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 static int n_occurrences PARAMS ((int, const char *));
397 static void expand_goto_internal PARAMS ((tree, rtx, rtx));
398 static int expand_fixup PARAMS ((tree, rtx, rtx));
399 static rtx expand_nl_handler_label PARAMS ((rtx, rtx));
400 static void expand_nl_goto_receiver PARAMS ((void));
401 static void expand_nl_goto_receivers PARAMS ((struct nesting *));
402 static void fixup_gotos PARAMS ((struct nesting *, rtx, tree,
404 static void expand_null_return_1 PARAMS ((rtx, int));
405 static void expand_value_return PARAMS ((rtx));
406 static int tail_recursion_args PARAMS ((tree, tree));
407 static void expand_cleanups PARAMS ((tree, tree, int, int));
408 static void check_seenlabel PARAMS ((void));
409 static void do_jump_if_equal PARAMS ((rtx, rtx, rtx, int));
410 static int estimate_case_costs PARAMS ((case_node_ptr));
411 static void group_case_nodes PARAMS ((case_node_ptr));
412 static void balance_case_nodes PARAMS ((case_node_ptr *,
414 static int node_has_low_bound PARAMS ((case_node_ptr, tree));
415 static int node_has_high_bound PARAMS ((case_node_ptr, tree));
416 static int node_is_bounded PARAMS ((case_node_ptr, tree));
417 static void emit_jump_if_reachable PARAMS ((rtx));
418 static void emit_case_nodes PARAMS ((rtx, case_node_ptr, rtx, tree));
419 static struct case_node *case_tree2list PARAMS ((case_node *, case_node *));
420 static void mark_cond_nesting PARAMS ((struct nesting *));
421 static void mark_loop_nesting PARAMS ((struct nesting *));
422 static void mark_block_nesting PARAMS ((struct nesting *));
423 static void mark_case_nesting PARAMS ((struct nesting *));
424 static void mark_case_node PARAMS ((struct case_node *));
425 static void mark_goto_fixup PARAMS ((struct goto_fixup *));
426 static void free_case_nodes PARAMS ((case_node_ptr));
429 using_eh_for_cleanups ()
431 using_eh_for_cleanups_p = 1;
434 /* Mark N (known to be a cond-nesting) for GC. */
437 mark_cond_nesting (n)
442 ggc_mark_rtx (n->exit_label);
443 ggc_mark_rtx (n->data.cond.endif_label);
444 ggc_mark_rtx (n->data.cond.next_label);
450 /* Mark N (known to be a loop-nesting) for GC. */
453 mark_loop_nesting (n)
459 ggc_mark_rtx (n->exit_label);
460 ggc_mark_rtx (n->data.loop.start_label);
461 ggc_mark_rtx (n->data.loop.end_label);
462 ggc_mark_rtx (n->data.loop.alt_end_label);
463 ggc_mark_rtx (n->data.loop.continue_label);
469 /* Mark N (known to be a block-nesting) for GC. */
472 mark_block_nesting (n)
477 struct label_chain *l;
479 ggc_mark_rtx (n->exit_label);
480 ggc_mark_rtx (n->data.block.stack_level);
481 ggc_mark_rtx (n->data.block.first_insn);
482 ggc_mark_tree (n->data.block.cleanups);
483 ggc_mark_tree (n->data.block.outer_cleanups);
485 for (l = n->data.block.label_chain; l != NULL; l = l->next)
488 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);
597 gcc_obstack_init (&stmt_obstack);
601 init_stmt_for_function ()
603 cfun->stmt = (struct stmt_status *) xmalloc (sizeof (struct stmt_status));
605 /* We are not currently within any block, conditional, loop or case. */
607 stack_block_stack = 0;
614 current_block_start_count = 0;
616 /* No gotos have been expanded yet. */
617 goto_fixup_chain = 0;
619 /* We are not processing a ({...}) grouping. */
620 expr_stmts_for_value = 0;
622 last_expr_value = NULL_RTX;
625 /* Return nonzero if anything is pushed on the loop, condition, or case
630 return cond_stack || loop_stack || case_stack;
633 /* Record the current file and line. Called from emit_line_note. */
635 set_file_and_line_for_stmt (file, line)
639 /* If we're outputting an inline function, and we add a line note,
640 there may be no CFUN->STMT information. So, there's no need to
644 emit_filename = file;
649 /* Emit a no-op instruction. */
656 last_insn = get_last_insn ();
658 && (GET_CODE (last_insn) == CODE_LABEL
659 || (GET_CODE (last_insn) == NOTE
660 && prev_real_insn (last_insn) == 0)))
661 emit_insn (gen_nop ());
664 /* Return the rtx-label that corresponds to a LABEL_DECL,
665 creating it if necessary. */
671 if (TREE_CODE (label) != LABEL_DECL)
674 if (DECL_RTL (label))
675 return DECL_RTL (label);
677 return DECL_RTL (label) = gen_label_rtx ();
680 /* Add an unconditional jump to LABEL as the next sequential instruction. */
686 do_pending_stack_adjust ();
687 emit_jump_insn (gen_jump (label));
691 /* Emit code to jump to the address
692 specified by the pointer expression EXP. */
695 expand_computed_goto (exp)
698 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
700 #ifdef POINTERS_EXTEND_UNSIGNED
701 x = convert_memory_address (Pmode, x);
705 /* Be sure the function is executable. */
706 if (current_function_check_memory_usage)
707 emit_library_call (chkr_check_exec_libfunc, LCT_CONST_MAKE_BLOCK,
708 VOIDmode, 1, x, ptr_mode);
710 do_pending_stack_adjust ();
711 emit_indirect_jump (x);
713 current_function_has_computed_jump = 1;
716 /* Handle goto statements and the labels that they can go to. */
718 /* Specify the location in the RTL code of a label LABEL,
719 which is a LABEL_DECL tree node.
721 This is used for the kind of label that the user can jump to with a
722 goto statement, and for alternatives of a switch or case statement.
723 RTL labels generated for loops and conditionals don't go through here;
724 they are generated directly at the RTL level, by other functions below.
726 Note that this has nothing to do with defining label *names*.
727 Languages vary in how they do that and what that even means. */
733 struct label_chain *p;
735 do_pending_stack_adjust ();
736 emit_label (label_rtx (label));
737 if (DECL_NAME (label))
738 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
740 if (stack_block_stack != 0)
742 p = (struct label_chain *) ggc_alloc (sizeof (struct label_chain));
743 p->next = stack_block_stack->data.block.label_chain;
744 stack_block_stack->data.block.label_chain = p;
749 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
750 from nested functions. */
753 declare_nonlocal_label (label)
756 rtx slot = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
758 nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
759 LABEL_PRESERVE_P (label_rtx (label)) = 1;
760 if (nonlocal_goto_handler_slots == 0)
762 emit_stack_save (SAVE_NONLOCAL,
763 &nonlocal_goto_stack_level,
764 PREV_INSN (tail_recursion_reentry));
766 nonlocal_goto_handler_slots
767 = gen_rtx_EXPR_LIST (VOIDmode, slot, nonlocal_goto_handler_slots);
770 /* Generate RTL code for a `goto' statement with target label LABEL.
771 LABEL should be a LABEL_DECL tree node that was or will later be
772 defined with `expand_label'. */
780 /* Check for a nonlocal goto to a containing function. */
781 context = decl_function_context (label);
782 if (context != 0 && context != current_function_decl)
784 struct function *p = find_function_data (context);
785 rtx label_ref = gen_rtx_LABEL_REF (Pmode, label_rtx (label));
786 rtx handler_slot, static_chain, save_area;
789 /* Find the corresponding handler slot for this label. */
790 handler_slot = p->x_nonlocal_goto_handler_slots;
791 for (link = p->x_nonlocal_labels; TREE_VALUE (link) != label;
792 link = TREE_CHAIN (link))
793 handler_slot = XEXP (handler_slot, 1);
794 handler_slot = XEXP (handler_slot, 0);
796 p->has_nonlocal_label = 1;
797 current_function_has_nonlocal_goto = 1;
798 LABEL_REF_NONLOCAL_P (label_ref) = 1;
800 /* Copy the rtl for the slots so that they won't be shared in
801 case the virtual stack vars register gets instantiated differently
802 in the parent than in the child. */
804 static_chain = copy_to_reg (lookup_static_chain (label));
806 /* Get addr of containing function's current nonlocal goto handler,
807 which will do any cleanups and then jump to the label. */
808 handler_slot = copy_to_reg (replace_rtx (copy_rtx (handler_slot),
809 virtual_stack_vars_rtx,
812 /* Get addr of containing function's nonlocal save area. */
813 save_area = p->x_nonlocal_goto_stack_level;
815 save_area = replace_rtx (copy_rtx (save_area),
816 virtual_stack_vars_rtx, static_chain);
818 #if HAVE_nonlocal_goto
819 if (HAVE_nonlocal_goto)
820 emit_insn (gen_nonlocal_goto (static_chain, handler_slot,
821 save_area, label_ref));
825 /* Restore frame pointer for containing function.
826 This sets the actual hard register used for the frame pointer
827 to the location of the function's incoming static chain info.
828 The non-local goto handler will then adjust it to contain the
829 proper value and reload the argument pointer, if needed. */
830 emit_move_insn (hard_frame_pointer_rtx, static_chain);
831 emit_stack_restore (SAVE_NONLOCAL, save_area, NULL_RTX);
833 /* USE of hard_frame_pointer_rtx added for consistency;
834 not clear if really needed. */
835 emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx));
836 emit_insn (gen_rtx_USE (VOIDmode, stack_pointer_rtx));
837 emit_indirect_jump (handler_slot);
841 expand_goto_internal (label, label_rtx (label), NULL_RTX);
844 /* Generate RTL code for a `goto' statement with target label BODY.
845 LABEL should be a LABEL_REF.
846 LAST_INSN, if non-0, is the rtx we should consider as the last
847 insn emitted (for the purposes of cleaning up a return). */
850 expand_goto_internal (body, label, last_insn)
855 struct nesting *block;
858 if (GET_CODE (label) != CODE_LABEL)
861 /* If label has already been defined, we can tell now
862 whether and how we must alter the stack level. */
864 if (PREV_INSN (label) != 0)
866 /* Find the innermost pending block that contains the label.
867 (Check containment by comparing insn-uids.)
868 Then restore the outermost stack level within that block,
869 and do cleanups of all blocks contained in it. */
870 for (block = block_stack; block; block = block->next)
872 if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
874 if (block->data.block.stack_level != 0)
875 stack_level = block->data.block.stack_level;
876 /* Execute the cleanups for blocks we are exiting. */
877 if (block->data.block.cleanups != 0)
879 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
880 do_pending_stack_adjust ();
886 /* Ensure stack adjust isn't done by emit_jump, as this
887 would clobber the stack pointer. This one should be
888 deleted as dead by flow. */
889 clear_pending_stack_adjust ();
890 do_pending_stack_adjust ();
892 /* Don't do this adjust if it's to the end label and this function
893 is to return with a depressed stack pointer. */
894 if (label == return_label
895 && (((TREE_CODE (TREE_TYPE (current_function_decl))
897 && (TYPE_RETURNS_STACK_DEPRESSED
898 (TREE_TYPE (current_function_decl))))))
901 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
904 if (body != 0 && DECL_TOO_LATE (body))
905 error ("jump to `%s' invalidly jumps into binding contour",
906 IDENTIFIER_POINTER (DECL_NAME (body)));
908 /* Label not yet defined: may need to put this goto
909 on the fixup list. */
910 else if (! expand_fixup (body, label, last_insn))
912 /* No fixup needed. Record that the label is the target
913 of at least one goto that has no fixup. */
915 TREE_ADDRESSABLE (body) = 1;
921 /* Generate if necessary a fixup for a goto
922 whose target label in tree structure (if any) is TREE_LABEL
923 and whose target in rtl is RTL_LABEL.
925 If LAST_INSN is nonzero, we pretend that the jump appears
926 after insn LAST_INSN instead of at the current point in the insn stream.
928 The fixup will be used later to insert insns just before the goto.
929 Those insns will restore the stack level as appropriate for the
930 target label, and will (in the case of C++) also invoke any object
931 destructors which have to be invoked when we exit the scopes which
932 are exited by the goto.
934 Value is nonzero if a fixup is made. */
937 expand_fixup (tree_label, rtl_label, last_insn)
942 struct nesting *block, *end_block;
944 /* See if we can recognize which block the label will be output in.
945 This is possible in some very common cases.
946 If we succeed, set END_BLOCK to that block.
947 Otherwise, set it to 0. */
950 && (rtl_label == cond_stack->data.cond.endif_label
951 || rtl_label == cond_stack->data.cond.next_label))
952 end_block = cond_stack;
953 /* If we are in a loop, recognize certain labels which
954 are likely targets. This reduces the number of fixups
955 we need to create. */
957 && (rtl_label == loop_stack->data.loop.start_label
958 || rtl_label == loop_stack->data.loop.end_label
959 || rtl_label == loop_stack->data.loop.continue_label))
960 end_block = loop_stack;
964 /* Now set END_BLOCK to the binding level to which we will return. */
968 struct nesting *next_block = end_block->all;
971 /* First see if the END_BLOCK is inside the innermost binding level.
972 If so, then no cleanups or stack levels are relevant. */
973 while (next_block && next_block != block)
974 next_block = next_block->all;
979 /* Otherwise, set END_BLOCK to the innermost binding level
980 which is outside the relevant control-structure nesting. */
981 next_block = block_stack->next;
982 for (block = block_stack; block != end_block; block = block->all)
983 if (block == next_block)
984 next_block = next_block->next;
985 end_block = next_block;
988 /* Does any containing block have a stack level or cleanups?
989 If not, no fixup is needed, and that is the normal case
990 (the only case, for standard C). */
991 for (block = block_stack; block != end_block; block = block->next)
992 if (block->data.block.stack_level != 0
993 || block->data.block.cleanups != 0)
996 if (block != end_block)
998 /* Ok, a fixup is needed. Add a fixup to the list of such. */
999 struct goto_fixup *fixup
1000 = (struct goto_fixup *) ggc_alloc (sizeof (struct goto_fixup));
1001 /* In case an old stack level is restored, make sure that comes
1002 after any pending stack adjust. */
1003 /* ?? If the fixup isn't to come at the present position,
1004 doing the stack adjust here isn't useful. Doing it with our
1005 settings at that location isn't useful either. Let's hope
1008 do_pending_stack_adjust ();
1009 fixup->target = tree_label;
1010 fixup->target_rtl = rtl_label;
1012 /* Create a BLOCK node and a corresponding matched set of
1013 NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes at
1014 this point. The notes will encapsulate any and all fixup
1015 code which we might later insert at this point in the insn
1016 stream. Also, the BLOCK node will be the parent (i.e. the
1017 `SUPERBLOCK') of any other BLOCK nodes which we might create
1018 later on when we are expanding the fixup code.
1020 Note that optimization passes (including expand_end_loop)
1021 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
1022 as a placeholder. */
1025 register rtx original_before_jump
1026 = last_insn ? last_insn : get_last_insn ();
1031 block = make_node (BLOCK);
1032 TREE_USED (block) = 1;
1034 if (!cfun->x_whole_function_mode_p)
1035 insert_block (block);
1039 = BLOCK_CHAIN (DECL_INITIAL (current_function_decl));
1040 BLOCK_CHAIN (DECL_INITIAL (current_function_decl))
1045 start = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
1046 if (cfun->x_whole_function_mode_p)
1047 NOTE_BLOCK (start) = block;
1048 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_DELETED);
1049 end = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
1050 if (cfun->x_whole_function_mode_p)
1051 NOTE_BLOCK (end) = block;
1052 fixup->context = block;
1054 emit_insns_after (start, original_before_jump);
1057 fixup->block_start_count = current_block_start_count;
1058 fixup->stack_level = 0;
1059 fixup->cleanup_list_list
1060 = ((block->data.block.outer_cleanups
1061 || block->data.block.cleanups)
1062 ? tree_cons (NULL_TREE, block->data.block.cleanups,
1063 block->data.block.outer_cleanups)
1065 fixup->next = goto_fixup_chain;
1066 goto_fixup_chain = fixup;
1072 /* Expand any needed fixups in the outputmost binding level of the
1073 function. FIRST_INSN is the first insn in the function. */
1076 expand_fixups (first_insn)
1079 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0);
1082 /* When exiting a binding contour, process all pending gotos requiring fixups.
1083 THISBLOCK is the structure that describes the block being exited.
1084 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1085 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1086 FIRST_INSN is the insn that began this contour.
1088 Gotos that jump out of this contour must restore the
1089 stack level and do the cleanups before actually jumping.
1091 DONT_JUMP_IN nonzero means report error there is a jump into this
1092 contour from before the beginning of the contour.
1093 This is also done if STACK_LEVEL is nonzero. */
1096 fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1097 struct nesting *thisblock;
1103 register struct goto_fixup *f, *prev;
1105 /* F is the fixup we are considering; PREV is the previous one. */
1106 /* We run this loop in two passes so that cleanups of exited blocks
1107 are run first, and blocks that are exited are marked so
1110 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1112 /* Test for a fixup that is inactive because it is already handled. */
1113 if (f->before_jump == 0)
1115 /* Delete inactive fixup from the chain, if that is easy to do. */
1117 prev->next = f->next;
1119 /* Has this fixup's target label been defined?
1120 If so, we can finalize it. */
1121 else if (PREV_INSN (f->target_rtl) != 0)
1123 register rtx cleanup_insns;
1125 /* If this fixup jumped into this contour from before the beginning
1126 of this contour, report an error. This code used to use
1127 the first non-label insn after f->target_rtl, but that's
1128 wrong since such can be added, by things like put_var_into_stack
1129 and have INSN_UIDs that are out of the range of the block. */
1130 /* ??? Bug: this does not detect jumping in through intermediate
1131 blocks that have stack levels or cleanups.
