_NESTING ();
2108 /* Make an entry on cond_stack for the cond we are entering. */
2110 thiscond->next = cond_stack;
2111 thiscond->all = nesting_stack;
2112 thiscond->depth = ++nesting_depth;
2113 thiscond->data.cond.next_label = gen_label_rtx ();
2114 /* Before we encounter an `else', we don't need a separate exit label
2115 unless there are supposed to be exit statements
2116 to exit this conditional. */
2117 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
2118 thiscond->data.cond.endif_label = thiscond->exit_label;
2119 cond_stack = thiscond;
2120 nesting_stack = thiscond;
2122 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
2125 /* Generate RTL between then-clause and the elseif-clause
2126 of an if-then-elseif-.... */
2129 expand_start_elseif (cond)
2132 if (cond_stack->data.cond.endif_label == 0)
2133 cond_stack->data.cond.endif_label = gen_label_rtx ();
2134 emit_jump (cond_stack->data.cond.endif_label);
2135 emit_label (cond_stack->data.cond.next_label);
2136 cond_stack->data.cond.next_label = gen_label_rtx ();
2137 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2140 /* Generate RTL between the then-clause and the else-clause
2141 of an if-then-else. */
2144 expand_start_else ()
2146 if (cond_stack->data.cond.endif_label == 0)
2147 cond_stack->data.cond.endif_label = gen_label_rtx ();
2149 emit_jump (cond_stack->data.cond.endif_label);
2150 emit_label (cond_stack->data.cond.next_label);
2151 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
2154 /* After calling expand_start_else, turn this "else" into an "else if"
2155 by providing another condition. */
2158 expand_elseif (cond)
2161 cond_stack->data.cond.next_label = gen_label_rtx ();
2162 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2165 /* Generate RTL for the end of an if-then.
2166 Pop the record for it off of cond_stack. */
2171 struct nesting *thiscond = cond_stack;
2173 do_pending_stack_adjust ();
2174 if (thiscond->data.cond.next_label)
2175 emit_label (thiscond->data.cond.next_label);
2176 if (thiscond->data.cond.endif_label)
2177 emit_label (thiscond->data.cond.endif_label);
2179 POPSTACK (cond_stack);
2185 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2186 loop should be exited by `exit_something'. This is a loop for which
2187 `expand_continue' will jump to the top of the loop.
2189 Make an entry on loop_stack to record the labels associated with
2193 expand_start_loop (exit_flag)
2196 register struct nesting *thisloop = ALLOC_NESTING ();
2198 /* Make an entry on loop_stack for the loop we are entering. */
2200 thisloop->next = loop_stack;
2201 thisloop->all = nesting_stack;
2202 thisloop->depth = ++nesting_depth;
2203 thisloop->data.loop.start_label = gen_label_rtx ();
2204 thisloop->data.loop.end_label = gen_label_rtx ();
2205 thisloop->data.loop.alt_end_label = 0;
2206 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2207 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2208 loop_stack = thisloop;
2209 nesting_stack = thisloop;
2211 do_pending_stack_adjust ();
2213 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2214 emit_label (thisloop->data.loop.start_label);
2219 /* Like expand_start_loop but for a loop where the continuation point
2220 (for expand_continue_loop) will be specified explicitly. */
2223 expand_start_loop_continue_elsewhere (exit_flag)
2226 struct nesting *thisloop = expand_start_loop (exit_flag);
2227 loop_stack->data.loop.continue_label = gen_label_rtx ();
2231 /* Specify the continuation point for a loop started with
2232 expand_start_loop_continue_elsewhere.
2233 Use this at the point in the code to which a continue statement
2237 expand_loop_continue_here ()
2239 do_pending_stack_adjust ();
2240 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2241 emit_label (loop_stack->data.loop.continue_label);
2244 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2245 Pop the block off of loop_stack. */
2250 rtx start_label = loop_stack->data.loop.start_label;
2251 rtx insn = get_last_insn ();
2252 int needs_end_jump = 1;
2254 /* Mark the continue-point at the top of the loop if none elsewhere. */
2255 if (start_label == loop_stack->data.loop.continue_label)
2256 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2258 do_pending_stack_adjust ();
2260 /* If optimizing, perhaps reorder the loop.
2261 First, try to use a condjump near the end.
2262 expand_exit_loop_if_false ends loops with unconditional jumps,
2265 if (test) goto label;
2267 goto loop_stack->data.loop.end_label
2271 If we find such a pattern, we can end the loop earlier. */
2274 && GET_CODE (insn) == CODE_LABEL
2275 && LABEL_NAME (insn) == NULL
2276 && GET_CODE (PREV_INSN (insn)) == BARRIER)
2279 rtx jump = PREV_INSN (PREV_INSN (label));
2281 if (GET_CODE (jump) == JUMP_INSN
2282 && GET_CODE (PATTERN (jump)) == SET
2283 && SET_DEST (PATTERN (jump)) == pc_rtx
2284 && GET_CODE (SET_SRC (PATTERN (jump))) == LABEL_REF
2285 && (XEXP (SET_SRC (PATTERN (jump)), 0)
2286 == loop_stack->data.loop.end_label))
2290 /* The test might be complex and reference LABEL multiple times,
2291 like the loop in loop_iterations to set vtop. To handle this,
2293 insn = PREV_INSN (label);
2294 reorder_insns (label, label, start_label);
2296 for (prev = PREV_INSN (jump); ; prev = PREV_INSN (prev))
2298 /* We ignore line number notes, but if we see any other note,
2299 in particular NOTE_INSN_BLOCK_*, NOTE_INSN_EH_REGION_*,
2300 NOTE_INSN_LOOP_*, we disable this optimization. */
2301 if (GET_CODE (prev) == NOTE)
2303 if (NOTE_LINE_NUMBER (prev) < 0)
2307 if (GET_CODE (prev) == CODE_LABEL)
2309 if (GET_CODE (prev) == JUMP_INSN)
2311 if (GET_CODE (PATTERN (prev)) == SET
2312 && SET_DEST (PATTERN (prev)) == pc_rtx
2313 && GET_CODE (SET_SRC (PATTERN (prev))) == IF_THEN_ELSE
2314 && (GET_CODE (XEXP (SET_SRC (PATTERN (prev)), 1))
2316 && XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0) == label)
2318 XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0)
2320 emit_note_after (NOTE_INSN_LOOP_END, prev);
2329 /* If the loop starts with a loop exit, roll that to the end where
2330 it will optimize together with the jump back.
2332 We look for the conditional branch to the exit, except that once
2333 we find such a branch, we don't look past 30 instructions.
2335 In more detail, if the loop presently looks like this (in pseudo-C):
2338 if (test) goto end_label;
2343 transform it to look like:
2349 if (test) goto end_label;
2350 goto newstart_label;
2353 Here, the `test' may actually consist of some reasonably complex
2354 code, terminating in a test. */
2359 ! (GET_CODE (insn) == JUMP_INSN
2360 && GET_CODE (PATTERN (insn)) == SET
2361 && SET_DEST (PATTERN (insn)) == pc_rtx
2362 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2366 rtx last_test_insn = NULL_RTX;
2368 /* Scan insns from the top of the loop looking for a qualified
2369 conditional exit. */
2370 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2371 insn = NEXT_INSN (insn))
2373 if (GET_CODE (insn) == NOTE)
2376 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2377 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2378 /* The code that actually moves the exit test will
2379 carefully leave BLOCK notes in their original
2380 location. That means, however, that we can't debug
2381 the exit test itself. So, we refuse to move code
2382 containing BLOCK notes at low optimization levels. */
2385 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG)
2387 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)
2391 /* We've come to the end of an EH region, but
2392 never saw the beginning of that region. That
2393 means that an EH region begins before the top
2394 of the loop, and ends in the middle of it. The
2395 existence of such a situation violates a basic
2396 assumption in this code, since that would imply
2397 that even when EH_REGIONS is zero, we might
2398 move code out of an exception region. */
2402 /* We must not walk into a nested loop. */
2403 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
2406 /* We already know this INSN is a NOTE, so there's no
2407 point in looking at it to see if it's a JUMP. */
2411 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2414 if (last_test_insn && num_insns > 30)
2418 /* We don't want to move a partial EH region. Consider:
2432 This isn't legal C++, but here's what it's supposed to
2433 mean: if cond() is true, stop looping. Otherwise,
2434 call bar, and keep looping. In addition, if cond
2435 throws an exception, catch it and keep looping. Such
2436 constructs are certainy legal in LISP.
2438 We should not move the `if (cond()) 0' test since then
2439 the EH-region for the try-block would be broken up.
2440 (In this case we would the EH_BEG note for the `try'
2441 and `if cond()' but not the call to bar() or the
2444 So we don't look for tests within an EH region. */
2447 if (GET_CODE (insn) == JUMP_INSN
2448 && GET_CODE (PATTERN (insn)) == SET
2449 && SET_DEST (PATTERN (insn)) == pc_rtx)
2451 /* This is indeed a jump. */
2452 rtx dest1 = NULL_RTX;
2453 rtx dest2 = NULL_RTX;
2454 rtx potential_last_test;
2455 if (GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE)
2457 /* A conditional jump. */
2458 dest1 = XEXP (SET_SRC (PATTERN (insn)), 1);
2459 dest2 = XEXP (SET_SRC (PATTERN (insn)), 2);
2460 potential_last_test = insn;
2464 /* An unconditional jump. */
2465 dest1 = SET_SRC (PATTERN (insn));
2466 /* Include the BARRIER after the JUMP. */
2467 potential_last_test = NEXT_INSN (insn);
2471 if (dest1 && GET_CODE (dest1) == LABEL_REF
2472 && ((XEXP (dest1, 0)
2473 == loop_stack->data.loop.alt_end_label)
2475 == loop_stack->data.loop.end_label)))
2477 last_test_insn = potential_last_test;
2481 /* If this was a conditional jump, there may be
2482 another label at which we should look. */
2489 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2491 /* We found one. Move everything from there up
2492 to the end of the loop, and add a jump into the loop
2493 to jump to there. */
2494 register rtx newstart_label = gen_label_rtx ();
2495 register rtx start_move = start_label;
2498 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2499 then we want to move this note also. */
2500 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2501 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2502 == NOTE_INSN_LOOP_CONT))
2503 start_move = PREV_INSN (start_move);
2505 emit_label_after (newstart_label, PREV_INSN (start_move));
2507 /* Actually move the insns. Start at the beginning, and
2508 keep copying insns until we've copied the
2510 for (insn = start_move; insn; insn = next_insn)
2512 /* Figure out which insn comes after this one. We have
2513 to do this before we move INSN. */
2514 if (insn == last_test_insn)
2515 /* We've moved all the insns. */
2516 next_insn = NULL_RTX;
2518 next_insn = NEXT_INSN (insn);
2520 if (GET_CODE (insn) == NOTE
2521 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2522 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2523 /* We don't want to move NOTE_INSN_BLOCK_BEGs or
2524 NOTE_INSN_BLOCK_ENDs because the correct generation
2525 of debugging information depends on these appearing
2526 in the same order in the RTL and in the tree
2527 structure, where they are represented as BLOCKs.
2528 So, we don't move block notes. Of course, moving
2529 the code inside the block is likely to make it
2530 impossible to debug the instructions in the exit
2531 test, but such is the price of optimization. */
2534 /* Move the INSN. */
2535 reorder_insns (insn, insn, get_last_insn ());
2538 emit_jump_insn_after (gen_jump (start_label),
2539 PREV_INSN (newstart_label));
2540 emit_barrier_after (PREV_INSN (newstart_label));
2541 start_label = newstart_label;
2547 emit_jump (start_label);
2548 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2550 emit_label (loop_stack->data.loop.end_label);
2552 POPSTACK (loop_stack);
2557 /* Generate a jump to the current loop's continue-point.
2558 This is usually the top of the loop, but may be specified
2559 explicitly elsewhere. If not currently inside a loop,
2560 return 0 and do nothing; caller will print an error message. */
2563 expand_continue_loop (whichloop)
2564 struct nesting *whichloop;
2568 whichloop = loop_stack;
2571 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2576 /* Generate a jump to exit the current loop. If not currently inside a loop,
2577 return 0 and do nothing; caller will print an error message. */
2580 expand_exit_loop (whichloop)
2581 struct nesting *whichloop;
2585 whichloop = loop_stack;
2588 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2592 /* Generate a conditional jump to exit the current loop if COND
2593 evaluates to zero. If not currently inside a loop,
2594 return 0 and do nothing; caller will print an error message. */
2597 expand_exit_loop_if_false (whichloop, cond)
2598 struct nesting *whichloop;
2601 rtx label = gen_label_rtx ();
2606 whichloop = loop_stack;
2609 /* In order to handle fixups, we actually create a conditional jump
2610 around a unconditional branch to exit the loop. If fixups are
2611 necessary, they go before the unconditional branch. */
2614 do_jump (cond, NULL_RTX, label);
2615 last_insn = get_last_insn ();
2616 if (GET_CODE (last_insn) == CODE_LABEL)
2617 whichloop->data.loop.alt_end_label = last_insn;
2618 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2625 /* Return nonzero if the loop nest is empty. Else return zero. */
2628 stmt_loop_nest_empty ()
2630 /* cfun->stmt can be NULL if we are building a call to get the
2631 EH context for a setjmp/longjmp EH target and the current
2632 function was a deferred inline function. */
2633 return (cfun->stmt == NULL || loop_stack == NULL);
2636 /* Return non-zero if we should preserve sub-expressions as separate
2637 pseudos. We never do so if we aren't optimizing. We always do so
2638 if -fexpensive-optimizations.
