1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000 Free Software Foundation, Inc.
5 This file is part of GNU CC.
7 GNU CC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GNU CC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNU CC; see the file COPYING. If not, write to
19 the Free Software Foundation, 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
23 /* This file handles the generation of rtl code from tree structure
24 above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
25 It also creates the rtl expressions for parameters and auto variables
26 and has full responsibility for allocating stack slots.
28 The functions whose names start with `expand_' are called by the
29 parser to generate RTL instructions for various kinds of constructs.
31 Some control and binding constructs require calling several such
32 functions at different times. For example, a simple if-then
33 is expanded by calling `expand_start_cond' (with the condition-expression
34 as argument) before parsing the then-clause and calling `expand_end_cond'
35 after parsing the then-clause. */
46 #include "insn-flags.h"
47 #include "insn-config.h"
48 #include "insn-codes.h"
50 #include "hard-reg-set.h"
59 #define obstack_chunk_alloc xmalloc
60 #define obstack_chunk_free free
61 struct obstack stmt_obstack;
63 /* Assume that case vectors are not pc-relative. */
64 #ifndef CASE_VECTOR_PC_RELATIVE
65 #define CASE_VECTOR_PC_RELATIVE 0
69 /* Functions and data structures for expanding case statements. */
71 /* Case label structure, used to hold info on labels within case
72 statements. We handle "range" labels; for a single-value label
73 as in C, the high and low limits are the same.
75 An AVL tree of case nodes is initially created, and later transformed
76 to a list linked via the RIGHT fields in the nodes. Nodes with
77 higher case values are later in the list.
79 Switch statements can be output in one of two forms. A branch table
80 is used if there are more than a few labels and the labels are dense
81 within the range between the smallest and largest case value. If a
82 branch table is used, no further manipulations are done with the case
85 The alternative to the use of a branch table is to generate a series
86 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
87 and PARENT fields to hold a binary tree. Initially the tree is
88 totally unbalanced, with everything on the right. We balance the tree
89 with nodes on the left having lower case values than the parent
90 and nodes on the right having higher values. We then output the tree
95 struct case_node *left; /* Left son in binary tree */
96 struct case_node *right; /* Right son in binary tree; also node chain */
97 struct case_node *parent; /* Parent of node in binary tree */
98 tree low; /* Lowest index value for this label */
99 tree high; /* Highest index value for this label */
100 tree code_label; /* Label to jump to when node matches */
104 typedef struct case_node case_node;
105 typedef struct case_node *case_node_ptr;
107 /* These are used by estimate_case_costs and balance_case_nodes. */
109 /* This must be a signed type, and non-ANSI compilers lack signed char. */
110 static short cost_table_[129];
111 static short *cost_table;
112 static int use_cost_table;
114 /* Stack of control and binding constructs we are currently inside.
116 These constructs begin when you call `expand_start_WHATEVER'
117 and end when you call `expand_end_WHATEVER'. This stack records
118 info about how the construct began that tells the end-function
119 what to do. It also may provide information about the construct
120 to alter the behavior of other constructs within the body.
121 For example, they may affect the behavior of C `break' and `continue'.
123 Each construct gets one `struct nesting' object.
124 All of these objects are chained through the `all' field.
125 `nesting_stack' points to the first object (innermost construct).
126 The position of an entry on `nesting_stack' is in its `depth' field.
128 Each type of construct has its own individual stack.
129 For example, loops have `loop_stack'. Each object points to the
130 next object of the same type through the `next' field.
132 Some constructs are visible to `break' exit-statements and others
133 are not. Which constructs are visible depends on the language.
134 Therefore, the data structure allows each construct to be visible
135 or not, according to the args given when the construct is started.
136 The construct is visible if the `exit_label' field is non-null.
137 In that case, the value should be a CODE_LABEL rtx. */
142 struct nesting *next;
147 /* For conds (if-then and if-then-else statements). */
150 /* Label for the end of the if construct.
151 There is none if EXITFLAG was not set
152 and no `else' has been seen yet. */
154 /* Label for the end of this alternative.
155 This may be the end of the if or the next else/elseif. */
161 /* Label at the top of the loop; place to loop back to. */
163 /* Label at the end of the whole construct. */
165 /* Label before a jump that branches to the end of the whole
166 construct. This is where destructors go if any. */
168 /* Label for `continue' statement to jump to;
169 this is in front of the stepper of the loop. */
172 /* For variable binding contours. */
175 /* Sequence number of this binding contour within the function,
176 in order of entry. */
177 int block_start_count;
178 /* Nonzero => value to restore stack to on exit. */
180 /* The NOTE that starts this contour.
181 Used by expand_goto to check whether the destination
182 is within each contour or not. */
184 /* Innermost containing binding contour that has a stack level. */
185 struct nesting *innermost_stack_block;
186 /* List of cleanups to be run on exit from this contour.
187 This is a list of expressions to be evaluated.
188 The TREE_PURPOSE of each link is the ..._DECL node
189 which the cleanup pertains to. */
191 /* List of cleanup-lists of blocks containing this block,
192 as they were at the locus where this block appears.
193 There is an element for each containing block,
194 ordered innermost containing block first.
195 The tail of this list can be 0,
196 if all remaining elements would be empty lists.
197 The element's TREE_VALUE is the cleanup-list of that block,
198 which may be null. */
200 /* Chain of labels defined inside this binding contour.
201 For contours that have stack levels or cleanups. */
202 struct label_chain *label_chain;
203 /* Number of function calls seen, as of start of this block. */
204 int n_function_calls;
205 /* Nonzero if this is associated with a EH region. */
206 int exception_region;
207 /* The saved target_temp_slot_level from our outer block.
208 We may reset target_temp_slot_level to be the level of
209 this block, if that is done, target_temp_slot_level
210 reverts to the saved target_temp_slot_level at the very
212 int block_target_temp_slot_level;
213 /* True if we are currently emitting insns in an area of
214 output code that is controlled by a conditional
215 expression. This is used by the cleanup handling code to
216 generate conditional cleanup actions. */
217 int conditional_code;
218 /* A place to move the start of the exception region for any
219 of the conditional cleanups, must be at the end or after
220 the start of the last unconditional cleanup, and before any
221 conditional branch points. */
222 rtx last_unconditional_cleanup;
223 /* When in a conditional context, this is the specific
224 cleanup list associated with last_unconditional_cleanup,
225 where we place the conditionalized cleanups. */
228 /* For switch (C) or case (Pascal) statements,
229 and also for dummies (see `expand_start_case_dummy'). */
232 /* The insn after which the case dispatch should finally
233 be emitted. Zero for a dummy. */
235 /* A list of case labels; it is first built as an AVL tree.
236 During expand_end_case, this is converted to a list, and may be
237 rearranged into a nearly balanced binary tree. */
238 struct case_node *case_list;
239 /* Label to jump to if no case matches. */
241 /* The expression to be dispatched on. */
243 /* Type that INDEX_EXPR should be converted to. */
245 /* Number of range exprs in case statement. */
247 /* Name of this kind of statement, for warnings. */
248 const char *printname;
249 /* Used to save no_line_numbers till we see the first case label.
250 We set this to -1 when we see the first case label in this
252 int line_number_status;
257 /* Allocate and return a new `struct nesting'. */
259 #define ALLOC_NESTING() \
260 (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
262 /* Pop the nesting stack element by element until we pop off
263 the element which is at the top of STACK.
264 Update all the other stacks, popping off elements from them
265 as we pop them from nesting_stack. */
267 #define POPSTACK(STACK) \
268 do { struct nesting *target = STACK; \
269 struct nesting *this; \
270 do { this = nesting_stack; \
271 if (loop_stack == this) \
272 loop_stack = loop_stack->next; \
273 if (cond_stack == this) \
274 cond_stack = cond_stack->next; \
275 if (block_stack == this) \
276 block_stack = block_stack->next; \
277 if (stack_block_stack == this) \
278 stack_block_stack = stack_block_stack->next; \
279 if (case_stack == this) \
280 case_stack = case_stack->next; \
281 nesting_depth = nesting_stack->depth - 1; \
282 nesting_stack = this->all; \
283 obstack_free (&stmt_obstack, this); } \
284 while (this != target); } while (0)
286 /* In some cases it is impossible to generate code for a forward goto
287 until the label definition is seen. This happens when it may be necessary
288 for the goto to reset the stack pointer: we don't yet know how to do that.
289 So expand_goto puts an entry on this fixup list.
290 Each time a binding contour that resets the stack is exited,
292 If the target label has now been defined, we can insert the proper code. */
296 /* Points to following fixup. */
297 struct goto_fixup *next;
298 /* Points to the insn before the jump insn.
299 If more code must be inserted, it goes after this insn. */
301 /* The LABEL_DECL that this jump is jumping to, or 0
302 for break, continue or return. */
304 /* The BLOCK for the place where this goto was found. */
306 /* The CODE_LABEL rtx that this is jumping to. */
308 /* Number of binding contours started in current function
309 before the label reference. */
310 int block_start_count;
311 /* The outermost stack level that should be restored for this jump.
312 Each time a binding contour that resets the stack is exited,
313 if the target label is *not* yet defined, this slot is updated. */
315 /* List of lists of cleanup expressions to be run by this goto.
316 There is one element for each block that this goto is within.
317 The tail of this list can be 0,
318 if all remaining elements would be empty.
319 The TREE_VALUE contains the cleanup list of that block as of the
320 time this goto was seen.
321 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
322 tree cleanup_list_list;
325 /* Within any binding contour that must restore a stack level,
326 all labels are recorded with a chain of these structures. */
330 /* Points to following fixup. */
331 struct label_chain *next;
337 /* Chain of all pending binding contours. */
338 struct nesting *x_block_stack;
340 /* If any new stacks are added here, add them to POPSTACKS too. */
342 /* Chain of all pending binding contours that restore stack levels
344 struct nesting *x_stack_block_stack;
346 /* Chain of all pending conditional statements. */
347 struct nesting *x_cond_stack;
349 /* Chain of all pending loops. */
350 struct nesting *x_loop_stack;
352 /* Chain of all pending case or switch statements. */
353 struct nesting *x_case_stack;
355 /* Separate chain including all of the above,
356 chained through the `all' field. */
357 struct nesting *x_nesting_stack;
359 /* Number of entries on nesting_stack now. */
362 /* Number of binding contours started so far in this function. */
363 int x_block_start_count;
365 /* Each time we expand an expression-statement,
366 record the expr's type and its RTL value here. */
367 tree x_last_expr_type;
368 rtx x_last_expr_value;
370 /* Nonzero if within a ({...}) grouping, in which case we must
371 always compute a value for each expr-stmt in case it is the last one. */
372 int x_expr_stmts_for_value;
374 /* Filename and line number of last line-number note,
375 whether we actually emitted it or not. */
376 const char *x_emit_filename;
379 struct goto_fixup *x_goto_fixup_chain;
382 #define block_stack (cfun->stmt->x_block_stack)
383 #define stack_block_stack (cfun->stmt->x_stack_block_stack)
384 #define cond_stack (cfun->stmt->x_cond_stack)
385 #define loop_stack (cfun->stmt->x_loop_stack)
386 #define case_stack (cfun->stmt->x_case_stack)
387 #define nesting_stack (cfun->stmt->x_nesting_stack)
388 #define nesting_depth (cfun->stmt->x_nesting_depth)
389 #define current_block_start_count (cfun->stmt->x_block_start_count)
390 #define last_expr_type (cfun->stmt->x_last_expr_type)
391 #define last_expr_value (cfun->stmt->x_last_expr_value)
392 #define expr_stmts_for_value (cfun->stmt->x_expr_stmts_for_value)
393 #define emit_filename (cfun->stmt->x_emit_filename)
394 #define emit_lineno (cfun->stmt->x_emit_lineno)
395 #define goto_fixup_chain (cfun->stmt->x_goto_fixup_chain)
397 /* Non-zero if we are using EH to handle cleanus. */
398 static int using_eh_for_cleanups_p = 0;
400 /* Character strings, each containing a single decimal digit. */
401 static char *digit_strings[10];
404 static int n_occurrences PARAMS ((int, const char *));
405 static void expand_goto_internal PARAMS ((tree, rtx, rtx));
406 static int expand_fixup PARAMS ((tree, rtx, rtx));
407 static rtx expand_nl_handler_label PARAMS ((rtx, rtx));
408 static void expand_nl_goto_receiver PARAMS ((void));
409 static void expand_nl_goto_receivers PARAMS ((struct nesting *));
410 static void fixup_gotos PARAMS ((struct nesting *, rtx, tree,
412 static void expand_null_return_1 PARAMS ((rtx, int));
413 static void expand_value_return PARAMS ((rtx));
414 static int tail_recursion_args PARAMS ((tree, tree));
415 static void expand_cleanups PARAMS ((tree, tree, int, int));
416 static void check_seenlabel PARAMS ((void));
417 static void do_jump_if_equal PARAMS ((rtx, rtx, rtx, int));
418 static int estimate_case_costs PARAMS ((case_node_ptr));
419 static void group_case_nodes PARAMS ((case_node_ptr));
420 static void balance_case_nodes PARAMS ((case_node_ptr *,
422 static int node_has_low_bound PARAMS ((case_node_ptr, tree));
423 static int node_has_high_bound PARAMS ((case_node_ptr, tree));
424 static int node_is_bounded PARAMS ((case_node_ptr, tree));
425 static void emit_jump_if_reachable PARAMS ((rtx));
426 static void emit_case_nodes PARAMS ((rtx, case_node_ptr, rtx, tree));
427 static int add_case_node PARAMS ((tree, tree, tree, tree *));
428 static struct case_node *case_tree2list PARAMS ((case_node *, case_node *));
429 static void mark_cond_nesting PARAMS ((struct nesting *));
430 static void mark_loop_nesting PARAMS ((struct nesting *));
431 static void mark_block_nesting PARAMS ((struct nesting *));
432 static void mark_case_nesting PARAMS ((struct nesting *));
433 static void mark_case_node PARAMS ((struct case_node *));
434 static void mark_goto_fixup PARAMS ((struct goto_fixup *));
438 using_eh_for_cleanups ()
440 using_eh_for_cleanups_p = 1;
443 /* Mark N (known to be a cond-nesting) for GC. */
446 mark_cond_nesting (n)
451 ggc_mark_rtx (n->exit_label);
452 ggc_mark_rtx (n->data.cond.endif_label);
453 ggc_mark_rtx (n->data.cond.next_label);
459 /* Mark N (known to be a loop-nesting) for GC. */
462 mark_loop_nesting (n)
468 ggc_mark_rtx (n->exit_label);
469 ggc_mark_rtx (n->data.loop.start_label);
470 ggc_mark_rtx (n->data.loop.end_label);
471 ggc_mark_rtx (n->data.loop.alt_end_label);
472 ggc_mark_rtx (n->data.loop.continue_label);
478 /* Mark N (known to be a block-nesting) for GC. */
481 mark_block_nesting (n)
486 struct label_chain *l;
488 ggc_mark_rtx (n->exit_label);
489 ggc_mark_rtx (n->data.block.stack_level);
490 ggc_mark_rtx (n->data.block.first_insn);
491 ggc_mark_tree (n->data.block.cleanups);
492 ggc_mark_tree (n->data.block.outer_cleanups);
494 for (l = n->data.block.label_chain; l != NULL; l = l->next)
495 ggc_mark_tree (l->label);
497 ggc_mark_rtx (n->data.block.last_unconditional_cleanup);
499 /* ??? cleanup_ptr never points outside the stack, does it? */
505 /* Mark N (known to be a case-nesting) for GC. */
508 mark_case_nesting (n)
513 ggc_mark_rtx (n->exit_label);
514 ggc_mark_rtx (n->data.case_stmt.start);
516 ggc_mark_tree (n->data.case_stmt.default_label);
517 ggc_mark_tree (n->data.case_stmt.index_expr);
518 ggc_mark_tree (n->data.case_stmt.nominal_type);
520 mark_case_node (n->data.case_stmt.case_list);
533 ggc_mark_tree (c->low);
534 ggc_mark_tree (c->high);
535 ggc_mark_tree (c->code_label);
537 mark_case_node (c->right);
538 mark_case_node (c->left);
546 struct goto_fixup *g;
551 ggc_mark_rtx (g->before_jump);
552 ggc_mark_tree (g->target);
553 ggc_mark_tree (g->context);
554 ggc_mark_rtx (g->target_rtl);
555 ggc_mark_rtx (g->stack_level);
556 ggc_mark_tree (g->cleanup_list_list);
562 /* Clear out all parts of the state in F that can safely be discarded
563 after the function has been compiled, to let garbage collection
564 reclaim the memory. */
570 /* We're about to free the function obstack. If we hold pointers to
571 things allocated there, then we'll try to mark them when we do
572 GC. So, we clear them out here explicitly. */
582 struct stmt_status *p;
587 mark_block_nesting (p->x_block_stack);
588 mark_cond_nesting (p->x_cond_stack);
589 mark_loop_nesting (p->x_loop_stack);
590 mark_case_nesting (p->x_case_stack);
592 ggc_mark_tree (p->x_last_expr_type);
593 /* last_epxr_value is only valid if last_expr_type is nonzero. */
594 if (p->x_last_expr_type)
595 ggc_mark_rtx (p->x_last_expr_value);
597 mark_goto_fixup (p->x_goto_fixup_chain);
605 gcc_obstack_init (&stmt_obstack);
607 for (i = 0; i < 10; i++)
609 digit_strings[i] = ggc_alloc_string (NULL, 1);
610 digit_strings[i][0] = '0' + i;
612 ggc_add_string_root (digit_strings, 10);
616 init_stmt_for_function ()
618 cfun->stmt = (struct stmt_status *) xmalloc (sizeof (struct stmt_status));
620 /* We are not currently within any block, conditional, loop or case. */
622 stack_block_stack = 0;
629 current_block_start_count = 0;
631 /* No gotos have been expanded yet. */
632 goto_fixup_chain = 0;
634 /* We are not processing a ({...}) grouping. */
635 expr_stmts_for_value = 0;
637 last_expr_value = NULL_RTX;
640 /* Return nonzero if anything is pushed on the loop, condition, or case
645 return cond_stack || loop_stack || case_stack;
648 /* Record the current file and line. Called from emit_line_note. */
650 set_file_and_line_for_stmt (file, line)
654 /* If we're outputting an inline function, and we add a line note,
655 there may be no CFUN->STMT information. So, there's no need to
659 emit_filename = file;
664 /* Emit a no-op instruction. */
671 last_insn = get_last_insn ();
673 && (GET_CODE (last_insn) == CODE_LABEL
674 || (GET_CODE (last_insn) == NOTE
675 && prev_real_insn (last_insn) == 0)))
676 emit_insn (gen_nop ());
679 /* Return the rtx-label that corresponds to a LABEL_DECL,
680 creating it if necessary. */
686 if (TREE_CODE (label) != LABEL_DECL)
689 if (DECL_RTL (label))
690 return DECL_RTL (label);
692 return DECL_RTL (label) = gen_label_rtx ();
695 /* Add an unconditional jump to LABEL as the next sequential instruction. */
701 do_pending_stack_adjust ();
702 emit_jump_insn (gen_jump (label));
706 /* Emit code to jump to the address
707 specified by the pointer expression EXP. */
710 expand_computed_goto (exp)
713 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
715 #ifdef POINTERS_EXTEND_UNSIGNED
716 x = convert_memory_address (Pmode, x);
720 /* Be sure the function is executable. */
721 if (current_function_check_memory_usage)
722 emit_library_call (chkr_check_exec_libfunc, 1,
723 VOIDmode, 1, x, ptr_mode);
725 do_pending_stack_adjust ();
726 emit_indirect_jump (x);
728 current_function_has_computed_jump = 1;
731 /* Handle goto statements and the labels that they can go to. */
733 /* Specify the location in the RTL code of a label LABEL,
734 which is a LABEL_DECL tree node.
736 This is used for the kind of label that the user can jump to with a
737 goto statement, and for alternatives of a switch or case statement.
