1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000 Free Software Foundation, Inc.
5 This file is part of GNU CC.
7 GNU CC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GNU CC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNU CC; see the file COPYING. If not, write to
19 the Free Software Foundation, 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
22 /* This file handles the generation of rtl code from tree structure
23 above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
24 It also creates the rtl expressions for parameters and auto variables
25 and has full responsibility for allocating stack slots.
27 The functions whose names start with `expand_' are called by the
28 parser to generate RTL instructions for various kinds of constructs.
30 Some control and binding constructs require calling several such
31 functions at different times. For example, a simple if-then
32 is expanded by calling `expand_start_cond' (with the condition-expression
33 as argument) before parsing the then-clause and calling `expand_end_cond'
34 after parsing the then-clause. */
45 #include "insn-flags.h"
46 #include "insn-config.h"
47 #include "insn-codes.h"
49 #include "hard-reg-set.h"
58 #define obstack_chunk_alloc xmalloc
59 #define obstack_chunk_free free
60 struct obstack stmt_obstack;
62 /* Assume that case vectors are not pc-relative. */
63 #ifndef CASE_VECTOR_PC_RELATIVE
64 #define CASE_VECTOR_PC_RELATIVE 0
67 /* Functions and data structures for expanding case statements. */
69 /* Case label structure, used to hold info on labels within case
70 statements. We handle "range" labels; for a single-value label
71 as in C, the high and low limits are the same.
73 An AVL tree of case nodes is initially created, and later transformed
74 to a list linked via the RIGHT fields in the nodes. Nodes with
75 higher case values are later in the list.
77 Switch statements can be output in one of two forms. A branch table
78 is used if there are more than a few labels and the labels are dense
79 within the range between the smallest and largest case value. If a
80 branch table is used, no further manipulations are done with the case
83 The alternative to the use of a branch table is to generate a series
84 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
85 and PARENT fields to hold a binary tree. Initially the tree is
86 totally unbalanced, with everything on the right. We balance the tree
87 with nodes on the left having lower case values than the parent
88 and nodes on the right having higher values. We then output the tree
93 struct case_node *left; /* Left son in binary tree */
94 struct case_node *right; /* Right son in binary tree; also node chain */
95 struct case_node *parent; /* Parent of node in binary tree */
96 tree low; /* Lowest index value for this label */
97 tree high; /* Highest index value for this label */
98 tree code_label; /* Label to jump to when node matches */
102 typedef struct case_node case_node;
103 typedef struct case_node *case_node_ptr;
105 /* These are used by estimate_case_costs and balance_case_nodes. */
107 /* This must be a signed type, and non-ANSI compilers lack signed char. */
108 static short cost_table_[129];
109 static short *cost_table;
110 static int use_cost_table;
112 /* Stack of control and binding constructs we are currently inside.
114 These constructs begin when you call `expand_start_WHATEVER'
115 and end when you call `expand_end_WHATEVER'. This stack records
116 info about how the construct began that tells the end-function
117 what to do. It also may provide information about the construct
118 to alter the behavior of other constructs within the body.
119 For example, they may affect the behavior of C `break' and `continue'.
121 Each construct gets one `struct nesting' object.
122 All of these objects are chained through the `all' field.
123 `nesting_stack' points to the first object (innermost construct).
124 The position of an entry on `nesting_stack' is in its `depth' field.
126 Each type of construct has its own individual stack.
127 For example, loops have `loop_stack'. Each object points to the
128 next object of the same type through the `next' field.
130 Some constructs are visible to `break' exit-statements and others
131 are not. Which constructs are visible depends on the language.
132 Therefore, the data structure allows each construct to be visible
133 or not, according to the args given when the construct is started.
134 The construct is visible if the `exit_label' field is non-null.
135 In that case, the value should be a CODE_LABEL rtx. */
140 struct nesting *next;
145 /* For conds (if-then and if-then-else statements). */
148 /* Label for the end of the if construct.
149 There is none if EXITFLAG was not set
150 and no `else' has been seen yet. */
152 /* Label for the end of this alternative.
153 This may be the end of the if or the next else/elseif. */
159 /* Label at the top of the loop; place to loop back to. */
161 /* Label at the end of the whole construct. */
163 /* Label before a jump that branches to the end of the whole
164 construct. This is where destructors go if any. */
166 /* Label for `continue' statement to jump to;
167 this is in front of the stepper of the loop. */
170 /* For variable binding contours. */
173 /* Sequence number of this binding contour within the function,
174 in order of entry. */
175 int block_start_count;
176 /* Nonzero => value to restore stack to on exit. */
178 /* The NOTE that starts this contour.
179 Used by expand_goto to check whether the destination
180 is within each contour or not. */
182 /* Innermost containing binding contour that has a stack level. */
183 struct nesting *innermost_stack_block;
184 /* List of cleanups to be run on exit from this contour.
185 This is a list of expressions to be evaluated.
186 The TREE_PURPOSE of each link is the ..._DECL node
187 which the cleanup pertains to. */
189 /* List of cleanup-lists of blocks containing this block,
190 as they were at the locus where this block appears.
191 There is an element for each containing block,
192 ordered innermost containing block first.
193 The tail of this list can be 0,
194 if all remaining elements would be empty lists.
195 The element's TREE_VALUE is the cleanup-list of that block,
196 which may be null. */
198 /* Chain of labels defined inside this binding contour.
199 For contours that have stack levels or cleanups. */
200 struct label_chain *label_chain;
201 /* Number of function calls seen, as of start of this block. */
202 int n_function_calls;
203 /* Nonzero if this is associated with a EH region. */
204 int exception_region;
205 /* The saved target_temp_slot_level from our outer block.
206 We may reset target_temp_slot_level to be the level of
207 this block, if that is done, target_temp_slot_level
208 reverts to the saved target_temp_slot_level at the very
210 int block_target_temp_slot_level;
211 /* True if we are currently emitting insns in an area of
212 output code that is controlled by a conditional
213 expression. This is used by the cleanup handling code to
214 generate conditional cleanup actions. */
215 int conditional_code;
216 /* A place to move the start of the exception region for any
217 of the conditional cleanups, must be at the end or after
218 the start of the last unconditional cleanup, and before any
219 conditional branch points. */
220 rtx last_unconditional_cleanup;
221 /* When in a conditional context, this is the specific
222 cleanup list associated with last_unconditional_cleanup,
223 where we place the conditionalized cleanups. */
226 /* For switch (C) or case (Pascal) statements,
227 and also for dummies (see `expand_start_case_dummy'). */
230 /* The insn after which the case dispatch should finally
231 be emitted. Zero for a dummy. */
233 /* A list of case labels; it is first built as an AVL tree.
234 During expand_end_case, this is converted to a list, and may be
235 rearranged into a nearly balanced binary tree. */
236 struct case_node *case_list;
237 /* Label to jump to if no case matches. */
239 /* The expression to be dispatched on. */
241 /* Type that INDEX_EXPR should be converted to. */
243 /* Name of this kind of statement, for warnings. */
244 const char *printname;
245 /* Used to save no_line_numbers till we see the first case label.
246 We set this to -1 when we see the first case label in this
248 int line_number_status;
253 /* Allocate and return a new `struct nesting'. */
255 #define ALLOC_NESTING() \
256 (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
258 /* Pop the nesting stack element by element until we pop off
259 the element which is at the top of STACK.
260 Update all the other stacks, popping off elements from them
261 as we pop them from nesting_stack. */
263 #define POPSTACK(STACK) \
264 do { struct nesting *target = STACK; \
265 struct nesting *this; \
266 do { this = nesting_stack; \
267 if (loop_stack == this) \
268 loop_stack = loop_stack->next; \
269 if (cond_stack == this) \
270 cond_stack = cond_stack->next; \
271 if (block_stack == this) \
272 block_stack = block_stack->next; \
273 if (stack_block_stack == this) \
274 stack_block_stack = stack_block_stack->next; \
275 if (case_stack == this) \
276 case_stack = case_stack->next; \
277 nesting_depth = nesting_stack->depth - 1; \
278 nesting_stack = this->all; \
279 obstack_free (&stmt_obstack, this); } \
280 while (this != target); } while (0)
282 /* In some cases it is impossible to generate code for a forward goto
283 until the label definition is seen. This happens when it may be necessary
284 for the goto to reset the stack pointer: we don't yet know how to do that.
285 So expand_goto puts an entry on this fixup list.
286 Each time a binding contour that resets the stack is exited,
288 If the target label has now been defined, we can insert the proper code. */
292 /* Points to following fixup. */
293 struct goto_fixup *next;
294 /* Points to the insn before the jump insn.
295 If more code must be inserted, it goes after this insn. */
297 /* The LABEL_DECL that this jump is jumping to, or 0
298 for break, continue or return. */
300 /* The BLOCK for the place where this goto was found. */
302 /* The CODE_LABEL rtx that this is jumping to. */
304 /* Number of binding contours started in current function
305 before the label reference. */
306 int block_start_count;
307 /* The outermost stack level that should be restored for this jump.
308 Each time a binding contour that resets the stack is exited,
309 if the target label is *not* yet defined, this slot is updated. */
311 /* List of lists of cleanup expressions to be run by this goto.
312 There is one element for each block that this goto is within.
313 The tail of this list can be 0,
314 if all remaining elements would be empty.
315 The TREE_VALUE contains the cleanup list of that block as of the
316 time this goto was seen.
317 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
318 tree cleanup_list_list;
321 /* Within any binding contour that must restore a stack level,
322 all labels are recorded with a chain of these structures. */
326 /* Points to following fixup. */
327 struct label_chain *next;
333 /* Chain of all pending binding contours. */
334 struct nesting *x_block_stack;
336 /* If any new stacks are added here, add them to POPSTACKS too. */
338 /* Chain of all pending binding contours that restore stack levels
340 struct nesting *x_stack_block_stack;
342 /* Chain of all pending conditional statements. */
343 struct nesting *x_cond_stack;
345 /* Chain of all pending loops. */
346 struct nesting *x_loop_stack;
348 /* Chain of all pending case or switch statements. */
349 struct nesting *x_case_stack;
351 /* Separate chain including all of the above,
352 chained through the `all' field. */
353 struct nesting *x_nesting_stack;
355 /* Number of entries on nesting_stack now. */
358 /* Number of binding contours started so far in this function. */
359 int x_block_start_count;
361 /* Each time we expand an expression-statement,
362 record the expr's type and its RTL value here. */
363 tree x_last_expr_type;
364 rtx x_last_expr_value;
366 /* Nonzero if within a ({...}) grouping, in which case we must
367 always compute a value for each expr-stmt in case it is the last one. */
368 int x_expr_stmts_for_value;
370 /* Filename and line number of last line-number note,
371 whether we actually emitted it or not. */
372 const char *x_emit_filename;
375 struct goto_fixup *x_goto_fixup_chain;
378 #define block_stack (cfun->stmt->x_block_stack)
379 #define stack_block_stack (cfun->stmt->x_stack_block_stack)
380 #define cond_stack (cfun->stmt->x_cond_stack)
381 #define loop_stack (cfun->stmt->x_loop_stack)
382 #define case_stack (cfun->stmt->x_case_stack)
383 #define nesting_stack (cfun->stmt->x_nesting_stack)
384 #define nesting_depth (cfun->stmt->x_nesting_depth)
385 #define current_block_start_count (cfun->stmt->x_block_start_count)
386 #define last_expr_type (cfun->stmt->x_last_expr_type)
387 #define last_expr_value (cfun->stmt->x_last_expr_value)
388 #define expr_stmts_for_value (cfun->stmt->x_expr_stmts_for_value)
389 #define emit_filename (cfun->stmt->x_emit_filename)
390 #define emit_lineno (cfun->stmt->x_emit_lineno)
391 #define goto_fixup_chain (cfun->stmt->x_goto_fixup_chain)
393 /* Non-zero if we are using EH to handle cleanus. */
394 static int using_eh_for_cleanups_p = 0;
396 /* Character strings, each containing a single decimal digit. */
397 static char *digit_strings[10];
399 static int n_occurrences PARAMS ((int, const char *));
400 static void expand_goto_internal PARAMS ((tree, rtx, rtx));
401 static int expand_fixup PARAMS ((tree, rtx, rtx));
402 static rtx expand_nl_handler_label PARAMS ((rtx, rtx));
403 static void expand_nl_goto_receiver PARAMS ((void));
404 static void expand_nl_goto_receivers PARAMS ((struct nesting *));
405 static void fixup_gotos PARAMS ((struct nesting *, rtx, tree,
407 static void expand_null_return_1 PARAMS ((rtx, int));
408 static void expand_value_return PARAMS ((rtx));
409 static int tail_recursion_args PARAMS ((tree, tree));
410 static void expand_cleanups PARAMS ((tree, tree, int, int));
411 static void check_seenlabel PARAMS ((void));
412 static void do_jump_if_equal PARAMS ((rtx, rtx, rtx, int));
413 static int estimate_case_costs PARAMS ((case_node_ptr));
414 static void group_case_nodes PARAMS ((case_node_ptr));
415 static void balance_case_nodes PARAMS ((case_node_ptr *,
417 static int node_has_low_bound PARAMS ((case_node_ptr, tree));
418 static int node_has_high_bound PARAMS ((case_node_ptr, tree));
419 static int node_is_bounded PARAMS ((case_node_ptr, tree));
420 static void emit_jump_if_reachable PARAMS ((rtx));
421 static void emit_case_nodes PARAMS ((rtx, case_node_ptr, rtx, tree));
422 static struct case_node *case_tree2list PARAMS ((case_node *, case_node *));
423 static void mark_cond_nesting PARAMS ((struct nesting *));
424 static void mark_loop_nesting PARAMS ((struct nesting *));
425 static void mark_block_nesting PARAMS ((struct nesting *));
426 static void mark_case_nesting PARAMS ((struct nesting *));
427 static void mark_case_node PARAMS ((struct case_node *));
428 static void mark_goto_fixup PARAMS ((struct goto_fixup *));
432 using_eh_for_cleanups ()
434 using_eh_for_cleanups_p = 1;
437 /* Mark N (known to be a cond-nesting) for GC. */
440 mark_cond_nesting (n)
445 ggc_mark_rtx (n->exit_label);
446 ggc_mark_rtx (n->data.cond.endif_label);
447 ggc_mark_rtx (n->data.cond.next_label);
453 /* Mark N (known to be a loop-nesting) for GC. */
456 mark_loop_nesting (n)
462 ggc_mark_rtx (n->exit_label);
463 ggc_mark_rtx (n->data.loop.start_label);
464 ggc_mark_rtx (n->data.loop.end_label);
465 ggc_mark_rtx (n->data.loop.alt_end_label);
466 ggc_mark_rtx (n->data.loop.continue_label);
472 /* Mark N (known to be a block-nesting) for GC. */
475 mark_block_nesting (n)
480 struct label_chain *l;
482 ggc_mark_rtx (n->exit_label);
483 ggc_mark_rtx (n->data.block.stack_level);
484 ggc_mark_rtx (n->data.block.first_insn);
485 ggc_mark_tree (n->data.block.cleanups);
486 ggc_mark_tree (n->data.block.outer_cleanups);
488 for (l = n->data.block.label_chain; l != NULL; l = l->next)
489 ggc_mark_tree (l->label);
491 ggc_mark_rtx (n->data.block.last_unconditional_cleanup);
493 /* ??? cleanup_ptr never points outside the stack, does it? */
499 /* Mark N (known to be a case-nesting) for GC. */
502 mark_case_nesting (n)
507 ggc_mark_rtx (n->exit_label);
508 ggc_mark_rtx (n->data.case_stmt.start);
510 ggc_mark_tree (n->data.case_stmt.default_label);
511 ggc_mark_tree (n->data.case_stmt.index_expr);
512 ggc_mark_tree (n->data.case_stmt.nominal_type);
514 mark_case_node (n->data.case_stmt.case_list);
527 ggc_mark_tree (c->low);
528 ggc_mark_tree (c->high);
529 ggc_mark_tree (c->code_label);
531 mark_case_node (c->right);
532 mark_case_node (c->left);
540 struct goto_fixup *g;
545 ggc_mark_rtx (g->before_jump);
546 ggc_mark_tree (g->target);
547 ggc_mark_tree (g->context);
548 ggc_mark_rtx (g->target_rtl);
549 ggc_mark_rtx (g->stack_level);
550 ggc_mark_tree (g->cleanup_list_list);
556 /* Clear out all parts of the state in F that can safely be discarded
557 after the function has been compiled, to let garbage collection
558 reclaim the memory. */
564 /* We're about to free the function obstack. If we hold pointers to
565 things allocated there, then we'll try to mark them when we do
566 GC. So, we clear them out here explicitly. */
576 struct stmt_status *p;
581 mark_block_nesting (p->x_block_stack);
582 mark_cond_nesting (p->x_cond_stack);
583 mark_loop_nesting (p->x_loop_stack);
584 mark_case_nesting (p->x_case_stack);
586 ggc_mark_tree (p->x_last_expr_type);
587 /* last_epxr_value is only valid if last_expr_type is nonzero. */
588 if (p->x_last_expr_type)
589 ggc_mark_rtx (p->x_last_expr_value);
591 mark_goto_fixup (p->x_goto_fixup_chain);
599 gcc_obstack_init (&stmt_obstack);
601 for (i = 0; i < 10; i++)
603 digit_strings[i] = ggc_alloc_string (NULL, 1);
604 digit_strings[i][0] = '0' + i;
606 ggc_add_string_root (digit_strings, 10);
610 init_stmt_for_function ()
612 cfun->stmt = (struct stmt_status *) xmalloc (sizeof (struct stmt_status));
614 /* We are not currently within any block, conditional, loop or case. */
616 stack_block_stack = 0;
623 current_block_start_count = 0;
625 /* No gotos have been expanded yet. */
626 goto_fixup_chain = 0;
628 /* We are not processing a ({...}) grouping. */
629 expr_stmts_for_value = 0;
631 last_expr_value = NULL_RTX;
634 /* Return nonzero if anything is pushed on the loop, condition, or case
639 return cond_stack || loop_stack || case_stack;
642 /* Record the current file and line. Called from emit_line_note. */
644 set_file_and_line_for_stmt (file, line)
648 /* If we're outputting an inline function, and we add a line note,
649 there may be no CFUN->STMT information. So, there's no need to
653 emit_filename = file;
658 /* Emit a no-op instruction. */
665 last_insn = get_last_insn ();
667 && (GET_CODE (last_insn) == CODE_LABEL
668 || (GET_CODE (last_insn) == NOTE
669 && prev_real_insn (last_insn) == 0)))
670 emit_insn (gen_nop ());
673 /* Return the rtx-label that corresponds to a LABEL_DECL,
674 creating it if necessary. */
680 if (TREE_CODE (label) != LABEL_DECL)
683 if (DECL_RTL (label))
684 return DECL_RTL (label);
686 return DECL_RTL (label) = gen_label_rtx ();
689 /* Add an unconditional jump to LABEL as the next sequential instruction. */
695 do_pending_stack_adjust ();
696 emit_jump_insn (gen_jump (label));
700 /* Emit code to jump to the address
701 specified by the pointer expression EXP. */
704 expand_computed_goto (exp)
707 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
709 #ifdef POINTERS_EXTEND_UNSIGNED
710 x = convert_memory_address (Pmode, x);
714 /* Be sure the function is executable. */
715 if (current_function_check_memory_usage)
716 emit_library_call (chkr_check_exec_libfunc, 1,
717 VOIDmode, 1, x, ptr_mode);
719 do_pending_stack_adjust ();
720 emit_indirect_jump (x);
722 current_function_has_computed_jump = 1;
725 /* Handle goto statements and the labels that they can go to. */
727 /* Specify the location in the RTL code of a label LABEL,
728 which is a LABEL_DECL tree node.
730 This is used for the kind of label that the user can jump to with a
731 goto statement, and for alternatives of a switch or case statement.
732 RTL labels generated for loops and conditionals don't go through here;
733 they are generated directly at the RTL level, by other functions below.