2640 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2641 the loop may still be a small one. */
2644 preserve_subexpressions_p ()
2648 if (flag_expensive_optimizations)
2651 if (optimize == 0 || cfun == 0 || cfun->stmt == 0 || loop_stack == 0)
2654 insn = get_last_insn_anywhere ();
2657 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2658 < n_non_fixed_regs * 3));
2662 /* Generate a jump to exit the current loop, conditional, binding contour
2663 or case statement. Not all such constructs are visible to this function,
2664 only those started with EXIT_FLAG nonzero. Individual languages use
2665 the EXIT_FLAG parameter to control which kinds of constructs you can
2668 If not currently inside anything that can be exited,
2669 return 0 and do nothing; caller will print an error message. */
2672 expand_exit_something ()
2676 for (n = nesting_stack; n; n = n->all)
2677 if (n->exit_label != 0)
2679 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2686 /* Generate RTL to return from the current function, with no value.
2687 (That is, we do not do anything about returning any value.) */
2690 expand_null_return ()
2692 struct nesting *block = block_stack;
2693 rtx last_insn = get_last_insn ();
2695 /* If this function was declared to return a value, but we
2696 didn't, clobber the return registers so that they are not
2697 propogated live to the rest of the function. */
2698 clobber_return_register ();
2700 /* Does any pending block have cleanups? */
2701 while (block && block->data.block.cleanups == 0)
2702 block = block->next;
2704 /* If yes, use a goto to return, since that runs cleanups. */
2706 expand_null_return_1 (last_insn, block != 0);
2709 /* Generate RTL to return from the current function, with value VAL. */
2712 expand_value_return (val)
2715 struct nesting *block = block_stack;
2716 rtx last_insn = get_last_insn ();
2717 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2719 /* Copy the value to the return location
2720 unless it's already there. */
2722 if (return_reg != val)
2724 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2725 #ifdef PROMOTE_FUNCTION_RETURN
2726 int unsignedp = TREE_UNSIGNED (type);
2727 enum machine_mode old_mode
2728 = DECL_MODE (DECL_RESULT (current_function_decl));
2729 enum machine_mode mode
2730 = promote_mode (type, old_mode, &unsignedp, 1);
2732 if (mode != old_mode)
2733 val = convert_modes (mode, old_mode, val, unsignedp);
2735 if (GET_CODE (return_reg) == PARALLEL)
2736 emit_group_load (return_reg, val, int_size_in_bytes (type),
2739 emit_move_insn (return_reg, val);
2742 /* Does any pending block have cleanups? */
2744 while (block && block->data.block.cleanups == 0)
2745 block = block->next;
2747 /* If yes, use a goto to return, since that runs cleanups.
2748 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2750 expand_null_return_1 (last_insn, block != 0);
2753 /* Output a return with no value. If LAST_INSN is nonzero,
2754 pretend that the return takes place after LAST_INSN.
2755 If USE_GOTO is nonzero then don't use a return instruction;
2756 go to the return label instead. This causes any cleanups
2757 of pending blocks to be executed normally. */
2760 expand_null_return_1 (last_insn, use_goto)
2764 rtx end_label = cleanup_label ? cleanup_label : return_label;
2766 clear_pending_stack_adjust ();
2767 do_pending_stack_adjust ();
2770 /* PCC-struct return always uses an epilogue. */
2771 if (current_function_returns_pcc_struct || use_goto)
2774 end_label = return_label = gen_label_rtx ();
2775 expand_goto_internal (NULL_TREE, end_label, last_insn);
2779 /* Otherwise output a simple return-insn if one is available,
2780 unless it won't do the job. */
2782 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2784 emit_jump_insn (gen_return ());
2790 /* Otherwise jump to the epilogue. */
2791 expand_goto_internal (NULL_TREE, end_label, last_insn);
2794 /* Generate RTL to evaluate the expression RETVAL and return it
2795 from the current function. */
2798 expand_return (retval)
2801 /* If there are any cleanups to be performed, then they will
2802 be inserted following LAST_INSN. It is desirable
2803 that the last_insn, for such purposes, should be the
2804 last insn before computing the return value. Otherwise, cleanups
2805 which call functions can clobber the return value. */
2806 /* ??? rms: I think that is erroneous, because in C++ it would
2807 run destructors on variables that might be used in the subsequent
2808 computation of the return value. */
2810 rtx result_rtl = DECL_RTL (DECL_RESULT (current_function_decl));
2811 register rtx val = 0;
2818 /* If function wants no value, give it none. */
2819 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2821 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2823 expand_null_return ();
2827 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2828 /* This is not sufficient. We also need to watch for cleanups of the
2829 expression we are about to expand. Unfortunately, we cannot know
2830 if it has cleanups until we expand it, and we want to change how we
2831 expand it depending upon if we need cleanups. We can't win. */
2833 cleanups = any_pending_cleanups (1);
2838 if (retval == error_mark_node)
2839 retval_rhs = NULL_TREE;
2840 else if (TREE_CODE (retval) == RESULT_DECL)
2841 retval_rhs = retval;
2842 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2843 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2844 retval_rhs = TREE_OPERAND (retval, 1);
2845 else if (VOID_TYPE_P (TREE_TYPE (retval)))
2846 /* Recognize tail-recursive call to void function. */
2847 retval_rhs = retval;
2849 retval_rhs = NULL_TREE;
2851 /* Only use `last_insn' if there are cleanups which must be run. */
2852 if (cleanups || cleanup_label != 0)
2853 last_insn = get_last_insn ();
2855 /* Distribute return down conditional expr if either of the sides
2856 may involve tail recursion (see test below). This enhances the number
2857 of tail recursions we see. Don't do this always since it can produce
2858 sub-optimal code in some cases and we distribute assignments into
2859 conditional expressions when it would help. */
2861 if (optimize && retval_rhs != 0
2862 && frame_offset == 0
2863 && TREE_CODE (retval_rhs) == COND_EXPR
2864 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2865 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2867 rtx label = gen_label_rtx ();
2870 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2871 start_cleanup_deferral ();
2872 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2873 DECL_RESULT (current_function_decl),
2874 TREE_OPERAND (retval_rhs, 1));
2875 TREE_SIDE_EFFECTS (expr) = 1;
2876 expand_return (expr);
2879 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2880 DECL_RESULT (current_function_decl),
2881 TREE_OPERAND (retval_rhs, 2));
2882 TREE_SIDE_EFFECTS (expr) = 1;
2883 expand_return (expr);
2884 end_cleanup_deferral ();
2888 /* Attempt to optimize the call if it is tail recursive. */
2889 if (flag_optimize_sibling_calls
2890 && retval_rhs != NULL_TREE
2891 && frame_offset == 0
2892 && TREE_CODE (retval_rhs) == CALL_EXPR
2893 && TREE_CODE (TREE_OPERAND (retval_rhs, 0)) == ADDR_EXPR
2894 && (TREE_OPERAND (TREE_OPERAND (retval_rhs, 0), 0)
2895 == current_function_decl)
2896 && optimize_tail_recursion (TREE_OPERAND (retval_rhs, 1), last_insn))
2900 /* This optimization is safe if there are local cleanups
2901 because expand_null_return takes care of them.
2902 ??? I think it should also be safe when there is a cleanup label,
2903 because expand_null_return takes care of them, too.
2904 Any reason why not? */
2905 if (HAVE_return && cleanup_label == 0
2906 && ! current_function_returns_pcc_struct
2907 && BRANCH_COST <= 1)
2909 /* If this is return x == y; then generate
2910 if (x == y) return 1; else return 0;
2911 if we can do it with explicit return insns and branches are cheap,
2912 but not if we have the corresponding scc insn. */
2915 switch (TREE_CODE (retval_rhs))
2941 case TRUTH_ANDIF_EXPR:
2942 case TRUTH_ORIF_EXPR:
2943 case TRUTH_AND_EXPR:
2945 case TRUTH_NOT_EXPR:
2946 case TRUTH_XOR_EXPR:
2949 op0 = gen_label_rtx ();
2950 jumpifnot (retval_rhs, op0);
2951 expand_value_return (const1_rtx);
2953 expand_value_return (const0_rtx);
2962 #endif /* HAVE_return */
2964 /* If the result is an aggregate that is being returned in one (or more)
2965 registers, load the registers here. The compiler currently can't handle
2966 copying a BLKmode value into registers. We could put this code in a
2967 more general area (for use by everyone instead of just function
2968 call/return), but until this feature is generally usable it is kept here
2969 (and in expand_call). The value must go into a pseudo in case there
2970 are cleanups that will clobber the real return register. */
2973 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2974 && GET_CODE (result_rtl) == REG)
2977 unsigned HOST_WIDE_INT bitpos, xbitpos;
2978 unsigned HOST_WIDE_INT big_endian_correction = 0;
2979 unsigned HOST_WIDE_INT bytes
2980 = int_size_in_bytes (TREE_TYPE (retval_rhs));
2981 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2982 unsigned int bitsize
2983 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)), BITS_PER_WORD);
2984 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2985 rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
2986 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2987 enum machine_mode tmpmode, result_reg_mode;
2989 /* Structures whose size is not a multiple of a word are aligned
2990 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
2991 machine, this means we must skip the empty high order bytes when
2992 calculating the bit offset. */
2993 if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD)
2994 big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
2997 /* Copy the structure BITSIZE bits at a time. */
2998 for (bitpos = 0, xbitpos = big_endian_correction;
2999 bitpos < bytes * BITS_PER_UNIT;
3000 bitpos += bitsize, xbitpos += bitsize)
3002 /* We need a new destination pseudo each time xbitpos is
3003 on a word boundary and when xbitpos == big_endian_correction
3004 (the first time through). */
3005 if (xbitpos % BITS_PER_WORD == 0
3006 || xbitpos == big_endian_correction)
3008 /* Generate an appropriate register. */
3009 dst = gen_reg_rtx (word_mode);
3010 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
3012 /* Clobber the destination before we move anything into it. */
3013 emit_insn (gen_rtx_CLOBBER (VOIDmode, dst));
3016 /* We need a new source operand each time bitpos is on a word
3018 if (bitpos % BITS_PER_WORD == 0)
3019 src = operand_subword_force (result_val,
3020 bitpos / BITS_PER_WORD,
3023 /* Use bitpos for the source extraction (left justified) and
3024 xbitpos for the destination store (right justified). */
3025 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
3026 extract_bit_field (src, bitsize,
3027 bitpos % BITS_PER_WORD, 1,
3028 NULL_RTX, word_mode, word_mode,
3029 bitsize, BITS_PER_WORD),
3030 bitsize, BITS_PER_WORD);
3033 /* Find the smallest integer mode large enough to hold the
3034 entire structure and use that mode instead of BLKmode
3035 on the USE insn for the return register. */
3036 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
3037 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
3038 tmpmode != VOIDmode;
3039 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
3041 /* Have we found a large enough mode? */
3042 if (GET_MODE_SIZE (tmpmode) >= bytes)
3046 /* No suitable mode found. */
3047 if (tmpmode == VOIDmode)
3050 PUT_MODE (result_rtl, tmpmode);
3052 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
3053 result_reg_mode = word_mode;
3055 result_reg_mode = tmpmode;
3056 result_reg = gen_reg_rtx (result_reg_mode);
3059 for (i = 0; i < n_regs; i++)
3060 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
3063 if (tmpmode != result_reg_mode)
3064 result_reg = gen_lowpart (tmpmode, result_reg);
3066 expand_value_return (result_reg);
3070 && !VOID_TYPE_P (TREE_TYPE (retval_rhs))
3071 && (GET_CODE (result_rtl) == REG
3072 || (GET_CODE (result_rtl) == PARALLEL)))
3074 /* Calculate the return value into a temporary (usually a pseudo
3076 val = assign_temp (TREE_TYPE (DECL_RESULT (current_function_decl)),
3078 val = expand_expr (retval_rhs, val, GET_MODE (val), 0);
3079 val = force_not_mem (val);
3081 /* Return the calculated value, doing cleanups first. */
3082 expand_value_return (val);
3086 /* No cleanups or no hard reg used;
3087 calculate value into hard return reg. */
3088 expand_expr (retval, const0_rtx, VOIDmode, 0);
3090 expand_value_return (result_rtl);
3094 /* Return 1 if the end of the generated RTX is not a barrier.
3095 This means code already compiled can drop through. */
3098 drop_through_at_end_p ()
3100 rtx insn = get_last_insn ();
3101 while (insn && GET_CODE (insn) == NOTE)
3102 insn = PREV_INSN (insn);
3103 return insn && GET_CODE (insn) != BARRIER;
3106 /* Attempt to optimize a potential tail recursion call into a goto.
3107 ARGUMENTS are the arguments to a CALL_EXPR; LAST_INSN indicates
3108 where to place the jump to the tail recursion label.
3110 Return TRUE if the call was optimized into a goto. */
3113 optimize_tail_recursion (arguments, last_insn)
3117 /* Finish checking validity, and if valid emit code to set the
3118 argument variables for the new call. */
3119 if (tail_recursion_args (arguments, DECL_ARGUMENTS (current_function_decl)))
3121 if (tail_recursion_label == 0)
3123 tail_recursion_label = gen_label_rtx ();
3124 emit_label_after (tail_recursion_label,
3125 tail_recursion_reentry);
3128 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
3135 /* Emit code to alter this function's formal parms for a tail-recursive call.