738 RTL labels generated for loops and conditionals don't go through here;
739 they are generated directly at the RTL level, by other functions below.
741 Note that this has nothing to do with defining label *names*.
742 Languages vary in how they do that and what that even means. */
748 struct label_chain *p;
750 do_pending_stack_adjust ();
751 emit_label (label_rtx (label));
752 if (DECL_NAME (label))
753 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
755 if (stack_block_stack != 0)
757 p = (struct label_chain *) oballoc (sizeof (struct label_chain));
758 p->next = stack_block_stack->data.block.label_chain;
759 stack_block_stack->data.block.label_chain = p;
764 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
765 from nested functions. */
768 declare_nonlocal_label (label)
771 rtx slot = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
773 nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
774 LABEL_PRESERVE_P (label_rtx (label)) = 1;
775 if (nonlocal_goto_handler_slots == 0)
777 emit_stack_save (SAVE_NONLOCAL,
778 &nonlocal_goto_stack_level,
779 PREV_INSN (tail_recursion_reentry));
781 nonlocal_goto_handler_slots
782 = gen_rtx_EXPR_LIST (VOIDmode, slot, nonlocal_goto_handler_slots);
785 /* Generate RTL code for a `goto' statement with target label LABEL.
786 LABEL should be a LABEL_DECL tree node that was or will later be
787 defined with `expand_label'. */
795 /* Check for a nonlocal goto to a containing function. */
796 context = decl_function_context (label);
797 if (context != 0 && context != current_function_decl)
799 struct function *p = find_function_data (context);
800 rtx label_ref = gen_rtx_LABEL_REF (Pmode, label_rtx (label));
801 rtx handler_slot, static_chain, save_area;
804 /* Find the corresponding handler slot for this label. */
805 handler_slot = p->x_nonlocal_goto_handler_slots;
806 for (link = p->x_nonlocal_labels; TREE_VALUE (link) != label;
807 link = TREE_CHAIN (link))
808 handler_slot = XEXP (handler_slot, 1);
809 handler_slot = XEXP (handler_slot, 0);
811 p->has_nonlocal_label = 1;
812 current_function_has_nonlocal_goto = 1;
813 LABEL_REF_NONLOCAL_P (label_ref) = 1;
815 /* Copy the rtl for the slots so that they won't be shared in
816 case the virtual stack vars register gets instantiated differently
817 in the parent than in the child. */
819 static_chain = copy_to_reg (lookup_static_chain (label));
821 /* Get addr of containing function's current nonlocal goto handler,
822 which will do any cleanups and then jump to the label. */
823 handler_slot = copy_to_reg (replace_rtx (copy_rtx (handler_slot),
824 virtual_stack_vars_rtx,
827 /* Get addr of containing function's nonlocal save area. */
828 save_area = p->x_nonlocal_goto_stack_level;
830 save_area = replace_rtx (copy_rtx (save_area),
831 virtual_stack_vars_rtx, static_chain);
833 #if HAVE_nonlocal_goto
834 if (HAVE_nonlocal_goto)
835 emit_insn (gen_nonlocal_goto (static_chain, handler_slot,
836 save_area, label_ref));
840 /* Restore frame pointer for containing function.
841 This sets the actual hard register used for the frame pointer
842 to the location of the function's incoming static chain info.
843 The non-local goto handler will then adjust it to contain the
844 proper value and reload the argument pointer, if needed. */
845 emit_move_insn (hard_frame_pointer_rtx, static_chain);
846 emit_stack_restore (SAVE_NONLOCAL, save_area, NULL_RTX);
848 /* USE of hard_frame_pointer_rtx added for consistency;
849 not clear if really needed. */
850 emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx));
851 emit_insn (gen_rtx_USE (VOIDmode, stack_pointer_rtx));
852 emit_indirect_jump (handler_slot);
856 expand_goto_internal (label, label_rtx (label), NULL_RTX);
859 /* Generate RTL code for a `goto' statement with target label BODY.
860 LABEL should be a LABEL_REF.
861 LAST_INSN, if non-0, is the rtx we should consider as the last
862 insn emitted (for the purposes of cleaning up a return). */
865 expand_goto_internal (body, label, last_insn)
870 struct nesting *block;
873 if (GET_CODE (label) != CODE_LABEL)
876 /* If label has already been defined, we can tell now
877 whether and how we must alter the stack level. */
879 if (PREV_INSN (label) != 0)
881 /* Find the innermost pending block that contains the label.
882 (Check containment by comparing insn-uids.)
883 Then restore the outermost stack level within that block,
884 and do cleanups of all blocks contained in it. */
885 for (block = block_stack; block; block = block->next)
887 if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
889 if (block->data.block.stack_level != 0)
890 stack_level = block->data.block.stack_level;
891 /* Execute the cleanups for blocks we are exiting. */
892 if (block->data.block.cleanups != 0)
894 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
895 do_pending_stack_adjust ();
901 /* Ensure stack adjust isn't done by emit_jump, as this
902 would clobber the stack pointer. This one should be
903 deleted as dead by flow. */
904 clear_pending_stack_adjust ();
905 do_pending_stack_adjust ();
907 /* Don't do this adjust if it's to the end label and this function
908 is to return with a depressed stack pointer. */
909 if (label == return_label
910 && (TYPE_RETURNS_STACK_DEPRESSED
911 (TREE_TYPE (current_function_decl))))
914 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
917 if (body != 0 && DECL_TOO_LATE (body))
918 error ("jump to `%s' invalidly jumps into binding contour",
919 IDENTIFIER_POINTER (DECL_NAME (body)));
921 /* Label not yet defined: may need to put this goto
922 on the fixup list. */
923 else if (! expand_fixup (body, label, last_insn))
925 /* No fixup needed. Record that the label is the target
926 of at least one goto that has no fixup. */
928 TREE_ADDRESSABLE (body) = 1;
934 /* Generate if necessary a fixup for a goto
935 whose target label in tree structure (if any) is TREE_LABEL
936 and whose target in rtl is RTL_LABEL.
938 If LAST_INSN is nonzero, we pretend that the jump appears
939 after insn LAST_INSN instead of at the current point in the insn stream.
941 The fixup will be used later to insert insns just before the goto.
942 Those insns will restore the stack level as appropriate for the
943 target label, and will (in the case of C++) also invoke any object
944 destructors which have to be invoked when we exit the scopes which
945 are exited by the goto.
947 Value is nonzero if a fixup is made. */
950 expand_fixup (tree_label, rtl_label, last_insn)
955 struct nesting *block, *end_block;
957 /* See if we can recognize which block the label will be output in.
958 This is possible in some very common cases.
959 If we succeed, set END_BLOCK to that block.
960 Otherwise, set it to 0. */
963 && (rtl_label == cond_stack->data.cond.endif_label
964 || rtl_label == cond_stack->data.cond.next_label))
965 end_block = cond_stack;
966 /* If we are in a loop, recognize certain labels which
967 are likely targets. This reduces the number of fixups
968 we need to create. */
970 && (rtl_label == loop_stack->data.loop.start_label
971 || rtl_label == loop_stack->data.loop.end_label
972 || rtl_label == loop_stack->data.loop.continue_label))
973 end_block = loop_stack;
977 /* Now set END_BLOCK to the binding level to which we will return. */
981 struct nesting *next_block = end_block->all;
984 /* First see if the END_BLOCK is inside the innermost binding level.
985 If so, then no cleanups or stack levels are relevant. */
986 while (next_block && next_block != block)
987 next_block = next_block->all;
992 /* Otherwise, set END_BLOCK to the innermost binding level
993 which is outside the relevant control-structure nesting. */
994 next_block = block_stack->next;
995 for (block = block_stack; block != end_block; block = block->all)
996 if (block == next_block)
997 next_block = next_block->next;
998 end_block = next_block;
1001 /* Does any containing block have a stack level or cleanups?
1002 If not, no fixup is needed, and that is the normal case
1003 (the only case, for standard C). */
1004 for (block = block_stack; block != end_block; block = block->next)
1005 if (block->data.block.stack_level != 0
1006 || block->data.block.cleanups != 0)
1009 if (block != end_block)
1011 /* Ok, a fixup is needed. Add a fixup to the list of such. */
1012 struct goto_fixup *fixup
1013 = (struct goto_fixup *) ggc_alloc (sizeof (struct goto_fixup));
1014 /* In case an old stack level is restored, make sure that comes
1015 after any pending stack adjust. */
1016 /* ?? If the fixup isn't to come at the present position,
1017 doing the stack adjust here isn't useful. Doing it with our
1018 settings at that location isn't useful either. Let's hope
1021 do_pending_stack_adjust ();
1022 fixup->target = tree_label;
1023 fixup->target_rtl = rtl_label;
1025 /* Create a BLOCK node and a corresponding matched set of
1026 NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes at
1027 this point. The notes will encapsulate any and all fixup
1028 code which we might later insert at this point in the insn
1029 stream. Also, the BLOCK node will be the parent (i.e. the
1030 `SUPERBLOCK') of any other BLOCK nodes which we might create
1031 later on when we are expanding the fixup code.
1033 Note that optimization passes (including expand_end_loop)
1034 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
1035 as a placeholder. */
1038 register rtx original_before_jump
1039 = last_insn ? last_insn : get_last_insn ();
1044 block = make_node (BLOCK);
1045 TREE_USED (block) = 1;
1047 if (!cfun->x_whole_function_mode_p)
1048 insert_block (block);
1052 = BLOCK_CHAIN (DECL_INITIAL (current_function_decl));
1053 BLOCK_CHAIN (DECL_INITIAL (current_function_decl))
1058 start = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
1059 if (cfun->x_whole_function_mode_p)
1060 NOTE_BLOCK (start) = block;
1061 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_DELETED);
1062 end = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
1063 if (cfun->x_whole_function_mode_p)
1064 NOTE_BLOCK (end) = block;
1065 fixup->context = block;
1067 emit_insns_after (start, original_before_jump);
1070 fixup->block_start_count = current_block_start_count;
1071 fixup->stack_level = 0;
1072 fixup->cleanup_list_list
1073 = ((block->data.block.outer_cleanups
1074 || block->data.block.cleanups)
1075 ? tree_cons (NULL_TREE, block->data.block.cleanups,
1076 block->data.block.outer_cleanups)
1078 fixup->next = goto_fixup_chain;
1079 goto_fixup_chain = fixup;
1087 /* Expand any needed fixups in the outputmost binding level of the
1088 function. FIRST_INSN is the first insn in the function. */
1091 expand_fixups (first_insn)
1094 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0);
1097 /* When exiting a binding contour, process all pending gotos requiring fixups.
1098 THISBLOCK is the structure that describes the block being exited.
1099 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1100 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1101 FIRST_INSN is the insn that began this contour.
1103 Gotos that jump out of this contour must restore the
1104 stack level and do the cleanups before actually jumping.
1106 DONT_JUMP_IN nonzero means report error there is a jump into this
1107 contour from before the beginning of the contour.
1108 This is also done if STACK_LEVEL is nonzero. */
1111 fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1112 struct nesting *thisblock;
1118 register struct goto_fixup *f, *prev;
1120 /* F is the fixup we are considering; PREV is the previous one. */
1121 /* We run this loop in two passes so that cleanups of exited blocks
1122 are run first, and blocks that are exited are marked so
1125 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1127 /* Test for a fixup that is inactive because it is already handled. */
1128 if (f->before_jump == 0)
1130 /* Delete inactive fixup from the chain, if that is easy to do. */
1132 prev->next = f->next;
1134 /* Has this fixup's target label been defined?
1135 If so, we can finalize it. */
1136 else if (PREV_INSN (f->target_rtl) != 0)
1138 register rtx cleanup_insns;
1140 /* If this fixup jumped into this contour from before the beginning
1141 of this contour, report an error. This code used to use
1142 the first non-label insn after f->target_rtl, but that's
1143 wrong since such can be added, by things like put_var_into_stack
1144 and have INSN_UIDs that are out of the range of the block. */
1145 /* ??? Bug: this does not detect jumping in through intermediate
1146 blocks that have stack levels or cleanups.
1147 It detects only a problem with the innermost block
1148 around the label. */
1150 && (dont_jump_in || stack_level || cleanup_list)
1151 && INSN_UID (first_insn) < INSN_UID (f->target_rtl)
1152 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1153 && ! DECL_ERROR_ISSUED (f->target))
1155 error_with_decl (f->target,
1156 "label `%s' used before containing binding contour");
1157 /* Prevent multiple errors for one label. */
1158 DECL_ERROR_ISSUED (f->target) = 1;
1161 /* We will expand the cleanups into a sequence of their own and
1162 then later on we will attach this new sequence to the insn
1163 stream just ahead of the actual jump insn. */
1167 /* Temporarily restore the lexical context where we will
1168 logically be inserting the fixup code. We do this for the
1169 sake of getting the debugging information right. */
1172 set_block (f->context);
1174 /* Expand the cleanups for blocks this jump exits. */
1175 if (f->cleanup_list_list)
1178 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1179 /* Marked elements correspond to blocks that have been closed.
1180 Do their cleanups. */
1181 if (TREE_ADDRESSABLE (lists)
1182 && TREE_VALUE (lists) != 0)
1184 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1185 /* Pop any pushes done in the cleanups,
1186 in case function is about to return. */
1187 do_pending_stack_adjust ();
1191 /* Restore stack level for the biggest contour that this
1192 jump jumps out of. */
1194 && ! (f->target_rtl == return_label
1195 && (TYPE_RETURNS_STACK_DEPRESSED
1196 (TREE_TYPE (current_function_decl)))))
1197 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1199 /* Finish up the sequence containing the insns which implement the
1200 necessary cleanups, and then attach that whole sequence to the
1201 insn stream just ahead of the actual jump insn. Attaching it
1202 at that point insures that any cleanups which are in fact
1203 implicit C++ object destructions (which must be executed upon
1204 leaving the block) appear (to the debugger) to be taking place
1205 in an area of the generated code where the object(s) being
1206 destructed are still "in scope". */
1208 cleanup_insns = get_insns ();
1212 emit_insns_after (cleanup_insns, f->before_jump);
1219 /* For any still-undefined labels, do the cleanups for this block now.
1220 We must do this now since items in the cleanup list may go out
1221 of scope when the block ends. */
1222 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1223 if (f->before_jump != 0
1224 && PREV_INSN (f->target_rtl) == 0
1225 /* Label has still not appeared. If we are exiting a block with
1226 a stack level to restore, that started before the fixup,
1227 mark this stack level as needing restoration
1228 when the fixup is later finalized. */
1230 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1231 means the label is undefined. That's erroneous, but possible. */
1232 && (thisblock->data.block.block_start_count
1233 <= f->block_start_count))
1235 tree lists = f->cleanup_list_list;
1238 for (; lists; lists = TREE_CHAIN (lists))
1239 /* If the following elt. corresponds to our containing block
1240 then the elt. must be for this block. */
1241 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
1245 set_block (f->context);
1246 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1247 do_pending_stack_adjust ();
1248 cleanup_insns = get_insns ();
1251 if (cleanup_insns != 0)
1253 = emit_insns_after (cleanup_insns, f->before_jump);
1255 f->cleanup_list_list = TREE_CHAIN (lists);
1259 f->stack_level = stack_level;
1263 /* Return the number of times character C occurs in string S. */
1265 n_occurrences (c, s)
1275 /* Generate RTL for an asm statement (explicit assembler code).
1276 BODY is a STRING_CST node containing the assembler code text,
1277 or an ADDR_EXPR containing a STRING_CST. */
1283 if (current_function_check_memory_usage)
1285 error ("`asm' cannot be used in function where memory usage is checked");
1289 if (TREE_CODE (body) == ADDR_EXPR)
1290 body = TREE_OPERAND (body, 0);
1292 emit_insn (gen_rtx_ASM_INPUT (VOIDmode,
1293 TREE_STRING_POINTER (body)));
1297 /* Generate RTL for an asm statement with arguments.
1298 STRING is the instruction template.
1299 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1300 Each output or input has an expression in the TREE_VALUE and
1301 a constraint-string in the TREE_PURPOSE.
1302 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1303 that is clobbered by this insn.
1305 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1306 Some elements of OUTPUTS may be replaced with trees representing temporary
1307 values. The caller should copy those temporary values to the originally
1310 VOL nonzero means the insn is volatile; don't optimize it. */
1313 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1314 tree string, outputs, inputs, clobbers;
1316 const char *filename;
1319 rtvec argvec, constraints;
1321 int ninputs = list_length (inputs);
1322 int noutputs = list_length (outputs);
1327 /* Vector of RTX's of evaluated output operands. */
1328 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1329 int *inout_opnum = (int *) alloca (noutputs * sizeof (int));
1330 rtx *real_output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1331 enum machine_mode *inout_mode
1332 = (enum machine_mode *) alloca (noutputs * sizeof (enum machine_mode));
1333 /* The insn we have emitted. */
1336 /* An ASM with no outputs needs to be treated as volatile, for now. */
1340 if (current_function_check_memory_usage)
1342 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1346 #ifdef MD_ASM_CLOBBERS
1347 /* Sometimes we wish to automatically clobber registers across an asm.
1348 Case in point is when the i386 backend moved from cc0 to a hard reg --
1349 maintaining source-level compatability means automatically clobbering
1350 the flags register. */
1351 MD_ASM_CLOBBERS (clobbers);
1354 if (current_function_check_memory_usage)
1356 error ("`asm' cannot be used in function where memory usage is checked");
1360 /* Count the number of meaningful clobbered registers, ignoring what
1361 we would ignore later. */
1363 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1365 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1367 i = decode_reg_name (regname);
1368 if (i >= 0 || i == -4)
1371 error ("unknown register name `%s' in `asm'", regname);
1376 /* Check that the number of alternatives is constant across all
1378 if (outputs || inputs)
1380 tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
1381 int nalternatives = n_occurrences (',', TREE_STRING_POINTER (tmp));
1384 if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
1386 error ("too many alternatives in `asm'");
1393 const char *constraint = TREE_STRING_POINTER (TREE_PURPOSE (tmp));
1395 if (n_occurrences (',', constraint) != nalternatives)
1397 error ("operand constraints for `asm' differ in number of alternatives");
1401 if (TREE_CHAIN (tmp))
1402 tmp = TREE_CHAIN (tmp);
1404 tmp = next, next = 0;
1408 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1410 tree val = TREE_VALUE (tail);
1411 tree type = TREE_TYPE (val);
1420 /* If there's an erroneous arg, emit no insn. */
1421 if (TREE_TYPE (val) == error_mark_node)
1424 /* Make sure constraint has `=' and does not have `+'. Also, see
1425 if it allows any register. Be liberal on the latter test, since
1426 the worst that happens if we get it wrong is we issue an error
1429 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1430 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1432 /* Allow the `=' or `+' to not be at the beginning of the string,
1433 since it wasn't explicitly documented that way, and there is a
1434 large body of code that puts it last. Swap the character to
1435 the front, so as not to uglify any place else. */
1439 if ((p = strchr (constraint, '=')) != NULL)
1441 if ((p = strchr (constraint, '+')) != NULL)
1444 error ("output operand constraint lacks `='");
1448 if (p != constraint)
1451 bcopy (constraint, constraint+1, p-constraint);
1454 warning ("output constraint `%c' for operand %d is not at the beginning", j, i);
1457 is_inout = constraint[0] == '+';
1458 /* Replace '+' with '='. */
1459 constraint[0] = '=';
1460 /* Make sure we can specify the matching operand. */
1461 if (is_inout && i > 9)
1463 error ("output operand constraint %d contains `+'", i);
1467 for (j = 1; j < c_len; j++)
1468 switch (constraint[j])
1472 error ("operand constraint contains '+' or '=' at illegal position.");
1476 if (i + 1 == ninputs + noutputs)
1478 error ("`%%' constraint used with last operand");
1483 case '?': case '!': case '*': case '&':
1484 case 'E': case 'F': case 'G': case 'H':
1485 case 's': case 'i': case 'n':
1486 case 'I': case 'J': case 'K': case 'L': case 'M':
1487 case 'N': case 'O': case 'P': case ',':
1488 #ifdef EXTRA_CONSTRAINT
1489 case 'Q': case 'R': case 'S': case 'T': case 'U':
1493 case '0': case '1': case '2': case '3': case '4':
1494 case '5': case '6': case '7': case '8': case '9':
1495 error ("matching constraint not valid in output operand");
1498 case 'V': case 'm': case 'o':
1503 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1504 excepting those that expand_call created. So match memory
1520 /* If an output operand is not a decl or indirect ref and our constraint
1521 allows a register, make a temporary to act as an intermediate.