1132 It detects only a problem with the innermost block
1133 around the label. */
1135 && (dont_jump_in || stack_level || cleanup_list)
1136 && INSN_UID (first_insn) < INSN_UID (f->target_rtl)
1137 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1138 && ! DECL_ERROR_ISSUED (f->target))
1140 error_with_decl (f->target,
1141 "label `%s' used before containing binding contour");
1142 /* Prevent multiple errors for one label. */
1143 DECL_ERROR_ISSUED (f->target) = 1;
1146 /* We will expand the cleanups into a sequence of their own and
1147 then later on we will attach this new sequence to the insn
1148 stream just ahead of the actual jump insn. */
1152 /* Temporarily restore the lexical context where we will
1153 logically be inserting the fixup code. We do this for the
1154 sake of getting the debugging information right. */
1157 set_block (f->context);
1159 /* Expand the cleanups for blocks this jump exits. */
1160 if (f->cleanup_list_list)
1163 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1164 /* Marked elements correspond to blocks that have been closed.
1165 Do their cleanups. */
1166 if (TREE_ADDRESSABLE (lists)
1167 && TREE_VALUE (lists) != 0)
1169 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1170 /* Pop any pushes done in the cleanups,
1171 in case function is about to return. */
1172 do_pending_stack_adjust ();
1176 /* Restore stack level for the biggest contour that this
1177 jump jumps out of. */
1179 && ! (f->target_rtl == return_label
1180 && ((TREE_CODE (TREE_TYPE (current_function_decl))
1182 && (TYPE_RETURNS_STACK_DEPRESSED
1183 (TREE_TYPE (current_function_decl))))))
1184 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1186 /* Finish up the sequence containing the insns which implement the
1187 necessary cleanups, and then attach that whole sequence to the
1188 insn stream just ahead of the actual jump insn. Attaching it
1189 at that point insures that any cleanups which are in fact
1190 implicit C++ object destructions (which must be executed upon
1191 leaving the block) appear (to the debugger) to be taking place
1192 in an area of the generated code where the object(s) being
1193 destructed are still "in scope". */
1195 cleanup_insns = get_insns ();
1199 emit_insns_after (cleanup_insns, f->before_jump);
1205 /* For any still-undefined labels, do the cleanups for this block now.
1206 We must do this now since items in the cleanup list may go out
1207 of scope when the block ends. */
1208 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1209 if (f->before_jump != 0
1210 && PREV_INSN (f->target_rtl) == 0
1211 /* Label has still not appeared. If we are exiting a block with
1212 a stack level to restore, that started before the fixup,
1213 mark this stack level as needing restoration
1214 when the fixup is later finalized. */
1216 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1217 means the label is undefined. That's erroneous, but possible. */
1218 && (thisblock->data.block.block_start_count
1219 <= f->block_start_count))
1221 tree lists = f->cleanup_list_list;
1224 for (; lists; lists = TREE_CHAIN (lists))
1225 /* If the following elt. corresponds to our containing block
1226 then the elt. must be for this block. */
1227 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
1231 set_block (f->context);
1232 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1233 do_pending_stack_adjust ();
1234 cleanup_insns = get_insns ();
1237 if (cleanup_insns != 0)
1239 = emit_insns_after (cleanup_insns, f->before_jump);
1241 f->cleanup_list_list = TREE_CHAIN (lists);
1245 f->stack_level = stack_level;
1249 /* Return the number of times character C occurs in string S. */
1251 n_occurrences (c, s)
1261 /* Generate RTL for an asm statement (explicit assembler code).
1262 BODY is a STRING_CST node containing the assembler code text,
1263 or an ADDR_EXPR containing a STRING_CST. */
1269 if (current_function_check_memory_usage)
1271 error ("`asm' cannot be used in function where memory usage is checked");
1275 if (TREE_CODE (body) == ADDR_EXPR)
1276 body = TREE_OPERAND (body, 0);
1278 emit_insn (gen_rtx_ASM_INPUT (VOIDmode,
1279 TREE_STRING_POINTER (body)));
1283 /* Generate RTL for an asm statement with arguments.
1284 STRING is the instruction template.
1285 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1286 Each output or input has an expression in the TREE_VALUE and
1287 a constraint-string in the TREE_PURPOSE.
1288 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1289 that is clobbered by this insn.
1291 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1292 Some elements of OUTPUTS may be replaced with trees representing temporary
1293 values. The caller should copy those temporary values to the originally
1296 VOL nonzero means the insn is volatile; don't optimize it. */
1299 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1300 tree string, outputs, inputs, clobbers;
1302 const char *filename;
1305 rtvec argvec, constraints;
1307 int ninputs = list_length (inputs);
1308 int noutputs = list_length (outputs);
1313 /* Vector of RTX's of evaluated output operands. */
1314 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1315 int *inout_opnum = (int *) alloca (noutputs * sizeof (int));
1316 rtx *real_output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1317 enum machine_mode *inout_mode
1318 = (enum machine_mode *) alloca (noutputs * sizeof (enum machine_mode));
1319 /* The insn we have emitted. */
1321 int old_generating_concat_p = generating_concat_p;
1323 /* An ASM with no outputs needs to be treated as volatile, for now. */
1327 if (current_function_check_memory_usage)
1329 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1333 #ifdef MD_ASM_CLOBBERS
1334 /* Sometimes we wish to automatically clobber registers across an asm.
1335 Case in point is when the i386 backend moved from cc0 to a hard reg --
1336 maintaining source-level compatability means automatically clobbering
1337 the flags register. */
1338 MD_ASM_CLOBBERS (clobbers);
1341 if (current_function_check_memory_usage)
1343 error ("`asm' cannot be used in function where memory usage is checked");
1347 /* Count the number of meaningful clobbered registers, ignoring what
1348 we would ignore later. */
1350 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1352 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1354 i = decode_reg_name (regname);
1355 if (i >= 0 || i == -4)
1358 error ("unknown register name `%s' in `asm'", regname);
1363 /* Check that the number of alternatives is constant across all
1365 if (outputs || inputs)
1367 tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
1368 int nalternatives = n_occurrences (',', TREE_STRING_POINTER (tmp));
1371 if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
1373 error ("too many alternatives in `asm'");
1380 const char *constraint = TREE_STRING_POINTER (TREE_PURPOSE (tmp));
1382 if (n_occurrences (',', constraint) != nalternatives)
1384 error ("operand constraints for `asm' differ in number of alternatives");
1388 if (TREE_CHAIN (tmp))
1389 tmp = TREE_CHAIN (tmp);
1391 tmp = next, next = 0;
1395 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1397 tree val = TREE_VALUE (tail);
1398 tree type = TREE_TYPE (val);
1399 const char *constraint;
1407 /* If there's an erroneous arg, emit no insn. */
1408 if (TREE_TYPE (val) == error_mark_node)
1411 /* Make sure constraint has `=' and does not have `+'. Also, see
1412 if it allows any register. Be liberal on the latter test, since
1413 the worst that happens if we get it wrong is we issue an error
1416 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1417 c_len = strlen (constraint);
1419 /* Allow the `=' or `+' to not be at the beginning of the string,
1420 since it wasn't explicitly documented that way, and there is a
1421 large body of code that puts it last. Swap the character to
1422 the front, so as not to uglify any place else. */
1426 if ((p = strchr (constraint, '=')) != NULL)
1428 if ((p = strchr (constraint, '+')) != NULL)
1431 error ("output operand constraint lacks `='");
1435 is_inout = *p == '+';
1439 /* Have to throw away this constraint string and get a new one. */
1440 char *buf = alloca (c_len + 1);
1443 memcpy (buf + 1, constraint, j);
1444 memcpy (buf + 1 + j, p + 1, c_len - j); /* not -j-1 - copy null */
1445 constraint = ggc_alloc_string (buf, c_len);
1449 "output constraint `%c' for operand %d is not at the beginning",
1453 /* Make sure we can specify the matching operand. */
1454 if (is_inout && i > 9)
1456 error ("output operand constraint %d contains `+'", i);
1460 for (j = 1; j < c_len; j++)
1461 switch (constraint[j])
1465 error ("operand constraint contains '+' or '=' at illegal position.");
1469 if (i + 1 == ninputs + noutputs)
1471 error ("`%%' constraint used with last operand");
1476 case '?': case '!': case '*': case '&': case '#':
1477 case 'E': case 'F': case 'G': case 'H':
1478 case 's': case 'i': case 'n':
1479 case 'I': case 'J': case 'K': case 'L': case 'M':
1480 case 'N': case 'O': case 'P': case ',':
1483 case '0': case '1': case '2': case '3': case '4':
1484 case '5': case '6': case '7': case '8': case '9':
1485 error ("matching constraint not valid in output operand");
1488 case 'V': case 'm': case 'o':
1493 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1494 excepting those that expand_call created. So match memory
1509 if (! ISALPHA (constraint[j]))
1511 error ("invalid punctuation `%c' in constraint",
1515 if (REG_CLASS_FROM_LETTER (constraint[j]) != NO_REGS)
1517 #ifdef EXTRA_CONSTRAINT
1520 /* Otherwise we can't assume anything about the nature of
1521 the constraint except that it isn't purely registers.
1522 Treat it like "g" and hope for the best. */
1530 /* If an output operand is not a decl or indirect ref and our constraint
1531 allows a register, make a temporary to act as an intermediate.
1532 Make the asm insn write into that, then our caller will copy it to
1533 the real output operand. Likewise for promoted variables. */
1535 generating_concat_p = 0;
1537 real_output_rtx[i] = NULL_RTX;
1538 if ((TREE_CODE (val) == INDIRECT_REF
1541 && (allows_mem || GET_CODE (DECL_RTL (val)) == REG)
1542 && ! (GET_CODE (DECL_RTL (val)) == REG
1543 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
1548 mark_addressable (TREE_VALUE (tail));
1551 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode,
1552 EXPAND_MEMORY_USE_WO);
1554 if (! allows_reg && GET_CODE (output_rtx[i]) != MEM)
1555 error ("output number %d not directly addressable", i);
1556 if ((! allows_mem && GET_CODE (output_rtx[i]) == MEM)
1557 || GET_CODE (output_rtx[i]) == CONCAT)
1559 real_output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1560 output_rtx[i] = gen_reg_rtx (GET_MODE (output_rtx[i]));
1562 emit_move_insn (output_rtx[i], real_output_rtx[i]);
1567 output_rtx[i] = assign_temp (type, 0, 0, 1);
1568 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1571 generating_concat_p = old_generating_concat_p;
1575 inout_mode[ninout] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)));
1576 inout_opnum[ninout++] = i;
1581 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1583 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1587 /* Make vectors for the expression-rtx and constraint strings. */
1589 argvec = rtvec_alloc (ninputs);
1590 constraints = rtvec_alloc (ninputs);
1592 body = gen_rtx_ASM_OPERANDS ((noutputs == 0 ? VOIDmode
1593 : GET_MODE (output_rtx[0])),
1594 TREE_STRING_POINTER (string),
1595 empty_string, 0, argvec, constraints,
1598 MEM_VOLATILE_P (body) = vol;
1600 /* Eval the inputs and put them into ARGVEC.
1601 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1604 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1607 int allows_reg = 0, allows_mem = 0;
1608 const char *constraint, *orig_constraint;
1612 /* If there's an erroneous arg, emit no insn,
1613 because the ASM_INPUT would get VOIDmode
1614 and that could cause a crash in reload. */
1615 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1618 /* ??? Can this happen, and does the error message make any sense? */
1619 if (TREE_PURPOSE (tail) == NULL_TREE)
1621 error ("hard register `%s' listed as input operand to `asm'",
1622 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1626 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1627 c_len = strlen (constraint);
1628 orig_constraint = constraint;
1630 /* Make sure constraint has neither `=', `+', nor '&'. */
1632 for (j = 0; j < c_len; j++)
1633 switch (constraint[j])
1635 case '+': case '=': case '&':
1636 if (constraint == orig_constraint)
1638 error ("input operand constraint contains `%c'",
1645 if (constraint == orig_constraint
1646 && i + 1 == ninputs - ninout)
1648 error ("`%%' constraint used with last operand");
1653 case 'V': case 'm': case 'o':
1658 case '?': case '!': case '*': case '#':
1659 case 'E': case 'F': case 'G': case 'H':
1660 case 's': case 'i': case 'n':
1661 case 'I': case 'J': case 'K': case 'L': case 'M':
1662 case 'N': case 'O': case 'P': case ',':
1665 /* Whether or not a numeric constraint allows a register is
1666 decided by the matching constraint, and so there is no need
1667 to do anything special with them. We must handle them in
1668 the default case, so that we don't unnecessarily force
1669 operands to memory. */
1670 case '0': case '1': case '2': case '3': case '4':
1671 case '5': case '6': case '7': case '8': case '9':
1672 if (constraint[j] >= '0' + noutputs)
1675 ("matching constraint references invalid operand number");
1679 /* Try and find the real constraint for this dup. */
1680 if ((j == 0 && c_len == 1)
1681 || (j == 1 && c_len == 2 && constraint[0] == '%'))
1685 for (j = constraint[j] - '0'; j > 0; --j)
1688 constraint = TREE_STRING_POINTER (TREE_PURPOSE (o));
1689 c_len = strlen (constraint);
1706 if (! ISALPHA (constraint[j]))
1708 error ("invalid punctuation `%c' in constraint",
1712 if (REG_CLASS_FROM_LETTER (constraint[j]) != NO_REGS)
1714 #ifdef EXTRA_CONSTRAINT
1717 /* Otherwise we can't assume anything about the nature of
1718 the constraint except that it isn't purely registers.
1719 Treat it like "g" and hope for the best. */
1727 if (! allows_reg && allows_mem)
1728 mark_addressable (TREE_VALUE (tail));
1730 op = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1732 /* Never pass a CONCAT to an ASM. */
1733 generating_concat_p = 0;
1734 if (GET_CODE (op) == CONCAT)
1735 op = force_reg (GET_MODE (op), op);
1737 if (asm_operand_ok (op, constraint) <= 0)
1740 op = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), op);
1741 else if (!allows_mem)
1742 warning ("asm operand %d probably doesn't match constraints", i);
1743 else if (CONSTANT_P (op))
1744 op = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1746 else if (GET_CODE (op) == REG
1747 || GET_CODE (op) == SUBREG
1748 || GET_CODE (op) == CONCAT)
1750 tree type = TREE_TYPE (TREE_VALUE (tail));
1751 rtx memloc = assign_temp (type, 1, 1, 1);
1753 emit_move_insn (memloc, op);
1757 else if (GET_CODE (op) == MEM && MEM_VOLATILE_P (op))
1758 /* We won't recognize volatile memory as available a
1759 memory_operand at this point. Ignore it. */
1761 else if (queued_subexp_p (op))
1764 /* ??? Leave this only until we have experience with what
1765 happens in combine and elsewhere when constraints are
1767 warning ("asm operand %d probably doesn't match constraints", i);
1769 generating_concat_p = old_generating_concat_p;
1770 ASM_OPERANDS_INPUT (body, i) = op;
1772 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, i)
1773 = gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1778 /* Protect all the operands from the queue now that they have all been
1781 generating_concat_p = 0;
1783 for (i = 0; i < ninputs - ninout; i++)
1784 ASM_OPERANDS_INPUT (body, i)
1785 = protect_from_queue (ASM_OPERANDS_INPUT (body, i), 0);
1787 for (i = 0; i < noutputs; i++)
1788 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1790 /* For in-out operands, copy output rtx to input rtx. */
1791 for (i = 0; i < ninout; i++)
1793 int j = inout_opnum[i];
1795 ASM_OPERANDS_INPUT (body, ninputs - ninout + i)
1797 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, ninputs - ninout + i)
1798 = gen_rtx_ASM_INPUT (inout_mode[i], digit_string (j));
1801 generating_concat_p = old_generating_concat_p;
1803 /* Now, for each output, construct an rtx
1804 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1805 ARGVEC CONSTRAINTS))
1806 If there is more than one, put them inside a PARALLEL. */
1808 if (noutputs == 1 && nclobbers == 0)
1810 ASM_OPERANDS_OUTPUT_CONSTRAINT (body)
1811 = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1812 insn = emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
1815 else if (noutputs == 0 && nclobbers == 0)
1817 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1818 insn = emit_insn (body);
1829 body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
1831 /* For each output operand, store a SET. */
1832 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1834 XVECEXP (body, 0, i)
1835 = gen_rtx_SET (VOIDmode,
1837 gen_rtx_ASM_OPERANDS
1838 (GET_MODE (output_rtx[i]),
1839 TREE_STRING_POINTER (string),
1840 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1841 i, argvec, constraints,
1844 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1847 /* If there are no outputs (but there are some clobbers)
1848 store the bare ASM_OPERANDS into the PARALLEL. */
1851 XVECEXP (body, 0, i++) = obody;
1853 /* Store (clobber REG) for each clobbered register specified. */
1855 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1857 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1858 int j = decode_reg_name (regname);
1862 if (j == -3) /* `cc', which is not a register */
1865 if (j == -4) /* `memory', don't cache memory across asm */
1867 XVECEXP (body, 0, i++)
1868 = gen_rtx_CLOBBER (VOIDmode,
1871 gen_rtx_SCRATCH (VOIDmode)));
1875 /* Ignore unknown register, error already signaled. */
1879 /* Use QImode since that's guaranteed to clobber just one reg. */
1880 XVECEXP (body, 0, i++)
1881 = gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (QImode, j));
1884 insn = emit_insn (body);
1887 /* For any outputs that needed reloading into registers, spill them
1888 back to where they belong. */
1889 for (i = 0; i < noutputs; ++i)
1890 if (real_output_rtx[i])
1891 emit_move_insn (real_output_rtx[i], output_rtx[i]);
1896 /* Generate RTL to evaluate the expression EXP
1897 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1900 expand_expr_stmt (exp)
1903 /* If -W, warn about statements with no side effects,
1904 except for an explicit cast to void (e.g. for assert()), and
1905 except inside a ({...}) where they may be useful. */
1906 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1908 if (! TREE_SIDE_EFFECTS (exp))
1910 if ((extra_warnings || warn_unused_value)
1911 && !(TREE_CODE (exp) == CONVERT_EXPR
1912 && VOID_TYPE_P (TREE_TYPE (exp))))
1913 warning_with_file_and_line (emit_filename, emit_lineno,
1914 "statement with no effect");
1916 else if (warn_unused_value)
1917 warn_if_unused_value (exp);
1920 /* If EXP is of function type and we are expanding statements for
1921 value, convert it to pointer-to-function. */
1922 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1923 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1925 /* The call to `expand_expr' could cause last_expr_type and
1926 last_expr_value to get reset. Therefore, we set last_expr_value
1927 and last_expr_type *after* calling expand_expr. */
1928 last_expr_value = expand_expr (exp,
1929 (expr_stmts_for_value
1930 ? NULL_RTX : const0_rtx),
1932 last_expr_type = TREE_TYPE (exp);
1934 /* If all we do is reference a volatile value in memory,
1935 copy it to a register to be sure it is actually touched. */
1936 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1937 && TREE_THIS_VOLATILE (exp))
1939 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1941 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1942 copy_to_reg (last_expr_value);
1945 rtx lab = gen_label_rtx ();
1947 /* Compare the value with itself to reference it. */
1948 emit_cmp_and_jump_insns (last_expr_value, last_expr_value, EQ,
1949 expand_expr (TYPE_SIZE (last_expr_type),
1950 NULL_RTX, VOIDmode, 0),
1952 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT,
1958 /* If this expression is part of a ({...}) and is in memory, we may have
1959 to preserve temporaries. */
1960 preserve_temp_slots (last_expr_value);
1962 /* Free any temporaries used to evaluate this expression. Any temporary
1963 used as a result of this expression will already have been preserved
1970 /* Warn if EXP contains any computations whose results are not used.