3136 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3137 FORMALS is the chain of decls of formals.
3138 Return 1 if this can be done;
3139 otherwise return 0 and do not emit any code. */
3142 tail_recursion_args (actuals, formals)
3143 tree actuals, formals;
3145 register tree a = actuals, f = formals;
3147 register rtx *argvec;
3149 /* Check that number and types of actuals are compatible
3150 with the formals. This is not always true in valid C code.
3151 Also check that no formal needs to be addressable
3152 and that all formals are scalars. */
3154 /* Also count the args. */
3156 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
3158 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a)))
3159 != TYPE_MAIN_VARIANT (TREE_TYPE (f)))
3161 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
3164 if (a != 0 || f != 0)
3167 /* Compute all the actuals. */
3169 argvec = (rtx *) alloca (i * sizeof (rtx));
3171 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3172 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
3174 /* Find which actual values refer to current values of previous formals.
3175 Copy each of them now, before any formal is changed. */
3177 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3181 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
3182 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
3183 { copy = 1; break; }
3185 argvec[i] = copy_to_reg (argvec[i]);
3188 /* Store the values of the actuals into the formals. */
3190 for (f = formals, a = actuals, i = 0; f;
3191 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
3193 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
3194 emit_move_insn (DECL_RTL (f), argvec[i]);
3196 convert_move (DECL_RTL (f), argvec[i],
3197 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
3204 /* Generate the RTL code for entering a binding contour.
3205 The variables are declared one by one, by calls to `expand_decl'.
3207 FLAGS is a bitwise or of the following flags:
3209 1 - Nonzero if this construct should be visible to
3212 2 - Nonzero if this contour does not require a
3213 NOTE_INSN_BLOCK_BEG note. Virtually all calls from
3214 language-independent code should set this flag because they
3215 will not create corresponding BLOCK nodes. (There should be
3216 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
3217 and BLOCKs.) If this flag is set, MARK_ENDS should be zero
3218 when expand_end_bindings is called.
3220 If we are creating a NOTE_INSN_BLOCK_BEG note, a BLOCK may
3221 optionally be supplied. If so, it becomes the NOTE_BLOCK for the
3225 expand_start_bindings_and_block (flags, block)
3229 struct nesting *thisblock = ALLOC_NESTING ();
3231 int exit_flag = ((flags & 1) != 0);
3232 int block_flag = ((flags & 2) == 0);
3234 /* If a BLOCK is supplied, then the caller should be requesting a
3235 NOTE_INSN_BLOCK_BEG note. */
3236 if (!block_flag && block)
3239 /* Create a note to mark the beginning of the block. */
3242 note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
3243 NOTE_BLOCK (note) = block;
3246 note = emit_note (NULL_PTR, NOTE_INSN_DELETED);
3248 /* Make an entry on block_stack for the block we are entering. */
3250 thisblock->next = block_stack;
3251 thisblock->all = nesting_stack;
3252 thisblock->depth = ++nesting_depth;
3253 thisblock->data.block.stack_level = 0;
3254 thisblock->data.block.cleanups = 0;
3255 thisblock->data.block.n_function_calls = 0;
3256 thisblock->data.block.exception_region = 0;
3257 thisblock->data.block.block_target_temp_slot_level = target_temp_slot_level;
3259 thisblock->data.block.conditional_code = 0;
3260 thisblock->data.block.last_unconditional_cleanup = note;
3261 /* When we insert instructions after the last unconditional cleanup,
3262 we don't adjust last_insn. That means that a later add_insn will
3263 clobber the instructions we've just added. The easiest way to
3264 fix this is to just insert another instruction here, so that the
3265 instructions inserted after the last unconditional cleanup are
3266 never the last instruction. */
3267 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3268 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
3271 && !(block_stack->data.block.cleanups == NULL_TREE
3272 && block_stack->data.block.outer_cleanups == NULL_TREE))
3273 thisblock->data.block.outer_cleanups
3274 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
3275 block_stack->data.block.outer_cleanups);
3277 thisblock->data.block.outer_cleanups = 0;
3278 thisblock->data.block.label_chain = 0;
3279 thisblock->data.block.innermost_stack_block = stack_block_stack;
3280 thisblock->data.block.first_insn = note;
3281 thisblock->data.block.block_start_count = ++current_block_start_count;
3282 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
3283 block_stack = thisblock;
3284 nesting_stack = thisblock;
3286 /* Make a new level for allocating stack slots. */
3290 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3291 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3292 expand_expr are made. After we end the region, we know that all
3293 space for all temporaries that were created by TARGET_EXPRs will be
3294 destroyed and their space freed for reuse. */
3297 expand_start_target_temps ()
3299 /* This is so that even if the result is preserved, the space
3300 allocated will be freed, as we know that it is no longer in use. */
3303 /* Start a new binding layer that will keep track of all cleanup
3304 actions to be performed. */
3305 expand_start_bindings (2);
3307 target_temp_slot_level = temp_slot_level;
3311 expand_end_target_temps ()
3313 expand_end_bindings (NULL_TREE, 0, 0);
3315 /* This is so that even if the result is preserved, the space
3316 allocated will be freed, as we know that it is no longer in use. */
3320 /* Given a pointer to a BLOCK node return non-zero if (and only if) the node
3321 in question represents the outermost pair of curly braces (i.e. the "body
3322 block") of a function or method.
3324 For any BLOCK node representing a "body block" of a function or method, the
3325 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
3326 represents the outermost (function) scope for the function or method (i.e.
3327 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
3328 *that* node in turn will point to the relevant FUNCTION_DECL node. */
3331 is_body_block (stmt)
3334 if (TREE_CODE (stmt) == BLOCK)
3336 tree parent = BLOCK_SUPERCONTEXT (stmt);
3338 if (parent && TREE_CODE (parent) == BLOCK)
3340 tree grandparent = BLOCK_SUPERCONTEXT (parent);
3342 if (grandparent && TREE_CODE (grandparent) == FUNCTION_DECL)
3350 /* Mark top block of block_stack as an implicit binding for an
3351 exception region. This is used to prevent infinite recursion when
3352 ending a binding with expand_end_bindings. It is only ever called
3353 by expand_eh_region_start, as that it the only way to create a
3354 block stack for a exception region. */
3357 mark_block_as_eh_region ()
3359 block_stack->data.block.exception_region = 1;
3360 if (block_stack->next
3361 && block_stack->next->data.block.conditional_code)
3363 block_stack->data.block.conditional_code
3364 = block_stack->next->data.block.conditional_code;
3365 block_stack->data.block.last_unconditional_cleanup
3366 = block_stack->next->data.block.last_unconditional_cleanup;
3367 block_stack->data.block.cleanup_ptr
3368 = block_stack->next->data.block.cleanup_ptr;
3372 /* True if we are currently emitting insns in an area of output code
3373 that is controlled by a conditional expression. This is used by
3374 the cleanup handling code to generate conditional cleanup actions. */
3377 conditional_context ()
3379 return block_stack && block_stack->data.block.conditional_code;
3382 /* Mark top block of block_stack as not for an implicit binding for an
3383 exception region. This is only ever done by expand_eh_region_end
3384 to let expand_end_bindings know that it is being called explicitly
3385 to end the binding layer for just the binding layer associated with
3386 the exception region, otherwise expand_end_bindings would try and
3387 end all implicit binding layers for exceptions regions, and then
3388 one normal binding layer. */
3391 mark_block_as_not_eh_region ()
3393 block_stack->data.block.exception_region = 0;
3396 /* True if the top block of block_stack was marked as for an exception
3397 region by mark_block_as_eh_region. */
3402 return cfun && block_stack && block_stack->data.block.exception_region;
3405 /* Emit a handler label for a nonlocal goto handler.
3406 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3409 expand_nl_handler_label (slot, before_insn)
3410 rtx slot, before_insn;
3413 rtx handler_label = gen_label_rtx ();
3415 /* Don't let jump_optimize delete the handler. */
3416 LABEL_PRESERVE_P (handler_label) = 1;
3419 emit_move_insn (slot, gen_rtx_LABEL_REF (Pmode, handler_label));
3420 insns = get_insns ();
3422 emit_insns_before (insns, before_insn);
3424 emit_label (handler_label);
3426 return handler_label;
3429 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3432 expand_nl_goto_receiver ()
3434 #ifdef HAVE_nonlocal_goto
3435 if (! HAVE_nonlocal_goto)
3437 /* First adjust our frame pointer to its actual value. It was
3438 previously set to the start of the virtual area corresponding to
3439 the stacked variables when we branched here and now needs to be
3440 adjusted to the actual hardware fp value.
3442 Assignments are to virtual registers are converted by
3443 instantiate_virtual_regs into the corresponding assignment
3444 to the underlying register (fp in this case) that makes
3445 the original assignment true.
3446 So the following insn will actually be
3447 decrementing fp by STARTING_FRAME_OFFSET. */
3448 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3450 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3451 if (fixed_regs[ARG_POINTER_REGNUM])
3453 #ifdef ELIMINABLE_REGS
3454 /* If the argument pointer can be eliminated in favor of the
3455 frame pointer, we don't need to restore it. We assume here
3456 that if such an elimination is present, it can always be used.
3457 This is the case on all known machines; if we don't make this
3458 assumption, we do unnecessary saving on many machines. */
3459 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3462 for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
3463 if (elim_regs[i].from == ARG_POINTER_REGNUM
3464 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3467 if (i == sizeof elim_regs / sizeof elim_regs [0])
3470 /* Now restore our arg pointer from the address at which it
3471 was saved in our stack frame.
3472 If there hasn't be space allocated for it yet, make
3474 if (arg_pointer_save_area == 0)
3475 arg_pointer_save_area
3476 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3477 emit_move_insn (virtual_incoming_args_rtx,
3478 /* We need a pseudo here, or else
3479 instantiate_virtual_regs_1 complains. */
3480 copy_to_reg (arg_pointer_save_area));
3485 #ifdef HAVE_nonlocal_goto_receiver
3486 if (HAVE_nonlocal_goto_receiver)
3487 emit_insn (gen_nonlocal_goto_receiver ());
3491 /* Make handlers for nonlocal gotos taking place in the function calls in
3495 expand_nl_goto_receivers (thisblock)
3496 struct nesting *thisblock;
3499 rtx afterward = gen_label_rtx ();
3504 /* Record the handler address in the stack slot for that purpose,
3505 during this block, saving and restoring the outer value. */
3506 if (thisblock->next != 0)
3507 for (slot = nonlocal_goto_handler_slots; slot; slot = XEXP (slot, 1))
3509 rtx save_receiver = gen_reg_rtx (Pmode);
3510 emit_move_insn (XEXP (slot, 0), save_receiver);
3513 emit_move_insn (save_receiver, XEXP (slot, 0));
3514 insns = get_insns ();
3516 emit_insns_before (insns, thisblock->data.block.first_insn);
3519 /* Jump around the handlers; they run only when specially invoked. */
3520 emit_jump (afterward);
3522 /* Make a separate handler for each label. */
3523 link = nonlocal_labels;
3524 slot = nonlocal_goto_handler_slots;
3525 label_list = NULL_RTX;
3526 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3527 /* Skip any labels we shouldn't be able to jump to from here,
3528 we generate one special handler for all of them below which just calls
3530 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3533 lab = expand_nl_handler_label (XEXP (slot, 0),
3534 thisblock->data.block.first_insn);
3535 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3537 expand_nl_goto_receiver ();
3539 /* Jump to the "real" nonlocal label. */
3540 expand_goto (TREE_VALUE (link));
3543 /* A second pass over all nonlocal labels; this time we handle those
3544 we should not be able to jump to at this point. */
3545 link = nonlocal_labels;
3546 slot = nonlocal_goto_handler_slots;
3548 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3549 if (DECL_TOO_LATE (TREE_VALUE (link)))
3552 lab = expand_nl_handler_label (XEXP (slot, 0),
3553 thisblock->data.block.first_insn);
3554 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3560 expand_nl_goto_receiver ();
3561 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "abort"), 0,
3566 nonlocal_goto_handler_labels = label_list;
3567 emit_label (afterward);
3570 /* Warn about any unused VARS (which may contain nodes other than
3571 VAR_DECLs, but such nodes are ignored). The nodes are connected
3572 via the TREE_CHAIN field. */
3575 warn_about_unused_variables (vars)
3580 if (warn_unused_variable)
3581 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3582 if (TREE_CODE (decl) == VAR_DECL
3583 && ! TREE_USED (decl)
3584 && ! DECL_IN_SYSTEM_HEADER (decl)
3585 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
3586 warning_with_decl (decl, "unused variable `%s'");
3589 /* Generate RTL code to terminate a binding contour.
3591 VARS is the chain of VAR_DECL nodes for the variables bound in this
3592 contour. There may actually be other nodes in this chain, but any
3593 nodes other than VAR_DECLS are ignored.
3595 MARK_ENDS is nonzero if we should put a note at the beginning
3596 and end of this binding contour.