1522 Make the asm insn write into that, then our caller will copy it to
1523 the real output operand. Likewise for promoted variables. */
1525 real_output_rtx[i] = NULL_RTX;
1526 if ((TREE_CODE (val) == INDIRECT_REF
1529 && (allows_mem || GET_CODE (DECL_RTL (val)) == REG)
1530 && ! (GET_CODE (DECL_RTL (val)) == REG
1531 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
1536 mark_addressable (TREE_VALUE (tail));
1539 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode,
1540 EXPAND_MEMORY_USE_WO);
1542 if (! allows_reg && GET_CODE (output_rtx[i]) != MEM)
1543 error ("output number %d not directly addressable", i);
1544 if (! allows_mem && GET_CODE (output_rtx[i]) == MEM)
1546 real_output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1547 output_rtx[i] = gen_reg_rtx (GET_MODE (output_rtx[i]));
1549 emit_move_insn (output_rtx[i], real_output_rtx[i]);
1554 output_rtx[i] = assign_temp (type, 0, 0, 1);
1555 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1560 inout_mode[ninout] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)));
1561 inout_opnum[ninout++] = i;
1566 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1568 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1572 /* Make vectors for the expression-rtx and constraint strings. */
1574 argvec = rtvec_alloc (ninputs);
1575 constraints = rtvec_alloc (ninputs);
1577 body = gen_rtx_ASM_OPERANDS (VOIDmode, TREE_STRING_POINTER (string),
1578 empty_string, 0, argvec, constraints,
1581 MEM_VOLATILE_P (body) = vol;
1583 /* Eval the inputs and put them into ARGVEC.
1584 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1587 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1590 int allows_reg = 0, allows_mem = 0;
1591 char *constraint, *orig_constraint;
1595 /* If there's an erroneous arg, emit no insn,
1596 because the ASM_INPUT would get VOIDmode
1597 and that could cause a crash in reload. */
1598 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1601 /* ??? Can this happen, and does the error message make any sense? */
1602 if (TREE_PURPOSE (tail) == NULL_TREE)
1604 error ("hard register `%s' listed as input operand to `asm'",
1605 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1609 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1610 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1611 orig_constraint = constraint;
1613 /* Make sure constraint has neither `=', `+', nor '&'. */
1615 for (j = 0; j < c_len; j++)
1616 switch (constraint[j])
1618 case '+': case '=': case '&':
1619 if (constraint == orig_constraint)
1621 error ("input operand constraint contains `%c'",
1628 if (constraint == orig_constraint
1629 && i + 1 == ninputs - ninout)
1631 error ("`%%' constraint used with last operand");
1636 case 'V': case 'm': case 'o':
1641 case '?': case '!': case '*':
1642 case 'E': case 'F': case 'G': case 'H': case 'X':
1643 case 's': case 'i': case 'n':
1644 case 'I': case 'J': case 'K': case 'L': case 'M':
1645 case 'N': case 'O': case 'P': case ',':
1646 #ifdef EXTRA_CONSTRAINT
1647 case 'Q': case 'R': case 'S': case 'T': case 'U':
1651 /* Whether or not a numeric constraint allows a register is
1652 decided by the matching constraint, and so there is no need
1653 to do anything special with them. We must handle them in
1654 the default case, so that we don't unnecessarily force
1655 operands to memory. */
1656 case '0': case '1': case '2': case '3': case '4':
1657 case '5': case '6': case '7': case '8': case '9':
1658 if (constraint[j] >= '0' + noutputs)
1661 ("matching constraint references invalid operand number");
1665 /* Try and find the real constraint for this dup. */
1666 if ((j == 0 && c_len == 1)
1667 || (j == 1 && c_len == 2 && constraint[0] == '%'))
1671 for (j = constraint[j] - '0'; j > 0; --j)
1674 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (o)));
1675 constraint = TREE_STRING_POINTER (TREE_PURPOSE (o));
1680 /* ... fall through ... */
1693 if (! allows_reg && allows_mem)
1694 mark_addressable (TREE_VALUE (tail));
1696 op = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1698 if (asm_operand_ok (op, constraint) <= 0)
1701 op = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), op);
1702 else if (!allows_mem)
1703 warning ("asm operand %d probably doesn't match constraints", i);
1704 else if (CONSTANT_P (op))
1705 op = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1707 else if (GET_CODE (op) == REG
1708 || GET_CODE (op) == SUBREG
1709 || GET_CODE (op) == CONCAT)
1711 tree type = TREE_TYPE (TREE_VALUE (tail));
1712 rtx memloc = assign_temp (type, 1, 1, 1);
1714 emit_move_insn (memloc, op);
1718 else if (GET_CODE (op) == MEM && MEM_VOLATILE_P (op))
1719 /* We won't recognize volatile memory as available a
1720 memory_operand at this point. Ignore it. */
1722 else if (queued_subexp_p (op))
1725 /* ??? Leave this only until we have experience with what
1726 happens in combine and elsewhere when constraints are
1728 warning ("asm operand %d probably doesn't match constraints", i);
1730 XVECEXP (body, 3, i) = op;
1732 XVECEXP (body, 4, i) /* constraints */
1733 = gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1738 /* Protect all the operands from the queue now that they have all been
1741 for (i = 0; i < ninputs - ninout; i++)
1742 XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0);
1744 for (i = 0; i < noutputs; i++)
1745 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1747 /* For in-out operands, copy output rtx to input rtx. */
1748 for (i = 0; i < ninout; i++)
1750 int j = inout_opnum[i];
1752 XVECEXP (body, 3, ninputs - ninout + i) /* argvec */
1754 XVECEXP (body, 4, ninputs - ninout + i) /* constraints */
1755 = gen_rtx_ASM_INPUT (inout_mode[i], digit_strings[j]);
1758 /* Now, for each output, construct an rtx
1759 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1760 ARGVEC CONSTRAINTS))
1761 If there is more than one, put them inside a PARALLEL. */
1763 if (noutputs == 1 && nclobbers == 0)
1765 XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1766 insn = emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
1769 else if (noutputs == 0 && nclobbers == 0)
1771 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1772 insn = emit_insn (body);
1783 body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
1785 /* For each output operand, store a SET. */
1786 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1788 XVECEXP (body, 0, i)
1789 = gen_rtx_SET (VOIDmode,
1791 gen_rtx_ASM_OPERANDS
1793 TREE_STRING_POINTER (string),
1794 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1795 i, argvec, constraints,
1798 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1801 /* If there are no outputs (but there are some clobbers)
1802 store the bare ASM_OPERANDS into the PARALLEL. */
1805 XVECEXP (body, 0, i++) = obody;
1807 /* Store (clobber REG) for each clobbered register specified. */
1809 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1811 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1812 int j = decode_reg_name (regname);
1816 if (j == -3) /* `cc', which is not a register */
1819 if (j == -4) /* `memory', don't cache memory across asm */
1821 XVECEXP (body, 0, i++)
1822 = gen_rtx_CLOBBER (VOIDmode,
1825 gen_rtx_SCRATCH (VOIDmode)));
1829 /* Ignore unknown register, error already signaled. */
1833 /* Use QImode since that's guaranteed to clobber just one reg. */
1834 XVECEXP (body, 0, i++)
1835 = gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (QImode, j));
1838 insn = emit_insn (body);
1841 /* For any outputs that needed reloading into registers, spill them
1842 back to where they belong. */
1843 for (i = 0; i < noutputs; ++i)
1844 if (real_output_rtx[i])
1845 emit_move_insn (real_output_rtx[i], output_rtx[i]);
1850 /* Generate RTL to evaluate the expression EXP
1851 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1854 expand_expr_stmt (exp)
1857 /* If -W, warn about statements with no side effects,
1858 except for an explicit cast to void (e.g. for assert()), and
1859 except inside a ({...}) where they may be useful. */
1860 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1862 if (! TREE_SIDE_EFFECTS (exp)
1863 && (extra_warnings || warn_unused_value)
1864 && !(TREE_CODE (exp) == CONVERT_EXPR
1865 && VOID_TYPE_P (TREE_TYPE (exp))))
1866 warning_with_file_and_line (emit_filename, emit_lineno,
1867 "statement with no effect");
1868 else if (warn_unused_value)
1869 warn_if_unused_value (exp);
1872 /* If EXP is of function type and we are expanding statements for
1873 value, convert it to pointer-to-function. */
1874 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1875 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1877 last_expr_type = TREE_TYPE (exp);
1878 last_expr_value = expand_expr (exp,
1879 (expr_stmts_for_value
1880 ? NULL_RTX : const0_rtx),
1883 /* If all we do is reference a volatile value in memory,
1884 copy it to a register to be sure it is actually touched. */
1885 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1886 && TREE_THIS_VOLATILE (exp))
1888 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1890 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1891 copy_to_reg (last_expr_value);
1894 rtx lab = gen_label_rtx ();
1896 /* Compare the value with itself to reference it. */
1897 emit_cmp_and_jump_insns (last_expr_value, last_expr_value, EQ,
1898 expand_expr (TYPE_SIZE (last_expr_type),
1899 NULL_RTX, VOIDmode, 0),
1901 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT,
1907 /* If this expression is part of a ({...}) and is in memory, we may have
1908 to preserve temporaries. */
1909 preserve_temp_slots (last_expr_value);
1911 /* Free any temporaries used to evaluate this expression. Any temporary
1912 used as a result of this expression will already have been preserved
1919 /* Warn if EXP contains any computations whose results are not used.
1920 Return 1 if a warning is printed; 0 otherwise. */
1923 warn_if_unused_value (exp)
1926 if (TREE_USED (exp))
1929 switch (TREE_CODE (exp))
1931 case PREINCREMENT_EXPR:
1932 case POSTINCREMENT_EXPR:
1933 case PREDECREMENT_EXPR:
1934 case POSTDECREMENT_EXPR:
1939 case METHOD_CALL_EXPR:
1941 case TRY_CATCH_EXPR:
1942 case WITH_CLEANUP_EXPR:
1944 /* We don't warn about COND_EXPR because it may be a useful
1945 construct if either arm contains a side effect. */
1950 /* For a binding, warn if no side effect within it. */
1951 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1954 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1956 case TRUTH_ORIF_EXPR:
1957 case TRUTH_ANDIF_EXPR:
1958 /* In && or ||, warn if 2nd operand has no side effect. */
1959 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1962 if (TREE_NO_UNUSED_WARNING (exp))
1964 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
1966 /* Let people do `(foo (), 0)' without a warning. */
1967 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1969 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1973 case NON_LVALUE_EXPR:
1974 /* Don't warn about values cast to void. */
1975 if (VOID_TYPE_P (TREE_TYPE (exp)))
1977 /* Don't warn about conversions not explicit in the user's program. */
1978 if (TREE_NO_UNUSED_WARNING (exp))
1980 /* Assignment to a cast usually results in a cast of a modify.
1981 Don't complain about that. There can be an arbitrary number of
1982 casts before the modify, so we must loop until we find the first
1983 non-cast expression and then test to see if that is a modify. */
1985 tree tem = TREE_OPERAND (exp, 0);
1987 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1988 tem = TREE_OPERAND (tem, 0);
1990 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
1991 || TREE_CODE (tem) == CALL_EXPR)
1997 /* Don't warn about automatic dereferencing of references, since
1998 the user cannot control it. */
1999 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
2000 return warn_if_unused_value (TREE_OPERAND (exp, 0));
2001 /* ... fall through ... */
2004 /* Referencing a volatile value is a side effect, so don't warn. */
2006 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
2007 && TREE_THIS_VOLATILE (exp))
2010 /* If this is an expression which has no operands, there is no value
2011 to be unused. There are no such language-independent codes,
2012 but front ends may define such. */
2013 if (TREE_CODE_CLASS (TREE_CODE (exp)) == 'e'
2014 && TREE_CODE_LENGTH (TREE_CODE (exp)) == 0)
2018 warning_with_file_and_line (emit_filename, emit_lineno,
2019 "value computed is not used");
2024 /* Clear out the memory of the last expression evaluated. */
2032 /* Begin a statement which will return a value.
2033 Return the RTL_EXPR for this statement expr.
2034 The caller must save that value and pass it to expand_end_stmt_expr. */
2037 expand_start_stmt_expr ()
2042 /* Make the RTL_EXPR node temporary, not momentary,
2043 so that rtl_expr_chain doesn't become garbage. */
2044 momentary = suspend_momentary ();
2045 t = make_node (RTL_EXPR);
2046 resume_momentary (momentary);
2047 do_pending_stack_adjust ();
2048 start_sequence_for_rtl_expr (t);
2050 expr_stmts_for_value++;
2054 /* Restore the previous state at the end of a statement that returns a value.
2055 Returns a tree node representing the statement's value and the
2056 insns to compute the value.
2058 The nodes of that expression have been freed by now, so we cannot use them.
2059 But we don't want to do that anyway; the expression has already been
2060 evaluated and now we just want to use the value. So generate a RTL_EXPR
2061 with the proper type and RTL value.
2063 If the last substatement was not an expression,
2064 return something with type `void'. */
2067 expand_end_stmt_expr (t)
2072 if (last_expr_type == 0)
2074 last_expr_type = void_type_node;
2075 last_expr_value = const0_rtx;
2077 else if (last_expr_value == 0)
2078 /* There are some cases where this can happen, such as when the
2079 statement is void type. */
2080 last_expr_value = const0_rtx;
2081 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
2082 /* Remove any possible QUEUED. */
2083 last_expr_value = protect_from_queue (last_expr_value, 0);
2087 TREE_TYPE (t) = last_expr_type;
2088 RTL_EXPR_RTL (t) = last_expr_value;
2089 RTL_EXPR_SEQUENCE (t) = get_insns ();
2091 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
2095 /* Don't consider deleting this expr or containing exprs at tree level. */
2096 TREE_SIDE_EFFECTS (t) = 1;
2097 /* Propagate volatility of the actual RTL expr. */
2098 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
2101 expr_stmts_for_value--;
2106 /* Generate RTL for the start of an if-then. COND is the expression
2107 whose truth should be tested.
2109 If EXITFLAG is nonzero, this conditional is visible to
2110 `exit_something'. */
2113 expand_start_cond (cond, exitflag)
2117 struct nesting *thiscond = ALLOC_NESTING ();
2119 /* Make an entry on cond_stack for the cond we are entering. */
2121 thiscond->next = cond_stack;
2122 thiscond->all = nesting_stack;
2123 thiscond->depth = ++nesting_depth;
2124 thiscond->data.cond.next_label = gen_label_rtx ();
2125 /* Before we encounter an `else', we don't need a separate exit label
2126 unless there are supposed to be exit statements
2127 to exit this conditional. */
2128 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
2129 thiscond->data.cond.endif_label = thiscond->exit_label;
2130 cond_stack = thiscond;
2131 nesting_stack = thiscond;
2133 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
2136 /* Generate RTL between then-clause and the elseif-clause
2137 of an if-then-elseif-.... */
2140 expand_start_elseif (cond)
2143 if (cond_stack->data.cond.endif_label == 0)
2144 cond_stack->data.cond.endif_label = gen_label_rtx ();
2145 emit_jump (cond_stack->data.cond.endif_label);
2146 emit_label (cond_stack->data.cond.next_label);
2147 cond_stack->data.cond.next_label = gen_label_rtx ();
2148 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2151 /* Generate RTL between the then-clause and the else-clause
2152 of an if-then-else. */
2155 expand_start_else ()
2157 if (cond_stack->data.cond.endif_label == 0)
2158 cond_stack->data.cond.endif_label = gen_label_rtx ();
2160 emit_jump (cond_stack->data.cond.endif_label);
2161 emit_label (cond_stack->data.cond.next_label);
2162 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
2165 /* After calling expand_start_else, turn this "else" into an "else if"
2166 by providing another condition. */
2169 expand_elseif (cond)
2172 cond_stack->data.cond.next_label = gen_label_rtx ();
2173 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2176 /* Generate RTL for the end of an if-then.
2177 Pop the record for it off of cond_stack. */
2182 struct nesting *thiscond = cond_stack;
2184 do_pending_stack_adjust ();
2185 if (thiscond->data.cond.next_label)
2186 emit_label (thiscond->data.cond.next_label);
2187 if (thiscond->data.cond.endif_label)
2188 emit_label (thiscond->data.cond.endif_label);
2190 POPSTACK (cond_stack);
2196 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2197 loop should be exited by `exit_something'. This is a loop for which
2198 `expand_continue' will jump to the top of the loop.
2200 Make an entry on loop_stack to record the labels associated with
2204 expand_start_loop (exit_flag)
2207 register struct nesting *thisloop = ALLOC_NESTING ();
2209 /* Make an entry on loop_stack for the loop we are entering. */
2211 thisloop->next = loop_stack;
2212 thisloop->all = nesting_stack;
2213 thisloop->depth = ++nesting_depth;
2214 thisloop->data.loop.start_label = gen_label_rtx ();
2215 thisloop->data.loop.end_label = gen_label_rtx ();
2216 thisloop->data.loop.alt_end_label = 0;
2217 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2218 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2219 loop_stack = thisloop;
2220 nesting_stack = thisloop;
2222 do_pending_stack_adjust ();
2224 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2225 emit_label (thisloop->data.loop.start_label);
2230 /* Like expand_start_loop but for a loop where the continuation point
2231 (for expand_continue_loop) will be specified explicitly. */
2234 expand_start_loop_continue_elsewhere (exit_flag)
2237 struct nesting *thisloop = expand_start_loop (exit_flag);
2238 loop_stack->data.loop.continue_label = gen_label_rtx ();
2242 /* Specify the continuation point for a loop started with
2243 expand_start_loop_continue_elsewhere.
2244 Use this at the point in the code to which a continue statement
2248 expand_loop_continue_here ()
2250 do_pending_stack_adjust ();
2251 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2252 emit_label (loop_stack->data.loop.continue_label);
2255 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2256 Pop the block off of loop_stack. */
2261 rtx start_label = loop_stack->data.loop.start_label;
2262 rtx insn = get_last_insn ();
2263 int needs_end_jump = 1;
2265 /* Mark the continue-point at the top of the loop if none elsewhere. */
2266 if (start_label == loop_stack->data.loop.continue_label)
2267 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2269 do_pending_stack_adjust ();
2271 /* If optimizing, perhaps reorder the loop.
2272 First, try to use a condjump near the end.
2273 expand_exit_loop_if_false ends loops with unconditional jumps,
2276 if (test) goto label;
2278 goto loop_stack->data.loop.end_label
2282 If we find such a pattern, we can end the loop earlier. */
2285 && GET_CODE (insn) == CODE_LABEL
2286 && LABEL_NAME (insn) == NULL
2287 && GET_CODE (PREV_INSN (insn)) == BARRIER)
2290 rtx jump = PREV_INSN (PREV_INSN (label));
2292 if (GET_CODE (jump) == JUMP_INSN
2293 && GET_CODE (PATTERN (jump)) == SET
2294 && SET_DEST (PATTERN (jump)) == pc_rtx
2295 && GET_CODE (SET_SRC (PATTERN (jump))) == LABEL_REF
2296 && (XEXP (SET_SRC (PATTERN (jump)), 0)
2297 == loop_stack->data.loop.end_label))
2301 /* The test might be complex and reference LABEL multiple times,
2302 like the loop in loop_iterations to set vtop. To handle this,
2304 insn = PREV_INSN (label);
2305 reorder_insns (label, label, start_label);
2307 for (prev = PREV_INSN (jump); ; prev = PREV_INSN (prev))
2309 /* We ignore line number notes, but if we see any other note,
2310 in particular NOTE_INSN_BLOCK_*, NOTE_INSN_EH_REGION_*,
2311 NOTE_INSN_LOOP_*, we disable this optimization. */
2312 if (GET_CODE (prev) == NOTE)
2314 if (NOTE_LINE_NUMBER (prev) < 0)
2318 if (GET_CODE (prev) == CODE_LABEL)
2320 if (GET_CODE (prev) == JUMP_INSN)
2322 if (GET_CODE (PATTERN (prev)) == SET
2323 && SET_DEST (PATTERN (prev)) == pc_rtx
2324 && GET_CODE (SET_SRC (PATTERN (prev))) == IF_THEN_ELSE
2325 && (GET_CODE (XEXP (SET_SRC (PATTERN (prev)), 1))
2327 && XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0) == label)
2329 XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0)
2331 emit_note_after (NOTE_INSN_LOOP_END, prev);
2340 /* If the loop starts with a loop exit, roll that to the end where
2341 it will optimize together with the jump back.
