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;
1314 const char *filename;
1317 rtvec argvec, constraints;
1319 int ninputs = list_length (inputs);
1320 int noutputs = list_length (outputs);
1325 /* Vector of RTX's of evaluated output operands. */
1326 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1327 int *inout_opnum = (int *) alloca (noutputs * sizeof (int));
1328 rtx *real_output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1329 enum machine_mode *inout_mode
1330 = (enum machine_mode *) alloca (noutputs * sizeof (enum machine_mode));
1331 /* The insn we have emitted. */
1334 /* An ASM with no outputs needs to be treated as volatile, for now. */
1338 if (current_function_check_memory_usage)
1340 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1344 #ifdef MD_ASM_CLOBBERS
1345 /* Sometimes we wish to automatically clobber registers across an asm.
1346 Case in point is when the i386 backend moved from cc0 to a hard reg --
1347 maintaining source-level compatability means automatically clobbering
1348 the flags register. */
1349 MD_ASM_CLOBBERS (clobbers);
1352 if (current_function_check_memory_usage)
1354 error ("`asm' cannot be used in function where memory usage is checked");
1358 /* Count the number of meaningful clobbered registers, ignoring what
1359 we would ignore later. */
1361 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1363 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1365 i = decode_reg_name (regname);
1366 if (i >= 0 || i == -4)
1369 error ("unknown register name `%s' in `asm'", regname);
1374 /* Check that the number of alternatives is constant across all
1376 if (outputs || inputs)
1378 tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
1379 int nalternatives = n_occurrences (',', TREE_STRING_POINTER (tmp));
1382 if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
1384 error ("too many alternatives in `asm'");
1391 const char *constraint = TREE_STRING_POINTER (TREE_PURPOSE (tmp));
1393 if (n_occurrences (',', constraint) != nalternatives)
1395 error ("operand constraints for `asm' differ in number of alternatives");
1399 if (TREE_CHAIN (tmp))
1400 tmp = TREE_CHAIN (tmp);
1402 tmp = next, next = 0;
1406 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1408 tree val = TREE_VALUE (tail);
1409 tree type = TREE_TYPE (val);
1418 /* If there's an erroneous arg, emit no insn. */
1419 if (TREE_TYPE (val) == error_mark_node)
1422 /* Make sure constraint has `=' and does not have `+'. Also, see
1423 if it allows any register. Be liberal on the latter test, since
1424 the worst that happens if we get it wrong is we issue an error
1427 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1428 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1430 /* Allow the `=' or `+' to not be at the beginning of the string,
1431 since it wasn't explicitly documented that way, and there is a
1432 large body of code that puts it last. Swap the character to
1433 the front, so as not to uglify any place else. */
1437 if ((p = strchr (constraint, '=')) != NULL)
1439 if ((p = strchr (constraint, '+')) != NULL)
1442 error ("output operand constraint lacks `='");
1446 if (p != constraint)
1449 bcopy (constraint, constraint+1, p-constraint);
1452 warning ("output constraint `%c' for operand %d is not at the beginning", j, i);
1455 is_inout = constraint[0] == '+';
1456 /* Replace '+' with '='. */
1457 constraint[0] = '=';
1458 /* Make sure we can specify the matching operand. */
1459 if (is_inout && i > 9)
1461 error ("output operand constraint %d contains `+'", i);
1465 for (j = 1; j < c_len; j++)
1466 switch (constraint[j])
1470 error ("operand constraint contains '+' or '=' at illegal position.");
1474 if (i + 1 == ninputs + noutputs)
1476 error ("`%%' constraint used with last operand");
1481 case '?': case '!': case '*': case '&':
1482 case 'E': case 'F': case 'G': case 'H':
1483 case 's': case 'i': case 'n':
1484 case 'I': case 'J': case 'K': case 'L': case 'M':
1485 case 'N': case 'O': case 'P': case ',':
1486 #ifdef EXTRA_CONSTRAINT
1487 case 'Q': case 'R': case 'S': case 'T': case 'U':
1491 case '0': case '1': case '2': case '3': case '4':
1492 case '5': case '6': case '7': case '8': case '9':
1493 error ("matching constraint not valid in output operand");
1496 case 'V': case 'm': case 'o':
1501 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1502 excepting those that expand_call created. So match memory
1518 /* If an output operand is not a decl or indirect ref and our constraint
1519 allows a register, make a temporary to act as an intermediate.
1520 Make the asm insn write into that, then our caller will copy it to
1521 the real output operand. Likewise for promoted variables. */
1523 real_output_rtx[i] = NULL_RTX;
1524 if ((TREE_CODE (val) == INDIRECT_REF
1527 && (allows_mem || GET_CODE (DECL_RTL (val)) == REG)
1528 && ! (GET_CODE (DECL_RTL (val)) == REG
1529 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
1534 mark_addressable (TREE_VALUE (tail));
1537 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode,
1538 EXPAND_MEMORY_USE_WO);
1540 if (! allows_reg && GET_CODE (output_rtx[i]) != MEM)
1541 error ("output number %d not directly addressable", i);
1542 if (! allows_mem && GET_CODE (output_rtx[i]) == MEM)
1544 real_output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1545 output_rtx[i] = gen_reg_rtx (GET_MODE (output_rtx[i]));
1547 emit_move_insn (output_rtx[i], real_output_rtx[i]);
1552 output_rtx[i] = assign_temp (type, 0, 0, 1);
1553 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1558 inout_mode[ninout] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)));
1559 inout_opnum[ninout++] = i;
1564 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1566 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1570 /* Make vectors for the expression-rtx and constraint strings. */
1572 argvec = rtvec_alloc (ninputs);
1573 constraints = rtvec_alloc (ninputs);
1575 body = gen_rtx_ASM_OPERANDS (VOIDmode, TREE_STRING_POINTER (string),
1576 empty_string, 0, argvec, constraints,
1579 MEM_VOLATILE_P (body) = vol;
1581 /* Eval the inputs and put them into ARGVEC.
1582 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1585 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1588 int allows_reg = 0, allows_mem = 0;
1589 char *constraint, *orig_constraint;
1593 /* If there's an erroneous arg, emit no insn,
1594 because the ASM_INPUT would get VOIDmode
1595 and that could cause a crash in reload. */
1596 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1599 /* ??? Can this happen, and does the error message make any sense? */
1600 if (TREE_PURPOSE (tail) == NULL_TREE)
1602 error ("hard register `%s' listed as input operand to `asm'",
1603 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1607 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1608 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1609 orig_constraint = constraint;
1611 /* Make sure constraint has neither `=', `+', nor '&'. */
1613 for (j = 0; j < c_len; j++)
1614 switch (constraint[j])
1616 case '+': case '=': case '&':
1617 if (constraint == orig_constraint)
1619 error ("input operand constraint contains `%c'",
1626 if (constraint == orig_constraint
1627 && i + 1 == ninputs - ninout)
1629 error ("`%%' constraint used with last operand");
1634 case 'V': case 'm': case 'o':
1639 case '?': case '!': case '*':
1640 case 'E': case 'F': case 'G': case 'H': case 'X':
1641 case 's': case 'i': case 'n':
1642 case 'I': case 'J': case 'K': case 'L': case 'M':
1643 case 'N': case 'O': case 'P': case ',':
1644 #ifdef EXTRA_CONSTRAINT
1645 case 'Q': case 'R': case 'S': case 'T': case 'U':
1649 /* Whether or not a numeric constraint allows a register is
1650 decided by the matching constraint, and so there is no need
1651 to do anything special with them. We must handle them in
1652 the default case, so that we don't unnecessarily force
1653 operands to memory. */
1654 case '0': case '1': case '2': case '3': case '4':
1655 case '5': case '6': case '7': case '8': case '9':
1656 if (constraint[j] >= '0' + noutputs)
1659 ("matching constraint references invalid operand number");
1663 /* Try and find the real constraint for this dup. */
1664 if ((j == 0 && c_len == 1)
1665 || (j == 1 && c_len == 2 && constraint[0] == '%'))
1669 for (j = constraint[j] - '0'; j > 0; --j)
1672 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (o)));
1673 constraint = TREE_STRING_POINTER (TREE_PURPOSE (o));
1678 /* ... fall through ... */
1691 if (! allows_reg && allows_mem)
1692 mark_addressable (TREE_VALUE (tail));
1694 op = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1696 if (asm_operand_ok (op, constraint) <= 0)
1699 op = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), op);
1700 else if (!allows_mem)
1701 warning ("asm operand %d probably doesn't match constraints", i);
1702 else if (CONSTANT_P (op))
1703 op = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1705 else if (GET_CODE (op) == REG
1706 || GET_CODE (op) == SUBREG
1707 || GET_CODE (op) == CONCAT)
1709 tree type = TREE_TYPE (TREE_VALUE (tail));
1710 rtx memloc = assign_temp (type, 1, 1, 1);
1712 emit_move_insn (memloc, op);
1716 else if (GET_CODE (op) == MEM && MEM_VOLATILE_P (op))
1717 /* We won't recognize volatile memory as available a
1718 memory_operand at this point. Ignore it. */
1720 else if (queued_subexp_p (op))
1723 /* ??? Leave this only until we have experience with what
1724 happens in combine and elsewhere when constraints are
1726 warning ("asm operand %d probably doesn't match constraints", i);
1728 XVECEXP (body, 3, i) = op;
1730 XVECEXP (body, 4, i) /* constraints */
1731 = gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1736 /* Protect all the operands from the queue now that they have all been
1739 for (i = 0; i < ninputs - ninout; i++)
1740 XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0);
1742 for (i = 0; i < noutputs; i++)
1743 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1745 /* For in-out operands, copy output rtx to input rtx. */
1746 for (i = 0; i < ninout; i++)
1748 int j = inout_opnum[i];
1750 XVECEXP (body, 3, ninputs - ninout + i) /* argvec */
1752 XVECEXP (body, 4, ninputs - ninout + i) /* constraints */
1753 = gen_rtx_ASM_INPUT (inout_mode[i], digit_strings[j]);
1756 /* Now, for each output, construct an rtx
1757 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1758 ARGVEC CONSTRAINTS))
1759 If there is more than one, put them inside a PARALLEL. */
1761 if (noutputs == 1 && nclobbers == 0)
1763 XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1764 insn = emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
1767 else if (noutputs == 0 && nclobbers == 0)
1769 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1770 insn = emit_insn (body);
1781 body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
1783 /* For each output operand, store a SET. */
1784 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1786 XVECEXP (body, 0, i)
1787 = gen_rtx_SET (VOIDmode,
1789 gen_rtx_ASM_OPERANDS
1791 TREE_STRING_POINTER (string),
1792 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1793 i, argvec, constraints,
1796 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1799 /* If there are no outputs (but there are some clobbers)
1800 store the bare ASM_OPERANDS into the PARALLEL. */
1803 XVECEXP (body, 0, i++) = obody;
1805 /* Store (clobber REG) for each clobbered register specified. */
1807 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1809 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1810 int j = decode_reg_name (regname);
1814 if (j == -3) /* `cc', which is not a register */
1817 if (j == -4) /* `memory', don't cache memory across asm */
1819 XVECEXP (body, 0, i++)
1820 = gen_rtx_CLOBBER (VOIDmode,
1823 gen_rtx_SCRATCH (VOIDmode)));
1827 /* Ignore unknown register, error already signaled. */
1831 /* Use QImode since that's guaranteed to clobber just one reg. */
1832 XVECEXP (body, 0, i++)
1833 = gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (QImode, j));
1836 insn = emit_insn (body);
1839 /* For any outputs that needed reloading into registers, spill them
1840 back to where they belong. */
1841 for (i = 0; i < noutputs; ++i)
1842 if (real_output_rtx[i])
1843 emit_move_insn (real_output_rtx[i], output_rtx[i]);
1848 /* Generate RTL to evaluate the expression EXP
1849 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1852 expand_expr_stmt (exp)
1855 /* If -W, warn about statements with no side effects,
1856 except for an explicit cast to void (e.g. for assert()), and
1857 except inside a ({...}) where they may be useful. */
1858 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1860 if (! TREE_SIDE_EFFECTS (exp)
1861 && (extra_warnings || warn_unused_value)
1862 && !(TREE_CODE (exp) == CONVERT_EXPR
1863 && TREE_TYPE (exp) == void_type_node))
1864 warning_with_file_and_line (emit_filename, emit_lineno,
1865 "statement with no effect");
1866 else if (warn_unused_value)
1867 warn_if_unused_value (exp);
1870 /* If EXP is of function type and we are expanding statements for
1871 value, convert it to pointer-to-function. */
1872 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1873 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1875 last_expr_type = TREE_TYPE (exp);
1876 last_expr_value = expand_expr (exp,
1877 (expr_stmts_for_value
1878 ? NULL_RTX : const0_rtx),
1881 /* If all we do is reference a volatile value in memory,
1882 copy it to a register to be sure it is actually touched. */
1883 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1884 && TREE_THIS_VOLATILE (exp))
1886 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1888 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1889 copy_to_reg (last_expr_value);
1892 rtx lab = gen_label_rtx ();
1894 /* Compare the value with itself to reference it. */
1895 emit_cmp_and_jump_insns (last_expr_value, last_expr_value, EQ,
1896 expand_expr (TYPE_SIZE (last_expr_type),
1897 NULL_RTX, VOIDmode, 0),
1899 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT,
1905 /* If this expression is part of a ({...}) and is in memory, we may have
1906 to preserve temporaries. */
1907 preserve_temp_slots (last_expr_value);
1909 /* Free any temporaries used to evaluate this expression. Any temporary
1910 used as a result of this expression will already have been preserved
1917 /* Warn if EXP contains any computations whose results are not used.
1918 Return 1 if a warning is printed; 0 otherwise. */
1921 warn_if_unused_value (exp)
1924 if (TREE_USED (exp))
1927 switch (TREE_CODE (exp))
1929 case PREINCREMENT_EXPR:
1930 case POSTINCREMENT_EXPR:
1931 case PREDECREMENT_EXPR:
1932 case POSTDECREMENT_EXPR:
1937 case METHOD_CALL_EXPR:
1939 case TRY_CATCH_EXPR:
1940 case WITH_CLEANUP_EXPR:
1942 /* We don't warn about COND_EXPR because it may be a useful
1943 construct if either arm contains a side effect. */
1948 /* For a binding, warn if no side effect within it. */
1949 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1952 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1954 case TRUTH_ORIF_EXPR:
1955 case TRUTH_ANDIF_EXPR:
1956 /* In && or ||, warn if 2nd operand has no side effect. */
1957 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1960 if (TREE_NO_UNUSED_WARNING (exp))
1962 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
1964 /* Let people do `(foo (), 0)' without a warning. */
1965 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1967 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1971 case NON_LVALUE_EXPR:
1972 /* Don't warn about values cast to void. */
1973 if (TREE_TYPE (exp) == void_type_node)
1975 /* Don't warn about conversions not explicit in the user's program. */
1976 if (TREE_NO_UNUSED_WARNING (exp))
1978 /* Assignment to a cast usually results in a cast of a modify.
1979 Don't complain about that. There can be an arbitrary number of
1980 casts before the modify, so we must loop until we find the first
1981 non-cast expression and then test to see if that is a modify. */
1983 tree tem = TREE_OPERAND (exp, 0);
1985 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1986 tem = TREE_OPERAND (tem, 0);
1988 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
1989 || TREE_CODE (tem) == CALL_EXPR)
1995 /* Don't warn about automatic dereferencing of references, since
1996 the user cannot control it. */
1997 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
1998 return warn_if_unused_value (TREE_OPERAND (exp, 0));
1999 /* ... fall through ... */
2002 /* Referencing a volatile value is a side effect, so don't warn. */
2004 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
2005 && TREE_THIS_VOLATILE (exp))
2008 warning_with_file_and_line (emit_filename, emit_lineno,
2009 "value computed is not used");
2014 /* Clear out the memory of the last expression evaluated. */
2022 /* Begin a statement which will return a value.