3598 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3599 (That is true automatically if the contour has a saved stack level.) */
3602 expand_end_bindings (vars, mark_ends, dont_jump_in)
3607 register struct nesting *thisblock;
3609 while (block_stack->data.block.exception_region)
3611 /* Because we don't need or want a new temporary level and
3612 because we didn't create one in expand_eh_region_start,
3613 create a fake one now to avoid removing one in
3614 expand_end_bindings. */
3617 block_stack->data.block.exception_region = 0;
3619 expand_end_bindings (NULL_TREE, 0, 0);
3622 /* Since expand_eh_region_start does an expand_start_bindings, we
3623 have to first end all the bindings that were created by
3624 expand_eh_region_start. */
3626 thisblock = block_stack;
3628 /* If any of the variables in this scope were not used, warn the
3630 warn_about_unused_variables (vars);
3632 if (thisblock->exit_label)
3634 do_pending_stack_adjust ();
3635 emit_label (thisblock->exit_label);
3638 /* If necessary, make handlers for nonlocal gotos taking
3639 place in the function calls in this block. */
3640 if (function_call_count != thisblock->data.block.n_function_calls
3642 /* Make handler for outermost block
3643 if there were any nonlocal gotos to this function. */
3644 && (thisblock->next == 0 ? current_function_has_nonlocal_label
3645 /* Make handler for inner block if it has something
3646 special to do when you jump out of it. */
3647 : (thisblock->data.block.cleanups != 0
3648 || thisblock->data.block.stack_level != 0)))
3649 expand_nl_goto_receivers (thisblock);
3651 /* Don't allow jumping into a block that has a stack level.
3652 Cleanups are allowed, though. */
3654 || thisblock->data.block.stack_level != 0)
3656 struct label_chain *chain;
3658 /* Any labels in this block are no longer valid to go to.
3659 Mark them to cause an error message. */
3660 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3662 DECL_TOO_LATE (chain->label) = 1;
3663 /* If any goto without a fixup came to this label,
3664 that must be an error, because gotos without fixups
3665 come from outside all saved stack-levels. */
3666 if (TREE_ADDRESSABLE (chain->label))
3667 error_with_decl (chain->label,
3668 "label `%s' used before containing binding contour");
3672 /* Restore stack level in effect before the block
3673 (only if variable-size objects allocated). */
3674 /* Perform any cleanups associated with the block. */
3676 if (thisblock->data.block.stack_level != 0
3677 || thisblock->data.block.cleanups != 0)
3682 /* Don't let cleanups affect ({...}) constructs. */
3683 int old_expr_stmts_for_value = expr_stmts_for_value;
3684 rtx old_last_expr_value = last_expr_value;
3685 tree old_last_expr_type = last_expr_type;
3686 expr_stmts_for_value = 0;
3688 /* Only clean up here if this point can actually be reached. */
3689 insn = get_last_insn ();
3690 if (GET_CODE (insn) == NOTE)
3691 insn = prev_nonnote_insn (insn);
3692 reachable = (! insn || GET_CODE (insn) != BARRIER);
3694 /* Do the cleanups. */
3695 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3697 do_pending_stack_adjust ();
3699 expr_stmts_for_value = old_expr_stmts_for_value;
3700 last_expr_value = old_last_expr_value;
3701 last_expr_type = old_last_expr_type;
3703 /* Restore the stack level. */
3705 if (reachable && thisblock->data.block.stack_level != 0)
3707 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3708 thisblock->data.block.stack_level, NULL_RTX);
3709 if (nonlocal_goto_handler_slots != 0)
3710 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3714 /* Any gotos out of this block must also do these things.
3715 Also report any gotos with fixups that came to labels in this
3717 fixup_gotos (thisblock,
3718 thisblock->data.block.stack_level,
3719 thisblock->data.block.cleanups,
3720 thisblock->data.block.first_insn,
3724 /* Mark the beginning and end of the scope if requested.
3725 We do this now, after running cleanups on the variables
3726 just going out of scope, so they are in scope for their cleanups. */
3730 rtx note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3731 NOTE_BLOCK (note) = NOTE_BLOCK (thisblock->data.block.first_insn);
3734 /* Get rid of the beginning-mark if we don't make an end-mark. */
3735 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3737 /* Restore the temporary level of TARGET_EXPRs. */
3738 target_temp_slot_level = thisblock->data.block.block_target_temp_slot_level;
3740 /* Restore block_stack level for containing block. */
3742 stack_block_stack = thisblock->data.block.innermost_stack_block;
3743 POPSTACK (block_stack);
3745 /* Pop the stack slot nesting and free any slots at this level. */
3749 /* Generate RTL for the automatic variable declaration DECL.
3750 (Other kinds of declarations are simply ignored if seen here.) */
3756 struct nesting *thisblock;
3759 type = TREE_TYPE (decl);
3761 /* Only automatic variables need any expansion done.
3762 Static and external variables, and external functions,
3763 will be handled by `assemble_variable' (called from finish_decl).
3764 TYPE_DECL and CONST_DECL require nothing.
3765 PARM_DECLs are handled in `assign_parms'. */
3767 if (TREE_CODE (decl) != VAR_DECL)
3769 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3772 thisblock = block_stack;
3774 /* Create the RTL representation for the variable. */
3776 if (type == error_mark_node)
3777 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, const0_rtx);
3778 else if (DECL_SIZE (decl) == 0)
3779 /* Variable with incomplete type. */
3781 if (DECL_INITIAL (decl) == 0)
3782 /* Error message was already done; now avoid a crash. */
3783 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3785 /* An initializer is going to decide the size of this array.
3786 Until we know the size, represent its address with a reg. */
3787 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode));
3789 set_mem_attributes (DECL_RTL (decl), decl, 1);
3791 else if (DECL_MODE (decl) != BLKmode
3792 /* If -ffloat-store, don't put explicit float vars
3794 && !(flag_float_store
3795 && TREE_CODE (type) == REAL_TYPE)
3796 && ! TREE_THIS_VOLATILE (decl)
3797 && ! TREE_ADDRESSABLE (decl)
3798 && (DECL_REGISTER (decl) || optimize)
3799 /* if -fcheck-memory-usage, check all variables. */
3800 && ! current_function_check_memory_usage)
3802 /* Automatic variable that can go in a register. */
3803 int unsignedp = TREE_UNSIGNED (type);
3804 enum machine_mode reg_mode
3805 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3807 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3808 mark_user_reg (DECL_RTL (decl));
3810 if (POINTER_TYPE_P (type))
3811 mark_reg_pointer (DECL_RTL (decl),
3812 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
3814 maybe_set_unchanging (DECL_RTL (decl), decl);
3817 else if (TREE_CODE (DECL_SIZE_UNIT (decl)) == INTEGER_CST
3818 && ! (flag_stack_check && ! STACK_CHECK_BUILTIN
3819 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl),
3820 STACK_CHECK_MAX_VAR_SIZE)))
3822 /* Variable of fixed size that goes on the stack. */
3826 /* If we previously made RTL for this decl, it must be an array
3827 whose size was determined by the initializer.
3828 The old address was a register; set that register now
3829 to the proper address. */
3830 if (DECL_RTL (decl) != 0)
3832 if (GET_CODE (DECL_RTL (decl)) != MEM
3833 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3835 oldaddr = XEXP (DECL_RTL (decl), 0);
3838 DECL_RTL (decl) = assign_temp (TREE_TYPE (decl), 1, 1, 1);
3840 /* Set alignment we actually gave this decl. */
3841 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3842 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3843 DECL_USER_ALIGN (decl) = 0;
3847 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3848 if (addr != oldaddr)
3849 emit_move_insn (oldaddr, addr);
3853 /* Dynamic-size object: must push space on the stack. */
3857 /* Record the stack pointer on entry to block, if have
3858 not already done so. */
3859 if (thisblock->data.block.stack_level == 0)
3861 do_pending_stack_adjust ();
3862 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3863 &thisblock->data.block.stack_level,
3864 thisblock->data.block.first_insn);
3865 stack_block_stack = thisblock;
3868 /* In function-at-a-time mode, variable_size doesn't expand this,
3870 if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
3871 expand_expr (TYPE_MAX_VALUE (TYPE_DOMAIN (type)),
3872 const0_rtx, VOIDmode, 0);
3874 /* Compute the variable's size, in bytes. */
3875 size = expand_expr (DECL_SIZE_UNIT (decl), NULL_RTX, VOIDmode, 0);
3878 /* Allocate space on the stack for the variable. Note that
3879 DECL_ALIGN says how the variable is to be aligned and we
3880 cannot use it to conclude anything about the alignment of
3882 address = allocate_dynamic_stack_space (size, NULL_RTX,
3883 TYPE_ALIGN (TREE_TYPE (decl)));
3885 /* Reference the variable indirect through that rtx. */
3886 DECL_RTL (decl) = gen_rtx_MEM (DECL_MODE (decl), address);
3888 set_mem_attributes (DECL_RTL (decl), decl, 1);
3890 /* Indicate the alignment we actually gave this variable. */
3891 #ifdef STACK_BOUNDARY
3892 DECL_ALIGN (decl) = STACK_BOUNDARY;
3894 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3896 DECL_USER_ALIGN (decl) = 0;
3900 /* Emit code to perform the initialization of a declaration DECL. */
3903 expand_decl_init (decl)
3906 int was_used = TREE_USED (decl);
3908 /* If this is a CONST_DECL, we don't have to generate any code, but
3909 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3910 to be set while in the obstack containing the constant. If we don't
3911 do this, we can lose if we have functions nested three deep and the middle
3912 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3913 the innermost function is the first to expand that STRING_CST. */
3914 if (TREE_CODE (decl) == CONST_DECL)
3916 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3917 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3918 EXPAND_INITIALIZER);
3922 if (TREE_STATIC (decl))
3925 /* Compute and store the initial value now. */
3927 if (DECL_INITIAL (decl) == error_mark_node)
3929 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3931 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3932 || code == POINTER_TYPE || code == REFERENCE_TYPE)
3933 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3937 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3939 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3940 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3944 /* Don't let the initialization count as "using" the variable. */
3945 TREE_USED (decl) = was_used;
3947 /* Free any temporaries we made while initializing the decl. */
3948 preserve_temp_slots (NULL_RTX);
3952 /* CLEANUP is an expression to be executed at exit from this binding contour;
3953 for example, in C++, it might call the destructor for this variable.
3955 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
3956 CLEANUP multiple times, and have the correct semantics. This
3957 happens in exception handling, for gotos, returns, breaks that
3958 leave the current scope.
3960 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3961 that is not associated with any particular variable. */
3964 expand_decl_cleanup (decl, cleanup)
3967 struct nesting *thisblock;
3969 /* Error if we are not in any block. */
3970 if (cfun == 0 || block_stack == 0)
3973 thisblock = block_stack;
3975 /* Record the cleanup if there is one. */
3981 tree *cleanups = &thisblock->data.block.cleanups;
3982 int cond_context = conditional_context ();
3986 rtx flag = gen_reg_rtx (word_mode);
3991 emit_move_insn (flag, const0_rtx);
3992 set_flag_0 = get_insns ();
3995 thisblock->data.block.last_unconditional_cleanup
3996 = emit_insns_after (set_flag_0,
3997 thisblock->data.block.last_unconditional_cleanup);
3999 emit_move_insn (flag, const1_rtx);
4001 /* All cleanups must be on the function_obstack. */
4002 push_obstacks_nochange ();
4003 resume_temporary_allocation ();
4005 cond = build_decl (VAR_DECL, NULL_TREE, type_for_mode (word_mode, 1));
4006 DECL_RTL (cond) = flag;
4008 /* Conditionalize the cleanup. */
4009 cleanup = build (COND_EXPR, void_type_node,
4010 truthvalue_conversion (cond),
4011 cleanup, integer_zero_node);
4012 cleanup = fold (cleanup);
4016 cleanups = thisblock->data.block.cleanup_ptr;
4019 /* All cleanups must be on the function_obstack. */
4020 push_obstacks_nochange ();
4021 resume_temporary_allocation ();
4022 cleanup = unsave_expr (cleanup);
4025 t = *cleanups = temp_tree_cons (decl, cleanup, *cleanups);
4028 /* If this block has a cleanup, it belongs in stack_block_stack. */
4029 stack_block_stack = thisblock;
4036 /* If this was optimized so that there is no exception region for the
4037 cleanup, then mark the TREE_LIST node, so that we can later tell
4038 if we need to call expand_eh_region_end. */
4039 if (! using_eh_for_cleanups_p
4040 || expand_eh_region_start_tree (decl, cleanup))
4041 TREE_ADDRESSABLE (t) = 1;
4042 /* If that started a new EH region, we're in a new block. */
4043 thisblock = block_stack;
4050 thisblock->data.block.last_unconditional_cleanup
4051 = emit_insns_after (seq,
4052 thisblock->data.block.last_unconditional_cleanup);
4056 thisblock->data.block.last_unconditional_cleanup
4058 /* When we insert instructions after the last unconditional cleanup,
4059 we don't adjust last_insn. That means that a later add_insn will
4060 clobber the instructions we've just added. The easiest way to
4061 fix this is to just insert another instruction here, so that the
4062 instructions inserted after the last unconditional cleanup are
4063 never the last instruction. */
4064 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4065 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
4071 /* Like expand_decl_cleanup, but suppress generating an exception handler
4072 to perform the cleanup. */
4076 expand_decl_cleanup_no_eh (decl, cleanup)
4079 int save_eh = using_eh_for_cleanups_p;
4082 using_eh_for_cleanups_p = 0;
4083 result = expand_decl_cleanup (decl, cleanup);
4084 using_eh_for_cleanups_p = save_eh;
4090 /* Arrange for the top element of the dynamic cleanup chain to be
4091 popped if we exit the current binding contour. DECL is the
4092 associated declaration, if any, otherwise NULL_TREE. If the
4093 current contour is left via an exception, then __sjthrow will pop
4094 the top element off the dynamic cleanup chain. The code that
4095 avoids doing the action we push into the cleanup chain in the
4096 exceptional case is contained in expand_cleanups.