2343 We look for the conditional branch to the exit, except that once
2344 we find such a branch, we don't look past 30 instructions.
2346 In more detail, if the loop presently looks like this (in pseudo-C):
2349 if (test) goto end_label;
2354 transform it to look like:
2360 if (test) goto end_label;
2361 goto newstart_label;
2364 Here, the `test' may actually consist of some reasonably complex
2365 code, terminating in a test. */
2370 ! (GET_CODE (insn) == JUMP_INSN
2371 && GET_CODE (PATTERN (insn)) == SET
2372 && SET_DEST (PATTERN (insn)) == pc_rtx
2373 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2377 rtx last_test_insn = NULL_RTX;
2379 /* Scan insns from the top of the loop looking for a qualified
2380 conditional exit. */
2381 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2382 insn = NEXT_INSN (insn))
2384 if (GET_CODE (insn) == NOTE)
2387 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2388 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2389 /* The code that actually moves the exit test will
2390 carefully leave BLOCK notes in their original
2391 location. That means, however, that we can't debug
2392 the exit test itself. So, we refuse to move code
2393 containing BLOCK notes at low optimization levels. */
2396 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG)
2398 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)
2402 /* We've come to the end of an EH region, but
2403 never saw the beginning of that region. That
2404 means that an EH region begins before the top
2405 of the loop, and ends in the middle of it. The
2406 existence of such a situation violates a basic
2407 assumption in this code, since that would imply
2408 that even when EH_REGIONS is zero, we might
2409 move code out of an exception region. */
2413 /* We must not walk into a nested loop. */
2414 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
2417 /* We already know this INSN is a NOTE, so there's no
2418 point in looking at it to see if it's a JUMP. */
2422 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2425 if (last_test_insn && num_insns > 30)
2429 /* We don't want to move a partial EH region. Consider:
2443 This isn't legal C++, but here's what it's supposed to
2444 mean: if cond() is true, stop looping. Otherwise,
2445 call bar, and keep looping. In addition, if cond
2446 throws an exception, catch it and keep looping. Such
2447 constructs are certainy legal in LISP.
2449 We should not move the `if (cond()) 0' test since then
2450 the EH-region for the try-block would be broken up.
2451 (In this case we would the EH_BEG note for the `try'
2452 and `if cond()' but not the call to bar() or the
2455 So we don't look for tests within an EH region. */
2458 if (GET_CODE (insn) == JUMP_INSN
2459 && GET_CODE (PATTERN (insn)) == SET
2460 && SET_DEST (PATTERN (insn)) == pc_rtx)
2462 /* This is indeed a jump. */
2463 rtx dest1 = NULL_RTX;
2464 rtx dest2 = NULL_RTX;
2465 rtx potential_last_test;
2466 if (GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE)
2468 /* A conditional jump. */
2469 dest1 = XEXP (SET_SRC (PATTERN (insn)), 1);
2470 dest2 = XEXP (SET_SRC (PATTERN (insn)), 2);
2471 potential_last_test = insn;
2475 /* An unconditional jump. */
2476 dest1 = SET_SRC (PATTERN (insn));
2477 /* Include the BARRIER after the JUMP. */
2478 potential_last_test = NEXT_INSN (insn);
2482 if (dest1 && GET_CODE (dest1) == LABEL_REF
2483 && ((XEXP (dest1, 0)
2484 == loop_stack->data.loop.alt_end_label)
2486 == loop_stack->data.loop.end_label)))
2488 last_test_insn = potential_last_test;
2492 /* If this was a conditional jump, there may be
2493 another label at which we should look. */
2500 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2502 /* We found one. Move everything from there up
2503 to the end of the loop, and add a jump into the loop
2504 to jump to there. */
2505 register rtx newstart_label = gen_label_rtx ();
2506 register rtx start_move = start_label;
2509 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2510 then we want to move this note also. */
2511 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2512 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2513 == NOTE_INSN_LOOP_CONT))
2514 start_move = PREV_INSN (start_move);
2516 emit_label_after (newstart_label, PREV_INSN (start_move));
2518 /* Actually move the insns. Start at the beginning, and
2519 keep copying insns until we've copied the
2521 for (insn = start_move; insn; insn = next_insn)
2523 /* Figure out which insn comes after this one. We have
2524 to do this before we move INSN. */
2525 if (insn == last_test_insn)
2526 /* We've moved all the insns. */
2527 next_insn = NULL_RTX;
2529 next_insn = NEXT_INSN (insn);
2531 if (GET_CODE (insn) == NOTE
2532 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2533 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2534 /* We don't want to move NOTE_INSN_BLOCK_BEGs or
2535 NOTE_INSN_BLOCK_ENDs because the correct generation
2536 of debugging information depends on these appearing
2537 in the same order in the RTL and in the tree
2538 structure, where they are represented as BLOCKs.
2539 So, we don't move block notes. Of course, moving
2540 the code inside the block is likely to make it
2541 impossible to debug the instructions in the exit
2542 test, but such is the price of optimization. */
2545 /* Move the INSN. */
2546 reorder_insns (insn, insn, get_last_insn ());
2549 emit_jump_insn_after (gen_jump (start_label),
2550 PREV_INSN (newstart_label));
2551 emit_barrier_after (PREV_INSN (newstart_label));
2552 start_label = newstart_label;
2558 emit_jump (start_label);
2559 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2561 emit_label (loop_stack->data.loop.end_label);
2563 POPSTACK (loop_stack);
2568 /* Generate a jump to the current loop's continue-point.
2569 This is usually the top of the loop, but may be specified
2570 explicitly elsewhere. If not currently inside a loop,
2571 return 0 and do nothing; caller will print an error message. */
2574 expand_continue_loop (whichloop)
2575 struct nesting *whichloop;
2579 whichloop = loop_stack;
2582 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2587 /* Generate a jump to exit the current loop. If not currently inside a loop,
2588 return 0 and do nothing; caller will print an error message. */
2591 expand_exit_loop (whichloop)
2592 struct nesting *whichloop;
2596 whichloop = loop_stack;
2599 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2603 /* Generate a conditional jump to exit the current loop if COND
2604 evaluates to zero. If not currently inside a loop,
2605 return 0 and do nothing; caller will print an error message. */
2608 expand_exit_loop_if_false (whichloop, cond)
2609 struct nesting *whichloop;
2612 rtx label = gen_label_rtx ();
2617 whichloop = loop_stack;
2620 /* In order to handle fixups, we actually create a conditional jump
2621 around a unconditional branch to exit the loop. If fixups are
2622 necessary, they go before the unconditional branch. */
2625 do_jump (cond, NULL_RTX, label);
2626 last_insn = get_last_insn ();
2627 if (GET_CODE (last_insn) == CODE_LABEL)
2628 whichloop->data.loop.alt_end_label = last_insn;
2629 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2636 /* Return nonzero if the loop nest is empty. Else return zero. */
2639 stmt_loop_nest_empty ()
2641 /* cfun->stmt can be NULL if we are building a call to get the
2642 EH context for a setjmp/longjmp EH target and the current
2643 function was a deferred inline function. */
2644 return (cfun->stmt == NULL || loop_stack == NULL);
2647 /* Return non-zero if we should preserve sub-expressions as separate
2648 pseudos. We never do so if we aren't optimizing. We always do so
2649 if -fexpensive-optimizations.
2651 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2652 the loop may still be a small one. */
2655 preserve_subexpressions_p ()
2659 if (flag_expensive_optimizations)
2662 if (optimize == 0 || cfun == 0 || cfun->stmt == 0 || loop_stack == 0)
2665 insn = get_last_insn_anywhere ();
2668 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2669 < n_non_fixed_regs * 3));
2673 /* Generate a jump to exit the current loop, conditional, binding contour
2674 or case statement. Not all such constructs are visible to this function,
2675 only those started with EXIT_FLAG nonzero. Individual languages use
2676 the EXIT_FLAG parameter to control which kinds of constructs you can
2679 If not currently inside anything that can be exited,
2680 return 0 and do nothing; caller will print an error message. */
2683 expand_exit_something ()
2687 for (n = nesting_stack; n; n = n->all)
2688 if (n->exit_label != 0)
2690 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2697 /* Generate RTL to return from the current function, with no value.
2698 (That is, we do not do anything about returning any value.) */
2701 expand_null_return ()
2703 struct nesting *block = block_stack;
2704 rtx last_insn = get_last_insn ();
2706 /* If this function was declared to return a value, but we
2707 didn't, clobber the return registers so that they are not
2708 propogated live to the rest of the function. */
2709 clobber_return_register ();
2711 /* Does any pending block have cleanups? */
2712 while (block && block->data.block.cleanups == 0)
2713 block = block->next;
2715 /* If yes, use a goto to return, since that runs cleanups. */
2717 expand_null_return_1 (last_insn, block != 0);
2720 /* Generate RTL to return from the current function, with value VAL. */
2723 expand_value_return (val)
2726 struct nesting *block = block_stack;
2727 rtx last_insn = get_last_insn ();
2728 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2730 /* Copy the value to the return location
2731 unless it's already there. */
2733 if (return_reg != val)
2735 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2736 #ifdef PROMOTE_FUNCTION_RETURN
2737 int unsignedp = TREE_UNSIGNED (type);
2738 enum machine_mode old_mode
2739 = DECL_MODE (DECL_RESULT (current_function_decl));
2740 enum machine_mode mode
2741 = promote_mode (type, old_mode, &unsignedp, 1);
2743 if (mode != old_mode)
2744 val = convert_modes (mode, old_mode, val, unsignedp);
2746 if (GET_CODE (return_reg) == PARALLEL)
2747 emit_group_load (return_reg, val, int_size_in_bytes (type),
2750 emit_move_insn (return_reg, val);
2753 /* Does any pending block have cleanups? */
2755 while (block && block->data.block.cleanups == 0)
2756 block = block->next;
2758 /* If yes, use a goto to return, since that runs cleanups.
2759 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2761 expand_null_return_1 (last_insn, block != 0);
2764 /* Output a return with no value. If LAST_INSN is nonzero,
2765 pretend that the return takes place after LAST_INSN.
2766 If USE_GOTO is nonzero then don't use a return instruction;
2767 go to the return label instead. This causes any cleanups
2768 of pending blocks to be executed normally. */
2771 expand_null_return_1 (last_insn, use_goto)
2775 rtx end_label = cleanup_label ? cleanup_label : return_label;
2777 clear_pending_stack_adjust ();
2778 do_pending_stack_adjust ();
2781 /* PCC-struct return always uses an epilogue. */
2782 if (current_function_returns_pcc_struct || use_goto)
2785 end_label = return_label = gen_label_rtx ();
2786 expand_goto_internal (NULL_TREE, end_label, last_insn);
2790 /* Otherwise output a simple return-insn if one is available,
2791 unless it won't do the job. */
2793 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2795 emit_jump_insn (gen_return ());
2801 /* Otherwise jump to the epilogue. */
2802 expand_goto_internal (NULL_TREE, end_label, last_insn);
2805 /* Generate RTL to evaluate the expression RETVAL and return it
2806 from the current function. */
2809 expand_return (retval)
2812 /* If there are any cleanups to be performed, then they will
2813 be inserted following LAST_INSN. It is desirable
2814 that the last_insn, for such purposes, should be the
2815 last insn before computing the return value. Otherwise, cleanups
2816 which call functions can clobber the return value. */
2817 /* ??? rms: I think that is erroneous, because in C++ it would
2818 run destructors on variables that might be used in the subsequent
2819 computation of the return value. */
2821 rtx result_rtl = DECL_RTL (DECL_RESULT (current_function_decl));
2822 register rtx val = 0;
2826 /* If function wants no value, give it none. */
2827 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2829 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2831 expand_null_return ();
2835 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2836 /* This is not sufficient. We also need to watch for cleanups of the
2837 expression we are about to expand. Unfortunately, we cannot know
2838 if it has cleanups until we expand it, and we want to change how we
2839 expand it depending upon if we need cleanups. We can't win. */
2841 cleanups = any_pending_cleanups (1);
2846 if (retval == error_mark_node)
2847 retval_rhs = NULL_TREE;
2848 else if (TREE_CODE (retval) == RESULT_DECL)
2849 retval_rhs = retval;
2850 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2851 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2852 retval_rhs = TREE_OPERAND (retval, 1);
2853 else if (VOID_TYPE_P (TREE_TYPE (retval)))
2854 /* Recognize tail-recursive call to void function. */
2855 retval_rhs = retval;
2857 retval_rhs = NULL_TREE;
2859 /* Only use `last_insn' if there are cleanups which must be run. */
2860 if (cleanups || cleanup_label != 0)
2861 last_insn = get_last_insn ();
2863 /* Distribute return down conditional expr if either of the sides
2864 may involve tail recursion (see test below). This enhances the number
2865 of tail recursions we see. Don't do this always since it can produce
2866 sub-optimal code in some cases and we distribute assignments into
2867 conditional expressions when it would help. */
2869 if (optimize && retval_rhs != 0
2870 && frame_offset == 0
2871 && TREE_CODE (retval_rhs) == COND_EXPR
2872 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2873 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2875 rtx label = gen_label_rtx ();
2878 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2879 start_cleanup_deferral ();
2880 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2881 DECL_RESULT (current_function_decl),
2882 TREE_OPERAND (retval_rhs, 1));
2883 TREE_SIDE_EFFECTS (expr) = 1;
2884 expand_return (expr);
2887 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2888 DECL_RESULT (current_function_decl),
2889 TREE_OPERAND (retval_rhs, 2));
2890 TREE_SIDE_EFFECTS (expr) = 1;
2891 expand_return (expr);
2892 end_cleanup_deferral ();
2896 /* If the result is an aggregate that is being returned in one (or more)
2897 registers, load the registers here. The compiler currently can't handle
2898 copying a BLKmode value into registers. We could put this code in a
2899 more general area (for use by everyone instead of just function
2900 call/return), but until this feature is generally usable it is kept here
2901 (and in expand_call). The value must go into a pseudo in case there
2902 are cleanups that will clobber the real return register. */
2905 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2906 && GET_CODE (result_rtl) == REG)
2909 unsigned HOST_WIDE_INT bitpos, xbitpos;
2910 unsigned HOST_WIDE_INT big_endian_correction = 0;
2911 unsigned HOST_WIDE_INT bytes
2912 = int_size_in_bytes (TREE_TYPE (retval_rhs));
2913 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2914 unsigned int bitsize
2915 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)), BITS_PER_WORD);
2916 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2917 rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
2918 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2919 enum machine_mode tmpmode, result_reg_mode;
2921 /* Structures whose size is not a multiple of a word are aligned
2922 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
2923 machine, this means we must skip the empty high order bytes when
2924 calculating the bit offset. */
2925 if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD)
2926 big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
2929 /* Copy the structure BITSIZE bits at a time. */
2930 for (bitpos = 0, xbitpos = big_endian_correction;
2931 bitpos < bytes * BITS_PER_UNIT;
2932 bitpos += bitsize, xbitpos += bitsize)
2934 /* We need a new destination pseudo each time xbitpos is
2935 on a word boundary and when xbitpos == big_endian_correction
2936 (the first time through). */
2937 if (xbitpos % BITS_PER_WORD == 0
2938 || xbitpos == big_endian_correction)
2940 /* Generate an appropriate register. */
2941 dst = gen_reg_rtx (word_mode);
2942 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
2944 /* Clobber the destination before we move anything into it. */
2945 emit_insn (gen_rtx_CLOBBER (VOIDmode, dst));
2948 /* We need a new source operand each time bitpos is on a word
2950 if (bitpos % BITS_PER_WORD == 0)
2951 src = operand_subword_force (result_val,
2952 bitpos / BITS_PER_WORD,
2955 /* Use bitpos for the source extraction (left justified) and
2956 xbitpos for the destination store (right justified). */
2957 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
2958 extract_bit_field (src, bitsize,
2959 bitpos % BITS_PER_WORD, 1,
2960 NULL_RTX, word_mode, word_mode,
2961 bitsize, BITS_PER_WORD),
2962 bitsize, BITS_PER_WORD);
2965 /* Find the smallest integer mode large enough to hold the
2966 entire structure and use that mode instead of BLKmode
2967 on the USE insn for the return register. */
2968 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2969 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
2970 tmpmode != VOIDmode;
2971 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
2973 /* Have we found a large enough mode? */
2974 if (GET_MODE_SIZE (tmpmode) >= bytes)
2978 /* No suitable mode found. */
2979 if (tmpmode == VOIDmode)
2982 PUT_MODE (result_rtl, tmpmode);
2984 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
2985 result_reg_mode = word_mode;
2987 result_reg_mode = tmpmode;
2988 result_reg = gen_reg_rtx (result_reg_mode);
2991 for (i = 0; i < n_regs; i++)
2992 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
2995 if (tmpmode != result_reg_mode)
2996 result_reg = gen_lowpart (tmpmode, result_reg);
2998 expand_value_return (result_reg);
3002 && !VOID_TYPE_P (TREE_TYPE (retval_rhs))
3003 && (GET_CODE (result_rtl) == REG
3004 || (GET_CODE (result_rtl) == PARALLEL)))
3006 /* Calculate the return value into a temporary (usually a pseudo
3008 val = assign_temp (TREE_TYPE (DECL_RESULT (current_function_decl)),
3010 val = expand_expr (retval_rhs, val, GET_MODE (val), 0);
3011 val = force_not_mem (val);
3013 /* Return the calculated value, doing cleanups first. */
3014 expand_value_return (val);
3018 /* No cleanups or no hard reg used;
3019 calculate value into hard return reg. */
3020 expand_expr (retval, const0_rtx, VOIDmode, 0);
3022 expand_value_return (result_rtl);
3026 /* Return 1 if the end of the generated RTX is not a barrier.
3027 This means code already compiled can drop through. */
3030 drop_through_at_end_p ()
3032 rtx insn = get_last_insn ();
3033 while (insn && GET_CODE (insn) == NOTE)
3034 insn = PREV_INSN (insn);
3035 return insn && GET_CODE (insn) != BARRIER;
3038 /* Attempt to optimize a potential tail recursion call into a goto.
3039 ARGUMENTS are the arguments to a CALL_EXPR; LAST_INSN indicates
3040 where to place the jump to the tail recursion label.
3042 Return TRUE if the call was optimized into a goto. */
3045 optimize_tail_recursion (arguments, last_insn)
3049 /* Finish checking validity, and if valid emit code to set the
3050 argument variables for the new call. */
3051 if (tail_recursion_args (arguments, DECL_ARGUMENTS (current_function_decl)))
3053 if (tail_recursion_label == 0)
3055 tail_recursion_label = gen_label_rtx ();
3056 emit_label_after (tail_recursion_label,
3057 tail_recursion_reentry);
3060 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
3067 /* Emit code to alter this function's formal parms for a tail-recursive call.
3068 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3069 FORMALS is the chain of decls of formals.
3070 Return 1 if this can be done;
3071 otherwise return 0 and do not emit any code. */
3074 tail_recursion_args (actuals, formals)
3075 tree actuals, formals;
3077 register tree a = actuals, f = formals;
3079 register rtx *argvec;
3081 /* Check that number and types of actuals are compatible
3082 with the formals. This is not always true in valid C code.