2023 Return the RTL_EXPR for this statement expr.
2024 The caller must save that value and pass it to expand_end_stmt_expr. */
2027 expand_start_stmt_expr ()
2032 /* Make the RTL_EXPR node temporary, not momentary,
2033 so that rtl_expr_chain doesn't become garbage. */
2034 momentary = suspend_momentary ();
2035 t = make_node (RTL_EXPR);
2036 resume_momentary (momentary);
2037 do_pending_stack_adjust ();
2038 start_sequence_for_rtl_expr (t);
2040 expr_stmts_for_value++;
2044 /* Restore the previous state at the end of a statement that returns a value.
2045 Returns a tree node representing the statement's value and the
2046 insns to compute the value.
2048 The nodes of that expression have been freed by now, so we cannot use them.
2049 But we don't want to do that anyway; the expression has already been
2050 evaluated and now we just want to use the value. So generate a RTL_EXPR
2051 with the proper type and RTL value.
2053 If the last substatement was not an expression,
2054 return something with type `void'. */
2057 expand_end_stmt_expr (t)
2062 if (last_expr_type == 0)
2064 last_expr_type = void_type_node;
2065 last_expr_value = const0_rtx;
2067 else if (last_expr_value == 0)
2068 /* There are some cases where this can happen, such as when the
2069 statement is void type. */
2070 last_expr_value = const0_rtx;
2071 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
2072 /* Remove any possible QUEUED. */
2073 last_expr_value = protect_from_queue (last_expr_value, 0);
2077 TREE_TYPE (t) = last_expr_type;
2078 RTL_EXPR_RTL (t) = last_expr_value;
2079 RTL_EXPR_SEQUENCE (t) = get_insns ();
2081 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
2085 /* Don't consider deleting this expr or containing exprs at tree level. */
2086 TREE_SIDE_EFFECTS (t) = 1;
2087 /* Propagate volatility of the actual RTL expr. */
2088 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
2091 expr_stmts_for_value--;
2096 /* Generate RTL for the start of an if-then. COND is the expression
2097 whose truth should be tested.
2099 If EXITFLAG is nonzero, this conditional is visible to
2100 `exit_something'. */
2103 expand_start_cond (cond, exitflag)
2107 struct nesting *thiscond = ALLOC_NESTING ();
2109 /* Make an entry on cond_stack for the cond we are entering. */
2111 thiscond->next = cond_stack;
2112 thiscond->all = nesting_stack;
2113 thiscond->depth = ++nesting_depth;
2114 thiscond->data.cond.next_label = gen_label_rtx ();
2115 /* Before we encounter an `else', we don't need a separate exit label
2116 unless there are supposed to be exit statements
2117 to exit this conditional. */
2118 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
2119 thiscond->data.cond.endif_label = thiscond->exit_label;
2120 cond_stack = thiscond;
2121 nesting_stack = thiscond;
2123 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
2126 /* Generate RTL between then-clause and the elseif-clause
2127 of an if-then-elseif-.... */
2130 expand_start_elseif (cond)
2133 if (cond_stack->data.cond.endif_label == 0)
2134 cond_stack->data.cond.endif_label = gen_label_rtx ();
2135 emit_jump (cond_stack->data.cond.endif_label);
2136 emit_label (cond_stack->data.cond.next_label);
2137 cond_stack->data.cond.next_label = gen_label_rtx ();
2138 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2141 /* Generate RTL between the then-clause and the else-clause
2142 of an if-then-else. */
2145 expand_start_else ()
2147 if (cond_stack->data.cond.endif_label == 0)
2148 cond_stack->data.cond.endif_label = gen_label_rtx ();
2150 emit_jump (cond_stack->data.cond.endif_label);
2151 emit_label (cond_stack->data.cond.next_label);
2152 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
2155 /* After calling expand_start_else, turn this "else" into an "else if"
2156 by providing another condition. */
2159 expand_elseif (cond)
2162 cond_stack->data.cond.next_label = gen_label_rtx ();
2163 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2166 /* Generate RTL for the end of an if-then.
2167 Pop the record for it off of cond_stack. */
2172 struct nesting *thiscond = cond_stack;
2174 do_pending_stack_adjust ();
2175 if (thiscond->data.cond.next_label)
2176 emit_label (thiscond->data.cond.next_label);
2177 if (thiscond->data.cond.endif_label)
2178 emit_label (thiscond->data.cond.endif_label);
2180 POPSTACK (cond_stack);
2186 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2187 loop should be exited by `exit_something'. This is a loop for which
2188 `expand_continue' will jump to the top of the loop.
2190 Make an entry on loop_stack to record the labels associated with
2194 expand_start_loop (exit_flag)
2197 register struct nesting *thisloop = ALLOC_NESTING ();
2199 /* Make an entry on loop_stack for the loop we are entering. */
2201 thisloop->next = loop_stack;
2202 thisloop->all = nesting_stack;
2203 thisloop->depth = ++nesting_depth;
2204 thisloop->data.loop.start_label = gen_label_rtx ();
2205 thisloop->data.loop.end_label = gen_label_rtx ();
2206 thisloop->data.loop.alt_end_label = 0;
2207 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2208 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2209 loop_stack = thisloop;
2210 nesting_stack = thisloop;
2212 do_pending_stack_adjust ();
2214 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2215 emit_label (thisloop->data.loop.start_label);
2220 /* Like expand_start_loop but for a loop where the continuation point
2221 (for expand_continue_loop) will be specified explicitly. */
2224 expand_start_loop_continue_elsewhere (exit_flag)
2227 struct nesting *thisloop = expand_start_loop (exit_flag);
2228 loop_stack->data.loop.continue_label = gen_label_rtx ();
2232 /* Specify the continuation point for a loop started with
2233 expand_start_loop_continue_elsewhere.
2234 Use this at the point in the code to which a continue statement
2238 expand_loop_continue_here ()
2240 do_pending_stack_adjust ();
2241 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2242 emit_label (loop_stack->data.loop.continue_label);
2245 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2246 Pop the block off of loop_stack. */
2251 rtx start_label = loop_stack->data.loop.start_label;
2252 rtx insn = get_last_insn ();
2253 int needs_end_jump = 1;
2255 /* Mark the continue-point at the top of the loop if none elsewhere. */
2256 if (start_label == loop_stack->data.loop.continue_label)
2257 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2259 do_pending_stack_adjust ();
2261 /* If optimizing, perhaps reorder the loop.
2262 First, try to use a condjump near the end.
2263 expand_exit_loop_if_false ends loops with unconditional jumps,
2266 if (test) goto label;
2268 goto loop_stack->data.loop.end_label
2272 If we find such a pattern, we can end the loop earlier. */
2275 && GET_CODE (insn) == CODE_LABEL
2276 && LABEL_NAME (insn) == NULL
2277 && GET_CODE (PREV_INSN (insn)) == BARRIER)
2280 rtx jump = PREV_INSN (PREV_INSN (label));
2282 if (GET_CODE (jump) == JUMP_INSN
2283 && GET_CODE (PATTERN (jump)) == SET
2284 && SET_DEST (PATTERN (jump)) == pc_rtx
2285 && GET_CODE (SET_SRC (PATTERN (jump))) == LABEL_REF
2286 && (XEXP (SET_SRC (PATTERN (jump)), 0)
2287 == loop_stack->data.loop.end_label))
2291 /* The test might be complex and reference LABEL multiple times,
2292 like the loop in loop_iterations to set vtop. To handle this,
2294 insn = PREV_INSN (label);
2295 reorder_insns (label, label, start_label);
2297 for (prev = PREV_INSN (jump); ; prev = PREV_INSN (prev))
2299 /* We ignore line number notes, but if we see any other note,
2300 in particular NOTE_INSN_BLOCK_*, NOTE_INSN_EH_REGION_*,
2301 NOTE_INSN_LOOP_*, we disable this optimization. */
2302 if (GET_CODE (prev) == NOTE)
2304 if (NOTE_LINE_NUMBER (prev) < 0)
2308 if (GET_CODE (prev) == CODE_LABEL)
2310 if (GET_CODE (prev) == JUMP_INSN)
2312 if (GET_CODE (PATTERN (prev)) == SET
2313 && SET_DEST (PATTERN (prev)) == pc_rtx
2314 && GET_CODE (SET_SRC (PATTERN (prev))) == IF_THEN_ELSE
2315 && (GET_CODE (XEXP (SET_SRC (PATTERN (prev)), 1))
2317 && XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0) == label)
2319 XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0)
2321 emit_note_after (NOTE_INSN_LOOP_END, prev);
2330 /* If the loop starts with a loop exit, roll that to the end where
2331 it will optimize together with the jump back.
2333 We look for the conditional branch to the exit, except that once
2334 we find such a branch, we don't look past 30 instructions.
2336 In more detail, if the loop presently looks like this (in pseudo-C):
2339 if (test) goto end_label;
2344 transform it to look like:
2350 if (test) goto end_label;
2351 goto newstart_label;
2354 Here, the `test' may actually consist of some reasonably complex
2355 code, terminating in a test. */
2360 ! (GET_CODE (insn) == JUMP_INSN
2361 && GET_CODE (PATTERN (insn)) == SET
2362 && SET_DEST (PATTERN (insn)) == pc_rtx
2363 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2367 rtx last_test_insn = NULL_RTX;
2369 /* Scan insns from the top of the loop looking for a qualified
2370 conditional exit. */
2371 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2372 insn = NEXT_INSN (insn))
2374 if (GET_CODE (insn) == NOTE)
2377 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2378 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2379 /* The code that actually moves the exit test will
2380 carefully leave BLOCK notes in their original
2381 location. That means, however, that we can't debug
2382 the exit test itself. So, we refuse to move code
2383 containing BLOCK notes at low optimization levels. */
2386 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG)
2388 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)
2392 /* We've come to the end of an EH region, but
2393 never saw the beginning of that region. That
2394 means that an EH region begins before the top
2395 of the loop, and ends in the middle of it. The
2396 existence of such a situation violates a basic
2397 assumption in this code, since that would imply
2398 that even when EH_REGIONS is zero, we might
2399 move code out of an exception region. */
2403 /* We must not walk into a nested loop. */
2404 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
2407 /* We already know this INSN is a NOTE, so there's no
2408 point in looking at it to see if it's a JUMP. */
2412 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2415 if (last_test_insn && num_insns > 30)
2419 /* We don't want to move a partial EH region. Consider:
2433 This isn't legal C++, but here's what it's supposed to
2434 mean: if cond() is true, stop looping. Otherwise,
2435 call bar, and keep looping. In addition, if cond
2436 throws an exception, catch it and keep looping. Such
2437 constructs are certainy legal in LISP.
2439 We should not move the `if (cond()) 0' test since then
2440 the EH-region for the try-block would be broken up.
2441 (In this case we would the EH_BEG note for the `try'
2442 and `if cond()' but not the call to bar() or the
2445 So we don't look for tests within an EH region. */
2448 if (GET_CODE (insn) == JUMP_INSN
2449 && GET_CODE (PATTERN (insn)) == SET
2450 && SET_DEST (PATTERN (insn)) == pc_rtx)
2452 /* This is indeed a jump. */
2453 rtx dest1 = NULL_RTX;
2454 rtx dest2 = NULL_RTX;
2455 rtx potential_last_test;
2456 if (GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE)
2458 /* A conditional jump. */
2459 dest1 = XEXP (SET_SRC (PATTERN (insn)), 1);
2460 dest2 = XEXP (SET_SRC (PATTERN (insn)), 2);
2461 potential_last_test = insn;
2465 /* An unconditional jump. */
2466 dest1 = SET_SRC (PATTERN (insn));
2467 /* Include the BARRIER after the JUMP. */
2468 potential_last_test = NEXT_INSN (insn);
2472 if (dest1 && GET_CODE (dest1) == LABEL_REF
2473 && ((XEXP (dest1, 0)
2474 == loop_stack->data.loop.alt_end_label)
2476 == loop_stack->data.loop.end_label)))
2478 last_test_insn = potential_last_test;
2482 /* If this was a conditional jump, there may be
2483 another label at which we should look. */
2490 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2492 /* We found one. Move everything from there up
2493 to the end of the loop, and add a jump into the loop
2494 to jump to there. */
2495 register rtx newstart_label = gen_label_rtx ();
2496 register rtx start_move = start_label;
2499 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2500 then we want to move this note also. */
2501 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2502 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2503 == NOTE_INSN_LOOP_CONT))
2504 start_move = PREV_INSN (start_move);
2506 emit_label_after (newstart_label, PREV_INSN (start_move));
2508 /* Actually move the insns. Start at the beginning, and
2509 keep copying insns until we've copied the
2511 for (insn = start_move; insn; insn = next_insn)
2513 /* Figure out which insn comes after this one. We have
2514 to do this before we move INSN. */
2515 if (insn == last_test_insn)
2516 /* We've moved all the insns. */
2517 next_insn = NULL_RTX;
2519 next_insn = NEXT_INSN (insn);
2521 if (GET_CODE (insn) == NOTE
2522 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2523 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2524 /* We don't want to move NOTE_INSN_BLOCK_BEGs or
2525 NOTE_INSN_BLOCK_ENDs because the correct generation
2526 of debugging information depends on these appearing
2527 in the same order in the RTL and in the tree
2528 structure, where they are represented as BLOCKs.
2529 So, we don't move block notes. Of course, moving
2530 the code inside the block is likely to make it
2531 impossible to debug the instructions in the exit
2532 test, but such is the price of optimization. */
2535 /* Move the INSN. */
2536 reorder_insns (insn, insn, get_last_insn ());
2539 emit_jump_insn_after (gen_jump (start_label),
2540 PREV_INSN (newstart_label));
2541 emit_barrier_after (PREV_INSN (newstart_label));
2542 start_label = newstart_label;
2548 emit_jump (start_label);
2549 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2551 emit_label (loop_stack->data.loop.end_label);
2553 POPSTACK (loop_stack);
2558 /* Generate a jump to the current loop's continue-point.
2559 This is usually the top of the loop, but may be specified
2560 explicitly elsewhere. If not currently inside a loop,
2561 return 0 and do nothing; caller will print an error message. */
2564 expand_continue_loop (whichloop)
2565 struct nesting *whichloop;
2569 whichloop = loop_stack;
2572 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2577 /* Generate a jump to exit the current loop. If not currently inside a loop,
2578 return 0 and do nothing; caller will print an error message. */
2581 expand_exit_loop (whichloop)
2582 struct nesting *whichloop;
2586 whichloop = loop_stack;
2589 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2593 /* Generate a conditional jump to exit the current loop if COND
2594 evaluates to zero. If not currently inside a loop,
2595 return 0 and do nothing; caller will print an error message. */
2598 expand_exit_loop_if_false (whichloop, cond)
2599 struct nesting *whichloop;
2602 rtx label = gen_label_rtx ();
2607 whichloop = loop_stack;
2610 /* In order to handle fixups, we actually create a conditional jump
2611 around a unconditional branch to exit the loop. If fixups are
2612 necessary, they go before the unconditional branch. */
2615 do_jump (cond, NULL_RTX, label);
2616 last_insn = get_last_insn ();
2617 if (GET_CODE (last_insn) == CODE_LABEL)
2618 whichloop->data.loop.alt_end_label = last_insn;
2619 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2626 /* Return nonzero if the loop nest is empty. Else return zero. */
2629 stmt_loop_nest_empty ()
2631 /* cfun->stmt can be NULL if we are building a call to get the
2632 EH context for a setjmp/longjmp EH target and the current
2633 function was a deferred inline function. */
2634 return (cfun->stmt == NULL || loop_stack == NULL);
2637 /* Return non-zero if we should preserve sub-expressions as separate
2638 pseudos. We never do so if we aren't optimizing. We always do so
2639 if -fexpensive-optimizations.
