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. */
22 /* This file handles the generation of rtl code from tree structure
23 above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
24 It also creates the rtl expressions for parameters and auto variables
25 and has full responsibility for allocating stack slots.
27 The functions whose names start with `expand_' are called by the
28 parser to generate RTL instructions for various kinds of constructs.
30 Some control and binding constructs require calling several such
31 functions at different times. For example, a simple if-then
32 is expanded by calling `expand_start_cond' (with the condition-expression
33 as argument) before parsing the then-clause and calling `expand_end_cond'
34 after parsing the then-clause. */
45 #include "insn-flags.h"
46 #include "insn-config.h"
47 #include "insn-codes.h"
49 #include "hard-reg-set.h"
58 #define obstack_chunk_alloc xmalloc
59 #define obstack_chunk_free free
60 struct obstack stmt_obstack;
62 /* Assume that case vectors are not pc-relative. */
63 #ifndef CASE_VECTOR_PC_RELATIVE
64 #define CASE_VECTOR_PC_RELATIVE 0
67 /* Functions and data structures for expanding case statements. */
69 /* Case label structure, used to hold info on labels within case
70 statements. We handle "range" labels; for a single-value label
71 as in C, the high and low limits are the same.
73 An AVL tree of case nodes is initially created, and later transformed
74 to a list linked via the RIGHT fields in the nodes. Nodes with
75 higher case values are later in the list.
77 Switch statements can be output in one of two forms. A branch table
78 is used if there are more than a few labels and the labels are dense
79 within the range between the smallest and largest case value. If a
80 branch table is used, no further manipulations are done with the case
83 The alternative to the use of a branch table is to generate a series
84 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
85 and PARENT fields to hold a binary tree. Initially the tree is
86 totally unbalanced, with everything on the right. We balance the tree
87 with nodes on the left having lower case values than the parent
88 and nodes on the right having higher values. We then output the tree
93 struct case_node *left; /* Left son in binary tree */
94 struct case_node *right; /* Right son in binary tree; also node chain */
95 struct case_node *parent; /* Parent of node in binary tree */
96 tree low; /* Lowest index value for this label */
97 tree high; /* Highest index value for this label */
98 tree code_label; /* Label to jump to when node matches */
102 typedef struct case_node case_node;
103 typedef struct case_node *case_node_ptr;
105 /* These are used by estimate_case_costs and balance_case_nodes. */
107 /* This must be a signed type, and non-ANSI compilers lack signed char. */
108 static short cost_table_[129];
109 static short *cost_table;
110 static int use_cost_table;
112 /* Stack of control and binding constructs we are currently inside.
114 These constructs begin when you call `expand_start_WHATEVER'
115 and end when you call `expand_end_WHATEVER'. This stack records
116 info about how the construct began that tells the end-function
117 what to do. It also may provide information about the construct
118 to alter the behavior of other constructs within the body.
119 For example, they may affect the behavior of C `break' and `continue'.
121 Each construct gets one `struct nesting' object.
122 All of these objects are chained through the `all' field.
123 `nesting_stack' points to the first object (innermost construct).
124 The position of an entry on `nesting_stack' is in its `depth' field.
126 Each type of construct has its own individual stack.
127 For example, loops have `loop_stack'. Each object points to the
128 next object of the same type through the `next' field.
130 Some constructs are visible to `break' exit-statements and others
131 are not. Which constructs are visible depends on the language.
132 Therefore, the data structure allows each construct to be visible
133 or not, according to the args given when the construct is started.
134 The construct is visible if the `exit_label' field is non-null.
135 In that case, the value should be a CODE_LABEL rtx. */
140 struct nesting *next;
145 /* For conds (if-then and if-then-else statements). */
148 /* Label for the end of the if construct.
149 There is none if EXITFLAG was not set
150 and no `else' has been seen yet. */
152 /* Label for the end of this alternative.
153 This may be the end of the if or the next else/elseif. */
159 /* Label at the top of the loop; place to loop back to. */
161 /* Label at the end of the whole construct. */
163 /* Label before a jump that branches to the end of the whole
164 construct. This is where destructors go if any. */
166 /* Label for `continue' statement to jump to;
167 this is in front of the stepper of the loop. */
170 /* For variable binding contours. */
173 /* Sequence number of this binding contour within the function,
174 in order of entry. */
175 int block_start_count;
176 /* Nonzero => value to restore stack to on exit. */
178 /* The NOTE that starts this contour.
179 Used by expand_goto to check whether the destination
180 is within each contour or not. */
182 /* Innermost containing binding contour that has a stack level. */
183 struct nesting *innermost_stack_block;
184 /* List of cleanups to be run on exit from this contour.
185 This is a list of expressions to be evaluated.
186 The TREE_PURPOSE of each link is the ..._DECL node
187 which the cleanup pertains to. */
189 /* List of cleanup-lists of blocks containing this block,
190 as they were at the locus where this block appears.
191 There is an element for each containing block,
192 ordered innermost containing block first.
193 The tail of this list can be 0,
194 if all remaining elements would be empty lists.
195 The element's TREE_VALUE is the cleanup-list of that block,
196 which may be null. */
198 /* Chain of labels defined inside this binding contour.
199 For contours that have stack levels or cleanups. */
200 struct label_chain *label_chain;
201 /* Number of function calls seen, as of start of this block. */
202 int n_function_calls;
203 /* Nonzero if this is associated with a EH region. */
204 int exception_region;
205 /* The saved target_temp_slot_level from our outer block.
206 We may reset target_temp_slot_level to be the level of
207 this block, if that is done, target_temp_slot_level
208 reverts to the saved target_temp_slot_level at the very
210 int block_target_temp_slot_level;
211 /* True if we are currently emitting insns in an area of
212 output code that is controlled by a conditional
213 expression. This is used by the cleanup handling code to
214 generate conditional cleanup actions. */
215 int conditional_code;
216 /* A place to move the start of the exception region for any
217 of the conditional cleanups, must be at the end or after
218 the start of the last unconditional cleanup, and before any
219 conditional branch points. */
220 rtx last_unconditional_cleanup;
221 /* When in a conditional context, this is the specific
222 cleanup list associated with last_unconditional_cleanup,
223 where we place the conditionalized cleanups. */
226 /* For switch (C) or case (Pascal) statements,
227 and also for dummies (see `expand_start_case_dummy'). */
230 /* The insn after which the case dispatch should finally
231 be emitted. Zero for a dummy. */
233 /* A list of case labels; it is first built as an AVL tree.
234 During expand_end_case, this is converted to a list, and may be
235 rearranged into a nearly balanced binary tree. */
236 struct case_node *case_list;
237 /* Label to jump to if no case matches. */
239 /* The expression to be dispatched on. */
241 /* Type that INDEX_EXPR should be converted to. */
243 /* Name of this kind of statement, for warnings. */
244 const char *printname;
245 /* Used to save no_line_numbers till we see the first case label.
246 We set this to -1 when we see the first case label in this
248 int line_number_status;
253 /* Allocate and return a new `struct nesting'. */
255 #define ALLOC_NESTING() \
256 (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
258 /* Pop the nesting stack element by element until we pop off
259 the element which is at the top of STACK.
260 Update all the other stacks, popping off elements from them
261 as we pop them from nesting_stack. */
263 #define POPSTACK(STACK) \
264 do { struct nesting *target = STACK; \
265 struct nesting *this; \
266 do { this = nesting_stack; \
267 if (loop_stack == this) \
268 loop_stack = loop_stack->next; \
269 if (cond_stack == this) \
270 cond_stack = cond_stack->next; \
271 if (block_stack == this) \
272 block_stack = block_stack->next; \
273 if (stack_block_stack == this) \
274 stack_block_stack = stack_block_stack->next; \
275 if (case_stack == this) \
276 case_stack = case_stack->next; \
277 nesting_depth = nesting_stack->depth - 1; \
278 nesting_stack = this->all; \
279 obstack_free (&stmt_obstack, this); } \
280 while (this != target); } while (0)
282 /* In some cases it is impossible to generate code for a forward goto
283 until the label definition is seen. This happens when it may be necessary
284 for the goto to reset the stack pointer: we don't yet know how to do that.
285 So expand_goto puts an entry on this fixup list.
286 Each time a binding contour that resets the stack is exited,
288 If the target label has now been defined, we can insert the proper code. */
292 /* Points to following fixup. */
293 struct goto_fixup *next;
294 /* Points to the insn before the jump insn.
295 If more code must be inserted, it goes after this insn. */
297 /* The LABEL_DECL that this jump is jumping to, or 0
298 for break, continue or return. */
300 /* The BLOCK for the place where this goto was found. */
302 /* The CODE_LABEL rtx that this is jumping to. */
304 /* Number of binding contours started in current function
305 before the label reference. */
306 int block_start_count;
307 /* The outermost stack level that should be restored for this jump.
308 Each time a binding contour that resets the stack is exited,
309 if the target label is *not* yet defined, this slot is updated. */
311 /* List of lists of cleanup expressions to be run by this goto.
312 There is one element for each block that this goto is within.
313 The tail of this list can be 0,
314 if all remaining elements would be empty.
315 The TREE_VALUE contains the cleanup list of that block as of the
316 time this goto was seen.
317 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
318 tree cleanup_list_list;
321 /* Within any binding contour that must restore a stack level,
322 all labels are recorded with a chain of these structures. */
326 /* Points to following fixup. */
327 struct label_chain *next;
333 /* Chain of all pending binding contours. */
334 struct nesting *x_block_stack;
336 /* If any new stacks are added here, add them to POPSTACKS too. */
338 /* Chain of all pending binding contours that restore stack levels
340 struct nesting *x_stack_block_stack;
342 /* Chain of all pending conditional statements. */
343 struct nesting *x_cond_stack;
345 /* Chain of all pending loops. */
346 struct nesting *x_loop_stack;
348 /* Chain of all pending case or switch statements. */
349 struct nesting *x_case_stack;
351 /* Separate chain including all of the above,
352 chained through the `all' field. */
353 struct nesting *x_nesting_stack;
355 /* Number of entries on nesting_stack now. */
358 /* Number of binding contours started so far in this function. */
359 int x_block_start_count;
361 /* Each time we expand an expression-statement,
362 record the expr's type and its RTL value here. */
363 tree x_last_expr_type;
364 rtx x_last_expr_value;
366 /* Nonzero if within a ({...}) grouping, in which case we must
367 always compute a value for each expr-stmt in case it is the last one. */
368 int x_expr_stmts_for_value;
370 /* Filename and line number of last line-number note,
371 whether we actually emitted it or not. */
372 const char *x_emit_filename;
375 struct goto_fixup *x_goto_fixup_chain;
378 #define block_stack (cfun->stmt->x_block_stack)
379 #define stack_block_stack (cfun->stmt->x_stack_block_stack)
380 #define cond_stack (cfun->stmt->x_cond_stack)
381 #define loop_stack (cfun->stmt->x_loop_stack)
382 #define case_stack (cfun->stmt->x_case_stack)
383 #define nesting_stack (cfun->stmt->x_nesting_stack)
384 #define nesting_depth (cfun->stmt->x_nesting_depth)
385 #define current_block_start_count (cfun->stmt->x_block_start_count)
386 #define last_expr_type (cfun->stmt->x_last_expr_type)
387 #define last_expr_value (cfun->stmt->x_last_expr_value)
388 #define expr_stmts_for_value (cfun->stmt->x_expr_stmts_for_value)
389 #define emit_filename (cfun->stmt->x_emit_filename)
390 #define emit_lineno (cfun->stmt->x_emit_lineno)
391 #define goto_fixup_chain (cfun->stmt->x_goto_fixup_chain)
393 /* Non-zero if we are using EH to handle cleanus. */
394 static int using_eh_for_cleanups_p = 0;
396 /* Character strings, each containing a single decimal digit. */
397 static char *digit_strings[10];
399 static int n_occurrences PARAMS ((int, const char *));
400 static void expand_goto_internal PARAMS ((tree, rtx, rtx));
401 static int expand_fixup PARAMS ((tree, rtx, rtx));
402 static rtx expand_nl_handler_label PARAMS ((rtx, rtx));
403 static void expand_nl_goto_receiver PARAMS ((void));
404 static void expand_nl_goto_receivers PARAMS ((struct nesting *));
405 static void fixup_gotos PARAMS ((struct nesting *, rtx, tree,
407 static void expand_null_return_1 PARAMS ((rtx, int));
408 static void expand_value_return PARAMS ((rtx));
409 static int tail_recursion_args PARAMS ((tree, tree));
410 static void expand_cleanups PARAMS ((tree, tree, int, int));
411 static void check_seenlabel PARAMS ((void));
412 static void do_jump_if_equal PARAMS ((rtx, rtx, rtx, int));
413 static int estimate_case_costs PARAMS ((case_node_ptr));
414 static void group_case_nodes PARAMS ((case_node_ptr));
415 static void balance_case_nodes PARAMS ((case_node_ptr *,
417 static int node_has_low_bound PARAMS ((case_node_ptr, tree));
418 static int node_has_high_bound PARAMS ((case_node_ptr, tree));
419 static int node_is_bounded PARAMS ((case_node_ptr, tree));
420 static void emit_jump_if_reachable PARAMS ((rtx));
421 static void emit_case_nodes PARAMS ((rtx, case_node_ptr, rtx, tree));
422 static struct case_node *case_tree2list PARAMS ((case_node *, case_node *));
423 static void mark_cond_nesting PARAMS ((struct nesting *));
424 static void mark_loop_nesting PARAMS ((struct nesting *));
425 static void mark_block_nesting PARAMS ((struct nesting *));
426 static void mark_case_nesting PARAMS ((struct nesting *));
427 static void mark_case_node PARAMS ((struct case_node *));
428 static void mark_goto_fixup PARAMS ((struct goto_fixup *));
429 static void free_case_nodes PARAMS ((case_node_ptr));
432 using_eh_for_cleanups ()
434 using_eh_for_cleanups_p = 1;
437 /* Mark N (known to be a cond-nesting) for GC. */
440 mark_cond_nesting (n)
445 ggc_mark_rtx (n->exit_label);
446 ggc_mark_rtx (n->data.cond.endif_label);
447 ggc_mark_rtx (n->data.cond.next_label);
453 /* Mark N (known to be a loop-nesting) for GC. */
456 mark_loop_nesting (n)
462 ggc_mark_rtx (n->exit_label);
463 ggc_mark_rtx (n->data.loop.start_label);
464 ggc_mark_rtx (n->data.loop.end_label);
465 ggc_mark_rtx (n->data.loop.alt_end_label);
466 ggc_mark_rtx (n->data.loop.continue_label);
472 /* Mark N (known to be a block-nesting) for GC. */
475 mark_block_nesting (n)
480 struct label_chain *l;
482 ggc_mark_rtx (n->exit_label);
483 ggc_mark_rtx (n->data.block.stack_level);
484 ggc_mark_rtx (n->data.block.first_insn);
485 ggc_mark_tree (n->data.block.cleanups);
486 ggc_mark_tree (n->data.block.outer_cleanups);
488 for (l = n->data.block.label_chain; l != NULL; l = l->next)
491 ggc_mark_tree (l->label);
494 ggc_mark_rtx (n->data.block.last_unconditional_cleanup);
496 /* ??? cleanup_ptr never points outside the stack, does it? */
502 /* Mark N (known to be a case-nesting) for GC. */
505 mark_case_nesting (n)
510 ggc_mark_rtx (n->exit_label);
511 ggc_mark_rtx (n->data.case_stmt.start);
513 ggc_mark_tree (n->data.case_stmt.default_label);
514 ggc_mark_tree (n->data.case_stmt.index_expr);
515 ggc_mark_tree (n->data.case_stmt.nominal_type);
517 mark_case_node (n->data.case_stmt.case_list);
530 ggc_mark_tree (c->low);
531 ggc_mark_tree (c->high);
532 ggc_mark_tree (c->code_label);
534 mark_case_node (c->right);
535 mark_case_node (c->left);
543 struct goto_fixup *g;
548 ggc_mark_rtx (g->before_jump);
549 ggc_mark_tree (g->target);
550 ggc_mark_tree (g->context);
551 ggc_mark_rtx (g->target_rtl);
552 ggc_mark_rtx (g->stack_level);
553 ggc_mark_tree (g->cleanup_list_list);
559 /* Clear out all parts of the state in F that can safely be discarded
560 after the function has been compiled, to let garbage collection
561 reclaim the memory. */
567 /* We're about to free the function obstack. If we hold pointers to
568 things allocated there, then we'll try to mark them when we do
569 GC. So, we clear them out here explicitly. */
579 struct stmt_status *p;
584 mark_block_nesting (p->x_block_stack);
585 mark_cond_nesting (p->x_cond_stack);
586 mark_loop_nesting (p->x_loop_stack);
587 mark_case_nesting (p->x_case_stack);
589 ggc_mark_tree (p->x_last_expr_type);
590 /* last_epxr_value is only valid if last_expr_type is nonzero. */
591 if (p->x_last_expr_type)
592 ggc_mark_rtx (p->x_last_expr_value);
594 mark_goto_fixup (p->x_goto_fixup_chain);
602 gcc_obstack_init (&stmt_obstack);
604 for (i = 0; i < 10; i++)
606 digit_strings[i] = ggc_alloc_string (NULL, 1);
607 digit_strings[i][0] = '0' + i;
609 ggc_add_string_root (digit_strings, 10);
613 init_stmt_for_function ()
615 cfun->stmt = (struct stmt_status *) xmalloc (sizeof (struct stmt_status));
617 /* We are not currently within any block, conditional, loop or case. */
619 stack_block_stack = 0;
626 current_block_start_count = 0;
628 /* No gotos have been expanded yet. */
629 goto_fixup_chain = 0;
631 /* We are not processing a ({...}) grouping. */
632 expr_stmts_for_value = 0;
634 last_expr_value = NULL_RTX;
637 /* Return nonzero if anything is pushed on the loop, condition, or case
642 return cond_stack || loop_stack || case_stack;
645 /* Record the current file and line. Called from emit_line_note. */
647 set_file_and_line_for_stmt (file, line)
651 /* If we're outputting an inline function, and we add a line note,
652 there may be no CFUN->STMT information. So, there's no need to
656 emit_filename = file;
661 /* Emit a no-op instruction. */
668 last_insn = get_last_insn ();
670 && (GET_CODE (last_insn) == CODE_LABEL
671 || (GET_CODE (last_insn) == NOTE
672 && prev_real_insn (last_insn) == 0)))
673 emit_insn (gen_nop ());
676 /* Return the rtx-label that corresponds to a LABEL_DECL,
677 creating it if necessary. */
683 if (TREE_CODE (label) != LABEL_DECL)
686 if (DECL_RTL (label))
687 return DECL_RTL (label);
689 return DECL_RTL (label) = gen_label_rtx ();
692 /* Add an unconditional jump to LABEL as the next sequential instruction. */
698 do_pending_stack_adjust ();
699 emit_jump_insn (gen_jump (label));
703 /* Emit code to jump to the address
704 specified by the pointer expression EXP. */
707 expand_computed_goto (exp)
710 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
712 #ifdef POINTERS_EXTEND_UNSIGNED
713 x = convert_memory_address (Pmode, x);
717 /* Be sure the function is executable. */
718 if (current_function_check_memory_usage)
719 emit_library_call (chkr_check_exec_libfunc, LCT_CONST_MAKE_BLOCK,
720 VOIDmode, 1, x, ptr_mode);
722 do_pending_stack_adjust ();
723 emit_indirect_jump (x);
725 current_function_has_computed_jump = 1;
728 /* Handle goto statements and the labels that they can go to. */
730 /* Specify the location in the RTL code of a label LABEL,
731 which is a LABEL_DECL tree node.
733 This is used for the kind of label that the user can jump to with a
734 goto statement, and for alternatives of a switch or case statement.