735 Note that this has nothing to do with defining label *names*.
736 Languages vary in how they do that and what that even means. */
742 struct label_chain *p;
744 do_pending_stack_adjust ();
745 emit_label (label_rtx (label));
746 if (DECL_NAME (label))
747 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
749 if (stack_block_stack != 0)
751 p = (struct label_chain *) oballoc (sizeof (struct label_chain));
752 p->next = stack_block_stack->data.block.label_chain;
753 stack_block_stack->data.block.label_chain = p;
758 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
759 from nested functions. */
762 declare_nonlocal_label (label)
765 rtx slot = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
767 nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
768 LABEL_PRESERVE_P (label_rtx (label)) = 1;
769 if (nonlocal_goto_handler_slots == 0)
771 emit_stack_save (SAVE_NONLOCAL,
772 &nonlocal_goto_stack_level,
773 PREV_INSN (tail_recursion_reentry));
775 nonlocal_goto_handler_slots
776 = gen_rtx_EXPR_LIST (VOIDmode, slot, nonlocal_goto_handler_slots);
779 /* Generate RTL code for a `goto' statement with target label LABEL.
780 LABEL should be a LABEL_DECL tree node that was or will later be
781 defined with `expand_label'. */
789 /* Check for a nonlocal goto to a containing function. */
790 context = decl_function_context (label);
791 if (context != 0 && context != current_function_decl)
793 struct function *p = find_function_data (context);
794 rtx label_ref = gen_rtx_LABEL_REF (Pmode, label_rtx (label));
795 rtx handler_slot, static_chain, save_area;
798 /* Find the corresponding handler slot for this label. */
799 handler_slot = p->x_nonlocal_goto_handler_slots;
800 for (link = p->x_nonlocal_labels; TREE_VALUE (link) != label;
801 link = TREE_CHAIN (link))
802 handler_slot = XEXP (handler_slot, 1);
803 handler_slot = XEXP (handler_slot, 0);
805 p->has_nonlocal_label = 1;
806 current_function_has_nonlocal_goto = 1;
807 LABEL_REF_NONLOCAL_P (label_ref) = 1;
809 /* Copy the rtl for the slots so that they won't be shared in
810 case the virtual stack vars register gets instantiated differently
811 in the parent than in the child. */
813 static_chain = copy_to_reg (lookup_static_chain (label));
815 /* Get addr of containing function's current nonlocal goto handler,
816 which will do any cleanups and then jump to the label. */
817 handler_slot = copy_to_reg (replace_rtx (copy_rtx (handler_slot),
818 virtual_stack_vars_rtx,
821 /* Get addr of containing function's nonlocal save area. */
822 save_area = p->x_nonlocal_goto_stack_level;
824 save_area = replace_rtx (copy_rtx (save_area),
825 virtual_stack_vars_rtx, static_chain);
827 #if HAVE_nonlocal_goto
828 if (HAVE_nonlocal_goto)
829 emit_insn (gen_nonlocal_goto (static_chain, handler_slot,
830 save_area, label_ref));
834 /* Restore frame pointer for containing function.
835 This sets the actual hard register used for the frame pointer
836 to the location of the function's incoming static chain info.
837 The non-local goto handler will then adjust it to contain the
838 proper value and reload the argument pointer, if needed. */
839 emit_move_insn (hard_frame_pointer_rtx, static_chain);
840 emit_stack_restore (SAVE_NONLOCAL, save_area, NULL_RTX);
842 /* USE of hard_frame_pointer_rtx added for consistency;
843 not clear if really needed. */
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 (handler_slot);
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 ();
901 /* Don't do this adjust if it's to the end label and this function
902 is to return with a depressed stack pointer. */
903 if (label == return_label
904 && (((TREE_CODE (TREE_TYPE (current_function_decl))
906 && (TYPE_RETURNS_STACK_DEPRESSED
907 (TREE_TYPE (current_function_decl))))))
910 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
913 if (body != 0 && DECL_TOO_LATE (body))
914 error ("jump to `%s' invalidly jumps into binding contour",
915 IDENTIFIER_POINTER (DECL_NAME (body)));
917 /* Label not yet defined: may need to put this goto
918 on the fixup list. */
919 else if (! expand_fixup (body, label, last_insn))
921 /* No fixup needed. Record that the label is the target
922 of at least one goto that has no fixup. */
924 TREE_ADDRESSABLE (body) = 1;
930 /* Generate if necessary a fixup for a goto
931 whose target label in tree structure (if any) is TREE_LABEL
932 and whose target in rtl is RTL_LABEL.
934 If LAST_INSN is nonzero, we pretend that the jump appears
935 after insn LAST_INSN instead of at the current point in the insn stream.
937 The fixup will be used later to insert insns just before the goto.
938 Those insns will restore the stack level as appropriate for the
939 target label, and will (in the case of C++) also invoke any object
940 destructors which have to be invoked when we exit the scopes which
941 are exited by the goto.
943 Value is nonzero if a fixup is made. */
946 expand_fixup (tree_label, rtl_label, last_insn)
951 struct nesting *block, *end_block;
953 /* See if we can recognize which block the label will be output in.
954 This is possible in some very common cases.
955 If we succeed, set END_BLOCK to that block.
956 Otherwise, set it to 0. */
959 && (rtl_label == cond_stack->data.cond.endif_label
960 || rtl_label == cond_stack->data.cond.next_label))
961 end_block = cond_stack;
962 /* If we are in a loop, recognize certain labels which
963 are likely targets. This reduces the number of fixups
964 we need to create. */
966 && (rtl_label == loop_stack->data.loop.start_label
967 || rtl_label == loop_stack->data.loop.end_label
968 || rtl_label == loop_stack->data.loop.continue_label))
969 end_block = loop_stack;
973 /* Now set END_BLOCK to the binding level to which we will return. */
977 struct nesting *next_block = end_block->all;
980 /* First see if the END_BLOCK is inside the innermost binding level.
981 If so, then no cleanups or stack levels are relevant. */
982 while (next_block && next_block != block)
983 next_block = next_block->all;
988 /* Otherwise, set END_BLOCK to the innermost binding level
989 which is outside the relevant control-structure nesting. */
990 next_block = block_stack->next;
991 for (block = block_stack; block != end_block; block = block->all)
992 if (block == next_block)
993 next_block = next_block->next;
994 end_block = next_block;
997 /* Does any containing block have a stack level or cleanups?
998 If not, no fixup is needed, and that is the normal case
999 (the only case, for standard C). */
1000 for (block = block_stack; block != end_block; block = block->next)
1001 if (block->data.block.stack_level != 0
1002 || block->data.block.cleanups != 0)
1005 if (block != end_block)
1007 /* Ok, a fixup is needed. Add a fixup to the list of such. */
1008 struct goto_fixup *fixup
1009 = (struct goto_fixup *) ggc_alloc (sizeof (struct goto_fixup));
1010 /* In case an old stack level is restored, make sure that comes
1011 after any pending stack adjust. */
1012 /* ?? If the fixup isn't to come at the present position,
1013 doing the stack adjust here isn't useful. Doing it with our
1014 settings at that location isn't useful either. Let's hope
1017 do_pending_stack_adjust ();
1018 fixup->target = tree_label;
1019 fixup->target_rtl = rtl_label;
1021 /* Create a BLOCK node and a corresponding matched set of
1022 NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes at
1023 this point. The notes will encapsulate any and all fixup
1024 code which we might later insert at this point in the insn
1025 stream. Also, the BLOCK node will be the parent (i.e. the
1026 `SUPERBLOCK') of any other BLOCK nodes which we might create
1027 later on when we are expanding the fixup code.
1029 Note that optimization passes (including expand_end_loop)
1030 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
1031 as a placeholder. */
1034 register rtx original_before_jump
1035 = last_insn ? last_insn : get_last_insn ();
1040 block = make_node (BLOCK);
1041 TREE_USED (block) = 1;
1043 if (!cfun->x_whole_function_mode_p)
1044 insert_block (block);
1048 = BLOCK_CHAIN (DECL_INITIAL (current_function_decl));
1049 BLOCK_CHAIN (DECL_INITIAL (current_function_decl))
1054 start = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
1055 if (cfun->x_whole_function_mode_p)
1056 NOTE_BLOCK (start) = block;
1057 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_DELETED);
1058 end = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
1059 if (cfun->x_whole_function_mode_p)
1060 NOTE_BLOCK (end) = block;
1061 fixup->context = block;
1063 emit_insns_after (start, original_before_jump);
1066 fixup->block_start_count = current_block_start_count;
1067 fixup->stack_level = 0;
1068 fixup->cleanup_list_list
1069 = ((block->data.block.outer_cleanups
1070 || block->data.block.cleanups)
1071 ? tree_cons (NULL_TREE, block->data.block.cleanups,
1072 block->data.block.outer_cleanups)
1074 fixup->next = goto_fixup_chain;
1075 goto_fixup_chain = fixup;
1081 /* Expand any needed fixups in the outputmost binding level of the
1082 function. FIRST_INSN is the first insn in the function. */
1085 expand_fixups (first_insn)
1088 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0);
1091 /* When exiting a binding contour, process all pending gotos requiring fixups.
1092 THISBLOCK is the structure that describes the block being exited.
1093 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1094 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1095 FIRST_INSN is the insn that began this contour.
1097 Gotos that jump out of this contour must restore the
1098 stack level and do the cleanups before actually jumping.
1100 DONT_JUMP_IN nonzero means report error there is a jump into this
1101 contour from before the beginning of the contour.
1102 This is also done if STACK_LEVEL is nonzero. */
1105 fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1106 struct nesting *thisblock;
1112 register struct goto_fixup *f, *prev;
1114 /* F is the fixup we are considering; PREV is the previous one. */
1115 /* We run this loop in two passes so that cleanups of exited blocks
1116 are run first, and blocks that are exited are marked so
1119 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1121 /* Test for a fixup that is inactive because it is already handled. */
1122 if (f->before_jump == 0)
1124 /* Delete inactive fixup from the chain, if that is easy to do. */
1126 prev->next = f->next;
1128 /* Has this fixup's target label been defined?
1129 If so, we can finalize it. */
1130 else if (PREV_INSN (f->target_rtl) != 0)
1132 register rtx cleanup_insns;
1134 /* If this fixup jumped into this contour from before the beginning
1135 of this contour, report an error. This code used to use
1136 the first non-label insn after f->target_rtl, but that's
1137 wrong since such can be added, by things like put_var_into_stack
1138 and have INSN_UIDs that are out of the range of the block. */
1139 /* ??? Bug: this does not detect jumping in through intermediate
1140 blocks that have stack levels or cleanups.
1141 It detects only a problem with the innermost block
1142 around the label. */
1144 && (dont_jump_in || stack_level || cleanup_list)
1145 && INSN_UID (first_insn) < INSN_UID (f->target_rtl)
1146 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1147 && ! DECL_ERROR_ISSUED (f->target))
1149 error_with_decl (f->target,
1150 "label `%s' used before containing binding contour");
1151 /* Prevent multiple errors for one label. */
1152 DECL_ERROR_ISSUED (f->target) = 1;
1155 /* We will expand the cleanups into a sequence of their own and
1156 then later on we will attach this new sequence to the insn
1157 stream just ahead of the actual jump insn. */
1161 /* Temporarily restore the lexical context where we will
1162 logically be inserting the fixup code. We do this for the
1163 sake of getting the debugging information right. */
1166 set_block (f->context);
1168 /* Expand the cleanups for blocks this jump exits. */
1169 if (f->cleanup_list_list)
1172 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1173 /* Marked elements correspond to blocks that have been closed.
1174 Do their cleanups. */
1175 if (TREE_ADDRESSABLE (lists)
1176 && TREE_VALUE (lists) != 0)
1178 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1179 /* Pop any pushes done in the cleanups,
1180 in case function is about to return. */
1181 do_pending_stack_adjust ();
1185 /* Restore stack level for the biggest contour that this
1186 jump jumps out of. */
1188 && ! (f->target_rtl == return_label
1189 && ((TREE_CODE (TREE_TYPE (current_function_decl))
1191 && (TYPE_RETURNS_STACK_DEPRESSED
1192 (TREE_TYPE (current_function_decl))))))
1193 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1195 /* Finish up the sequence containing the insns which implement the
1196 necessary cleanups, and then attach that whole sequence to the
1197 insn stream just ahead of the actual jump insn. Attaching it
1198 at that point insures that any cleanups which are in fact
1199 implicit C++ object destructions (which must be executed upon
1200 leaving the block) appear (to the debugger) to be taking place
1201 in an area of the generated code where the object(s) being
1202 destructed are still "in scope". */
1204 cleanup_insns = get_insns ();
1208 emit_insns_after (cleanup_insns, f->before_jump);
1214 /* For any still-undefined labels, do the cleanups for this block now.
1215 We must do this now since items in the cleanup list may go out
1216 of scope when the block ends. */
1217 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1218 if (f->before_jump != 0
1219 && PREV_INSN (f->target_rtl) == 0
1220 /* Label has still not appeared. If we are exiting a block with
1221 a stack level to restore, that started before the fixup,
1222 mark this stack level as needing restoration
1223 when the fixup is later finalized. */
1225 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1226 means the label is undefined. That's erroneous, but possible. */
1227 && (thisblock->data.block.block_start_count
1228 <= f->block_start_count))
1230 tree lists = f->cleanup_list_list;
1233 for (; lists; lists = TREE_CHAIN (lists))
1234 /* If the following elt. corresponds to our containing block
1235 then the elt. must be for this block. */
1236 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
1240 set_block (f->context);
1241 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1242 do_pending_stack_adjust ();
1243 cleanup_insns = get_insns ();
1246 if (cleanup_insns != 0)
1248 = emit_insns_after (cleanup_insns, f->before_jump);
1250 f->cleanup_list_list = TREE_CHAIN (lists);
1254 f->stack_level = stack_level;
1258 /* Return the number of times character C occurs in string S. */
1260 n_occurrences (c, s)
1270 /* Generate RTL for an asm statement (explicit assembler code).
1271 BODY is a STRING_CST node containing the assembler code text,
1272 or an ADDR_EXPR containing a STRING_CST. */
1278 if (current_function_check_memory_usage)
1280 error ("`asm' cannot be used in function where memory usage is checked");
1284 if (TREE_CODE (body) == ADDR_EXPR)
1285 body = TREE_OPERAND (body, 0);
1287 emit_insn (gen_rtx_ASM_INPUT (VOIDmode,
1288 TREE_STRING_POINTER (body)));
1292 /* Generate RTL for an asm statement with arguments.
1293 STRING is the instruction template.
1294 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1295 Each output or input has an expression in the TREE_VALUE and
1296 a constraint-string in the TREE_PURPOSE.
1297 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1298 that is clobbered by this insn.
1300 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1301 Some elements of OUTPUTS may be replaced with trees representing temporary
1302 values. The caller should copy those temporary values to the originally
1305 VOL nonzero means the insn is volatile; don't optimize it. */
1308 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1309 tree string, outputs, inputs, clobbers;
1311 const char *filename;
1314 rtvec argvec, constraints;
1316 int ninputs = list_length (inputs);
1317 int noutputs = list_length (outputs);
1322 /* Vector of RTX's of evaluated output operands. */
1323 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1324 int *inout_opnum = (int *) alloca (noutputs * sizeof (int));
1325 rtx *real_output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1326 enum machine_mode *inout_mode
1327 = (enum machine_mode *) alloca (noutputs * sizeof (enum machine_mode));
1328 /* The insn we have emitted. */
1330 int old_generating_concat_p = generating_concat_p;
1332 /* An ASM with no outputs needs to be treated as volatile, for now. */
1336 if (current_function_check_memory_usage)
1338 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1342 #ifdef MD_ASM_CLOBBERS
1343 /* Sometimes we wish to automatically clobber registers across an asm.
1344 Case in point is when the i386 backend moved from cc0 to a hard reg --
1345 maintaining source-level compatability means automatically clobbering
1346 the flags register. */
1347 MD_ASM_CLOBBERS (clobbers);
1350 if (current_function_check_memory_usage)
1352 error ("`asm' cannot be used in function where memory usage is checked");
1356 /* Count the number of meaningful clobbered registers, ignoring what
1357 we would ignore later. */
1359 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1361 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1363 i = decode_reg_name (regname);
1364 if (i >= 0 || i == -4)
1367 error ("unknown register name `%s' in `asm'", regname);
1372 /* Check that the number of alternatives is constant across all
1374 if (outputs || inputs)
1376 tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
1377 int nalternatives = n_occurrences (',', TREE_STRING_POINTER (tmp));
1380 if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
1382 error ("too many alternatives in `asm'");
1389 const char *constraint = TREE_STRING_POINTER (TREE_PURPOSE (tmp));
1391 if (n_occurrences (',', constraint) != nalternatives)
1393 error ("operand constraints for `asm' differ in number of alternatives");
1397 if (TREE_CHAIN (tmp))
1398 tmp = TREE_CHAIN (tmp);
1400 tmp = next, next = 0;
1404 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1406 tree val = TREE_VALUE (tail);
1407 tree type = TREE_TYPE (val);
1416 /* If there's an erroneous arg, emit no insn. */
1417 if (TREE_TYPE (val) == error_mark_node)
1420 /* Make sure constraint has `=' and does not have `+'. Also, see
1421 if it allows any register. Be liberal on the latter test, since
1422 the worst that happens if we get it wrong is we issue an error
1425 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1426 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1428 /* Allow the `=' or `+' to not be at the beginning of the string,
1429 since it wasn't explicitly documented that way, and there is a
1430 large body of code that puts it last. Swap the character to
1431 the front, so as not to uglify any place else. */
1435 if ((p = strchr (constraint, '=')) != NULL)
1437 if ((p = strchr (constraint, '+')) != NULL)
1440 error ("output operand constraint lacks `='");
1444 if (p != constraint)
1447 bcopy (constraint, constraint+1, p-constraint);
1450 warning ("output constraint `%c' for operand %d is not at the beginning", j, i);
1453 is_inout = constraint[0] == '+';
1454 /* Replace '+' with '='. */
1455 constraint[0] = '=';
1456 /* Make sure we can specify the matching operand. */
1457 if (is_inout && i > 9)
1459 error ("output operand constraint %d contains `+'", i);
1463 for (j = 1; j < c_len; j++)
1464 switch (constraint[j])
1468 error ("operand constraint contains '+' or '=' at illegal position.");
1472 if (i + 1 == ninputs + noutputs)
1474 error ("`%%' constraint used with last operand");
1479 case '?': case '!': case '*': case '&':
1480 case 'E': case 'F': case 'G': case 'H':
1481 case 's': case 'i': case 'n':
1482 case 'I': case 'J': case 'K': case 'L': case 'M':
1483 case 'N': case 'O': case 'P': case ',':
1486 case '0': case '1': case '2': case '3': case '4':
1487 case '5': case '6': case '7': case '8': case '9':
1488 error ("matching constraint not valid in output operand");
1491 case 'V': case 'm': case 'o':
1496 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1497 excepting those that expand_call created. So match memory
1512 if (! ISALPHA (constraint[j]))
1514 error ("invalid punctuation `%c' in constraint",
1518 if (REG_CLASS_FROM_LETTER (constraint[j]) != NO_REGS)
1520 #ifdef EXTRA_CONSTRAINT
1523 /* Otherwise we can't assume anything about the nature of
1524 the constraint except that it isn't purely registers.
1525 Treat it like "g" and hope for the best. */
1533 /* If an output operand is not a decl or indirect ref and our constraint
1534 allows a register, make a temporary to act as an intermediate.