2641 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2642 the loop may still be a small one. */
2645 preserve_subexpressions_p ()
2649 if (flag_expensive_optimizations)
2652 if (optimize == 0 || cfun == 0 || cfun->stmt == 0 || loop_stack == 0)
2655 insn = get_last_insn_anywhere ();
2658 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2659 < n_non_fixed_regs * 3));
2663 /* Generate a jump to exit the current loop, conditional, binding contour
2664 or case statement. Not all such constructs are visible to this function,
2665 only those started with EXIT_FLAG nonzero. Individual languages use
2666 the EXIT_FLAG parameter to control which kinds of constructs you can
2669 If not currently inside anything that can be exited,
2670 return 0 and do nothing; caller will print an error message. */
2673 expand_exit_something ()
2677 for (n = nesting_stack; n; n = n->all)
2678 if (n->exit_label != 0)
2680 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2687 /* Generate RTL to return from the current function, with no value.
2688 (That is, we do not do anything about returning any value.) */
2691 expand_null_return ()
2693 struct nesting *block = block_stack;
2694 rtx last_insn = get_last_insn ();
2696 /* If this function was declared to return a value, but we
2697 didn't, clobber the return registers so that they are not
2698 propogated live to the rest of the function. */
2699 clobber_return_register ();
2701 /* Does any pending block have cleanups? */
2702 while (block && block->data.block.cleanups == 0)
2703 block = block->next;
2705 /* If yes, use a goto to return, since that runs cleanups. */
2707 expand_null_return_1 (last_insn, block != 0);
2710 /* Generate RTL to return from the current function, with value VAL. */
2713 expand_value_return (val)
2716 struct nesting *block = block_stack;
2717 rtx last_insn = get_last_insn ();
2718 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2720 /* Copy the value to the return location
2721 unless it's already there. */
2723 if (return_reg != val)
2725 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2726 #ifdef PROMOTE_FUNCTION_RETURN
2727 int unsignedp = TREE_UNSIGNED (type);
2728 enum machine_mode old_mode
2729 = DECL_MODE (DECL_RESULT (current_function_decl));
2730 enum machine_mode mode
2731 = promote_mode (type, old_mode, &unsignedp, 1);
2733 if (mode != old_mode)
2734 val = convert_modes (mode, old_mode, val, unsignedp);
2736 if (GET_CODE (return_reg) == PARALLEL)
2737 emit_group_load (return_reg, val, int_size_in_bytes (type),
2740 emit_move_insn (return_reg, val);
2743 /* Does any pending block have cleanups? */
2745 while (block && block->data.block.cleanups == 0)
2746 block = block->next;
2748 /* If yes, use a goto to return, since that runs cleanups.
2749 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2751 expand_null_return_1 (last_insn, block != 0);
2754 /* Output a return with no value. If LAST_INSN is nonzero,
2755 pretend that the return takes place after LAST_INSN.
2756 If USE_GOTO is nonzero then don't use a return instruction;
2757 go to the return label instead. This causes any cleanups
2758 of pending blocks to be executed normally. */
2761 expand_null_return_1 (last_insn, use_goto)
2765 rtx end_label = cleanup_label ? cleanup_label : return_label;
2767 clear_pending_stack_adjust ();
2768 do_pending_stack_adjust ();
2771 /* PCC-struct return always uses an epilogue. */
2772 if (current_function_returns_pcc_struct || use_goto)
2775 end_label = return_label = gen_label_rtx ();
2776 expand_goto_internal (NULL_TREE, end_label, last_insn);
2780 /* Otherwise output a simple return-insn if one is available,
2781 unless it won't do the job. */
2783 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2785 emit_jump_insn (gen_return ());
2791 /* Otherwise jump to the epilogue. */
2792 expand_goto_internal (NULL_TREE, end_label, last_insn);
2795 /* Generate RTL to evaluate the expression RETVAL and return it
2796 from the current function. */
2799 expand_return (retval)
2802 /* If there are any cleanups to be performed, then they will
2803 be inserted following LAST_INSN. It is desirable
2804 that the last_insn, for such purposes, should be the
2805 last insn before computing the return value. Otherwise, cleanups
2806 which call functions can clobber the return value. */
2807 /* ??? rms: I think that is erroneous, because in C++ it would
2808 run destructors on variables that might be used in the subsequent
2809 computation of the return value. */
2811 rtx result_rtl = DECL_RTL (DECL_RESULT (current_function_decl));
2812 register rtx val = 0;
2819 /* If function wants no value, give it none. */
2820 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2822 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2824 expand_null_return ();
2828 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2829 /* This is not sufficient. We also need to watch for cleanups of the
2830 expression we are about to expand. Unfortunately, we cannot know
2831 if it has cleanups until we expand it, and we want to change how we
2832 expand it depending upon if we need cleanups. We can't win. */
2834 cleanups = any_pending_cleanups (1);
2839 if (TREE_CODE (retval) == RESULT_DECL)
2840 retval_rhs = retval;
2841 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2842 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2843 retval_rhs = TREE_OPERAND (retval, 1);
2844 else if (TREE_TYPE (retval) == void_type_node)
2845 /* Recognize tail-recursive call to void function. */
2846 retval_rhs = retval;
2848 retval_rhs = NULL_TREE;
2850 /* Only use `last_insn' if there are cleanups which must be run. */
2851 if (cleanups || cleanup_label != 0)
2852 last_insn = get_last_insn ();
2854 /* Distribute return down conditional expr if either of the sides
2855 may involve tail recursion (see test below). This enhances the number
2856 of tail recursions we see. Don't do this always since it can produce
2857 sub-optimal code in some cases and we distribute assignments into
2858 conditional expressions when it would help. */
2860 if (optimize && retval_rhs != 0
2861 && frame_offset == 0
2862 && TREE_CODE (retval_rhs) == COND_EXPR
2863 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2864 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2866 rtx label = gen_label_rtx ();
2869 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2870 start_cleanup_deferral ();
2871 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2872 DECL_RESULT (current_function_decl),
2873 TREE_OPERAND (retval_rhs, 1));
2874 TREE_SIDE_EFFECTS (expr) = 1;
2875 expand_return (expr);
2878 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2879 DECL_RESULT (current_function_decl),
2880 TREE_OPERAND (retval_rhs, 2));
2881 TREE_SIDE_EFFECTS (expr) = 1;
2882 expand_return (expr);
2883 end_cleanup_deferral ();
2887 /* Attempt to optimize the call if it is tail recursive. */
2888 if (flag_optimize_sibling_calls
2889 && retval_rhs != NULL_TREE
2890 && frame_offset == 0
2891 && TREE_CODE (retval_rhs) == CALL_EXPR
2892 && TREE_CODE (TREE_OPERAND (retval_rhs, 0)) == ADDR_EXPR
2893 && (TREE_OPERAND (TREE_OPERAND (retval_rhs, 0), 0)
2894 == current_function_decl)
2895 && optimize_tail_recursion (TREE_OPERAND (retval_rhs, 1), last_insn))
2899 /* This optimization is safe if there are local cleanups
2900 because expand_null_return takes care of them.
2901 ??? I think it should also be safe when there is a cleanup label,
2902 because expand_null_return takes care of them, too.
2903 Any reason why not? */
2904 if (HAVE_return && cleanup_label == 0
2905 && ! current_function_returns_pcc_struct
2906 && BRANCH_COST <= 1)
2908 /* If this is return x == y; then generate
2909 if (x == y) return 1; else return 0;
2910 if we can do it with explicit return insns and branches are cheap,
2911 but not if we have the corresponding scc insn. */
2914 switch (TREE_CODE (retval_rhs))
2940 case TRUTH_ANDIF_EXPR:
2941 case TRUTH_ORIF_EXPR:
2942 case TRUTH_AND_EXPR:
2944 case TRUTH_NOT_EXPR:
2945 case TRUTH_XOR_EXPR:
2948 op0 = gen_label_rtx ();
2949 jumpifnot (retval_rhs, op0);
2950 expand_value_return (const1_rtx);
2952 expand_value_return (const0_rtx);
2961 #endif /* HAVE_return */
2963 /* If the result is an aggregate that is being returned in one (or more)
2964 registers, load the registers here. The compiler currently can't handle
2965 copying a BLKmode value into registers. We could put this code in a
2966 more general area (for use by everyone instead of just function
2967 call/return), but until this feature is generally usable it is kept here
2968 (and in expand_call). The value must go into a pseudo in case there
2969 are cleanups that will clobber the real return register. */
2972 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2973 && GET_CODE (result_rtl) == REG)
2976 unsigned HOST_WIDE_INT bitpos, xbitpos;
2977 unsigned HOST_WIDE_INT big_endian_correction = 0;
2978 unsigned HOST_WIDE_INT bytes
2979 = int_size_in_bytes (TREE_TYPE (retval_rhs));
2980 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2981 unsigned int bitsize
2982 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)), BITS_PER_WORD);
2983 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2984 rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
2985 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2986 enum machine_mode tmpmode, result_reg_mode;
2988 /* Structures whose size is not a multiple of a word are aligned
2989 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
2990 machine, this means we must skip the empty high order bytes when
2991 calculating the bit offset. */
2992 if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD)
2993 big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
2996 /* Copy the structure BITSIZE bits at a time. */
2997 for (bitpos = 0, xbitpos = big_endian_correction;
2998 bitpos < bytes * BITS_PER_UNIT;
2999 bitpos += bitsize, xbitpos += bitsize)
3001 /* We need a new destination pseudo each time xbitpos is
3002 on a word boundary and when xbitpos == big_endian_correction
3003 (the first time through). */
3004 if (xbitpos % BITS_PER_WORD == 0
3005 || xbitpos == big_endian_correction)
3007 /* Generate an appropriate register. */
3008 dst = gen_reg_rtx (word_mode);
3009 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
3011 /* Clobber the destination before we move anything into it. */
3012 emit_insn (gen_rtx_CLOBBER (VOIDmode, dst));
3015 /* We need a new source operand each time bitpos is on a word
3017 if (bitpos % BITS_PER_WORD == 0)
3018 src = operand_subword_force (result_val,
3019 bitpos / BITS_PER_WORD,
3022 /* Use bitpos for the source extraction (left justified) and
3023 xbitpos for the destination store (right justified). */
3024 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
3025 extract_bit_field (src, bitsize,
3026 bitpos % BITS_PER_WORD, 1,
3027 NULL_RTX, word_mode, word_mode,
3028 bitsize, BITS_PER_WORD),
3029 bitsize, BITS_PER_WORD);
3032 /* Find the smallest integer mode large enough to hold the
3033 entire structure and use that mode instead of BLKmode
3034 on the USE insn for the return register. */
3035 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
3036 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
3037 tmpmode != VOIDmode;
3038 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
3040 /* Have we found a large enough mode? */
3041 if (GET_MODE_SIZE (tmpmode) >= bytes)
3045 /* No suitable mode found. */
3046 if (tmpmode == VOIDmode)
3049 PUT_MODE (result_rtl, tmpmode);
3051 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
3052 result_reg_mode = word_mode;
3054 result_reg_mode = tmpmode;
3055 result_reg = gen_reg_rtx (result_reg_mode);
3058 for (i = 0; i < n_regs; i++)
3059 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
3062 if (tmpmode != result_reg_mode)
3063 result_reg = gen_lowpart (tmpmode, result_reg);
3065 expand_value_return (result_reg);
3069 && TREE_TYPE (retval_rhs) != void_type_node
3070 && (GET_CODE (result_rtl) == REG
3071 || (GET_CODE (result_rtl) == PARALLEL)))
3073 /* Calculate the return value into a temporary (usually a pseudo
3075 val = assign_temp (TREE_TYPE (DECL_RESULT (current_function_decl)),
3077 val = expand_expr (retval_rhs, val, GET_MODE (val), 0);
3078 val = force_not_mem (val);
3080 /* Return the calculated value, doing cleanups first. */
3081 expand_value_return (val);
3085 /* No cleanups or no hard reg used;
3086 calculate value into hard return reg. */
3087 expand_expr (retval, const0_rtx, VOIDmode, 0);
3089 expand_value_return (result_rtl);
3093 /* Return 1 if the end of the generated RTX is not a barrier.
3094 This means code already compiled can drop through. */
3097 drop_through_at_end_p ()
3099 rtx insn = get_last_insn ();
3100 while (insn && GET_CODE (insn) == NOTE)
3101 insn = PREV_INSN (insn);
3102 return insn && GET_CODE (insn) != BARRIER;
3105 /* Attempt to optimize a potential tail recursion call into a goto.
3106 ARGUMENTS are the arguments to a CALL_EXPR; LAST_INSN indicates
3107 where to place the jump to the tail recursion label.
3109 Return TRUE if the call was optimized into a goto. */
3112 optimize_tail_recursion (arguments, last_insn)
3116 /* Finish checking validity, and if valid emit code to set the
3117 argument variables for the new call. */
3118 if (tail_recursion_args (arguments, DECL_ARGUMENTS (current_function_decl)))
3120 if (tail_recursion_label == 0)
3122 tail_recursion_label = gen_label_rtx ();
3123 emit_label_after (tail_recursion_label,
3124 tail_recursion_reentry);
3127 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
3134 /* Emit code to alter this function's formal parms for a tail-recursive call.
3135 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3136 FORMALS is the chain of decls of formals.
3137 Return 1 if this can be done;
3138 otherwise return 0 and do not emit any code. */
3141 tail_recursion_args (actuals, formals)
3142 tree actuals, formals;
3144 register tree a = actuals, f = formals;
3146 register rtx *argvec;
3148 /* Check that number and types of actuals are compatible
3149 with the formals. This is not always true in valid C code.
3150 Also check that no formal needs to be addressable
3151 and that all formals are scalars. */
3153 /* Also count the args. */
3155 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
3157 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a)))
3158 != TYPE_MAIN_VARIANT (TREE_TYPE (f)))
3160 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
3163 if (a != 0 || f != 0)
3166 /* Compute all the actuals. */
3168 argvec = (rtx *) alloca (i * sizeof (rtx));
3170 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3171 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
3173 /* Find which actual values refer to current values of previous formals.
3174 Copy each of them now, before any formal is changed. */
3176 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3180 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
3181 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
3182 { copy = 1; break; }
3184 argvec[i] = copy_to_reg (argvec[i]);
3187 /* Store the values of the actuals into the formals. */
3189 for (f = formals, a = actuals, i = 0; f;
3190 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
3192 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
3193 emit_move_insn (DECL_RTL (f), argvec[i]);
3195 convert_move (DECL_RTL (f), argvec[i],
3196 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
3203 /* Generate the RTL code for entering a binding contour.
3204 The variables are declared one by one, by calls to `expand_decl'.
3206 FLAGS is a bitwise or of the following flags:
3208 1 - Nonzero if this construct should be visible to
3211 2 - Nonzero if this contour does not require a
3212 NOTE_INSN_BLOCK_BEG note. Virtually all calls from
3213 language-independent code should set this flag because they
3214 will not create corresponding BLOCK nodes. (There should be
3215 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
3216 and BLOCKs.) If this flag is set, MARK_ENDS should be zero
3217 when expand_end_bindings is called.