4098 This routine is only used by expand_eh_region_start, and that is
4099 the only way in which an exception region should be started. This
4100 routine is only used when using the setjmp/longjmp codegen method
4101 for exception handling. */
4104 expand_dcc_cleanup (decl)
4107 struct nesting *thisblock;
4110 /* Error if we are not in any block. */
4111 if (cfun == 0 || block_stack == 0)
4113 thisblock = block_stack;
4115 /* Record the cleanup for the dynamic handler chain. */
4117 /* All cleanups must be on the function_obstack. */
4118 push_obstacks_nochange ();
4119 resume_temporary_allocation ();
4120 cleanup = make_node (POPDCC_EXPR);
4123 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4124 thisblock->data.block.cleanups
4125 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4127 /* If this block has a cleanup, it belongs in stack_block_stack. */
4128 stack_block_stack = thisblock;
4132 /* Arrange for the top element of the dynamic handler chain to be
4133 popped if we exit the current binding contour. DECL is the
4134 associated declaration, if any, otherwise NULL_TREE. If the current
4135 contour is left via an exception, then __sjthrow will pop the top
4136 element off the dynamic handler chain. The code that avoids doing
4137 the action we push into the handler chain in the exceptional case
4138 is contained in expand_cleanups.
4140 This routine is only used by expand_eh_region_start, and that is
4141 the only way in which an exception region should be started. This
4142 routine is only used when using the setjmp/longjmp codegen method
4143 for exception handling. */
4146 expand_dhc_cleanup (decl)
4149 struct nesting *thisblock;
4152 /* Error if we are not in any block. */
4153 if (cfun == 0 || block_stack == 0)
4155 thisblock = block_stack;
4157 /* Record the cleanup for the dynamic handler chain. */
4159 /* All cleanups must be on the function_obstack. */
4160 push_obstacks_nochange ();
4161 resume_temporary_allocation ();
4162 cleanup = make_node (POPDHC_EXPR);
4165 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4166 thisblock->data.block.cleanups
4167 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4169 /* If this block has a cleanup, it belongs in stack_block_stack. */
4170 stack_block_stack = thisblock;
4174 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4175 DECL_ELTS is the list of elements that belong to DECL's type.
4176 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4179 expand_anon_union_decl (decl, cleanup, decl_elts)
4180 tree decl, cleanup, decl_elts;
4182 struct nesting *thisblock = cfun == 0 ? 0 : block_stack;
4186 /* If any of the elements are addressable, so is the entire union. */
4187 for (t = decl_elts; t; t = TREE_CHAIN (t))
4188 if (TREE_ADDRESSABLE (TREE_VALUE (t)))
4190 TREE_ADDRESSABLE (decl) = 1;
4195 expand_decl_cleanup (decl, cleanup);
4196 x = DECL_RTL (decl);
4198 /* Go through the elements, assigning RTL to each. */
4199 for (t = decl_elts; t; t = TREE_CHAIN (t))
4201 tree decl_elt = TREE_VALUE (t);
4202 tree cleanup_elt = TREE_PURPOSE (t);
4203 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
4205 /* Propagate the union's alignment to the elements. */
4206 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
4207 DECL_USER_ALIGN (decl_elt) = DECL_USER_ALIGN (decl);
4209 /* If the element has BLKmode and the union doesn't, the union is
4210 aligned such that the element doesn't need to have BLKmode, so
4211 change the element's mode to the appropriate one for its size. */
4212 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
4213 DECL_MODE (decl_elt) = mode
4214 = mode_for_size_tree (DECL_SIZE (decl_elt), MODE_INT, 1);
4216 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4217 instead create a new MEM rtx with the proper mode. */
4218 if (GET_CODE (x) == MEM)
4220 if (mode == GET_MODE (x))
4221 DECL_RTL (decl_elt) = x;
4224 DECL_RTL (decl_elt) = gen_rtx_MEM (mode, copy_rtx (XEXP (x, 0)));
4225 MEM_COPY_ATTRIBUTES (DECL_RTL (decl_elt), x);
4228 else if (GET_CODE (x) == REG)
4230 if (mode == GET_MODE (x))
4231 DECL_RTL (decl_elt) = x;
4233 DECL_RTL (decl_elt) = gen_rtx_SUBREG (mode, x, 0);
4238 /* Record the cleanup if there is one. */
4241 thisblock->data.block.cleanups
4242 = temp_tree_cons (decl_elt, cleanup_elt,
4243 thisblock->data.block.cleanups);
4247 /* Expand a list of cleanups LIST.
4248 Elements may be expressions or may be nested lists.
4250 If DONT_DO is nonnull, then any list-element
4251 whose TREE_PURPOSE matches DONT_DO is omitted.
4252 This is sometimes used to avoid a cleanup associated with
4253 a value that is being returned out of the scope.
4255 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
4256 goto and handle protection regions specially in that case.
4258 If REACHABLE, we emit code, otherwise just inform the exception handling
4259 code about this finalization. */
4262 expand_cleanups (list, dont_do, in_fixup, reachable)
4269 for (tail = list; tail; tail = TREE_CHAIN (tail))
4270 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
4272 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
4273 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
4278 tree cleanup = TREE_VALUE (tail);
4280 /* See expand_d{h,c}c_cleanup for why we avoid this. */
4281 if (TREE_CODE (cleanup) != POPDHC_EXPR
4282 && TREE_CODE (cleanup) != POPDCC_EXPR
4283 /* See expand_eh_region_start_tree for this case. */
4284 && ! TREE_ADDRESSABLE (tail))
4286 cleanup = protect_with_terminate (cleanup);
4287 expand_eh_region_end (cleanup);
4293 /* Cleanups may be run multiple times. For example,
4294 when exiting a binding contour, we expand the
4295 cleanups associated with that contour. When a goto
4296 within that binding contour has a target outside that
4297 contour, it will expand all cleanups from its scope to
4298 the target. Though the cleanups are expanded multiple
4299 times, the control paths are non-overlapping so the
4300 cleanups will not be executed twice. */
4302 /* We may need to protect fixups with rethrow regions. */
4303 int protect = (in_fixup && ! TREE_ADDRESSABLE (tail));
4306 expand_fixup_region_start ();
4308 /* The cleanup might contain try-blocks, so we have to
4309 preserve our current queue. */
4311 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
4314 expand_fixup_region_end (TREE_VALUE (tail));
4321 /* Mark when the context we are emitting RTL for as a conditional
4322 context, so that any cleanup actions we register with
4323 expand_decl_init will be properly conditionalized when those
4324 cleanup actions are later performed. Must be called before any
4325 expression (tree) is expanded that is within a conditional context. */
4328 start_cleanup_deferral ()
4330 /* block_stack can be NULL if we are inside the parameter list. It is
4331 OK to do nothing, because cleanups aren't possible here. */
4333 ++block_stack->data.block.conditional_code;
4336 /* Mark the end of a conditional region of code. Because cleanup
4337 deferrals may be nested, we may still be in a conditional region
4338 after we end the currently deferred cleanups, only after we end all
4339 deferred cleanups, are we back in unconditional code. */
4342 end_cleanup_deferral ()
4344 /* block_stack can be NULL if we are inside the parameter list. It is
4345 OK to do nothing, because cleanups aren't possible here. */
4347 --block_stack->data.block.conditional_code;
4350 /* Move all cleanups from the current block_stack
4351 to the containing block_stack, where they are assumed to
4352 have been created. If anything can cause a temporary to
4353 be created, but not expanded for more than one level of
4354 block_stacks, then this code will have to change. */
4359 struct nesting *block = block_stack;
4360 struct nesting *outer = block->next;
4362 outer->data.block.cleanups
4363 = chainon (block->data.block.cleanups,
4364 outer->data.block.cleanups);
4365 block->data.block.cleanups = 0;
4369 last_cleanup_this_contour ()
4371 if (block_stack == 0)
4374 return block_stack->data.block.cleanups;
4377 /* Return 1 if there are any pending cleanups at this point.
4378 If THIS_CONTOUR is nonzero, check the current contour as well.
4379 Otherwise, look only at the contours that enclose this one. */
4382 any_pending_cleanups (this_contour)
4385 struct nesting *block;
4387 if (cfun == NULL || cfun->stmt == NULL || block_stack == 0)
4390 if (this_contour && block_stack->data.block.cleanups != NULL)
4392 if (block_stack->data.block.cleanups == 0
4393 && block_stack->data.block.outer_cleanups == 0)
4396 for (block = block_stack->next; block; block = block->next)
4397 if (block->data.block.cleanups != 0)
4403 /* Enter a case (Pascal) or switch (C) statement.
4404 Push a block onto case_stack and nesting_stack
4405 to accumulate the case-labels that are seen
4406 and to record the labels generated for the statement.
4408 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4409 Otherwise, this construct is transparent for `exit_something'.
4411 EXPR is the index-expression to be dispatched on.
4412 TYPE is its nominal type. We could simply convert EXPR to this type,
4413 but instead we take short cuts. */
4416 expand_start_case (exit_flag, expr, type, printname)
4420 const char *printname;
4422 register struct nesting *thiscase = ALLOC_NESTING ();
4424 /* Make an entry on case_stack for the case we are entering. */
4426 thiscase->next = case_stack;
4427 thiscase->all = nesting_stack;
4428 thiscase->depth = ++nesting_depth;
4429 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
4430 thiscase->data.case_stmt.case_list = 0;
4431 thiscase->data.case_stmt.index_expr = expr;
4432 thiscase->data.case_stmt.nominal_type = type;
4433 thiscase->data.case_stmt.default_label = 0;
4434 thiscase->data.case_stmt.num_ranges = 0;
4435 thiscase->data.case_stmt.printname = printname;
4436 thiscase->data.case_stmt.line_number_status = force_line_numbers ();
4437 case_stack = thiscase;
4438 nesting_stack = thiscase;
4440 do_pending_stack_adjust ();
4442 /* Make sure case_stmt.start points to something that won't
4443 need any transformation before expand_end_case. */
4444 if (GET_CODE (get_last_insn ()) != NOTE)
4445 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4447 thiscase->data.case_stmt.start = get_last_insn ();
4449 start_cleanup_deferral ();
4453 /* Start a "dummy case statement" within which case labels are invalid
4454 and are not connected to any larger real case statement.
4455 This can be used if you don't want to let a case statement jump
4456 into the middle of certain kinds of constructs. */
4459 expand_start_case_dummy ()
4461 register struct nesting *thiscase = ALLOC_NESTING ();
4463 /* Make an entry on case_stack for the dummy. */
4465 thiscase->next = case_stack;
4466 thiscase->all = nesting_stack;
4467 thiscase->depth = ++nesting_depth;
4468 thiscase->exit_label = 0;
4469 thiscase->data.case_stmt.case_list = 0;
4470 thiscase->data.case_stmt.start = 0;
4471 thiscase->data.case_stmt.nominal_type = 0;
4472 thiscase->data.case_stmt.default_label = 0;
4473 thiscase->data.case_stmt.num_ranges = 0;
4474 case_stack = thiscase;
4475 nesting_stack = thiscase;
4476 start_cleanup_deferral ();
4479 /* End a dummy case statement. */
4482 expand_end_case_dummy ()
4484 end_cleanup_deferral ();
4485 POPSTACK (case_stack);
4488 /* Return the data type of the index-expression
4489 of the innermost case statement, or null if none. */
4492 case_index_expr_type ()
4495 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
4502 /* If this is the first label, warn if any insns have been emitted. */
4503 if (case_stack->data.case_stmt.line_number_status >= 0)
4507 restore_line_number_status
4508 (case_stack->data.case_stmt.line_number_status);
4509 case_stack->data.case_stmt.line_number_status = -1;
4511 for (insn = case_stack->data.case_stmt.start;
4513 insn = NEXT_INSN (insn))
4515 if (GET_CODE (insn) == CODE_LABEL)
4517 if (GET_CODE (insn) != NOTE
4518 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4521 insn = PREV_INSN (insn);
4522 while (insn && (GET_CODE (insn) != NOTE || NOTE_LINE_NUMBER (insn) < 0));
4524 /* If insn is zero, then there must have been a syntax error. */
4526 warning_with_file_and_line (NOTE_SOURCE_FILE(insn),
4527 NOTE_LINE_NUMBER(insn),
4528 "unreachable code at beginning of %s",
4529 case_stack->data.case_stmt.printname);
4536 /* Accumulate one case or default label inside a case or switch statement.
4537 VALUE is the value of the case (a null pointer, for a default label).
4538 The function CONVERTER, when applied to arguments T and V,
4539 converts the value V to the type T.
4541 If not currently inside a case or switch statement, return 1 and do
4542 nothing. The caller will print a language-specific error message.
4543 If VALUE is a duplicate or overlaps, return 2 and do nothing
4544 except store the (first) duplicate node in *DUPLICATE.
4545 If VALUE is out of range, return 3 and do nothing.
4546 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4547 Return 0 on success.