1535 Make the asm insn write into that, then our caller will copy it to
1536 the real output operand. Likewise for promoted variables. */
1538 generating_concat_p = 0;
1540 real_output_rtx[i] = NULL_RTX;
1541 if ((TREE_CODE (val) == INDIRECT_REF
1544 && (allows_mem || GET_CODE (DECL_RTL (val)) == REG)
1545 && ! (GET_CODE (DECL_RTL (val)) == REG
1546 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
1551 mark_addressable (TREE_VALUE (tail));
1554 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode,
1555 EXPAND_MEMORY_USE_WO);
1557 if (! allows_reg && GET_CODE (output_rtx[i]) != MEM)
1558 error ("output number %d not directly addressable", i);
1559 if ((! allows_mem && GET_CODE (output_rtx[i]) == MEM)
1560 || GET_CODE (output_rtx[i]) == CONCAT)
1562 real_output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1563 output_rtx[i] = gen_reg_rtx (GET_MODE (output_rtx[i]));
1565 emit_move_insn (output_rtx[i], real_output_rtx[i]);
1570 output_rtx[i] = assign_temp (type, 0, 0, 1);
1571 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1574 generating_concat_p = old_generating_concat_p;
1578 inout_mode[ninout] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)));
1579 inout_opnum[ninout++] = i;
1584 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1586 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1590 /* Make vectors for the expression-rtx and constraint strings. */
1592 argvec = rtvec_alloc (ninputs);
1593 constraints = rtvec_alloc (ninputs);
1595 body = gen_rtx_ASM_OPERANDS ((noutputs == 0 ? VOIDmode
1596 : GET_MODE (output_rtx[0])),
1597 TREE_STRING_POINTER (string),
1598 empty_string, 0, argvec, constraints,
1601 MEM_VOLATILE_P (body) = vol;
1603 /* Eval the inputs and put them into ARGVEC.
1604 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1607 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1610 int allows_reg = 0, allows_mem = 0;
1611 char *constraint, *orig_constraint;
1615 /* If there's an erroneous arg, emit no insn,
1616 because the ASM_INPUT would get VOIDmode
1617 and that could cause a crash in reload. */
1618 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1621 /* ??? Can this happen, and does the error message make any sense? */
1622 if (TREE_PURPOSE (tail) == NULL_TREE)
1624 error ("hard register `%s' listed as input operand to `asm'",
1625 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1629 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1630 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1631 orig_constraint = constraint;
1633 /* Make sure constraint has neither `=', `+', nor '&'. */
1635 for (j = 0; j < c_len; j++)
1636 switch (constraint[j])
1638 case '+': case '=': case '&':
1639 if (constraint == orig_constraint)
1641 error ("input operand constraint contains `%c'",
1648 if (constraint == orig_constraint
1649 && i + 1 == ninputs - ninout)
1651 error ("`%%' constraint used with last operand");
1656 case 'V': case 'm': case 'o':
1661 case '?': case '!': case '*':
1662 case 'E': case 'F': case 'G': case 'H':
1663 case 's': case 'i': case 'n':
1664 case 'I': case 'J': case 'K': case 'L': case 'M':
1665 case 'N': case 'O': case 'P': case ',':
1668 /* Whether or not a numeric constraint allows a register is
1669 decided by the matching constraint, and so there is no need
1670 to do anything special with them. We must handle them in
1671 the default case, so that we don't unnecessarily force
1672 operands to memory. */
1673 case '0': case '1': case '2': case '3': case '4':
1674 case '5': case '6': case '7': case '8': case '9':
1675 if (constraint[j] >= '0' + noutputs)
1678 ("matching constraint references invalid operand number");
1682 /* Try and find the real constraint for this dup. */
1683 if ((j == 0 && c_len == 1)
1684 || (j == 1 && c_len == 2 && constraint[0] == '%'))
1688 for (j = constraint[j] - '0'; j > 0; --j)
1691 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (o)));
1692 constraint = TREE_STRING_POINTER (TREE_PURPOSE (o));
1709 if (! ISALPHA (constraint[j]))
1711 error ("invalid punctuation `%c' in constraint",
1715 if (REG_CLASS_FROM_LETTER (constraint[j]) != NO_REGS)
1717 #ifdef EXTRA_CONSTRAINT
1720 /* Otherwise we can't assume anything about the nature of
1721 the constraint except that it isn't purely registers.
1722 Treat it like "g" and hope for the best. */
1730 if (! allows_reg && allows_mem)
1731 mark_addressable (TREE_VALUE (tail));
1733 op = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1735 /* Never pass a CONCAT to an ASM. */
1736 generating_concat_p = 0;
1737 if (GET_CODE (op) == CONCAT)
1738 op = force_reg (GET_MODE (op), op);
1740 if (asm_operand_ok (op, constraint) <= 0)
1743 op = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), op);
1744 else if (!allows_mem)
1745 warning ("asm operand %d probably doesn't match constraints", i);
1746 else if (CONSTANT_P (op))
1747 op = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1749 else if (GET_CODE (op) == REG
1750 || GET_CODE (op) == SUBREG
1751 || GET_CODE (op) == CONCAT)
1753 tree type = TREE_TYPE (TREE_VALUE (tail));
1754 rtx memloc = assign_temp (type, 1, 1, 1);
1756 emit_move_insn (memloc, op);
1760 else if (GET_CODE (op) == MEM && MEM_VOLATILE_P (op))
1761 /* We won't recognize volatile memory as available a
1762 memory_operand at this point. Ignore it. */
1764 else if (queued_subexp_p (op))
1767 /* ??? Leave this only until we have experience with what
1768 happens in combine and elsewhere when constraints are
1770 warning ("asm operand %d probably doesn't match constraints", i);
1772 generating_concat_p = old_generating_concat_p;
1773 ASM_OPERANDS_INPUT (body, i) = op;
1775 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, i)
1776 = gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1781 /* Protect all the operands from the queue now that they have all been
1784 generating_concat_p = 0;
1786 for (i = 0; i < ninputs - ninout; i++)
1787 ASM_OPERANDS_INPUT (body, i)
1788 = protect_from_queue (ASM_OPERANDS_INPUT (body, i), 0);
1790 for (i = 0; i < noutputs; i++)
1791 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1793 /* For in-out operands, copy output rtx to input rtx. */
1794 for (i = 0; i < ninout; i++)
1796 int j = inout_opnum[i];
1798 ASM_OPERANDS_INPUT (body, ninputs - ninout + i)
1800 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, ninputs - ninout + i)
1801 = gen_rtx_ASM_INPUT (inout_mode[i], digit_strings[j]);
1804 generating_concat_p = old_generating_concat_p;
1806 /* Now, for each output, construct an rtx
1807 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1808 ARGVEC CONSTRAINTS))
1809 If there is more than one, put them inside a PARALLEL. */
1811 if (noutputs == 1 && nclobbers == 0)
1813 ASM_OPERANDS_OUTPUT_CONSTRAINT (body)
1814 = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1815 insn = emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
1818 else if (noutputs == 0 && nclobbers == 0)
1820 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1821 insn = emit_insn (body);
1832 body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
1834 /* For each output operand, store a SET. */
1835 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1837 XVECEXP (body, 0, i)
1838 = gen_rtx_SET (VOIDmode,
1840 gen_rtx_ASM_OPERANDS
1841 (GET_MODE (output_rtx[i]),
1842 TREE_STRING_POINTER (string),
1843 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1844 i, argvec, constraints,
1847 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1850 /* If there are no outputs (but there are some clobbers)
1851 store the bare ASM_OPERANDS into the PARALLEL. */
1854 XVECEXP (body, 0, i++) = obody;
1856 /* Store (clobber REG) for each clobbered register specified. */
1858 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1860 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1861 int j = decode_reg_name (regname);
1865 if (j == -3) /* `cc', which is not a register */
1868 if (j == -4) /* `memory', don't cache memory across asm */
1870 XVECEXP (body, 0, i++)
1871 = gen_rtx_CLOBBER (VOIDmode,
1874 gen_rtx_SCRATCH (VOIDmode)));
1878 /* Ignore unknown register, error already signaled. */
1882 /* Use QImode since that's guaranteed to clobber just one reg. */
1883 XVECEXP (body, 0, i++)
1884 = gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (QImode, j));
1887 insn = emit_insn (body);
1890 /* For any outputs that needed reloading into registers, spill them
1891 back to where they belong. */
1892 for (i = 0; i < noutputs; ++i)
1893 if (real_output_rtx[i])
1894 emit_move_insn (real_output_rtx[i], output_rtx[i]);
1899 /* Generate RTL to evaluate the expression EXP
1900 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1903 expand_expr_stmt (exp)
1906 /* If -W, warn about statements with no side effects,
1907 except for an explicit cast to void (e.g. for assert()), and
1908 except inside a ({...}) where they may be useful. */
1909 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1911 if (! TREE_SIDE_EFFECTS (exp)
1912 && (extra_warnings || warn_unused_value)
1913 && !(TREE_CODE (exp) == CONVERT_EXPR
1914 && VOID_TYPE_P (TREE_TYPE (exp))))
1915 warning_with_file_and_line (emit_filename, emit_lineno,
1916 "statement with no effect");
1917 else if (warn_unused_value)
1918 warn_if_unused_value (exp);
1921 /* If EXP is of function type and we are expanding statements for
1922 value, convert it to pointer-to-function. */
1923 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1924 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1926 /* The call to `expand_expr' could cause last_expr_type and
1927 last_expr_value to get reset. Therefore, we set last_expr_value
1928 and last_expr_type *after* calling expand_expr. */
1929 last_expr_value = expand_expr (exp,
1930 (expr_stmts_for_value
1931 ? NULL_RTX : const0_rtx),
1933 last_expr_type = TREE_TYPE (exp);
1935 /* If all we do is reference a volatile value in memory,
1936 copy it to a register to be sure it is actually touched. */
1937 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1938 && TREE_THIS_VOLATILE (exp))
1940 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1942 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1943 copy_to_reg (last_expr_value);
1946 rtx lab = gen_label_rtx ();
1948 /* Compare the value with itself to reference it. */
1949 emit_cmp_and_jump_insns (last_expr_value, last_expr_value, EQ,
1950 expand_expr (TYPE_SIZE (last_expr_type),
1951 NULL_RTX, VOIDmode, 0),
1953 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT,
1959 /* If this expression is part of a ({...}) and is in memory, we may have
1960 to preserve temporaries. */
1961 preserve_temp_slots (last_expr_value);
1963 /* Free any temporaries used to evaluate this expression. Any temporary
1964 used as a result of this expression will already have been preserved
1971 /* Warn if EXP contains any computations whose results are not used.
1972 Return 1 if a warning is printed; 0 otherwise. */
1975 warn_if_unused_value (exp)
1978 if (TREE_USED (exp))
1981 switch (TREE_CODE (exp))
1983 case PREINCREMENT_EXPR:
1984 case POSTINCREMENT_EXPR:
1985 case PREDECREMENT_EXPR:
1986 case POSTDECREMENT_EXPR:
1991 case METHOD_CALL_EXPR:
1993 case TRY_CATCH_EXPR:
1994 case WITH_CLEANUP_EXPR:
1996 /* We don't warn about COND_EXPR because it may be a useful
1997 construct if either arm contains a side effect. */
2002 /* For a binding, warn if no side effect within it. */
2003 return warn_if_unused_value (TREE_OPERAND (exp, 1));
2006 return warn_if_unused_value (TREE_OPERAND (exp, 1));
2008 case TRUTH_ORIF_EXPR:
2009 case TRUTH_ANDIF_EXPR:
2010 /* In && or ||, warn if 2nd operand has no side effect. */
2011 return warn_if_unused_value (TREE_OPERAND (exp, 1));
2014 if (TREE_NO_UNUSED_WARNING (exp))
2016 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
2018 /* Let people do `(foo (), 0)' without a warning. */
2019 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
2021 return warn_if_unused_value (TREE_OPERAND (exp, 1));
2025 case NON_LVALUE_EXPR:
2026 /* Don't warn about values cast to void. */
2027 if (VOID_TYPE_P (TREE_TYPE (exp)))
2029 /* Don't warn about conversions not explicit in the user's program. */
2030 if (TREE_NO_UNUSED_WARNING (exp))
2032 /* Assignment to a cast usually results in a cast of a modify.
2033 Don't complain about that. There can be an arbitrary number of
2034 casts before the modify, so we must loop until we find the first
2035 non-cast expression and then test to see if that is a modify. */
2037 tree tem = TREE_OPERAND (exp, 0);
2039 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
2040 tem = TREE_OPERAND (tem, 0);
2042 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
2043 || TREE_CODE (tem) == CALL_EXPR)
2049 /* Don't warn about automatic dereferencing of references, since
2050 the user cannot control it. */
2051 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
2052 return warn_if_unused_value (TREE_OPERAND (exp, 0));
2056 /* Referencing a volatile value is a side effect, so don't warn. */
2058 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
2059 && TREE_THIS_VOLATILE (exp))
2062 /* If this is an expression which has no operands, there is no value
2063 to be unused. There are no such language-independent codes,
2064 but front ends may define such. */
2065 if (TREE_CODE_CLASS (TREE_CODE (exp)) == 'e'
2066 && TREE_CODE_LENGTH (TREE_CODE (exp)) == 0)
2070 warning_with_file_and_line (emit_filename, emit_lineno,
2071 "value computed is not used");
2076 /* Clear out the memory of the last expression evaluated. */
2084 /* Begin a statement which will return a value.
2085 Return the RTL_EXPR for this statement expr.
2086 The caller must save that value and pass it to expand_end_stmt_expr. */
2089 expand_start_stmt_expr ()
2094 /* Make the RTL_EXPR node temporary, not momentary,
2095 so that rtl_expr_chain doesn't become garbage. */
2096 momentary = suspend_momentary ();
2097 t = make_node (RTL_EXPR);
2098 resume_momentary (momentary);
2099 do_pending_stack_adjust ();
2100 start_sequence_for_rtl_expr (t);
2102 expr_stmts_for_value++;
2106 /* Restore the previous state at the end of a statement that returns a value.
2107 Returns a tree node representing the statement's value and the
2108 insns to compute the value.
2110 The nodes of that expression have been freed by now, so we cannot use them.
2111 But we don't want to do that anyway; the expression has already been
2112 evaluated and now we just want to use the value. So generate a RTL_EXPR
2113 with the proper type and RTL value.
2115 If the last substatement was not an expression,
2116 return something with type `void'. */
2119 expand_end_stmt_expr (t)
2124 if (last_expr_type == 0)
2126 last_expr_type = void_type_node;
2127 last_expr_value = const0_rtx;
2129 else if (last_expr_value == 0)
2130 /* There are some cases where this can happen, such as when the
2131 statement is void type. */
2132 last_expr_value = const0_rtx;
2133 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
2134 /* Remove any possible QUEUED. */
2135 last_expr_value = protect_from_queue (last_expr_value, 0);
2139 TREE_TYPE (t) = last_expr_type;
2140 RTL_EXPR_RTL (t) = last_expr_value;
2141 RTL_EXPR_SEQUENCE (t) = get_insns ();
2143 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
2147 /* Don't consider deleting this expr or containing exprs at tree level. */
2148 TREE_SIDE_EFFECTS (t) = 1;
2149 /* Propagate volatility of the actual RTL expr. */
2150 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
2153 expr_stmts_for_value--;
2158 /* Generate RTL for the start of an if-then. COND is the expression
2159 whose truth should be tested.
2161 If EXITFLAG is nonzero, this conditional is visible to
2162 `exit_something'. */
2165 expand_start_cond (cond, exitflag)
2169 struct nesting *thiscond = ALLOC_NESTING ();
2171 /* Make an entry on cond_stack for the cond we are entering. */
2173 thiscond->next = cond_stack;
2174 thiscond->all = nesting_stack;
2175 thiscond->depth = ++nesting_depth;
2176 thiscond->data.cond.next_label = gen_label_rtx ();
2177 /* Before we encounter an `else', we don't need a separate exit label
2178 unless there are supposed to be exit statements
2179 to exit this conditional. */
2180 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
2181 thiscond->data.cond.endif_label = thiscond->exit_label;
2182 cond_stack = thiscond;
2183 nesting_stack = thiscond;
2185 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
2188 /* Generate RTL between then-clause and the elseif-clause
2189 of an if-then-elseif-.... */
2192 expand_start_elseif (cond)
2195 if (cond_stack->data.cond.endif_label == 0)
2196 cond_stack->data.cond.endif_label = gen_label_rtx ();
2197 emit_jump (cond_stack->data.cond.endif_label);
2198 emit_label (cond_stack->data.cond.next_label);
2199 cond_stack->data.cond.next_label = gen_label_rtx ();
2200 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2203 /* Generate RTL between the then-clause and the else-clause
2204 of an if-then-else. */
2207 expand_start_else ()
2209 if (cond_stack->data.cond.endif_label == 0)
2210 cond_stack->data.cond.endif_label = gen_label_rtx ();
2212 emit_jump (cond_stack->data.cond.endif_label);
2213 emit_label (cond_stack->data.cond.next_label);
2214 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
2217 /* After calling expand_start_else, turn this "else" into an "else if"
2218 by providing another condition. */
2221 expand_elseif (cond)
2224 cond_stack->data.cond.next_label = gen_label_rtx ();
2225 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2228 /* Generate RTL for the end of an if-then.
2229 Pop the record for it off of cond_stack. */
2234 struct nesting *thiscond = cond_stack;
2236 do_pending_stack_adjust ();
2237 if (thiscond->data.cond.next_label)
2238 emit_label (thiscond->data.cond.next_label);
2239 if (thiscond->data.cond.endif_label)
2240 emit_label (thiscond->data.cond.endif_label);
2242 POPSTACK (cond_stack);
2246 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2247 loop should be exited by `exit_something'. This is a loop for which
2248 `expand_continue' will jump to the top of the loop.
2250 Make an entry on loop_stack to record the labels associated with
2254 expand_start_loop (exit_flag)
2257 register struct nesting *thisloop = ALLOC_NESTING ();
2259 /* Make an entry on loop_stack for the loop we are entering. */
2261 thisloop->next = loop_stack;
2262 thisloop->all = nesting_stack;
2263 thisloop->depth = ++nesting_depth;
2264 thisloop->data.loop.start_label = gen_label_rtx ();
2265 thisloop->data.loop.end_label = gen_label_rtx ();
2266 thisloop->data.loop.alt_end_label = 0;
2267 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2268 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2269 loop_stack = thisloop;
2270 nesting_stack = thisloop;
2272 do_pending_stack_adjust ();
2274 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2275 emit_label (thisloop->data.loop.start_label);
2280 /* Like expand_start_loop but for a loop where the continuation point
2281 (for expand_continue_loop) will be specified explicitly. */
2284 expand_start_loop_continue_elsewhere (exit_flag)
2287 struct nesting *thisloop = expand_start_loop (exit_flag);
2288 loop_stack->data.loop.continue_label = gen_label_rtx ();
2292 /* Specify the continuation point for a loop started with
2293 expand_start_loop_continue_elsewhere.
2294 Use this at the point in the code to which a continue statement
2298 expand_loop_continue_here ()
2300 do_pending_stack_adjust ();
2301 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2302 emit_label (loop_stack->data.loop.continue_label);
2305 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2306 Pop the block off of loop_stack. */
2311 rtx start_label = loop_stack->data.loop.start_label;
2312 rtx insn = get_last_insn ();
2313 int needs_end_jump = 1;
2315 /* Mark the continue-point at the top of the loop if none elsewhere. */
2316 if (start_label == loop_stack->data.loop.continue_label)
2317 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2319 do_pending_stack_adjust ();
2321 /* If optimizing, perhaps reorder the loop.
2322 First, try to use a condjump near the end.
2323 expand_exit_loop_if_false ends loops with unconditional jumps,
2326 if (test) goto label;
2328 goto loop_stack->data.loop.end_label
2332 If we find such a pattern, we can end the loop earlier. */
2335 && GET_CODE (insn) == CODE_LABEL
2336 && LABEL_NAME (insn) == NULL
2337 && GET_CODE (PREV_INSN (insn)) == BARRIER)
2340 rtx jump = PREV_INSN (PREV_INSN (label));
2342 if (GET_CODE (jump) == JUMP_INSN
2343 && GET_CODE (PATTERN (jump)) == SET
2344 && SET_DEST (PATTERN (jump)) == pc_rtx
2345 && GET_CODE (SET_SRC (PATTERN (jump))) == LABEL_REF
2346 && (XEXP (SET_SRC (PATTERN (jump)), 0)
2347 == loop_stack->data.loop.end_label))
2351 /* The test might be complex and reference LABEL multiple times,
2352 like the loop in loop_iterations to set vtop. To handle this,
2354 insn = PREV_INSN (label);
2355 reorder_insns (label, label, start_label);
2357 for (prev = PREV_INSN (jump);; prev = PREV_INSN (prev))
2359 /* We ignore line number notes, but if we see any other note,
2360 in particular NOTE_INSN_BLOCK_*, NOTE_INSN_EH_REGION_*,
2361 NOTE_INSN_LOOP_*, we disable this optimization. */
2362 if (GET_CODE (prev) == NOTE)
2364 if (NOTE_LINE_NUMBER (prev) < 0)
2368 if (GET_CODE (prev) == CODE_LABEL)
2370 if (GET_CODE (prev) == JUMP_INSN)
2372 if (GET_CODE (PATTERN (prev)) == SET
2373 && SET_DEST (PATTERN (prev)) == pc_rtx
2374 && GET_CODE (SET_SRC (PATTERN (prev))) == IF_THEN_ELSE
2375 && (GET_CODE (XEXP (SET_SRC (PATTERN (prev)), 1))
2377 && XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0) == label)
2379 XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0)
2381 emit_note_after (NOTE_INSN_LOOP_END, prev);
2390 /* If the loop starts with a loop exit, roll that to the end where
2391 it will optimize together with the jump back.
