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-config.h"
47 #include "hard-reg-set.h"
56 #define obstack_chunk_alloc xmalloc
57 #define obstack_chunk_free free
58 struct obstack stmt_obstack;
60 /* Assume that case vectors are not pc-relative. */
61 #ifndef CASE_VECTOR_PC_RELATIVE
62 #define CASE_VECTOR_PC_RELATIVE 0
65 /* Functions and data structures for expanding case statements. */
67 /* Case label structure, used to hold info on labels within case
68 statements. We handle "range" labels; for a single-value label
69 as in C, the high and low limits are the same.
71 An AVL tree of case nodes is initially created, and later transformed
72 to a list linked via the RIGHT fields in the nodes. Nodes with
73 higher case values are later in the list.
75 Switch statements can be output in one of two forms. A branch table
76 is used if there are more than a few labels and the labels are dense
77 within the range between the smallest and largest case value. If a
78 branch table is used, no further manipulations are done with the case
81 The alternative to the use of a branch table is to generate a series
82 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
83 and PARENT fields to hold a binary tree. Initially the tree is
84 totally unbalanced, with everything on the right. We balance the tree
85 with nodes on the left having lower case values than the parent
86 and nodes on the right having higher values. We then output the tree
91 struct case_node *left; /* Left son in binary tree */
92 struct case_node *right; /* Right son in binary tree; also node chain */
93 struct case_node *parent; /* Parent of node in binary tree */
94 tree low; /* Lowest index value for this label */
95 tree high; /* Highest index value for this label */
96 tree code_label; /* Label to jump to when node matches */
100 typedef struct case_node case_node;
101 typedef struct case_node *case_node_ptr;
103 /* These are used by estimate_case_costs and balance_case_nodes. */
105 /* This must be a signed type, and non-ANSI compilers lack signed char. */
106 static short cost_table_[129];
107 static int use_cost_table;
108 static int cost_table_initialized;
110 /* Special care is needed because we allow -1, but TREE_INT_CST_LOW
112 #define COST_TABLE(I) cost_table_[(unsigned HOST_WIDE_INT)((I) + 1)]
114 /* Stack of control and binding constructs we are currently inside.
116 These constructs begin when you call `expand_start_WHATEVER'
117 and end when you call `expand_end_WHATEVER'. This stack records
118 info about how the construct began that tells the end-function
119 what to do. It also may provide information about the construct
120 to alter the behavior of other constructs within the body.
121 For example, they may affect the behavior of C `break' and `continue'.
123 Each construct gets one `struct nesting' object.
124 All of these objects are chained through the `all' field.
125 `nesting_stack' points to the first object (innermost construct).
126 The position of an entry on `nesting_stack' is in its `depth' field.
128 Each type of construct has its own individual stack.
129 For example, loops have `loop_stack'. Each object points to the
130 next object of the same type through the `next' field.
132 Some constructs are visible to `break' exit-statements and others
133 are not. Which constructs are visible depends on the language.
134 Therefore, the data structure allows each construct to be visible
135 or not, according to the args given when the construct is started.
136 The construct is visible if the `exit_label' field is non-null.
137 In that case, the value should be a CODE_LABEL rtx. */
142 struct nesting *next;
147 /* For conds (if-then and if-then-else statements). */
150 /* Label for the end of the if construct.
151 There is none if EXITFLAG was not set
152 and no `else' has been seen yet. */
154 /* Label for the end of this alternative.
155 This may be the end of the if or the next else/elseif. */
161 /* Label at the top of the loop; place to loop back to. */
163 /* Label at the end of the whole construct. */
165 /* Label before a jump that branches to the end of the whole
166 construct. This is where destructors go if any. */
168 /* Label for `continue' statement to jump to;
169 this is in front of the stepper of the loop. */
172 /* For variable binding contours. */
175 /* Sequence number of this binding contour within the function,
176 in order of entry. */
177 int block_start_count;
178 /* Nonzero => value to restore stack to on exit. */
180 /* The NOTE that starts this contour.
181 Used by expand_goto to check whether the destination
182 is within each contour or not. */
184 /* Innermost containing binding contour that has a stack level. */
185 struct nesting *innermost_stack_block;
186 /* List of cleanups to be run on exit from this contour.
187 This is a list of expressions to be evaluated.
188 The TREE_PURPOSE of each link is the ..._DECL node
189 which the cleanup pertains to. */
191 /* List of cleanup-lists of blocks containing this block,
192 as they were at the locus where this block appears.
193 There is an element for each containing block,
194 ordered innermost containing block first.
195 The tail of this list can be 0,
196 if all remaining elements would be empty lists.
197 The element's TREE_VALUE is the cleanup-list of that block,
198 which may be null. */
200 /* Chain of labels defined inside this binding contour.
201 For contours that have stack levels or cleanups. */
202 struct label_chain *label_chain;
203 /* Number of function calls seen, as of start of this block. */
204 int n_function_calls;
205 /* Nonzero if this is associated with a EH region. */
206 int exception_region;
207 /* The saved target_temp_slot_level from our outer block.
208 We may reset target_temp_slot_level to be the level of
209 this block, if that is done, target_temp_slot_level
210 reverts to the saved target_temp_slot_level at the very
212 int block_target_temp_slot_level;
213 /* True if we are currently emitting insns in an area of
214 output code that is controlled by a conditional
215 expression. This is used by the cleanup handling code to
216 generate conditional cleanup actions. */
217 int conditional_code;
218 /* A place to move the start of the exception region for any
219 of the conditional cleanups, must be at the end or after
220 the start of the last unconditional cleanup, and before any
221 conditional branch points. */
222 rtx last_unconditional_cleanup;
223 /* When in a conditional context, this is the specific
224 cleanup list associated with last_unconditional_cleanup,
225 where we place the conditionalized cleanups. */
228 /* For switch (C) or case (Pascal) statements,
229 and also for dummies (see `expand_start_case_dummy'). */
232 /* The insn after which the case dispatch should finally
233 be emitted. Zero for a dummy. */
235 /* A list of case labels; it is first built as an AVL tree.
236 During expand_end_case, this is converted to a list, and may be
237 rearranged into a nearly balanced binary tree. */
238 struct case_node *case_list;
239 /* Label to jump to if no case matches. */
241 /* The expression to be dispatched on. */
243 /* Type that INDEX_EXPR should be converted to. */
245 /* Name of this kind of statement, for warnings. */
246 const char *printname;
247 /* Used to save no_line_numbers till we see the first case label.
248 We set this to -1 when we see the first case label in this
250 int line_number_status;
255 /* Allocate and return a new `struct nesting'. */
257 #define ALLOC_NESTING() \
258 (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
260 /* Pop the nesting stack element by element until we pop off
261 the element which is at the top of STACK.
262 Update all the other stacks, popping off elements from them
263 as we pop them from nesting_stack. */
265 #define POPSTACK(STACK) \
266 do { struct nesting *target = STACK; \
267 struct nesting *this; \
268 do { this = nesting_stack; \
269 if (loop_stack == this) \
270 loop_stack = loop_stack->next; \
271 if (cond_stack == this) \
272 cond_stack = cond_stack->next; \
273 if (block_stack == this) \
274 block_stack = block_stack->next; \
275 if (stack_block_stack == this) \
276 stack_block_stack = stack_block_stack->next; \
277 if (case_stack == this) \
278 case_stack = case_stack->next; \
279 nesting_depth = nesting_stack->depth - 1; \
280 nesting_stack = this->all; \
281 obstack_free (&stmt_obstack, this); } \
282 while (this != target); } while (0)
284 /* In some cases it is impossible to generate code for a forward goto
285 until the label definition is seen. This happens when it may be necessary
286 for the goto to reset the stack pointer: we don't yet know how to do that.
287 So expand_goto puts an entry on this fixup list.
288 Each time a binding contour that resets the stack is exited,
290 If the target label has now been defined, we can insert the proper code. */
294 /* Points to following fixup. */
295 struct goto_fixup *next;
296 /* Points to the insn before the jump insn.
297 If more code must be inserted, it goes after this insn. */
299 /* The LABEL_DECL that this jump is jumping to, or 0
300 for break, continue or return. */
302 /* The BLOCK for the place where this goto was found. */
304 /* The CODE_LABEL rtx that this is jumping to. */
306 /* Number of binding contours started in current function
307 before the label reference. */
308 int block_start_count;
309 /* The outermost stack level that should be restored for this jump.
310 Each time a binding contour that resets the stack is exited,
311 if the target label is *not* yet defined, this slot is updated. */
313 /* List of lists of cleanup expressions to be run by this goto.
314 There is one element for each block that this goto is within.
315 The tail of this list can be 0,
316 if all remaining elements would be empty.
317 The TREE_VALUE contains the cleanup list of that block as of the
318 time this goto was seen.
319 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
320 tree cleanup_list_list;
323 /* Within any binding contour that must restore a stack level,
324 all labels are recorded with a chain of these structures. */
328 /* Points to following fixup. */
329 struct label_chain *next;
335 /* Chain of all pending binding contours. */
336 struct nesting *x_block_stack;
338 /* If any new stacks are added here, add them to POPSTACKS too. */
340 /* Chain of all pending binding contours that restore stack levels
342 struct nesting *x_stack_block_stack;
344 /* Chain of all pending conditional statements. */
345 struct nesting *x_cond_stack;
347 /* Chain of all pending loops. */
348 struct nesting *x_loop_stack;
350 /* Chain of all pending case or switch statements. */
351 struct nesting *x_case_stack;
353 /* Separate chain including all of the above,
354 chained through the `all' field. */
355 struct nesting *x_nesting_stack;
357 /* Number of entries on nesting_stack now. */
360 /* Number of binding contours started so far in this function. */
361 int x_block_start_count;
363 /* Each time we expand an expression-statement,
364 record the expr's type and its RTL value here. */
365 tree x_last_expr_type;
366 rtx x_last_expr_value;
368 /* Nonzero if within a ({...}) grouping, in which case we must
369 always compute a value for each expr-stmt in case it is the last one. */
370 int x_expr_stmts_for_value;
372 /* Filename and line number of last line-number note,
373 whether we actually emitted it or not. */
374 const char *x_emit_filename;
377 struct goto_fixup *x_goto_fixup_chain;
380 #define block_stack (cfun->stmt->x_block_stack)
381 #define stack_block_stack (cfun->stmt->x_stack_block_stack)
382 #define cond_stack (cfun->stmt->x_cond_stack)
383 #define loop_stack (cfun->stmt->x_loop_stack)
384 #define case_stack (cfun->stmt->x_case_stack)
385 #define nesting_stack (cfun->stmt->x_nesting_stack)
386 #define nesting_depth (cfun->stmt->x_nesting_depth)
387 #define current_block_start_count (cfun->stmt->x_block_start_count)
388 #define last_expr_type (cfun->stmt->x_last_expr_type)
389 #define last_expr_value (cfun->stmt->x_last_expr_value)
390 #define expr_stmts_for_value (cfun->stmt->x_expr_stmts_for_value)
391 #define emit_filename (cfun->stmt->x_emit_filename)
392 #define emit_lineno (cfun->stmt->x_emit_lineno)
393 #define goto_fixup_chain (cfun->stmt->x_goto_fixup_chain)
395 /* Non-zero if we are using EH to handle cleanus. */
396 static int using_eh_for_cleanups_p = 0;
398 static int n_occurrences PARAMS ((int, const char *));
399 static void expand_goto_internal PARAMS ((tree, rtx, rtx));
400 static int expand_fixup PARAMS ((tree, rtx, rtx));
401 static rtx expand_nl_handler_label PARAMS ((rtx, rtx));
402 static void expand_nl_goto_receiver PARAMS ((void));
403 static void expand_nl_goto_receivers PARAMS ((struct nesting *));
404 static void fixup_gotos PARAMS ((struct nesting *, rtx, tree,
406 static void expand_null_return_1 PARAMS ((rtx, int));
407 static void expand_value_return PARAMS ((rtx));
408 static int tail_recursion_args PARAMS ((tree, tree));
409 static void expand_cleanups PARAMS ((tree, tree, int, int));
410 static void check_seenlabel PARAMS ((void));
411 static void do_jump_if_equal PARAMS ((rtx, rtx, rtx, int));
412 static int estimate_case_costs PARAMS ((case_node_ptr));
413 static void group_case_nodes PARAMS ((case_node_ptr));
414 static void balance_case_nodes PARAMS ((case_node_ptr *,
416 static int node_has_low_bound PARAMS ((case_node_ptr, tree));
417 static int node_has_high_bound PARAMS ((case_node_ptr, tree));
418 static int node_is_bounded PARAMS ((case_node_ptr, tree));
419 static void emit_jump_if_reachable PARAMS ((rtx));
420 static void emit_case_nodes PARAMS ((rtx, case_node_ptr, rtx, tree));
421 static struct case_node *case_tree2list PARAMS ((case_node *, case_node *));
422 static void mark_cond_nesting PARAMS ((struct nesting *));
423 static void mark_loop_nesting PARAMS ((struct nesting *));
424 static void mark_block_nesting PARAMS ((struct nesting *));
425 static void mark_case_nesting PARAMS ((struct nesting *));
426 static void mark_case_node PARAMS ((struct case_node *));
427 static void mark_goto_fixup PARAMS ((struct goto_fixup *));
428 static void free_case_nodes PARAMS ((case_node_ptr));
431 using_eh_for_cleanups ()
433 using_eh_for_cleanups_p = 1;
436 /* Mark N (known to be a cond-nesting) for GC. */
439 mark_cond_nesting (n)
444 ggc_mark_rtx (n->exit_label);
445 ggc_mark_rtx (n->data.cond.endif_label);
446 ggc_mark_rtx (n->data.cond.next_label);
452 /* Mark N (known to be a loop-nesting) for GC. */
455 mark_loop_nesting (n)
461 ggc_mark_rtx (n->exit_label);
462 ggc_mark_rtx (n->data.loop.start_label);
463 ggc_mark_rtx (n->data.loop.end_label);
464 ggc_mark_rtx (n->data.loop.alt_end_label);
465 ggc_mark_rtx (n->data.loop.continue_label);
471 /* Mark N (known to be a block-nesting) for GC. */
474 mark_block_nesting (n)
479 struct label_chain *l;
481 ggc_mark_rtx (n->exit_label);
482 ggc_mark_rtx (n->data.block.stack_level);
483 ggc_mark_rtx (n->data.block.first_insn);
484 ggc_mark_tree (n->data.block.cleanups);
485 ggc_mark_tree (n->data.block.outer_cleanups);
487 for (l = n->data.block.label_chain; l != NULL; l = l->next)
490 ggc_mark_tree (l->label);
493 ggc_mark_rtx (n->data.block.last_unconditional_cleanup);
495 /* ??? cleanup_ptr never points outside the stack, does it? */
501 /* Mark N (known to be a case-nesting) for GC. */
504 mark_case_nesting (n)
509 ggc_mark_rtx (n->exit_label);
510 ggc_mark_rtx (n->data.case_stmt.start);
512 ggc_mark_tree (n->data.case_stmt.default_label);
513 ggc_mark_tree (n->data.case_stmt.index_expr);
514 ggc_mark_tree (n->data.case_stmt.nominal_type);
516 mark_case_node (n->data.case_stmt.case_list);
529 ggc_mark_tree (c->low);
530 ggc_mark_tree (c->high);
531 ggc_mark_tree (c->code_label);
533 mark_case_node (c->right);
534 mark_case_node (c->left);
542 struct goto_fixup *g;
547 ggc_mark_rtx (g->before_jump);
548 ggc_mark_tree (g->target);
549 ggc_mark_tree (g->context);
550 ggc_mark_rtx (g->target_rtl);
551 ggc_mark_rtx (g->stack_level);
552 ggc_mark_tree (g->cleanup_list_list);
558 /* Clear out all parts of the state in F that can safely be discarded
559 after the function has been compiled, to let garbage collection
560 reclaim the memory. */
566 /* We're about to free the function obstack. If we hold pointers to
567 things allocated there, then we'll try to mark them when we do
568 GC. So, we clear them out here explicitly. */
578 struct stmt_status *p;
583 mark_block_nesting (p->x_block_stack);
584 mark_cond_nesting (p->x_cond_stack);
585 mark_loop_nesting (p->x_loop_stack);
586 mark_case_nesting (p->x_case_stack);
588 ggc_mark_tree (p->x_last_expr_type);
589 /* last_epxr_value is only valid if last_expr_type is nonzero. */
590 if (p->x_last_expr_type)
591 ggc_mark_rtx (p->x_last_expr_value);
593 mark_goto_fixup (p->x_goto_fixup_chain);
599 gcc_obstack_init (&stmt_obstack);
603 init_stmt_for_function ()
605 cfun->stmt = (struct stmt_status *) xmalloc (sizeof (struct stmt_status));
607 /* We are not currently within any block, conditional, loop or case. */
609 stack_block_stack = 0;
616 current_block_start_count = 0;
618 /* No gotos have been expanded yet. */
619 goto_fixup_chain = 0;
621 /* We are not processing a ({...}) grouping. */
622 expr_stmts_for_value = 0;
624 last_expr_value = NULL_RTX;
627 /* Return nonzero if anything is pushed on the loop, condition, or case
632 return cond_stack || loop_stack || case_stack;
635 /* Record the current file and line. Called from emit_line_note. */
637 set_file_and_line_for_stmt (file, line)
641 /* If we're outputting an inline function, and we add a line note,
642 there may be no CFUN->STMT information. So, there's no need to
646 emit_filename = file;
651 /* Emit a no-op instruction. */
658 last_insn = get_last_insn ();
660 && (GET_CODE (last_insn) == CODE_LABEL
661 || (GET_CODE (last_insn) == NOTE
662 && prev_real_insn (last_insn) == 0)))
663 emit_insn (gen_nop ());
666 /* Return the rtx-label that corresponds to a LABEL_DECL,
667 creating it if necessary. */
673 if (TREE_CODE (label) != LABEL_DECL)
676 if (!DECL_RTL_SET_P (label))
677 SET_DECL_RTL (label, gen_label_rtx ());
679 return DECL_RTL (label);
683 /* Add an unconditional jump to LABEL as the next sequential instruction. */
689 do_pending_stack_adjust ();
690 emit_jump_insn (gen_jump (label));
694 /* Emit code to jump to the address
695 specified by the pointer expression EXP. */
698 expand_computed_goto (exp)
701 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
703 #ifdef POINTERS_EXTEND_UNSIGNED
704 x = convert_memory_address (Pmode, x);
708 /* Be sure the function is executable. */
709 if (current_function_check_memory_usage)
710 emit_library_call (chkr_check_exec_libfunc, LCT_CONST_MAKE_BLOCK,
711 VOIDmode, 1, x, ptr_mode);
713 do_pending_stack_adjust ();
714 emit_indirect_jump (x);
716 current_function_has_computed_jump = 1;
719 /* Handle goto statements and the labels that they can go to. */
721 /* Specify the location in the RTL code of a label LABEL,
722 which is a LABEL_DECL tree node.
724 This is used for the kind of label that the user can jump to with a
725 goto statement, and for alternatives of a switch or case statement.
726 RTL labels generated for loops and conditionals don't go through here;
727 they are generated directly at the RTL level, by other functions below.
729 Note that this has nothing to do with defining label *names*.
730 Languages vary in how they do that and what that even means. */
736 struct label_chain *p;
738 do_pending_stack_adjust ();
739 emit_label (label_rtx (label));
740 if (DECL_NAME (label))
741 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
743 if (stack_block_stack != 0)
745 p = (struct label_chain *) ggc_alloc (sizeof (struct label_chain));
746 p->next = stack_block_stack->data.block.label_chain;
747 stack_block_stack->data.block.label_chain = p;
752 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
753 from nested functions. */
756 declare_nonlocal_label (label)
759 rtx slot = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
761 nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
762 LABEL_PRESERVE_P (label_rtx (label)) = 1;
763 if (nonlocal_goto_handler_slots == 0)
765 emit_stack_save (SAVE_NONLOCAL,
766 &nonlocal_goto_stack_level,
767 PREV_INSN (tail_recursion_reentry));
769 nonlocal_goto_handler_slots
770 = gen_rtx_EXPR_LIST (VOIDmode, slot, nonlocal_goto_handler_slots);
773 /* Generate RTL code for a `goto' statement with target label LABEL.