4549 Extended to handle range statements. */
4552 pushcase (value, converter, label, duplicate)
4553 register tree value;
4554 tree (*converter) PARAMS ((tree, tree));
4555 register tree label;
4561 /* Fail if not inside a real case statement. */
4562 if (! (case_stack && case_stack->data.case_stmt.start))
4565 if (stack_block_stack
4566 && stack_block_stack->depth > case_stack->depth)
4569 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4570 nominal_type = case_stack->data.case_stmt.nominal_type;
4572 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4573 if (index_type == error_mark_node)
4576 /* Convert VALUE to the type in which the comparisons are nominally done. */
4578 value = (*converter) (nominal_type, value);
4582 /* Fail if this value is out of range for the actual type of the index
4583 (which may be narrower than NOMINAL_TYPE). */
4585 && (TREE_CONSTANT_OVERFLOW (value)
4586 || ! int_fits_type_p (value, index_type)))
4589 /* Fail if this is a duplicate or overlaps another entry. */
4592 if (case_stack->data.case_stmt.default_label != 0)
4594 *duplicate = case_stack->data.case_stmt.default_label;
4597 case_stack->data.case_stmt.default_label = label;
4600 return add_case_node (value, value, label, duplicate);
4602 expand_label (label);
4606 /* Like pushcase but this case applies to all values between VALUE1 and
4607 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4608 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4609 starts at VALUE1 and ends at the highest value of the index type.
4610 If both are NULL, this case applies to all values.
4612 The return value is the same as that of pushcase but there is one
4613 additional error code: 4 means the specified range was empty. */
4616 pushcase_range (value1, value2, converter, label, duplicate)
4617 register tree value1, value2;
4618 tree (*converter) PARAMS ((tree, tree));
4619 register tree label;
4625 /* Fail if not inside a real case statement. */
4626 if (! (case_stack && case_stack->data.case_stmt.start))
4629 if (stack_block_stack
4630 && stack_block_stack->depth > case_stack->depth)
4633 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4634 nominal_type = case_stack->data.case_stmt.nominal_type;
4636 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4637 if (index_type == error_mark_node)
4642 /* Convert VALUEs to type in which the comparisons are nominally done
4643 and replace any unspecified value with the corresponding bound. */
4645 value1 = TYPE_MIN_VALUE (index_type);
4647 value2 = TYPE_MAX_VALUE (index_type);
4649 /* Fail if the range is empty. Do this before any conversion since
4650 we want to allow out-of-range empty ranges. */
4651 if (value2 != 0 && tree_int_cst_lt (value2, value1))
4654 /* If the max was unbounded, use the max of the nominal_type we are
4655 converting to. Do this after the < check above to suppress false
4658 value2 = TYPE_MAX_VALUE (nominal_type);
4660 value1 = (*converter) (nominal_type, value1);
4661 value2 = (*converter) (nominal_type, value2);
4663 /* Fail if these values are out of range. */
4664 if (TREE_CONSTANT_OVERFLOW (value1)
4665 || ! int_fits_type_p (value1, index_type))
4668 if (TREE_CONSTANT_OVERFLOW (value2)
4669 || ! int_fits_type_p (value2, index_type))
4672 return add_case_node (value1, value2, label, duplicate);
4675 /* Do the actual insertion of a case label for pushcase and pushcase_range
4676 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4677 slowdown for large switch statements. */
4680 add_case_node (low, high, label, duplicate)
4685 struct case_node *p, **q, *r;
4687 q = &case_stack->data.case_stmt.case_list;
4694 /* Keep going past elements distinctly greater than HIGH. */
4695 if (tree_int_cst_lt (high, p->low))
4698 /* or distinctly less than LOW. */
4699 else if (tree_int_cst_lt (p->high, low))
4704 /* We have an overlap; this is an error. */
4705 *duplicate = p->code_label;
4710 /* Add this label to the chain, and succeed.
4711 Copy LOW, HIGH so they are on temporary rather than momentary
4712 obstack and will thus survive till the end of the case statement. */
4714 r = (struct case_node *) oballoc (sizeof (struct case_node));
4715 r->low = copy_node (low);
4717 /* If the bounds are equal, turn this into the one-value case. */
4719 if (tree_int_cst_equal (low, high))
4723 r->high = copy_node (high);
4724 case_stack->data.case_stmt.num_ranges++;
4727 r->code_label = label;
4728 expand_label (label);
4738 struct case_node *s;
4744 if (! (b = p->balance))
4745 /* Growth propagation from left side. */
4752 if ((p->left = s = r->right))
4761 if ((r->parent = s))
4769 case_stack->data.case_stmt.case_list = r;
4772 /* r->balance == +1 */
4777 struct case_node *t = r->right;
4779 if ((p->left = s = t->right))
4783 if ((r->right = s = t->left))
4797 if ((t->parent = s))
4805 case_stack->data.case_stmt.case_list = t;
4812 /* p->balance == +1; growth of left side balances the node. */
4822 if (! (b = p->balance))
4823 /* Growth propagation from right side. */
4831 if ((p->right = s = r->left))
4839 if ((r->parent = s))
4848 case_stack->data.case_stmt.case_list = r;
4852 /* r->balance == -1 */
4856 struct case_node *t = r->left;
4858 if ((p->right = s = t->left))
4863 if ((r->left = s = t->right))
4877 if ((t->parent = s))
4886 case_stack->data.case_stmt.case_list = t;
4892 /* p->balance == -1; growth of right side balances the node. */
4906 /* Returns the number of possible values of TYPE.
4907 Returns -1 if the number is unknown, variable, or if the number does not
4908 fit in a HOST_WIDE_INT.
4909 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4910 do not increase monotonically (there may be duplicates);
4911 to 1 if the values increase monotonically, but not always by 1;
4912 otherwise sets it to 0. */
4915 all_cases_count (type, spareness)
4920 HOST_WIDE_INT count, minval, lastval;
4924 switch (TREE_CODE (type))
4931 count = 1 << BITS_PER_UNIT;
4936 if (TYPE_MAX_VALUE (type) != 0
4937 && 0 != (t = fold (build (MINUS_EXPR, type, TYPE_MAX_VALUE (type),
4938 TYPE_MIN_VALUE (type))))
4939 && 0 != (t = fold (build (PLUS_EXPR, type, t,
4940 convert (type, integer_zero_node))))
4941 && host_integerp (t, 1))
4942 count = tree_low_cst (t, 1);
4948 /* Don't waste time with enumeral types with huge values. */
4949 if (! host_integerp (TYPE_MIN_VALUE (type), 0)
4950 || TYPE_MAX_VALUE (type) == 0
4951 || ! host_integerp (TYPE_MAX_VALUE (type), 0))
4954 lastval = minval = tree_low_cst (TYPE_MIN_VALUE (type), 0);
4957 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4959 HOST_WIDE_INT thisval = tree_low_cst (TREE_VALUE (t), 0);
4961 if (*spareness == 2 || thisval < lastval)
4963 else if (thisval != minval + count)
4973 #define BITARRAY_TEST(ARRAY, INDEX) \
4974 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4975 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4976 #define BITARRAY_SET(ARRAY, INDEX) \
4977 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4978 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4980 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4981 with the case values we have seen, assuming the case expression
4983 SPARSENESS is as determined by all_cases_count.
4985 The time needed is proportional to COUNT, unless
4986 SPARSENESS is 2, in which case quadratic time is needed. */
4989 mark_seen_cases (type, cases_seen, count, sparseness)
4991 unsigned char *cases_seen;
4992 HOST_WIDE_INT count;
4995 tree next_node_to_try = NULL_TREE;
4996 HOST_WIDE_INT next_node_offset = 0;
4998 register struct case_node *n, *root = case_stack->data.case_stmt.case_list;
4999 tree val = make_node (INTEGER_CST);
5001 TREE_TYPE (val) = type;
5004 else if (sparseness == 2)
5007 unsigned HOST_WIDE_INT xlo;
5009 /* This less efficient loop is only needed to handle
5010 duplicate case values (multiple enum constants
5011 with the same value). */
5012 TREE_TYPE (val) = TREE_TYPE (root->low);
5013 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
5014 t = TREE_CHAIN (t), xlo++)
5016 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (TREE_VALUE (t));
5017 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (TREE_VALUE (t));
5021 /* Keep going past elements distinctly greater than VAL. */
5022 if (tree_int_cst_lt (val, n->low))
5025 /* or distinctly less than VAL. */
5026 else if (tree_int_cst_lt (n->high, val))
5031 /* We have found a matching range. */
5032 BITARRAY_SET (cases_seen, xlo);
5042 case_stack->data.case_stmt.case_list = root = case_tree2list (root, 0);
5044 for (n = root; n; n = n->right)
5046 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
5047 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
5048 while ( ! tree_int_cst_lt (n->high, val))
5050 /* Calculate (into xlo) the "offset" of the integer (val).
5051 The element with lowest value has offset 0, the next smallest
5052 element has offset 1, etc. */
5054 unsigned HOST_WIDE_INT xlo;
5058 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
5060 /* The TYPE_VALUES will be in increasing order, so
5061 starting searching where we last ended. */
5062 t = next_node_to_try;
5063 xlo = next_node_offset;
5069 t = TYPE_VALUES (type);
5072 if (tree_int_cst_equal (val, TREE_VALUE (t)))
5074 next_node_to_try = TREE_CHAIN (t);
5075 next_node_offset = xlo + 1;
5080 if (t == next_node_to_try)
5089 t = TYPE_MIN_VALUE (type);
5091 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
5095 add_double (xlo, xhi,
5096 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5100 if (xhi == 0 && xlo < (unsigned HOST_WIDE_INT) count)
5101 BITARRAY_SET (cases_seen, xlo);
5103 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5105 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
5111 /* Called when the index of a switch statement is an enumerated type
5112 and there is no default label.
5114 Checks that all enumeration literals are covered by the case
5115 expressions of a switch. Also, warn if there are any extra
5116 switch cases that are *not* elements of the enumerated type.
5118 If all enumeration literals were covered by the case expressions,
5119 turn one of the expressions into the default expression since it should
5120 not be possible to fall through such a switch. */
5123 check_for_full_enumeration_handling (type)
5126 register struct case_node *n;
5127 register tree chain;
5128 #if 0 /* variable used by 'if 0'ed code below. */
5129 register struct case_node **l;
5133 /* True iff the selector type is a numbered set mode. */
5136 /* The number of possible selector values. */
5139 /* For each possible selector value. a one iff it has been matched
5140 by a case value alternative. */
5141 unsigned char *cases_seen;
5143 /* The allocated size of cases_seen, in chars. */
5144 HOST_WIDE_INT bytes_needed;
5149 size = all_cases_count (type, &sparseness);
5150 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
5152 if (size > 0 && size < 600000
5153 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5154 this optimization if we don't have enough memory rather than
5155 aborting, as xmalloc would do. */
5156 && (cases_seen = (unsigned char *) calloc (bytes_needed, 1)) != NULL)
5159 tree v = TYPE_VALUES (type);
5161 /* The time complexity of this code is normally O(N), where
5162 N being the number of members in the enumerated type.
5163 However, if type is a ENUMERAL_TYPE whose values do not
5164 increase monotonically, O(N*log(N)) time may be needed. */
5166 mark_seen_cases (type, cases_seen, size, sparseness);
5168 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
5169 if (BITARRAY_TEST(cases_seen, i) == 0)
5170 warning ("enumeration value `%s' not handled in switch",
5171 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
5176 /* Now we go the other way around; we warn if there are case
5177 expressions that don't correspond to enumerators. This can
5178 occur since C and C++ don't enforce type-checking of
5179 assignments to enumeration variables. */
5181 if (case_stack->data.case_stmt.case_list
5182 && case_stack->data.case_stmt.case_list->left)
5183 case_stack->data.case_stmt.case_list
5184 = case_tree2list (case_stack->data.case_stmt.case_list, 0);
5186 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
5188 for (chain = TYPE_VALUES (type);
5189 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
5190 chain = TREE_CHAIN (chain))
5195 if (TYPE_NAME (type) == 0)
5196 warning ("case value `%ld' not in enumerated type",
5197 (long) TREE_INT_CST_LOW (n->low));
5199 warning ("case value `%ld' not in enumerated type `%s'",
5200 (long) TREE_INT_CST_LOW (n->low),
5201 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5204 : DECL_NAME (TYPE_NAME (type))));
5206 if (!tree_int_cst_equal (n->low, n->high))
5208 for (chain = TYPE_VALUES (type);
5209 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
5210 chain = TREE_CHAIN (chain))
5215 if (TYPE_NAME (type) == 0)
5216 warning ("case value `%ld' not in enumerated type",
5217 (long) TREE_INT_CST_LOW (n->high));
5219 warning ("case value `%ld' not in enumerated type `%s'",
5220 (long) TREE_INT_CST_LOW (n->high),
5221 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5224 : DECL_NAME (TYPE_NAME (type))));
5230 /* ??? This optimization is disabled because it causes valid programs to
5231 fail. ANSI C does not guarantee that an expression with enum type
5232 will have a value that is the same as one of the enumeration literals. */
5234 /* If all values were found as case labels, make one of them the default
5235 label. Thus, this switch will never fall through. We arbitrarily pick
5236 the last one to make the default since this is likely the most
5237 efficient choice. */
5241 for (l = &case_stack->data.case_stmt.case_list;
5246 case_stack->data.case_stmt.default_label = (*l)->code_label;
5253 /* Terminate a case (Pascal) or switch (C) statement
5254 in which ORIG_INDEX is the expression to be tested.