735 RTL labels generated for loops and conditionals don't go through here;
736 they are generated directly at the RTL level, by other functions below.
738 Note that this has nothing to do with defining label *names*.
739 Languages vary in how they do that and what that even means. */
745 struct label_chain *p;
747 do_pending_stack_adjust ();
748 emit_label (label_rtx (label));
749 if (DECL_NAME (label))
750 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
752 if (stack_block_stack != 0)
754 p = (struct label_chain *) ggc_alloc (sizeof (struct label_chain));
755 p->next = stack_block_stack->data.block.label_chain;
756 stack_block_stack->data.block.label_chain = p;
761 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
762 from nested functions. */
765 declare_nonlocal_label (label)
768 rtx slot = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
770 nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
771 LABEL_PRESERVE_P (label_rtx (label)) = 1;
772 if (nonlocal_goto_handler_slots == 0)
774 emit_stack_save (SAVE_NONLOCAL,
775 &nonlocal_goto_stack_level,
776 PREV_INSN (tail_recursion_reentry));
778 nonlocal_goto_handler_slots
779 = gen_rtx_EXPR_LIST (VOIDmode, slot, nonlocal_goto_handler_slots);
782 /* Generate RTL code for a `goto' statement with target label LABEL.
783 LABEL should be a LABEL_DECL tree node that was or will later be
784 defined with `expand_label'. */
792 /* Check for a nonlocal goto to a containing function. */
793 context = decl_function_context (label);
794 if (context != 0 && context != current_function_decl)
796 struct function *p = find_function_data (context);
797 rtx label_ref = gen_rtx_LABEL_REF (Pmode, label_rtx (label));
798 rtx handler_slot, static_chain, save_area;
801 /* Find the corresponding handler slot for this label. */
802 handler_slot = p->x_nonlocal_goto_handler_slots;
803 for (link = p->x_nonlocal_labels; TREE_VALUE (link) != label;
804 link = TREE_CHAIN (link))
805 handler_slot = XEXP (handler_slot, 1);
806 handler_slot = XEXP (handler_slot, 0);
808 p->has_nonlocal_label = 1;
809 current_function_has_nonlocal_goto = 1;
810 LABEL_REF_NONLOCAL_P (label_ref) = 1;
812 /* Copy the rtl for the slots so that they won't be shared in
813 case the virtual stack vars register gets instantiated differently
814 in the parent than in the child. */
816 static_chain = copy_to_reg (lookup_static_chain (label));
818 /* Get addr of containing function's current nonlocal goto handler,
819 which will do any cleanups and then jump to the label. */
820 handler_slot = copy_to_reg (replace_rtx (copy_rtx (handler_slot),
821 virtual_stack_vars_rtx,
824 /* Get addr of containing function's nonlocal save area. */
825 save_area = p->x_nonlocal_goto_stack_level;
827 save_area = replace_rtx (copy_rtx (save_area),
828 virtual_stack_vars_rtx, static_chain);
830 #if HAVE_nonlocal_goto
831 if (HAVE_nonlocal_goto)
832 emit_insn (gen_nonlocal_goto (static_chain, handler_slot,
833 save_area, label_ref));
837 /* Restore frame pointer for containing function.
838 This sets the actual hard register used for the frame pointer
839 to the location of the function's incoming static chain info.
840 The non-local goto handler will then adjust it to contain the
841 proper value and reload the argument pointer, if needed. */
842 emit_move_insn (hard_frame_pointer_rtx, static_chain);
843 emit_stack_restore (SAVE_NONLOCAL, save_area, NULL_RTX);
845 /* USE of hard_frame_pointer_rtx added for consistency;
846 not clear if really needed. */
847 emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx));
848 emit_insn (gen_rtx_USE (VOIDmode, stack_pointer_rtx));
849 emit_indirect_jump (handler_slot);
853 expand_goto_internal (label, label_rtx (label), NULL_RTX);
856 /* Generate RTL code for a `goto' statement with target label BODY.
857 LABEL should be a LABEL_REF.
858 LAST_INSN, if non-0, is the rtx we should consider as the last
859 insn emitted (for the purposes of cleaning up a return). */
862 expand_goto_internal (body, label, last_insn)
867 struct nesting *block;
870 if (GET_CODE (label) != CODE_LABEL)
873 /* If label has already been defined, we can tell now
874 whether and how we must alter the stack level. */
876 if (PREV_INSN (label) != 0)
878 /* Find the innermost pending block that contains the label.
879 (Check containment by comparing insn-uids.)
880 Then restore the outermost stack level within that block,
881 and do cleanups of all blocks contained in it. */
882 for (block = block_stack; block; block = block->next)
884 if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
886 if (block->data.block.stack_level != 0)
887 stack_level = block->data.block.stack_level;
888 /* Execute the cleanups for blocks we are exiting. */
889 if (block->data.block.cleanups != 0)
891 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
892 do_pending_stack_adjust ();
898 /* Ensure stack adjust isn't done by emit_jump, as this
899 would clobber the stack pointer. This one should be
900 deleted as dead by flow. */
901 clear_pending_stack_adjust ();
902 do_pending_stack_adjust ();
904 /* Don't do this adjust if it's to the end label and this function
905 is to return with a depressed stack pointer. */
906 if (label == return_label
907 && (((TREE_CODE (TREE_TYPE (current_function_decl))
909 && (TYPE_RETURNS_STACK_DEPRESSED
910 (TREE_TYPE (current_function_decl))))))
913 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
916 if (body != 0 && DECL_TOO_LATE (body))
917 error ("jump to `%s' invalidly jumps into binding contour",
918 IDENTIFIER_POINTER (DECL_NAME (body)));
920 /* Label not yet defined: may need to put this goto
921 on the fixup list. */
922 else if (! expand_fixup (body, label, last_insn))
924 /* No fixup needed. Record that the label is the target
925 of at least one goto that has no fixup. */
927 TREE_ADDRESSABLE (body) = 1;
933 /* Generate if necessary a fixup for a goto
934 whose target label in tree structure (if any) is TREE_LABEL
935 and whose target in rtl is RTL_LABEL.
937 If LAST_INSN is nonzero, we pretend that the jump appears
938 after insn LAST_INSN instead of at the current point in the insn stream.
940 The fixup will be used later to insert insns just before the goto.
941 Those insns will restore the stack level as appropriate for the
942 target label, and will (in the case of C++) also invoke any object
943 destructors which have to be invoked when we exit the scopes which
944 are exited by the goto.
946 Value is nonzero if a fixup is made. */
949 expand_fixup (tree_label, rtl_label, last_insn)
954 struct nesting *block, *end_block;
956 /* See if we can recognize which block the label will be output in.
957 This is possible in some very common cases.
958 If we succeed, set END_BLOCK to that block.
959 Otherwise, set it to 0. */
962 && (rtl_label == cond_stack->data.cond.endif_label
963 || rtl_label == cond_stack->data.cond.next_label))
964 end_block = cond_stack;
965 /* If we are in a loop, recognize certain labels which
966 are likely targets. This reduces the number of fixups
967 we need to create. */
969 && (rtl_label == loop_stack->data.loop.start_label
970 || rtl_label == loop_stack->data.loop.end_label
971 || rtl_label == loop_stack->data.loop.continue_label))
972 end_block = loop_stack;
976 /* Now set END_BLOCK to the binding level to which we will return. */
980 struct nesting *next_block = end_block->all;
983 /* First see if the END_BLOCK is inside the innermost binding level.
984 If so, then no cleanups or stack levels are relevant. */
985 while (next_block && next_block != block)
986 next_block = next_block->all;
991 /* Otherwise, set END_BLOCK to the innermost binding level
992 which is outside the relevant control-structure nesting. */
993 next_block = block_stack->next;
994 for (block = block_stack; block != end_block; block = block->all)
995 if (block == next_block)
996 next_block = next_block->next;
997 end_block = next_block;
1000 /* Does any containing block have a stack level or cleanups?
1001 If not, no fixup is needed, and that is the normal case
1002 (the only case, for standard C). */
1003 for (block = block_stack; block != end_block; block = block->next)
1004 if (block->data.block.stack_level != 0
1005 || block->data.block.cleanups != 0)
1008 if (block != end_block)
1010 /* Ok, a fixup is needed. Add a fixup to the list of such. */
1011 struct goto_fixup *fixup
1012 = (struct goto_fixup *) ggc_alloc (sizeof (struct goto_fixup));
1013 /* In case an old stack level is restored, make sure that comes
1014 after any pending stack adjust. */
1015 /* ?? If the fixup isn't to come at the present position,
1016 doing the stack adjust here isn't useful. Doing it with our
1017 settings at that location isn't useful either. Let's hope
1020 do_pending_stack_adjust ();
1021 fixup->target = tree_label;
1022 fixup->target_rtl = rtl_label;
1024 /* Create a BLOCK node and a corresponding matched set of
1025 NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes at
1026 this point. The notes will encapsulate any and all fixup
1027 code which we might later insert at this point in the insn
1028 stream. Also, the BLOCK node will be the parent (i.e. the
1029 `SUPERBLOCK') of any other BLOCK nodes which we might create
1030 later on when we are expanding the fixup code.
1032 Note that optimization passes (including expand_end_loop)
1033 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
1034 as a placeholder. */
1037 register rtx original_before_jump
1038 = last_insn ? last_insn : get_last_insn ();
1043 block = make_node (BLOCK);
1044 TREE_USED (block) = 1;
1046 if (!cfun->x_whole_function_mode_p)
1047 insert_block (block);
1051 = BLOCK_CHAIN (DECL_INITIAL (current_function_decl));
1052 BLOCK_CHAIN (DECL_INITIAL (current_function_decl))
1057 start = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
1058 if (cfun->x_whole_function_mode_p)
1059 NOTE_BLOCK (start) = block;
1060 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_DELETED);
1061 end = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
1062 if (cfun->x_whole_function_mode_p)
1063 NOTE_BLOCK (end) = block;
1064 fixup->context = block;
1066 emit_insns_after (start, original_before_jump);
1069 fixup->block_start_count = current_block_start_count;
1070 fixup->stack_level = 0;
1071 fixup->cleanup_list_list
1072 = ((block->data.block.outer_cleanups
1073 || block->data.block.cleanups)
1074 ? tree_cons (NULL_TREE, block->data.block.cleanups,
1075 block->data.block.outer_cleanups)
1077 fixup->next = goto_fixup_chain;
1078 goto_fixup_chain = fixup;
1084 /* Expand any needed fixups in the outputmost binding level of the
1085 function. FIRST_INSN is the first insn in the function. */
1088 expand_fixups (first_insn)
1091 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0);
1094 /* When exiting a binding contour, process all pending gotos requiring fixups.
1095 THISBLOCK is the structure that describes the block being exited.
1096 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1097 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1098 FIRST_INSN is the insn that began this contour.
1100 Gotos that jump out of this contour must restore the
1101 stack level and do the cleanups before actually jumping.
1103 DONT_JUMP_IN nonzero means report error there is a jump into this
1104 contour from before the beginning of the contour.
1105 This is also done if STACK_LEVEL is nonzero. */
1108 fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1109 struct nesting *thisblock;
1115 register struct goto_fixup *f, *prev;
1117 /* F is the fixup we are considering; PREV is the previous one. */
1118 /* We run this loop in two passes so that cleanups of exited blocks
1119 are run first, and blocks that are exited are marked so
1122 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1124 /* Test for a fixup that is inactive because it is already handled. */
1125 if (f->before_jump == 0)
1127 /* Delete inactive fixup from the chain, if that is easy to do. */
1129 prev->next = f->next;
1131 /* Has this fixup's target label been defined?
1132 If so, we can finalize it. */
1133 else if (PREV_INSN (f->target_rtl) != 0)
1135 register rtx cleanup_insns;
1137 /* If this fixup jumped into this contour from before the beginning
1138 of this contour, report an error. This code used to use
1139 the first non-label insn after f->target_rtl, but that's
1140 wrong since such can be added, by things like put_var_into_stack
1141 and have INSN_UIDs that are out of the range of the block. */
1142 /* ??? Bug: this does not detect jumping in through intermediate
1143 blocks that have stack levels or cleanups.
1144 It detects only a problem with the innermost block
1145 around the label. */
1147 && (dont_jump_in || stack_level || cleanup_list)
1148 && INSN_UID (first_insn) < INSN_UID (f->target_rtl)
1149 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1150 && ! DECL_ERROR_ISSUED (f->target))
1152 error_with_decl (f->target,
1153 "label `%s' used before containing binding contour");
1154 /* Prevent multiple errors for one label. */
1155 DECL_ERROR_ISSUED (f->target) = 1;
1158 /* We will expand the cleanups into a sequence of their own and
1159 then later on we will attach this new sequence to the insn
1160 stream just ahead of the actual jump insn. */
1164 /* Temporarily restore the lexical context where we will
1165 logically be inserting the fixup code. We do this for the
1166 sake of getting the debugging information right. */
1169 set_block (f->context);
1171 /* Expand the cleanups for blocks this jump exits. */
1172 if (f->cleanup_list_list)
1175 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1176 /* Marked elements correspond to blocks that have been closed.
1177 Do their cleanups. */
1178 if (TREE_ADDRESSABLE (lists)
1179 && TREE_VALUE (lists) != 0)
1181 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1182 /* Pop any pushes done in the cleanups,
1183 in case function is about to return. */
1184 do_pending_stack_adjust ();
1188 /* Restore stack level for the biggest contour that this
1189 jump jumps out of. */
1191 && ! (f->target_rtl == return_label
1192 && ((TREE_CODE (TREE_TYPE (current_function_decl))
1194 && (TYPE_RETURNS_STACK_DEPRESSED
1195 (TREE_TYPE (current_function_decl))))))
1196 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1198 /* Finish up the sequence containing the insns which implement the
1199 necessary cleanups, and then attach that whole sequence to the
1200 insn stream just ahead of the actual jump insn. Attaching it
1201 at that point insures that any cleanups which are in fact
1202 implicit C++ object destructions (which must be executed upon
1203 leaving the block) appear (to the debugger) to be taking place
1204 in an area of the generated code where the object(s) being
1205 destructed are still "in scope". */
1207 cleanup_insns = get_insns ();
1211 emit_insns_after (cleanup_insns, f->before_jump);
1217 /* For any still-undefined labels, do the cleanups for this block now.
1218 We must do this now since items in the cleanup list may go out
1219 of scope when the block ends. */
1220 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1221 if (f->before_jump != 0
1222 && PREV_INSN (f->target_rtl) == 0
1223 /* Label has still not appeared. If we are exiting a block with
1224 a stack level to restore, that started before the fixup,
1225 mark this stack level as needing restoration
1226 when the fixup is later finalized. */
1228 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1229 means the label is undefined. That's erroneous, but possible. */
1230 && (thisblock->data.block.block_start_count
1231 <= f->block_start_count))
1233 tree lists = f->cleanup_list_list;
1236 for (; lists; lists = TREE_CHAIN (lists))
1237 /* If the following elt. corresponds to our containing block
1238 then the elt. must be for this block. */
1239 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
1243 set_block (f->context);
1244 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1245 do_pending_stack_adjust ();
1246 cleanup_insns = get_insns ();
1249 if (cleanup_insns != 0)
1251 = emit_insns_after (cleanup_insns, f->before_jump);
1253 f->cleanup_list_list = TREE_CHAIN (lists);
1257 f->stack_level = stack_level;
1261 /* Return the number of times character C occurs in string S. */
1263 n_occurrences (c, s)
1273 /* Generate RTL for an asm statement (explicit assembler code).
1274 BODY is a STRING_CST node containing the assembler code text,
1275 or an ADDR_EXPR containing a STRING_CST. */
1281 if (current_function_check_memory_usage)
1283 error ("`asm' cannot be used in function where memory usage is checked");
1287 if (TREE_CODE (body) == ADDR_EXPR)
1288 body = TREE_OPERAND (body, 0);
1290 emit_insn (gen_rtx_ASM_INPUT (VOIDmode,
1291 TREE_STRING_POINTER (body)));
1295 /* Generate RTL for an asm statement with arguments.
1296 STRING is the instruction template.
1297 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1298 Each output or input has an expression in the TREE_VALUE and
1299 a constraint-string in the TREE_PURPOSE.
1300 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1301 that is clobbered by this insn.
1303 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1304 Some elements of OUTPUTS may be replaced with trees representing temporary
1305 values. The caller should copy those temporary values to the originally
1308 VOL nonzero means the insn is volatile; don't optimize it. */
1311 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1312 tree string, outputs, inputs, clobbers;
1314 const char *filename;
1317 rtvec argvec, constraints;
1319 int ninputs = list_length (inputs);
1320 int noutputs = list_length (outputs);
1325 /* Vector of RTX's of evaluated output operands. */
1326 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1327 int *inout_opnum = (int *) alloca (noutputs * sizeof (int));
1328 rtx *real_output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1329 enum machine_mode *inout_mode
1330 = (enum machine_mode *) alloca (noutputs * sizeof (enum machine_mode));
1331 /* The insn we have emitted. */
1333 int old_generating_concat_p = generating_concat_p;
1335 /* An ASM with no outputs needs to be treated as volatile, for now. */
1339 if (current_function_check_memory_usage)
1341 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1345 #ifdef MD_ASM_CLOBBERS
1346 /* Sometimes we wish to automatically clobber registers across an asm.
1347 Case in point is when the i386 backend moved from cc0 to a hard reg --
1348 maintaining source-level compatability means automatically clobbering
1349 the flags register. */
1350 MD_ASM_CLOBBERS (clobbers);
1353 if (current_function_check_memory_usage)
1355 error ("`asm' cannot be used in function where memory usage is checked");
1359 /* Count the number of meaningful clobbered registers, ignoring what
1360 we would ignore later. */
1362 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1364 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1366 i = decode_reg_name (regname);
1367 if (i >= 0 || i == -4)
1370 error ("unknown register name `%s' in `asm'", regname);
1375 /* Check that the number of alternatives is constant across all
1377 if (outputs || inputs)
1379 tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
1380 int nalternatives = n_occurrences (',', TREE_STRING_POINTER (tmp));
1383 if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
1385 error ("too many alternatives in `asm'");
1392 const char *constraint = TREE_STRING_POINTER (TREE_PURPOSE (tmp));
1394 if (n_occurrences (',', constraint) != nalternatives)
1396 error ("operand constraints for `asm' differ in number of alternatives");
1400 if (TREE_CHAIN (tmp))
1401 tmp = TREE_CHAIN (tmp);
1403 tmp = next, next = 0;
1407 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1409 tree val = TREE_VALUE (tail);
1410 tree type = TREE_TYPE (val);
1419 /* If there's an erroneous arg, emit no insn. */
1420 if (TREE_TYPE (val) == error_mark_node)
1423 /* Make sure constraint has `=' and does not have `+'. Also, see
1424 if it allows any register. Be liberal on the latter test, since
1425 the worst that happens if we get it wrong is we issue an error
1428 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1429 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1431 /* Allow the `=' or `+' to not be at the beginning of the string,
1432 since it wasn't explicitly documented that way, and there is a
1433 large body of code that puts it last. Swap the character to
1434 the front, so as not to uglify any place else. */
1438 if ((p = strchr (constraint, '=')) != NULL)
1440 if ((p = strchr (constraint, '+')) != NULL)
1443 error ("output operand constraint lacks `='");
1447 if (p != constraint)
1450 bcopy (constraint, constraint+1, p-constraint);
1453 warning ("output constraint `%c' for operand %d is not at the beginning", j, i);
1456 is_inout = constraint[0] == '+';
1457 /* Replace '+' with '='. */
1458 constraint[0] = '=';
1459 /* Make sure we can specify the matching operand. */
1460 if (is_inout && i > 9)
1462 error ("output operand constraint %d contains `+'", i);
1466 for (j = 1; j < c_len; j++)
1467 switch (constraint[j])
1471 error ("operand constraint contains '+' or '=' at illegal position.");
1475 if (i + 1 == ninputs + noutputs)
1477 error ("`%%' constraint used with last operand");
1482 case '?': case '!': case '*': case '&': case '#':
1483 case 'E': case 'F': case 'G': case 'H':
1484 case 's': case 'i': case 'n':
1485 case 'I': case 'J': case 'K': case 'L': case 'M':
1486 case 'N': case 'O': case 'P': case ',':
1489 case '0': case '1': case '2': case '3': case '4':
1490 case '5': case '6': case '7': case '8': case '9':
1491 error ("matching constraint not valid in output operand");
1494 case 'V': case 'm': case 'o':
1499 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1500 excepting those that expand_call created. So match memory
1515 if (! ISALPHA (constraint[j]))
1517 error ("invalid punctuation `%c' in constraint",
1521 if (REG_CLASS_FROM_LETTER (constraint[j]) != NO_REGS)
1523 #ifdef EXTRA_CONSTRAINT
1526 /* Otherwise we can't assume anything about the nature of
1527 the constraint except that it isn't purely registers.