2393 We look for the conditional branch to the exit, except that once
2394 we find such a branch, we don't look past 30 instructions.
2396 In more detail, if the loop presently looks like this (in pseudo-C):
2399 if (test) goto end_label;
2404 transform it to look like:
2410 if (test) goto end_label;
2411 goto newstart_label;
2414 Here, the `test' may actually consist of some reasonably complex
2415 code, terminating in a test. */
2420 ! (GET_CODE (insn) == JUMP_INSN
2421 && GET_CODE (PATTERN (insn)) == SET
2422 && SET_DEST (PATTERN (insn)) == pc_rtx
2423 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2427 rtx last_test_insn = NULL_RTX;
2429 /* Scan insns from the top of the loop looking for a qualified
2430 conditional exit. */
2431 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2432 insn = NEXT_INSN (insn))
2434 if (GET_CODE (insn) == NOTE)
2437 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2438 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2439 /* The code that actually moves the exit test will
2440 carefully leave BLOCK notes in their original
2441 location. That means, however, that we can't debug
2442 the exit test itself. So, we refuse to move code
2443 containing BLOCK notes at low optimization levels. */
2446 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG)
2448 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)
2452 /* We've come to the end of an EH region, but
2453 never saw the beginning of that region. That
2454 means that an EH region begins before the top
2455 of the loop, and ends in the middle of it. The
2456 existence of such a situation violates a basic
2457 assumption in this code, since that would imply
2458 that even when EH_REGIONS is zero, we might
2459 move code out of an exception region. */
2463 /* We must not walk into a nested loop. */
2464 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
2467 /* We already know this INSN is a NOTE, so there's no
2468 point in looking at it to see if it's a JUMP. */
2472 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2475 if (last_test_insn && num_insns > 30)
2479 /* We don't want to move a partial EH region. Consider:
2493 This isn't legal C++, but here's what it's supposed to
2494 mean: if cond() is true, stop looping. Otherwise,
2495 call bar, and keep looping. In addition, if cond
2496 throws an exception, catch it and keep looping. Such
2497 constructs are certainy legal in LISP.
2499 We should not move the `if (cond()) 0' test since then
2500 the EH-region for the try-block would be broken up.
2501 (In this case we would the EH_BEG note for the `try'
2502 and `if cond()' but not the call to bar() or the
2505 So we don't look for tests within an EH region. */
2508 if (GET_CODE (insn) == JUMP_INSN
2509 && GET_CODE (PATTERN (insn)) == SET
2510 && SET_DEST (PATTERN (insn)) == pc_rtx)
2512 /* This is indeed a jump. */
2513 rtx dest1 = NULL_RTX;
2514 rtx dest2 = NULL_RTX;
2515 rtx potential_last_test;
2516 if (GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE)
2518 /* A conditional jump. */
2519 dest1 = XEXP (SET_SRC (PATTERN (insn)), 1);
2520 dest2 = XEXP (SET_SRC (PATTERN (insn)), 2);
2521 potential_last_test = insn;
2525 /* An unconditional jump. */
2526 dest1 = SET_SRC (PATTERN (insn));
2527 /* Include the BARRIER after the JUMP. */
2528 potential_last_test = NEXT_INSN (insn);
2532 if (dest1 && GET_CODE (dest1) == LABEL_REF
2533 && ((XEXP (dest1, 0)
2534 == loop_stack->data.loop.alt_end_label)
2536 == loop_stack->data.loop.end_label)))
2538 last_test_insn = potential_last_test;
2542 /* If this was a conditional jump, there may be
2543 another label at which we should look. */
2550 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2552 /* We found one. Move everything from there up
2553 to the end of the loop, and add a jump into the loop
2554 to jump to there. */
2555 register rtx newstart_label = gen_label_rtx ();
2556 register rtx start_move = start_label;
2559 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2560 then we want to move this note also. */
2561 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2562 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2563 == NOTE_INSN_LOOP_CONT))
2564 start_move = PREV_INSN (start_move);
2566 emit_label_after (newstart_label, PREV_INSN (start_move));
2568 /* Actually move the insns. Start at the beginning, and
2569 keep copying insns until we've copied the
2571 for (insn = start_move; insn; insn = next_insn)
2573 /* Figure out which insn comes after this one. We have
2574 to do this before we move INSN. */
2575 if (insn == last_test_insn)
2576 /* We've moved all the insns. */
2577 next_insn = NULL_RTX;
2579 next_insn = NEXT_INSN (insn);
2581 if (GET_CODE (insn) == NOTE
2582 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2583 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2584 /* We don't want to move NOTE_INSN_BLOCK_BEGs or
2585 NOTE_INSN_BLOCK_ENDs because the correct generation
2586 of debugging information depends on these appearing
2587 in the same order in the RTL and in the tree
2588 structure, where they are represented as BLOCKs.
2589 So, we don't move block notes. Of course, moving
2590 the code inside the block is likely to make it
2591 impossible to debug the instructions in the exit
2592 test, but such is the price of optimization. */
2595 /* Move the INSN. */
2596 reorder_insns (insn, insn, get_last_insn ());
2599 emit_jump_insn_after (gen_jump (start_label),
2600 PREV_INSN (newstart_label));
2601 emit_barrier_after (PREV_INSN (newstart_label));
2602 start_label = newstart_label;
2608 emit_jump (start_label);
2609 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2611 emit_label (loop_stack->data.loop.end_label);
2613 POPSTACK (loop_stack);
2618 /* Generate a jump to the current loop's continue-point.
2619 This is usually the top of the loop, but may be specified
2620 explicitly elsewhere. If not currently inside a loop,
2621 return 0 and do nothing; caller will print an error message. */
2624 expand_continue_loop (whichloop)
2625 struct nesting *whichloop;
2629 whichloop = loop_stack;
2632 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2637 /* Generate a jump to exit the current loop. If not currently inside a loop,
2638 return 0 and do nothing; caller will print an error message. */
2641 expand_exit_loop (whichloop)
2642 struct nesting *whichloop;
2646 whichloop = loop_stack;
2649 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2653 /* Generate a conditional jump to exit the current loop if COND
2654 evaluates to zero. If not currently inside a loop,
2655 return 0 and do nothing; caller will print an error message. */
2658 expand_exit_loop_if_false (whichloop, cond)
2659 struct nesting *whichloop;
2662 rtx label = gen_label_rtx ();
2667 whichloop = loop_stack;
2670 /* In order to handle fixups, we actually create a conditional jump
2671 around a unconditional branch to exit the loop. If fixups are
2672 necessary, they go before the unconditional branch. */
2674 do_jump (cond, NULL_RTX, label);
2675 last_insn = get_last_insn ();
2676 if (GET_CODE (last_insn) == CODE_LABEL)
2677 whichloop->data.loop.alt_end_label = last_insn;
2678 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2685 /* Return nonzero if the loop nest is empty. Else return zero. */
2688 stmt_loop_nest_empty ()
2690 /* cfun->stmt can be NULL if we are building a call to get the
2691 EH context for a setjmp/longjmp EH target and the current
2692 function was a deferred inline function. */
2693 return (cfun->stmt == NULL || loop_stack == NULL);
2696 /* Return non-zero if we should preserve sub-expressions as separate
2697 pseudos. We never do so if we aren't optimizing. We always do so
2698 if -fexpensive-optimizations.
2700 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2701 the loop may still be a small one. */
2704 preserve_subexpressions_p ()
2708 if (flag_expensive_optimizations)
2711 if (optimize == 0 || cfun == 0 || cfun->stmt == 0 || loop_stack == 0)
2714 insn = get_last_insn_anywhere ();
2717 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2718 < n_non_fixed_regs * 3));
2722 /* Generate a jump to exit the current loop, conditional, binding contour
2723 or case statement. Not all such constructs are visible to this function,
2724 only those started with EXIT_FLAG nonzero. Individual languages use
2725 the EXIT_FLAG parameter to control which kinds of constructs you can
2728 If not currently inside anything that can be exited,
2729 return 0 and do nothing; caller will print an error message. */
2732 expand_exit_something ()
2736 for (n = nesting_stack; n; n = n->all)
2737 if (n->exit_label != 0)
2739 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2746 /* Generate RTL to return from the current function, with no value.
2747 (That is, we do not do anything about returning any value.) */
2750 expand_null_return ()
2752 struct nesting *block = block_stack;
2753 rtx last_insn = get_last_insn ();
2755 /* If this function was declared to return a value, but we
2756 didn't, clobber the return registers so that they are not
2757 propogated live to the rest of the function. */
2758 clobber_return_register ();
2760 /* Does any pending block have cleanups? */
2761 while (block && block->data.block.cleanups == 0)
2762 block = block->next;
2764 /* If yes, use a goto to return, since that runs cleanups. */
2766 expand_null_return_1 (last_insn, block != 0);
2769 /* Generate RTL to return from the current function, with value VAL. */
2772 expand_value_return (val)
2775 struct nesting *block = block_stack;
2776 rtx last_insn = get_last_insn ();
2777 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2779 /* Copy the value to the return location
2780 unless it's already there. */
2782 if (return_reg != val)
2784 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2785 #ifdef PROMOTE_FUNCTION_RETURN
2786 int unsignedp = TREE_UNSIGNED (type);
2787 enum machine_mode old_mode
2788 = DECL_MODE (DECL_RESULT (current_function_decl));
2789 enum machine_mode mode
2790 = promote_mode (type, old_mode, &unsignedp, 1);
2792 if (mode != old_mode)
2793 val = convert_modes (mode, old_mode, val, unsignedp);
2795 if (GET_CODE (return_reg) == PARALLEL)
2796 emit_group_load (return_reg, val, int_size_in_bytes (type),
2799 emit_move_insn (return_reg, val);
2802 /* Does any pending block have cleanups? */
2804 while (block && block->data.block.cleanups == 0)
2805 block = block->next;
2807 /* If yes, use a goto to return, since that runs cleanups.
2808 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2810 expand_null_return_1 (last_insn, block != 0);
2813 /* Output a return with no value. If LAST_INSN is nonzero,
2814 pretend that the return takes place after LAST_INSN.
2815 If USE_GOTO is nonzero then don't use a return instruction;
2816 go to the return label instead. This causes any cleanups
2817 of pending blocks to be executed normally. */
2820 expand_null_return_1 (last_insn, use_goto)
2824 rtx end_label = cleanup_label ? cleanup_label : return_label;
2826 clear_pending_stack_adjust ();
2827 do_pending_stack_adjust ();
2830 /* PCC-struct return always uses an epilogue. */
2831 if (current_function_returns_pcc_struct || use_goto)
2834 end_label = return_label = gen_label_rtx ();
2835 expand_goto_internal (NULL_TREE, end_label, last_insn);
2839 /* Otherwise output a simple return-insn if one is available,
2840 unless it won't do the job. */
2842 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2844 emit_jump_insn (gen_return ());
2850 /* Otherwise jump to the epilogue. */
2851 expand_goto_internal (NULL_TREE, end_label, last_insn);
2854 /* Generate RTL to evaluate the expression RETVAL and return it
2855 from the current function. */
2858 expand_return (retval)
2861 /* If there are any cleanups to be performed, then they will
2862 be inserted following LAST_INSN. It is desirable
2863 that the last_insn, for such purposes, should be the
2864 last insn before computing the return value. Otherwise, cleanups
2865 which call functions can clobber the return value. */
2866 /* ??? rms: I think that is erroneous, because in C++ it would
2867 run destructors on variables that might be used in the subsequent
2868 computation of the return value. */
2870 rtx result_rtl = DECL_RTL (DECL_RESULT (current_function_decl));
2871 register rtx val = 0;
2875 /* If function wants no value, give it none. */
2876 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2878 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2880 expand_null_return ();
2884 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2885 /* This is not sufficient. We also need to watch for cleanups of the
2886 expression we are about to expand. Unfortunately, we cannot know
2887 if it has cleanups until we expand it, and we want to change how we
2888 expand it depending upon if we need cleanups. We can't win. */
2890 cleanups = any_pending_cleanups (1);
2895 if (retval == error_mark_node)
2896 retval_rhs = NULL_TREE;
2897 else if (TREE_CODE (retval) == RESULT_DECL)
2898 retval_rhs = retval;
2899 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2900 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2901 retval_rhs = TREE_OPERAND (retval, 1);
2902 else if (VOID_TYPE_P (TREE_TYPE (retval)))
2903 /* Recognize tail-recursive call to void function. */
2904 retval_rhs = retval;
2906 retval_rhs = NULL_TREE;
2908 /* Only use `last_insn' if there are cleanups which must be run. */
2909 if (cleanups || cleanup_label != 0)
2910 last_insn = get_last_insn ();
2912 /* Distribute return down conditional expr if either of the sides
2913 may involve tail recursion (see test below). This enhances the number
2914 of tail recursions we see. Don't do this always since it can produce
2915 sub-optimal code in some cases and we distribute assignments into
2916 conditional expressions when it would help. */
2918 if (optimize && retval_rhs != 0
2919 && frame_offset == 0
2920 && TREE_CODE (retval_rhs) == COND_EXPR
2921 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2922 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2924 rtx label = gen_label_rtx ();
2927 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2928 start_cleanup_deferral ();
2929 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2930 DECL_RESULT (current_function_decl),
2931 TREE_OPERAND (retval_rhs, 1));
2932 TREE_SIDE_EFFECTS (expr) = 1;
2933 expand_return (expr);
2936 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2937 DECL_RESULT (current_function_decl),
2938 TREE_OPERAND (retval_rhs, 2));
2939 TREE_SIDE_EFFECTS (expr) = 1;
2940 expand_return (expr);
2941 end_cleanup_deferral ();
2945 /* If the result is an aggregate that is being returned in one (or more)
2946 registers, load the registers here. The compiler currently can't handle
2947 copying a BLKmode value into registers. We could put this code in a
2948 more general area (for use by everyone instead of just function
2949 call/return), but until this feature is generally usable it is kept here
2950 (and in expand_call). The value must go into a pseudo in case there
2951 are cleanups that will clobber the real return register. */
2954 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2955 && GET_CODE (result_rtl) == REG)
2958 unsigned HOST_WIDE_INT bitpos, xbitpos;
2959 unsigned HOST_WIDE_INT big_endian_correction = 0;
2960 unsigned HOST_WIDE_INT bytes
2961 = int_size_in_bytes (TREE_TYPE (retval_rhs));
2962 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2963 unsigned int bitsize
2964 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)), BITS_PER_WORD);
2965 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2966 rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
2967 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2968 enum machine_mode tmpmode, result_reg_mode;
2970 /* Structures whose size is not a multiple of a word are aligned
2971 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
2972 machine, this means we must skip the empty high order bytes when
2973 calculating the bit offset. */
2974 if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD)
2975 big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
2978 /* Copy the structure BITSIZE bits at a time. */
2979 for (bitpos = 0, xbitpos = big_endian_correction;
2980 bitpos < bytes * BITS_PER_UNIT;
2981 bitpos += bitsize, xbitpos += bitsize)
2983 /* We need a new destination pseudo each time xbitpos is
2984 on a word boundary and when xbitpos == big_endian_correction
2985 (the first time through). */
2986 if (xbitpos % BITS_PER_WORD == 0
2987 || xbitpos == big_endian_correction)
2989 /* Generate an appropriate register. */
2990 dst = gen_reg_rtx (word_mode);
2991 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
2993 /* Clobber the destination before we move anything into it. */
2994 emit_insn (gen_rtx_CLOBBER (VOIDmode, dst));
2997 /* We need a new source operand each time bitpos is on a word
2999 if (bitpos % BITS_PER_WORD == 0)
3000 src = operand_subword_force (result_val,
3001 bitpos / BITS_PER_WORD,
3004 /* Use bitpos for the source extraction (left justified) and
3005 xbitpos for the destination store (right justified). */
3006 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
3007 extract_bit_field (src, bitsize,
3008 bitpos % BITS_PER_WORD, 1,
3009 NULL_RTX, word_mode, word_mode,
3010 bitsize, BITS_PER_WORD),
3011 bitsize, BITS_PER_WORD);
3014 /* Find the smallest integer mode large enough to hold the
3015 entire structure and use that mode instead of BLKmode
3016 on the USE insn for the return register. */
3017 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
3018 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
3019 tmpmode != VOIDmode;
3020 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
3022 /* Have we found a large enough mode? */
3023 if (GET_MODE_SIZE (tmpmode) >= bytes)
3027 /* No suitable mode found. */
3028 if (tmpmode == VOIDmode)
3031 PUT_MODE (result_rtl, tmpmode);
3033 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
3034 result_reg_mode = word_mode;
3036 result_reg_mode = tmpmode;
3037 result_reg = gen_reg_rtx (result_reg_mode);
3040 for (i = 0; i < n_regs; i++)
3041 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
3044 if (tmpmode != result_reg_mode)
3045 result_reg = gen_lowpart (tmpmode, result_reg);
3047 expand_value_return (result_reg);
3051 && !VOID_TYPE_P (TREE_TYPE (retval_rhs))
3052 && (GET_CODE (result_rtl) == REG
3053 || (GET_CODE (result_rtl) == PARALLEL)))
3055 /* Calculate the return value into a temporary (usually a pseudo
3057 val = assign_temp (TREE_TYPE (DECL_RESULT (current_function_decl)),
3059 val = expand_expr (retval_rhs, val, GET_MODE (val), 0);
3060 val = force_not_mem (val);
3062 /* Return the calculated value, doing cleanups first. */
3063 expand_value_return (val);
3067 /* No cleanups or no hard reg used;
3068 calculate value into hard return reg. */
3069 expand_expr (retval, const0_rtx, VOIDmode, 0);
3071 expand_value_return (result_rtl);
3075 /* Return 1 if the end of the generated RTX is not a barrier.
3076 This means code already compiled can drop through. */
3079 drop_through_at_end_p ()
3081 rtx insn = get_last_insn ();
3082 while (insn && GET_CODE (insn) == NOTE)
3083 insn = PREV_INSN (insn);
3084 return insn && GET_CODE (insn) != BARRIER;
3087 /* Attempt to optimize a potential tail recursion call into a goto.
3088 ARGUMENTS are the arguments to a CALL_EXPR; LAST_INSN indicates
3089 where to place the jump to the tail recursion label.
3091 Return TRUE if the call was optimized into a goto. */
3094 optimize_tail_recursion (arguments, last_insn)
3098 /* Finish checking validity, and if valid emit code to set the
3099 argument variables for the new call. */
3100 if (tail_recursion_args (arguments, DECL_ARGUMENTS (current_function_decl)))
3102 if (tail_recursion_label == 0)
3104 tail_recursion_label = gen_label_rtx ();
3105 emit_label_after (tail_recursion_label,
3106 tail_recursion_reentry);
3109 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
3116 /* Emit code to alter this function's formal parms for a tail-recursive call.
3117 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3118 FORMALS is the chain of decls of formals.
3119 Return 1 if this can be done;
3120 otherwise return 0 and do not emit any code. */
3123 tail_recursion_args (actuals, formals)
3124 tree actuals, formals;
3126 register tree a = actuals, f = formals;
3128 register rtx *argvec;
3130 /* Check that number and types of actuals are compatible
3131 with the formals. This is not always true in valid C code.