774 LABEL should be a LABEL_DECL tree node that was or will later be
775 defined with `expand_label'. */
783 /* Check for a nonlocal goto to a containing function. */
784 context = decl_function_context (label);
785 if (context != 0 && context != current_function_decl)
787 struct function *p = find_function_data (context);
788 rtx label_ref = gen_rtx_LABEL_REF (Pmode, label_rtx (label));
789 rtx handler_slot, static_chain, save_area, insn;
792 /* Find the corresponding handler slot for this label. */
793 handler_slot = p->x_nonlocal_goto_handler_slots;
794 for (link = p->x_nonlocal_labels; TREE_VALUE (link) != label;
795 link = TREE_CHAIN (link))
796 handler_slot = XEXP (handler_slot, 1);
797 handler_slot = XEXP (handler_slot, 0);
799 p->has_nonlocal_label = 1;
800 current_function_has_nonlocal_goto = 1;
801 LABEL_REF_NONLOCAL_P (label_ref) = 1;
803 /* Copy the rtl for the slots so that they won't be shared in
804 case the virtual stack vars register gets instantiated differently
805 in the parent than in the child. */
807 static_chain = copy_to_reg (lookup_static_chain (label));
809 /* Get addr of containing function's current nonlocal goto handler,
810 which will do any cleanups and then jump to the label. */
811 handler_slot = copy_to_reg (replace_rtx (copy_rtx (handler_slot),
812 virtual_stack_vars_rtx,
815 /* Get addr of containing function's nonlocal save area. */
816 save_area = p->x_nonlocal_goto_stack_level;
818 save_area = replace_rtx (copy_rtx (save_area),
819 virtual_stack_vars_rtx, static_chain);
821 #if HAVE_nonlocal_goto
822 if (HAVE_nonlocal_goto)
823 emit_insn (gen_nonlocal_goto (static_chain, handler_slot,
824 save_area, label_ref));
828 /* Restore frame pointer for containing function.
829 This sets the actual hard register used for the frame pointer
830 to the location of the function's incoming static chain info.
831 The non-local goto handler will then adjust it to contain the
832 proper value and reload the argument pointer, if needed. */
833 emit_move_insn (hard_frame_pointer_rtx, static_chain);
834 emit_stack_restore (SAVE_NONLOCAL, save_area, NULL_RTX);
836 /* USE of hard_frame_pointer_rtx added for consistency;
837 not clear if really needed. */
838 emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx));
839 emit_insn (gen_rtx_USE (VOIDmode, stack_pointer_rtx));
840 emit_indirect_jump (handler_slot);
843 /* Search backwards to the jump insn and mark it as a
845 for (insn = get_last_insn ();
846 GET_CODE (insn) != JUMP_INSN;
847 insn = PREV_INSN (insn))
849 REG_NOTES (insn) = alloc_EXPR_LIST (REG_NON_LOCAL_GOTO, const0_rtx,
853 expand_goto_internal (label, label_rtx (label), NULL_RTX);
856 /* Generate RTL code for a `goto' statement with target label BODY.
857 LABEL should be a LABEL_REF.
858 LAST_INSN, if non-0, is the rtx we should consider as the last
859 insn emitted (for the purposes of cleaning up a return). */
862 expand_goto_internal (body, label, last_insn)
867 struct nesting *block;
870 if (GET_CODE (label) != CODE_LABEL)
873 /* If label has already been defined, we can tell now
874 whether and how we must alter the stack level. */
876 if (PREV_INSN (label) != 0)
878 /* Find the innermost pending block that contains the label.
879 (Check containment by comparing insn-uids.)
880 Then restore the outermost stack level within that block,
881 and do cleanups of all blocks contained in it. */
882 for (block = block_stack; block; block = block->next)
884 if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
886 if (block->data.block.stack_level != 0)
887 stack_level = block->data.block.stack_level;
888 /* Execute the cleanups for blocks we are exiting. */
889 if (block->data.block.cleanups != 0)
891 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
892 do_pending_stack_adjust ();
898 /* Ensure stack adjust isn't done by emit_jump, as this
899 would clobber the stack pointer. This one should be
900 deleted as dead by flow. */
901 clear_pending_stack_adjust ();
902 do_pending_stack_adjust ();
904 /* Don't do this adjust if it's to the end label and this function
905 is to return with a depressed stack pointer. */
906 if (label == return_label
907 && (((TREE_CODE (TREE_TYPE (current_function_decl))
909 && (TYPE_RETURNS_STACK_DEPRESSED
910 (TREE_TYPE (current_function_decl))))))
913 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
916 if (body != 0 && DECL_TOO_LATE (body))
917 error ("jump to `%s' invalidly jumps into binding contour",
918 IDENTIFIER_POINTER (DECL_NAME (body)));
920 /* Label not yet defined: may need to put this goto
921 on the fixup list. */
922 else if (! expand_fixup (body, label, last_insn))
924 /* No fixup needed. Record that the label is the target
925 of at least one goto that has no fixup. */
927 TREE_ADDRESSABLE (body) = 1;
933 /* Generate if necessary a fixup for a goto
934 whose target label in tree structure (if any) is TREE_LABEL
935 and whose target in rtl is RTL_LABEL.
937 If LAST_INSN is nonzero, we pretend that the jump appears
938 after insn LAST_INSN instead of at the current point in the insn stream.
940 The fixup will be used later to insert insns just before the goto.
941 Those insns will restore the stack level as appropriate for the
942 target label, and will (in the case of C++) also invoke any object
943 destructors which have to be invoked when we exit the scopes which
944 are exited by the goto.
946 Value is nonzero if a fixup is made. */
949 expand_fixup (tree_label, rtl_label, last_insn)
954 struct nesting *block, *end_block;
956 /* See if we can recognize which block the label will be output in.
957 This is possible in some very common cases.
958 If we succeed, set END_BLOCK to that block.
959 Otherwise, set it to 0. */
962 && (rtl_label == cond_stack->data.cond.endif_label
963 || rtl_label == cond_stack->data.cond.next_label))
964 end_block = cond_stack;
965 /* If we are in a loop, recognize certain labels which
966 are likely targets. This reduces the number of fixups
967 we need to create. */
969 && (rtl_label == loop_stack->data.loop.start_label
970 || rtl_label == loop_stack->data.loop.end_label
971 || rtl_label == loop_stack->data.loop.continue_label))
972 end_block = loop_stack;
976 /* Now set END_BLOCK to the binding level to which we will return. */
980 struct nesting *next_block = end_block->all;
983 /* First see if the END_BLOCK is inside the innermost binding level.
984 If so, then no cleanups or stack levels are relevant. */
985 while (next_block && next_block != block)
986 next_block = next_block->all;
991 /* Otherwise, set END_BLOCK to the innermost binding level
992 which is outside the relevant control-structure nesting. */
993 next_block = block_stack->next;
994 for (block = block_stack; block != end_block; block = block->all)
995 if (block == next_block)
996 next_block = next_block->next;
997 end_block = next_block;
1000 /* Does any containing block have a stack level or cleanups?
1001 If not, no fixup is needed, and that is the normal case
1002 (the only case, for standard C). */
1003 for (block = block_stack; block != end_block; block = block->next)
1004 if (block->data.block.stack_level != 0
1005 || block->data.block.cleanups != 0)
1008 if (block != end_block)
1010 /* Ok, a fixup is needed. Add a fixup to the list of such. */
1011 struct goto_fixup *fixup
1012 = (struct goto_fixup *) ggc_alloc (sizeof (struct goto_fixup));
1013 /* In case an old stack level is restored, make sure that comes
1014 after any pending stack adjust. */
1015 /* ?? If the fixup isn't to come at the present position,
1016 doing the stack adjust here isn't useful. Doing it with our
1017 settings at that location isn't useful either. Let's hope
1020 do_pending_stack_adjust ();
1021 fixup->target = tree_label;
1022 fixup->target_rtl = rtl_label;
1024 /* Create a BLOCK node and a corresponding matched set of
1025 NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes at
1026 this point. The notes will encapsulate any and all fixup
1027 code which we might later insert at this point in the insn
1028 stream. Also, the BLOCK node will be the parent (i.e. the
1029 `SUPERBLOCK') of any other BLOCK nodes which we might create
1030 later on when we are expanding the fixup code.
1032 Note that optimization passes (including expand_end_loop)
1033 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
1034 as a placeholder. */
1037 register rtx original_before_jump
1038 = last_insn ? last_insn : get_last_insn ();
1043 block = make_node (BLOCK);
1044 TREE_USED (block) = 1;
1046 if (!cfun->x_whole_function_mode_p)
1047 insert_block (block);
1051 = BLOCK_CHAIN (DECL_INITIAL (current_function_decl));
1052 BLOCK_CHAIN (DECL_INITIAL (current_function_decl))
1057 start = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
1058 if (cfun->x_whole_function_mode_p)
1059 NOTE_BLOCK (start) = block;
1060 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_DELETED);
1061 end = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
1062 if (cfun->x_whole_function_mode_p)
1063 NOTE_BLOCK (end) = block;
1064 fixup->context = block;
1066 emit_insns_after (start, original_before_jump);
1069 fixup->block_start_count = current_block_start_count;
1070 fixup->stack_level = 0;
1071 fixup->cleanup_list_list
1072 = ((block->data.block.outer_cleanups
1073 || block->data.block.cleanups)
1074 ? tree_cons (NULL_TREE, block->data.block.cleanups,
1075 block->data.block.outer_cleanups)
1077 fixup->next = goto_fixup_chain;
1078 goto_fixup_chain = fixup;
1084 /* Expand any needed fixups in the outputmost binding level of the
1085 function. FIRST_INSN is the first insn in the function. */
1088 expand_fixups (first_insn)
1091 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0);
1094 /* When exiting a binding contour, process all pending gotos requiring fixups.
1095 THISBLOCK is the structure that describes the block being exited.
1096 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1097 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1098 FIRST_INSN is the insn that began this contour.
1100 Gotos that jump out of this contour must restore the
1101 stack level and do the cleanups before actually jumping.
1103 DONT_JUMP_IN nonzero means report error there is a jump into this
1104 contour from before the beginning of the contour.
1105 This is also done if STACK_LEVEL is nonzero. */
1108 fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1109 struct nesting *thisblock;
1115 register struct goto_fixup *f, *prev;
1117 /* F is the fixup we are considering; PREV is the previous one. */
1118 /* We run this loop in two passes so that cleanups of exited blocks
1119 are run first, and blocks that are exited are marked so
1122 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1124 /* Test for a fixup that is inactive because it is already handled. */
1125 if (f->before_jump == 0)
1127 /* Delete inactive fixup from the chain, if that is easy to do. */
1129 prev->next = f->next;
1131 /* Has this fixup's target label been defined?
1132 If so, we can finalize it. */
1133 else if (PREV_INSN (f->target_rtl) != 0)
1135 register rtx cleanup_insns;
1137 /* If this fixup jumped into this contour from before the beginning
1138 of this contour, report an error. This code used to use
1139 the first non-label insn after f->target_rtl, but that's
1140 wrong since such can be added, by things like put_var_into_stack
1141 and have INSN_UIDs that are out of the range of the block. */
1142 /* ??? Bug: this does not detect jumping in through intermediate
1143 blocks that have stack levels or cleanups.
1144 It detects only a problem with the innermost block
1145 around the label. */
1147 && (dont_jump_in || stack_level || cleanup_list)
1148 && INSN_UID (first_insn) < INSN_UID (f->target_rtl)
1149 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1150 && ! DECL_ERROR_ISSUED (f->target))
1152 error_with_decl (f->target,
1153 "label `%s' used before containing binding contour");
1154 /* Prevent multiple errors for one label. */
1155 DECL_ERROR_ISSUED (f->target) = 1;
1158 /* We will expand the cleanups into a sequence of their own and
1159 then later on we will attach this new sequence to the insn
1160 stream just ahead of the actual jump insn. */
1164 /* Temporarily restore the lexical context where we will
1165 logically be inserting the fixup code. We do this for the
1166 sake of getting the debugging information right. */
1169 set_block (f->context);
1171 /* Expand the cleanups for blocks this jump exits. */
1172 if (f->cleanup_list_list)
1175 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1176 /* Marked elements correspond to blocks that have been closed.
1177 Do their cleanups. */
1178 if (TREE_ADDRESSABLE (lists)
1179 && TREE_VALUE (lists) != 0)
1181 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1182 /* Pop any pushes done in the cleanups,
1183 in case function is about to return. */
1184 do_pending_stack_adjust ();
1188 /* Restore stack level for the biggest contour that this
1189 jump jumps out of. */
1191 && ! (f->target_rtl == return_label
1192 && ((TREE_CODE (TREE_TYPE (current_function_decl))
1194 && (TYPE_RETURNS_STACK_DEPRESSED
1195 (TREE_TYPE (current_function_decl))))))
1196 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1198 /* Finish up the sequence containing the insns which implement the
1199 necessary cleanups, and then attach that whole sequence to the
1200 insn stream just ahead of the actual jump insn. Attaching it
1201 at that point insures that any cleanups which are in fact
1202 implicit C++ object destructions (which must be executed upon
1203 leaving the block) appear (to the debugger) to be taking place
1204 in an area of the generated code where the object(s) being
1205 destructed are still "in scope". */
1207 cleanup_insns = get_insns ();
1211 emit_insns_after (cleanup_insns, f->before_jump);
1217 /* For any still-undefined labels, do the cleanups for this block now.
1218 We must do this now since items in the cleanup list may go out
1219 of scope when the block ends. */
1220 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1221 if (f->before_jump != 0
1222 && PREV_INSN (f->target_rtl) == 0
1223 /* Label has still not appeared. If we are exiting a block with
1224 a stack level to restore, that started before the fixup,
1225 mark this stack level as needing restoration
1226 when the fixup is later finalized. */
1228 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1229 means the label is undefined. That's erroneous, but possible. */
1230 && (thisblock->data.block.block_start_count
1231 <= f->block_start_count))
1233 tree lists = f->cleanup_list_list;
1236 for (; lists; lists = TREE_CHAIN (lists))
1237 /* If the following elt. corresponds to our containing block
1238 then the elt. must be for this block. */
1239 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
1243 set_block (f->context);
1244 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1245 do_pending_stack_adjust ();
1246 cleanup_insns = get_insns ();
1249 if (cleanup_insns != 0)
1251 = emit_insns_after (cleanup_insns, f->before_jump);
1253 f->cleanup_list_list = TREE_CHAIN (lists);
1257 f->stack_level = stack_level;
1261 /* Return the number of times character C occurs in string S. */
1263 n_occurrences (c, s)
1273 /* Generate RTL for an asm statement (explicit assembler code).
1274 BODY is a STRING_CST node containing the assembler code text,
1275 or an ADDR_EXPR containing a STRING_CST. */
1281 if (current_function_check_memory_usage)
1283 error ("`asm' cannot be used in function where memory usage is checked");
1287 if (TREE_CODE (body) == ADDR_EXPR)
1288 body = TREE_OPERAND (body, 0);
1290 emit_insn (gen_rtx_ASM_INPUT (VOIDmode,
1291 TREE_STRING_POINTER (body)));
1295 /* Generate RTL for an asm statement with arguments.
1296 STRING is the instruction template.
1297 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1298 Each output or input has an expression in the TREE_VALUE and
1299 a constraint-string in the TREE_PURPOSE.
1300 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1301 that is clobbered by this insn.
1303 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1304 Some elements of OUTPUTS may be replaced with trees representing temporary
1305 values. The caller should copy those temporary values to the originally
1308 VOL nonzero means the insn is volatile; don't optimize it. */
1311 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1312 tree string, outputs, inputs, clobbers;
1314 const char *filename;
1317 rtvec argvec, constraints;
1319 int ninputs = list_length (inputs);
1320 int noutputs = list_length (outputs);
1325 /* Vector of RTX's of evaluated output operands. */
1326 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1327 int *inout_opnum = (int *) alloca (noutputs * sizeof (int));
1328 rtx *real_output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1329 enum machine_mode *inout_mode
1330 = (enum machine_mode *) alloca (noutputs * sizeof (enum machine_mode));
1331 /* The insn we have emitted. */
1333 int old_generating_concat_p = generating_concat_p;
1335 /* An ASM with no outputs needs to be treated as volatile, for now. */
1339 if (current_function_check_memory_usage)
1341 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1345 #ifdef MD_ASM_CLOBBERS
1346 /* Sometimes we wish to automatically clobber registers across an asm.
1347 Case in point is when the i386 backend moved from cc0 to a hard reg --
1348 maintaining source-level compatability means automatically clobbering
1349 the flags register. */
1350 MD_ASM_CLOBBERS (clobbers);
1353 if (current_function_check_memory_usage)
1355 error ("`asm' cannot be used in function where memory usage is checked");
1359 /* Count the number of meaningful clobbered registers, ignoring what
1360 we would ignore later. */
1362 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1364 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1366 i = decode_reg_name (regname);
1367 if (i >= 0 || i == -4)
1370 error ("unknown register name `%s' in `asm'", regname);
1375 /* Check that the number of alternatives is constant across all
1377 if (outputs || inputs)
1379 tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
1380 int nalternatives = n_occurrences (',', TREE_STRING_POINTER (tmp));
1383 if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
1385 error ("too many alternatives in `asm'");
1392 const char *constraint = TREE_STRING_POINTER (TREE_PURPOSE (tmp));
1394 if (n_occurrences (',', constraint) != nalternatives)
1396 error ("operand constraints for `asm' differ in number of alternatives");
1400 if (TREE_CHAIN (tmp))
1401 tmp = TREE_CHAIN (tmp);
1403 tmp = next, next = 0;
1407 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1409 tree val = TREE_VALUE (tail);
1410 tree type = TREE_TYPE (val);
1411 const char *constraint;
1419 /* If there's an erroneous arg, emit no insn. */
1420 if (TREE_TYPE (val) == error_mark_node)
1423 /* Make sure constraint has `=' and does not have `+'. Also, see
1424 if it allows any register. Be liberal on the latter test, since
1425 the worst that happens if we get it wrong is we issue an error
1428 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1429 c_len = strlen (constraint);
1431 /* Allow the `=' or `+' to not be at the beginning of the string,
1432 since it wasn't explicitly documented that way, and there is a
1433 large body of code that puts it last. Swap the character to
1434 the front, so as not to uglify any place else. */
1438 if ((p = strchr (constraint, '=')) != NULL)
1440 if ((p = strchr (constraint, '+')) != NULL)
1443 error ("output operand constraint lacks `='");
1447 is_inout = *p == '+';
1451 /* Have to throw away this constraint string and get a new one. */
1452 char *buf = alloca (c_len + 1);
1455 memcpy (buf + 1, constraint, j);
1456 memcpy (buf + 1 + j, p + 1, c_len - j); /* not -j-1 - copy null */
1457 constraint = ggc_alloc_string (buf, c_len);
1461 "output constraint `%c' for operand %d is not at the beginning",
1465 /* Make sure we can specify the matching operand. */
1466 if (is_inout && i > 9)
1468 error ("output operand constraint %d contains `+'", i);
1472 for (j = 1; j < c_len; j++)
1473 switch (constraint[j])
1477 error ("operand constraint contains '+' or '=' at illegal position.");
1481 if (i + 1 == ninputs + noutputs)
1483 error ("`%%' constraint used with last operand");
1488 case '?': case '!': case '*': case '&': case '#':
1489 case 'E': case 'F': case 'G': case 'H':
1490 case 's': case 'i': case 'n':
1491 case 'I': case 'J': case 'K': case 'L': case 'M':
1492 case 'N': case 'O': case 'P': case ',':
1495 case '0': case '1': case '2': case '3': case '4':
1496 case '5': case '6': case '7': case '8': case '9':
1497 error ("matching constraint not valid in output operand");
1500 case 'V': case 'm': case 'o':
1505 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1506 excepting those that expand_call created. So match memory
1521 if (! ISALPHA (constraint[j]))
1523 error ("invalid punctuation `%c' in constraint",
1527 if (REG_CLASS_FROM_LETTER (constraint[j]) != NO_REGS)
1529 #ifdef EXTRA_CONSTRAINT
1532 /* Otherwise we can't assume anything about the nature of
1533 the constraint except that it isn't purely registers.
1534 Treat it like "g" and hope for the best. */
1542 /* If an output operand is not a decl or indirect ref and our constraint
1543 allows a register, make a temporary to act as an intermediate.
