1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 88, 89, 92-98, 1999 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
22 /* This file handles the generation of rtl code from tree structure
23 above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
24 It also creates the rtl expressions for parameters and auto variables
25 and has full responsibility for allocating stack slots.
27 The functions whose names start with `expand_' are called by the
28 parser to generate RTL instructions for various kinds of constructs.
30 Some control and binding constructs require calling several such
31 functions at different times. For example, a simple if-then
32 is expanded by calling `expand_start_cond' (with the condition-expression
33 as argument) before parsing the then-clause and calling `expand_end_cond'
34 after parsing the then-clause. */
45 #include "insn-flags.h"
46 #include "insn-config.h"
47 #include "insn-codes.h"
49 #include "hard-reg-set.h"
58 #define obstack_chunk_alloc xmalloc
59 #define obstack_chunk_free free
60 struct obstack stmt_obstack;
62 /* Assume that case vectors are not pc-relative. */
63 #ifndef CASE_VECTOR_PC_RELATIVE
64 #define CASE_VECTOR_PC_RELATIVE 0
68 /* Functions and data structures for expanding case statements. */
70 /* Case label structure, used to hold info on labels within case
71 statements. We handle "range" labels; for a single-value label
72 as in C, the high and low limits are the same.
74 An AVL tree of case nodes is initially created, and later transformed
75 to a list linked via the RIGHT fields in the nodes. Nodes with
76 higher case values are later in the list.
78 Switch statements can be output in one of two forms. A branch table
79 is used if there are more than a few labels and the labels are dense
80 within the range between the smallest and largest case value. If a
81 branch table is used, no further manipulations are done with the case
84 The alternative to the use of a branch table is to generate a series
85 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
86 and PARENT fields to hold a binary tree. Initially the tree is
87 totally unbalanced, with everything on the right. We balance the tree
88 with nodes on the left having lower case values than the parent
89 and nodes on the right having higher values. We then output the tree
94 struct case_node *left; /* Left son in binary tree */
95 struct case_node *right; /* Right son in binary tree; also node chain */
96 struct case_node *parent; /* Parent of node in binary tree */
97 tree low; /* Lowest index value for this label */
98 tree high; /* Highest index value for this label */
99 tree code_label; /* Label to jump to when node matches */
103 typedef struct case_node case_node;
104 typedef struct case_node *case_node_ptr;
106 /* These are used by estimate_case_costs and balance_case_nodes. */
108 /* This must be a signed type, and non-ANSI compilers lack signed char. */
109 static short cost_table_[129];
110 static short *cost_table;
111 static int use_cost_table;
113 /* Stack of control and binding constructs we are currently inside.
115 These constructs begin when you call `expand_start_WHATEVER'
116 and end when you call `expand_end_WHATEVER'. This stack records
117 info about how the construct began that tells the end-function
118 what to do. It also may provide information about the construct
119 to alter the behavior of other constructs within the body.
120 For example, they may affect the behavior of C `break' and `continue'.
122 Each construct gets one `struct nesting' object.
123 All of these objects are chained through the `all' field.
124 `nesting_stack' points to the first object (innermost construct).
125 The position of an entry on `nesting_stack' is in its `depth' field.
127 Each type of construct has its own individual stack.
128 For example, loops have `loop_stack'. Each object points to the
129 next object of the same type through the `next' field.
131 Some constructs are visible to `break' exit-statements and others
132 are not. Which constructs are visible depends on the language.
133 Therefore, the data structure allows each construct to be visible
134 or not, according to the args given when the construct is started.
135 The construct is visible if the `exit_label' field is non-null.
136 In that case, the value should be a CODE_LABEL rtx. */
141 struct nesting *next;
146 /* For conds (if-then and if-then-else statements). */
149 /* Label for the end of the if construct.
150 There is none if EXITFLAG was not set
151 and no `else' has been seen yet. */
153 /* Label for the end of this alternative.
154 This may be the end of the if or the next else/elseif. */
160 /* Label at the top of the loop; place to loop back to. */
162 /* Label at the end of the whole construct. */
164 /* Label before a jump that branches to the end of the whole
165 construct. This is where destructors go if any. */
167 /* Label for `continue' statement to jump to;
168 this is in front of the stepper of the loop. */
171 /* For variable binding contours. */
174 /* Sequence number of this binding contour within the function,
175 in order of entry. */
176 int block_start_count;
177 /* Nonzero => value to restore stack to on exit. */
179 /* The NOTE that starts this contour.
180 Used by expand_goto to check whether the destination
181 is within each contour or not. */
183 /* Innermost containing binding contour that has a stack level. */
184 struct nesting *innermost_stack_block;
185 /* List of cleanups to be run on exit from this contour.
186 This is a list of expressions to be evaluated.
187 The TREE_PURPOSE of each link is the ..._DECL node
188 which the cleanup pertains to. */
190 /* List of cleanup-lists of blocks containing this block,
191 as they were at the locus where this block appears.
192 There is an element for each containing block,
193 ordered innermost containing block first.
194 The tail of this list can be 0,
195 if all remaining elements would be empty lists.
196 The element's TREE_VALUE is the cleanup-list of that block,
197 which may be null. */
199 /* Chain of labels defined inside this binding contour.
200 For contours that have stack levels or cleanups. */
201 struct label_chain *label_chain;
202 /* Number of function calls seen, as of start of this block. */
203 int n_function_calls;
204 /* Nonzero if this is associated with a EH region. */
205 int exception_region;
206 /* The saved target_temp_slot_level from our outer block.
207 We may reset target_temp_slot_level to be the level of
208 this block, if that is done, target_temp_slot_level
209 reverts to the saved target_temp_slot_level at the very
211 int block_target_temp_slot_level;
212 /* True if we are currently emitting insns in an area of
213 output code that is controlled by a conditional
214 expression. This is used by the cleanup handling code to
215 generate conditional cleanup actions. */
216 int conditional_code;
217 /* A place to move the start of the exception region for any
218 of the conditional cleanups, must be at the end or after
219 the start of the last unconditional cleanup, and before any
220 conditional branch points. */
221 rtx last_unconditional_cleanup;
222 /* When in a conditional context, this is the specific
223 cleanup list associated with last_unconditional_cleanup,
224 where we place the conditionalized cleanups. */
227 /* For switch (C) or case (Pascal) statements,
228 and also for dummies (see `expand_start_case_dummy'). */
231 /* The insn after which the case dispatch should finally
232 be emitted. Zero for a dummy. */
234 /* A list of case labels; it is first built as an AVL tree.
235 During expand_end_case, this is converted to a list, and may be
236 rearranged into a nearly balanced binary tree. */
237 struct case_node *case_list;
238 /* Label to jump to if no case matches. */
240 /* The expression to be dispatched on. */
242 /* Type that INDEX_EXPR should be converted to. */
244 /* Number of range exprs in case statement. */
246 /* Name of this kind of statement, for warnings. */
247 const char *printname;
248 /* Used to save no_line_numbers till we see the first case label.
249 We set this to -1 when we see the first case label in this
251 int line_number_status;
256 /* Allocate and return a new `struct nesting'. */
258 #define ALLOC_NESTING() \
259 (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
261 /* Pop the nesting stack element by element until we pop off
262 the element which is at the top of STACK.
263 Update all the other stacks, popping off elements from them
264 as we pop them from nesting_stack. */
266 #define POPSTACK(STACK) \
267 do { struct nesting *target = STACK; \
268 struct nesting *this; \
269 do { this = nesting_stack; \
270 if (loop_stack == this) \
271 loop_stack = loop_stack->next; \
272 if (cond_stack == this) \
273 cond_stack = cond_stack->next; \
274 if (block_stack == this) \
275 block_stack = block_stack->next; \
276 if (stack_block_stack == this) \
277 stack_block_stack = stack_block_stack->next; \
278 if (case_stack == this) \
279 case_stack = case_stack->next; \
280 nesting_depth = nesting_stack->depth - 1; \
281 nesting_stack = this->all; \
282 obstack_free (&stmt_obstack, this); } \
283 while (this != target); } while (0)
285 /* In some cases it is impossible to generate code for a forward goto
286 until the label definition is seen. This happens when it may be necessary
287 for the goto to reset the stack pointer: we don't yet know how to do that.
288 So expand_goto puts an entry on this fixup list.
289 Each time a binding contour that resets the stack is exited,
291 If the target label has now been defined, we can insert the proper code. */
295 /* Points to following fixup. */
296 struct goto_fixup *next;
297 /* Points to the insn before the jump insn.
298 If more code must be inserted, it goes after this insn. */
300 /* The LABEL_DECL that this jump is jumping to, or 0
301 for break, continue or return. */
303 /* The BLOCK for the place where this goto was found. */
305 /* The CODE_LABEL rtx that this is jumping to. */
307 /* Number of binding contours started in current function
308 before the label reference. */
309 int block_start_count;
310 /* The outermost stack level that should be restored for this jump.
311 Each time a binding contour that resets the stack is exited,
312 if the target label is *not* yet defined, this slot is updated. */
314 /* List of lists of cleanup expressions to be run by this goto.
315 There is one element for each block that this goto is within.
316 The tail of this list can be 0,
317 if all remaining elements would be empty.
318 The TREE_VALUE contains the cleanup list of that block as of the
319 time this goto was seen.
320 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
321 tree cleanup_list_list;
324 /* Within any binding contour that must restore a stack level,
325 all labels are recorded with a chain of these structures. */
329 /* Points to following fixup. */
330 struct label_chain *next;
336 /* Chain of all pending binding contours. */
337 struct nesting *x_block_stack;
339 /* If any new stacks are added here, add them to POPSTACKS too. */
341 /* Chain of all pending binding contours that restore stack levels
343 struct nesting *x_stack_block_stack;
345 /* Chain of all pending conditional statements. */
346 struct nesting *x_cond_stack;
348 /* Chain of all pending loops. */
349 struct nesting *x_loop_stack;
351 /* Chain of all pending case or switch statements. */
352 struct nesting *x_case_stack;
354 /* Separate chain including all of the above,
355 chained through the `all' field. */
356 struct nesting *x_nesting_stack;
358 /* Number of entries on nesting_stack now. */
361 /* Number of binding contours started so far in this function. */
362 int x_block_start_count;
364 /* Each time we expand an expression-statement,
365 record the expr's type and its RTL value here. */
366 tree x_last_expr_type;
367 rtx x_last_expr_value;
369 /* Nonzero if within a ({...}) grouping, in which case we must
370 always compute a value for each expr-stmt in case it is the last one. */
371 int x_expr_stmts_for_value;
373 /* Filename and line number of last line-number note,
374 whether we actually emitted it or not. */
375 char *x_emit_filename;
378 struct goto_fixup *x_goto_fixup_chain;
381 #define block_stack (current_function->stmt->x_block_stack)
382 #define stack_block_stack (current_function->stmt->x_stack_block_stack)
383 #define cond_stack (current_function->stmt->x_cond_stack)
384 #define loop_stack (current_function->stmt->x_loop_stack)
385 #define case_stack (current_function->stmt->x_case_stack)
386 #define nesting_stack (current_function->stmt->x_nesting_stack)
387 #define nesting_depth (current_function->stmt->x_nesting_depth)
388 #define current_block_start_count (current_function->stmt->x_block_start_count)
389 #define last_expr_type (current_function->stmt->x_last_expr_type)
390 #define last_expr_value (current_function->stmt->x_last_expr_value)
391 #define expr_stmts_for_value (current_function->stmt->x_expr_stmts_for_value)
392 #define emit_filename (current_function->stmt->x_emit_filename)
393 #define emit_lineno (current_function->stmt->x_emit_lineno)
394 #define goto_fixup_chain (current_function->stmt->x_goto_fixup_chain)
396 /* Non-zero if we are using EH to handle cleanus. */
397 static int using_eh_for_cleanups_p = 0;
399 /* Character strings, each containing a single decimal digit. */
400 static char *digit_strings[10];
403 static int n_occurrences PROTO((int, const char *));
404 static void expand_goto_internal PROTO((tree, rtx, rtx));
405 static int expand_fixup PROTO((tree, rtx, rtx));
406 static rtx expand_nl_handler_label PROTO((rtx, rtx));
407 static void expand_nl_goto_receiver PROTO((void));
408 static void expand_nl_goto_receivers PROTO((struct nesting *));
409 static void fixup_gotos PROTO((struct nesting *, rtx, tree,
411 static void expand_null_return_1 PROTO((rtx, int));
412 static void expand_value_return PROTO((rtx));
413 static int tail_recursion_args PROTO((tree, tree));
414 static void expand_cleanups PROTO((tree, tree, int, int));
415 static void check_seenlabel PROTO((void));
416 static void do_jump_if_equal PROTO((rtx, rtx, rtx, int));
417 static int estimate_case_costs PROTO((case_node_ptr));
418 static void group_case_nodes PROTO((case_node_ptr));
419 static void balance_case_nodes PROTO((case_node_ptr *,
421 static int node_has_low_bound PROTO((case_node_ptr, tree));
422 static int node_has_high_bound PROTO((case_node_ptr, tree));
423 static int node_is_bounded PROTO((case_node_ptr, tree));
424 static void emit_jump_if_reachable PROTO((rtx));
425 static void emit_case_nodes PROTO((rtx, case_node_ptr, rtx, tree));
426 static int add_case_node PROTO((tree, tree, tree, tree *));
427 static struct case_node *case_tree2list PROTO((case_node *, case_node *));
428 static void mark_cond_nesting PROTO((struct nesting *));
429 static void mark_loop_nesting PROTO((struct nesting *));
430 static void mark_block_nesting PROTO((struct nesting *));
431 static void mark_case_nesting PROTO((struct nesting *));
432 static void mark_goto_fixup PROTO((struct goto_fixup *));
436 using_eh_for_cleanups ()
438 using_eh_for_cleanups_p = 1;
441 /* Mark N (known to be a cond-nesting) for GC. */
444 mark_cond_nesting (n)
449 ggc_mark_rtx (n->exit_label);
450 ggc_mark_rtx (n->data.cond.endif_label);
451 ggc_mark_rtx (n->data.cond.next_label);
457 /* Mark N (known to be a loop-nesting) for GC. */
460 mark_loop_nesting (n)
466 ggc_mark_rtx (n->exit_label);
467 ggc_mark_rtx (n->data.loop.start_label);
468 ggc_mark_rtx (n->data.loop.end_label);
469 ggc_mark_rtx (n->data.loop.alt_end_label);
470 ggc_mark_rtx (n->data.loop.continue_label);
476 /* Mark N (known to be a block-nesting) for GC. */
479 mark_block_nesting (n)
484 struct label_chain *l;
486 ggc_mark_rtx (n->exit_label);
487 ggc_mark_rtx (n->data.block.stack_level);
488 ggc_mark_rtx (n->data.block.first_insn);
489 ggc_mark_tree (n->data.block.cleanups);
490 ggc_mark_tree (n->data.block.outer_cleanups);
492 for (l = n->data.block.label_chain; l != NULL; l = l->next)
493 ggc_mark_tree (l->label);
495 ggc_mark_rtx (n->data.block.last_unconditional_cleanup);
497 /* ??? cleanup_ptr never points outside the stack, does it? */
503 /* Mark N (known to be a case-nesting) for GC. */
506 mark_case_nesting (n)
511 struct case_node *node;
513 ggc_mark_rtx (n->exit_label);
514 ggc_mark_rtx (n->data.case_stmt.start);
516 node = n->data.case_stmt.case_list;
519 ggc_mark_tree (node->low);
520 ggc_mark_tree (node->high);
521 ggc_mark_tree (node->code_label);
525 ggc_mark_tree (n->data.case_stmt.default_label);
526 ggc_mark_tree (n->data.case_stmt.index_expr);
527 ggc_mark_tree (n->data.case_stmt.nominal_type);
537 struct goto_fixup *g;
541 ggc_mark_rtx (g->before_jump);
542 ggc_mark_tree (g->target);
543 ggc_mark_tree (g->context);
544 ggc_mark_rtx (g->target_rtl);
545 ggc_mark_rtx (g->stack_level);
546 ggc_mark_tree (g->cleanup_list_list);
552 /* Clear out all parts of the state in F that can safely be discarded
553 after the function has been compiled, to let garbage collection
554 reclaim the memory. */
560 /* We're about to free the function obstack. If we hold pointers to
561 things allocated there, then we'll try to mark them when we do
562 GC. So, we clear them out here explicitly. */
572 struct stmt_status *p;
577 mark_block_nesting (p->x_block_stack);
578 mark_cond_nesting (p->x_cond_stack);
579 mark_loop_nesting (p->x_loop_stack);
580 mark_case_nesting (p->x_case_stack);
582 ggc_mark_tree (p->x_last_expr_type);
583 /* last_epxr_value is only valid if last_expr_type is nonzero. */
584 if (p->x_last_expr_type)
585 ggc_mark_rtx (p->x_last_expr_value);
587 mark_goto_fixup (p->x_goto_fixup_chain);
595 gcc_obstack_init (&stmt_obstack);
597 for (i = 0; i < 10; i++)
599 digit_strings[i] = ggc_alloc_string (NULL, 1);
600 digit_strings[i][0] = '0' + i;
602 ggc_add_string_root (digit_strings, 10);
606 init_stmt_for_function ()
608 current_function->stmt
609 = (struct stmt_status *) xmalloc (sizeof (struct stmt_status));
611 /* We are not currently within any block, conditional, loop or case. */
613 stack_block_stack = 0;
620 current_block_start_count = 0;
622 /* No gotos have been expanded yet. */
623 goto_fixup_chain = 0;
625 /* We are not processing a ({...}) grouping. */
626 expr_stmts_for_value = 0;
628 last_expr_value = NULL_RTX;
631 /* Return nonzero if anything is pushed on the loop, condition, or case
636 return cond_stack || loop_stack || case_stack;
639 /* Record the current file and line. Called from emit_line_note. */
641 set_file_and_line_for_stmt (file, line)
645 emit_filename = file;
649 /* Emit a no-op instruction. */
656 last_insn = get_last_insn ();
658 && (GET_CODE (last_insn) == CODE_LABEL
659 || (GET_CODE (last_insn) == NOTE
660 && prev_real_insn (last_insn) == 0)))
661 emit_insn (gen_nop ());
664 /* Return the rtx-label that corresponds to a LABEL_DECL,
665 creating it if necessary. */
671 if (TREE_CODE (label) != LABEL_DECL)
674 if (DECL_RTL (label))
675 return DECL_RTL (label);
677 return DECL_RTL (label) = gen_label_rtx ();
680 /* Add an unconditional jump to LABEL as the next sequential instruction. */
686 do_pending_stack_adjust ();
687 emit_jump_insn (gen_jump (label));
691 /* Emit code to jump to the address
692 specified by the pointer expression EXP. */
695 expand_computed_goto (exp)
698 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
700 #ifdef POINTERS_EXTEND_UNSIGNED
701 x = convert_memory_address (Pmode, x);
705 /* Be sure the function is executable. */
706 if (current_function_check_memory_usage)
707 emit_library_call (chkr_check_exec_libfunc, 1,
708 VOIDmode, 1, x, ptr_mode);
710 do_pending_stack_adjust ();
711 emit_indirect_jump (x);
713 current_function_has_computed_jump = 1;
716 /* Handle goto statements and the labels that they can go to. */
718 /* Specify the location in the RTL code of a label LABEL,
719 which is a LABEL_DECL tree node.
721 This is used for the kind of label that the user can jump to with a
722 goto statement, and for alternatives of a switch or case statement.
723 RTL labels generated for loops and conditionals don't go through here;
724 they are generated directly at the RTL level, by other functions below.
726 Note that this has nothing to do with defining label *names*.
727 Languages vary in how they do that and what that even means. */
733 struct label_chain *p;
735 do_pending_stack_adjust ();
736 emit_label (label_rtx (label));
737 if (DECL_NAME (label))
738 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
740 if (stack_block_stack != 0)
742 p = (struct label_chain *) oballoc (sizeof (struct label_chain));
743 p->next = stack_block_stack->data.block.label_chain;
744 stack_block_stack->data.block.label_chain = p;
749 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
750 from nested functions. */
753 declare_nonlocal_label (label)
756 rtx slot = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
758 nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
759 LABEL_PRESERVE_P (label_rtx (label)) = 1;
760 if (nonlocal_goto_handler_slots == 0)
762 emit_stack_save (SAVE_NONLOCAL,
763 &nonlocal_goto_stack_level,
764 PREV_INSN (tail_recursion_reentry));
766 nonlocal_goto_handler_slots
767 = gen_rtx_EXPR_LIST (VOIDmode, slot, nonlocal_goto_handler_slots);
770 /* Generate RTL code for a `goto' statement with target label LABEL.