1971 Return 1 if a warning is printed; 0 otherwise. */
1974 warn_if_unused_value (exp)
1977 if (TREE_USED (exp))
1980 /* Don't warn about void constructs. This includes casting to void,
1981 void function calls, and statement expressions with a final cast
1983 if (VOID_TYPE_P (TREE_TYPE (exp)))
1986 switch (TREE_CODE (exp))
1988 case PREINCREMENT_EXPR:
1989 case POSTINCREMENT_EXPR:
1990 case PREDECREMENT_EXPR:
1991 case POSTDECREMENT_EXPR:
1996 case METHOD_CALL_EXPR:
1998 case TRY_CATCH_EXPR:
1999 case WITH_CLEANUP_EXPR:
2004 /* For a binding, warn if no side effect within it. */
2005 return warn_if_unused_value (TREE_OPERAND (exp, 1));
2008 return warn_if_unused_value (TREE_OPERAND (exp, 1));
2010 case TRUTH_ORIF_EXPR:
2011 case TRUTH_ANDIF_EXPR:
2012 /* In && or ||, warn if 2nd operand has no side effect. */
2013 return warn_if_unused_value (TREE_OPERAND (exp, 1));
2016 if (TREE_NO_UNUSED_WARNING (exp))
2018 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
2020 /* Let people do `(foo (), 0)' without a warning. */
2021 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
2023 return warn_if_unused_value (TREE_OPERAND (exp, 1));
2027 case NON_LVALUE_EXPR:
2028 /* Don't warn about conversions not explicit in the user's program. */
2029 if (TREE_NO_UNUSED_WARNING (exp))
2031 /* Assignment to a cast usually results in a cast of a modify.
2032 Don't complain about that. There can be an arbitrary number of
2033 casts before the modify, so we must loop until we find the first
2034 non-cast expression and then test to see if that is a modify. */
2036 tree tem = TREE_OPERAND (exp, 0);
2038 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
2039 tem = TREE_OPERAND (tem, 0);
2041 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
2042 || TREE_CODE (tem) == CALL_EXPR)
2048 /* Don't warn about automatic dereferencing of references, since
2049 the user cannot control it. */
2050 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
2051 return warn_if_unused_value (TREE_OPERAND (exp, 0));
2055 /* Referencing a volatile value is a side effect, so don't warn. */
2057 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
2058 && TREE_THIS_VOLATILE (exp))
2061 /* If this is an expression with side effects, don't warn. */
2062 if (TREE_SIDE_EFFECTS (exp))
2065 /* If this is an expression which has no operands, there is no value
2066 to be unused. There are no such language-independent codes,
2067 but front ends may define such. */
2068 if (TREE_CODE_CLASS (TREE_CODE (exp)) == 'e'
2069 && TREE_CODE_LENGTH (TREE_CODE (exp)) == 0)
2073 warning_with_file_and_line (emit_filename, emit_lineno,
2074 "value computed is not used");
2079 /* Clear out the memory of the last expression evaluated. */
2087 /* Begin a statement which will return a value.
2088 Return the RTL_EXPR for this statement expr.
2089 The caller must save that value and pass it to expand_end_stmt_expr. */
2092 expand_start_stmt_expr ()
2096 /* Make the RTL_EXPR node temporary, not momentary,
2097 so that rtl_expr_chain doesn't become garbage. */
2098 t = make_node (RTL_EXPR);
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 /* Begin a null, aka do { } while (0) "loop". But since the contents
2293 of said loop can still contain a break, we must frob the loop nest. */
2296 expand_start_null_loop ()
2298 register struct nesting *thisloop = ALLOC_NESTING ();
2300 /* Make an entry on loop_stack for the loop we are entering. */
2302 thisloop->next = loop_stack;
2303 thisloop->all = nesting_stack;
2304 thisloop->depth = ++nesting_depth;
2305 thisloop->data.loop.start_label = emit_note (NULL, NOTE_INSN_DELETED);
2306 thisloop->data.loop.end_label = gen_label_rtx ();
2307 thisloop->data.loop.alt_end_label = NULL_RTX;
2308 thisloop->data.loop.continue_label = thisloop->data.loop.end_label;
2309 thisloop->exit_label = thisloop->data.loop.end_label;
2310 loop_stack = thisloop;
2311 nesting_stack = thisloop;
2316 /* Specify the continuation point for a loop started with
2317 expand_start_loop_continue_elsewhere.
2318 Use this at the point in the code to which a continue statement
2322 expand_loop_continue_here ()
2324 do_pending_stack_adjust ();
2325 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2326 emit_label (loop_stack->data.loop.continue_label);
2329 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2330 Pop the block off of loop_stack. */
2335 rtx start_label = loop_stack->data.loop.start_label;
2336 rtx insn = get_last_insn ();
2337 int needs_end_jump = 1;
2339 /* Mark the continue-point at the top of the loop if none elsewhere. */
2340 if (start_label == loop_stack->data.loop.continue_label)
2341 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2343 do_pending_stack_adjust ();
2345 /* If optimizing, perhaps reorder the loop.
2346 First, try to use a condjump near the end.
2347 expand_exit_loop_if_false ends loops with unconditional jumps,
2350 if (test) goto label;
2352 goto loop_stack->data.loop.end_label
2356 If we find such a pattern, we can end the loop earlier. */
2359 && GET_CODE (insn) == CODE_LABEL
2360 && LABEL_NAME (insn) == NULL
2361 && GET_CODE (PREV_INSN (insn)) == BARRIER)
2364 rtx jump = PREV_INSN (PREV_INSN (label));
2366 if (GET_CODE (jump) == JUMP_INSN
2367 && GET_CODE (PATTERN (jump)) == SET
2368 && SET_DEST (PATTERN (jump)) == pc_rtx
2369 && GET_CODE (SET_SRC (PATTERN (jump))) == LABEL_REF
2370 && (XEXP (SET_SRC (PATTERN (jump)), 0)
2371 == loop_stack->data.loop.end_label))
2375 /* The test might be complex and reference LABEL multiple times,
2376 like the loop in loop_iterations to set vtop. To handle this,
2378 insn = PREV_INSN (label);
2379 reorder_insns (label, label, start_label);
2381 for (prev = PREV_INSN (jump);; prev = PREV_INSN (prev))
2383 /* We ignore line number notes, but if we see any other note,
2384 in particular NOTE_INSN_BLOCK_*, NOTE_INSN_EH_REGION_*,
2385 NOTE_INSN_LOOP_*, we disable this optimization. */
2386 if (GET_CODE (prev) == NOTE)
2388 if (NOTE_LINE_NUMBER (prev) < 0)
2392 if (GET_CODE (prev) == CODE_LABEL)
2394 if (GET_CODE (prev) == JUMP_INSN)
2396 if (GET_CODE (PATTERN (prev)) == SET
2397 && SET_DEST (PATTERN (prev)) == pc_rtx
2398 && GET_CODE (SET_SRC (PATTERN (prev))) == IF_THEN_ELSE
2399 && (GET_CODE (XEXP (SET_SRC (PATTERN (prev)), 1))
2401 && XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0) == label)
2403 XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0)
2405 emit_note_after (NOTE_INSN_LOOP_END, prev);
2414 /* If the loop starts with a loop exit, roll that to the end where
2415 it will optimize together with the jump back.
2417 We look for the conditional branch to the exit, except that once
2418 we find such a branch, we don't look past 30 instructions.
2420 In more detail, if the loop presently looks like this (in pseudo-C):
2423 if (test) goto end_label;
2428 transform it to look like:
2434 if (test) goto end_label;
2435 goto newstart_label;
2438 Here, the `test' may actually consist of some reasonably complex
2439 code, terminating in a test. */
2444 ! (GET_CODE (insn) == JUMP_INSN
2445 && GET_CODE (PATTERN (insn)) == SET
2446 && SET_DEST (PATTERN (insn)) == pc_rtx
2447 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2451 rtx last_test_insn = NULL_RTX;
2453 /* Scan insns from the top of the loop looking for a qualified
2454 conditional exit. */
2455 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2456 insn = NEXT_INSN (insn))
2458 if (GET_CODE (insn) == NOTE)
2461 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2462 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2463 /* The code that actually moves the exit test will
2464 carefully leave BLOCK notes in their original
2465 location. That means, however, that we can't debug
2466 the exit test itself. So, we refuse to move code
2467 containing BLOCK notes at low optimization levels. */
2470 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG)
2472 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)
2476 /* We've come to the end of an EH region, but
2477 never saw the beginning of that region. That
2478 means that an EH region begins before the top
2479 of the loop, and ends in the middle of it. The
2480 existence of such a situation violates a basic
2481 assumption in this code, since that would imply
2482 that even when EH_REGIONS is zero, we might
2483 move code out of an exception region. */
2487 /* We must not walk into a nested loop. */
2488 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
2491 /* We already know this INSN is a NOTE, so there's no
2492 point in looking at it to see if it's a JUMP. */
2496 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2499 if (last_test_insn && num_insns > 30)
2503 /* We don't want to move a partial EH region. Consider:
2517 This isn't legal C++, but here's what it's supposed to
2518 mean: if cond() is true, stop looping. Otherwise,
2519 call bar, and keep looping. In addition, if cond
2520 throws an exception, catch it and keep looping. Such
2521 constructs are certainy legal in LISP.
2523 We should not move the `if (cond()) 0' test since then
2524 the EH-region for the try-block would be broken up.
2525 (In this case we would the EH_BEG note for the `try'
2526 and `if cond()' but not the call to bar() or the
2529 So we don't look for tests within an EH region. */
2532 if (GET_CODE (insn) == JUMP_INSN
2533 && GET_CODE (PATTERN (insn)) == SET
2534 && SET_DEST (PATTERN (insn)) == pc_rtx)
2536 /* This is indeed a jump. */
2537 rtx dest1 = NULL_RTX;
2538 rtx dest2 = NULL_RTX;
2539 rtx potential_last_test;
2540 if (GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE)
2542 /* A conditional jump. */
2543 dest1 = XEXP (SET_SRC (PATTERN (insn)), 1);
2544 dest2 = XEXP (SET_SRC (PATTERN (insn)), 2);
2545 potential_last_test = insn;
2549 /* An unconditional jump. */
2550 dest1 = SET_SRC (PATTERN (insn));
2551 /* Include the BARRIER after the JUMP. */
2552 potential_last_test = NEXT_INSN (insn);
2556 if (dest1 && GET_CODE (dest1) == LABEL_REF
2557 && ((XEXP (dest1, 0)
2558 == loop_stack->data.loop.alt_end_label)
2560 == loop_stack->data.loop.end_label)))
2562 last_test_insn = potential_last_test;
2566 /* If this was a conditional jump, there may be
2567 another label at which we should look. */
2574 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2576 /* We found one. Move everything from there up
2577 to the end of the loop, and add a jump into the loop
2578 to jump to there. */
2579 register rtx newstart_label = gen_label_rtx ();
2580 register rtx start_move = start_label;
2583 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2584 then we want to move this note also. */
2585 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2586 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2587 == NOTE_INSN_LOOP_CONT))
2588 start_move = PREV_INSN (start_move);
2590 emit_label_after (newstart_label, PREV_INSN (start_move));
2592 /* Actually move the insns. Start at the beginning, and
2593 keep copying insns until we've copied the
2595 for (insn = start_move; insn; insn = next_insn)
2597 /* Figure out which insn comes after this one. We have
2598 to do this before we move INSN. */
2599 if (insn == last_test_insn)
2600 /* We've moved all the insns. */
2601 next_insn = NULL_RTX;
2603 next_insn = NEXT_INSN (insn);
2605 if (GET_CODE (insn) == NOTE
2606 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2607 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2608 /* We don't want to move NOTE_INSN_BLOCK_BEGs or
2609 NOTE_INSN_BLOCK_ENDs because the correct generation
2610 of debugging information depends on these appearing
2611 in the same order in the RTL and in the tree
2612 structure, where they are represented as BLOCKs.
2613 So, we don't move block notes. Of course, moving
2614 the code inside the block is likely to make it
2615 impossible to debug the instructions in the exit
2616 test, but such is the price of optimization. */
2619 /* Move the INSN. */
2620 reorder_insns (insn, insn, get_last_insn ());
2623 emit_jump_insn_after (gen_jump (start_label),
2624 PREV_INSN (newstart_label));
2625 emit_barrier_after (PREV_INSN (newstart_label));
2626 start_label = newstart_label;
2632 emit_jump (start_label);
2633 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2635 emit_label (loop_stack->data.loop.end_label);
2637 POPSTACK (loop_stack);
2642 /* Finish a null loop, aka do { } while (0). */
2645 expand_end_null_loop ()
2647 do_pending_stack_adjust ();
2648 emit_label (loop_stack->data.loop.end_label);
2650 POPSTACK (loop_stack);
2655 /* Generate a jump to the current loop's continue-point.
2656 This is usually the top of the loop, but may be specified
2657 explicitly elsewhere. If not currently inside a loop,
2658 return 0 and do nothing; caller will print an error message. */
2661 expand_continue_loop (whichloop)
2662 struct nesting *whichloop;
2666 whichloop = loop_stack;
2669 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2674 /* Generate a jump to exit the current loop. If not currently inside a loop,
2675 return 0 and do nothing; caller will print an error message. */
2678 expand_exit_loop (whichloop)
2679 struct nesting *whichloop;
2683 whichloop = loop_stack;
2686 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2690 /* Generate a conditional jump to exit the current loop if COND
2691 evaluates to zero. If not currently inside a loop,
2692 return 0 and do nothing; caller will print an error message. */
2695 expand_exit_loop_if_false (whichloop, cond)
2696 struct nesting *whichloop;
2699 rtx label = gen_label_rtx ();
2704 whichloop = loop_stack;
2707 /* In order to handle fixups, we actually create a conditional jump
2708 around a unconditional branch to exit the loop. If fixups are
2709 necessary, they go before the unconditional branch. */
2711 do_jump (cond, NULL_RTX, label);
2712 last_insn = get_last_insn ();
2713 if (GET_CODE (last_insn) == CODE_LABEL)
2714 whichloop->data.loop.alt_end_label = last_insn;
2715 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2722 /* Return nonzero if the loop nest is empty. Else return zero. */
2725 stmt_loop_nest_empty ()
2727 /* cfun->stmt can be NULL if we are building a call to get the
2728 EH context for a setjmp/longjmp EH target and the current
2729 function was a deferred inline function. */
2730 return (cfun->stmt == NULL || loop_stack == NULL);
2733 /* Return non-zero if we should preserve sub-expressions as separate
2734 pseudos. We never do so if we aren't optimizing. We always do so
2735 if -fexpensive-optimizations.
2737 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2738 the loop may still be a small one. */
2741 preserve_subexpressions_p ()
2745 if (flag_expensive_optimizations)
2748 if (optimize == 0 || cfun == 0 || cfun->stmt == 0 || loop_stack == 0)
2751 insn = get_last_insn_anywhere ();
2754 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2755 < n_non_fixed_regs * 3));
2759 /* Generate a jump to exit the current loop, conditional, binding contour
2760 or case statement. Not all such constructs are visible to this function,
2761 only those started with EXIT_FLAG nonzero. Individual languages use
2762 the EXIT_FLAG parameter to control which kinds of constructs you can
2765 If not currently inside anything that can be exited,
2766 return 0 and do nothing; caller will print an error message. */
2769 expand_exit_something ()
2773 for (n = nesting_stack; n; n = n->all)
2774 if (n->exit_label != 0)
2776 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2783 /* Generate RTL to return from the current function, with no value.
2784 (That is, we do not do anything about returning any value.) */
2787 expand_null_return ()
2789 struct nesting *block = block_stack;
2790 rtx last_insn = get_last_insn ();
2792 /* If this function was declared to return a value, but we
2793 didn't, clobber the return registers so that they are not
2794 propogated live to the rest of the function. */
2795 clobber_return_register ();
2797 /* Does any pending block have cleanups? */
2798 while (block && block->data.block.cleanups == 0)
2799 block = block->next;
2801 /* If yes, use a goto to return, since that runs cleanups. */
2803 expand_null_return_1 (last_insn, block != 0);
2806 /* Generate RTL to return from the current function, with value VAL. */
2809 expand_value_return (val)
2812 struct nesting *block = block_stack;
2813 rtx last_insn = get_last_insn ();
2814 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2816 /* Copy the value to the return location
2817 unless it's already there. */
2819 if (return_reg != val)
2821 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2822 #ifdef PROMOTE_FUNCTION_RETURN
2823 int unsignedp = TREE_UNSIGNED (type);
2824 enum machine_mode old_mode
2825 = DECL_MODE (DECL_RESULT (current_function_decl));
2826 enum machine_mode mode
2827 = promote_mode (type, old_mode, &unsignedp, 1);
2829 if (mode != old_mode)
2830 val = convert_modes (mode, old_mode, val, unsignedp);
2832 if (GET_CODE (return_reg) == PARALLEL)
2833 emit_group_load (return_reg, val, int_size_in_bytes (type),
2836 emit_move_insn (return_reg, val);
2839 /* Does any pending block have cleanups? */
2841 while (block && block->data.block.cleanups == 0)
2842 block = block->next;
2844 /* If yes, use a goto to return, since that runs cleanups.