1544 Make the asm insn write into that, then our caller will copy it to
1545 the real output operand. Likewise for promoted variables. */
1547 generating_concat_p = 0;
1549 real_output_rtx[i] = NULL_RTX;
1550 if ((TREE_CODE (val) == INDIRECT_REF
1553 && (allows_mem || GET_CODE (DECL_RTL (val)) == REG)
1554 && ! (GET_CODE (DECL_RTL (val)) == REG
1555 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
1560 mark_addressable (TREE_VALUE (tail));
1563 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode,
1564 EXPAND_MEMORY_USE_WO);
1566 if (! allows_reg && GET_CODE (output_rtx[i]) != MEM)
1567 error ("output number %d not directly addressable", i);
1568 if ((! allows_mem && GET_CODE (output_rtx[i]) == MEM)
1569 || GET_CODE (output_rtx[i]) == CONCAT)
1571 real_output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1572 output_rtx[i] = gen_reg_rtx (GET_MODE (output_rtx[i]));
1574 emit_move_insn (output_rtx[i], real_output_rtx[i]);
1579 output_rtx[i] = assign_temp (type, 0, 0, 1);
1580 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1583 generating_concat_p = old_generating_concat_p;
1587 inout_mode[ninout] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)));
1588 inout_opnum[ninout++] = i;
1593 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1595 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1599 /* Make vectors for the expression-rtx and constraint strings. */
1601 argvec = rtvec_alloc (ninputs);
1602 constraints = rtvec_alloc (ninputs);
1604 body = gen_rtx_ASM_OPERANDS ((noutputs == 0 ? VOIDmode
1605 : GET_MODE (output_rtx[0])),
1606 TREE_STRING_POINTER (string),
1607 empty_string, 0, argvec, constraints,
1610 MEM_VOLATILE_P (body) = vol;
1612 /* Eval the inputs and put them into ARGVEC.
1613 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1616 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1619 int allows_reg = 0, allows_mem = 0;
1620 const char *constraint, *orig_constraint;
1624 /* If there's an erroneous arg, emit no insn,
1625 because the ASM_INPUT would get VOIDmode
1626 and that could cause a crash in reload. */
1627 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1630 /* ??? Can this happen, and does the error message make any sense? */
1631 if (TREE_PURPOSE (tail) == NULL_TREE)
1633 error ("hard register `%s' listed as input operand to `asm'",
1634 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1638 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1639 c_len = strlen (constraint);
1640 orig_constraint = constraint;
1642 /* Make sure constraint has neither `=', `+', nor '&'. */
1644 for (j = 0; j < c_len; j++)
1645 switch (constraint[j])
1647 case '+': case '=': case '&':
1648 if (constraint == orig_constraint)
1650 error ("input operand constraint contains `%c'",
1657 if (constraint == orig_constraint
1658 && i + 1 == ninputs - ninout)
1660 error ("`%%' constraint used with last operand");
1665 case 'V': case 'm': case 'o':
1670 case '?': case '!': case '*': case '#':
1671 case 'E': case 'F': case 'G': case 'H':
1672 case 's': case 'i': case 'n':
1673 case 'I': case 'J': case 'K': case 'L': case 'M':
1674 case 'N': case 'O': case 'P': case ',':
1677 /* Whether or not a numeric constraint allows a register is
1678 decided by the matching constraint, and so there is no need
1679 to do anything special with them. We must handle them in
1680 the default case, so that we don't unnecessarily force
1681 operands to memory. */
1682 case '0': case '1': case '2': case '3': case '4':
1683 case '5': case '6': case '7': case '8': case '9':
1684 if (constraint[j] >= '0' + noutputs)
1687 ("matching constraint references invalid operand number");
1691 /* Try and find the real constraint for this dup. */
1692 if ((j == 0 && c_len == 1)
1693 || (j == 1 && c_len == 2 && constraint[0] == '%'))
1697 for (j = constraint[j] - '0'; j > 0; --j)
1700 constraint = TREE_STRING_POINTER (TREE_PURPOSE (o));
1701 c_len = strlen (constraint);
1718 if (! ISALPHA (constraint[j]))
1720 error ("invalid punctuation `%c' in constraint",
1724 if (REG_CLASS_FROM_LETTER (constraint[j]) != NO_REGS)
1726 #ifdef EXTRA_CONSTRAINT
1729 /* Otherwise we can't assume anything about the nature of
1730 the constraint except that it isn't purely registers.
1731 Treat it like "g" and hope for the best. */
1739 if (! allows_reg && allows_mem)
1740 mark_addressable (TREE_VALUE (tail));
1742 op = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1744 /* Never pass a CONCAT to an ASM. */
1745 generating_concat_p = 0;
1746 if (GET_CODE (op) == CONCAT)
1747 op = force_reg (GET_MODE (op), op);
1749 if (asm_operand_ok (op, constraint) <= 0)
1752 op = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), op);
1753 else if (!allows_mem)
1754 warning ("asm operand %d probably doesn't match constraints", i);
1755 else if (CONSTANT_P (op))
1756 op = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1758 else if (GET_CODE (op) == REG
1759 || GET_CODE (op) == SUBREG
1760 || GET_CODE (op) == CONCAT)
1762 tree type = TREE_TYPE (TREE_VALUE (tail));
1763 tree qual_type = build_qualified_type (type,
1765 | TYPE_QUAL_CONST));
1766 rtx memloc = assign_temp (qual_type, 1, 1, 1);
1768 emit_move_insn (memloc, op);
1772 else if (GET_CODE (op) == MEM && MEM_VOLATILE_P (op))
1773 /* We won't recognize volatile memory as available a
1774 memory_operand at this point. Ignore it. */
1776 else if (queued_subexp_p (op))
1779 /* ??? Leave this only until we have experience with what
1780 happens in combine and elsewhere when constraints are
1782 warning ("asm operand %d probably doesn't match constraints", i);
1784 generating_concat_p = old_generating_concat_p;
1785 ASM_OPERANDS_INPUT (body, i) = op;
1787 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, i)
1788 = gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1793 /* Protect all the operands from the queue now that they have all been
1796 generating_concat_p = 0;
1798 for (i = 0; i < ninputs - ninout; i++)
1799 ASM_OPERANDS_INPUT (body, i)
1800 = protect_from_queue (ASM_OPERANDS_INPUT (body, i), 0);
1802 for (i = 0; i < noutputs; i++)
1803 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1805 /* For in-out operands, copy output rtx to input rtx. */
1806 for (i = 0; i < ninout; i++)
1808 int j = inout_opnum[i];
1810 ASM_OPERANDS_INPUT (body, ninputs - ninout + i)
1812 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, ninputs - ninout + i)
1813 = gen_rtx_ASM_INPUT (inout_mode[i], digit_string (j));
1816 generating_concat_p = old_generating_concat_p;
1818 /* Now, for each output, construct an rtx
1819 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1820 ARGVEC CONSTRAINTS))
1821 If there is more than one, put them inside a PARALLEL. */
1823 if (noutputs == 1 && nclobbers == 0)
1825 ASM_OPERANDS_OUTPUT_CONSTRAINT (body)
1826 = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1827 insn = emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
1830 else if (noutputs == 0 && nclobbers == 0)
1832 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1833 insn = emit_insn (body);
1844 body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
1846 /* For each output operand, store a SET. */
1847 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1849 XVECEXP (body, 0, i)
1850 = gen_rtx_SET (VOIDmode,
1852 gen_rtx_ASM_OPERANDS
1853 (GET_MODE (output_rtx[i]),
1854 TREE_STRING_POINTER (string),
1855 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1856 i, argvec, constraints,
1859 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1862 /* If there are no outputs (but there are some clobbers)
1863 store the bare ASM_OPERANDS into the PARALLEL. */
1866 XVECEXP (body, 0, i++) = obody;
1868 /* Store (clobber REG) for each clobbered register specified. */
1870 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1872 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1873 int j = decode_reg_name (regname);
1877 if (j == -3) /* `cc', which is not a register */
1880 if (j == -4) /* `memory', don't cache memory across asm */
1882 XVECEXP (body, 0, i++)
1883 = gen_rtx_CLOBBER (VOIDmode,
1886 gen_rtx_SCRATCH (VOIDmode)));
1890 /* Ignore unknown register, error already signaled. */
1894 /* Use QImode since that's guaranteed to clobber just one reg. */
1895 XVECEXP (body, 0, i++)
1896 = gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (QImode, j));
1899 insn = emit_insn (body);
1902 /* For any outputs that needed reloading into registers, spill them
1903 back to where they belong. */
1904 for (i = 0; i < noutputs; ++i)
1905 if (real_output_rtx[i])
1906 emit_move_insn (real_output_rtx[i], output_rtx[i]);
1911 /* Generate RTL to evaluate the expression EXP
1912 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1915 expand_expr_stmt (exp)
1918 /* If -W, warn about statements with no side effects,
1919 except for an explicit cast to void (e.g. for assert()), and
1920 except inside a ({...}) where they may be useful. */
1921 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1923 if (! TREE_SIDE_EFFECTS (exp))
1925 if ((extra_warnings || warn_unused_value)
1926 && !(TREE_CODE (exp) == CONVERT_EXPR
1927 && VOID_TYPE_P (TREE_TYPE (exp))))
1928 warning_with_file_and_line (emit_filename, emit_lineno,
1929 "statement with no effect");
1931 else if (warn_unused_value)
1932 warn_if_unused_value (exp);
1935 /* If EXP is of function type and we are expanding statements for
1936 value, convert it to pointer-to-function. */
1937 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1938 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1940 /* The call to `expand_expr' could cause last_expr_type and
1941 last_expr_value to get reset. Therefore, we set last_expr_value
1942 and last_expr_type *after* calling expand_expr. */
1943 last_expr_value = expand_expr (exp,
1944 (expr_stmts_for_value
1945 ? NULL_RTX : const0_rtx),
1947 last_expr_type = TREE_TYPE (exp);
1949 /* If all we do is reference a volatile value in memory,
1950 copy it to a register to be sure it is actually touched. */
1951 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1952 && TREE_THIS_VOLATILE (exp))
1954 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1956 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1957 copy_to_reg (last_expr_value);
1960 rtx lab = gen_label_rtx ();
1962 /* Compare the value with itself to reference it. */
1963 emit_cmp_and_jump_insns (last_expr_value, last_expr_value, EQ,
1964 expand_expr (TYPE_SIZE (last_expr_type),
1965 NULL_RTX, VOIDmode, 0),
1967 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT,
1973 /* If this expression is part of a ({...}) and is in memory, we may have
1974 to preserve temporaries. */
1975 preserve_temp_slots (last_expr_value);
1977 /* Free any temporaries used to evaluate this expression. Any temporary
1978 used as a result of this expression will already have been preserved
1985 /* Warn if EXP contains any computations whose results are not used.
1986 Return 1 if a warning is printed; 0 otherwise. */
1989 warn_if_unused_value (exp)
1992 if (TREE_USED (exp))
1995 /* Don't warn about void constructs. This includes casting to void,
1996 void function calls, and statement expressions with a final cast
1998 if (VOID_TYPE_P (TREE_TYPE (exp)))
2001 /* If this is an expression with side effects, don't warn. */
2002 if (TREE_SIDE_EFFECTS (exp))
2005 switch (TREE_CODE (exp))
2007 case PREINCREMENT_EXPR:
2008 case POSTINCREMENT_EXPR:
2009 case PREDECREMENT_EXPR:
2010 case POSTDECREMENT_EXPR:
2015 case METHOD_CALL_EXPR:
2017 case TRY_CATCH_EXPR:
2018 case WITH_CLEANUP_EXPR:
2023 /* For a binding, warn if no side effect within it. */
2024 return warn_if_unused_value (TREE_OPERAND (exp, 1));
2027 return warn_if_unused_value (TREE_OPERAND (exp, 1));
2029 case TRUTH_ORIF_EXPR:
2030 case TRUTH_ANDIF_EXPR:
2031 /* In && or ||, warn if 2nd operand has no side effect. */
2032 return warn_if_unused_value (TREE_OPERAND (exp, 1));
2035 if (TREE_NO_UNUSED_WARNING (exp))
2037 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
2039 /* Let people do `(foo (), 0)' without a warning. */
2040 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
2042 return warn_if_unused_value (TREE_OPERAND (exp, 1));
2046 case NON_LVALUE_EXPR:
2047 /* Don't warn about conversions not explicit in the user's program. */
2048 if (TREE_NO_UNUSED_WARNING (exp))
2050 /* Assignment to a cast usually results in a cast of a modify.
2051 Don't complain about that. There can be an arbitrary number of
2052 casts before the modify, so we must loop until we find the first
2053 non-cast expression and then test to see if that is a modify. */
2055 tree tem = TREE_OPERAND (exp, 0);
2057 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
2058 tem = TREE_OPERAND (tem, 0);
2060 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
2061 || TREE_CODE (tem) == CALL_EXPR)
2067 /* Don't warn about automatic dereferencing of references, since
2068 the user cannot control it. */
2069 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
2070 return warn_if_unused_value (TREE_OPERAND (exp, 0));
2074 /* Referencing a volatile value is a side effect, so don't warn. */
2076 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
2077 && TREE_THIS_VOLATILE (exp))
2080 /* If this is an expression which has no operands, there is no value
2081 to be unused. There are no such language-independent codes,
2082 but front ends may define such. */
2083 if (TREE_CODE_CLASS (TREE_CODE (exp)) == 'e'
2084 && TREE_CODE_LENGTH (TREE_CODE (exp)) == 0)
2088 warning_with_file_and_line (emit_filename, emit_lineno,
2089 "value computed is not used");
2094 /* Clear out the memory of the last expression evaluated. */
2102 /* Begin a statement which will return a value.
2103 Return the RTL_EXPR for this statement expr.
2104 The caller must save that value and pass it to expand_end_stmt_expr. */
2107 expand_start_stmt_expr ()
2111 /* Make the RTL_EXPR node temporary, not momentary,
2112 so that rtl_expr_chain doesn't become garbage. */
2113 t = make_node (RTL_EXPR);
2114 do_pending_stack_adjust ();
2115 start_sequence_for_rtl_expr (t);
2117 expr_stmts_for_value++;
2121 /* Restore the previous state at the end of a statement that returns a value.
2122 Returns a tree node representing the statement's value and the
2123 insns to compute the value.
2125 The nodes of that expression have been freed by now, so we cannot use them.
2126 But we don't want to do that anyway; the expression has already been
2127 evaluated and now we just want to use the value. So generate a RTL_EXPR
2128 with the proper type and RTL value.
2130 If the last substatement was not an expression,
2131 return something with type `void'. */
2134 expand_end_stmt_expr (t)
2139 if (last_expr_type == 0)
2141 last_expr_type = void_type_node;
2142 last_expr_value = const0_rtx;
2144 else if (last_expr_value == 0)
2145 /* There are some cases where this can happen, such as when the
2146 statement is void type. */
2147 last_expr_value = const0_rtx;
2148 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
2149 /* Remove any possible QUEUED. */
2150 last_expr_value = protect_from_queue (last_expr_value, 0);
2154 TREE_TYPE (t) = last_expr_type;
2155 RTL_EXPR_RTL (t) = last_expr_value;
2156 RTL_EXPR_SEQUENCE (t) = get_insns ();
2158 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
2162 /* Don't consider deleting this expr or containing exprs at tree level. */
2163 TREE_SIDE_EFFECTS (t) = 1;
2164 /* Propagate volatility of the actual RTL expr. */
2165 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
2168 expr_stmts_for_value--;
2173 /* Generate RTL for the start of an if-then. COND is the expression
2174 whose truth should be tested.
2176 If EXITFLAG is nonzero, this conditional is visible to
2177 `exit_something'. */
2180 expand_start_cond (cond, exitflag)
2184 struct nesting *thiscond = ALLOC_NESTING ();
2186 /* Make an entry on cond_stack for the cond we are entering. */
2188 thiscond->next = cond_stack;
2189 thiscond->all = nesting_stack;
2190 thiscond->depth = ++nesting_depth;
2191 thiscond->data.cond.next_label = gen_label_rtx ();
2192 /* Before we encounter an `else', we don't need a separate exit label
2193 unless there are supposed to be exit statements
2194 to exit this conditional. */
2195 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
2196 thiscond->data.cond.endif_label = thiscond->exit_label;
2197 cond_stack = thiscond;
2198 nesting_stack = thiscond;
2200 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
2203 /* Generate RTL between then-clause and the elseif-clause
2204 of an if-then-elseif-.... */
2207 expand_start_elseif (cond)
2210 if (cond_stack->data.cond.endif_label == 0)
2211 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 = gen_label_rtx ();
2215 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2218 /* Generate RTL between the then-clause and the else-clause
2219 of an if-then-else. */
2222 expand_start_else ()
2224 if (cond_stack->data.cond.endif_label == 0)
2225 cond_stack->data.cond.endif_label = gen_label_rtx ();
2227 emit_jump (cond_stack->data.cond.endif_label);
2228 emit_label (cond_stack->data.cond.next_label);
2229 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
2232 /* After calling expand_start_else, turn this "else" into an "else if"
2233 by providing another condition. */
2236 expand_elseif (cond)
2239 cond_stack->data.cond.next_label = gen_label_rtx ();
2240 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2243 /* Generate RTL for the end of an if-then.
2244 Pop the record for it off of cond_stack. */
2249 struct nesting *thiscond = cond_stack;
2251 do_pending_stack_adjust ();
2252 if (thiscond->data.cond.next_label)
2253 emit_label (thiscond->data.cond.next_label);
2254 if (thiscond->data.cond.endif_label)
2255 emit_label (thiscond->data.cond.endif_label);
2257 POPSTACK (cond_stack);
2261 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2262 loop should be exited by `exit_something'. This is a loop for which
2263 `expand_continue' will jump to the top of the loop.
2265 Make an entry on loop_stack to record the labels associated with
2269 expand_start_loop (exit_flag)
2272 register struct nesting *thisloop = ALLOC_NESTING ();
2274 /* Make an entry on loop_stack for the loop we are entering. */
2276 thisloop->next = loop_stack;
2277 thisloop->all = nesting_stack;
2278 thisloop->depth = ++nesting_depth;
2279 thisloop->data.loop.start_label = gen_label_rtx ();
2280 thisloop->data.loop.end_label = gen_label_rtx ();
2281 thisloop->data.loop.alt_end_label = 0;
2282 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2283 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2284 loop_stack = thisloop;
2285 nesting_stack = thisloop;
2287 do_pending_stack_adjust ();
2289 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2290 emit_label (thisloop->data.loop.start_label);
2295 /* Like expand_start_loop but for a loop where the continuation point
2296 (for expand_continue_loop) will be specified explicitly. */
2299 expand_start_loop_continue_elsewhere (exit_flag)
2302 struct nesting *thisloop = expand_start_loop (exit_flag);
2303 loop_stack->data.loop.continue_label = gen_label_rtx ();
2307 /* Begin a null, aka do { } while (0) "loop". But since the contents
2308 of said loop can still contain a break, we must frob the loop nest. */
2311 expand_start_null_loop ()
2313 register struct nesting *thisloop = ALLOC_NESTING ();
2315 /* Make an entry on loop_stack for the loop we are entering. */
2317 thisloop->next = loop_stack;
2318 thisloop->all = nesting_stack;
2319 thisloop->depth = ++nesting_depth;
2320 thisloop->data.loop.start_label = emit_note (NULL, NOTE_INSN_DELETED);
2321 thisloop->data.loop.end_label = gen_label_rtx ();
2322 thisloop->data.loop.alt_end_label = NULL_RTX;
2323 thisloop->data.loop.continue_label = thisloop->data.loop.end_label;
2324 thisloop->exit_label = thisloop->data.loop.end_label;
2325 loop_stack = thisloop;
2326 nesting_stack = thisloop;
2331 /* Specify the continuation point for a loop started with
2332 expand_start_loop_continue_elsewhere.
2333 Use this at the point in the code to which a continue statement
2337 expand_loop_continue_here ()
2339 do_pending_stack_adjust ();
2340 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2341 emit_label (loop_stack->data.loop.continue_label);
2344 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2345 Pop the block off of loop_stack. */
2350 rtx start_label = loop_stack->data.loop.start_label;
2351 rtx insn = get_last_insn ();
2352 int needs_end_jump = 1;
2354 /* Mark the continue-point at the top of the loop if none elsewhere. */
2355 if (start_label == loop_stack->data.loop.continue_label)
2356 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2358 do_pending_stack_adjust ();
2360 /* If optimizing, perhaps reorder the loop.