3219 If we are creating a NOTE_INSN_BLOCK_BEG note, a BLOCK may
3220 optionally be supplied. If so, it becomes the NOTE_BLOCK for the
3224 expand_start_bindings_and_block (flags, block)
3228 struct nesting *thisblock = ALLOC_NESTING ();
3230 int exit_flag = ((flags & 1) != 0);
3231 int block_flag = ((flags & 2) == 0);
3233 /* If a BLOCK is supplied, then the caller should be requesting a
3234 NOTE_INSN_BLOCK_BEG note. */
3235 if (!block_flag && block)
3238 /* Create a note to mark the beginning of the block. */
3241 note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
3242 NOTE_BLOCK (note) = block;
3245 note = emit_note (NULL_PTR, NOTE_INSN_DELETED);
3247 /* Make an entry on block_stack for the block we are entering. */
3249 thisblock->next = block_stack;
3250 thisblock->all = nesting_stack;
3251 thisblock->depth = ++nesting_depth;
3252 thisblock->data.block.stack_level = 0;
3253 thisblock->data.block.cleanups = 0;
3254 thisblock->data.block.n_function_calls = 0;
3255 thisblock->data.block.exception_region = 0;
3256 thisblock->data.block.block_target_temp_slot_level = target_temp_slot_level;
3258 thisblock->data.block.conditional_code = 0;
3259 thisblock->data.block.last_unconditional_cleanup = note;
3260 /* When we insert instructions after the last unconditional cleanup,
3261 we don't adjust last_insn. That means that a later add_insn will
3262 clobber the instructions we've just added. The easiest way to
3263 fix this is to just insert another instruction here, so that the
3264 instructions inserted after the last unconditional cleanup are
3265 never the last instruction. */
3266 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3267 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
3270 && !(block_stack->data.block.cleanups == NULL_TREE
3271 && block_stack->data.block.outer_cleanups == NULL_TREE))
3272 thisblock->data.block.outer_cleanups
3273 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
3274 block_stack->data.block.outer_cleanups);
3276 thisblock->data.block.outer_cleanups = 0;
3277 thisblock->data.block.label_chain = 0;
3278 thisblock->data.block.innermost_stack_block = stack_block_stack;
3279 thisblock->data.block.first_insn = note;
3280 thisblock->data.block.block_start_count = ++current_block_start_count;
3281 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
3282 block_stack = thisblock;
3283 nesting_stack = thisblock;
3285 /* Make a new level for allocating stack slots. */
3289 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3290 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3291 expand_expr are made. After we end the region, we know that all
3292 space for all temporaries that were created by TARGET_EXPRs will be
3293 destroyed and their space freed for reuse. */
3296 expand_start_target_temps ()
3298 /* This is so that even if the result is preserved, the space
3299 allocated will be freed, as we know that it is no longer in use. */
3302 /* Start a new binding layer that will keep track of all cleanup
3303 actions to be performed. */
3304 expand_start_bindings (2);
3306 target_temp_slot_level = temp_slot_level;
3310 expand_end_target_temps ()
3312 expand_end_bindings (NULL_TREE, 0, 0);
3314 /* This is so that even if the result is preserved, the space
3315 allocated will be freed, as we know that it is no longer in use. */
3319 /* Given a pointer to a BLOCK node return non-zero if (and only if) the node
3320 in question represents the outermost pair of curly braces (i.e. the "body
3321 block") of a function or method.
3323 For any BLOCK node representing a "body block" of a function or method, the
3324 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
3325 represents the outermost (function) scope for the function or method (i.e.
3326 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
3327 *that* node in turn will point to the relevant FUNCTION_DECL node. */
3330 is_body_block (stmt)
3333 if (TREE_CODE (stmt) == BLOCK)
3335 tree parent = BLOCK_SUPERCONTEXT (stmt);
3337 if (parent && TREE_CODE (parent) == BLOCK)
3339 tree grandparent = BLOCK_SUPERCONTEXT (parent);
3341 if (grandparent && TREE_CODE (grandparent) == FUNCTION_DECL)
3349 /* Mark top block of block_stack as an implicit binding for an
3350 exception region. This is used to prevent infinite recursion when
3351 ending a binding with expand_end_bindings. It is only ever called
3352 by expand_eh_region_start, as that it the only way to create a
3353 block stack for a exception region. */
3356 mark_block_as_eh_region ()
3358 block_stack->data.block.exception_region = 1;
3359 if (block_stack->next
3360 && block_stack->next->data.block.conditional_code)
3362 block_stack->data.block.conditional_code
3363 = block_stack->next->data.block.conditional_code;
3364 block_stack->data.block.last_unconditional_cleanup
3365 = block_stack->next->data.block.last_unconditional_cleanup;
3366 block_stack->data.block.cleanup_ptr
3367 = block_stack->next->data.block.cleanup_ptr;
3371 /* True if we are currently emitting insns in an area of output code
3372 that is controlled by a conditional expression. This is used by
3373 the cleanup handling code to generate conditional cleanup actions. */
3376 conditional_context ()
3378 return block_stack && block_stack->data.block.conditional_code;
3381 /* Mark top block of block_stack as not for an implicit binding for an
3382 exception region. This is only ever done by expand_eh_region_end
3383 to let expand_end_bindings know that it is being called explicitly
3384 to end the binding layer for just the binding layer associated with
3385 the exception region, otherwise expand_end_bindings would try and
3386 end all implicit binding layers for exceptions regions, and then
3387 one normal binding layer. */
3390 mark_block_as_not_eh_region ()
3392 block_stack->data.block.exception_region = 0;
3395 /* True if the top block of block_stack was marked as for an exception
3396 region by mark_block_as_eh_region. */
3401 return cfun && block_stack && block_stack->data.block.exception_region;
3404 /* Emit a handler label for a nonlocal goto handler.
3405 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3408 expand_nl_handler_label (slot, before_insn)
3409 rtx slot, before_insn;
3412 rtx handler_label = gen_label_rtx ();
3414 /* Don't let jump_optimize delete the handler. */
3415 LABEL_PRESERVE_P (handler_label) = 1;
3418 emit_move_insn (slot, gen_rtx_LABEL_REF (Pmode, handler_label));
3419 insns = get_insns ();
3421 emit_insns_before (insns, before_insn);
3423 emit_label (handler_label);
3425 return handler_label;
3428 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3431 expand_nl_goto_receiver ()
3433 #ifdef HAVE_nonlocal_goto
3434 if (! HAVE_nonlocal_goto)
3436 /* First adjust our frame pointer to its actual value. It was
3437 previously set to the start of the virtual area corresponding to
3438 the stacked variables when we branched here and now needs to be
3439 adjusted to the actual hardware fp value.
3441 Assignments are to virtual registers are converted by
3442 instantiate_virtual_regs into the corresponding assignment
3443 to the underlying register (fp in this case) that makes
3444 the original assignment true.
3445 So the following insn will actually be
3446 decrementing fp by STARTING_FRAME_OFFSET. */
3447 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3449 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3450 if (fixed_regs[ARG_POINTER_REGNUM])
3452 #ifdef ELIMINABLE_REGS
3453 /* If the argument pointer can be eliminated in favor of the
3454 frame pointer, we don't need to restore it. We assume here
3455 that if such an elimination is present, it can always be used.
3456 This is the case on all known machines; if we don't make this
3457 assumption, we do unnecessary saving on many machines. */
3458 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3461 for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
3462 if (elim_regs[i].from == ARG_POINTER_REGNUM
3463 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3466 if (i == sizeof elim_regs / sizeof elim_regs [0])
3469 /* Now restore our arg pointer from the address at which it
3470 was saved in our stack frame.
3471 If there hasn't be space allocated for it yet, make
3473 if (arg_pointer_save_area == 0)
3474 arg_pointer_save_area
3475 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3476 emit_move_insn (virtual_incoming_args_rtx,
3477 /* We need a pseudo here, or else
3478 instantiate_virtual_regs_1 complains. */
3479 copy_to_reg (arg_pointer_save_area));
3484 #ifdef HAVE_nonlocal_goto_receiver
3485 if (HAVE_nonlocal_goto_receiver)
3486 emit_insn (gen_nonlocal_goto_receiver ());
3490 /* Make handlers for nonlocal gotos taking place in the function calls in
3494 expand_nl_goto_receivers (thisblock)
3495 struct nesting *thisblock;
3498 rtx afterward = gen_label_rtx ();
3503 /* Record the handler address in the stack slot for that purpose,
3504 during this block, saving and restoring the outer value. */
3505 if (thisblock->next != 0)
3506 for (slot = nonlocal_goto_handler_slots; slot; slot = XEXP (slot, 1))
3508 rtx save_receiver = gen_reg_rtx (Pmode);
3509 emit_move_insn (XEXP (slot, 0), save_receiver);
3512 emit_move_insn (save_receiver, XEXP (slot, 0));
3513 insns = get_insns ();
3515 emit_insns_before (insns, thisblock->data.block.first_insn);
3518 /* Jump around the handlers; they run only when specially invoked. */
3519 emit_jump (afterward);
3521 /* Make a separate handler for each label. */
3522 link = nonlocal_labels;
3523 slot = nonlocal_goto_handler_slots;
3524 label_list = NULL_RTX;
3525 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3526 /* Skip any labels we shouldn't be able to jump to from here,
3527 we generate one special handler for all of them below which just calls
3529 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3532 lab = expand_nl_handler_label (XEXP (slot, 0),
3533 thisblock->data.block.first_insn);
3534 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3536 expand_nl_goto_receiver ();
3538 /* Jump to the "real" nonlocal label. */
3539 expand_goto (TREE_VALUE (link));
3542 /* A second pass over all nonlocal labels; this time we handle those
3543 we should not be able to jump to at this point. */
3544 link = nonlocal_labels;
3545 slot = nonlocal_goto_handler_slots;
3547 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3548 if (DECL_TOO_LATE (TREE_VALUE (link)))
3551 lab = expand_nl_handler_label (XEXP (slot, 0),
3552 thisblock->data.block.first_insn);
3553 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3559 expand_nl_goto_receiver ();
3560 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "abort"), 0,
3565 nonlocal_goto_handler_labels = label_list;
3566 emit_label (afterward);
3569 /* Warn about any unused VARS (which may contain nodes other than
3570 VAR_DECLs, but such nodes are ignored). The nodes are connected
3571 via the TREE_CHAIN field. */
3574 warn_about_unused_variables (vars)
3579 if (warn_unused_variable)
3580 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3581 if (TREE_CODE (decl) == VAR_DECL
3582 && ! TREE_USED (decl)
3583 && ! DECL_IN_SYSTEM_HEADER (decl)
3584 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
3585 warning_with_decl (decl, "unused variable `%s'");
3588 /* Generate RTL code to terminate a binding contour.
3590 VARS is the chain of VAR_DECL nodes for the variables bound in this
3591 contour. There may actually be other nodes in this chain, but any
3592 nodes other than VAR_DECLS are ignored.
3594 MARK_ENDS is nonzero if we should put a note at the beginning
3595 and end of this binding contour.
3597 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3598 (That is true automatically if the contour has a saved stack level.) */
3601 expand_end_bindings (vars, mark_ends, dont_jump_in)
3606 register struct nesting *thisblock;
3608 while (block_stack->data.block.exception_region)
3610 /* Because we don't need or want a new temporary level and
3611 because we didn't create one in expand_eh_region_start,
3612 create a fake one now to avoid removing one in
3613 expand_end_bindings. */
3616 block_stack->data.block.exception_region = 0;
3618 expand_end_bindings (NULL_TREE, 0, 0);
3621 /* Since expand_eh_region_start does an expand_start_bindings, we
3622 have to first end all the bindings that were created by
3623 expand_eh_region_start. */
3625 thisblock = block_stack;
3627 /* If any of the variables in this scope were not used, warn the
3629 warn_about_unused_variables (vars);
3631 if (thisblock->exit_label)
3633 do_pending_stack_adjust ();
3634 emit_label (thisblock->exit_label);
3637 /* If necessary, make handlers for nonlocal gotos taking
3638 place in the function calls in this block. */
3639 if (function_call_count != thisblock->data.block.n_function_calls
3641 /* Make handler for outermost block
3642 if there were any nonlocal gotos to this function. */
3643 && (thisblock->next == 0 ? current_function_has_nonlocal_label
3644 /* Make handler for inner block if it has something
3645 special to do when you jump out of it. */
3646 : (thisblock->data.block.cleanups != 0
3647 || thisblock->data.block.stack_level != 0)))
3648 expand_nl_goto_receivers (thisblock);
3650 /* Don't allow jumping into a block that has a stack level.
3651 Cleanups are allowed, though. */
3653 || thisblock->data.block.stack_level != 0)
3655 struct label_chain *chain;
3657 /* Any labels in this block are no longer valid to go to.
3658 Mark them to cause an error message. */
3659 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3661 DECL_TOO_LATE (chain->label) = 1;
3662 /* If any goto without a fixup came to this label,
3663 that must be an error, because gotos without fixups
3664 come from outside all saved stack-levels. */
3665 if (TREE_ADDRESSABLE (chain->label))
3666 error_with_decl (chain->label,
3667 "label `%s' used before containing binding contour");
3671 /* Restore stack level in effect before the block
3672 (only if variable-size objects allocated). */
3673 /* Perform any cleanups associated with the block. */
3675 if (thisblock->data.block.stack_level != 0
3676 || thisblock->data.block.cleanups != 0)
3681 /* Don't let cleanups affect ({...}) constructs. */
3682 int old_expr_stmts_for_value = expr_stmts_for_value;
3683 rtx old_last_expr_value = last_expr_value;
3684 tree old_last_expr_type = last_expr_type;
3685 expr_stmts_for_value = 0;
3687 /* Only clean up here if this point can actually be reached. */
3688 insn = get_last_insn ();
3689 if (GET_CODE (insn) == NOTE)
3690 insn = prev_nonnote_insn (insn);
3691 reachable = (! insn || GET_CODE (insn) != BARRIER);
3693 /* Do the cleanups. */
3694 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3696 do_pending_stack_adjust ();
3698 expr_stmts_for_value = old_expr_stmts_for_value;
3699 last_expr_value = old_last_expr_value;
3700 last_expr_type = old_last_expr_type;
3702 /* Restore the stack level. */
3704 if (reachable && thisblock->data.block.stack_level != 0)
3706 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3707 thisblock->data.block.stack_level, NULL_RTX);
3708 if (nonlocal_goto_handler_slots != 0)
3709 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3713 /* Any gotos out of this block must also do these things.
3714 Also report any gotos with fixups that came to labels in this
3716 fixup_gotos (thisblock,
3717 thisblock->data.block.stack_level,
3718 thisblock->data.block.cleanups,
3719 thisblock->data.block.first_insn,
3723 /* Mark the beginning and end of the scope if requested.
3724 We do this now, after running cleanups on the variables
3725 just going out of scope, so they are in scope for their cleanups. */
3729 rtx note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3730 NOTE_BLOCK (note) = NOTE_BLOCK (thisblock->data.block.first_insn);
3733 /* Get rid of the beginning-mark if we don't make an end-mark. */
3734 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3736 /* Restore the temporary level of TARGET_EXPRs. */
3737 target_temp_slot_level = thisblock->data.block.block_target_temp_slot_level;
3739 /* Restore block_stack level for containing block. */
3741 stack_block_stack = thisblock->data.block.innermost_stack_block;
3742 POPSTACK (block_stack);
3744 /* Pop the stack slot nesting and free any slots at this level. */
3748 /* Generate RTL for the automatic variable declaration DECL.
3749 (Other kinds of declarations are simply ignored if seen here.) */
3755 struct nesting *thisblock;
3758 type = TREE_TYPE (decl);
3760 /* Only automatic variables need any expansion done.
3761 Static and external variables, and external functions,
3762 will be handled by `assemble_variable' (called from finish_decl).