2845 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2847 expand_null_return_1 (last_insn, block != 0);
2850 /* Output a return with no value. If LAST_INSN is nonzero,
2851 pretend that the return takes place after LAST_INSN.
2852 If USE_GOTO is nonzero then don't use a return instruction;
2853 go to the return label instead. This causes any cleanups
2854 of pending blocks to be executed normally. */
2857 expand_null_return_1 (last_insn, use_goto)
2861 rtx end_label = cleanup_label ? cleanup_label : return_label;
2863 clear_pending_stack_adjust ();
2864 do_pending_stack_adjust ();
2867 /* PCC-struct return always uses an epilogue. */
2868 if (current_function_returns_pcc_struct || use_goto)
2871 end_label = return_label = gen_label_rtx ();
2872 expand_goto_internal (NULL_TREE, end_label, last_insn);
2876 /* Otherwise output a simple return-insn if one is available,
2877 unless it won't do the job. */
2879 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2881 emit_jump_insn (gen_return ());
2887 /* Otherwise jump to the epilogue. */
2888 expand_goto_internal (NULL_TREE, end_label, last_insn);
2891 /* Generate RTL to evaluate the expression RETVAL and return it
2892 from the current function. */
2895 expand_return (retval)
2898 /* If there are any cleanups to be performed, then they will
2899 be inserted following LAST_INSN. It is desirable
2900 that the last_insn, for such purposes, should be the
2901 last insn before computing the return value. Otherwise, cleanups
2902 which call functions can clobber the return value. */
2903 /* ??? rms: I think that is erroneous, because in C++ it would
2904 run destructors on variables that might be used in the subsequent
2905 computation of the return value. */
2907 rtx result_rtl = DECL_RTL (DECL_RESULT (current_function_decl));
2908 register rtx val = 0;
2912 /* If function wants no value, give it none. */
2913 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2915 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2917 expand_null_return ();
2921 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2922 /* This is not sufficient. We also need to watch for cleanups of the
2923 expression we are about to expand. Unfortunately, we cannot know
2924 if it has cleanups until we expand it, and we want to change how we
2925 expand it depending upon if we need cleanups. We can't win. */
2927 cleanups = any_pending_cleanups (1);
2932 if (retval == error_mark_node)
2933 retval_rhs = NULL_TREE;
2934 else if (TREE_CODE (retval) == RESULT_DECL)
2935 retval_rhs = retval;
2936 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2937 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2938 retval_rhs = TREE_OPERAND (retval, 1);
2939 else if (VOID_TYPE_P (TREE_TYPE (retval)))
2940 /* Recognize tail-recursive call to void function. */
2941 retval_rhs = retval;
2943 retval_rhs = NULL_TREE;
2945 /* Only use `last_insn' if there are cleanups which must be run. */
2946 if (cleanups || cleanup_label != 0)
2947 last_insn = get_last_insn ();
2949 /* Distribute return down conditional expr if either of the sides
2950 may involve tail recursion (see test below). This enhances the number
2951 of tail recursions we see. Don't do this always since it can produce
2952 sub-optimal code in some cases and we distribute assignments into
2953 conditional expressions when it would help. */
2955 if (optimize && retval_rhs != 0
2956 && frame_offset == 0
2957 && TREE_CODE (retval_rhs) == COND_EXPR
2958 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2959 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2961 rtx label = gen_label_rtx ();
2964 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2965 start_cleanup_deferral ();
2966 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2967 DECL_RESULT (current_function_decl),
2968 TREE_OPERAND (retval_rhs, 1));
2969 TREE_SIDE_EFFECTS (expr) = 1;
2970 expand_return (expr);
2973 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2974 DECL_RESULT (current_function_decl),
2975 TREE_OPERAND (retval_rhs, 2));
2976 TREE_SIDE_EFFECTS (expr) = 1;
2977 expand_return (expr);
2978 end_cleanup_deferral ();
2982 /* If the result is an aggregate that is being returned in one (or more)
2983 registers, load the registers here. The compiler currently can't handle
2984 copying a BLKmode value into registers. We could put this code in a
2985 more general area (for use by everyone instead of just function
2986 call/return), but until this feature is generally usable it is kept here
2987 (and in expand_call). The value must go into a pseudo in case there
2988 are cleanups that will clobber the real return register. */
2991 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2992 && GET_CODE (result_rtl) == REG)
2995 unsigned HOST_WIDE_INT bitpos, xbitpos;
2996 unsigned HOST_WIDE_INT big_endian_correction = 0;
2997 unsigned HOST_WIDE_INT bytes
2998 = int_size_in_bytes (TREE_TYPE (retval_rhs));
2999 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
3000 unsigned int bitsize
3001 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)), BITS_PER_WORD);
3002 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
3003 rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
3004 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
3005 enum machine_mode tmpmode, result_reg_mode;
3007 /* Structures whose size is not a multiple of a word are aligned
3008 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
3009 machine, this means we must skip the empty high order bytes when
3010 calculating the bit offset. */
3011 if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD)
3012 big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
3015 /* Copy the structure BITSIZE bits at a time. */
3016 for (bitpos = 0, xbitpos = big_endian_correction;
3017 bitpos < bytes * BITS_PER_UNIT;
3018 bitpos += bitsize, xbitpos += bitsize)
3020 /* We need a new destination pseudo each time xbitpos is
3021 on a word boundary and when xbitpos == big_endian_correction
3022 (the first time through). */
3023 if (xbitpos % BITS_PER_WORD == 0
3024 || xbitpos == big_endian_correction)
3026 /* Generate an appropriate register. */
3027 dst = gen_reg_rtx (word_mode);
3028 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
3030 /* Clobber the destination before we move anything into it. */
3031 emit_insn (gen_rtx_CLOBBER (VOIDmode, dst));
3034 /* We need a new source operand each time bitpos is on a word
3036 if (bitpos % BITS_PER_WORD == 0)
3037 src = operand_subword_force (result_val,
3038 bitpos / BITS_PER_WORD,
3041 /* Use bitpos for the source extraction (left justified) and
3042 xbitpos for the destination store (right justified). */
3043 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
3044 extract_bit_field (src, bitsize,
3045 bitpos % BITS_PER_WORD, 1,
3046 NULL_RTX, word_mode, word_mode,
3047 bitsize, BITS_PER_WORD),
3048 bitsize, BITS_PER_WORD);
3051 /* Find the smallest integer mode large enough to hold the
3052 entire structure and use that mode instead of BLKmode
3053 on the USE insn for the return register. */
3054 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
3055 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
3056 tmpmode != VOIDmode;
3057 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
3059 /* Have we found a large enough mode? */
3060 if (GET_MODE_SIZE (tmpmode) >= bytes)
3064 /* No suitable mode found. */
3065 if (tmpmode == VOIDmode)
3068 PUT_MODE (result_rtl, tmpmode);
3070 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
3071 result_reg_mode = word_mode;
3073 result_reg_mode = tmpmode;
3074 result_reg = gen_reg_rtx (result_reg_mode);
3077 for (i = 0; i < n_regs; i++)
3078 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
3081 if (tmpmode != result_reg_mode)
3082 result_reg = gen_lowpart (tmpmode, result_reg);
3084 expand_value_return (result_reg);
3088 && !VOID_TYPE_P (TREE_TYPE (retval_rhs))
3089 && (GET_CODE (result_rtl) == REG
3090 || (GET_CODE (result_rtl) == PARALLEL)))
3092 /* Calculate the return value into a temporary (usually a pseudo
3094 val = assign_temp (TREE_TYPE (DECL_RESULT (current_function_decl)),
3096 val = expand_expr (retval_rhs, val, GET_MODE (val), 0);
3097 val = force_not_mem (val);
3099 /* Return the calculated value, doing cleanups first. */
3100 expand_value_return (val);
3104 /* No cleanups or no hard reg used;
3105 calculate value into hard return reg. */
3106 expand_expr (retval, const0_rtx, VOIDmode, 0);
3108 expand_value_return (result_rtl);
3112 /* Return 1 if the end of the generated RTX is not a barrier.
3113 This means code already compiled can drop through. */
3116 drop_through_at_end_p ()
3118 rtx insn = get_last_insn ();
3119 while (insn && GET_CODE (insn) == NOTE)
3120 insn = PREV_INSN (insn);
3121 return insn && GET_CODE (insn) != BARRIER;
3124 /* Attempt to optimize a potential tail recursion call into a goto.
3125 ARGUMENTS are the arguments to a CALL_EXPR; LAST_INSN indicates
3126 where to place the jump to the tail recursion label.
3128 Return TRUE if the call was optimized into a goto. */
3131 optimize_tail_recursion (arguments, last_insn)
3135 /* Finish checking validity, and if valid emit code to set the
3136 argument variables for the new call. */
3137 if (tail_recursion_args (arguments, DECL_ARGUMENTS (current_function_decl)))
3139 if (tail_recursion_label == 0)
3141 tail_recursion_label = gen_label_rtx ();
3142 emit_label_after (tail_recursion_label,
3143 tail_recursion_reentry);
3146 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
3153 /* Emit code to alter this function's formal parms for a tail-recursive call.
3154 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3155 FORMALS is the chain of decls of formals.
3156 Return 1 if this can be done;
3157 otherwise return 0 and do not emit any code. */
3160 tail_recursion_args (actuals, formals)
3161 tree actuals, formals;
3163 register tree a = actuals, f = formals;
3165 register rtx *argvec;
3167 /* Check that number and types of actuals are compatible
3168 with the formals. This is not always true in valid C code.
3169 Also check that no formal needs to be addressable
3170 and that all formals are scalars. */
3172 /* Also count the args. */
3174 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
3176 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a)))
3177 != TYPE_MAIN_VARIANT (TREE_TYPE (f)))
3179 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
3182 if (a != 0 || f != 0)
3185 /* Compute all the actuals. */
3187 argvec = (rtx *) alloca (i * sizeof (rtx));
3189 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3190 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
3192 /* Find which actual values refer to current values of previous formals.
3193 Copy each of them now, before any formal is changed. */
3195 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3199 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
3200 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
3206 argvec[i] = copy_to_reg (argvec[i]);
3209 /* Store the values of the actuals into the formals. */
3211 for (f = formals, a = actuals, i = 0; f;
3212 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
3214 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
3215 emit_move_insn (DECL_RTL (f), argvec[i]);
3217 convert_move (DECL_RTL (f), argvec[i],
3218 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
3225 /* Generate the RTL code for entering a binding contour.
3226 The variables are declared one by one, by calls to `expand_decl'.
3228 FLAGS is a bitwise or of the following flags:
3230 1 - Nonzero if this construct should be visible to
3233 2 - Nonzero if this contour does not require a
3234 NOTE_INSN_BLOCK_BEG note. Virtually all calls from
3235 language-independent code should set this flag because they
3236 will not create corresponding BLOCK nodes. (There should be
3237 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
3238 and BLOCKs.) If this flag is set, MARK_ENDS should be zero
3239 when expand_end_bindings is called.
3241 If we are creating a NOTE_INSN_BLOCK_BEG note, a BLOCK may
3242 optionally be supplied. If so, it becomes the NOTE_BLOCK for the
3246 expand_start_bindings_and_block (flags, block)
3250 struct nesting *thisblock = ALLOC_NESTING ();
3252 int exit_flag = ((flags & 1) != 0);
3253 int block_flag = ((flags & 2) == 0);
3255 /* If a BLOCK is supplied, then the caller should be requesting a
3256 NOTE_INSN_BLOCK_BEG note. */
3257 if (!block_flag && block)
3260 /* Create a note to mark the beginning of the block. */
3263 note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
3264 NOTE_BLOCK (note) = block;
3267 note = emit_note (NULL_PTR, NOTE_INSN_DELETED);
3269 /* Make an entry on block_stack for the block we are entering. */
3271 thisblock->next = block_stack;
3272 thisblock->all = nesting_stack;
3273 thisblock->depth = ++nesting_depth;
3274 thisblock->data.block.stack_level = 0;
3275 thisblock->data.block.cleanups = 0;
3276 thisblock->data.block.n_function_calls = 0;
3277 thisblock->data.block.exception_region = 0;
3278 thisblock->data.block.block_target_temp_slot_level = target_temp_slot_level;
3280 thisblock->data.block.conditional_code = 0;
3281 thisblock->data.block.last_unconditional_cleanup = note;
3282 /* When we insert instructions after the last unconditional cleanup,
3283 we don't adjust last_insn. That means that a later add_insn will
3284 clobber the instructions we've just added. The easiest way to
3285 fix this is to just insert another instruction here, so that the
3286 instructions inserted after the last unconditional cleanup are
3287 never the last instruction. */
3288 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3289 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
3292 && !(block_stack->data.block.cleanups == NULL_TREE
3293 && block_stack->data.block.outer_cleanups == NULL_TREE))
3294 thisblock->data.block.outer_cleanups
3295 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
3296 block_stack->data.block.outer_cleanups);
3298 thisblock->data.block.outer_cleanups = 0;
3299 thisblock->data.block.label_chain = 0;
3300 thisblock->data.block.innermost_stack_block = stack_block_stack;
3301 thisblock->data.block.first_insn = note;
3302 thisblock->data.block.block_start_count = ++current_block_start_count;
3303 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
3304 block_stack = thisblock;
3305 nesting_stack = thisblock;
3307 /* Make a new level for allocating stack slots. */
3311 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3312 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3313 expand_expr are made. After we end the region, we know that all
3314 space for all temporaries that were created by TARGET_EXPRs will be
3315 destroyed and their space freed for reuse. */
3318 expand_start_target_temps ()
3320 /* This is so that even if the result is preserved, the space
3321 allocated will be freed, as we know that it is no longer in use. */
3324 /* Start a new binding layer that will keep track of all cleanup
3325 actions to be performed. */
3326 expand_start_bindings (2);
3328 target_temp_slot_level = temp_slot_level;
3332 expand_end_target_temps ()
3334 expand_end_bindings (NULL_TREE, 0, 0);
3336 /* This is so that even if the result is preserved, the space
3337 allocated will be freed, as we know that it is no longer in use. */
3341 /* Given a pointer to a BLOCK node return non-zero if (and only if) the node
3342 in question represents the outermost pair of curly braces (i.e. the "body
3343 block") of a function or method.
3345 For any BLOCK node representing a "body block" of a function or method, the
3346 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
3347 represents the outermost (function) scope for the function or method (i.e.
3348 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
3349 *that* node in turn will point to the relevant FUNCTION_DECL node. */
3352 is_body_block (stmt)
3355 if (TREE_CODE (stmt) == BLOCK)
3357 tree parent = BLOCK_SUPERCONTEXT (stmt);
3359 if (parent && TREE_CODE (parent) == BLOCK)
3361 tree grandparent = BLOCK_SUPERCONTEXT (parent);
3363 if (grandparent && TREE_CODE (grandparent) == FUNCTION_DECL)
3371 /* Mark top block of block_stack as an implicit binding for an
3372 exception region. This is used to prevent infinite recursion when
3373 ending a binding with expand_end_bindings. It is only ever called
3374 by expand_eh_region_start, as that it the only way to create a
3375 block stack for a exception region. */
3378 mark_block_as_eh_region ()
3380 block_stack->data.block.exception_region = 1;
3381 if (block_stack->next
3382 && block_stack->next->data.block.conditional_code)
3384 block_stack->data.block.conditional_code
3385 = block_stack->next->data.block.conditional_code;
3386 block_stack->data.block.last_unconditional_cleanup
3387 = block_stack->next->data.block.last_unconditional_cleanup;
3388 block_stack->data.block.cleanup_ptr
3389 = block_stack->next->data.block.cleanup_ptr;
3393 /* True if we are currently emitting insns in an area of output code
3394 that is controlled by a conditional expression. This is used by
3395 the cleanup handling code to generate conditional cleanup actions. */
3398 conditional_context ()
3400 return block_stack && block_stack->data.block.conditional_code;
3403 /* Mark top block of block_stack as not for an implicit binding for an
3404 exception region. This is only ever done by expand_eh_region_end
3405 to let expand_end_bindings know that it is being called explicitly
3406 to end the binding layer for just the binding layer associated with
3407 the exception region, otherwise expand_end_bindings would try and
3408 end all implicit binding layers for exceptions regions, and then
3409 one normal binding layer. */
3412 mark_block_as_not_eh_region ()
3414 block_stack->data.block.exception_region = 0;
3417 /* True if the top block of block_stack was marked as for an exception
3418 region by mark_block_as_eh_region. */
3423 return cfun && block_stack && block_stack->data.block.exception_region;
3426 /* Emit a handler label for a nonlocal goto handler.
3427 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3430 expand_nl_handler_label (slot, before_insn)
3431 rtx slot, before_insn;
3434 rtx handler_label = gen_label_rtx ();
3436 /* Don't let jump_optimize delete the handler. */
3437 LABEL_PRESERVE_P (handler_label) = 1;
3440 emit_move_insn (slot, gen_rtx_LABEL_REF (Pmode, handler_label));
3441 insns = get_insns ();
3443 emit_insns_before (insns, before_insn);
3445 emit_label (handler_label);
3447 return handler_label;
3450 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3453 expand_nl_goto_receiver ()
3455 #ifdef HAVE_nonlocal_goto
3456 if (! HAVE_nonlocal_goto)
3458 /* First adjust our frame pointer to its actual value. It was
3459 previously set to the start of the virtual area corresponding to
3460 the stacked variables when we branched here and now needs to be
3461 adjusted to the actual hardware fp value.
3463 Assignments are to virtual registers are converted by
3464 instantiate_virtual_regs into the corresponding assignment
3465 to the underlying register (fp in this case) that makes
3466 the original assignment true.