2361 First, try to use a condjump near the end.
2362 expand_exit_loop_if_false ends loops with unconditional jumps,
2365 if (test) goto label;
2367 goto loop_stack->data.loop.end_label
2371 If we find such a pattern, we can end the loop earlier. */
2374 && GET_CODE (insn) == CODE_LABEL
2375 && LABEL_NAME (insn) == NULL
2376 && GET_CODE (PREV_INSN (insn)) == BARRIER)
2379 rtx jump = PREV_INSN (PREV_INSN (label));
2381 if (GET_CODE (jump) == JUMP_INSN
2382 && GET_CODE (PATTERN (jump)) == SET
2383 && SET_DEST (PATTERN (jump)) == pc_rtx
2384 && GET_CODE (SET_SRC (PATTERN (jump))) == LABEL_REF
2385 && (XEXP (SET_SRC (PATTERN (jump)), 0)
2386 == loop_stack->data.loop.end_label))
2390 /* The test might be complex and reference LABEL multiple times,
2391 like the loop in loop_iterations to set vtop. To handle this,
2393 insn = PREV_INSN (label);
2394 reorder_insns (label, label, start_label);
2396 for (prev = PREV_INSN (jump);; prev = PREV_INSN (prev))
2398 /* We ignore line number notes, but if we see any other note,
2399 in particular NOTE_INSN_BLOCK_*, NOTE_INSN_EH_REGION_*,
2400 NOTE_INSN_LOOP_*, we disable this optimization. */
2401 if (GET_CODE (prev) == NOTE)
2403 if (NOTE_LINE_NUMBER (prev) < 0)
2407 if (GET_CODE (prev) == CODE_LABEL)
2409 if (GET_CODE (prev) == JUMP_INSN)
2411 if (GET_CODE (PATTERN (prev)) == SET
2412 && SET_DEST (PATTERN (prev)) == pc_rtx
2413 && GET_CODE (SET_SRC (PATTERN (prev))) == IF_THEN_ELSE
2414 && (GET_CODE (XEXP (SET_SRC (PATTERN (prev)), 1))
2416 && XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0) == label)
2418 XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0)
2420 emit_note_after (NOTE_INSN_LOOP_END, prev);
2429 /* If the loop starts with a loop exit, roll that to the end where
2430 it will optimize together with the jump back.
2432 We look for the conditional branch to the exit, except that once
2433 we find such a branch, we don't look past 30 instructions.
2435 In more detail, if the loop presently looks like this (in pseudo-C):
2438 if (test) goto end_label;
2443 transform it to look like:
2449 if (test) goto end_label;
2450 goto newstart_label;
2453 Here, the `test' may actually consist of some reasonably complex
2454 code, terminating in a test. */
2459 ! (GET_CODE (insn) == JUMP_INSN
2460 && GET_CODE (PATTERN (insn)) == SET
2461 && SET_DEST (PATTERN (insn)) == pc_rtx
2462 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2466 rtx last_test_insn = NULL_RTX;
2468 /* Scan insns from the top of the loop looking for a qualified
2469 conditional exit. */
2470 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2471 insn = NEXT_INSN (insn))
2473 if (GET_CODE (insn) == NOTE)
2476 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2477 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2478 /* The code that actually moves the exit test will
2479 carefully leave BLOCK notes in their original
2480 location. That means, however, that we can't debug
2481 the exit test itself. So, we refuse to move code
2482 containing BLOCK notes at low optimization levels. */
2485 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG)
2487 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)
2491 /* We've come to the end of an EH region, but
2492 never saw the beginning of that region. That
2493 means that an EH region begins before the top
2494 of the loop, and ends in the middle of it. The
2495 existence of such a situation violates a basic
2496 assumption in this code, since that would imply
2497 that even when EH_REGIONS is zero, we might
2498 move code out of an exception region. */
2502 /* We must not walk into a nested loop. */
2503 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
2506 /* We already know this INSN is a NOTE, so there's no
2507 point in looking at it to see if it's a JUMP. */
2511 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2514 if (last_test_insn && num_insns > 30)
2518 /* We don't want to move a partial EH region. Consider:
2532 This isn't legal C++, but here's what it's supposed to
2533 mean: if cond() is true, stop looping. Otherwise,
2534 call bar, and keep looping. In addition, if cond
2535 throws an exception, catch it and keep looping. Such
2536 constructs are certainy legal in LISP.
2538 We should not move the `if (cond()) 0' test since then
2539 the EH-region for the try-block would be broken up.
2540 (In this case we would the EH_BEG note for the `try'
2541 and `if cond()' but not the call to bar() or the
2544 So we don't look for tests within an EH region. */
2547 if (GET_CODE (insn) == JUMP_INSN
2548 && GET_CODE (PATTERN (insn)) == SET
2549 && SET_DEST (PATTERN (insn)) == pc_rtx)
2551 /* This is indeed a jump. */
2552 rtx dest1 = NULL_RTX;
2553 rtx dest2 = NULL_RTX;
2554 rtx potential_last_test;
2555 if (GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE)
2557 /* A conditional jump. */
2558 dest1 = XEXP (SET_SRC (PATTERN (insn)), 1);
2559 dest2 = XEXP (SET_SRC (PATTERN (insn)), 2);
2560 potential_last_test = insn;
2564 /* An unconditional jump. */
2565 dest1 = SET_SRC (PATTERN (insn));
2566 /* Include the BARRIER after the JUMP. */
2567 potential_last_test = NEXT_INSN (insn);
2571 if (dest1 && GET_CODE (dest1) == LABEL_REF
2572 && ((XEXP (dest1, 0)
2573 == loop_stack->data.loop.alt_end_label)
2575 == loop_stack->data.loop.end_label)))
2577 last_test_insn = potential_last_test;
2581 /* If this was a conditional jump, there may be
2582 another label at which we should look. */
2589 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2591 /* We found one. Move everything from there up
2592 to the end of the loop, and add a jump into the loop
2593 to jump to there. */
2594 register rtx newstart_label = gen_label_rtx ();
2595 register rtx start_move = start_label;
2598 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2599 then we want to move this note also. */
2600 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2601 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2602 == NOTE_INSN_LOOP_CONT))
2603 start_move = PREV_INSN (start_move);
2605 emit_label_after (newstart_label, PREV_INSN (start_move));
2607 /* Actually move the insns. Start at the beginning, and
2608 keep copying insns until we've copied the
2610 for (insn = start_move; insn; insn = next_insn)
2612 /* Figure out which insn comes after this one. We have
2613 to do this before we move INSN. */
2614 if (insn == last_test_insn)
2615 /* We've moved all the insns. */
2616 next_insn = NULL_RTX;
2618 next_insn = NEXT_INSN (insn);
2620 if (GET_CODE (insn) == NOTE
2621 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2622 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2623 /* We don't want to move NOTE_INSN_BLOCK_BEGs or
2624 NOTE_INSN_BLOCK_ENDs because the correct generation
2625 of debugging information depends on these appearing
2626 in the same order in the RTL and in the tree
2627 structure, where they are represented as BLOCKs.
2628 So, we don't move block notes. Of course, moving
2629 the code inside the block is likely to make it
2630 impossible to debug the instructions in the exit
2631 test, but such is the price of optimization. */
2634 /* Move the INSN. */
2635 reorder_insns (insn, insn, get_last_insn ());
2638 emit_jump_insn_after (gen_jump (start_label),
2639 PREV_INSN (newstart_label));
2640 emit_barrier_after (PREV_INSN (newstart_label));
2641 start_label = newstart_label;
2647 emit_jump (start_label);
2648 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2650 emit_label (loop_stack->data.loop.end_label);
2652 POPSTACK (loop_stack);
2657 /* Finish a null loop, aka do { } while (0). */
2660 expand_end_null_loop ()
2662 do_pending_stack_adjust ();
2663 emit_label (loop_stack->data.loop.end_label);
2665 POPSTACK (loop_stack);
2670 /* Generate a jump to the current loop's continue-point.
2671 This is usually the top of the loop, but may be specified
2672 explicitly elsewhere. If not currently inside a loop,
2673 return 0 and do nothing; caller will print an error message. */
2676 expand_continue_loop (whichloop)
2677 struct nesting *whichloop;
2681 whichloop = loop_stack;
2684 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2689 /* Generate a jump to exit the current loop. If not currently inside a loop,
2690 return 0 and do nothing; caller will print an error message. */
2693 expand_exit_loop (whichloop)
2694 struct nesting *whichloop;
2698 whichloop = loop_stack;
2701 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2705 /* Generate a conditional jump to exit the current loop if COND
2706 evaluates to zero. If not currently inside a loop,
2707 return 0 and do nothing; caller will print an error message. */
2710 expand_exit_loop_if_false (whichloop, cond)
2711 struct nesting *whichloop;
2714 rtx label = gen_label_rtx ();
2719 whichloop = loop_stack;
2722 /* In order to handle fixups, we actually create a conditional jump
2723 around a unconditional branch to exit the loop. If fixups are
2724 necessary, they go before the unconditional branch. */
2726 do_jump (cond, NULL_RTX, label);
2727 last_insn = get_last_insn ();
2728 if (GET_CODE (last_insn) == CODE_LABEL)
2729 whichloop->data.loop.alt_end_label = last_insn;
2730 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2737 /* Return nonzero if the loop nest is empty. Else return zero. */
2740 stmt_loop_nest_empty ()
2742 /* cfun->stmt can be NULL if we are building a call to get the
2743 EH context for a setjmp/longjmp EH target and the current
2744 function was a deferred inline function. */
2745 return (cfun->stmt == NULL || loop_stack == NULL);
2748 /* Return non-zero if we should preserve sub-expressions as separate
2749 pseudos. We never do so if we aren't optimizing. We always do so
2750 if -fexpensive-optimizations.
2752 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2753 the loop may still be a small one. */
2756 preserve_subexpressions_p ()
2760 if (flag_expensive_optimizations)
2763 if (optimize == 0 || cfun == 0 || cfun->stmt == 0 || loop_stack == 0)
2766 insn = get_last_insn_anywhere ();
2769 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2770 < n_non_fixed_regs * 3));
2774 /* Generate a jump to exit the current loop, conditional, binding contour
2775 or case statement. Not all such constructs are visible to this function,
2776 only those started with EXIT_FLAG nonzero. Individual languages use
2777 the EXIT_FLAG parameter to control which kinds of constructs you can
2780 If not currently inside anything that can be exited,
2781 return 0 and do nothing; caller will print an error message. */
2784 expand_exit_something ()
2788 for (n = nesting_stack; n; n = n->all)
2789 if (n->exit_label != 0)
2791 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2798 /* Generate RTL to return from the current function, with no value.
2799 (That is, we do not do anything about returning any value.) */
2802 expand_null_return ()
2804 struct nesting *block = block_stack;
2805 rtx last_insn = get_last_insn ();
2807 /* If this function was declared to return a value, but we
2808 didn't, clobber the return registers so that they are not
2809 propogated live to the rest of the function. */
2810 clobber_return_register ();
2812 /* Does any pending block have cleanups? */
2813 while (block && block->data.block.cleanups == 0)
2814 block = block->next;
2816 /* If yes, use a goto to return, since that runs cleanups. */
2818 expand_null_return_1 (last_insn, block != 0);
2821 /* Generate RTL to return from the current function, with value VAL. */
2824 expand_value_return (val)
2827 struct nesting *block = block_stack;
2828 rtx last_insn = get_last_insn ();
2829 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2831 /* Copy the value to the return location
2832 unless it's already there. */
2834 if (return_reg != val)
2836 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2837 #ifdef PROMOTE_FUNCTION_RETURN
2838 int unsignedp = TREE_UNSIGNED (type);
2839 enum machine_mode old_mode
2840 = DECL_MODE (DECL_RESULT (current_function_decl));
2841 enum machine_mode mode
2842 = promote_mode (type, old_mode, &unsignedp, 1);
2844 if (mode != old_mode)
2845 val = convert_modes (mode, old_mode, val, unsignedp);
2847 if (GET_CODE (return_reg) == PARALLEL)
2848 emit_group_load (return_reg, val, int_size_in_bytes (type),
2851 emit_move_insn (return_reg, val);
2854 /* Does any pending block have cleanups? */
2856 while (block && block->data.block.cleanups == 0)
2857 block = block->next;
2859 /* If yes, use a goto to return, since that runs cleanups.
2860 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2862 expand_null_return_1 (last_insn, block != 0);
2865 /* Output a return with no value. If LAST_INSN is nonzero,
2866 pretend that the return takes place after LAST_INSN.
2867 If USE_GOTO is nonzero then don't use a return instruction;
2868 go to the return label instead. This causes any cleanups
2869 of pending blocks to be executed normally. */
2872 expand_null_return_1 (last_insn, use_goto)
2876 rtx end_label = cleanup_label ? cleanup_label : return_label;
2878 clear_pending_stack_adjust ();
2879 do_pending_stack_adjust ();
2882 /* PCC-struct return always uses an epilogue. */
2883 if (current_function_returns_pcc_struct || use_goto)
2886 end_label = return_label = gen_label_rtx ();
2887 expand_goto_internal (NULL_TREE, end_label, last_insn);
2891 /* Otherwise output a simple return-insn if one is available,
2892 unless it won't do the job. */
2894 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2896 emit_jump_insn (gen_return ());
2902 /* Otherwise jump to the epilogue. */
2903 expand_goto_internal (NULL_TREE, end_label, last_insn);
2906 /* Generate RTL to evaluate the expression RETVAL and return it
2907 from the current function. */
2910 expand_return (retval)
2913 /* If there are any cleanups to be performed, then they will
2914 be inserted following LAST_INSN. It is desirable
2915 that the last_insn, for such purposes, should be the
2916 last insn before computing the return value. Otherwise, cleanups
2917 which call functions can clobber the return value. */
2918 /* ??? rms: I think that is erroneous, because in C++ it would
2919 run destructors on variables that might be used in the subsequent
2920 computation of the return value. */
2923 register rtx val = 0;
2927 /* If function wants no value, give it none. */
2928 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2930 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2932 expand_null_return ();
2936 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2937 /* This is not sufficient. We also need to watch for cleanups of the
2938 expression we are about to expand. Unfortunately, we cannot know
2939 if it has cleanups until we expand it, and we want to change how we
2940 expand it depending upon if we need cleanups. We can't win. */
2942 cleanups = any_pending_cleanups (1);
2947 if (retval == error_mark_node)
2949 /* Treat this like a return of no value from a function that
2951 expand_null_return ();
2954 else if (TREE_CODE (retval) == RESULT_DECL)
2955 retval_rhs = retval;
2956 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2957 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2958 retval_rhs = TREE_OPERAND (retval, 1);
2959 else if (VOID_TYPE_P (TREE_TYPE (retval)))
2960 /* Recognize tail-recursive call to void function. */
2961 retval_rhs = retval;
2963 retval_rhs = NULL_TREE;
2965 /* Only use `last_insn' if there are cleanups which must be run. */
2966 if (cleanups || cleanup_label != 0)
2967 last_insn = get_last_insn ();
2969 /* Distribute return down conditional expr if either of the sides
2970 may involve tail recursion (see test below). This enhances the number
2971 of tail recursions we see. Don't do this always since it can produce
2972 sub-optimal code in some cases and we distribute assignments into
2973 conditional expressions when it would help. */
2975 if (optimize && retval_rhs != 0
2976 && frame_offset == 0
2977 && TREE_CODE (retval_rhs) == COND_EXPR
2978 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2979 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2981 rtx label = gen_label_rtx ();
2984 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2985 start_cleanup_deferral ();
2986 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2987 DECL_RESULT (current_function_decl),
2988 TREE_OPERAND (retval_rhs, 1));
2989 TREE_SIDE_EFFECTS (expr) = 1;
2990 expand_return (expr);
2993 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2994 DECL_RESULT (current_function_decl),
2995 TREE_OPERAND (retval_rhs, 2));
2996 TREE_SIDE_EFFECTS (expr) = 1;
2997 expand_return (expr);
2998 end_cleanup_deferral ();
3002 result_rtl = DECL_RTL (DECL_RESULT (current_function_decl));
3004 /* If the result is an aggregate that is being returned in one (or more)
3005 registers, load the registers here. The compiler currently can't handle
3006 copying a BLKmode value into registers. We could put this code in a
3007 more general area (for use by everyone instead of just function
3008 call/return), but until this feature is generally usable it is kept here
3009 (and in expand_call). The value must go into a pseudo in case there
3010 are cleanups that will clobber the real return register. */
3013 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
3014 && GET_CODE (result_rtl) == REG)
3017 unsigned HOST_WIDE_INT bitpos, xbitpos;
3018 unsigned HOST_WIDE_INT big_endian_correction = 0;
3019 unsigned HOST_WIDE_INT bytes
3020 = int_size_in_bytes (TREE_TYPE (retval_rhs));
3021 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
3022 unsigned int bitsize
3023 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)), BITS_PER_WORD);
3024 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
3025 rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
3026 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
3027 enum machine_mode tmpmode, result_reg_mode;
3031 expand_null_return ();
3035 /* Structures whose size is not a multiple of a word are aligned
3036 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
3037 machine, this means we must skip the empty high order bytes when
3038 calculating the bit offset. */
3039 if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD)
3040 big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
3043 /* Copy the structure BITSIZE bits at a time. */
3044 for (bitpos = 0, xbitpos = big_endian_correction;
3045 bitpos < bytes * BITS_PER_UNIT;
3046 bitpos += bitsize, xbitpos += bitsize)
3048 /* We need a new destination pseudo each time xbitpos is
3049 on a word boundary and when xbitpos == big_endian_correction
3050 (the first time through). */
3051 if (xbitpos % BITS_PER_WORD == 0
3052 || xbitpos == big_endian_correction)
3054 /* Generate an appropriate register. */
3055 dst = gen_reg_rtx (word_mode);
3056 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
3058 /* Clobber the destination before we move anything into it. */
3059 emit_insn (gen_rtx_CLOBBER (VOIDmode, dst));
3062 /* We need a new source operand each time bitpos is on a word
3064 if (bitpos % BITS_PER_WORD == 0)
3065 src = operand_subword_force (result_val,
3066 bitpos / BITS_PER_WORD,
3069 /* Use bitpos for the source extraction (left justified) and
3070 xbitpos for the destination store (right justified). */
3071 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
3072 extract_bit_field (src, bitsize,
3073 bitpos % BITS_PER_WORD, 1,
3074 NULL_RTX, word_mode, word_mode,
3075 bitsize, BITS_PER_WORD),
3076 bitsize, BITS_PER_WORD);
3079 /* Find the smallest integer mode large enough to hold the
3080 entire structure and use that mode instead of BLKmode
3081 on the USE insn for the return register. */
3082 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
3083 tmpmode != VOIDmode;
3084 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
3085 /* Have we found a large enough mode? */
3086 if (GET_MODE_SIZE (tmpmode) >= bytes)
3089 /* No suitable mode found. */
3090 if (tmpmode == VOIDmode)
3093 PUT_MODE (result_rtl, tmpmode);
3095 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
3096 result_reg_mode = word_mode;
3098 result_reg_mode = tmpmode;
3099 result_reg = gen_reg_rtx (result_reg_mode);
3102 for (i = 0; i < n_regs; i++)
3103 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
3106 if (tmpmode != result_reg_mode)
3107 result_reg = gen_lowpart (tmpmode, result_reg);
3109 expand_value_return (result_reg);
3113 && !VOID_TYPE_P (TREE_TYPE (retval_rhs))
3114 && (GET_CODE (result_rtl) == REG
3115 || (GET_CODE (result_rtl) == PARALLEL)))
3117 /* Calculate the return value into a temporary (usually a pseudo
3119 tree ot = TREE_TYPE (DECL_RESULT (current_function_decl));
3120 tree nt = build_qualified_type (ot, TYPE_QUALS (ot) | TYPE_QUAL_CONST);
3122 val = assign_temp (nt, 0, 0, 1);
3123 val = expand_expr (retval_rhs, val, GET_MODE (val), 0);
3124 val = force_not_mem (val);
3126 /* Return the calculated value, doing cleanups first. */
3127 expand_value_return (val);
3131 /* No cleanups or no hard reg used;
3132 calculate value into hard return reg. */
3133 expand_expr (retval, const0_rtx, VOIDmode, 0);
3135 expand_value_return (result_rtl);
3139 /* Return 1 if the end of the generated RTX is not a barrier.
3140 This means code already compiled can drop through. */
3143 drop_through_at_end_p ()
3145 rtx insn = get_last_insn ();
3146 while (insn && GET_CODE (insn) == NOTE)
3147 insn = PREV_INSN (insn);
3148 return insn && GET_CODE (insn) != BARRIER;
3151 /* Attempt to optimize a potential tail recursion call into a goto.
3152 ARGUMENTS are the arguments to a CALL_EXPR; LAST_INSN indicates
3153 where to place the jump to the tail recursion label.