771 LABEL should be a LABEL_DECL tree node that was or will later be
772 defined with `expand_label'. */
780 /* Check for a nonlocal goto to a containing function. */
781 context = decl_function_context (label);
782 if (context != 0 && context != current_function_decl)
784 struct function *p = find_function_data (context);
785 rtx label_ref = gen_rtx_LABEL_REF (Pmode, label_rtx (label));
786 rtx temp, handler_slot;
789 /* Find the corresponding handler slot for this label. */
790 handler_slot = p->x_nonlocal_goto_handler_slots;
791 for (link = p->x_nonlocal_labels; TREE_VALUE (link) != label;
792 link = TREE_CHAIN (link))
793 handler_slot = XEXP (handler_slot, 1);
794 handler_slot = XEXP (handler_slot, 0);
796 p->has_nonlocal_label = 1;
797 current_function_has_nonlocal_goto = 1;
798 LABEL_REF_NONLOCAL_P (label_ref) = 1;
800 /* Copy the rtl for the slots so that they won't be shared in
801 case the virtual stack vars register gets instantiated differently
802 in the parent than in the child. */
804 #if HAVE_nonlocal_goto
805 if (HAVE_nonlocal_goto)
806 emit_insn (gen_nonlocal_goto (lookup_static_chain (label),
807 copy_rtx (handler_slot),
808 copy_rtx (p->x_nonlocal_goto_stack_level),
815 /* Restore frame pointer for containing function.
816 This sets the actual hard register used for the frame pointer
817 to the location of the function's incoming static chain info.
818 The non-local goto handler will then adjust it to contain the
819 proper value and reload the argument pointer, if needed. */
820 emit_move_insn (hard_frame_pointer_rtx, lookup_static_chain (label));
822 /* We have now loaded the frame pointer hardware register with
823 the address of that corresponds to the start of the virtual
824 stack vars. So replace virtual_stack_vars_rtx in all
825 addresses we use with stack_pointer_rtx. */
827 /* Get addr of containing function's current nonlocal goto handler,
828 which will do any cleanups and then jump to the label. */
829 addr = copy_rtx (handler_slot);
830 temp = copy_to_reg (replace_rtx (addr, virtual_stack_vars_rtx,
831 hard_frame_pointer_rtx));
833 /* Restore the stack pointer. Note this uses fp just restored. */
834 addr = p->x_nonlocal_goto_stack_level;
836 addr = replace_rtx (copy_rtx (addr),
837 virtual_stack_vars_rtx,
838 hard_frame_pointer_rtx);
840 emit_stack_restore (SAVE_NONLOCAL, addr, NULL_RTX);
842 /* USE of hard_frame_pointer_rtx added for consistency; not clear if
844 emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx));
845 emit_insn (gen_rtx_USE (VOIDmode, stack_pointer_rtx));
846 emit_indirect_jump (temp);
850 expand_goto_internal (label, label_rtx (label), NULL_RTX);
853 /* Generate RTL code for a `goto' statement with target label BODY.
854 LABEL should be a LABEL_REF.
855 LAST_INSN, if non-0, is the rtx we should consider as the last
856 insn emitted (for the purposes of cleaning up a return). */
859 expand_goto_internal (body, label, last_insn)
864 struct nesting *block;
867 if (GET_CODE (label) != CODE_LABEL)
870 /* If label has already been defined, we can tell now
871 whether and how we must alter the stack level. */
873 if (PREV_INSN (label) != 0)
875 /* Find the innermost pending block that contains the label.
876 (Check containment by comparing insn-uids.)
877 Then restore the outermost stack level within that block,
878 and do cleanups of all blocks contained in it. */
879 for (block = block_stack; block; block = block->next)
881 if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
883 if (block->data.block.stack_level != 0)
884 stack_level = block->data.block.stack_level;
885 /* Execute the cleanups for blocks we are exiting. */
886 if (block->data.block.cleanups != 0)
888 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
889 do_pending_stack_adjust ();
895 /* Ensure stack adjust isn't done by emit_jump, as this
896 would clobber the stack pointer. This one should be
897 deleted as dead by flow. */
898 clear_pending_stack_adjust ();
899 do_pending_stack_adjust ();
900 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
903 if (body != 0 && DECL_TOO_LATE (body))
904 error ("jump to `%s' invalidly jumps into binding contour",
905 IDENTIFIER_POINTER (DECL_NAME (body)));
907 /* Label not yet defined: may need to put this goto
908 on the fixup list. */
909 else if (! expand_fixup (body, label, last_insn))
911 /* No fixup needed. Record that the label is the target
912 of at least one goto that has no fixup. */
914 TREE_ADDRESSABLE (body) = 1;
920 /* Generate if necessary a fixup for a goto
921 whose target label in tree structure (if any) is TREE_LABEL
922 and whose target in rtl is RTL_LABEL.
924 If LAST_INSN is nonzero, we pretend that the jump appears
925 after insn LAST_INSN instead of at the current point in the insn stream.
927 The fixup will be used later to insert insns just before the goto.
928 Those insns will restore the stack level as appropriate for the
929 target label, and will (in the case of C++) also invoke any object
930 destructors which have to be invoked when we exit the scopes which
931 are exited by the goto.
933 Value is nonzero if a fixup is made. */
936 expand_fixup (tree_label, rtl_label, last_insn)
941 struct nesting *block, *end_block;
943 /* See if we can recognize which block the label will be output in.
944 This is possible in some very common cases.
945 If we succeed, set END_BLOCK to that block.
946 Otherwise, set it to 0. */
949 && (rtl_label == cond_stack->data.cond.endif_label
950 || rtl_label == cond_stack->data.cond.next_label))
951 end_block = cond_stack;
952 /* If we are in a loop, recognize certain labels which
953 are likely targets. This reduces the number of fixups
954 we need to create. */
956 && (rtl_label == loop_stack->data.loop.start_label
957 || rtl_label == loop_stack->data.loop.end_label
958 || rtl_label == loop_stack->data.loop.continue_label))
959 end_block = loop_stack;
963 /* Now set END_BLOCK to the binding level to which we will return. */
967 struct nesting *next_block = end_block->all;
970 /* First see if the END_BLOCK is inside the innermost binding level.
971 If so, then no cleanups or stack levels are relevant. */
972 while (next_block && next_block != block)
973 next_block = next_block->all;
978 /* Otherwise, set END_BLOCK to the innermost binding level
979 which is outside the relevant control-structure nesting. */
980 next_block = block_stack->next;
981 for (block = block_stack; block != end_block; block = block->all)
982 if (block == next_block)
983 next_block = next_block->next;
984 end_block = next_block;
987 /* Does any containing block have a stack level or cleanups?
988 If not, no fixup is needed, and that is the normal case
989 (the only case, for standard C). */
990 for (block = block_stack; block != end_block; block = block->next)
991 if (block->data.block.stack_level != 0
992 || block->data.block.cleanups != 0)
995 if (block != end_block)
997 /* Ok, a fixup is needed. Add a fixup to the list of such. */
998 struct goto_fixup *fixup
999 = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup));
1000 /* In case an old stack level is restored, make sure that comes
1001 after any pending stack adjust. */
1002 /* ?? If the fixup isn't to come at the present position,
1003 doing the stack adjust here isn't useful. Doing it with our
1004 settings at that location isn't useful either. Let's hope
1007 do_pending_stack_adjust ();
1008 fixup->target = tree_label;
1009 fixup->target_rtl = rtl_label;
1011 /* Create a BLOCK node and a corresponding matched set of
1012 NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes at
1013 this point. The notes will encapsulate any and all fixup
1014 code which we might later insert at this point in the insn
1015 stream. Also, the BLOCK node will be the parent (i.e. the
1016 `SUPERBLOCK') of any other BLOCK nodes which we might create
1017 later on when we are expanding the fixup code.
1019 Note that optimization passes (including expand_end_loop)
1020 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
1021 as a placeholder. */
1024 register rtx original_before_jump
1025 = last_insn ? last_insn : get_last_insn ();
1030 block = make_node (BLOCK);
1031 TREE_USED (block) = 1;
1033 if (!current_function->x_whole_function_mode_p)
1034 insert_block (block);
1038 = BLOCK_CHAIN (DECL_INITIAL (current_function_decl));
1039 BLOCK_CHAIN (DECL_INITIAL (current_function_decl))
1044 start = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
1045 if (current_function->x_whole_function_mode_p)
1046 NOTE_BLOCK (start) = block;
1047 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_DELETED);
1048 end = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
1049 if (current_function->x_whole_function_mode_p)
1050 NOTE_BLOCK (end) = block;
1051 fixup->context = block;
1053 emit_insns_after (start, original_before_jump);
1056 fixup->block_start_count = current_block_start_count;
1057 fixup->stack_level = 0;
1058 fixup->cleanup_list_list
1059 = ((block->data.block.outer_cleanups
1060 || block->data.block.cleanups)
1061 ? tree_cons (NULL_TREE, block->data.block.cleanups,
1062 block->data.block.outer_cleanups)
1064 fixup->next = goto_fixup_chain;
1065 goto_fixup_chain = fixup;
1073 /* Expand any needed fixups in the outputmost binding level of the
1074 function. FIRST_INSN is the first insn in the function. */
1077 expand_fixups (first_insn)
1080 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0);
1083 /* When exiting a binding contour, process all pending gotos requiring fixups.
1084 THISBLOCK is the structure that describes the block being exited.
1085 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1086 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1087 FIRST_INSN is the insn that began this contour.
1089 Gotos that jump out of this contour must restore the
1090 stack level and do the cleanups before actually jumping.
1092 DONT_JUMP_IN nonzero means report error there is a jump into this
1093 contour from before the beginning of the contour.
1094 This is also done if STACK_LEVEL is nonzero. */
1097 fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1098 struct nesting *thisblock;
1104 register struct goto_fixup *f, *prev;
1106 /* F is the fixup we are considering; PREV is the previous one. */
1107 /* We run this loop in two passes so that cleanups of exited blocks
1108 are run first, and blocks that are exited are marked so
1111 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1113 /* Test for a fixup that is inactive because it is already handled. */
1114 if (f->before_jump == 0)
1116 /* Delete inactive fixup from the chain, if that is easy to do. */
1118 prev->next = f->next;
1120 /* Has this fixup's target label been defined?
1121 If so, we can finalize it. */
1122 else if (PREV_INSN (f->target_rtl) != 0)
1124 register rtx cleanup_insns;
1126 /* If this fixup jumped into this contour from before the beginning
1127 of this contour, report an error. This code used to use
1128 the first non-label insn after f->target_rtl, but that's
1129 wrong since such can be added, by things like put_var_into_stack
1130 and have INSN_UIDs that are out of the range of the block. */
1131 /* ??? Bug: this does not detect jumping in through intermediate
1132 blocks that have stack levels or cleanups.
1133 It detects only a problem with the innermost block
1134 around the label. */
1136 && (dont_jump_in || stack_level || cleanup_list)
1137 && INSN_UID (first_insn) < INSN_UID (f->target_rtl)
1138 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1139 && ! DECL_ERROR_ISSUED (f->target))
1141 error_with_decl (f->target,
1142 "label `%s' used before containing binding contour");
1143 /* Prevent multiple errors for one label. */
1144 DECL_ERROR_ISSUED (f->target) = 1;
1147 /* We will expand the cleanups into a sequence of their own and
1148 then later on we will attach this new sequence to the insn
1149 stream just ahead of the actual jump insn. */
1153 /* Temporarily restore the lexical context where we will
1154 logically be inserting the fixup code. We do this for the
1155 sake of getting the debugging information right. */
1158 set_block (f->context);
1160 /* Expand the cleanups for blocks this jump exits. */
1161 if (f->cleanup_list_list)
1164 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1165 /* Marked elements correspond to blocks that have been closed.
1166 Do their cleanups. */
1167 if (TREE_ADDRESSABLE (lists)
1168 && TREE_VALUE (lists) != 0)
1170 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1171 /* Pop any pushes done in the cleanups,
1172 in case function is about to return. */
1173 do_pending_stack_adjust ();
1177 /* Restore stack level for the biggest contour that this
1178 jump jumps out of. */
1180 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1182 /* Finish up the sequence containing the insns which implement the
1183 necessary cleanups, and then attach that whole sequence to the
1184 insn stream just ahead of the actual jump insn. Attaching it
1185 at that point insures that any cleanups which are in fact
1186 implicit C++ object destructions (which must be executed upon
1187 leaving the block) appear (to the debugger) to be taking place
1188 in an area of the generated code where the object(s) being
1189 destructed are still "in scope". */
1191 cleanup_insns = get_insns ();
1195 emit_insns_after (cleanup_insns, f->before_jump);
1202 /* For any still-undefined labels, do the cleanups for this block now.
1203 We must do this now since items in the cleanup list may go out
1204 of scope when the block ends. */
1205 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1206 if (f->before_jump != 0
1207 && PREV_INSN (f->target_rtl) == 0
1208 /* Label has still not appeared. If we are exiting a block with
1209 a stack level to restore, that started before the fixup,
1210 mark this stack level as needing restoration
1211 when the fixup is later finalized. */
1213 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1214 means the label is undefined. That's erroneous, but possible. */
1215 && (thisblock->data.block.block_start_count
1216 <= f->block_start_count))
1218 tree lists = f->cleanup_list_list;
1221 for (; lists; lists = TREE_CHAIN (lists))
1222 /* If the following elt. corresponds to our containing block
1223 then the elt. must be for this block. */
1224 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
1228 set_block (f->context);
1229 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1230 do_pending_stack_adjust ();
1231 cleanup_insns = get_insns ();
1234 if (cleanup_insns != 0)
1236 = emit_insns_after (cleanup_insns, f->before_jump);
1238 f->cleanup_list_list = TREE_CHAIN (lists);
1242 f->stack_level = stack_level;
1246 /* Return the number of times character C occurs in string S. */
1248 n_occurrences (c, s)
1258 /* Generate RTL for an asm statement (explicit assembler code).
1259 BODY is a STRING_CST node containing the assembler code text,
1260 or an ADDR_EXPR containing a STRING_CST. */
1266 if (current_function_check_memory_usage)
1268 error ("`asm' cannot be used in function where memory usage is checked");
1272 if (TREE_CODE (body) == ADDR_EXPR)
1273 body = TREE_OPERAND (body, 0);
1275 emit_insn (gen_rtx_ASM_INPUT (VOIDmode,
1276 TREE_STRING_POINTER (body)));
1280 /* Generate RTL for an asm statement with arguments.
1281 STRING is the instruction template.
1282 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1283 Each output or input has an expression in the TREE_VALUE and
1284 a constraint-string in the TREE_PURPOSE.
1285 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1286 that is clobbered by this insn.
1288 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1289 Some elements of OUTPUTS may be replaced with trees representing temporary
1290 values. The caller should copy those temporary values to the originally
1293 VOL nonzero means the insn is volatile; don't optimize it. */
1296 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1297 tree string, outputs, inputs, clobbers;
1302 rtvec argvec, constraints;
1304 int ninputs = list_length (inputs);
1305 int noutputs = list_length (outputs);
1310 /* Vector of RTX's of evaluated output operands. */
1311 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1312 int *inout_opnum = (int *) alloca (noutputs * sizeof (int));
1313 rtx *real_output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1314 enum machine_mode *inout_mode
1315 = (enum machine_mode *) alloca (noutputs * sizeof (enum machine_mode));
1316 /* The insn we have emitted. */
1319 /* An ASM with no outputs needs to be treated as volatile, for now. */
1323 if (current_function_check_memory_usage)
1325 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1329 #ifdef MD_ASM_CLOBBERS
1330 /* Sometimes we wish to automatically clobber registers across an asm.
1331 Case in point is when the i386 backend moved from cc0 to a hard reg --
1332 maintaining source-level compatability means automatically clobbering
1333 the flags register. */
1334 MD_ASM_CLOBBERS (clobbers);
1337 if (current_function_check_memory_usage)
1339 error ("`asm' cannot be used in function where memory usage is checked");
1343 /* Count the number of meaningful clobbered registers, ignoring what
1344 we would ignore later. */
1346 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1348 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1350 i = decode_reg_name (regname);
1351 if (i >= 0 || i == -4)
1354 error ("unknown register name `%s' in `asm'", regname);
1359 /* Check that the number of alternatives is constant across all
1361 if (outputs || inputs)
1363 tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
1364 int nalternatives = n_occurrences (',', TREE_STRING_POINTER (tmp));
1367 if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
1369 error ("too many alternatives in `asm'");
1376 char *constraint = TREE_STRING_POINTER (TREE_PURPOSE (tmp));
1378 if (n_occurrences (',', constraint) != nalternatives)
1380 error ("operand constraints for `asm' differ in number of alternatives");
1384 if (TREE_CHAIN (tmp))
1385 tmp = TREE_CHAIN (tmp);
1387 tmp = next, next = 0;
1391 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1393 tree val = TREE_VALUE (tail);
1394 tree type = TREE_TYPE (val);
1403 /* If there's an erroneous arg, emit no insn. */
1404 if (TREE_TYPE (val) == error_mark_node)
1407 /* Make sure constraint has `=' and does not have `+'. Also, see
1408 if it allows any register. Be liberal on the latter test, since
1409 the worst that happens if we get it wrong is we issue an error
1412 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1413 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1415 /* Allow the `=' or `+' to not be at the beginning of the string,
1416 since it wasn't explicitly documented that way, and there is a
1417 large body of code that puts it last. Swap the character to
1418 the front, so as not to uglify any place else. */
1422 if ((p = strchr (constraint, '=')) != NULL)
1424 if ((p = strchr (constraint, '+')) != NULL)
1427 error ("output operand constraint lacks `='");
1431 if (p != constraint)
1434 bcopy (constraint, constraint+1, p-constraint);
1437 warning ("output constraint `%c' for operand %d is not at the beginning", j, i);
1440 is_inout = constraint[0] == '+';
1441 /* Replace '+' with '='. */
1442 constraint[0] = '=';
1443 /* Make sure we can specify the matching operand. */
1444 if (is_inout && i > 9)
1446 error ("output operand constraint %d contains `+'", i);
1450 for (j = 1; j < c_len; j++)
1451 switch (constraint[j])
1455 error ("operand constraint contains '+' or '=' at illegal position.");
1459 if (i + 1 == ninputs + noutputs)
1461 error ("`%%' constraint used with last operand");
1466 case '?': case '!': case '*': case '&':
1467 case 'E': case 'F': case 'G': case 'H':
1468 case 's': case 'i': case 'n':
1469 case 'I': case 'J': case 'K': case 'L': case 'M':
1470 case 'N': case 'O': case 'P': case ',':
1471 #ifdef EXTRA_CONSTRAINT
1472 case 'Q': case 'R': case 'S': case 'T': case 'U':
1476 case '0': case '1': case '2': case '3': case '4':
1477 case '5': case '6': case '7': case '8': case '9':
1478 error ("matching constraint not valid in output operand");
1481 case 'V': case 'm': case 'o':
1486 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1487 excepting those that expand_call created. So match memory
1503 /* If an output operand is not a decl or indirect ref and our constraint
1504 allows a register, make a temporary to act as an intermediate.