3083 Also check that no formal needs to be addressable
3084 and that all formals are scalars. */
3086 /* Also count the args. */
3088 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
3090 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a)))
3091 != TYPE_MAIN_VARIANT (TREE_TYPE (f)))
3093 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
3096 if (a != 0 || f != 0)
3099 /* Compute all the actuals. */
3101 argvec = (rtx *) alloca (i * sizeof (rtx));
3103 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3104 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
3106 /* Find which actual values refer to current values of previous formals.
3107 Copy each of them now, before any formal is changed. */
3109 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3113 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
3114 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
3115 { copy = 1; break; }
3117 argvec[i] = copy_to_reg (argvec[i]);
3120 /* Store the values of the actuals into the formals. */
3122 for (f = formals, a = actuals, i = 0; f;
3123 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
3125 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
3126 emit_move_insn (DECL_RTL (f), argvec[i]);
3128 convert_move (DECL_RTL (f), argvec[i],
3129 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
3136 /* Generate the RTL code for entering a binding contour.
3137 The variables are declared one by one, by calls to `expand_decl'.
3139 FLAGS is a bitwise or of the following flags:
3141 1 - Nonzero if this construct should be visible to
3144 2 - Nonzero if this contour does not require a
3145 NOTE_INSN_BLOCK_BEG note. Virtually all calls from
3146 language-independent code should set this flag because they
3147 will not create corresponding BLOCK nodes. (There should be
3148 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
3149 and BLOCKs.) If this flag is set, MARK_ENDS should be zero
3150 when expand_end_bindings is called.
3152 If we are creating a NOTE_INSN_BLOCK_BEG note, a BLOCK may
3153 optionally be supplied. If so, it becomes the NOTE_BLOCK for the
3157 expand_start_bindings_and_block (flags, block)
3161 struct nesting *thisblock = ALLOC_NESTING ();
3163 int exit_flag = ((flags & 1) != 0);
3164 int block_flag = ((flags & 2) == 0);
3166 /* If a BLOCK is supplied, then the caller should be requesting a
3167 NOTE_INSN_BLOCK_BEG note. */
3168 if (!block_flag && block)
3171 /* Create a note to mark the beginning of the block. */
3174 note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
3175 NOTE_BLOCK (note) = block;
3178 note = emit_note (NULL_PTR, NOTE_INSN_DELETED);
3180 /* Make an entry on block_stack for the block we are entering. */
3182 thisblock->next = block_stack;
3183 thisblock->all = nesting_stack;
3184 thisblock->depth = ++nesting_depth;
3185 thisblock->data.block.stack_level = 0;
3186 thisblock->data.block.cleanups = 0;
3187 thisblock->data.block.n_function_calls = 0;
3188 thisblock->data.block.exception_region = 0;
3189 thisblock->data.block.block_target_temp_slot_level = target_temp_slot_level;
3191 thisblock->data.block.conditional_code = 0;
3192 thisblock->data.block.last_unconditional_cleanup = note;
3193 /* When we insert instructions after the last unconditional cleanup,
3194 we don't adjust last_insn. That means that a later add_insn will
3195 clobber the instructions we've just added. The easiest way to
3196 fix this is to just insert another instruction here, so that the
3197 instructions inserted after the last unconditional cleanup are
3198 never the last instruction. */
3199 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3200 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
3203 && !(block_stack->data.block.cleanups == NULL_TREE
3204 && block_stack->data.block.outer_cleanups == NULL_TREE))
3205 thisblock->data.block.outer_cleanups
3206 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
3207 block_stack->data.block.outer_cleanups);
3209 thisblock->data.block.outer_cleanups = 0;
3210 thisblock->data.block.label_chain = 0;
3211 thisblock->data.block.innermost_stack_block = stack_block_stack;
3212 thisblock->data.block.first_insn = note;
3213 thisblock->data.block.block_start_count = ++current_block_start_count;
3214 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
3215 block_stack = thisblock;
3216 nesting_stack = thisblock;
3218 /* Make a new level for allocating stack slots. */
3222 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3223 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3224 expand_expr are made. After we end the region, we know that all
3225 space for all temporaries that were created by TARGET_EXPRs will be
3226 destroyed and their space freed for reuse. */
3229 expand_start_target_temps ()
3231 /* This is so that even if the result is preserved, the space
3232 allocated will be freed, as we know that it is no longer in use. */
3235 /* Start a new binding layer that will keep track of all cleanup
3236 actions to be performed. */
3237 expand_start_bindings (2);
3239 target_temp_slot_level = temp_slot_level;
3243 expand_end_target_temps ()
3245 expand_end_bindings (NULL_TREE, 0, 0);
3247 /* This is so that even if the result is preserved, the space
3248 allocated will be freed, as we know that it is no longer in use. */
3252 /* Given a pointer to a BLOCK node return non-zero if (and only if) the node
3253 in question represents the outermost pair of curly braces (i.e. the "body
3254 block") of a function or method.
3256 For any BLOCK node representing a "body block" of a function or method, the
3257 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
3258 represents the outermost (function) scope for the function or method (i.e.
3259 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
3260 *that* node in turn will point to the relevant FUNCTION_DECL node. */
3263 is_body_block (stmt)
3266 if (TREE_CODE (stmt) == BLOCK)
3268 tree parent = BLOCK_SUPERCONTEXT (stmt);
3270 if (parent && TREE_CODE (parent) == BLOCK)
3272 tree grandparent = BLOCK_SUPERCONTEXT (parent);
3274 if (grandparent && TREE_CODE (grandparent) == FUNCTION_DECL)
3282 /* Mark top block of block_stack as an implicit binding for an
3283 exception region. This is used to prevent infinite recursion when
3284 ending a binding with expand_end_bindings. It is only ever called
3285 by expand_eh_region_start, as that it the only way to create a
3286 block stack for a exception region. */
3289 mark_block_as_eh_region ()
3291 block_stack->data.block.exception_region = 1;
3292 if (block_stack->next
3293 && block_stack->next->data.block.conditional_code)
3295 block_stack->data.block.conditional_code
3296 = block_stack->next->data.block.conditional_code;
3297 block_stack->data.block.last_unconditional_cleanup
3298 = block_stack->next->data.block.last_unconditional_cleanup;
3299 block_stack->data.block.cleanup_ptr
3300 = block_stack->next->data.block.cleanup_ptr;
3304 /* True if we are currently emitting insns in an area of output code
3305 that is controlled by a conditional expression. This is used by
3306 the cleanup handling code to generate conditional cleanup actions. */
3309 conditional_context ()
3311 return block_stack && block_stack->data.block.conditional_code;
3314 /* Mark top block of block_stack as not for an implicit binding for an
3315 exception region. This is only ever done by expand_eh_region_end
3316 to let expand_end_bindings know that it is being called explicitly
3317 to end the binding layer for just the binding layer associated with
3318 the exception region, otherwise expand_end_bindings would try and
3319 end all implicit binding layers for exceptions regions, and then
3320 one normal binding layer. */
3323 mark_block_as_not_eh_region ()
3325 block_stack->data.block.exception_region = 0;
3328 /* True if the top block of block_stack was marked as for an exception
3329 region by mark_block_as_eh_region. */
3334 return cfun && block_stack && block_stack->data.block.exception_region;
3337 /* Emit a handler label for a nonlocal goto handler.
3338 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3341 expand_nl_handler_label (slot, before_insn)
3342 rtx slot, before_insn;
3345 rtx handler_label = gen_label_rtx ();
3347 /* Don't let jump_optimize delete the handler. */
3348 LABEL_PRESERVE_P (handler_label) = 1;
3351 emit_move_insn (slot, gen_rtx_LABEL_REF (Pmode, handler_label));
3352 insns = get_insns ();
3354 emit_insns_before (insns, before_insn);
3356 emit_label (handler_label);
3358 return handler_label;
3361 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3364 expand_nl_goto_receiver ()
3366 #ifdef HAVE_nonlocal_goto
3367 if (! HAVE_nonlocal_goto)
3369 /* First adjust our frame pointer to its actual value. It was
3370 previously set to the start of the virtual area corresponding to
3371 the stacked variables when we branched here and now needs to be
3372 adjusted to the actual hardware fp value.
3374 Assignments are to virtual registers are converted by
3375 instantiate_virtual_regs into the corresponding assignment
3376 to the underlying register (fp in this case) that makes
3377 the original assignment true.
3378 So the following insn will actually be
3379 decrementing fp by STARTING_FRAME_OFFSET. */
3380 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3382 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3383 if (fixed_regs[ARG_POINTER_REGNUM])
3385 #ifdef ELIMINABLE_REGS
3386 /* If the argument pointer can be eliminated in favor of the
3387 frame pointer, we don't need to restore it. We assume here
3388 that if such an elimination is present, it can always be used.
3389 This is the case on all known machines; if we don't make this
3390 assumption, we do unnecessary saving on many machines. */
3391 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3394 for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
3395 if (elim_regs[i].from == ARG_POINTER_REGNUM
3396 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3399 if (i == sizeof elim_regs / sizeof elim_regs [0])
3402 /* Now restore our arg pointer from the address at which it
3403 was saved in our stack frame.
3404 If there hasn't be space allocated for it yet, make
3406 if (arg_pointer_save_area == 0)
3407 arg_pointer_save_area
3408 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3409 emit_move_insn (virtual_incoming_args_rtx,
3410 /* We need a pseudo here, or else
3411 instantiate_virtual_regs_1 complains. */
3412 copy_to_reg (arg_pointer_save_area));
3417 #ifdef HAVE_nonlocal_goto_receiver
3418 if (HAVE_nonlocal_goto_receiver)
3419 emit_insn (gen_nonlocal_goto_receiver ());
3423 /* Make handlers for nonlocal gotos taking place in the function calls in
3427 expand_nl_goto_receivers (thisblock)
3428 struct nesting *thisblock;
3431 rtx afterward = gen_label_rtx ();
3436 /* Record the handler address in the stack slot for that purpose,
3437 during this block, saving and restoring the outer value. */
3438 if (thisblock->next != 0)
3439 for (slot = nonlocal_goto_handler_slots; slot; slot = XEXP (slot, 1))
3441 rtx save_receiver = gen_reg_rtx (Pmode);
3442 emit_move_insn (XEXP (slot, 0), save_receiver);
3445 emit_move_insn (save_receiver, XEXP (slot, 0));
3446 insns = get_insns ();
3448 emit_insns_before (insns, thisblock->data.block.first_insn);
3451 /* Jump around the handlers; they run only when specially invoked. */
3452 emit_jump (afterward);
3454 /* Make a separate handler for each label. */
3455 link = nonlocal_labels;
3456 slot = nonlocal_goto_handler_slots;
3457 label_list = NULL_RTX;
3458 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3459 /* Skip any labels we shouldn't be able to jump to from here,
3460 we generate one special handler for all of them below which just calls
3462 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3465 lab = expand_nl_handler_label (XEXP (slot, 0),
3466 thisblock->data.block.first_insn);
3467 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3469 expand_nl_goto_receiver ();
3471 /* Jump to the "real" nonlocal label. */
3472 expand_goto (TREE_VALUE (link));
3475 /* A second pass over all nonlocal labels; this time we handle those
3476 we should not be able to jump to at this point. */
3477 link = nonlocal_labels;
3478 slot = nonlocal_goto_handler_slots;
3480 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3481 if (DECL_TOO_LATE (TREE_VALUE (link)))
3484 lab = expand_nl_handler_label (XEXP (slot, 0),
3485 thisblock->data.block.first_insn);
3486 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3492 expand_nl_goto_receiver ();
3493 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "abort"), 0,
3498 nonlocal_goto_handler_labels = label_list;
3499 emit_label (afterward);
3502 /* Warn about any unused VARS (which may contain nodes other than
3503 VAR_DECLs, but such nodes are ignored). The nodes are connected
3504 via the TREE_CHAIN field. */
3507 warn_about_unused_variables (vars)
3512 if (warn_unused_variable)
3513 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3514 if (TREE_CODE (decl) == VAR_DECL
3515 && ! TREE_USED (decl)
3516 && ! DECL_IN_SYSTEM_HEADER (decl)
3517 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
3518 warning_with_decl (decl, "unused variable `%s'");
3521 /* Generate RTL code to terminate a binding contour.
3523 VARS is the chain of VAR_DECL nodes for the variables bound in this
3524 contour. There may actually be other nodes in this chain, but any
3525 nodes other than VAR_DECLS are ignored.
3527 MARK_ENDS is nonzero if we should put a note at the beginning
3528 and end of this binding contour.
3530 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3531 (That is true automatically if the contour has a saved stack level.) */
3534 expand_end_bindings (vars, mark_ends, dont_jump_in)
3539 register struct nesting *thisblock;
3541 while (block_stack->data.block.exception_region)
3543 /* Because we don't need or want a new temporary level and
3544 because we didn't create one in expand_eh_region_start,
3545 create a fake one now to avoid removing one in
3546 expand_end_bindings. */
3549 block_stack->data.block.exception_region = 0;
3551 expand_end_bindings (NULL_TREE, 0, 0);
3554 /* Since expand_eh_region_start does an expand_start_bindings, we
3555 have to first end all the bindings that were created by
3556 expand_eh_region_start. */
3558 thisblock = block_stack;
3560 /* If any of the variables in this scope were not used, warn the
3562 warn_about_unused_variables (vars);
3564 if (thisblock->exit_label)
3566 do_pending_stack_adjust ();
3567 emit_label (thisblock->exit_label);
3570 /* If necessary, make handlers for nonlocal gotos taking
3571 place in the function calls in this block. */
3572 if (function_call_count != thisblock->data.block.n_function_calls
3574 /* Make handler for outermost block
3575 if there were any nonlocal gotos to this function. */
3576 && (thisblock->next == 0 ? current_function_has_nonlocal_label
3577 /* Make handler for inner block if it has something
3578 special to do when you jump out of it. */
3579 : (thisblock->data.block.cleanups != 0
3580 || thisblock->data.block.stack_level != 0)))
3581 expand_nl_goto_receivers (thisblock);
3583 /* Don't allow jumping into a block that has a stack level.
3584 Cleanups are allowed, though. */
3586 || thisblock->data.block.stack_level != 0)
3588 struct label_chain *chain;
3590 /* Any labels in this block are no longer valid to go to.
3591 Mark them to cause an error message. */
3592 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3594 DECL_TOO_LATE (chain->label) = 1;
3595 /* If any goto without a fixup came to this label,
3596 that must be an error, because gotos without fixups
3597 come from outside all saved stack-levels. */
3598 if (TREE_ADDRESSABLE (chain->label))
3599 error_with_decl (chain->label,
3600 "label `%s' used before containing binding contour");
3604 /* Restore stack level in effect before the block
3605 (only if variable-size objects allocated). */
3606 /* Perform any cleanups associated with the block. */
3608 if (thisblock->data.block.stack_level != 0
3609 || thisblock->data.block.cleanups != 0)
3614 /* Don't let cleanups affect ({...}) constructs. */
3615 int old_expr_stmts_for_value = expr_stmts_for_value;
3616 rtx old_last_expr_value = last_expr_value;
3617 tree old_last_expr_type = last_expr_type;
3618 expr_stmts_for_value = 0;
3620 /* Only clean up here if this point can actually be reached. */
3621 insn = get_last_insn ();
3622 if (GET_CODE (insn) == NOTE)
3623 insn = prev_nonnote_insn (insn);
3624 reachable = (! insn || GET_CODE (insn) != BARRIER);
3626 /* Do the cleanups. */
3627 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3629 do_pending_stack_adjust ();
3631 expr_stmts_for_value = old_expr_stmts_for_value;
3632 last_expr_value = old_last_expr_value;
3633 last_expr_type = old_last_expr_type;
3635 /* Restore the stack level. */
3637 if (reachable && thisblock->data.block.stack_level != 0)
3639 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3640 thisblock->data.block.stack_level, NULL_RTX);
3641 if (nonlocal_goto_handler_slots != 0)
3642 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3646 /* Any gotos out of this block must also do these things.
3647 Also report any gotos with fixups that came to labels in this
3649 fixup_gotos (thisblock,
3650 thisblock->data.block.stack_level,
3651 thisblock->data.block.cleanups,
3652 thisblock->data.block.first_insn,
3656 /* Mark the beginning and end of the scope if requested.
3657 We do this now, after running cleanups on the variables
3658 just going out of scope, so they are in scope for their cleanups. */
3662 rtx note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3663 NOTE_BLOCK (note) = NOTE_BLOCK (thisblock->data.block.first_insn);
3666 /* Get rid of the beginning-mark if we don't make an end-mark. */
3667 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3669 /* Restore the temporary level of TARGET_EXPRs. */
3670 target_temp_slot_level = thisblock->data.block.block_target_temp_slot_level;
3672 /* Restore block_stack level for containing block. */
3674 stack_block_stack = thisblock->data.block.innermost_stack_block;
3675 POPSTACK (block_stack);
3677 /* Pop the stack slot nesting and free any slots at this level. */
3681 /* Generate code to save the stack pointer at the start of the current block
3682 and set up to restore it on exit. */
3685 save_stack_pointer ()
3687 struct nesting *thisblock = block_stack;
3689 if (thisblock->data.block.stack_level == 0)
3691 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3692 &thisblock->data.block.stack_level,
3693 thisblock->data.block.first_insn);
3694 stack_block_stack = thisblock;
3698 /* Generate RTL for the automatic variable declaration DECL.
3699 (Other kinds of declarations are simply ignored if seen here.) */
3705 struct nesting *thisblock;
3708 type = TREE_TYPE (decl);
3710 /* Only automatic variables need any expansion done.
3711 Static and external variables, and external functions,
3712 will be handled by `assemble_variable' (called from finish_decl).
3713 TYPE_DECL and CONST_DECL require nothing.
3714 PARM_DECLs are handled in `assign_parms'. */
3716 if (TREE_CODE (decl) != VAR_DECL)
3718 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3721 thisblock = block_stack;
3723 /* Create the RTL representation for the variable. */
3725 if (type == error_mark_node)
3726 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, const0_rtx);
3727 else if (DECL_SIZE (decl) == 0)
3728 /* Variable with incomplete type. */
3730 if (DECL_INITIAL (decl) == 0)
3731 /* Error message was already done; now avoid a crash. */
3732 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3734 /* An initializer is going to decide the size of this array.
3735 Until we know the size, represent its address with a reg. */
3736 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode));
3738 set_mem_attributes (DECL_RTL (decl), decl, 1);
3740 else if (DECL_MODE (decl) != BLKmode
3741 /* If -ffloat-store, don't put explicit float vars
3743 && !(flag_float_store
3744 && TREE_CODE (type) == REAL_TYPE)
3745 && ! TREE_THIS_VOLATILE (decl)
3746 && ! TREE_ADDRESSABLE (decl)
3747 && (DECL_REGISTER (decl) || optimize)
3748 /* if -fcheck-memory-usage, check all variables. */
3749 && ! current_function_check_memory_usage)
3751 /* Automatic variable that can go in a register. */
3752 int unsignedp = TREE_UNSIGNED (type);
3753 enum machine_mode reg_mode
3754 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3756 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3757 mark_user_reg (DECL_RTL (decl));
3759 if (POINTER_TYPE_P (type))
3760 mark_reg_pointer (DECL_RTL (decl),
3761 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
3763 maybe_set_unchanging (DECL_RTL (decl), decl);
3766 else if (TREE_CODE (DECL_SIZE_UNIT (decl)) == INTEGER_CST
3767 && ! (flag_stack_check && ! STACK_CHECK_BUILTIN
3768 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl),
3769 STACK_CHECK_MAX_VAR_SIZE)))
3771 /* Variable of fixed size that goes on the stack. */
3775 /* If we previously made RTL for this decl, it must be an array
3776 whose size was determined by the initializer.
