1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000 Free Software Foundation, Inc.
5 This file is part of GNU CC.
7 GNU CC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GNU CC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNU CC; see the file COPYING. If not, write to
19 the Free Software Foundation, 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
23 /* This file handles the generation of rtl code from tree structure
24 above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
25 It also creates the rtl expressions for parameters and auto variables
26 and has full responsibility for allocating stack slots.
28 The functions whose names start with `expand_' are called by the
29 parser to generate RTL instructions for various kinds of constructs.
31 Some control and binding constructs require calling several such
32 functions at different times. For example, a simple if-then
33 is expanded by calling `expand_start_cond' (with the condition-expression
34 as argument) before parsing the then-clause and calling `expand_end_cond'
35 after parsing the then-clause. */
46 #include "insn-flags.h"
47 #include "insn-config.h"
48 #include "insn-codes.h"
50 #include "hard-reg-set.h"
59 #define obstack_chunk_alloc xmalloc
60 #define obstack_chunk_free free
61 struct obstack stmt_obstack;
63 /* Assume that case vectors are not pc-relative. */
64 #ifndef CASE_VECTOR_PC_RELATIVE
65 #define CASE_VECTOR_PC_RELATIVE 0
69 /* Functions and data structures for expanding case statements. */
71 /* Case label structure, used to hold info on labels within case
72 statements. We handle "range" labels; for a single-value label
73 as in C, the high and low limits are the same.
75 An AVL tree of case nodes is initially created, and later transformed
76 to a list linked via the RIGHT fields in the nodes. Nodes with
77 higher case values are later in the list.
79 Switch statements can be output in one of two forms. A branch table
80 is used if there are more than a few labels and the labels are dense
81 within the range between the smallest and largest case value. If a
82 branch table is used, no further manipulations are done with the case
85 The alternative to the use of a branch table is to generate a series
86 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
87 and PARENT fields to hold a binary tree. Initially the tree is
88 totally unbalanced, with everything on the right. We balance the tree
89 with nodes on the left having lower case values than the parent
90 and nodes on the right having higher values. We then output the tree
95 struct case_node *left; /* Left son in binary tree */
96 struct case_node *right; /* Right son in binary tree; also node chain */
97 struct case_node *parent; /* Parent of node in binary tree */
98 tree low; /* Lowest index value for this label */
99 tree high; /* Highest index value for this label */
100 tree code_label; /* Label to jump to when node matches */
104 typedef struct case_node case_node;
105 typedef struct case_node *case_node_ptr;
107 /* These are used by estimate_case_costs and balance_case_nodes. */
109 /* This must be a signed type, and non-ANSI compilers lack signed char. */
110 static short cost_table_[129];
111 static short *cost_table;
112 static int use_cost_table;
114 /* Stack of control and binding constructs we are currently inside.
116 These constructs begin when you call `expand_start_WHATEVER'
117 and end when you call `expand_end_WHATEVER'. This stack records
118 info about how the construct began that tells the end-function
119 what to do. It also may provide information about the construct
120 to alter the behavior of other constructs within the body.
121 For example, they may affect the behavior of C `break' and `continue'.
123 Each construct gets one `struct nesting' object.
124 All of these objects are chained through the `all' field.
125 `nesting_stack' points to the first object (innermost construct).
126 The position of an entry on `nesting_stack' is in its `depth' field.
128 Each type of construct has its own individual stack.
129 For example, loops have `loop_stack'. Each object points to the
130 next object of the same type through the `next' field.
132 Some constructs are visible to `break' exit-statements and others
133 are not. Which constructs are visible depends on the language.
134 Therefore, the data structure allows each construct to be visible
135 or not, according to the args given when the construct is started.
136 The construct is visible if the `exit_label' field is non-null.
137 In that case, the value should be a CODE_LABEL rtx. */
142 struct nesting *next;
147 /* For conds (if-then and if-then-else statements). */
150 /* Label for the end of the if construct.
151 There is none if EXITFLAG was not set
152 and no `else' has been seen yet. */
154 /* Label for the end of this alternative.
155 This may be the end of the if or the next else/elseif. */
161 /* Label at the top of the loop; place to loop back to. */
163 /* Label at the end of the whole construct. */
165 /* Label before a jump that branches to the end of the whole
166 construct. This is where destructors go if any. */
168 /* Label for `continue' statement to jump to;
169 this is in front of the stepper of the loop. */
172 /* For variable binding contours. */
175 /* Sequence number of this binding contour within the function,
176 in order of entry. */
177 int block_start_count;
178 /* Nonzero => value to restore stack to on exit. */
180 /* The NOTE that starts this contour.
181 Used by expand_goto to check whether the destination
182 is within each contour or not. */
184 /* Innermost containing binding contour that has a stack level. */
185 struct nesting *innermost_stack_block;
186 /* List of cleanups to be run on exit from this contour.
187 This is a list of expressions to be evaluated.
188 The TREE_PURPOSE of each link is the ..._DECL node
189 which the cleanup pertains to. */
191 /* List of cleanup-lists of blocks containing this block,
192 as they were at the locus where this block appears.
193 There is an element for each containing block,
194 ordered innermost containing block first.
195 The tail of this list can be 0,
196 if all remaining elements would be empty lists.
197 The element's TREE_VALUE is the cleanup-list of that block,
198 which may be null. */
200 /* Chain of labels defined inside this binding contour.
201 For contours that have stack levels or cleanups. */
202 struct label_chain *label_chain;
203 /* Number of function calls seen, as of start of this block. */
204 int n_function_calls;
205 /* Nonzero if this is associated with a EH region. */
206 int exception_region;
207 /* The saved target_temp_slot_level from our outer block.
208 We may reset target_temp_slot_level to be the level of
209 this block, if that is done, target_temp_slot_level
210 reverts to the saved target_temp_slot_level at the very
212 int block_target_temp_slot_level;
213 /* True if we are currently emitting insns in an area of
214 output code that is controlled by a conditional
215 expression. This is used by the cleanup handling code to
216 generate conditional cleanup actions. */
217 int conditional_code;
218 /* A place to move the start of the exception region for any
219 of the conditional cleanups, must be at the end or after
220 the start of the last unconditional cleanup, and before any
221 conditional branch points. */
222 rtx last_unconditional_cleanup;
223 /* When in a conditional context, this is the specific
224 cleanup list associated with last_unconditional_cleanup,
225 where we place the conditionalized cleanups. */
228 /* For switch (C) or case (Pascal) statements,
229 and also for dummies (see `expand_start_case_dummy'). */
232 /* The insn after which the case dispatch should finally
233 be emitted. Zero for a dummy. */
235 /* A list of case labels; it is first built as an AVL tree.
236 During expand_end_case, this is converted to a list, and may be
237 rearranged into a nearly balanced binary tree. */
238 struct case_node *case_list;
239 /* Label to jump to if no case matches. */
241 /* The expression to be dispatched on. */
243 /* Type that INDEX_EXPR should be converted to. */
245 /* Number of range exprs in case statement. */
247 /* Name of this kind of statement, for warnings. */
248 const char *printname;
249 /* Used to save no_line_numbers till we see the first case label.
250 We set this to -1 when we see the first case label in this
252 int line_number_status;
257 /* Allocate and return a new `struct nesting'. */
259 #define ALLOC_NESTING() \
260 (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
262 /* Pop the nesting stack element by element until we pop off
263 the element which is at the top of STACK.
264 Update all the other stacks, popping off elements from them
265 as we pop them from nesting_stack. */
267 #define POPSTACK(STACK) \
268 do { struct nesting *target = STACK; \
269 struct nesting *this; \
270 do { this = nesting_stack; \
271 if (loop_stack == this) \
272 loop_stack = loop_stack->next; \
273 if (cond_stack == this) \
274 cond_stack = cond_stack->next; \
275 if (block_stack == this) \
276 block_stack = block_stack->next; \
277 if (stack_block_stack == this) \
278 stack_block_stack = stack_block_stack->next; \
279 if (case_stack == this) \
280 case_stack = case_stack->next; \
281 nesting_depth = nesting_stack->depth - 1; \
282 nesting_stack = this->all; \
283 obstack_free (&stmt_obstack, this); } \
284 while (this != target); } while (0)
286 /* In some cases it is impossible to generate code for a forward goto
287 until the label definition is seen. This happens when it may be necessary
288 for the goto to reset the stack pointer: we don't yet know how to do that.
289 So expand_goto puts an entry on this fixup list.
290 Each time a binding contour that resets the stack is exited,
292 If the target label has now been defined, we can insert the proper code. */
296 /* Points to following fixup. */
297 struct goto_fixup *next;
298 /* Points to the insn before the jump insn.
299 If more code must be inserted, it goes after this insn. */
301 /* The LABEL_DECL that this jump is jumping to, or 0
302 for break, continue or return. */
304 /* The BLOCK for the place where this goto was found. */
306 /* The CODE_LABEL rtx that this is jumping to. */
308 /* Number of binding contours started in current function
309 before the label reference. */
310 int block_start_count;
311 /* The outermost stack level that should be restored for this jump.
312 Each time a binding contour that resets the stack is exited,
313 if the target label is *not* yet defined, this slot is updated. */
315 /* List of lists of cleanup expressions to be run by this goto.
316 There is one element for each block that this goto is within.
317 The tail of this list can be 0,
318 if all remaining elements would be empty.
319 The TREE_VALUE contains the cleanup list of that block as of the
320 time this goto was seen.
321 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
322 tree cleanup_list_list;
325 /* Within any binding contour that must restore a stack level,
326 all labels are recorded with a chain of these structures. */
330 /* Points to following fixup. */
331 struct label_chain *next;
337 /* Chain of all pending binding contours. */
338 struct nesting *x_block_stack;
340 /* If any new stacks are added here, add them to POPSTACKS too. */
342 /* Chain of all pending binding contours that restore stack levels
344 struct nesting *x_stack_block_stack;
346 /* Chain of all pending conditional statements. */
347 struct nesting *x_cond_stack;
349 /* Chain of all pending loops. */
350 struct nesting *x_loop_stack;
352 /* Chain of all pending case or switch statements. */
353 struct nesting *x_case_stack;
355 /* Separate chain including all of the above,
356 chained through the `all' field. */
357 struct nesting *x_nesting_stack;
359 /* Number of entries on nesting_stack now. */
362 /* Number of binding contours started so far in this function. */
363 int x_block_start_count;
365 /* Each time we expand an expression-statement,
366 record the expr's type and its RTL value here. */
367 tree x_last_expr_type;
368 rtx x_last_expr_value;
370 /* Nonzero if within a ({...}) grouping, in which case we must
371 always compute a value for each expr-stmt in case it is the last one. */
372 int x_expr_stmts_for_value;
374 /* Filename and line number of last line-number note,
375 whether we actually emitted it or not. */
376 const char *x_emit_filename;
379 struct goto_fixup *x_goto_fixup_chain;
382 #define block_stack (cfun->stmt->x_block_stack)
383 #define stack_block_stack (cfun->stmt->x_stack_block_stack)
384 #define cond_stack (cfun->stmt->x_cond_stack)
385 #define loop_stack (cfun->stmt->x_loop_stack)
386 #define case_stack (cfun->stmt->x_case_stack)
387 #define nesting_stack (cfun->stmt->x_nesting_stack)
388 #define nesting_depth (cfun->stmt->x_nesting_depth)
389 #define current_block_start_count (cfun->stmt->x_block_start_count)
390 #define last_expr_type (cfun->stmt->x_last_expr_type)
391 #define last_expr_value (cfun->stmt->x_last_expr_value)
392 #define expr_stmts_for_value (cfun->stmt->x_expr_stmts_for_value)
393 #define emit_filename (cfun->stmt->x_emit_filename)
394 #define emit_lineno (cfun->stmt->x_emit_lineno)
395 #define goto_fixup_chain (cfun->stmt->x_goto_fixup_chain)
397 /* Non-zero if we are using EH to handle cleanus. */
398 static int using_eh_for_cleanups_p = 0;
400 /* Character strings, each containing a single decimal digit. */
401 static char *digit_strings[10];
404 static int n_occurrences PARAMS ((int, const char *));
405 static void expand_goto_internal PARAMS ((tree, rtx, rtx));
406 static int expand_fixup PARAMS ((tree, rtx, rtx));
407 static rtx expand_nl_handler_label PARAMS ((rtx, rtx));
408 static void expand_nl_goto_receiver PARAMS ((void));
409 static void expand_nl_goto_receivers PARAMS ((struct nesting *));
410 static void fixup_gotos PARAMS ((struct nesting *, rtx, tree,
412 static void expand_null_return_1 PARAMS ((rtx, int));
413 static void expand_value_return PARAMS ((rtx));
414 static int tail_recursion_args PARAMS ((tree, tree));
415 static void expand_cleanups PARAMS ((tree, tree, int, int));
416 static void check_seenlabel PARAMS ((void));
417 static void do_jump_if_equal PARAMS ((rtx, rtx, rtx, int));
418 static int estimate_case_costs PARAMS ((case_node_ptr));
419 static void group_case_nodes PARAMS ((case_node_ptr));
420 static void balance_case_nodes PARAMS ((case_node_ptr *,
422 static int node_has_low_bound PARAMS ((case_node_ptr, tree));
423 static int node_has_high_bound PARAMS ((case_node_ptr, tree));
424 static int node_is_bounded PARAMS ((case_node_ptr, tree));
425 static void emit_jump_if_reachable PARAMS ((rtx));
426 static void emit_case_nodes PARAMS ((rtx, case_node_ptr, rtx, tree));
427 static int add_case_node PARAMS ((tree, tree, tree, tree *));
428 static struct case_node *case_tree2list PARAMS ((case_node *, case_node *));
429 static void mark_cond_nesting PARAMS ((struct nesting *));
430 static void mark_loop_nesting PARAMS ((struct nesting *));
431 static void mark_block_nesting PARAMS ((struct nesting *));
432 static void mark_case_nesting PARAMS ((struct nesting *));
433 static void mark_case_node PARAMS ((struct case_node *));
434 static void mark_goto_fixup PARAMS ((struct goto_fixup *));
438 using_eh_for_cleanups ()
440 using_eh_for_cleanups_p = 1;
443 /* Mark N (known to be a cond-nesting) for GC. */
446 mark_cond_nesting (n)
451 ggc_mark_rtx (n->exit_label);
452 ggc_mark_rtx (n->data.cond.endif_label);
453 ggc_mark_rtx (n->data.cond.next_label);
459 /* Mark N (known to be a loop-nesting) for GC. */
462 mark_loop_nesting (n)
468 ggc_mark_rtx (n->exit_label);
469 ggc_mark_rtx (n->data.loop.start_label);
470 ggc_mark_rtx (n->data.loop.end_label);
471 ggc_mark_rtx (n->data.loop.alt_end_label);
472 ggc_mark_rtx (n->data.loop.continue_label);
478 /* Mark N (known to be a block-nesting) for GC. */
481 mark_block_nesting (n)
486 struct label_chain *l;
488 ggc_mark_rtx (n->exit_label);
489 ggc_mark_rtx (n->data.block.stack_level);
490 ggc_mark_rtx (n->data.block.first_insn);
491 ggc_mark_tree (n->data.block.cleanups);
492 ggc_mark_tree (n->data.block.outer_cleanups);
494 for (l = n->data.block.label_chain; l != NULL; l = l->next)
495 ggc_mark_tree (l->label);
497 ggc_mark_rtx (n->data.block.last_unconditional_cleanup);
499 /* ??? cleanup_ptr never points outside the stack, does it? */
505 /* Mark N (known to be a case-nesting) for GC. */
508 mark_case_nesting (n)
513 ggc_mark_rtx (n->exit_label);
514 ggc_mark_rtx (n->data.case_stmt.start);
516 ggc_mark_tree (n->data.case_stmt.default_label);
517 ggc_mark_tree (n->data.case_stmt.index_expr);
518 ggc_mark_tree (n->data.case_stmt.nominal_type);
520 mark_case_node (n->data.case_stmt.case_list);
533 ggc_mark_tree (c->low);
534 ggc_mark_tree (c->high);
535 ggc_mark_tree (c->code_label);
537 mark_case_node (c->right);
538 mark_case_node (c->left);
546 struct goto_fixup *g;
551 ggc_mark_rtx (g->before_jump);
552 ggc_mark_tree (g->target);
553 ggc_mark_tree (g->context);
554 ggc_mark_rtx (g->target_rtl);
555 ggc_mark_rtx (g->stack_level);
556 ggc_mark_tree (g->cleanup_list_list);
562 /* Clear out all parts of the state in F that can safely be discarded
563 after the function has been compiled, to let garbage collection
564 reclaim the memory. */
570 /* We're about to free the function obstack. If we hold pointers to
571 things allocated there, then we'll try to mark them when we do
572 GC. So, we clear them out here explicitly. */
582 struct stmt_status *p;
587 mark_block_nesting (p->x_block_stack);
588 mark_cond_nesting (p->x_cond_stack);
589 mark_loop_nesting (p->x_loop_stack);
590 mark_case_nesting (p->x_case_stack);
592 ggc_mark_tree (p->x_last_expr_type);
593 /* last_epxr_value is only valid if last_expr_type is nonzero. */
594 if (p->x_last_expr_type)
595 ggc_mark_rtx (p->x_last_expr_value);
597 mark_goto_fixup (p->x_goto_fixup_chain);
605 gcc_obstack_init (&stmt_obstack);
607 for (i = 0; i < 10; i++)
609 digit_strings[i] = ggc_alloc_string (NULL, 1);
610 digit_strings[i][0] = '0' + i;
612 ggc_add_string_root (digit_strings, 10);
616 init_stmt_for_function ()
618 cfun->stmt = (struct stmt_status *) xmalloc (sizeof (struct stmt_status));
620 /* We are not currently within any block, conditional, loop or case. */
622 stack_block_stack = 0;
629 current_block_start_count = 0;
631 /* No gotos have been expanded yet. */
632 goto_fixup_chain = 0;
634 /* We are not processing a ({...}) grouping. */
635 expr_stmts_for_value = 0;
637 last_expr_value = NULL_RTX;
640 /* Return nonzero if anything is pushed on the loop, condition, or case
645 return cond_stack || loop_stack || case_stack;
648 /* Record the current file and line. Called from emit_line_note. */
650 set_file_and_line_for_stmt (file, line)
654 /* If we're outputting an inline function, and we add a line note,
655 there may be no CFUN->STMT information. So, there's no need to
659 emit_filename = file;
664 /* Emit a no-op instruction. */
671 last_insn = get_last_insn ();
673 && (GET_CODE (last_insn) == CODE_LABEL
674 || (GET_CODE (last_insn) == NOTE
675 && prev_real_insn (last_insn) == 0)))
676 emit_insn (gen_nop ());
679 /* Return the rtx-label that corresponds to a LABEL_DECL,
680 creating it if necessary. */
686 if (TREE_CODE (label) != LABEL_DECL)
689 if (DECL_RTL (label))
690 return DECL_RTL (label);
692 return DECL_RTL (label) = gen_label_rtx ();
695 /* Add an unconditional jump to LABEL as the next sequential instruction. */
701 do_pending_stack_adjust ();
702 emit_jump_insn (gen_jump (label));
706 /* Emit code to jump to the address
707 specified by the pointer expression EXP. */
710 expand_computed_goto (exp)
713 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
715 #ifdef POINTERS_EXTEND_UNSIGNED
716 x = convert_memory_address (Pmode, x);
720 /* Be sure the function is executable. */
721 if (current_function_check_memory_usage)
722 emit_library_call (chkr_check_exec_libfunc, 1,
723 VOIDmode, 1, x, ptr_mode);
725 do_pending_stack_adjust ();
726 emit_indirect_jump (x);
728 current_function_has_computed_jump = 1;
731 /* Handle goto statements and the labels that they can go to. */
733 /* Specify the location in the RTL code of a label LABEL,
734 which is a LABEL_DECL tree node.
736 This is used for the kind of label that the user can jump to with a
737 goto statement, and for alternatives of a switch or case statement.
738 RTL labels generated for loops and conditionals don't go through here;
739 they are generated directly at the RTL level, by other functions below.