1505 Make the asm insn write into that, then our caller will copy it to
1506 the real output operand. Likewise for promoted variables. */
1508 real_output_rtx[i] = NULL_RTX;
1509 if ((TREE_CODE (val) == INDIRECT_REF
1511 || (TREE_CODE_CLASS (TREE_CODE (val)) == 'd'
1512 && (allows_mem || GET_CODE (DECL_RTL (val)) == REG)
1513 && ! (GET_CODE (DECL_RTL (val)) == REG
1514 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
1519 mark_addressable (TREE_VALUE (tail));
1522 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode,
1523 EXPAND_MEMORY_USE_WO);
1525 if (! allows_reg && GET_CODE (output_rtx[i]) != MEM)
1526 error ("output number %d not directly addressable", i);
1527 if (! allows_mem && GET_CODE (output_rtx[i]) == MEM)
1529 real_output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1530 output_rtx[i] = gen_reg_rtx (GET_MODE (output_rtx[i]));
1532 emit_move_insn (output_rtx[i], real_output_rtx[i]);
1537 output_rtx[i] = assign_temp (type, 0, 0, 0);
1538 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1543 inout_mode[ninout] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)));
1544 inout_opnum[ninout++] = i;
1549 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1551 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1555 /* Make vectors for the expression-rtx and constraint strings. */
1557 argvec = rtvec_alloc (ninputs);
1558 constraints = rtvec_alloc (ninputs);
1560 body = gen_rtx_ASM_OPERANDS (VOIDmode, TREE_STRING_POINTER (string),
1561 empty_string, 0, argvec, constraints,
1564 MEM_VOLATILE_P (body) = vol;
1566 /* Eval the inputs and put them into ARGVEC.
1567 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1570 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1573 int allows_reg = 0, allows_mem = 0;
1574 char *constraint, *orig_constraint;
1578 /* If there's an erroneous arg, emit no insn,
1579 because the ASM_INPUT would get VOIDmode
1580 and that could cause a crash in reload. */
1581 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1584 /* ??? Can this happen, and does the error message make any sense? */
1585 if (TREE_PURPOSE (tail) == NULL_TREE)
1587 error ("hard register `%s' listed as input operand to `asm'",
1588 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1592 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1593 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1594 orig_constraint = constraint;
1596 /* Make sure constraint has neither `=', `+', nor '&'. */
1598 for (j = 0; j < c_len; j++)
1599 switch (constraint[j])
1601 case '+': case '=': case '&':
1602 if (constraint == orig_constraint)
1604 error ("input operand constraint contains `%c'",
1611 if (constraint == orig_constraint
1612 && i + 1 == ninputs - ninout)
1614 error ("`%%' constraint used with last operand");
1619 case 'V': case 'm': case 'o':
1624 case '?': case '!': case '*':
1625 case 'E': case 'F': case 'G': case 'H': case 'X':
1626 case 's': case 'i': case 'n':
1627 case 'I': case 'J': case 'K': case 'L': case 'M':
1628 case 'N': case 'O': case 'P': case ',':
1629 #ifdef EXTRA_CONSTRAINT
1630 case 'Q': case 'R': case 'S': case 'T': case 'U':
1634 /* Whether or not a numeric constraint allows a register is
1635 decided by the matching constraint, and so there is no need
1636 to do anything special with them. We must handle them in
1637 the default case, so that we don't unnecessarily force
1638 operands to memory. */
1639 case '0': case '1': case '2': case '3': case '4':
1640 case '5': case '6': case '7': case '8': case '9':
1641 if (constraint[j] >= '0' + noutputs)
1644 ("matching constraint references invalid operand number");
1648 /* Try and find the real constraint for this dup. */
1649 if ((j == 0 && c_len == 1)
1650 || (j == 1 && c_len == 2 && constraint[0] == '%'))
1654 for (j = constraint[j] - '0'; j > 0; --j)
1657 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (o)));
1658 constraint = TREE_STRING_POINTER (TREE_PURPOSE (o));
1663 /* ... fall through ... */
1676 if (! allows_reg && allows_mem)
1677 mark_addressable (TREE_VALUE (tail));
1679 op = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1681 if (asm_operand_ok (op, constraint) <= 0)
1684 op = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), op);
1685 else if (!allows_mem)
1686 warning ("asm operand %d probably doesn't match constraints", i);
1687 else if (CONSTANT_P (op))
1688 op = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1690 else if (GET_CODE (op) == REG
1691 || GET_CODE (op) == SUBREG
1692 || GET_CODE (op) == CONCAT)
1694 tree type = TREE_TYPE (TREE_VALUE (tail));
1695 rtx memloc = assign_temp (type, 1, 1, 1);
1697 emit_move_insn (memloc, op);
1701 else if (GET_CODE (op) == MEM && MEM_VOLATILE_P (op))
1702 /* We won't recognize volatile memory as available a
1703 memory_operand at this point. Ignore it. */
1705 else if (queued_subexp_p (op))
1708 /* ??? Leave this only until we have experience with what
1709 happens in combine and elsewhere when constraints are
1711 warning ("asm operand %d probably doesn't match constraints", i);
1713 XVECEXP (body, 3, i) = op;
1715 XVECEXP (body, 4, i) /* constraints */
1716 = gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1721 /* Protect all the operands from the queue now that they have all been
1724 for (i = 0; i < ninputs - ninout; i++)
1725 XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0);
1727 for (i = 0; i < noutputs; i++)
1728 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1730 /* For in-out operands, copy output rtx to input rtx. */
1731 for (i = 0; i < ninout; i++)
1733 int j = inout_opnum[i];
1735 XVECEXP (body, 3, ninputs - ninout + i) /* argvec */
1737 XVECEXP (body, 4, ninputs - ninout + i) /* constraints */
1738 = gen_rtx_ASM_INPUT (inout_mode[i], digit_strings[j]);
1741 /* Now, for each output, construct an rtx
1742 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1743 ARGVEC CONSTRAINTS))
1744 If there is more than one, put them inside a PARALLEL. */
1746 if (noutputs == 1 && nclobbers == 0)
1748 XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1749 insn = emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
1752 else if (noutputs == 0 && nclobbers == 0)
1754 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1755 insn = emit_insn (body);
1766 body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
1768 /* For each output operand, store a SET. */
1769 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1771 XVECEXP (body, 0, i)
1772 = gen_rtx_SET (VOIDmode,
1774 gen_rtx_ASM_OPERANDS
1776 TREE_STRING_POINTER (string),
1777 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1778 i, argvec, constraints,
1781 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1784 /* If there are no outputs (but there are some clobbers)
1785 store the bare ASM_OPERANDS into the PARALLEL. */
1788 XVECEXP (body, 0, i++) = obody;
1790 /* Store (clobber REG) for each clobbered register specified. */
1792 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1794 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1795 int j = decode_reg_name (regname);
1799 if (j == -3) /* `cc', which is not a register */
1802 if (j == -4) /* `memory', don't cache memory across asm */
1804 XVECEXP (body, 0, i++)
1805 = gen_rtx_CLOBBER (VOIDmode,
1808 gen_rtx_SCRATCH (VOIDmode)));
1812 /* Ignore unknown register, error already signaled. */
1816 /* Use QImode since that's guaranteed to clobber just one reg. */
1817 XVECEXP (body, 0, i++)
1818 = gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (QImode, j));
1821 insn = emit_insn (body);
1824 /* For any outputs that needed reloading into registers, spill them
1825 back to where they belong. */
1826 for (i = 0; i < noutputs; ++i)
1827 if (real_output_rtx[i])
1828 emit_move_insn (real_output_rtx[i], output_rtx[i]);
1833 /* Generate RTL to evaluate the expression EXP
1834 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1837 expand_expr_stmt (exp)
1840 /* If -W, warn about statements with no side effects,
1841 except for an explicit cast to void (e.g. for assert()), and
1842 except inside a ({...}) where they may be useful. */
1843 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1845 if (! TREE_SIDE_EFFECTS (exp) && (extra_warnings || warn_unused)
1846 && !(TREE_CODE (exp) == CONVERT_EXPR
1847 && TREE_TYPE (exp) == void_type_node))
1848 warning_with_file_and_line (emit_filename, emit_lineno,
1849 "statement with no effect");
1850 else if (warn_unused)
1851 warn_if_unused_value (exp);
1854 /* If EXP is of function type and we are expanding statements for
1855 value, convert it to pointer-to-function. */
1856 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1857 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1859 last_expr_type = TREE_TYPE (exp);
1860 last_expr_value = expand_expr (exp,
1861 (expr_stmts_for_value
1862 ? NULL_RTX : const0_rtx),
1865 /* If all we do is reference a volatile value in memory,
1866 copy it to a register to be sure it is actually touched. */
1867 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1868 && TREE_THIS_VOLATILE (exp))
1870 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1872 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1873 copy_to_reg (last_expr_value);
1876 rtx lab = gen_label_rtx ();
1878 /* Compare the value with itself to reference it. */
1879 emit_cmp_and_jump_insns (last_expr_value, last_expr_value, EQ,
1880 expand_expr (TYPE_SIZE (last_expr_type),
1881 NULL_RTX, VOIDmode, 0),
1883 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT,
1889 /* If this expression is part of a ({...}) and is in memory, we may have
1890 to preserve temporaries. */
1891 preserve_temp_slots (last_expr_value);
1893 /* Free any temporaries used to evaluate this expression. Any temporary
1894 used as a result of this expression will already have been preserved
1901 /* Warn if EXP contains any computations whose results are not used.
1902 Return 1 if a warning is printed; 0 otherwise. */
1905 warn_if_unused_value (exp)
1908 if (TREE_USED (exp))
1911 switch (TREE_CODE (exp))
1913 case PREINCREMENT_EXPR:
1914 case POSTINCREMENT_EXPR:
1915 case PREDECREMENT_EXPR:
1916 case POSTDECREMENT_EXPR:
1921 case METHOD_CALL_EXPR:
1923 case TRY_CATCH_EXPR:
1924 case WITH_CLEANUP_EXPR:
1926 /* We don't warn about COND_EXPR because it may be a useful
1927 construct if either arm contains a side effect. */
1932 /* For a binding, warn if no side effect within it. */
1933 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1936 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1938 case TRUTH_ORIF_EXPR:
1939 case TRUTH_ANDIF_EXPR:
1940 /* In && or ||, warn if 2nd operand has no side effect. */
1941 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1944 if (TREE_NO_UNUSED_WARNING (exp))
1946 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
1948 /* Let people do `(foo (), 0)' without a warning. */
1949 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1951 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1955 case NON_LVALUE_EXPR:
1956 /* Don't warn about values cast to void. */
1957 if (TREE_TYPE (exp) == void_type_node)
1959 /* Don't warn about conversions not explicit in the user's program. */
1960 if (TREE_NO_UNUSED_WARNING (exp))
1962 /* Assignment to a cast usually results in a cast of a modify.
1963 Don't complain about that. There can be an arbitrary number of
1964 casts before the modify, so we must loop until we find the first
1965 non-cast expression and then test to see if that is a modify. */
1967 tree tem = TREE_OPERAND (exp, 0);
1969 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1970 tem = TREE_OPERAND (tem, 0);
1972 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
1973 || TREE_CODE (tem) == CALL_EXPR)
1979 /* Don't warn about automatic dereferencing of references, since
1980 the user cannot control it. */
1981 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
1982 return warn_if_unused_value (TREE_OPERAND (exp, 0));
1983 /* ... fall through ... */
1986 /* Referencing a volatile value is a side effect, so don't warn. */
1987 if ((TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
1988 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
1989 && TREE_THIS_VOLATILE (exp))
1992 warning_with_file_and_line (emit_filename, emit_lineno,
1993 "value computed is not used");
1998 /* Clear out the memory of the last expression evaluated. */
2006 /* Begin a statement which will return a value.
2007 Return the RTL_EXPR for this statement expr.
2008 The caller must save that value and pass it to expand_end_stmt_expr. */
2011 expand_start_stmt_expr ()
2016 /* Make the RTL_EXPR node temporary, not momentary,
2017 so that rtl_expr_chain doesn't become garbage. */
2018 momentary = suspend_momentary ();
2019 t = make_node (RTL_EXPR);
2020 resume_momentary (momentary);
2021 do_pending_stack_adjust ();
2022 start_sequence_for_rtl_expr (t);
2024 expr_stmts_for_value++;
2028 /* Restore the previous state at the end of a statement that returns a value.
2029 Returns a tree node representing the statement's value and the
2030 insns to compute the value.
2032 The nodes of that expression have been freed by now, so we cannot use them.
2033 But we don't want to do that anyway; the expression has already been
2034 evaluated and now we just want to use the value. So generate a RTL_EXPR
2035 with the proper type and RTL value.
2037 If the last substatement was not an expression,
2038 return something with type `void'. */
2041 expand_end_stmt_expr (t)
2046 if (last_expr_type == 0)
2048 last_expr_type = void_type_node;
2049 last_expr_value = const0_rtx;
2051 else if (last_expr_value == 0)
2052 /* There are some cases where this can happen, such as when the
2053 statement is void type. */
2054 last_expr_value = const0_rtx;
2055 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
2056 /* Remove any possible QUEUED. */
2057 last_expr_value = protect_from_queue (last_expr_value, 0);
2061 TREE_TYPE (t) = last_expr_type;
2062 RTL_EXPR_RTL (t) = last_expr_value;
2063 RTL_EXPR_SEQUENCE (t) = get_insns ();
2065 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
2069 /* Don't consider deleting this expr or containing exprs at tree level. */
2070 TREE_SIDE_EFFECTS (t) = 1;
2071 /* Propagate volatility of the actual RTL expr. */
2072 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
2075 expr_stmts_for_value--;
2080 /* Generate RTL for the start of an if-then. COND is the expression
2081 whose truth should be tested.
2083 If EXITFLAG is nonzero, this conditional is visible to
2084 `exit_something'. */
2087 expand_start_cond (cond, exitflag)
2091 struct nesting *thiscond = ALLOC_NESTING ();
2093 /* Make an entry on cond_stack for the cond we are entering. */
2095 thiscond->next = cond_stack;
2096 thiscond->all = nesting_stack;
2097 thiscond->depth = ++nesting_depth;
2098 thiscond->data.cond.next_label = gen_label_rtx ();
2099 /* Before we encounter an `else', we don't need a separate exit label
2100 unless there are supposed to be exit statements
2101 to exit this conditional. */
2102 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
2103 thiscond->data.cond.endif_label = thiscond->exit_label;
2104 cond_stack = thiscond;
2105 nesting_stack = thiscond;
2107 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
2110 /* Generate RTL between then-clause and the elseif-clause
2111 of an if-then-elseif-.... */
2114 expand_start_elseif (cond)
2117 if (cond_stack->data.cond.endif_label == 0)
2118 cond_stack->data.cond.endif_label = gen_label_rtx ();
2119 emit_jump (cond_stack->data.cond.endif_label);
2120 emit_label (cond_stack->data.cond.next_label);
2121 cond_stack->data.cond.next_label = gen_label_rtx ();
2122 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2125 /* Generate RTL between the then-clause and the else-clause
2126 of an if-then-else. */
2129 expand_start_else ()
2131 if (cond_stack->data.cond.endif_label == 0)
2132 cond_stack->data.cond.endif_label = gen_label_rtx ();
2134 emit_jump (cond_stack->data.cond.endif_label);
2135 emit_label (cond_stack->data.cond.next_label);
2136 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
2139 /* After calling expand_start_else, turn this "else" into an "else if"
2140 by providing another condition. */
2143 expand_elseif (cond)
2146 cond_stack->data.cond.next_label = gen_label_rtx ();
2147 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2150 /* Generate RTL for the end of an if-then.
2151 Pop the record for it off of cond_stack. */
2156 struct nesting *thiscond = cond_stack;
2158 do_pending_stack_adjust ();
2159 if (thiscond->data.cond.next_label)
2160 emit_label (thiscond->data.cond.next_label);
2161 if (thiscond->data.cond.endif_label)
2162 emit_label (thiscond->data.cond.endif_label);
2164 POPSTACK (cond_stack);
2170 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2171 loop should be exited by `exit_something'. This is a loop for which
2172 `expand_continue' will jump to the top of the loop.
2174 Make an entry on loop_stack to record the labels associated with
2178 expand_start_loop (exit_flag)
2181 register struct nesting *thisloop = ALLOC_NESTING ();
2183 /* Make an entry on loop_stack for the loop we are entering. */
2185 thisloop->next = loop_stack;
2186 thisloop->all = nesting_stack;
2187 thisloop->depth = ++nesting_depth;
2188 thisloop->data.loop.start_label = gen_label_rtx ();
2189 thisloop->data.loop.end_label = gen_label_rtx ();
2190 thisloop->data.loop.alt_end_label = 0;
2191 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2192 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2193 loop_stack = thisloop;
2194 nesting_stack = thisloop;
2196 do_pending_stack_adjust ();
2198 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2199 emit_label (thisloop->data.loop.start_label);
2204 /* Like expand_start_loop but for a loop where the continuation point
2205 (for expand_continue_loop) will be specified explicitly. */
2208 expand_start_loop_continue_elsewhere (exit_flag)
2211 struct nesting *thisloop = expand_start_loop (exit_flag);
2212 loop_stack->data.loop.continue_label = gen_label_rtx ();
2216 /* Specify the continuation point for a loop started with
2217 expand_start_loop_continue_elsewhere.
2218 Use this at the point in the code to which a continue statement
2222 expand_loop_continue_here ()
2224 do_pending_stack_adjust ();
2225 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2226 emit_label (loop_stack->data.loop.continue_label);
2229 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2230 Pop the block off of loop_stack. */
2235 rtx start_label = loop_stack->data.loop.start_label;
2236 rtx insn = get_last_insn ();
2237 int needs_end_jump = 1;
2239 /* Mark the continue-point at the top of the loop if none elsewhere. */
2240 if (start_label == loop_stack->data.loop.continue_label)
2241 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2243 do_pending_stack_adjust ();
2245 /* If optimizing, perhaps reorder the loop.
2246 First, try to use a condjump near the end.
2247 expand_exit_loop_if_false ends loops with unconditional jumps,
2250 if (test) goto label;
2252 goto loop_stack->data.loop.end_label
2256 If we find such a pattern, we can end the loop earlier. */
2259 && GET_CODE (insn) == CODE_LABEL
2260 && LABEL_NAME (insn) == NULL
2261 && GET_CODE (PREV_INSN (insn)) == BARRIER)
2264 rtx jump = PREV_INSN (PREV_INSN (label));
2266 if (GET_CODE (jump) == JUMP_INSN
2267 && GET_CODE (PATTERN (jump)) == SET
2268 && SET_DEST (PATTERN (jump)) == pc_rtx
2269 && GET_CODE (SET_SRC (PATTERN (jump))) == LABEL_REF
2270 && (XEXP (SET_SRC (PATTERN (jump)), 0)
2271 == loop_stack->data.loop.end_label))
2275 /* The test might be complex and reference LABEL multiple times,
2276 like the loop in loop_iterations to set vtop. To handle this,
2278 insn = PREV_INSN (label);
2279 reorder_insns (label, label, start_label);
2281 for (prev = PREV_INSN (jump); ; prev = PREV_INSN (prev))
2283 /* We ignore line number notes, but if we see any other note,
2284 in particular NOTE_INSN_BLOCK_*, NOTE_INSN_EH_REGION_*,
2285 NOTE_INSN_LOOP_*, we disable this optimization. */
2286 if (GET_CODE (prev) == NOTE)
2288 if (NOTE_LINE_NUMBER (prev) < 0)
2292 if (GET_CODE (prev) == CODE_LABEL)
2294 if (GET_CODE (prev) == JUMP_INSN)
2296 if (GET_CODE (PATTERN (prev)) == SET
2297 && SET_DEST (PATTERN (prev)) == pc_rtx
2298 && GET_CODE (SET_SRC (PATTERN (prev))) == IF_THEN_ELSE
2299 && (GET_CODE (XEXP (SET_SRC (PATTERN (prev)), 1))
2301 && XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0) == label)
2303 XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0)
2305 emit_note_after (NOTE_INSN_LOOP_END, prev);
2314 /* If the loop starts with a loop exit, roll that to the end where
2315 it will optimize together with the jump back.
2317 We look for the conditional branch to the exit, except that once
2318 we find such a branch, we don't look past 30 instructions.