5255 Generate the code to test it and jump to the right place. */
5258 expand_end_case (orig_index)
5261 tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE, orig_minval;
5262 rtx default_label = 0;
5263 register struct case_node *n;
5271 register struct nesting *thiscase = case_stack;
5272 tree index_expr, index_type;
5275 /* Don't crash due to previous errors. */
5276 if (thiscase == NULL)
5279 table_label = gen_label_rtx ();
5280 index_expr = thiscase->data.case_stmt.index_expr;
5281 index_type = TREE_TYPE (index_expr);
5282 unsignedp = TREE_UNSIGNED (index_type);
5284 do_pending_stack_adjust ();
5286 /* This might get an spurious warning in the presence of a syntax error;
5287 it could be fixed by moving the call to check_seenlabel after the
5288 check for error_mark_node, and copying the code of check_seenlabel that
5289 deals with case_stack->data.case_stmt.line_number_status /
5290 restore_line_number_status in front of the call to end_cleanup_deferral;
5291 However, this might miss some useful warnings in the presence of
5292 non-syntax errors. */
5295 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5296 if (index_type != error_mark_node)
5298 /* If switch expression was an enumerated type, check that all
5299 enumeration literals are covered by the cases.
5300 No sense trying this if there's a default case, however. */
5302 if (!thiscase->data.case_stmt.default_label
5303 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
5304 && TREE_CODE (index_expr) != INTEGER_CST)
5305 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
5307 /* If we don't have a default-label, create one here,
5308 after the body of the switch. */
5309 if (thiscase->data.case_stmt.default_label == 0)
5311 thiscase->data.case_stmt.default_label
5312 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5313 expand_label (thiscase->data.case_stmt.default_label);
5315 default_label = label_rtx (thiscase->data.case_stmt.default_label);
5317 before_case = get_last_insn ();
5319 if (thiscase->data.case_stmt.case_list
5320 && thiscase->data.case_stmt.case_list->left)
5321 thiscase->data.case_stmt.case_list
5322 = case_tree2list(thiscase->data.case_stmt.case_list, 0);
5324 /* Simplify the case-list before we count it. */
5325 group_case_nodes (thiscase->data.case_stmt.case_list);
5327 /* Get upper and lower bounds of case values.
5328 Also convert all the case values to the index expr's data type. */
5331 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5333 /* Check low and high label values are integers. */
5334 if (TREE_CODE (n->low) != INTEGER_CST)
5336 if (TREE_CODE (n->high) != INTEGER_CST)
5339 n->low = convert (index_type, n->low);
5340 n->high = convert (index_type, n->high);
5342 /* Count the elements and track the largest and smallest
5343 of them (treating them as signed even if they are not). */
5351 if (INT_CST_LT (n->low, minval))
5353 if (INT_CST_LT (maxval, n->high))
5356 /* A range counts double, since it requires two compares. */
5357 if (! tree_int_cst_equal (n->low, n->high))
5361 orig_minval = minval;
5363 /* Compute span of values. */
5365 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
5367 end_cleanup_deferral ();
5371 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
5373 emit_jump (default_label);
5376 /* If range of values is much bigger than number of values,
5377 make a sequence of conditional branches instead of a dispatch.
5378 If the switch-index is a constant, do it this way
5379 because we can optimize it. */
5381 #ifndef CASE_VALUES_THRESHOLD
5383 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
5385 /* If machine does not have a case insn that compares the
5386 bounds, this means extra overhead for dispatch tables
5387 which raises the threshold for using them. */
5388 #define CASE_VALUES_THRESHOLD 5
5389 #endif /* HAVE_casesi */
5390 #endif /* CASE_VALUES_THRESHOLD */
5392 else if (count < CASE_VALUES_THRESHOLD
5393 || compare_tree_int (range, 10 * count) > 0
5394 /* RANGE may be signed, and really large ranges will show up
5395 as negative numbers. */
5396 || compare_tree_int (range, 0) < 0
5397 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5400 || TREE_CODE (index_expr) == INTEGER_CST
5401 /* These will reduce to a constant. */
5402 || (TREE_CODE (index_expr) == CALL_EXPR
5403 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
5404 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
5405 && DECL_BUILT_IN_CLASS (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_NORMAL
5406 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
5407 || (TREE_CODE (index_expr) == COMPOUND_EXPR
5408 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
5410 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5412 /* If the index is a short or char that we do not have
5413 an insn to handle comparisons directly, convert it to
5414 a full integer now, rather than letting each comparison
5415 generate the conversion. */
5417 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
5418 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
5419 == CODE_FOR_nothing))
5421 enum machine_mode wider_mode;
5422 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
5423 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
5424 if (cmp_optab->handlers[(int) wider_mode].insn_code
5425 != CODE_FOR_nothing)
5427 index = convert_to_mode (wider_mode, index, unsignedp);
5433 do_pending_stack_adjust ();
5435 index = protect_from_queue (index, 0);
5436 if (GET_CODE (index) == MEM)
5437 index = copy_to_reg (index);
5438 if (GET_CODE (index) == CONST_INT
5439 || TREE_CODE (index_expr) == INTEGER_CST)
5441 /* Make a tree node with the proper constant value
5442 if we don't already have one. */
5443 if (TREE_CODE (index_expr) != INTEGER_CST)
5446 = build_int_2 (INTVAL (index),
5447 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
5448 index_expr = convert (index_type, index_expr);
5451 /* For constant index expressions we need only
5452 issue a unconditional branch to the appropriate
5453 target code. The job of removing any unreachable
5454 code is left to the optimisation phase if the
5455 "-O" option is specified. */
5456 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5457 if (! tree_int_cst_lt (index_expr, n->low)
5458 && ! tree_int_cst_lt (n->high, index_expr))
5462 emit_jump (label_rtx (n->code_label));
5464 emit_jump (default_label);
5468 /* If the index expression is not constant we generate
5469 a binary decision tree to select the appropriate
5470 target code. This is done as follows:
5472 The list of cases is rearranged into a binary tree,
5473 nearly optimal assuming equal probability for each case.
5475 The tree is transformed into RTL, eliminating
5476 redundant test conditions at the same time.
5478 If program flow could reach the end of the
5479 decision tree an unconditional jump to the
5480 default code is emitted. */
5483 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
5484 && estimate_case_costs (thiscase->data.case_stmt.case_list));
5485 balance_case_nodes (&thiscase->data.case_stmt.case_list,
5487 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
5488 default_label, index_type);
5489 emit_jump_if_reachable (default_label);
5498 enum machine_mode index_mode = SImode;
5499 int index_bits = GET_MODE_BITSIZE (index_mode);
5501 enum machine_mode op_mode;
5503 /* Convert the index to SImode. */
5504 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
5505 > GET_MODE_BITSIZE (index_mode))
5507 enum machine_mode omode = TYPE_MODE (index_type);
5508 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
5510 /* We must handle the endpoints in the original mode. */
5511 index_expr = build (MINUS_EXPR, index_type,
5512 index_expr, minval);
5513 minval = integer_zero_node;
5514 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5515 emit_cmp_and_jump_insns (rangertx, index, LTU, NULL_RTX,
5516 omode, 1, 0, default_label);
5517 /* Now we can safely truncate. */
5518 index = convert_to_mode (index_mode, index, 0);
5522 if (TYPE_MODE (index_type) != index_mode)
5524 index_expr = convert (type_for_size (index_bits, 0),
5526 index_type = TREE_TYPE (index_expr);
5529 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5532 index = protect_from_queue (index, 0);
5533 do_pending_stack_adjust ();
5535 op_mode = insn_data[(int)CODE_FOR_casesi].operand[0].mode;
5536 if (! (*insn_data[(int)CODE_FOR_casesi].operand[0].predicate)
5538 index = copy_to_mode_reg (op_mode, index);
5540 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
5542 op_mode = insn_data[(int)CODE_FOR_casesi].operand[1].mode;
5543 if (! (*insn_data[(int)CODE_FOR_casesi].operand[1].predicate)
5545 op1 = copy_to_mode_reg (op_mode, op1);
5547 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
5549 op_mode = insn_data[(int)CODE_FOR_casesi].operand[2].mode;
5550 if (! (*insn_data[(int)CODE_FOR_casesi].operand[2].predicate)
5552 op2 = copy_to_mode_reg (op_mode, op2);
5554 emit_jump_insn (gen_casesi (index, op1, op2,
5555 table_label, default_label));
5559 #ifdef HAVE_tablejump
5560 if (! win && HAVE_tablejump)
5562 index_type = thiscase->data.case_stmt.nominal_type;
5563 index_expr = fold (build (MINUS_EXPR, index_type,
5564 convert (index_type, index_expr),
5565 convert (index_type, minval)));
5566 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5568 index = protect_from_queue (index, 0);
5569 do_pending_stack_adjust ();
5571 do_tablejump (index, TYPE_MODE (index_type),
5572 expand_expr (range, NULL_RTX, VOIDmode, 0),
5573 table_label, default_label);
5580 /* Get table of labels to jump to, in order of case index. */
5582 ncases = TREE_INT_CST_LOW (range) + 1;
5583 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
5584 bzero ((char *) labelvec, ncases * sizeof (rtx));
5586 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5588 register HOST_WIDE_INT i
5589 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
5594 = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
5595 if (i + TREE_INT_CST_LOW (orig_minval)
5596 == TREE_INT_CST_LOW (n->high))
5602 /* Fill in the gaps with the default. */
5603 for (i = 0; i < ncases; i++)
5604 if (labelvec[i] == 0)
5605 labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
5607 /* Output the table */
5608 emit_label (table_label);
5610 if (CASE_VECTOR_PC_RELATIVE || flag_pic)
5611 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
5612 gen_rtx_LABEL_REF (Pmode, table_label),
5613 gen_rtvec_v (ncases, labelvec),
5614 const0_rtx, const0_rtx));
5616 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
5617 gen_rtvec_v (ncases, labelvec)));
5619 /* If the case insn drops through the table,
5620 after the table we must jump to the default-label.
5621 Otherwise record no drop-through after the table. */
5622 #ifdef CASE_DROPS_THROUGH
5623 emit_jump (default_label);
5629 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
5630 reorder_insns (before_case, get_last_insn (),
5631 thiscase->data.case_stmt.start);
5634 end_cleanup_deferral ();
5636 if (thiscase->exit_label)
5637 emit_label (thiscase->exit_label);
5639 POPSTACK (case_stack);
5644 /* Convert the tree NODE into a list linked by the right field, with the left
5645 field zeroed. RIGHT is used for recursion; it is a list to be placed
5646 rightmost in the resulting list. */
5648 static struct case_node *
5649 case_tree2list (node, right)
5650 struct case_node *node, *right;
5652 struct case_node *left;
5655 right = case_tree2list (node->right, right);
5657 node->right = right;
5658 if ((left = node->left))
5661 return case_tree2list (left, node);
5667 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5670 do_jump_if_equal (op1, op2, label, unsignedp)
5671 rtx op1, op2, label;
5674 if (GET_CODE (op1) == CONST_INT
5675 && GET_CODE (op2) == CONST_INT)
5677 if (INTVAL (op1) == INTVAL (op2))
5682 enum machine_mode mode = GET_MODE (op1);
5683 if (mode == VOIDmode)
5684 mode = GET_MODE (op2);
5685 emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX, mode, unsignedp,
5690 /* Not all case values are encountered equally. This function
5691 uses a heuristic to weight case labels, in cases where that
5692 looks like a reasonable thing to do.
5694 Right now, all we try to guess is text, and we establish the
5697 chars above space: 16
5706 If we find any cases in the switch that are not either -1 or in the range
5707 of valid ASCII characters, or are control characters other than those
5708 commonly used with "\", don't treat this switch scanning text.
5710 Return 1 if these nodes are suitable for cost estimation, otherwise
5714 estimate_case_costs (node)
5717 tree min_ascii = build_int_2 (-1, -1);
5718 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5722 /* If we haven't already made the cost table, make it now. Note that the
5723 lower bound of the table is -1, not zero. */
5725 if (cost_table == NULL)
5727 cost_table = cost_table_ + 1;
5729 for (i = 0; i < 128; i++)
5733 else if (ISPUNCT (i))
5735 else if (ISCNTRL (i))
5739 cost_table[' '] = 8;
5740 cost_table['\t'] = 4;
5741 cost_table['\0'] = 4;
5742 cost_table['\n'] = 2;
5743 cost_table['\f'] = 1;
5744 cost_table['\v'] = 1;
5745 cost_table['\b'] = 1;
5748 /* See if all the case expressions look like text. It is text if the
5749 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5750 as signed arithmetic since we don't want to ever access cost_table with a
5751 value less than -1. Also check that none of the constants in a range
5752 are strange control characters. */
5754 for (n = node; n; n = n->right)
5756 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5759 for (i = (HOST_WIDE_INT) TREE_INT_CST_LOW (n->low);
5760 i <= (HOST_WIDE_INT) TREE_INT_CST_LOW (n->high); i++)
5761 if (cost_table[i] < 0)
5765 /* All interesting values are within the range of interesting
5766 ASCII characters. */
5770 /* Scan an ordered list of case nodes
5771 combining those with consecutive values or ranges.
5773 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5776 group_case_nodes (head)
5779 case_node_ptr node = head;
5783 rtx lb = next_real_insn (label_rtx (node->code_label));
5785 case_node_ptr np = node;
5787 /* Try to group the successors of NODE with NODE. */
5788 while (((np = np->right) != 0)
5789 /* Do they jump to the same place? */
5790 && ((lb2 = next_real_insn (label_rtx (np->code_label))) == lb
5791 || (lb != 0 && lb2 != 0
5792 && simplejump_p (lb)
5793 && simplejump_p (lb2)
5794 && rtx_equal_p (SET_SRC (PATTERN (lb)),
5795 SET_SRC (PATTERN (lb2)))))
5796 /* Are their ranges consecutive? */
5797 && tree_int_cst_equal (np->low,
5798 fold (build (PLUS_EXPR,
5799 TREE_TYPE (node->high),
5802 /* An overflow is not consecutive. */
5803 && tree_int_cst_lt (node->high,
5804 fold (build (PLUS_EXPR,
5805 TREE_TYPE (node->high),
5807 integer_one_node))))
5809 node->high = np->high;
5811 /* NP is the first node after NODE which can't be grouped with it.