3132 Also check that no formal needs to be addressable
3133 and that all formals are scalars. */
3135 /* Also count the args. */
3137 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
3139 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a)))
3140 != TYPE_MAIN_VARIANT (TREE_TYPE (f)))
3142 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
3145 if (a != 0 || f != 0)
3148 /* Compute all the actuals. */
3150 argvec = (rtx *) alloca (i * sizeof (rtx));
3152 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3153 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
3155 /* Find which actual values refer to current values of previous formals.
3156 Copy each of them now, before any formal is changed. */
3158 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3162 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
3163 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
3169 argvec[i] = copy_to_reg (argvec[i]);
3172 /* Store the values of the actuals into the formals. */
3174 for (f = formals, a = actuals, i = 0; f;
3175 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
3177 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
3178 emit_move_insn (DECL_RTL (f), argvec[i]);
3180 convert_move (DECL_RTL (f), argvec[i],
3181 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
3188 /* Generate the RTL code for entering a binding contour.
3189 The variables are declared one by one, by calls to `expand_decl'.
3191 FLAGS is a bitwise or of the following flags:
3193 1 - Nonzero if this construct should be visible to
3196 2 - Nonzero if this contour does not require a
3197 NOTE_INSN_BLOCK_BEG note. Virtually all calls from
3198 language-independent code should set this flag because they
3199 will not create corresponding BLOCK nodes. (There should be
3200 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
3201 and BLOCKs.) If this flag is set, MARK_ENDS should be zero
3202 when expand_end_bindings is called.
3204 If we are creating a NOTE_INSN_BLOCK_BEG note, a BLOCK may
3205 optionally be supplied. If so, it becomes the NOTE_BLOCK for the
3209 expand_start_bindings_and_block (flags, block)
3213 struct nesting *thisblock = ALLOC_NESTING ();
3215 int exit_flag = ((flags & 1) != 0);
3216 int block_flag = ((flags & 2) == 0);
3218 /* If a BLOCK is supplied, then the caller should be requesting a
3219 NOTE_INSN_BLOCK_BEG note. */
3220 if (!block_flag && block)
3223 /* Create a note to mark the beginning of the block. */
3226 note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
3227 NOTE_BLOCK (note) = block;
3230 note = emit_note (NULL_PTR, NOTE_INSN_DELETED);
3232 /* Make an entry on block_stack for the block we are entering. */
3234 thisblock->next = block_stack;
3235 thisblock->all = nesting_stack;
3236 thisblock->depth = ++nesting_depth;
3237 thisblock->data.block.stack_level = 0;
3238 thisblock->data.block.cleanups = 0;
3239 thisblock->data.block.n_function_calls = 0;
3240 thisblock->data.block.exception_region = 0;
3241 thisblock->data.block.block_target_temp_slot_level = target_temp_slot_level;
3243 thisblock->data.block.conditional_code = 0;
3244 thisblock->data.block.last_unconditional_cleanup = note;
3245 /* When we insert instructions after the last unconditional cleanup,
3246 we don't adjust last_insn. That means that a later add_insn will
3247 clobber the instructions we've just added. The easiest way to
3248 fix this is to just insert another instruction here, so that the
3249 instructions inserted after the last unconditional cleanup are
3250 never the last instruction. */
3251 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3252 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
3255 && !(block_stack->data.block.cleanups == NULL_TREE
3256 && block_stack->data.block.outer_cleanups == NULL_TREE))
3257 thisblock->data.block.outer_cleanups
3258 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
3259 block_stack->data.block.outer_cleanups);
3261 thisblock->data.block.outer_cleanups = 0;
3262 thisblock->data.block.label_chain = 0;
3263 thisblock->data.block.innermost_stack_block = stack_block_stack;
3264 thisblock->data.block.first_insn = note;
3265 thisblock->data.block.block_start_count = ++current_block_start_count;
3266 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
3267 block_stack = thisblock;
3268 nesting_stack = thisblock;
3270 /* Make a new level for allocating stack slots. */
3274 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3275 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3276 expand_expr are made. After we end the region, we know that all
3277 space for all temporaries that were created by TARGET_EXPRs will be
3278 destroyed and their space freed for reuse. */
3281 expand_start_target_temps ()
3283 /* This is so that even if the result is preserved, the space
3284 allocated will be freed, as we know that it is no longer in use. */
3287 /* Start a new binding layer that will keep track of all cleanup
3288 actions to be performed. */
3289 expand_start_bindings (2);
3291 target_temp_slot_level = temp_slot_level;
3295 expand_end_target_temps ()
3297 expand_end_bindings (NULL_TREE, 0, 0);
3299 /* This is so that even if the result is preserved, the space
3300 allocated will be freed, as we know that it is no longer in use. */
3304 /* Given a pointer to a BLOCK node return non-zero if (and only if) the node
3305 in question represents the outermost pair of curly braces (i.e. the "body
3306 block") of a function or method.
3308 For any BLOCK node representing a "body block" of a function or method, the
3309 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
3310 represents the outermost (function) scope for the function or method (i.e.
3311 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
3312 *that* node in turn will point to the relevant FUNCTION_DECL node. */
3315 is_body_block (stmt)
3318 if (TREE_CODE (stmt) == BLOCK)
3320 tree parent = BLOCK_SUPERCONTEXT (stmt);
3322 if (parent && TREE_CODE (parent) == BLOCK)
3324 tree grandparent = BLOCK_SUPERCONTEXT (parent);
3326 if (grandparent && TREE_CODE (grandparent) == FUNCTION_DECL)
3334 /* Mark top block of block_stack as an implicit binding for an
3335 exception region. This is used to prevent infinite recursion when
3336 ending a binding with expand_end_bindings. It is only ever called
3337 by expand_eh_region_start, as that it the only way to create a
3338 block stack for a exception region. */
3341 mark_block_as_eh_region ()
3343 block_stack->data.block.exception_region = 1;
3344 if (block_stack->next
3345 && block_stack->next->data.block.conditional_code)
3347 block_stack->data.block.conditional_code
3348 = block_stack->next->data.block.conditional_code;
3349 block_stack->data.block.last_unconditional_cleanup
3350 = block_stack->next->data.block.last_unconditional_cleanup;
3351 block_stack->data.block.cleanup_ptr
3352 = block_stack->next->data.block.cleanup_ptr;
3356 /* True if we are currently emitting insns in an area of output code
3357 that is controlled by a conditional expression. This is used by
3358 the cleanup handling code to generate conditional cleanup actions. */
3361 conditional_context ()
3363 return block_stack && block_stack->data.block.conditional_code;
3366 /* Mark top block of block_stack as not for an implicit binding for an
3367 exception region. This is only ever done by expand_eh_region_end
3368 to let expand_end_bindings know that it is being called explicitly
3369 to end the binding layer for just the binding layer associated with
3370 the exception region, otherwise expand_end_bindings would try and
3371 end all implicit binding layers for exceptions regions, and then
3372 one normal binding layer. */
3375 mark_block_as_not_eh_region ()
3377 block_stack->data.block.exception_region = 0;
3380 /* True if the top block of block_stack was marked as for an exception
3381 region by mark_block_as_eh_region. */
3386 return cfun && block_stack && block_stack->data.block.exception_region;
3389 /* Emit a handler label for a nonlocal goto handler.
3390 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3393 expand_nl_handler_label (slot, before_insn)
3394 rtx slot, before_insn;
3397 rtx handler_label = gen_label_rtx ();
3399 /* Don't let jump_optimize delete the handler. */
3400 LABEL_PRESERVE_P (handler_label) = 1;
3403 emit_move_insn (slot, gen_rtx_LABEL_REF (Pmode, handler_label));
3404 insns = get_insns ();
3406 emit_insns_before (insns, before_insn);
3408 emit_label (handler_label);
3410 return handler_label;
3413 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3416 expand_nl_goto_receiver ()
3418 #ifdef HAVE_nonlocal_goto
3419 if (! HAVE_nonlocal_goto)
3421 /* First adjust our frame pointer to its actual value. It was
3422 previously set to the start of the virtual area corresponding to
3423 the stacked variables when we branched here and now needs to be
3424 adjusted to the actual hardware fp value.
3426 Assignments are to virtual registers are converted by
3427 instantiate_virtual_regs into the corresponding assignment
3428 to the underlying register (fp in this case) that makes
3429 the original assignment true.
3430 So the following insn will actually be
3431 decrementing fp by STARTING_FRAME_OFFSET. */
3432 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3434 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3435 if (fixed_regs[ARG_POINTER_REGNUM])
3437 #ifdef ELIMINABLE_REGS
3438 /* If the argument pointer can be eliminated in favor of the
3439 frame pointer, we don't need to restore it. We assume here
3440 that if such an elimination is present, it can always be used.
3441 This is the case on all known machines; if we don't make this
3442 assumption, we do unnecessary saving on many machines. */
3443 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3446 for (i = 0; i < ARRAY_SIZE (elim_regs); i++)
3447 if (elim_regs[i].from == ARG_POINTER_REGNUM
3448 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3451 if (i == ARRAY_SIZE (elim_regs))
3454 /* Now restore our arg pointer from the address at which it
3455 was saved in our stack frame.
3456 If there hasn't be space allocated for it yet, make
3458 if (arg_pointer_save_area == 0)
3459 arg_pointer_save_area
3460 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3461 emit_move_insn (virtual_incoming_args_rtx,
3462 /* We need a pseudo here, or else
3463 instantiate_virtual_regs_1 complains. */
3464 copy_to_reg (arg_pointer_save_area));
3469 #ifdef HAVE_nonlocal_goto_receiver
3470 if (HAVE_nonlocal_goto_receiver)
3471 emit_insn (gen_nonlocal_goto_receiver ());
3475 /* Make handlers for nonlocal gotos taking place in the function calls in
3479 expand_nl_goto_receivers (thisblock)
3480 struct nesting *thisblock;
3483 rtx afterward = gen_label_rtx ();
3488 /* Record the handler address in the stack slot for that purpose,
3489 during this block, saving and restoring the outer value. */
3490 if (thisblock->next != 0)
3491 for (slot = nonlocal_goto_handler_slots; slot; slot = XEXP (slot, 1))
3493 rtx save_receiver = gen_reg_rtx (Pmode);
3494 emit_move_insn (XEXP (slot, 0), save_receiver);
3497 emit_move_insn (save_receiver, XEXP (slot, 0));
3498 insns = get_insns ();
3500 emit_insns_before (insns, thisblock->data.block.first_insn);
3503 /* Jump around the handlers; they run only when specially invoked. */
3504 emit_jump (afterward);
3506 /* Make a separate handler for each label. */
3507 link = nonlocal_labels;
3508 slot = nonlocal_goto_handler_slots;
3509 label_list = NULL_RTX;
3510 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3511 /* Skip any labels we shouldn't be able to jump to from here,
3512 we generate one special handler for all of them below which just calls
3514 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3517 lab = expand_nl_handler_label (XEXP (slot, 0),
3518 thisblock->data.block.first_insn);
3519 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3521 expand_nl_goto_receiver ();
3523 /* Jump to the "real" nonlocal label. */
3524 expand_goto (TREE_VALUE (link));
3527 /* A second pass over all nonlocal labels; this time we handle those
3528 we should not be able to jump to at this point. */
3529 link = nonlocal_labels;
3530 slot = nonlocal_goto_handler_slots;
3532 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3533 if (DECL_TOO_LATE (TREE_VALUE (link)))
3536 lab = expand_nl_handler_label (XEXP (slot, 0),
3537 thisblock->data.block.first_insn);
3538 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3544 expand_nl_goto_receiver ();
3545 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "abort"), 0,
3550 nonlocal_goto_handler_labels = label_list;
3551 emit_label (afterward);
3554 /* Warn about any unused VARS (which may contain nodes other than
3555 VAR_DECLs, but such nodes are ignored). The nodes are connected
3556 via the TREE_CHAIN field. */
3559 warn_about_unused_variables (vars)
3564 if (warn_unused_variable)
3565 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3566 if (TREE_CODE (decl) == VAR_DECL
3567 && ! TREE_USED (decl)
3568 && ! DECL_IN_SYSTEM_HEADER (decl)
3569 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
3570 warning_with_decl (decl, "unused variable `%s'");
3573 /* Generate RTL code to terminate a binding contour.
3575 VARS is the chain of VAR_DECL nodes for the variables bound in this
3576 contour. There may actually be other nodes in this chain, but any
3577 nodes other than VAR_DECLS are ignored.
3579 MARK_ENDS is nonzero if we should put a note at the beginning
3580 and end of this binding contour.
3582 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3583 (That is true automatically if the contour has a saved stack level.) */
3586 expand_end_bindings (vars, mark_ends, dont_jump_in)
3591 register struct nesting *thisblock;
3593 while (block_stack->data.block.exception_region)
3595 /* Because we don't need or want a new temporary level and
3596 because we didn't create one in expand_eh_region_start,
3597 create a fake one now to avoid removing one in
3598 expand_end_bindings. */
3601 block_stack->data.block.exception_region = 0;
3603 expand_end_bindings (NULL_TREE, 0, 0);
3606 /* Since expand_eh_region_start does an expand_start_bindings, we
3607 have to first end all the bindings that were created by
3608 expand_eh_region_start. */
3610 thisblock = block_stack;
3612 /* If any of the variables in this scope were not used, warn the
3614 warn_about_unused_variables (vars);
3616 if (thisblock->exit_label)
3618 do_pending_stack_adjust ();
3619 emit_label (thisblock->exit_label);
3622 /* If necessary, make handlers for nonlocal gotos taking
3623 place in the function calls in this block. */
3624 if (function_call_count != thisblock->data.block.n_function_calls
3626 /* Make handler for outermost block
3627 if there were any nonlocal gotos to this function. */
3628 && (thisblock->next == 0 ? current_function_has_nonlocal_label
3629 /* Make handler for inner block if it has something
3630 special to do when you jump out of it. */
3631 : (thisblock->data.block.cleanups != 0
3632 || thisblock->data.block.stack_level != 0)))
3633 expand_nl_goto_receivers (thisblock);
3635 /* Don't allow jumping into a block that has a stack level.
3636 Cleanups are allowed, though. */
3638 || thisblock->data.block.stack_level != 0)
3640 struct label_chain *chain;
3642 /* Any labels in this block are no longer valid to go to.
3643 Mark them to cause an error message. */
3644 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3646 DECL_TOO_LATE (chain->label) = 1;
3647 /* If any goto without a fixup came to this label,
3648 that must be an error, because gotos without fixups
3649 come from outside all saved stack-levels. */
3650 if (TREE_ADDRESSABLE (chain->label))
3651 error_with_decl (chain->label,
3652 "label `%s' used before containing binding contour");
3656 /* Restore stack level in effect before the block
3657 (only if variable-size objects allocated). */
3658 /* Perform any cleanups associated with the block. */
3660 if (thisblock->data.block.stack_level != 0
3661 || thisblock->data.block.cleanups != 0)
3666 /* Don't let cleanups affect ({...}) constructs. */
3667 int old_expr_stmts_for_value = expr_stmts_for_value;
3668 rtx old_last_expr_value = last_expr_value;
3669 tree old_last_expr_type = last_expr_type;
3670 expr_stmts_for_value = 0;
3672 /* Only clean up here if this point can actually be reached. */
3673 insn = get_last_insn ();
3674 if (GET_CODE (insn) == NOTE)
3675 insn = prev_nonnote_insn (insn);
3676 reachable = (! insn || GET_CODE (insn) != BARRIER);
3678 /* Do the cleanups. */
3679 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3681 do_pending_stack_adjust ();
3683 expr_stmts_for_value = old_expr_stmts_for_value;
3684 last_expr_value = old_last_expr_value;
3685 last_expr_type = old_last_expr_type;
3687 /* Restore the stack level. */
3689 if (reachable && thisblock->data.block.stack_level != 0)
3691 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3692 thisblock->data.block.stack_level, NULL_RTX);
3693 if (nonlocal_goto_handler_slots != 0)
3694 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3698 /* Any gotos out of this block must also do these things.
3699 Also report any gotos with fixups that came to labels in this
3701 fixup_gotos (thisblock,
3702 thisblock->data.block.stack_level,
3703 thisblock->data.block.cleanups,
3704 thisblock->data.block.first_insn,
3708 /* Mark the beginning and end of the scope if requested.
3709 We do this now, after running cleanups on the variables
3710 just going out of scope, so they are in scope for their cleanups. */
3714 rtx note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3715 NOTE_BLOCK (note) = NOTE_BLOCK (thisblock->data.block.first_insn);
3718 /* Get rid of the beginning-mark if we don't make an end-mark. */
3719 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3721 /* Restore the temporary level of TARGET_EXPRs. */
3722 target_temp_slot_level = thisblock->data.block.block_target_temp_slot_level;
3724 /* Restore block_stack level for containing block. */
3726 stack_block_stack = thisblock->data.block.innermost_stack_block;
3727 POPSTACK (block_stack);
3729 /* Pop the stack slot nesting and free any slots at this level. */
3733 /* Generate code to save the stack pointer at the start of the current block
3734 and set up to restore it on exit. */
3737 save_stack_pointer ()
3739 struct nesting *thisblock = block_stack;
3741 if (thisblock->data.block.stack_level == 0)
3743 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3744 &thisblock->data.block.stack_level,
3745 thisblock->data.block.first_insn);
3746 stack_block_stack = thisblock;
3750 /* Generate RTL for the automatic variable declaration DECL.
3751 (Other kinds of declarations are simply ignored if seen here.) */
3757 struct nesting *thisblock;
3760 type = TREE_TYPE (decl);
3762 /* Only automatic variables need any expansion done.
3763 Static and external variables, and external functions,
3764 will be handled by `assemble_variable' (called from finish_decl).
3765 TYPE_DECL and CONST_DECL require nothing.
3766 PARM_DECLs are handled in `assign_parms'. */
3768 if (TREE_CODE (decl) != VAR_DECL)
3770 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3773 thisblock = block_stack;
3775 /* Create the RTL representation for the variable. */
3777 if (type == error_mark_node)
3778 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, const0_rtx);
3779 else if (DECL_SIZE (decl) == 0)
3780 /* Variable with incomplete type. */
3782 if (DECL_INITIAL (decl) == 0)
3783 /* Error message was already done; now avoid a crash. */
3784 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3786 /* An initializer is going to decide the size of this array.
3787 Until we know the size, represent its address with a reg. */
3788 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode));
3790 set_mem_attributes (DECL_RTL (decl), decl, 1);
3792 else if (DECL_MODE (decl) != BLKmode
3793 /* If -ffloat-store, don't put explicit float vars
3795 && !(flag_float_store
3796 && TREE_CODE (type) == REAL_TYPE)
3797 && ! TREE_THIS_VOLATILE (decl)
3798 && ! TREE_ADDRESSABLE (decl)
3799 && (DECL_REGISTER (decl) || optimize)
3800 /* if -fcheck-memory-usage, check all variables. */
3801 && ! current_function_check_memory_usage)
3803 /* Automatic variable that can go in a register. */
3804 int unsignedp = TREE_UNSIGNED (type);
3805 enum machine_mode reg_mode
3806 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3808 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3809 mark_user_reg (DECL_RTL (decl));
3811 if (POINTER_TYPE_P (type))
3812 mark_reg_pointer (DECL_RTL (decl),
3813 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
3815 maybe_set_unchanging (DECL_RTL (decl), decl);
3818 else if (TREE_CODE (DECL_SIZE_UNIT (decl)) == INTEGER_CST
3819 && ! (flag_stack_check && ! STACK_CHECK_BUILTIN
3820 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl),
3821 STACK_CHECK_MAX_VAR_SIZE)))
3823 /* Variable of fixed size that goes on the stack. */
3827 /* If we previously made RTL for this decl, it must be an array
3828 whose size was determined by the initializer.