2320 In more detail, if the loop presently looks like this (in pseudo-C):
2323 if (test) goto end_label;
2328 transform it to look like:
2334 if (test) goto end_label;
2335 goto newstart_label;
2338 Here, the `test' may actually consist of some reasonably complex
2339 code, terminating in a test. */
2344 ! (GET_CODE (insn) == JUMP_INSN
2345 && GET_CODE (PATTERN (insn)) == SET
2346 && SET_DEST (PATTERN (insn)) == pc_rtx
2347 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2351 rtx last_test_insn = NULL_RTX;
2353 /* Scan insns from the top of the loop looking for a qualified
2354 conditional exit. */
2355 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2356 insn = NEXT_INSN (insn))
2358 if (GET_CODE (insn) == NOTE)
2361 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2362 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2363 /* The code that actually moves the exit test will
2364 carefully leave BLOCK notes in their original
2365 location. That means, however, that we can't debug
2366 the exit test itself. So, we refuse to move code
2367 containing BLOCK notes at low optimization levels. */
2370 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG)
2372 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)
2376 /* We've come to the end of an EH region, but
2377 never saw the beginning of that region. That
2378 means that an EH region begins before the top
2379 of the loop, and ends in the middle of it. The
2380 existence of such a situation violates a basic
2381 assumption in this code, since that would imply
2382 that even when EH_REGIONS is zero, we might
2383 move code out of an exception region. */
2387 /* We must not walk into a nested loop. */
2388 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
2391 /* We already know this INSN is a NOTE, so there's no
2392 point in looking at it to see if it's a JUMP. */
2396 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2399 if (last_test_insn && num_insns > 30)
2403 /* We don't want to move a partial EH region. Consider:
2417 This isn't legal C++, but here's what it's supposed to
2418 mean: if cond() is true, stop looping. Otherwise,
2419 call bar, and keep looping. In addition, if cond
2420 throws an exception, catch it and keep looping. Such
2421 constructs are certainy legal in LISP.
2423 We should not move the `if (cond()) 0' test since then
2424 the EH-region for the try-block would be broken up.
2425 (In this case we would the EH_BEG note for the `try'
2426 and `if cond()' but not the call to bar() or the
2429 So we don't look for tests within an EH region. */
2432 if (GET_CODE (insn) == JUMP_INSN
2433 && GET_CODE (PATTERN (insn)) == SET
2434 && SET_DEST (PATTERN (insn)) == pc_rtx)
2436 /* This is indeed a jump. */
2437 rtx dest1 = NULL_RTX;
2438 rtx dest2 = NULL_RTX;
2439 rtx potential_last_test;
2440 if (GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE)
2442 /* A conditional jump. */
2443 dest1 = XEXP (SET_SRC (PATTERN (insn)), 1);
2444 dest2 = XEXP (SET_SRC (PATTERN (insn)), 2);
2445 potential_last_test = insn;
2449 /* An unconditional jump. */
2450 dest1 = SET_SRC (PATTERN (insn));
2451 /* Include the BARRIER after the JUMP. */
2452 potential_last_test = NEXT_INSN (insn);
2456 if (dest1 && GET_CODE (dest1) == LABEL_REF
2457 && ((XEXP (dest1, 0)
2458 == loop_stack->data.loop.alt_end_label)
2460 == loop_stack->data.loop.end_label)))
2462 last_test_insn = potential_last_test;
2466 /* If this was a conditional jump, there may be
2467 another label at which we should look. */
2474 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2476 /* We found one. Move everything from there up
2477 to the end of the loop, and add a jump into the loop
2478 to jump to there. */
2479 register rtx newstart_label = gen_label_rtx ();
2480 register rtx start_move = start_label;
2483 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2484 then we want to move this note also. */
2485 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2486 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2487 == NOTE_INSN_LOOP_CONT))
2488 start_move = PREV_INSN (start_move);
2490 emit_label_after (newstart_label, PREV_INSN (start_move));
2492 /* Actually move the insns. Start at the beginning, and
2493 keep copying insns until we've copied the
2495 for (insn = start_move; insn; insn = next_insn)
2497 /* Figure out which insn comes after this one. We have
2498 to do this before we move INSN. */
2499 if (insn == last_test_insn)
2500 /* We've moved all the insns. */
2501 next_insn = NULL_RTX;
2503 next_insn = NEXT_INSN (insn);
2505 if (GET_CODE (insn) == NOTE
2506 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2507 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2508 /* We don't want to move NOTE_INSN_BLOCK_BEGs or
2509 NOTE_INSN_BLOCK_ENDs because the correct generation
2510 of debugging information depends on these appearing
2511 in the same order in the RTL and in the tree
2512 structure, where they are represented as BLOCKs.
2513 So, we don't move block notes. Of course, moving
2514 the code inside the block is likely to make it
2515 impossible to debug the instructions in the exit
2516 test, but such is the price of optimization. */
2519 /* Move the INSN. */
2520 reorder_insns (insn, insn, get_last_insn ());
2523 emit_jump_insn_after (gen_jump (start_label),
2524 PREV_INSN (newstart_label));
2525 emit_barrier_after (PREV_INSN (newstart_label));
2526 start_label = newstart_label;
2532 emit_jump (start_label);
2533 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2535 emit_label (loop_stack->data.loop.end_label);
2537 POPSTACK (loop_stack);
2542 /* Generate a jump to the current loop's continue-point.
2543 This is usually the top of the loop, but may be specified
2544 explicitly elsewhere. If not currently inside a loop,
2545 return 0 and do nothing; caller will print an error message. */
2548 expand_continue_loop (whichloop)
2549 struct nesting *whichloop;
2553 whichloop = loop_stack;
2556 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2561 /* Generate a jump to exit the current loop. If not currently inside a loop,
2562 return 0 and do nothing; caller will print an error message. */
2565 expand_exit_loop (whichloop)
2566 struct nesting *whichloop;
2570 whichloop = loop_stack;
2573 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2577 /* Generate a conditional jump to exit the current loop if COND
2578 evaluates to zero. If not currently inside a loop,
2579 return 0 and do nothing; caller will print an error message. */
2582 expand_exit_loop_if_false (whichloop, cond)
2583 struct nesting *whichloop;
2586 rtx label = gen_label_rtx ();
2591 whichloop = loop_stack;
2594 /* In order to handle fixups, we actually create a conditional jump
2595 around a unconditional branch to exit the loop. If fixups are
2596 necessary, they go before the unconditional branch. */
2599 do_jump (cond, NULL_RTX, label);
2600 last_insn = get_last_insn ();
2601 if (GET_CODE (last_insn) == CODE_LABEL)
2602 whichloop->data.loop.alt_end_label = last_insn;
2603 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2610 /* Return nonzero if the loop nest is empty. Else return zero. */
2613 stmt_loop_nest_empty ()
2615 return (loop_stack == NULL);
2618 /* Return non-zero if we should preserve sub-expressions as separate
2619 pseudos. We never do so if we aren't optimizing. We always do so
2620 if -fexpensive-optimizations.
2622 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2623 the loop may still be a small one. */
2626 preserve_subexpressions_p ()
2630 if (flag_expensive_optimizations)
2633 if (optimize == 0 || current_function == 0
2634 || current_function->stmt == 0 || loop_stack == 0)
2637 insn = get_last_insn_anywhere ();
2640 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2641 < n_non_fixed_regs * 3));
2645 /* Generate a jump to exit the current loop, conditional, binding contour
2646 or case statement. Not all such constructs are visible to this function,
2647 only those started with EXIT_FLAG nonzero. Individual languages use
2648 the EXIT_FLAG parameter to control which kinds of constructs you can
2651 If not currently inside anything that can be exited,
2652 return 0 and do nothing; caller will print an error message. */
2655 expand_exit_something ()
2659 for (n = nesting_stack; n; n = n->all)
2660 if (n->exit_label != 0)
2662 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2669 /* Generate RTL to return from the current function, with no value.
2670 (That is, we do not do anything about returning any value.) */
2673 expand_null_return ()
2675 struct nesting *block = block_stack;
2676 rtx last_insn = get_last_insn ();
2678 /* If this function was declared to return a value, but we
2679 didn't, clobber the return registers so that they are not
2680 propogated live to the rest of the function. */
2682 diddle_return_value (CLOBBER);
2684 /* Does any pending block have cleanups? */
2686 while (block && block->data.block.cleanups == 0)
2687 block = block->next;
2689 /* If yes, use a goto to return, since that runs cleanups. */
2691 expand_null_return_1 (last_insn, block != 0);
2694 /* Generate RTL to return from the current function, with value VAL. */
2697 expand_value_return (val)
2700 struct nesting *block = block_stack;
2701 rtx last_insn = get_last_insn ();
2702 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2704 /* Copy the value to the return location
2705 unless it's already there. */
2707 if (return_reg != val)
2709 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2710 #ifdef PROMOTE_FUNCTION_RETURN
2711 int unsignedp = TREE_UNSIGNED (type);
2712 enum machine_mode old_mode
2713 = DECL_MODE (DECL_RESULT (current_function_decl));
2714 enum machine_mode mode
2715 = promote_mode (type, old_mode, &unsignedp, 1);
2717 if (mode != old_mode)
2718 val = convert_modes (mode, old_mode, val, unsignedp);
2720 if (GET_CODE (return_reg) == PARALLEL)
2721 emit_group_load (return_reg, val, int_size_in_bytes (type),
2722 TYPE_ALIGN (type) / BITS_PER_UNIT);
2724 emit_move_insn (return_reg, val);
2727 diddle_return_value (USE);
2729 /* Does any pending block have cleanups? */
2731 while (block && block->data.block.cleanups == 0)
2732 block = block->next;
2734 /* If yes, use a goto to return, since that runs cleanups.
2735 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2737 expand_null_return_1 (last_insn, block != 0);
2740 /* Output a return with no value. If LAST_INSN is nonzero,
2741 pretend that the return takes place after LAST_INSN.
2742 If USE_GOTO is nonzero then don't use a return instruction;
2743 go to the return label instead. This causes any cleanups
2744 of pending blocks to be executed normally. */
2747 expand_null_return_1 (last_insn, use_goto)
2751 rtx end_label = cleanup_label ? cleanup_label : return_label;
2753 clear_pending_stack_adjust ();
2754 do_pending_stack_adjust ();
2757 /* PCC-struct return always uses an epilogue. */
2758 if (current_function_returns_pcc_struct || use_goto)
2761 end_label = return_label = gen_label_rtx ();
2762 expand_goto_internal (NULL_TREE, end_label, last_insn);
2766 /* Otherwise output a simple return-insn if one is available,
2767 unless it won't do the job. */
2769 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2771 emit_jump_insn (gen_return ());
2777 /* Otherwise jump to the epilogue. */
2778 expand_goto_internal (NULL_TREE, end_label, last_insn);
2781 /* Generate RTL to evaluate the expression RETVAL and return it
2782 from the current function. */
2785 expand_return (retval)
2788 /* If there are any cleanups to be performed, then they will
2789 be inserted following LAST_INSN. It is desirable
2790 that the last_insn, for such purposes, should be the
2791 last insn before computing the return value. Otherwise, cleanups
2792 which call functions can clobber the return value. */
2793 /* ??? rms: I think that is erroneous, because in C++ it would
2794 run destructors on variables that might be used in the subsequent
2795 computation of the return value. */
2797 rtx result_rtl = DECL_RTL (DECL_RESULT (current_function_decl));
2798 register rtx val = 0;
2803 /* If function wants no value, give it none. */
2804 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2806 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2808 expand_null_return ();
2812 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2813 /* This is not sufficient. We also need to watch for cleanups of the
2814 expression we are about to expand. Unfortunately, we cannot know
2815 if it has cleanups until we expand it, and we want to change how we
2816 expand it depending upon if we need cleanups. We can't win. */
2818 cleanups = any_pending_cleanups (1);
2823 if (TREE_CODE (retval) == RESULT_DECL)
2824 retval_rhs = retval;
2825 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2826 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2827 retval_rhs = TREE_OPERAND (retval, 1);
2828 else if (TREE_TYPE (retval) == void_type_node)
2829 /* Recognize tail-recursive call to void function. */
2830 retval_rhs = retval;
2832 retval_rhs = NULL_TREE;
2834 /* Only use `last_insn' if there are cleanups which must be run. */
2835 if (cleanups || cleanup_label != 0)
2836 last_insn = get_last_insn ();
2838 /* Distribute return down conditional expr if either of the sides
2839 may involve tail recursion (see test below). This enhances the number
2840 of tail recursions we see. Don't do this always since it can produce
2841 sub-optimal code in some cases and we distribute assignments into
2842 conditional expressions when it would help. */
2844 if (optimize && retval_rhs != 0
2845 && frame_offset == 0
2846 && TREE_CODE (retval_rhs) == COND_EXPR
2847 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2848 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2850 rtx label = gen_label_rtx ();
2853 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2854 start_cleanup_deferral ();
2855 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2856 DECL_RESULT (current_function_decl),
2857 TREE_OPERAND (retval_rhs, 1));
2858 TREE_SIDE_EFFECTS (expr) = 1;
2859 expand_return (expr);
2862 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2863 DECL_RESULT (current_function_decl),
2864 TREE_OPERAND (retval_rhs, 2));
2865 TREE_SIDE_EFFECTS (expr) = 1;
2866 expand_return (expr);
2867 end_cleanup_deferral ();
2871 /* Attempt to optimize the call if it is tail recursive. */
2872 if (optimize_tail_recursion (retval_rhs, last_insn))
2876 /* This optimization is safe if there are local cleanups
2877 because expand_null_return takes care of them.
2878 ??? I think it should also be safe when there is a cleanup label,
2879 because expand_null_return takes care of them, too.
2880 Any reason why not? */
2881 if (HAVE_return && cleanup_label == 0
2882 && ! current_function_returns_pcc_struct
2883 && BRANCH_COST <= 1)
2885 /* If this is return x == y; then generate
2886 if (x == y) return 1; else return 0;
2887 if we can do it with explicit return insns and branches are cheap,
2888 but not if we have the corresponding scc insn. */
2891 switch (TREE_CODE (retval_rhs))
2917 case TRUTH_ANDIF_EXPR:
2918 case TRUTH_ORIF_EXPR:
2919 case TRUTH_AND_EXPR:
2921 case TRUTH_NOT_EXPR:
2922 case TRUTH_XOR_EXPR:
2925 op0 = gen_label_rtx ();
2926 jumpifnot (retval_rhs, op0);
2927 expand_value_return (const1_rtx);
2929 expand_value_return (const0_rtx);
2938 #endif /* HAVE_return */
2940 /* If the result is an aggregate that is being returned in one (or more)
2941 registers, load the registers here. The compiler currently can't handle
2942 copying a BLKmode value into registers. We could put this code in a
2943 more general area (for use by everyone instead of just function
2944 call/return), but until this feature is generally usable it is kept here
2945 (and in expand_call). The value must go into a pseudo in case there
2946 are cleanups that will clobber the real return register. */
2949 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2950 && GET_CODE (result_rtl) == REG)
2952 int i, bitpos, xbitpos;
2953 int big_endian_correction = 0;
2954 int bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2955 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2956 int bitsize = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)),
2957 (unsigned int)BITS_PER_WORD);
2958 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2959 rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
2960 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2961 enum machine_mode tmpmode, result_reg_mode;
2963 /* Structures whose size is not a multiple of a word are aligned
2964 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
2965 machine, this means we must skip the empty high order bytes when
2966 calculating the bit offset. */
2967 if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD)
2968 big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
2971 /* Copy the structure BITSIZE bits at a time. */
2972 for (bitpos = 0, xbitpos = big_endian_correction;
2973 bitpos < bytes * BITS_PER_UNIT;
2974 bitpos += bitsize, xbitpos += bitsize)
2976 /* We need a new destination pseudo each time xbitpos is
2977 on a word boundary and when xbitpos == big_endian_correction
2978 (the first time through). */
2979 if (xbitpos % BITS_PER_WORD == 0
2980 || xbitpos == big_endian_correction)
2982 /* Generate an appropriate register. */
2983 dst = gen_reg_rtx (word_mode);
2984 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
2986 /* Clobber the destination before we move anything into it. */
2987 emit_insn (gen_rtx_CLOBBER (VOIDmode, dst));
2990 /* We need a new source operand each time bitpos is on a word
2992 if (bitpos % BITS_PER_WORD == 0)
2993 src = operand_subword_force (result_val,
2994 bitpos / BITS_PER_WORD,
2997 /* Use bitpos for the source extraction (left justified) and
2998 xbitpos for the destination store (right justified). */
2999 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
3000 extract_bit_field (src, bitsize,
3001 bitpos % BITS_PER_WORD, 1,
3002 NULL_RTX, word_mode,
3004 bitsize / BITS_PER_UNIT,
3006 bitsize / BITS_PER_UNIT, BITS_PER_WORD);
3009 /* Find the smallest integer mode large enough to hold the
3010 entire structure and use that mode instead of BLKmode
3011 on the USE insn for the return register. */
3012 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
3013 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
3014 tmpmode != VOIDmode;
3015 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
3017 /* Have we found a large enough mode? */
3018 if (GET_MODE_SIZE (tmpmode) >= bytes)
3022 /* No suitable mode found. */
3023 if (tmpmode == VOIDmode)
3026 PUT_MODE (result_rtl, tmpmode);
3028 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
3029 result_reg_mode = word_mode;
3031 result_reg_mode = tmpmode;
3032 result_reg = gen_reg_rtx (result_reg_mode);
3035 for (i = 0; i < n_regs; i++)
3036 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
3039 if (tmpmode != result_reg_mode)
3040 result_reg = gen_lowpart (tmpmode, result_reg);
3042 expand_value_return (result_reg);
3046 && TREE_TYPE (retval_rhs) != void_type_node
3047 && (GET_CODE (result_rtl) == REG
3048 || (GET_CODE (result_rtl) == PARALLEL)))
3050 /* Calculate the return value into a temporary (usually a pseudo
3052 val = assign_temp (TREE_TYPE (DECL_RESULT (current_function_decl)),
3054 val = expand_expr (retval_rhs, val, GET_MODE (val), 0);
3055 val = force_not_mem (val);
3057 /* Return the calculated value, doing cleanups first. */
3058 expand_value_return (val);
3062 /* No cleanups or no hard reg used;
3063 calculate value into hard return reg. */
3064 expand_expr (retval, const0_rtx, VOIDmode, 0);
3066 expand_value_return (result_rtl);
3070 /* Return 1 if the end of the generated RTX is not a barrier.
3071 This means code already compiled can drop through. */
3074 drop_through_at_end_p ()
3076 rtx insn = get_last_insn ();
3077 while (insn && GET_CODE (insn) == NOTE)
3078 insn = PREV_INSN (insn);
3079 return insn && GET_CODE (insn) != BARRIER;
3082 /* Test CALL_EXPR to determine if it is a potential tail recursion call
3083 and emit code to optimize the tail recursion. LAST_INSN indicates where
3084 to place the jump to the tail recursion label. Return TRUE if the
3085 call was optimized into a goto.
3087 This is only used by expand_return, but expand_call is expected to
3091 optimize_tail_recursion (call_expr, last_insn)
3095 /* For tail-recursive call to current function,
3096 just jump back to the beginning.
3097 It's unsafe if any auto variable in this function
3098 has its address taken; for simplicity,
3099 require stack frame to be empty. */
3100 if (optimize && call_expr != 0
3101 && frame_offset == 0
3102 && TREE_CODE (call_expr) == CALL_EXPR
3103 && TREE_CODE (TREE_OPERAND (call_expr, 0)) == ADDR_EXPR
3104 && TREE_OPERAND (TREE_OPERAND (call_expr, 0), 0) == current_function_decl
3105 /* Finish checking validity, and if valid emit code
3106 to set the argument variables for the new call. */
3107 && tail_recursion_args (TREE_OPERAND (call_expr, 1),
3108 DECL_ARGUMENTS (current_function_decl)))
3110 if (tail_recursion_label == 0)
3112 tail_recursion_label = gen_label_rtx ();
3113 emit_label_after (tail_recursion_label,
3114 tail_recursion_reentry);
3117 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
3125 /* Emit code to alter this function's formal parms for a tail-recursive call.
3126 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3127 FORMALS is the chain of decls of formals.
3128 Return 1 if this can be done;
3129 otherwise return 0 and do not emit any code. */
3132 tail_recursion_args (actuals, formals)
3133 tree actuals, formals;
3135 register tree a = actuals, f = formals;
3137 register rtx *argvec;
3139 /* Check that number and types of actuals are compatible
3140 with the formals. This is not always true in valid C code.