3155 Return TRUE if the call was optimized into a goto. */
3158 optimize_tail_recursion (arguments, last_insn)
3162 /* Finish checking validity, and if valid emit code to set the
3163 argument variables for the new call. */
3164 if (tail_recursion_args (arguments, DECL_ARGUMENTS (current_function_decl)))
3166 if (tail_recursion_label == 0)
3168 tail_recursion_label = gen_label_rtx ();
3169 emit_label_after (tail_recursion_label,
3170 tail_recursion_reentry);
3173 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
3180 /* Emit code to alter this function's formal parms for a tail-recursive call.
3181 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3182 FORMALS is the chain of decls of formals.
3183 Return 1 if this can be done;
3184 otherwise return 0 and do not emit any code. */
3187 tail_recursion_args (actuals, formals)
3188 tree actuals, formals;
3190 register tree a = actuals, f = formals;
3192 register rtx *argvec;
3194 /* Check that number and types of actuals are compatible
3195 with the formals. This is not always true in valid C code.
3196 Also check that no formal needs to be addressable
3197 and that all formals are scalars. */
3199 /* Also count the args. */
3201 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
3203 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a)))
3204 != TYPE_MAIN_VARIANT (TREE_TYPE (f)))
3206 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
3209 if (a != 0 || f != 0)
3212 /* Compute all the actuals. */
3214 argvec = (rtx *) alloca (i * sizeof (rtx));
3216 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3217 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
3219 /* Find which actual values refer to current values of previous formals.
3220 Copy each of them now, before any formal is changed. */
3222 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3226 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
3227 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
3233 argvec[i] = copy_to_reg (argvec[i]);
3236 /* Store the values of the actuals into the formals. */
3238 for (f = formals, a = actuals, i = 0; f;
3239 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
3241 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
3242 emit_move_insn (DECL_RTL (f), argvec[i]);
3244 convert_move (DECL_RTL (f), argvec[i],
3245 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
3252 /* Generate the RTL code for entering a binding contour.
3253 The variables are declared one by one, by calls to `expand_decl'.
3255 FLAGS is a bitwise or of the following flags:
3257 1 - Nonzero if this construct should be visible to
3260 2 - Nonzero if this contour does not require a
3261 NOTE_INSN_BLOCK_BEG note. Virtually all calls from
3262 language-independent code should set this flag because they
3263 will not create corresponding BLOCK nodes. (There should be
3264 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
3265 and BLOCKs.) If this flag is set, MARK_ENDS should be zero
3266 when expand_end_bindings is called.
3268 If we are creating a NOTE_INSN_BLOCK_BEG note, a BLOCK may
3269 optionally be supplied. If so, it becomes the NOTE_BLOCK for the
3273 expand_start_bindings_and_block (flags, block)
3277 struct nesting *thisblock = ALLOC_NESTING ();
3279 int exit_flag = ((flags & 1) != 0);
3280 int block_flag = ((flags & 2) == 0);
3282 /* If a BLOCK is supplied, then the caller should be requesting a
3283 NOTE_INSN_BLOCK_BEG note. */
3284 if (!block_flag && block)
3287 /* Create a note to mark the beginning of the block. */
3290 note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
3291 NOTE_BLOCK (note) = block;
3294 note = emit_note (NULL_PTR, NOTE_INSN_DELETED);
3296 /* Make an entry on block_stack for the block we are entering. */
3298 thisblock->next = block_stack;
3299 thisblock->all = nesting_stack;
3300 thisblock->depth = ++nesting_depth;
3301 thisblock->data.block.stack_level = 0;
3302 thisblock->data.block.cleanups = 0;
3303 thisblock->data.block.n_function_calls = 0;
3304 thisblock->data.block.exception_region = 0;
3305 thisblock->data.block.block_target_temp_slot_level = target_temp_slot_level;
3307 thisblock->data.block.conditional_code = 0;
3308 thisblock->data.block.last_unconditional_cleanup = note;
3309 /* When we insert instructions after the last unconditional cleanup,
3310 we don't adjust last_insn. That means that a later add_insn will
3311 clobber the instructions we've just added. The easiest way to
3312 fix this is to just insert another instruction here, so that the
3313 instructions inserted after the last unconditional cleanup are
3314 never the last instruction. */
3315 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3316 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
3319 && !(block_stack->data.block.cleanups == NULL_TREE
3320 && block_stack->data.block.outer_cleanups == NULL_TREE))
3321 thisblock->data.block.outer_cleanups
3322 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
3323 block_stack->data.block.outer_cleanups);
3325 thisblock->data.block.outer_cleanups = 0;
3326 thisblock->data.block.label_chain = 0;
3327 thisblock->data.block.innermost_stack_block = stack_block_stack;
3328 thisblock->data.block.first_insn = note;
3329 thisblock->data.block.block_start_count = ++current_block_start_count;
3330 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
3331 block_stack = thisblock;
3332 nesting_stack = thisblock;
3334 /* Make a new level for allocating stack slots. */
3338 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3339 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3340 expand_expr are made. After we end the region, we know that all
3341 space for all temporaries that were created by TARGET_EXPRs will be
3342 destroyed and their space freed for reuse. */
3345 expand_start_target_temps ()
3347 /* This is so that even if the result is preserved, the space
3348 allocated will be freed, as we know that it is no longer in use. */
3351 /* Start a new binding layer that will keep track of all cleanup
3352 actions to be performed. */
3353 expand_start_bindings (2);
3355 target_temp_slot_level = temp_slot_level;
3359 expand_end_target_temps ()
3361 expand_end_bindings (NULL_TREE, 0, 0);
3363 /* This is so that even if the result is preserved, the space
3364 allocated will be freed, as we know that it is no longer in use. */
3368 /* Given a pointer to a BLOCK node return non-zero if (and only if) the node
3369 in question represents the outermost pair of curly braces (i.e. the "body
3370 block") of a function or method.
3372 For any BLOCK node representing a "body block" of a function or method, the
3373 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
3374 represents the outermost (function) scope for the function or method (i.e.
3375 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
3376 *that* node in turn will point to the relevant FUNCTION_DECL node. */
3379 is_body_block (stmt)
3382 if (TREE_CODE (stmt) == BLOCK)
3384 tree parent = BLOCK_SUPERCONTEXT (stmt);
3386 if (parent && TREE_CODE (parent) == BLOCK)
3388 tree grandparent = BLOCK_SUPERCONTEXT (parent);
3390 if (grandparent && TREE_CODE (grandparent) == FUNCTION_DECL)
3398 /* Mark top block of block_stack as an implicit binding for an
3399 exception region. This is used to prevent infinite recursion when
3400 ending a binding with expand_end_bindings. It is only ever called
3401 by expand_eh_region_start, as that it the only way to create a
3402 block stack for a exception region. */
3405 mark_block_as_eh_region ()
3407 block_stack->data.block.exception_region = 1;
3408 if (block_stack->next
3409 && block_stack->next->data.block.conditional_code)
3411 block_stack->data.block.conditional_code
3412 = block_stack->next->data.block.conditional_code;
3413 block_stack->data.block.last_unconditional_cleanup
3414 = block_stack->next->data.block.last_unconditional_cleanup;
3415 block_stack->data.block.cleanup_ptr
3416 = block_stack->next->data.block.cleanup_ptr;
3420 /* True if we are currently emitting insns in an area of output code
3421 that is controlled by a conditional expression. This is used by
3422 the cleanup handling code to generate conditional cleanup actions. */
3425 conditional_context ()
3427 return block_stack && block_stack->data.block.conditional_code;
3430 /* Mark top block of block_stack as not for an implicit binding for an
3431 exception region. This is only ever done by expand_eh_region_end
3432 to let expand_end_bindings know that it is being called explicitly
3433 to end the binding layer for just the binding layer associated with
3434 the exception region, otherwise expand_end_bindings would try and
3435 end all implicit binding layers for exceptions regions, and then
3436 one normal binding layer. */
3439 mark_block_as_not_eh_region ()
3441 block_stack->data.block.exception_region = 0;
3444 /* True if the top block of block_stack was marked as for an exception
3445 region by mark_block_as_eh_region. */
3450 return cfun && block_stack && block_stack->data.block.exception_region;
3453 /* Emit a handler label for a nonlocal goto handler.
3454 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3457 expand_nl_handler_label (slot, before_insn)
3458 rtx slot, before_insn;
3461 rtx handler_label = gen_label_rtx ();
3463 /* Don't let jump_optimize delete the handler. */
3464 LABEL_PRESERVE_P (handler_label) = 1;
3467 emit_move_insn (slot, gen_rtx_LABEL_REF (Pmode, handler_label));
3468 insns = get_insns ();
3470 emit_insns_before (insns, before_insn);
3472 emit_label (handler_label);
3474 return handler_label;
3477 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3480 expand_nl_goto_receiver ()
3482 #ifdef HAVE_nonlocal_goto
3483 if (! HAVE_nonlocal_goto)
3485 /* First adjust our frame pointer to its actual value. It was
3486 previously set to the start of the virtual area corresponding to
3487 the stacked variables when we branched here and now needs to be
3488 adjusted to the actual hardware fp value.
3490 Assignments are to virtual registers are converted by
3491 instantiate_virtual_regs into the corresponding assignment
3492 to the underlying register (fp in this case) that makes
3493 the original assignment true.
3494 So the following insn will actually be
3495 decrementing fp by STARTING_FRAME_OFFSET. */
3496 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3498 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3499 if (fixed_regs[ARG_POINTER_REGNUM])
3501 #ifdef ELIMINABLE_REGS
3502 /* If the argument pointer can be eliminated in favor of the
3503 frame pointer, we don't need to restore it. We assume here
3504 that if such an elimination is present, it can always be used.
3505 This is the case on all known machines; if we don't make this
3506 assumption, we do unnecessary saving on many machines. */
3507 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3510 for (i = 0; i < ARRAY_SIZE (elim_regs); i++)
3511 if (elim_regs[i].from == ARG_POINTER_REGNUM
3512 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3515 if (i == ARRAY_SIZE (elim_regs))
3518 /* Now restore our arg pointer from the address at which it
3519 was saved in our stack frame.
3520 If there hasn't be space allocated for it yet, make
3522 if (arg_pointer_save_area == 0)
3523 arg_pointer_save_area
3524 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3525 emit_move_insn (virtual_incoming_args_rtx,
3526 /* We need a pseudo here, or else
3527 instantiate_virtual_regs_1 complains. */
3528 copy_to_reg (arg_pointer_save_area));
3533 #ifdef HAVE_nonlocal_goto_receiver
3534 if (HAVE_nonlocal_goto_receiver)
3535 emit_insn (gen_nonlocal_goto_receiver ());
3539 /* Make handlers for nonlocal gotos taking place in the function calls in
3543 expand_nl_goto_receivers (thisblock)
3544 struct nesting *thisblock;
3547 rtx afterward = gen_label_rtx ();
3552 /* Record the handler address in the stack slot for that purpose,
3553 during this block, saving and restoring the outer value. */
3554 if (thisblock->next != 0)
3555 for (slot = nonlocal_goto_handler_slots; slot; slot = XEXP (slot, 1))
3557 rtx save_receiver = gen_reg_rtx (Pmode);
3558 emit_move_insn (XEXP (slot, 0), save_receiver);
3561 emit_move_insn (save_receiver, XEXP (slot, 0));
3562 insns = get_insns ();
3564 emit_insns_before (insns, thisblock->data.block.first_insn);
3567 /* Jump around the handlers; they run only when specially invoked. */
3568 emit_jump (afterward);
3570 /* Make a separate handler for each label. */
3571 link = nonlocal_labels;
3572 slot = nonlocal_goto_handler_slots;
3573 label_list = NULL_RTX;
3574 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3575 /* Skip any labels we shouldn't be able to jump to from here,
3576 we generate one special handler for all of them below which just calls
3578 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3581 lab = expand_nl_handler_label (XEXP (slot, 0),
3582 thisblock->data.block.first_insn);
3583 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3585 expand_nl_goto_receiver ();
3587 /* Jump to the "real" nonlocal label. */
3588 expand_goto (TREE_VALUE (link));
3591 /* A second pass over all nonlocal labels; this time we handle those
3592 we should not be able to jump to at this point. */
3593 link = nonlocal_labels;
3594 slot = nonlocal_goto_handler_slots;
3596 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3597 if (DECL_TOO_LATE (TREE_VALUE (link)))
3600 lab = expand_nl_handler_label (XEXP (slot, 0),
3601 thisblock->data.block.first_insn);
3602 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3608 expand_nl_goto_receiver ();
3609 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "abort"), 0,
3614 nonlocal_goto_handler_labels = label_list;
3615 emit_label (afterward);
3618 /* Warn about any unused VARS (which may contain nodes other than
3619 VAR_DECLs, but such nodes are ignored). The nodes are connected
3620 via the TREE_CHAIN field. */
3623 warn_about_unused_variables (vars)
3628 if (warn_unused_variable)
3629 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3630 if (TREE_CODE (decl) == VAR_DECL
3631 && ! TREE_USED (decl)
3632 && ! DECL_IN_SYSTEM_HEADER (decl)
3633 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
3634 warning_with_decl (decl, "unused variable `%s'");
3637 /* Generate RTL code to terminate a binding contour.
3639 VARS is the chain of VAR_DECL nodes for the variables bound in this
3640 contour. There may actually be other nodes in this chain, but any
3641 nodes other than VAR_DECLS are ignored.
3643 MARK_ENDS is nonzero if we should put a note at the beginning
3644 and end of this binding contour.
3646 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3647 (That is true automatically if the contour has a saved stack level.) */
3650 expand_end_bindings (vars, mark_ends, dont_jump_in)
3655 register struct nesting *thisblock;
3657 while (block_stack->data.block.exception_region)
3659 /* Because we don't need or want a new temporary level and
3660 because we didn't create one in expand_eh_region_start,
3661 create a fake one now to avoid removing one in
3662 expand_end_bindings. */
3665 block_stack->data.block.exception_region = 0;
3667 expand_end_bindings (NULL_TREE, 0, 0);
3670 /* Since expand_eh_region_start does an expand_start_bindings, we
3671 have to first end all the bindings that were created by
3672 expand_eh_region_start. */
3674 thisblock = block_stack;
3676 /* If any of the variables in this scope were not used, warn the
3678 warn_about_unused_variables (vars);
3680 if (thisblock->exit_label)
3682 do_pending_stack_adjust ();
3683 emit_label (thisblock->exit_label);
3686 /* If necessary, make handlers for nonlocal gotos taking
3687 place in the function calls in this block. */
3688 if (function_call_count != thisblock->data.block.n_function_calls
3690 /* Make handler for outermost block
3691 if there were any nonlocal gotos to this function. */
3692 && (thisblock->next == 0 ? current_function_has_nonlocal_label
3693 /* Make handler for inner block if it has something
3694 special to do when you jump out of it. */
3695 : (thisblock->data.block.cleanups != 0
3696 || thisblock->data.block.stack_level != 0)))
3697 expand_nl_goto_receivers (thisblock);
3699 /* Don't allow jumping into a block that has a stack level.
3700 Cleanups are allowed, though. */
3702 || thisblock->data.block.stack_level != 0)
3704 struct label_chain *chain;
3706 /* Any labels in this block are no longer valid to go to.
3707 Mark them to cause an error message. */
3708 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3710 DECL_TOO_LATE (chain->label) = 1;
3711 /* If any goto without a fixup came to this label,
3712 that must be an error, because gotos without fixups
3713 come from outside all saved stack-levels. */
3714 if (TREE_ADDRESSABLE (chain->label))
3715 error_with_decl (chain->label,
3716 "label `%s' used before containing binding contour");
3720 /* Restore stack level in effect before the block
3721 (only if variable-size objects allocated). */
3722 /* Perform any cleanups associated with the block. */
3724 if (thisblock->data.block.stack_level != 0
3725 || thisblock->data.block.cleanups != 0)
3730 /* Don't let cleanups affect ({...}) constructs. */
3731 int old_expr_stmts_for_value = expr_stmts_for_value;
3732 rtx old_last_expr_value = last_expr_value;
3733 tree old_last_expr_type = last_expr_type;
3734 expr_stmts_for_value = 0;
3736 /* Only clean up here if this point can actually be reached. */
3737 insn = get_last_insn ();
3738 if (GET_CODE (insn) == NOTE)
3739 insn = prev_nonnote_insn (insn);
3740 reachable = (! insn || GET_CODE (insn) != BARRIER);
3742 /* Do the cleanups. */
3743 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3745 do_pending_stack_adjust ();
3747 expr_stmts_for_value = old_expr_stmts_for_value;
3748 last_expr_value = old_last_expr_value;
3749 last_expr_type = old_last_expr_type;
3751 /* Restore the stack level. */
3753 if (reachable && thisblock->data.block.stack_level != 0)
3755 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3756 thisblock->data.block.stack_level, NULL_RTX);
3757 if (nonlocal_goto_handler_slots != 0)
3758 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3762 /* Any gotos out of this block must also do these things.
3763 Also report any gotos with fixups that came to labels in this
3765 fixup_gotos (thisblock,
3766 thisblock->data.block.stack_level,
3767 thisblock->data.block.cleanups,
3768 thisblock->data.block.first_insn,
3772 /* Mark the beginning and end of the scope if requested.
3773 We do this now, after running cleanups on the variables
3774 just going out of scope, so they are in scope for their cleanups. */
3778 rtx note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3779 NOTE_BLOCK (note) = NOTE_BLOCK (thisblock->data.block.first_insn);
3782 /* Get rid of the beginning-mark if we don't make an end-mark. */
3783 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3785 /* Restore the temporary level of TARGET_EXPRs. */
3786 target_temp_slot_level = thisblock->data.block.block_target_temp_slot_level;
3788 /* Restore block_stack level for containing block. */
3790 stack_block_stack = thisblock->data.block.innermost_stack_block;
3791 POPSTACK (block_stack);
3793 /* Pop the stack slot nesting and free any slots at this level. */
3797 /* Generate code to save the stack pointer at the start of the current block
3798 and set up to restore it on exit. */
3801 save_stack_pointer ()
3803 struct nesting *thisblock = block_stack;
3805 if (thisblock->data.block.stack_level == 0)
3807 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3808 &thisblock->data.block.stack_level,
3809 thisblock->data.block.first_insn);
3810 stack_block_stack = thisblock;
3814 /* Generate RTL for the automatic variable declaration DECL.
3815 (Other kinds of declarations are simply ignored if seen here.) */
3821 struct nesting *thisblock;
3824 type = TREE_TYPE (decl);
3826 /* Only automatic variables need any expansion done.
3827 Static and external variables, and external functions,
3828 will be handled by `assemble_variable' (called from finish_decl).
3829 TYPE_DECL and CONST_DECL require nothing.
3830 PARM_DECLs are handled in `assign_parms'. */
3832 if (TREE_CODE (decl) != VAR_DECL)
3834 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3837 thisblock = block_stack;
3839 /* Create the RTL representation for the variable. */
3841 if (type == error_mark_node)
3842 SET_DECL_RTL (decl, gen_rtx_MEM (BLKmode, const0_rtx));
3844 else if (DECL_SIZE (decl) == 0)
3845 /* Variable with incomplete type. */
3847 if (DECL_INITIAL (decl) == 0)
3848 /* Error message was already done; now avoid a crash. */
3849 SET_DECL_RTL (decl, gen_rtx_MEM (BLKmode, const0_rtx));
3851 /* An initializer is going to decide the size of this array.
3852 Until we know the size, represent its address with a reg. */
3853 SET_DECL_RTL (decl, gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode)));
3855 set_mem_attributes (DECL_RTL (decl), decl, 1);
3857 else if (DECL_MODE (decl) != BLKmode
3858 /* If -ffloat-store, don't put explicit float vars
3860 && !(flag_float_store
3861 && TREE_CODE (type) == REAL_TYPE)
3862 && ! TREE_THIS_VOLATILE (decl)
3863 && (DECL_REGISTER (decl) || optimize)
3864 /* if -fcheck-memory-usage, check all variables. */
3865 && ! current_function_check_memory_usage)
3867 /* Automatic variable that can go in a register. */
3868 int unsignedp = TREE_UNSIGNED (type);
3869 enum machine_mode reg_mode
3870 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3872 SET_DECL_RTL (decl, gen_reg_rtx (reg_mode));
3873 mark_user_reg (DECL_RTL (decl));
3875 if (POINTER_TYPE_P (type))
3876 mark_reg_pointer (DECL_RTL (decl),
3877 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
3879 maybe_set_unchanging (DECL_RTL (decl), decl);
3881 /* If something wants our address, try to use ADDRESSOF. */
3882 if (TREE_ADDRESSABLE (decl))
3883 put_var_into_stack (decl);
3886 else if (TREE_CODE (DECL_SIZE_UNIT (decl)) == INTEGER_CST
3887 && ! (flag_stack_check && ! STACK_CHECK_BUILTIN
3888 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl),
3889 STACK_CHECK_MAX_VAR_SIZE)))
3891 /* Variable of fixed size that goes on the stack. */
3895 /* If we previously made RTL for this decl, it must be an array
3896 whose size was determined by the initializer.