3467 So the following insn will actually be
3468 decrementing fp by STARTING_FRAME_OFFSET. */
3469 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3471 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3472 if (fixed_regs[ARG_POINTER_REGNUM])
3474 #ifdef ELIMINABLE_REGS
3475 /* If the argument pointer can be eliminated in favor of the
3476 frame pointer, we don't need to restore it. We assume here
3477 that if such an elimination is present, it can always be used.
3478 This is the case on all known machines; if we don't make this
3479 assumption, we do unnecessary saving on many machines. */
3480 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3483 for (i = 0; i < ARRAY_SIZE (elim_regs); i++)
3484 if (elim_regs[i].from == ARG_POINTER_REGNUM
3485 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3488 if (i == ARRAY_SIZE (elim_regs))
3491 /* Now restore our arg pointer from the address at which it
3492 was saved in our stack frame.
3493 If there hasn't be space allocated for it yet, make
3495 if (arg_pointer_save_area == 0)
3496 arg_pointer_save_area
3497 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3498 emit_move_insn (virtual_incoming_args_rtx,
3499 /* We need a pseudo here, or else
3500 instantiate_virtual_regs_1 complains. */
3501 copy_to_reg (arg_pointer_save_area));
3506 #ifdef HAVE_nonlocal_goto_receiver
3507 if (HAVE_nonlocal_goto_receiver)
3508 emit_insn (gen_nonlocal_goto_receiver ());
3512 /* Make handlers for nonlocal gotos taking place in the function calls in
3516 expand_nl_goto_receivers (thisblock)
3517 struct nesting *thisblock;
3520 rtx afterward = gen_label_rtx ();
3525 /* Record the handler address in the stack slot for that purpose,
3526 during this block, saving and restoring the outer value. */
3527 if (thisblock->next != 0)
3528 for (slot = nonlocal_goto_handler_slots; slot; slot = XEXP (slot, 1))
3530 rtx save_receiver = gen_reg_rtx (Pmode);
3531 emit_move_insn (XEXP (slot, 0), save_receiver);
3534 emit_move_insn (save_receiver, XEXP (slot, 0));
3535 insns = get_insns ();
3537 emit_insns_before (insns, thisblock->data.block.first_insn);
3540 /* Jump around the handlers; they run only when specially invoked. */
3541 emit_jump (afterward);
3543 /* Make a separate handler for each label. */
3544 link = nonlocal_labels;
3545 slot = nonlocal_goto_handler_slots;
3546 label_list = NULL_RTX;
3547 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3548 /* Skip any labels we shouldn't be able to jump to from here,
3549 we generate one special handler for all of them below which just calls
3551 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3554 lab = expand_nl_handler_label (XEXP (slot, 0),
3555 thisblock->data.block.first_insn);
3556 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3558 expand_nl_goto_receiver ();
3560 /* Jump to the "real" nonlocal label. */
3561 expand_goto (TREE_VALUE (link));
3564 /* A second pass over all nonlocal labels; this time we handle those
3565 we should not be able to jump to at this point. */
3566 link = nonlocal_labels;
3567 slot = nonlocal_goto_handler_slots;
3569 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3570 if (DECL_TOO_LATE (TREE_VALUE (link)))
3573 lab = expand_nl_handler_label (XEXP (slot, 0),
3574 thisblock->data.block.first_insn);
3575 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3581 expand_nl_goto_receiver ();
3582 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "abort"), 0,
3587 nonlocal_goto_handler_labels = label_list;
3588 emit_label (afterward);
3591 /* Warn about any unused VARS (which may contain nodes other than
3592 VAR_DECLs, but such nodes are ignored). The nodes are connected
3593 via the TREE_CHAIN field. */
3596 warn_about_unused_variables (vars)
3601 if (warn_unused_variable)
3602 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3603 if (TREE_CODE (decl) == VAR_DECL
3604 && ! TREE_USED (decl)
3605 && ! DECL_IN_SYSTEM_HEADER (decl)
3606 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
3607 warning_with_decl (decl, "unused variable `%s'");
3610 /* Generate RTL code to terminate a binding contour.
3612 VARS is the chain of VAR_DECL nodes for the variables bound in this
3613 contour. There may actually be other nodes in this chain, but any
3614 nodes other than VAR_DECLS are ignored.
3616 MARK_ENDS is nonzero if we should put a note at the beginning
3617 and end of this binding contour.
3619 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3620 (That is true automatically if the contour has a saved stack level.) */
3623 expand_end_bindings (vars, mark_ends, dont_jump_in)
3628 register struct nesting *thisblock;
3630 while (block_stack->data.block.exception_region)
3632 /* Because we don't need or want a new temporary level and
3633 because we didn't create one in expand_eh_region_start,
3634 create a fake one now to avoid removing one in
3635 expand_end_bindings. */
3638 block_stack->data.block.exception_region = 0;
3640 expand_end_bindings (NULL_TREE, 0, 0);
3643 /* Since expand_eh_region_start does an expand_start_bindings, we
3644 have to first end all the bindings that were created by
3645 expand_eh_region_start. */
3647 thisblock = block_stack;
3649 /* If any of the variables in this scope were not used, warn the
3651 warn_about_unused_variables (vars);
3653 if (thisblock->exit_label)
3655 do_pending_stack_adjust ();
3656 emit_label (thisblock->exit_label);
3659 /* If necessary, make handlers for nonlocal gotos taking
3660 place in the function calls in this block. */
3661 if (function_call_count != thisblock->data.block.n_function_calls
3663 /* Make handler for outermost block
3664 if there were any nonlocal gotos to this function. */
3665 && (thisblock->next == 0 ? current_function_has_nonlocal_label
3666 /* Make handler for inner block if it has something
3667 special to do when you jump out of it. */
3668 : (thisblock->data.block.cleanups != 0
3669 || thisblock->data.block.stack_level != 0)))
3670 expand_nl_goto_receivers (thisblock);
3672 /* Don't allow jumping into a block that has a stack level.
3673 Cleanups are allowed, though. */
3675 || thisblock->data.block.stack_level != 0)
3677 struct label_chain *chain;
3679 /* Any labels in this block are no longer valid to go to.
3680 Mark them to cause an error message. */
3681 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3683 DECL_TOO_LATE (chain->label) = 1;
3684 /* If any goto without a fixup came to this label,
3685 that must be an error, because gotos without fixups
3686 come from outside all saved stack-levels. */
3687 if (TREE_ADDRESSABLE (chain->label))
3688 error_with_decl (chain->label,
3689 "label `%s' used before containing binding contour");
3693 /* Restore stack level in effect before the block
3694 (only if variable-size objects allocated). */
3695 /* Perform any cleanups associated with the block. */
3697 if (thisblock->data.block.stack_level != 0
3698 || thisblock->data.block.cleanups != 0)
3703 /* Don't let cleanups affect ({...}) constructs. */
3704 int old_expr_stmts_for_value = expr_stmts_for_value;
3705 rtx old_last_expr_value = last_expr_value;
3706 tree old_last_expr_type = last_expr_type;
3707 expr_stmts_for_value = 0;
3709 /* Only clean up here if this point can actually be reached. */
3710 insn = get_last_insn ();
3711 if (GET_CODE (insn) == NOTE)
3712 insn = prev_nonnote_insn (insn);
3713 reachable = (! insn || GET_CODE (insn) != BARRIER);
3715 /* Do the cleanups. */
3716 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3718 do_pending_stack_adjust ();
3720 expr_stmts_for_value = old_expr_stmts_for_value;
3721 last_expr_value = old_last_expr_value;
3722 last_expr_type = old_last_expr_type;
3724 /* Restore the stack level. */
3726 if (reachable && thisblock->data.block.stack_level != 0)
3728 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3729 thisblock->data.block.stack_level, NULL_RTX);
3730 if (nonlocal_goto_handler_slots != 0)
3731 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3735 /* Any gotos out of this block must also do these things.
3736 Also report any gotos with fixups that came to labels in this
3738 fixup_gotos (thisblock,
3739 thisblock->data.block.stack_level,
3740 thisblock->data.block.cleanups,
3741 thisblock->data.block.first_insn,
3745 /* Mark the beginning and end of the scope if requested.
3746 We do this now, after running cleanups on the variables
3747 just going out of scope, so they are in scope for their cleanups. */
3751 rtx note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3752 NOTE_BLOCK (note) = NOTE_BLOCK (thisblock->data.block.first_insn);
3755 /* Get rid of the beginning-mark if we don't make an end-mark. */
3756 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3758 /* Restore the temporary level of TARGET_EXPRs. */
3759 target_temp_slot_level = thisblock->data.block.block_target_temp_slot_level;
3761 /* Restore block_stack level for containing block. */
3763 stack_block_stack = thisblock->data.block.innermost_stack_block;
3764 POPSTACK (block_stack);
3766 /* Pop the stack slot nesting and free any slots at this level. */
3770 /* Generate code to save the stack pointer at the start of the current block
3771 and set up to restore it on exit. */
3774 save_stack_pointer ()
3776 struct nesting *thisblock = block_stack;
3778 if (thisblock->data.block.stack_level == 0)
3780 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3781 &thisblock->data.block.stack_level,
3782 thisblock->data.block.first_insn);
3783 stack_block_stack = thisblock;
3787 /* Generate RTL for the automatic variable declaration DECL.
3788 (Other kinds of declarations are simply ignored if seen here.) */
3794 struct nesting *thisblock;
3797 type = TREE_TYPE (decl);
3799 /* Only automatic variables need any expansion done.
3800 Static and external variables, and external functions,
3801 will be handled by `assemble_variable' (called from finish_decl).
3802 TYPE_DECL and CONST_DECL require nothing.
3803 PARM_DECLs are handled in `assign_parms'. */
3805 if (TREE_CODE (decl) != VAR_DECL)
3807 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3810 thisblock = block_stack;
3812 /* Create the RTL representation for the variable. */
3814 if (type == error_mark_node)
3815 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, const0_rtx);
3816 else if (DECL_SIZE (decl) == 0)
3817 /* Variable with incomplete type. */
3819 if (DECL_INITIAL (decl) == 0)
3820 /* Error message was already done; now avoid a crash. */
3821 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3823 /* An initializer is going to decide the size of this array.
3824 Until we know the size, represent its address with a reg. */
3825 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode));
3827 set_mem_attributes (DECL_RTL (decl), decl, 1);
3829 else if (DECL_MODE (decl) != BLKmode
3830 /* If -ffloat-store, don't put explicit float vars
3832 && !(flag_float_store
3833 && TREE_CODE (type) == REAL_TYPE)
3834 && ! TREE_THIS_VOLATILE (decl)
3835 && (DECL_REGISTER (decl) || optimize)
3836 /* if -fcheck-memory-usage, check all variables. */
3837 && ! current_function_check_memory_usage)
3839 /* Automatic variable that can go in a register. */
3840 int unsignedp = TREE_UNSIGNED (type);
3841 enum machine_mode reg_mode
3842 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3844 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3845 mark_user_reg (DECL_RTL (decl));
3847 if (POINTER_TYPE_P (type))
3848 mark_reg_pointer (DECL_RTL (decl),
3849 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
3851 maybe_set_unchanging (DECL_RTL (decl), decl);
3853 /* If something wants our address, try to use ADDRESSOF. */
3854 if (TREE_ADDRESSABLE (decl))
3855 put_var_into_stack (decl);
3858 else if (TREE_CODE (DECL_SIZE_UNIT (decl)) == INTEGER_CST
3859 && ! (flag_stack_check && ! STACK_CHECK_BUILTIN
3860 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl),
3861 STACK_CHECK_MAX_VAR_SIZE)))
3863 /* Variable of fixed size that goes on the stack. */
3867 /* If we previously made RTL for this decl, it must be an array
3868 whose size was determined by the initializer.
3869 The old address was a register; set that register now
3870 to the proper address. */
3871 if (DECL_RTL (decl) != 0)
3873 if (GET_CODE (DECL_RTL (decl)) != MEM
3874 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3876 oldaddr = XEXP (DECL_RTL (decl), 0);
3879 DECL_RTL (decl) = assign_temp (TREE_TYPE (decl), 1, 1, 1);
3881 /* Set alignment we actually gave this decl. */
3882 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3883 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3884 DECL_USER_ALIGN (decl) = 0;
3888 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3889 if (addr != oldaddr)
3890 emit_move_insn (oldaddr, addr);
3894 /* Dynamic-size object: must push space on the stack. */
3898 /* Record the stack pointer on entry to block, if have
3899 not already done so. */
3900 do_pending_stack_adjust ();
3901 save_stack_pointer ();
3903 /* In function-at-a-time mode, variable_size doesn't expand this,
3905 if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
3906 expand_expr (TYPE_MAX_VALUE (TYPE_DOMAIN (type)),
3907 const0_rtx, VOIDmode, 0);
3909 /* Compute the variable's size, in bytes. */
3910 size = expand_expr (DECL_SIZE_UNIT (decl), NULL_RTX, VOIDmode, 0);
3913 /* Allocate space on the stack for the variable. Note that
3914 DECL_ALIGN says how the variable is to be aligned and we
3915 cannot use it to conclude anything about the alignment of
3917 address = allocate_dynamic_stack_space (size, NULL_RTX,
3918 TYPE_ALIGN (TREE_TYPE (decl)));
3920 /* Reference the variable indirect through that rtx. */
3921 DECL_RTL (decl) = gen_rtx_MEM (DECL_MODE (decl), address);
3923 set_mem_attributes (DECL_RTL (decl), decl, 1);
3925 /* Indicate the alignment we actually gave this variable. */
3926 #ifdef STACK_BOUNDARY
3927 DECL_ALIGN (decl) = STACK_BOUNDARY;
3929 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3931 DECL_USER_ALIGN (decl) = 0;
3935 /* Emit code to perform the initialization of a declaration DECL. */
3938 expand_decl_init (decl)
3941 int was_used = TREE_USED (decl);
3943 /* If this is a CONST_DECL, we don't have to generate any code, but
3944 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3945 to be set while in the obstack containing the constant. If we don't
3946 do this, we can lose if we have functions nested three deep and the middle
3947 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3948 the innermost function is the first to expand that STRING_CST. */
3949 if (TREE_CODE (decl) == CONST_DECL)
3951 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3952 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3953 EXPAND_INITIALIZER);
3957 if (TREE_STATIC (decl))
3960 /* Compute and store the initial value now. */
3962 if (DECL_INITIAL (decl) == error_mark_node)
3964 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3966 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3967 || code == POINTER_TYPE || code == REFERENCE_TYPE)
3968 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3972 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3974 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3975 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3979 /* Don't let the initialization count as "using" the variable. */
3980 TREE_USED (decl) = was_used;
3982 /* Free any temporaries we made while initializing the decl. */
3983 preserve_temp_slots (NULL_RTX);
3987 /* CLEANUP is an expression to be executed at exit from this binding contour;
3988 for example, in C++, it might call the destructor for this variable.
3990 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
3991 CLEANUP multiple times, and have the correct semantics. This
3992 happens in exception handling, for gotos, returns, breaks that
3993 leave the current scope.
3995 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3996 that is not associated with any particular variable. */
3999 expand_decl_cleanup (decl, cleanup)
4002 struct nesting *thisblock;
4004 /* Error if we are not in any block. */
4005 if (cfun == 0 || block_stack == 0)
4008 thisblock = block_stack;
4010 /* Record the cleanup if there is one. */
4016 tree *cleanups = &thisblock->data.block.cleanups;
4017 int cond_context = conditional_context ();
4021 rtx flag = gen_reg_rtx (word_mode);
4026 emit_move_insn (flag, const0_rtx);
4027 set_flag_0 = get_insns ();
4030 thisblock->data.block.last_unconditional_cleanup
4031 = emit_insns_after (set_flag_0,
4032 thisblock->data.block.last_unconditional_cleanup);
4034 emit_move_insn (flag, const1_rtx);
4036 cond = build_decl (VAR_DECL, NULL_TREE, type_for_mode (word_mode, 1));
4037 DECL_RTL (cond) = flag;
4039 /* Conditionalize the cleanup. */
4040 cleanup = build (COND_EXPR, void_type_node,
4041 truthvalue_conversion (cond),
4042 cleanup, integer_zero_node);
4043 cleanup = fold (cleanup);
4045 cleanups = thisblock->data.block.cleanup_ptr;
4048 cleanup = unsave_expr (cleanup);
4050 t = *cleanups = tree_cons (decl, cleanup, *cleanups);
4053 /* If this block has a cleanup, it belongs in stack_block_stack. */
4054 stack_block_stack = thisblock;
4061 /* If this was optimized so that there is no exception region for the
4062 cleanup, then mark the TREE_LIST node, so that we can later tell
4063 if we need to call expand_eh_region_end. */
4064 if (! using_eh_for_cleanups_p
4065 || expand_eh_region_start_tree (decl, cleanup))
4066 TREE_ADDRESSABLE (t) = 1;
4067 /* If that started a new EH region, we're in a new block. */
4068 thisblock = block_stack;
4075 thisblock->data.block.last_unconditional_cleanup
4076 = emit_insns_after (seq,
4077 thisblock->data.block.last_unconditional_cleanup);
4081 thisblock->data.block.last_unconditional_cleanup
4083 /* When we insert instructions after the last unconditional cleanup,
4084 we don't adjust last_insn. That means that a later add_insn will
4085 clobber the instructions we've just added. The easiest way to
4086 fix this is to just insert another instruction here, so that the
4087 instructions inserted after the last unconditional cleanup are
4088 never the last instruction. */
4089 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4090 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
4096 /* Like expand_decl_cleanup, but suppress generating an exception handler
4097 to perform the cleanup. */
4101 expand_decl_cleanup_no_eh (decl, cleanup)
4104 int save_eh = using_eh_for_cleanups_p;
4107 using_eh_for_cleanups_p = 0;
4108 result = expand_decl_cleanup (decl, cleanup);
4109 using_eh_for_cleanups_p = save_eh;
4115 /* Arrange for the top element of the dynamic cleanup chain to be
4116 popped if we exit the current binding contour. DECL is the
4117 associated declaration, if any, otherwise NULL_TREE. If the
4118 current contour is left via an exception, then __sjthrow will pop
4119 the top element off the dynamic cleanup chain. The code that
4120 avoids doing the action we push into the cleanup chain in the
4121 exceptional case is contained in expand_cleanups.