3141 Also check that no formal needs to be addressable
3142 and that all formals are scalars. */
3144 /* Also count the args. */
3146 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
3148 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a)))
3149 != TYPE_MAIN_VARIANT (TREE_TYPE (f)))
3151 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
3154 if (a != 0 || f != 0)
3157 /* Compute all the actuals. */
3159 argvec = (rtx *) alloca (i * sizeof (rtx));
3161 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3162 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
3164 /* Find which actual values refer to current values of previous formals.
3165 Copy each of them now, before any formal is changed. */
3167 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3171 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
3172 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
3173 { copy = 1; break; }
3175 argvec[i] = copy_to_reg (argvec[i]);
3178 /* Store the values of the actuals into the formals. */
3180 for (f = formals, a = actuals, i = 0; f;
3181 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
3183 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
3184 emit_move_insn (DECL_RTL (f), argvec[i]);
3186 convert_move (DECL_RTL (f), argvec[i],
3187 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
3194 /* Generate the RTL code for entering a binding contour.
3195 The variables are declared one by one, by calls to `expand_decl'.
3197 FLAGS is a bitwise or of the following flags:
3199 1 - Nonzero if this construct should be visible to
3202 2 - Nonzero if this contour does not require a
3203 NOTE_INSN_BLOCK_BEG note. Virtually all calls from
3204 language-independent code should set this flag because they
3205 will not create corresponding BLOCK nodes. (There should be
3206 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
3207 and BLOCKs.) If this flag is set, MARK_ENDS should be zero
3208 when expand_end_bindings is called.
3210 If we are creating a NOTE_INSN_BLOCK_BEG note, a BLOCK may
3211 optionally be supplied. If so, it becomes the NOTE_BLOCK for the
3215 expand_start_bindings_and_block (flags, block)
3219 struct nesting *thisblock = ALLOC_NESTING ();
3221 int exit_flag = ((flags & 1) != 0);
3222 int block_flag = ((flags & 2) == 0);
3224 /* If a BLOCK is supplied, then the caller should be requesting a
3225 NOTE_INSN_BLOCK_BEG note. */
3226 if (!block_flag && block)
3229 /* Create a note to mark the beginning of the block. */
3232 note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
3233 NOTE_BLOCK (note) = block;
3236 note = emit_note (NULL_PTR, NOTE_INSN_DELETED);
3238 /* Make an entry on block_stack for the block we are entering. */
3240 thisblock->next = block_stack;
3241 thisblock->all = nesting_stack;
3242 thisblock->depth = ++nesting_depth;
3243 thisblock->data.block.stack_level = 0;
3244 thisblock->data.block.cleanups = 0;
3245 thisblock->data.block.n_function_calls = 0;
3246 thisblock->data.block.exception_region = 0;
3247 thisblock->data.block.block_target_temp_slot_level = target_temp_slot_level;
3249 thisblock->data.block.conditional_code = 0;
3250 thisblock->data.block.last_unconditional_cleanup = note;
3251 /* When we insert instructions after the last unconditional cleanup,
3252 we don't adjust last_insn. That means that a later add_insn will
3253 clobber the instructions we've just added. The easiest way to
3254 fix this is to just insert another instruction here, so that the
3255 instructions inserted after the last unconditional cleanup are
3256 never the last instruction. */
3257 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3258 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
3261 && !(block_stack->data.block.cleanups == NULL_TREE
3262 && block_stack->data.block.outer_cleanups == NULL_TREE))
3263 thisblock->data.block.outer_cleanups
3264 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
3265 block_stack->data.block.outer_cleanups);
3267 thisblock->data.block.outer_cleanups = 0;
3268 thisblock->data.block.label_chain = 0;
3269 thisblock->data.block.innermost_stack_block = stack_block_stack;
3270 thisblock->data.block.first_insn = note;
3271 thisblock->data.block.block_start_count = ++current_block_start_count;
3272 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
3273 block_stack = thisblock;
3274 nesting_stack = thisblock;
3276 /* Make a new level for allocating stack slots. */
3280 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3281 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3282 expand_expr are made. After we end the region, we know that all
3283 space for all temporaries that were created by TARGET_EXPRs will be
3284 destroyed and their space freed for reuse. */
3287 expand_start_target_temps ()
3289 /* This is so that even if the result is preserved, the space
3290 allocated will be freed, as we know that it is no longer in use. */
3293 /* Start a new binding layer that will keep track of all cleanup
3294 actions to be performed. */
3295 expand_start_bindings (2);
3297 target_temp_slot_level = temp_slot_level;
3301 expand_end_target_temps ()
3303 expand_end_bindings (NULL_TREE, 0, 0);
3305 /* This is so that even if the result is preserved, the space
3306 allocated will be freed, as we know that it is no longer in use. */
3310 /* Mark top block of block_stack as an implicit binding for an
3311 exception region. This is used to prevent infinite recursion when
3312 ending a binding with expand_end_bindings. It is only ever called
3313 by expand_eh_region_start, as that it the only way to create a
3314 block stack for a exception region. */
3317 mark_block_as_eh_region ()
3319 block_stack->data.block.exception_region = 1;
3320 if (block_stack->next
3321 && block_stack->next->data.block.conditional_code)
3323 block_stack->data.block.conditional_code
3324 = block_stack->next->data.block.conditional_code;
3325 block_stack->data.block.last_unconditional_cleanup
3326 = block_stack->next->data.block.last_unconditional_cleanup;
3327 block_stack->data.block.cleanup_ptr
3328 = block_stack->next->data.block.cleanup_ptr;
3332 /* True if we are currently emitting insns in an area of output code
3333 that is controlled by a conditional expression. This is used by
3334 the cleanup handling code to generate conditional cleanup actions. */
3337 conditional_context ()
3339 return block_stack && block_stack->data.block.conditional_code;
3342 /* Mark top block of block_stack as not for an implicit binding for an
3343 exception region. This is only ever done by expand_eh_region_end
3344 to let expand_end_bindings know that it is being called explicitly
3345 to end the binding layer for just the binding layer associated with
3346 the exception region, otherwise expand_end_bindings would try and
3347 end all implicit binding layers for exceptions regions, and then
3348 one normal binding layer. */
3351 mark_block_as_not_eh_region ()
3353 block_stack->data.block.exception_region = 0;
3356 /* True if the top block of block_stack was marked as for an exception
3357 region by mark_block_as_eh_region. */
3362 return (current_function && block_stack
3363 && block_stack->data.block.exception_region);
3366 /* Emit a handler label for a nonlocal goto handler.
3367 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3370 expand_nl_handler_label (slot, before_insn)
3371 rtx slot, before_insn;
3374 rtx handler_label = gen_label_rtx ();
3376 /* Don't let jump_optimize delete the handler. */
3377 LABEL_PRESERVE_P (handler_label) = 1;
3380 emit_move_insn (slot, gen_rtx_LABEL_REF (Pmode, handler_label));
3381 insns = get_insns ();
3383 emit_insns_before (insns, before_insn);
3385 emit_label (handler_label);
3387 return handler_label;
3390 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3393 expand_nl_goto_receiver ()
3395 #ifdef HAVE_nonlocal_goto
3396 if (! HAVE_nonlocal_goto)
3398 /* First adjust our frame pointer to its actual value. It was
3399 previously set to the start of the virtual area corresponding to
3400 the stacked variables when we branched here and now needs to be
3401 adjusted to the actual hardware fp value.
3403 Assignments are to virtual registers are converted by
3404 instantiate_virtual_regs into the corresponding assignment
3405 to the underlying register (fp in this case) that makes
3406 the original assignment true.
3407 So the following insn will actually be
3408 decrementing fp by STARTING_FRAME_OFFSET. */
3409 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3411 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3412 if (fixed_regs[ARG_POINTER_REGNUM])
3414 #ifdef ELIMINABLE_REGS
3415 /* If the argument pointer can be eliminated in favor of the
3416 frame pointer, we don't need to restore it. We assume here
3417 that if such an elimination is present, it can always be used.
3418 This is the case on all known machines; if we don't make this
3419 assumption, we do unnecessary saving on many machines. */
3420 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3423 for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
3424 if (elim_regs[i].from == ARG_POINTER_REGNUM
3425 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3428 if (i == sizeof elim_regs / sizeof elim_regs [0])
3431 /* Now restore our arg pointer from the address at which it
3432 was saved in our stack frame.
3433 If there hasn't be space allocated for it yet, make
3435 if (arg_pointer_save_area == 0)
3436 arg_pointer_save_area
3437 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3438 emit_move_insn (virtual_incoming_args_rtx,
3439 /* We need a pseudo here, or else
3440 instantiate_virtual_regs_1 complains. */
3441 copy_to_reg (arg_pointer_save_area));
3446 #ifdef HAVE_nonlocal_goto_receiver
3447 if (HAVE_nonlocal_goto_receiver)
3448 emit_insn (gen_nonlocal_goto_receiver ());
3452 /* Make handlers for nonlocal gotos taking place in the function calls in
3456 expand_nl_goto_receivers (thisblock)
3457 struct nesting *thisblock;
3460 rtx afterward = gen_label_rtx ();
3465 /* Record the handler address in the stack slot for that purpose,
3466 during this block, saving and restoring the outer value. */
3467 if (thisblock->next != 0)
3468 for (slot = nonlocal_goto_handler_slots; slot; slot = XEXP (slot, 1))
3470 rtx save_receiver = gen_reg_rtx (Pmode);
3471 emit_move_insn (XEXP (slot, 0), save_receiver);
3474 emit_move_insn (save_receiver, XEXP (slot, 0));
3475 insns = get_insns ();
3477 emit_insns_before (insns, thisblock->data.block.first_insn);
3480 /* Jump around the handlers; they run only when specially invoked. */
3481 emit_jump (afterward);
3483 /* Make a separate handler for each label. */
3484 link = nonlocal_labels;
3485 slot = nonlocal_goto_handler_slots;
3486 label_list = NULL_RTX;
3487 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3488 /* Skip any labels we shouldn't be able to jump to from here,
3489 we generate one special handler for all of them below which just calls
3491 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3494 lab = expand_nl_handler_label (XEXP (slot, 0),
3495 thisblock->data.block.first_insn);
3496 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3498 expand_nl_goto_receiver ();
3500 /* Jump to the "real" nonlocal label. */
3501 expand_goto (TREE_VALUE (link));
3504 /* A second pass over all nonlocal labels; this time we handle those
3505 we should not be able to jump to at this point. */
3506 link = nonlocal_labels;
3507 slot = nonlocal_goto_handler_slots;
3509 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3510 if (DECL_TOO_LATE (TREE_VALUE (link)))
3513 lab = expand_nl_handler_label (XEXP (slot, 0),
3514 thisblock->data.block.first_insn);
3515 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3521 expand_nl_goto_receiver ();
3522 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "abort"), 0,
3527 nonlocal_goto_handler_labels = label_list;
3528 emit_label (afterward);
3531 /* Warn about any unused VARS (which may contain nodes other than
3532 VAR_DECLs, but such nodes are ignored). The nodes are connected
3533 via the TREE_CHAIN field. */
3536 warn_about_unused_variables (vars)
3542 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3543 if (TREE_CODE (decl) == VAR_DECL
3544 && ! TREE_USED (decl)
3545 && ! DECL_IN_SYSTEM_HEADER (decl)
3546 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
3547 warning_with_decl (decl, "unused variable `%s'");
3550 /* Generate RTL code to terminate a binding contour.
3552 VARS is the chain of VAR_DECL nodes for the variables bound in this
3553 contour. There may actually be other nodes in this chain, but any
3554 nodes other than VAR_DECLS are ignored.
3556 MARK_ENDS is nonzero if we should put a note at the beginning
3557 and end of this binding contour.
3559 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3560 (That is true automatically if the contour has a saved stack level.) */
3563 expand_end_bindings (vars, mark_ends, dont_jump_in)
3568 register struct nesting *thisblock;
3571 while (block_stack->data.block.exception_region)
3573 /* Because we don't need or want a new temporary level and
3574 because we didn't create one in expand_eh_region_start,
3575 create a fake one now to avoid removing one in
3576 expand_end_bindings. */
3579 block_stack->data.block.exception_region = 0;
3581 expand_end_bindings (NULL_TREE, 0, 0);
3584 /* Since expand_eh_region_start does an expand_start_bindings, we
3585 have to first end all the bindings that were created by
3586 expand_eh_region_start. */
3588 thisblock = block_stack;
3590 /* If any of the variables in this scope were not used, warn the
3592 warn_about_unused_variables (vars);
3594 if (thisblock->exit_label)
3596 do_pending_stack_adjust ();
3597 emit_label (thisblock->exit_label);
3600 /* If necessary, make handlers for nonlocal gotos taking
3601 place in the function calls in this block. */
3602 if (function_call_count != thisblock->data.block.n_function_calls
3604 /* Make handler for outermost block
3605 if there were any nonlocal gotos to this function. */
3606 && (thisblock->next == 0 ? current_function_has_nonlocal_label
3607 /* Make handler for inner block if it has something
3608 special to do when you jump out of it. */
3609 : (thisblock->data.block.cleanups != 0
3610 || thisblock->data.block.stack_level != 0)))
3611 expand_nl_goto_receivers (thisblock);
3613 /* Don't allow jumping into a block that has a stack level.
3614 Cleanups are allowed, though. */
3616 || thisblock->data.block.stack_level != 0)
3618 struct label_chain *chain;
3620 /* Any labels in this block are no longer valid to go to.
3621 Mark them to cause an error message. */
3622 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3624 DECL_TOO_LATE (chain->label) = 1;
3625 /* If any goto without a fixup came to this label,
3626 that must be an error, because gotos without fixups
3627 come from outside all saved stack-levels. */
3628 if (TREE_ADDRESSABLE (chain->label))
3629 error_with_decl (chain->label,
3630 "label `%s' used before containing binding contour");
3634 /* Restore stack level in effect before the block
3635 (only if variable-size objects allocated). */
3636 /* Perform any cleanups associated with the block. */
3638 if (thisblock->data.block.stack_level != 0
3639 || thisblock->data.block.cleanups != 0)
3641 /* Only clean up here if this point can actually be reached. */
3642 int reachable = GET_CODE (get_last_insn ()) != BARRIER;
3644 /* Don't let cleanups affect ({...}) constructs. */
3645 int old_expr_stmts_for_value = expr_stmts_for_value;
3646 rtx old_last_expr_value = last_expr_value;
3647 tree old_last_expr_type = last_expr_type;
3648 expr_stmts_for_value = 0;
3650 /* Do the cleanups. */
3651 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3653 do_pending_stack_adjust ();
3655 expr_stmts_for_value = old_expr_stmts_for_value;
3656 last_expr_value = old_last_expr_value;
3657 last_expr_type = old_last_expr_type;
3659 /* Restore the stack level. */
3661 if (reachable && thisblock->data.block.stack_level != 0)
3663 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3664 thisblock->data.block.stack_level, NULL_RTX);
3665 if (nonlocal_goto_handler_slots != 0)
3666 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3670 /* Any gotos out of this block must also do these things.
3671 Also report any gotos with fixups that came to labels in this
3673 fixup_gotos (thisblock,
3674 thisblock->data.block.stack_level,
3675 thisblock->data.block.cleanups,
3676 thisblock->data.block.first_insn,
3680 /* Mark the beginning and end of the scope if requested.
3681 We do this now, after running cleanups on the variables
3682 just going out of scope, so they are in scope for their cleanups. */
3686 rtx note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3687 NOTE_BLOCK (note) = NOTE_BLOCK (thisblock->data.block.first_insn);
3690 /* Get rid of the beginning-mark if we don't make an end-mark. */
3691 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3693 /* If doing stupid register allocation, make sure lives of all
3694 register variables declared here extend thru end of scope. */
3697 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3698 if (TREE_CODE (decl) == VAR_DECL && DECL_RTL (decl))
3699 use_variable (DECL_RTL (decl));
3701 /* Restore the temporary level of TARGET_EXPRs. */
3702 target_temp_slot_level = thisblock->data.block.block_target_temp_slot_level;
3704 /* Restore block_stack level for containing block. */
3706 stack_block_stack = thisblock->data.block.innermost_stack_block;
3707 POPSTACK (block_stack);
3709 /* Pop the stack slot nesting and free any slots at this level. */
3713 /* Generate RTL for the automatic variable declaration DECL.
3714 (Other kinds of declarations are simply ignored if seen here.) */
3720 struct nesting *thisblock;
3723 type = TREE_TYPE (decl);
3725 /* Only automatic variables need any expansion done.
3726 Static and external variables, and external functions,
3727 will be handled by `assemble_variable' (called from finish_decl).
3728 TYPE_DECL and CONST_DECL require nothing.
3729 PARM_DECLs are handled in `assign_parms'. */
3731 if (TREE_CODE (decl) != VAR_DECL)
3733 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3736 thisblock = block_stack;
3738 /* Create the RTL representation for the variable. */
3740 if (type == error_mark_node)
3741 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, const0_rtx);
3742 else if (DECL_SIZE (decl) == 0)
3743 /* Variable with incomplete type. */
3745 if (DECL_INITIAL (decl) == 0)
3746 /* Error message was already done; now avoid a crash. */
3747 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3749 /* An initializer is going to decide the size of this array.
3750 Until we know the size, represent its address with a reg. */
3751 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode));
3752 MEM_SET_IN_STRUCT_P (DECL_RTL (decl), AGGREGATE_TYPE_P (type));
3754 else if (DECL_MODE (decl) != BLKmode
3755 /* If -ffloat-store, don't put explicit float vars
3757 && !(flag_float_store
3758 && TREE_CODE (type) == REAL_TYPE)
3759 && ! TREE_THIS_VOLATILE (decl)
3760 && ! TREE_ADDRESSABLE (decl)
3761 && (DECL_REGISTER (decl) || ! obey_regdecls)
3762 /* if -fcheck-memory-usage, check all variables. */
3763 && ! current_function_check_memory_usage)
3765 /* Automatic variable that can go in a register. */
3766 int unsignedp = TREE_UNSIGNED (type);
3767 enum machine_mode reg_mode
3768 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3770 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3771 mark_user_reg (DECL_RTL (decl));
3773 if (POINTER_TYPE_P (type))
3774 mark_reg_pointer (DECL_RTL (decl),
3775 (TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl)))
3779 else if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST
3780 && ! (flag_stack_check && ! STACK_CHECK_BUILTIN
3781 && (TREE_INT_CST_HIGH (DECL_SIZE (decl)) != 0
3782 || (TREE_INT_CST_LOW (DECL_SIZE (decl))
3783 > STACK_CHECK_MAX_VAR_SIZE * BITS_PER_UNIT))))
3785 /* Variable of fixed size that goes on the stack. */
3789 /* If we previously made RTL for this decl, it must be an array
3790 whose size was determined by the initializer.