3897 The old address was a register; set that register now
3898 to the proper address. */
3899 if (DECL_RTL_SET_P (decl))
3901 if (GET_CODE (DECL_RTL (decl)) != MEM
3902 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3904 oldaddr = XEXP (DECL_RTL (decl), 0);
3908 assign_temp (TREE_TYPE (decl), 1, 1, 1));
3910 /* Set alignment we actually gave this decl. */
3911 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3912 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3913 DECL_USER_ALIGN (decl) = 0;
3917 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3918 if (addr != oldaddr)
3919 emit_move_insn (oldaddr, addr);
3923 /* Dynamic-size object: must push space on the stack. */
3927 /* Record the stack pointer on entry to block, if have
3928 not already done so. */
3929 do_pending_stack_adjust ();
3930 save_stack_pointer ();
3932 /* In function-at-a-time mode, variable_size doesn't expand this,
3934 if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
3935 expand_expr (TYPE_MAX_VALUE (TYPE_DOMAIN (type)),
3936 const0_rtx, VOIDmode, 0);
3938 /* Compute the variable's size, in bytes. */
3939 size = expand_expr (DECL_SIZE_UNIT (decl), NULL_RTX, VOIDmode, 0);
3942 /* Allocate space on the stack for the variable. Note that
3943 DECL_ALIGN says how the variable is to be aligned and we
3944 cannot use it to conclude anything about the alignment of
3946 address = allocate_dynamic_stack_space (size, NULL_RTX,
3947 TYPE_ALIGN (TREE_TYPE (decl)));
3949 /* Reference the variable indirect through that rtx. */
3950 SET_DECL_RTL (decl, gen_rtx_MEM (DECL_MODE (decl), address));
3952 set_mem_attributes (DECL_RTL (decl), decl, 1);
3954 /* Indicate the alignment we actually gave this variable. */
3955 #ifdef STACK_BOUNDARY
3956 DECL_ALIGN (decl) = STACK_BOUNDARY;
3958 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3960 DECL_USER_ALIGN (decl) = 0;
3964 /* Emit code to perform the initialization of a declaration DECL. */
3967 expand_decl_init (decl)
3970 int was_used = TREE_USED (decl);
3972 /* If this is a CONST_DECL, we don't have to generate any code, but
3973 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3974 to be set while in the obstack containing the constant. If we don't
3975 do this, we can lose if we have functions nested three deep and the middle
3976 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3977 the innermost function is the first to expand that STRING_CST. */
3978 if (TREE_CODE (decl) == CONST_DECL)
3980 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3981 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3982 EXPAND_INITIALIZER);
3986 if (TREE_STATIC (decl))
3989 /* Compute and store the initial value now. */
3991 if (DECL_INITIAL (decl) == error_mark_node)
3993 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3995 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3996 || code == POINTER_TYPE || code == REFERENCE_TYPE)
3997 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
4001 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
4003 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
4004 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
4008 /* Don't let the initialization count as "using" the variable. */
4009 TREE_USED (decl) = was_used;
4011 /* Free any temporaries we made while initializing the decl. */
4012 preserve_temp_slots (NULL_RTX);
4016 /* CLEANUP is an expression to be executed at exit from this binding contour;
4017 for example, in C++, it might call the destructor for this variable.
4019 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
4020 CLEANUP multiple times, and have the correct semantics. This
4021 happens in exception handling, for gotos, returns, breaks that
4022 leave the current scope.
4024 If CLEANUP is nonzero and DECL is zero, we record a cleanup
4025 that is not associated with any particular variable. */
4028 expand_decl_cleanup (decl, cleanup)
4031 struct nesting *thisblock;
4033 /* Error if we are not in any block. */
4034 if (cfun == 0 || block_stack == 0)
4037 thisblock = block_stack;
4039 /* Record the cleanup if there is one. */
4045 tree *cleanups = &thisblock->data.block.cleanups;
4046 int cond_context = conditional_context ();
4050 rtx flag = gen_reg_rtx (word_mode);
4055 emit_move_insn (flag, const0_rtx);
4056 set_flag_0 = get_insns ();
4059 thisblock->data.block.last_unconditional_cleanup
4060 = emit_insns_after (set_flag_0,
4061 thisblock->data.block.last_unconditional_cleanup);
4063 emit_move_insn (flag, const1_rtx);
4065 cond = build_decl (VAR_DECL, NULL_TREE, type_for_mode (word_mode, 1));
4066 SET_DECL_RTL (cond, flag);
4068 /* Conditionalize the cleanup. */
4069 cleanup = build (COND_EXPR, void_type_node,
4070 truthvalue_conversion (cond),
4071 cleanup, integer_zero_node);
4072 cleanup = fold (cleanup);
4074 cleanups = thisblock->data.block.cleanup_ptr;
4077 cleanup = unsave_expr (cleanup);
4079 t = *cleanups = tree_cons (decl, cleanup, *cleanups);
4082 /* If this block has a cleanup, it belongs in stack_block_stack. */
4083 stack_block_stack = thisblock;
4090 /* If this was optimized so that there is no exception region for the
4091 cleanup, then mark the TREE_LIST node, so that we can later tell
4092 if we need to call expand_eh_region_end. */
4093 if (! using_eh_for_cleanups_p
4094 || expand_eh_region_start_tree (decl, cleanup))
4095 TREE_ADDRESSABLE (t) = 1;
4096 /* If that started a new EH region, we're in a new block. */
4097 thisblock = block_stack;
4104 thisblock->data.block.last_unconditional_cleanup
4105 = emit_insns_after (seq,
4106 thisblock->data.block.last_unconditional_cleanup);
4110 thisblock->data.block.last_unconditional_cleanup
4112 /* When we insert instructions after the last unconditional cleanup,
4113 we don't adjust last_insn. That means that a later add_insn will
4114 clobber the instructions we've just added. The easiest way to
4115 fix this is to just insert another instruction here, so that the
4116 instructions inserted after the last unconditional cleanup are
4117 never the last instruction. */
4118 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4119 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
4125 /* Like expand_decl_cleanup, but suppress generating an exception handler
4126 to perform the cleanup. */
4130 expand_decl_cleanup_no_eh (decl, cleanup)
4133 int save_eh = using_eh_for_cleanups_p;
4136 using_eh_for_cleanups_p = 0;
4137 result = expand_decl_cleanup (decl, cleanup);
4138 using_eh_for_cleanups_p = save_eh;
4144 /* Arrange for the top element of the dynamic cleanup chain to be
4145 popped if we exit the current binding contour. DECL is the
4146 associated declaration, if any, otherwise NULL_TREE. If the
4147 current contour is left via an exception, then __sjthrow will pop
4148 the top element off the dynamic cleanup chain. The code that
4149 avoids doing the action we push into the cleanup chain in the
4150 exceptional case is contained in expand_cleanups.
4152 This routine is only used by expand_eh_region_start, and that is
4153 the only way in which an exception region should be started. This
4154 routine is only used when using the setjmp/longjmp codegen method
4155 for exception handling. */
4158 expand_dcc_cleanup (decl)
4161 struct nesting *thisblock;
4164 /* Error if we are not in any block. */
4165 if (cfun == 0 || block_stack == 0)
4167 thisblock = block_stack;
4169 /* Record the cleanup for the dynamic handler chain. */
4171 cleanup = make_node (POPDCC_EXPR);
4173 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4174 thisblock->data.block.cleanups
4175 = tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4177 /* If this block has a cleanup, it belongs in stack_block_stack. */
4178 stack_block_stack = thisblock;
4182 /* Arrange for the top element of the dynamic handler chain to be
4183 popped if we exit the current binding contour. DECL is the
4184 associated declaration, if any, otherwise NULL_TREE. If the current
4185 contour is left via an exception, then __sjthrow will pop the top
4186 element off the dynamic handler chain. The code that avoids doing
4187 the action we push into the handler chain in the exceptional case
4188 is contained in expand_cleanups.
4190 This routine is only used by expand_eh_region_start, and that is
4191 the only way in which an exception region should be started. This
4192 routine is only used when using the setjmp/longjmp codegen method
4193 for exception handling. */
4196 expand_dhc_cleanup (decl)
4199 struct nesting *thisblock;
4202 /* Error if we are not in any block. */
4203 if (cfun == 0 || block_stack == 0)
4205 thisblock = block_stack;
4207 /* Record the cleanup for the dynamic handler chain. */
4209 cleanup = make_node (POPDHC_EXPR);
4211 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4212 thisblock->data.block.cleanups
4213 = tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4215 /* If this block has a cleanup, it belongs in stack_block_stack. */
4216 stack_block_stack = thisblock;
4220 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4221 DECL_ELTS is the list of elements that belong to DECL's type.
4222 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4225 expand_anon_union_decl (decl, cleanup, decl_elts)
4226 tree decl, cleanup, decl_elts;
4228 struct nesting *thisblock = cfun == 0 ? 0 : block_stack;
4232 /* If any of the elements are addressable, so is the entire union. */
4233 for (t = decl_elts; t; t = TREE_CHAIN (t))
4234 if (TREE_ADDRESSABLE (TREE_VALUE (t)))
4236 TREE_ADDRESSABLE (decl) = 1;
4241 expand_decl_cleanup (decl, cleanup);
4242 x = DECL_RTL (decl);
4244 /* Go through the elements, assigning RTL to each. */
4245 for (t = decl_elts; t; t = TREE_CHAIN (t))
4247 tree decl_elt = TREE_VALUE (t);
4248 tree cleanup_elt = TREE_PURPOSE (t);
4249 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
4251 /* Propagate the union's alignment to the elements. */
4252 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
4253 DECL_USER_ALIGN (decl_elt) = DECL_USER_ALIGN (decl);
4255 /* If the element has BLKmode and the union doesn't, the union is
4256 aligned such that the element doesn't need to have BLKmode, so
4257 change the element's mode to the appropriate one for its size. */
4258 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
4259 DECL_MODE (decl_elt) = mode
4260 = mode_for_size_tree (DECL_SIZE (decl_elt), MODE_INT, 1);
4262 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4263 instead create a new MEM rtx with the proper mode. */
4264 if (GET_CODE (x) == MEM)
4266 if (mode == GET_MODE (x))
4267 SET_DECL_RTL (decl_elt, x);
4270 SET_DECL_RTL (decl_elt,
4271 gen_rtx_MEM (mode, copy_rtx (XEXP (x, 0))));
4272 MEM_COPY_ATTRIBUTES (DECL_RTL (decl_elt), x);
4275 else if (GET_CODE (x) == REG)
4277 if (mode == GET_MODE (x))
4278 SET_DECL_RTL (decl_elt, x);
4280 SET_DECL_RTL (decl_elt, gen_rtx_SUBREG (mode, x, 0));
4285 /* Record the cleanup if there is one. */
4288 thisblock->data.block.cleanups
4289 = tree_cons (decl_elt, cleanup_elt,
4290 thisblock->data.block.cleanups);
4294 /* Expand a list of cleanups LIST.
4295 Elements may be expressions or may be nested lists.
4297 If DONT_DO is nonnull, then any list-element
4298 whose TREE_PURPOSE matches DONT_DO is omitted.
4299 This is sometimes used to avoid a cleanup associated with
4300 a value that is being returned out of the scope.
4302 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
4303 goto and handle protection regions specially in that case.
4305 If REACHABLE, we emit code, otherwise just inform the exception handling
4306 code about this finalization. */
4309 expand_cleanups (list, dont_do, in_fixup, reachable)
4316 for (tail = list; tail; tail = TREE_CHAIN (tail))
4317 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
4319 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
4320 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
4325 tree cleanup = TREE_VALUE (tail);
4327 /* See expand_d{h,c}c_cleanup for why we avoid this. */
4328 if (TREE_CODE (cleanup) != POPDHC_EXPR
4329 && TREE_CODE (cleanup) != POPDCC_EXPR
4330 /* See expand_eh_region_start_tree for this case. */
4331 && ! TREE_ADDRESSABLE (tail))
4333 cleanup = protect_with_terminate (cleanup);
4334 expand_eh_region_end (cleanup);
4340 /* Cleanups may be run multiple times. For example,
4341 when exiting a binding contour, we expand the
4342 cleanups associated with that contour. When a goto
4343 within that binding contour has a target outside that
4344 contour, it will expand all cleanups from its scope to
4345 the target. Though the cleanups are expanded multiple
4346 times, the control paths are non-overlapping so the
4347 cleanups will not be executed twice. */
4349 /* We may need to protect fixups with rethrow regions. */
4350 int protect = (in_fixup && ! TREE_ADDRESSABLE (tail));
4353 expand_fixup_region_start ();
4355 /* The cleanup might contain try-blocks, so we have to
4356 preserve our current queue. */
4358 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
4361 expand_fixup_region_end (TREE_VALUE (tail));
4368 /* Mark when the context we are emitting RTL for as a conditional
4369 context, so that any cleanup actions we register with
4370 expand_decl_init will be properly conditionalized when those
4371 cleanup actions are later performed. Must be called before any
4372 expression (tree) is expanded that is within a conditional context. */
4375 start_cleanup_deferral ()
4377 /* block_stack can be NULL if we are inside the parameter list. It is
4378 OK to do nothing, because cleanups aren't possible here. */
4380 ++block_stack->data.block.conditional_code;
4383 /* Mark the end of a conditional region of code. Because cleanup
4384 deferrals may be nested, we may still be in a conditional region
4385 after we end the currently deferred cleanups, only after we end all
4386 deferred cleanups, are we back in unconditional code. */
4389 end_cleanup_deferral ()
4391 /* block_stack can be NULL if we are inside the parameter list. It is
4392 OK to do nothing, because cleanups aren't possible here. */
4394 --block_stack->data.block.conditional_code;
4397 /* Move all cleanups from the current block_stack
4398 to the containing block_stack, where they are assumed to
4399 have been created. If anything can cause a temporary to
4400 be created, but not expanded for more than one level of
4401 block_stacks, then this code will have to change. */
4406 struct nesting *block = block_stack;
4407 struct nesting *outer = block->next;
4409 outer->data.block.cleanups
4410 = chainon (block->data.block.cleanups,
4411 outer->data.block.cleanups);
4412 block->data.block.cleanups = 0;
4416 last_cleanup_this_contour ()
4418 if (block_stack == 0)
4421 return block_stack->data.block.cleanups;
4424 /* Return 1 if there are any pending cleanups at this point.
4425 If THIS_CONTOUR is nonzero, check the current contour as well.
4426 Otherwise, look only at the contours that enclose this one. */
4429 any_pending_cleanups (this_contour)
4432 struct nesting *block;
4434 if (cfun == NULL || cfun->stmt == NULL || block_stack == 0)
4437 if (this_contour && block_stack->data.block.cleanups != NULL)
4439 if (block_stack->data.block.cleanups == 0
4440 && block_stack->data.block.outer_cleanups == 0)
4443 for (block = block_stack->next; block; block = block->next)
4444 if (block->data.block.cleanups != 0)
4450 /* Enter a case (Pascal) or switch (C) statement.
4451 Push a block onto case_stack and nesting_stack
4452 to accumulate the case-labels that are seen
4453 and to record the labels generated for the statement.
4455 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4456 Otherwise, this construct is transparent for `exit_something'.
4458 EXPR is the index-expression to be dispatched on.
4459 TYPE is its nominal type. We could simply convert EXPR to this type,
4460 but instead we take short cuts. */
4463 expand_start_case (exit_flag, expr, type, printname)
4467 const char *printname;
4469 register struct nesting *thiscase = ALLOC_NESTING ();
4471 /* Make an entry on case_stack for the case we are entering. */
4473 thiscase->next = case_stack;
4474 thiscase->all = nesting_stack;
4475 thiscase->depth = ++nesting_depth;
4476 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
4477 thiscase->data.case_stmt.case_list = 0;
4478 thiscase->data.case_stmt.index_expr = expr;
4479 thiscase->data.case_stmt.nominal_type = type;
4480 thiscase->data.case_stmt.default_label = 0;
4481 thiscase->data.case_stmt.printname = printname;
4482 thiscase->data.case_stmt.line_number_status = force_line_numbers ();
4483 case_stack = thiscase;
4484 nesting_stack = thiscase;
4486 do_pending_stack_adjust ();
4488 /* Make sure case_stmt.start points to something that won't
4489 need any transformation before expand_end_case. */
4490 if (GET_CODE (get_last_insn ()) != NOTE)
4491 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4493 thiscase->data.case_stmt.start = get_last_insn ();
4495 start_cleanup_deferral ();
4498 /* Start a "dummy case statement" within which case labels are invalid
4499 and are not connected to any larger real case statement.
4500 This can be used if you don't want to let a case statement jump
4501 into the middle of certain kinds of constructs. */
4504 expand_start_case_dummy ()
4506 register struct nesting *thiscase = ALLOC_NESTING ();
4508 /* Make an entry on case_stack for the dummy. */
4510 thiscase->next = case_stack;
4511 thiscase->all = nesting_stack;
4512 thiscase->depth = ++nesting_depth;
4513 thiscase->exit_label = 0;
4514 thiscase->data.case_stmt.case_list = 0;
4515 thiscase->data.case_stmt.start = 0;
4516 thiscase->data.case_stmt.nominal_type = 0;
4517 thiscase->data.case_stmt.default_label = 0;
4518 case_stack = thiscase;
4519 nesting_stack = thiscase;
4520 start_cleanup_deferral ();
4523 /* End a dummy case statement. */
4526 expand_end_case_dummy ()
4528 end_cleanup_deferral ();
4529 POPSTACK (case_stack);
4532 /* Return the data type of the index-expression
4533 of the innermost case statement, or null if none. */
4536 case_index_expr_type ()
4539 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
4546 /* If this is the first label, warn if any insns have been emitted. */
4547 if (case_stack->data.case_stmt.line_number_status >= 0)
4551 restore_line_number_status
4552 (case_stack->data.case_stmt.line_number_status);
4553 case_stack->data.case_stmt.line_number_status = -1;
4555 for (insn = case_stack->data.case_stmt.start;
4557 insn = NEXT_INSN (insn))
4559 if (GET_CODE (insn) == CODE_LABEL)
4561 if (GET_CODE (insn) != NOTE
4562 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4565 insn = PREV_INSN (insn);
4566 while (insn && (GET_CODE (insn) != NOTE || NOTE_LINE_NUMBER (insn) < 0));
4568 /* If insn is zero, then there must have been a syntax error. */
4570 warning_with_file_and_line (NOTE_SOURCE_FILE (insn),
4571 NOTE_LINE_NUMBER (insn),
4572 "unreachable code at beginning of %s",
4573 case_stack->data.case_stmt.printname);
4580 /* Accumulate one case or default label inside a case or switch statement.
4581 VALUE is the value of the case (a null pointer, for a default label).
4582 The function CONVERTER, when applied to arguments T and V,
4583 converts the value V to the type T.
4585 If not currently inside a case or switch statement, return 1 and do
4586 nothing. The caller will print a language-specific error message.
4587 If VALUE is a duplicate or overlaps, return 2 and do nothing
4588 except store the (first) duplicate node in *DUPLICATE.
4589 If VALUE is out of range, return 3 and do nothing.
4590 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4591 Return 0 on success.
4593 Extended to handle range statements. */
4596 pushcase (value, converter, label, duplicate)
4597 register tree value;
4598 tree (*converter) PARAMS ((tree, tree));
4599 register tree label;
4605 /* Fail if not inside a real case statement. */
4606 if (! (case_stack && case_stack->data.case_stmt.start))
4609 if (stack_block_stack
4610 && stack_block_stack->depth > case_stack->depth)
4613 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4614 nominal_type = case_stack->data.case_stmt.nominal_type;
4616 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4617 if (index_type == error_mark_node)
4620 /* Convert VALUE to the type in which the comparisons are nominally done. */
4622 value = (*converter) (nominal_type, value);
4626 /* Fail if this value is out of range for the actual type of the index
4627 (which may be narrower than NOMINAL_TYPE). */
4629 && (TREE_CONSTANT_OVERFLOW (value)
4630 || ! int_fits_type_p (value, index_type)))
4633 return add_case_node (value, value, label, duplicate);
4636 /* Like pushcase but this case applies to all values between VALUE1 and
4637 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4638 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4639 starts at VALUE1 and ends at the highest value of the index type.