741 Note that this has nothing to do with defining label *names*.
742 Languages vary in how they do that and what that even means. */
748 struct label_chain *p;
750 do_pending_stack_adjust ();
751 emit_label (label_rtx (label));
752 if (DECL_NAME (label))
753 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
755 if (stack_block_stack != 0)
757 p = (struct label_chain *) oballoc (sizeof (struct label_chain));
758 p->next = stack_block_stack->data.block.label_chain;
759 stack_block_stack->data.block.label_chain = p;
764 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
765 from nested functions. */
768 declare_nonlocal_label (label)
771 rtx slot = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
773 nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
774 LABEL_PRESERVE_P (label_rtx (label)) = 1;
775 if (nonlocal_goto_handler_slots == 0)
777 emit_stack_save (SAVE_NONLOCAL,
778 &nonlocal_goto_stack_level,
779 PREV_INSN (tail_recursion_reentry));
781 nonlocal_goto_handler_slots
782 = gen_rtx_EXPR_LIST (VOIDmode, slot, nonlocal_goto_handler_slots);
785 /* Generate RTL code for a `goto' statement with target label LABEL.
786 LABEL should be a LABEL_DECL tree node that was or will later be
787 defined with `expand_label'. */
795 /* Check for a nonlocal goto to a containing function. */
796 context = decl_function_context (label);
797 if (context != 0 && context != current_function_decl)
799 struct function *p = find_function_data (context);
800 rtx label_ref = gen_rtx_LABEL_REF (Pmode, label_rtx (label));
801 rtx temp, handler_slot;
804 /* Find the corresponding handler slot for this label. */
805 handler_slot = p->x_nonlocal_goto_handler_slots;
806 for (link = p->x_nonlocal_labels; TREE_VALUE (link) != label;
807 link = TREE_CHAIN (link))
808 handler_slot = XEXP (handler_slot, 1);
809 handler_slot = XEXP (handler_slot, 0);
811 p->has_nonlocal_label = 1;
812 current_function_has_nonlocal_goto = 1;
813 LABEL_REF_NONLOCAL_P (label_ref) = 1;
815 /* Copy the rtl for the slots so that they won't be shared in
816 case the virtual stack vars register gets instantiated differently
817 in the parent than in the child. */
819 #if HAVE_nonlocal_goto
820 if (HAVE_nonlocal_goto)
821 emit_insn (gen_nonlocal_goto (lookup_static_chain (label),
822 copy_rtx (handler_slot),
823 copy_rtx (p->x_nonlocal_goto_stack_level),
830 /* Restore frame pointer for containing function.
831 This sets the actual hard register used for the frame pointer
832 to the location of the function's incoming static chain info.
833 The non-local goto handler will then adjust it to contain the
834 proper value and reload the argument pointer, if needed. */
835 emit_move_insn (hard_frame_pointer_rtx, lookup_static_chain (label));
837 /* We have now loaded the frame pointer hardware register with
838 the address of that corresponds to the start of the virtual
839 stack vars. So replace virtual_stack_vars_rtx in all
840 addresses we use with stack_pointer_rtx. */
842 /* Get addr of containing function's current nonlocal goto handler,
843 which will do any cleanups and then jump to the label. */
844 addr = copy_rtx (handler_slot);
845 temp = copy_to_reg (replace_rtx (addr, virtual_stack_vars_rtx,
846 hard_frame_pointer_rtx));
848 /* Restore the stack pointer. Note this uses fp just restored. */
849 addr = p->x_nonlocal_goto_stack_level;
851 addr = replace_rtx (copy_rtx (addr),
852 virtual_stack_vars_rtx,
853 hard_frame_pointer_rtx);
855 emit_stack_restore (SAVE_NONLOCAL, addr, NULL_RTX);
857 /* USE of hard_frame_pointer_rtx added for consistency; not clear if
859 emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx));
860 emit_insn (gen_rtx_USE (VOIDmode, stack_pointer_rtx));
861 emit_indirect_jump (temp);
865 expand_goto_internal (label, label_rtx (label), NULL_RTX);
868 /* Generate RTL code for a `goto' statement with target label BODY.
869 LABEL should be a LABEL_REF.
870 LAST_INSN, if non-0, is the rtx we should consider as the last
871 insn emitted (for the purposes of cleaning up a return). */
874 expand_goto_internal (body, label, last_insn)
879 struct nesting *block;
882 if (GET_CODE (label) != CODE_LABEL)
885 /* If label has already been defined, we can tell now
886 whether and how we must alter the stack level. */
888 if (PREV_INSN (label) != 0)
890 /* Find the innermost pending block that contains the label.
891 (Check containment by comparing insn-uids.)
892 Then restore the outermost stack level within that block,
893 and do cleanups of all blocks contained in it. */
894 for (block = block_stack; block; block = block->next)
896 if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
898 if (block->data.block.stack_level != 0)
899 stack_level = block->data.block.stack_level;
900 /* Execute the cleanups for blocks we are exiting. */
901 if (block->data.block.cleanups != 0)
903 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
904 do_pending_stack_adjust ();
910 /* Ensure stack adjust isn't done by emit_jump, as this
911 would clobber the stack pointer. This one should be
912 deleted as dead by flow. */
913 clear_pending_stack_adjust ();
914 do_pending_stack_adjust ();
915 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
918 if (body != 0 && DECL_TOO_LATE (body))
919 error ("jump to `%s' invalidly jumps into binding contour",
920 IDENTIFIER_POINTER (DECL_NAME (body)));
922 /* Label not yet defined: may need to put this goto
923 on the fixup list. */
924 else if (! expand_fixup (body, label, last_insn))
926 /* No fixup needed. Record that the label is the target
927 of at least one goto that has no fixup. */
929 TREE_ADDRESSABLE (body) = 1;
935 /* Generate if necessary a fixup for a goto
936 whose target label in tree structure (if any) is TREE_LABEL
937 and whose target in rtl is RTL_LABEL.
939 If LAST_INSN is nonzero, we pretend that the jump appears
940 after insn LAST_INSN instead of at the current point in the insn stream.
942 The fixup will be used later to insert insns just before the goto.
943 Those insns will restore the stack level as appropriate for the
944 target label, and will (in the case of C++) also invoke any object
945 destructors which have to be invoked when we exit the scopes which
946 are exited by the goto.
948 Value is nonzero if a fixup is made. */
951 expand_fixup (tree_label, rtl_label, last_insn)
956 struct nesting *block, *end_block;
958 /* See if we can recognize which block the label will be output in.
959 This is possible in some very common cases.
960 If we succeed, set END_BLOCK to that block.
961 Otherwise, set it to 0. */
964 && (rtl_label == cond_stack->data.cond.endif_label
965 || rtl_label == cond_stack->data.cond.next_label))
966 end_block = cond_stack;
967 /* If we are in a loop, recognize certain labels which
968 are likely targets. This reduces the number of fixups
969 we need to create. */
971 && (rtl_label == loop_stack->data.loop.start_label
972 || rtl_label == loop_stack->data.loop.end_label
973 || rtl_label == loop_stack->data.loop.continue_label))
974 end_block = loop_stack;
978 /* Now set END_BLOCK to the binding level to which we will return. */
982 struct nesting *next_block = end_block->all;
985 /* First see if the END_BLOCK is inside the innermost binding level.
986 If so, then no cleanups or stack levels are relevant. */
987 while (next_block && next_block != block)
988 next_block = next_block->all;
993 /* Otherwise, set END_BLOCK to the innermost binding level
994 which is outside the relevant control-structure nesting. */
995 next_block = block_stack->next;
996 for (block = block_stack; block != end_block; block = block->all)
997 if (block == next_block)
998 next_block = next_block->next;
999 end_block = next_block;
1002 /* Does any containing block have a stack level or cleanups?
1003 If not, no fixup is needed, and that is the normal case
1004 (the only case, for standard C). */
1005 for (block = block_stack; block != end_block; block = block->next)
1006 if (block->data.block.stack_level != 0
1007 || block->data.block.cleanups != 0)
1010 if (block != end_block)
1012 /* Ok, a fixup is needed. Add a fixup to the list of such. */
1013 struct goto_fixup *fixup
1014 = (struct goto_fixup *) ggc_alloc_obj (sizeof (struct goto_fixup), 0);
1015 /* In case an old stack level is restored, make sure that comes
1016 after any pending stack adjust. */
1017 /* ?? If the fixup isn't to come at the present position,
1018 doing the stack adjust here isn't useful. Doing it with our
1019 settings at that location isn't useful either. Let's hope
1022 do_pending_stack_adjust ();
1023 fixup->target = tree_label;
1024 fixup->target_rtl = rtl_label;
1026 /* Create a BLOCK node and a corresponding matched set of
1027 NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes at
1028 this point. The notes will encapsulate any and all fixup
1029 code which we might later insert at this point in the insn
1030 stream. Also, the BLOCK node will be the parent (i.e. the
1031 `SUPERBLOCK') of any other BLOCK nodes which we might create
1032 later on when we are expanding the fixup code.
1034 Note that optimization passes (including expand_end_loop)
1035 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
1036 as a placeholder. */
1039 register rtx original_before_jump
1040 = last_insn ? last_insn : get_last_insn ();
1045 block = make_node (BLOCK);
1046 TREE_USED (block) = 1;
1048 if (!cfun->x_whole_function_mode_p)
1049 insert_block (block);
1053 = BLOCK_CHAIN (DECL_INITIAL (current_function_decl));
1054 BLOCK_CHAIN (DECL_INITIAL (current_function_decl))
1059 start = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
1060 if (cfun->x_whole_function_mode_p)
1061 NOTE_BLOCK (start) = block;
1062 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_DELETED);
1063 end = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
1064 if (cfun->x_whole_function_mode_p)
1065 NOTE_BLOCK (end) = block;
1066 fixup->context = block;
1068 emit_insns_after (start, original_before_jump);
1071 fixup->block_start_count = current_block_start_count;
1072 fixup->stack_level = 0;
1073 fixup->cleanup_list_list
1074 = ((block->data.block.outer_cleanups
1075 || block->data.block.cleanups)
1076 ? tree_cons (NULL_TREE, block->data.block.cleanups,
1077 block->data.block.outer_cleanups)
1079 fixup->next = goto_fixup_chain;
1080 goto_fixup_chain = fixup;
1088 /* Expand any needed fixups in the outputmost binding level of the
1089 function. FIRST_INSN is the first insn in the function. */
1092 expand_fixups (first_insn)
1095 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0);
1098 /* When exiting a binding contour, process all pending gotos requiring fixups.
1099 THISBLOCK is the structure that describes the block being exited.
1100 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1101 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1102 FIRST_INSN is the insn that began this contour.
1104 Gotos that jump out of this contour must restore the
1105 stack level and do the cleanups before actually jumping.
1107 DONT_JUMP_IN nonzero means report error there is a jump into this
1108 contour from before the beginning of the contour.
1109 This is also done if STACK_LEVEL is nonzero. */
1112 fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1113 struct nesting *thisblock;
1119 register struct goto_fixup *f, *prev;
1121 /* F is the fixup we are considering; PREV is the previous one. */
1122 /* We run this loop in two passes so that cleanups of exited blocks
1123 are run first, and blocks that are exited are marked so
1126 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1128 /* Test for a fixup that is inactive because it is already handled. */
1129 if (f->before_jump == 0)
1131 /* Delete inactive fixup from the chain, if that is easy to do. */
1133 prev->next = f->next;
1135 /* Has this fixup's target label been defined?
1136 If so, we can finalize it. */
1137 else if (PREV_INSN (f->target_rtl) != 0)
1139 register rtx cleanup_insns;
1141 /* If this fixup jumped into this contour from before the beginning
1142 of this contour, report an error. This code used to use
1143 the first non-label insn after f->target_rtl, but that's
1144 wrong since such can be added, by things like put_var_into_stack
1145 and have INSN_UIDs that are out of the range of the block. */
1146 /* ??? Bug: this does not detect jumping in through intermediate
1147 blocks that have stack levels or cleanups.
1148 It detects only a problem with the innermost block
1149 around the label. */
1151 && (dont_jump_in || stack_level || cleanup_list)
1152 && INSN_UID (first_insn) < INSN_UID (f->target_rtl)
1153 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1154 && ! DECL_ERROR_ISSUED (f->target))
1156 error_with_decl (f->target,
1157 "label `%s' used before containing binding contour");
1158 /* Prevent multiple errors for one label. */
1159 DECL_ERROR_ISSUED (f->target) = 1;
1162 /* We will expand the cleanups into a sequence of their own and
1163 then later on we will attach this new sequence to the insn
1164 stream just ahead of the actual jump insn. */
1168 /* Temporarily restore the lexical context where we will
1169 logically be inserting the fixup code. We do this for the
1170 sake of getting the debugging information right. */
1173 set_block (f->context);
1175 /* Expand the cleanups for blocks this jump exits. */
1176 if (f->cleanup_list_list)
1179 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1180 /* Marked elements correspond to blocks that have been closed.
1181 Do their cleanups. */
1182 if (TREE_ADDRESSABLE (lists)
1183 && TREE_VALUE (lists) != 0)
1185 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1186 /* Pop any pushes done in the cleanups,
1187 in case function is about to return. */
1188 do_pending_stack_adjust ();
1192 /* Restore stack level for the biggest contour that this
1193 jump jumps out of. */
1195 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1197 /* Finish up the sequence containing the insns which implement the
1198 necessary cleanups, and then attach that whole sequence to the
1199 insn stream just ahead of the actual jump insn. Attaching it
1200 at that point insures that any cleanups which are in fact
1201 implicit C++ object destructions (which must be executed upon
1202 leaving the block) appear (to the debugger) to be taking place
1203 in an area of the generated code where the object(s) being
1204 destructed are still "in scope". */
1206 cleanup_insns = get_insns ();
1210 emit_insns_after (cleanup_insns, f->before_jump);
1217 /* For any still-undefined labels, do the cleanups for this block now.
1218 We must do this now since items in the cleanup list may go out
1219 of scope when the block ends. */
1220 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1221 if (f->before_jump != 0
1222 && PREV_INSN (f->target_rtl) == 0
1223 /* Label has still not appeared. If we are exiting a block with
1224 a stack level to restore, that started before the fixup,
1225 mark this stack level as needing restoration
1226 when the fixup is later finalized. */
1228 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1229 means the label is undefined. That's erroneous, but possible. */
1230 && (thisblock->data.block.block_start_count
1231 <= f->block_start_count))
1233 tree lists = f->cleanup_list_list;
1236 for (; lists; lists = TREE_CHAIN (lists))
1237 /* If the following elt. corresponds to our containing block
1238 then the elt. must be for this block. */
1239 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
1243 set_block (f->context);
1244 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1245 do_pending_stack_adjust ();
1246 cleanup_insns = get_insns ();
1249 if (cleanup_insns != 0)
1251 = emit_insns_after (cleanup_insns, f->before_jump);
1253 f->cleanup_list_list = TREE_CHAIN (lists);
1257 f->stack_level = stack_level;
1261 /* Return the number of times character C occurs in string S. */
1263 n_occurrences (c, s)
1273 /* Generate RTL for an asm statement (explicit assembler code).
1274 BODY is a STRING_CST node containing the assembler code text,
1275 or an ADDR_EXPR containing a STRING_CST. */
1281 if (current_function_check_memory_usage)
1283 error ("`asm' cannot be used in function where memory usage is checked");
1287 if (TREE_CODE (body) == ADDR_EXPR)
1288 body = TREE_OPERAND (body, 0);
1290 emit_insn (gen_rtx_ASM_INPUT (VOIDmode,
1291 TREE_STRING_POINTER (body)));
1295 /* Generate RTL for an asm statement with arguments.
1296 STRING is the instruction template.
1297 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1298 Each output or input has an expression in the TREE_VALUE and
1299 a constraint-string in the TREE_PURPOSE.
1300 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1301 that is clobbered by this insn.
1303 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1304 Some elements of OUTPUTS may be replaced with trees representing temporary
1305 values. The caller should copy those temporary values to the originally
1308 VOL nonzero means the insn is volatile; don't optimize it. */
1311 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1312 tree string, outputs, inputs, clobbers;
1317 rtvec argvec, constraints;
1319 int ninputs = list_length (inputs);
1320 int noutputs = list_length (outputs);
1325 /* Vector of RTX's of evaluated output operands. */
1326 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1327 int *inout_opnum = (int *) alloca (noutputs * sizeof (int));
1328 rtx *real_output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1329 enum machine_mode *inout_mode
1330 = (enum machine_mode *) alloca (noutputs * sizeof (enum machine_mode));
1331 /* The insn we have emitted. */
1334 /* An ASM with no outputs needs to be treated as volatile, for now. */
1338 if (current_function_check_memory_usage)
1340 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1344 #ifdef MD_ASM_CLOBBERS
1345 /* Sometimes we wish to automatically clobber registers across an asm.
1346 Case in point is when the i386 backend moved from cc0 to a hard reg --
1347 maintaining source-level compatability means automatically clobbering
1348 the flags register. */
1349 MD_ASM_CLOBBERS (clobbers);
1352 if (current_function_check_memory_usage)
1354 error ("`asm' cannot be used in function where memory usage is checked");
1358 /* Count the number of meaningful clobbered registers, ignoring what
1359 we would ignore later. */
1361 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1363 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1365 i = decode_reg_name (regname);
1366 if (i >= 0 || i == -4)
1369 error ("unknown register name `%s' in `asm'", regname);
1374 /* Check that the number of alternatives is constant across all
1376 if (outputs || inputs)
1378 tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
1379 int nalternatives = n_occurrences (',', TREE_STRING_POINTER (tmp));
1382 if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
1384 error ("too many alternatives in `asm'");
1391 const char *constraint = TREE_STRING_POINTER (TREE_PURPOSE (tmp));
1393 if (n_occurrences (',', constraint) != nalternatives)
1395 error ("operand constraints for `asm' differ in number of alternatives");
1399 if (TREE_CHAIN (tmp))
1400 tmp = TREE_CHAIN (tmp);
1402 tmp = next, next = 0;
1406 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1408 tree val = TREE_VALUE (tail);
1409 tree type = TREE_TYPE (val);
1418 /* If there's an erroneous arg, emit no insn. */
1419 if (TREE_TYPE (val) == error_mark_node)
1422 /* Make sure constraint has `=' and does not have `+'. Also, see
1423 if it allows any register. Be liberal on the latter test, since
1424 the worst that happens if we get it wrong is we issue an error
1427 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1428 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1430 /* Allow the `=' or `+' to not be at the beginning of the string,
1431 since it wasn't explicitly documented that way, and there is a
1432 large body of code that puts it last. Swap the character to
1433 the front, so as not to uglify any place else. */
1437 if ((p = strchr (constraint, '=')) != NULL)
1439 if ((p = strchr (constraint, '+')) != NULL)
1442 error ("output operand constraint lacks `='");
1446 if (p != constraint)
1449 bcopy (constraint, constraint+1, p-constraint);
1452 warning ("output constraint `%c' for operand %d is not at the beginning", j, i);
1455 is_inout = constraint[0] == '+';
1456 /* Replace '+' with '='. */
1457 constraint[0] = '=';
1458 /* Make sure we can specify the matching operand. */
1459 if (is_inout && i > 9)
1461 error ("output operand constraint %d contains `+'", i);
1465 for (j = 1; j < c_len; j++)
1466 switch (constraint[j])
1470 error ("operand constraint contains '+' or '=' at illegal position.");
1474 if (i + 1 == ninputs + noutputs)
1476 error ("`%%' constraint used with last operand");
1481 case '?': case '!': case '*': case '&':
1482 case 'E': case 'F': case 'G': case 'H':
1483 case 's': case 'i': case 'n':
1484 case 'I': case 'J': case 'K': case 'L': case 'M':
1485 case 'N': case 'O': case 'P': case ',':
1486 #ifdef EXTRA_CONSTRAINT
1487 case 'Q': case 'R': case 'S': case 'T': case 'U':
1491 case '0': case '1': case '2': case '3': case '4':
1492 case '5': case '6': case '7': case '8': case '9':
1493 error ("matching constraint not valid in output operand");
1496 case 'V': case 'm': case 'o':
1501 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1502 excepting those that expand_call created. So match memory
1518 /* If an output operand is not a decl or indirect ref and our constraint
1519 allows a register, make a temporary to act as an intermediate.