4123 This routine is only used by expand_eh_region_start, and that is
4124 the only way in which an exception region should be started. This
4125 routine is only used when using the setjmp/longjmp codegen method
4126 for exception handling. */
4129 expand_dcc_cleanup (decl)
4132 struct nesting *thisblock;
4135 /* Error if we are not in any block. */
4136 if (cfun == 0 || block_stack == 0)
4138 thisblock = block_stack;
4140 /* Record the cleanup for the dynamic handler chain. */
4142 cleanup = make_node (POPDCC_EXPR);
4144 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4145 thisblock->data.block.cleanups
4146 = tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4148 /* If this block has a cleanup, it belongs in stack_block_stack. */
4149 stack_block_stack = thisblock;
4153 /* Arrange for the top element of the dynamic handler chain to be
4154 popped if we exit the current binding contour. DECL is the
4155 associated declaration, if any, otherwise NULL_TREE. If the current
4156 contour is left via an exception, then __sjthrow will pop the top
4157 element off the dynamic handler chain. The code that avoids doing
4158 the action we push into the handler chain in the exceptional case
4159 is contained in expand_cleanups.
4161 This routine is only used by expand_eh_region_start, and that is
4162 the only way in which an exception region should be started. This
4163 routine is only used when using the setjmp/longjmp codegen method
4164 for exception handling. */
4167 expand_dhc_cleanup (decl)
4170 struct nesting *thisblock;
4173 /* Error if we are not in any block. */
4174 if (cfun == 0 || block_stack == 0)
4176 thisblock = block_stack;
4178 /* Record the cleanup for the dynamic handler chain. */
4180 cleanup = make_node (POPDHC_EXPR);
4182 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4183 thisblock->data.block.cleanups
4184 = tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4186 /* If this block has a cleanup, it belongs in stack_block_stack. */
4187 stack_block_stack = thisblock;
4191 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4192 DECL_ELTS is the list of elements that belong to DECL's type.
4193 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4196 expand_anon_union_decl (decl, cleanup, decl_elts)
4197 tree decl, cleanup, decl_elts;
4199 struct nesting *thisblock = cfun == 0 ? 0 : block_stack;
4203 /* If any of the elements are addressable, so is the entire union. */
4204 for (t = decl_elts; t; t = TREE_CHAIN (t))
4205 if (TREE_ADDRESSABLE (TREE_VALUE (t)))
4207 TREE_ADDRESSABLE (decl) = 1;
4212 expand_decl_cleanup (decl, cleanup);
4213 x = DECL_RTL (decl);
4215 /* Go through the elements, assigning RTL to each. */
4216 for (t = decl_elts; t; t = TREE_CHAIN (t))
4218 tree decl_elt = TREE_VALUE (t);
4219 tree cleanup_elt = TREE_PURPOSE (t);
4220 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
4222 /* Propagate the union's alignment to the elements. */
4223 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
4224 DECL_USER_ALIGN (decl_elt) = DECL_USER_ALIGN (decl);
4226 /* If the element has BLKmode and the union doesn't, the union is
4227 aligned such that the element doesn't need to have BLKmode, so
4228 change the element's mode to the appropriate one for its size. */
4229 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
4230 DECL_MODE (decl_elt) = mode
4231 = mode_for_size_tree (DECL_SIZE (decl_elt), MODE_INT, 1);
4233 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4234 instead create a new MEM rtx with the proper mode. */
4235 if (GET_CODE (x) == MEM)
4237 if (mode == GET_MODE (x))
4238 DECL_RTL (decl_elt) = x;
4241 DECL_RTL (decl_elt) = gen_rtx_MEM (mode, copy_rtx (XEXP (x, 0)));
4242 MEM_COPY_ATTRIBUTES (DECL_RTL (decl_elt), x);
4245 else if (GET_CODE (x) == REG)
4247 if (mode == GET_MODE (x))
4248 DECL_RTL (decl_elt) = x;
4250 DECL_RTL (decl_elt) = gen_rtx_SUBREG (mode, x, 0);
4255 /* Record the cleanup if there is one. */
4258 thisblock->data.block.cleanups
4259 = tree_cons (decl_elt, cleanup_elt,
4260 thisblock->data.block.cleanups);
4264 /* Expand a list of cleanups LIST.
4265 Elements may be expressions or may be nested lists.
4267 If DONT_DO is nonnull, then any list-element
4268 whose TREE_PURPOSE matches DONT_DO is omitted.
4269 This is sometimes used to avoid a cleanup associated with
4270 a value that is being returned out of the scope.
4272 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
4273 goto and handle protection regions specially in that case.
4275 If REACHABLE, we emit code, otherwise just inform the exception handling
4276 code about this finalization. */
4279 expand_cleanups (list, dont_do, in_fixup, reachable)
4286 for (tail = list; tail; tail = TREE_CHAIN (tail))
4287 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
4289 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
4290 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
4295 tree cleanup = TREE_VALUE (tail);
4297 /* See expand_d{h,c}c_cleanup for why we avoid this. */
4298 if (TREE_CODE (cleanup) != POPDHC_EXPR
4299 && TREE_CODE (cleanup) != POPDCC_EXPR
4300 /* See expand_eh_region_start_tree for this case. */
4301 && ! TREE_ADDRESSABLE (tail))
4303 cleanup = protect_with_terminate (cleanup);
4304 expand_eh_region_end (cleanup);
4310 /* Cleanups may be run multiple times. For example,
4311 when exiting a binding contour, we expand the
4312 cleanups associated with that contour. When a goto
4313 within that binding contour has a target outside that
4314 contour, it will expand all cleanups from its scope to
4315 the target. Though the cleanups are expanded multiple
4316 times, the control paths are non-overlapping so the
4317 cleanups will not be executed twice. */
4319 /* We may need to protect fixups with rethrow regions. */
4320 int protect = (in_fixup && ! TREE_ADDRESSABLE (tail));
4323 expand_fixup_region_start ();
4325 /* The cleanup might contain try-blocks, so we have to
4326 preserve our current queue. */
4328 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
4331 expand_fixup_region_end (TREE_VALUE (tail));
4338 /* Mark when the context we are emitting RTL for as a conditional
4339 context, so that any cleanup actions we register with
4340 expand_decl_init will be properly conditionalized when those
4341 cleanup actions are later performed. Must be called before any
4342 expression (tree) is expanded that is within a conditional context. */
4345 start_cleanup_deferral ()
4347 /* block_stack can be NULL if we are inside the parameter list. It is
4348 OK to do nothing, because cleanups aren't possible here. */
4350 ++block_stack->data.block.conditional_code;
4353 /* Mark the end of a conditional region of code. Because cleanup
4354 deferrals may be nested, we may still be in a conditional region
4355 after we end the currently deferred cleanups, only after we end all
4356 deferred cleanups, are we back in unconditional code. */
4359 end_cleanup_deferral ()
4361 /* block_stack can be NULL if we are inside the parameter list. It is
4362 OK to do nothing, because cleanups aren't possible here. */
4364 --block_stack->data.block.conditional_code;
4367 /* Move all cleanups from the current block_stack
4368 to the containing block_stack, where they are assumed to
4369 have been created. If anything can cause a temporary to
4370 be created, but not expanded for more than one level of
4371 block_stacks, then this code will have to change. */
4376 struct nesting *block = block_stack;
4377 struct nesting *outer = block->next;
4379 outer->data.block.cleanups
4380 = chainon (block->data.block.cleanups,
4381 outer->data.block.cleanups);
4382 block->data.block.cleanups = 0;
4386 last_cleanup_this_contour ()
4388 if (block_stack == 0)
4391 return block_stack->data.block.cleanups;
4394 /* Return 1 if there are any pending cleanups at this point.
4395 If THIS_CONTOUR is nonzero, check the current contour as well.
4396 Otherwise, look only at the contours that enclose this one. */
4399 any_pending_cleanups (this_contour)
4402 struct nesting *block;
4404 if (cfun == NULL || cfun->stmt == NULL || block_stack == 0)
4407 if (this_contour && block_stack->data.block.cleanups != NULL)
4409 if (block_stack->data.block.cleanups == 0
4410 && block_stack->data.block.outer_cleanups == 0)
4413 for (block = block_stack->next; block; block = block->next)
4414 if (block->data.block.cleanups != 0)
4420 /* Enter a case (Pascal) or switch (C) statement.
4421 Push a block onto case_stack and nesting_stack
4422 to accumulate the case-labels that are seen
4423 and to record the labels generated for the statement.
4425 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4426 Otherwise, this construct is transparent for `exit_something'.
4428 EXPR is the index-expression to be dispatched on.
4429 TYPE is its nominal type. We could simply convert EXPR to this type,
4430 but instead we take short cuts. */
4433 expand_start_case (exit_flag, expr, type, printname)
4437 const char *printname;
4439 register struct nesting *thiscase = ALLOC_NESTING ();
4441 /* Make an entry on case_stack for the case we are entering. */
4443 thiscase->next = case_stack;
4444 thiscase->all = nesting_stack;
4445 thiscase->depth = ++nesting_depth;
4446 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
4447 thiscase->data.case_stmt.case_list = 0;
4448 thiscase->data.case_stmt.index_expr = expr;
4449 thiscase->data.case_stmt.nominal_type = type;
4450 thiscase->data.case_stmt.default_label = 0;
4451 thiscase->data.case_stmt.printname = printname;
4452 thiscase->data.case_stmt.line_number_status = force_line_numbers ();
4453 case_stack = thiscase;
4454 nesting_stack = thiscase;
4456 do_pending_stack_adjust ();
4458 /* Make sure case_stmt.start points to something that won't
4459 need any transformation before expand_end_case. */
4460 if (GET_CODE (get_last_insn ()) != NOTE)
4461 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4463 thiscase->data.case_stmt.start = get_last_insn ();
4465 start_cleanup_deferral ();
4468 /* Start a "dummy case statement" within which case labels are invalid
4469 and are not connected to any larger real case statement.
4470 This can be used if you don't want to let a case statement jump
4471 into the middle of certain kinds of constructs. */
4474 expand_start_case_dummy ()
4476 register struct nesting *thiscase = ALLOC_NESTING ();
4478 /* Make an entry on case_stack for the dummy. */
4480 thiscase->next = case_stack;
4481 thiscase->all = nesting_stack;
4482 thiscase->depth = ++nesting_depth;
4483 thiscase->exit_label = 0;
4484 thiscase->data.case_stmt.case_list = 0;
4485 thiscase->data.case_stmt.start = 0;
4486 thiscase->data.case_stmt.nominal_type = 0;
4487 thiscase->data.case_stmt.default_label = 0;
4488 case_stack = thiscase;
4489 nesting_stack = thiscase;
4490 start_cleanup_deferral ();
4493 /* End a dummy case statement. */
4496 expand_end_case_dummy ()
4498 end_cleanup_deferral ();
4499 POPSTACK (case_stack);
4502 /* Return the data type of the index-expression
4503 of the innermost case statement, or null if none. */
4506 case_index_expr_type ()
4509 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
4516 /* If this is the first label, warn if any insns have been emitted. */
4517 if (case_stack->data.case_stmt.line_number_status >= 0)
4521 restore_line_number_status
4522 (case_stack->data.case_stmt.line_number_status);
4523 case_stack->data.case_stmt.line_number_status = -1;
4525 for (insn = case_stack->data.case_stmt.start;
4527 insn = NEXT_INSN (insn))
4529 if (GET_CODE (insn) == CODE_LABEL)
4531 if (GET_CODE (insn) != NOTE
4532 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4535 insn = PREV_INSN (insn);
4536 while (insn && (GET_CODE (insn) != NOTE || NOTE_LINE_NUMBER (insn) < 0));
4538 /* If insn is zero, then there must have been a syntax error. */
4540 warning_with_file_and_line (NOTE_SOURCE_FILE (insn),
4541 NOTE_LINE_NUMBER (insn),
4542 "unreachable code at beginning of %s",
4543 case_stack->data.case_stmt.printname);
4550 /* Accumulate one case or default label inside a case or switch statement.
4551 VALUE is the value of the case (a null pointer, for a default label).
4552 The function CONVERTER, when applied to arguments T and V,
4553 converts the value V to the type T.
4555 If not currently inside a case or switch statement, return 1 and do
4556 nothing. The caller will print a language-specific error message.
4557 If VALUE is a duplicate or overlaps, return 2 and do nothing
4558 except store the (first) duplicate node in *DUPLICATE.
4559 If VALUE is out of range, return 3 and do nothing.
4560 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4561 Return 0 on success.
4563 Extended to handle range statements. */
4566 pushcase (value, converter, label, duplicate)
4567 register tree value;
4568 tree (*converter) PARAMS ((tree, tree));
4569 register tree label;
4575 /* Fail if not inside a real case statement. */
4576 if (! (case_stack && case_stack->data.case_stmt.start))
4579 if (stack_block_stack
4580 && stack_block_stack->depth > case_stack->depth)
4583 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4584 nominal_type = case_stack->data.case_stmt.nominal_type;
4586 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4587 if (index_type == error_mark_node)
4590 /* Convert VALUE to the type in which the comparisons are nominally done. */
4592 value = (*converter) (nominal_type, value);
4596 /* Fail if this value is out of range for the actual type of the index
4597 (which may be narrower than NOMINAL_TYPE). */
4599 && (TREE_CONSTANT_OVERFLOW (value)
4600 || ! int_fits_type_p (value, index_type)))
4603 return add_case_node (value, value, label, duplicate);
4606 /* Like pushcase but this case applies to all values between VALUE1 and
4607 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4608 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4609 starts at VALUE1 and ends at the highest value of the index type.
4610 If both are NULL, this case applies to all values.
4612 The return value is the same as that of pushcase but there is one
4613 additional error code: 4 means the specified range was empty. */
4616 pushcase_range (value1, value2, converter, label, duplicate)
4617 register tree value1, value2;
4618 tree (*converter) PARAMS ((tree, tree));
4619 register tree label;
4625 /* Fail if not inside a real case statement. */
4626 if (! (case_stack && case_stack->data.case_stmt.start))
4629 if (stack_block_stack
4630 && stack_block_stack->depth > case_stack->depth)
4633 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4634 nominal_type = case_stack->data.case_stmt.nominal_type;
4636 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4637 if (index_type == error_mark_node)
4642 /* Convert VALUEs to type in which the comparisons are nominally done
4643 and replace any unspecified value with the corresponding bound. */
4645 value1 = TYPE_MIN_VALUE (index_type);
4647 value2 = TYPE_MAX_VALUE (index_type);
4649 /* Fail if the range is empty. Do this before any conversion since
4650 we want to allow out-of-range empty ranges. */
4651 if (value2 != 0 && tree_int_cst_lt (value2, value1))
4654 /* If the max was unbounded, use the max of the nominal_type we are
4655 converting to. Do this after the < check above to suppress false
4658 value2 = TYPE_MAX_VALUE (nominal_type);
4660 value1 = (*converter) (nominal_type, value1);
4661 value2 = (*converter) (nominal_type, value2);
4663 /* Fail if these values are out of range. */
4664 if (TREE_CONSTANT_OVERFLOW (value1)
4665 || ! int_fits_type_p (value1, index_type))
4668 if (TREE_CONSTANT_OVERFLOW (value2)
4669 || ! int_fits_type_p (value2, index_type))
4672 return add_case_node (value1, value2, label, duplicate);
4675 /* Do the actual insertion of a case label for pushcase and pushcase_range
4676 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4677 slowdown for large switch statements. */
4680 add_case_node (low, high, label, duplicate)
4685 struct case_node *p, **q, *r;
4687 /* If there's no HIGH value, then this is not a case range; it's
4688 just a simple case label. But that's just a degenerate case
4693 /* Handle default labels specially. */
4696 if (case_stack->data.case_stmt.default_label != 0)
4698 *duplicate = case_stack->data.case_stmt.default_label;
4701 case_stack->data.case_stmt.default_label = label;
4702 expand_label (label);
4706 q = &case_stack->data.case_stmt.case_list;
4713 /* Keep going past elements distinctly greater than HIGH. */
4714 if (tree_int_cst_lt (high, p->low))
4717 /* or distinctly less than LOW. */
4718 else if (tree_int_cst_lt (p->high, low))
4723 /* We have an overlap; this is an error. */
4724 *duplicate = p->code_label;
4729 /* Add this label to the chain, and succeed.
4730 Copy LOW, HIGH so they are on temporary rather than momentary
4731 obstack and will thus survive till the end of the case statement. */
4733 r = (struct case_node *) xmalloc (sizeof (struct case_node));
4734 r->low = copy_node (low);
4736 /* If the bounds are equal, turn this into the one-value case. */
4737 if (tree_int_cst_equal (low, high))
4740 r->high = copy_node (high);
4742 r->code_label = label;
4743 expand_label (label);
4753 struct case_node *s;
4759 if (! (b = p->balance))
4760 /* Growth propagation from left side. */
4767 if ((p->left = s = r->right))
4776 if ((r->parent = s))
4784 case_stack->data.case_stmt.case_list = r;
4787 /* r->balance == +1 */
4792 struct case_node *t = r->right;
4794 if ((p->left = s = t->right))
4798 if ((r->right = s = t->left))
4812 if ((t->parent = s))
4820 case_stack->data.case_stmt.case_list = t;
4827 /* p->balance == +1; growth of left side balances the node. */
4837 if (! (b = p->balance))
4838 /* Growth propagation from right side. */
4846 if ((p->right = s = r->left))
4854 if ((r->parent = s))
4863 case_stack->data.case_stmt.case_list = r;
4867 /* r->balance == -1 */
4871 struct case_node *t = r->left;
4873 if ((p->right = s = t->left))
4878 if ((r->left = s = t->right))
4892 if ((t->parent = s))
4901 case_stack->data.case_stmt.case_list = t;
4907 /* p->balance == -1; growth of right side balances the node. */
4920 /* Returns the number of possible values of TYPE.
4921 Returns -1 if the number is unknown, variable, or if the number does not
4922 fit in a HOST_WIDE_INT.