4640 If both are NULL, this case applies to all values.
4642 The return value is the same as that of pushcase but there is one
4643 additional error code: 4 means the specified range was empty. */
4646 pushcase_range (value1, value2, converter, label, duplicate)
4647 register tree value1, value2;
4648 tree (*converter) PARAMS ((tree, tree));
4649 register tree label;
4655 /* Fail if not inside a real case statement. */
4656 if (! (case_stack && case_stack->data.case_stmt.start))
4659 if (stack_block_stack
4660 && stack_block_stack->depth > case_stack->depth)
4663 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4664 nominal_type = case_stack->data.case_stmt.nominal_type;
4666 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4667 if (index_type == error_mark_node)
4672 /* Convert VALUEs to type in which the comparisons are nominally done
4673 and replace any unspecified value with the corresponding bound. */
4675 value1 = TYPE_MIN_VALUE (index_type);
4677 value2 = TYPE_MAX_VALUE (index_type);
4679 /* Fail if the range is empty. Do this before any conversion since
4680 we want to allow out-of-range empty ranges. */
4681 if (value2 != 0 && tree_int_cst_lt (value2, value1))
4684 /* If the max was unbounded, use the max of the nominal_type we are
4685 converting to. Do this after the < check above to suppress false
4688 value2 = TYPE_MAX_VALUE (nominal_type);
4690 value1 = (*converter) (nominal_type, value1);
4691 value2 = (*converter) (nominal_type, value2);
4693 /* Fail if these values are out of range. */
4694 if (TREE_CONSTANT_OVERFLOW (value1)
4695 || ! int_fits_type_p (value1, index_type))
4698 if (TREE_CONSTANT_OVERFLOW (value2)
4699 || ! int_fits_type_p (value2, index_type))
4702 return add_case_node (value1, value2, label, duplicate);
4705 /* Do the actual insertion of a case label for pushcase and pushcase_range
4706 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4707 slowdown for large switch statements. */
4710 add_case_node (low, high, label, duplicate)
4715 struct case_node *p, **q, *r;
4717 /* If there's no HIGH value, then this is not a case range; it's
4718 just a simple case label. But that's just a degenerate case
4723 /* Handle default labels specially. */
4726 if (case_stack->data.case_stmt.default_label != 0)
4728 *duplicate = case_stack->data.case_stmt.default_label;
4731 case_stack->data.case_stmt.default_label = label;
4732 expand_label (label);
4736 q = &case_stack->data.case_stmt.case_list;
4743 /* Keep going past elements distinctly greater than HIGH. */
4744 if (tree_int_cst_lt (high, p->low))
4747 /* or distinctly less than LOW. */
4748 else if (tree_int_cst_lt (p->high, low))
4753 /* We have an overlap; this is an error. */
4754 *duplicate = p->code_label;
4759 /* Add this label to the chain, and succeed. */
4761 r = (struct case_node *) xmalloc (sizeof (struct case_node));
4764 /* If the bounds are equal, turn this into the one-value case. */
4765 if (tree_int_cst_equal (low, high))
4770 r->code_label = label;
4771 expand_label (label);
4781 struct case_node *s;
4787 if (! (b = p->balance))
4788 /* Growth propagation from left side. */
4795 if ((p->left = s = r->right))
4804 if ((r->parent = s))
4812 case_stack->data.case_stmt.case_list = r;
4815 /* r->balance == +1 */
4820 struct case_node *t = r->right;
4822 if ((p->left = s = t->right))
4826 if ((r->right = s = t->left))
4840 if ((t->parent = s))
4848 case_stack->data.case_stmt.case_list = t;
4855 /* p->balance == +1; growth of left side balances the node. */
4865 if (! (b = p->balance))
4866 /* Growth propagation from right side. */
4874 if ((p->right = s = r->left))
4882 if ((r->parent = s))
4891 case_stack->data.case_stmt.case_list = r;
4895 /* r->balance == -1 */
4899 struct case_node *t = r->left;
4901 if ((p->right = s = t->left))
4906 if ((r->left = s = t->right))
4920 if ((t->parent = s))
4929 case_stack->data.case_stmt.case_list = t;
4935 /* p->balance == -1; growth of right side balances the node. */
4948 /* Returns the number of possible values of TYPE.
4949 Returns -1 if the number is unknown, variable, or if the number does not
4950 fit in a HOST_WIDE_INT.
4951 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4952 do not increase monotonically (there may be duplicates);
4953 to 1 if the values increase monotonically, but not always by 1;
4954 otherwise sets it to 0. */
4957 all_cases_count (type, spareness)
4962 HOST_WIDE_INT count, minval, lastval;
4966 switch (TREE_CODE (type))
4973 count = 1 << BITS_PER_UNIT;
4978 if (TYPE_MAX_VALUE (type) != 0
4979 && 0 != (t = fold (build (MINUS_EXPR, type, TYPE_MAX_VALUE (type),
4980 TYPE_MIN_VALUE (type))))
4981 && 0 != (t = fold (build (PLUS_EXPR, type, t,
4982 convert (type, integer_zero_node))))
4983 && host_integerp (t, 1))
4984 count = tree_low_cst (t, 1);
4990 /* Don't waste time with enumeral types with huge values. */
4991 if (! host_integerp (TYPE_MIN_VALUE (type), 0)
4992 || TYPE_MAX_VALUE (type) == 0
4993 || ! host_integerp (TYPE_MAX_VALUE (type), 0))
4996 lastval = minval = tree_low_cst (TYPE_MIN_VALUE (type), 0);
4999 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
5001 HOST_WIDE_INT thisval = tree_low_cst (TREE_VALUE (t), 0);
5003 if (*spareness == 2 || thisval < lastval)
5005 else if (thisval != minval + count)
5015 #define BITARRAY_TEST(ARRAY, INDEX) \
5016 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
5017 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
5018 #define BITARRAY_SET(ARRAY, INDEX) \
5019 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
5020 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
5022 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
5023 with the case values we have seen, assuming the case expression
5025 SPARSENESS is as determined by all_cases_count.
5027 The time needed is proportional to COUNT, unless
5028 SPARSENESS is 2, in which case quadratic time is needed. */
5031 mark_seen_cases (type, cases_seen, count, sparseness)
5033 unsigned char *cases_seen;
5034 HOST_WIDE_INT count;
5037 tree next_node_to_try = NULL_TREE;
5038 HOST_WIDE_INT next_node_offset = 0;
5040 register struct case_node *n, *root = case_stack->data.case_stmt.case_list;
5041 tree val = make_node (INTEGER_CST);
5043 TREE_TYPE (val) = type;
5047 else if (sparseness == 2)
5050 unsigned HOST_WIDE_INT xlo;
5052 /* This less efficient loop is only needed to handle
5053 duplicate case values (multiple enum constants
5054 with the same value). */
5055 TREE_TYPE (val) = TREE_TYPE (root->low);
5056 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
5057 t = TREE_CHAIN (t), xlo++)
5059 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (TREE_VALUE (t));
5060 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (TREE_VALUE (t));
5064 /* Keep going past elements distinctly greater than VAL. */
5065 if (tree_int_cst_lt (val, n->low))
5068 /* or distinctly less than VAL. */
5069 else if (tree_int_cst_lt (n->high, val))
5074 /* We have found a matching range. */
5075 BITARRAY_SET (cases_seen, xlo);
5085 case_stack->data.case_stmt.case_list = root = case_tree2list (root, 0);
5087 for (n = root; n; n = n->right)
5089 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
5090 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
5091 while (! tree_int_cst_lt (n->high, val))
5093 /* Calculate (into xlo) the "offset" of the integer (val).
5094 The element with lowest value has offset 0, the next smallest
5095 element has offset 1, etc. */
5097 unsigned HOST_WIDE_INT xlo;
5101 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
5103 /* The TYPE_VALUES will be in increasing order, so
5104 starting searching where we last ended. */
5105 t = next_node_to_try;
5106 xlo = next_node_offset;
5112 t = TYPE_VALUES (type);
5115 if (tree_int_cst_equal (val, TREE_VALUE (t)))
5117 next_node_to_try = TREE_CHAIN (t);
5118 next_node_offset = xlo + 1;
5123 if (t == next_node_to_try)
5132 t = TYPE_MIN_VALUE (type);
5134 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
5138 add_double (xlo, xhi,
5139 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5143 if (xhi == 0 && xlo < (unsigned HOST_WIDE_INT) count)
5144 BITARRAY_SET (cases_seen, xlo);
5146 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5148 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
5154 /* Called when the index of a switch statement is an enumerated type
5155 and there is no default label.
5157 Checks that all enumeration literals are covered by the case
5158 expressions of a switch. Also, warn if there are any extra
5159 switch cases that are *not* elements of the enumerated type.
5161 If all enumeration literals were covered by the case expressions,
5162 turn one of the expressions into the default expression since it should
5163 not be possible to fall through such a switch. */
5166 check_for_full_enumeration_handling (type)
5169 register struct case_node *n;
5170 register tree chain;
5171 #if 0 /* variable used by 'if 0'ed code below. */
5172 register struct case_node **l;
5176 /* True iff the selector type is a numbered set mode. */
5179 /* The number of possible selector values. */
5182 /* For each possible selector value. a one iff it has been matched
5183 by a case value alternative. */
5184 unsigned char *cases_seen;
5186 /* The allocated size of cases_seen, in chars. */
5187 HOST_WIDE_INT bytes_needed;
5192 size = all_cases_count (type, &sparseness);
5193 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
5195 if (size > 0 && size < 600000
5196 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5197 this optimization if we don't have enough memory rather than
5198 aborting, as xmalloc would do. */
5200 (unsigned char *) really_call_calloc (bytes_needed, 1)) != NULL)
5203 tree v = TYPE_VALUES (type);
5205 /* The time complexity of this code is normally O(N), where
5206 N being the number of members in the enumerated type.
5207 However, if type is a ENUMERAL_TYPE whose values do not
5208 increase monotonically, O(N*log(N)) time may be needed. */
5210 mark_seen_cases (type, cases_seen, size, sparseness);
5212 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
5213 if (BITARRAY_TEST (cases_seen, i) == 0)
5214 warning ("enumeration value `%s' not handled in switch",
5215 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
5220 /* Now we go the other way around; we warn if there are case
5221 expressions that don't correspond to enumerators. This can
5222 occur since C and C++ don't enforce type-checking of
5223 assignments to enumeration variables. */
5225 if (case_stack->data.case_stmt.case_list
5226 && case_stack->data.case_stmt.case_list->left)
5227 case_stack->data.case_stmt.case_list
5228 = case_tree2list (case_stack->data.case_stmt.case_list, 0);
5230 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
5232 for (chain = TYPE_VALUES (type);
5233 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
5234 chain = TREE_CHAIN (chain))
5239 if (TYPE_NAME (type) == 0)
5240 warning ("case value `%ld' not in enumerated type",
5241 (long) TREE_INT_CST_LOW (n->low));
5243 warning ("case value `%ld' not in enumerated type `%s'",
5244 (long) TREE_INT_CST_LOW (n->low),
5245 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5248 : DECL_NAME (TYPE_NAME (type))));
5250 if (!tree_int_cst_equal (n->low, n->high))
5252 for (chain = TYPE_VALUES (type);
5253 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
5254 chain = TREE_CHAIN (chain))
5259 if (TYPE_NAME (type) == 0)
5260 warning ("case value `%ld' not in enumerated type",
5261 (long) TREE_INT_CST_LOW (n->high));
5263 warning ("case value `%ld' not in enumerated type `%s'",
5264 (long) TREE_INT_CST_LOW (n->high),
5265 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5268 : DECL_NAME (TYPE_NAME (type))));
5274 /* ??? This optimization is disabled because it causes valid programs to
5275 fail. ANSI C does not guarantee that an expression with enum type
5276 will have a value that is the same as one of the enumeration literals. */
5278 /* If all values were found as case labels, make one of them the default
5279 label. Thus, this switch will never fall through. We arbitrarily pick
5280 the last one to make the default since this is likely the most
5281 efficient choice. */
5285 for (l = &case_stack->data.case_stmt.case_list;
5290 case_stack->data.case_stmt.default_label = (*l)->code_label;
5296 /* Free CN, and its children. */
5299 free_case_nodes (cn)
5304 free_case_nodes (cn->left);
5305 free_case_nodes (cn->right);
5311 /* Terminate a case (Pascal) or switch (C) statement
5312 in which ORIG_INDEX is the expression to be tested.
5313 Generate the code to test it and jump to the right place. */
5316 expand_end_case (orig_index)
5319 tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE, orig_minval;
5320 rtx default_label = 0;
5321 register struct case_node *n;
5329 register struct nesting *thiscase = case_stack;
5330 tree index_expr, index_type;
5333 /* Don't crash due to previous errors. */
5334 if (thiscase == NULL)
5337 table_label = gen_label_rtx ();
5338 index_expr = thiscase->data.case_stmt.index_expr;
5339 index_type = TREE_TYPE (index_expr);
5340 unsignedp = TREE_UNSIGNED (index_type);
5342 do_pending_stack_adjust ();
5344 /* This might get an spurious warning in the presence of a syntax error;
5345 it could be fixed by moving the call to check_seenlabel after the
5346 check for error_mark_node, and copying the code of check_seenlabel that
5347 deals with case_stack->data.case_stmt.line_number_status /
5348 restore_line_number_status in front of the call to end_cleanup_deferral;
5349 However, this might miss some useful warnings in the presence of
5350 non-syntax errors. */
5353 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5354 if (index_type != error_mark_node)
5356 /* If switch expression was an enumerated type, check that all
5357 enumeration literals are covered by the cases.
5358 No sense trying this if there's a default case, however. */
5360 if (!thiscase->data.case_stmt.default_label
5361 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
5362 && TREE_CODE (index_expr) != INTEGER_CST)
5363 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
5365 /* If we don't have a default-label, create one here,
5366 after the body of the switch. */
5367 if (thiscase->data.case_stmt.default_label == 0)
5369 thiscase->data.case_stmt.default_label
5370 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5371 expand_label (thiscase->data.case_stmt.default_label);
5373 default_label = label_rtx (thiscase->data.case_stmt.default_label);
5375 before_case = get_last_insn ();
5377 if (thiscase->data.case_stmt.case_list
5378 && thiscase->data.case_stmt.case_list->left)
5379 thiscase->data.case_stmt.case_list
5380 = case_tree2list (thiscase->data.case_stmt.case_list, 0);
5382 /* Simplify the case-list before we count it. */
5383 group_case_nodes (thiscase->data.case_stmt.case_list);
5385 /* Get upper and lower bounds of case values.
5386 Also convert all the case values to the index expr's data type. */
5389 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5391 /* Check low and high label values are integers. */
5392 if (TREE_CODE (n->low) != INTEGER_CST)
5394 if (TREE_CODE (n->high) != INTEGER_CST)
5397 n->low = convert (index_type, n->low);
5398 n->high = convert (index_type, n->high);
5400 /* Count the elements and track the largest and smallest
5401 of them (treating them as signed even if they are not). */
5409 if (INT_CST_LT (n->low, minval))
5411 if (INT_CST_LT (maxval, n->high))
5414 /* A range counts double, since it requires two compares. */
5415 if (! tree_int_cst_equal (n->low, n->high))
5419 orig_minval = minval;
5421 /* Compute span of values. */
5423 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
5425 end_cleanup_deferral ();
5429 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
5431 emit_jump (default_label);
5434 /* If range of values is much bigger than number of values,
5435 make a sequence of conditional branches instead of a dispatch.
5436 If the switch-index is a constant, do it this way
5437 because we can optimize it. */
5439 #ifndef CASE_VALUES_THRESHOLD
5441 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
5443 /* If machine does not have a case insn that compares the
5444 bounds, this means extra overhead for dispatch tables
5445 which raises the threshold for using them. */
5446 #define CASE_VALUES_THRESHOLD 5
5447 #endif /* HAVE_casesi */
5448 #endif /* CASE_VALUES_THRESHOLD */
5450 else if (count < CASE_VALUES_THRESHOLD
5451 || compare_tree_int (range, 10 * count) > 0
5452 /* RANGE may be signed, and really large ranges will show up
5453 as negative numbers. */
5454 || compare_tree_int (range, 0) < 0
5455 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5458 || TREE_CODE (index_expr) == INTEGER_CST
5459 /* These will reduce to a constant. */
5460 || (TREE_CODE (index_expr) == CALL_EXPR
5461 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
5462 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
5463 && DECL_BUILT_IN_CLASS (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_NORMAL
5464 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
5465 || (TREE_CODE (index_expr) == COMPOUND_EXPR
5466 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
5468 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5470 /* If the index is a short or char that we do not have
5471 an insn to handle comparisons directly, convert it to
5472 a full integer now, rather than letting each comparison
5473 generate the conversion. */
5475 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
5476 && (cmp_optab->handlers[(int) GET_MODE (index)].insn_code
5477 == CODE_FOR_nothing))
5479 enum machine_mode wider_mode;
5480 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
5481 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
5482 if (cmp_optab->handlers[(int) wider_mode].insn_code
5483 != CODE_FOR_nothing)
5485 index = convert_to_mode (wider_mode, index, unsignedp);
5491 do_pending_stack_adjust ();
5493 index = protect_from_queue (index, 0);
5494 if (GET_CODE (index) == MEM)
5495 index = copy_to_reg (index);
5496 if (GET_CODE (index) == CONST_INT
5497 || TREE_CODE (index_expr) == INTEGER_CST)
5499 /* Make a tree node with the proper constant value
5500 if we don't already have one. */
5501 if (TREE_CODE (index_expr) != INTEGER_CST)
5504 = build_int_2 (INTVAL (index),
5505 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
5506 index_expr = convert (index_type, index_expr);
5509 /* For constant index expressions we need only
5510 issue a unconditional branch to the appropriate
5511 target code. The job of removing any unreachable
5512 code is left to the optimisation phase if the
5513 "-O" option is specified. */
5514 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5515 if (! tree_int_cst_lt (index_expr, n->low)
5516 && ! tree_int_cst_lt (n->high, index_expr))
5520 emit_jump (label_rtx (n->code_label));
5522 emit_jump (default_label);
5526 /* If the index expression is not constant we generate
5527 a binary decision tree to select the appropriate
5528 target code. This is done as follows:
5530 The list of cases is rearranged into a binary tree,
5531 nearly optimal assuming equal probability for each case.
5533 The tree is transformed into RTL, eliminating
5534 redundant test conditions at the same time.
5536 If program flow could reach the end of the
5537 decision tree an unconditional jump to the
5538 default code is emitted. */
5541 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
5542 && estimate_case_costs (thiscase->data.case_stmt.case_list));
5543 balance_case_nodes (&thiscase->data.case_stmt.case_list,
5545 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
5546 default_label, index_type);
5547 emit_jump_if_reachable (default_label);
5556 enum machine_mode index_mode = SImode;
5557 int index_bits = GET_MODE_BITSIZE (index_mode);
5559 enum machine_mode op_mode;
5561 /* Convert the index to SImode. */
5562 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
5563 > GET_MODE_BITSIZE (index_mode))
5565 enum machine_mode omode = TYPE_MODE (index_type);
5566 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
5568 /* We must handle the endpoints in the original mode. */
5569 index_expr = build (MINUS_EXPR, index_type,
5570 index_expr, minval);
5571 minval = integer_zero_node;
5572 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5573 emit_cmp_and_jump_insns (rangertx, index, LTU, NULL_RTX,
5574 omode, 1, 0, default_label);
5575 /* Now we can safely truncate. */
5576 index = convert_to_mode (index_mode, index, 0);
5580 if (TYPE_MODE (index_type) != index_mode)
5582 index_expr = convert (type_for_size (index_bits, 0),
5584 index_type = TREE_TYPE (index_expr);
5587 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5590 index = protect_from_queue (index, 0);
5591 do_pending_stack_adjust ();
5593 op_mode = insn_data[(int) CODE_FOR_casesi].operand[0].mode;
5594 if (! (*insn_data[(int) CODE_FOR_casesi].operand[0].predicate)
5596 index = copy_to_mode_reg (op_mode, index);
5598 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
5600 op_mode = insn_data[(int) CODE_FOR_casesi].operand[1].mode;
5601 if (! (*insn_data[(int) CODE_FOR_casesi].operand[1].predicate)
5603 op1 = copy_to_mode_reg (op_mode, op1);
5605 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
5607 op_mode = insn_data[(int) CODE_FOR_casesi].operand[2].mode;
5608 if (! (*insn_data[(int) CODE_FOR_casesi].operand[2].predicate)
5610 op2 = copy_to_mode_reg (op_mode, op2);
5612 emit_jump_insn (gen_casesi (index, op1, op2,
5613 table_label, default_label));
5617 #ifdef HAVE_tablejump
5618 if (! win && HAVE_tablejump)
5620 index_type = thiscase->data.case_stmt.nominal_type;
5621 index_expr = fold (build (MINUS_EXPR, index_type,
5622 convert (index_type, index_expr),
5623 convert (index_type, minval)));
5624 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5626 index = protect_from_queue (index, 0);
5627 do_pending_stack_adjust ();
5629 do_tablejump (index, TYPE_MODE (index_type),
5630 expand_expr (range, NULL_RTX, VOIDmode, 0),
5631 table_label, default_label);
5638 /* Get table of labels to jump to, in order of case index. */
5640 ncases = TREE_INT_CST_LOW (range) + 1;
5641 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
5642 memset ((char *) labelvec, 0, ncases * sizeof (rtx));
5644 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5646 register HOST_WIDE_INT i
5647 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
5652 = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
5653 if (i + TREE_INT_CST_LOW (orig_minval)
5654 == TREE_INT_CST_LOW (n->high))
5660 /* Fill in the gaps with the default. */
5661 for (i = 0; i < ncases; i++)
5662 if (labelvec[i] == 0)
5663 labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
5665 /* Output the table */
5666 emit_label (table_label);
5668 if (CASE_VECTOR_PC_RELATIVE || flag_pic)
5669 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
5670 gen_rtx_LABEL_REF (Pmode, table_label),
5671 gen_rtvec_v (ncases, labelvec),
5672 const0_rtx, const0_rtx));
5674 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
5675 gen_rtvec_v (ncases, labelvec)));
5677 /* If the case insn drops through the table,
5678 after the table we must jump to the default-label.