1520 Make the asm insn write into that, then our caller will copy it to
1521 the real output operand. Likewise for promoted variables. */
1523 real_output_rtx[i] = NULL_RTX;
1524 if ((TREE_CODE (val) == INDIRECT_REF
1527 && (allows_mem || GET_CODE (DECL_RTL (val)) == REG)
1528 && ! (GET_CODE (DECL_RTL (val)) == REG
1529 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
1534 mark_addressable (TREE_VALUE (tail));
1537 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode,
1538 EXPAND_MEMORY_USE_WO);
1540 if (! allows_reg && GET_CODE (output_rtx[i]) != MEM)
1541 error ("output number %d not directly addressable", i);
1542 if (! allows_mem && GET_CODE (output_rtx[i]) == MEM)
1544 real_output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1545 output_rtx[i] = gen_reg_rtx (GET_MODE (output_rtx[i]));
1547 emit_move_insn (output_rtx[i], real_output_rtx[i]);
1552 output_rtx[i] = assign_temp (type, 0, 0, 1);
1553 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1558 inout_mode[ninout] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)));
1559 inout_opnum[ninout++] = i;
1564 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1566 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1570 /* Make vectors for the expression-rtx and constraint strings. */
1572 argvec = rtvec_alloc (ninputs);
1573 constraints = rtvec_alloc (ninputs);
1575 body = gen_rtx_ASM_OPERANDS (VOIDmode, TREE_STRING_POINTER (string),
1576 empty_string, 0, argvec, constraints,
1579 MEM_VOLATILE_P (body) = vol;
1581 /* Eval the inputs and put them into ARGVEC.
1582 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1585 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1588 int allows_reg = 0, allows_mem = 0;
1589 char *constraint, *orig_constraint;
1593 /* If there's an erroneous arg, emit no insn,
1594 because the ASM_INPUT would get VOIDmode
1595 and that could cause a crash in reload. */
1596 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1599 /* ??? Can this happen, and does the error message make any sense? */
1600 if (TREE_PURPOSE (tail) == NULL_TREE)
1602 error ("hard register `%s' listed as input operand to `asm'",
1603 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1607 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1608 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1609 orig_constraint = constraint;
1611 /* Make sure constraint has neither `=', `+', nor '&'. */
1613 for (j = 0; j < c_len; j++)
1614 switch (constraint[j])
1616 case '+': case '=': case '&':
1617 if (constraint == orig_constraint)
1619 error ("input operand constraint contains `%c'",
1626 if (constraint == orig_constraint
1627 && i + 1 == ninputs - ninout)
1629 error ("`%%' constraint used with last operand");
1634 case 'V': case 'm': case 'o':
1639 case '?': case '!': case '*':
1640 case 'E': case 'F': case 'G': case 'H': case 'X':
1641 case 's': case 'i': case 'n':
1642 case 'I': case 'J': case 'K': case 'L': case 'M':
1643 case 'N': case 'O': case 'P': case ',':
1644 #ifdef EXTRA_CONSTRAINT
1645 case 'Q': case 'R': case 'S': case 'T': case 'U':
1649 /* Whether or not a numeric constraint allows a register is
1650 decided by the matching constraint, and so there is no need
1651 to do anything special with them. We must handle them in
1652 the default case, so that we don't unnecessarily force
1653 operands to memory. */
1654 case '0': case '1': case '2': case '3': case '4':
1655 case '5': case '6': case '7': case '8': case '9':
1656 if (constraint[j] >= '0' + noutputs)
1659 ("matching constraint references invalid operand number");
1663 /* Try and find the real constraint for this dup. */
1664 if ((j == 0 && c_len == 1)
1665 || (j == 1 && c_len == 2 && constraint[0] == '%'))
1669 for (j = constraint[j] - '0'; j > 0; --j)
1672 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (o)));
1673 constraint = TREE_STRING_POINTER (TREE_PURPOSE (o));
1678 /* ... fall through ... */
1691 if (! allows_reg && allows_mem)
1692 mark_addressable (TREE_VALUE (tail));
1694 op = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1696 if (asm_operand_ok (op, constraint) <= 0)
1699 op = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), op);
1700 else if (!allows_mem)
1701 warning ("asm operand %d probably doesn't match constraints", i);
1702 else if (CONSTANT_P (op))
1703 op = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1705 else if (GET_CODE (op) == REG
1706 || GET_CODE (op) == SUBREG
1707 || GET_CODE (op) == CONCAT)
1709 tree type = TREE_TYPE (TREE_VALUE (tail));
1710 rtx memloc = assign_temp (type, 1, 1, 1);
1712 emit_move_insn (memloc, op);
1716 else if (GET_CODE (op) == MEM && MEM_VOLATILE_P (op))
1717 /* We won't recognize volatile memory as available a
1718 memory_operand at this point. Ignore it. */
1720 else if (queued_subexp_p (op))
1723 /* ??? Leave this only until we have experience with what
1724 happens in combine and elsewhere when constraints are
1726 warning ("asm operand %d probably doesn't match constraints", i);
1728 XVECEXP (body, 3, i) = op;
1730 XVECEXP (body, 4, i) /* constraints */
1731 = gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1736 /* Protect all the operands from the queue now that they have all been
1739 for (i = 0; i < ninputs - ninout; i++)
1740 XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0);
1742 for (i = 0; i < noutputs; i++)
1743 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1745 /* For in-out operands, copy output rtx to input rtx. */
1746 for (i = 0; i < ninout; i++)
1748 int j = inout_opnum[i];
1750 XVECEXP (body, 3, ninputs - ninout + i) /* argvec */
1752 XVECEXP (body, 4, ninputs - ninout + i) /* constraints */
1753 = gen_rtx_ASM_INPUT (inout_mode[i], digit_strings[j]);
1756 /* Now, for each output, construct an rtx
1757 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1758 ARGVEC CONSTRAINTS))
1759 If there is more than one, put them inside a PARALLEL. */
1761 if (noutputs == 1 && nclobbers == 0)
1763 XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1764 insn = emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
1767 else if (noutputs == 0 && nclobbers == 0)
1769 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1770 insn = emit_insn (body);
1781 body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
1783 /* For each output operand, store a SET. */
1784 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1786 XVECEXP (body, 0, i)
1787 = gen_rtx_SET (VOIDmode,
1789 gen_rtx_ASM_OPERANDS
1791 TREE_STRING_POINTER (string),
1792 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1793 i, argvec, constraints,
1796 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1799 /* If there are no outputs (but there are some clobbers)
1800 store the bare ASM_OPERANDS into the PARALLEL. */
1803 XVECEXP (body, 0, i++) = obody;
1805 /* Store (clobber REG) for each clobbered register specified. */
1807 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1809 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1810 int j = decode_reg_name (regname);
1814 if (j == -3) /* `cc', which is not a register */
1817 if (j == -4) /* `memory', don't cache memory across asm */
1819 XVECEXP (body, 0, i++)
1820 = gen_rtx_CLOBBER (VOIDmode,
1823 gen_rtx_SCRATCH (VOIDmode)));
1827 /* Ignore unknown register, error already signaled. */
1831 /* Use QImode since that's guaranteed to clobber just one reg. */
1832 XVECEXP (body, 0, i++)
1833 = gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (QImode, j));
1836 insn = emit_insn (body);
1839 /* For any outputs that needed reloading into registers, spill them
1840 back to where they belong. */
1841 for (i = 0; i < noutputs; ++i)
1842 if (real_output_rtx[i])
1843 emit_move_insn (real_output_rtx[i], output_rtx[i]);
1848 /* Generate RTL to evaluate the expression EXP
1849 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1852 expand_expr_stmt (exp)
1855 /* If -W, warn about statements with no side effects,
1856 except for an explicit cast to void (e.g. for assert()), and
1857 except inside a ({...}) where they may be useful. */
1858 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1860 if (! TREE_SIDE_EFFECTS (exp) && (extra_warnings || warn_unused)
1861 && !(TREE_CODE (exp) == CONVERT_EXPR
1862 && TREE_TYPE (exp) == void_type_node))
1863 warning_with_file_and_line (emit_filename, emit_lineno,
1864 "statement with no effect");
1865 else if (warn_unused)
1866 warn_if_unused_value (exp);
1869 /* If EXP is of function type and we are expanding statements for
1870 value, convert it to pointer-to-function. */
1871 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1872 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1874 last_expr_type = TREE_TYPE (exp);
1875 last_expr_value = expand_expr (exp,
1876 (expr_stmts_for_value
1877 ? NULL_RTX : const0_rtx),
1880 /* If all we do is reference a volatile value in memory,
1881 copy it to a register to be sure it is actually touched. */
1882 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1883 && TREE_THIS_VOLATILE (exp))
1885 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1887 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1888 copy_to_reg (last_expr_value);
1891 rtx lab = gen_label_rtx ();
1893 /* Compare the value with itself to reference it. */
1894 emit_cmp_and_jump_insns (last_expr_value, last_expr_value, EQ,
1895 expand_expr (TYPE_SIZE (last_expr_type),
1896 NULL_RTX, VOIDmode, 0),
1898 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT,
1904 /* If this expression is part of a ({...}) and is in memory, we may have
1905 to preserve temporaries. */
1906 preserve_temp_slots (last_expr_value);
1908 /* Free any temporaries used to evaluate this expression. Any temporary
1909 used as a result of this expression will already have been preserved
1916 /* Warn if EXP contains any computations whose results are not used.
1917 Return 1 if a warning is printed; 0 otherwise. */
1920 warn_if_unused_value (exp)
1923 if (TREE_USED (exp))
1926 switch (TREE_CODE (exp))
1928 case PREINCREMENT_EXPR:
1929 case POSTINCREMENT_EXPR:
1930 case PREDECREMENT_EXPR:
1931 case POSTDECREMENT_EXPR:
1936 case METHOD_CALL_EXPR:
1938 case TRY_CATCH_EXPR:
1939 case WITH_CLEANUP_EXPR:
1941 /* We don't warn about COND_EXPR because it may be a useful
1942 construct if either arm contains a side effect. */
1947 /* For a binding, warn if no side effect within it. */
1948 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1951 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1953 case TRUTH_ORIF_EXPR:
1954 case TRUTH_ANDIF_EXPR:
1955 /* In && or ||, warn if 2nd operand has no side effect. */
1956 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1959 if (TREE_NO_UNUSED_WARNING (exp))
1961 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
1963 /* Let people do `(foo (), 0)' without a warning. */
1964 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1966 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1970 case NON_LVALUE_EXPR:
1971 /* Don't warn about values cast to void. */
1972 if (TREE_TYPE (exp) == void_type_node)
1974 /* Don't warn about conversions not explicit in the user's program. */
1975 if (TREE_NO_UNUSED_WARNING (exp))
1977 /* Assignment to a cast usually results in a cast of a modify.
1978 Don't complain about that. There can be an arbitrary number of
1979 casts before the modify, so we must loop until we find the first
1980 non-cast expression and then test to see if that is a modify. */
1982 tree tem = TREE_OPERAND (exp, 0);
1984 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1985 tem = TREE_OPERAND (tem, 0);
1987 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
1988 || TREE_CODE (tem) == CALL_EXPR)
1994 /* Don't warn about automatic dereferencing of references, since
1995 the user cannot control it. */
1996 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
1997 return warn_if_unused_value (TREE_OPERAND (exp, 0));
1998 /* ... fall through ... */
2001 /* Referencing a volatile value is a side effect, so don't warn. */
2003 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
2004 && TREE_THIS_VOLATILE (exp))
2007 warning_with_file_and_line (emit_filename, emit_lineno,
2008 "value computed is not used");
2013 /* Clear out the memory of the last expression evaluated. */
2021 /* Begin a statement which will return a value.
2022 Return the RTL_EXPR for this statement expr.
2023 The caller must save that value and pass it to expand_end_stmt_expr. */
2026 expand_start_stmt_expr ()
2031 /* Make the RTL_EXPR node temporary, not momentary,
2032 so that rtl_expr_chain doesn't become garbage. */
2033 momentary = suspend_momentary ();
2034 t = make_node (RTL_EXPR);
2035 resume_momentary (momentary);
2036 do_pending_stack_adjust ();
2037 start_sequence_for_rtl_expr (t);
2039 expr_stmts_for_value++;
2043 /* Restore the previous state at the end of a statement that returns a value.
2044 Returns a tree node representing the statement's value and the
2045 insns to compute the value.
2047 The nodes of that expression have been freed by now, so we cannot use them.
2048 But we don't want to do that anyway; the expression has already been
2049 evaluated and now we just want to use the value. So generate a RTL_EXPR
2050 with the proper type and RTL value.
2052 If the last substatement was not an expression,
2053 return something with type `void'. */
2056 expand_end_stmt_expr (t)
2061 if (last_expr_type == 0)
2063 last_expr_type = void_type_node;
2064 last_expr_value = const0_rtx;
2066 else if (last_expr_value == 0)
2067 /* There are some cases where this can happen, such as when the
2068 statement is void type. */
2069 last_expr_value = const0_rtx;
2070 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
2071 /* Remove any possible QUEUED. */
2072 last_expr_value = protect_from_queue (last_expr_value, 0);
2076 TREE_TYPE (t) = last_expr_type;
2077 RTL_EXPR_RTL (t) = last_expr_value;
2078 RTL_EXPR_SEQUENCE (t) = get_insns ();
2080 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
2084 /* Don't consider deleting this expr or containing exprs at tree level. */
2085 TREE_SIDE_EFFECTS (t) = 1;
2086 /* Propagate volatility of the actual RTL expr. */
2087 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
2090 expr_stmts_for_value--;
2095 /* Generate RTL for the start of an if-then. COND is the expression
2096 whose truth should be tested.
2098 If EXITFLAG is nonzero, this conditional is visible to
2099 `exit_something'. */
2102 expand_start_cond (cond, exitflag)
2106 struct nesting *thiscond = ALLOC_NESTING ();
2108 /* Make an entry on cond_stack for the cond we are entering. */
2110 thiscond->next = cond_stack;
2111 thiscond->all = nesting_stack;
2112 thiscond->depth = ++nesting_depth;
2113 thiscond->data.cond.next_label = gen_label_rtx ();
2114 /* Before we encounter an `else', we don't need a separate exit label
2115 unless there are supposed to be exit statements
2116 to exit this conditional. */
2117 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
2118 thiscond->data.cond.endif_label = thiscond->exit_label;
2119 cond_stack = thiscond;
2120 nesting_stack = thiscond;
2122 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
2125 /* Generate RTL between then-clause and the elseif-clause
2126 of an if-then-elseif-.... */
2129 expand_start_elseif (cond)
2132 if (cond_stack->data.cond.endif_label == 0)
2133 cond_stack->data.cond.endif_label = gen_label_rtx ();
2134 emit_jump (cond_stack->data.cond.endif_label);
2135 emit_label (cond_stack->data.cond.next_label);
2136 cond_stack->data.cond.next_label = gen_label_rtx ();
2137 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2140 /* Generate RTL between the then-clause and the else-clause
2141 of an if-then-else. */
2144 expand_start_else ()
2146 if (cond_stack->data.cond.endif_label == 0)
2147 cond_stack->data.cond.endif_label = gen_label_rtx ();
2149 emit_jump (cond_stack->data.cond.endif_label);
2150 emit_label (cond_stack->data.cond.next_label);
2151 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
2154 /* After calling expand_start_else, turn this "else" into an "else if"
2155 by providing another condition. */
2158 expand_elseif (cond)
2161 cond_stack->data.cond.next_label = gen_label_rtx ();
2162 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2165 /* Generate RTL for the end of an if-then.
2166 Pop the record for it off of cond_stack. */
2171 struct nesting *thiscond = cond_stack;
2173 do_pending_stack_adjust ();
2174 if (thiscond->data.cond.next_label)
2175 emit_label (thiscond->data.cond.next_label);
2176 if (thiscond->data.cond.endif_label)
2177 emit_label (thiscond->data.cond.endif_label);
2179 POPSTACK (cond_stack);
2185 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2186 loop should be exited by `exit_something'. This is a loop for which
2187 `expand_continue' will jump to the top of the loop.
2189 Make an entry on loop_stack to record the labels associated with
2193 expand_start_loop (exit_flag)
2196 register struct nesting *thisloop = ALLOC_NESTING ();
2198 /* Make an entry on loop_stack for the loop we are entering. */
2200 thisloop->next = loop_stack;
2201 thisloop->all = nesting_stack;
2202 thisloop->depth = ++nesting_depth;
2203 thisloop->data.loop.start_label = gen_label_rtx ();
2204 thisloop->data.loop.end_label = gen_label_rtx ();
2205 thisloop->data.loop.alt_end_label = 0;
2206 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2207 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2208 loop_stack = thisloop;
2209 nesting_stack = thisloop;
2211 do_pending_stack_adjust ();
2213 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2214 emit_label (thisloop->data.loop.start_label);
2219 /* Like expand_start_loop but for a loop where the continuation point
2220 (for expand_continue_loop) will be specified explicitly. */
2223 expand_start_loop_continue_elsewhere (exit_flag)
2226 struct nesting *thisloop = expand_start_loop (exit_flag);
2227 loop_stack->data.loop.continue_label = gen_label_rtx ();
2231 /* Specify the continuation point for a loop started with
2232 expand_start_loop_continue_elsewhere.
2233 Use this at the point in the code to which a continue statement
2237 expand_loop_continue_here ()
2239 do_pending_stack_adjust ();
2240 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2241 emit_label (loop_stack->data.loop.continue_label);
2244 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2245 Pop the block off of loop_stack. */
2250 rtx start_label = loop_stack->data.loop.start_label;
2251 rtx insn = get_last_insn ();
2252 int needs_end_jump = 1;
2254 /* Mark the continue-point at the top of the loop if none elsewhere. */
2255 if (start_label == loop_stack->data.loop.continue_label)
2256 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2258 do_pending_stack_adjust ();
2260 /* If optimizing, perhaps reorder the loop.
2261 First, try to use a condjump near the end.
2262 expand_exit_loop_if_false ends loops with unconditional jumps,
2265 if (test) goto label;
2267 goto loop_stack->data.loop.end_label
2271 If we find such a pattern, we can end the loop earlier. */
2274 && GET_CODE (insn) == CODE_LABEL
2275 && LABEL_NAME (insn) == NULL
2276 && GET_CODE (PREV_INSN (insn)) == BARRIER)
2279 rtx jump = PREV_INSN (PREV_INSN (label));
2281 if (GET_CODE (jump) == JUMP_INSN
2282 && GET_CODE (PATTERN (jump)) == SET
2283 && SET_DEST (PATTERN (jump)) == pc_rtx
2284 && GET_CODE (SET_SRC (PATTERN (jump))) == LABEL_REF
2285 && (XEXP (SET_SRC (PATTERN (jump)), 0)
2286 == loop_stack->data.loop.end_label))
2290 /* The test might be complex and reference LABEL multiple times,
2291 like the loop in loop_iterations to set vtop. To handle this,
2293 insn = PREV_INSN (label);
2294 reorder_insns (label, label, start_label);
2296 for (prev = PREV_INSN (jump); ; prev = PREV_INSN (prev))
2298 /* We ignore line number notes, but if we see any other note,
2299 in particular NOTE_INSN_BLOCK_*, NOTE_INSN_EH_REGION_*,
2300 NOTE_INSN_LOOP_*, we disable this optimization. */
2301 if (GET_CODE (prev) == NOTE)
2303 if (NOTE_LINE_NUMBER (prev) < 0)
2307 if (GET_CODE (prev) == CODE_LABEL)
2309 if (GET_CODE (prev) == JUMP_INSN)
2311 if (GET_CODE (PATTERN (prev)) == SET
2312 && SET_DEST (PATTERN (prev)) == pc_rtx
2313 && GET_CODE (SET_SRC (PATTERN (prev))) == IF_THEN_ELSE
2314 && (GET_CODE (XEXP (SET_SRC (PATTERN (prev)), 1))
2316 && XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0) == label)
2318 XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0)
2320 emit_note_after (NOTE_INSN_LOOP_END, prev);
2329 /* If the loop starts with a loop exit, roll that to the end where
2330 it will optimize together with the jump back.