3763 TYPE_DECL and CONST_DECL require nothing.
3764 PARM_DECLs are handled in `assign_parms'. */
3766 if (TREE_CODE (decl) != VAR_DECL)
3768 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3771 thisblock = block_stack;
3773 /* Create the RTL representation for the variable. */
3775 if (type == error_mark_node)
3776 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, const0_rtx);
3777 else if (DECL_SIZE (decl) == 0)
3778 /* Variable with incomplete type. */
3780 if (DECL_INITIAL (decl) == 0)
3781 /* Error message was already done; now avoid a crash. */
3782 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3784 /* An initializer is going to decide the size of this array.
3785 Until we know the size, represent its address with a reg. */
3786 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode));
3787 MEM_SET_IN_STRUCT_P (DECL_RTL (decl), AGGREGATE_TYPE_P (type));
3789 else if (DECL_MODE (decl) != BLKmode
3790 /* If -ffloat-store, don't put explicit float vars
3792 && !(flag_float_store
3793 && TREE_CODE (type) == REAL_TYPE)
3794 && ! TREE_THIS_VOLATILE (decl)
3795 && ! TREE_ADDRESSABLE (decl)
3796 && (DECL_REGISTER (decl) || optimize)
3797 /* if -fcheck-memory-usage, check all variables. */
3798 && ! current_function_check_memory_usage)
3800 /* Automatic variable that can go in a register. */
3801 int unsignedp = TREE_UNSIGNED (type);
3802 enum machine_mode reg_mode
3803 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3805 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3806 mark_user_reg (DECL_RTL (decl));
3808 if (POINTER_TYPE_P (type))
3809 mark_reg_pointer (DECL_RTL (decl),
3810 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
3814 else if (TREE_CODE (DECL_SIZE_UNIT (decl)) == INTEGER_CST
3815 && ! (flag_stack_check && ! STACK_CHECK_BUILTIN
3816 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl),
3817 STACK_CHECK_MAX_VAR_SIZE)))
3819 /* Variable of fixed size that goes on the stack. */
3823 /* If we previously made RTL for this decl, it must be an array
3824 whose size was determined by the initializer.
3825 The old address was a register; set that register now
3826 to the proper address. */
3827 if (DECL_RTL (decl) != 0)
3829 if (GET_CODE (DECL_RTL (decl)) != MEM
3830 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3832 oldaddr = XEXP (DECL_RTL (decl), 0);
3835 DECL_RTL (decl) = assign_temp (TREE_TYPE (decl), 1, 1, 1);
3836 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3837 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3839 /* Set alignment we actually gave this decl. */
3840 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3841 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3845 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3846 if (addr != oldaddr)
3847 emit_move_insn (oldaddr, addr);
3850 /* If this is a memory ref that contains aggregate components,
3851 mark it as such for cse and loop optimize. */
3852 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3853 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3855 /* If this is in memory because of -ffloat-store,
3856 set the volatile bit, to prevent optimizations from
3857 undoing the effects. */
3858 if (flag_float_store && TREE_CODE (type) == REAL_TYPE)
3859 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3862 MEM_ALIAS_SET (DECL_RTL (decl)) = get_alias_set (decl);
3865 /* Dynamic-size object: must push space on the stack. */
3869 /* Record the stack pointer on entry to block, if have
3870 not already done so. */
3871 if (thisblock->data.block.stack_level == 0)
3873 do_pending_stack_adjust ();
3874 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3875 &thisblock->data.block.stack_level,
3876 thisblock->data.block.first_insn);
3877 stack_block_stack = thisblock;
3880 /* In function-at-a-time mode, variable_size doesn't expand this,
3882 if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
3883 expand_expr (TYPE_MAX_VALUE (TYPE_DOMAIN (type)),
3884 const0_rtx, VOIDmode, 0);
3886 /* Compute the variable's size, in bytes. */
3887 size = expand_expr (DECL_SIZE_UNIT (decl), NULL_RTX, VOIDmode, 0);
3890 /* Allocate space on the stack for the variable. Note that
3891 DECL_ALIGN says how the variable is to be aligned and we
3892 cannot use it to conclude anything about the alignment of
3894 address = allocate_dynamic_stack_space (size, NULL_RTX,
3895 TYPE_ALIGN (TREE_TYPE (decl)));
3897 /* Reference the variable indirect through that rtx. */
3898 DECL_RTL (decl) = gen_rtx_MEM (DECL_MODE (decl), address);
3900 /* If this is a memory ref that contains aggregate components,
3901 mark it as such for cse and loop optimize. */
3902 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3903 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3905 /* Indicate the alignment we actually gave this variable. */
3906 #ifdef STACK_BOUNDARY
3907 DECL_ALIGN (decl) = STACK_BOUNDARY;
3909 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3913 if (TREE_THIS_VOLATILE (decl))
3914 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3916 if (TREE_READONLY (decl))
3917 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
3920 /* Emit code to perform the initialization of a declaration DECL. */
3923 expand_decl_init (decl)
3926 int was_used = TREE_USED (decl);
3928 /* If this is a CONST_DECL, we don't have to generate any code, but
3929 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3930 to be set while in the obstack containing the constant. If we don't
3931 do this, we can lose if we have functions nested three deep and the middle
3932 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3933 the innermost function is the first to expand that STRING_CST. */
3934 if (TREE_CODE (decl) == CONST_DECL)
3936 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3937 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3938 EXPAND_INITIALIZER);
3942 if (TREE_STATIC (decl))
3945 /* Compute and store the initial value now. */
3947 if (DECL_INITIAL (decl) == error_mark_node)
3949 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3951 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3952 || code == POINTER_TYPE || code == REFERENCE_TYPE)
3953 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3957 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3959 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3960 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3964 /* Don't let the initialization count as "using" the variable. */
3965 TREE_USED (decl) = was_used;
3967 /* Free any temporaries we made while initializing the decl. */
3968 preserve_temp_slots (NULL_RTX);
3972 /* CLEANUP is an expression to be executed at exit from this binding contour;
3973 for example, in C++, it might call the destructor for this variable.
3975 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
3976 CLEANUP multiple times, and have the correct semantics. This
3977 happens in exception handling, for gotos, returns, breaks that
3978 leave the current scope.
3980 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3981 that is not associated with any particular variable. */
3984 expand_decl_cleanup (decl, cleanup)
3987 struct nesting *thisblock;
3989 /* Error if we are not in any block. */
3990 if (cfun == 0 || block_stack == 0)
3993 thisblock = block_stack;
3995 /* Record the cleanup if there is one. */
4001 tree *cleanups = &thisblock->data.block.cleanups;
4002 int cond_context = conditional_context ();
4006 rtx flag = gen_reg_rtx (word_mode);
4011 emit_move_insn (flag, const0_rtx);
4012 set_flag_0 = get_insns ();
4015 thisblock->data.block.last_unconditional_cleanup
4016 = emit_insns_after (set_flag_0,
4017 thisblock->data.block.last_unconditional_cleanup);
4019 emit_move_insn (flag, const1_rtx);
4021 /* All cleanups must be on the function_obstack. */
4022 push_obstacks_nochange ();
4023 resume_temporary_allocation ();
4025 cond = build_decl (VAR_DECL, NULL_TREE, type_for_mode (word_mode, 1));
4026 DECL_RTL (cond) = flag;
4028 /* Conditionalize the cleanup. */
4029 cleanup = build (COND_EXPR, void_type_node,
4030 truthvalue_conversion (cond),
4031 cleanup, integer_zero_node);
4032 cleanup = fold (cleanup);
4036 cleanups = thisblock->data.block.cleanup_ptr;
4039 /* All cleanups must be on the function_obstack. */
4040 push_obstacks_nochange ();
4041 resume_temporary_allocation ();
4042 cleanup = unsave_expr (cleanup);
4045 t = *cleanups = temp_tree_cons (decl, cleanup, *cleanups);
4048 /* If this block has a cleanup, it belongs in stack_block_stack. */
4049 stack_block_stack = thisblock;
4056 /* If this was optimized so that there is no exception region for the
4057 cleanup, then mark the TREE_LIST node, so that we can later tell
4058 if we need to call expand_eh_region_end. */
4059 if (! using_eh_for_cleanups_p
4060 || expand_eh_region_start_tree (decl, cleanup))
4061 TREE_ADDRESSABLE (t) = 1;
4062 /* If that started a new EH region, we're in a new block. */
4063 thisblock = block_stack;
4070 thisblock->data.block.last_unconditional_cleanup
4071 = emit_insns_after (seq,
4072 thisblock->data.block.last_unconditional_cleanup);
4076 thisblock->data.block.last_unconditional_cleanup
4078 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
4084 /* Like expand_decl_cleanup, but suppress generating an exception handler
4085 to perform the cleanup. */
4089 expand_decl_cleanup_no_eh (decl, cleanup)
4092 int save_eh = using_eh_for_cleanups_p;
4095 using_eh_for_cleanups_p = 0;
4096 result = expand_decl_cleanup (decl, cleanup);
4097 using_eh_for_cleanups_p = save_eh;
4103 /* Arrange for the top element of the dynamic cleanup chain to be
4104 popped if we exit the current binding contour. DECL is the
4105 associated declaration, if any, otherwise NULL_TREE. If the
4106 current contour is left via an exception, then __sjthrow will pop
4107 the top element off the dynamic cleanup chain. The code that
4108 avoids doing the action we push into the cleanup chain in the
4109 exceptional case is contained in expand_cleanups.
4111 This routine is only used by expand_eh_region_start, and that is
4112 the only way in which an exception region should be started. This
4113 routine is only used when using the setjmp/longjmp codegen method
4114 for exception handling. */
4117 expand_dcc_cleanup (decl)
4120 struct nesting *thisblock;
4123 /* Error if we are not in any block. */
4124 if (cfun == 0 || block_stack == 0)
4126 thisblock = block_stack;
4128 /* Record the cleanup for the dynamic handler chain. */
4130 /* All cleanups must be on the function_obstack. */
4131 push_obstacks_nochange ();
4132 resume_temporary_allocation ();
4133 cleanup = make_node (POPDCC_EXPR);
4136 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4137 thisblock->data.block.cleanups
4138 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4140 /* If this block has a cleanup, it belongs in stack_block_stack. */
4141 stack_block_stack = thisblock;
4145 /* Arrange for the top element of the dynamic handler chain to be
4146 popped if we exit the current binding contour. DECL is the
4147 associated declaration, if any, otherwise NULL_TREE. If the current
4148 contour is left via an exception, then __sjthrow will pop the top
4149 element off the dynamic handler chain. The code that avoids doing
4150 the action we push into the handler chain in the exceptional case
4151 is contained in expand_cleanups.
4153 This routine is only used by expand_eh_region_start, and that is
4154 the only way in which an exception region should be started. This
4155 routine is only used when using the setjmp/longjmp codegen method
4156 for exception handling. */
4159 expand_dhc_cleanup (decl)
4162 struct nesting *thisblock;
4165 /* Error if we are not in any block. */
4166 if (cfun == 0 || block_stack == 0)
4168 thisblock = block_stack;
4170 /* Record the cleanup for the dynamic handler chain. */
4172 /* All cleanups must be on the function_obstack. */
4173 push_obstacks_nochange ();
4174 resume_temporary_allocation ();
4175 cleanup = make_node (POPDHC_EXPR);
4178 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4179 thisblock->data.block.cleanups
4180 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4182 /* If this block has a cleanup, it belongs in stack_block_stack. */
4183 stack_block_stack = thisblock;
4187 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4188 DECL_ELTS is the list of elements that belong to DECL's type.
4189 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4192 expand_anon_union_decl (decl, cleanup, decl_elts)
4193 tree decl, cleanup, decl_elts;
4195 struct nesting *thisblock = cfun == 0 ? 0 : block_stack;
4199 /* If any of the elements are addressable, so is the entire union. */
4200 for (t = decl_elts; t; t = TREE_CHAIN (t))
4201 if (TREE_ADDRESSABLE (TREE_VALUE (t)))
4203 TREE_ADDRESSABLE (decl) = 1;
4208 expand_decl_cleanup (decl, cleanup);
4209 x = DECL_RTL (decl);
4211 /* Go through the elements, assigning RTL to each. */
4212 for (t = decl_elts; t; t = TREE_CHAIN (t))
4214 tree decl_elt = TREE_VALUE (t);
4215 tree cleanup_elt = TREE_PURPOSE (t);
4216 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
4218 /* Propagate the union's alignment to the elements. */
4219 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
4221 /* If the element has BLKmode and the union doesn't, the union is
4222 aligned such that the element doesn't need to have BLKmode, so
4223 change the element's mode to the appropriate one for its size. */
4224 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
4225 DECL_MODE (decl_elt) = mode
4226 = mode_for_size_tree (DECL_SIZE (decl_elt), MODE_INT, 1);
4228 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4229 instead create a new MEM rtx with the proper mode. */
4230 if (GET_CODE (x) == MEM)
4232 if (mode == GET_MODE (x))
4233 DECL_RTL (decl_elt) = x;
4236 DECL_RTL (decl_elt) = gen_rtx_MEM (mode, copy_rtx (XEXP (x, 0)));
4237 MEM_COPY_ATTRIBUTES (DECL_RTL (decl_elt), x);
4240 else if (GET_CODE (x) == REG)
4242 if (mode == GET_MODE (x))
4243 DECL_RTL (decl_elt) = x;
4245 DECL_RTL (decl_elt) = gen_rtx_SUBREG (mode, x, 0);
4250 /* Record the cleanup if there is one. */
4253 thisblock->data.block.cleanups
4254 = temp_tree_cons (decl_elt, cleanup_elt,
4255 thisblock->data.block.cleanups);
4259 /* Expand a list of cleanups LIST.
4260 Elements may be expressions or may be nested lists.
4262 If DONT_DO is nonnull, then any list-element
4263 whose TREE_PURPOSE matches DONT_DO is omitted.
4264 This is sometimes used to avoid a cleanup associated with
4265 a value that is being returned out of the scope.
4267 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
4268 goto and handle protection regions specially in that case.
4270 If REACHABLE, we emit code, otherwise just inform the exception handling
4271 code about this finalization. */
4274 expand_cleanups (list, dont_do, in_fixup, reachable)
4281 for (tail = list; tail; tail = TREE_CHAIN (tail))
4282 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
4284 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
4285 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
4290 tree cleanup = TREE_VALUE (tail);
4292 /* See expand_d{h,c}c_cleanup for why we avoid this. */
4293 if (TREE_CODE (cleanup) != POPDHC_EXPR
4294 && TREE_CODE (cleanup) != POPDCC_EXPR
4295 /* See expand_eh_region_start_tree for this case. */
4296 && ! TREE_ADDRESSABLE (tail))
4298 cleanup = protect_with_terminate (cleanup);
4299 expand_eh_region_end (cleanup);
4305 /* Cleanups may be run multiple times. For example,
4306 when exiting a binding contour, we expand the
4307 cleanups associated with that contour. When a goto
4308 within that binding contour has a target outside that
4309 contour, it will expand all cleanups from its scope to
4310 the target. Though the cleanups are expanded multiple
4311 times, the control paths are non-overlapping so the
4312 cleanups will not be executed twice. */
4314 /* We may need to protect fixups with rethrow regions. */
4315 int protect = (in_fixup && ! TREE_ADDRESSABLE (tail));
4318 expand_fixup_region_start ();
4320 /* The cleanup might contain try-blocks, so we have to
4321 preserve our current queue. */
4323 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
4326 expand_fixup_region_end (TREE_VALUE (tail));
4333 /* Mark when the context we are emitting RTL for as a conditional
4334 context, so that any cleanup actions we register with
4335 expand_decl_init will be properly conditionalized when those
4336 cleanup actions are later performed. Must be called before any
4337 expression (tree) is expanded that is within a conditional context. */
4340 start_cleanup_deferral ()
4342 /* block_stack can be NULL if we are inside the parameter list. It is
4343 OK to do nothing, because cleanups aren't possible here. */
4345 ++block_stack->data.block.conditional_code;
4348 /* Mark the end of a conditional region of code. Because cleanup
4349 deferrals may be nested, we may still be in a conditional region
4350 after we end the currently deferred cleanups, only after we end all
4351 deferred cleanups, are we back in unconditional code. */
4354 end_cleanup_deferral ()
4356 /* block_stack can be NULL if we are inside the parameter list. It is
4357 OK to do nothing, because cleanups aren't possible here. */
4359 --block_stack->data.block.conditional_code;
4362 /* Move all cleanups from the current block_stack
4363 to the containing block_stack, where they are assumed to
4364 have been created. If anything can cause a temporary to
4365 be created, but not expanded for more than one level of
4366 block_stacks, then this code will have to change. */
4371 struct nesting *block = block_stack;
4372 struct nesting *outer = block->next;
4374 outer->data.block.cleanups
4375 = chainon (block->data.block.cleanups,
4376 outer->data.block.cleanups);
4377 block->data.block.cleanups = 0;
4381 last_cleanup_this_contour ()
4383 if (block_stack == 0)
4386 return block_stack->data.block.cleanups;
4389 /* Return 1 if there are any pending cleanups at this point.