3829 The old address was a register; set that register now
3830 to the proper address. */
3831 if (DECL_RTL (decl) != 0)
3833 if (GET_CODE (DECL_RTL (decl)) != MEM
3834 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3836 oldaddr = XEXP (DECL_RTL (decl), 0);
3839 DECL_RTL (decl) = assign_temp (TREE_TYPE (decl), 1, 1, 1);
3841 /* Set alignment we actually gave this decl. */
3842 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3843 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3844 DECL_USER_ALIGN (decl) = 0;
3848 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3849 if (addr != oldaddr)
3850 emit_move_insn (oldaddr, addr);
3854 /* Dynamic-size object: must push space on the stack. */
3858 /* Record the stack pointer on entry to block, if have
3859 not already done so. */
3860 do_pending_stack_adjust ();
3861 save_stack_pointer ();
3863 /* In function-at-a-time mode, variable_size doesn't expand this,
3865 if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
3866 expand_expr (TYPE_MAX_VALUE (TYPE_DOMAIN (type)),
3867 const0_rtx, VOIDmode, 0);
3869 /* Compute the variable's size, in bytes. */
3870 size = expand_expr (DECL_SIZE_UNIT (decl), NULL_RTX, VOIDmode, 0);
3873 /* Allocate space on the stack for the variable. Note that
3874 DECL_ALIGN says how the variable is to be aligned and we
3875 cannot use it to conclude anything about the alignment of
3877 address = allocate_dynamic_stack_space (size, NULL_RTX,
3878 TYPE_ALIGN (TREE_TYPE (decl)));
3880 /* Reference the variable indirect through that rtx. */
3881 DECL_RTL (decl) = gen_rtx_MEM (DECL_MODE (decl), address);
3883 set_mem_attributes (DECL_RTL (decl), decl, 1);
3885 /* Indicate the alignment we actually gave this variable. */
3886 #ifdef STACK_BOUNDARY
3887 DECL_ALIGN (decl) = STACK_BOUNDARY;
3889 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3891 DECL_USER_ALIGN (decl) = 0;
3895 /* Emit code to perform the initialization of a declaration DECL. */
3898 expand_decl_init (decl)
3901 int was_used = TREE_USED (decl);
3903 /* If this is a CONST_DECL, we don't have to generate any code, but
3904 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3905 to be set while in the obstack containing the constant. If we don't
3906 do this, we can lose if we have functions nested three deep and the middle
3907 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3908 the innermost function is the first to expand that STRING_CST. */
3909 if (TREE_CODE (decl) == CONST_DECL)
3911 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3912 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3913 EXPAND_INITIALIZER);
3917 if (TREE_STATIC (decl))
3920 /* Compute and store the initial value now. */
3922 if (DECL_INITIAL (decl) == error_mark_node)
3924 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3926 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3927 || code == POINTER_TYPE || code == REFERENCE_TYPE)
3928 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3932 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3934 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3935 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3939 /* Don't let the initialization count as "using" the variable. */
3940 TREE_USED (decl) = was_used;
3942 /* Free any temporaries we made while initializing the decl. */
3943 preserve_temp_slots (NULL_RTX);
3947 /* CLEANUP is an expression to be executed at exit from this binding contour;
3948 for example, in C++, it might call the destructor for this variable.
3950 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
3951 CLEANUP multiple times, and have the correct semantics. This
3952 happens in exception handling, for gotos, returns, breaks that
3953 leave the current scope.
3955 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3956 that is not associated with any particular variable. */
3959 expand_decl_cleanup (decl, cleanup)
3962 struct nesting *thisblock;
3964 /* Error if we are not in any block. */
3965 if (cfun == 0 || block_stack == 0)
3968 thisblock = block_stack;
3970 /* Record the cleanup if there is one. */
3976 tree *cleanups = &thisblock->data.block.cleanups;
3977 int cond_context = conditional_context ();
3981 rtx flag = gen_reg_rtx (word_mode);
3986 emit_move_insn (flag, const0_rtx);
3987 set_flag_0 = get_insns ();
3990 thisblock->data.block.last_unconditional_cleanup
3991 = emit_insns_after (set_flag_0,
3992 thisblock->data.block.last_unconditional_cleanup);
3994 emit_move_insn (flag, const1_rtx);
3996 /* All cleanups must be on the function_obstack. */
3997 push_obstacks_nochange ();
3998 resume_temporary_allocation ();
4000 cond = build_decl (VAR_DECL, NULL_TREE, type_for_mode (word_mode, 1));
4001 DECL_RTL (cond) = flag;
4003 /* Conditionalize the cleanup. */
4004 cleanup = build (COND_EXPR, void_type_node,
4005 truthvalue_conversion (cond),
4006 cleanup, integer_zero_node);
4007 cleanup = fold (cleanup);
4011 cleanups = thisblock->data.block.cleanup_ptr;
4014 /* All cleanups must be on the function_obstack. */
4015 push_obstacks_nochange ();
4016 resume_temporary_allocation ();
4017 cleanup = unsave_expr (cleanup);
4020 t = *cleanups = temp_tree_cons (decl, cleanup, *cleanups);
4023 /* If this block has a cleanup, it belongs in stack_block_stack. */
4024 stack_block_stack = thisblock;
4031 /* If this was optimized so that there is no exception region for the
4032 cleanup, then mark the TREE_LIST node, so that we can later tell
4033 if we need to call expand_eh_region_end. */
4034 if (! using_eh_for_cleanups_p
4035 || expand_eh_region_start_tree (decl, cleanup))
4036 TREE_ADDRESSABLE (t) = 1;
4037 /* If that started a new EH region, we're in a new block. */
4038 thisblock = block_stack;
4045 thisblock->data.block.last_unconditional_cleanup
4046 = emit_insns_after (seq,
4047 thisblock->data.block.last_unconditional_cleanup);
4051 thisblock->data.block.last_unconditional_cleanup
4053 /* When we insert instructions after the last unconditional cleanup,
4054 we don't adjust last_insn. That means that a later add_insn will
4055 clobber the instructions we've just added. The easiest way to
4056 fix this is to just insert another instruction here, so that the
4057 instructions inserted after the last unconditional cleanup are
4058 never the last instruction. */
4059 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4060 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
4066 /* Like expand_decl_cleanup, but suppress generating an exception handler
4067 to perform the cleanup. */
4071 expand_decl_cleanup_no_eh (decl, cleanup)
4074 int save_eh = using_eh_for_cleanups_p;
4077 using_eh_for_cleanups_p = 0;
4078 result = expand_decl_cleanup (decl, cleanup);
4079 using_eh_for_cleanups_p = save_eh;
4085 /* Arrange for the top element of the dynamic cleanup chain to be
4086 popped if we exit the current binding contour. DECL is the
4087 associated declaration, if any, otherwise NULL_TREE. If the
4088 current contour is left via an exception, then __sjthrow will pop
4089 the top element off the dynamic cleanup chain. The code that
4090 avoids doing the action we push into the cleanup chain in the
4091 exceptional case is contained in expand_cleanups.
4093 This routine is only used by expand_eh_region_start, and that is
4094 the only way in which an exception region should be started. This
4095 routine is only used when using the setjmp/longjmp codegen method
4096 for exception handling. */
4099 expand_dcc_cleanup (decl)
4102 struct nesting *thisblock;
4105 /* Error if we are not in any block. */
4106 if (cfun == 0 || block_stack == 0)
4108 thisblock = block_stack;
4110 /* Record the cleanup for the dynamic handler chain. */
4112 /* All cleanups must be on the function_obstack. */
4113 push_obstacks_nochange ();
4114 resume_temporary_allocation ();
4115 cleanup = make_node (POPDCC_EXPR);
4118 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4119 thisblock->data.block.cleanups
4120 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4122 /* If this block has a cleanup, it belongs in stack_block_stack. */
4123 stack_block_stack = thisblock;
4127 /* Arrange for the top element of the dynamic handler chain to be
4128 popped if we exit the current binding contour. DECL is the
4129 associated declaration, if any, otherwise NULL_TREE. If the current
4130 contour is left via an exception, then __sjthrow will pop the top
4131 element off the dynamic handler chain. The code that avoids doing
4132 the action we push into the handler chain in the exceptional case
4133 is contained in expand_cleanups.
4135 This routine is only used by expand_eh_region_start, and that is
4136 the only way in which an exception region should be started. This
4137 routine is only used when using the setjmp/longjmp codegen method
4138 for exception handling. */
4141 expand_dhc_cleanup (decl)
4144 struct nesting *thisblock;
4147 /* Error if we are not in any block. */
4148 if (cfun == 0 || block_stack == 0)
4150 thisblock = block_stack;
4152 /* Record the cleanup for the dynamic handler chain. */
4154 /* All cleanups must be on the function_obstack. */
4155 push_obstacks_nochange ();
4156 resume_temporary_allocation ();
4157 cleanup = make_node (POPDHC_EXPR);
4160 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4161 thisblock->data.block.cleanups
4162 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4164 /* If this block has a cleanup, it belongs in stack_block_stack. */
4165 stack_block_stack = thisblock;
4169 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4170 DECL_ELTS is the list of elements that belong to DECL's type.
4171 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4174 expand_anon_union_decl (decl, cleanup, decl_elts)
4175 tree decl, cleanup, decl_elts;
4177 struct nesting *thisblock = cfun == 0 ? 0 : block_stack;
4181 /* If any of the elements are addressable, so is the entire union. */
4182 for (t = decl_elts; t; t = TREE_CHAIN (t))
4183 if (TREE_ADDRESSABLE (TREE_VALUE (t)))
4185 TREE_ADDRESSABLE (decl) = 1;
4190 expand_decl_cleanup (decl, cleanup);
4191 x = DECL_RTL (decl);
4193 /* Go through the elements, assigning RTL to each. */
4194 for (t = decl_elts; t; t = TREE_CHAIN (t))
4196 tree decl_elt = TREE_VALUE (t);
4197 tree cleanup_elt = TREE_PURPOSE (t);
4198 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
4200 /* Propagate the union's alignment to the elements. */
4201 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
4202 DECL_USER_ALIGN (decl_elt) = DECL_USER_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 (DECL_SIZE (decl_elt), MODE_INT, 1);
4211 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4212 instead create a new MEM rtx with the proper mode. */
4213 if (GET_CODE (x) == MEM)
4215 if (mode == GET_MODE (x))
4216 DECL_RTL (decl_elt) = x;
4219 DECL_RTL (decl_elt) = gen_rtx_MEM (mode, copy_rtx (XEXP (x, 0)));
4220 MEM_COPY_ATTRIBUTES (DECL_RTL (decl_elt), x);
4223 else if (GET_CODE (x) == REG)
4225 if (mode == GET_MODE (x))
4226 DECL_RTL (decl_elt) = x;
4228 DECL_RTL (decl_elt) = gen_rtx_SUBREG (mode, x, 0);
4233 /* Record the cleanup if there is one. */
4236 thisblock->data.block.cleanups
4237 = temp_tree_cons (decl_elt, cleanup_elt,
4238 thisblock->data.block.cleanups);
4242 /* Expand a list of cleanups LIST.
4243 Elements may be expressions or may be nested lists.
4245 If DONT_DO is nonnull, then any list-element
4246 whose TREE_PURPOSE matches DONT_DO is omitted.
4247 This is sometimes used to avoid a cleanup associated with
4248 a value that is being returned out of the scope.
4250 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
4251 goto and handle protection regions specially in that case.
4253 If REACHABLE, we emit code, otherwise just inform the exception handling
4254 code about this finalization. */
4257 expand_cleanups (list, dont_do, in_fixup, reachable)
4264 for (tail = list; tail; tail = TREE_CHAIN (tail))
4265 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
4267 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
4268 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
4273 tree cleanup = TREE_VALUE (tail);
4275 /* See expand_d{h,c}c_cleanup for why we avoid this. */
4276 if (TREE_CODE (cleanup) != POPDHC_EXPR
4277 && TREE_CODE (cleanup) != POPDCC_EXPR
4278 /* See expand_eh_region_start_tree for this case. */
4279 && ! TREE_ADDRESSABLE (tail))
4281 cleanup = protect_with_terminate (cleanup);
4282 expand_eh_region_end (cleanup);
4288 /* Cleanups may be run multiple times. For example,
4289 when exiting a binding contour, we expand the
4290 cleanups associated with that contour. When a goto
4291 within that binding contour has a target outside that
4292 contour, it will expand all cleanups from its scope to
4293 the target. Though the cleanups are expanded multiple
4294 times, the control paths are non-overlapping so the
4295 cleanups will not be executed twice. */
4297 /* We may need to protect fixups with rethrow regions. */
4298 int protect = (in_fixup && ! TREE_ADDRESSABLE (tail));
4301 expand_fixup_region_start ();
4303 /* The cleanup might contain try-blocks, so we have to
4304 preserve our current queue. */
4306 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
4309 expand_fixup_region_end (TREE_VALUE (tail));
4316 /* Mark when the context we are emitting RTL for as a conditional
4317 context, so that any cleanup actions we register with
4318 expand_decl_init will be properly conditionalized when those
4319 cleanup actions are later performed. Must be called before any
4320 expression (tree) is expanded that is within a conditional context. */
4323 start_cleanup_deferral ()
4325 /* block_stack can be NULL if we are inside the parameter list. It is
4326 OK to do nothing, because cleanups aren't possible here. */
4328 ++block_stack->data.block.conditional_code;
4331 /* Mark the end of a conditional region of code. Because cleanup
4332 deferrals may be nested, we may still be in a conditional region
4333 after we end the currently deferred cleanups, only after we end all
4334 deferred cleanups, are we back in unconditional code. */
4337 end_cleanup_deferral ()
4339 /* block_stack can be NULL if we are inside the parameter list. It is
4340 OK to do nothing, because cleanups aren't possible here. */
4342 --block_stack->data.block.conditional_code;
4345 /* Move all cleanups from the current block_stack
4346 to the containing block_stack, where they are assumed to
4347 have been created. If anything can cause a temporary to
4348 be created, but not expanded for more than one level of
4349 block_stacks, then this code will have to change. */
4354 struct nesting *block = block_stack;
4355 struct nesting *outer = block->next;
4357 outer->data.block.cleanups
4358 = chainon (block->data.block.cleanups,
4359 outer->data.block.cleanups);
4360 block->data.block.cleanups = 0;
4364 last_cleanup_this_contour ()
4366 if (block_stack == 0)
4369 return block_stack->data.block.cleanups;
4372 /* Return 1 if there are any pending cleanups at this point.
4373 If THIS_CONTOUR is nonzero, check the current contour as well.
4374 Otherwise, look only at the contours that enclose this one. */
4377 any_pending_cleanups (this_contour)
4380 struct nesting *block;
4382 if (cfun == NULL || cfun->stmt == NULL || block_stack == 0)
4385 if (this_contour && block_stack->data.block.cleanups != NULL)
4387 if (block_stack->data.block.cleanups == 0
4388 && block_stack->data.block.outer_cleanups == 0)
4391 for (block = block_stack->next; block; block = block->next)
4392 if (block->data.block.cleanups != 0)
4398 /* Enter a case (Pascal) or switch (C) statement.
4399 Push a block onto case_stack and nesting_stack
4400 to accumulate the case-labels that are seen
4401 and to record the labels generated for the statement.
4403 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4404 Otherwise, this construct is transparent for `exit_something'.
4406 EXPR is the index-expression to be dispatched on.
4407 TYPE is its nominal type. We could simply convert EXPR to this type,
4408 but instead we take short cuts. */
4411 expand_start_case (exit_flag, expr, type, printname)
4415 const char *printname;
4417 register struct nesting *thiscase = ALLOC_NESTING ();
4419 /* Make an entry on case_stack for the case we are entering. */
4421 thiscase->next = case_stack;
4422 thiscase->all = nesting_stack;
4423 thiscase->depth = ++nesting_depth;
4424 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
4425 thiscase->data.case_stmt.case_list = 0;
4426 thiscase->data.case_stmt.index_expr = expr;
4427 thiscase->data.case_stmt.nominal_type = type;
4428 thiscase->data.case_stmt.default_label = 0;
4429 thiscase->data.case_stmt.printname = printname;
4430 thiscase->data.case_stmt.line_number_status = force_line_numbers ();
4431 case_stack = thiscase;
4432 nesting_stack = thiscase;
4434 do_pending_stack_adjust ();
4436 /* Make sure case_stmt.start points to something that won't
4437 need any transformation before expand_end_case. */
4438 if (GET_CODE (get_last_insn ()) != NOTE)
4439 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4441 thiscase->data.case_stmt.start = get_last_insn ();
4443 start_cleanup_deferral ();
4446 /* Start a "dummy case statement" within which case labels are invalid
4447 and are not connected to any larger real case statement.
4448 This can be used if you don't want to let a case statement jump
4449 into the middle of certain kinds of constructs. */
4452 expand_start_case_dummy ()
4454 register struct nesting *thiscase = ALLOC_NESTING ();
4456 /* Make an entry on case_stack for the dummy. */
4458 thiscase->next = case_stack;
4459 thiscase->all = nesting_stack;
4460 thiscase->depth = ++nesting_depth;
4461 thiscase->exit_label = 0;
4462 thiscase->data.case_stmt.case_list = 0;
4463 thiscase->data.case_stmt.start = 0;
4464 thiscase->data.case_stmt.nominal_type = 0;
4465 thiscase->data.case_stmt.default_label = 0;
4466 case_stack = thiscase;
4467 nesting_stack = thiscase;
4468 start_cleanup_deferral ();
4471 /* End a dummy case statement. */
4474 expand_end_case_dummy ()
4476 end_cleanup_deferral ();
4477 POPSTACK (case_stack);
4480 /* Return the data type of the index-expression
4481 of the innermost case statement, or null if none. */
4484 case_index_expr_type ()
4487 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
4494 /* If this is the first label, warn if any insns have been emitted. */
4495 if (case_stack->data.case_stmt.line_number_status >= 0)
4499 restore_line_number_status
4500 (case_stack->data.case_stmt.line_number_status);
4501 case_stack->data.case_stmt.line_number_status = -1;
4503 for (insn = case_stack->data.case_stmt.start;
4505 insn = NEXT_INSN (insn))
4507 if (GET_CODE (insn) == CODE_LABEL)
4509 if (GET_CODE (insn) != NOTE
4510 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4513 insn = PREV_INSN (insn);
4514 while (insn && (GET_CODE (insn) != NOTE || NOTE_LINE_NUMBER (insn) < 0));
4516 /* If insn is zero, then there must have been a syntax error. */
4518 warning_with_file_and_line (NOTE_SOURCE_FILE (insn),
4519 NOTE_LINE_NUMBER (insn),
4520 "unreachable code at beginning of %s",
4521 case_stack->data.case_stmt.printname);
4528 /* Accumulate one case or default label inside a case or switch statement.
4529 VALUE is the value of the case (a null pointer, for a default label).
4530 The function CONVERTER, when applied to arguments T and V,
4531 converts the value V to the type T.
4533 If not currently inside a case or switch statement, return 1 and do
4534 nothing. The caller will print a language-specific error message.
4535 If VALUE is a duplicate or overlaps, return 2 and do nothing
4536 except store the (first) duplicate node in *DUPLICATE.
4537 If VALUE is out of range, return 3 and do nothing.
4538 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4539 Return 0 on success.
4541 Extended to handle range statements. */
4544 pushcase (value, converter, label, duplicate)
4545 register tree value;
4546 tree (*converter) PARAMS ((tree, tree));
4547 register tree label;
4553 /* Fail if not inside a real case statement. */
4554 if (! (case_stack && case_stack->data.case_stmt.start))
4557 if (stack_block_stack
4558 && stack_block_stack->depth > case_stack->depth)
4561 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4562 nominal_type = case_stack->data.case_stmt.nominal_type;
4564 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4565 if (index_type == error_mark_node)
4568 /* Convert VALUE to the type in which the comparisons are nominally done. */
4570 value = (*converter) (nominal_type, value);
4574 /* Fail if this value is out of range for the actual type of the index
4575 (which may be narrower than NOMINAL_TYPE). */
4577 && (TREE_CONSTANT_OVERFLOW (value)
4578 || ! int_fits_type_p (value, index_type)))
4581 return add_case_node (value, value, label, duplicate);
4584 /* Like pushcase but this case applies to all values between VALUE1 and
4585 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4586 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4587 starts at VALUE1 and ends at the highest value of the index type.