4923 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4924 do not increase monotonically (there may be duplicates);
4925 to 1 if the values increase monotonically, but not always by 1;
4926 otherwise sets it to 0. */
4929 all_cases_count (type, spareness)
4934 HOST_WIDE_INT count, minval, lastval;
4938 switch (TREE_CODE (type))
4945 count = 1 << BITS_PER_UNIT;
4950 if (TYPE_MAX_VALUE (type) != 0
4951 && 0 != (t = fold (build (MINUS_EXPR, type, TYPE_MAX_VALUE (type),
4952 TYPE_MIN_VALUE (type))))
4953 && 0 != (t = fold (build (PLUS_EXPR, type, t,
4954 convert (type, integer_zero_node))))
4955 && host_integerp (t, 1))
4956 count = tree_low_cst (t, 1);
4962 /* Don't waste time with enumeral types with huge values. */
4963 if (! host_integerp (TYPE_MIN_VALUE (type), 0)
4964 || TYPE_MAX_VALUE (type) == 0
4965 || ! host_integerp (TYPE_MAX_VALUE (type), 0))
4968 lastval = minval = tree_low_cst (TYPE_MIN_VALUE (type), 0);
4971 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4973 HOST_WIDE_INT thisval = tree_low_cst (TREE_VALUE (t), 0);
4975 if (*spareness == 2 || thisval < lastval)
4977 else if (thisval != minval + count)
4987 #define BITARRAY_TEST(ARRAY, INDEX) \
4988 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4989 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4990 #define BITARRAY_SET(ARRAY, INDEX) \
4991 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4992 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4994 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4995 with the case values we have seen, assuming the case expression
4997 SPARSENESS is as determined by all_cases_count.
4999 The time needed is proportional to COUNT, unless
5000 SPARSENESS is 2, in which case quadratic time is needed. */
5003 mark_seen_cases (type, cases_seen, count, sparseness)
5005 unsigned char *cases_seen;
5006 HOST_WIDE_INT count;
5009 tree next_node_to_try = NULL_TREE;
5010 HOST_WIDE_INT next_node_offset = 0;
5012 register struct case_node *n, *root = case_stack->data.case_stmt.case_list;
5013 tree val = make_node (INTEGER_CST);
5015 TREE_TYPE (val) = type;
5019 else if (sparseness == 2)
5022 unsigned HOST_WIDE_INT xlo;
5024 /* This less efficient loop is only needed to handle
5025 duplicate case values (multiple enum constants
5026 with the same value). */
5027 TREE_TYPE (val) = TREE_TYPE (root->low);
5028 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
5029 t = TREE_CHAIN (t), xlo++)
5031 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (TREE_VALUE (t));
5032 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (TREE_VALUE (t));
5036 /* Keep going past elements distinctly greater than VAL. */
5037 if (tree_int_cst_lt (val, n->low))
5040 /* or distinctly less than VAL. */
5041 else if (tree_int_cst_lt (n->high, val))
5046 /* We have found a matching range. */
5047 BITARRAY_SET (cases_seen, xlo);
5057 case_stack->data.case_stmt.case_list = root = case_tree2list (root, 0);
5059 for (n = root; n; n = n->right)
5061 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
5062 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
5063 while (! tree_int_cst_lt (n->high, val))
5065 /* Calculate (into xlo) the "offset" of the integer (val).
5066 The element with lowest value has offset 0, the next smallest
5067 element has offset 1, etc. */
5069 unsigned HOST_WIDE_INT xlo;
5073 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
5075 /* The TYPE_VALUES will be in increasing order, so
5076 starting searching where we last ended. */
5077 t = next_node_to_try;
5078 xlo = next_node_offset;
5084 t = TYPE_VALUES (type);
5087 if (tree_int_cst_equal (val, TREE_VALUE (t)))
5089 next_node_to_try = TREE_CHAIN (t);
5090 next_node_offset = xlo + 1;
5095 if (t == next_node_to_try)
5104 t = TYPE_MIN_VALUE (type);
5106 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
5110 add_double (xlo, xhi,
5111 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5115 if (xhi == 0 && xlo < (unsigned HOST_WIDE_INT) count)
5116 BITARRAY_SET (cases_seen, xlo);
5118 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5120 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
5126 /* Called when the index of a switch statement is an enumerated type
5127 and there is no default label.
5129 Checks that all enumeration literals are covered by the case
5130 expressions of a switch. Also, warn if there are any extra
5131 switch cases that are *not* elements of the enumerated type.
5133 If all enumeration literals were covered by the case expressions,
5134 turn one of the expressions into the default expression since it should
5135 not be possible to fall through such a switch. */
5138 check_for_full_enumeration_handling (type)
5141 register struct case_node *n;
5142 register tree chain;
5143 #if 0 /* variable used by 'if 0'ed code below. */
5144 register struct case_node **l;
5148 /* True iff the selector type is a numbered set mode. */
5151 /* The number of possible selector values. */
5154 /* For each possible selector value. a one iff it has been matched
5155 by a case value alternative. */
5156 unsigned char *cases_seen;
5158 /* The allocated size of cases_seen, in chars. */
5159 HOST_WIDE_INT bytes_needed;
5164 size = all_cases_count (type, &sparseness);
5165 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
5167 if (size > 0 && size < 600000
5168 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5169 this optimization if we don't have enough memory rather than
5170 aborting, as xmalloc would do. */
5171 && (cases_seen = (unsigned char *) calloc (bytes_needed, 1)) != NULL)
5174 tree v = TYPE_VALUES (type);
5176 /* The time complexity of this code is normally O(N), where
5177 N being the number of members in the enumerated type.
5178 However, if type is a ENUMERAL_TYPE whose values do not
5179 increase monotonically, O(N*log(N)) time may be needed. */
5181 mark_seen_cases (type, cases_seen, size, sparseness);
5183 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
5184 if (BITARRAY_TEST (cases_seen, i) == 0)
5185 warning ("enumeration value `%s' not handled in switch",
5186 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
5191 /* Now we go the other way around; we warn if there are case
5192 expressions that don't correspond to enumerators. This can
5193 occur since C and C++ don't enforce type-checking of
5194 assignments to enumeration variables. */
5196 if (case_stack->data.case_stmt.case_list
5197 && case_stack->data.case_stmt.case_list->left)
5198 case_stack->data.case_stmt.case_list
5199 = case_tree2list (case_stack->data.case_stmt.case_list, 0);
5201 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
5203 for (chain = TYPE_VALUES (type);
5204 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
5205 chain = TREE_CHAIN (chain))
5210 if (TYPE_NAME (type) == 0)
5211 warning ("case value `%ld' not in enumerated type",
5212 (long) TREE_INT_CST_LOW (n->low));
5214 warning ("case value `%ld' not in enumerated type `%s'",
5215 (long) TREE_INT_CST_LOW (n->low),
5216 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5219 : DECL_NAME (TYPE_NAME (type))));
5221 if (!tree_int_cst_equal (n->low, n->high))
5223 for (chain = TYPE_VALUES (type);
5224 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
5225 chain = TREE_CHAIN (chain))
5230 if (TYPE_NAME (type) == 0)
5231 warning ("case value `%ld' not in enumerated type",
5232 (long) TREE_INT_CST_LOW (n->high));
5234 warning ("case value `%ld' not in enumerated type `%s'",
5235 (long) TREE_INT_CST_LOW (n->high),
5236 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5239 : DECL_NAME (TYPE_NAME (type))));
5245 /* ??? This optimization is disabled because it causes valid programs to
5246 fail. ANSI C does not guarantee that an expression with enum type
5247 will have a value that is the same as one of the enumeration literals. */
5249 /* If all values were found as case labels, make one of them the default
5250 label. Thus, this switch will never fall through. We arbitrarily pick
5251 the last one to make the default since this is likely the most
5252 efficient choice. */
5256 for (l = &case_stack->data.case_stmt.case_list;
5261 case_stack->data.case_stmt.default_label = (*l)->code_label;
5267 /* Free CN, and its children. */
5270 free_case_nodes (cn)
5275 free_case_nodes (cn->left);
5276 free_case_nodes (cn->right);
5282 /* Terminate a case (Pascal) or switch (C) statement
5283 in which ORIG_INDEX is the expression to be tested.
5284 Generate the code to test it and jump to the right place. */
5287 expand_end_case (orig_index)
5290 tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE, orig_minval;
5291 rtx default_label = 0;
5292 register struct case_node *n;
5300 register struct nesting *thiscase = case_stack;
5301 tree index_expr, index_type;
5304 /* Don't crash due to previous errors. */
5305 if (thiscase == NULL)
5308 table_label = gen_label_rtx ();
5309 index_expr = thiscase->data.case_stmt.index_expr;
5310 index_type = TREE_TYPE (index_expr);
5311 unsignedp = TREE_UNSIGNED (index_type);
5313 do_pending_stack_adjust ();
5315 /* This might get an spurious warning in the presence of a syntax error;
5316 it could be fixed by moving the call to check_seenlabel after the
5317 check for error_mark_node, and copying the code of check_seenlabel that
5318 deals with case_stack->data.case_stmt.line_number_status /
5319 restore_line_number_status in front of the call to end_cleanup_deferral;
5320 However, this might miss some useful warnings in the presence of
5321 non-syntax errors. */
5324 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5325 if (index_type != error_mark_node)
5327 /* If switch expression was an enumerated type, check that all
5328 enumeration literals are covered by the cases.
5329 No sense trying this if there's a default case, however. */
5331 if (!thiscase->data.case_stmt.default_label
5332 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
5333 && TREE_CODE (index_expr) != INTEGER_CST)
5334 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
5336 /* If we don't have a default-label, create one here,
5337 after the body of the switch. */
5338 if (thiscase->data.case_stmt.default_label == 0)
5340 thiscase->data.case_stmt.default_label
5341 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5342 expand_label (thiscase->data.case_stmt.default_label);
5344 default_label = label_rtx (thiscase->data.case_stmt.default_label);
5346 before_case = get_last_insn ();
5348 if (thiscase->data.case_stmt.case_list
5349 && thiscase->data.case_stmt.case_list->left)
5350 thiscase->data.case_stmt.case_list
5351 = case_tree2list (thiscase->data.case_stmt.case_list, 0);
5353 /* Simplify the case-list before we count it. */
5354 group_case_nodes (thiscase->data.case_stmt.case_list);
5356 /* Get upper and lower bounds of case values.
5357 Also convert all the case values to the index expr's data type. */
5360 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5362 /* Check low and high label values are integers. */
5363 if (TREE_CODE (n->low) != INTEGER_CST)
5365 if (TREE_CODE (n->high) != INTEGER_CST)
5368 n->low = convert (index_type, n->low);
5369 n->high = convert (index_type, n->high);
5371 /* Count the elements and track the largest and smallest
5372 of them (treating them as signed even if they are not). */
5380 if (INT_CST_LT (n->low, minval))
5382 if (INT_CST_LT (maxval, n->high))
5385 /* A range counts double, since it requires two compares. */
5386 if (! tree_int_cst_equal (n->low, n->high))
5390 orig_minval = minval;
5392 /* Compute span of values. */
5394 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
5396 end_cleanup_deferral ();
5400 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
5402 emit_jump (default_label);
5405 /* If range of values is much bigger than number of values,
5406 make a sequence of conditional branches instead of a dispatch.
5407 If the switch-index is a constant, do it this way
5408 because we can optimize it. */
5410 #ifndef CASE_VALUES_THRESHOLD
5412 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
5414 /* If machine does not have a case insn that compares the
5415 bounds, this means extra overhead for dispatch tables
5416 which raises the threshold for using them. */
5417 #define CASE_VALUES_THRESHOLD 5
5418 #endif /* HAVE_casesi */
5419 #endif /* CASE_VALUES_THRESHOLD */
5421 else if (count < CASE_VALUES_THRESHOLD
5422 || compare_tree_int (range, 10 * count) > 0
5423 /* RANGE may be signed, and really large ranges will show up
5424 as negative numbers. */
5425 || compare_tree_int (range, 0) < 0
5426 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5429 || TREE_CODE (index_expr) == INTEGER_CST
5430 /* These will reduce to a constant. */
5431 || (TREE_CODE (index_expr) == CALL_EXPR
5432 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
5433 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
5434 && DECL_BUILT_IN_CLASS (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_NORMAL
5435 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
5436 || (TREE_CODE (index_expr) == COMPOUND_EXPR
5437 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
5439 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5441 /* If the index is a short or char that we do not have
5442 an insn to handle comparisons directly, convert it to
5443 a full integer now, rather than letting each comparison
5444 generate the conversion. */
5446 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
5447 && (cmp_optab->handlers[(int) GET_MODE (index)].insn_code
5448 == CODE_FOR_nothing))
5450 enum machine_mode wider_mode;
5451 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
5452 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
5453 if (cmp_optab->handlers[(int) wider_mode].insn_code
5454 != CODE_FOR_nothing)
5456 index = convert_to_mode (wider_mode, index, unsignedp);
5462 do_pending_stack_adjust ();
5464 index = protect_from_queue (index, 0);
5465 if (GET_CODE (index) == MEM)
5466 index = copy_to_reg (index);
5467 if (GET_CODE (index) == CONST_INT
5468 || TREE_CODE (index_expr) == INTEGER_CST)
5470 /* Make a tree node with the proper constant value
5471 if we don't already have one. */
5472 if (TREE_CODE (index_expr) != INTEGER_CST)
5475 = build_int_2 (INTVAL (index),
5476 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
5477 index_expr = convert (index_type, index_expr);
5480 /* For constant index expressions we need only
5481 issue a unconditional branch to the appropriate
5482 target code. The job of removing any unreachable
5483 code is left to the optimisation phase if the
5484 "-O" option is specified. */
5485 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5486 if (! tree_int_cst_lt (index_expr, n->low)
5487 && ! tree_int_cst_lt (n->high, index_expr))
5491 emit_jump (label_rtx (n->code_label));
5493 emit_jump (default_label);
5497 /* If the index expression is not constant we generate
5498 a binary decision tree to select the appropriate
5499 target code. This is done as follows:
5501 The list of cases is rearranged into a binary tree,
5502 nearly optimal assuming equal probability for each case.
5504 The tree is transformed into RTL, eliminating
5505 redundant test conditions at the same time.
5507 If program flow could reach the end of the
5508 decision tree an unconditional jump to the
5509 default code is emitted. */
5512 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
5513 && estimate_case_costs (thiscase->data.case_stmt.case_list));
5514 balance_case_nodes (&thiscase->data.case_stmt.case_list,
5516 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
5517 default_label, index_type);
5518 emit_jump_if_reachable (default_label);
5527 enum machine_mode index_mode = SImode;
5528 int index_bits = GET_MODE_BITSIZE (index_mode);
5530 enum machine_mode op_mode;
5532 /* Convert the index to SImode. */
5533 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
5534 > GET_MODE_BITSIZE (index_mode))
5536 enum machine_mode omode = TYPE_MODE (index_type);
5537 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
5539 /* We must handle the endpoints in the original mode. */
5540 index_expr = build (MINUS_EXPR, index_type,
5541 index_expr, minval);
5542 minval = integer_zero_node;
5543 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5544 emit_cmp_and_jump_insns (rangertx, index, LTU, NULL_RTX,
5545 omode, 1, 0, default_label);
5546 /* Now we can safely truncate. */
5547 index = convert_to_mode (index_mode, index, 0);
5551 if (TYPE_MODE (index_type) != index_mode)
5553 index_expr = convert (type_for_size (index_bits, 0),
5555 index_type = TREE_TYPE (index_expr);
5558 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5561 index = protect_from_queue (index, 0);
5562 do_pending_stack_adjust ();
5564 op_mode = insn_data[(int) CODE_FOR_casesi].operand[0].mode;
5565 if (! (*insn_data[(int) CODE_FOR_casesi].operand[0].predicate)
5567 index = copy_to_mode_reg (op_mode, index);
5569 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
5571 op_mode = insn_data[(int) CODE_FOR_casesi].operand[1].mode;
5572 if (! (*insn_data[(int) CODE_FOR_casesi].operand[1].predicate)
5574 op1 = copy_to_mode_reg (op_mode, op1);
5576 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
5578 op_mode = insn_data[(int) CODE_FOR_casesi].operand[2].mode;
5579 if (! (*insn_data[(int) CODE_FOR_casesi].operand[2].predicate)
5581 op2 = copy_to_mode_reg (op_mode, op2);
5583 emit_jump_insn (gen_casesi (index, op1, op2,
5584 table_label, default_label));
5588 #ifdef HAVE_tablejump
5589 if (! win && HAVE_tablejump)
5591 index_type = thiscase->data.case_stmt.nominal_type;
5592 index_expr = fold (build (MINUS_EXPR, index_type,
5593 convert (index_type, index_expr),
5594 convert (index_type, minval)));
5595 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5597 index = protect_from_queue (index, 0);
5598 do_pending_stack_adjust ();
5600 do_tablejump (index, TYPE_MODE (index_type),
5601 expand_expr (range, NULL_RTX, VOIDmode, 0),
5602 table_label, default_label);
5609 /* Get table of labels to jump to, in order of case index. */
5611 ncases = TREE_INT_CST_LOW (range) + 1;
5612 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
5613 memset ((char *) labelvec, 0, ncases * sizeof (rtx));
5615 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5617 register HOST_WIDE_INT i
5618 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
5623 = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
5624 if (i + TREE_INT_CST_LOW (orig_minval)
5625 == TREE_INT_CST_LOW (n->high))
5631 /* Fill in the gaps with the default. */
5632 for (i = 0; i < ncases; i++)
5633 if (labelvec[i] == 0)
5634 labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
5636 /* Output the table */
5637 emit_label (table_label);
5639 if (CASE_VECTOR_PC_RELATIVE || flag_pic)
5640 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
5641 gen_rtx_LABEL_REF (Pmode, table_label),
5642 gen_rtvec_v (ncases, labelvec),
5643 const0_rtx, const0_rtx));
5645 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
5646 gen_rtvec_v (ncases, labelvec)));
5648 /* If the case insn drops through the table,
5649 after the table we must jump to the default-label.