1528 Treat it like "g" and hope for the best. */
1536 /* If an output operand is not a decl or indirect ref and our constraint
1537 allows a register, make a temporary to act as an intermediate.
1538 Make the asm insn write into that, then our caller will copy it to
1539 the real output operand. Likewise for promoted variables. */
1541 generating_concat_p = 0;
1543 real_output_rtx[i] = NULL_RTX;
1544 if ((TREE_CODE (val) == INDIRECT_REF
1547 && (allows_mem || GET_CODE (DECL_RTL (val)) == REG)
1548 && ! (GET_CODE (DECL_RTL (val)) == REG
1549 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
1554 mark_addressable (TREE_VALUE (tail));
1557 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode,
1558 EXPAND_MEMORY_USE_WO);
1560 if (! allows_reg && GET_CODE (output_rtx[i]) != MEM)
1561 error ("output number %d not directly addressable", i);
1562 if ((! allows_mem && GET_CODE (output_rtx[i]) == MEM)
1563 || GET_CODE (output_rtx[i]) == CONCAT)
1565 real_output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1566 output_rtx[i] = gen_reg_rtx (GET_MODE (output_rtx[i]));
1568 emit_move_insn (output_rtx[i], real_output_rtx[i]);
1573 output_rtx[i] = assign_temp (type, 0, 0, 1);
1574 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1577 generating_concat_p = old_generating_concat_p;
1581 inout_mode[ninout] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)));
1582 inout_opnum[ninout++] = i;
1587 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1589 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1593 /* Make vectors for the expression-rtx and constraint strings. */
1595 argvec = rtvec_alloc (ninputs);
1596 constraints = rtvec_alloc (ninputs);
1598 body = gen_rtx_ASM_OPERANDS ((noutputs == 0 ? VOIDmode
1599 : GET_MODE (output_rtx[0])),
1600 TREE_STRING_POINTER (string),
1601 empty_string, 0, argvec, constraints,
1604 MEM_VOLATILE_P (body) = vol;
1606 /* Eval the inputs and put them into ARGVEC.
1607 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1610 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1613 int allows_reg = 0, allows_mem = 0;
1614 char *constraint, *orig_constraint;
1618 /* If there's an erroneous arg, emit no insn,
1619 because the ASM_INPUT would get VOIDmode
1620 and that could cause a crash in reload. */
1621 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1624 /* ??? Can this happen, and does the error message make any sense? */
1625 if (TREE_PURPOSE (tail) == NULL_TREE)
1627 error ("hard register `%s' listed as input operand to `asm'",
1628 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1632 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1633 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1634 orig_constraint = constraint;
1636 /* Make sure constraint has neither `=', `+', nor '&'. */
1638 for (j = 0; j < c_len; j++)
1639 switch (constraint[j])
1641 case '+': case '=': case '&':
1642 if (constraint == orig_constraint)
1644 error ("input operand constraint contains `%c'",
1651 if (constraint == orig_constraint
1652 && i + 1 == ninputs - ninout)
1654 error ("`%%' constraint used with last operand");
1659 case 'V': case 'm': case 'o':
1664 case '?': case '!': case '*': case '#':
1665 case 'E': case 'F': case 'G': case 'H':
1666 case 's': case 'i': case 'n':
1667 case 'I': case 'J': case 'K': case 'L': case 'M':
1668 case 'N': case 'O': case 'P': case ',':
1671 /* Whether or not a numeric constraint allows a register is
1672 decided by the matching constraint, and so there is no need
1673 to do anything special with them. We must handle them in
1674 the default case, so that we don't unnecessarily force
1675 operands to memory. */
1676 case '0': case '1': case '2': case '3': case '4':
1677 case '5': case '6': case '7': case '8': case '9':
1678 if (constraint[j] >= '0' + noutputs)
1681 ("matching constraint references invalid operand number");
1685 /* Try and find the real constraint for this dup. */
1686 if ((j == 0 && c_len == 1)
1687 || (j == 1 && c_len == 2 && constraint[0] == '%'))
1691 for (j = constraint[j] - '0'; j > 0; --j)
1694 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (o)));
1695 constraint = TREE_STRING_POINTER (TREE_PURPOSE (o));
1712 if (! ISALPHA (constraint[j]))
1714 error ("invalid punctuation `%c' in constraint",
1718 if (REG_CLASS_FROM_LETTER (constraint[j]) != NO_REGS)
1720 #ifdef EXTRA_CONSTRAINT
1723 /* Otherwise we can't assume anything about the nature of
1724 the constraint except that it isn't purely registers.
1725 Treat it like "g" and hope for the best. */
1733 if (! allows_reg && allows_mem)
1734 mark_addressable (TREE_VALUE (tail));
1736 op = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1738 /* Never pass a CONCAT to an ASM. */
1739 generating_concat_p = 0;
1740 if (GET_CODE (op) == CONCAT)
1741 op = force_reg (GET_MODE (op), op);
1743 if (asm_operand_ok (op, constraint) <= 0)
1746 op = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), op);
1747 else if (!allows_mem)
1748 warning ("asm operand %d probably doesn't match constraints", i);
1749 else if (CONSTANT_P (op))
1750 op = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1752 else if (GET_CODE (op) == REG
1753 || GET_CODE (op) == SUBREG
1754 || GET_CODE (op) == CONCAT)
1756 tree type = TREE_TYPE (TREE_VALUE (tail));
1757 rtx memloc = assign_temp (type, 1, 1, 1);
1759 emit_move_insn (memloc, op);
1763 else if (GET_CODE (op) == MEM && MEM_VOLATILE_P (op))
1764 /* We won't recognize volatile memory as available a
1765 memory_operand at this point. Ignore it. */
1767 else if (queued_subexp_p (op))
1770 /* ??? Leave this only until we have experience with what
1771 happens in combine and elsewhere when constraints are
1773 warning ("asm operand %d probably doesn't match constraints", i);
1775 generating_concat_p = old_generating_concat_p;
1776 ASM_OPERANDS_INPUT (body, i) = op;
1778 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, i)
1779 = gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1784 /* Protect all the operands from the queue now that they have all been
1787 generating_concat_p = 0;
1789 for (i = 0; i < ninputs - ninout; i++)
1790 ASM_OPERANDS_INPUT (body, i)
1791 = protect_from_queue (ASM_OPERANDS_INPUT (body, i), 0);
1793 for (i = 0; i < noutputs; i++)
1794 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1796 /* For in-out operands, copy output rtx to input rtx. */
1797 for (i = 0; i < ninout; i++)
1799 int j = inout_opnum[i];
1801 ASM_OPERANDS_INPUT (body, ninputs - ninout + i)
1803 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, ninputs - ninout + i)
1804 = gen_rtx_ASM_INPUT (inout_mode[i], digit_strings[j]);
1807 generating_concat_p = old_generating_concat_p;
1809 /* Now, for each output, construct an rtx
1810 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1811 ARGVEC CONSTRAINTS))
1812 If there is more than one, put them inside a PARALLEL. */
1814 if (noutputs == 1 && nclobbers == 0)
1816 ASM_OPERANDS_OUTPUT_CONSTRAINT (body)
1817 = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1818 insn = emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
1821 else if (noutputs == 0 && nclobbers == 0)
1823 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1824 insn = emit_insn (body);
1835 body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
1837 /* For each output operand, store a SET. */
1838 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1840 XVECEXP (body, 0, i)
1841 = gen_rtx_SET (VOIDmode,
1843 gen_rtx_ASM_OPERANDS
1844 (GET_MODE (output_rtx[i]),
1845 TREE_STRING_POINTER (string),
1846 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1847 i, argvec, constraints,
1850 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1853 /* If there are no outputs (but there are some clobbers)
1854 store the bare ASM_OPERANDS into the PARALLEL. */
1857 XVECEXP (body, 0, i++) = obody;
1859 /* Store (clobber REG) for each clobbered register specified. */
1861 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1863 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1864 int j = decode_reg_name (regname);
1868 if (j == -3) /* `cc', which is not a register */
1871 if (j == -4) /* `memory', don't cache memory across asm */
1873 XVECEXP (body, 0, i++)
1874 = gen_rtx_CLOBBER (VOIDmode,
1877 gen_rtx_SCRATCH (VOIDmode)));
1881 /* Ignore unknown register, error already signaled. */
1885 /* Use QImode since that's guaranteed to clobber just one reg. */
1886 XVECEXP (body, 0, i++)
1887 = gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (QImode, j));
1890 insn = emit_insn (body);
1893 /* For any outputs that needed reloading into registers, spill them
1894 back to where they belong. */
1895 for (i = 0; i < noutputs; ++i)
1896 if (real_output_rtx[i])
1897 emit_move_insn (real_output_rtx[i], output_rtx[i]);
1902 /* Generate RTL to evaluate the expression EXP
1903 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1906 expand_expr_stmt (exp)
1909 /* If -W, warn about statements with no side effects,
1910 except for an explicit cast to void (e.g. for assert()), and
1911 except inside a ({...}) where they may be useful. */
1912 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1914 if (! TREE_SIDE_EFFECTS (exp))
1916 if ((extra_warnings || warn_unused_value)
1917 && !(TREE_CODE (exp) == CONVERT_EXPR
1918 && VOID_TYPE_P (TREE_TYPE (exp))))
1919 warning_with_file_and_line (emit_filename, emit_lineno,
1920 "statement with no effect");
1922 else if (warn_unused_value)
1923 warn_if_unused_value (exp);
1926 /* If EXP is of function type and we are expanding statements for
1927 value, convert it to pointer-to-function. */
1928 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1929 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1931 /* The call to `expand_expr' could cause last_expr_type and
1932 last_expr_value to get reset. Therefore, we set last_expr_value
1933 and last_expr_type *after* calling expand_expr. */
1934 last_expr_value = expand_expr (exp,
1935 (expr_stmts_for_value
1936 ? NULL_RTX : const0_rtx),
1938 last_expr_type = TREE_TYPE (exp);
1940 /* If all we do is reference a volatile value in memory,
1941 copy it to a register to be sure it is actually touched. */
1942 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1943 && TREE_THIS_VOLATILE (exp))
1945 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1947 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1948 copy_to_reg (last_expr_value);
1951 rtx lab = gen_label_rtx ();
1953 /* Compare the value with itself to reference it. */
1954 emit_cmp_and_jump_insns (last_expr_value, last_expr_value, EQ,
1955 expand_expr (TYPE_SIZE (last_expr_type),
1956 NULL_RTX, VOIDmode, 0),
1958 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT,
1964 /* If this expression is part of a ({...}) and is in memory, we may have
1965 to preserve temporaries. */
1966 preserve_temp_slots (last_expr_value);
1968 /* Free any temporaries used to evaluate this expression. Any temporary
1969 used as a result of this expression will already have been preserved
1976 /* Warn if EXP contains any computations whose results are not used.
1977 Return 1 if a warning is printed; 0 otherwise. */
1980 warn_if_unused_value (exp)
1983 if (TREE_USED (exp))
1986 /* Don't warn about void constructs. This includes casting to void,
1987 void function calls, and statement expressions with a final cast
1989 if (VOID_TYPE_P (TREE_TYPE (exp)))
1992 switch (TREE_CODE (exp))
1994 case PREINCREMENT_EXPR:
1995 case POSTINCREMENT_EXPR:
1996 case PREDECREMENT_EXPR:
1997 case POSTDECREMENT_EXPR:
2002 case METHOD_CALL_EXPR:
2004 case TRY_CATCH_EXPR:
2005 case WITH_CLEANUP_EXPR:
2007 /* We don't warn about COND_EXPR because it may be a useful
2008 construct if either arm contains a side effect. */
2013 /* For a binding, warn if no side effect within it. */
2014 return warn_if_unused_value (TREE_OPERAND (exp, 1));
2017 return warn_if_unused_value (TREE_OPERAND (exp, 1));
2019 case TRUTH_ORIF_EXPR:
2020 case TRUTH_ANDIF_EXPR:
2021 /* In && or ||, warn if 2nd operand has no side effect. */
2022 return warn_if_unused_value (TREE_OPERAND (exp, 1));
2025 if (TREE_NO_UNUSED_WARNING (exp))
2027 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
2029 /* Let people do `(foo (), 0)' without a warning. */
2030 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
2032 return warn_if_unused_value (TREE_OPERAND (exp, 1));
2036 case NON_LVALUE_EXPR:
2037 /* Don't warn about conversions not explicit in the user's program. */
2038 if (TREE_NO_UNUSED_WARNING (exp))
2040 /* Assignment to a cast usually results in a cast of a modify.
2041 Don't complain about that. There can be an arbitrary number of
2042 casts before the modify, so we must loop until we find the first
2043 non-cast expression and then test to see if that is a modify. */
2045 tree tem = TREE_OPERAND (exp, 0);
2047 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
2048 tem = TREE_OPERAND (tem, 0);
2050 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
2051 || TREE_CODE (tem) == CALL_EXPR)
2057 /* Don't warn about automatic dereferencing of references, since
2058 the user cannot control it. */
2059 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
2060 return warn_if_unused_value (TREE_OPERAND (exp, 0));
2064 /* Referencing a volatile value is a side effect, so don't warn. */
2066 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
2067 && TREE_THIS_VOLATILE (exp))
2070 /* If this is an expression which has no operands, there is no value
2071 to be unused. There are no such language-independent codes,
2072 but front ends may define such. */
2073 if (TREE_CODE_CLASS (TREE_CODE (exp)) == 'e'
2074 && TREE_CODE_LENGTH (TREE_CODE (exp)) == 0)
2078 warning_with_file_and_line (emit_filename, emit_lineno,
2079 "value computed is not used");
2084 /* Clear out the memory of the last expression evaluated. */
2092 /* Begin a statement which will return a value.
2093 Return the RTL_EXPR for this statement expr.
2094 The caller must save that value and pass it to expand_end_stmt_expr. */
2097 expand_start_stmt_expr ()
2101 /* Make the RTL_EXPR node temporary, not momentary,
2102 so that rtl_expr_chain doesn't become garbage. */
2103 t = make_node (RTL_EXPR);
2104 do_pending_stack_adjust ();
2105 start_sequence_for_rtl_expr (t);
2107 expr_stmts_for_value++;
2111 /* Restore the previous state at the end of a statement that returns a value.
2112 Returns a tree node representing the statement's value and the
2113 insns to compute the value.
2115 The nodes of that expression have been freed by now, so we cannot use them.
2116 But we don't want to do that anyway; the expression has already been
2117 evaluated and now we just want to use the value. So generate a RTL_EXPR
2118 with the proper type and RTL value.
2120 If the last substatement was not an expression,
2121 return something with type `void'. */
2124 expand_end_stmt_expr (t)
2129 if (last_expr_type == 0)
2131 last_expr_type = void_type_node;
2132 last_expr_value = const0_rtx;
2134 else if (last_expr_value == 0)
2135 /* There are some cases where this can happen, such as when the
2136 statement is void type. */
2137 last_expr_value = const0_rtx;
2138 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
2139 /* Remove any possible QUEUED. */
2140 last_expr_value = protect_from_queue (last_expr_value, 0);
2144 TREE_TYPE (t) = last_expr_type;
2145 RTL_EXPR_RTL (t) = last_expr_value;
2146 RTL_EXPR_SEQUENCE (t) = get_insns ();
2148 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
2152 /* Don't consider deleting this expr or containing exprs at tree level. */
2153 TREE_SIDE_EFFECTS (t) = 1;
2154 /* Propagate volatility of the actual RTL expr. */
2155 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
2158 expr_stmts_for_value--;
2163 /* Generate RTL for the start of an if-then. COND is the expression
2164 whose truth should be tested.
2166 If EXITFLAG is nonzero, this conditional is visible to
2167 `exit_something'. */
2170 expand_start_cond (cond, exitflag)
2174 struct nesting *thiscond = ALLOC_NESTING ();
2176 /* Make an entry on cond_stack for the cond we are entering. */
2178 thiscond->next = cond_stack;
2179 thiscond->all = nesting_stack;
2180 thiscond->depth = ++nesting_depth;
2181 thiscond->data.cond.next_label = gen_label_rtx ();
2182 /* Before we encounter an `else', we don't need a separate exit label
2183 unless there are supposed to be exit statements
2184 to exit this conditional. */
2185 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
2186 thiscond->data.cond.endif_label = thiscond->exit_label;
2187 cond_stack = thiscond;
2188 nesting_stack = thiscond;
2190 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
2193 /* Generate RTL between then-clause and the elseif-clause
2194 of an if-then-elseif-.... */
2197 expand_start_elseif (cond)
2200 if (cond_stack->data.cond.endif_label == 0)
2201 cond_stack->data.cond.endif_label = gen_label_rtx ();
2202 emit_jump (cond_stack->data.cond.endif_label);
2203 emit_label (cond_stack->data.cond.next_label);
2204 cond_stack->data.cond.next_label = gen_label_rtx ();
2205 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2208 /* Generate RTL between the then-clause and the else-clause
2209 of an if-then-else. */
2212 expand_start_else ()
2214 if (cond_stack->data.cond.endif_label == 0)
2215 cond_stack->data.cond.endif_label = gen_label_rtx ();
2217 emit_jump (cond_stack->data.cond.endif_label);
2218 emit_label (cond_stack->data.cond.next_label);
2219 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
2222 /* After calling expand_start_else, turn this "else" into an "else if"
2223 by providing another condition. */
2226 expand_elseif (cond)
2229 cond_stack->data.cond.next_label = gen_label_rtx ();
2230 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2233 /* Generate RTL for the end of an if-then.
2234 Pop the record for it off of cond_stack. */
2239 struct nesting *thiscond = cond_stack;
2241 do_pending_stack_adjust ();
2242 if (thiscond->data.cond.next_label)
2243 emit_label (thiscond->data.cond.next_label);
2244 if (thiscond->data.cond.endif_label)
2245 emit_label (thiscond->data.cond.endif_label);
2247 POPSTACK (cond_stack);
2251 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2252 loop should be exited by `exit_something'. This is a loop for which
2253 `expand_continue' will jump to the top of the loop.
2255 Make an entry on loop_stack to record the labels associated with
2259 expand_start_loop (exit_flag)
2262 register struct nesting *thisloop = ALLOC_NESTING ();
2264 /* Make an entry on loop_stack for the loop we are entering. */
2266 thisloop->next = loop_stack;
2267 thisloop->all = nesting_stack;
2268 thisloop->depth = ++nesting_depth;
2269 thisloop->data.loop.start_label = gen_label_rtx ();
2270 thisloop->data.loop.end_label = gen_label_rtx ();
2271 thisloop->data.loop.alt_end_label = 0;
2272 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2273 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2274 loop_stack = thisloop;
2275 nesting_stack = thisloop;
2277 do_pending_stack_adjust ();
2279 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2280 emit_label (thisloop->data.loop.start_label);
2285 /* Like expand_start_loop but for a loop where the continuation point
2286 (for expand_continue_loop) will be specified explicitly. */
2289 expand_start_loop_continue_elsewhere (exit_flag)
2292 struct nesting *thisloop = expand_start_loop (exit_flag);
2293 loop_stack->data.loop.continue_label = gen_label_rtx ();
2297 /* Specify the continuation point for a loop started with
2298 expand_start_loop_continue_elsewhere.