4390 If THIS_CONTOUR is nonzero, check the current contour as well.
4391 Otherwise, look only at the contours that enclose this one. */
4394 any_pending_cleanups (this_contour)
4397 struct nesting *block;
4399 if (cfun == NULL || cfun->stmt == NULL || block_stack == 0)
4402 if (this_contour && block_stack->data.block.cleanups != NULL)
4404 if (block_stack->data.block.cleanups == 0
4405 && block_stack->data.block.outer_cleanups == 0)
4408 for (block = block_stack->next; block; block = block->next)
4409 if (block->data.block.cleanups != 0)
4415 /* Enter a case (Pascal) or switch (C) statement.
4416 Push a block onto case_stack and nesting_stack
4417 to accumulate the case-labels that are seen
4418 and to record the labels generated for the statement.
4420 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4421 Otherwise, this construct is transparent for `exit_something'.
4423 EXPR is the index-expression to be dispatched on.
4424 TYPE is its nominal type. We could simply convert EXPR to this type,
4425 but instead we take short cuts. */
4428 expand_start_case (exit_flag, expr, type, printname)
4432 const char *printname;
4434 register struct nesting *thiscase = ALLOC_NESTING ();
4436 /* Make an entry on case_stack for the case we are entering. */
4438 thiscase->next = case_stack;
4439 thiscase->all = nesting_stack;
4440 thiscase->depth = ++nesting_depth;
4441 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
4442 thiscase->data.case_stmt.case_list = 0;
4443 thiscase->data.case_stmt.index_expr = expr;
4444 thiscase->data.case_stmt.nominal_type = type;
4445 thiscase->data.case_stmt.default_label = 0;
4446 thiscase->data.case_stmt.num_ranges = 0;
4447 thiscase->data.case_stmt.printname = printname;
4448 thiscase->data.case_stmt.line_number_status = force_line_numbers ();
4449 case_stack = thiscase;
4450 nesting_stack = thiscase;
4452 do_pending_stack_adjust ();
4454 /* Make sure case_stmt.start points to something that won't
4455 need any transformation before expand_end_case. */
4456 if (GET_CODE (get_last_insn ()) != NOTE)
4457 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4459 thiscase->data.case_stmt.start = get_last_insn ();
4461 start_cleanup_deferral ();
4465 /* Start a "dummy case statement" within which case labels are invalid
4466 and are not connected to any larger real case statement.
4467 This can be used if you don't want to let a case statement jump
4468 into the middle of certain kinds of constructs. */
4471 expand_start_case_dummy ()
4473 register struct nesting *thiscase = ALLOC_NESTING ();
4475 /* Make an entry on case_stack for the dummy. */
4477 thiscase->next = case_stack;
4478 thiscase->all = nesting_stack;
4479 thiscase->depth = ++nesting_depth;
4480 thiscase->exit_label = 0;
4481 thiscase->data.case_stmt.case_list = 0;
4482 thiscase->data.case_stmt.start = 0;
4483 thiscase->data.case_stmt.nominal_type = 0;
4484 thiscase->data.case_stmt.default_label = 0;
4485 thiscase->data.case_stmt.num_ranges = 0;
4486 case_stack = thiscase;
4487 nesting_stack = thiscase;
4488 start_cleanup_deferral ();
4491 /* End a dummy case statement. */
4494 expand_end_case_dummy ()
4496 end_cleanup_deferral ();
4497 POPSTACK (case_stack);
4500 /* Return the data type of the index-expression
4501 of the innermost case statement, or null if none. */
4504 case_index_expr_type ()
4507 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
4514 /* If this is the first label, warn if any insns have been emitted. */
4515 if (case_stack->data.case_stmt.line_number_status >= 0)
4519 restore_line_number_status
4520 (case_stack->data.case_stmt.line_number_status);
4521 case_stack->data.case_stmt.line_number_status = -1;
4523 for (insn = case_stack->data.case_stmt.start;
4525 insn = NEXT_INSN (insn))
4527 if (GET_CODE (insn) == CODE_LABEL)
4529 if (GET_CODE (insn) != NOTE
4530 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4533 insn = PREV_INSN (insn);
4534 while (insn && (GET_CODE (insn) != NOTE || NOTE_LINE_NUMBER (insn) < 0));
4536 /* If insn is zero, then there must have been a syntax error. */
4538 warning_with_file_and_line (NOTE_SOURCE_FILE(insn),
4539 NOTE_LINE_NUMBER(insn),
4540 "unreachable code at beginning of %s",
4541 case_stack->data.case_stmt.printname);
4548 /* Accumulate one case or default label inside a case or switch statement.
4549 VALUE is the value of the case (a null pointer, for a default label).
4550 The function CONVERTER, when applied to arguments T and V,
4551 converts the value V to the type T.
4553 If not currently inside a case or switch statement, return 1 and do
4554 nothing. The caller will print a language-specific error message.
4555 If VALUE is a duplicate or overlaps, return 2 and do nothing
4556 except store the (first) duplicate node in *DUPLICATE.
4557 If VALUE is out of range, return 3 and do nothing.
4558 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4559 Return 0 on success.
4561 Extended to handle range statements. */
4564 pushcase (value, converter, label, duplicate)
4565 register tree value;
4566 tree (*converter) PARAMS ((tree, tree));
4567 register tree label;
4573 /* Fail if not inside a real case statement. */
4574 if (! (case_stack && case_stack->data.case_stmt.start))
4577 if (stack_block_stack
4578 && stack_block_stack->depth > case_stack->depth)
4581 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4582 nominal_type = case_stack->data.case_stmt.nominal_type;
4584 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4585 if (index_type == error_mark_node)
4588 /* Convert VALUE to the type in which the comparisons are nominally done. */
4590 value = (*converter) (nominal_type, value);
4594 /* Fail if this value is out of range for the actual type of the index
4595 (which may be narrower than NOMINAL_TYPE). */
4597 && (TREE_CONSTANT_OVERFLOW (value)
4598 || ! int_fits_type_p (value, index_type)))
4601 /* Fail if this is a duplicate or overlaps another entry. */
4604 if (case_stack->data.case_stmt.default_label != 0)
4606 *duplicate = case_stack->data.case_stmt.default_label;
4609 case_stack->data.case_stmt.default_label = label;
4612 return add_case_node (value, value, label, duplicate);
4614 expand_label (label);
4618 /* Like pushcase but this case applies to all values between VALUE1 and
4619 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4620 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4621 starts at VALUE1 and ends at the highest value of the index type.
4622 If both are NULL, this case applies to all values.
4624 The return value is the same as that of pushcase but there is one
4625 additional error code: 4 means the specified range was empty. */
4628 pushcase_range (value1, value2, converter, label, duplicate)
4629 register tree value1, value2;
4630 tree (*converter) PARAMS ((tree, tree));
4631 register tree label;
4637 /* Fail if not inside a real case statement. */
4638 if (! (case_stack && case_stack->data.case_stmt.start))
4641 if (stack_block_stack
4642 && stack_block_stack->depth > case_stack->depth)
4645 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4646 nominal_type = case_stack->data.case_stmt.nominal_type;
4648 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4649 if (index_type == error_mark_node)
4654 /* Convert VALUEs to type in which the comparisons are nominally done
4655 and replace any unspecified value with the corresponding bound. */
4657 value1 = TYPE_MIN_VALUE (index_type);
4659 value2 = TYPE_MAX_VALUE (index_type);
4661 /* Fail if the range is empty. Do this before any conversion since
4662 we want to allow out-of-range empty ranges. */
4663 if (value2 != 0 && tree_int_cst_lt (value2, value1))
4666 /* If the max was unbounded, use the max of the nominal_type we are
4667 converting to. Do this after the < check above to suppress false
4670 value2 = TYPE_MAX_VALUE (nominal_type);
4672 value1 = (*converter) (nominal_type, value1);
4673 value2 = (*converter) (nominal_type, value2);
4675 /* Fail if these values are out of range. */
4676 if (TREE_CONSTANT_OVERFLOW (value1)
4677 || ! int_fits_type_p (value1, index_type))
4680 if (TREE_CONSTANT_OVERFLOW (value2)
4681 || ! int_fits_type_p (value2, index_type))
4684 return add_case_node (value1, value2, label, duplicate);
4687 /* Do the actual insertion of a case label for pushcase and pushcase_range
4688 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4689 slowdown for large switch statements. */
4692 add_case_node (low, high, label, duplicate)
4697 struct case_node *p, **q, *r;
4699 q = &case_stack->data.case_stmt.case_list;
4706 /* Keep going past elements distinctly greater than HIGH. */
4707 if (tree_int_cst_lt (high, p->low))
4710 /* or distinctly less than LOW. */
4711 else if (tree_int_cst_lt (p->high, low))
4716 /* We have an overlap; this is an error. */
4717 *duplicate = p->code_label;
4722 /* Add this label to the chain, and succeed.
4723 Copy LOW, HIGH so they are on temporary rather than momentary
4724 obstack and will thus survive till the end of the case statement. */
4726 r = (struct case_node *) oballoc (sizeof (struct case_node));
4727 r->low = copy_node (low);
4729 /* If the bounds are equal, turn this into the one-value case. */
4731 if (tree_int_cst_equal (low, high))
4735 r->high = copy_node (high);
4736 case_stack->data.case_stmt.num_ranges++;
4739 r->code_label = label;
4740 expand_label (label);
4750 struct case_node *s;
4756 if (! (b = p->balance))
4757 /* Growth propagation from left side. */
4764 if ((p->left = s = r->right))
4773 if ((r->parent = s))
4781 case_stack->data.case_stmt.case_list = r;
4784 /* r->balance == +1 */
4789 struct case_node *t = r->right;
4791 if ((p->left = s = t->right))
4795 if ((r->right = s = t->left))
4809 if ((t->parent = s))
4817 case_stack->data.case_stmt.case_list = t;
4824 /* p->balance == +1; growth of left side balances the node. */
4834 if (! (b = p->balance))
4835 /* Growth propagation from right side. */
4843 if ((p->right = s = r->left))
4851 if ((r->parent = s))
4860 case_stack->data.case_stmt.case_list = r;
4864 /* r->balance == -1 */
4868 struct case_node *t = r->left;
4870 if ((p->right = s = t->left))
4875 if ((r->left = s = t->right))
4889 if ((t->parent = s))
4898 case_stack->data.case_stmt.case_list = t;
4904 /* p->balance == -1; growth of right side balances the node. */
4918 /* Returns the number of possible values of TYPE.
4919 Returns -1 if the number is unknown, variable, or if the number does not
4920 fit in a HOST_WIDE_INT.
4921 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4922 do not increase monotonically (there may be duplicates);
4923 to 1 if the values increase monotonically, but not always by 1;
4924 otherwise sets it to 0. */
4927 all_cases_count (type, spareness)
4932 HOST_WIDE_INT count, minval, lastval;
4936 switch (TREE_CODE (type))
4943 count = 1 << BITS_PER_UNIT;
4948 if (TYPE_MAX_VALUE (type) != 0
4949 && 0 != (t = fold (build (MINUS_EXPR, type, TYPE_MAX_VALUE (type),
4950 TYPE_MIN_VALUE (type))))
4951 && 0 != (t = fold (build (PLUS_EXPR, type, t,
4952 convert (type, integer_zero_node))))
4953 && host_integerp (t, 1))
4954 count = tree_low_cst (t, 1);
4960 /* Don't waste time with enumeral types with huge values. */
4961 if (! host_integerp (TYPE_MIN_VALUE (type), 0)
4962 || TYPE_MAX_VALUE (type) == 0
4963 || ! host_integerp (TYPE_MAX_VALUE (type), 0))
4966 lastval = minval = tree_low_cst (TYPE_MIN_VALUE (type), 0);
4969 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4971 HOST_WIDE_INT thisval = tree_low_cst (TREE_VALUE (t), 0);
4973 if (*spareness == 2 || thisval < lastval)
4975 else if (thisval != minval + count)
4985 #define BITARRAY_TEST(ARRAY, INDEX) \
4986 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4987 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4988 #define BITARRAY_SET(ARRAY, INDEX) \
4989 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4990 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4992 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4993 with the case values we have seen, assuming the case expression
4995 SPARSENESS is as determined by all_cases_count.
4997 The time needed is proportional to COUNT, unless
4998 SPARSENESS is 2, in which case quadratic time is needed. */
5001 mark_seen_cases (type, cases_seen, count, sparseness)
5003 unsigned char *cases_seen;
5004 HOST_WIDE_INT count;
5007 tree next_node_to_try = NULL_TREE;
5008 HOST_WIDE_INT next_node_offset = 0;
5010 register struct case_node *n, *root = case_stack->data.case_stmt.case_list;
5011 tree val = make_node (INTEGER_CST);
5013 TREE_TYPE (val) = type;
5016 else if (sparseness == 2)
5019 unsigned HOST_WIDE_INT xlo;
5021 /* This less efficient loop is only needed to handle
5022 duplicate case values (multiple enum constants
5023 with the same value). */
5024 TREE_TYPE (val) = TREE_TYPE (root->low);
5025 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
5026 t = TREE_CHAIN (t), xlo++)
5028 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (TREE_VALUE (t));
5029 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (TREE_VALUE (t));
5033 /* Keep going past elements distinctly greater than VAL. */
5034 if (tree_int_cst_lt (val, n->low))
5037 /* or distinctly less than VAL. */
5038 else if (tree_int_cst_lt (n->high, val))
5043 /* We have found a matching range. */
5044 BITARRAY_SET (cases_seen, xlo);
5054 case_stack->data.case_stmt.case_list = root = case_tree2list (root, 0);
5056 for (n = root; n; n = n->right)
5058 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
5059 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
5060 while ( ! tree_int_cst_lt (n->high, val))
5062 /* Calculate (into xlo) the "offset" of the integer (val).
5063 The element with lowest value has offset 0, the next smallest
5064 element has offset 1, etc. */
5066 unsigned HOST_WIDE_INT xlo;
5070 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
5072 /* The TYPE_VALUES will be in increasing order, so
5073 starting searching where we last ended. */
5074 t = next_node_to_try;
5075 xlo = next_node_offset;
5081 t = TYPE_VALUES (type);
5084 if (tree_int_cst_equal (val, TREE_VALUE (t)))
5086 next_node_to_try = TREE_CHAIN (t);
5087 next_node_offset = xlo + 1;
5092 if (t == next_node_to_try)
5101 t = TYPE_MIN_VALUE (type);
5103 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
5107 add_double (xlo, xhi,
5108 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5112 if (xhi == 0 && xlo < (unsigned HOST_WIDE_INT) count)
5113 BITARRAY_SET (cases_seen, xlo);
5115 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5117 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
5123 /* Called when the index of a switch statement is an enumerated type
5124 and there is no default label.