2332 We look for the conditional branch to the exit, except that once
2333 we find such a branch, we don't look past 30 instructions.
2335 In more detail, if the loop presently looks like this (in pseudo-C):
2338 if (test) goto end_label;
2343 transform it to look like:
2349 if (test) goto end_label;
2350 goto newstart_label;
2353 Here, the `test' may actually consist of some reasonably complex
2354 code, terminating in a test. */
2359 ! (GET_CODE (insn) == JUMP_INSN
2360 && GET_CODE (PATTERN (insn)) == SET
2361 && SET_DEST (PATTERN (insn)) == pc_rtx
2362 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2366 rtx last_test_insn = NULL_RTX;
2368 /* Scan insns from the top of the loop looking for a qualified
2369 conditional exit. */
2370 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2371 insn = NEXT_INSN (insn))
2373 if (GET_CODE (insn) == NOTE)
2376 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2377 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2378 /* The code that actually moves the exit test will
2379 carefully leave BLOCK notes in their original
2380 location. That means, however, that we can't debug
2381 the exit test itself. So, we refuse to move code
2382 containing BLOCK notes at low optimization levels. */
2385 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG)
2387 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)
2391 /* We've come to the end of an EH region, but
2392 never saw the beginning of that region. That
2393 means that an EH region begins before the top
2394 of the loop, and ends in the middle of it. The
2395 existence of such a situation violates a basic
2396 assumption in this code, since that would imply
2397 that even when EH_REGIONS is zero, we might
2398 move code out of an exception region. */
2402 /* We must not walk into a nested loop. */
2403 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
2406 /* We already know this INSN is a NOTE, so there's no
2407 point in looking at it to see if it's a JUMP. */
2411 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2414 if (last_test_insn && num_insns > 30)
2418 /* We don't want to move a partial EH region. Consider:
2432 This isn't legal C++, but here's what it's supposed to
2433 mean: if cond() is true, stop looping. Otherwise,
2434 call bar, and keep looping. In addition, if cond
2435 throws an exception, catch it and keep looping. Such
2436 constructs are certainy legal in LISP.
2438 We should not move the `if (cond()) 0' test since then
2439 the EH-region for the try-block would be broken up.
2440 (In this case we would the EH_BEG note for the `try'
2441 and `if cond()' but not the call to bar() or the
2444 So we don't look for tests within an EH region. */
2447 if (GET_CODE (insn) == JUMP_INSN
2448 && GET_CODE (PATTERN (insn)) == SET
2449 && SET_DEST (PATTERN (insn)) == pc_rtx)
2451 /* This is indeed a jump. */
2452 rtx dest1 = NULL_RTX;
2453 rtx dest2 = NULL_RTX;
2454 rtx potential_last_test;
2455 if (GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE)
2457 /* A conditional jump. */
2458 dest1 = XEXP (SET_SRC (PATTERN (insn)), 1);
2459 dest2 = XEXP (SET_SRC (PATTERN (insn)), 2);
2460 potential_last_test = insn;
2464 /* An unconditional jump. */
2465 dest1 = SET_SRC (PATTERN (insn));
2466 /* Include the BARRIER after the JUMP. */
2467 potential_last_test = NEXT_INSN (insn);
2471 if (dest1 && GET_CODE (dest1) == LABEL_REF
2472 && ((XEXP (dest1, 0)
2473 == loop_stack->data.loop.alt_end_label)
2475 == loop_stack->data.loop.end_label)))
2477 last_test_insn = potential_last_test;
2481 /* If this was a conditional jump, there may be
2482 another label at which we should look. */
2489 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2491 /* We found one. Move everything from there up
2492 to the end of the loop, and add a jump into the loop
2493 to jump to there. */
2494 register rtx newstart_label = gen_label_rtx ();
2495 register rtx start_move = start_label;
2498 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2499 then we want to move this note also. */
2500 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2501 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2502 == NOTE_INSN_LOOP_CONT))
2503 start_move = PREV_INSN (start_move);
2505 emit_label_after (newstart_label, PREV_INSN (start_move));
2507 /* Actually move the insns. Start at the beginning, and
2508 keep copying insns until we've copied the
2510 for (insn = start_move; insn; insn = next_insn)
2512 /* Figure out which insn comes after this one. We have
2513 to do this before we move INSN. */
2514 if (insn == last_test_insn)
2515 /* We've moved all the insns. */
2516 next_insn = NULL_RTX;
2518 next_insn = NEXT_INSN (insn);
2520 if (GET_CODE (insn) == NOTE
2521 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2522 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2523 /* We don't want to move NOTE_INSN_BLOCK_BEGs or
2524 NOTE_INSN_BLOCK_ENDs because the correct generation
2525 of debugging information depends on these appearing
2526 in the same order in the RTL and in the tree
2527 structure, where they are represented as BLOCKs.
2528 So, we don't move block notes. Of course, moving
2529 the code inside the block is likely to make it
2530 impossible to debug the instructions in the exit
2531 test, but such is the price of optimization. */
2534 /* Move the INSN. */
2535 reorder_insns (insn, insn, get_last_insn ());
2538 emit_jump_insn_after (gen_jump (start_label),
2539 PREV_INSN (newstart_label));
2540 emit_barrier_after (PREV_INSN (newstart_label));
2541 start_label = newstart_label;
2547 emit_jump (start_label);
2548 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2550 emit_label (loop_stack->data.loop.end_label);
2552 POPSTACK (loop_stack);
2557 /* Generate a jump to the current loop's continue-point.
2558 This is usually the top of the loop, but may be specified
2559 explicitly elsewhere. If not currently inside a loop,
2560 return 0 and do nothing; caller will print an error message. */
2563 expand_continue_loop (whichloop)
2564 struct nesting *whichloop;
2568 whichloop = loop_stack;
2571 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2576 /* Generate a jump to exit the current loop. If not currently inside a loop,
2577 return 0 and do nothing; caller will print an error message. */
2580 expand_exit_loop (whichloop)
2581 struct nesting *whichloop;
2585 whichloop = loop_stack;
2588 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2592 /* Generate a conditional jump to exit the current loop if COND
2593 evaluates to zero. If not currently inside a loop,
2594 return 0 and do nothing; caller will print an error message. */
2597 expand_exit_loop_if_false (whichloop, cond)
2598 struct nesting *whichloop;
2601 rtx label = gen_label_rtx ();
2606 whichloop = loop_stack;
2609 /* In order to handle fixups, we actually create a conditional jump
2610 around a unconditional branch to exit the loop. If fixups are
2611 necessary, they go before the unconditional branch. */
2614 do_jump (cond, NULL_RTX, label);
2615 last_insn = get_last_insn ();
2616 if (GET_CODE (last_insn) == CODE_LABEL)
2617 whichloop->data.loop.alt_end_label = last_insn;
2618 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2625 /* Return nonzero if the loop nest is empty. Else return zero. */
2628 stmt_loop_nest_empty ()
2630 /* cfun->stmt can be NULL if we are building a call to get the
2631 EH context for a setjmp/longjmp EH target and the current
2632 function was a deferred inline function. */
2633 return (cfun->stmt == NULL || loop_stack == NULL);
2636 /* Return non-zero if we should preserve sub-expressions as separate
2637 pseudos. We never do so if we aren't optimizing. We always do so
2638 if -fexpensive-optimizations.
2640 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2641 the loop may still be a small one. */
2644 preserve_subexpressions_p ()
2648 if (flag_expensive_optimizations)
2651 if (optimize == 0 || cfun == 0 || cfun->stmt == 0 || loop_stack == 0)
2654 insn = get_last_insn_anywhere ();
2657 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2658 < n_non_fixed_regs * 3));
2662 /* Generate a jump to exit the current loop, conditional, binding contour
2663 or case statement. Not all such constructs are visible to this function,
2664 only those started with EXIT_FLAG nonzero. Individual languages use
2665 the EXIT_FLAG parameter to control which kinds of constructs you can
2668 If not currently inside anything that can be exited,
2669 return 0 and do nothing; caller will print an error message. */
2672 expand_exit_something ()
2676 for (n = nesting_stack; n; n = n->all)
2677 if (n->exit_label != 0)
2679 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2686 /* Generate RTL to return from the current function, with no value.
2687 (That is, we do not do anything about returning any value.) */
2690 expand_null_return ()
2692 struct nesting *block = block_stack;
2693 rtx last_insn = get_last_insn ();
2695 /* If this function was declared to return a value, but we
2696 didn't, clobber the return registers so that they are not
2697 propogated live to the rest of the function. */
2698 clobber_return_register ();
2700 /* Does any pending block have cleanups? */
2701 while (block && block->data.block.cleanups == 0)
2702 block = block->next;
2704 /* If yes, use a goto to return, since that runs cleanups. */
2706 expand_null_return_1 (last_insn, block != 0);
2709 /* Generate RTL to return from the current function, with value VAL. */
2712 expand_value_return (val)
2715 struct nesting *block = block_stack;
2716 rtx last_insn = get_last_insn ();
2717 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2719 /* Copy the value to the return location
2720 unless it's already there. */
2722 if (return_reg != val)
2724 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2725 #ifdef PROMOTE_FUNCTION_RETURN
2726 int unsignedp = TREE_UNSIGNED (type);
2727 enum machine_mode old_mode
2728 = DECL_MODE (DECL_RESULT (current_function_decl));
2729 enum machine_mode mode
2730 = promote_mode (type, old_mode, &unsignedp, 1);
2732 if (mode != old_mode)
2733 val = convert_modes (mode, old_mode, val, unsignedp);
2735 if (GET_CODE (return_reg) == PARALLEL)
2736 emit_group_load (return_reg, val, int_size_in_bytes (type),
2739 emit_move_insn (return_reg, val);
2742 /* Does any pending block have cleanups? */
2744 while (block && block->data.block.cleanups == 0)
2745 block = block->next;
2747 /* If yes, use a goto to return, since that runs cleanups.
2748 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2750 expand_null_return_1 (last_insn, block != 0);
2753 /* Output a return with no value. If LAST_INSN is nonzero,
2754 pretend that the return takes place after LAST_INSN.
2755 If USE_GOTO is nonzero then don't use a return instruction;
2756 go to the return label instead. This causes any cleanups
2757 of pending blocks to be executed normally. */
2760 expand_null_return_1 (last_insn, use_goto)
2764 rtx end_label = cleanup_label ? cleanup_label : return_label;
2766 clear_pending_stack_adjust ();
2767 do_pending_stack_adjust ();
2770 /* PCC-struct return always uses an epilogue. */
2771 if (current_function_returns_pcc_struct || use_goto)
2774 end_label = return_label = gen_label_rtx ();
2775 expand_goto_internal (NULL_TREE, end_label, last_insn);
2779 /* Otherwise output a simple return-insn if one is available,
2780 unless it won't do the job. */
2782 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2784 emit_jump_insn (gen_return ());
2790 /* Otherwise jump to the epilogue. */
2791 expand_goto_internal (NULL_TREE, end_label, last_insn);
2794 /* Generate RTL to evaluate the expression RETVAL and return it
2795 from the current function. */
2798 expand_return (retval)
2801 /* If there are any cleanups to be performed, then they will
2802 be inserted following LAST_INSN. It is desirable
2803 that the last_insn, for such purposes, should be the
2804 last insn before computing the return value. Otherwise, cleanups
2805 which call functions can clobber the return value. */
2806 /* ??? rms: I think that is erroneous, because in C++ it would
2807 run destructors on variables that might be used in the subsequent
2808 computation of the return value. */
2810 rtx result_rtl = DECL_RTL (DECL_RESULT (current_function_decl));
2811 register rtx val = 0;
2818 /* If function wants no value, give it none. */
2819 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2821 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2823 expand_null_return ();
2827 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2828 /* This is not sufficient. We also need to watch for cleanups of the
2829 expression we are about to expand. Unfortunately, we cannot know
2830 if it has cleanups until we expand it, and we want to change how we
2831 expand it depending upon if we need cleanups. We can't win. */
2833 cleanups = any_pending_cleanups (1);
2838 if (TREE_CODE (retval) == RESULT_DECL)
2839 retval_rhs = retval;
2840 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2841 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2842 retval_rhs = TREE_OPERAND (retval, 1);
2843 else if (TREE_TYPE (retval) == void_type_node)
2844 /* Recognize tail-recursive call to void function. */
2845 retval_rhs = retval;
2847 retval_rhs = NULL_TREE;
2849 /* Only use `last_insn' if there are cleanups which must be run. */
2850 if (cleanups || cleanup_label != 0)
2851 last_insn = get_last_insn ();
2853 /* Distribute return down conditional expr if either of the sides
2854 may involve tail recursion (see test below). This enhances the number
2855 of tail recursions we see. Don't do this always since it can produce
2856 sub-optimal code in some cases and we distribute assignments into
2857 conditional expressions when it would help. */
2859 if (optimize && retval_rhs != 0
2860 && frame_offset == 0
2861 && TREE_CODE (retval_rhs) == COND_EXPR
2862 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2863 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2865 rtx label = gen_label_rtx ();
2868 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2869 start_cleanup_deferral ();
2870 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2871 DECL_RESULT (current_function_decl),
2872 TREE_OPERAND (retval_rhs, 1));
2873 TREE_SIDE_EFFECTS (expr) = 1;
2874 expand_return (expr);
2877 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2878 DECL_RESULT (current_function_decl),
2879 TREE_OPERAND (retval_rhs, 2));
2880 TREE_SIDE_EFFECTS (expr) = 1;
2881 expand_return (expr);
2882 end_cleanup_deferral ();
2886 /* Attempt to optimize the call if it is tail recursive. */
2887 if (flag_optimize_sibling_calls
2888 && retval_rhs != NULL_TREE
2889 && frame_offset == 0
2890 && TREE_CODE (retval_rhs) == CALL_EXPR
2891 && TREE_CODE (TREE_OPERAND (retval_rhs, 0)) == ADDR_EXPR
2892 && (TREE_OPERAND (TREE_OPERAND (retval_rhs, 0), 0)
2893 == current_function_decl)
2894 && optimize_tail_recursion (TREE_OPERAND (retval_rhs, 1), last_insn))
2898 /* This optimization is safe if there are local cleanups
2899 because expand_null_return takes care of them.
2900 ??? I think it should also be safe when there is a cleanup label,
2901 because expand_null_return takes care of them, too.
2902 Any reason why not? */
2903 if (HAVE_return && cleanup_label == 0
2904 && ! current_function_returns_pcc_struct
2905 && BRANCH_COST <= 1)
2907 /* If this is return x == y; then generate
2908 if (x == y) return 1; else return 0;
2909 if we can do it with explicit return insns and branches are cheap,
2910 but not if we have the corresponding scc insn. */
2913 switch (TREE_CODE (retval_rhs))
2939 case TRUTH_ANDIF_EXPR:
2940 case TRUTH_ORIF_EXPR:
2941 case TRUTH_AND_EXPR:
2943 case TRUTH_NOT_EXPR:
2944 case TRUTH_XOR_EXPR:
2947 op0 = gen_label_rtx ();
2948 jumpifnot (retval_rhs, op0);
2949 expand_value_return (const1_rtx);
2951 expand_value_return (const0_rtx);
2960 #endif /* HAVE_return */
2962 /* If the result is an aggregate that is being returned in one (or more)
2963 registers, load the registers here. The compiler currently can't handle
2964 copying a BLKmode value into registers. We could put this code in a
2965 more general area (for use by everyone instead of just function
2966 call/return), but until this feature is generally usable it is kept here
2967 (and in expand_call). The value must go into a pseudo in case there
2968 are cleanups that will clobber the real return register. */
2971 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2972 && GET_CODE (result_rtl) == REG)
2975 unsigned HOST_WIDE_INT bitpos, xbitpos;
2976 unsigned HOST_WIDE_INT big_endian_correction = 0;
2977 unsigned HOST_WIDE_INT bytes
2978 = int_size_in_bytes (TREE_TYPE (retval_rhs));
2979 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2980 unsigned int bitsize
2981 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)), BITS_PER_WORD);
2982 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2983 rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
2984 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2985 enum machine_mode tmpmode, result_reg_mode;
2987 /* Structures whose size is not a multiple of a word are aligned
2988 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
2989 machine, this means we must skip the empty high order bytes when
2990 calculating the bit offset. */
2991 if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD)
2992 big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
2995 /* Copy the structure BITSIZE bits at a time. */
2996 for (bitpos = 0, xbitpos = big_endian_correction;
2997 bitpos < bytes * BITS_PER_UNIT;
2998 bitpos += bitsize, xbitpos += bitsize)
3000 /* We need a new destination pseudo each time xbitpos is
3001 on a word boundary and when xbitpos == big_endian_correction
3002 (the first time through). */
3003 if (xbitpos % BITS_PER_WORD == 0
3004 || xbitpos == big_endian_correction)
3006 /* Generate an appropriate register. */
3007 dst = gen_reg_rtx (word_mode);
3008 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
3010 /* Clobber the destination before we move anything into it. */
3011 emit_insn (gen_rtx_CLOBBER (VOIDmode, dst));
3014 /* We need a new source operand each time bitpos is on a word
3016 if (bitpos % BITS_PER_WORD == 0)
3017 src = operand_subword_force (result_val,
3018 bitpos / BITS_PER_WORD,
3021 /* Use bitpos for the source extraction (left justified) and
3022 xbitpos for the destination store (right justified). */
3023 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
3024 extract_bit_field (src, bitsize,
3025 bitpos % BITS_PER_WORD, 1,
3026 NULL_RTX, word_mode, word_mode,
3027 bitsize, BITS_PER_WORD),
3028 bitsize, BITS_PER_WORD);
3031 /* Find the smallest integer mode large enough to hold the
3032 entire structure and use that mode instead of BLKmode
3033 on the USE insn for the return register. */
3034 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
3035 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
3036 tmpmode != VOIDmode;
3037 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
3039 /* Have we found a large enough mode? */
3040 if (GET_MODE_SIZE (tmpmode) >= bytes)
3044 /* No suitable mode found. */
3045 if (tmpmode == VOIDmode)
3048 PUT_MODE (result_rtl, tmpmode);
3050 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
3051 result_reg_mode = word_mode;
3053 result_reg_mode = tmpmode;
3054 result_reg = gen_reg_rtx (result_reg_mode);
3057 for (i = 0; i < n_regs; i++)
3058 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
3061 if (tmpmode != result_reg_mode)
3062 result_reg = gen_lowpart (tmpmode, result_reg);
3064 expand_value_return (result_reg);
3068 && TREE_TYPE (retval_rhs) != void_type_node
3069 && (GET_CODE (result_rtl) == REG
3070 || (GET_CODE (result_rtl) == PARALLEL)))
3072 /* Calculate the return value into a temporary (usually a pseudo
3074 val = assign_temp (TREE_TYPE (DECL_RESULT (current_function_decl)),
3076 val = expand_expr (retval_rhs, val, GET_MODE (val), 0);
3077 val = force_not_mem (val);
3079 /* Return the calculated value, doing cleanups first. */
3080 expand_value_return (val);
3084 /* No cleanups or no hard reg used;
3085 calculate value into hard return reg. */
3086 expand_expr (retval, const0_rtx, VOIDmode, 0);
3088 expand_value_return (result_rtl);
3092 /* Return 1 if the end of the generated RTX is not a barrier.
3093 This means code already compiled can drop through. */
3096 drop_through_at_end_p ()
3098 rtx insn = get_last_insn ();
3099 while (insn && GET_CODE (insn) == NOTE)
3100 insn = PREV_INSN (insn);
3101 return insn && GET_CODE (insn) != BARRIER;
3104 /* Attempt to optimize a potential tail recursion call into a goto.
3105 ARGUMENTS are the arguments to a CALL_EXPR; LAST_INSN indicates
3106 where to place the jump to the tail recursion label.