2299 Use this at the point in the code to which a continue statement
2303 expand_loop_continue_here ()
2305 do_pending_stack_adjust ();
2306 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2307 emit_label (loop_stack->data.loop.continue_label);
2310 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2311 Pop the block off of loop_stack. */
2316 rtx start_label = loop_stack->data.loop.start_label;
2317 rtx insn = get_last_insn ();
2318 int needs_end_jump = 1;
2320 /* Mark the continue-point at the top of the loop if none elsewhere. */
2321 if (start_label == loop_stack->data.loop.continue_label)
2322 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2324 do_pending_stack_adjust ();
2326 /* If optimizing, perhaps reorder the loop.
2327 First, try to use a condjump near the end.
2328 expand_exit_loop_if_false ends loops with unconditional jumps,
2331 if (test) goto label;
2333 goto loop_stack->data.loop.end_label
2337 If we find such a pattern, we can end the loop earlier. */
2340 && GET_CODE (insn) == CODE_LABEL
2341 && LABEL_NAME (insn) == NULL
2342 && GET_CODE (PREV_INSN (insn)) == BARRIER)
2345 rtx jump = PREV_INSN (PREV_INSN (label));
2347 if (GET_CODE (jump) == JUMP_INSN
2348 && GET_CODE (PATTERN (jump)) == SET
2349 && SET_DEST (PATTERN (jump)) == pc_rtx
2350 && GET_CODE (SET_SRC (PATTERN (jump))) == LABEL_REF
2351 && (XEXP (SET_SRC (PATTERN (jump)), 0)
2352 == loop_stack->data.loop.end_label))
2356 /* The test might be complex and reference LABEL multiple times,
2357 like the loop in loop_iterations to set vtop. To handle this,
2359 insn = PREV_INSN (label);
2360 reorder_insns (label, label, start_label);
2362 for (prev = PREV_INSN (jump);; prev = PREV_INSN (prev))
2364 /* We ignore line number notes, but if we see any other note,
2365 in particular NOTE_INSN_BLOCK_*, NOTE_INSN_EH_REGION_*,
2366 NOTE_INSN_LOOP_*, we disable this optimization. */
2367 if (GET_CODE (prev) == NOTE)
2369 if (NOTE_LINE_NUMBER (prev) < 0)
2373 if (GET_CODE (prev) == CODE_LABEL)
2375 if (GET_CODE (prev) == JUMP_INSN)
2377 if (GET_CODE (PATTERN (prev)) == SET
2378 && SET_DEST (PATTERN (prev)) == pc_rtx
2379 && GET_CODE (SET_SRC (PATTERN (prev))) == IF_THEN_ELSE
2380 && (GET_CODE (XEXP (SET_SRC (PATTERN (prev)), 1))
2382 && XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0) == label)
2384 XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0)
2386 emit_note_after (NOTE_INSN_LOOP_END, prev);
2395 /* If the loop starts with a loop exit, roll that to the end where
2396 it will optimize together with the jump back.
2398 We look for the conditional branch to the exit, except that once
2399 we find such a branch, we don't look past 30 instructions.
2401 In more detail, if the loop presently looks like this (in pseudo-C):
2404 if (test) goto end_label;
2409 transform it to look like:
2415 if (test) goto end_label;
2416 goto newstart_label;
2419 Here, the `test' may actually consist of some reasonably complex
2420 code, terminating in a test. */
2425 ! (GET_CODE (insn) == JUMP_INSN
2426 && GET_CODE (PATTERN (insn)) == SET
2427 && SET_DEST (PATTERN (insn)) == pc_rtx
2428 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2432 rtx last_test_insn = NULL_RTX;
2434 /* Scan insns from the top of the loop looking for a qualified
2435 conditional exit. */
2436 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2437 insn = NEXT_INSN (insn))
2439 if (GET_CODE (insn) == NOTE)
2442 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2443 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2444 /* The code that actually moves the exit test will
2445 carefully leave BLOCK notes in their original
2446 location. That means, however, that we can't debug
2447 the exit test itself. So, we refuse to move code
2448 containing BLOCK notes at low optimization levels. */
2451 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG)
2453 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)
2457 /* We've come to the end of an EH region, but
2458 never saw the beginning of that region. That
2459 means that an EH region begins before the top
2460 of the loop, and ends in the middle of it. The
2461 existence of such a situation violates a basic
2462 assumption in this code, since that would imply
2463 that even when EH_REGIONS is zero, we might
2464 move code out of an exception region. */
2468 /* We must not walk into a nested loop. */
2469 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
2472 /* We already know this INSN is a NOTE, so there's no
2473 point in looking at it to see if it's a JUMP. */
2477 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2480 if (last_test_insn && num_insns > 30)
2484 /* We don't want to move a partial EH region. Consider:
2498 This isn't legal C++, but here's what it's supposed to
2499 mean: if cond() is true, stop looping. Otherwise,
2500 call bar, and keep looping. In addition, if cond
2501 throws an exception, catch it and keep looping. Such
2502 constructs are certainy legal in LISP.
2504 We should not move the `if (cond()) 0' test since then
2505 the EH-region for the try-block would be broken up.
2506 (In this case we would the EH_BEG note for the `try'
2507 and `if cond()' but not the call to bar() or the
2510 So we don't look for tests within an EH region. */
2513 if (GET_CODE (insn) == JUMP_INSN
2514 && GET_CODE (PATTERN (insn)) == SET
2515 && SET_DEST (PATTERN (insn)) == pc_rtx)
2517 /* This is indeed a jump. */
2518 rtx dest1 = NULL_RTX;
2519 rtx dest2 = NULL_RTX;
2520 rtx potential_last_test;
2521 if (GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE)
2523 /* A conditional jump. */
2524 dest1 = XEXP (SET_SRC (PATTERN (insn)), 1);
2525 dest2 = XEXP (SET_SRC (PATTERN (insn)), 2);
2526 potential_last_test = insn;
2530 /* An unconditional jump. */
2531 dest1 = SET_SRC (PATTERN (insn));
2532 /* Include the BARRIER after the JUMP. */
2533 potential_last_test = NEXT_INSN (insn);
2537 if (dest1 && GET_CODE (dest1) == LABEL_REF
2538 && ((XEXP (dest1, 0)
2539 == loop_stack->data.loop.alt_end_label)
2541 == loop_stack->data.loop.end_label)))
2543 last_test_insn = potential_last_test;
2547 /* If this was a conditional jump, there may be
2548 another label at which we should look. */
2555 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2557 /* We found one. Move everything from there up
2558 to the end of the loop, and add a jump into the loop
2559 to jump to there. */
2560 register rtx newstart_label = gen_label_rtx ();
2561 register rtx start_move = start_label;
2564 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2565 then we want to move this note also. */
2566 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2567 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2568 == NOTE_INSN_LOOP_CONT))
2569 start_move = PREV_INSN (start_move);
2571 emit_label_after (newstart_label, PREV_INSN (start_move));
2573 /* Actually move the insns. Start at the beginning, and
2574 keep copying insns until we've copied the
2576 for (insn = start_move; insn; insn = next_insn)
2578 /* Figure out which insn comes after this one. We have
2579 to do this before we move INSN. */
2580 if (insn == last_test_insn)
2581 /* We've moved all the insns. */
2582 next_insn = NULL_RTX;
2584 next_insn = NEXT_INSN (insn);
2586 if (GET_CODE (insn) == NOTE
2587 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2588 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2589 /* We don't want to move NOTE_INSN_BLOCK_BEGs or
2590 NOTE_INSN_BLOCK_ENDs because the correct generation
2591 of debugging information depends on these appearing
2592 in the same order in the RTL and in the tree
2593 structure, where they are represented as BLOCKs.
2594 So, we don't move block notes. Of course, moving
2595 the code inside the block is likely to make it
2596 impossible to debug the instructions in the exit
2597 test, but such is the price of optimization. */
2600 /* Move the INSN. */
2601 reorder_insns (insn, insn, get_last_insn ());
2604 emit_jump_insn_after (gen_jump (start_label),
2605 PREV_INSN (newstart_label));
2606 emit_barrier_after (PREV_INSN (newstart_label));
2607 start_label = newstart_label;
2613 emit_jump (start_label);
2614 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2616 emit_label (loop_stack->data.loop.end_label);
2618 POPSTACK (loop_stack);
2623 /* Generate a jump to the current loop's continue-point.
2624 This is usually the top of the loop, but may be specified
2625 explicitly elsewhere. If not currently inside a loop,
2626 return 0 and do nothing; caller will print an error message. */
2629 expand_continue_loop (whichloop)
2630 struct nesting *whichloop;
2634 whichloop = loop_stack;
2637 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2642 /* Generate a jump to exit the current loop. If not currently inside a loop,
2643 return 0 and do nothing; caller will print an error message. */
2646 expand_exit_loop (whichloop)
2647 struct nesting *whichloop;
2651 whichloop = loop_stack;
2654 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2658 /* Generate a conditional jump to exit the current loop if COND
2659 evaluates to zero. If not currently inside a loop,
2660 return 0 and do nothing; caller will print an error message. */
2663 expand_exit_loop_if_false (whichloop, cond)
2664 struct nesting *whichloop;
2667 rtx label = gen_label_rtx ();
2672 whichloop = loop_stack;
2675 /* In order to handle fixups, we actually create a conditional jump
2676 around a unconditional branch to exit the loop. If fixups are
2677 necessary, they go before the unconditional branch. */
2679 do_jump (cond, NULL_RTX, label);
2680 last_insn = get_last_insn ();
2681 if (GET_CODE (last_insn) == CODE_LABEL)
2682 whichloop->data.loop.alt_end_label = last_insn;
2683 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2690 /* Return nonzero if the loop nest is empty. Else return zero. */
2693 stmt_loop_nest_empty ()
2695 /* cfun->stmt can be NULL if we are building a call to get the
2696 EH context for a setjmp/longjmp EH target and the current
2697 function was a deferred inline function. */
2698 return (cfun->stmt == NULL || loop_stack == NULL);
2701 /* Return non-zero if we should preserve sub-expressions as separate
2702 pseudos. We never do so if we aren't optimizing. We always do so
2703 if -fexpensive-optimizations.
2705 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2706 the loop may still be a small one. */
2709 preserve_subexpressions_p ()
2713 if (flag_expensive_optimizations)
2716 if (optimize == 0 || cfun == 0 || cfun->stmt == 0 || loop_stack == 0)
2719 insn = get_last_insn_anywhere ();
2722 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2723 < n_non_fixed_regs * 3));
2727 /* Generate a jump to exit the current loop, conditional, binding contour
2728 or case statement. Not all such constructs are visible to this function,
2729 only those started with EXIT_FLAG nonzero. Individual languages use
2730 the EXIT_FLAG parameter to control which kinds of constructs you can
2733 If not currently inside anything that can be exited,
2734 return 0 and do nothing; caller will print an error message. */
2737 expand_exit_something ()
2741 for (n = nesting_stack; n; n = n->all)
2742 if (n->exit_label != 0)
2744 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2751 /* Generate RTL to return from the current function, with no value.
2752 (That is, we do not do anything about returning any value.) */
2755 expand_null_return ()
2757 struct nesting *block = block_stack;
2758 rtx last_insn = get_last_insn ();
2760 /* If this function was declared to return a value, but we
2761 didn't, clobber the return registers so that they are not
2762 propogated live to the rest of the function. */
2763 clobber_return_register ();
2765 /* Does any pending block have cleanups? */
2766 while (block && block->data.block.cleanups == 0)
2767 block = block->next;
2769 /* If yes, use a goto to return, since that runs cleanups. */
2771 expand_null_return_1 (last_insn, block != 0);
2774 /* Generate RTL to return from the current function, with value VAL. */
2777 expand_value_return (val)
2780 struct nesting *block = block_stack;
2781 rtx last_insn = get_last_insn ();
2782 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2784 /* Copy the value to the return location
2785 unless it's already there. */
2787 if (return_reg != val)
2789 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2790 #ifdef PROMOTE_FUNCTION_RETURN
2791 int unsignedp = TREE_UNSIGNED (type);
2792 enum machine_mode old_mode
2793 = DECL_MODE (DECL_RESULT (current_function_decl));
2794 enum machine_mode mode
2795 = promote_mode (type, old_mode, &unsignedp, 1);
2797 if (mode != old_mode)
2798 val = convert_modes (mode, old_mode, val, unsignedp);
2800 if (GET_CODE (return_reg) == PARALLEL)
2801 emit_group_load (return_reg, val, int_size_in_bytes (type),
2804 emit_move_insn (return_reg, val);
2807 /* Does any pending block have cleanups? */
2809 while (block && block->data.block.cleanups == 0)
2810 block = block->next;
2812 /* If yes, use a goto to return, since that runs cleanups.
2813 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2815 expand_null_return_1 (last_insn, block != 0);
2818 /* Output a return with no value. If LAST_INSN is nonzero,
2819 pretend that the return takes place after LAST_INSN.
2820 If USE_GOTO is nonzero then don't use a return instruction;
2821 go to the return label instead. This causes any cleanups
2822 of pending blocks to be executed normally. */
2825 expand_null_return_1 (last_insn, use_goto)
2829 rtx end_label = cleanup_label ? cleanup_label : return_label;
2831 clear_pending_stack_adjust ();
2832 do_pending_stack_adjust ();
2835 /* PCC-struct return always uses an epilogue. */
2836 if (current_function_returns_pcc_struct || use_goto)
2839 end_label = return_label = gen_label_rtx ();
2840 expand_goto_internal (NULL_TREE, end_label, last_insn);
2844 /* Otherwise output a simple return-insn if one is available,
2845 unless it won't do the job. */
2847 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2849 emit_jump_insn (gen_return ());
2855 /* Otherwise jump to the epilogue. */
2856 expand_goto_internal (NULL_TREE, end_label, last_insn);
2859 /* Generate RTL to evaluate the expression RETVAL and return it
2860 from the current function. */
2863 expand_return (retval)
2866 /* If there are any cleanups to be performed, then they will
2867 be inserted following LAST_INSN. It is desirable
2868 that the last_insn, for such purposes, should be the
2869 last insn before computing the return value. Otherwise, cleanups
2870 which call functions can clobber the return value. */
2871 /* ??? rms: I think that is erroneous, because in C++ it would
2872 run destructors on variables that might be used in the subsequent
2873 computation of the return value. */
2875 rtx result_rtl = DECL_RTL (DECL_RESULT (current_function_decl));
2876 register rtx val = 0;
2880 /* If function wants no value, give it none. */
2881 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2883 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2885 expand_null_return ();
2889 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2890 /* This is not sufficient. We also need to watch for cleanups of the
2891 expression we are about to expand. Unfortunately, we cannot know
2892 if it has cleanups until we expand it, and we want to change how we
2893 expand it depending upon if we need cleanups. We can't win. */
2895 cleanups = any_pending_cleanups (1);
2900 if (retval == error_mark_node)
2901 retval_rhs = NULL_TREE;
2902 else if (TREE_CODE (retval) == RESULT_DECL)
2903 retval_rhs = retval;
2904 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2905 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2906 retval_rhs = TREE_OPERAND (retval, 1);
2907 else if (VOID_TYPE_P (TREE_TYPE (retval)))
2908 /* Recognize tail-recursive call to void function. */
2909 retval_rhs = retval;
2911 retval_rhs = NULL_TREE;
2913 /* Only use `last_insn' if there are cleanups which must be run. */
2914 if (cleanups || cleanup_label != 0)
2915 last_insn = get_last_insn ();
2917 /* Distribute return down conditional expr if either of the sides
2918 may involve tail recursion (see test below). This enhances the number
2919 of tail recursions we see. Don't do this always since it can produce
2920 sub-optimal code in some cases and we distribute assignments into
2921 conditional expressions when it would help. */
2923 if (optimize && retval_rhs != 0
2924 && frame_offset == 0
2925 && TREE_CODE (retval_rhs) == COND_EXPR
2926 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2927 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2929 rtx label = gen_label_rtx ();
2932 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2933 start_cleanup_deferral ();
2934 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2935 DECL_RESULT (current_function_decl),
2936 TREE_OPERAND (retval_rhs, 1));
2937 TREE_SIDE_EFFECTS (expr) = 1;
2938 expand_return (expr);
2941 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2942 DECL_RESULT (current_function_decl),
2943 TREE_OPERAND (retval_rhs, 2));
2944 TREE_SIDE_EFFECTS (expr) = 1;
2945 expand_return (expr);
2946 end_cleanup_deferral ();
2950 /* If the result is an aggregate that is being returned in one (or more)
2951 registers, load the registers here. The compiler currently can't handle
2952 copying a BLKmode value into registers. We could put this code in a
2953 more general area (for use by everyone instead of just function
2954 call/return), but until this feature is generally usable it is kept here
2955 (and in expand_call). The value must go into a pseudo in case there
2956 are cleanups that will clobber the real return register. */
2959 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2960 && GET_CODE (result_rtl) == REG)
2963 unsigned HOST_WIDE_INT bitpos, xbitpos;
2964 unsigned HOST_WIDE_INT big_endian_correction = 0;
2965 unsigned HOST_WIDE_INT bytes
2966 = int_size_in_bytes (TREE_TYPE (retval_rhs));
2967 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2968 unsigned int bitsize
2969 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)), BITS_PER_WORD);
2970 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2971 rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
2972 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2973 enum machine_mode tmpmode, result_reg_mode;
2975 /* Structures whose size is not a multiple of a word are aligned
2976 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
2977 machine, this means we must skip the empty high order bytes when
2978 calculating the bit offset. */
2979 if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD)
2980 big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
2983 /* Copy the structure BITSIZE bits at a time. */
2984 for (bitpos = 0, xbitpos = big_endian_correction;
2985 bitpos < bytes * BITS_PER_UNIT;
2986 bitpos += bitsize, xbitpos += bitsize)
2988 /* We need a new destination pseudo each time xbitpos is
2989 on a word boundary and when xbitpos == big_endian_correction
2990 (the first time through). */
2991 if (xbitpos % BITS_PER_WORD == 0
2992 || xbitpos == big_endian_correction)
2994 /* Generate an appropriate register. */
2995 dst = gen_reg_rtx (word_mode);
2996 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
2998 /* Clobber the destination before we move anything into it. */
2999 emit_insn (gen_rtx_CLOBBER (VOIDmode, dst));
3002 /* We need a new source operand each time bitpos is on a word
3004 if (bitpos % BITS_PER_WORD == 0)
3005 src = operand_subword_force (result_val,
3006 bitpos / BITS_PER_WORD,
3009 /* Use bitpos for the source extraction (left justified) and
3010 xbitpos for the destination store (right justified). */
3011 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
3012 extract_bit_field (src, bitsize,
3013 bitpos % BITS_PER_WORD, 1,
3014 NULL_RTX, word_mode, word_mode,
3015 bitsize, BITS_PER_WORD),
3016 bitsize, BITS_PER_WORD);
3019 /* Find the smallest integer mode large enough to hold the
3020 entire structure and use that mode instead of BLKmode
3021 on the USE insn for the return register. */
3022 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
3023 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
3024 tmpmode != VOIDmode;
3025 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
3027 /* Have we found a large enough mode? */
3028 if (GET_MODE_SIZE (tmpmode) >= bytes)
3032 /* No suitable mode found. */
3033 if (tmpmode == VOIDmode)
3036 PUT_MODE (result_rtl, tmpmode);
3038 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
3039 result_reg_mode = word_mode;
3041 result_reg_mode = tmpmode;
3042 result_reg = gen_reg_rtx (result_reg_mode);
3045 for (i = 0; i < n_regs; i++)
3046 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
3049 if (tmpmode != result_reg_mode)
3050 result_reg = gen_lowpart (tmpmode, result_reg);
3052 expand_value_return (result_reg);
3056 && !VOID_TYPE_P (TREE_TYPE (retval_rhs))
3057 && (GET_CODE (result_rtl) == REG
3058 || (GET_CODE (result_rtl) == PARALLEL)))
3060 /* Calculate the return value into a temporary (usually a pseudo
3062 val = assign_temp (TREE_TYPE (DECL_RESULT (current_function_decl)),
3064 val = expand_expr (retval_rhs, val, GET_MODE (val), 0);
3065 val = force_not_mem (val);
3067 /* Return the calculated value, doing cleanups first. */
3068 expand_value_return (val);
3072 /* No cleanups or no hard reg used;
3073 calculate value into hard return reg. */
3074 expand_expr (retval, const0_rtx, VOIDmode, 0);
3076 expand_value_return (result_rtl);
3080 /* Return 1 if the end of the generated RTX is not a barrier.