5126 Checks that all enumeration literals are covered by the case
5127 expressions of a switch. Also, warn if there are any extra
5128 switch cases that are *not* elements of the enumerated type.
5130 If all enumeration literals were covered by the case expressions,
5131 turn one of the expressions into the default expression since it should
5132 not be possible to fall through such a switch. */
5135 check_for_full_enumeration_handling (type)
5138 register struct case_node *n;
5139 register tree chain;
5140 #if 0 /* variable used by 'if 0'ed code below. */
5141 register struct case_node **l;
5145 /* True iff the selector type is a numbered set mode. */
5148 /* The number of possible selector values. */
5151 /* For each possible selector value. a one iff it has been matched
5152 by a case value alternative. */
5153 unsigned char *cases_seen;
5155 /* The allocated size of cases_seen, in chars. */
5156 HOST_WIDE_INT bytes_needed;
5161 size = all_cases_count (type, &sparseness);
5162 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
5164 if (size > 0 && size < 600000
5165 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5166 this optimization if we don't have enough memory rather than
5167 aborting, as xmalloc would do. */
5168 && (cases_seen = (unsigned char *) calloc (bytes_needed, 1)) != NULL)
5171 tree v = TYPE_VALUES (type);
5173 /* The time complexity of this code is normally O(N), where
5174 N being the number of members in the enumerated type.
5175 However, if type is a ENUMERAL_TYPE whose values do not
5176 increase monotonically, O(N*log(N)) time may be needed. */
5178 mark_seen_cases (type, cases_seen, size, sparseness);
5180 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
5181 if (BITARRAY_TEST(cases_seen, i) == 0)
5182 warning ("enumeration value `%s' not handled in switch",
5183 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
5188 /* Now we go the other way around; we warn if there are case
5189 expressions that don't correspond to enumerators. This can
5190 occur since C and C++ don't enforce type-checking of
5191 assignments to enumeration variables. */
5193 if (case_stack->data.case_stmt.case_list
5194 && case_stack->data.case_stmt.case_list->left)
5195 case_stack->data.case_stmt.case_list
5196 = case_tree2list (case_stack->data.case_stmt.case_list, 0);
5198 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
5200 for (chain = TYPE_VALUES (type);
5201 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
5202 chain = TREE_CHAIN (chain))
5207 if (TYPE_NAME (type) == 0)
5208 warning ("case value `%ld' not in enumerated type",
5209 (long) TREE_INT_CST_LOW (n->low));
5211 warning ("case value `%ld' not in enumerated type `%s'",
5212 (long) TREE_INT_CST_LOW (n->low),
5213 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5216 : DECL_NAME (TYPE_NAME (type))));
5218 if (!tree_int_cst_equal (n->low, n->high))
5220 for (chain = TYPE_VALUES (type);
5221 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
5222 chain = TREE_CHAIN (chain))
5227 if (TYPE_NAME (type) == 0)
5228 warning ("case value `%ld' not in enumerated type",
5229 (long) TREE_INT_CST_LOW (n->high));
5231 warning ("case value `%ld' not in enumerated type `%s'",
5232 (long) TREE_INT_CST_LOW (n->high),
5233 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5236 : DECL_NAME (TYPE_NAME (type))));
5242 /* ??? This optimization is disabled because it causes valid programs to
5243 fail. ANSI C does not guarantee that an expression with enum type
5244 will have a value that is the same as one of the enumeration literals. */
5246 /* If all values were found as case labels, make one of them the default
5247 label. Thus, this switch will never fall through. We arbitrarily pick
5248 the last one to make the default since this is likely the most
5249 efficient choice. */
5253 for (l = &case_stack->data.case_stmt.case_list;
5258 case_stack->data.case_stmt.default_label = (*l)->code_label;
5265 /* Terminate a case (Pascal) or switch (C) statement
5266 in which ORIG_INDEX is the expression to be tested.
5267 Generate the code to test it and jump to the right place. */
5270 expand_end_case (orig_index)
5273 tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE, orig_minval;
5274 rtx default_label = 0;
5275 register struct case_node *n;
5283 register struct nesting *thiscase = case_stack;
5284 tree index_expr, index_type;
5287 /* Don't crash due to previous errors. */
5288 if (thiscase == NULL)
5291 table_label = gen_label_rtx ();
5292 index_expr = thiscase->data.case_stmt.index_expr;
5293 index_type = TREE_TYPE (index_expr);
5294 unsignedp = TREE_UNSIGNED (index_type);
5296 do_pending_stack_adjust ();
5298 /* This might get an spurious warning in the presence of a syntax error;
5299 it could be fixed by moving the call to check_seenlabel after the
5300 check for error_mark_node, and copying the code of check_seenlabel that
5301 deals with case_stack->data.case_stmt.line_number_status /
5302 restore_line_number_status in front of the call to end_cleanup_deferral;
5303 However, this might miss some useful warnings in the presence of
5304 non-syntax errors. */
5307 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5308 if (index_type != error_mark_node)
5310 /* If switch expression was an enumerated type, check that all
5311 enumeration literals are covered by the cases.
5312 No sense trying this if there's a default case, however. */
5314 if (!thiscase->data.case_stmt.default_label
5315 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
5316 && TREE_CODE (index_expr) != INTEGER_CST)
5317 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
5319 /* If we don't have a default-label, create one here,
5320 after the body of the switch. */
5321 if (thiscase->data.case_stmt.default_label == 0)
5323 thiscase->data.case_stmt.default_label
5324 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5325 expand_label (thiscase->data.case_stmt.default_label);
5327 default_label = label_rtx (thiscase->data.case_stmt.default_label);
5329 before_case = get_last_insn ();
5331 if (thiscase->data.case_stmt.case_list
5332 && thiscase->data.case_stmt.case_list->left)
5333 thiscase->data.case_stmt.case_list
5334 = case_tree2list(thiscase->data.case_stmt.case_list, 0);
5336 /* Simplify the case-list before we count it. */
5337 group_case_nodes (thiscase->data.case_stmt.case_list);
5339 /* Get upper and lower bounds of case values.
5340 Also convert all the case values to the index expr's data type. */
5343 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5345 /* Check low and high label values are integers. */
5346 if (TREE_CODE (n->low) != INTEGER_CST)
5348 if (TREE_CODE (n->high) != INTEGER_CST)
5351 n->low = convert (index_type, n->low);
5352 n->high = convert (index_type, n->high);
5354 /* Count the elements and track the largest and smallest
5355 of them (treating them as signed even if they are not). */
5363 if (INT_CST_LT (n->low, minval))
5365 if (INT_CST_LT (maxval, n->high))
5368 /* A range counts double, since it requires two compares. */
5369 if (! tree_int_cst_equal (n->low, n->high))
5373 orig_minval = minval;
5375 /* Compute span of values. */
5377 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
5379 end_cleanup_deferral ();
5383 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
5385 emit_jump (default_label);
5388 /* If range of values is much bigger than number of values,
5389 make a sequence of conditional branches instead of a dispatch.
5390 If the switch-index is a constant, do it this way
5391 because we can optimize it. */
5393 #ifndef CASE_VALUES_THRESHOLD
5395 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
5397 /* If machine does not have a case insn that compares the
5398 bounds, this means extra overhead for dispatch tables
5399 which raises the threshold for using them. */
5400 #define CASE_VALUES_THRESHOLD 5
5401 #endif /* HAVE_casesi */
5402 #endif /* CASE_VALUES_THRESHOLD */
5404 else if (count < CASE_VALUES_THRESHOLD
5405 || compare_tree_int (range, 10 * count) > 0
5406 /* RANGE may be signed, and really large ranges will show up
5407 as negative numbers. */
5408 || compare_tree_int (range, 0) < 0
5409 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5412 || TREE_CODE (index_expr) == INTEGER_CST
5413 /* These will reduce to a constant. */
5414 || (TREE_CODE (index_expr) == CALL_EXPR
5415 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
5416 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
5417 && DECL_BUILT_IN_CLASS (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_NORMAL
5418 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
5419 || (TREE_CODE (index_expr) == COMPOUND_EXPR
5420 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
5422 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5424 /* If the index is a short or char that we do not have
5425 an insn to handle comparisons directly, convert it to
5426 a full integer now, rather than letting each comparison
5427 generate the conversion. */
5429 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
5430 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
5431 == CODE_FOR_nothing))
5433 enum machine_mode wider_mode;
5434 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
5435 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
5436 if (cmp_optab->handlers[(int) wider_mode].insn_code
5437 != CODE_FOR_nothing)
5439 index = convert_to_mode (wider_mode, index, unsignedp);
5445 do_pending_stack_adjust ();
5447 index = protect_from_queue (index, 0);
5448 if (GET_CODE (index) == MEM)
5449 index = copy_to_reg (index);
5450 if (GET_CODE (index) == CONST_INT
5451 || TREE_CODE (index_expr) == INTEGER_CST)
5453 /* Make a tree node with the proper constant value
5454 if we don't already have one. */
5455 if (TREE_CODE (index_expr) != INTEGER_CST)
5458 = build_int_2 (INTVAL (index),
5459 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
5460 index_expr = convert (index_type, index_expr);
5463 /* For constant index expressions we need only
5464 issue a unconditional branch to the appropriate
5465 target code. The job of removing any unreachable
5466 code is left to the optimisation phase if the
5467 "-O" option is specified. */
5468 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5469 if (! tree_int_cst_lt (index_expr, n->low)
5470 && ! tree_int_cst_lt (n->high, index_expr))
5474 emit_jump (label_rtx (n->code_label));
5476 emit_jump (default_label);
5480 /* If the index expression is not constant we generate
5481 a binary decision tree to select the appropriate
5482 target code. This is done as follows:
5484 The list of cases is rearranged into a binary tree,
5485 nearly optimal assuming equal probability for each case.
5487 The tree is transformed into RTL, eliminating
5488 redundant test conditions at the same time.
5490 If program flow could reach the end of the
5491 decision tree an unconditional jump to the
5492 default code is emitted. */
5495 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
5496 && estimate_case_costs (thiscase->data.case_stmt.case_list));
5497 balance_case_nodes (&thiscase->data.case_stmt.case_list,
5499 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
5500 default_label, index_type);
5501 emit_jump_if_reachable (default_label);
5510 enum machine_mode index_mode = SImode;
5511 int index_bits = GET_MODE_BITSIZE (index_mode);
5513 enum machine_mode op_mode;
5515 /* Convert the index to SImode. */
5516 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
5517 > GET_MODE_BITSIZE (index_mode))
5519 enum machine_mode omode = TYPE_MODE (index_type);
5520 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
5522 /* We must handle the endpoints in the original mode. */
5523 index_expr = build (MINUS_EXPR, index_type,
5524 index_expr, minval);
5525 minval = integer_zero_node;
5526 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5527 emit_cmp_and_jump_insns (rangertx, index, LTU, NULL_RTX,
5528 omode, 1, 0, default_label);
5529 /* Now we can safely truncate. */
5530 index = convert_to_mode (index_mode, index, 0);
5534 if (TYPE_MODE (index_type) != index_mode)
5536 index_expr = convert (type_for_size (index_bits, 0),
5538 index_type = TREE_TYPE (index_expr);
5541 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5544 index = protect_from_queue (index, 0);
5545 do_pending_stack_adjust ();
5547 op_mode = insn_data[(int)CODE_FOR_casesi].operand[0].mode;
5548 if (! (*insn_data[(int)CODE_FOR_casesi].operand[0].predicate)
5550 index = copy_to_mode_reg (op_mode, index);
5552 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
5554 op_mode = insn_data[(int)CODE_FOR_casesi].operand[1].mode;
5555 if (! (*insn_data[(int)CODE_FOR_casesi].operand[1].predicate)
5557 op1 = copy_to_mode_reg (op_mode, op1);
5559 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
5561 op_mode = insn_data[(int)CODE_FOR_casesi].operand[2].mode;
5562 if (! (*insn_data[(int)CODE_FOR_casesi].operand[2].predicate)
5564 op2 = copy_to_mode_reg (op_mode, op2);
5566 emit_jump_insn (gen_casesi (index, op1, op2,
5567 table_label, default_label));
5571 #ifdef HAVE_tablejump
5572 if (! win && HAVE_tablejump)
5574 index_expr = convert (thiscase->data.case_stmt.nominal_type,
5575 fold (build (MINUS_EXPR, index_type,
5576 index_expr, minval)));
5577 index_type = TREE_TYPE (index_expr);
5578 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5580 index = protect_from_queue (index, 0);
5581 do_pending_stack_adjust ();
5583 do_tablejump (index, TYPE_MODE (index_type),
5584 expand_expr (range, NULL_RTX, VOIDmode, 0),
5585 table_label, default_label);
5592 /* Get table of labels to jump to, in order of case index. */
5594 ncases = TREE_INT_CST_LOW (range) + 1;
5595 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
5596 bzero ((char *) labelvec, ncases * sizeof (rtx));
5598 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5600 register HOST_WIDE_INT i
5601 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
5606 = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
5607 if (i + TREE_INT_CST_LOW (orig_minval)
5608 == TREE_INT_CST_LOW (n->high))
5614 /* Fill in the gaps with the default. */
5615 for (i = 0; i < ncases; i++)
5616 if (labelvec[i] == 0)
5617 labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
5619 /* Output the table */
5620 emit_label (table_label);
5622 if (CASE_VECTOR_PC_RELATIVE || flag_pic)
5623 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
5624 gen_rtx_LABEL_REF (Pmode, table_label),
5625 gen_rtvec_v (ncases, labelvec),
5626 const0_rtx, const0_rtx));
5628 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
5629 gen_rtvec_v (ncases, labelvec)));
5631 /* If the case insn drops through the table,
5632 after the table we must jump to the default-label.
5633 Otherwise record no drop-through after the table. */
5634 #ifdef CASE_DROPS_THROUGH
5635 emit_jump (default_label);
5641 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
5642 reorder_insns (before_case, get_last_insn (),
5643 thiscase->data.case_stmt.start);
5646 end_cleanup_deferral ();
5648 if (thiscase->exit_label)
5649 emit_label (thiscase->exit_label);
5651 POPSTACK (case_stack);
5656 /* Convert the tree NODE into a list linked by the right field, with the left
5657 field zeroed. RIGHT is used for recursion; it is a list to be placed
5658 rightmost in the resulting list. */
5660 static struct case_node *
5661 case_tree2list (node, right)
5662 struct case_node *node, *right;
5664 struct case_node *left;
5667 right = case_tree2list (node->right, right);
5669 node->right = right;
5670 if ((left = node->left))
5673 return case_tree2list (left, node);
5679 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5682 do_jump_if_equal (op1, op2, label, unsignedp)
5683 rtx op1, op2, label;
5686 if (GET_CODE (op1) == CONST_INT
5687 && GET_CODE (op2) == CONST_INT)
5689 if (INTVAL (op1) == INTVAL (op2))
5694 enum machine_mode mode = GET_MODE (op1);
5695 if (mode == VOIDmode)
5696 mode = GET_MODE (op2);
5697 emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX, mode, unsignedp,
5702 /* Not all case values are encountered equally. This function
5703 uses a heuristic to weight case labels, in cases where that
5704 looks like a reasonable thing to do.
5706 Right now, all we try to guess is text, and we establish the
5709 chars above space: 16
5718 If we find any cases in the switch that are not either -1 or in the range
5719 of valid ASCII characters, or are control characters other than those
5720 commonly used with "\", don't treat this switch scanning text.