3108 Return TRUE if the call was optimized into a goto. */
3111 optimize_tail_recursion (arguments, last_insn)
3115 /* Finish checking validity, and if valid emit code to set the
3116 argument variables for the new call. */
3117 if (tail_recursion_args (arguments, DECL_ARGUMENTS (current_function_decl)))
3119 if (tail_recursion_label == 0)
3121 tail_recursion_label = gen_label_rtx ();
3122 emit_label_after (tail_recursion_label,
3123 tail_recursion_reentry);
3126 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
3133 /* Emit code to alter this function's formal parms for a tail-recursive call.
3134 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3135 FORMALS is the chain of decls of formals.
3136 Return 1 if this can be done;
3137 otherwise return 0 and do not emit any code. */
3140 tail_recursion_args (actuals, formals)
3141 tree actuals, formals;
3143 register tree a = actuals, f = formals;
3145 register rtx *argvec;
3147 /* Check that number and types of actuals are compatible
3148 with the formals. This is not always true in valid C code.
3149 Also check that no formal needs to be addressable
3150 and that all formals are scalars. */
3152 /* Also count the args. */
3154 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
3156 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a)))
3157 != TYPE_MAIN_VARIANT (TREE_TYPE (f)))
3159 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
3162 if (a != 0 || f != 0)
3165 /* Compute all the actuals. */
3167 argvec = (rtx *) alloca (i * sizeof (rtx));
3169 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3170 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
3172 /* Find which actual values refer to current values of previous formals.
3173 Copy each of them now, before any formal is changed. */
3175 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3179 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
3180 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
3181 { copy = 1; break; }
3183 argvec[i] = copy_to_reg (argvec[i]);
3186 /* Store the values of the actuals into the formals. */
3188 for (f = formals, a = actuals, i = 0; f;
3189 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
3191 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
3192 emit_move_insn (DECL_RTL (f), argvec[i]);
3194 convert_move (DECL_RTL (f), argvec[i],
3195 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
3202 /* Generate the RTL code for entering a binding contour.
3203 The variables are declared one by one, by calls to `expand_decl'.
3205 FLAGS is a bitwise or of the following flags:
3207 1 - Nonzero if this construct should be visible to
3210 2 - Nonzero if this contour does not require a
3211 NOTE_INSN_BLOCK_BEG note. Virtually all calls from
3212 language-independent code should set this flag because they
3213 will not create corresponding BLOCK nodes. (There should be
3214 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
3215 and BLOCKs.) If this flag is set, MARK_ENDS should be zero
3216 when expand_end_bindings is called.
3218 If we are creating a NOTE_INSN_BLOCK_BEG note, a BLOCK may
3219 optionally be supplied. If so, it becomes the NOTE_BLOCK for the
3223 expand_start_bindings_and_block (flags, block)
3227 struct nesting *thisblock = ALLOC_NESTING ();
3229 int exit_flag = ((flags & 1) != 0);
3230 int block_flag = ((flags & 2) == 0);
3232 /* If a BLOCK is supplied, then the caller should be requesting a
3233 NOTE_INSN_BLOCK_BEG note. */
3234 if (!block_flag && block)
3237 /* Create a note to mark the beginning of the block. */
3240 note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
3241 NOTE_BLOCK (note) = block;
3244 note = emit_note (NULL_PTR, NOTE_INSN_DELETED);
3246 /* Make an entry on block_stack for the block we are entering. */
3248 thisblock->next = block_stack;
3249 thisblock->all = nesting_stack;
3250 thisblock->depth = ++nesting_depth;
3251 thisblock->data.block.stack_level = 0;
3252 thisblock->data.block.cleanups = 0;
3253 thisblock->data.block.n_function_calls = 0;
3254 thisblock->data.block.exception_region = 0;
3255 thisblock->data.block.block_target_temp_slot_level = target_temp_slot_level;
3257 thisblock->data.block.conditional_code = 0;
3258 thisblock->data.block.last_unconditional_cleanup = note;
3259 /* When we insert instructions after the last unconditional cleanup,
3260 we don't adjust last_insn. That means that a later add_insn will
3261 clobber the instructions we've just added. The easiest way to
3262 fix this is to just insert another instruction here, so that the
3263 instructions inserted after the last unconditional cleanup are
3264 never the last instruction. */
3265 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3266 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
3269 && !(block_stack->data.block.cleanups == NULL_TREE
3270 && block_stack->data.block.outer_cleanups == NULL_TREE))
3271 thisblock->data.block.outer_cleanups
3272 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
3273 block_stack->data.block.outer_cleanups);
3275 thisblock->data.block.outer_cleanups = 0;
3276 thisblock->data.block.label_chain = 0;
3277 thisblock->data.block.innermost_stack_block = stack_block_stack;
3278 thisblock->data.block.first_insn = note;
3279 thisblock->data.block.block_start_count = ++current_block_start_count;
3280 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
3281 block_stack = thisblock;
3282 nesting_stack = thisblock;
3284 /* Make a new level for allocating stack slots. */
3288 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3289 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3290 expand_expr are made. After we end the region, we know that all
3291 space for all temporaries that were created by TARGET_EXPRs will be
3292 destroyed and their space freed for reuse. */
3295 expand_start_target_temps ()
3297 /* This is so that even if the result is preserved, the space
3298 allocated will be freed, as we know that it is no longer in use. */
3301 /* Start a new binding layer that will keep track of all cleanup
3302 actions to be performed. */
3303 expand_start_bindings (2);
3305 target_temp_slot_level = temp_slot_level;
3309 expand_end_target_temps ()
3311 expand_end_bindings (NULL_TREE, 0, 0);
3313 /* This is so that even if the result is preserved, the space
3314 allocated will be freed, as we know that it is no longer in use. */
3318 /* Given a pointer to a BLOCK node return non-zero if (and only if) the node
3319 in question represents the outermost pair of curly braces (i.e. the "body
3320 block") of a function or method.
3322 For any BLOCK node representing a "body block" of a function or method, the
3323 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
3324 represents the outermost (function) scope for the function or method (i.e.
3325 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
3326 *that* node in turn will point to the relevant FUNCTION_DECL node. */
3329 is_body_block (stmt)
3332 if (TREE_CODE (stmt) == BLOCK)
3334 tree parent = BLOCK_SUPERCONTEXT (stmt);
3336 if (parent && TREE_CODE (parent) == BLOCK)
3338 tree grandparent = BLOCK_SUPERCONTEXT (parent);
3340 if (grandparent && TREE_CODE (grandparent) == FUNCTION_DECL)
3348 /* Mark top block of block_stack as an implicit binding for an
3349 exception region. This is used to prevent infinite recursion when
3350 ending a binding with expand_end_bindings. It is only ever called
3351 by expand_eh_region_start, as that it the only way to create a
3352 block stack for a exception region. */
3355 mark_block_as_eh_region ()
3357 block_stack->data.block.exception_region = 1;
3358 if (block_stack->next
3359 && block_stack->next->data.block.conditional_code)
3361 block_stack->data.block.conditional_code
3362 = block_stack->next->data.block.conditional_code;
3363 block_stack->data.block.last_unconditional_cleanup
3364 = block_stack->next->data.block.last_unconditional_cleanup;
3365 block_stack->data.block.cleanup_ptr
3366 = block_stack->next->data.block.cleanup_ptr;
3370 /* True if we are currently emitting insns in an area of output code
3371 that is controlled by a conditional expression. This is used by
3372 the cleanup handling code to generate conditional cleanup actions. */
3375 conditional_context ()
3377 return block_stack && block_stack->data.block.conditional_code;
3380 /* Mark top block of block_stack as not for an implicit binding for an
3381 exception region. This is only ever done by expand_eh_region_end
3382 to let expand_end_bindings know that it is being called explicitly
3383 to end the binding layer for just the binding layer associated with
3384 the exception region, otherwise expand_end_bindings would try and
3385 end all implicit binding layers for exceptions regions, and then
3386 one normal binding layer. */
3389 mark_block_as_not_eh_region ()
3391 block_stack->data.block.exception_region = 0;
3394 /* True if the top block of block_stack was marked as for an exception
3395 region by mark_block_as_eh_region. */
3400 return cfun && block_stack && block_stack->data.block.exception_region;
3403 /* Emit a handler label for a nonlocal goto handler.
3404 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3407 expand_nl_handler_label (slot, before_insn)
3408 rtx slot, before_insn;
3411 rtx handler_label = gen_label_rtx ();
3413 /* Don't let jump_optimize delete the handler. */
3414 LABEL_PRESERVE_P (handler_label) = 1;
3417 emit_move_insn (slot, gen_rtx_LABEL_REF (Pmode, handler_label));
3418 insns = get_insns ();
3420 emit_insns_before (insns, before_insn);
3422 emit_label (handler_label);
3424 return handler_label;
3427 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3430 expand_nl_goto_receiver ()
3432 #ifdef HAVE_nonlocal_goto
3433 if (! HAVE_nonlocal_goto)
3435 /* First adjust our frame pointer to its actual value. It was
3436 previously set to the start of the virtual area corresponding to
3437 the stacked variables when we branched here and now needs to be
3438 adjusted to the actual hardware fp value.
3440 Assignments are to virtual registers are converted by
3441 instantiate_virtual_regs into the corresponding assignment
3442 to the underlying register (fp in this case) that makes
3443 the original assignment true.
3444 So the following insn will actually be
3445 decrementing fp by STARTING_FRAME_OFFSET. */
3446 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3448 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3449 if (fixed_regs[ARG_POINTER_REGNUM])
3451 #ifdef ELIMINABLE_REGS
3452 /* If the argument pointer can be eliminated in favor of the
3453 frame pointer, we don't need to restore it. We assume here
3454 that if such an elimination is present, it can always be used.
3455 This is the case on all known machines; if we don't make this
3456 assumption, we do unnecessary saving on many machines. */
3457 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3460 for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
3461 if (elim_regs[i].from == ARG_POINTER_REGNUM
3462 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3465 if (i == sizeof elim_regs / sizeof elim_regs [0])
3468 /* Now restore our arg pointer from the address at which it
3469 was saved in our stack frame.
3470 If there hasn't be space allocated for it yet, make
3472 if (arg_pointer_save_area == 0)
3473 arg_pointer_save_area
3474 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3475 emit_move_insn (virtual_incoming_args_rtx,
3476 /* We need a pseudo here, or else
3477 instantiate_virtual_regs_1 complains. */
3478 copy_to_reg (arg_pointer_save_area));
3483 #ifdef HAVE_nonlocal_goto_receiver
3484 if (HAVE_nonlocal_goto_receiver)
3485 emit_insn (gen_nonlocal_goto_receiver ());
3489 /* Make handlers for nonlocal gotos taking place in the function calls in
3493 expand_nl_goto_receivers (thisblock)
3494 struct nesting *thisblock;
3497 rtx afterward = gen_label_rtx ();
3502 /* Record the handler address in the stack slot for that purpose,
3503 during this block, saving and restoring the outer value. */
3504 if (thisblock->next != 0)
3505 for (slot = nonlocal_goto_handler_slots; slot; slot = XEXP (slot, 1))
3507 rtx save_receiver = gen_reg_rtx (Pmode);
3508 emit_move_insn (XEXP (slot, 0), save_receiver);
3511 emit_move_insn (save_receiver, XEXP (slot, 0));
3512 insns = get_insns ();
3514 emit_insns_before (insns, thisblock->data.block.first_insn);
3517 /* Jump around the handlers; they run only when specially invoked. */
3518 emit_jump (afterward);
3520 /* Make a separate handler for each label. */
3521 link = nonlocal_labels;
3522 slot = nonlocal_goto_handler_slots;
3523 label_list = NULL_RTX;
3524 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3525 /* Skip any labels we shouldn't be able to jump to from here,
3526 we generate one special handler for all of them below which just calls
3528 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3531 lab = expand_nl_handler_label (XEXP (slot, 0),
3532 thisblock->data.block.first_insn);
3533 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3535 expand_nl_goto_receiver ();
3537 /* Jump to the "real" nonlocal label. */
3538 expand_goto (TREE_VALUE (link));
3541 /* A second pass over all nonlocal labels; this time we handle those
3542 we should not be able to jump to at this point. */
3543 link = nonlocal_labels;
3544 slot = nonlocal_goto_handler_slots;
3546 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3547 if (DECL_TOO_LATE (TREE_VALUE (link)))
3550 lab = expand_nl_handler_label (XEXP (slot, 0),
3551 thisblock->data.block.first_insn);
3552 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3558 expand_nl_goto_receiver ();
3559 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "abort"), 0,
3564 nonlocal_goto_handler_labels = label_list;
3565 emit_label (afterward);
3568 /* Warn about any unused VARS (which may contain nodes other than
3569 VAR_DECLs, but such nodes are ignored). The nodes are connected
3570 via the TREE_CHAIN field. */
3573 warn_about_unused_variables (vars)
3579 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3580 if (TREE_CODE (decl) == VAR_DECL
3581 && ! TREE_USED (decl)
3582 && ! DECL_IN_SYSTEM_HEADER (decl)
3583 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
3584 warning_with_decl (decl, "unused variable `%s'");
3587 /* Generate RTL code to terminate a binding contour.
3589 VARS is the chain of VAR_DECL nodes for the variables bound in this
3590 contour. There may actually be other nodes in this chain, but any
3591 nodes other than VAR_DECLS are ignored.
3593 MARK_ENDS is nonzero if we should put a note at the beginning
3594 and end of this binding contour.
3596 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3597 (That is true automatically if the contour has a saved stack level.) */
3600 expand_end_bindings (vars, mark_ends, dont_jump_in)
3605 register struct nesting *thisblock;
3607 while (block_stack->data.block.exception_region)
3609 /* Because we don't need or want a new temporary level and
3610 because we didn't create one in expand_eh_region_start,
3611 create a fake one now to avoid removing one in
3612 expand_end_bindings. */
3615 block_stack->data.block.exception_region = 0;
3617 expand_end_bindings (NULL_TREE, 0, 0);
3620 /* Since expand_eh_region_start does an expand_start_bindings, we
3621 have to first end all the bindings that were created by
3622 expand_eh_region_start. */
3624 thisblock = block_stack;
3626 /* If any of the variables in this scope were not used, warn the
3628 warn_about_unused_variables (vars);
3630 if (thisblock->exit_label)
3632 do_pending_stack_adjust ();
3633 emit_label (thisblock->exit_label);
3636 /* If necessary, make handlers for nonlocal gotos taking
3637 place in the function calls in this block. */
3638 if (function_call_count != thisblock->data.block.n_function_calls
3640 /* Make handler for outermost block
3641 if there were any nonlocal gotos to this function. */
3642 && (thisblock->next == 0 ? current_function_has_nonlocal_label
3643 /* Make handler for inner block if it has something
3644 special to do when you jump out of it. */
3645 : (thisblock->data.block.cleanups != 0
3646 || thisblock->data.block.stack_level != 0)))
3647 expand_nl_goto_receivers (thisblock);
3649 /* Don't allow jumping into a block that has a stack level.
3650 Cleanups are allowed, though. */
3652 || thisblock->data.block.stack_level != 0)
3654 struct label_chain *chain;
3656 /* Any labels in this block are no longer valid to go to.
3657 Mark them to cause an error message. */
3658 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3660 DECL_TOO_LATE (chain->label) = 1;
3661 /* If any goto without a fixup came to this label,
3662 that must be an error, because gotos without fixups
3663 come from outside all saved stack-levels. */
3664 if (TREE_ADDRESSABLE (chain->label))
3665 error_with_decl (chain->label,
3666 "label `%s' used before containing binding contour");
3670 /* Restore stack level in effect before the block
3671 (only if variable-size objects allocated). */
3672 /* Perform any cleanups associated with the block. */
3674 if (thisblock->data.block.stack_level != 0
3675 || thisblock->data.block.cleanups != 0)
3677 /* Only clean up here if this point can actually be reached. */
3678 int reachable = GET_CODE (get_last_insn ()) != BARRIER;
3680 /* Don't let cleanups affect ({...}) constructs. */
3681 int old_expr_stmts_for_value = expr_stmts_for_value;
3682 rtx old_last_expr_value = last_expr_value;
3683 tree old_last_expr_type = last_expr_type;
3684 expr_stmts_for_value = 0;
3686 /* Do the cleanups. */
3687 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3689 do_pending_stack_adjust ();
3691 expr_stmts_for_value = old_expr_stmts_for_value;
3692 last_expr_value = old_last_expr_value;
3693 last_expr_type = old_last_expr_type;
3695 /* Restore the stack level. */
3697 if (reachable && thisblock->data.block.stack_level != 0)
3699 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3700 thisblock->data.block.stack_level, NULL_RTX);
3701 if (nonlocal_goto_handler_slots != 0)
3702 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3706 /* Any gotos out of this block must also do these things.
3707 Also report any gotos with fixups that came to labels in this
3709 fixup_gotos (thisblock,
3710 thisblock->data.block.stack_level,
3711 thisblock->data.block.cleanups,
3712 thisblock->data.block.first_insn,
3716 /* Mark the beginning and end of the scope if requested.
3717 We do this now, after running cleanups on the variables
3718 just going out of scope, so they are in scope for their cleanups. */
3722 rtx note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3723 NOTE_BLOCK (note) = NOTE_BLOCK (thisblock->data.block.first_insn);
3726 /* Get rid of the beginning-mark if we don't make an end-mark. */
3727 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3729 /* Restore the temporary level of TARGET_EXPRs. */
3730 target_temp_slot_level = thisblock->data.block.block_target_temp_slot_level;
3732 /* Restore block_stack level for containing block. */
3734 stack_block_stack = thisblock->data.block.innermost_stack_block;
3735 POPSTACK (block_stack);
3737 /* Pop the stack slot nesting and free any slots at this level. */
3741 /* Generate RTL for the automatic variable declaration DECL.
3742 (Other kinds of declarations are simply ignored if seen here.) */
3748 struct nesting *thisblock;
3751 type = TREE_TYPE (decl);
3753 /* Only automatic variables need any expansion done.
3754 Static and external variables, and external functions,
3755 will be handled by `assemble_variable' (called from finish_decl).
3756 TYPE_DECL and CONST_DECL require nothing.
3757 PARM_DECLs are handled in `assign_parms'. */
3759 if (TREE_CODE (decl) != VAR_DECL)
3761 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3764 thisblock = block_stack;
3766 /* Create the RTL representation for the variable. */
3768 if (type == error_mark_node)
3769 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, const0_rtx);
3770 else if (DECL_SIZE (decl) == 0)
3771 /* Variable with incomplete type. */
3773 if (DECL_INITIAL (decl) == 0)
3774 /* Error message was already done; now avoid a crash. */
3775 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3777 /* An initializer is going to decide the size of this array.
3778 Until we know the size, represent its address with a reg. */
3779 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode));
3780 MEM_SET_IN_STRUCT_P (DECL_RTL (decl), AGGREGATE_TYPE_P (type));
3782 else if (DECL_MODE (decl) != BLKmode
3783 /* If -ffloat-store, don't put explicit float vars
3785 && !(flag_float_store
3786 && TREE_CODE (type) == REAL_TYPE)
3787 && ! TREE_THIS_VOLATILE (decl)
3788 && ! TREE_ADDRESSABLE (decl)
3789 && (DECL_REGISTER (decl) || optimize)
3790 /* if -fcheck-memory-usage, check all variables. */
3791 && ! current_function_check_memory_usage)
3793 /* Automatic variable that can go in a register. */
3794 int unsignedp = TREE_UNSIGNED (type);
3795 enum machine_mode reg_mode
3796 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3798 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3799 mark_user_reg (DECL_RTL (decl));
3801 if (POINTER_TYPE_P (type))
3802 mark_reg_pointer (DECL_RTL (decl),
3803 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
3807 else if (TREE_CODE (DECL_SIZE_UNIT (decl)) == INTEGER_CST
3808 && ! (flag_stack_check && ! STACK_CHECK_BUILTIN
3809 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl),
3810 STACK_CHECK_MAX_VAR_SIZE)))
3812 /* Variable of fixed size that goes on the stack. */
3816 /* If we previously made RTL for this decl, it must be an array
3817 whose size was determined by the initializer.