3791 The old address was a register; set that register now
3792 to the proper address. */
3793 if (DECL_RTL (decl) != 0)
3795 if (GET_CODE (DECL_RTL (decl)) != MEM
3796 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3798 oldaddr = XEXP (DECL_RTL (decl), 0);
3801 DECL_RTL (decl) = assign_temp (TREE_TYPE (decl), 1, 1, 1);
3802 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3803 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3805 /* Set alignment we actually gave this decl. */
3806 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3807 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3811 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3812 if (addr != oldaddr)
3813 emit_move_insn (oldaddr, addr);
3816 /* If this is a memory ref that contains aggregate components,
3817 mark it as such for cse and loop optimize. */
3818 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3819 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3821 /* If this is in memory because of -ffloat-store,
3822 set the volatile bit, to prevent optimizations from
3823 undoing the effects. */
3824 if (flag_float_store && TREE_CODE (type) == REAL_TYPE)
3825 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3828 MEM_ALIAS_SET (DECL_RTL (decl)) = get_alias_set (decl);
3831 /* Dynamic-size object: must push space on the stack. */
3835 /* Record the stack pointer on entry to block, if have
3836 not already done so. */
3837 if (thisblock->data.block.stack_level == 0)
3839 do_pending_stack_adjust ();
3840 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3841 &thisblock->data.block.stack_level,
3842 thisblock->data.block.first_insn);
3843 stack_block_stack = thisblock;
3846 /* In function-at-a-time mode, variable_size doesn't expand this,
3848 if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
3849 expand_expr (TYPE_MAX_VALUE (TYPE_DOMAIN (type)),
3850 const0_rtx, VOIDmode, 0);
3852 /* Compute the variable's size, in bytes. */
3853 size = expand_expr (size_binop (CEIL_DIV_EXPR,
3855 size_int (BITS_PER_UNIT)),
3856 NULL_RTX, VOIDmode, 0);
3859 /* Allocate space on the stack for the variable. Note that
3860 DECL_ALIGN says how the variable is to be aligned and we
3861 cannot use it to conclude anything about the alignment of
3863 address = allocate_dynamic_stack_space (size, NULL_RTX,
3864 TYPE_ALIGN (TREE_TYPE (decl)));
3866 /* Reference the variable indirect through that rtx. */
3867 DECL_RTL (decl) = gen_rtx_MEM (DECL_MODE (decl), address);
3869 /* If this is a memory ref that contains aggregate components,
3870 mark it as such for cse and loop optimize. */
3871 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3872 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3874 /* Indicate the alignment we actually gave this variable. */
3875 #ifdef STACK_BOUNDARY
3876 DECL_ALIGN (decl) = STACK_BOUNDARY;
3878 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3882 if (TREE_THIS_VOLATILE (decl))
3883 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3884 #if 0 /* A variable is not necessarily unchanging
3885 just because it is const. RTX_UNCHANGING_P
3886 means no change in the function,
3887 not merely no change in the variable's scope.
3888 It is correct to set RTX_UNCHANGING_P if the variable's scope
3889 is the whole function. There's no convenient way to test that. */
3890 if (TREE_READONLY (decl))
3891 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
3894 /* If doing stupid register allocation, make sure life of any
3895 register variable starts here, at the start of its scope. */
3898 use_variable (DECL_RTL (decl));
3903 /* Emit code to perform the initialization of a declaration DECL. */
3906 expand_decl_init (decl)
3909 int was_used = TREE_USED (decl);
3911 /* If this is a CONST_DECL, we don't have to generate any code, but
3912 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3913 to be set while in the obstack containing the constant. If we don't
3914 do this, we can lose if we have functions nested three deep and the middle
3915 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3916 the innermost function is the first to expand that STRING_CST. */
3917 if (TREE_CODE (decl) == CONST_DECL)
3919 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3920 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3921 EXPAND_INITIALIZER);
3925 if (TREE_STATIC (decl))
3928 /* Compute and store the initial value now. */
3930 if (DECL_INITIAL (decl) == error_mark_node)
3932 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3934 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3935 || code == POINTER_TYPE || code == REFERENCE_TYPE)
3936 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3940 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3942 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3943 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3947 /* Don't let the initialization count as "using" the variable. */
3948 TREE_USED (decl) = was_used;
3950 /* Free any temporaries we made while initializing the decl. */
3951 preserve_temp_slots (NULL_RTX);
3955 /* CLEANUP is an expression to be executed at exit from this binding contour;
3956 for example, in C++, it might call the destructor for this variable.
3958 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
3959 CLEANUP multiple times, and have the correct semantics. This
3960 happens in exception handling, for gotos, returns, breaks that
3961 leave the current scope.
3963 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3964 that is not associated with any particular variable. */
3967 expand_decl_cleanup (decl, cleanup)
3970 struct nesting *thisblock;
3972 /* Error if we are not in any block. */
3973 if (current_function == 0 || block_stack == 0)
3976 thisblock = block_stack;
3978 /* Record the cleanup if there is one. */
3984 tree *cleanups = &thisblock->data.block.cleanups;
3985 int cond_context = conditional_context ();
3989 rtx flag = gen_reg_rtx (word_mode);
3994 emit_move_insn (flag, const0_rtx);
3995 set_flag_0 = get_insns ();
3998 thisblock->data.block.last_unconditional_cleanup
3999 = emit_insns_after (set_flag_0,
4000 thisblock->data.block.last_unconditional_cleanup);
4002 emit_move_insn (flag, const1_rtx);
4004 /* All cleanups must be on the function_obstack. */
4005 push_obstacks_nochange ();
4006 resume_temporary_allocation ();
4008 cond = build_decl (VAR_DECL, NULL_TREE, type_for_mode (word_mode, 1));
4009 DECL_RTL (cond) = flag;
4011 /* Conditionalize the cleanup. */
4012 cleanup = build (COND_EXPR, void_type_node,
4013 truthvalue_conversion (cond),
4014 cleanup, integer_zero_node);
4015 cleanup = fold (cleanup);
4019 cleanups = thisblock->data.block.cleanup_ptr;
4022 /* All cleanups must be on the function_obstack. */
4023 push_obstacks_nochange ();
4024 resume_temporary_allocation ();
4025 cleanup = unsave_expr (cleanup);
4028 t = *cleanups = temp_tree_cons (decl, cleanup, *cleanups);
4031 /* If this block has a cleanup, it belongs in stack_block_stack. */
4032 stack_block_stack = thisblock;
4039 /* If this was optimized so that there is no exception region for the
4040 cleanup, then mark the TREE_LIST node, so that we can later tell
4041 if we need to call expand_eh_region_end. */
4042 if (! using_eh_for_cleanups_p
4043 || expand_eh_region_start_tree (decl, cleanup))
4044 TREE_ADDRESSABLE (t) = 1;
4045 /* If that started a new EH region, we're in a new block. */
4046 thisblock = block_stack;
4053 thisblock->data.block.last_unconditional_cleanup
4054 = emit_insns_after (seq,
4055 thisblock->data.block.last_unconditional_cleanup);
4059 thisblock->data.block.last_unconditional_cleanup
4061 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
4067 /* Like expand_decl_cleanup, but suppress generating an exception handler
4068 to perform the cleanup. */
4072 expand_decl_cleanup_no_eh (decl, cleanup)
4075 int save_eh = using_eh_for_cleanups_p;
4078 using_eh_for_cleanups_p = 0;
4079 result = expand_decl_cleanup (decl, cleanup);
4080 using_eh_for_cleanups_p = save_eh;
4086 /* Arrange for the top element of the dynamic cleanup chain to be
4087 popped if we exit the current binding contour. DECL is the
4088 associated declaration, if any, otherwise NULL_TREE. If the
4089 current contour is left via an exception, then __sjthrow will pop
4090 the top element off the dynamic cleanup chain. The code that
4091 avoids doing the action we push into the cleanup chain in the
4092 exceptional case is contained in expand_cleanups.
4094 This routine is only used by expand_eh_region_start, and that is
4095 the only way in which an exception region should be started. This
4096 routine is only used when using the setjmp/longjmp codegen method
4097 for exception handling. */
4100 expand_dcc_cleanup (decl)
4103 struct nesting *thisblock;
4106 /* Error if we are not in any block. */
4107 if (current_function == 0 || block_stack == 0)
4109 thisblock = block_stack;
4111 /* Record the cleanup for the dynamic handler chain. */
4113 /* All cleanups must be on the function_obstack. */
4114 push_obstacks_nochange ();
4115 resume_temporary_allocation ();
4116 cleanup = make_node (POPDCC_EXPR);
4119 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4120 thisblock->data.block.cleanups
4121 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4123 /* If this block has a cleanup, it belongs in stack_block_stack. */
4124 stack_block_stack = thisblock;
4128 /* Arrange for the top element of the dynamic handler chain to be
4129 popped if we exit the current binding contour. DECL is the
4130 associated declaration, if any, otherwise NULL_TREE. If the current
4131 contour is left via an exception, then __sjthrow will pop the top
4132 element off the dynamic handler chain. The code that avoids doing
4133 the action we push into the handler chain in the exceptional case
4134 is contained in expand_cleanups.
4136 This routine is only used by expand_eh_region_start, and that is
4137 the only way in which an exception region should be started. This
4138 routine is only used when using the setjmp/longjmp codegen method
4139 for exception handling. */
4142 expand_dhc_cleanup (decl)
4145 struct nesting *thisblock;
4148 /* Error if we are not in any block. */
4149 if (current_function == 0 || block_stack == 0)
4151 thisblock = block_stack;
4153 /* Record the cleanup for the dynamic handler chain. */
4155 /* All cleanups must be on the function_obstack. */
4156 push_obstacks_nochange ();
4157 resume_temporary_allocation ();
4158 cleanup = make_node (POPDHC_EXPR);
4161 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4162 thisblock->data.block.cleanups
4163 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4165 /* If this block has a cleanup, it belongs in stack_block_stack. */
4166 stack_block_stack = thisblock;
4170 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4171 DECL_ELTS is the list of elements that belong to DECL's type.
4172 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4175 expand_anon_union_decl (decl, cleanup, decl_elts)
4176 tree decl, cleanup, decl_elts;
4178 struct nesting *thisblock = current_function == 0 ? 0 : block_stack;
4182 /* If any of the elements are addressable, so is the entire union. */
4183 for (t = decl_elts; t; t = TREE_CHAIN (t))
4184 if (TREE_ADDRESSABLE (TREE_VALUE (t)))
4186 TREE_ADDRESSABLE (decl) = 1;
4191 expand_decl_cleanup (decl, cleanup);
4192 x = DECL_RTL (decl);
4194 /* Go through the elements, assigning RTL to each. */
4195 for (t = decl_elts; t; t = TREE_CHAIN (t))
4197 tree decl_elt = TREE_VALUE (t);
4198 tree cleanup_elt = TREE_PURPOSE (t);
4199 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
4201 /* Propagate the union's alignment to the elements. */
4202 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
4204 /* If the element has BLKmode and the union doesn't, the union is
4205 aligned such that the element doesn't need to have BLKmode, so
4206 change the element's mode to the appropriate one for its size. */
4207 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
4208 DECL_MODE (decl_elt) = mode
4209 = mode_for_size (TREE_INT_CST_LOW (DECL_SIZE (decl_elt)),
4212 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4213 instead create a new MEM rtx with the proper mode. */
4214 if (GET_CODE (x) == MEM)
4216 if (mode == GET_MODE (x))
4217 DECL_RTL (decl_elt) = x;
4220 DECL_RTL (decl_elt) = gen_rtx_MEM (mode, copy_rtx (XEXP (x, 0)));
4221 MEM_COPY_ATTRIBUTES (DECL_RTL (decl_elt), x);
4222 RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x);
4225 else if (GET_CODE (x) == REG)
4227 if (mode == GET_MODE (x))
4228 DECL_RTL (decl_elt) = x;
4230 DECL_RTL (decl_elt) = gen_rtx_SUBREG (mode, x, 0);
4235 /* Record the cleanup if there is one. */
4238 thisblock->data.block.cleanups
4239 = temp_tree_cons (decl_elt, cleanup_elt,
4240 thisblock->data.block.cleanups);
4244 /* Expand a list of cleanups LIST.
4245 Elements may be expressions or may be nested lists.
4247 If DONT_DO is nonnull, then any list-element
4248 whose TREE_PURPOSE matches DONT_DO is omitted.
4249 This is sometimes used to avoid a cleanup associated with
4250 a value that is being returned out of the scope.
4252 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
4253 goto and handle protection regions specially in that case.
4255 If REACHABLE, we emit code, otherwise just inform the exception handling
4256 code about this finalization. */
4259 expand_cleanups (list, dont_do, in_fixup, reachable)
4266 for (tail = list; tail; tail = TREE_CHAIN (tail))
4267 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
4269 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
4270 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
4275 tree cleanup = TREE_VALUE (tail);
4277 /* See expand_d{h,c}c_cleanup for why we avoid this. */
4278 if (TREE_CODE (cleanup) != POPDHC_EXPR
4279 && TREE_CODE (cleanup) != POPDCC_EXPR
4280 /* See expand_eh_region_start_tree for this case. */
4281 && ! TREE_ADDRESSABLE (tail))
4283 cleanup = protect_with_terminate (cleanup);
4284 expand_eh_region_end (cleanup);
4290 /* Cleanups may be run multiple times. For example,
4291 when exiting a binding contour, we expand the
4292 cleanups associated with that contour. When a goto
4293 within that binding contour has a target outside that
4294 contour, it will expand all cleanups from its scope to
4295 the target. Though the cleanups are expanded multiple
4296 times, the control paths are non-overlapping so the
4297 cleanups will not be executed twice. */
4299 /* We may need to protect fixups with rethrow regions. */
4300 int protect = (in_fixup && ! TREE_ADDRESSABLE (tail));
4303 expand_fixup_region_start ();
4305 /* The cleanup might contain try-blocks, so we have to
4306 preserve our current queue. */
4308 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
4311 expand_fixup_region_end (TREE_VALUE (tail));
4318 /* Mark when the context we are emitting RTL for as a conditional
4319 context, so that any cleanup actions we register with
4320 expand_decl_init will be properly conditionalized when those
4321 cleanup actions are later performed. Must be called before any
4322 expression (tree) is expanded that is within a conditional context. */
4325 start_cleanup_deferral ()
4327 /* block_stack can be NULL if we are inside the parameter list. It is
4328 OK to do nothing, because cleanups aren't possible here. */
4330 ++block_stack->data.block.conditional_code;
4333 /* Mark the end of a conditional region of code. Because cleanup
4334 deferrals may be nested, we may still be in a conditional region
4335 after we end the currently deferred cleanups, only after we end all
4336 deferred cleanups, are we back in unconditional code. */
4339 end_cleanup_deferral ()
4341 /* block_stack can be NULL if we are inside the parameter list. It is
4342 OK to do nothing, because cleanups aren't possible here. */
4344 --block_stack->data.block.conditional_code;
4347 /* Move all cleanups from the current block_stack
4348 to the containing block_stack, where they are assumed to
4349 have been created. If anything can cause a temporary to
4350 be created, but not expanded for more than one level of
4351 block_stacks, then this code will have to change. */
4356 struct nesting *block = block_stack;
4357 struct nesting *outer = block->next;
4359 outer->data.block.cleanups
4360 = chainon (block->data.block.cleanups,
4361 outer->data.block.cleanups);
4362 block->data.block.cleanups = 0;
4366 last_cleanup_this_contour ()
4368 if (block_stack == 0)
4371 return block_stack->data.block.cleanups;
4374 /* Return 1 if there are any pending cleanups at this point.
4375 If THIS_CONTOUR is nonzero, check the current contour as well.
4376 Otherwise, look only at the contours that enclose this one. */
4379 any_pending_cleanups (this_contour)
4382 struct nesting *block;
4384 if (current_function == NULL || current_function->stmt == NULL
4385 || block_stack == 0)
4388 if (this_contour && block_stack->data.block.cleanups != NULL)
4390 if (block_stack->data.block.cleanups == 0
4391 && block_stack->data.block.outer_cleanups == 0)
4394 for (block = block_stack->next; block; block = block->next)
4395 if (block->data.block.cleanups != 0)
4401 /* Enter a case (Pascal) or switch (C) statement.
4402 Push a block onto case_stack and nesting_stack
4403 to accumulate the case-labels that are seen
4404 and to record the labels generated for the statement.
4406 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4407 Otherwise, this construct is transparent for `exit_something'.
4409 EXPR is the index-expression to be dispatched on.
4410 TYPE is its nominal type. We could simply convert EXPR to this type,
4411 but instead we take short cuts. */
4414 expand_start_case (exit_flag, expr, type, printname)
4418 const char *printname;
4420 register struct nesting *thiscase = ALLOC_NESTING ();
4422 /* Make an entry on case_stack for the case we are entering. */
4424 thiscase->next = case_stack;
4425 thiscase->all = nesting_stack;
4426 thiscase->depth = ++nesting_depth;
4427 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
4428 thiscase->data.case_stmt.case_list = 0;
4429 thiscase->data.case_stmt.index_expr = expr;
4430 thiscase->data.case_stmt.nominal_type = type;
4431 thiscase->data.case_stmt.default_label = 0;
4432 thiscase->data.case_stmt.num_ranges = 0;
4433 thiscase->data.case_stmt.printname = printname;
4434 thiscase->data.case_stmt.line_number_status = force_line_numbers ();
4435 case_stack = thiscase;
4436 nesting_stack = thiscase;
4438 do_pending_stack_adjust ();
4440 /* Make sure case_stmt.start points to something that won't
4441 need any transformation before expand_end_case. */
4442 if (GET_CODE (get_last_insn ()) != NOTE)
4443 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4445 thiscase->data.case_stmt.start = get_last_insn ();
4447 start_cleanup_deferral ();
4451 /* Start a "dummy case statement" within which case labels are invalid
4452 and are not connected to any larger real case statement.
4453 This can be used if you don't want to let a case statement jump
4454 into the middle of certain kinds of constructs. */
4457 expand_start_case_dummy ()
4459 register struct nesting *thiscase = ALLOC_NESTING ();
4461 /* Make an entry on case_stack for the dummy. */
4463 thiscase->next = case_stack;
4464 thiscase->all = nesting_stack;
4465 thiscase->depth = ++nesting_depth;
4466 thiscase->exit_label = 0;
4467 thiscase->data.case_stmt.case_list = 0;
4468 thiscase->data.case_stmt.start = 0;
4469 thiscase->data.case_stmt.nominal_type = 0;
4470 thiscase->data.case_stmt.default_label = 0;
4471 thiscase->data.case_stmt.num_ranges = 0;
4472 case_stack = thiscase;
4473 nesting_stack = thiscase;
4474 start_cleanup_deferral ();
4477 /* End a dummy case statement. */
4480 expand_end_case_dummy ()
4482 end_cleanup_deferral ();
4483 POPSTACK (case_stack);
4486 /* Return the data type of the index-expression
4487 of the innermost case statement, or null if none. */
4490 case_index_expr_type ()
4493 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
4500 /* If this is the first label, warn if any insns have been emitted. */
4501 if (case_stack->data.case_stmt.line_number_status >= 0)
4505 restore_line_number_status
4506 (case_stack->data.case_stmt.line_number_status);
4507 case_stack->data.case_stmt.line_number_status = -1;
4509 for (insn = case_stack->data.case_stmt.start;
4511 insn = NEXT_INSN (insn))
4513 if (GET_CODE (insn) == CODE_LABEL)
4515 if (GET_CODE (insn) != NOTE
4516 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4519 insn = PREV_INSN (insn);
4520 while (insn && (GET_CODE (insn) != NOTE || NOTE_LINE_NUMBER (insn) < 0));
4522 /* If insn is zero, then there must have been a syntax error. */
4524 warning_with_file_and_line (NOTE_SOURCE_FILE(insn),
4525 NOTE_LINE_NUMBER(insn),
4526 "unreachable code at beginning of %s",
4527 case_stack->data.case_stmt.printname);
4534 /* Accumulate one case or default label inside a case or switch statement.
4535 VALUE is the value of the case (a null pointer, for a default label).
4536 The function CONVERTER, when applied to arguments T and V,
4537 converts the value V to the type T.
4539 If not currently inside a case or switch statement, return 1 and do
4540 nothing. The caller will print a language-specific error message.
4541 If VALUE is a duplicate or overlaps, return 2 and do nothing
4542 except store the (first) duplicate node in *DUPLICATE.
4543 If VALUE is out of range, return 3 and do nothing.
4544 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4545 Return 0 on success.
4547 Extended to handle range statements. */
4550 pushcase (value, converter, label, duplicate)
4551 register tree value;
4552 tree (*converter) PROTO((tree, tree));
4553 register tree label;
4559 /* Fail if not inside a real case statement. */
4560 if (! (case_stack && case_stack->data.case_stmt.start))
4563 if (stack_block_stack
4564 && stack_block_stack->depth > case_stack->depth)
4567 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4568 nominal_type = case_stack->data.case_stmt.nominal_type;
4570 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4571 if (index_type == error_mark_node)
4574 /* Convert VALUE to the type in which the comparisons are nominally done. */
4576 value = (*converter) (nominal_type, value);
4580 /* Fail if this value is out of range for the actual type of the index
4581 (which may be narrower than NOMINAL_TYPE). */
4583 && (TREE_CONSTANT_OVERFLOW (value)
4584 || ! int_fits_type_p (value, index_type)))
4587 /* Fail if this is a duplicate or overlaps another entry. */
4590 if (case_stack->data.case_stmt.default_label != 0)
4592 *duplicate = case_stack->data.case_stmt.default_label;
4595 case_stack->data.case_stmt.default_label = label;
4598 return add_case_node (value, value, label, duplicate);
4600 expand_label (label);
4604 /* Like pushcase but this case applies to all values between VALUE1 and
4605 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4606 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4607 starts at VALUE1 and ends at the highest value of the index type.