4588 If both are NULL, this case applies to all values.
4590 The return value is the same as that of pushcase but there is one
4591 additional error code: 4 means the specified range was empty. */
4594 pushcase_range (value1, value2, converter, label, duplicate)
4595 register tree value1, value2;
4596 tree (*converter) PARAMS ((tree, tree));
4597 register tree label;
4603 /* Fail if not inside a real case statement. */
4604 if (! (case_stack && case_stack->data.case_stmt.start))
4607 if (stack_block_stack
4608 && stack_block_stack->depth > case_stack->depth)
4611 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4612 nominal_type = case_stack->data.case_stmt.nominal_type;
4614 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4615 if (index_type == error_mark_node)
4620 /* Convert VALUEs to type in which the comparisons are nominally done
4621 and replace any unspecified value with the corresponding bound. */
4623 value1 = TYPE_MIN_VALUE (index_type);
4625 value2 = TYPE_MAX_VALUE (index_type);
4627 /* Fail if the range is empty. Do this before any conversion since
4628 we want to allow out-of-range empty ranges. */
4629 if (value2 != 0 && tree_int_cst_lt (value2, value1))
4632 /* If the max was unbounded, use the max of the nominal_type we are
4633 converting to. Do this after the < check above to suppress false
4636 value2 = TYPE_MAX_VALUE (nominal_type);
4638 value1 = (*converter) (nominal_type, value1);
4639 value2 = (*converter) (nominal_type, value2);
4641 /* Fail if these values are out of range. */
4642 if (TREE_CONSTANT_OVERFLOW (value1)
4643 || ! int_fits_type_p (value1, index_type))
4646 if (TREE_CONSTANT_OVERFLOW (value2)
4647 || ! int_fits_type_p (value2, index_type))
4650 return add_case_node (value1, value2, label, duplicate);
4653 /* Do the actual insertion of a case label for pushcase and pushcase_range
4654 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4655 slowdown for large switch statements. */
4658 add_case_node (low, high, label, duplicate)
4663 struct case_node *p, **q, *r;
4665 /* If there's no HIGH value, then this is not a case range; it's
4666 just a simple case label. But that's just a degenerate case
4671 /* Handle default labels specially. */
4674 if (case_stack->data.case_stmt.default_label != 0)
4676 *duplicate = case_stack->data.case_stmt.default_label;
4679 case_stack->data.case_stmt.default_label = label;
4680 expand_label (label);
4684 q = &case_stack->data.case_stmt.case_list;
4691 /* Keep going past elements distinctly greater than HIGH. */
4692 if (tree_int_cst_lt (high, p->low))
4695 /* or distinctly less than LOW. */
4696 else if (tree_int_cst_lt (p->high, low))
4701 /* We have an overlap; this is an error. */
4702 *duplicate = p->code_label;
4707 /* Add this label to the chain, and succeed.
4708 Copy LOW, HIGH so they are on temporary rather than momentary
4709 obstack and will thus survive till the end of the case statement. */
4711 r = (struct case_node *) oballoc (sizeof (struct case_node));
4712 r->low = copy_node (low);
4714 /* If the bounds are equal, turn this into the one-value case. */
4715 if (tree_int_cst_equal (low, high))
4718 r->high = copy_node (high);
4720 r->code_label = label;
4721 expand_label (label);
4731 struct case_node *s;
4737 if (! (b = p->balance))
4738 /* Growth propagation from left side. */
4745 if ((p->left = s = r->right))
4754 if ((r->parent = s))
4762 case_stack->data.case_stmt.case_list = r;
4765 /* r->balance == +1 */
4770 struct case_node *t = r->right;
4772 if ((p->left = s = t->right))
4776 if ((r->right = s = t->left))
4790 if ((t->parent = s))
4798 case_stack->data.case_stmt.case_list = t;
4805 /* p->balance == +1; growth of left side balances the node. */
4815 if (! (b = p->balance))
4816 /* Growth propagation from right side. */
4824 if ((p->right = s = r->left))
4832 if ((r->parent = s))
4841 case_stack->data.case_stmt.case_list = r;
4845 /* r->balance == -1 */
4849 struct case_node *t = r->left;
4851 if ((p->right = s = t->left))
4856 if ((r->left = s = t->right))
4870 if ((t->parent = s))
4879 case_stack->data.case_stmt.case_list = t;
4885 /* p->balance == -1; growth of right side balances the node. */
4898 /* Returns the number of possible values of TYPE.
4899 Returns -1 if the number is unknown, variable, or if the number does not
4900 fit in a HOST_WIDE_INT.
4901 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4902 do not increase monotonically (there may be duplicates);
4903 to 1 if the values increase monotonically, but not always by 1;
4904 otherwise sets it to 0. */
4907 all_cases_count (type, spareness)
4912 HOST_WIDE_INT count, minval, lastval;
4916 switch (TREE_CODE (type))
4923 count = 1 << BITS_PER_UNIT;
4928 if (TYPE_MAX_VALUE (type) != 0
4929 && 0 != (t = fold (build (MINUS_EXPR, type, TYPE_MAX_VALUE (type),
4930 TYPE_MIN_VALUE (type))))
4931 && 0 != (t = fold (build (PLUS_EXPR, type, t,
4932 convert (type, integer_zero_node))))
4933 && host_integerp (t, 1))
4934 count = tree_low_cst (t, 1);
4940 /* Don't waste time with enumeral types with huge values. */
4941 if (! host_integerp (TYPE_MIN_VALUE (type), 0)
4942 || TYPE_MAX_VALUE (type) == 0
4943 || ! host_integerp (TYPE_MAX_VALUE (type), 0))
4946 lastval = minval = tree_low_cst (TYPE_MIN_VALUE (type), 0);
4949 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4951 HOST_WIDE_INT thisval = tree_low_cst (TREE_VALUE (t), 0);
4953 if (*spareness == 2 || thisval < lastval)
4955 else if (thisval != minval + count)
4965 #define BITARRAY_TEST(ARRAY, INDEX) \
4966 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4967 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4968 #define BITARRAY_SET(ARRAY, INDEX) \
4969 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4970 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4972 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4973 with the case values we have seen, assuming the case expression
4975 SPARSENESS is as determined by all_cases_count.
4977 The time needed is proportional to COUNT, unless
4978 SPARSENESS is 2, in which case quadratic time is needed. */
4981 mark_seen_cases (type, cases_seen, count, sparseness)
4983 unsigned char *cases_seen;
4984 HOST_WIDE_INT count;
4987 tree next_node_to_try = NULL_TREE;
4988 HOST_WIDE_INT next_node_offset = 0;
4990 register struct case_node *n, *root = case_stack->data.case_stmt.case_list;
4991 tree val = make_node (INTEGER_CST);
4993 TREE_TYPE (val) = type;
4997 else if (sparseness == 2)
5000 unsigned HOST_WIDE_INT xlo;
5002 /* This less efficient loop is only needed to handle
5003 duplicate case values (multiple enum constants
5004 with the same value). */
5005 TREE_TYPE (val) = TREE_TYPE (root->low);
5006 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
5007 t = TREE_CHAIN (t), xlo++)
5009 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (TREE_VALUE (t));
5010 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (TREE_VALUE (t));
5014 /* Keep going past elements distinctly greater than VAL. */
5015 if (tree_int_cst_lt (val, n->low))
5018 /* or distinctly less than VAL. */
5019 else if (tree_int_cst_lt (n->high, val))
5024 /* We have found a matching range. */
5025 BITARRAY_SET (cases_seen, xlo);
5035 case_stack->data.case_stmt.case_list = root = case_tree2list (root, 0);
5037 for (n = root; n; n = n->right)
5039 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
5040 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
5041 while (! tree_int_cst_lt (n->high, val))
5043 /* Calculate (into xlo) the "offset" of the integer (val).
5044 The element with lowest value has offset 0, the next smallest
5045 element has offset 1, etc. */
5047 unsigned HOST_WIDE_INT xlo;
5051 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
5053 /* The TYPE_VALUES will be in increasing order, so
5054 starting searching where we last ended. */
5055 t = next_node_to_try;
5056 xlo = next_node_offset;
5062 t = TYPE_VALUES (type);
5065 if (tree_int_cst_equal (val, TREE_VALUE (t)))
5067 next_node_to_try = TREE_CHAIN (t);
5068 next_node_offset = xlo + 1;
5073 if (t == next_node_to_try)
5082 t = TYPE_MIN_VALUE (type);
5084 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
5088 add_double (xlo, xhi,
5089 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5093 if (xhi == 0 && xlo < (unsigned HOST_WIDE_INT) count)
5094 BITARRAY_SET (cases_seen, xlo);
5096 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5098 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
5104 /* Called when the index of a switch statement is an enumerated type
5105 and there is no default label.
5107 Checks that all enumeration literals are covered by the case
5108 expressions of a switch. Also, warn if there are any extra
5109 switch cases that are *not* elements of the enumerated type.
5111 If all enumeration literals were covered by the case expressions,
5112 turn one of the expressions into the default expression since it should
5113 not be possible to fall through such a switch. */
5116 check_for_full_enumeration_handling (type)
5119 register struct case_node *n;
5120 register tree chain;
5121 #if 0 /* variable used by 'if 0'ed code below. */
5122 register struct case_node **l;
5126 /* True iff the selector type is a numbered set mode. */
5129 /* The number of possible selector values. */
5132 /* For each possible selector value. a one iff it has been matched
5133 by a case value alternative. */
5134 unsigned char *cases_seen;
5136 /* The allocated size of cases_seen, in chars. */
5137 HOST_WIDE_INT bytes_needed;
5142 size = all_cases_count (type, &sparseness);
5143 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
5145 if (size > 0 && size < 600000
5146 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5147 this optimization if we don't have enough memory rather than
5148 aborting, as xmalloc would do. */
5149 && (cases_seen = (unsigned char *) calloc (bytes_needed, 1)) != NULL)
5152 tree v = TYPE_VALUES (type);
5154 /* The time complexity of this code is normally O(N), where
5155 N being the number of members in the enumerated type.
5156 However, if type is a ENUMERAL_TYPE whose values do not
5157 increase monotonically, O(N*log(N)) time may be needed. */
5159 mark_seen_cases (type, cases_seen, size, sparseness);
5161 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
5162 if (BITARRAY_TEST (cases_seen, i) == 0)
5163 warning ("enumeration value `%s' not handled in switch",
5164 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
5169 /* Now we go the other way around; we warn if there are case
5170 expressions that don't correspond to enumerators. This can
5171 occur since C and C++ don't enforce type-checking of
5172 assignments to enumeration variables. */
5174 if (case_stack->data.case_stmt.case_list
5175 && case_stack->data.case_stmt.case_list->left)
5176 case_stack->data.case_stmt.case_list
5177 = case_tree2list (case_stack->data.case_stmt.case_list, 0);
5179 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
5181 for (chain = TYPE_VALUES (type);
5182 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
5183 chain = TREE_CHAIN (chain))
5188 if (TYPE_NAME (type) == 0)
5189 warning ("case value `%ld' not in enumerated type",
5190 (long) TREE_INT_CST_LOW (n->low));
5192 warning ("case value `%ld' not in enumerated type `%s'",
5193 (long) TREE_INT_CST_LOW (n->low),
5194 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5197 : DECL_NAME (TYPE_NAME (type))));
5199 if (!tree_int_cst_equal (n->low, n->high))
5201 for (chain = TYPE_VALUES (type);
5202 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
5203 chain = TREE_CHAIN (chain))
5208 if (TYPE_NAME (type) == 0)
5209 warning ("case value `%ld' not in enumerated type",
5210 (long) TREE_INT_CST_LOW (n->high));
5212 warning ("case value `%ld' not in enumerated type `%s'",
5213 (long) TREE_INT_CST_LOW (n->high),
5214 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5217 : DECL_NAME (TYPE_NAME (type))));
5223 /* ??? This optimization is disabled because it causes valid programs to
5224 fail. ANSI C does not guarantee that an expression with enum type
5225 will have a value that is the same as one of the enumeration literals. */
5227 /* If all values were found as case labels, make one of them the default
5228 label. Thus, this switch will never fall through. We arbitrarily pick
5229 the last one to make the default since this is likely the most
5230 efficient choice. */
5234 for (l = &case_stack->data.case_stmt.case_list;
5239 case_stack->data.case_stmt.default_label = (*l)->code_label;
5246 /* Terminate a case (Pascal) or switch (C) statement
5247 in which ORIG_INDEX is the expression to be tested.
5248 Generate the code to test it and jump to the right place. */
5251 expand_end_case (orig_index)
5254 tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE, orig_minval;
5255 rtx default_label = 0;
5256 register struct case_node *n;
5264 register struct nesting *thiscase = case_stack;
5265 tree index_expr, index_type;
5268 /* Don't crash due to previous errors. */
5269 if (thiscase == NULL)
5272 table_label = gen_label_rtx ();
5273 index_expr = thiscase->data.case_stmt.index_expr;
5274 index_type = TREE_TYPE (index_expr);
5275 unsignedp = TREE_UNSIGNED (index_type);
5277 do_pending_stack_adjust ();
5279 /* This might get an spurious warning in the presence of a syntax error;
5280 it could be fixed by moving the call to check_seenlabel after the
5281 check for error_mark_node, and copying the code of check_seenlabel that
5282 deals with case_stack->data.case_stmt.line_number_status /
5283 restore_line_number_status in front of the call to end_cleanup_deferral;
5284 However, this might miss some useful warnings in the presence of
5285 non-syntax errors. */
5288 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5289 if (index_type != error_mark_node)
5291 /* If switch expression was an enumerated type, check that all
5292 enumeration literals are covered by the cases.
5293 No sense trying this if there's a default case, however. */
5295 if (!thiscase->data.case_stmt.default_label
5296 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
5297 && TREE_CODE (index_expr) != INTEGER_CST)
5298 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
5300 /* If we don't have a default-label, create one here,
5301 after the body of the switch. */
5302 if (thiscase->data.case_stmt.default_label == 0)
5304 thiscase->data.case_stmt.default_label
5305 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5306 expand_label (thiscase->data.case_stmt.default_label);
5308 default_label = label_rtx (thiscase->data.case_stmt.default_label);
5310 before_case = get_last_insn ();
5312 if (thiscase->data.case_stmt.case_list
5313 && thiscase->data.case_stmt.case_list->left)
5314 thiscase->data.case_stmt.case_list
5315 = case_tree2list (thiscase->data.case_stmt.case_list, 0);
5317 /* Simplify the case-list before we count it. */
5318 group_case_nodes (thiscase->data.case_stmt.case_list);
5320 /* Get upper and lower bounds of case values.
5321 Also convert all the case values to the index expr's data type. */
5324 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5326 /* Check low and high label values are integers. */
5327 if (TREE_CODE (n->low) != INTEGER_CST)
5329 if (TREE_CODE (n->high) != INTEGER_CST)
5332 n->low = convert (index_type, n->low);
5333 n->high = convert (index_type, n->high);
5335 /* Count the elements and track the largest and smallest
5336 of them (treating them as signed even if they are not). */
5344 if (INT_CST_LT (n->low, minval))
5346 if (INT_CST_LT (maxval, n->high))
5349 /* A range counts double, since it requires two compares. */
5350 if (! tree_int_cst_equal (n->low, n->high))
5354 orig_minval = minval;
5356 /* Compute span of values. */
5358 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
5360 end_cleanup_deferral ();
5364 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
5366 emit_jump (default_label);
5369 /* If range of values is much bigger than number of values,
5370 make a sequence of conditional branches instead of a dispatch.
5371 If the switch-index is a constant, do it this way
5372 because we can optimize it. */
5374 #ifndef CASE_VALUES_THRESHOLD
5376 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
5378 /* If machine does not have a case insn that compares the
5379 bounds, this means extra overhead for dispatch tables
5380 which raises the threshold for using them. */
5381 #define CASE_VALUES_THRESHOLD 5
5382 #endif /* HAVE_casesi */
5383 #endif /* CASE_VALUES_THRESHOLD */
5385 else if (count < CASE_VALUES_THRESHOLD
5386 || compare_tree_int (range, 10 * count) > 0
5387 /* RANGE may be signed, and really large ranges will show up
5388 as negative numbers. */
5389 || compare_tree_int (range, 0) < 0
5390 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5393 || TREE_CODE (index_expr) == INTEGER_CST
5394 /* These will reduce to a constant. */
5395 || (TREE_CODE (index_expr) == CALL_EXPR
5396 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
5397 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
5398 && DECL_BUILT_IN_CLASS (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_NORMAL
5399 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
5400 || (TREE_CODE (index_expr) == COMPOUND_EXPR
5401 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
5403 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5405 /* If the index is a short or char that we do not have
5406 an insn to handle comparisons directly, convert it to
5407 a full integer now, rather than letting each comparison
5408 generate the conversion. */
5410 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
5411 && (cmp_optab->handlers[(int) GET_MODE (index)].insn_code
5412 == CODE_FOR_nothing))
5414 enum machine_mode wider_mode;
5415 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
5416 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
5417 if (cmp_optab->handlers[(int) wider_mode].insn_code
5418 != CODE_FOR_nothing)
5420 index = convert_to_mode (wider_mode, index, unsignedp);
5426 do_pending_stack_adjust ();
5428 index = protect_from_queue (index, 0);
5429 if (GET_CODE (index) == MEM)
5430 index = copy_to_reg (index);
5431 if (GET_CODE (index) == CONST_INT
5432 || TREE_CODE (index_expr) == INTEGER_CST)
5434 /* Make a tree node with the proper constant value
5435 if we don't already have one. */
5436 if (TREE_CODE (index_expr) != INTEGER_CST)
5439 = build_int_2 (INTVAL (index),
5440 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
5441 index_expr = convert (index_type, index_expr);
5444 /* For constant index expressions we need only
5445 issue a unconditional branch to the appropriate
5446 target code. The job of removing any unreachable
5447 code is left to the optimisation phase if the
5448 "-O" option is specified. */
5449 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5450 if (! tree_int_cst_lt (index_expr, n->low)
5451 && ! tree_int_cst_lt (n->high, index_expr))
5455 emit_jump (label_rtx (n->code_label));
5457 emit_jump (default_label);
5461 /* If the index expression is not constant we generate
5462 a binary decision tree to select the appropriate
5463 target code. This is done as follows:
5465 The list of cases is rearranged into a binary tree,
5466 nearly optimal assuming equal probability for each case.
5468 The tree is transformed into RTL, eliminating
5469 redundant test conditions at the same time.
5471 If program flow could reach the end of the
5472 decision tree an unconditional jump to the
5473 default code is emitted. */
5476 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
5477 && estimate_case_costs (thiscase->data.case_stmt.case_list));
5478 balance_case_nodes (&thiscase->data.case_stmt.case_list,
5480 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
5481 default_label, index_type);
5482 emit_jump_if_reachable (default_label);
5491 enum machine_mode index_mode = SImode;
5492 int index_bits = GET_MODE_BITSIZE (index_mode);
5494 enum machine_mode op_mode;
5496 /* Convert the index to SImode. */
5497 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
5498 > GET_MODE_BITSIZE (index_mode))
5500 enum machine_mode omode = TYPE_MODE (index_type);
5501 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
5503 /* We must handle the endpoints in the original mode. */
5504 index_expr = build (MINUS_EXPR, index_type,
5505 index_expr, minval);
5506 minval = integer_zero_node;
5507 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5508 emit_cmp_and_jump_insns (rangertx, index, LTU, NULL_RTX,
5509 omode, 1, 0, default_label);
5510 /* Now we can safely truncate. */
5511 index = convert_to_mode (index_mode, index, 0);
5515 if (TYPE_MODE (index_type) != index_mode)
5517 index_expr = convert (type_for_size (index_bits, 0),
5519 index_type = TREE_TYPE (index_expr);
5522 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5525 index = protect_from_queue (index, 0);
5526 do_pending_stack_adjust ();
5528 op_mode = insn_data[(int) CODE_FOR_casesi].operand[0].mode;
5529 if (! (*insn_data[(int) CODE_FOR_casesi].operand[0].predicate)
5531 index = copy_to_mode_reg (op_mode, index);
5533 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
5535 op_mode = insn_data[(int) CODE_FOR_casesi].operand[1].mode;
5536 if (! (*insn_data[(int) CODE_FOR_casesi].operand[1].predicate)
5538 op1 = copy_to_mode_reg (op_mode, op1);
5540 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
5542 op_mode = insn_data[(int) CODE_FOR_casesi].operand[2].mode;
5543 if (! (*insn_data[(int) CODE_FOR_casesi].operand[2].predicate)
5545 op2 = copy_to_mode_reg (op_mode, op2);
5547 emit_jump_insn (gen_casesi (index, op1, op2,
5548 table_label, default_label));
5552 #ifdef HAVE_tablejump
5553 if (! win && HAVE_tablejump)
5555 index_type = thiscase->data.case_stmt.nominal_type;
5556 index_expr = fold (build (MINUS_EXPR, index_type,
5557 convert (index_type, index_expr),
5558 convert (index_type, minval)));
5559 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5561 index = protect_from_queue (index, 0);
5562 do_pending_stack_adjust ();
5564 do_tablejump (index, TYPE_MODE (index_type),
5565 expand_expr (range, NULL_RTX, VOIDmode, 0),
5566 table_label, default_label);
5573 /* Get table of labels to jump to, in order of case index. */
5575 ncases = TREE_INT_CST_LOW (range) + 1;
5576 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
5577 bzero ((char *) labelvec, ncases * sizeof (rtx));
5579 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5581 register HOST_WIDE_INT i
5582 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
5587 = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
5588 if (i + TREE_INT_CST_LOW (orig_minval)
5589 == TREE_INT_CST_LOW (n->high))
5595 /* Fill in the gaps with the default. */
5596 for (i = 0; i < ncases; i++)
5597 if (labelvec[i] == 0)
5598 labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
5600 /* Output the table */
5601 emit_label (table_label);
5603 if (CASE_VECTOR_PC_RELATIVE || flag_pic)
5604 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
5605 gen_rtx_LABEL_REF (Pmode, table_label),
5606 gen_rtvec_v (ncases, labelvec),
5607 const0_rtx, const0_rtx));
5609 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
5610 gen_rtvec_v (ncases, labelvec)));
5612 /* If the case insn drops through the table,
5613 after the table we must jump to the default-label.