3818 The old address was a register; set that register now
3819 to the proper address. */
3820 if (DECL_RTL (decl) != 0)
3822 if (GET_CODE (DECL_RTL (decl)) != MEM
3823 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3825 oldaddr = XEXP (DECL_RTL (decl), 0);
3828 DECL_RTL (decl) = assign_temp (TREE_TYPE (decl), 1, 1, 1);
3829 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3830 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3832 /* Set alignment we actually gave this decl. */
3833 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3834 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3838 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3839 if (addr != oldaddr)
3840 emit_move_insn (oldaddr, addr);
3843 /* If this is a memory ref that contains aggregate components,
3844 mark it as such for cse and loop optimize. */
3845 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3846 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3848 /* If this is in memory because of -ffloat-store,
3849 set the volatile bit, to prevent optimizations from
3850 undoing the effects. */
3851 if (flag_float_store && TREE_CODE (type) == REAL_TYPE)
3852 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3855 MEM_ALIAS_SET (DECL_RTL (decl)) = get_alias_set (decl);
3858 /* Dynamic-size object: must push space on the stack. */
3862 /* Record the stack pointer on entry to block, if have
3863 not already done so. */
3864 if (thisblock->data.block.stack_level == 0)
3866 do_pending_stack_adjust ();
3867 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3868 &thisblock->data.block.stack_level,
3869 thisblock->data.block.first_insn);
3870 stack_block_stack = thisblock;
3873 /* In function-at-a-time mode, variable_size doesn't expand this,
3875 if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
3876 expand_expr (TYPE_MAX_VALUE (TYPE_DOMAIN (type)),
3877 const0_rtx, VOIDmode, 0);
3879 /* Compute the variable's size, in bytes. */
3880 size = expand_expr (DECL_SIZE_UNIT (decl), NULL_RTX, VOIDmode, 0);
3883 /* Allocate space on the stack for the variable. Note that
3884 DECL_ALIGN says how the variable is to be aligned and we
3885 cannot use it to conclude anything about the alignment of
3887 address = allocate_dynamic_stack_space (size, NULL_RTX,
3888 TYPE_ALIGN (TREE_TYPE (decl)));
3890 /* Reference the variable indirect through that rtx. */
3891 DECL_RTL (decl) = gen_rtx_MEM (DECL_MODE (decl), address);
3893 /* If this is a memory ref that contains aggregate components,
3894 mark it as such for cse and loop optimize. */
3895 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3896 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3898 /* Indicate the alignment we actually gave this variable. */
3899 #ifdef STACK_BOUNDARY
3900 DECL_ALIGN (decl) = STACK_BOUNDARY;
3902 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3906 if (TREE_THIS_VOLATILE (decl))
3907 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3909 if (TREE_READONLY (decl))
3910 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
3913 /* Emit code to perform the initialization of a declaration DECL. */
3916 expand_decl_init (decl)
3919 int was_used = TREE_USED (decl);
3921 /* If this is a CONST_DECL, we don't have to generate any code, but
3922 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3923 to be set while in the obstack containing the constant. If we don't
3924 do this, we can lose if we have functions nested three deep and the middle
3925 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3926 the innermost function is the first to expand that STRING_CST. */
3927 if (TREE_CODE (decl) == CONST_DECL)
3929 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3930 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3931 EXPAND_INITIALIZER);
3935 if (TREE_STATIC (decl))
3938 /* Compute and store the initial value now. */
3940 if (DECL_INITIAL (decl) == error_mark_node)
3942 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3944 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3945 || code == POINTER_TYPE || code == REFERENCE_TYPE)
3946 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3950 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3952 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3953 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3957 /* Don't let the initialization count as "using" the variable. */
3958 TREE_USED (decl) = was_used;
3960 /* Free any temporaries we made while initializing the decl. */
3961 preserve_temp_slots (NULL_RTX);
3965 /* CLEANUP is an expression to be executed at exit from this binding contour;
3966 for example, in C++, it might call the destructor for this variable.
3968 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
3969 CLEANUP multiple times, and have the correct semantics. This
3970 happens in exception handling, for gotos, returns, breaks that
3971 leave the current scope.
3973 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3974 that is not associated with any particular variable. */
3977 expand_decl_cleanup (decl, cleanup)
3980 struct nesting *thisblock;
3982 /* Error if we are not in any block. */
3983 if (cfun == 0 || block_stack == 0)
3986 thisblock = block_stack;
3988 /* Record the cleanup if there is one. */
3994 tree *cleanups = &thisblock->data.block.cleanups;
3995 int cond_context = conditional_context ();
3999 rtx flag = gen_reg_rtx (word_mode);
4004 emit_move_insn (flag, const0_rtx);
4005 set_flag_0 = get_insns ();
4008 thisblock->data.block.last_unconditional_cleanup
4009 = emit_insns_after (set_flag_0,
4010 thisblock->data.block.last_unconditional_cleanup);
4012 emit_move_insn (flag, const1_rtx);
4014 /* All cleanups must be on the function_obstack. */
4015 push_obstacks_nochange ();
4016 resume_temporary_allocation ();
4018 cond = build_decl (VAR_DECL, NULL_TREE, type_for_mode (word_mode, 1));
4019 DECL_RTL (cond) = flag;
4021 /* Conditionalize the cleanup. */
4022 cleanup = build (COND_EXPR, void_type_node,
4023 truthvalue_conversion (cond),
4024 cleanup, integer_zero_node);
4025 cleanup = fold (cleanup);
4029 cleanups = thisblock->data.block.cleanup_ptr;
4032 /* All cleanups must be on the function_obstack. */
4033 push_obstacks_nochange ();
4034 resume_temporary_allocation ();
4035 cleanup = unsave_expr (cleanup);
4038 t = *cleanups = temp_tree_cons (decl, cleanup, *cleanups);
4041 /* If this block has a cleanup, it belongs in stack_block_stack. */
4042 stack_block_stack = thisblock;
4049 /* If this was optimized so that there is no exception region for the
4050 cleanup, then mark the TREE_LIST node, so that we can later tell
4051 if we need to call expand_eh_region_end. */
4052 if (! using_eh_for_cleanups_p
4053 || expand_eh_region_start_tree (decl, cleanup))
4054 TREE_ADDRESSABLE (t) = 1;
4055 /* If that started a new EH region, we're in a new block. */
4056 thisblock = block_stack;
4063 thisblock->data.block.last_unconditional_cleanup
4064 = emit_insns_after (seq,
4065 thisblock->data.block.last_unconditional_cleanup);
4069 thisblock->data.block.last_unconditional_cleanup
4071 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
4077 /* Like expand_decl_cleanup, but suppress generating an exception handler
4078 to perform the cleanup. */
4082 expand_decl_cleanup_no_eh (decl, cleanup)
4085 int save_eh = using_eh_for_cleanups_p;
4088 using_eh_for_cleanups_p = 0;
4089 result = expand_decl_cleanup (decl, cleanup);
4090 using_eh_for_cleanups_p = save_eh;
4096 /* Arrange for the top element of the dynamic cleanup chain to be
4097 popped if we exit the current binding contour. DECL is the
4098 associated declaration, if any, otherwise NULL_TREE. If the
4099 current contour is left via an exception, then __sjthrow will pop
4100 the top element off the dynamic cleanup chain. The code that
4101 avoids doing the action we push into the cleanup chain in the
4102 exceptional case is contained in expand_cleanups.
4104 This routine is only used by expand_eh_region_start, and that is
4105 the only way in which an exception region should be started. This
4106 routine is only used when using the setjmp/longjmp codegen method
4107 for exception handling. */
4110 expand_dcc_cleanup (decl)
4113 struct nesting *thisblock;
4116 /* Error if we are not in any block. */
4117 if (cfun == 0 || block_stack == 0)
4119 thisblock = block_stack;
4121 /* Record the cleanup for the dynamic handler chain. */
4123 /* All cleanups must be on the function_obstack. */
4124 push_obstacks_nochange ();
4125 resume_temporary_allocation ();
4126 cleanup = make_node (POPDCC_EXPR);
4129 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4130 thisblock->data.block.cleanups
4131 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4133 /* If this block has a cleanup, it belongs in stack_block_stack. */
4134 stack_block_stack = thisblock;
4138 /* Arrange for the top element of the dynamic handler chain to be
4139 popped if we exit the current binding contour. DECL is the
4140 associated declaration, if any, otherwise NULL_TREE. If the current
4141 contour is left via an exception, then __sjthrow will pop the top
4142 element off the dynamic handler chain. The code that avoids doing
4143 the action we push into the handler chain in the exceptional case
4144 is contained in expand_cleanups.
4146 This routine is only used by expand_eh_region_start, and that is
4147 the only way in which an exception region should be started. This
4148 routine is only used when using the setjmp/longjmp codegen method
4149 for exception handling. */
4152 expand_dhc_cleanup (decl)
4155 struct nesting *thisblock;
4158 /* Error if we are not in any block. */
4159 if (cfun == 0 || block_stack == 0)
4161 thisblock = block_stack;
4163 /* Record the cleanup for the dynamic handler chain. */
4165 /* All cleanups must be on the function_obstack. */
4166 push_obstacks_nochange ();
4167 resume_temporary_allocation ();
4168 cleanup = make_node (POPDHC_EXPR);
4171 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4172 thisblock->data.block.cleanups
4173 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4175 /* If this block has a cleanup, it belongs in stack_block_stack. */
4176 stack_block_stack = thisblock;
4180 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4181 DECL_ELTS is the list of elements that belong to DECL's type.
4182 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4185 expand_anon_union_decl (decl, cleanup, decl_elts)
4186 tree decl, cleanup, decl_elts;
4188 struct nesting *thisblock = cfun == 0 ? 0 : block_stack;
4192 /* If any of the elements are addressable, so is the entire union. */
4193 for (t = decl_elts; t; t = TREE_CHAIN (t))
4194 if (TREE_ADDRESSABLE (TREE_VALUE (t)))
4196 TREE_ADDRESSABLE (decl) = 1;
4201 expand_decl_cleanup (decl, cleanup);
4202 x = DECL_RTL (decl);
4204 /* Go through the elements, assigning RTL to each. */
4205 for (t = decl_elts; t; t = TREE_CHAIN (t))
4207 tree decl_elt = TREE_VALUE (t);
4208 tree cleanup_elt = TREE_PURPOSE (t);
4209 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
4211 /* Propagate the union's alignment to the elements. */
4212 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
4214 /* If the element has BLKmode and the union doesn't, the union is
4215 aligned such that the element doesn't need to have BLKmode, so
4216 change the element's mode to the appropriate one for its size. */
4217 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
4218 DECL_MODE (decl_elt) = mode
4219 = mode_for_size_tree (DECL_SIZE (decl_elt), MODE_INT, 1);
4221 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4222 instead create a new MEM rtx with the proper mode. */
4223 if (GET_CODE (x) == MEM)
4225 if (mode == GET_MODE (x))
4226 DECL_RTL (decl_elt) = x;
4229 DECL_RTL (decl_elt) = gen_rtx_MEM (mode, copy_rtx (XEXP (x, 0)));
4230 MEM_COPY_ATTRIBUTES (DECL_RTL (decl_elt), x);
4231 RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x);
4234 else if (GET_CODE (x) == REG)
4236 if (mode == GET_MODE (x))
4237 DECL_RTL (decl_elt) = x;
4239 DECL_RTL (decl_elt) = gen_rtx_SUBREG (mode, x, 0);
4244 /* Record the cleanup if there is one. */
4247 thisblock->data.block.cleanups
4248 = temp_tree_cons (decl_elt, cleanup_elt,
4249 thisblock->data.block.cleanups);
4253 /* Expand a list of cleanups LIST.
4254 Elements may be expressions or may be nested lists.
4256 If DONT_DO is nonnull, then any list-element
4257 whose TREE_PURPOSE matches DONT_DO is omitted.
4258 This is sometimes used to avoid a cleanup associated with
4259 a value that is being returned out of the scope.
4261 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
4262 goto and handle protection regions specially in that case.
4264 If REACHABLE, we emit code, otherwise just inform the exception handling
4265 code about this finalization. */
4268 expand_cleanups (list, dont_do, in_fixup, reachable)
4275 for (tail = list; tail; tail = TREE_CHAIN (tail))
4276 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
4278 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
4279 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
4284 tree cleanup = TREE_VALUE (tail);
4286 /* See expand_d{h,c}c_cleanup for why we avoid this. */
4287 if (TREE_CODE (cleanup) != POPDHC_EXPR
4288 && TREE_CODE (cleanup) != POPDCC_EXPR
4289 /* See expand_eh_region_start_tree for this case. */
4290 && ! TREE_ADDRESSABLE (tail))
4292 cleanup = protect_with_terminate (cleanup);
4293 expand_eh_region_end (cleanup);
4299 /* Cleanups may be run multiple times. For example,
4300 when exiting a binding contour, we expand the
4301 cleanups associated with that contour. When a goto
4302 within that binding contour has a target outside that
4303 contour, it will expand all cleanups from its scope to
4304 the target. Though the cleanups are expanded multiple
4305 times, the control paths are non-overlapping so the
4306 cleanups will not be executed twice. */
4308 /* We may need to protect fixups with rethrow regions. */
4309 int protect = (in_fixup && ! TREE_ADDRESSABLE (tail));
4312 expand_fixup_region_start ();
4314 /* The cleanup might contain try-blocks, so we have to
4315 preserve our current queue. */
4317 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
4320 expand_fixup_region_end (TREE_VALUE (tail));
4327 /* Mark when the context we are emitting RTL for as a conditional
4328 context, so that any cleanup actions we register with
4329 expand_decl_init will be properly conditionalized when those
4330 cleanup actions are later performed. Must be called before any
4331 expression (tree) is expanded that is within a conditional context. */
4334 start_cleanup_deferral ()
4336 /* block_stack can be NULL if we are inside the parameter list. It is
4337 OK to do nothing, because cleanups aren't possible here. */
4339 ++block_stack->data.block.conditional_code;
4342 /* Mark the end of a conditional region of code. Because cleanup
4343 deferrals may be nested, we may still be in a conditional region
4344 after we end the currently deferred cleanups, only after we end all
4345 deferred cleanups, are we back in unconditional code. */
4348 end_cleanup_deferral ()
4350 /* block_stack can be NULL if we are inside the parameter list. It is
4351 OK to do nothing, because cleanups aren't possible here. */
4353 --block_stack->data.block.conditional_code;
4356 /* Move all cleanups from the current block_stack
4357 to the containing block_stack, where they are assumed to
4358 have been created. If anything can cause a temporary to
4359 be created, but not expanded for more than one level of
4360 block_stacks, then this code will have to change. */
4365 struct nesting *block = block_stack;
4366 struct nesting *outer = block->next;
4368 outer->data.block.cleanups
4369 = chainon (block->data.block.cleanups,
4370 outer->data.block.cleanups);
4371 block->data.block.cleanups = 0;
4375 last_cleanup_this_contour ()
4377 if (block_stack == 0)
4380 return block_stack->data.block.cleanups;
4383 /* Return 1 if there are any pending cleanups at this point.
4384 If THIS_CONTOUR is nonzero, check the current contour as well.
4385 Otherwise, look only at the contours that enclose this one. */
4388 any_pending_cleanups (this_contour)
4391 struct nesting *block;
4393 if (cfun == NULL || cfun->stmt == NULL || block_stack == 0)
4396 if (this_contour && block_stack->data.block.cleanups != NULL)
4398 if (block_stack->data.block.cleanups == 0
4399 && block_stack->data.block.outer_cleanups == 0)
4402 for (block = block_stack->next; block; block = block->next)
4403 if (block->data.block.cleanups != 0)
4409 /* Enter a case (Pascal) or switch (C) statement.
4410 Push a block onto case_stack and nesting_stack
4411 to accumulate the case-labels that are seen
4412 and to record the labels generated for the statement.
4414 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4415 Otherwise, this construct is transparent for `exit_something'.
4417 EXPR is the index-expression to be dispatched on.
4418 TYPE is its nominal type. We could simply convert EXPR to this type,
4419 but instead we take short cuts. */
4422 expand_start_case (exit_flag, expr, type, printname)
4426 const char *printname;
4428 register struct nesting *thiscase = ALLOC_NESTING ();
4430 /* Make an entry on case_stack for the case we are entering. */
4432 thiscase->next = case_stack;
4433 thiscase->all = nesting_stack;
4434 thiscase->depth = ++nesting_depth;
4435 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
4436 thiscase->data.case_stmt.case_list = 0;
4437 thiscase->data.case_stmt.index_expr = expr;
4438 thiscase->data.case_stmt.nominal_type = type;
4439 thiscase->data.case_stmt.default_label = 0;
4440 thiscase->data.case_stmt.num_ranges = 0;
4441 thiscase->data.case_stmt.printname = printname;
4442 thiscase->data.case_stmt.line_number_status = force_line_numbers ();
4443 case_stack = thiscase;
4444 nesting_stack = thiscase;
4446 do_pending_stack_adjust ();
4448 /* Make sure case_stmt.start points to something that won't
4449 need any transformation before expand_end_case. */
4450 if (GET_CODE (get_last_insn ()) != NOTE)
4451 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4453 thiscase->data.case_stmt.start = get_last_insn ();
4455 start_cleanup_deferral ();
4459 /* Start a "dummy case statement" within which case labels are invalid
4460 and are not connected to any larger real case statement.
4461 This can be used if you don't want to let a case statement jump
4462 into the middle of certain kinds of constructs. */
4465 expand_start_case_dummy ()
4467 register struct nesting *thiscase = ALLOC_NESTING ();
4469 /* Make an entry on case_stack for the dummy. */
4471 thiscase->next = case_stack;
4472 thiscase->all = nesting_stack;
4473 thiscase->depth = ++nesting_depth;
4474 thiscase->exit_label = 0;
4475 thiscase->data.case_stmt.case_list = 0;
4476 thiscase->data.case_stmt.start = 0;
4477 thiscase->data.case_stmt.nominal_type = 0;
4478 thiscase->data.case_stmt.default_label = 0;
4479 thiscase->data.case_stmt.num_ranges = 0;
4480 case_stack = thiscase;
4481 nesting_stack = thiscase;
4482 start_cleanup_deferral ();
4485 /* End a dummy case statement. */
4488 expand_end_case_dummy ()
4490 end_cleanup_deferral ();
4491 POPSTACK (case_stack);
4494 /* Return the data type of the index-expression
4495 of the innermost case statement, or null if none. */
4498 case_index_expr_type ()
4501 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
4508 /* If this is the first label, warn if any insns have been emitted. */
4509 if (case_stack->data.case_stmt.line_number_status >= 0)
4513 restore_line_number_status
4514 (case_stack->data.case_stmt.line_number_status);
4515 case_stack->data.case_stmt.line_number_status = -1;
4517 for (insn = case_stack->data.case_stmt.start;
4519 insn = NEXT_INSN (insn))
4521 if (GET_CODE (insn) == CODE_LABEL)
4523 if (GET_CODE (insn) != NOTE
4524 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4527 insn = PREV_INSN (insn);
4528 while (insn && (GET_CODE (insn) != NOTE || NOTE_LINE_NUMBER (insn) < 0));
4530 /* If insn is zero, then there must have been a syntax error. */
4532 warning_with_file_and_line (NOTE_SOURCE_FILE(insn),
4533 NOTE_LINE_NUMBER(insn),
4534 "unreachable code at beginning of %s",
4535 case_stack->data.case_stmt.printname);
4542 /* Accumulate one case or default label inside a case or switch statement.
4543 VALUE is the value of the case (a null pointer, for a default label).
4544 The function CONVERTER, when applied to arguments T and V,
4545 converts the value V to the type T.
4547 If not currently inside a case or switch statement, return 1 and do
4548 nothing. The caller will print a language-specific error message.
4549 If VALUE is a duplicate or overlaps, return 2 and do nothing
4550 except store the (first) duplicate node in *DUPLICATE.
4551 If VALUE is out of range, return 3 and do nothing.
4552 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4553 Return 0 on success.