3777 The old address was a register; set that register now
3778 to the proper address. */
3779 if (DECL_RTL (decl) != 0)
3781 if (GET_CODE (DECL_RTL (decl)) != MEM
3782 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3784 oldaddr = XEXP (DECL_RTL (decl), 0);
3787 DECL_RTL (decl) = assign_temp (TREE_TYPE (decl), 1, 1, 1);
3789 /* Set alignment we actually gave this decl. */
3790 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3791 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3792 DECL_USER_ALIGN (decl) = 0;
3796 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3797 if (addr != oldaddr)
3798 emit_move_insn (oldaddr, addr);
3802 /* Dynamic-size object: must push space on the stack. */
3806 /* Record the stack pointer on entry to block, if have
3807 not already done so. */
3808 do_pending_stack_adjust ();
3809 save_stack_pointer ();
3811 /* In function-at-a-time mode, variable_size doesn't expand this,
3813 if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
3814 expand_expr (TYPE_MAX_VALUE (TYPE_DOMAIN (type)),
3815 const0_rtx, VOIDmode, 0);
3817 /* Compute the variable's size, in bytes. */
3818 size = expand_expr (DECL_SIZE_UNIT (decl), NULL_RTX, VOIDmode, 0);
3821 /* Allocate space on the stack for the variable. Note that
3822 DECL_ALIGN says how the variable is to be aligned and we
3823 cannot use it to conclude anything about the alignment of
3825 address = allocate_dynamic_stack_space (size, NULL_RTX,
3826 TYPE_ALIGN (TREE_TYPE (decl)));
3828 /* Reference the variable indirect through that rtx. */
3829 DECL_RTL (decl) = gen_rtx_MEM (DECL_MODE (decl), address);
3831 set_mem_attributes (DECL_RTL (decl), decl, 1);
3833 /* Indicate the alignment we actually gave this variable. */
3834 #ifdef STACK_BOUNDARY
3835 DECL_ALIGN (decl) = STACK_BOUNDARY;
3837 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3839 DECL_USER_ALIGN (decl) = 0;
3843 /* Emit code to perform the initialization of a declaration DECL. */
3846 expand_decl_init (decl)
3849 int was_used = TREE_USED (decl);
3851 /* If this is a CONST_DECL, we don't have to generate any code, but
3852 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3853 to be set while in the obstack containing the constant. If we don't
3854 do this, we can lose if we have functions nested three deep and the middle
3855 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3856 the innermost function is the first to expand that STRING_CST. */
3857 if (TREE_CODE (decl) == CONST_DECL)
3859 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3860 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3861 EXPAND_INITIALIZER);
3865 if (TREE_STATIC (decl))
3868 /* Compute and store the initial value now. */
3870 if (DECL_INITIAL (decl) == error_mark_node)
3872 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3874 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3875 || code == POINTER_TYPE || code == REFERENCE_TYPE)
3876 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3880 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3882 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3883 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3887 /* Don't let the initialization count as "using" the variable. */
3888 TREE_USED (decl) = was_used;
3890 /* Free any temporaries we made while initializing the decl. */
3891 preserve_temp_slots (NULL_RTX);
3895 /* CLEANUP is an expression to be executed at exit from this binding contour;
3896 for example, in C++, it might call the destructor for this variable.
3898 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
3899 CLEANUP multiple times, and have the correct semantics. This
3900 happens in exception handling, for gotos, returns, breaks that
3901 leave the current scope.
3903 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3904 that is not associated with any particular variable. */
3907 expand_decl_cleanup (decl, cleanup)
3910 struct nesting *thisblock;
3912 /* Error if we are not in any block. */
3913 if (cfun == 0 || block_stack == 0)
3916 thisblock = block_stack;
3918 /* Record the cleanup if there is one. */
3924 tree *cleanups = &thisblock->data.block.cleanups;
3925 int cond_context = conditional_context ();
3929 rtx flag = gen_reg_rtx (word_mode);
3934 emit_move_insn (flag, const0_rtx);
3935 set_flag_0 = get_insns ();
3938 thisblock->data.block.last_unconditional_cleanup
3939 = emit_insns_after (set_flag_0,
3940 thisblock->data.block.last_unconditional_cleanup);
3942 emit_move_insn (flag, const1_rtx);
3944 /* All cleanups must be on the function_obstack. */
3945 push_obstacks_nochange ();
3946 resume_temporary_allocation ();
3948 cond = build_decl (VAR_DECL, NULL_TREE, type_for_mode (word_mode, 1));
3949 DECL_RTL (cond) = flag;
3951 /* Conditionalize the cleanup. */
3952 cleanup = build (COND_EXPR, void_type_node,
3953 truthvalue_conversion (cond),
3954 cleanup, integer_zero_node);
3955 cleanup = fold (cleanup);
3959 cleanups = thisblock->data.block.cleanup_ptr;
3962 /* All cleanups must be on the function_obstack. */
3963 push_obstacks_nochange ();
3964 resume_temporary_allocation ();
3965 cleanup = unsave_expr (cleanup);
3968 t = *cleanups = temp_tree_cons (decl, cleanup, *cleanups);
3971 /* If this block has a cleanup, it belongs in stack_block_stack. */
3972 stack_block_stack = thisblock;
3979 /* If this was optimized so that there is no exception region for the
3980 cleanup, then mark the TREE_LIST node, so that we can later tell
3981 if we need to call expand_eh_region_end. */
3982 if (! using_eh_for_cleanups_p
3983 || expand_eh_region_start_tree (decl, cleanup))
3984 TREE_ADDRESSABLE (t) = 1;
3985 /* If that started a new EH region, we're in a new block. */
3986 thisblock = block_stack;
3993 thisblock->data.block.last_unconditional_cleanup
3994 = emit_insns_after (seq,
3995 thisblock->data.block.last_unconditional_cleanup);
3999 thisblock->data.block.last_unconditional_cleanup
4001 /* When we insert instructions after the last unconditional cleanup,
4002 we don't adjust last_insn. That means that a later add_insn will
4003 clobber the instructions we've just added. The easiest way to
4004 fix this is to just insert another instruction here, so that the
4005 instructions inserted after the last unconditional cleanup are
4006 never the last instruction. */
4007 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4008 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
4014 /* Like expand_decl_cleanup, but suppress generating an exception handler
4015 to perform the cleanup. */
4019 expand_decl_cleanup_no_eh (decl, cleanup)
4022 int save_eh = using_eh_for_cleanups_p;
4025 using_eh_for_cleanups_p = 0;
4026 result = expand_decl_cleanup (decl, cleanup);
4027 using_eh_for_cleanups_p = save_eh;
4033 /* Arrange for the top element of the dynamic cleanup chain to be
4034 popped if we exit the current binding contour. DECL is the
4035 associated declaration, if any, otherwise NULL_TREE. If the
4036 current contour is left via an exception, then __sjthrow will pop
4037 the top element off the dynamic cleanup chain. The code that
4038 avoids doing the action we push into the cleanup chain in the
4039 exceptional case is contained in expand_cleanups.
4041 This routine is only used by expand_eh_region_start, and that is
4042 the only way in which an exception region should be started. This
4043 routine is only used when using the setjmp/longjmp codegen method
4044 for exception handling. */
4047 expand_dcc_cleanup (decl)
4050 struct nesting *thisblock;
4053 /* Error if we are not in any block. */
4054 if (cfun == 0 || block_stack == 0)
4056 thisblock = block_stack;
4058 /* Record the cleanup for the dynamic handler chain. */
4060 /* All cleanups must be on the function_obstack. */
4061 push_obstacks_nochange ();
4062 resume_temporary_allocation ();
4063 cleanup = make_node (POPDCC_EXPR);
4066 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4067 thisblock->data.block.cleanups
4068 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4070 /* If this block has a cleanup, it belongs in stack_block_stack. */
4071 stack_block_stack = thisblock;
4075 /* Arrange for the top element of the dynamic handler chain to be
4076 popped if we exit the current binding contour. DECL is the
4077 associated declaration, if any, otherwise NULL_TREE. If the current
4078 contour is left via an exception, then __sjthrow will pop the top
4079 element off the dynamic handler chain. The code that avoids doing
4080 the action we push into the handler chain in the exceptional case
4081 is contained in expand_cleanups.
4083 This routine is only used by expand_eh_region_start, and that is
4084 the only way in which an exception region should be started. This
4085 routine is only used when using the setjmp/longjmp codegen method
4086 for exception handling. */
4089 expand_dhc_cleanup (decl)
4092 struct nesting *thisblock;
4095 /* Error if we are not in any block. */
4096 if (cfun == 0 || block_stack == 0)
4098 thisblock = block_stack;
4100 /* Record the cleanup for the dynamic handler chain. */
4102 /* All cleanups must be on the function_obstack. */
4103 push_obstacks_nochange ();
4104 resume_temporary_allocation ();
4105 cleanup = make_node (POPDHC_EXPR);
4108 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4109 thisblock->data.block.cleanups
4110 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4112 /* If this block has a cleanup, it belongs in stack_block_stack. */
4113 stack_block_stack = thisblock;
4117 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4118 DECL_ELTS is the list of elements that belong to DECL's type.
4119 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4122 expand_anon_union_decl (decl, cleanup, decl_elts)
4123 tree decl, cleanup, decl_elts;
4125 struct nesting *thisblock = cfun == 0 ? 0 : block_stack;
4129 /* If any of the elements are addressable, so is the entire union. */
4130 for (t = decl_elts; t; t = TREE_CHAIN (t))
4131 if (TREE_ADDRESSABLE (TREE_VALUE (t)))
4133 TREE_ADDRESSABLE (decl) = 1;
4138 expand_decl_cleanup (decl, cleanup);
4139 x = DECL_RTL (decl);
4141 /* Go through the elements, assigning RTL to each. */
4142 for (t = decl_elts; t; t = TREE_CHAIN (t))
4144 tree decl_elt = TREE_VALUE (t);
4145 tree cleanup_elt = TREE_PURPOSE (t);
4146 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
4148 /* Propagate the union's alignment to the elements. */
4149 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
4150 DECL_USER_ALIGN (decl_elt) = DECL_USER_ALIGN (decl);
4152 /* If the element has BLKmode and the union doesn't, the union is
4153 aligned such that the element doesn't need to have BLKmode, so
4154 change the element's mode to the appropriate one for its size. */
4155 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
4156 DECL_MODE (decl_elt) = mode
4157 = mode_for_size_tree (DECL_SIZE (decl_elt), MODE_INT, 1);
4159 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4160 instead create a new MEM rtx with the proper mode. */
4161 if (GET_CODE (x) == MEM)
4163 if (mode == GET_MODE (x))
4164 DECL_RTL (decl_elt) = x;
4167 DECL_RTL (decl_elt) = gen_rtx_MEM (mode, copy_rtx (XEXP (x, 0)));
4168 MEM_COPY_ATTRIBUTES (DECL_RTL (decl_elt), x);
4171 else if (GET_CODE (x) == REG)
4173 if (mode == GET_MODE (x))
4174 DECL_RTL (decl_elt) = x;
4176 DECL_RTL (decl_elt) = gen_rtx_SUBREG (mode, x, 0);
4181 /* Record the cleanup if there is one. */
4184 thisblock->data.block.cleanups
4185 = temp_tree_cons (decl_elt, cleanup_elt,
4186 thisblock->data.block.cleanups);
4190 /* Expand a list of cleanups LIST.
4191 Elements may be expressions or may be nested lists.
4193 If DONT_DO is nonnull, then any list-element
4194 whose TREE_PURPOSE matches DONT_DO is omitted.
4195 This is sometimes used to avoid a cleanup associated with
4196 a value that is being returned out of the scope.
4198 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
4199 goto and handle protection regions specially in that case.
4201 If REACHABLE, we emit code, otherwise just inform the exception handling
4202 code about this finalization. */
4205 expand_cleanups (list, dont_do, in_fixup, reachable)
4212 for (tail = list; tail; tail = TREE_CHAIN (tail))
4213 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
4215 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
4216 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
4221 tree cleanup = TREE_VALUE (tail);
4223 /* See expand_d{h,c}c_cleanup for why we avoid this. */
4224 if (TREE_CODE (cleanup) != POPDHC_EXPR
4225 && TREE_CODE (cleanup) != POPDCC_EXPR
4226 /* See expand_eh_region_start_tree for this case. */
4227 && ! TREE_ADDRESSABLE (tail))
4229 cleanup = protect_with_terminate (cleanup);
4230 expand_eh_region_end (cleanup);
4236 /* Cleanups may be run multiple times. For example,
4237 when exiting a binding contour, we expand the
4238 cleanups associated with that contour. When a goto
4239 within that binding contour has a target outside that
4240 contour, it will expand all cleanups from its scope to
4241 the target. Though the cleanups are expanded multiple
4242 times, the control paths are non-overlapping so the
4243 cleanups will not be executed twice. */
4245 /* We may need to protect fixups with rethrow regions. */
4246 int protect = (in_fixup && ! TREE_ADDRESSABLE (tail));
4249 expand_fixup_region_start ();
4251 /* The cleanup might contain try-blocks, so we have to
4252 preserve our current queue. */
4254 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
4257 expand_fixup_region_end (TREE_VALUE (tail));
4264 /* Mark when the context we are emitting RTL for as a conditional
4265 context, so that any cleanup actions we register with
4266 expand_decl_init will be properly conditionalized when those
4267 cleanup actions are later performed. Must be called before any
4268 expression (tree) is expanded that is within a conditional context. */
4271 start_cleanup_deferral ()
4273 /* block_stack can be NULL if we are inside the parameter list. It is
4274 OK to do nothing, because cleanups aren't possible here. */
4276 ++block_stack->data.block.conditional_code;
4279 /* Mark the end of a conditional region of code. Because cleanup
4280 deferrals may be nested, we may still be in a conditional region
4281 after we end the currently deferred cleanups, only after we end all
4282 deferred cleanups, are we back in unconditional code. */
4285 end_cleanup_deferral ()
4287 /* block_stack can be NULL if we are inside the parameter list. It is
4288 OK to do nothing, because cleanups aren't possible here. */
4290 --block_stack->data.block.conditional_code;
4293 /* Move all cleanups from the current block_stack
4294 to the containing block_stack, where they are assumed to
4295 have been created. If anything can cause a temporary to
4296 be created, but not expanded for more than one level of
4297 block_stacks, then this code will have to change. */
4302 struct nesting *block = block_stack;
4303 struct nesting *outer = block->next;
4305 outer->data.block.cleanups
4306 = chainon (block->data.block.cleanups,
4307 outer->data.block.cleanups);
4308 block->data.block.cleanups = 0;
4312 last_cleanup_this_contour ()
4314 if (block_stack == 0)
4317 return block_stack->data.block.cleanups;
4320 /* Return 1 if there are any pending cleanups at this point.
4321 If THIS_CONTOUR is nonzero, check the current contour as well.
4322 Otherwise, look only at the contours that enclose this one. */
4325 any_pending_cleanups (this_contour)
4328 struct nesting *block;
4330 if (cfun == NULL || cfun->stmt == NULL || block_stack == 0)
4333 if (this_contour && block_stack->data.block.cleanups != NULL)
4335 if (block_stack->data.block.cleanups == 0
4336 && block_stack->data.block.outer_cleanups == 0)
4339 for (block = block_stack->next; block; block = block->next)
4340 if (block->data.block.cleanups != 0)
4346 /* Enter a case (Pascal) or switch (C) statement.
4347 Push a block onto case_stack and nesting_stack
4348 to accumulate the case-labels that are seen
4349 and to record the labels generated for the statement.
4351 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4352 Otherwise, this construct is transparent for `exit_something'.
4354 EXPR is the index-expression to be dispatched on.
4355 TYPE is its nominal type. We could simply convert EXPR to this type,
4356 but instead we take short cuts. */
4359 expand_start_case (exit_flag, expr, type, printname)
4363 const char *printname;
4365 register struct nesting *thiscase = ALLOC_NESTING ();
4367 /* Make an entry on case_stack for the case we are entering. */
4369 thiscase->next = case_stack;
4370 thiscase->all = nesting_stack;
4371 thiscase->depth = ++nesting_depth;
4372 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
4373 thiscase->data.case_stmt.case_list = 0;
4374 thiscase->data.case_stmt.index_expr = expr;
4375 thiscase->data.case_stmt.nominal_type = type;
4376 thiscase->data.case_stmt.default_label = 0;
4377 thiscase->data.case_stmt.num_ranges = 0;
4378 thiscase->data.case_stmt.printname = printname;
4379 thiscase->data.case_stmt.line_number_status = force_line_numbers ();
4380 case_stack = thiscase;
4381 nesting_stack = thiscase;
4383 do_pending_stack_adjust ();
4385 /* Make sure case_stmt.start points to something that won't
4386 need any transformation before expand_end_case. */
4387 if (GET_CODE (get_last_insn ()) != NOTE)
4388 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4390 thiscase->data.case_stmt.start = get_last_insn ();
4392 start_cleanup_deferral ();
4396 /* Start a "dummy case statement" within which case labels are invalid
4397 and are not connected to any larger real case statement.
4398 This can be used if you don't want to let a case statement jump
4399 into the middle of certain kinds of constructs. */
4402 expand_start_case_dummy ()
4404 register struct nesting *thiscase = ALLOC_NESTING ();
4406 /* Make an entry on case_stack for the dummy. */
4408 thiscase->next = case_stack;
4409 thiscase->all = nesting_stack;
4410 thiscase->depth = ++nesting_depth;
4411 thiscase->exit_label = 0;
4412 thiscase->data.case_stmt.case_list = 0;
4413 thiscase->data.case_stmt.start = 0;
4414 thiscase->data.case_stmt.nominal_type = 0;
4415 thiscase->data.case_stmt.default_label = 0;
4416 thiscase->data.case_stmt.num_ranges = 0;
4417 case_stack = thiscase;
4418 nesting_stack = thiscase;
4419 start_cleanup_deferral ();
4422 /* End a dummy case statement. */
4425 expand_end_case_dummy ()
4427 end_cleanup_deferral ();
4428 POPSTACK (case_stack);
4431 /* Return the data type of the index-expression
4432 of the innermost case statement, or null if none. */
4435 case_index_expr_type ()
4438 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
4445 /* If this is the first label, warn if any insns have been emitted. */
4446 if (case_stack->data.case_stmt.line_number_status >= 0)
4450 restore_line_number_status
4451 (case_stack->data.case_stmt.line_number_status);
4452 case_stack->data.case_stmt.line_number_status = -1;
4454 for (insn = case_stack->data.case_stmt.start;
4456 insn = NEXT_INSN (insn))
4458 if (GET_CODE (insn) == CODE_LABEL)
4460 if (GET_CODE (insn) != NOTE
4461 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4464 insn = PREV_INSN (insn);
4465 while (insn && (GET_CODE (insn) != NOTE || NOTE_LINE_NUMBER (insn) < 0));
4467 /* If insn is zero, then there must have been a syntax error. */
4469 warning_with_file_and_line (NOTE_SOURCE_FILE(insn),
4470 NOTE_LINE_NUMBER(insn),
4471 "unreachable code at beginning of %s",
4472 case_stack->data.case_stmt.printname);
4479 /* Accumulate one case or default label inside a case or switch statement.
4480 VALUE is the value of the case (a null pointer, for a default label).
4481 The function CONVERTER, when applied to arguments T and V,
4482 converts the value V to the type T.
4484 If not currently inside a case or switch statement, return 1 and do
4485 nothing. The caller will print a language-specific error message.
4486 If VALUE is a duplicate or overlaps, return 2 and do nothing
4487 except store the (first) duplicate node in *DUPLICATE.
4488 If VALUE is out of range, return 3 and do nothing.
4489 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4490 Return 0 on success.