5812 Delete the nodes in between, and move on to that node. */
5818 /* Take an ordered list of case nodes
5819 and transform them into a near optimal binary tree,
5820 on the assumption that any target code selection value is as
5821 likely as any other.
5823 The transformation is performed by splitting the ordered
5824 list into two equal sections plus a pivot. The parts are
5825 then attached to the pivot as left and right branches. Each
5826 branch is then transformed recursively. */
5829 balance_case_nodes (head, parent)
5830 case_node_ptr *head;
5831 case_node_ptr parent;
5833 register case_node_ptr np;
5841 register case_node_ptr *npp;
5844 /* Count the number of entries on branch. Also count the ranges. */
5848 if (!tree_int_cst_equal (np->low, np->high))
5852 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5856 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5864 /* Split this list if it is long enough for that to help. */
5869 /* Find the place in the list that bisects the list's total cost,
5870 Here I gets half the total cost. */
5875 /* Skip nodes while their cost does not reach that amount. */
5876 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5877 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5878 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5881 npp = &(*npp)->right;
5886 /* Leave this branch lopsided, but optimize left-hand
5887 side and fill in `parent' fields for right-hand side. */
5889 np->parent = parent;
5890 balance_case_nodes (&np->left, np);
5891 for (; np->right; np = np->right)
5892 np->right->parent = np;
5896 /* If there are just three nodes, split at the middle one. */
5898 npp = &(*npp)->right;
5901 /* Find the place in the list that bisects the list's total cost,
5902 where ranges count as 2.
5903 Here I gets half the total cost. */
5904 i = (i + ranges + 1) / 2;
5907 /* Skip nodes while their cost does not reach that amount. */
5908 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5913 npp = &(*npp)->right;
5918 np->parent = parent;
5921 /* Optimize each of the two split parts. */
5922 balance_case_nodes (&np->left, np);
5923 balance_case_nodes (&np->right, np);
5927 /* Else leave this branch as one level,
5928 but fill in `parent' fields. */
5930 np->parent = parent;
5931 for (; np->right; np = np->right)
5932 np->right->parent = np;
5937 /* Search the parent sections of the case node tree
5938 to see if a test for the lower bound of NODE would be redundant.
5939 INDEX_TYPE is the type of the index expression.
5941 The instructions to generate the case decision tree are
5942 output in the same order as nodes are processed so it is
5943 known that if a parent node checks the range of the current
5944 node minus one that the current node is bounded at its lower
5945 span. Thus the test would be redundant. */
5948 node_has_low_bound (node, index_type)
5953 case_node_ptr pnode;
5955 /* If the lower bound of this node is the lowest value in the index type,
5956 we need not test it. */
5958 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5961 /* If this node has a left branch, the value at the left must be less
5962 than that at this node, so it cannot be bounded at the bottom and
5963 we need not bother testing any further. */
5968 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5969 node->low, integer_one_node));
5971 /* If the subtraction above overflowed, we can't verify anything.
5972 Otherwise, look for a parent that tests our value - 1. */
5974 if (! tree_int_cst_lt (low_minus_one, node->low))
5977 for (pnode = node->parent; pnode; pnode = pnode->parent)
5978 if (tree_int_cst_equal (low_minus_one, pnode->high))
5984 /* Search the parent sections of the case node tree
5985 to see if a test for the upper bound of NODE would be redundant.
5986 INDEX_TYPE is the type of the index expression.
5988 The instructions to generate the case decision tree are
5989 output in the same order as nodes are processed so it is
5990 known that if a parent node checks the range of the current
5991 node plus one that the current node is bounded at its upper
5992 span. Thus the test would be redundant. */
5995 node_has_high_bound (node, index_type)
6000 case_node_ptr pnode;
6002 /* If there is no upper bound, obviously no test is needed. */
6004 if (TYPE_MAX_VALUE (index_type) == NULL)
6007 /* If the upper bound of this node is the highest value in the type
6008 of the index expression, we need not test against it. */
6010 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
6013 /* If this node has a right branch, the value at the right must be greater
6014 than that at this node, so it cannot be bounded at the top and
6015 we need not bother testing any further. */
6020 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
6021 node->high, integer_one_node));
6023 /* If the addition above overflowed, we can't verify anything.
6024 Otherwise, look for a parent that tests our value + 1. */
6026 if (! tree_int_cst_lt (node->high, high_plus_one))
6029 for (pnode = node->parent; pnode; pnode = pnode->parent)
6030 if (tree_int_cst_equal (high_plus_one, pnode->low))
6036 /* Search the parent sections of the
6037 case node tree to see if both tests for the upper and lower
6038 bounds of NODE would be redundant. */
6041 node_is_bounded (node, index_type)
6045 return (node_has_low_bound (node, index_type)
6046 && node_has_high_bound (node, index_type));
6049 /* Emit an unconditional jump to LABEL unless it would be dead code. */
6052 emit_jump_if_reachable (label)
6055 if (GET_CODE (get_last_insn ()) != BARRIER)
6059 /* Emit step-by-step code to select a case for the value of INDEX.
6060 The thus generated decision tree follows the form of the
6061 case-node binary tree NODE, whose nodes represent test conditions.
6062 INDEX_TYPE is the type of the index of the switch.
6064 Care is taken to prune redundant tests from the decision tree
6065 by detecting any boundary conditions already checked by
6066 emitted rtx. (See node_has_high_bound, node_has_low_bound
6067 and node_is_bounded, above.)
6069 Where the test conditions can be shown to be redundant we emit
6070 an unconditional jump to the target code. As a further
6071 optimization, the subordinates of a tree node are examined to
6072 check for bounded nodes. In this case conditional and/or
6073 unconditional jumps as a result of the boundary check for the
6074 current node are arranged to target the subordinates associated
6075 code for out of bound conditions on the current node.
6077 We can assume that when control reaches the code generated here,
6078 the index value has already been compared with the parents
6079 of this node, and determined to be on the same side of each parent
6080 as this node is. Thus, if this node tests for the value 51,
6081 and a parent tested for 52, we don't need to consider
6082 the possibility of a value greater than 51. If another parent
6083 tests for the value 50, then this node need not test anything. */
6086 emit_case_nodes (index, node, default_label, index_type)
6092 /* If INDEX has an unsigned type, we must make unsigned branches. */
6093 int unsignedp = TREE_UNSIGNED (index_type);
6094 enum machine_mode mode = GET_MODE (index);
6096 /* See if our parents have already tested everything for us.
6097 If they have, emit an unconditional jump for this node. */
6098 if (node_is_bounded (node, index_type))
6099 emit_jump (label_rtx (node->code_label));
6101 else if (tree_int_cst_equal (node->low, node->high))
6103 /* Node is single valued. First see if the index expression matches
6104 this node and then check our children, if any. */
6106 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
6107 label_rtx (node->code_label), unsignedp);
6109 if (node->right != 0 && node->left != 0)
6111 /* This node has children on both sides.
6112 Dispatch to one side or the other
6113 by comparing the index value with this node's value.
6114 If one subtree is bounded, check that one first,
6115 so we can avoid real branches in the tree. */
6117 if (node_is_bounded (node->right, index_type))
6119 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6121 GT, NULL_RTX, mode, unsignedp, 0,
6122 label_rtx (node->right->code_label));
6123 emit_case_nodes (index, node->left, default_label, index_type);
6126 else if (node_is_bounded (node->left, index_type))
6128 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6130 LT, NULL_RTX, mode, unsignedp, 0,
6131 label_rtx (node->left->code_label));
6132 emit_case_nodes (index, node->right, default_label, index_type);
6137 /* Neither node is bounded. First distinguish the two sides;
6138 then emit the code for one side at a time. */
6141 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6143 /* See if the value is on the right. */
6144 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6146 GT, NULL_RTX, mode, unsignedp, 0,
6147 label_rtx (test_label));
6149 /* Value must be on the left.
6150 Handle the left-hand subtree. */
6151 emit_case_nodes (index, node->left, default_label, index_type);
6152 /* If left-hand subtree does nothing,
6154 emit_jump_if_reachable (default_label);
6156 /* Code branches here for the right-hand subtree. */
6157 expand_label (test_label);
6158 emit_case_nodes (index, node->right, default_label, index_type);
6162 else if (node->right != 0 && node->left == 0)
6164 /* Here we have a right child but no left so we issue conditional
6165 branch to default and process the right child.
6167 Omit the conditional branch to default if we it avoid only one
6168 right child; it costs too much space to save so little time. */
6170 if (node->right->right || node->right->left
6171 || !tree_int_cst_equal (node->right->low, node->right->high))
6173 if (!node_has_low_bound (node, index_type))
6175 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6178 LT, NULL_RTX, mode, unsignedp, 0,
6182 emit_case_nodes (index, node->right, default_label, index_type);
6185 /* We cannot process node->right normally
6186 since we haven't ruled out the numbers less than
6187 this node's value. So handle node->right explicitly. */
6188 do_jump_if_equal (index,
6189 expand_expr (node->right->low, NULL_RTX,
6191 label_rtx (node->right->code_label), unsignedp);
6194 else if (node->right == 0 && node->left != 0)
6196 /* Just one subtree, on the left. */
6198 #if 0 /* The following code and comment were formerly part
6199 of the condition here, but they didn't work
6200 and I don't understand what the idea was. -- rms. */
6201 /* If our "most probable entry" is less probable
6202 than the default label, emit a jump to
6203 the default label using condition codes
6204 already lying around. With no right branch,
6205 a branch-greater-than will get us to the default
6208 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
6211 if (node->left->left || node->left->right
6212 || !tree_int_cst_equal (node->left->low, node->left->high))
6214 if (!node_has_high_bound (node, index_type))
6216 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6219 GT, NULL_RTX, mode, unsignedp, 0,
6223 emit_case_nodes (index, node->left, default_label, index_type);
6226 /* We cannot process node->left normally
6227 since we haven't ruled out the numbers less than
6228 this node's value. So handle node->left explicitly. */
6229 do_jump_if_equal (index,
6230 expand_expr (node->left->low, NULL_RTX,
6232 label_rtx (node->left->code_label), unsignedp);
6237 /* Node is a range. These cases are very similar to those for a single
6238 value, except that we do not start by testing whether this node
6239 is the one to branch to. */
6241 if (node->right != 0 && node->left != 0)
6243 /* Node has subtrees on both sides.
6244 If the right-hand subtree is bounded,
6245 test for it first, since we can go straight there.
6246 Otherwise, we need to make a branch in the control structure,
6247 then handle the two subtrees. */
6248 tree test_label = 0;
6251 if (node_is_bounded (node->right, index_type))
6252 /* Right hand node is fully bounded so we can eliminate any
6253 testing and branch directly to the target code. */
6254 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6256 GT, NULL_RTX, mode, unsignedp, 0,
6257 label_rtx (node->right->code_label));
6260 /* Right hand node requires testing.
6261 Branch to a label where we will handle it later. */
6263 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6264 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6266 GT, NULL_RTX, mode, unsignedp, 0,
6267 label_rtx (test_label));
6270 /* Value belongs to this node or to the left-hand subtree. */
6272 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6274 GE, NULL_RTX, mode, unsignedp, 0,
6275 label_rtx (node->code_label));
6277 /* Handle the left-hand subtree. */
6278 emit_case_nodes (index, node->left, default_label, index_type);
6280 /* If right node had to be handled later, do that now. */
6284 /* If the left-hand subtree fell through,
6285 don't let it fall into the right-hand subtree. */
6286 emit_jump_if_reachable (default_label);
6288 expand_label (test_label);
6289 emit_case_nodes (index, node->right, default_label, index_type);
6293 else if (node->right != 0 && node->left == 0)
6295 /* Deal with values to the left of this node,
6296 if they are possible. */
6297 if (!node_has_low_bound (node, index_type))
6299 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6301 LT, NULL_RTX, mode, unsignedp, 0,
6305 /* Value belongs to this node or to the right-hand subtree. */
6307 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6309 LE, NULL_RTX, mode, unsignedp, 0,
6310 label_rtx (node->code_label));
6312 emit_case_nodes (index, node->right, default_label, index_type);
6315 else if (node->right == 0 && node->left != 0)
6317 /* Deal with values to the right of this node,
6318 if they are possible. */
6319 if (!node_has_high_bound (node, index_type))
6321 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6323 GT, NULL_RTX, mode, unsignedp, 0,
6327 /* Value belongs to this node or to the left-hand subtree. */
6329 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6331 GE, NULL_RTX, mode, unsignedp, 0,
6332 label_rtx (node->code_label));
6334 emit_case_nodes (index, node->left, default_label, index_type);
6339 /* Node has no children so we check low and high bounds to remove
6340 redundant tests. Only one of the bounds can exist,
6341 since otherwise this node is bounded--a case tested already. */
6343 if (!node_has_high_bound (node, index_type))
6345 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6347 GT, NULL_RTX, mode, unsignedp, 0,
6351 if (!node_has_low_bound (node, index_type))
6353 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6355 LT, NULL_RTX, mode, unsignedp, 0,
6359 emit_jump (label_rtx (node->code_label));