4608 If both are NULL, this case applies to all values.
4610 The return value is the same as that of pushcase but there is one
4611 additional error code: 4 means the specified range was empty. */
4614 pushcase_range (value1, value2, converter, label, duplicate)
4615 register tree value1, value2;
4616 tree (*converter) PROTO((tree, tree));
4617 register tree label;
4623 /* Fail if not inside a real case statement. */
4624 if (! (case_stack && case_stack->data.case_stmt.start))
4627 if (stack_block_stack
4628 && stack_block_stack->depth > case_stack->depth)
4631 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4632 nominal_type = case_stack->data.case_stmt.nominal_type;
4634 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4635 if (index_type == error_mark_node)
4640 /* Convert VALUEs to type in which the comparisons are nominally done
4641 and replace any unspecified value with the corresponding bound. */
4643 value1 = TYPE_MIN_VALUE (index_type);
4645 value2 = TYPE_MAX_VALUE (index_type);
4647 /* Fail if the range is empty. Do this before any conversion since
4648 we want to allow out-of-range empty ranges. */
4649 if (value2 != 0 && tree_int_cst_lt (value2, value1))
4652 /* If the max was unbounded, use the max of the nominal_type we are
4653 converting to. Do this after the < check above to suppress false
4656 value2 = TYPE_MAX_VALUE (nominal_type);
4658 value1 = (*converter) (nominal_type, value1);
4659 value2 = (*converter) (nominal_type, value2);
4661 /* Fail if these values are out of range. */
4662 if (TREE_CONSTANT_OVERFLOW (value1)
4663 || ! int_fits_type_p (value1, index_type))
4666 if (TREE_CONSTANT_OVERFLOW (value2)
4667 || ! int_fits_type_p (value2, index_type))
4670 return add_case_node (value1, value2, label, duplicate);
4673 /* Do the actual insertion of a case label for pushcase and pushcase_range
4674 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4675 slowdown for large switch statements. */
4678 add_case_node (low, high, label, duplicate)
4683 struct case_node *p, **q, *r;
4685 q = &case_stack->data.case_stmt.case_list;
4692 /* Keep going past elements distinctly greater than HIGH. */
4693 if (tree_int_cst_lt (high, p->low))
4696 /* or distinctly less than LOW. */
4697 else if (tree_int_cst_lt (p->high, low))
4702 /* We have an overlap; this is an error. */
4703 *duplicate = p->code_label;
4708 /* Add this label to the chain, and succeed.
4709 Copy LOW, HIGH so they are on temporary rather than momentary
4710 obstack and will thus survive till the end of the case statement. */
4712 r = (struct case_node *) oballoc (sizeof (struct case_node));
4713 r->low = copy_node (low);
4715 /* If the bounds are equal, turn this into the one-value case. */
4717 if (tree_int_cst_equal (low, high))
4721 r->high = copy_node (high);
4722 case_stack->data.case_stmt.num_ranges++;
4725 r->code_label = label;
4726 expand_label (label);
4736 struct case_node *s;
4742 if (! (b = p->balance))
4743 /* Growth propagation from left side. */
4750 if ((p->left = s = r->right))
4759 if ((r->parent = s))
4767 case_stack->data.case_stmt.case_list = r;
4770 /* r->balance == +1 */
4775 struct case_node *t = r->right;
4777 if ((p->left = s = t->right))
4781 if ((r->right = s = t->left))
4795 if ((t->parent = s))
4803 case_stack->data.case_stmt.case_list = t;
4810 /* p->balance == +1; growth of left side balances the node. */
4820 if (! (b = p->balance))
4821 /* Growth propagation from right side. */
4829 if ((p->right = s = r->left))
4837 if ((r->parent = s))
4846 case_stack->data.case_stmt.case_list = r;
4850 /* r->balance == -1 */
4854 struct case_node *t = r->left;
4856 if ((p->right = s = t->left))
4861 if ((r->left = s = t->right))
4875 if ((t->parent = s))
4884 case_stack->data.case_stmt.case_list = t;
4890 /* p->balance == -1; growth of right side balances the node. */
4904 /* Returns the number of possible values of TYPE.
4905 Returns -1 if the number is unknown or variable.
4906 Returns -2 if the number does not fit in a HOST_WIDE_INT.
4907 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4908 do not increase monotonically (there may be duplicates);
4909 to 1 if the values increase monotonically, but not always by 1;
4910 otherwise sets it to 0. */
4913 all_cases_count (type, spareness)
4917 HOST_WIDE_INT count;
4920 switch (TREE_CODE (type))
4927 count = 1 << BITS_PER_UNIT;
4931 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4932 || TYPE_MAX_VALUE (type) == NULL
4933 || TREE_CODE (TYPE_MAX_VALUE (type)) != INTEGER_CST)
4938 = TREE_INT_CST_LOW (TYPE_MAX_VALUE (type))
4939 - TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + 1
4940 but with overflow checking. */
4941 tree mint = TYPE_MIN_VALUE (type);
4942 tree maxt = TYPE_MAX_VALUE (type);
4943 HOST_WIDE_INT lo, hi;
4944 neg_double(TREE_INT_CST_LOW (mint), TREE_INT_CST_HIGH (mint),
4946 add_double(TREE_INT_CST_LOW (maxt), TREE_INT_CST_HIGH (maxt),
4948 add_double (lo, hi, 1, 0, &lo, &hi);
4949 if (hi != 0 || lo < 0)
4956 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4958 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4959 || TREE_CODE (TREE_VALUE (t)) != INTEGER_CST
4960 || TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + count
4961 != TREE_INT_CST_LOW (TREE_VALUE (t)))
4965 if (*spareness == 1)
4967 tree prev = TREE_VALUE (TYPE_VALUES (type));
4968 for (t = TYPE_VALUES (type); t = TREE_CHAIN (t), t != NULL_TREE; )
4970 if (! tree_int_cst_lt (prev, TREE_VALUE (t)))
4975 prev = TREE_VALUE (t);
4984 #define BITARRAY_TEST(ARRAY, INDEX) \
4985 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4986 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4987 #define BITARRAY_SET(ARRAY, INDEX) \
4988 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4989 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4991 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4992 with the case values we have seen, assuming the case expression
4994 SPARSENESS is as determined by all_cases_count.
4996 The time needed is proportional to COUNT, unless
4997 SPARSENESS is 2, in which case quadratic time is needed. */
5000 mark_seen_cases (type, cases_seen, count, sparseness)
5002 unsigned char *cases_seen;
5006 tree next_node_to_try = NULL_TREE;
5007 long next_node_offset = 0;
5009 register struct case_node *n, *root = case_stack->data.case_stmt.case_list;
5010 tree val = make_node (INTEGER_CST);
5011 TREE_TYPE (val) = type;
5014 else if (sparseness == 2)
5019 /* This less efficient loop is only needed to handle
5020 duplicate case values (multiple enum constants
5021 with the same value). */
5022 TREE_TYPE (val) = TREE_TYPE (root->low);
5023 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
5024 t = TREE_CHAIN (t), xlo++)
5026 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (TREE_VALUE (t));
5027 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (TREE_VALUE (t));
5031 /* Keep going past elements distinctly greater than VAL. */
5032 if (tree_int_cst_lt (val, n->low))
5035 /* or distinctly less than VAL. */
5036 else if (tree_int_cst_lt (n->high, val))
5041 /* We have found a matching range. */
5042 BITARRAY_SET (cases_seen, xlo);
5052 case_stack->data.case_stmt.case_list = root = case_tree2list (root, 0);
5053 for (n = root; n; n = n->right)
5055 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
5056 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
5057 while ( ! tree_int_cst_lt (n->high, val))
5059 /* Calculate (into xlo) the "offset" of the integer (val).
5060 The element with lowest value has offset 0, the next smallest
5061 element has offset 1, etc. */
5063 HOST_WIDE_INT xlo, xhi;
5065 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
5067 /* The TYPE_VALUES will be in increasing order, so
5068 starting searching where we last ended. */
5069 t = next_node_to_try;
5070 xlo = next_node_offset;
5076 t = TYPE_VALUES (type);
5079 if (tree_int_cst_equal (val, TREE_VALUE (t)))
5081 next_node_to_try = TREE_CHAIN (t);
5082 next_node_offset = xlo + 1;
5087 if (t == next_node_to_try)
5096 t = TYPE_MIN_VALUE (type);
5098 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
5102 add_double (xlo, xhi,
5103 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5107 if (xhi == 0 && xlo >= 0 && xlo < count)
5108 BITARRAY_SET (cases_seen, xlo);
5109 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5111 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
5117 /* Called when the index of a switch statement is an enumerated type
5118 and there is no default label.
5120 Checks that all enumeration literals are covered by the case
5121 expressions of a switch. Also, warn if there are any extra
5122 switch cases that are *not* elements of the enumerated type.
5124 If all enumeration literals were covered by the case expressions,
5125 turn one of the expressions into the default expression since it should
5126 not be possible to fall through such a switch. */
5129 check_for_full_enumeration_handling (type)
5132 register struct case_node *n;
5133 register tree chain;
5134 #if 0 /* variable used by 'if 0'ed code below. */
5135 register struct case_node **l;
5139 /* True iff the selector type is a numbered set mode. */
5142 /* The number of possible selector values. */
5145 /* For each possible selector value. a one iff it has been matched
5146 by a case value alternative. */
5147 unsigned char *cases_seen;
5149 /* The allocated size of cases_seen, in chars. */
5155 size = all_cases_count (type, &sparseness);
5156 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
5158 if (size > 0 && size < 600000
5159 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5160 this optimization if we don't have enough memory rather than
5161 aborting, as xmalloc would do. */
5162 && (cases_seen = (unsigned char *) calloc (bytes_needed, 1)) != NULL)
5165 tree v = TYPE_VALUES (type);
5167 /* The time complexity of this code is normally O(N), where
5168 N being the number of members in the enumerated type.
5169 However, if type is a ENUMERAL_TYPE whose values do not
5170 increase monotonically, O(N*log(N)) time may be needed. */
5172 mark_seen_cases (type, cases_seen, size, sparseness);
5174 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
5176 if (BITARRAY_TEST(cases_seen, i) == 0)
5177 warning ("enumeration value `%s' not handled in switch",
5178 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
5184 /* Now we go the other way around; we warn if there are case
5185 expressions that don't correspond to enumerators. This can
5186 occur since C and C++ don't enforce type-checking of
5187 assignments to enumeration variables. */
5189 if (case_stack->data.case_stmt.case_list
5190 && case_stack->data.case_stmt.case_list->left)
5191 case_stack->data.case_stmt.case_list
5192 = case_tree2list (case_stack->data.case_stmt.case_list, 0);
5194 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
5196 for (chain = TYPE_VALUES (type);
5197 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
5198 chain = TREE_CHAIN (chain))
5203 if (TYPE_NAME (type) == 0)
5204 warning ("case value `%ld' not in enumerated type",
5205 (long) TREE_INT_CST_LOW (n->low));
5207 warning ("case value `%ld' not in enumerated type `%s'",
5208 (long) TREE_INT_CST_LOW (n->low),
5209 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5212 : DECL_NAME (TYPE_NAME (type))));
5214 if (!tree_int_cst_equal (n->low, n->high))
5216 for (chain = TYPE_VALUES (type);
5217 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
5218 chain = TREE_CHAIN (chain))
5223 if (TYPE_NAME (type) == 0)
5224 warning ("case value `%ld' not in enumerated type",
5225 (long) TREE_INT_CST_LOW (n->high));
5227 warning ("case value `%ld' not in enumerated type `%s'",
5228 (long) TREE_INT_CST_LOW (n->high),
5229 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5232 : DECL_NAME (TYPE_NAME (type))));
5238 /* ??? This optimization is disabled because it causes valid programs to
5239 fail. ANSI C does not guarantee that an expression with enum type
5240 will have a value that is the same as one of the enumeration literals. */
5242 /* If all values were found as case labels, make one of them the default
5243 label. Thus, this switch will never fall through. We arbitrarily pick
5244 the last one to make the default since this is likely the most
5245 efficient choice. */
5249 for (l = &case_stack->data.case_stmt.case_list;
5254 case_stack->data.case_stmt.default_label = (*l)->code_label;
5261 /* Terminate a case (Pascal) or switch (C) statement
5262 in which ORIG_INDEX is the expression to be tested.
5263 Generate the code to test it and jump to the right place. */
5266 expand_end_case (orig_index)
5269 tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE, orig_minval;
5270 rtx default_label = 0;
5271 register struct case_node *n;
5279 register struct nesting *thiscase = case_stack;
5280 tree index_expr, index_type;
5283 /* Don't crash due to previous errors. */
5284 if (thiscase == NULL)
5287 table_label = gen_label_rtx ();
5288 index_expr = thiscase->data.case_stmt.index_expr;
5289 index_type = TREE_TYPE (index_expr);
5290 unsignedp = TREE_UNSIGNED (index_type);
5292 do_pending_stack_adjust ();
5294 /* This might get an spurious warning in the presence of a syntax error;
5295 it could be fixed by moving the call to check_seenlabel after the
5296 check for error_mark_node, and copying the code of check_seenlabel that
5297 deals with case_stack->data.case_stmt.line_number_status /
5298 restore_line_number_status in front of the call to end_cleanup_deferral;
5299 However, this might miss some useful warnings in the presence of
5300 non-syntax errors. */
5303 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5304 if (index_type != error_mark_node)
5306 /* If switch expression was an enumerated type, check that all
5307 enumeration literals are covered by the cases.
5308 No sense trying this if there's a default case, however. */
5310 if (!thiscase->data.case_stmt.default_label
5311 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
5312 && TREE_CODE (index_expr) != INTEGER_CST)
5313 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
5315 /* If we don't have a default-label, create one here,
5316 after the body of the switch. */
5317 if (thiscase->data.case_stmt.default_label == 0)
5319 thiscase->data.case_stmt.default_label
5320 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5321 expand_label (thiscase->data.case_stmt.default_label);
5323 default_label = label_rtx (thiscase->data.case_stmt.default_label);
5325 before_case = get_last_insn ();
5327 if (thiscase->data.case_stmt.case_list
5328 && thiscase->data.case_stmt.case_list->left)
5329 thiscase->data.case_stmt.case_list
5330 = case_tree2list(thiscase->data.case_stmt.case_list, 0);
5332 /* Simplify the case-list before we count it. */
5333 group_case_nodes (thiscase->data.case_stmt.case_list);
5335 /* Get upper and lower bounds of case values.
5336 Also convert all the case values to the index expr's data type. */
5339 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5341 /* Check low and high label values are integers. */
5342 if (TREE_CODE (n->low) != INTEGER_CST)
5344 if (TREE_CODE (n->high) != INTEGER_CST)
5347 n->low = convert (index_type, n->low);
5348 n->high = convert (index_type, n->high);
5350 /* Count the elements and track the largest and smallest
5351 of them (treating them as signed even if they are not). */
5359 if (INT_CST_LT (n->low, minval))
5361 if (INT_CST_LT (maxval, n->high))
5364 /* A range counts double, since it requires two compares. */
5365 if (! tree_int_cst_equal (n->low, n->high))
5369 orig_minval = minval;
5371 /* Compute span of values. */
5373 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
5375 end_cleanup_deferral ();
5379 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
5381 emit_jump (default_label);
5384 /* If range of values is much bigger than number of values,
5385 make a sequence of conditional branches instead of a dispatch.
5386 If the switch-index is a constant, do it this way
5387 because we can optimize it. */
5389 #ifndef CASE_VALUES_THRESHOLD
5391 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
5393 /* If machine does not have a case insn that compares the
5394 bounds, this means extra overhead for dispatch tables
5395 which raises the threshold for using them. */
5396 #define CASE_VALUES_THRESHOLD 5
5397 #endif /* HAVE_casesi */
5398 #endif /* CASE_VALUES_THRESHOLD */
5400 else if (TREE_INT_CST_HIGH (range) != 0
5401 || count < (unsigned int) CASE_VALUES_THRESHOLD
5402 || ((unsigned HOST_WIDE_INT) (TREE_INT_CST_LOW (range))
5404 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5407 || TREE_CODE (index_expr) == INTEGER_CST
5408 /* These will reduce to a constant. */
5409 || (TREE_CODE (index_expr) == CALL_EXPR
5410 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
5411 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
5412 && DECL_BUILT_IN_CLASS (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_NORMAL
5413 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
5414 || (TREE_CODE (index_expr) == COMPOUND_EXPR
5415 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
5417 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5419 /* If the index is a short or char that we do not have
5420 an insn to handle comparisons directly, convert it to
5421 a full integer now, rather than letting each comparison
5422 generate the conversion. */
5424 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
5425 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
5426 == CODE_FOR_nothing))
5428 enum machine_mode wider_mode;
5429 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
5430 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
5431 if (cmp_optab->handlers[(int) wider_mode].insn_code
5432 != CODE_FOR_nothing)
5434 index = convert_to_mode (wider_mode, index, unsignedp);
5440 do_pending_stack_adjust ();
5442 index = protect_from_queue (index, 0);
5443 if (GET_CODE (index) == MEM)
5444 index = copy_to_reg (index);
5445 if (GET_CODE (index) == CONST_INT
5446 || TREE_CODE (index_expr) == INTEGER_CST)
5448 /* Make a tree node with the proper constant value
5449 if we don't already have one. */
5450 if (TREE_CODE (index_expr) != INTEGER_CST)
5453 = build_int_2 (INTVAL (index),
5454 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
5455 index_expr = convert (index_type, index_expr);
5458 /* For constant index expressions we need only
5459 issue a unconditional branch to the appropriate
5460 target code. The job of removing any unreachable
5461 code is left to the optimisation phase if the
5462 "-O" option is specified. */
5463 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5464 if (! tree_int_cst_lt (index_expr, n->low)
5465 && ! tree_int_cst_lt (n->high, index_expr))
5469 emit_jump (label_rtx (n->code_label));
5471 emit_jump (default_label);
5475 /* If the index expression is not constant we generate
5476 a binary decision tree to select the appropriate
5477 target code. This is done as follows:
5479 The list of cases is rearranged into a binary tree,
5480 nearly optimal assuming equal probability for each case.
5482 The tree is transformed into RTL, eliminating
5483 redundant test conditions at the same time.