3081 This means code already compiled can drop through. */
3084 drop_through_at_end_p ()
3086 rtx insn = get_last_insn ();
3087 while (insn && GET_CODE (insn) == NOTE)
3088 insn = PREV_INSN (insn);
3089 return insn && GET_CODE (insn) != BARRIER;
3092 /* Attempt to optimize a potential tail recursion call into a goto.
3093 ARGUMENTS are the arguments to a CALL_EXPR; LAST_INSN indicates
3094 where to place the jump to the tail recursion label.
3096 Return TRUE if the call was optimized into a goto. */
3099 optimize_tail_recursion (arguments, last_insn)
3103 /* Finish checking validity, and if valid emit code to set the
3104 argument variables for the new call. */
3105 if (tail_recursion_args (arguments, DECL_ARGUMENTS (current_function_decl)))
3107 if (tail_recursion_label == 0)
3109 tail_recursion_label = gen_label_rtx ();
3110 emit_label_after (tail_recursion_label,
3111 tail_recursion_reentry);
3114 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
3121 /* Emit code to alter this function's formal parms for a tail-recursive call.
3122 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3123 FORMALS is the chain of decls of formals.
3124 Return 1 if this can be done;
3125 otherwise return 0 and do not emit any code. */
3128 tail_recursion_args (actuals, formals)
3129 tree actuals, formals;
3131 register tree a = actuals, f = formals;
3133 register rtx *argvec;
3135 /* Check that number and types of actuals are compatible
3136 with the formals. This is not always true in valid C code.
3137 Also check that no formal needs to be addressable
3138 and that all formals are scalars. */
3140 /* Also count the args. */
3142 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
3144 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a)))
3145 != TYPE_MAIN_VARIANT (TREE_TYPE (f)))
3147 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
3150 if (a != 0 || f != 0)
3153 /* Compute all the actuals. */
3155 argvec = (rtx *) alloca (i * sizeof (rtx));
3157 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3158 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
3160 /* Find which actual values refer to current values of previous formals.
3161 Copy each of them now, before any formal is changed. */
3163 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3167 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
3168 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
3174 argvec[i] = copy_to_reg (argvec[i]);
3177 /* Store the values of the actuals into the formals. */
3179 for (f = formals, a = actuals, i = 0; f;
3180 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
3182 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
3183 emit_move_insn (DECL_RTL (f), argvec[i]);
3185 convert_move (DECL_RTL (f), argvec[i],
3186 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
3193 /* Generate the RTL code for entering a binding contour.
3194 The variables are declared one by one, by calls to `expand_decl'.
3196 FLAGS is a bitwise or of the following flags:
3198 1 - Nonzero if this construct should be visible to
3201 2 - Nonzero if this contour does not require a
3202 NOTE_INSN_BLOCK_BEG note. Virtually all calls from
3203 language-independent code should set this flag because they
3204 will not create corresponding BLOCK nodes. (There should be
3205 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
3206 and BLOCKs.) If this flag is set, MARK_ENDS should be zero
3207 when expand_end_bindings is called.
3209 If we are creating a NOTE_INSN_BLOCK_BEG note, a BLOCK may
3210 optionally be supplied. If so, it becomes the NOTE_BLOCK for the
3214 expand_start_bindings_and_block (flags, block)
3218 struct nesting *thisblock = ALLOC_NESTING ();
3220 int exit_flag = ((flags & 1) != 0);
3221 int block_flag = ((flags & 2) == 0);
3223 /* If a BLOCK is supplied, then the caller should be requesting a
3224 NOTE_INSN_BLOCK_BEG note. */
3225 if (!block_flag && block)
3228 /* Create a note to mark the beginning of the block. */
3231 note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
3232 NOTE_BLOCK (note) = block;
3235 note = emit_note (NULL_PTR, NOTE_INSN_DELETED);
3237 /* Make an entry on block_stack for the block we are entering. */
3239 thisblock->next = block_stack;
3240 thisblock->all = nesting_stack;
3241 thisblock->depth = ++nesting_depth;
3242 thisblock->data.block.stack_level = 0;
3243 thisblock->data.block.cleanups = 0;
3244 thisblock->data.block.n_function_calls = 0;
3245 thisblock->data.block.exception_region = 0;
3246 thisblock->data.block.block_target_temp_slot_level = target_temp_slot_level;
3248 thisblock->data.block.conditional_code = 0;
3249 thisblock->data.block.last_unconditional_cleanup = note;
3250 /* When we insert instructions after the last unconditional cleanup,
3251 we don't adjust last_insn. That means that a later add_insn will
3252 clobber the instructions we've just added. The easiest way to
3253 fix this is to just insert another instruction here, so that the
3254 instructions inserted after the last unconditional cleanup are
3255 never the last instruction. */
3256 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3257 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
3260 && !(block_stack->data.block.cleanups == NULL_TREE
3261 && block_stack->data.block.outer_cleanups == NULL_TREE))
3262 thisblock->data.block.outer_cleanups
3263 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
3264 block_stack->data.block.outer_cleanups);
3266 thisblock->data.block.outer_cleanups = 0;
3267 thisblock->data.block.label_chain = 0;
3268 thisblock->data.block.innermost_stack_block = stack_block_stack;
3269 thisblock->data.block.first_insn = note;
3270 thisblock->data.block.block_start_count = ++current_block_start_count;
3271 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
3272 block_stack = thisblock;
3273 nesting_stack = thisblock;
3275 /* Make a new level for allocating stack slots. */
3279 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3280 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3281 expand_expr are made. After we end the region, we know that all
3282 space for all temporaries that were created by TARGET_EXPRs will be
3283 destroyed and their space freed for reuse. */
3286 expand_start_target_temps ()
3288 /* This is so that even if the result is preserved, the space
3289 allocated will be freed, as we know that it is no longer in use. */
3292 /* Start a new binding layer that will keep track of all cleanup
3293 actions to be performed. */
3294 expand_start_bindings (2);
3296 target_temp_slot_level = temp_slot_level;
3300 expand_end_target_temps ()
3302 expand_end_bindings (NULL_TREE, 0, 0);
3304 /* This is so that even if the result is preserved, the space
3305 allocated will be freed, as we know that it is no longer in use. */
3309 /* Given a pointer to a BLOCK node return non-zero if (and only if) the node
3310 in question represents the outermost pair of curly braces (i.e. the "body
3311 block") of a function or method.
3313 For any BLOCK node representing a "body block" of a function or method, the
3314 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
3315 represents the outermost (function) scope for the function or method (i.e.
3316 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
3317 *that* node in turn will point to the relevant FUNCTION_DECL node. */
3320 is_body_block (stmt)
3323 if (TREE_CODE (stmt) == BLOCK)
3325 tree parent = BLOCK_SUPERCONTEXT (stmt);
3327 if (parent && TREE_CODE (parent) == BLOCK)
3329 tree grandparent = BLOCK_SUPERCONTEXT (parent);
3331 if (grandparent && TREE_CODE (grandparent) == FUNCTION_DECL)
3339 /* Mark top block of block_stack as an implicit binding for an
3340 exception region. This is used to prevent infinite recursion when
3341 ending a binding with expand_end_bindings. It is only ever called
3342 by expand_eh_region_start, as that it the only way to create a
3343 block stack for a exception region. */
3346 mark_block_as_eh_region ()
3348 block_stack->data.block.exception_region = 1;
3349 if (block_stack->next
3350 && block_stack->next->data.block.conditional_code)
3352 block_stack->data.block.conditional_code
3353 = block_stack->next->data.block.conditional_code;
3354 block_stack->data.block.last_unconditional_cleanup
3355 = block_stack->next->data.block.last_unconditional_cleanup;
3356 block_stack->data.block.cleanup_ptr
3357 = block_stack->next->data.block.cleanup_ptr;
3361 /* True if we are currently emitting insns in an area of output code
3362 that is controlled by a conditional expression. This is used by
3363 the cleanup handling code to generate conditional cleanup actions. */
3366 conditional_context ()
3368 return block_stack && block_stack->data.block.conditional_code;
3371 /* Mark top block of block_stack as not for an implicit binding for an
3372 exception region. This is only ever done by expand_eh_region_end
3373 to let expand_end_bindings know that it is being called explicitly
3374 to end the binding layer for just the binding layer associated with
3375 the exception region, otherwise expand_end_bindings would try and
3376 end all implicit binding layers for exceptions regions, and then
3377 one normal binding layer. */
3380 mark_block_as_not_eh_region ()
3382 block_stack->data.block.exception_region = 0;
3385 /* True if the top block of block_stack was marked as for an exception
3386 region by mark_block_as_eh_region. */
3391 return cfun && block_stack && block_stack->data.block.exception_region;
3394 /* Emit a handler label for a nonlocal goto handler.
3395 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3398 expand_nl_handler_label (slot, before_insn)
3399 rtx slot, before_insn;
3402 rtx handler_label = gen_label_rtx ();
3404 /* Don't let jump_optimize delete the handler. */
3405 LABEL_PRESERVE_P (handler_label) = 1;
3408 emit_move_insn (slot, gen_rtx_LABEL_REF (Pmode, handler_label));
3409 insns = get_insns ();
3411 emit_insns_before (insns, before_insn);
3413 emit_label (handler_label);
3415 return handler_label;
3418 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3421 expand_nl_goto_receiver ()
3423 #ifdef HAVE_nonlocal_goto
3424 if (! HAVE_nonlocal_goto)
3426 /* First adjust our frame pointer to its actual value. It was
3427 previously set to the start of the virtual area corresponding to
3428 the stacked variables when we branched here and now needs to be
3429 adjusted to the actual hardware fp value.
3431 Assignments are to virtual registers are converted by
3432 instantiate_virtual_regs into the corresponding assignment
3433 to the underlying register (fp in this case) that makes
3434 the original assignment true.
3435 So the following insn will actually be
3436 decrementing fp by STARTING_FRAME_OFFSET. */
3437 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3439 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3440 if (fixed_regs[ARG_POINTER_REGNUM])
3442 #ifdef ELIMINABLE_REGS
3443 /* If the argument pointer can be eliminated in favor of the
3444 frame pointer, we don't need to restore it. We assume here
3445 that if such an elimination is present, it can always be used.
3446 This is the case on all known machines; if we don't make this
3447 assumption, we do unnecessary saving on many machines. */
3448 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3451 for (i = 0; i < ARRAY_SIZE (elim_regs); i++)
3452 if (elim_regs[i].from == ARG_POINTER_REGNUM
3453 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3456 if (i == ARRAY_SIZE (elim_regs))
3459 /* Now restore our arg pointer from the address at which it
3460 was saved in our stack frame.
3461 If there hasn't be space allocated for it yet, make
3463 if (arg_pointer_save_area == 0)
3464 arg_pointer_save_area
3465 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3466 emit_move_insn (virtual_incoming_args_rtx,
3467 /* We need a pseudo here, or else
3468 instantiate_virtual_regs_1 complains. */
3469 copy_to_reg (arg_pointer_save_area));
3474 #ifdef HAVE_nonlocal_goto_receiver
3475 if (HAVE_nonlocal_goto_receiver)
3476 emit_insn (gen_nonlocal_goto_receiver ());
3480 /* Make handlers for nonlocal gotos taking place in the function calls in
3484 expand_nl_goto_receivers (thisblock)
3485 struct nesting *thisblock;
3488 rtx afterward = gen_label_rtx ();
3493 /* Record the handler address in the stack slot for that purpose,
3494 during this block, saving and restoring the outer value. */
3495 if (thisblock->next != 0)
3496 for (slot = nonlocal_goto_handler_slots; slot; slot = XEXP (slot, 1))
3498 rtx save_receiver = gen_reg_rtx (Pmode);
3499 emit_move_insn (XEXP (slot, 0), save_receiver);
3502 emit_move_insn (save_receiver, XEXP (slot, 0));
3503 insns = get_insns ();
3505 emit_insns_before (insns, thisblock->data.block.first_insn);
3508 /* Jump around the handlers; they run only when specially invoked. */
3509 emit_jump (afterward);
3511 /* Make a separate handler for each label. */
3512 link = nonlocal_labels;
3513 slot = nonlocal_goto_handler_slots;
3514 label_list = NULL_RTX;
3515 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3516 /* Skip any labels we shouldn't be able to jump to from here,
3517 we generate one special handler for all of them below which just calls
3519 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3522 lab = expand_nl_handler_label (XEXP (slot, 0),
3523 thisblock->data.block.first_insn);
3524 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3526 expand_nl_goto_receiver ();
3528 /* Jump to the "real" nonlocal label. */
3529 expand_goto (TREE_VALUE (link));
3532 /* A second pass over all nonlocal labels; this time we handle those
3533 we should not be able to jump to at this point. */
3534 link = nonlocal_labels;
3535 slot = nonlocal_goto_handler_slots;
3537 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3538 if (DECL_TOO_LATE (TREE_VALUE (link)))
3541 lab = expand_nl_handler_label (XEXP (slot, 0),
3542 thisblock->data.block.first_insn);
3543 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3549 expand_nl_goto_receiver ();
3550 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "abort"), 0,
3555 nonlocal_goto_handler_labels = label_list;
3556 emit_label (afterward);
3559 /* Warn about any unused VARS (which may contain nodes other than
3560 VAR_DECLs, but such nodes are ignored). The nodes are connected
3561 via the TREE_CHAIN field. */
3564 warn_about_unused_variables (vars)
3569 if (warn_unused_variable)
3570 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3571 if (TREE_CODE (decl) == VAR_DECL
3572 && ! TREE_USED (decl)
3573 && ! DECL_IN_SYSTEM_HEADER (decl)
3574 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
3575 warning_with_decl (decl, "unused variable `%s'");
3578 /* Generate RTL code to terminate a binding contour.
3580 VARS is the chain of VAR_DECL nodes for the variables bound in this
3581 contour. There may actually be other nodes in this chain, but any
3582 nodes other than VAR_DECLS are ignored.
3584 MARK_ENDS is nonzero if we should put a note at the beginning
3585 and end of this binding contour.
3587 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3588 (That is true automatically if the contour has a saved stack level.) */
3591 expand_end_bindings (vars, mark_ends, dont_jump_in)
3596 register struct nesting *thisblock;
3598 while (block_stack->data.block.exception_region)
3600 /* Because we don't need or want a new temporary level and
3601 because we didn't create one in expand_eh_region_start,
3602 create a fake one now to avoid removing one in
3603 expand_end_bindings. */
3606 block_stack->data.block.exception_region = 0;
3608 expand_end_bindings (NULL_TREE, 0, 0);
3611 /* Since expand_eh_region_start does an expand_start_bindings, we
3612 have to first end all the bindings that were created by
3613 expand_eh_region_start. */
3615 thisblock = block_stack;
3617 /* If any of the variables in this scope were not used, warn the
3619 warn_about_unused_variables (vars);
3621 if (thisblock->exit_label)
3623 do_pending_stack_adjust ();
3624 emit_label (thisblock->exit_label);
3627 /* If necessary, make handlers for nonlocal gotos taking
3628 place in the function calls in this block. */
3629 if (function_call_count != thisblock->data.block.n_function_calls
3631 /* Make handler for outermost block
3632 if there were any nonlocal gotos to this function. */
3633 && (thisblock->next == 0 ? current_function_has_nonlocal_label
3634 /* Make handler for inner block if it has something
3635 special to do when you jump out of it. */
3636 : (thisblock->data.block.cleanups != 0
3637 || thisblock->data.block.stack_level != 0)))
3638 expand_nl_goto_receivers (thisblock);
3640 /* Don't allow jumping into a block that has a stack level.
3641 Cleanups are allowed, though. */
3643 || thisblock->data.block.stack_level != 0)
3645 struct label_chain *chain;
3647 /* Any labels in this block are no longer valid to go to.
3648 Mark them to cause an error message. */
3649 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3651 DECL_TOO_LATE (chain->label) = 1;
3652 /* If any goto without a fixup came to this label,
3653 that must be an error, because gotos without fixups
3654 come from outside all saved stack-levels. */
3655 if (TREE_ADDRESSABLE (chain->label))
3656 error_with_decl (chain->label,
3657 "label `%s' used before containing binding contour");
3661 /* Restore stack level in effect before the block
3662 (only if variable-size objects allocated). */
3663 /* Perform any cleanups associated with the block. */
3665 if (thisblock->data.block.stack_level != 0
3666 || thisblock->data.block.cleanups != 0)
3671 /* Don't let cleanups affect ({...}) constructs. */
3672 int old_expr_stmts_for_value = expr_stmts_for_value;
3673 rtx old_last_expr_value = last_expr_value;
3674 tree old_last_expr_type = last_expr_type;
3675 expr_stmts_for_value = 0;
3677 /* Only clean up here if this point can actually be reached. */
3678 insn = get_last_insn ();
3679 if (GET_CODE (insn) == NOTE)
3680 insn = prev_nonnote_insn (insn);
3681 reachable = (! insn || GET_CODE (insn) != BARRIER);
3683 /* Do the cleanups. */
3684 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3686 do_pending_stack_adjust ();
3688 expr_stmts_for_value = old_expr_stmts_for_value;
3689 last_expr_value = old_last_expr_value;
3690 last_expr_type = old_last_expr_type;
3692 /* Restore the stack level. */
3694 if (reachable && thisblock->data.block.stack_level != 0)
3696 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3697 thisblock->data.block.stack_level, NULL_RTX);
3698 if (nonlocal_goto_handler_slots != 0)
3699 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3703 /* Any gotos out of this block must also do these things.
3704 Also report any gotos with fixups that came to labels in this
3706 fixup_gotos (thisblock,
3707 thisblock->data.block.stack_level,
3708 thisblock->data.block.cleanups,
3709 thisblock->data.block.first_insn,
3713 /* Mark the beginning and end of the scope if requested.
3714 We do this now, after running cleanups on the variables
3715 just going out of scope, so they are in scope for their cleanups. */
3719 rtx note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3720 NOTE_BLOCK (note) = NOTE_BLOCK (thisblock->data.block.first_insn);
3723 /* Get rid of the beginning-mark if we don't make an end-mark. */
3724 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3726 /* Restore the temporary level of TARGET_EXPRs. */
3727 target_temp_slot_level = thisblock->data.block.block_target_temp_slot_level;
3729 /* Restore block_stack level for containing block. */
3731 stack_block_stack = thisblock->data.block.innermost_stack_block;
3732 POPSTACK (block_stack);
3734 /* Pop the stack slot nesting and free any slots at this level. */
3738 /* Generate code to save the stack pointer at the start of the current block
3739 and set up to restore it on exit. */
3742 save_stack_pointer ()
3744 struct nesting *thisblock = block_stack;
3746 if (thisblock->data.block.stack_level == 0)
3748 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3749 &thisblock->data.block.stack_level,
3750 thisblock->data.block.first_insn);
3751 stack_block_stack = thisblock;
3755 /* Generate RTL for the automatic variable declaration DECL.