4492 Extended to handle range statements. */
4495 pushcase (value, converter, label, duplicate)
4496 register tree value;
4497 tree (*converter) PARAMS ((tree, tree));
4498 register tree label;
4504 /* Fail if not inside a real case statement. */
4505 if (! (case_stack && case_stack->data.case_stmt.start))
4508 if (stack_block_stack
4509 && stack_block_stack->depth > case_stack->depth)
4512 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4513 nominal_type = case_stack->data.case_stmt.nominal_type;
4515 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4516 if (index_type == error_mark_node)
4519 /* Convert VALUE to the type in which the comparisons are nominally done. */
4521 value = (*converter) (nominal_type, value);
4525 /* Fail if this value is out of range for the actual type of the index
4526 (which may be narrower than NOMINAL_TYPE). */
4528 && (TREE_CONSTANT_OVERFLOW (value)
4529 || ! int_fits_type_p (value, index_type)))
4532 /* Fail if this is a duplicate or overlaps another entry. */
4535 if (case_stack->data.case_stmt.default_label != 0)
4537 *duplicate = case_stack->data.case_stmt.default_label;
4540 case_stack->data.case_stmt.default_label = label;
4543 return add_case_node (value, value, label, duplicate);
4545 expand_label (label);
4549 /* Like pushcase but this case applies to all values between VALUE1 and
4550 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4551 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4552 starts at VALUE1 and ends at the highest value of the index type.
4553 If both are NULL, this case applies to all values.
4555 The return value is the same as that of pushcase but there is one
4556 additional error code: 4 means the specified range was empty. */
4559 pushcase_range (value1, value2, converter, label, duplicate)
4560 register tree value1, value2;
4561 tree (*converter) PARAMS ((tree, tree));
4562 register tree label;
4568 /* Fail if not inside a real case statement. */
4569 if (! (case_stack && case_stack->data.case_stmt.start))
4572 if (stack_block_stack
4573 && stack_block_stack->depth > case_stack->depth)
4576 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4577 nominal_type = case_stack->data.case_stmt.nominal_type;
4579 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4580 if (index_type == error_mark_node)
4585 /* Convert VALUEs to type in which the comparisons are nominally done
4586 and replace any unspecified value with the corresponding bound. */
4588 value1 = TYPE_MIN_VALUE (index_type);
4590 value2 = TYPE_MAX_VALUE (index_type);
4592 /* Fail if the range is empty. Do this before any conversion since
4593 we want to allow out-of-range empty ranges. */
4594 if (value2 != 0 && tree_int_cst_lt (value2, value1))
4597 /* If the max was unbounded, use the max of the nominal_type we are
4598 converting to. Do this after the < check above to suppress false
4601 value2 = TYPE_MAX_VALUE (nominal_type);
4603 value1 = (*converter) (nominal_type, value1);
4604 value2 = (*converter) (nominal_type, value2);
4606 /* Fail if these values are out of range. */
4607 if (TREE_CONSTANT_OVERFLOW (value1)
4608 || ! int_fits_type_p (value1, index_type))
4611 if (TREE_CONSTANT_OVERFLOW (value2)
4612 || ! int_fits_type_p (value2, index_type))
4615 return add_case_node (value1, value2, label, duplicate);
4618 /* Do the actual insertion of a case label for pushcase and pushcase_range
4619 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4620 slowdown for large switch statements. */
4623 add_case_node (low, high, label, duplicate)
4628 struct case_node *p, **q, *r;
4630 q = &case_stack->data.case_stmt.case_list;
4637 /* Keep going past elements distinctly greater than HIGH. */
4638 if (tree_int_cst_lt (high, p->low))
4641 /* or distinctly less than LOW. */
4642 else if (tree_int_cst_lt (p->high, low))
4647 /* We have an overlap; this is an error. */
4648 *duplicate = p->code_label;
4653 /* Add this label to the chain, and succeed.
4654 Copy LOW, HIGH so they are on temporary rather than momentary
4655 obstack and will thus survive till the end of the case statement. */
4657 r = (struct case_node *) oballoc (sizeof (struct case_node));
4658 r->low = copy_node (low);
4660 /* If the bounds are equal, turn this into the one-value case. */
4662 if (tree_int_cst_equal (low, high))
4666 r->high = copy_node (high);
4667 case_stack->data.case_stmt.num_ranges++;
4670 r->code_label = label;
4671 expand_label (label);
4681 struct case_node *s;
4687 if (! (b = p->balance))
4688 /* Growth propagation from left side. */
4695 if ((p->left = s = r->right))
4704 if ((r->parent = s))
4712 case_stack->data.case_stmt.case_list = r;
4715 /* r->balance == +1 */
4720 struct case_node *t = r->right;
4722 if ((p->left = s = t->right))
4726 if ((r->right = s = t->left))
4740 if ((t->parent = s))
4748 case_stack->data.case_stmt.case_list = t;
4755 /* p->balance == +1; growth of left side balances the node. */
4765 if (! (b = p->balance))
4766 /* Growth propagation from right side. */
4774 if ((p->right = s = r->left))
4782 if ((r->parent = s))
4791 case_stack->data.case_stmt.case_list = r;
4795 /* r->balance == -1 */
4799 struct case_node *t = r->left;
4801 if ((p->right = s = t->left))
4806 if ((r->left = s = t->right))
4820 if ((t->parent = s))
4829 case_stack->data.case_stmt.case_list = t;
4835 /* p->balance == -1; growth of right side balances the node. */
4849 /* Returns the number of possible values of TYPE.
4850 Returns -1 if the number is unknown, variable, or if the number does not
4851 fit in a HOST_WIDE_INT.
4852 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4853 do not increase monotonically (there may be duplicates);
4854 to 1 if the values increase monotonically, but not always by 1;
4855 otherwise sets it to 0. */
4858 all_cases_count (type, spareness)
4863 HOST_WIDE_INT count, minval, lastval;
4867 switch (TREE_CODE (type))
4874 count = 1 << BITS_PER_UNIT;
4879 if (TYPE_MAX_VALUE (type) != 0
4880 && 0 != (t = fold (build (MINUS_EXPR, type, TYPE_MAX_VALUE (type),
4881 TYPE_MIN_VALUE (type))))
4882 && 0 != (t = fold (build (PLUS_EXPR, type, t,
4883 convert (type, integer_zero_node))))
4884 && host_integerp (t, 1))
4885 count = tree_low_cst (t, 1);
4891 /* Don't waste time with enumeral types with huge values. */
4892 if (! host_integerp (TYPE_MIN_VALUE (type), 0)
4893 || TYPE_MAX_VALUE (type) == 0
4894 || ! host_integerp (TYPE_MAX_VALUE (type), 0))
4897 lastval = minval = tree_low_cst (TYPE_MIN_VALUE (type), 0);
4900 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4902 HOST_WIDE_INT thisval = tree_low_cst (TREE_VALUE (t), 0);
4904 if (*spareness == 2 || thisval < lastval)
4906 else if (thisval != minval + count)
4916 #define BITARRAY_TEST(ARRAY, INDEX) \
4917 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4918 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4919 #define BITARRAY_SET(ARRAY, INDEX) \
4920 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4921 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4923 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4924 with the case values we have seen, assuming the case expression
4926 SPARSENESS is as determined by all_cases_count.
4928 The time needed is proportional to COUNT, unless
4929 SPARSENESS is 2, in which case quadratic time is needed. */
4932 mark_seen_cases (type, cases_seen, count, sparseness)
4934 unsigned char *cases_seen;
4935 HOST_WIDE_INT count;
4938 tree next_node_to_try = NULL_TREE;
4939 HOST_WIDE_INT next_node_offset = 0;
4941 register struct case_node *n, *root = case_stack->data.case_stmt.case_list;
4942 tree val = make_node (INTEGER_CST);
4944 TREE_TYPE (val) = type;
4947 else if (sparseness == 2)
4950 unsigned HOST_WIDE_INT xlo;
4952 /* This less efficient loop is only needed to handle
4953 duplicate case values (multiple enum constants
4954 with the same value). */
4955 TREE_TYPE (val) = TREE_TYPE (root->low);
4956 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
4957 t = TREE_CHAIN (t), xlo++)
4959 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (TREE_VALUE (t));
4960 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (TREE_VALUE (t));
4964 /* Keep going past elements distinctly greater than VAL. */
4965 if (tree_int_cst_lt (val, n->low))
4968 /* or distinctly less than VAL. */
4969 else if (tree_int_cst_lt (n->high, val))
4974 /* We have found a matching range. */
4975 BITARRAY_SET (cases_seen, xlo);
4985 case_stack->data.case_stmt.case_list = root = case_tree2list (root, 0);
4987 for (n = root; n; n = n->right)
4989 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
4990 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
4991 while ( ! tree_int_cst_lt (n->high, val))
4993 /* Calculate (into xlo) the "offset" of the integer (val).
4994 The element with lowest value has offset 0, the next smallest
4995 element has offset 1, etc. */
4997 unsigned HOST_WIDE_INT xlo;
5001 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
5003 /* The TYPE_VALUES will be in increasing order, so
5004 starting searching where we last ended. */
5005 t = next_node_to_try;
5006 xlo = next_node_offset;
5012 t = TYPE_VALUES (type);
5015 if (tree_int_cst_equal (val, TREE_VALUE (t)))
5017 next_node_to_try = TREE_CHAIN (t);
5018 next_node_offset = xlo + 1;
5023 if (t == next_node_to_try)
5032 t = TYPE_MIN_VALUE (type);
5034 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
5038 add_double (xlo, xhi,
5039 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5043 if (xhi == 0 && xlo < (unsigned HOST_WIDE_INT) count)
5044 BITARRAY_SET (cases_seen, xlo);
5046 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5048 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
5054 /* Called when the index of a switch statement is an enumerated type
5055 and there is no default label.
5057 Checks that all enumeration literals are covered by the case
5058 expressions of a switch. Also, warn if there are any extra
5059 switch cases that are *not* elements of the enumerated type.
5061 If all enumeration literals were covered by the case expressions,
5062 turn one of the expressions into the default expression since it should
5063 not be possible to fall through such a switch. */
5066 check_for_full_enumeration_handling (type)
5069 register struct case_node *n;
5070 register tree chain;
5071 #if 0 /* variable used by 'if 0'ed code below. */
5072 register struct case_node **l;
5076 /* True iff the selector type is a numbered set mode. */
5079 /* The number of possible selector values. */
5082 /* For each possible selector value. a one iff it has been matched
5083 by a case value alternative. */
5084 unsigned char *cases_seen;
5086 /* The allocated size of cases_seen, in chars. */
5087 HOST_WIDE_INT bytes_needed;
5092 size = all_cases_count (type, &sparseness);
5093 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
5095 if (size > 0 && size < 600000
5096 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5097 this optimization if we don't have enough memory rather than
5098 aborting, as xmalloc would do. */
5099 && (cases_seen = (unsigned char *) calloc (bytes_needed, 1)) != NULL)
5102 tree v = TYPE_VALUES (type);
5104 /* The time complexity of this code is normally O(N), where
5105 N being the number of members in the enumerated type.
5106 However, if type is a ENUMERAL_TYPE whose values do not
5107 increase monotonically, O(N*log(N)) time may be needed. */
5109 mark_seen_cases (type, cases_seen, size, sparseness);
5111 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
5112 if (BITARRAY_TEST(cases_seen, i) == 0)
5113 warning ("enumeration value `%s' not handled in switch",
5114 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
5119 /* Now we go the other way around; we warn if there are case
5120 expressions that don't correspond to enumerators. This can
5121 occur since C and C++ don't enforce type-checking of
5122 assignments to enumeration variables. */
5124 if (case_stack->data.case_stmt.case_list
5125 && case_stack->data.case_stmt.case_list->left)
5126 case_stack->data.case_stmt.case_list
5127 = case_tree2list (case_stack->data.case_stmt.case_list, 0);
5129 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
5131 for (chain = TYPE_VALUES (type);
5132 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
5133 chain = TREE_CHAIN (chain))
5138 if (TYPE_NAME (type) == 0)
5139 warning ("case value `%ld' not in enumerated type",
5140 (long) TREE_INT_CST_LOW (n->low));
5142 warning ("case value `%ld' not in enumerated type `%s'",
5143 (long) TREE_INT_CST_LOW (n->low),
5144 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5147 : DECL_NAME (TYPE_NAME (type))));
5149 if (!tree_int_cst_equal (n->low, n->high))
5151 for (chain = TYPE_VALUES (type);
5152 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
5153 chain = TREE_CHAIN (chain))
5158 if (TYPE_NAME (type) == 0)
5159 warning ("case value `%ld' not in enumerated type",
5160 (long) TREE_INT_CST_LOW (n->high));
5162 warning ("case value `%ld' not in enumerated type `%s'",
5163 (long) TREE_INT_CST_LOW (n->high),
5164 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5167 : DECL_NAME (TYPE_NAME (type))));
5173 /* ??? This optimization is disabled because it causes valid programs to
5174 fail. ANSI C does not guarantee that an expression with enum type
5175 will have a value that is the same as one of the enumeration literals. */
5177 /* If all values were found as case labels, make one of them the default
5178 label. Thus, this switch will never fall through. We arbitrarily pick
5179 the last one to make the default since this is likely the most
5180 efficient choice. */
5184 for (l = &case_stack->data.case_stmt.case_list;
5189 case_stack->data.case_stmt.default_label = (*l)->code_label;
5196 /* Terminate a case (Pascal) or switch (C) statement
5197 in which ORIG_INDEX is the expression to be tested.
5198 Generate the code to test it and jump to the right place. */
5201 expand_end_case (orig_index)
5204 tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE, orig_minval;
5205 rtx default_label = 0;
5206 register struct case_node *n;
5214 register struct nesting *thiscase = case_stack;
5215 tree index_expr, index_type;
5218 /* Don't crash due to previous errors. */
5219 if (thiscase == NULL)
5222 table_label = gen_label_rtx ();
5223 index_expr = thiscase->data.case_stmt.index_expr;
5224 index_type = TREE_TYPE (index_expr);
5225 unsignedp = TREE_UNSIGNED (index_type);
5227 do_pending_stack_adjust ();
5229 /* This might get an spurious warning in the presence of a syntax error;
5230 it could be fixed by moving the call to check_seenlabel after the
5231 check for error_mark_node, and copying the code of check_seenlabel that
5232 deals with case_stack->data.case_stmt.line_number_status /
5233 restore_line_number_status in front of the call to end_cleanup_deferral;
5234 However, this might miss some useful warnings in the presence of
5235 non-syntax errors. */
5238 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5239 if (index_type != error_mark_node)
5241 /* If switch expression was an enumerated type, check that all
5242 enumeration literals are covered by the cases.
5243 No sense trying this if there's a default case, however. */
5245 if (!thiscase->data.case_stmt.default_label
5246 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
5247 && TREE_CODE (index_expr) != INTEGER_CST)
5248 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
5250 /* If we don't have a default-label, create one here,
5251 after the body of the switch. */
5252 if (thiscase->data.case_stmt.default_label == 0)
5254 thiscase->data.case_stmt.default_label
5255 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5256 expand_label (thiscase->data.case_stmt.default_label);
5258 default_label = label_rtx (thiscase->data.case_stmt.default_label);
5260 before_case = get_last_insn ();
5262 if (thiscase->data.case_stmt.case_list
5263 && thiscase->data.case_stmt.case_list->left)
5264 thiscase->data.case_stmt.case_list
5265 = case_tree2list(thiscase->data.case_stmt.case_list, 0);
5267 /* Simplify the case-list before we count it. */
5268 group_case_nodes (thiscase->data.case_stmt.case_list);
5270 /* Get upper and lower bounds of case values.
5271 Also convert all the case values to the index expr's data type. */
5274 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5276 /* Check low and high label values are integers. */
5277 if (TREE_CODE (n->low) != INTEGER_CST)
5279 if (TREE_CODE (n->high) != INTEGER_CST)
5282 n->low = convert (index_type, n->low);
5283 n->high = convert (index_type, n->high);
5285 /* Count the elements and track the largest and smallest
5286 of them (treating them as signed even if they are not). */
5294 if (INT_CST_LT (n->low, minval))
5296 if (INT_CST_LT (maxval, n->high))
5299 /* A range counts double, since it requires two compares. */
5300 if (! tree_int_cst_equal (n->low, n->high))
5304 orig_minval = minval;
5306 /* Compute span of values. */
5308 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
5310 end_cleanup_deferral ();
5314 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
5316 emit_jump (default_label);
5319 /* If range of values is much bigger than number of values,
5320 make a sequence of conditional branches instead of a dispatch.
5321 If the switch-index is a constant, do it this way
5322 because we can optimize it. */
5324 #ifndef CASE_VALUES_THRESHOLD
5326 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
5328 /* If machine does not have a case insn that compares the
5329 bounds, this means extra overhead for dispatch tables
5330 which raises the threshold for using them. */
5331 #define CASE_VALUES_THRESHOLD 5
5332 #endif /* HAVE_casesi */
5333 #endif /* CASE_VALUES_THRESHOLD */
5335 else if (count < CASE_VALUES_THRESHOLD
5336 || compare_tree_int (range, 10 * count) > 0
5337 /* RANGE may be signed, and really large ranges will show up
5338 as negative numbers. */
5339 || compare_tree_int (range, 0) < 0
5340 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5343 || TREE_CODE (index_expr) == INTEGER_CST
5344 /* These will reduce to a constant. */
5345 || (TREE_CODE (index_expr) == CALL_EXPR
5346 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
5347 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
5348 && DECL_BUILT_IN_CLASS (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_NORMAL
5349 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
5350 || (TREE_CODE (index_expr) == COMPOUND_EXPR
5351 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
5353 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5355 /* If the index is a short or char that we do not have
5356 an insn to handle comparisons directly, convert it to
5357 a full integer now, rather than letting each comparison
5358 generate the conversion. */
5360 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
5361 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
5362 == CODE_FOR_nothing))
5364 enum machine_mode wider_mode;
5365 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
5366 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
5367 if (cmp_optab->handlers[(int) wider_mode].insn_code
5368 != CODE_FOR_nothing)
5370 index = convert_to_mode (wider_mode, index, unsignedp);
5376 do_pending_stack_adjust ();
5378 index = protect_from_queue (index, 0);
5379 if (GET_CODE (index) == MEM)
5380 index = copy_to_reg (index);
5381 if (GET_CODE (index) == CONST_INT
5382 || TREE_CODE (index_expr) == INTEGER_CST)
5384 /* Make a tree node with the proper constant value
5385 if we don't already have one. */
5386 if (TREE_CODE (index_expr) != INTEGER_CST)
5389 = build_int_2 (INTVAL (index),
5390 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
5391 index_expr = convert (index_type, index_expr);
5394 /* For constant index expressions we need only
5395 issue a unconditional branch to the appropriate
5396 target code. The job of removing any unreachable
5397 code is left to the optimisation phase if the
5398 "-O" option is specified. */
5399 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5400 if (! tree_int_cst_lt (index_expr, n->low)
5401 && ! tree_int_cst_lt (n->high, index_expr))
5405 emit_jump (label_rtx (n->code_label));
5407 emit_jump (default_label);
5411 /* If the index expression is not constant we generate
5412 a binary decision tree to select the appropriate
5413 target code. This is done as follows:
5415 The list of cases is rearranged into a binary tree,
5416 nearly optimal assuming equal probability for each case.
5418 The tree is transformed into RTL, eliminating
5419 redundant test conditions at the same time.