5485 If program flow could reach the end of the
5486 decision tree an unconditional jump to the
5487 default code is emitted. */
5490 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
5491 && estimate_case_costs (thiscase->data.case_stmt.case_list));
5492 balance_case_nodes (&thiscase->data.case_stmt.case_list,
5494 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
5495 default_label, index_type);
5496 emit_jump_if_reachable (default_label);
5505 enum machine_mode index_mode = SImode;
5506 int index_bits = GET_MODE_BITSIZE (index_mode);
5508 enum machine_mode op_mode;
5510 /* Convert the index to SImode. */
5511 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
5512 > GET_MODE_BITSIZE (index_mode))
5514 enum machine_mode omode = TYPE_MODE (index_type);
5515 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
5517 /* We must handle the endpoints in the original mode. */
5518 index_expr = build (MINUS_EXPR, index_type,
5519 index_expr, minval);
5520 minval = integer_zero_node;
5521 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5522 emit_cmp_and_jump_insns (rangertx, index, LTU, NULL_RTX,
5523 omode, 1, 0, default_label);
5524 /* Now we can safely truncate. */
5525 index = convert_to_mode (index_mode, index, 0);
5529 if (TYPE_MODE (index_type) != index_mode)
5531 index_expr = convert (type_for_size (index_bits, 0),
5533 index_type = TREE_TYPE (index_expr);
5536 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5539 index = protect_from_queue (index, 0);
5540 do_pending_stack_adjust ();
5542 op_mode = insn_data[(int)CODE_FOR_casesi].operand[0].mode;
5543 if (! (*insn_data[(int)CODE_FOR_casesi].operand[0].predicate)
5545 index = copy_to_mode_reg (op_mode, index);
5547 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
5549 op_mode = insn_data[(int)CODE_FOR_casesi].operand[1].mode;
5550 if (! (*insn_data[(int)CODE_FOR_casesi].operand[1].predicate)
5552 op1 = copy_to_mode_reg (op_mode, op1);
5554 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
5556 op_mode = insn_data[(int)CODE_FOR_casesi].operand[2].mode;
5557 if (! (*insn_data[(int)CODE_FOR_casesi].operand[2].predicate)
5559 op2 = copy_to_mode_reg (op_mode, op2);
5561 emit_jump_insn (gen_casesi (index, op1, op2,
5562 table_label, default_label));
5566 #ifdef HAVE_tablejump
5567 if (! win && HAVE_tablejump)
5569 index_expr = convert (thiscase->data.case_stmt.nominal_type,
5570 fold (build (MINUS_EXPR, index_type,
5571 index_expr, minval)));
5572 index_type = TREE_TYPE (index_expr);
5573 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5575 index = protect_from_queue (index, 0);
5576 do_pending_stack_adjust ();
5578 do_tablejump (index, TYPE_MODE (index_type),
5579 expand_expr (range, NULL_RTX, VOIDmode, 0),
5580 table_label, default_label);
5587 /* Get table of labels to jump to, in order of case index. */
5589 ncases = TREE_INT_CST_LOW (range) + 1;
5590 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
5591 bzero ((char *) labelvec, ncases * sizeof (rtx));
5593 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5595 register HOST_WIDE_INT i
5596 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
5601 = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
5602 if (i + TREE_INT_CST_LOW (orig_minval)
5603 == TREE_INT_CST_LOW (n->high))
5609 /* Fill in the gaps with the default. */
5610 for (i = 0; i < ncases; i++)
5611 if (labelvec[i] == 0)
5612 labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
5614 /* Output the table */
5615 emit_label (table_label);
5617 if (CASE_VECTOR_PC_RELATIVE || flag_pic)
5618 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
5619 gen_rtx_LABEL_REF (Pmode, table_label),
5620 gen_rtvec_v (ncases, labelvec),
5621 const0_rtx, const0_rtx));
5623 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
5624 gen_rtvec_v (ncases, labelvec)));
5626 /* If the case insn drops through the table,
5627 after the table we must jump to the default-label.
5628 Otherwise record no drop-through after the table. */
5629 #ifdef CASE_DROPS_THROUGH
5630 emit_jump (default_label);
5636 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
5637 reorder_insns (before_case, get_last_insn (),
5638 thiscase->data.case_stmt.start);
5641 end_cleanup_deferral ();
5643 if (thiscase->exit_label)
5644 emit_label (thiscase->exit_label);
5646 POPSTACK (case_stack);
5651 /* Convert the tree NODE into a list linked by the right field, with the left
5652 field zeroed. RIGHT is used for recursion; it is a list to be placed
5653 rightmost in the resulting list. */
5655 static struct case_node *
5656 case_tree2list (node, right)
5657 struct case_node *node, *right;
5659 struct case_node *left;
5662 right = case_tree2list (node->right, right);
5664 node->right = right;
5665 if ((left = node->left))
5668 return case_tree2list (left, node);
5674 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5677 do_jump_if_equal (op1, op2, label, unsignedp)
5678 rtx op1, op2, label;
5681 if (GET_CODE (op1) == CONST_INT
5682 && GET_CODE (op2) == CONST_INT)
5684 if (INTVAL (op1) == INTVAL (op2))
5689 enum machine_mode mode = GET_MODE (op1);
5690 if (mode == VOIDmode)
5691 mode = GET_MODE (op2);
5692 emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX, mode, unsignedp,
5697 /* Not all case values are encountered equally. This function
5698 uses a heuristic to weight case labels, in cases where that
5699 looks like a reasonable thing to do.
5701 Right now, all we try to guess is text, and we establish the
5704 chars above space: 16
5713 If we find any cases in the switch that are not either -1 or in the range
5714 of valid ASCII characters, or are control characters other than those
5715 commonly used with "\", don't treat this switch scanning text.
5717 Return 1 if these nodes are suitable for cost estimation, otherwise
5721 estimate_case_costs (node)
5724 tree min_ascii = build_int_2 (-1, -1);
5725 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5729 /* If we haven't already made the cost table, make it now. Note that the
5730 lower bound of the table is -1, not zero. */
5732 if (cost_table == NULL)
5734 cost_table = cost_table_ + 1;
5736 for (i = 0; i < 128; i++)
5740 else if (ISPUNCT (i))
5742 else if (ISCNTRL (i))
5746 cost_table[' '] = 8;
5747 cost_table['\t'] = 4;
5748 cost_table['\0'] = 4;
5749 cost_table['\n'] = 2;
5750 cost_table['\f'] = 1;
5751 cost_table['\v'] = 1;
5752 cost_table['\b'] = 1;
5755 /* See if all the case expressions look like text. It is text if the
5756 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5757 as signed arithmetic since we don't want to ever access cost_table with a
5758 value less than -1. Also check that none of the constants in a range
5759 are strange control characters. */
5761 for (n = node; n; n = n->right)
5763 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5766 for (i = TREE_INT_CST_LOW (n->low); i <= TREE_INT_CST_LOW (n->high); i++)
5767 if (cost_table[i] < 0)
5771 /* All interesting values are within the range of interesting
5772 ASCII characters. */
5776 /* Scan an ordered list of case nodes
5777 combining those with consecutive values or ranges.
5779 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5782 group_case_nodes (head)
5785 case_node_ptr node = head;
5789 rtx lb = next_real_insn (label_rtx (node->code_label));
5791 case_node_ptr np = node;
5793 /* Try to group the successors of NODE with NODE. */
5794 while (((np = np->right) != 0)
5795 /* Do they jump to the same place? */
5796 && ((lb2 = next_real_insn (label_rtx (np->code_label))) == lb
5797 || (lb != 0 && lb2 != 0
5798 && simplejump_p (lb)
5799 && simplejump_p (lb2)
5800 && rtx_equal_p (SET_SRC (PATTERN (lb)),
5801 SET_SRC (PATTERN (lb2)))))
5802 /* Are their ranges consecutive? */
5803 && tree_int_cst_equal (np->low,
5804 fold (build (PLUS_EXPR,
5805 TREE_TYPE (node->high),
5808 /* An overflow is not consecutive. */
5809 && tree_int_cst_lt (node->high,
5810 fold (build (PLUS_EXPR,
5811 TREE_TYPE (node->high),
5813 integer_one_node))))
5815 node->high = np->high;
5817 /* NP is the first node after NODE which can't be grouped with it.
5818 Delete the nodes in between, and move on to that node. */
5824 /* Take an ordered list of case nodes
5825 and transform them into a near optimal binary tree,
5826 on the assumption that any target code selection value is as
5827 likely as any other.
5829 The transformation is performed by splitting the ordered
5830 list into two equal sections plus a pivot. The parts are
5831 then attached to the pivot as left and right branches. Each
5832 branch is then transformed recursively. */
5835 balance_case_nodes (head, parent)
5836 case_node_ptr *head;
5837 case_node_ptr parent;
5839 register case_node_ptr np;
5847 register case_node_ptr *npp;
5850 /* Count the number of entries on branch. Also count the ranges. */
5854 if (!tree_int_cst_equal (np->low, np->high))
5858 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5862 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5870 /* Split this list if it is long enough for that to help. */
5875 /* Find the place in the list that bisects the list's total cost,
5876 Here I gets half the total cost. */
5881 /* Skip nodes while their cost does not reach that amount. */
5882 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5883 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5884 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5887 npp = &(*npp)->right;
5892 /* Leave this branch lopsided, but optimize left-hand
5893 side and fill in `parent' fields for right-hand side. */
5895 np->parent = parent;
5896 balance_case_nodes (&np->left, np);
5897 for (; np->right; np = np->right)
5898 np->right->parent = np;
5902 /* If there are just three nodes, split at the middle one. */
5904 npp = &(*npp)->right;
5907 /* Find the place in the list that bisects the list's total cost,
5908 where ranges count as 2.
5909 Here I gets half the total cost. */
5910 i = (i + ranges + 1) / 2;
5913 /* Skip nodes while their cost does not reach that amount. */
5914 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5919 npp = &(*npp)->right;
5924 np->parent = parent;
5927 /* Optimize each of the two split parts. */
5928 balance_case_nodes (&np->left, np);
5929 balance_case_nodes (&np->right, np);
5933 /* Else leave this branch as one level,
5934 but fill in `parent' fields. */
5936 np->parent = parent;
5937 for (; np->right; np = np->right)
5938 np->right->parent = np;
5943 /* Search the parent sections of the case node tree
5944 to see if a test for the lower bound of NODE would be redundant.
5945 INDEX_TYPE is the type of the index expression.
5947 The instructions to generate the case decision tree are
5948 output in the same order as nodes are processed so it is
5949 known that if a parent node checks the range of the current
5950 node minus one that the current node is bounded at its lower
5951 span. Thus the test would be redundant. */
5954 node_has_low_bound (node, index_type)
5959 case_node_ptr pnode;
5961 /* If the lower bound of this node is the lowest value in the index type,
5962 we need not test it. */
5964 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5967 /* If this node has a left branch, the value at the left must be less
5968 than that at this node, so it cannot be bounded at the bottom and
5969 we need not bother testing any further. */
5974 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5975 node->low, integer_one_node));
5977 /* If the subtraction above overflowed, we can't verify anything.
5978 Otherwise, look for a parent that tests our value - 1. */
5980 if (! tree_int_cst_lt (low_minus_one, node->low))
5983 for (pnode = node->parent; pnode; pnode = pnode->parent)
5984 if (tree_int_cst_equal (low_minus_one, pnode->high))
5990 /* Search the parent sections of the case node tree
5991 to see if a test for the upper bound of NODE would be redundant.
5992 INDEX_TYPE is the type of the index expression.
5994 The instructions to generate the case decision tree are
5995 output in the same order as nodes are processed so it is
5996 known that if a parent node checks the range of the current
5997 node plus one that the current node is bounded at its upper
5998 span. Thus the test would be redundant. */
6001 node_has_high_bound (node, index_type)
6006 case_node_ptr pnode;
6008 /* If there is no upper bound, obviously no test is needed. */
6010 if (TYPE_MAX_VALUE (index_type) == NULL)
6013 /* If the upper bound of this node is the highest value in the type
6014 of the index expression, we need not test against it. */
6016 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
6019 /* If this node has a right branch, the value at the right must be greater
6020 than that at this node, so it cannot be bounded at the top and
6021 we need not bother testing any further. */
6026 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
6027 node->high, integer_one_node));
6029 /* If the addition above overflowed, we can't verify anything.
6030 Otherwise, look for a parent that tests our value + 1. */
6032 if (! tree_int_cst_lt (node->high, high_plus_one))
6035 for (pnode = node->parent; pnode; pnode = pnode->parent)
6036 if (tree_int_cst_equal (high_plus_one, pnode->low))
6042 /* Search the parent sections of the
6043 case node tree to see if both tests for the upper and lower
6044 bounds of NODE would be redundant. */
6047 node_is_bounded (node, index_type)
6051 return (node_has_low_bound (node, index_type)
6052 && node_has_high_bound (node, index_type));
6055 /* Emit an unconditional jump to LABEL unless it would be dead code. */
6058 emit_jump_if_reachable (label)
6061 if (GET_CODE (get_last_insn ()) != BARRIER)
6065 /* Emit step-by-step code to select a case for the value of INDEX.
6066 The thus generated decision tree follows the form of the
6067 case-node binary tree NODE, whose nodes represent test conditions.
6068 INDEX_TYPE is the type of the index of the switch.
6070 Care is taken to prune redundant tests from the decision tree
6071 by detecting any boundary conditions already checked by
6072 emitted rtx. (See node_has_high_bound, node_has_low_bound
6073 and node_is_bounded, above.)
6075 Where the test conditions can be shown to be redundant we emit
6076 an unconditional jump to the target code. As a further
6077 optimization, the subordinates of a tree node are examined to
6078 check for bounded nodes. In this case conditional and/or
6079 unconditional jumps as a result of the boundary check for the
6080 current node are arranged to target the subordinates associated
6081 code for out of bound conditions on the current node.
6083 We can assume that when control reaches the code generated here,
6084 the index value has already been compared with the parents
6085 of this node, and determined to be on the same side of each parent
6086 as this node is. Thus, if this node tests for the value 51,
6087 and a parent tested for 52, we don't need to consider
6088 the possibility of a value greater than 51. If another parent
6089 tests for the value 50, then this node need not test anything. */
6092 emit_case_nodes (index, node, default_label, index_type)
6098 /* If INDEX has an unsigned type, we must make unsigned branches. */
6099 int unsignedp = TREE_UNSIGNED (index_type);
6100 enum machine_mode mode = GET_MODE (index);
6102 /* See if our parents have already tested everything for us.
6103 If they have, emit an unconditional jump for this node. */
6104 if (node_is_bounded (node, index_type))
6105 emit_jump (label_rtx (node->code_label));
6107 else if (tree_int_cst_equal (node->low, node->high))
6109 /* Node is single valued. First see if the index expression matches
6110 this node and then check our children, if any. */
6112 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
6113 label_rtx (node->code_label), unsignedp);
6115 if (node->right != 0 && node->left != 0)
6117 /* This node has children on both sides.
6118 Dispatch to one side or the other
6119 by comparing the index value with this node's value.
6120 If one subtree is bounded, check that one first,
6121 so we can avoid real branches in the tree. */
6123 if (node_is_bounded (node->right, index_type))
6125 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6127 GT, NULL_RTX, mode, unsignedp, 0,
6128 label_rtx (node->right->code_label));
6129 emit_case_nodes (index, node->left, default_label, index_type);
6132 else if (node_is_bounded (node->left, index_type))
6134 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6136 LT, NULL_RTX, mode, unsignedp, 0,
6137 label_rtx (node->left->code_label));
6138 emit_case_nodes (index, node->right, default_label, index_type);
6143 /* Neither node is bounded. First distinguish the two sides;
6144 then emit the code for one side at a time. */
6147 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6149 /* See if the value is on the right. */
6150 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6152 GT, NULL_RTX, mode, unsignedp, 0,
6153 label_rtx (test_label));
6155 /* Value must be on the left.
6156 Handle the left-hand subtree. */
6157 emit_case_nodes (index, node->left, default_label, index_type);
6158 /* If left-hand subtree does nothing,
6160 emit_jump_if_reachable (default_label);
6162 /* Code branches here for the right-hand subtree. */
6163 expand_label (test_label);
6164 emit_case_nodes (index, node->right, default_label, index_type);
6168 else if (node->right != 0 && node->left == 0)
6170 /* Here we have a right child but no left so we issue conditional
6171 branch to default and process the right child.
6173 Omit the conditional branch to default if we it avoid only one
6174 right child; it costs too much space to save so little time. */
6176 if (node->right->right || node->right->left
6177 || !tree_int_cst_equal (node->right->low, node->right->high))
6179 if (!node_has_low_bound (node, index_type))
6181 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6184 LT, NULL_RTX, mode, unsignedp, 0,
6188 emit_case_nodes (index, node->right, default_label, index_type);
6191 /* We cannot process node->right normally
6192 since we haven't ruled out the numbers less than
6193 this node's value. So handle node->right explicitly. */
6194 do_jump_if_equal (index,
6195 expand_expr (node->right->low, NULL_RTX,
6197 label_rtx (node->right->code_label), unsignedp);
6200 else if (node->right == 0 && node->left != 0)
6202 /* Just one subtree, on the left. */
6204 #if 0 /* The following code and comment were formerly part
6205 of the condition here, but they didn't work
6206 and I don't understand what the idea was. -- rms. */
6207 /* If our "most probable entry" is less probable
6208 than the default label, emit a jump to
6209 the default label using condition codes
6210 already lying around. With no right branch,
6211 a branch-greater-than will get us to the default
6214 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
6217 if (node->left->left || node->left->right
6218 || !tree_int_cst_equal (node->left->low, node->left->high))
6220 if (!node_has_high_bound (node, index_type))
6222 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6225 GT, NULL_RTX, mode, unsignedp, 0,
6229 emit_case_nodes (index, node->left, default_label, index_type);
6232 /* We cannot process node->left normally
6233 since we haven't ruled out the numbers less than
6234 this node's value. So handle node->left explicitly. */
6235 do_jump_if_equal (index,
6236 expand_expr (node->left->low, NULL_RTX,
6238 label_rtx (node->left->code_label), unsignedp);
6243 /* Node is a range. These cases are very similar to those for a single
6244 value, except that we do not start by testing whether this node
6245 is the one to branch to. */
6247 if (node->right != 0 && node->left != 0)
6249 /* Node has subtrees on both sides.
6250 If the right-hand subtree is bounded,
6251 test for it first, since we can go straight there.
6252 Otherwise, we need to make a branch in the control structure,
6253 then handle the two subtrees. */
6254 tree test_label = 0;
6257 if (node_is_bounded (node->right, index_type))
6258 /* Right hand node is fully bounded so we can eliminate any
6259 testing and branch directly to the target code. */
6260 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6262 GT, NULL_RTX, mode, unsignedp, 0,
6263 label_rtx (node->right->code_label));
6266 /* Right hand node requires testing.
6267 Branch to a label where we will handle it later. */
6269 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6270 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6272 GT, NULL_RTX, mode, unsignedp, 0,
6273 label_rtx (test_label));
6276 /* Value belongs to this node or to the left-hand subtree. */
6278 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6280 GE, NULL_RTX, mode, unsignedp, 0,
6281 label_rtx (node->code_label));
6283 /* Handle the left-hand subtree. */
6284 emit_case_nodes (index, node->left, default_label, index_type);
6286 /* If right node had to be handled later, do that now. */
6290 /* If the left-hand subtree fell through,
6291 don't let it fall into the right-hand subtree. */
6292 emit_jump_if_reachable (default_label);
6294 expand_label (test_label);
6295 emit_case_nodes (index, node->right, default_label, index_type);
6299 else if (node->right != 0 && node->left == 0)
6301 /* Deal with values to the left of this node,
6302 if they are possible. */
6303 if (!node_has_low_bound (node, index_type))
6305 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6307 LT, NULL_RTX, mode, unsignedp, 0,
6311 /* Value belongs to this node or to the right-hand subtree. */
6313 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6315 LE, NULL_RTX, mode, unsignedp, 0,
6316 label_rtx (node->code_label));
6318 emit_case_nodes (index, node->right, default_label, index_type);
6321 else if (node->right == 0 && node->left != 0)
6323 /* Deal with values to the right of this node,
6324 if they are possible. */
6325 if (!node_has_high_bound (node, index_type))
6327 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6329 GT, NULL_RTX, mode, unsignedp, 0,
6333 /* Value belongs to this node or to the left-hand subtree. */
6335 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6337 GE, NULL_RTX, mode, unsignedp, 0,
6338 label_rtx (node->code_label));
6340 emit_case_nodes (index, node->left, default_label, index_type);
6345 /* Node has no children so we check low and high bounds to remove
6346 redundant tests. Only one of the bounds can exist,
6347 since otherwise this node is bounded--a case tested already. */
6349 if (!node_has_high_bound (node, index_type))
6351 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6353 GT, NULL_RTX, mode, unsignedp, 0,
6357 if (!node_has_low_bound (node, index_type))
6359 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6361 LT, NULL_RTX, mode, unsignedp, 0,
6365 emit_jump (label_rtx (node->code_label));
6370 /* These routines are used by the loop unrolling code. They copy BLOCK trees
6371 so that the debugging info will be correct for the unrolled loop. */
6374 find_loop_tree_blocks ()
6376 identify_blocks (DECL_INITIAL (current_function_decl), get_insns ());
6380 unroll_block_trees ()
6382 tree block = DECL_INITIAL (current_function_decl);
6384 reorder_blocks (block, get_insns ());