5679 Otherwise record no drop-through after the table. */
5680 #ifdef CASE_DROPS_THROUGH
5681 emit_jump (default_label);
5687 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
5688 reorder_insns (before_case, get_last_insn (),
5689 thiscase->data.case_stmt.start);
5692 end_cleanup_deferral ();
5694 if (thiscase->exit_label)
5695 emit_label (thiscase->exit_label);
5697 free_case_nodes (case_stack->data.case_stmt.case_list);
5698 POPSTACK (case_stack);
5703 /* Convert the tree NODE into a list linked by the right field, with the left
5704 field zeroed. RIGHT is used for recursion; it is a list to be placed
5705 rightmost in the resulting list. */
5707 static struct case_node *
5708 case_tree2list (node, right)
5709 struct case_node *node, *right;
5711 struct case_node *left;
5714 right = case_tree2list (node->right, right);
5716 node->right = right;
5717 if ((left = node->left))
5720 return case_tree2list (left, node);
5726 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5729 do_jump_if_equal (op1, op2, label, unsignedp)
5730 rtx op1, op2, label;
5733 if (GET_CODE (op1) == CONST_INT
5734 && GET_CODE (op2) == CONST_INT)
5736 if (INTVAL (op1) == INTVAL (op2))
5741 enum machine_mode mode = GET_MODE (op1);
5742 if (mode == VOIDmode)
5743 mode = GET_MODE (op2);
5744 emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX, mode, unsignedp,
5749 /* Not all case values are encountered equally. This function
5750 uses a heuristic to weight case labels, in cases where that
5751 looks like a reasonable thing to do.
5753 Right now, all we try to guess is text, and we establish the
5756 chars above space: 16
5765 If we find any cases in the switch that are not either -1 or in the range
5766 of valid ASCII characters, or are control characters other than those
5767 commonly used with "\", don't treat this switch scanning text.
5769 Return 1 if these nodes are suitable for cost estimation, otherwise
5773 estimate_case_costs (node)
5776 tree min_ascii = integer_minus_one_node;
5777 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5781 /* If we haven't already made the cost table, make it now. Note that the
5782 lower bound of the table is -1, not zero. */
5784 if (! cost_table_initialized)
5786 cost_table_initialized = 1;
5788 for (i = 0; i < 128; i++)
5791 COST_TABLE (i) = 16;
5792 else if (ISPUNCT (i))
5794 else if (ISCNTRL (i))
5795 COST_TABLE (i) = -1;
5798 COST_TABLE (' ') = 8;
5799 COST_TABLE ('\t') = 4;
5800 COST_TABLE ('\0') = 4;
5801 COST_TABLE ('\n') = 2;
5802 COST_TABLE ('\f') = 1;
5803 COST_TABLE ('\v') = 1;
5804 COST_TABLE ('\b') = 1;
5807 /* See if all the case expressions look like text. It is text if the
5808 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5809 as signed arithmetic since we don't want to ever access cost_table with a
5810 value less than -1. Also check that none of the constants in a range
5811 are strange control characters. */
5813 for (n = node; n; n = n->right)
5815 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5818 for (i = (HOST_WIDE_INT) TREE_INT_CST_LOW (n->low);
5819 i <= (HOST_WIDE_INT) TREE_INT_CST_LOW (n->high); i++)
5820 if (COST_TABLE (i) < 0)
5824 /* All interesting values are within the range of interesting
5825 ASCII characters. */
5829 /* Scan an ordered list of case nodes
5830 combining those with consecutive values or ranges.
5832 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5835 group_case_nodes (head)
5838 case_node_ptr node = head;
5842 rtx lb = next_real_insn (label_rtx (node->code_label));
5844 case_node_ptr np = node;
5846 /* Try to group the successors of NODE with NODE. */
5847 while (((np = np->right) != 0)
5848 /* Do they jump to the same place? */
5849 && ((lb2 = next_real_insn (label_rtx (np->code_label))) == lb
5850 || (lb != 0 && lb2 != 0
5851 && simplejump_p (lb)
5852 && simplejump_p (lb2)
5853 && rtx_equal_p (SET_SRC (PATTERN (lb)),
5854 SET_SRC (PATTERN (lb2)))))
5855 /* Are their ranges consecutive? */
5856 && tree_int_cst_equal (np->low,
5857 fold (build (PLUS_EXPR,
5858 TREE_TYPE (node->high),
5861 /* An overflow is not consecutive. */
5862 && tree_int_cst_lt (node->high,
5863 fold (build (PLUS_EXPR,
5864 TREE_TYPE (node->high),
5866 integer_one_node))))
5868 node->high = np->high;
5870 /* NP is the first node after NODE which can't be grouped with it.
5871 Delete the nodes in between, and move on to that node. */
5877 /* Take an ordered list of case nodes
5878 and transform them into a near optimal binary tree,
5879 on the assumption that any target code selection value is as
5880 likely as any other.
5882 The transformation is performed by splitting the ordered
5883 list into two equal sections plus a pivot. The parts are
5884 then attached to the pivot as left and right branches. Each
5885 branch is then transformed recursively. */
5888 balance_case_nodes (head, parent)
5889 case_node_ptr *head;
5890 case_node_ptr parent;
5892 register case_node_ptr np;
5900 register case_node_ptr *npp;
5903 /* Count the number of entries on branch. Also count the ranges. */
5907 if (!tree_int_cst_equal (np->low, np->high))
5911 cost += COST_TABLE (TREE_INT_CST_LOW (np->high));
5915 cost += COST_TABLE (TREE_INT_CST_LOW (np->low));
5923 /* Split this list if it is long enough for that to help. */
5928 /* Find the place in the list that bisects the list's total cost,
5929 Here I gets half the total cost. */
5934 /* Skip nodes while their cost does not reach that amount. */
5935 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5936 i -= COST_TABLE (TREE_INT_CST_LOW ((*npp)->high));
5937 i -= COST_TABLE (TREE_INT_CST_LOW ((*npp)->low));
5940 npp = &(*npp)->right;
5945 /* Leave this branch lopsided, but optimize left-hand
5946 side and fill in `parent' fields for right-hand side. */
5948 np->parent = parent;
5949 balance_case_nodes (&np->left, np);
5950 for (; np->right; np = np->right)
5951 np->right->parent = np;
5955 /* If there are just three nodes, split at the middle one. */
5957 npp = &(*npp)->right;
5960 /* Find the place in the list that bisects the list's total cost,
5961 where ranges count as 2.
5962 Here I gets half the total cost. */
5963 i = (i + ranges + 1) / 2;
5966 /* Skip nodes while their cost does not reach that amount. */
5967 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5972 npp = &(*npp)->right;
5977 np->parent = parent;
5980 /* Optimize each of the two split parts. */
5981 balance_case_nodes (&np->left, np);
5982 balance_case_nodes (&np->right, np);
5986 /* Else leave this branch as one level,
5987 but fill in `parent' fields. */
5989 np->parent = parent;
5990 for (; np->right; np = np->right)
5991 np->right->parent = np;
5996 /* Search the parent sections of the case node tree
5997 to see if a test for the lower bound of NODE would be redundant.
5998 INDEX_TYPE is the type of the index expression.
6000 The instructions to generate the case decision tree are
6001 output in the same order as nodes are processed so it is
6002 known that if a parent node checks the range of the current
6003 node minus one that the current node is bounded at its lower
6004 span. Thus the test would be redundant. */
6007 node_has_low_bound (node, index_type)
6012 case_node_ptr pnode;
6014 /* If the lower bound of this node is the lowest value in the index type,
6015 we need not test it. */
6017 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
6020 /* If this node has a left branch, the value at the left must be less
6021 than that at this node, so it cannot be bounded at the bottom and
6022 we need not bother testing any further. */
6027 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
6028 node->low, integer_one_node));
6030 /* If the subtraction above overflowed, we can't verify anything.
6031 Otherwise, look for a parent that tests our value - 1. */
6033 if (! tree_int_cst_lt (low_minus_one, node->low))
6036 for (pnode = node->parent; pnode; pnode = pnode->parent)
6037 if (tree_int_cst_equal (low_minus_one, pnode->high))
6043 /* Search the parent sections of the case node tree
6044 to see if a test for the upper bound of NODE would be redundant.
6045 INDEX_TYPE is the type of the index expression.
6047 The instructions to generate the case decision tree are
6048 output in the same order as nodes are processed so it is
6049 known that if a parent node checks the range of the current
6050 node plus one that the current node is bounded at its upper
6051 span. Thus the test would be redundant. */
6054 node_has_high_bound (node, index_type)
6059 case_node_ptr pnode;
6061 /* If there is no upper bound, obviously no test is needed. */
6063 if (TYPE_MAX_VALUE (index_type) == NULL)
6066 /* If the upper bound of this node is the highest value in the type
6067 of the index expression, we need not test against it. */
6069 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
6072 /* If this node has a right branch, the value at the right must be greater
6073 than that at this node, so it cannot be bounded at the top and
6074 we need not bother testing any further. */
6079 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
6080 node->high, integer_one_node));
6082 /* If the addition above overflowed, we can't verify anything.
6083 Otherwise, look for a parent that tests our value + 1. */
6085 if (! tree_int_cst_lt (node->high, high_plus_one))
6088 for (pnode = node->parent; pnode; pnode = pnode->parent)
6089 if (tree_int_cst_equal (high_plus_one, pnode->low))
6095 /* Search the parent sections of the
6096 case node tree to see if both tests for the upper and lower
6097 bounds of NODE would be redundant. */
6100 node_is_bounded (node, index_type)
6104 return (node_has_low_bound (node, index_type)
6105 && node_has_high_bound (node, index_type));
6108 /* Emit an unconditional jump to LABEL unless it would be dead code. */
6111 emit_jump_if_reachable (label)
6114 if (GET_CODE (get_last_insn ()) != BARRIER)
6118 /* Emit step-by-step code to select a case for the value of INDEX.
6119 The thus generated decision tree follows the form of the
6120 case-node binary tree NODE, whose nodes represent test conditions.
6121 INDEX_TYPE is the type of the index of the switch.
6123 Care is taken to prune redundant tests from the decision tree
6124 by detecting any boundary conditions already checked by
6125 emitted rtx. (See node_has_high_bound, node_has_low_bound
6126 and node_is_bounded, above.)
6128 Where the test conditions can be shown to be redundant we emit
6129 an unconditional jump to the target code. As a further
6130 optimization, the subordinates of a tree node are examined to
6131 check for bounded nodes. In this case conditional and/or
6132 unconditional jumps as a result of the boundary check for the
6133 current node are arranged to target the subordinates associated
6134 code for out of bound conditions on the current node.
6136 We can assume that when control reaches the code generated here,
6137 the index value has already been compared with the parents
6138 of this node, and determined to be on the same side of each parent
6139 as this node is. Thus, if this node tests for the value 51,
6140 and a parent tested for 52, we don't need to consider
6141 the possibility of a value greater than 51. If another parent
6142 tests for the value 50, then this node need not test anything. */
6145 emit_case_nodes (index, node, default_label, index_type)
6151 /* If INDEX has an unsigned type, we must make unsigned branches. */
6152 int unsignedp = TREE_UNSIGNED (index_type);
6153 enum machine_mode mode = GET_MODE (index);
6155 /* See if our parents have already tested everything for us.
6156 If they have, emit an unconditional jump for this node. */
6157 if (node_is_bounded (node, index_type))
6158 emit_jump (label_rtx (node->code_label));
6160 else if (tree_int_cst_equal (node->low, node->high))
6162 /* Node is single valued. First see if the index expression matches
6163 this node and then check our children, if any. */
6165 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
6166 label_rtx (node->code_label), unsignedp);
6168 if (node->right != 0 && node->left != 0)
6170 /* This node has children on both sides.
6171 Dispatch to one side or the other
6172 by comparing the index value with this node's value.
6173 If one subtree is bounded, check that one first,
6174 so we can avoid real branches in the tree. */
6176 if (node_is_bounded (node->right, index_type))
6178 emit_cmp_and_jump_insns (index,
6179 expand_expr (node->high, NULL_RTX,
6181 GT, NULL_RTX, mode, unsignedp, 0,
6182 label_rtx (node->right->code_label));
6183 emit_case_nodes (index, node->left, default_label, index_type);
6186 else if (node_is_bounded (node->left, index_type))
6188 emit_cmp_and_jump_insns (index,
6189 expand_expr (node->high, NULL_RTX,
6191 LT, NULL_RTX, mode, unsignedp, 0,
6192 label_rtx (node->left->code_label));
6193 emit_case_nodes (index, node->right, default_label, index_type);
6198 /* Neither node is bounded. First distinguish the two sides;
6199 then emit the code for one side at a time. */
6201 tree test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6203 /* See if the value is on the right. */
6204 emit_cmp_and_jump_insns (index,
6205 expand_expr (node->high, NULL_RTX,
6207 GT, NULL_RTX, mode, unsignedp, 0,
6208 label_rtx (test_label));
6210 /* Value must be on the left.
6211 Handle the left-hand subtree. */
6212 emit_case_nodes (index, node->left, default_label, index_type);
6213 /* If left-hand subtree does nothing,
6215 emit_jump_if_reachable (default_label);
6217 /* Code branches here for the right-hand subtree. */
6218 expand_label (test_label);
6219 emit_case_nodes (index, node->right, default_label, index_type);
6223 else if (node->right != 0 && node->left == 0)
6225 /* Here we have a right child but no left so we issue conditional
6226 branch to default and process the right child.
6228 Omit the conditional branch to default if we it avoid only one
6229 right child; it costs too much space to save so little time. */
6231 if (node->right->right || node->right->left
6232 || !tree_int_cst_equal (node->right->low, node->right->high))
6234 if (!node_has_low_bound (node, index_type))
6236 emit_cmp_and_jump_insns (index,
6237 expand_expr (node->high, NULL_RTX,
6239 LT, NULL_RTX, mode, unsignedp, 0,
6243 emit_case_nodes (index, node->right, default_label, index_type);
6246 /* We cannot process node->right normally
6247 since we haven't ruled out the numbers less than
6248 this node's value. So handle node->right explicitly. */
6249 do_jump_if_equal (index,
6250 expand_expr (node->right->low, NULL_RTX,
6252 label_rtx (node->right->code_label), unsignedp);
6255 else if (node->right == 0 && node->left != 0)
6257 /* Just one subtree, on the left. */
6259 #if 0 /* The following code and comment were formerly part
6260 of the condition here, but they didn't work
6261 and I don't understand what the idea was. -- rms. */
6262 /* If our "most probable entry" is less probable
6263 than the default label, emit a jump to
6264 the default label using condition codes
6265 already lying around. With no right branch,
6266 a branch-greater-than will get us to the default
6269 && COST_TABLE (TREE_INT_CST_LOW (node->high)) < 12)
6272 if (node->left->left || node->left->right
6273 || !tree_int_cst_equal (node->left->low, node->left->high))
6275 if (!node_has_high_bound (node, index_type))
6277 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6280 GT, NULL_RTX, mode, unsignedp, 0,
6284 emit_case_nodes (index, node->left, default_label, index_type);
6287 /* We cannot process node->left normally
6288 since we haven't ruled out the numbers less than
6289 this node's value. So handle node->left explicitly. */
6290 do_jump_if_equal (index,
6291 expand_expr (node->left->low, NULL_RTX,
6293 label_rtx (node->left->code_label), unsignedp);
6298 /* Node is a range. These cases are very similar to those for a single
6299 value, except that we do not start by testing whether this node
6300 is the one to branch to. */
6302 if (node->right != 0 && node->left != 0)
6304 /* Node has subtrees on both sides.
6305 If the right-hand subtree is bounded,
6306 test for it first, since we can go straight there.
6307 Otherwise, we need to make a branch in the control structure,
6308 then handle the two subtrees. */
6309 tree test_label = 0;
6311 if (node_is_bounded (node->right, index_type))
6312 /* Right hand node is fully bounded so we can eliminate any
6313 testing and branch directly to the target code. */
6314 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6316 GT, NULL_RTX, mode, unsignedp, 0,
6317 label_rtx (node->right->code_label));
6320 /* Right hand node requires testing.
6321 Branch to a label where we will handle it later. */
6323 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6324 emit_cmp_and_jump_insns (index,
6325 expand_expr (node->high, NULL_RTX,
6327 GT, NULL_RTX, mode, unsignedp, 0,
6328 label_rtx (test_label));
6331 /* Value belongs to this node or to the left-hand subtree. */
6333 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6335 GE, NULL_RTX, mode, unsignedp, 0,
6336 label_rtx (node->code_label));
6338 /* Handle the left-hand subtree. */
6339 emit_case_nodes (index, node->left, default_label, index_type);
6341 /* If right node had to be handled later, do that now. */
6345 /* If the left-hand subtree fell through,
6346 don't let it fall into the right-hand subtree. */
6347 emit_jump_if_reachable (default_label);
6349 expand_label (test_label);
6350 emit_case_nodes (index, node->right, default_label, index_type);
6354 else if (node->right != 0 && node->left == 0)
6356 /* Deal with values to the left of this node,
6357 if they are possible. */
6358 if (!node_has_low_bound (node, index_type))
6360 emit_cmp_and_jump_insns (index,
6361 expand_expr (node->low, NULL_RTX,
6363 LT, NULL_RTX, mode, unsignedp, 0,
6367 /* Value belongs to this node or to the right-hand subtree. */
6369 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6371 LE, NULL_RTX, mode, unsignedp, 0,
6372 label_rtx (node->code_label));
6374 emit_case_nodes (index, node->right, default_label, index_type);
6377 else if (node->right == 0 && node->left != 0)
6379 /* Deal with values to the right of this node,
6380 if they are possible. */
6381 if (!node_has_high_bound (node, index_type))
6383 emit_cmp_and_jump_insns (index,
6384 expand_expr (node->high, NULL_RTX,
6386 GT, NULL_RTX, mode, unsignedp, 0,
6390 /* Value belongs to this node or to the left-hand subtree. */
6392 emit_cmp_and_jump_insns (index,
6393 expand_expr (node->low, NULL_RTX,
6395 GE, NULL_RTX, mode, unsignedp, 0,
6396 label_rtx (node->code_label));
6398 emit_case_nodes (index, node->left, default_label, index_type);
6403 /* Node has no children so we check low and high bounds to remove
6404 redundant tests. Only one of the bounds can exist,
6405 since otherwise this node is bounded--a case tested already. */
6407 if (!node_has_high_bound (node, index_type))
6409 emit_cmp_and_jump_insns (index,
6410 expand_expr (node->high, NULL_RTX,
6412 GT, NULL_RTX, mode, unsignedp, 0,
6416 if (!node_has_low_bound (node, index_type))
6418 emit_cmp_and_jump_insns (index,
6419 expand_expr (node->low, NULL_RTX,
6421 LT, NULL_RTX, mode, unsignedp, 0,
6425 emit_jump (label_rtx (node->code_label));