4555 Extended to handle range statements. */
4558 pushcase (value, converter, label, duplicate)
4559 register tree value;
4560 tree (*converter) PARAMS ((tree, tree));
4561 register tree label;
4567 /* Fail if not inside a real case statement. */
4568 if (! (case_stack && case_stack->data.case_stmt.start))
4571 if (stack_block_stack
4572 && stack_block_stack->depth > case_stack->depth)
4575 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4576 nominal_type = case_stack->data.case_stmt.nominal_type;
4578 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4579 if (index_type == error_mark_node)
4582 /* Convert VALUE to the type in which the comparisons are nominally done. */
4584 value = (*converter) (nominal_type, value);
4588 /* Fail if this value is out of range for the actual type of the index
4589 (which may be narrower than NOMINAL_TYPE). */
4591 && (TREE_CONSTANT_OVERFLOW (value)
4592 || ! int_fits_type_p (value, index_type)))
4595 /* Fail if this is a duplicate or overlaps another entry. */
4598 if (case_stack->data.case_stmt.default_label != 0)
4600 *duplicate = case_stack->data.case_stmt.default_label;
4603 case_stack->data.case_stmt.default_label = label;
4606 return add_case_node (value, value, label, duplicate);
4608 expand_label (label);
4612 /* Like pushcase but this case applies to all values between VALUE1 and
4613 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4614 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4615 starts at VALUE1 and ends at the highest value of the index type.
4616 If both are NULL, this case applies to all values.
4618 The return value is the same as that of pushcase but there is one
4619 additional error code: 4 means the specified range was empty. */
4622 pushcase_range (value1, value2, converter, label, duplicate)
4623 register tree value1, value2;
4624 tree (*converter) PARAMS ((tree, tree));
4625 register tree label;
4631 /* Fail if not inside a real case statement. */
4632 if (! (case_stack && case_stack->data.case_stmt.start))
4635 if (stack_block_stack
4636 && stack_block_stack->depth > case_stack->depth)
4639 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4640 nominal_type = case_stack->data.case_stmt.nominal_type;
4642 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4643 if (index_type == error_mark_node)
4648 /* Convert VALUEs to type in which the comparisons are nominally done
4649 and replace any unspecified value with the corresponding bound. */
4651 value1 = TYPE_MIN_VALUE (index_type);
4653 value2 = TYPE_MAX_VALUE (index_type);
4655 /* Fail if the range is empty. Do this before any conversion since
4656 we want to allow out-of-range empty ranges. */
4657 if (value2 != 0 && tree_int_cst_lt (value2, value1))
4660 /* If the max was unbounded, use the max of the nominal_type we are
4661 converting to. Do this after the < check above to suppress false
4664 value2 = TYPE_MAX_VALUE (nominal_type);
4666 value1 = (*converter) (nominal_type, value1);
4667 value2 = (*converter) (nominal_type, value2);
4669 /* Fail if these values are out of range. */
4670 if (TREE_CONSTANT_OVERFLOW (value1)
4671 || ! int_fits_type_p (value1, index_type))
4674 if (TREE_CONSTANT_OVERFLOW (value2)
4675 || ! int_fits_type_p (value2, index_type))
4678 return add_case_node (value1, value2, label, duplicate);
4681 /* Do the actual insertion of a case label for pushcase and pushcase_range
4682 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4683 slowdown for large switch statements. */
4686 add_case_node (low, high, label, duplicate)
4691 struct case_node *p, **q, *r;
4693 q = &case_stack->data.case_stmt.case_list;
4700 /* Keep going past elements distinctly greater than HIGH. */
4701 if (tree_int_cst_lt (high, p->low))
4704 /* or distinctly less than LOW. */
4705 else if (tree_int_cst_lt (p->high, low))
4710 /* We have an overlap; this is an error. */
4711 *duplicate = p->code_label;
4716 /* Add this label to the chain, and succeed.
4717 Copy LOW, HIGH so they are on temporary rather than momentary
4718 obstack and will thus survive till the end of the case statement. */
4720 r = (struct case_node *) oballoc (sizeof (struct case_node));
4721 r->low = copy_node (low);
4723 /* If the bounds are equal, turn this into the one-value case. */
4725 if (tree_int_cst_equal (low, high))
4729 r->high = copy_node (high);
4730 case_stack->data.case_stmt.num_ranges++;
4733 r->code_label = label;
4734 expand_label (label);
4744 struct case_node *s;
4750 if (! (b = p->balance))
4751 /* Growth propagation from left side. */
4758 if ((p->left = s = r->right))
4767 if ((r->parent = s))
4775 case_stack->data.case_stmt.case_list = r;
4778 /* r->balance == +1 */
4783 struct case_node *t = r->right;
4785 if ((p->left = s = t->right))
4789 if ((r->right = s = t->left))
4803 if ((t->parent = s))
4811 case_stack->data.case_stmt.case_list = t;
4818 /* p->balance == +1; growth of left side balances the node. */
4828 if (! (b = p->balance))
4829 /* Growth propagation from right side. */
4837 if ((p->right = s = r->left))
4845 if ((r->parent = s))
4854 case_stack->data.case_stmt.case_list = r;
4858 /* r->balance == -1 */
4862 struct case_node *t = r->left;
4864 if ((p->right = s = t->left))
4869 if ((r->left = s = t->right))
4883 if ((t->parent = s))
4892 case_stack->data.case_stmt.case_list = t;
4898 /* p->balance == -1; growth of right side balances the node. */
4912 /* Returns the number of possible values of TYPE.
4913 Returns -1 if the number is unknown, variable, or if the number does not
4914 fit in a HOST_WIDE_INT.
4915 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4916 do not increase monotonically (there may be duplicates);
4917 to 1 if the values increase monotonically, but not always by 1;
4918 otherwise sets it to 0. */
4921 all_cases_count (type, spareness)
4926 HOST_WIDE_INT count, minval, lastval;
4930 switch (TREE_CODE (type))
4937 count = 1 << BITS_PER_UNIT;
4942 if (TYPE_MAX_VALUE (type) != 0
4943 && 0 != (t = fold (build (MINUS_EXPR, type, TYPE_MAX_VALUE (type),
4944 TYPE_MIN_VALUE (type))))
4945 && 0 != (t = fold (build (PLUS_EXPR, type, t,
4946 convert (type, integer_zero_node))))
4947 && host_integerp (t, 1))
4948 count = tree_low_cst (t, 1);
4954 /* Don't waste time with enumeral types with huge values. */
4955 if (! host_integerp (TYPE_MIN_VALUE (type), 0)
4956 || TYPE_MAX_VALUE (type) == 0
4957 || ! host_integerp (TYPE_MAX_VALUE (type), 0))
4960 lastval = minval = tree_low_cst (TYPE_MIN_VALUE (type), 0);
4963 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4965 HOST_WIDE_INT thisval = tree_low_cst (TREE_VALUE (t), 0);
4967 if (*spareness == 2 || thisval < lastval)
4969 else if (thisval != minval + count)
4979 #define BITARRAY_TEST(ARRAY, INDEX) \
4980 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4981 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4982 #define BITARRAY_SET(ARRAY, INDEX) \
4983 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4984 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4986 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4987 with the case values we have seen, assuming the case expression
4989 SPARSENESS is as determined by all_cases_count.
4991 The time needed is proportional to COUNT, unless
4992 SPARSENESS is 2, in which case quadratic time is needed. */
4995 mark_seen_cases (type, cases_seen, count, sparseness)
4997 unsigned char *cases_seen;
4998 HOST_WIDE_INT count;
5001 tree next_node_to_try = NULL_TREE;
5002 HOST_WIDE_INT next_node_offset = 0;
5004 register struct case_node *n, *root = case_stack->data.case_stmt.case_list;
5005 tree val = make_node (INTEGER_CST);
5007 TREE_TYPE (val) = type;
5010 else if (sparseness == 2)
5013 unsigned HOST_WIDE_INT xlo;
5015 /* This less efficient loop is only needed to handle
5016 duplicate case values (multiple enum constants
5017 with the same value). */
5018 TREE_TYPE (val) = TREE_TYPE (root->low);
5019 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
5020 t = TREE_CHAIN (t), xlo++)
5022 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (TREE_VALUE (t));
5023 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (TREE_VALUE (t));
5027 /* Keep going past elements distinctly greater than VAL. */
5028 if (tree_int_cst_lt (val, n->low))
5031 /* or distinctly less than VAL. */
5032 else if (tree_int_cst_lt (n->high, val))
5037 /* We have found a matching range. */
5038 BITARRAY_SET (cases_seen, xlo);
5048 case_stack->data.case_stmt.case_list = root = case_tree2list (root, 0);
5050 for (n = root; n; n = n->right)
5052 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
5053 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
5054 while ( ! tree_int_cst_lt (n->high, val))
5056 /* Calculate (into xlo) the "offset" of the integer (val).
5057 The element with lowest value has offset 0, the next smallest
5058 element has offset 1, etc. */
5060 unsigned HOST_WIDE_INT xlo;
5064 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
5066 /* The TYPE_VALUES will be in increasing order, so
5067 starting searching where we last ended. */
5068 t = next_node_to_try;
5069 xlo = next_node_offset;
5075 t = TYPE_VALUES (type);
5078 if (tree_int_cst_equal (val, TREE_VALUE (t)))
5080 next_node_to_try = TREE_CHAIN (t);
5081 next_node_offset = xlo + 1;
5086 if (t == next_node_to_try)
5095 t = TYPE_MIN_VALUE (type);
5097 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
5101 add_double (xlo, xhi,
5102 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5106 if (xhi == 0 && xlo < (unsigned HOST_WIDE_INT) count)
5107 BITARRAY_SET (cases_seen, xlo);
5109 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5111 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
5117 /* Called when the index of a switch statement is an enumerated type
5118 and there is no default label.
5120 Checks that all enumeration literals are covered by the case
5121 expressions of a switch. Also, warn if there are any extra
5122 switch cases that are *not* elements of the enumerated type.
5124 If all enumeration literals were covered by the case expressions,
5125 turn one of the expressions into the default expression since it should
5126 not be possible to fall through such a switch. */
5129 check_for_full_enumeration_handling (type)
5132 register struct case_node *n;
5133 register tree chain;
5134 #if 0 /* variable used by 'if 0'ed code below. */
5135 register struct case_node **l;
5139 /* True iff the selector type is a numbered set mode. */
5142 /* The number of possible selector values. */
5145 /* For each possible selector value. a one iff it has been matched
5146 by a case value alternative. */
5147 unsigned char *cases_seen;
5149 /* The allocated size of cases_seen, in chars. */
5150 HOST_WIDE_INT bytes_needed;
5155 size = all_cases_count (type, &sparseness);
5156 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
5158 if (size > 0 && size < 600000
5159 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5160 this optimization if we don't have enough memory rather than
5161 aborting, as xmalloc would do. */
5162 && (cases_seen = (unsigned char *) calloc (bytes_needed, 1)) != NULL)
5165 tree v = TYPE_VALUES (type);
5167 /* The time complexity of this code is normally O(N), where
5168 N being the number of members in the enumerated type.
5169 However, if type is a ENUMERAL_TYPE whose values do not
5170 increase monotonically, O(N*log(N)) time may be needed. */
5172 mark_seen_cases (type, cases_seen, size, sparseness);
5174 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
5175 if (BITARRAY_TEST(cases_seen, i) == 0)
5176 warning ("enumeration value `%s' not handled in switch",
5177 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
5182 /* Now we go the other way around; we warn if there are case
5183 expressions that don't correspond to enumerators. This can
5184 occur since C and C++ don't enforce type-checking of
5185 assignments to enumeration variables. */
5187 if (case_stack->data.case_stmt.case_list
5188 && case_stack->data.case_stmt.case_list->left)
5189 case_stack->data.case_stmt.case_list
5190 = case_tree2list (case_stack->data.case_stmt.case_list, 0);
5192 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
5194 for (chain = TYPE_VALUES (type);
5195 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
5196 chain = TREE_CHAIN (chain))
5201 if (TYPE_NAME (type) == 0)
5202 warning ("case value `%ld' not in enumerated type",
5203 (long) TREE_INT_CST_LOW (n->low));
5205 warning ("case value `%ld' not in enumerated type `%s'",
5206 (long) TREE_INT_CST_LOW (n->low),
5207 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5210 : DECL_NAME (TYPE_NAME (type))));
5212 if (!tree_int_cst_equal (n->low, n->high))
5214 for (chain = TYPE_VALUES (type);
5215 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
5216 chain = TREE_CHAIN (chain))
5221 if (TYPE_NAME (type) == 0)
5222 warning ("case value `%ld' not in enumerated type",
5223 (long) TREE_INT_CST_LOW (n->high));
5225 warning ("case value `%ld' not in enumerated type `%s'",
5226 (long) TREE_INT_CST_LOW (n->high),
5227 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5230 : DECL_NAME (TYPE_NAME (type))));
5236 /* ??? This optimization is disabled because it causes valid programs to
5237 fail. ANSI C does not guarantee that an expression with enum type
5238 will have a value that is the same as one of the enumeration literals. */
5240 /* If all values were found as case labels, make one of them the default
5241 label. Thus, this switch will never fall through. We arbitrarily pick
5242 the last one to make the default since this is likely the most
5243 efficient choice. */
5247 for (l = &case_stack->data.case_stmt.case_list;
5252 case_stack->data.case_stmt.default_label = (*l)->code_label;
5259 /* Terminate a case (Pascal) or switch (C) statement
5260 in which ORIG_INDEX is the expression to be tested.
5261 Generate the code to test it and jump to the right place. */
5264 expand_end_case (orig_index)
5267 tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE, orig_minval;
5268 rtx default_label = 0;
5269 register struct case_node *n;
5277 register struct nesting *thiscase = case_stack;
5278 tree index_expr, index_type;
5281 /* Don't crash due to previous errors. */
5282 if (thiscase == NULL)
5285 table_label = gen_label_rtx ();
5286 index_expr = thiscase->data.case_stmt.index_expr;
5287 index_type = TREE_TYPE (index_expr);
5288 unsignedp = TREE_UNSIGNED (index_type);
5290 do_pending_stack_adjust ();
5292 /* This might get an spurious warning in the presence of a syntax error;
5293 it could be fixed by moving the call to check_seenlabel after the
5294 check for error_mark_node, and copying the code of check_seenlabel that
5295 deals with case_stack->data.case_stmt.line_number_status /
5296 restore_line_number_status in front of the call to end_cleanup_deferral;
5297 However, this might miss some useful warnings in the presence of
5298 non-syntax errors. */
5301 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5302 if (index_type != error_mark_node)
5304 /* If switch expression was an enumerated type, check that all
5305 enumeration literals are covered by the cases.
5306 No sense trying this if there's a default case, however. */
5308 if (!thiscase->data.case_stmt.default_label
5309 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
5310 && TREE_CODE (index_expr) != INTEGER_CST)
5311 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
5313 /* If we don't have a default-label, create one here,
5314 after the body of the switch. */
5315 if (thiscase->data.case_stmt.default_label == 0)
5317 thiscase->data.case_stmt.default_label
5318 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5319 expand_label (thiscase->data.case_stmt.default_label);
5321 default_label = label_rtx (thiscase->data.case_stmt.default_label);
5323 before_case = get_last_insn ();
5325 if (thiscase->data.case_stmt.case_list
5326 && thiscase->data.case_stmt.case_list->left)
5327 thiscase->data.case_stmt.case_list
5328 = case_tree2list(thiscase->data.case_stmt.case_list, 0);
5330 /* Simplify the case-list before we count it. */
5331 group_case_nodes (thiscase->data.case_stmt.case_list);
5333 /* Get upper and lower bounds of case values.
5334 Also convert all the case values to the index expr's data type. */
5337 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5339 /* Check low and high label values are integers. */
5340 if (TREE_CODE (n->low) != INTEGER_CST)
5342 if (TREE_CODE (n->high) != INTEGER_CST)
5345 n->low = convert (index_type, n->low);
5346 n->high = convert (index_type, n->high);
5348 /* Count the elements and track the largest and smallest
5349 of them (treating them as signed even if they are not). */
5357 if (INT_CST_LT (n->low, minval))
5359 if (INT_CST_LT (maxval, n->high))
5362 /* A range counts double, since it requires two compares. */
5363 if (! tree_int_cst_equal (n->low, n->high))
5367 orig_minval = minval;
5369 /* Compute span of values. */
5371 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
5373 end_cleanup_deferral ();
5377 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
5379 emit_jump (default_label);
5382 /* If range of values is much bigger than number of values,
5383 make a sequence of conditional branches instead of a dispatch.
5384 If the switch-index is a constant, do it this way
5385 because we can optimize it. */
5387 #ifndef CASE_VALUES_THRESHOLD
5389 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
5391 /* If machine does not have a case insn that compares the
5392 bounds, this means extra overhead for dispatch tables
5393 which raises the threshold for using them. */
5394 #define CASE_VALUES_THRESHOLD 5
5395 #endif /* HAVE_casesi */
5396 #endif /* CASE_VALUES_THRESHOLD */
5398 else if (count < CASE_VALUES_THRESHOLD
5399 || compare_tree_int (range, 10 * count) > 0
5400 /* RANGE may be signed, and really large ranges will show up
5401 as negative numbers. */
5402 || compare_tree_int (range, 0) < 0
5403 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5406 || TREE_CODE (index_expr) == INTEGER_CST
5407 /* These will reduce to a constant. */
5408 || (TREE_CODE (index_expr) == CALL_EXPR
5409 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
5410 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
5411 && DECL_BUILT_IN_CLASS (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_NORMAL
5412 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
5413 || (TREE_CODE (index_expr) == COMPOUND_EXPR
5414 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
5416 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5418 /* If the index is a short or char that we do not have
5419 an insn to handle comparisons directly, convert it to
5420 a full integer now, rather than letting each comparison
5421 generate the conversion. */
5423 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
5424 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
5425 == CODE_FOR_nothing))
5427 enum machine_mode wider_mode;
5428 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
5429 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
5430 if (cmp_optab->handlers[(int) wider_mode].insn_code
5431 != CODE_FOR_nothing)
5433 index = convert_to_mode (wider_mode, index, unsignedp);
5439 do_pending_stack_adjust ();
5441 index = protect_from_queue (index, 0);
5442 if (GET_CODE (index) == MEM)
5443 index = copy_to_reg (index);
5444 if (GET_CODE (index) == CONST_INT
5445 || TREE_CODE (index_expr) == INTEGER_CST)
5447 /* Make a tree node with the proper constant value
5448 if we don't already have one. */
5449 if (TREE_CODE (index_expr) != INTEGER_CST)
5452 = build_int_2 (INTVAL (index),
5453 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
5454 index_expr = convert (index_type, index_expr);
5457 /* For constant index expressions we need only
5458 issue a unconditional branch to the appropriate
5459 target code. The job of removing any unreachable
5460 code is left to the optimisation phase if the
5461 "-O" option is specified. */
5462 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5463 if (! tree_int_cst_lt (index_expr, n->low)
5464 && ! tree_int_cst_lt (n->high, index_expr))
5468 emit_jump (label_rtx (n->code_label));
5470 emit_jump (default_label);
5474 /* If the index expression is not constant we generate
5475 a binary decision tree to select the appropriate
5476 target code. This is done as follows:
5478 The list of cases is rearranged into a binary tree,
5479 nearly optimal assuming equal probability for each case.
5481 The tree is transformed into RTL, eliminating
5482 redundant test conditions at the same time.