5421 If program flow could reach the end of the
5422 decision tree an unconditional jump to the
5423 default code is emitted. */
5426 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
5427 && estimate_case_costs (thiscase->data.case_stmt.case_list));
5428 balance_case_nodes (&thiscase->data.case_stmt.case_list,
5430 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
5431 default_label, index_type);
5432 emit_jump_if_reachable (default_label);
5441 enum machine_mode index_mode = SImode;
5442 int index_bits = GET_MODE_BITSIZE (index_mode);
5444 enum machine_mode op_mode;
5446 /* Convert the index to SImode. */
5447 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
5448 > GET_MODE_BITSIZE (index_mode))
5450 enum machine_mode omode = TYPE_MODE (index_type);
5451 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
5453 /* We must handle the endpoints in the original mode. */
5454 index_expr = build (MINUS_EXPR, index_type,
5455 index_expr, minval);
5456 minval = integer_zero_node;
5457 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5458 emit_cmp_and_jump_insns (rangertx, index, LTU, NULL_RTX,
5459 omode, 1, 0, default_label);
5460 /* Now we can safely truncate. */
5461 index = convert_to_mode (index_mode, index, 0);
5465 if (TYPE_MODE (index_type) != index_mode)
5467 index_expr = convert (type_for_size (index_bits, 0),
5469 index_type = TREE_TYPE (index_expr);
5472 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5475 index = protect_from_queue (index, 0);
5476 do_pending_stack_adjust ();
5478 op_mode = insn_data[(int)CODE_FOR_casesi].operand[0].mode;
5479 if (! (*insn_data[(int)CODE_FOR_casesi].operand[0].predicate)
5481 index = copy_to_mode_reg (op_mode, index);
5483 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
5485 op_mode = insn_data[(int)CODE_FOR_casesi].operand[1].mode;
5486 if (! (*insn_data[(int)CODE_FOR_casesi].operand[1].predicate)
5488 op1 = copy_to_mode_reg (op_mode, op1);
5490 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
5492 op_mode = insn_data[(int)CODE_FOR_casesi].operand[2].mode;
5493 if (! (*insn_data[(int)CODE_FOR_casesi].operand[2].predicate)
5495 op2 = copy_to_mode_reg (op_mode, op2);
5497 emit_jump_insn (gen_casesi (index, op1, op2,
5498 table_label, default_label));
5502 #ifdef HAVE_tablejump
5503 if (! win && HAVE_tablejump)
5505 index_type = thiscase->data.case_stmt.nominal_type;
5506 index_expr = fold (build (MINUS_EXPR, index_type,
5507 convert (index_type, index_expr),
5508 convert (index_type, minval)));
5509 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5511 index = protect_from_queue (index, 0);
5512 do_pending_stack_adjust ();
5514 do_tablejump (index, TYPE_MODE (index_type),
5515 expand_expr (range, NULL_RTX, VOIDmode, 0),
5516 table_label, default_label);
5523 /* Get table of labels to jump to, in order of case index. */
5525 ncases = TREE_INT_CST_LOW (range) + 1;
5526 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
5527 bzero ((char *) labelvec, ncases * sizeof (rtx));
5529 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5531 register HOST_WIDE_INT i
5532 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
5537 = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
5538 if (i + TREE_INT_CST_LOW (orig_minval)
5539 == TREE_INT_CST_LOW (n->high))
5545 /* Fill in the gaps with the default. */
5546 for (i = 0; i < ncases; i++)
5547 if (labelvec[i] == 0)
5548 labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
5550 /* Output the table */
5551 emit_label (table_label);
5553 if (CASE_VECTOR_PC_RELATIVE || flag_pic)
5554 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
5555 gen_rtx_LABEL_REF (Pmode, table_label),
5556 gen_rtvec_v (ncases, labelvec),
5557 const0_rtx, const0_rtx));
5559 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
5560 gen_rtvec_v (ncases, labelvec)));
5562 /* If the case insn drops through the table,
5563 after the table we must jump to the default-label.
5564 Otherwise record no drop-through after the table. */
5565 #ifdef CASE_DROPS_THROUGH
5566 emit_jump (default_label);
5572 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
5573 reorder_insns (before_case, get_last_insn (),
5574 thiscase->data.case_stmt.start);
5577 end_cleanup_deferral ();
5579 if (thiscase->exit_label)
5580 emit_label (thiscase->exit_label);
5582 POPSTACK (case_stack);
5587 /* Convert the tree NODE into a list linked by the right field, with the left
5588 field zeroed. RIGHT is used for recursion; it is a list to be placed
5589 rightmost in the resulting list. */
5591 static struct case_node *
5592 case_tree2list (node, right)
5593 struct case_node *node, *right;
5595 struct case_node *left;
5598 right = case_tree2list (node->right, right);
5600 node->right = right;
5601 if ((left = node->left))
5604 return case_tree2list (left, node);
5610 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5613 do_jump_if_equal (op1, op2, label, unsignedp)
5614 rtx op1, op2, label;
5617 if (GET_CODE (op1) == CONST_INT
5618 && GET_CODE (op2) == CONST_INT)
5620 if (INTVAL (op1) == INTVAL (op2))
5625 enum machine_mode mode = GET_MODE (op1);
5626 if (mode == VOIDmode)
5627 mode = GET_MODE (op2);
5628 emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX, mode, unsignedp,
5633 /* Not all case values are encountered equally. This function
5634 uses a heuristic to weight case labels, in cases where that
5635 looks like a reasonable thing to do.
5637 Right now, all we try to guess is text, and we establish the
5640 chars above space: 16
5649 If we find any cases in the switch that are not either -1 or in the range
5650 of valid ASCII characters, or are control characters other than those
5651 commonly used with "\", don't treat this switch scanning text.
5653 Return 1 if these nodes are suitable for cost estimation, otherwise
5657 estimate_case_costs (node)
5660 tree min_ascii = build_int_2 (-1, -1);
5661 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5665 /* If we haven't already made the cost table, make it now. Note that the
5666 lower bound of the table is -1, not zero. */
5668 if (cost_table == NULL)
5670 cost_table = cost_table_ + 1;
5672 for (i = 0; i < 128; i++)
5676 else if (ISPUNCT (i))
5678 else if (ISCNTRL (i))
5682 cost_table[' '] = 8;
5683 cost_table['\t'] = 4;
5684 cost_table['\0'] = 4;
5685 cost_table['\n'] = 2;
5686 cost_table['\f'] = 1;
5687 cost_table['\v'] = 1;
5688 cost_table['\b'] = 1;
5691 /* See if all the case expressions look like text. It is text if the
5692 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5693 as signed arithmetic since we don't want to ever access cost_table with a
5694 value less than -1. Also check that none of the constants in a range
5695 are strange control characters. */
5697 for (n = node; n; n = n->right)
5699 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5702 for (i = (HOST_WIDE_INT) TREE_INT_CST_LOW (n->low);
5703 i <= (HOST_WIDE_INT) TREE_INT_CST_LOW (n->high); i++)
5704 if (cost_table[i] < 0)
5708 /* All interesting values are within the range of interesting
5709 ASCII characters. */
5713 /* Scan an ordered list of case nodes
5714 combining those with consecutive values or ranges.
5716 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5719 group_case_nodes (head)
5722 case_node_ptr node = head;
5726 rtx lb = next_real_insn (label_rtx (node->code_label));
5728 case_node_ptr np = node;
5730 /* Try to group the successors of NODE with NODE. */
5731 while (((np = np->right) != 0)
5732 /* Do they jump to the same place? */
5733 && ((lb2 = next_real_insn (label_rtx (np->code_label))) == lb
5734 || (lb != 0 && lb2 != 0
5735 && simplejump_p (lb)
5736 && simplejump_p (lb2)
5737 && rtx_equal_p (SET_SRC (PATTERN (lb)),
5738 SET_SRC (PATTERN (lb2)))))
5739 /* Are their ranges consecutive? */
5740 && tree_int_cst_equal (np->low,
5741 fold (build (PLUS_EXPR,
5742 TREE_TYPE (node->high),
5745 /* An overflow is not consecutive. */
5746 && tree_int_cst_lt (node->high,
5747 fold (build (PLUS_EXPR,
5748 TREE_TYPE (node->high),
5750 integer_one_node))))
5752 node->high = np->high;
5754 /* NP is the first node after NODE which can't be grouped with it.
5755 Delete the nodes in between, and move on to that node. */
5761 /* Take an ordered list of case nodes
5762 and transform them into a near optimal binary tree,
5763 on the assumption that any target code selection value is as
5764 likely as any other.
5766 The transformation is performed by splitting the ordered
5767 list into two equal sections plus a pivot. The parts are
5768 then attached to the pivot as left and right branches. Each
5769 branch is then transformed recursively. */
5772 balance_case_nodes (head, parent)
5773 case_node_ptr *head;
5774 case_node_ptr parent;
5776 register case_node_ptr np;
5784 register case_node_ptr *npp;
5787 /* Count the number of entries on branch. Also count the ranges. */
5791 if (!tree_int_cst_equal (np->low, np->high))
5795 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5799 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5807 /* Split this list if it is long enough for that to help. */
5812 /* Find the place in the list that bisects the list's total cost,
5813 Here I gets half the total cost. */
5818 /* Skip nodes while their cost does not reach that amount. */
5819 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5820 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5821 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5824 npp = &(*npp)->right;
5829 /* Leave this branch lopsided, but optimize left-hand
5830 side and fill in `parent' fields for right-hand side. */
5832 np->parent = parent;
5833 balance_case_nodes (&np->left, np);
5834 for (; np->right; np = np->right)
5835 np->right->parent = np;
5839 /* If there are just three nodes, split at the middle one. */
5841 npp = &(*npp)->right;
5844 /* Find the place in the list that bisects the list's total cost,
5845 where ranges count as 2.
5846 Here I gets half the total cost. */
5847 i = (i + ranges + 1) / 2;
5850 /* Skip nodes while their cost does not reach that amount. */
5851 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5856 npp = &(*npp)->right;
5861 np->parent = parent;
5864 /* Optimize each of the two split parts. */
5865 balance_case_nodes (&np->left, np);
5866 balance_case_nodes (&np->right, np);
5870 /* Else leave this branch as one level,
5871 but fill in `parent' fields. */
5873 np->parent = parent;
5874 for (; np->right; np = np->right)
5875 np->right->parent = np;
5880 /* Search the parent sections of the case node tree
5881 to see if a test for the lower bound of NODE would be redundant.
5882 INDEX_TYPE is the type of the index expression.
5884 The instructions to generate the case decision tree are
5885 output in the same order as nodes are processed so it is
5886 known that if a parent node checks the range of the current
5887 node minus one that the current node is bounded at its lower
5888 span. Thus the test would be redundant. */
5891 node_has_low_bound (node, index_type)
5896 case_node_ptr pnode;
5898 /* If the lower bound of this node is the lowest value in the index type,
5899 we need not test it. */
5901 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5904 /* If this node has a left branch, the value at the left must be less
5905 than that at this node, so it cannot be bounded at the bottom and
5906 we need not bother testing any further. */
5911 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5912 node->low, integer_one_node));
5914 /* If the subtraction above overflowed, we can't verify anything.
5915 Otherwise, look for a parent that tests our value - 1. */
5917 if (! tree_int_cst_lt (low_minus_one, node->low))
5920 for (pnode = node->parent; pnode; pnode = pnode->parent)
5921 if (tree_int_cst_equal (low_minus_one, pnode->high))
5927 /* Search the parent sections of the case node tree
5928 to see if a test for the upper bound of NODE would be redundant.
5929 INDEX_TYPE is the type of the index expression.
5931 The instructions to generate the case decision tree are
5932 output in the same order as nodes are processed so it is
5933 known that if a parent node checks the range of the current
5934 node plus one that the current node is bounded at its upper
5935 span. Thus the test would be redundant. */
5938 node_has_high_bound (node, index_type)
5943 case_node_ptr pnode;
5945 /* If there is no upper bound, obviously no test is needed. */
5947 if (TYPE_MAX_VALUE (index_type) == NULL)
5950 /* If the upper bound of this node is the highest value in the type
5951 of the index expression, we need not test against it. */
5953 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
5956 /* If this node has a right branch, the value at the right must be greater
5957 than that at this node, so it cannot be bounded at the top and
5958 we need not bother testing any further. */
5963 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
5964 node->high, integer_one_node));
5966 /* If the addition above overflowed, we can't verify anything.
5967 Otherwise, look for a parent that tests our value + 1. */
5969 if (! tree_int_cst_lt (node->high, high_plus_one))
5972 for (pnode = node->parent; pnode; pnode = pnode->parent)
5973 if (tree_int_cst_equal (high_plus_one, pnode->low))
5979 /* Search the parent sections of the
5980 case node tree to see if both tests for the upper and lower
5981 bounds of NODE would be redundant. */
5984 node_is_bounded (node, index_type)
5988 return (node_has_low_bound (node, index_type)
5989 && node_has_high_bound (node, index_type));
5992 /* Emit an unconditional jump to LABEL unless it would be dead code. */
5995 emit_jump_if_reachable (label)
5998 if (GET_CODE (get_last_insn ()) != BARRIER)
6002 /* Emit step-by-step code to select a case for the value of INDEX.
6003 The thus generated decision tree follows the form of the
6004 case-node binary tree NODE, whose nodes represent test conditions.
6005 INDEX_TYPE is the type of the index of the switch.
6007 Care is taken to prune redundant tests from the decision tree
6008 by detecting any boundary conditions already checked by
6009 emitted rtx. (See node_has_high_bound, node_has_low_bound
6010 and node_is_bounded, above.)
6012 Where the test conditions can be shown to be redundant we emit
6013 an unconditional jump to the target code. As a further
6014 optimization, the subordinates of a tree node are examined to
6015 check for bounded nodes. In this case conditional and/or
6016 unconditional jumps as a result of the boundary check for the
6017 current node are arranged to target the subordinates associated
6018 code for out of bound conditions on the current node.
6020 We can assume that when control reaches the code generated here,
6021 the index value has already been compared with the parents
6022 of this node, and determined to be on the same side of each parent
6023 as this node is. Thus, if this node tests for the value 51,
6024 and a parent tested for 52, we don't need to consider
6025 the possibility of a value greater than 51. If another parent
6026 tests for the value 50, then this node need not test anything. */
6029 emit_case_nodes (index, node, default_label, index_type)
6035 /* If INDEX has an unsigned type, we must make unsigned branches. */
6036 int unsignedp = TREE_UNSIGNED (index_type);
6037 enum machine_mode mode = GET_MODE (index);
6039 /* See if our parents have already tested everything for us.
6040 If they have, emit an unconditional jump for this node. */
6041 if (node_is_bounded (node, index_type))
6042 emit_jump (label_rtx (node->code_label));
6044 else if (tree_int_cst_equal (node->low, node->high))
6046 /* Node is single valued. First see if the index expression matches
6047 this node and then check our children, if any. */
6049 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
6050 label_rtx (node->code_label), unsignedp);
6052 if (node->right != 0 && node->left != 0)
6054 /* This node has children on both sides.
6055 Dispatch to one side or the other
6056 by comparing the index value with this node's value.
6057 If one subtree is bounded, check that one first,
6058 so we can avoid real branches in the tree. */
6060 if (node_is_bounded (node->right, index_type))
6062 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6064 GT, NULL_RTX, mode, unsignedp, 0,
6065 label_rtx (node->right->code_label));
6066 emit_case_nodes (index, node->left, default_label, index_type);
6069 else if (node_is_bounded (node->left, index_type))
6071 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6073 LT, NULL_RTX, mode, unsignedp, 0,
6074 label_rtx (node->left->code_label));
6075 emit_case_nodes (index, node->right, default_label, index_type);
6080 /* Neither node is bounded. First distinguish the two sides;
6081 then emit the code for one side at a time. */
6084 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6086 /* See if the value is on the right. */
6087 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6089 GT, NULL_RTX, mode, unsignedp, 0,
6090 label_rtx (test_label));
6092 /* Value must be on the left.
6093 Handle the left-hand subtree. */
6094 emit_case_nodes (index, node->left, default_label, index_type);
6095 /* If left-hand subtree does nothing,
6097 emit_jump_if_reachable (default_label);
6099 /* Code branches here for the right-hand subtree. */
6100 expand_label (test_label);
6101 emit_case_nodes (index, node->right, default_label, index_type);
6105 else if (node->right != 0 && node->left == 0)
6107 /* Here we have a right child but no left so we issue conditional
6108 branch to default and process the right child.
6110 Omit the conditional branch to default if we it avoid only one
6111 right child; it costs too much space to save so little time. */
6113 if (node->right->right || node->right->left
6114 || !tree_int_cst_equal (node->right->low, node->right->high))
6116 if (!node_has_low_bound (node, index_type))
6118 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6121 LT, NULL_RTX, mode, unsignedp, 0,
6125 emit_case_nodes (index, node->right, default_label, index_type);
6128 /* We cannot process node->right normally
6129 since we haven't ruled out the numbers less than
6130 this node's value. So handle node->right explicitly. */
6131 do_jump_if_equal (index,
6132 expand_expr (node->right->low, NULL_RTX,
6134 label_rtx (node->right->code_label), unsignedp);
6137 else if (node->right == 0 && node->left != 0)
6139 /* Just one subtree, on the left. */
6141 #if 0 /* The following code and comment were formerly part
6142 of the condition here, but they didn't work
6143 and I don't understand what the idea was. -- rms. */
6144 /* If our "most probable entry" is less probable
6145 than the default label, emit a jump to
6146 the default label using condition codes
6147 already lying around. With no right branch,
6148 a branch-greater-than will get us to the default
6151 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
6154 if (node->left->left || node->left->right
6155 || !tree_int_cst_equal (node->left->low, node->left->high))
6157 if (!node_has_high_bound (node, index_type))
6159 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6162 GT, NULL_RTX, mode, unsignedp, 0,
6166 emit_case_nodes (index, node->left, default_label, index_type);
6169 /* We cannot process node->left normally
6170 since we haven't ruled out the numbers less than
6171 this node's value. So handle node->left explicitly. */
6172 do_jump_if_equal (index,
6173 expand_expr (node->left->low, NULL_RTX,
6175 label_rtx (node->left->code_label), unsignedp);
6180 /* Node is a range. These cases are very similar to those for a single
6181 value, except that we do not start by testing whether this node
6182 is the one to branch to. */
6184 if (node->right != 0 && node->left != 0)
6186 /* Node has subtrees on both sides.
6187 If the right-hand subtree is bounded,
6188 test for it first, since we can go straight there.
6189 Otherwise, we need to make a branch in the control structure,
6190 then handle the two subtrees. */
6191 tree test_label = 0;
6194 if (node_is_bounded (node->right, index_type))
6195 /* Right hand node is fully bounded so we can eliminate any
6196 testing and branch directly to the target code. */
6197 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6199 GT, NULL_RTX, mode, unsignedp, 0,
6200 label_rtx (node->right->code_label));
6203 /* Right hand node requires testing.
6204 Branch to a label where we will handle it later. */
6206 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6207 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6209 GT, NULL_RTX, mode, unsignedp, 0,
6210 label_rtx (test_label));
6213 /* Value belongs to this node or to the left-hand subtree. */
6215 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6217 GE, NULL_RTX, mode, unsignedp, 0,
6218 label_rtx (node->code_label));
6220 /* Handle the left-hand subtree. */
6221 emit_case_nodes (index, node->left, default_label, index_type);
6223 /* If right node had to be handled later, do that now. */
6227 /* If the left-hand subtree fell through,
6228 don't let it fall into the right-hand subtree. */
6229 emit_jump_if_reachable (default_label);
6231 expand_label (test_label);
6232 emit_case_nodes (index, node->right, default_label, index_type);
6236 else if (node->right != 0 && node->left == 0)
6238 /* Deal with values to the left of this node,
6239 if they are possible. */
6240 if (!node_has_low_bound (node, index_type))
6242 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6244 LT, NULL_RTX, mode, unsignedp, 0,
6248 /* Value belongs to this node or to the right-hand subtree. */
6250 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6252 LE, NULL_RTX, mode, unsignedp, 0,
6253 label_rtx (node->code_label));
6255 emit_case_nodes (index, node->right, default_label, index_type);
6258 else if (node->right == 0 && node->left != 0)
6260 /* Deal with values to the right of this node,
6261 if they are possible. */
6262 if (!node_has_high_bound (node, index_type))
6264 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6266 GT, NULL_RTX, mode, unsignedp, 0,
6270 /* Value belongs to this node or to the left-hand subtree. */
6272 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6274 GE, NULL_RTX, mode, unsignedp, 0,
6275 label_rtx (node->code_label));
6277 emit_case_nodes (index, node->left, default_label, index_type);
6282 /* Node has no children so we check low and high bounds to remove
6283 redundant tests. Only one of the bounds can exist,
6284 since otherwise this node is bounded--a case tested already. */
6286 if (!node_has_high_bound (node, index_type))
6288 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6290 GT, NULL_RTX, mode, unsignedp, 0,
6294 if (!node_has_low_bound (node, index_type))
6296 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6298 LT, NULL_RTX, mode, unsignedp, 0,
6302 emit_jump (label_rtx (node->code_label));