3756 (Other kinds of declarations are simply ignored if seen here.) */
3762 struct nesting *thisblock;
3765 type = TREE_TYPE (decl);
3767 /* Only automatic variables need any expansion done.
3768 Static and external variables, and external functions,
3769 will be handled by `assemble_variable' (called from finish_decl).
3770 TYPE_DECL and CONST_DECL require nothing.
3771 PARM_DECLs are handled in `assign_parms'. */
3773 if (TREE_CODE (decl) != VAR_DECL)
3775 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3778 thisblock = block_stack;
3780 /* Create the RTL representation for the variable. */
3782 if (type == error_mark_node)
3783 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, const0_rtx);
3784 else if (DECL_SIZE (decl) == 0)
3785 /* Variable with incomplete type. */
3787 if (DECL_INITIAL (decl) == 0)
3788 /* Error message was already done; now avoid a crash. */
3789 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3791 /* An initializer is going to decide the size of this array.
3792 Until we know the size, represent its address with a reg. */
3793 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode));
3795 set_mem_attributes (DECL_RTL (decl), decl, 1);
3797 else if (DECL_MODE (decl) != BLKmode
3798 /* If -ffloat-store, don't put explicit float vars
3800 && !(flag_float_store
3801 && TREE_CODE (type) == REAL_TYPE)
3802 && ! TREE_THIS_VOLATILE (decl)
3803 && ! TREE_ADDRESSABLE (decl)
3804 && (DECL_REGISTER (decl) || optimize)
3805 /* if -fcheck-memory-usage, check all variables. */
3806 && ! current_function_check_memory_usage)
3808 /* Automatic variable that can go in a register. */
3809 int unsignedp = TREE_UNSIGNED (type);
3810 enum machine_mode reg_mode
3811 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3813 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3814 mark_user_reg (DECL_RTL (decl));
3816 if (POINTER_TYPE_P (type))
3817 mark_reg_pointer (DECL_RTL (decl),
3818 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
3820 maybe_set_unchanging (DECL_RTL (decl), decl);
3823 else if (TREE_CODE (DECL_SIZE_UNIT (decl)) == INTEGER_CST
3824 && ! (flag_stack_check && ! STACK_CHECK_BUILTIN
3825 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl),
3826 STACK_CHECK_MAX_VAR_SIZE)))
3828 /* Variable of fixed size that goes on the stack. */
3832 /* If we previously made RTL for this decl, it must be an array
3833 whose size was determined by the initializer.
3834 The old address was a register; set that register now
3835 to the proper address. */
3836 if (DECL_RTL (decl) != 0)
3838 if (GET_CODE (DECL_RTL (decl)) != MEM
3839 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3841 oldaddr = XEXP (DECL_RTL (decl), 0);
3844 DECL_RTL (decl) = assign_temp (TREE_TYPE (decl), 1, 1, 1);
3846 /* Set alignment we actually gave this decl. */
3847 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3848 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3849 DECL_USER_ALIGN (decl) = 0;
3853 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3854 if (addr != oldaddr)
3855 emit_move_insn (oldaddr, addr);
3859 /* Dynamic-size object: must push space on the stack. */
3863 /* Record the stack pointer on entry to block, if have
3864 not already done so. */
3865 do_pending_stack_adjust ();
3866 save_stack_pointer ();
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 cond = build_decl (VAR_DECL, NULL_TREE, type_for_mode (word_mode, 1));
4002 DECL_RTL (cond) = flag;
4004 /* Conditionalize the cleanup. */
4005 cleanup = build (COND_EXPR, void_type_node,
4006 truthvalue_conversion (cond),
4007 cleanup, integer_zero_node);
4008 cleanup = fold (cleanup);
4010 cleanups = thisblock->data.block.cleanup_ptr;
4013 cleanup = unsave_expr (cleanup);
4015 t = *cleanups = tree_cons (decl, cleanup, *cleanups);
4018 /* If this block has a cleanup, it belongs in stack_block_stack. */
4019 stack_block_stack = thisblock;
4026 /* If this was optimized so that there is no exception region for the
4027 cleanup, then mark the TREE_LIST node, so that we can later tell
4028 if we need to call expand_eh_region_end. */
4029 if (! using_eh_for_cleanups_p
4030 || expand_eh_region_start_tree (decl, cleanup))
4031 TREE_ADDRESSABLE (t) = 1;
4032 /* If that started a new EH region, we're in a new block. */
4033 thisblock = block_stack;
4040 thisblock->data.block.last_unconditional_cleanup
4041 = emit_insns_after (seq,
4042 thisblock->data.block.last_unconditional_cleanup);
4046 thisblock->data.block.last_unconditional_cleanup
4048 /* When we insert instructions after the last unconditional cleanup,
4049 we don't adjust last_insn. That means that a later add_insn will
4050 clobber the instructions we've just added. The easiest way to
4051 fix this is to just insert another instruction here, so that the
4052 instructions inserted after the last unconditional cleanup are
4053 never the last instruction. */
4054 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4055 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
4061 /* Like expand_decl_cleanup, but suppress generating an exception handler
4062 to perform the cleanup. */
4066 expand_decl_cleanup_no_eh (decl, cleanup)
4069 int save_eh = using_eh_for_cleanups_p;
4072 using_eh_for_cleanups_p = 0;
4073 result = expand_decl_cleanup (decl, cleanup);
4074 using_eh_for_cleanups_p = save_eh;
4080 /* Arrange for the top element of the dynamic cleanup chain to be
4081 popped if we exit the current binding contour. DECL is the
4082 associated declaration, if any, otherwise NULL_TREE. If the
4083 current contour is left via an exception, then __sjthrow will pop
4084 the top element off the dynamic cleanup chain. The code that
4085 avoids doing the action we push into the cleanup chain in the
4086 exceptional case is contained in expand_cleanups.
4088 This routine is only used by expand_eh_region_start, and that is
4089 the only way in which an exception region should be started. This
4090 routine is only used when using the setjmp/longjmp codegen method
4091 for exception handling. */
4094 expand_dcc_cleanup (decl)
4097 struct nesting *thisblock;
4100 /* Error if we are not in any block. */
4101 if (cfun == 0 || block_stack == 0)
4103 thisblock = block_stack;
4105 /* Record the cleanup for the dynamic handler chain. */
4107 cleanup = make_node (POPDCC_EXPR);
4109 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4110 thisblock->data.block.cleanups
4111 = tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4113 /* If this block has a cleanup, it belongs in stack_block_stack. */
4114 stack_block_stack = thisblock;
4118 /* Arrange for the top element of the dynamic handler chain to be
4119 popped if we exit the current binding contour. DECL is the
4120 associated declaration, if any, otherwise NULL_TREE. If the current
4121 contour is left via an exception, then __sjthrow will pop the top
4122 element off the dynamic handler chain. The code that avoids doing
4123 the action we push into the handler chain in the exceptional case
4124 is contained in expand_cleanups.
4126 This routine is only used by expand_eh_region_start, and that is
4127 the only way in which an exception region should be started. This
4128 routine is only used when using the setjmp/longjmp codegen method
4129 for exception handling. */
4132 expand_dhc_cleanup (decl)
4135 struct nesting *thisblock;
4138 /* Error if we are not in any block. */
4139 if (cfun == 0 || block_stack == 0)
4141 thisblock = block_stack;
4143 /* Record the cleanup for the dynamic handler chain. */
4145 cleanup = make_node (POPDHC_EXPR);
4147 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4148 thisblock->data.block.cleanups
4149 = tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4151 /* If this block has a cleanup, it belongs in stack_block_stack. */
4152 stack_block_stack = thisblock;
4156 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4157 DECL_ELTS is the list of elements that belong to DECL's type.
4158 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4161 expand_anon_union_decl (decl, cleanup, decl_elts)
4162 tree decl, cleanup, decl_elts;
4164 struct nesting *thisblock = cfun == 0 ? 0 : block_stack;
4168 /* If any of the elements are addressable, so is the entire union. */
4169 for (t = decl_elts; t; t = TREE_CHAIN (t))
4170 if (TREE_ADDRESSABLE (TREE_VALUE (t)))
4172 TREE_ADDRESSABLE (decl) = 1;
4177 expand_decl_cleanup (decl, cleanup);
4178 x = DECL_RTL (decl);
4180 /* Go through the elements, assigning RTL to each. */
4181 for (t = decl_elts; t; t = TREE_CHAIN (t))
4183 tree decl_elt = TREE_VALUE (t);
4184 tree cleanup_elt = TREE_PURPOSE (t);
4185 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
4187 /* Propagate the union's alignment to the elements. */
4188 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
4189 DECL_USER_ALIGN (decl_elt) = DECL_USER_ALIGN (decl);
4191 /* If the element has BLKmode and the union doesn't, the union is
4192 aligned such that the element doesn't need to have BLKmode, so
4193 change the element's mode to the appropriate one for its size. */
4194 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
4195 DECL_MODE (decl_elt) = mode
4196 = mode_for_size_tree (DECL_SIZE (decl_elt), MODE_INT, 1);
4198 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4199 instead create a new MEM rtx with the proper mode. */
4200 if (GET_CODE (x) == MEM)
4202 if (mode == GET_MODE (x))
4203 DECL_RTL (decl_elt) = x;
4206 DECL_RTL (decl_elt) = gen_rtx_MEM (mode, copy_rtx (XEXP (x, 0)));
4207 MEM_COPY_ATTRIBUTES (DECL_RTL (decl_elt), x);
4210 else if (GET_CODE (x) == REG)
4212 if (mode == GET_MODE (x))
4213 DECL_RTL (decl_elt) = x;
4215 DECL_RTL (decl_elt) = gen_rtx_SUBREG (mode, x, 0);
4220 /* Record the cleanup if there is one. */
4223 thisblock->data.block.cleanups
4224 = tree_cons (decl_elt, cleanup_elt,
4225 thisblock->data.block.cleanups);
4229 /* Expand a list of cleanups LIST.
4230 Elements may be expressions or may be nested lists.
4232 If DONT_DO is nonnull, then any list-element
4233 whose TREE_PURPOSE matches DONT_DO is omitted.
4234 This is sometimes used to avoid a cleanup associated with
4235 a value that is being returned out of the scope.
4237 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
4238 goto and handle protection regions specially in that case.
4240 If REACHABLE, we emit code, otherwise just inform the exception handling
4241 code about this finalization. */
4244 expand_cleanups (list, dont_do, in_fixup, reachable)
4251 for (tail = list; tail; tail = TREE_CHAIN (tail))
4252 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
4254 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
4255 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
4260 tree cleanup = TREE_VALUE (tail);
4262 /* See expand_d{h,c}c_cleanup for why we avoid this. */
4263 if (TREE_CODE (cleanup) != POPDHC_EXPR
4264 && TREE_CODE (cleanup) != POPDCC_EXPR
4265 /* See expand_eh_region_start_tree for this case. */
4266 && ! TREE_ADDRESSABLE (tail))
4268 cleanup = protect_with_terminate (cleanup);
4269 expand_eh_region_end (cleanup);
4275 /* Cleanups may be run multiple times. For example,
4276 when exiting a binding contour, we expand the
4277 cleanups associated with that contour. When a goto
4278 within that binding contour has a target outside that
4279 contour, it will expand all cleanups from its scope to
4280 the target. Though the cleanups are expanded multiple
4281 times, the control paths are non-overlapping so the
4282 cleanups will not be executed twice. */
4284 /* We may need to protect fixups with rethrow regions. */
4285 int protect = (in_fixup && ! TREE_ADDRESSABLE (tail));
4288 expand_fixup_region_start ();
4290 /* The cleanup might contain try-blocks, so we have to
4291 preserve our current queue. */
4293 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
4296 expand_fixup_region_end (TREE_VALUE (tail));
4303 /* Mark when the context we are emitting RTL for as a conditional
4304 context, so that any cleanup actions we register with
4305 expand_decl_init will be properly conditionalized when those
4306 cleanup actions are later performed. Must be called before any
4307 expression (tree) is expanded that is within a conditional context. */
4310 start_cleanup_deferral ()
4312 /* block_stack can be NULL if we are inside the parameter list. It is
4313 OK to do nothing, because cleanups aren't possible here. */
4315 ++block_stack->data.block.conditional_code;
4318 /* Mark the end of a conditional region of code. Because cleanup
4319 deferrals may be nested, we may still be in a conditional region
4320 after we end the currently deferred cleanups, only after we end all
4321 deferred cleanups, are we back in unconditional code. */
4324 end_cleanup_deferral ()
4326 /* block_stack can be NULL if we are inside the parameter list. It is
4327 OK to do nothing, because cleanups aren't possible here. */
4329 --block_stack->data.block.conditional_code;
4332 /* Move all cleanups from the current block_stack
4333 to the containing block_stack, where they are assumed to
4334 have been created. If anything can cause a temporary to
4335 be created, but not expanded for more than one level of
4336 block_stacks, then this code will have to change. */
4341 struct nesting *block = block_stack;
4342 struct nesting *outer = block->next;
4344 outer->data.block.cleanups
4345 = chainon (block->data.block.cleanups,
4346 outer->data.block.cleanups);
4347 block->data.block.cleanups = 0;
4351 last_cleanup_this_contour ()
4353 if (block_stack == 0)
4356 return block_stack->data.block.cleanups;
4359 /* Return 1 if there are any pending cleanups at this point.
4360 If THIS_CONTOUR is nonzero, check the current contour as well.
4361 Otherwise, look only at the contours that enclose this one. */
4364 any_pending_cleanups (this_contour)
4367 struct nesting *block;
4369 if (cfun == NULL || cfun->stmt == NULL || block_stack == 0)
4372 if (this_contour && block_stack->data.block.cleanups != NULL)
4374 if (block_stack->data.block.cleanups == 0
4375 && block_stack->data.block.outer_cleanups == 0)
4378 for (block = block_stack->next; block; block = block->next)
4379 if (block->data.block.cleanups != 0)
4385 /* Enter a case (Pascal) or switch (C) statement.
4386 Push a block onto case_stack and nesting_stack
4387 to accumulate the case-labels that are seen
4388 and to record the labels generated for the statement.
4390 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4391 Otherwise, this construct is transparent for `exit_something'.
4393 EXPR is the index-expression to be dispatched on.
4394 TYPE is its nominal type. We could simply convert EXPR to this type,
4395 but instead we take short cuts. */
4398 expand_start_case (exit_flag, expr, type, printname)
4402 const char *printname;
4404 register struct nesting *thiscase = ALLOC_NESTING ();
4406 /* Make an entry on case_stack for the case we are entering. */
4408 thiscase->next = case_stack;
4409 thiscase->all = nesting_stack;
4410 thiscase->depth = ++nesting_depth;
4411 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
4412 thiscase->data.case_stmt.case_list = 0;
4413 thiscase->data.case_stmt.index_expr = expr;
4414 thiscase->data.case_stmt.nominal_type = type;
4415 thiscase->data.case_stmt.default_label = 0;
4416 thiscase->data.case_stmt.printname = printname;
4417 thiscase->data.case_stmt.line_number_status = force_line_numbers ();
4418 case_stack = thiscase;
4419 nesting_stack = thiscase;
4421 do_pending_stack_adjust ();
4423 /* Make sure case_stmt.start points to something that won't
4424 need any transformation before expand_end_case. */
4425 if (GET_CODE (get_last_insn ()) != NOTE)
4426 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4428 thiscase->data.case_stmt.start = get_last_insn ();
4430 start_cleanup_deferral ();
4433 /* Start a "dummy case statement" within which case labels are invalid
4434 and are not connected to any larger real case statement.
4435 This can be used if you don't want to let a case statement jump
4436 into the middle of certain kinds of constructs. */
4439 expand_start_case_dummy ()
4441 register struct nesting *thiscase = ALLOC_NESTING ();
4443 /* Make an entry on case_stack for the dummy. */
4445 thiscase->next = case_stack;
4446 thiscase->all = nesting_stack;
4447 thiscase->depth = ++nesting_depth;
4448 thiscase->exit_label = 0;
4449 thiscase->data.case_stmt.case_list = 0;
4450 thiscase->data.case_stmt.start = 0;
4451 thiscase->data.case_stmt.nominal_type = 0;
4452 thiscase->data.case_stmt.default_label = 0;
4453 case_stack = thiscase;
4454 nesting_stack = thiscase;
4455 start_cleanup_deferral ();
4458 /* End a dummy case statement. */
4461 expand_end_case_dummy ()
4463 end_cleanup_deferral ();
4464 POPSTACK (case_stack);
4467 /* Return the data type of the index-expression
4468 of the innermost case statement, or null if none. */
4471 case_index_expr_type ()
4474 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
4481 /* If this is the first label, warn if any insns have been emitted. */
4482 if (case_stack->data.case_stmt.line_number_status >= 0)
4486 restore_line_number_status
4487 (case_stack->data.case_stmt.line_number_status);
4488 case_stack->data.case_stmt.line_number_status = -1;
4490 for (insn = case_stack->data.case_stmt.start;
4492 insn = NEXT_INSN (insn))
4494 if (GET_CODE (insn) == CODE_LABEL)
4496 if (GET_CODE (insn) != NOTE
4497 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4500 insn = PREV_INSN (insn);
4501 while (insn && (GET_CODE (insn) != NOTE || NOTE_LINE_NUMBER (insn) < 0));
4503 /* If insn is zero, then there must have been a syntax error. */
4505 warning_with_file_and_line (NOTE_SOURCE_FILE (insn),
4506 NOTE_LINE_NUMBER (insn),
4507 "unreachable code at beginning of %s",
4508 case_stack->data.case_stmt.printname);
4515 /* Accumulate one case or default label inside a case or switch statement.
4516 VALUE is the value of the case (a null pointer, for a default label).
4517 The function CONVERTER, when applied to arguments T and V,
4518 converts the value V to the type T.
4520 If not currently inside a case or switch statement, return 1 and do
4521 nothing. The caller will print a language-specific error message.
4522 If VALUE is a duplicate or overlaps, return 2 and do nothing
4523 except store the (first) duplicate node in *DUPLICATE.
4524 If VALUE is out of range, return 3 and do nothing.
4525 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4526 Return 0 on success.
4528 Extended to handle range statements. */
4531 pushcase (value, converter, label, duplicate)
4532 register tree value;
4533 tree (*converter) PARAMS ((tree, tree));
4534 register tree label;
4540 /* Fail if not inside a real case statement. */
4541 if (! (case_stack && case_stack->data.case_stmt.start))
4544 if (stack_block_stack
4545 && stack_block_stack->depth > case_stack->depth)
4548 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4549 nominal_type = case_stack->data.case_stmt.nominal_type;
4551 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4552 if (index_type == error_mark_node)
4555 /* Convert VALUE to the type in which the comparisons are nominally done. */
4557 value = (*converter) (nominal_type, value);
4561 /* Fail if this value is out of range for the actual type of the index
4562 (which may be narrower than NOMINAL_TYPE). */
4564 && (TREE_CONSTANT_OVERFLOW (value)
4565 || ! int_fits_type_p (value, index_type)))
4568 return add_case_node (value, value, label, duplicate);
4571 /* Like pushcase but this case applies to all values between VALUE1 and
4572 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4573 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4574 starts at VALUE1 and ends at the highest value of the index type.