5484 If program flow could reach the end of the
5485 decision tree an unconditional jump to the
5486 default code is emitted. */
5489 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
5490 && estimate_case_costs (thiscase->data.case_stmt.case_list));
5491 balance_case_nodes (&thiscase->data.case_stmt.case_list,
5493 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
5494 default_label, index_type);
5495 emit_jump_if_reachable (default_label);
5504 enum machine_mode index_mode = SImode;
5505 int index_bits = GET_MODE_BITSIZE (index_mode);
5507 enum machine_mode op_mode;
5509 /* Convert the index to SImode. */
5510 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
5511 > GET_MODE_BITSIZE (index_mode))
5513 enum machine_mode omode = TYPE_MODE (index_type);
5514 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
5516 /* We must handle the endpoints in the original mode. */
5517 index_expr = build (MINUS_EXPR, index_type,
5518 index_expr, minval);
5519 minval = integer_zero_node;
5520 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5521 emit_cmp_and_jump_insns (rangertx, index, LTU, NULL_RTX,
5522 omode, 1, 0, default_label);
5523 /* Now we can safely truncate. */
5524 index = convert_to_mode (index_mode, index, 0);
5528 if (TYPE_MODE (index_type) != index_mode)
5530 index_expr = convert (type_for_size (index_bits, 0),
5532 index_type = TREE_TYPE (index_expr);
5535 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5538 index = protect_from_queue (index, 0);
5539 do_pending_stack_adjust ();
5541 op_mode = insn_data[(int)CODE_FOR_casesi].operand[0].mode;
5542 if (! (*insn_data[(int)CODE_FOR_casesi].operand[0].predicate)
5544 index = copy_to_mode_reg (op_mode, index);
5546 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
5548 op_mode = insn_data[(int)CODE_FOR_casesi].operand[1].mode;
5549 if (! (*insn_data[(int)CODE_FOR_casesi].operand[1].predicate)
5551 op1 = copy_to_mode_reg (op_mode, op1);
5553 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
5555 op_mode = insn_data[(int)CODE_FOR_casesi].operand[2].mode;
5556 if (! (*insn_data[(int)CODE_FOR_casesi].operand[2].predicate)
5558 op2 = copy_to_mode_reg (op_mode, op2);
5560 emit_jump_insn (gen_casesi (index, op1, op2,
5561 table_label, default_label));
5565 #ifdef HAVE_tablejump
5566 if (! win && HAVE_tablejump)
5568 index_expr = convert (thiscase->data.case_stmt.nominal_type,
5569 fold (build (MINUS_EXPR, index_type,
5570 index_expr, minval)));
5571 index_type = TREE_TYPE (index_expr);
5572 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5574 index = protect_from_queue (index, 0);
5575 do_pending_stack_adjust ();
5577 do_tablejump (index, TYPE_MODE (index_type),
5578 expand_expr (range, NULL_RTX, VOIDmode, 0),
5579 table_label, default_label);
5586 /* Get table of labels to jump to, in order of case index. */
5588 ncases = TREE_INT_CST_LOW (range) + 1;
5589 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
5590 bzero ((char *) labelvec, ncases * sizeof (rtx));
5592 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5594 register HOST_WIDE_INT i
5595 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
5600 = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
5601 if (i + TREE_INT_CST_LOW (orig_minval)
5602 == TREE_INT_CST_LOW (n->high))
5608 /* Fill in the gaps with the default. */
5609 for (i = 0; i < ncases; i++)
5610 if (labelvec[i] == 0)
5611 labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
5613 /* Output the table */
5614 emit_label (table_label);
5616 if (CASE_VECTOR_PC_RELATIVE || flag_pic)
5617 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
5618 gen_rtx_LABEL_REF (Pmode, table_label),
5619 gen_rtvec_v (ncases, labelvec),
5620 const0_rtx, const0_rtx));
5622 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
5623 gen_rtvec_v (ncases, labelvec)));
5625 /* If the case insn drops through the table,
5626 after the table we must jump to the default-label.
5627 Otherwise record no drop-through after the table. */
5628 #ifdef CASE_DROPS_THROUGH
5629 emit_jump (default_label);
5635 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
5636 reorder_insns (before_case, get_last_insn (),
5637 thiscase->data.case_stmt.start);
5640 end_cleanup_deferral ();
5642 if (thiscase->exit_label)
5643 emit_label (thiscase->exit_label);
5645 POPSTACK (case_stack);
5650 /* Convert the tree NODE into a list linked by the right field, with the left
5651 field zeroed. RIGHT is used for recursion; it is a list to be placed
5652 rightmost in the resulting list. */
5654 static struct case_node *
5655 case_tree2list (node, right)
5656 struct case_node *node, *right;
5658 struct case_node *left;
5661 right = case_tree2list (node->right, right);
5663 node->right = right;
5664 if ((left = node->left))
5667 return case_tree2list (left, node);
5673 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5676 do_jump_if_equal (op1, op2, label, unsignedp)
5677 rtx op1, op2, label;
5680 if (GET_CODE (op1) == CONST_INT
5681 && GET_CODE (op2) == CONST_INT)
5683 if (INTVAL (op1) == INTVAL (op2))
5688 enum machine_mode mode = GET_MODE (op1);
5689 if (mode == VOIDmode)
5690 mode = GET_MODE (op2);
5691 emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX, mode, unsignedp,
5696 /* Not all case values are encountered equally. This function
5697 uses a heuristic to weight case labels, in cases where that
5698 looks like a reasonable thing to do.
5700 Right now, all we try to guess is text, and we establish the
5703 chars above space: 16
5712 If we find any cases in the switch that are not either -1 or in the range
5713 of valid ASCII characters, or are control characters other than those
5714 commonly used with "\", don't treat this switch scanning text.
5716 Return 1 if these nodes are suitable for cost estimation, otherwise
5720 estimate_case_costs (node)
5723 tree min_ascii = build_int_2 (-1, -1);
5724 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5728 /* If we haven't already made the cost table, make it now. Note that the
5729 lower bound of the table is -1, not zero. */
5731 if (cost_table == NULL)
5733 cost_table = cost_table_ + 1;
5735 for (i = 0; i < 128; i++)
5739 else if (ISPUNCT (i))
5741 else if (ISCNTRL (i))
5745 cost_table[' '] = 8;
5746 cost_table['\t'] = 4;
5747 cost_table['\0'] = 4;
5748 cost_table['\n'] = 2;
5749 cost_table['\f'] = 1;
5750 cost_table['\v'] = 1;
5751 cost_table['\b'] = 1;
5754 /* See if all the case expressions look like text. It is text if the
5755 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5756 as signed arithmetic since we don't want to ever access cost_table with a
5757 value less than -1. Also check that none of the constants in a range
5758 are strange control characters. */
5760 for (n = node; n; n = n->right)
5762 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5765 for (i = (HOST_WIDE_INT) TREE_INT_CST_LOW (n->low);
5766 i <= (HOST_WIDE_INT) TREE_INT_CST_LOW (n->high); i++)
5767 if (cost_table[i] < 0)
5771 /* All interesting values are within the range of interesting
5772 ASCII characters. */
5776 /* Scan an ordered list of case nodes
5777 combining those with consecutive values or ranges.
5779 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5782 group_case_nodes (head)
5785 case_node_ptr node = head;
5789 rtx lb = next_real_insn (label_rtx (node->code_label));
5791 case_node_ptr np = node;
5793 /* Try to group the successors of NODE with NODE. */
5794 while (((np = np->right) != 0)
5795 /* Do they jump to the same place? */
5796 && ((lb2 = next_real_insn (label_rtx (np->code_label))) == lb
5797 || (lb != 0 && lb2 != 0
5798 && simplejump_p (lb)
5799 && simplejump_p (lb2)
5800 && rtx_equal_p (SET_SRC (PATTERN (lb)),
5801 SET_SRC (PATTERN (lb2)))))
5802 /* Are their ranges consecutive? */
5803 && tree_int_cst_equal (np->low,
5804 fold (build (PLUS_EXPR,
5805 TREE_TYPE (node->high),
5808 /* An overflow is not consecutive. */
5809 && tree_int_cst_lt (node->high,
5810 fold (build (PLUS_EXPR,
5811 TREE_TYPE (node->high),
5813 integer_one_node))))
5815 node->high = np->high;
5817 /* NP is the first node after NODE which can't be grouped with it.
5818 Delete the nodes in between, and move on to that node. */
5824 /* Take an ordered list of case nodes
5825 and transform them into a near optimal binary tree,
5826 on the assumption that any target code selection value is as
5827 likely as any other.
5829 The transformation is performed by splitting the ordered
5830 list into two equal sections plus a pivot. The parts are
5831 then attached to the pivot as left and right branches. Each
5832 branch is then transformed recursively. */
5835 balance_case_nodes (head, parent)
5836 case_node_ptr *head;
5837 case_node_ptr parent;
5839 register case_node_ptr np;
5847 register case_node_ptr *npp;
5850 /* Count the number of entries on branch. Also count the ranges. */
5854 if (!tree_int_cst_equal (np->low, np->high))
5858 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5862 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5870 /* Split this list if it is long enough for that to help. */
5875 /* Find the place in the list that bisects the list's total cost,
5876 Here I gets half the total cost. */
5881 /* Skip nodes while their cost does not reach that amount. */
5882 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5883 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5884 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5887 npp = &(*npp)->right;
5892 /* Leave this branch lopsided, but optimize left-hand
5893 side and fill in `parent' fields for right-hand side. */
5895 np->parent = parent;
5896 balance_case_nodes (&np->left, np);
5897 for (; np->right; np = np->right)
5898 np->right->parent = np;
5902 /* If there are just three nodes, split at the middle one. */
5904 npp = &(*npp)->right;
5907 /* Find the place in the list that bisects the list's total cost,
5908 where ranges count as 2.
5909 Here I gets half the total cost. */
5910 i = (i + ranges + 1) / 2;
5913 /* Skip nodes while their cost does not reach that amount. */
5914 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5919 npp = &(*npp)->right;
5924 np->parent = parent;
5927 /* Optimize each of the two split parts. */
5928 balance_case_nodes (&np->left, np);
5929 balance_case_nodes (&np->right, np);
5933 /* Else leave this branch as one level,
5934 but fill in `parent' fields. */
5936 np->parent = parent;
5937 for (; np->right; np = np->right)
5938 np->right->parent = np;
5943 /* Search the parent sections of the case node tree
5944 to see if a test for the lower bound of NODE would be redundant.
5945 INDEX_TYPE is the type of the index expression.
5947 The instructions to generate the case decision tree are
5948 output in the same order as nodes are processed so it is
5949 known that if a parent node checks the range of the current
5950 node minus one that the current node is bounded at its lower
5951 span. Thus the test would be redundant. */
5954 node_has_low_bound (node, index_type)
5959 case_node_ptr pnode;
5961 /* If the lower bound of this node is the lowest value in the index type,
5962 we need not test it. */
5964 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5967 /* If this node has a left branch, the value at the left must be less
5968 than that at this node, so it cannot be bounded at the bottom and
5969 we need not bother testing any further. */
5974 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5975 node->low, integer_one_node));
5977 /* If the subtraction above overflowed, we can't verify anything.
5978 Otherwise, look for a parent that tests our value - 1. */
5980 if (! tree_int_cst_lt (low_minus_one, node->low))
5983 for (pnode = node->parent; pnode; pnode = pnode->parent)
5984 if (tree_int_cst_equal (low_minus_one, pnode->high))
5990 /* Search the parent sections of the case node tree
5991 to see if a test for the upper bound of NODE would be redundant.
5992 INDEX_TYPE is the type of the index expression.
5994 The instructions to generate the case decision tree are
5995 output in the same order as nodes are processed so it is
5996 known that if a parent node checks the range of the current
5997 node plus one that the current node is bounded at its upper
5998 span. Thus the test would be redundant. */
6001 node_has_high_bound (node, index_type)
6006 case_node_ptr pnode;
6008 /* If there is no upper bound, obviously no test is needed. */
6010 if (TYPE_MAX_VALUE (index_type) == NULL)
6013 /* If the upper bound of this node is the highest value in the type
6014 of the index expression, we need not test against it. */
6016 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
6019 /* If this node has a right branch, the value at the right must be greater
6020 than that at this node, so it cannot be bounded at the top and
6021 we need not bother testing any further. */
6026 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
6027 node->high, integer_one_node));
6029 /* If the addition above overflowed, we can't verify anything.
6030 Otherwise, look for a parent that tests our value + 1. */
6032 if (! tree_int_cst_lt (node->high, high_plus_one))
6035 for (pnode = node->parent; pnode; pnode = pnode->parent)
6036 if (tree_int_cst_equal (high_plus_one, pnode->low))
6042 /* Search the parent sections of the
6043 case node tree to see if both tests for the upper and lower
6044 bounds of NODE would be redundant. */
6047 node_is_bounded (node, index_type)
6051 return (node_has_low_bound (node, index_type)
6052 && node_has_high_bound (node, index_type));
6055 /* Emit an unconditional jump to LABEL unless it would be dead code. */
6058 emit_jump_if_reachable (label)
6061 if (GET_CODE (get_last_insn ()) != BARRIER)
6065 /* Emit step-by-step code to select a case for the value of INDEX.
6066 The thus generated decision tree follows the form of the
6067 case-node binary tree NODE, whose nodes represent test conditions.
6068 INDEX_TYPE is the type of the index of the switch.
6070 Care is taken to prune redundant tests from the decision tree
6071 by detecting any boundary conditions already checked by
6072 emitted rtx. (See node_has_high_bound, node_has_low_bound
6073 and node_is_bounded, above.)
6075 Where the test conditions can be shown to be redundant we emit
6076 an unconditional jump to the target code. As a further
6077 optimization, the subordinates of a tree node are examined to
6078 check for bounded nodes. In this case conditional and/or
6079 unconditional jumps as a result of the boundary check for the
6080 current node are arranged to target the subordinates associated
6081 code for out of bound conditions on the current node.
6083 We can assume that when control reaches the code generated here,
6084 the index value has already been compared with the parents
6085 of this node, and determined to be on the same side of each parent
6086 as this node is. Thus, if this node tests for the value 51,
6087 and a parent tested for 52, we don't need to consider
6088 the possibility of a value greater than 51. If another parent
6089 tests for the value 50, then this node need not test anything. */
6092 emit_case_nodes (index, node, default_label, index_type)
6098 /* If INDEX has an unsigned type, we must make unsigned branches. */
6099 int unsignedp = TREE_UNSIGNED (index_type);
6100 enum machine_mode mode = GET_MODE (index);
6102 /* See if our parents have already tested everything for us.
6103 If they have, emit an unconditional jump for this node. */
6104 if (node_is_bounded (node, index_type))
6105 emit_jump (label_rtx (node->code_label));
6107 else if (tree_int_cst_equal (node->low, node->high))
6109 /* Node is single valued. First see if the index expression matches
6110 this node and then check our children, if any. */
6112 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
6113 label_rtx (node->code_label), unsignedp);
6115 if (node->right != 0 && node->left != 0)
6117 /* This node has children on both sides.
6118 Dispatch to one side or the other
6119 by comparing the index value with this node's value.
6120 If one subtree is bounded, check that one first,
6121 so we can avoid real branches in the tree. */
6123 if (node_is_bounded (node->right, index_type))
6125 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6127 GT, NULL_RTX, mode, unsignedp, 0,
6128 label_rtx (node->right->code_label));
6129 emit_case_nodes (index, node->left, default_label, index_type);
6132 else if (node_is_bounded (node->left, index_type))
6134 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6136 LT, NULL_RTX, mode, unsignedp, 0,
6137 label_rtx (node->left->code_label));
6138 emit_case_nodes (index, node->right, default_label, index_type);
6143 /* Neither node is bounded. First distinguish the two sides;
6144 then emit the code for one side at a time. */
6147 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6149 /* See if the value is on the right. */
6150 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6152 GT, NULL_RTX, mode, unsignedp, 0,
6153 label_rtx (test_label));
6155 /* Value must be on the left.
6156 Handle the left-hand subtree. */
6157 emit_case_nodes (index, node->left, default_label, index_type);
6158 /* If left-hand subtree does nothing,
6160 emit_jump_if_reachable (default_label);
6162 /* Code branches here for the right-hand subtree. */
6163 expand_label (test_label);
6164 emit_case_nodes (index, node->right, default_label, index_type);
6168 else if (node->right != 0 && node->left == 0)
6170 /* Here we have a right child but no left so we issue conditional
6171 branch to default and process the right child.
6173 Omit the conditional branch to default if we it avoid only one
6174 right child; it costs too much space to save so little time. */
6176 if (node->right->right || node->right->left
6177 || !tree_int_cst_equal (node->right->low, node->right->high))
6179 if (!node_has_low_bound (node, index_type))
6181 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6184 LT, NULL_RTX, mode, unsignedp, 0,
6188 emit_case_nodes (index, node->right, default_label, index_type);
6191 /* We cannot process node->right normally
6192 since we haven't ruled out the numbers less than
6193 this node's value. So handle node->right explicitly. */
6194 do_jump_if_equal (index,
6195 expand_expr (node->right->low, NULL_RTX,
6197 label_rtx (node->right->code_label), unsignedp);
6200 else if (node->right == 0 && node->left != 0)
6202 /* Just one subtree, on the left. */
6204 #if 0 /* The following code and comment were formerly part
6205 of the condition here, but they didn't work
6206 and I don't understand what the idea was. -- rms. */
6207 /* If our "most probable entry" is less probable
6208 than the default label, emit a jump to
6209 the default label using condition codes
6210 already lying around. With no right branch,
6211 a branch-greater-than will get us to the default
6214 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
6217 if (node->left->left || node->left->right
6218 || !tree_int_cst_equal (node->left->low, node->left->high))
6220 if (!node_has_high_bound (node, index_type))
6222 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6225 GT, NULL_RTX, mode, unsignedp, 0,
6229 emit_case_nodes (index, node->left, default_label, index_type);
6232 /* We cannot process node->left normally
6233 since we haven't ruled out the numbers less than
6234 this node's value. So handle node->left explicitly. */
6235 do_jump_if_equal (index,
6236 expand_expr (node->left->low, NULL_RTX,
6238 label_rtx (node->left->code_label), unsignedp);
6243 /* Node is a range. These cases are very similar to those for a single
6244 value, except that we do not start by testing whether this node
6245 is the one to branch to. */
6247 if (node->right != 0 && node->left != 0)
6249 /* Node has subtrees on both sides.
6250 If the right-hand subtree is bounded,
6251 test for it first, since we can go straight there.
6252 Otherwise, we need to make a branch in the control structure,
6253 then handle the two subtrees. */
6254 tree test_label = 0;
6257 if (node_is_bounded (node->right, index_type))
6258 /* Right hand node is fully bounded so we can eliminate any
6259 testing and branch directly to the target code. */
6260 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6262 GT, NULL_RTX, mode, unsignedp, 0,
6263 label_rtx (node->right->code_label));
6266 /* Right hand node requires testing.
6267 Branch to a label where we will handle it later. */
6269 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6270 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6272 GT, NULL_RTX, mode, unsignedp, 0,
6273 label_rtx (test_label));
6276 /* Value belongs to this node or to the left-hand subtree. */
6278 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6280 GE, NULL_RTX, mode, unsignedp, 0,
6281 label_rtx (node->code_label));
6283 /* Handle the left-hand subtree. */
6284 emit_case_nodes (index, node->left, default_label, index_type);
6286 /* If right node had to be handled later, do that now. */
6290 /* If the left-hand subtree fell through,
6291 don't let it fall into the right-hand subtree. */
6292 emit_jump_if_reachable (default_label);
6294 expand_label (test_label);
6295 emit_case_nodes (index, node->right, default_label, index_type);
6299 else if (node->right != 0 && node->left == 0)
6301 /* Deal with values to the left of this node,
6302 if they are possible. */
6303 if (!node_has_low_bound (node, index_type))
6305 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6307 LT, NULL_RTX, mode, unsignedp, 0,
6311 /* Value belongs to this node or to the right-hand subtree. */
6313 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6315 LE, NULL_RTX, mode, unsignedp, 0,
6316 label_rtx (node->code_label));
6318 emit_case_nodes (index, node->right, default_label, index_type);
6321 else if (node->right == 0 && node->left != 0)
6323 /* Deal with values to the right of this node,
6324 if they are possible. */
6325 if (!node_has_high_bound (node, index_type))
6327 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6329 GT, NULL_RTX, mode, unsignedp, 0,
6333 /* Value belongs to this node or to the left-hand subtree. */
6335 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6337 GE, NULL_RTX, mode, unsignedp, 0,
6338 label_rtx (node->code_label));
6340 emit_case_nodes (index, node->left, default_label, index_type);
6345 /* Node has no children so we check low and high bounds to remove
6346 redundant tests. Only one of the bounds can exist,
6347 since otherwise this node is bounded--a case tested already. */
6349 if (!node_has_high_bound (node, index_type))
6351 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6353 GT, NULL_RTX, mode, unsignedp, 0,
6357 if (!node_has_low_bound (node, index_type))
6359 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6361 LT, NULL_RTX, mode, unsignedp, 0,
6365 emit_jump (label_rtx (node->code_label));