5650 Otherwise record no drop-through after the table. */
5651 #ifdef CASE_DROPS_THROUGH
5652 emit_jump (default_label);
5658 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
5659 reorder_insns (before_case, get_last_insn (),
5660 thiscase->data.case_stmt.start);
5663 end_cleanup_deferral ();
5665 if (thiscase->exit_label)
5666 emit_label (thiscase->exit_label);
5668 free_case_nodes (case_stack->data.case_stmt.case_list);
5669 POPSTACK (case_stack);
5674 /* Convert the tree NODE into a list linked by the right field, with the left
5675 field zeroed. RIGHT is used for recursion; it is a list to be placed
5676 rightmost in the resulting list. */
5678 static struct case_node *
5679 case_tree2list (node, right)
5680 struct case_node *node, *right;
5682 struct case_node *left;
5685 right = case_tree2list (node->right, right);
5687 node->right = right;
5688 if ((left = node->left))
5691 return case_tree2list (left, node);
5697 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5700 do_jump_if_equal (op1, op2, label, unsignedp)
5701 rtx op1, op2, label;
5704 if (GET_CODE (op1) == CONST_INT
5705 && GET_CODE (op2) == CONST_INT)
5707 if (INTVAL (op1) == INTVAL (op2))
5712 enum machine_mode mode = GET_MODE (op1);
5713 if (mode == VOIDmode)
5714 mode = GET_MODE (op2);
5715 emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX, mode, unsignedp,
5720 /* Not all case values are encountered equally. This function
5721 uses a heuristic to weight case labels, in cases where that
5722 looks like a reasonable thing to do.
5724 Right now, all we try to guess is text, and we establish the
5727 chars above space: 16
5736 If we find any cases in the switch that are not either -1 or in the range
5737 of valid ASCII characters, or are control characters other than those
5738 commonly used with "\", don't treat this switch scanning text.
5740 Return 1 if these nodes are suitable for cost estimation, otherwise
5744 estimate_case_costs (node)
5747 tree min_ascii = build_int_2 (-1, -1);
5748 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5752 /* If we haven't already made the cost table, make it now. Note that the
5753 lower bound of the table is -1, not zero. */
5755 if (cost_table == NULL)
5757 cost_table = cost_table_ + 1;
5759 for (i = 0; i < 128; i++)
5763 else if (ISPUNCT (i))
5765 else if (ISCNTRL (i))
5769 cost_table[' '] = 8;
5770 cost_table['\t'] = 4;
5771 cost_table['\0'] = 4;
5772 cost_table['\n'] = 2;
5773 cost_table['\f'] = 1;
5774 cost_table['\v'] = 1;
5775 cost_table['\b'] = 1;
5778 /* See if all the case expressions look like text. It is text if the
5779 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5780 as signed arithmetic since we don't want to ever access cost_table with a
5781 value less than -1. Also check that none of the constants in a range
5782 are strange control characters. */
5784 for (n = node; n; n = n->right)
5786 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5789 for (i = (HOST_WIDE_INT) TREE_INT_CST_LOW (n->low);
5790 i <= (HOST_WIDE_INT) TREE_INT_CST_LOW (n->high); i++)
5791 if (cost_table[i] < 0)
5795 /* All interesting values are within the range of interesting
5796 ASCII characters. */
5800 /* Scan an ordered list of case nodes
5801 combining those with consecutive values or ranges.
5803 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5806 group_case_nodes (head)
5809 case_node_ptr node = head;
5813 rtx lb = next_real_insn (label_rtx (node->code_label));
5815 case_node_ptr np = node;
5817 /* Try to group the successors of NODE with NODE. */
5818 while (((np = np->right) != 0)
5819 /* Do they jump to the same place? */
5820 && ((lb2 = next_real_insn (label_rtx (np->code_label))) == lb
5821 || (lb != 0 && lb2 != 0
5822 && simplejump_p (lb)
5823 && simplejump_p (lb2)
5824 && rtx_equal_p (SET_SRC (PATTERN (lb)),
5825 SET_SRC (PATTERN (lb2)))))
5826 /* Are their ranges consecutive? */
5827 && tree_int_cst_equal (np->low,
5828 fold (build (PLUS_EXPR,
5829 TREE_TYPE (node->high),
5832 /* An overflow is not consecutive. */
5833 && tree_int_cst_lt (node->high,
5834 fold (build (PLUS_EXPR,
5835 TREE_TYPE (node->high),
5837 integer_one_node))))
5839 node->high = np->high;
5841 /* NP is the first node after NODE which can't be grouped with it.
5842 Delete the nodes in between, and move on to that node. */
5848 /* Take an ordered list of case nodes
5849 and transform them into a near optimal binary tree,
5850 on the assumption that any target code selection value is as
5851 likely as any other.
5853 The transformation is performed by splitting the ordered
5854 list into two equal sections plus a pivot. The parts are
5855 then attached to the pivot as left and right branches. Each
5856 branch is then transformed recursively. */
5859 balance_case_nodes (head, parent)
5860 case_node_ptr *head;
5861 case_node_ptr parent;
5863 register case_node_ptr np;
5871 register case_node_ptr *npp;
5874 /* Count the number of entries on branch. Also count the ranges. */
5878 if (!tree_int_cst_equal (np->low, np->high))
5882 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5886 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5894 /* Split this list if it is long enough for that to help. */
5899 /* Find the place in the list that bisects the list's total cost,
5900 Here I gets half the total cost. */
5905 /* Skip nodes while their cost does not reach that amount. */
5906 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5907 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5908 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5911 npp = &(*npp)->right;
5916 /* Leave this branch lopsided, but optimize left-hand
5917 side and fill in `parent' fields for right-hand side. */
5919 np->parent = parent;
5920 balance_case_nodes (&np->left, np);
5921 for (; np->right; np = np->right)
5922 np->right->parent = np;
5926 /* If there are just three nodes, split at the middle one. */
5928 npp = &(*npp)->right;
5931 /* Find the place in the list that bisects the list's total cost,
5932 where ranges count as 2.
5933 Here I gets half the total cost. */
5934 i = (i + ranges + 1) / 2;
5937 /* Skip nodes while their cost does not reach that amount. */
5938 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5943 npp = &(*npp)->right;
5948 np->parent = parent;
5951 /* Optimize each of the two split parts. */
5952 balance_case_nodes (&np->left, np);
5953 balance_case_nodes (&np->right, np);
5957 /* Else leave this branch as one level,
5958 but fill in `parent' fields. */
5960 np->parent = parent;
5961 for (; np->right; np = np->right)
5962 np->right->parent = np;
5967 /* Search the parent sections of the case node tree
5968 to see if a test for the lower bound of NODE would be redundant.
5969 INDEX_TYPE is the type of the index expression.
5971 The instructions to generate the case decision tree are
5972 output in the same order as nodes are processed so it is
5973 known that if a parent node checks the range of the current
5974 node minus one that the current node is bounded at its lower
5975 span. Thus the test would be redundant. */
5978 node_has_low_bound (node, index_type)
5983 case_node_ptr pnode;
5985 /* If the lower bound of this node is the lowest value in the index type,
5986 we need not test it. */
5988 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5991 /* If this node has a left branch, the value at the left must be less
5992 than that at this node, so it cannot be bounded at the bottom and
5993 we need not bother testing any further. */
5998 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5999 node->low, integer_one_node));
6001 /* If the subtraction above overflowed, we can't verify anything.
6002 Otherwise, look for a parent that tests our value - 1. */
6004 if (! tree_int_cst_lt (low_minus_one, node->low))
6007 for (pnode = node->parent; pnode; pnode = pnode->parent)
6008 if (tree_int_cst_equal (low_minus_one, pnode->high))
6014 /* Search the parent sections of the case node tree
6015 to see if a test for the upper bound of NODE would be redundant.
6016 INDEX_TYPE is the type of the index expression.
6018 The instructions to generate the case decision tree are
6019 output in the same order as nodes are processed so it is
6020 known that if a parent node checks the range of the current
6021 node plus one that the current node is bounded at its upper
6022 span. Thus the test would be redundant. */
6025 node_has_high_bound (node, index_type)
6030 case_node_ptr pnode;
6032 /* If there is no upper bound, obviously no test is needed. */
6034 if (TYPE_MAX_VALUE (index_type) == NULL)
6037 /* If the upper bound of this node is the highest value in the type
6038 of the index expression, we need not test against it. */
6040 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
6043 /* If this node has a right branch, the value at the right must be greater
6044 than that at this node, so it cannot be bounded at the top and
6045 we need not bother testing any further. */
6050 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
6051 node->high, integer_one_node));
6053 /* If the addition above overflowed, we can't verify anything.
6054 Otherwise, look for a parent that tests our value + 1. */
6056 if (! tree_int_cst_lt (node->high, high_plus_one))
6059 for (pnode = node->parent; pnode; pnode = pnode->parent)
6060 if (tree_int_cst_equal (high_plus_one, pnode->low))
6066 /* Search the parent sections of the
6067 case node tree to see if both tests for the upper and lower
6068 bounds of NODE would be redundant. */
6071 node_is_bounded (node, index_type)
6075 return (node_has_low_bound (node, index_type)
6076 && node_has_high_bound (node, index_type));
6079 /* Emit an unconditional jump to LABEL unless it would be dead code. */
6082 emit_jump_if_reachable (label)
6085 if (GET_CODE (get_last_insn ()) != BARRIER)
6089 /* Emit step-by-step code to select a case for the value of INDEX.
6090 The thus generated decision tree follows the form of the
6091 case-node binary tree NODE, whose nodes represent test conditions.
6092 INDEX_TYPE is the type of the index of the switch.
6094 Care is taken to prune redundant tests from the decision tree
6095 by detecting any boundary conditions already checked by
6096 emitted rtx. (See node_has_high_bound, node_has_low_bound
6097 and node_is_bounded, above.)
6099 Where the test conditions can be shown to be redundant we emit
6100 an unconditional jump to the target code. As a further
6101 optimization, the subordinates of a tree node are examined to
6102 check for bounded nodes. In this case conditional and/or
6103 unconditional jumps as a result of the boundary check for the
6104 current node are arranged to target the subordinates associated
6105 code for out of bound conditions on the current node.
6107 We can assume that when control reaches the code generated here,
6108 the index value has already been compared with the parents
6109 of this node, and determined to be on the same side of each parent
6110 as this node is. Thus, if this node tests for the value 51,
6111 and a parent tested for 52, we don't need to consider
6112 the possibility of a value greater than 51. If another parent
6113 tests for the value 50, then this node need not test anything. */
6116 emit_case_nodes (index, node, default_label, index_type)
6122 /* If INDEX has an unsigned type, we must make unsigned branches. */
6123 int unsignedp = TREE_UNSIGNED (index_type);
6124 enum machine_mode mode = GET_MODE (index);
6126 /* See if our parents have already tested everything for us.
6127 If they have, emit an unconditional jump for this node. */
6128 if (node_is_bounded (node, index_type))
6129 emit_jump (label_rtx (node->code_label));
6131 else if (tree_int_cst_equal (node->low, node->high))
6133 /* Node is single valued. First see if the index expression matches
6134 this node and then check our children, if any. */
6136 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
6137 label_rtx (node->code_label), unsignedp);
6139 if (node->right != 0 && node->left != 0)
6141 /* This node has children on both sides.
6142 Dispatch to one side or the other
6143 by comparing the index value with this node's value.
6144 If one subtree is bounded, check that one first,
6145 so we can avoid real branches in the tree. */
6147 if (node_is_bounded (node->right, index_type))
6149 emit_cmp_and_jump_insns (index,
6150 expand_expr (node->high, NULL_RTX,
6152 GT, NULL_RTX, mode, unsignedp, 0,
6153 label_rtx (node->right->code_label));
6154 emit_case_nodes (index, node->left, default_label, index_type);
6157 else if (node_is_bounded (node->left, index_type))
6159 emit_cmp_and_jump_insns (index,
6160 expand_expr (node->high, NULL_RTX,
6162 LT, NULL_RTX, mode, unsignedp, 0,
6163 label_rtx (node->left->code_label));
6164 emit_case_nodes (index, node->right, default_label, index_type);
6169 /* Neither node is bounded. First distinguish the two sides;
6170 then emit the code for one side at a time. */
6172 tree test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6174 /* See if the value is on the right. */
6175 emit_cmp_and_jump_insns (index,
6176 expand_expr (node->high, NULL_RTX,
6178 GT, NULL_RTX, mode, unsignedp, 0,
6179 label_rtx (test_label));
6181 /* Value must be on the left.
6182 Handle the left-hand subtree. */
6183 emit_case_nodes (index, node->left, default_label, index_type);
6184 /* If left-hand subtree does nothing,
6186 emit_jump_if_reachable (default_label);
6188 /* Code branches here for the right-hand subtree. */
6189 expand_label (test_label);
6190 emit_case_nodes (index, node->right, default_label, index_type);
6194 else if (node->right != 0 && node->left == 0)
6196 /* Here we have a right child but no left so we issue conditional
6197 branch to default and process the right child.
6199 Omit the conditional branch to default if we it avoid only one
6200 right child; it costs too much space to save so little time. */
6202 if (node->right->right || node->right->left
6203 || !tree_int_cst_equal (node->right->low, node->right->high))
6205 if (!node_has_low_bound (node, index_type))
6207 emit_cmp_and_jump_insns (index,
6208 expand_expr (node->high, NULL_RTX,
6210 LT, NULL_RTX, mode, unsignedp, 0,
6214 emit_case_nodes (index, node->right, default_label, index_type);
6217 /* We cannot process node->right normally
6218 since we haven't ruled out the numbers less than
6219 this node's value. So handle node->right explicitly. */
6220 do_jump_if_equal (index,
6221 expand_expr (node->right->low, NULL_RTX,
6223 label_rtx (node->right->code_label), unsignedp);
6226 else if (node->right == 0 && node->left != 0)
6228 /* Just one subtree, on the left. */
6230 #if 0 /* The following code and comment were formerly part
6231 of the condition here, but they didn't work
6232 and I don't understand what the idea was. -- rms. */
6233 /* If our "most probable entry" is less probable
6234 than the default label, emit a jump to
6235 the default label using condition codes
6236 already lying around. With no right branch,
6237 a branch-greater-than will get us to the default
6240 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
6243 if (node->left->left || node->left->right
6244 || !tree_int_cst_equal (node->left->low, node->left->high))
6246 if (!node_has_high_bound (node, index_type))
6248 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6251 GT, NULL_RTX, mode, unsignedp, 0,
6255 emit_case_nodes (index, node->left, default_label, index_type);
6258 /* We cannot process node->left normally
6259 since we haven't ruled out the numbers less than
6260 this node's value. So handle node->left explicitly. */
6261 do_jump_if_equal (index,
6262 expand_expr (node->left->low, NULL_RTX,
6264 label_rtx (node->left->code_label), unsignedp);
6269 /* Node is a range. These cases are very similar to those for a single
6270 value, except that we do not start by testing whether this node
6271 is the one to branch to. */
6273 if (node->right != 0 && node->left != 0)
6275 /* Node has subtrees on both sides.
6276 If the right-hand subtree is bounded,
6277 test for it first, since we can go straight there.
6278 Otherwise, we need to make a branch in the control structure,
6279 then handle the two subtrees. */
6280 tree test_label = 0;
6282 if (node_is_bounded (node->right, index_type))
6283 /* Right hand node is fully bounded so we can eliminate any
6284 testing and branch directly to the target code. */
6285 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6287 GT, NULL_RTX, mode, unsignedp, 0,
6288 label_rtx (node->right->code_label));
6291 /* Right hand node requires testing.
6292 Branch to a label where we will handle it later. */
6294 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6295 emit_cmp_and_jump_insns (index,
6296 expand_expr (node->high, NULL_RTX,
6298 GT, NULL_RTX, mode, unsignedp, 0,
6299 label_rtx (test_label));
6302 /* Value belongs to this node or to the left-hand subtree. */
6304 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6306 GE, NULL_RTX, mode, unsignedp, 0,
6307 label_rtx (node->code_label));
6309 /* Handle the left-hand subtree. */
6310 emit_case_nodes (index, node->left, default_label, index_type);
6312 /* If right node had to be handled later, do that now. */
6316 /* If the left-hand subtree fell through,
6317 don't let it fall into the right-hand subtree. */
6318 emit_jump_if_reachable (default_label);
6320 expand_label (test_label);
6321 emit_case_nodes (index, node->right, default_label, index_type);
6325 else if (node->right != 0 && node->left == 0)
6327 /* Deal with values to the left of this node,
6328 if they are possible. */
6329 if (!node_has_low_bound (node, index_type))
6331 emit_cmp_and_jump_insns (index,
6332 expand_expr (node->low, NULL_RTX,
6334 LT, NULL_RTX, mode, unsignedp, 0,
6338 /* Value belongs to this node or to the right-hand subtree. */
6340 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6342 LE, NULL_RTX, mode, unsignedp, 0,
6343 label_rtx (node->code_label));
6345 emit_case_nodes (index, node->right, default_label, index_type);
6348 else if (node->right == 0 && node->left != 0)
6350 /* Deal with values to the right of this node,
6351 if they are possible. */
6352 if (!node_has_high_bound (node, index_type))
6354 emit_cmp_and_jump_insns (index,
6355 expand_expr (node->high, NULL_RTX,
6357 GT, NULL_RTX, mode, unsignedp, 0,
6361 /* Value belongs to this node or to the left-hand subtree. */
6363 emit_cmp_and_jump_insns (index,
6364 expand_expr (node->low, NULL_RTX,
6366 GE, NULL_RTX, mode, unsignedp, 0,
6367 label_rtx (node->code_label));
6369 emit_case_nodes (index, node->left, default_label, index_type);
6374 /* Node has no children so we check low and high bounds to remove
6375 redundant tests. Only one of the bounds can exist,
6376 since otherwise this node is bounded--a case tested already. */
6378 if (!node_has_high_bound (node, index_type))
6380 emit_cmp_and_jump_insns (index,
6381 expand_expr (node->high, NULL_RTX,
6383 GT, NULL_RTX, mode, unsignedp, 0,
6387 if (!node_has_low_bound (node, index_type))
6389 emit_cmp_and_jump_insns (index,
6390 expand_expr (node->low, NULL_RTX,
6392 LT, NULL_RTX, mode, unsignedp, 0,
6396 emit_jump (label_rtx (node->code_label));