4575 If both are NULL, this case applies to all values.
4577 The return value is the same as that of pushcase but there is one
4578 additional error code: 4 means the specified range was empty. */
4581 pushcase_range (value1, value2, converter, label, duplicate)
4582 register tree value1, value2;
4583 tree (*converter) PARAMS ((tree, tree));
4584 register tree label;
4590 /* Fail if not inside a real case statement. */
4591 if (! (case_stack && case_stack->data.case_stmt.start))
4594 if (stack_block_stack
4595 && stack_block_stack->depth > case_stack->depth)
4598 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4599 nominal_type = case_stack->data.case_stmt.nominal_type;
4601 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4602 if (index_type == error_mark_node)
4607 /* Convert VALUEs to type in which the comparisons are nominally done
4608 and replace any unspecified value with the corresponding bound. */
4610 value1 = TYPE_MIN_VALUE (index_type);
4612 value2 = TYPE_MAX_VALUE (index_type);
4614 /* Fail if the range is empty. Do this before any conversion since
4615 we want to allow out-of-range empty ranges. */
4616 if (value2 != 0 && tree_int_cst_lt (value2, value1))
4619 /* If the max was unbounded, use the max of the nominal_type we are
4620 converting to. Do this after the < check above to suppress false
4623 value2 = TYPE_MAX_VALUE (nominal_type);
4625 value1 = (*converter) (nominal_type, value1);
4626 value2 = (*converter) (nominal_type, value2);
4628 /* Fail if these values are out of range. */
4629 if (TREE_CONSTANT_OVERFLOW (value1)
4630 || ! int_fits_type_p (value1, index_type))
4633 if (TREE_CONSTANT_OVERFLOW (value2)
4634 || ! int_fits_type_p (value2, index_type))
4637 return add_case_node (value1, value2, label, duplicate);
4640 /* Do the actual insertion of a case label for pushcase and pushcase_range
4641 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4642 slowdown for large switch statements. */
4645 add_case_node (low, high, label, duplicate)
4650 struct case_node *p, **q, *r;
4652 /* If there's no HIGH value, then this is not a case range; it's
4653 just a simple case label. But that's just a degenerate case
4658 /* Handle default labels specially. */
4661 if (case_stack->data.case_stmt.default_label != 0)
4663 *duplicate = case_stack->data.case_stmt.default_label;
4666 case_stack->data.case_stmt.default_label = label;
4667 expand_label (label);
4671 q = &case_stack->data.case_stmt.case_list;
4678 /* Keep going past elements distinctly greater than HIGH. */
4679 if (tree_int_cst_lt (high, p->low))
4682 /* or distinctly less than LOW. */
4683 else if (tree_int_cst_lt (p->high, low))
4688 /* We have an overlap; this is an error. */
4689 *duplicate = p->code_label;
4694 /* Add this label to the chain, and succeed.
4695 Copy LOW, HIGH so they are on temporary rather than momentary
4696 obstack and will thus survive till the end of the case statement. */
4698 r = (struct case_node *) xmalloc (sizeof (struct case_node));
4699 r->low = copy_node (low);
4701 /* If the bounds are equal, turn this into the one-value case. */
4702 if (tree_int_cst_equal (low, high))
4705 r->high = copy_node (high);
4707 r->code_label = label;
4708 expand_label (label);
4718 struct case_node *s;
4724 if (! (b = p->balance))
4725 /* Growth propagation from left side. */
4732 if ((p->left = s = r->right))
4741 if ((r->parent = s))
4749 case_stack->data.case_stmt.case_list = r;
4752 /* r->balance == +1 */
4757 struct case_node *t = r->right;
4759 if ((p->left = s = t->right))
4763 if ((r->right = s = t->left))
4777 if ((t->parent = s))
4785 case_stack->data.case_stmt.case_list = t;
4792 /* p->balance == +1; growth of left side balances the node. */
4802 if (! (b = p->balance))
4803 /* Growth propagation from right side. */
4811 if ((p->right = s = r->left))
4819 if ((r->parent = s))
4828 case_stack->data.case_stmt.case_list = r;
4832 /* r->balance == -1 */
4836 struct case_node *t = r->left;
4838 if ((p->right = s = t->left))
4843 if ((r->left = s = t->right))
4857 if ((t->parent = s))
4866 case_stack->data.case_stmt.case_list = t;
4872 /* p->balance == -1; growth of right side balances the node. */
4885 /* Returns the number of possible values of TYPE.
4886 Returns -1 if the number is unknown, variable, or if the number does not
4887 fit in a HOST_WIDE_INT.
4888 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4889 do not increase monotonically (there may be duplicates);
4890 to 1 if the values increase monotonically, but not always by 1;
4891 otherwise sets it to 0. */
4894 all_cases_count (type, spareness)
4899 HOST_WIDE_INT count, minval, lastval;
4903 switch (TREE_CODE (type))
4910 count = 1 << BITS_PER_UNIT;
4915 if (TYPE_MAX_VALUE (type) != 0
4916 && 0 != (t = fold (build (MINUS_EXPR, type, TYPE_MAX_VALUE (type),
4917 TYPE_MIN_VALUE (type))))
4918 && 0 != (t = fold (build (PLUS_EXPR, type, t,
4919 convert (type, integer_zero_node))))
4920 && host_integerp (t, 1))
4921 count = tree_low_cst (t, 1);
4927 /* Don't waste time with enumeral types with huge values. */
4928 if (! host_integerp (TYPE_MIN_VALUE (type), 0)
4929 || TYPE_MAX_VALUE (type) == 0
4930 || ! host_integerp (TYPE_MAX_VALUE (type), 0))
4933 lastval = minval = tree_low_cst (TYPE_MIN_VALUE (type), 0);
4936 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4938 HOST_WIDE_INT thisval = tree_low_cst (TREE_VALUE (t), 0);
4940 if (*spareness == 2 || thisval < lastval)
4942 else if (thisval != minval + count)
4952 #define BITARRAY_TEST(ARRAY, INDEX) \
4953 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4954 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4955 #define BITARRAY_SET(ARRAY, INDEX) \
4956 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4957 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4959 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4960 with the case values we have seen, assuming the case expression
4962 SPARSENESS is as determined by all_cases_count.
4964 The time needed is proportional to COUNT, unless
4965 SPARSENESS is 2, in which case quadratic time is needed. */
4968 mark_seen_cases (type, cases_seen, count, sparseness)
4970 unsigned char *cases_seen;
4971 HOST_WIDE_INT count;
4974 tree next_node_to_try = NULL_TREE;
4975 HOST_WIDE_INT next_node_offset = 0;
4977 register struct case_node *n, *root = case_stack->data.case_stmt.case_list;
4978 tree val = make_node (INTEGER_CST);
4980 TREE_TYPE (val) = type;
4984 else if (sparseness == 2)
4987 unsigned HOST_WIDE_INT xlo;
4989 /* This less efficient loop is only needed to handle
4990 duplicate case values (multiple enum constants
4991 with the same value). */
4992 TREE_TYPE (val) = TREE_TYPE (root->low);
4993 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
4994 t = TREE_CHAIN (t), xlo++)
4996 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (TREE_VALUE (t));
4997 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (TREE_VALUE (t));
5001 /* Keep going past elements distinctly greater than VAL. */
5002 if (tree_int_cst_lt (val, n->low))
5005 /* or distinctly less than VAL. */
5006 else if (tree_int_cst_lt (n->high, val))
5011 /* We have found a matching range. */
5012 BITARRAY_SET (cases_seen, xlo);
5022 case_stack->data.case_stmt.case_list = root = case_tree2list (root, 0);
5024 for (n = root; n; n = n->right)
5026 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
5027 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
5028 while (! tree_int_cst_lt (n->high, val))
5030 /* Calculate (into xlo) the "offset" of the integer (val).
5031 The element with lowest value has offset 0, the next smallest
5032 element has offset 1, etc. */
5034 unsigned HOST_WIDE_INT xlo;
5038 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
5040 /* The TYPE_VALUES will be in increasing order, so
5041 starting searching where we last ended. */
5042 t = next_node_to_try;
5043 xlo = next_node_offset;
5049 t = TYPE_VALUES (type);
5052 if (tree_int_cst_equal (val, TREE_VALUE (t)))
5054 next_node_to_try = TREE_CHAIN (t);
5055 next_node_offset = xlo + 1;
5060 if (t == next_node_to_try)
5069 t = TYPE_MIN_VALUE (type);
5071 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
5075 add_double (xlo, xhi,
5076 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5080 if (xhi == 0 && xlo < (unsigned HOST_WIDE_INT) count)
5081 BITARRAY_SET (cases_seen, xlo);
5083 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5085 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
5091 /* Called when the index of a switch statement is an enumerated type
5092 and there is no default label.
5094 Checks that all enumeration literals are covered by the case
5095 expressions of a switch. Also, warn if there are any extra
5096 switch cases that are *not* elements of the enumerated type.
5098 If all enumeration literals were covered by the case expressions,
5099 turn one of the expressions into the default expression since it should
5100 not be possible to fall through such a switch. */
5103 check_for_full_enumeration_handling (type)
5106 register struct case_node *n;
5107 register tree chain;
5108 #if 0 /* variable used by 'if 0'ed code below. */
5109 register struct case_node **l;
5113 /* True iff the selector type is a numbered set mode. */
5116 /* The number of possible selector values. */
5119 /* For each possible selector value. a one iff it has been matched
5120 by a case value alternative. */
5121 unsigned char *cases_seen;
5123 /* The allocated size of cases_seen, in chars. */
5124 HOST_WIDE_INT bytes_needed;
5129 size = all_cases_count (type, &sparseness);
5130 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
5132 if (size > 0 && size < 600000
5133 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5134 this optimization if we don't have enough memory rather than
5135 aborting, as xmalloc would do. */
5136 && (cases_seen = (unsigned char *) calloc (bytes_needed, 1)) != NULL)
5139 tree v = TYPE_VALUES (type);
5141 /* The time complexity of this code is normally O(N), where
5142 N being the number of members in the enumerated type.
5143 However, if type is a ENUMERAL_TYPE whose values do not
5144 increase monotonically, O(N*log(N)) time may be needed. */
5146 mark_seen_cases (type, cases_seen, size, sparseness);
5148 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
5149 if (BITARRAY_TEST (cases_seen, i) == 0)
5150 warning ("enumeration value `%s' not handled in switch",
5151 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
5156 /* Now we go the other way around; we warn if there are case
5157 expressions that don't correspond to enumerators. This can
5158 occur since C and C++ don't enforce type-checking of
5159 assignments to enumeration variables. */
5161 if (case_stack->data.case_stmt.case_list
5162 && case_stack->data.case_stmt.case_list->left)
5163 case_stack->data.case_stmt.case_list
5164 = case_tree2list (case_stack->data.case_stmt.case_list, 0);
5166 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
5168 for (chain = TYPE_VALUES (type);
5169 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
5170 chain = TREE_CHAIN (chain))
5175 if (TYPE_NAME (type) == 0)
5176 warning ("case value `%ld' not in enumerated type",
5177 (long) TREE_INT_CST_LOW (n->low));
5179 warning ("case value `%ld' not in enumerated type `%s'",
5180 (long) TREE_INT_CST_LOW (n->low),
5181 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5184 : DECL_NAME (TYPE_NAME (type))));
5186 if (!tree_int_cst_equal (n->low, n->high))
5188 for (chain = TYPE_VALUES (type);
5189 chain && !tree_int_cst_equal (n->high, 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->high));
5199 warning ("case value `%ld' not in enumerated type `%s'",
5200 (long) TREE_INT_CST_LOW (n->high),
5201 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5204 : DECL_NAME (TYPE_NAME (type))));
5210 /* ??? This optimization is disabled because it causes valid programs to
5211 fail. ANSI C does not guarantee that an expression with enum type
5212 will have a value that is the same as one of the enumeration literals. */
5214 /* If all values were found as case labels, make one of them the default
5215 label. Thus, this switch will never fall through. We arbitrarily pick
5216 the last one to make the default since this is likely the most
5217 efficient choice. */
5221 for (l = &case_stack->data.case_stmt.case_list;
5226 case_stack->data.case_stmt.default_label = (*l)->code_label;
5232 /* Free CN, and its children. */
5235 free_case_nodes (cn)
5240 free_case_nodes (cn->left);
5241 free_case_nodes (cn->right);
5247 /* Terminate a case (Pascal) or switch (C) statement
5248 in which ORIG_INDEX is the expression to be tested.
5249 Generate the code to test it and jump to the right place. */
5252 expand_end_case (orig_index)
5255 tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE, orig_minval;
5256 rtx default_label = 0;
5257 register struct case_node *n;
5265 register struct nesting *thiscase = case_stack;
5266 tree index_expr, index_type;
5269 /* Don't crash due to previous errors. */
5270 if (thiscase == NULL)
5273 table_label = gen_label_rtx ();
5274 index_expr = thiscase->data.case_stmt.index_expr;
5275 index_type = TREE_TYPE (index_expr);
5276 unsignedp = TREE_UNSIGNED (index_type);
5278 do_pending_stack_adjust ();
5280 /* This might get an spurious warning in the presence of a syntax error;
5281 it could be fixed by moving the call to check_seenlabel after the
5282 check for error_mark_node, and copying the code of check_seenlabel that
5283 deals with case_stack->data.case_stmt.line_number_status /
5284 restore_line_number_status in front of the call to end_cleanup_deferral;
5285 However, this might miss some useful warnings in the presence of
5286 non-syntax errors. */
5289 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5290 if (index_type != error_mark_node)
5292 /* If switch expression was an enumerated type, check that all
5293 enumeration literals are covered by the cases.
5294 No sense trying this if there's a default case, however. */
5296 if (!thiscase->data.case_stmt.default_label
5297 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
5298 && TREE_CODE (index_expr) != INTEGER_CST)
5299 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
5301 /* If we don't have a default-label, create one here,
5302 after the body of the switch. */
5303 if (thiscase->data.case_stmt.default_label == 0)
5305 thiscase->data.case_stmt.default_label
5306 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5307 expand_label (thiscase->data.case_stmt.default_label);
5309 default_label = label_rtx (thiscase->data.case_stmt.default_label);
5311 before_case = get_last_insn ();
5313 if (thiscase->data.case_stmt.case_list
5314 && thiscase->data.case_stmt.case_list->left)
5315 thiscase->data.case_stmt.case_list
5316 = case_tree2list (thiscase->data.case_stmt.case_list, 0);
5318 /* Simplify the case-list before we count it. */
5319 group_case_nodes (thiscase->data.case_stmt.case_list);
5321 /* Get upper and lower bounds of case values.
5322 Also convert all the case values to the index expr's data type. */
5325 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5327 /* Check low and high label values are integers. */
5328 if (TREE_CODE (n->low) != INTEGER_CST)
5330 if (TREE_CODE (n->high) != INTEGER_CST)
5333 n->low = convert (index_type, n->low);
5334 n->high = convert (index_type, n->high);
5336 /* Count the elements and track the largest and smallest
5337 of them (treating them as signed even if they are not). */
5345 if (INT_CST_LT (n->low, minval))
5347 if (INT_CST_LT (maxval, n->high))
5350 /* A range counts double, since it requires two compares. */
5351 if (! tree_int_cst_equal (n->low, n->high))
5355 orig_minval = minval;
5357 /* Compute span of values. */
5359 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
5361 end_cleanup_deferral ();
5365 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
5367 emit_jump (default_label);
5370 /* If range of values is much bigger than number of values,
5371 make a sequence of conditional branches instead of a dispatch.
5372 If the switch-index is a constant, do it this way
5373 because we can optimize it. */
5375 #ifndef CASE_VALUES_THRESHOLD
5377 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
5379 /* If machine does not have a case insn that compares the
5380 bounds, this means extra overhead for dispatch tables
5381 which raises the threshold for using them. */
5382 #define CASE_VALUES_THRESHOLD 5
5383 #endif /* HAVE_casesi */
5384 #endif /* CASE_VALUES_THRESHOLD */
5386 else if (count < CASE_VALUES_THRESHOLD
5387 || compare_tree_int (range, 10 * count) > 0
5388 /* RANGE may be signed, and really large ranges will show up
5389 as negative numbers. */
5390 || compare_tree_int (range, 0) < 0
5391 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5394 || TREE_CODE (index_expr) == INTEGER_CST
5395 /* These will reduce to a constant. */
5396 || (TREE_CODE (index_expr) == CALL_EXPR
5397 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
5398 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
5399 && DECL_BUILT_IN_CLASS (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_NORMAL
5400 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
5401 || (TREE_CODE (index_expr) == COMPOUND_EXPR
5402 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
5404 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5406 /* If the index is a short or char that we do not have
5407 an insn to handle comparisons directly, convert it to
5408 a full integer now, rather than letting each comparison
5409 generate the conversion. */
5411 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
5412 && (cmp_optab->handlers[(int) GET_MODE (index)].insn_code
5413 == CODE_FOR_nothing))
5415 enum machine_mode wider_mode;
5416 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
5417 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
5418 if (cmp_optab->handlers[(int) wider_mode].insn_code
5419 != CODE_FOR_nothing)
5421 index = convert_to_mode (wider_mode, index, unsignedp);
5427 do_pending_stack_adjust ();
5429 index = protect_from_queue (index, 0);
5430 if (GET_CODE (index) == MEM)
5431 index = copy_to_reg (index);
5432 if (GET_CODE (index) == CONST_INT
5433 || TREE_CODE (index_expr) == INTEGER_CST)
5435 /* Make a tree node with the proper constant value
5436 if we don't already have one. */
5437 if (TREE_CODE (index_expr) != INTEGER_CST)
5440 = build_int_2 (INTVAL (index),
5441 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
5442 index_expr = convert (index_type, index_expr);
5445 /* For constant index expressions we need only
5446 issue a unconditional branch to the appropriate
5447 target code. The job of removing any unreachable
5448 code is left to the optimisation phase if the
5449 "-O" option is specified. */
5450 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5451 if (! tree_int_cst_lt (index_expr, n->low)
5452 && ! tree_int_cst_lt (n->high, index_expr))
5456 emit_jump (label_rtx (n->code_label));
5458 emit_jump (default_label);
5462 /* If the index expression is not constant we generate
5463 a binary decision tree to select the appropriate
5464 target code. This is done as follows:
5466 The list of cases is rearranged into a binary tree,
5467 nearly optimal assuming equal probability for each case.
5469 The tree is transformed into RTL, eliminating
5470 redundant test conditions at the same time.