5614 Otherwise record no drop-through after the table. */
5615 #ifdef CASE_DROPS_THROUGH
5616 emit_jump (default_label);
5622 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
5623 reorder_insns (before_case, get_last_insn (),
5624 thiscase->data.case_stmt.start);
5627 end_cleanup_deferral ();
5629 if (thiscase->exit_label)
5630 emit_label (thiscase->exit_label);
5632 POPSTACK (case_stack);
5637 /* Convert the tree NODE into a list linked by the right field, with the left
5638 field zeroed. RIGHT is used for recursion; it is a list to be placed
5639 rightmost in the resulting list. */
5641 static struct case_node *
5642 case_tree2list (node, right)
5643 struct case_node *node, *right;
5645 struct case_node *left;
5648 right = case_tree2list (node->right, right);
5650 node->right = right;
5651 if ((left = node->left))
5654 return case_tree2list (left, node);
5660 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5663 do_jump_if_equal (op1, op2, label, unsignedp)
5664 rtx op1, op2, label;
5667 if (GET_CODE (op1) == CONST_INT
5668 && GET_CODE (op2) == CONST_INT)
5670 if (INTVAL (op1) == INTVAL (op2))
5675 enum machine_mode mode = GET_MODE (op1);
5676 if (mode == VOIDmode)
5677 mode = GET_MODE (op2);
5678 emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX, mode, unsignedp,
5683 /* Not all case values are encountered equally. This function
5684 uses a heuristic to weight case labels, in cases where that
5685 looks like a reasonable thing to do.
5687 Right now, all we try to guess is text, and we establish the
5690 chars above space: 16
5699 If we find any cases in the switch that are not either -1 or in the range
5700 of valid ASCII characters, or are control characters other than those
5701 commonly used with "\", don't treat this switch scanning text.
5703 Return 1 if these nodes are suitable for cost estimation, otherwise
5707 estimate_case_costs (node)
5710 tree min_ascii = build_int_2 (-1, -1);
5711 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5715 /* If we haven't already made the cost table, make it now. Note that the
5716 lower bound of the table is -1, not zero. */
5718 if (cost_table == NULL)
5720 cost_table = cost_table_ + 1;
5722 for (i = 0; i < 128; i++)
5726 else if (ISPUNCT (i))
5728 else if (ISCNTRL (i))
5732 cost_table[' '] = 8;
5733 cost_table['\t'] = 4;
5734 cost_table['\0'] = 4;
5735 cost_table['\n'] = 2;
5736 cost_table['\f'] = 1;
5737 cost_table['\v'] = 1;
5738 cost_table['\b'] = 1;
5741 /* See if all the case expressions look like text. It is text if the
5742 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5743 as signed arithmetic since we don't want to ever access cost_table with a
5744 value less than -1. Also check that none of the constants in a range
5745 are strange control characters. */
5747 for (n = node; n; n = n->right)
5749 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5752 for (i = (HOST_WIDE_INT) TREE_INT_CST_LOW (n->low);
5753 i <= (HOST_WIDE_INT) TREE_INT_CST_LOW (n->high); i++)
5754 if (cost_table[i] < 0)
5758 /* All interesting values are within the range of interesting
5759 ASCII characters. */
5763 /* Scan an ordered list of case nodes
5764 combining those with consecutive values or ranges.
5766 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5769 group_case_nodes (head)
5772 case_node_ptr node = head;
5776 rtx lb = next_real_insn (label_rtx (node->code_label));
5778 case_node_ptr np = node;
5780 /* Try to group the successors of NODE with NODE. */
5781 while (((np = np->right) != 0)
5782 /* Do they jump to the same place? */
5783 && ((lb2 = next_real_insn (label_rtx (np->code_label))) == lb
5784 || (lb != 0 && lb2 != 0
5785 && simplejump_p (lb)
5786 && simplejump_p (lb2)
5787 && rtx_equal_p (SET_SRC (PATTERN (lb)),
5788 SET_SRC (PATTERN (lb2)))))
5789 /* Are their ranges consecutive? */
5790 && tree_int_cst_equal (np->low,
5791 fold (build (PLUS_EXPR,
5792 TREE_TYPE (node->high),
5795 /* An overflow is not consecutive. */
5796 && tree_int_cst_lt (node->high,
5797 fold (build (PLUS_EXPR,
5798 TREE_TYPE (node->high),
5800 integer_one_node))))
5802 node->high = np->high;
5804 /* NP is the first node after NODE which can't be grouped with it.
5805 Delete the nodes in between, and move on to that node. */
5811 /* Take an ordered list of case nodes
5812 and transform them into a near optimal binary tree,
5813 on the assumption that any target code selection value is as
5814 likely as any other.
5816 The transformation is performed by splitting the ordered
5817 list into two equal sections plus a pivot. The parts are
5818 then attached to the pivot as left and right branches. Each
5819 branch is then transformed recursively. */
5822 balance_case_nodes (head, parent)
5823 case_node_ptr *head;
5824 case_node_ptr parent;
5826 register case_node_ptr np;
5834 register case_node_ptr *npp;
5837 /* Count the number of entries on branch. Also count the ranges. */
5841 if (!tree_int_cst_equal (np->low, np->high))
5845 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5849 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5857 /* Split this list if it is long enough for that to help. */
5862 /* Find the place in the list that bisects the list's total cost,
5863 Here I gets half the total cost. */
5868 /* Skip nodes while their cost does not reach that amount. */
5869 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5870 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5871 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5874 npp = &(*npp)->right;
5879 /* Leave this branch lopsided, but optimize left-hand
5880 side and fill in `parent' fields for right-hand side. */
5882 np->parent = parent;
5883 balance_case_nodes (&np->left, np);
5884 for (; np->right; np = np->right)
5885 np->right->parent = np;
5889 /* If there are just three nodes, split at the middle one. */
5891 npp = &(*npp)->right;
5894 /* Find the place in the list that bisects the list's total cost,
5895 where ranges count as 2.
5896 Here I gets half the total cost. */
5897 i = (i + ranges + 1) / 2;
5900 /* Skip nodes while their cost does not reach that amount. */
5901 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5906 npp = &(*npp)->right;
5911 np->parent = parent;
5914 /* Optimize each of the two split parts. */
5915 balance_case_nodes (&np->left, np);
5916 balance_case_nodes (&np->right, np);
5920 /* Else leave this branch as one level,
5921 but fill in `parent' fields. */
5923 np->parent = parent;
5924 for (; np->right; np = np->right)
5925 np->right->parent = np;
5930 /* Search the parent sections of the case node tree
5931 to see if a test for the lower bound of NODE would be redundant.
5932 INDEX_TYPE is the type of the index expression.
5934 The instructions to generate the case decision tree are
5935 output in the same order as nodes are processed so it is
5936 known that if a parent node checks the range of the current
5937 node minus one that the current node is bounded at its lower
5938 span. Thus the test would be redundant. */
5941 node_has_low_bound (node, index_type)
5946 case_node_ptr pnode;
5948 /* If the lower bound of this node is the lowest value in the index type,
5949 we need not test it. */
5951 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5954 /* If this node has a left branch, the value at the left must be less
5955 than that at this node, so it cannot be bounded at the bottom and
5956 we need not bother testing any further. */
5961 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5962 node->low, integer_one_node));
5964 /* If the subtraction above overflowed, we can't verify anything.
5965 Otherwise, look for a parent that tests our value - 1. */
5967 if (! tree_int_cst_lt (low_minus_one, node->low))
5970 for (pnode = node->parent; pnode; pnode = pnode->parent)
5971 if (tree_int_cst_equal (low_minus_one, pnode->high))
5977 /* Search the parent sections of the case node tree
5978 to see if a test for the upper bound of NODE would be redundant.
5979 INDEX_TYPE is the type of the index expression.
5981 The instructions to generate the case decision tree are
5982 output in the same order as nodes are processed so it is
5983 known that if a parent node checks the range of the current
5984 node plus one that the current node is bounded at its upper
5985 span. Thus the test would be redundant. */
5988 node_has_high_bound (node, index_type)
5993 case_node_ptr pnode;
5995 /* If there is no upper bound, obviously no test is needed. */
5997 if (TYPE_MAX_VALUE (index_type) == NULL)
6000 /* If the upper bound of this node is the highest value in the type
6001 of the index expression, we need not test against it. */
6003 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
6006 /* If this node has a right branch, the value at the right must be greater
6007 than that at this node, so it cannot be bounded at the top and
6008 we need not bother testing any further. */
6013 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
6014 node->high, integer_one_node));
6016 /* If the addition above overflowed, we can't verify anything.
6017 Otherwise, look for a parent that tests our value + 1. */
6019 if (! tree_int_cst_lt (node->high, high_plus_one))
6022 for (pnode = node->parent; pnode; pnode = pnode->parent)
6023 if (tree_int_cst_equal (high_plus_one, pnode->low))
6029 /* Search the parent sections of the
6030 case node tree to see if both tests for the upper and lower
6031 bounds of NODE would be redundant. */
6034 node_is_bounded (node, index_type)
6038 return (node_has_low_bound (node, index_type)
6039 && node_has_high_bound (node, index_type));
6042 /* Emit an unconditional jump to LABEL unless it would be dead code. */
6045 emit_jump_if_reachable (label)
6048 if (GET_CODE (get_last_insn ()) != BARRIER)
6052 /* Emit step-by-step code to select a case for the value of INDEX.
6053 The thus generated decision tree follows the form of the
6054 case-node binary tree NODE, whose nodes represent test conditions.
6055 INDEX_TYPE is the type of the index of the switch.
6057 Care is taken to prune redundant tests from the decision tree
6058 by detecting any boundary conditions already checked by
6059 emitted rtx. (See node_has_high_bound, node_has_low_bound
6060 and node_is_bounded, above.)
6062 Where the test conditions can be shown to be redundant we emit
6063 an unconditional jump to the target code. As a further
6064 optimization, the subordinates of a tree node are examined to
6065 check for bounded nodes. In this case conditional and/or
6066 unconditional jumps as a result of the boundary check for the
6067 current node are arranged to target the subordinates associated
6068 code for out of bound conditions on the current node.
6070 We can assume that when control reaches the code generated here,
6071 the index value has already been compared with the parents
6072 of this node, and determined to be on the same side of each parent
6073 as this node is. Thus, if this node tests for the value 51,
6074 and a parent tested for 52, we don't need to consider
6075 the possibility of a value greater than 51. If another parent
6076 tests for the value 50, then this node need not test anything. */
6079 emit_case_nodes (index, node, default_label, index_type)
6085 /* If INDEX has an unsigned type, we must make unsigned branches. */
6086 int unsignedp = TREE_UNSIGNED (index_type);
6087 enum machine_mode mode = GET_MODE (index);
6089 /* See if our parents have already tested everything for us.
6090 If they have, emit an unconditional jump for this node. */
6091 if (node_is_bounded (node, index_type))
6092 emit_jump (label_rtx (node->code_label));
6094 else if (tree_int_cst_equal (node->low, node->high))
6096 /* Node is single valued. First see if the index expression matches
6097 this node and then check our children, if any. */
6099 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
6100 label_rtx (node->code_label), unsignedp);
6102 if (node->right != 0 && node->left != 0)
6104 /* This node has children on both sides.
6105 Dispatch to one side or the other
6106 by comparing the index value with this node's value.
6107 If one subtree is bounded, check that one first,
6108 so we can avoid real branches in the tree. */
6110 if (node_is_bounded (node->right, index_type))
6112 emit_cmp_and_jump_insns (index,
6113 expand_expr (node->high, NULL_RTX,
6115 GT, NULL_RTX, mode, unsignedp, 0,
6116 label_rtx (node->right->code_label));
6117 emit_case_nodes (index, node->left, default_label, index_type);
6120 else if (node_is_bounded (node->left, index_type))
6122 emit_cmp_and_jump_insns (index,
6123 expand_expr (node->high, NULL_RTX,
6125 LT, NULL_RTX, mode, unsignedp, 0,
6126 label_rtx (node->left->code_label));
6127 emit_case_nodes (index, node->right, default_label, index_type);
6132 /* Neither node is bounded. First distinguish the two sides;
6133 then emit the code for one side at a time. */
6135 tree test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6137 /* See if the value is on the right. */
6138 emit_cmp_and_jump_insns (index,
6139 expand_expr (node->high, NULL_RTX,
6141 GT, NULL_RTX, mode, unsignedp, 0,
6142 label_rtx (test_label));
6144 /* Value must be on the left.
6145 Handle the left-hand subtree. */
6146 emit_case_nodes (index, node->left, default_label, index_type);
6147 /* If left-hand subtree does nothing,
6149 emit_jump_if_reachable (default_label);
6151 /* Code branches here for the right-hand subtree. */
6152 expand_label (test_label);
6153 emit_case_nodes (index, node->right, default_label, index_type);
6157 else if (node->right != 0 && node->left == 0)
6159 /* Here we have a right child but no left so we issue conditional
6160 branch to default and process the right child.
6162 Omit the conditional branch to default if we it avoid only one
6163 right child; it costs too much space to save so little time. */
6165 if (node->right->right || node->right->left
6166 || !tree_int_cst_equal (node->right->low, node->right->high))
6168 if (!node_has_low_bound (node, index_type))
6170 emit_cmp_and_jump_insns (index,
6171 expand_expr (node->high, NULL_RTX,
6173 LT, NULL_RTX, mode, unsignedp, 0,
6177 emit_case_nodes (index, node->right, default_label, index_type);
6180 /* We cannot process node->right normally
6181 since we haven't ruled out the numbers less than
6182 this node's value. So handle node->right explicitly. */
6183 do_jump_if_equal (index,
6184 expand_expr (node->right->low, NULL_RTX,
6186 label_rtx (node->right->code_label), unsignedp);
6189 else if (node->right == 0 && node->left != 0)
6191 /* Just one subtree, on the left. */
6193 #if 0 /* The following code and comment were formerly part
6194 of the condition here, but they didn't work
6195 and I don't understand what the idea was. -- rms. */
6196 /* If our "most probable entry" is less probable
6197 than the default label, emit a jump to
6198 the default label using condition codes
6199 already lying around. With no right branch,
6200 a branch-greater-than will get us to the default
6203 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
6206 if (node->left->left || node->left->right
6207 || !tree_int_cst_equal (node->left->low, node->left->high))
6209 if (!node_has_high_bound (node, index_type))
6211 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6214 GT, NULL_RTX, mode, unsignedp, 0,
6218 emit_case_nodes (index, node->left, default_label, index_type);
6221 /* We cannot process node->left normally
6222 since we haven't ruled out the numbers less than
6223 this node's value. So handle node->left explicitly. */
6224 do_jump_if_equal (index,
6225 expand_expr (node->left->low, NULL_RTX,
6227 label_rtx (node->left->code_label), unsignedp);
6232 /* Node is a range. These cases are very similar to those for a single
6233 value, except that we do not start by testing whether this node
6234 is the one to branch to. */
6236 if (node->right != 0 && node->left != 0)
6238 /* Node has subtrees on both sides.
6239 If the right-hand subtree is bounded,
6240 test for it first, since we can go straight there.
6241 Otherwise, we need to make a branch in the control structure,
6242 then handle the two subtrees. */
6243 tree test_label = 0;
6245 if (node_is_bounded (node->right, index_type))
6246 /* Right hand node is fully bounded so we can eliminate any
6247 testing and branch directly to the target code. */
6248 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6250 GT, NULL_RTX, mode, unsignedp, 0,
6251 label_rtx (node->right->code_label));
6254 /* Right hand node requires testing.
6255 Branch to a label where we will handle it later. */
6257 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6258 emit_cmp_and_jump_insns (index,
6259 expand_expr (node->high, NULL_RTX,
6261 GT, NULL_RTX, mode, unsignedp, 0,
6262 label_rtx (test_label));
6265 /* Value belongs to this node or to the left-hand subtree. */
6267 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6269 GE, NULL_RTX, mode, unsignedp, 0,
6270 label_rtx (node->code_label));
6272 /* Handle the left-hand subtree. */
6273 emit_case_nodes (index, node->left, default_label, index_type);
6275 /* If right node had to be handled later, do that now. */
6279 /* If the left-hand subtree fell through,
6280 don't let it fall into the right-hand subtree. */
6281 emit_jump_if_reachable (default_label);
6283 expand_label (test_label);
6284 emit_case_nodes (index, node->right, default_label, index_type);
6288 else if (node->right != 0 && node->left == 0)
6290 /* Deal with values to the left of this node,
6291 if they are possible. */
6292 if (!node_has_low_bound (node, index_type))
6294 emit_cmp_and_jump_insns (index,
6295 expand_expr (node->low, NULL_RTX,
6297 LT, NULL_RTX, mode, unsignedp, 0,
6301 /* Value belongs to this node or to the right-hand subtree. */
6303 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6305 LE, NULL_RTX, mode, unsignedp, 0,
6306 label_rtx (node->code_label));
6308 emit_case_nodes (index, node->right, default_label, index_type);
6311 else if (node->right == 0 && node->left != 0)
6313 /* Deal with values to the right of this node,
6314 if they are possible. */
6315 if (!node_has_high_bound (node, index_type))
6317 emit_cmp_and_jump_insns (index,
6318 expand_expr (node->high, NULL_RTX,
6320 GT, NULL_RTX, mode, unsignedp, 0,
6324 /* Value belongs to this node or to the left-hand subtree. */
6326 emit_cmp_and_jump_insns (index,
6327 expand_expr (node->low, NULL_RTX,
6329 GE, NULL_RTX, mode, unsignedp, 0,
6330 label_rtx (node->code_label));
6332 emit_case_nodes (index, node->left, default_label, index_type);
6337 /* Node has no children so we check low and high bounds to remove
6338 redundant tests. Only one of the bounds can exist,
6339 since otherwise this node is bounded--a case tested already. */
6341 if (!node_has_high_bound (node, index_type))
6343 emit_cmp_and_jump_insns (index,
6344 expand_expr (node->high, NULL_RTX,
6346 GT, NULL_RTX, mode, unsignedp, 0,
6350 if (!node_has_low_bound (node, index_type))
6352 emit_cmp_and_jump_insns (index,
6353 expand_expr (node->low, NULL_RTX,
6355 LT, NULL_RTX, mode, unsignedp, 0,
6359 emit_jump (label_rtx (node->code_label));