5722 Return 1 if these nodes are suitable for cost estimation, otherwise
5726 estimate_case_costs (node)
5729 tree min_ascii = build_int_2 (-1, -1);
5730 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5734 /* If we haven't already made the cost table, make it now. Note that the
5735 lower bound of the table is -1, not zero. */
5737 if (cost_table == NULL)
5739 cost_table = cost_table_ + 1;
5741 for (i = 0; i < 128; i++)
5745 else if (ISPUNCT (i))
5747 else if (ISCNTRL (i))
5751 cost_table[' '] = 8;
5752 cost_table['\t'] = 4;
5753 cost_table['\0'] = 4;
5754 cost_table['\n'] = 2;
5755 cost_table['\f'] = 1;
5756 cost_table['\v'] = 1;
5757 cost_table['\b'] = 1;
5760 /* See if all the case expressions look like text. It is text if the
5761 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5762 as signed arithmetic since we don't want to ever access cost_table with a
5763 value less than -1. Also check that none of the constants in a range
5764 are strange control characters. */
5766 for (n = node; n; n = n->right)
5768 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5771 for (i = (HOST_WIDE_INT) TREE_INT_CST_LOW (n->low);
5772 i <= (HOST_WIDE_INT) TREE_INT_CST_LOW (n->high); i++)
5773 if (cost_table[i] < 0)
5777 /* All interesting values are within the range of interesting
5778 ASCII characters. */
5782 /* Scan an ordered list of case nodes
5783 combining those with consecutive values or ranges.
5785 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5788 group_case_nodes (head)
5791 case_node_ptr node = head;
5795 rtx lb = next_real_insn (label_rtx (node->code_label));
5797 case_node_ptr np = node;
5799 /* Try to group the successors of NODE with NODE. */
5800 while (((np = np->right) != 0)
5801 /* Do they jump to the same place? */
5802 && ((lb2 = next_real_insn (label_rtx (np->code_label))) == lb
5803 || (lb != 0 && lb2 != 0
5804 && simplejump_p (lb)
5805 && simplejump_p (lb2)
5806 && rtx_equal_p (SET_SRC (PATTERN (lb)),
5807 SET_SRC (PATTERN (lb2)))))
5808 /* Are their ranges consecutive? */
5809 && tree_int_cst_equal (np->low,
5810 fold (build (PLUS_EXPR,
5811 TREE_TYPE (node->high),
5814 /* An overflow is not consecutive. */
5815 && tree_int_cst_lt (node->high,
5816 fold (build (PLUS_EXPR,
5817 TREE_TYPE (node->high),
5819 integer_one_node))))
5821 node->high = np->high;
5823 /* NP is the first node after NODE which can't be grouped with it.
5824 Delete the nodes in between, and move on to that node. */
5830 /* Take an ordered list of case nodes
5831 and transform them into a near optimal binary tree,
5832 on the assumption that any target code selection value is as
5833 likely as any other.
5835 The transformation is performed by splitting the ordered
5836 list into two equal sections plus a pivot. The parts are
5837 then attached to the pivot as left and right branches. Each
5838 branch is then transformed recursively. */
5841 balance_case_nodes (head, parent)
5842 case_node_ptr *head;
5843 case_node_ptr parent;
5845 register case_node_ptr np;
5853 register case_node_ptr *npp;
5856 /* Count the number of entries on branch. Also count the ranges. */
5860 if (!tree_int_cst_equal (np->low, np->high))
5864 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5868 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5876 /* Split this list if it is long enough for that to help. */
5881 /* Find the place in the list that bisects the list's total cost,
5882 Here I gets half the total cost. */
5887 /* Skip nodes while their cost does not reach that amount. */
5888 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5889 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5890 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5893 npp = &(*npp)->right;
5898 /* Leave this branch lopsided, but optimize left-hand
5899 side and fill in `parent' fields for right-hand side. */
5901 np->parent = parent;
5902 balance_case_nodes (&np->left, np);
5903 for (; np->right; np = np->right)
5904 np->right->parent = np;
5908 /* If there are just three nodes, split at the middle one. */
5910 npp = &(*npp)->right;
5913 /* Find the place in the list that bisects the list's total cost,
5914 where ranges count as 2.
5915 Here I gets half the total cost. */
5916 i = (i + ranges + 1) / 2;
5919 /* Skip nodes while their cost does not reach that amount. */
5920 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5925 npp = &(*npp)->right;
5930 np->parent = parent;
5933 /* Optimize each of the two split parts. */
5934 balance_case_nodes (&np->left, np);
5935 balance_case_nodes (&np->right, np);
5939 /* Else leave this branch as one level,
5940 but fill in `parent' fields. */
5942 np->parent = parent;
5943 for (; np->right; np = np->right)
5944 np->right->parent = np;
5949 /* Search the parent sections of the case node tree
5950 to see if a test for the lower bound of NODE would be redundant.
5951 INDEX_TYPE is the type of the index expression.
5953 The instructions to generate the case decision tree are
5954 output in the same order as nodes are processed so it is
5955 known that if a parent node checks the range of the current
5956 node minus one that the current node is bounded at its lower
5957 span. Thus the test would be redundant. */
5960 node_has_low_bound (node, index_type)
5965 case_node_ptr pnode;
5967 /* If the lower bound of this node is the lowest value in the index type,
5968 we need not test it. */
5970 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5973 /* If this node has a left branch, the value at the left must be less
5974 than that at this node, so it cannot be bounded at the bottom and
5975 we need not bother testing any further. */
5980 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5981 node->low, integer_one_node));
5983 /* If the subtraction above overflowed, we can't verify anything.
5984 Otherwise, look for a parent that tests our value - 1. */
5986 if (! tree_int_cst_lt (low_minus_one, node->low))
5989 for (pnode = node->parent; pnode; pnode = pnode->parent)
5990 if (tree_int_cst_equal (low_minus_one, pnode->high))
5996 /* Search the parent sections of the case node tree
5997 to see if a test for the upper bound of NODE would be redundant.
5998 INDEX_TYPE is the type of the index expression.
6000 The instructions to generate the case decision tree are
6001 output in the same order as nodes are processed so it is
6002 known that if a parent node checks the range of the current
6003 node plus one that the current node is bounded at its upper
6004 span. Thus the test would be redundant. */
6007 node_has_high_bound (node, index_type)
6012 case_node_ptr pnode;
6014 /* If there is no upper bound, obviously no test is needed. */
6016 if (TYPE_MAX_VALUE (index_type) == NULL)
6019 /* If the upper bound of this node is the highest value in the type
6020 of the index expression, we need not test against it. */
6022 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
6025 /* If this node has a right branch, the value at the right must be greater
6026 than that at this node, so it cannot be bounded at the top and
6027 we need not bother testing any further. */
6032 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
6033 node->high, integer_one_node));
6035 /* If the addition above overflowed, we can't verify anything.
6036 Otherwise, look for a parent that tests our value + 1. */
6038 if (! tree_int_cst_lt (node->high, high_plus_one))
6041 for (pnode = node->parent; pnode; pnode = pnode->parent)
6042 if (tree_int_cst_equal (high_plus_one, pnode->low))
6048 /* Search the parent sections of the
6049 case node tree to see if both tests for the upper and lower
6050 bounds of NODE would be redundant. */
6053 node_is_bounded (node, index_type)
6057 return (node_has_low_bound (node, index_type)
6058 && node_has_high_bound (node, index_type));
6061 /* Emit an unconditional jump to LABEL unless it would be dead code. */
6064 emit_jump_if_reachable (label)
6067 if (GET_CODE (get_last_insn ()) != BARRIER)
6071 /* Emit step-by-step code to select a case for the value of INDEX.
6072 The thus generated decision tree follows the form of the
6073 case-node binary tree NODE, whose nodes represent test conditions.
6074 INDEX_TYPE is the type of the index of the switch.
6076 Care is taken to prune redundant tests from the decision tree
6077 by detecting any boundary conditions already checked by
6078 emitted rtx. (See node_has_high_bound, node_has_low_bound
6079 and node_is_bounded, above.)
6081 Where the test conditions can be shown to be redundant we emit
6082 an unconditional jump to the target code. As a further
6083 optimization, the subordinates of a tree node are examined to
6084 check for bounded nodes. In this case conditional and/or
6085 unconditional jumps as a result of the boundary check for the
6086 current node are arranged to target the subordinates associated
6087 code for out of bound conditions on the current node.
6089 We can assume that when control reaches the code generated here,
6090 the index value has already been compared with the parents
6091 of this node, and determined to be on the same side of each parent
6092 as this node is. Thus, if this node tests for the value 51,
6093 and a parent tested for 52, we don't need to consider
6094 the possibility of a value greater than 51. If another parent
6095 tests for the value 50, then this node need not test anything. */
6098 emit_case_nodes (index, node, default_label, index_type)
6104 /* If INDEX has an unsigned type, we must make unsigned branches. */
6105 int unsignedp = TREE_UNSIGNED (index_type);
6106 enum machine_mode mode = GET_MODE (index);
6108 /* See if our parents have already tested everything for us.
6109 If they have, emit an unconditional jump for this node. */
6110 if (node_is_bounded (node, index_type))
6111 emit_jump (label_rtx (node->code_label));
6113 else if (tree_int_cst_equal (node->low, node->high))
6115 /* Node is single valued. First see if the index expression matches
6116 this node and then check our children, if any. */
6118 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
6119 label_rtx (node->code_label), unsignedp);
6121 if (node->right != 0 && node->left != 0)
6123 /* This node has children on both sides.
6124 Dispatch to one side or the other
6125 by comparing the index value with this node's value.
6126 If one subtree is bounded, check that one first,
6127 so we can avoid real branches in the tree. */
6129 if (node_is_bounded (node->right, index_type))
6131 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6133 GT, NULL_RTX, mode, unsignedp, 0,
6134 label_rtx (node->right->code_label));
6135 emit_case_nodes (index, node->left, default_label, index_type);
6138 else if (node_is_bounded (node->left, index_type))
6140 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6142 LT, NULL_RTX, mode, unsignedp, 0,
6143 label_rtx (node->left->code_label));
6144 emit_case_nodes (index, node->right, default_label, index_type);
6149 /* Neither node is bounded. First distinguish the two sides;
6150 then emit the code for one side at a time. */
6153 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6155 /* See if the value is on the right. */
6156 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6158 GT, NULL_RTX, mode, unsignedp, 0,
6159 label_rtx (test_label));
6161 /* Value must be on the left.
6162 Handle the left-hand subtree. */
6163 emit_case_nodes (index, node->left, default_label, index_type);
6164 /* If left-hand subtree does nothing,
6166 emit_jump_if_reachable (default_label);
6168 /* Code branches here for the right-hand subtree. */
6169 expand_label (test_label);
6170 emit_case_nodes (index, node->right, default_label, index_type);
6174 else if (node->right != 0 && node->left == 0)
6176 /* Here we have a right child but no left so we issue conditional
6177 branch to default and process the right child.
6179 Omit the conditional branch to default if we it avoid only one
6180 right child; it costs too much space to save so little time. */
6182 if (node->right->right || node->right->left
6183 || !tree_int_cst_equal (node->right->low, node->right->high))
6185 if (!node_has_low_bound (node, index_type))
6187 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6190 LT, NULL_RTX, mode, unsignedp, 0,
6194 emit_case_nodes (index, node->right, default_label, index_type);
6197 /* We cannot process node->right normally
6198 since we haven't ruled out the numbers less than
6199 this node's value. So handle node->right explicitly. */
6200 do_jump_if_equal (index,
6201 expand_expr (node->right->low, NULL_RTX,
6203 label_rtx (node->right->code_label), unsignedp);
6206 else if (node->right == 0 && node->left != 0)
6208 /* Just one subtree, on the left. */
6210 #if 0 /* The following code and comment were formerly part
6211 of the condition here, but they didn't work
6212 and I don't understand what the idea was. -- rms. */
6213 /* If our "most probable entry" is less probable
6214 than the default label, emit a jump to
6215 the default label using condition codes
6216 already lying around. With no right branch,
6217 a branch-greater-than will get us to the default
6220 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
6223 if (node->left->left || node->left->right
6224 || !tree_int_cst_equal (node->left->low, node->left->high))
6226 if (!node_has_high_bound (node, index_type))
6228 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6231 GT, NULL_RTX, mode, unsignedp, 0,
6235 emit_case_nodes (index, node->left, default_label, index_type);
6238 /* We cannot process node->left normally
6239 since we haven't ruled out the numbers less than
6240 this node's value. So handle node->left explicitly. */
6241 do_jump_if_equal (index,
6242 expand_expr (node->left->low, NULL_RTX,
6244 label_rtx (node->left->code_label), unsignedp);
6249 /* Node is a range. These cases are very similar to those for a single
6250 value, except that we do not start by testing whether this node
6251 is the one to branch to. */
6253 if (node->right != 0 && node->left != 0)
6255 /* Node has subtrees on both sides.
6256 If the right-hand subtree is bounded,
6257 test for it first, since we can go straight there.
6258 Otherwise, we need to make a branch in the control structure,
6259 then handle the two subtrees. */
6260 tree test_label = 0;
6263 if (node_is_bounded (node->right, index_type))
6264 /* Right hand node is fully bounded so we can eliminate any
6265 testing and branch directly to the target code. */
6266 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6268 GT, NULL_RTX, mode, unsignedp, 0,
6269 label_rtx (node->right->code_label));
6272 /* Right hand node requires testing.
6273 Branch to a label where we will handle it later. */
6275 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6276 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6278 GT, NULL_RTX, mode, unsignedp, 0,
6279 label_rtx (test_label));
6282 /* Value belongs to this node or to the left-hand subtree. */
6284 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6286 GE, NULL_RTX, mode, unsignedp, 0,
6287 label_rtx (node->code_label));
6289 /* Handle the left-hand subtree. */
6290 emit_case_nodes (index, node->left, default_label, index_type);
6292 /* If right node had to be handled later, do that now. */
6296 /* If the left-hand subtree fell through,
6297 don't let it fall into the right-hand subtree. */
6298 emit_jump_if_reachable (default_label);
6300 expand_label (test_label);
6301 emit_case_nodes (index, node->right, default_label, index_type);
6305 else if (node->right != 0 && node->left == 0)
6307 /* Deal with values to the left of this node,
6308 if they are possible. */
6309 if (!node_has_low_bound (node, index_type))
6311 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6313 LT, NULL_RTX, mode, unsignedp, 0,
6317 /* Value belongs to this node or to the right-hand subtree. */
6319 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6321 LE, NULL_RTX, mode, unsignedp, 0,
6322 label_rtx (node->code_label));
6324 emit_case_nodes (index, node->right, default_label, index_type);
6327 else if (node->right == 0 && node->left != 0)
6329 /* Deal with values to the right of this node,
6330 if they are possible. */
6331 if (!node_has_high_bound (node, index_type))
6333 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6335 GT, NULL_RTX, mode, unsignedp, 0,
6339 /* Value belongs to this node or to the left-hand subtree. */
6341 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6343 GE, NULL_RTX, mode, unsignedp, 0,
6344 label_rtx (node->code_label));
6346 emit_case_nodes (index, node->left, default_label, index_type);
6351 /* Node has no children so we check low and high bounds to remove
6352 redundant tests. Only one of the bounds can exist,
6353 since otherwise this node is bounded--a case tested already. */
6355 if (!node_has_high_bound (node, index_type))
6357 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6359 GT, NULL_RTX, mode, unsignedp, 0,
6363 if (!node_has_low_bound (node, index_type))
6365 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6367 LT, NULL_RTX, mode, unsignedp, 0,
6371 emit_jump (label_rtx (node->code_label));