5472 If program flow could reach the end of the
5473 decision tree an unconditional jump to the
5474 default code is emitted. */
5477 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
5478 && estimate_case_costs (thiscase->data.case_stmt.case_list));
5479 balance_case_nodes (&thiscase->data.case_stmt.case_list,
5481 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
5482 default_label, index_type);
5483 emit_jump_if_reachable (default_label);
5492 enum machine_mode index_mode = SImode;
5493 int index_bits = GET_MODE_BITSIZE (index_mode);
5495 enum machine_mode op_mode;
5497 /* Convert the index to SImode. */
5498 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
5499 > GET_MODE_BITSIZE (index_mode))
5501 enum machine_mode omode = TYPE_MODE (index_type);
5502 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
5504 /* We must handle the endpoints in the original mode. */
5505 index_expr = build (MINUS_EXPR, index_type,
5506 index_expr, minval);
5507 minval = integer_zero_node;
5508 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5509 emit_cmp_and_jump_insns (rangertx, index, LTU, NULL_RTX,
5510 omode, 1, 0, default_label);
5511 /* Now we can safely truncate. */
5512 index = convert_to_mode (index_mode, index, 0);
5516 if (TYPE_MODE (index_type) != index_mode)
5518 index_expr = convert (type_for_size (index_bits, 0),
5520 index_type = TREE_TYPE (index_expr);
5523 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5526 index = protect_from_queue (index, 0);
5527 do_pending_stack_adjust ();
5529 op_mode = insn_data[(int) CODE_FOR_casesi].operand[0].mode;
5530 if (! (*insn_data[(int) CODE_FOR_casesi].operand[0].predicate)
5532 index = copy_to_mode_reg (op_mode, index);
5534 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
5536 op_mode = insn_data[(int) CODE_FOR_casesi].operand[1].mode;
5537 if (! (*insn_data[(int) CODE_FOR_casesi].operand[1].predicate)
5539 op1 = copy_to_mode_reg (op_mode, op1);
5541 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
5543 op_mode = insn_data[(int) CODE_FOR_casesi].operand[2].mode;
5544 if (! (*insn_data[(int) CODE_FOR_casesi].operand[2].predicate)
5546 op2 = copy_to_mode_reg (op_mode, op2);
5548 emit_jump_insn (gen_casesi (index, op1, op2,
5549 table_label, default_label));
5553 #ifdef HAVE_tablejump
5554 if (! win && HAVE_tablejump)
5556 index_type = thiscase->data.case_stmt.nominal_type;
5557 index_expr = fold (build (MINUS_EXPR, index_type,
5558 convert (index_type, index_expr),
5559 convert (index_type, minval)));
5560 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5562 index = protect_from_queue (index, 0);
5563 do_pending_stack_adjust ();
5565 do_tablejump (index, TYPE_MODE (index_type),
5566 expand_expr (range, NULL_RTX, VOIDmode, 0),
5567 table_label, default_label);
5574 /* Get table of labels to jump to, in order of case index. */
5576 ncases = TREE_INT_CST_LOW (range) + 1;
5577 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
5578 bzero ((char *) labelvec, ncases * sizeof (rtx));
5580 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5582 register HOST_WIDE_INT i
5583 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
5588 = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
5589 if (i + TREE_INT_CST_LOW (orig_minval)
5590 == TREE_INT_CST_LOW (n->high))
5596 /* Fill in the gaps with the default. */
5597 for (i = 0; i < ncases; i++)
5598 if (labelvec[i] == 0)
5599 labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
5601 /* Output the table */
5602 emit_label (table_label);
5604 if (CASE_VECTOR_PC_RELATIVE || flag_pic)
5605 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
5606 gen_rtx_LABEL_REF (Pmode, table_label),
5607 gen_rtvec_v (ncases, labelvec),
5608 const0_rtx, const0_rtx));
5610 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
5611 gen_rtvec_v (ncases, labelvec)));
5613 /* If the case insn drops through the table,
5614 after the table we must jump to the default-label.
5615 Otherwise record no drop-through after the table. */
5616 #ifdef CASE_DROPS_THROUGH
5617 emit_jump (default_label);
5623 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
5624 reorder_insns (before_case, get_last_insn (),
5625 thiscase->data.case_stmt.start);
5628 end_cleanup_deferral ();
5630 if (thiscase->exit_label)
5631 emit_label (thiscase->exit_label);
5633 free_case_nodes (case_stack->data.case_stmt.case_list);
5634 POPSTACK (case_stack);
5639 /* Convert the tree NODE into a list linked by the right field, with the left
5640 field zeroed. RIGHT is used for recursion; it is a list to be placed
5641 rightmost in the resulting list. */
5643 static struct case_node *
5644 case_tree2list (node, right)
5645 struct case_node *node, *right;
5647 struct case_node *left;
5650 right = case_tree2list (node->right, right);
5652 node->right = right;
5653 if ((left = node->left))
5656 return case_tree2list (left, node);
5662 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5665 do_jump_if_equal (op1, op2, label, unsignedp)
5666 rtx op1, op2, label;
5669 if (GET_CODE (op1) == CONST_INT
5670 && GET_CODE (op2) == CONST_INT)
5672 if (INTVAL (op1) == INTVAL (op2))
5677 enum machine_mode mode = GET_MODE (op1);
5678 if (mode == VOIDmode)
5679 mode = GET_MODE (op2);
5680 emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX, mode, unsignedp,
5685 /* Not all case values are encountered equally. This function
5686 uses a heuristic to weight case labels, in cases where that
5687 looks like a reasonable thing to do.
5689 Right now, all we try to guess is text, and we establish the
5692 chars above space: 16
5701 If we find any cases in the switch that are not either -1 or in the range
5702 of valid ASCII characters, or are control characters other than those
5703 commonly used with "\", don't treat this switch scanning text.
5705 Return 1 if these nodes are suitable for cost estimation, otherwise
5709 estimate_case_costs (node)
5712 tree min_ascii = build_int_2 (-1, -1);
5713 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5717 /* If we haven't already made the cost table, make it now. Note that the
5718 lower bound of the table is -1, not zero. */
5720 if (cost_table == NULL)
5722 cost_table = cost_table_ + 1;
5724 for (i = 0; i < 128; i++)
5728 else if (ISPUNCT (i))
5730 else if (ISCNTRL (i))
5734 cost_table[' '] = 8;
5735 cost_table['\t'] = 4;
5736 cost_table['\0'] = 4;
5737 cost_table['\n'] = 2;
5738 cost_table['\f'] = 1;
5739 cost_table['\v'] = 1;
5740 cost_table['\b'] = 1;
5743 /* See if all the case expressions look like text. It is text if the
5744 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5745 as signed arithmetic since we don't want to ever access cost_table with a
5746 value less than -1. Also check that none of the constants in a range
5747 are strange control characters. */
5749 for (n = node; n; n = n->right)
5751 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5754 for (i = (HOST_WIDE_INT) TREE_INT_CST_LOW (n->low);
5755 i <= (HOST_WIDE_INT) TREE_INT_CST_LOW (n->high); i++)
5756 if (cost_table[i] < 0)
5760 /* All interesting values are within the range of interesting
5761 ASCII characters. */
5765 /* Scan an ordered list of case nodes
5766 combining those with consecutive values or ranges.
5768 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5771 group_case_nodes (head)
5774 case_node_ptr node = head;
5778 rtx lb = next_real_insn (label_rtx (node->code_label));
5780 case_node_ptr np = node;
5782 /* Try to group the successors of NODE with NODE. */
5783 while (((np = np->right) != 0)
5784 /* Do they jump to the same place? */
5785 && ((lb2 = next_real_insn (label_rtx (np->code_label))) == lb
5786 || (lb != 0 && lb2 != 0
5787 && simplejump_p (lb)
5788 && simplejump_p (lb2)
5789 && rtx_equal_p (SET_SRC (PATTERN (lb)),
5790 SET_SRC (PATTERN (lb2)))))
5791 /* Are their ranges consecutive? */
5792 && tree_int_cst_equal (np->low,
5793 fold (build (PLUS_EXPR,
5794 TREE_TYPE (node->high),
5797 /* An overflow is not consecutive. */
5798 && tree_int_cst_lt (node->high,
5799 fold (build (PLUS_EXPR,
5800 TREE_TYPE (node->high),
5802 integer_one_node))))
5804 node->high = np->high;
5806 /* NP is the first node after NODE which can't be grouped with it.
5807 Delete the nodes in between, and move on to that node. */
5813 /* Take an ordered list of case nodes
5814 and transform them into a near optimal binary tree,
5815 on the assumption that any target code selection value is as
5816 likely as any other.
5818 The transformation is performed by splitting the ordered
5819 list into two equal sections plus a pivot. The parts are
5820 then attached to the pivot as left and right branches. Each
5821 branch is then transformed recursively. */
5824 balance_case_nodes (head, parent)
5825 case_node_ptr *head;
5826 case_node_ptr parent;
5828 register case_node_ptr np;
5836 register case_node_ptr *npp;
5839 /* Count the number of entries on branch. Also count the ranges. */
5843 if (!tree_int_cst_equal (np->low, np->high))
5847 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5851 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5859 /* Split this list if it is long enough for that to help. */
5864 /* Find the place in the list that bisects the list's total cost,
5865 Here I gets half the total cost. */
5870 /* Skip nodes while their cost does not reach that amount. */
5871 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5872 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5873 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5876 npp = &(*npp)->right;
5881 /* Leave this branch lopsided, but optimize left-hand
5882 side and fill in `parent' fields for right-hand side. */
5884 np->parent = parent;
5885 balance_case_nodes (&np->left, np);
5886 for (; np->right; np = np->right)
5887 np->right->parent = np;
5891 /* If there are just three nodes, split at the middle one. */
5893 npp = &(*npp)->right;
5896 /* Find the place in the list that bisects the list's total cost,
5897 where ranges count as 2.
5898 Here I gets half the total cost. */
5899 i = (i + ranges + 1) / 2;
5902 /* Skip nodes while their cost does not reach that amount. */
5903 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5908 npp = &(*npp)->right;
5913 np->parent = parent;
5916 /* Optimize each of the two split parts. */
5917 balance_case_nodes (&np->left, np);
5918 balance_case_nodes (&np->right, np);
5922 /* Else leave this branch as one level,
5923 but fill in `parent' fields. */
5925 np->parent = parent;
5926 for (; np->right; np = np->right)
5927 np->right->parent = np;
5932 /* Search the parent sections of the case node tree
5933 to see if a test for the lower bound of NODE would be redundant.
5934 INDEX_TYPE is the type of the index expression.
5936 The instructions to generate the case decision tree are
5937 output in the same order as nodes are processed so it is
5938 known that if a parent node checks the range of the current
5939 node minus one that the current node is bounded at its lower
5940 span. Thus the test would be redundant. */
5943 node_has_low_bound (node, index_type)
5948 case_node_ptr pnode;
5950 /* If the lower bound of this node is the lowest value in the index type,
5951 we need not test it. */
5953 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5956 /* If this node has a left branch, the value at the left must be less
5957 than that at this node, so it cannot be bounded at the bottom and
5958 we need not bother testing any further. */
5963 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5964 node->low, integer_one_node));
5966 /* If the subtraction above overflowed, we can't verify anything.
5967 Otherwise, look for a parent that tests our value - 1. */
5969 if (! tree_int_cst_lt (low_minus_one, node->low))
5972 for (pnode = node->parent; pnode; pnode = pnode->parent)
5973 if (tree_int_cst_equal (low_minus_one, pnode->high))
5979 /* Search the parent sections of the case node tree
5980 to see if a test for the upper bound of NODE would be redundant.
5981 INDEX_TYPE is the type of the index expression.
5983 The instructions to generate the case decision tree are
5984 output in the same order as nodes are processed so it is
5985 known that if a parent node checks the range of the current
5986 node plus one that the current node is bounded at its upper
5987 span. Thus the test would be redundant. */
5990 node_has_high_bound (node, index_type)
5995 case_node_ptr pnode;
5997 /* If there is no upper bound, obviously no test is needed. */
5999 if (TYPE_MAX_VALUE (index_type) == NULL)
6002 /* If the upper bound of this node is the highest value in the type
6003 of the index expression, we need not test against it. */
6005 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
6008 /* If this node has a right branch, the value at the right must be greater
6009 than that at this node, so it cannot be bounded at the top and
6010 we need not bother testing any further. */
6015 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
6016 node->high, integer_one_node));
6018 /* If the addition above overflowed, we can't verify anything.
6019 Otherwise, look for a parent that tests our value + 1. */
6021 if (! tree_int_cst_lt (node->high, high_plus_one))
6024 for (pnode = node->parent; pnode; pnode = pnode->parent)
6025 if (tree_int_cst_equal (high_plus_one, pnode->low))
6031 /* Search the parent sections of the
6032 case node tree to see if both tests for the upper and lower
6033 bounds of NODE would be redundant. */
6036 node_is_bounded (node, index_type)
6040 return (node_has_low_bound (node, index_type)
6041 && node_has_high_bound (node, index_type));
6044 /* Emit an unconditional jump to LABEL unless it would be dead code. */
6047 emit_jump_if_reachable (label)
6050 if (GET_CODE (get_last_insn ()) != BARRIER)
6054 /* Emit step-by-step code to select a case for the value of INDEX.
6055 The thus generated decision tree follows the form of the
6056 case-node binary tree NODE, whose nodes represent test conditions.
6057 INDEX_TYPE is the type of the index of the switch.
6059 Care is taken to prune redundant tests from the decision tree
6060 by detecting any boundary conditions already checked by
6061 emitted rtx. (See node_has_high_bound, node_has_low_bound
6062 and node_is_bounded, above.)
6064 Where the test conditions can be shown to be redundant we emit
6065 an unconditional jump to the target code. As a further
6066 optimization, the subordinates of a tree node are examined to
6067 check for bounded nodes. In this case conditional and/or
6068 unconditional jumps as a result of the boundary check for the
6069 current node are arranged to target the subordinates associated
6070 code for out of bound conditions on the current node.
6072 We can assume that when control reaches the code generated here,
6073 the index value has already been compared with the parents
6074 of this node, and determined to be on the same side of each parent
6075 as this node is. Thus, if this node tests for the value 51,
6076 and a parent tested for 52, we don't need to consider
6077 the possibility of a value greater than 51. If another parent
6078 tests for the value 50, then this node need not test anything. */
6081 emit_case_nodes (index, node, default_label, index_type)
6087 /* If INDEX has an unsigned type, we must make unsigned branches. */
6088 int unsignedp = TREE_UNSIGNED (index_type);
6089 enum machine_mode mode = GET_MODE (index);
6091 /* See if our parents have already tested everything for us.
6092 If they have, emit an unconditional jump for this node. */
6093 if (node_is_bounded (node, index_type))
6094 emit_jump (label_rtx (node->code_label));
6096 else if (tree_int_cst_equal (node->low, node->high))
6098 /* Node is single valued. First see if the index expression matches
6099 this node and then check our children, if any. */
6101 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
6102 label_rtx (node->code_label), unsignedp);
6104 if (node->right != 0 && node->left != 0)
6106 /* This node has children on both sides.
6107 Dispatch to one side or the other
6108 by comparing the index value with this node's value.
6109 If one subtree is bounded, check that one first,
6110 so we can avoid real branches in the tree. */
6112 if (node_is_bounded (node->right, index_type))
6114 emit_cmp_and_jump_insns (index,
6115 expand_expr (node->high, NULL_RTX,
6117 GT, NULL_RTX, mode, unsignedp, 0,
6118 label_rtx (node->right->code_label));
6119 emit_case_nodes (index, node->left, default_label, index_type);
6122 else if (node_is_bounded (node->left, index_type))
6124 emit_cmp_and_jump_insns (index,
6125 expand_expr (node->high, NULL_RTX,
6127 LT, NULL_RTX, mode, unsignedp, 0,
6128 label_rtx (node->left->code_label));
6129 emit_case_nodes (index, node->right, default_label, index_type);
6134 /* Neither node is bounded. First distinguish the two sides;
6135 then emit the code for one side at a time. */
6137 tree test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6139 /* See if the value is on the right. */
6140 emit_cmp_and_jump_insns (index,
6141 expand_expr (node->high, NULL_RTX,
6143 GT, NULL_RTX, mode, unsignedp, 0,
6144 label_rtx (test_label));
6146 /* Value must be on the left.
6147 Handle the left-hand subtree. */
6148 emit_case_nodes (index, node->left, default_label, index_type);
6149 /* If left-hand subtree does nothing,
6151 emit_jump_if_reachable (default_label);
6153 /* Code branches here for the right-hand subtree. */
6154 expand_label (test_label);
6155 emit_case_nodes (index, node->right, default_label, index_type);
6159 else if (node->right != 0 && node->left == 0)
6161 /* Here we have a right child but no left so we issue conditional
6162 branch to default and process the right child.
6164 Omit the conditional branch to default if we it avoid only one
6165 right child; it costs too much space to save so little time. */
6167 if (node->right->right || node->right->left
6168 || !tree_int_cst_equal (node->right->low, node->right->high))
6170 if (!node_has_low_bound (node, index_type))
6172 emit_cmp_and_jump_insns (index,
6173 expand_expr (node->high, NULL_RTX,
6175 LT, NULL_RTX, mode, unsignedp, 0,
6179 emit_case_nodes (index, node->right, default_label, index_type);
6182 /* We cannot process node->right normally
6183 since we haven't ruled out the numbers less than
6184 this node's value. So handle node->right explicitly. */
6185 do_jump_if_equal (index,
6186 expand_expr (node->right->low, NULL_RTX,
6188 label_rtx (node->right->code_label), unsignedp);
6191 else if (node->right == 0 && node->left != 0)
6193 /* Just one subtree, on the left. */
6195 #if 0 /* The following code and comment were formerly part
6196 of the condition here, but they didn't work
6197 and I don't understand what the idea was. -- rms. */
6198 /* If our "most probable entry" is less probable
6199 than the default label, emit a jump to
6200 the default label using condition codes
6201 already lying around. With no right branch,
6202 a branch-greater-than will get us to the default
6205 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
6208 if (node->left->left || node->left->right
6209 || !tree_int_cst_equal (node->left->low, node->left->high))
6211 if (!node_has_high_bound (node, index_type))
6213 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6216 GT, NULL_RTX, mode, unsignedp, 0,
6220 emit_case_nodes (index, node->left, default_label, index_type);
6223 /* We cannot process node->left normally
6224 since we haven't ruled out the numbers less than
6225 this node's value. So handle node->left explicitly. */
6226 do_jump_if_equal (index,
6227 expand_expr (node->left->low, NULL_RTX,
6229 label_rtx (node->left->code_label), unsignedp);
6234 /* Node is a range. These cases are very similar to those for a single
6235 value, except that we do not start by testing whether this node
6236 is the one to branch to. */
6238 if (node->right != 0 && node->left != 0)
6240 /* Node has subtrees on both sides.
6241 If the right-hand subtree is bounded,
6242 test for it first, since we can go straight there.
6243 Otherwise, we need to make a branch in the control structure,
6244 then handle the two subtrees. */
6245 tree test_label = 0;
6247 if (node_is_bounded (node->right, index_type))
6248 /* Right hand node is fully bounded so we can eliminate any
6249 testing and branch directly to the target code. */
6250 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6252 GT, NULL_RTX, mode, unsignedp, 0,
6253 label_rtx (node->right->code_label));
6256 /* Right hand node requires testing.
6257 Branch to a label where we will handle it later. */
6259 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6260 emit_cmp_and_jump_insns (index,
6261 expand_expr (node->high, NULL_RTX,
6263 GT, NULL_RTX, mode, unsignedp, 0,
6264 label_rtx (test_label));
6267 /* Value belongs to this node or to the left-hand subtree. */
6269 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6271 GE, NULL_RTX, mode, unsignedp, 0,
6272 label_rtx (node->code_label));
6274 /* Handle the left-hand subtree. */
6275 emit_case_nodes (index, node->left, default_label, index_type);
6277 /* If right node had to be handled later, do that now. */
6281 /* If the left-hand subtree fell through,
6282 don't let it fall into the right-hand subtree. */
6283 emit_jump_if_reachable (default_label);
6285 expand_label (test_label);
6286 emit_case_nodes (index, node->right, default_label, index_type);
6290 else if (node->right != 0 && node->left == 0)
6292 /* Deal with values to the left of this node,
6293 if they are possible. */
6294 if (!node_has_low_bound (node, index_type))
6296 emit_cmp_and_jump_insns (index,
6297 expand_expr (node->low, NULL_RTX,
6299 LT, NULL_RTX, mode, unsignedp, 0,
6303 /* Value belongs to this node or to the right-hand subtree. */
6305 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6307 LE, NULL_RTX, mode, unsignedp, 0,
6308 label_rtx (node->code_label));
6310 emit_case_nodes (index, node->right, default_label, index_type);
6313 else if (node->right == 0 && node->left != 0)
6315 /* Deal with values to the right of this node,
6316 if they are possible. */
6317 if (!node_has_high_bound (node, index_type))
6319 emit_cmp_and_jump_insns (index,
6320 expand_expr (node->high, NULL_RTX,
6322 GT, NULL_RTX, mode, unsignedp, 0,
6326 /* Value belongs to this node or to the left-hand subtree. */
6328 emit_cmp_and_jump_insns (index,
6329 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,
6346 expand_expr (node->high, NULL_RTX,
6348 GT, NULL_RTX, mode, unsignedp, 0,
6352 if (!node_has_low_bound (node, index_type))
6354 emit_cmp_and_jump_insns (index,
6355 expand_expr (node->low, NULL_RTX,
6357 LT, NULL_RTX, mode, unsignedp, 0,
6361 emit_jump (label_rtx (node->code_label));